Satellite data lift the veil on offshore platforms in the South China Sea

NASA Astrophysics Data System (ADS)

Liu, Yongxue; Sun, Chao; Sun, Jiaqi; Li, Hongyi; Zhan, Wenfeng; Yang, Yuhao; Zhang, Siyu

2016-09-01

Oil and gas exploration in the South China Sea (SCS) has garnered global attention recently; however, uncertainty regarding the accurate number of offshore platforms in the SCS, let alone their detailed spatial distribution and dynamic change, may lead to significant misjudgment of the true status of offshore hydrocarbon production in the region. Using both fresh and archived space-borne images with multiple resolutions, we enumerated the number, distribution, and annual rate of increase of offshore platforms across the SCS. Our results show that: (1) a total of 1082 platforms are present in the SCS, mainly located in shallow-water; and (2) offshore oil/gas exploitation in the SCS is increasing in intensity and advancing from shallow to deep water, and even to ultra-deep-water. Nevertheless, our findings suggest that oil and gas exploration in the SCS may have been over-estimated by one-third in previous reports. However, this overestimation does not imply any amelioration of the potential for future maritime disputes, since the rate of increase of platforms in disputed waters is twice that in undisputed waters.

Satellite data lift the veil on offshore platforms in the South China Sea

PubMed Central

Liu, Yongxue; Sun, Chao; Sun, Jiaqi; Li, Hongyi; Zhan, Wenfeng; Yang, Yuhao; Zhang, Siyu

2016-01-01

Oil and gas exploration in the South China Sea (SCS) has garnered global attention recently; however, uncertainty regarding the accurate number of offshore platforms in the SCS, let alone their detailed spatial distribution and dynamic change, may lead to significant misjudgment of the true status of offshore hydrocarbon production in the region. Using both fresh and archived space-borne images with multiple resolutions, we enumerated the number, distribution, and annual rate of increase of offshore platforms across the SCS. Our results show that: (1) a total of 1082 platforms are present in the SCS, mainly located in shallow-water; and (2) offshore oil/gas exploitation in the SCS is increasing in intensity and advancing from shallow to deep water, and even to ultra-deep-water. Nevertheless, our findings suggest that oil and gas exploration in the SCS may have been over-estimated by one-third in previous reports. However, this overestimation does not imply any amelioration of the potential for future maritime disputes, since the rate of increase of platforms in disputed waters is twice that in undisputed waters. PMID:27641542

Efficient preliminary floating offshore wind turbine design and testing methodologies and application to a concrete spar design.

PubMed

Matha, Denis; Sandner, Frank; Molins, Climent; Campos, Alexis; Cheng, Po Wen

2015-02-28

The current key challenge in the floating offshore wind turbine industry and research is on designing economic floating systems that can compete with fixed-bottom offshore turbines in terms of levelized cost of energy. The preliminary platform design, as well as early experimental design assessments, are critical elements in the overall design process. In this contribution, a brief review of current floating offshore wind turbine platform pre-design and scaled testing methodologies is provided, with a focus on their ability to accommodate the coupled dynamic behaviour of floating offshore wind systems. The exemplary design and testing methodology for a monolithic concrete spar platform as performed within the European KIC AFOSP project is presented. Results from the experimental tests compared to numerical simulations are presented and analysed and show very good agreement for relevant basic dynamic platform properties. Extreme and fatigue loads and cost analysis of the AFOSP system confirm the viability of the presented design process. In summary, the exemplary application of the reduced design and testing methodology for AFOSP confirms that it represents a viable procedure during pre-design of floating offshore wind turbine platforms. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Marine Fouling Assemblages on Offshore Gas Platforms in the Southern North Sea: Effects of Depth and Distance from Shore on Biodiversity

PubMed Central

van der Stap, Tim; Coolen, Joop W. P.; Lindeboom, Han J.

2016-01-01

Offshore platforms are known to act as artificial reefs, though there is on-going debate on whether this effect is beneficial or harmful for the life in the surrounding marine environment. Knowing what species exist on and around the offshore platforms and what environmental variables influence this species assemblage is crucial for a better understanding of the impact of offshore platforms on marine life. Information on this is limited for offshore platforms in the southern North Sea. This study aims to fill this gap in our knowledge and to determine how the composition and the abundance of species assemblages changes with depth and along a distance-from-shore gradient. The species assemblages on five offshore gas platforms in the southern North Sea have been inventoried using Remotely Operated Vehicles inspection footage. A total of 30 taxa were identified. A Generalised Additive Model of the species richness showed a significant non-linear relation with water depth (p = 0.001): from a low richness in shallow waters it increases with depth until 15–20 m, after which richness decreases again. Using PERMANOVA, water depth (p≤0.001), community age (p≤0.001) and the interaction between distance from shore and community age (p≤0.001) showed a significant effect on the species assemblages. Future research should focus on the effect additional environmental variables have on the species assemblages. PMID:26745870

An air quality emission inventory of offshore operations for the exploration and production of petroleum by the Mexican oil industry

NASA Astrophysics Data System (ADS)

Villasenor, R.; Magdaleno, M.; Quintanar, A.; Gallardo, J. C.; López, M. T.; Jurado, R.; Miranda, A.; Aguilar, M.; Melgarejo, L. A.; Palmerín, E.; Vallejo, C. J.; Barchet, W. R.

An air quality screening study was performed to assess the impacts of emissions from the offshore operations of the oil and gas exploration and production by Mexican industry in the Campeche Sound, which includes the states of Tabasco and Campeche in southeast Mexico. The major goal of this study was the compilation of an emission inventory (EI) for elevated, boom and ground level flares, processes, internal combustion engines and fugitive emissions. This inventory is so far the most comprehensive emission register that has ever been developed for the Mexican petroleum industry in this area. The EI considered 174 offshore platforms, the compression station at Atasta, and the Maritime Ports at Dos Bocas and Cayo Arcas. The offshore facilities identified as potential emitters in the area were the following: (1) trans-shipment stations, (2) a maritime floating port terminal, (3) drilling platforms, (4) crude oil recovering platforms, (5) crude oil production platforms, (6) linking platforms, (7) water injection platforms, (8) pumping platforms, (9) shelter platforms, (10) telecommunication platforms, (11) crude oil measurement platforms, and (12) flaring platforms. Crude oil storage tanks, helicopters and marine ship tankers were also considered to have an EI accurate enough for air quality regulations and mesoscale modeling of atmospheric pollutants. Historical ambient data measure at two onshore petroleum facilities were analyzed to measure air quality impacts on nearby inhabited coastal areas, and a source-receptor relationship for flares at the Ixtoc marine complex was performed to investigate health-based standards for offshore workers. A preliminary air quality model simulation was performed to observe the transport and dispersion patterns of SO 2, which is the main pollutant emitted from the offshore platforms. The meteorological wind and temperature fields were generated with CALMET, a diagnostic meteorological model that used surface observations and upper air soundings from a 4-day field campaign conducted in February of 1999. The CALMET meteorological output and the generated EI drove the transport and dispersion model, CALPUFF. Model results were compared with SO 2 measurements taken from the monitoring network at Dos Bocas.

Application of GNSS Methods for Monitoring Offshore Platform Deformation

NASA Astrophysics Data System (ADS)

Myint, Khin Cho; Nasir Matori, Abd; Gohari, Adel

2018-03-01

Global Navigation Satellite System (GNSS) has become a powerful tool for high-precision deformation monitoring application. Monitoring of deformation and subsidence of offshore platform due to factors such as shallow gas phenomena. GNSS is the technical interoperability and compatibility between various satellite navigation systems such as modernized GPS, Galileo, reconstructed GLONASS to be used by civilian users. It has been known that excessive deformation affects platform structurally, causing loss of production and affects the efficiency of the machinery on board the platform. GNSS have been proven to be one of the most precise positioning methods where by users can get accuracy to the nearest centimeter of a given position from carrier phase measurement processing of GPS signals. This research is aimed at using GNSS technique, which is one of the most standard methods to monitor the deformation of offshore platforms. Therefore, station modeling, which accounts for the spatial correlated errors, and hence speeds up the ambiguity resolution process is employed. It was found that GNSS combines the high accuracy of the results monitoring the offshore platforms deformation with the possibility of survey.

Twelve years in offshore for Doris C. G

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1979-04-12

The offshore engineering operations of Doris have included the design of concrete and steel offshore structures, the design and construction of diving and underwater equipment, offshore equipment, vessels, and heavy mooring systems, and the design and installation of pipelines and risers. The company has also engaged in pipelaying, marine operations, diving, and inspection and maintenance work. Some achievements in 1978 were the completion, tow-out, and installation of the Ninian central platform and the design of an additional riser for the Frigg field manifold compression platform to connect the Piper field to the Frigg gas pipeline. The articulated gravity tower formore » concrete platforms was certified by Norsk Veritas in 1978, but fatigue tests on the articulating ball joint are continuing. New designs include the fixed gravity structure with removable floats, which makes the substructure much smaller, so that concrete platforms become economically feasible in water depths previously considered prohibitive, and the steel-and-concrete hybrid platform, which has been fully developed and certified as safe and economical.« less

Stakeholders Opinions on Multi-Use Deep Water Offshore Platform in Hsiao-Liu-Chiu, Taiwan

PubMed Central

Sie, Ya-Tsune; Chang, Yang-Chi; Lu, Shiau-Yun

2018-01-01

This paper describes a group model building activity designed to elicit the potential effects a projected multi-use deep water offshore platform may have on its local environment, including ecological and socio-economic issues. As such a platform is proposed for construction around the island of Hsiao-Liu-Chiu, Taiwan, we organized several meetings with the local stakeholders and structured the debates using group modeling methods to promote consensus. During the process, the participants iteratively built and revised a causal-loop diagram that summarizes their opinions. Overall, local stakeholders concluded that a multi-use deep water offshore marine platform might have beneficial effects for Hsiao-Liu-Chiu because more tourists and fish could be attracted by the structure, but they also raised some potential problems regarding the law in Taiwan and the design of the offshore platform, especially its resistance to extreme weather. We report the method used and the main results and insights gained during the process. PMID:29415521

Risk-based process safety assessment and control measures design for offshore process facilities.

PubMed

Khan, Faisal I; Sadiq, Rehan; Husain, Tahir

2002-09-02

Process operation is the most hazardous activity next to the transportation and drilling operation on an offshore oil and gas (OOG) platform. Past experiences of onshore and offshore oil and gas activities have revealed that a small mis-happening in the process operation might escalate to a catastrophe. This is of especial concern in the OOG platform due to the limited space and compact geometry of the process area, less ventilation, and difficult escape routes. On an OOG platform, each extra control measure, which is implemented, not only occupies space on the platform and increases congestion but also adds extra load to the platform. Eventualities in the OOG platform process operation can be avoided through incorporating the appropriate control measures at the early design stage. In this paper, the authors describe a methodology for risk-based process safety decision making for OOG activities. The methodology is applied to various offshore process units, that is, the compressor, separators, flash drum and driers of an OOG platform. Based on the risk potential, appropriate safety measures are designed for each unit. This paper also illustrates that implementation of the designed safety measures reduces the high Fatal accident rate (FAR) values to an acceptable level.

33 CFR 165.155 - Northville Industries Offshore Platform, Riverhead, Long Island, New York-safety zone.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Platform, Riverhead, Long Island, New York-safety zone. 165.155 Section 165.155 Navigation and Navigable...—safety zone. (a) The following area is established as a safety zone during the specified condition: (1... (LPG) vessel is moored at the Offshore Platform. The safety zone remains in effect until the LPG vessel...

33 CFR 165.155 - Northville Industries Offshore Platform, Riverhead, Long Island, New York-safety zone.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Platform, Riverhead, Long Island, New York-safety zone. 165.155 Section 165.155 Navigation and Navigable...—safety zone. (a) The following area is established as a safety zone during the specified condition: (1... (LPG) vessel is moored at the Offshore Platform. The safety zone remains in effect until the LPG vessel...

Development of fast wireless detection system for fixed offshore platform

NASA Astrophysics Data System (ADS)

Li, Zhigang; Yu, Yan; Jiao, Dong; Wang, Jie; Li, Zhirui; Ou, Jinping

2011-04-01

Offshore platforms' security is concerned since in 1950s and 1960s, and in the early 1980s some important specifications and standards are built, and all these provide technical basis of fixed platform design, construction, installation and evaluation. With the condition that more and more platforms are in serving over age, the research about the evaluation and detection technology of offshore platform has been a hotspot, especially underwater detection, and assessment method based on the finite element calculation. For fixed platform structure detection, conventional NDT methods, such as eddy current, magnetic powder, permeate, X-ray and ultrasonic, etc, are generally used. These techniques are more mature, intuitive, but underwater detection needs underwater robot, the necessary supporting tools of auxiliary equipment, and trained professional team, thus resources and cost used are considerable, installation time of test equipment is long. This project presents a new kind of fast wireless detection and damage diagnosis system for fixed offshore platform using wireless sensor networks, that is, wireless sensor nodes can be put quickly on the offshore platform, detect offshore platform structure global status by wireless communication, and then make diagnosis. This system is operated simply, suitable for offshore platform integrity states rapid assessment. The designed system consists in intelligence acquisition equipment and 8 wireless collection nodes, the whole system has 64 collection channels, namely every wireless collection node has eight 16-bit accuracy of A/D channels. Wireless collection node, integrated with vibration sensing unit, embedded low-power micro-processing unit, wireless transceiver unit, large-capacity power unit, and GPS time synchronization unit, can finish the functions such as vibration data collection, initial analysis, data storage, data wireless transmission. Intelligence acquisition equipment, integrated with high-performance computation unit, wireless transceiver unit, mobile power unit and embedded data analysis software, can totally control multi-wireless collection nodes, receive and analyze data, parameter identification. Data is transmitted at the 2.4GHz wireless communication channel, every sensing data channel in charge of data transmission is in a stable frequency band, control channel responsible for the control of power parameters is in a public frequency band. The test is initially conducted for the designed system, experimental results show that the system has good application prospects and practical value with fast arrangement, high sampling rate, high resolution, capacity of low frequency detection.

Real-time Monitoring of Subsea Gas Pipelines, Offshore Platforms, and Ship Inspection Scores Using an Automatic Identification System

NASA Astrophysics Data System (ADS)

Artana, K. B.; Pitana, T.; Dinariyana, D. P.; Ariana, M.; Kristianto, D.; Pratiwi, E.

2018-06-01

The aim of this research is to develop an algorithm and application that can perform real-time monitoring of the safety operation of offshore platforms and subsea gas pipelines as well as determine the need for ship inspection using data obtained from automatic identification system (AIS). The research also focuses on the integration of shipping database, AIS data, and others to develop a prototype for designing a real-time monitoring system of offshore platforms and pipelines. A simple concept is used in the development of this prototype, which is achieved by using an overlaying map that outlines the coordinates of the offshore platform and subsea gas pipeline with the ship's coordinates (longitude/latitude) as detected by AIS. Using such information, we can then build an early warning system (EWS) relayed through short message service (SMS), email, or other means when the ship enters the restricted and exclusion zone of platforms and pipelines. The ship inspection system is developed by combining several attributes. Then, decision analysis software is employed to prioritize the vessel's four attributes, including ship age, ship type, classification, and flag state. Results show that the EWS can increase the safety level of offshore platforms and pipelines, as well as the efficient use of patrol boats in monitoring the safety of the facilities. Meanwhile, ship inspection enables the port to prioritize the ship to be inspected in accordance with the priority ranking inspection score.

How a good understanding of the physical oceanography of your offshore renewables site can drive down project costs.

NASA Astrophysics Data System (ADS)

Royle, J.

2016-02-01

For an offshore renewables plant to be viable it must be safe and cost effective to build and maintain (i.e. the conditions mustn't be too harsh to excessively impede operations at the site), it must also have an energetic enough resource to make the project attractive to investors. In order to strike the correct balance between cost and resource reliable datasets describing the meteorological and oceanographic (metocean) environment needs to be collected, analysed and its findings correctly applied . This presentation will use three real world examples from Iberdrola`s portfolio of offshore windfarms in Europe to demonstrate the economic benefits of good quality metocean data and robust analysis. The three examples are: 1) Moving from traditional frequency domain persistence statistics to time domain installation schedules driven by reliable metocean data reduces uncertainty and allows the developer to have better handle on weather risk during contract negotiations. 2) By comparing the planned installation schedules from a well validated metocean dataset with a coarser low cost unvalidated metocean dataset we can show that each Euro invested in the quality of metocean data can reduce the uncertainty in installation schedules by four Euros. 3) Careful consideration of co-varying wave and tidal parameters can justify lower cost designs, such as lower platform levels leading to shorter and cheaper offshore wind turbine foundations. By considering the above examples we will prove the case for investing in analysis of well validated metocean models as a basis for sound financial planning of offshore renewables installations.

Issues in offshore platform research - Part 1: Semi-submersibles

NASA Astrophysics Data System (ADS)

Sharma, R.; Kim, Tae-Wan; Sha, O. P.; Misra, S. C.

2010-09-01

Availability of economic and efficient energy resources is crucial to a nation's development. Because of their low cost and advancement in drilling and exploration technologies, oil and gas based energy systems are the most widely used energy source throughout the world. The inexpensive oil and gas based energy systems are used for everything, i.e., from transportation of goods and people to the harvesting of crops for food. As the energy demand continues to rise, there is strong need for inexpensive energy solutions. An offshore platform is a large structure that is used to house workers and machinery needed to drill wells in the ocean bed, extract oil and/or natural gas, process the produced fluids, and ship or pipe them to shore. Depending on the circumstances, the offshore platform can be fixed (to the ocean floor) or can consist of an artificial island or can float. Semi-submersibles are used for various purposes in offshore and marine engineering, e.g. crane vessels, drilling vessels, tourist vessels, production platforms and accommodation facilities, etc. The challenges of deepwater drilling have further motivated the researchers to design optimum choices for semi-submersibles for a chosen operating depth. In our series of eight papers, we discuss the design and production aspects of all the types of offshore platforms. In the present part I, we present an introduction and critical analysis of semi-submersibles.

Sediment porewater toxicity assessment studies in the vicinity of offshore oil and gas production platforms in the Gulf of Mexico

USGS Publications Warehouse

Carr, R.S.; Chapman, D.C.; Presley, B.J.; Biedenbach, J.M.; Robertson, L.; Boothe, P.; Kilada, R.; Wade, T.; Montagna, P.

1996-01-01

As part of a multidisciplinary program to assess the potential long-term impacts of offshore oil and gas exploration and production activities in the Gulf of Mexico, sediment chemical analyses and porewater toxicity tests were conducted in the vicinity of five offshore platforms. Based on data from sea urchin fertilization and embryological development assays, toxicity was observed near four of the five platforms sampled; the majority of the toxic samples were collected within 150 m of a platform. There was excellent agreement among the results of porewater tests with three different species (sea urchin embryological development, polychaete reproduction, and copepod nauplii survival). The sediment concentrations of several metals were well in excess of sediment quality assessment guidelines at a number of stations, and good agreement was observed between predicted and observed toxicity. Porewater metal concentrations compared with EC50, LOEC, and NOEC values generated for water-only exposures indicated that the porewater concentrations for several metals were high enough to account for the observed toxicity. Results of these studies utilizing highly sensitive toxicity tests suggest that the contaminant-induced impacts from offshore platforms are limited to a localized area in the immediate vicinity of the platforms. 

Portable life support for instrumentation of an offshore platform

NASA Technical Reports Server (NTRS)

Mull, M. M.; Coffin, C. L.

1972-01-01

A compressor was used to supply air through a nylon hose to the offshore platform field engineer working at the bottom of the piling. Air quality in the pile was sampled periodically for carbon dioxide, carbon monoxide, hydrogen sulfide, and combustible gases by an universal tester and an explosion meter.

Made in Norway -- Produsert i Norge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lia, A.

1996-08-01

This paper reviews the technology advances that have occurred as a result of the harsh offshore conditions and rigid environmental conditions that the Norwegian offshore has created. Over 25 years of offshore oil and gas production on the Norwegian continental shelf have given an impressive number of technological innovations. It includes the submerged turret loading system, concrete gravity based platforms, and the use of various platform configurations for protection against icebergs. This paper reviews the history of these and other Norwegian based technologies.

Development of jacket platform tsunami risk rating system in waters offshore North Borneo

NASA Astrophysics Data System (ADS)

Lee, H. E.; Liew, M. S.; Mardi, N. H.; Na, K. L.; Toloue, Iraj; Wong, S. K.

2016-09-01

This work details the simulation of tsunami waves generated by seaquakes in the Manila Trench and their effect on fixed oil and gas jacket platforms in waters offshore North Borneo. For this study, a four-leg living quarter jacket platform located in a water depth of 63m is modelled in SACS v5.3. Malaysia has traditionally been perceived to be safe from the hazards of earthquakes and tsunamis. Local design practices tend to neglect tsunami waves and include no such provisions. In 2004, a 9.3 M w seaquake occurred off the northwest coast of Aceh, which generated tsunami waves that caused destruction in Malaysia totalling US 25 million and 68 deaths. This event prompted an awareness of the need to study the reliability of fixed offshore platforms scattered throughout Malaysian waters. In this paper, we present a review of research on the seismicity of the Manila Trench, which is perceived to be high risk for Southeast Asia. From the tsunami numerical model TUNA-M2, we extract computer-simulated tsunami waves at prescribed grid points in the vicinity of the platforms in the region. Using wave heights as input, we simulate the tsunami using SACS v5.3 structural analysis software of offshore platforms, which is widely accepted by the industry. We employ the nonlinear solitary wave theory in our tsunami loading calculations for the platforms, and formulate a platform-specific risk quantification system. We then perform an intensive structural sensitivity analysis and derive a corresponding platform-specific risk rating model.

Floating Offshore Wind in Hawaii: Potential for Jobs and Economic Impacts from Three Future Scenarios

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jimenez, Tony; Keyser, David; Tegen, Suzanne

Construction of the first offshore wind power plant in the United States began in 2015, off the coast of Rhode Island, using fixed platform structures that are appropriate for shallow seafloors, like those located off the East Coast and mid-Atlantic. However, floating platforms, which have yet to be deployed commercially, will likely need to be anchored to the deeper seafloor if deployed in Hawaiian waters. To analyze the employment and economic potential for floating offshore wind off Hawaii's coasts, the Bureau of Ocean Energy Management commissioned the National Renewable Energy Laboratory (NREL) to analyze two hypothetical deployment scenarios for Hawaii:more » 400 MW of offshore wind by 2050 and 800 MW of offshore wind by 2050. The results of this analysis can be used to better understand the general scale of economic opportunities that could result from offshore wind development.« less

A study of rotor and platform design trade-offs for large-scale floating vertical axis wind turbines

NASA Astrophysics Data System (ADS)

Griffith, D. Todd; Paquette, Joshua; Barone, Matthew; Goupee, Andrew J.; Fowler, Matthew J.; Bull, Diana; Owens, Brian

2016-09-01

Vertical axis wind turbines are receiving significant attention for offshore siting. In general, offshore wind offers proximity to large populations centers, a vast & more consistent wind resource, and a scale-up opportunity, to name a few beneficial characteristics. On the other hand, offshore wind suffers from high levelized cost of energy (LCOE) and in particular high balance of system (BoS) costs owing to accessibility challenges and limited project experience. To address these challenges associated with offshore wind, Sandia National Laboratories is researching large-scale (MW class) offshore floating vertical axis wind turbines (VAWTs). The motivation for this work is that floating VAWTs are a potential transformative technology solution to reduce offshore wind LCOE in deep-water locations. This paper explores performance and cost trade-offs within the design space for floating VAWTs between the configurations for the rotor and platform.

Effects of offshore platforms on soft-bottom macro-benthic assemblages: a case study in a Mediterranean gas field.

PubMed

Terlizzi, Antonio; Bevilacqua, Stanislao; Scuderi, Danilo; Fiorentino, Dario; Guarnieri, Giuseppe; Giangrande, Adriana; Licciano, Margherita; Felline, Serena; Fraschetti, Simonetta

2008-07-01

The exploitation of fossil fuels in the Mediterranean Sea will likely lead to an increase in the number of offshore platforms, a recognized threat for marine biodiversity. To date, in this basin, few attempts have been made to assess the impact of offshore gas and oil platforms on the biodiversity of benthic assemblages. Here, we adopted a structured experimental design coupled with high taxonomic resolution to outline putative effects of gas platforms on soft-bottom macrofauna assemblages in the North Ionian Sea. The analysis was based on a total of 20,295 specimens of 405 taxa, almost entirely identified at species level. Multivariate and univariate analyses showed idiosyncratic patterns of assemblage change with increasing distance from the platforms. Potential reasons underlying such inconsistency are analyzed and the view that structured experimental monitoring is a crucial tool to quantify the extent and magnitude of potential threats and to provide sound baseline information on biodiversity patterns is supported.

Pile Driving

NASA Technical Reports Server (NTRS)

1987-01-01

Machine-oriented structural engineering firm TERA, Inc. is engaged in a project to evaluate the reliability of offshore pile driving prediction methods to eventually predict the best pile driving technique for each new offshore oil platform. Phase I Pile driving records of 48 offshore platforms including such information as blow counts, soil composition and pertinent construction details were digitized. In Phase II, pile driving records were statistically compared with current methods of prediction. Result was development of modular software, the CRIPS80 Software Design Analyzer System, that companies can use to evaluate other prediction procedures or other data bases.

Damage to offshore infrastructure in the Gulf of Mexico by hurricanes Katrina and Rita

NASA Astrophysics Data System (ADS)

Cruz, A. M.; Krausmann, E.

2009-04-01

The damage inflicted by hurricanes Katrina and Rita to the Gulf-of-Mexico's (GoM) oil and gas production, both onshore and offshore, has shown the proneness of industry to Natech accidents (natural hazard-triggered hazardous-materials releases). In order to contribute towards a better understanding of Natech events, we assessed the damage to and hazardous-materials releases from offshore oil and natural-gas platforms and pipelines induced by hurricanes Katrina and Rita. Data was obtained through a review of published literature and interviews with government officials and industry representatives from the affected region. We also reviewed over 60,000 records of reported hazardous-materials releases from the National Response Center's (NRC) database to identify and analyze the hazardous-materials releases directly attributed to offshore oil and gas platforms and pipelines affected by the two hurricanes. Our results show that hurricanes Katrina and Rita destroyed at least 113 platforms, and severely damaged at least 53 others. Sixty percent of the facilities destroyed were built 30 years ago or more prior to the adoption of the more stringent design standards that went into effect after 1977. The storms also destroyed 5 drilling rigs and severely damaged 19 mobile offshore drilling units (MODUs). Some 19 MODUs lost their moorings and became adrift during the storms which not only posed a danger to existing facilities but the dragging anchors also damaged pipelines and other infrastructure. Structural damage to platforms included toppling of sections, and tilting or leaning of platforms. Possible causes for failure of structural and non-structural components of platforms included loading caused by wave inundation of the deck. Failure of rigs attached to platforms was also observed resulting in significant damage to the platform or adjacent infrastructure, as well as damage to equipment, living quarters and helipads. The failures are attributable to tie-down components and occurred on both fixed and floating platforms. The total number of pipelines damaged by Hurricanes Katrina and Rita as of May 1, 2006, was 457. Pipeline damage was mostly caused by damage or failure of the host platform or its development and production piping, the impact of dragging and displaced objects, and pipeline interaction at a crossing. Damage to pipelines was a major contributing factor in delaying start up of offshore oil and gas production. During our analysis of the NRC database we identified 611 reported hazardous-materials releases directly attributed to offshore platforms and pipelines affected by the two hurricanes. There were twice as many releases during Hurricane Katrina than during Rita; 80% or more of the releases reported in the NRC database occurred from platforms. Our analysis suggests that the majority of releases were petroleum products, such as crude oil and condensate, followed by natural gas. In both Katrina and Rita, releases were more likely in the front, right quadrant of the storm. Storm-surge values were highest closer to the coastline. This may help explain the higher number of releases in shallow waters. The higher number of hazardous-materials releases from platforms during Katrina may partly be attributed to the higher wind speeds for this storm as it approached land.

Design Calculations 93’ MLW Structure East Coast Air Combat Maneuvering Range Offshore Kitty Hawk, North Carolina.

DTIC Science & Technology

1976-09-01

CALCULATIONS 93’ MLW PLATFORM EAST COAST AIR COMBAT MANEUVERING RANGE OFFSHORE KITTY HAWK, NORTH CAROLINA CONTRACT NO. N62477-76-C-0179 MODIFICATION NO. P0001...of structures comprising the U.S. Navy East Coast Air Combat Maneuvering Range. Its purpose is to provide a platform to support electronic...All portions of the platform above elevation (-) 4.0 feet will be painted. 2. All main structural members located within the splash zone will have an

On the effects of basic platform design characteristics on floating offshore wind turbine control and their mitigation

NASA Astrophysics Data System (ADS)

Olondriz, Joannes; Elorza, Iker; Trojaola, Ignacio; Pujana, Aron; Landaluze, Joseba

2016-09-01

Semi-submersible floating offshore wind turbines present significant advantages over other designs in terms of cost, deployment, maintenance and site-independence. However, these advantages are achieved by shifting a part of the burden of stabilising the platform pitch and roll motions to the turbine control system. A study is presented here of the effects of basic platform dimensions on the performance of a standard pitch controller and the possible methods for mitigating said effects.

Helical piles: an innovative foundation design option for offshore wind turbines.

PubMed

Byrne, B W; Houlsby, G T

2015-02-28

Offshore wind turbines play a key part in the renewable energy strategy in the UK and Europe as well as in other parts of the world (for example, China). The majority of current developments, certainly in UK waters, have taken place in relatively shallow water and close to shore. This limits the scale of the engineering to relatively simple structures, such as those using monopile foundations, and these have been the most common design to date, in UK waters. However, as larger turbines are designed, or they are placed in deeper water, it will be necessary to use multi-footing structures such as tripods or jackets. For these designs, the tension on the upwind footing becomes the critical design condition. Driven pile foundations could be used, as could suction-installed foundations. However, in this paper, we present another concept-the use of helical pile foundations. These foundations are routinely applied onshore where large tension capacities are required. However, for use offshore, a significant upscaling of the technology will be needed, particularly of the equipment required for installation of the piles. A clear understanding of the relevant geotechnical engineering will be needed if this upscaling is to be successful. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

[Relationship of job stress with job burnout and quality of work life in workers for offshore oil platforms].

PubMed

Zhang, Y; Liu, X L; Wei, T D; Lan, Y J

2017-03-20

Objective: To evaluate the current status of job burnout and qual ity of work life (QWL) in workers for offshore oil platforms, and to analyze the relationship of job stress with job burnout and QWL and the direct and indirect effects of job stress on QWL. Methods: Cluster random sampling was used to select 382 work-ers for 8 oil platforms of China National Offshore Oil Corporation in October 2015. A self - designed questionnaire was used to collect the individual characteristics of subjects. The Quality of Work Life Scale (QWL7 - 32) , Occupa-tional Stress Inventory - Revised Edition (OSI - R) , and Maslach Burnout Inventory - General Survey (MBI - GS) were used to investigate the QWL, job stress, and job burnout of subjects. Results: Among all the workers for offshore oil platforms, 87.2% had mild job burnout. The total QWL score was 116.01 ± 16.73; 8.3% of the workers had poor QWL, and 68.5% had moderate QWL. QWL was reduced with heavier task, vaguer task, and increasing mental stress and physical stress ( P <0.05) , and increased with more social support ( P <0.05) . Job stress had di-rect and indirect effects on QWL; stress reaction had the most effect on QWL (total effect size - 0.509) , followed by social support (total effect size 0.444) . Conclusion: Most workers for offshore oil platforms have mild job burn-out and moderate QWL. Job stress is associated with job burnout and QWL, and stress reaction and social support have relatively high influence on QWL.

Motion performance and mooring system of a floating offshore wind turbine

NASA Astrophysics Data System (ADS)

Zhao, Jing; Zhang, Liang; Wu, Haitao

2012-09-01

The development of offshore wind farms was originally carried out in shallow water areas with fixed (seabed mounted) structures. However, countries with limited shallow water areas require innovative floating platforms to deploy wind turbines offshore in order to harness wind energy to generate electricity in deep seas. The performances of motion and mooring system dynamics are vital to designing a cost effective and durable floating platform. This paper describes a numerical model to simulate dynamic behavior of a new semi-submersible type floating offshore wind turbine (FOWT) system. The wind turbine was modeled as a wind block with a certain thrust coefficient, and the hydrodynamics and mooring system dynamics of the platform were calculated by SESAM software. The effect of change in environmental conditions on the dynamic response of the system under wave and wind loading was examined. The results indicate that the semi-submersible concept has excellent performance and SESAM could be an effective tool for floating wind turbine design and analysis.

Rarefaction Shock Wave Cutter for Offshore Oil-Gas Platform Removal Final Report CRADA No. TC02009.0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glenn, L. A.; Barker, J.

This was a collaborative effort between Lawrence Livermore National Security, LLC/Lawrence Livermore National Laboratory (LLNL) (formerly the University of California) and Jet Research Center, a wholly owned division of Halliburton Energy Services, Inc. to design and prototype an improved explosive cutter for cutting the support legs of offshore oil and gas platforms.

Natural frequency and vibration analysis of jacket type foundation for offshore wind power

NASA Astrophysics Data System (ADS)

Hung, Y.-C.; Chang, Y.-Y.; Chen, S.-Y.

2017-12-01

There are various types of foundation structure for offshore wind power, engineers may assess the condition of ocean at wind farm, and arrange the transportation, installation of each structure members, furthermore, considering the ability of manufacture steel structure as well, then make an optimum design. To design jacket offshore structure, unlike onshore cases, offshore structure also need to estimate the wave excitation effect. The aim of this paper is to study the difference of natural frequency between different kinds of structural stiffness and discuss the effect of different setting of boundary condition during analysis, besides, compare this value with the natural frequency of sea wave, in order to avoid the resonance effect. In this paper, the finite element analysis software ABAQUS is used to model and analyze the natural vibration behavior of the jacket structure.

RADIATION DOSE AND RISK TO RECREATIONAL FISHERMEN FROM INGESTION OF FISH CAUGHT NEAR EIGHT OIL PLATFORMS IN THE GULF OF MEXICO

DOE Office of Scientific and Technical Information (OSTI.GOV)

MEINHOLD,A.F.; HOLTZMAN,S.

1998-06-01

Offshore production of oil and gas is accompanied by a saline wastewater, called produced water. Produced water discharges to the Gulf of Mexico often contain elevated concentrations of radionuclides that occur naturally in the geologic reservoir along with the oil and gas. These radionuclides may accumulate in organisms that live near offshore oil and gas structures. Because recreational fishing in the Gulf of Mexico is concentrated near oil and gas platforms, there is the potential for increased risks to recreational fishermen from the ingestion of radionuclides in fish caught near produced water discharges. This analysis investigated the potential risk tomore » recreational fishermen from radium and lead-210 in offshore produced water discharges to the Gulf of Mexico. The assessment used data collected at eight discharging offshore platforms and two reference locations. These data were collected in a USDOE funded project titled ``Environmental and Economic Assessment of Discharges from Gulf of Mexico Region Oil and Gas Operations'', here called the USDOE Field Study. The risk assessments were done to support risk managers in developing regulations and permits for offshore discharges of produced water.« less

Go to work or report sick? A focus group study on decisions of sickness presence among offshore catering section workers

PubMed Central

2011-01-01

Background To identify and explore the factors promoting sickness presenteeism among offshore catering section workers. Methods Twenty men and women, working in the offshore catering section onboard three offshore oil and gas production platforms on the Norwegian Continental Shelf, participated in three focus groups. Data from the focus groups were analysed according to a phenomenological approach, and supported by theories on presenteeism. Results The results show that the decision to attend work despite illness, first and foremost, was based on the severity of the health complaint. Other factors identified were; the individual's location once the health complaint occurred, job satisfaction, the norms of the team, and experiences of how company policies on sickness absenteeism were implemented by the catering section leaders. Conclusions Offshore working conditions may promote sickness presenteeism. The factors promoting sickness presenteeism onboard the platforms reflected experiences of a healthy work environment. PMID:21418561

Go to work or report sick? A focus group study on decisions of sickness presence among offshore catering section workers.

PubMed

Krohne, Kariann; Magnussen, Liv Heide

2011-03-18

To identify and explore the factors promoting sickness presenteeism among offshore catering section workers. Twenty men and women, working in the offshore catering section onboard three offshore oil and gas production platforms on the Norwegian Continental Shelf, participated in three focus groups. Data from the focus groups were analysed according to a phenomenological approach, and supported by theories on presenteeism. The results show that the decision to attend work despite illness, first and foremost, was based on the severity of the health complaint. Other factors identified were; the individual's location once the health complaint occurred, job satisfaction, the norms of the team, and experiences of how company policies on sickness absenteeism were implemented by the catering section leaders. Offshore working conditions may promote sickness presenteeism. The factors promoting sickness presenteeism onboard the platforms reflected experiences of a healthy work environment.

Inadequate environmental monitoring around offshore oil and gas platforms on the Grand Bank of Eastern Canada: are risks to marine birds known?

PubMed

Burke, C M; Montevecchi, W A; Wiese, F K

2012-08-15

Petroleum exploration and production on the Grand Bank of eastern Canada overlaps with productive marine habitat that supports over 40 million marine birds annually. Environmental assessments for oil and gas projects in the region predict insignificant adverse effects on marine birds from oil spills, incineration in platform flares and collisions. Limited baseline data on seasonal occupancies and a failure to quantify the nature and extent of marine bird attraction to platforms and related mortality undermines these assessments. We conducted 22 surveys to offshore platforms on the Grand Bank during 1999-2003 to measure avian associations with platforms and to determine the level of monitoring needed to assess the risks to marine birds. We document seasonal shifts in marine bird occurrences and higher densities of auks (fall) and shearwaters (summer) around platforms relative to surrounding areas. The limited temporal and spatial coverage of our surveys is more robust than existing industry monitoring efforts, yet it is still inadequate to quantify the scale of marine bird associations with platforms or their associated mortality risks. Systematic observations by independent biologists on vessels and platforms are needed to generate reliable assessments of risks to marine birds. Instead, the regulatory body for offshore oil and gas in eastern Canada (Canada - Newfoundland and Labrador Offshore Petroleum Board; C-NLOPB) supports industry self-reporting as the accepted form of environmental monitoring. Conflicting responsibilities of oil and gas regulatory agencies for both energy development and environmental monitoring are major barriers to transparency, unbiased scientific inquiry and adequate environmental protection. Similar conflicts with the oil and gas regulatory body in the United States, the former Minerals and Management Service (MMS) were identified by the U.S. President as a major contributor to the Deepwater Horizon disaster in the Gulf of Mexico. The MMS has since been restructured into the Bureau of Ocean Energy Management, (BOEM) with separate departments responsible for drilling leases and the regulation of drilling activities. Similar restructuring of the oil and gas regulatory bodies in Canada is needed for better public information, scientific investigation and environmental protection in the offshore. Copyright © 2012 Elsevier Ltd. All rights reserved.

Determination of current loads of floating platform for special purposes

NASA Astrophysics Data System (ADS)

Ma, Guang-ying; Yao, Yun-long; Zhao, Chen-yao

2017-08-01

This article studied a new floating offshore platform for special purposes, which was assembled by standard floating modules. The environmental load calculation of the platform is an important part of the research of the ocean platform, which has always been paid attention to by engineers. In addition to wave loads, the wind loads and current loads are also important environmental factors that affect the dynamic response of the offshore platform. The current loads on the bottom structure should not be ignored. By Fluent software, the hydrostatic conditions and external current loads of the platform were calculated in this paper. The coefficient which is independent of the current velocity, namely, current force coefficient, can be fitted through current loads, which can be used for the consequent hydrodynamic and mooring analyses.

78 FR 12037 - Announcement of the American Petroleum Institute's Standards Activities

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-21

... Execution, 1st Edition Standard 2CCU, Offshore Cargo Container Design, Manufacturing and Inspection, 1st... Integrity Management of Fixed Offshore Structures, 1st Edition Recommended Practice 2SM, Design, Manufacture... Offshore Production Platforms, 8th Edition Specification 14F, Design and Installation of Electrical Systems...

Foundations for offshore wind turbines.

PubMed

Byrne, B W; Houlsby, G T

2003-12-15

An important engineering challenge of today, and a vital one for the future, is to develop and harvest alternative sources of energy. This is a firm priority in the UK, with the government setting a target of 10% of electricity from renewable sources by 2010. A component central to this commitment will be to harvest electrical power from the vast energy reserves offshore, through wind turbines or current or wave power generators. The most mature of these technologies is that of wind, as much technology transfer can be gained from onshore experience. Onshore wind farms, although supplying 'green energy', tend to provoke some objections on aesthetic grounds. These objections can be countered by locating the turbines offshore, where it will also be possible to install larger capacity turbines, thus maximizing the potential of each wind farm location. This paper explores some civil-engineering problems encountered for offshore wind turbines. A critical component is the connection of the structure to the ground, and in particular how the load applied to the structure is transferred safely to the surrounding soil. We review previous work on the design of offshore foundations, and then present some simple design calculations for sizing foundations and structures appropriate to the wind-turbine problem. We examine the deficiencies in the current design approaches, and the research currently under way to overcome these deficiencies. Designs must be improved so that these alternative energy sources can compete economically with traditional energy suppliers.

Association of sea turtles with petroleum platforms in the north-central Gulf of Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lohoefener, R.; Hoggard, W.; Mullin, K.

1990-06-01

There are over 4,500 petroleum platforms in the north-central Gulf of Mexico. Explosives are commonly used to remove platforms and have the potential to kill nearby sea turtles. From June 1988-June 1990, the authors used aerial surveys to study turtle density and the spatial relationship between turtles and platforms offshore of Louisiana. They sighted 316 turtles most of which (92%) were loggerheads. Seventy-eight percent were sighted just east of the Mississippi River offshore of the Chandeleur Islands. East of the river, turtle densities ranged from 0.92 (winter) to 4.83 turtles/100 sq km (spring). West of the river, annual densities rangedmore » from 0.11-0.50 turtles/100 sq km. East of the river, three statistical tests indicated that turtles were generally closer to platforms than expected by chance alone. West of the river, turtles were randomly located with respect to platform locations. Before explosives are used, current mitigation measures require that no turtle can be sighted within 1,000 m of the platform. East of the river, the probability of a turtle being within 1,000 m of any platform selected at random was about 60%; west of the river, 2-7%. West of the river to about 92 W, the mitigation measures should protect turtles but offshore of the Chandeleur Islands, special precautions should be taken.« less

Quantifying the Hurricane Risk to Offshore Wind Power (Invited)

NASA Astrophysics Data System (ADS)

Apt, J.; Rose, S.; Jaramillo, P.; Small, M.

2013-12-01

The U.S. Department of Energy has estimated that over 50 GW of offshore wind power will be required for the United States to generate 20% of its electricity from wind. Developers are actively planning offshore wind farms along the U.S. Atlantic and Gulf coasts and several leases have been signed for offshore sites. These planned projects are in areas that are sometimes struck by hurricanes. Whether that risk will grow as a result of climate change is uncertain. Recent years have seen an increase in hurricane activity in the Atlantic basin (1) and, all else being equal, warmer sea surface temperatures can be expected to lead to increased storm intensity. We have developed a method to estimate the catastrophe risk to offshore wind power using simulated hurricanes (2). In Texas, the most vulnerable region we studied, 10% of offshore wind power could be offline simultaneously due to hurricane damage with a 100-year return period and 6% could be destroyed in any 10-year period. Much of the hurricane risk to offshore wind turbines can be mitigated by designing turbines for higher maximum wind speeds, ensuring that turbine nacelles can turn quickly to track the wind direction even when grid power is lost, and building in areas with lower risk. 1. Iris Grossmann and M. Granger Morgan, "Tropical Cyclones, Climate Change, and Scientific Uncertainty: What do we know, what does it mean, and what should be done?," Climatic Change, 108, pp 543-579, 2011. 2. Carnegie Mellon Electricity Industry Center Working Paper CEIC-13-07, http://wpweb2.tepper.cmu.edu/electricity/papers/ceic-13-07.asp This work was supported in part by the EPA STAR fellowship program, a grant from the Alfred P. Sloan Foundation and EPRI to the Carnegie Mellon Electricity Industry Center, and by the Doris Duke Charitable Foundation, the R.K. Mellon Foundation and the Heinz Endowments for support of the RenewElec program at Carnegie Mellon University. This research was also supported in part by the Climate and Energy Decision Making (CEDM) center created through a cooperative agreement between the National Science Foundation (SES-0949710) and Carnegie Mellon University.

Bird interactions with offshore oil and gas platforms: review of impacts and monitoring techniques.

PubMed

Ronconi, Robert A; Allard, Karel A; Taylor, Philip D

2015-01-01

Thousands of oil and gas platforms are currently operating in offshore waters globally, and this industry is expected to expand in coming decades. Although the potential environmental impacts of offshore oil and gas activities are widely recognized, there is limited understanding of their impacts on migratory and resident birds. A literature review identified 24 studies and reports of bird-platform interactions, most being qualitative and half having been peer-reviewed. The most frequently observed effect, for seabirds and landbirds, is attraction and sometimes collisions associated with lights and flares; episodic events have caused the deaths of hundreds or even thousands of birds. Though typically unpredictable, anecdotally, it is known that poor weather, such as fog, precipitation and low cloud cover, can exacerbate the effect of nocturnal attraction to lights, especially when coincidental with bird migrations. Other effects include provision of foraging and roosting opportunities, increased exposure to oil and hazardous environments, increased exposure to predators, or repulsion from feeding sites. Current approaches to monitoring birds at offshore platforms have focused on observer-based methods which can offer species-level bird identification, quantify seasonal patterns of relative abundance and distribution, and document avian mortality events and underlying factors. Observer-based monitoring is time-intensive, limited in spatial and temporal coverage, and suffers without clear protocols and when not conducted by trained, independent observers. These difficulties are exacerbated because deleterious bird-platform interaction is episodic and likely requires the coincidence of multiple factors (e.g., darkness, cloud, fog, rain conditions, occurrence of birds in vicinity). Collectively, these considerations suggest a need to implement supplemental systems for monitoring bird activities around offshore platforms. Instrument-based approaches, such as radar, cameras, acoustic recordings, and telemetry, hold promise for continuous monitoring. Recommendations are provided for a rigorous and comprehensive monitoring approach within an adaptive management framework. Copyright © 2014 Elsevier Ltd. All rights reserved.

Remocean : a marine radar as a safety tool for offshore platforms

NASA Astrophysics Data System (ADS)

Serafino, Francesco; Ludeno, Giovanni; Arturi, Daniele; Lugni, Claudio; Natale, Antonio; Soldovieri, Francesco

2013-04-01

In the recent years, there is a growing interest towards offshore platforms for electric power energy with a focus to the ones exploiting wind or sea surface currents force. In this frame, an important role can be played the marine X-band radar systems, which are able to acquire high resolution information (of the order of the meters) on the sea state (direction and height of the waves) and sea surface current in a range of several kilometers from the radar platform. The information gained from the radar is therefore very useful for many issues related to the offshore platforms installation and safety. In fact, the X-band radar system can be deployed to gain a long-term information about the direction and the velocity of sea surface current so to drive in a proper way the installation of the turbines by choosing the right areas; to use the information about the long-term sea state monitoring to evaluate the vulnerability of the platforms not only against the extreme climate events but also against the structural solicitation due to ordinary conditions; to gain indirect information about the wind intensity and direction for the right management of the wind farms. In this work, we will present the marine radar system designed and developed by REMOCEAN (www.remocean.com), a Spin-off of the National Research Council (CNR, Italy). In particular, we will present the application of the REMOCEAN system to the case of the monitoring of the sea state for the offshore platform safety in real conditions.

Seabirds at risk around offshore oil platforms in the north-west Atlantic.

PubMed

Wiese, F K; Montevecchi, W A; Davoren, G K; Huettmann, F; Diamond, A W; Linke, J

2001-12-01

Seabirds aggregate around oil drilling platforms and rigs in above average numbers due to night lighting, flaring, food and other visual cues. Bird mortality has been documented due to impact on the structure, oiling and incineration by the flare. The environmental circumstances for offshore hydrocarbon development in North-west Atlantic are unique because of the harsh climate, cold waters and because enormous seabird concentrations inhabit and move through the Grand Banks in autumn (storm-petrels, Oceanodroma spp), winter (dovekies, Alle alle, murres, Uria spp), spring and summer (shearwaters, Puffinus spp). Many species are planktivorous and attracted to artificial light sources. Most of the seabirds in the region are long-distance migrants, and hydrocarbon development in the North-west Atlantic could affect both regional and global breeding populations. Regulators need to take responsibility for these circumstances. It is essential to implement comprehensive, independent arm's length monitoring of potential avian impacts of offshore hydrocarbon platforms in the North-west Atlantic. This should include quantifying and determining the nature, timing and extent of bird mortality caused by these structures. Based on existing evidence of potential impacts of offshore hydrocarbon platforms on seabirds, it is difficult to understand why this has not been, and is not being, systematically implemented.

Investigation on the effect of geometrical and geotechnical parameters on elongated offshore piles using fuzzy inference systems

NASA Astrophysics Data System (ADS)

Aminfar, Ali; Mojtahedi, Alireza; Ahmadi, Hamid; Aminfar, Mohammad Hossain

2017-06-01

Among numerous offshore structures used in oil extraction, jacket platforms are still the most favorable ones in shallow waters. In such structures, log piles are used to pin the substructure of the platform to the seabed. The pile's geometrical and geotechnical properties are considered as the main parameters in designing these structures. In this study, ANSYS was used as the FE modeling software to study the geometrical and geotechnical properties of the offshore piles and their effects on supporting jacket platforms. For this purpose, the FE analysis has been done to provide the preliminary data for the fuzzy-logic post-process. The resulting data were implemented to create Fuzzy Inference System (FIS) classifications. The resultant data of the sensitivity analysis suggested that the orientation degree is the main factor in the pile's geometrical behavior because piles which had the optimal operational degree of about 5° are more sustained. Finally, the results showed that the related fuzzified data supported the FE model and provided an insight for extended offshore pile designs.

Study on dynamic characteristics of hydraulic pumping unit on offshore platform

NASA Astrophysics Data System (ADS)

Chang, Zong-yu; Yu, Yan-qun; Qi, Yao-guang

2017-12-01

A new technology of offshore oil rod pumping production is developed for offshore heavy oil recovery. A new type of miniature hydraulic pumping unit with long-stroke, low pumping speed and compact structure is designed based on the spatial characteristics of offshore platforms. By combining the strengths of sinusoidal velocity curve and trapezoidal velocity curve, a kinematical model of the acceleration, the velocity and displacement of the pumping unit's hanging point is established. The results show that the pumping unit has good kinematic characteristics of smooth motion and small dynamic load. The multi-degree-of-freedom dynamic model of the single-well pumping unit is established. The first and second order natural frequencies of the sucker rod string subsystem and the pumping unit subsystem are studied. The results show that the first and the second order natural frequencies among the pumping rod string, pumping unit-platform subsystem and the dynamic excitation have differences over 5 times from each other, indicating that resonance phenomenon will not appear during the operation and the dynamic requirements for field use are met in the system.

Offshore platform sourced pollution monitoring using space-borne fully polarimetric C and X band synthetic aperture radar.

PubMed

Singha, Suman; Ressel, Rudolf

2016-11-15

Use of polarimetric SAR data for offshore pollution monitoring is relatively new and shows great potential for operational offshore platform monitoring. This paper describes the development of an automated oil spill detection chain for operational purposes based on C-band (RADARSAT-2) and X-band (TerraSAR-X) fully polarimetric images, wherein we use polarimetric features to characterize oil spills and look-alikes. Numbers of near coincident TerraSAR-X and RADARSAT-2 images have been acquired over offshore platforms. Ten polarimetric feature parameters were extracted from different types of oil and 'look-alike' spots and divided into training and validation dataset. Extracted features were then used to develop a pixel based Artificial Neural Network classifier. Mutual information contents among extracted features were assessed and feature parameters were ranked according to their ability to discriminate between oil spill and look-alike spots. Polarimetric features such as Scattering Diversity, Surface Scattering Fraction and Span proved to be most suitable for operational services. Copyright © 2016 Elsevier Ltd. All rights reserved.

OTEC Cold Water Pipe-Platform Subsystem Dynamic Interaction Validation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varley, Robert; Halkyard, John; Johnson, Peter

A commercial floating 100-megawatt (MW) ocean thermal energy conversion (OTEC) power plant will require a cold water pipe (CWP) with a diameter of 10-meter (m) and length of up to 1,000 m. The mass of the cold water pipe, including entrained water, can exceed the mass of the platform supporting it. The offshore industry uses software-modeling tools to develop platform and riser (pipe) designs to survive the offshore environment. These tools are typically validated by scale model tests in facilities able to replicate real at-sea meteorological and ocean (metocean) conditions to provide the understanding and confidence to proceed to finalmore » design and full-scale fabrication. However, today’s offshore platforms (similar to and usually larger than those needed for OTEC applications) incorporate risers (or pipes) with diameters well under one meter. Secondly, the preferred construction method for large diameter OTEC CWPs is the use of composite materials, primarily a form of fiber-reinforced plastic (FRP). The use of these material results in relatively low pipe stiffness and large strains compared to steel construction. These factors suggest the need for further validation of offshore industry software tools. The purpose of this project was to validate the ability to model numerically the dynamic interaction between a large cold water-filled fiberglass pipe and a floating OTEC platform excited by metocean weather conditions using measurements from a scale model tested in an ocean basin test facility.« less

Ecological and political issues surrounding decommissioning of offshore oil facilities in the Southern California Bight

USGS Publications Warehouse

Schroeder, Donna M.; Love, Milton S.

2004-01-01

To aid legislators, resource managers, and the general public, this paper summarizes and clarifies some of the issues and options that the federal government and the state of California face in decommissioning offshore oil and gas production platforms, particularly as these relate to platform ecology. Both local marine ecology and political climate play a role in decommissioning offshore oil production platforms. Compared to the relatively supportive political climate in the Gulf of Mexico for “rigs-to-reefs” programs, conflicting social values among stakeholders in Southern California increases the need for understanding ecological impacts of various decommissioning alternatives (which range from total removal to allowing some or all of platform structure to remain in the ocean). Additional scientific needs in the decommissioning process include further assessment of platform habitat quality, estimation of regional impacts of decommissioning alternatives to marine populations, and determination of biological effects of any residual contaminants. The principal management need is a ranking of environmental priorities (e.g. species-of-interest and marine habitats). Because considerable numbers of economically important species reside near oil platforms, National Oceanic and Atmospheric Administration Fisheries should consider the consequences of decommissioning alternatives in their overall management plans. Management strategies could include designating reefed platforms as marine protected areas. The overarching conclusion from both ecological and political perspectives is that decommissioning decisions should be made on a case-by-case basis.

Proceedings of the Conference Arctic '85; Civil Engineering in the Artic offshore

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, F.L.; Machemehl, J.L.

1985-01-01

Topics of the 1985 Conference included: Arctic construction, Arctic foundation, Arctic structures, and ocean effects. Arctic terminals and coastal offshore bases, protecting the Arctic environment, and probabilistic methods in Arctic offshore engineering were also discussed. Ice mechanics, marine pipelines in the Arctic, and the role of universities in training civil engineers for Arctic offshore development were highlighted. Sessions on remote sensing, surveying, and mapping were included, and offshore installations in the Bering Sea were discussed. Another topic of discussion was research in Civil Engineering for development of the Arctic offshore. The overall thrust of the conference was the application ofmore » Arctic offshore engineering principles and research in the field of oil and gas exploration and exploitation activity.« less

Using coral disease prevalence to assess the effects of concentrating tourism activities on offshore reefs in a tropical marine park.

PubMed

Lamb, Joleah B; Willis, Bette L

2011-10-01

Concentrating tourism activities can be an effective way to closely manage high-use parks and minimize the extent of the effects of visitors on plants and animals, although considerable investment in permanent tourism facilities may be required. On coral reefs, a variety of human-related disturbances have been associated with elevated levels of coral disease, but the effects of reef-based tourist facilities (e.g., permanent offshore visitor platforms) on coral health have not been assessed. In partnership with reef managers and the tourism industry, we tested the effectiveness of concentrating tourism activities as a strategy for managing tourism on coral reefs. We compared prevalence of brown band disease, white syndromes, black band disease, skeletal eroding band, and growth anomalies among reefs with and without permanent tourism platforms within the Great Barrier Reef Marine Park. Coral diseases were 15 times more prevalent at reefs with offshore tourism platforms than at nearby reefs without platforms. The maximum prevalence and maximum number of cases of each disease type were recorded at reefs with permanently moored tourism platforms. Diseases affected 10 coral genera from 7 families at reefs with platforms and 4 coral genera from 3 families at reefs without platforms. The greatest number of disease cases occurred within the spatially dominant acroporid corals, which exhibited 18-fold greater disease prevalence at reefs with platforms than at reefs without platforms. Neither the percent cover of acroporids nor overall coral cover differed significantly between reefs with and without platforms, which suggests that neither factor was responsible for the elevated levels of disease. Identifying how tourism activities and platforms facilitate coral disease in marine parks will help ensure ongoing conservation of coral assemblages and tourism. ©2011 Society for Conservation Biology.

Foundation Analysis East Coast Air Combat Maneuvering Range Offshore Kitty Hawk, North Carolina.

DTIC Science & Technology

1976-09-01

1976 86 2 3 025 TABLE OF CONTENTS SECTION TITLE PAGE 1.0 INTRODUCTION 1.1 Introduction 1.01 1.2 Methods of Analysis 1.01 1.3 Personnel Resumes 1.02...piling into the desired penetration. 1.2 METHODS OF ANALYSIS The method employed to perform the computation of pipe pile capacity curves, as presented...AD-A163 522 FOUNDATION ANALYSIS EAST COAST AIR COMBAT NANsUVERING 14S RANGE OFFSHORE KITT.. CU) CREST ENGINEERING INC TULSA OK SEP 76 27-M7-97 CNES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rashid, A.; Nygaard, C.

The use of concrete in marine environment has gained tremendous popularity in the past decade and is continued to be a very popular material for marine industry in the world today. It has a very diversified use from large offshore platforms and floating structures in the North Sea, Canada and South America to offshore loading terminals and junction platforms in shallow waters in the marshes of southern Louisiana in the Gulf of Mexico. Also, precast concrete sections are extensively used all over the world in the construction of marine structures. Because of their large variety of shapes and sizes, theymore » can be tailored to fit multiple applications in marine environment. The added quality control in the fabrication yard and the ease of installation by lifting makes them a very attractive option. The use of precast concrete sections is gaining a lot of popularity in South America. A lot of fabrication yards are manufacturing these sections locally. There are hundreds of offshore concrete platforms utilizing these sections in Lake Maracaibo, Venezuela. The paper discusses the use of concrete for offshore structures including floaters. It describes some general concepts and advantages to be gained by the use of concrete (precast and cast-in-place) in marine environment. It also discusses some general design considerations required for the use of different types of precast concrete sections that can be utilized for oil and gas platforms and loading terminals. Lastly the paper describes some typical examples of concrete platforms built out of concrete piles, precast concrete girders and beam sections and concrete decking.« less

Computationally inexpensive approach for pitch control of offshore wind turbine on barge floating platform.

PubMed

Zuo, Shan; Song, Y D; Wang, Lei; Song, Qing-wang

2013-01-01

Offshore floating wind turbine (OFWT) has gained increasing attention during the past decade because of the offshore high-quality wind power and complex load environment. The control system is a tradeoff between power tracking and fatigue load reduction in the above-rated wind speed area. In allusion to the external disturbances and uncertain system parameters of OFWT due to the proximity to load centers and strong wave coupling, this paper proposes a computationally inexpensive robust adaptive control approach with memory-based compensation for blade pitch control. The method is tested and compared with a baseline controller and a conventional individual blade pitch controller with the "NREL offshore 5 MW baseline wind turbine" being mounted on a barge platform run on FAST and Matlab/Simulink, operating in the above-rated condition. It is shown that the advanced control approach is not only robust to complex wind and wave disturbances but adaptive to varying and uncertain system parameters as well. The simulation results demonstrate that the proposed method performs better in reducing power fluctuations, fatigue loads and platform vibration as compared to the conventional individual blade pitch control.

Computationally Inexpensive Approach for Pitch Control of Offshore Wind Turbine on Barge Floating Platform

PubMed Central

Zuo, Shan; Song, Y. D.; Wang, Lei; Song, Qing-wang

2013-01-01

Offshore floating wind turbine (OFWT) has gained increasing attention during the past decade because of the offshore high-quality wind power and complex load environment. The control system is a tradeoff between power tracking and fatigue load reduction in the above-rated wind speed area. In allusion to the external disturbances and uncertain system parameters of OFWT due to the proximity to load centers and strong wave coupling, this paper proposes a computationally inexpensive robust adaptive control approach with memory-based compensation for blade pitch control. The method is tested and compared with a baseline controller and a conventional individual blade pitch controller with the “NREL offshore 5 MW baseline wind turbine” being mounted on a barge platform run on FAST and Matlab/Simulink, operating in the above-rated condition. It is shown that the advanced control approach is not only robust to complex wind and wave disturbances but adaptive to varying and uncertain system parameters as well. The simulation results demonstrate that the proposed method performs better in reducing power fluctuations, fatigue loads and platform vibration as compared to the conventional individual blade pitch control. PMID:24453834

Floating Offshore Wind in California: Gross Potential for Jobs and Economic Impacts from Two Future Scenarios

DOE Office of Scientific and Technical Information (OSTI.GOV)

Speer, Bethany; Keyser, David; Tegen, Suzanne

Construction of the first offshore wind farm in the United States began in 2015, using fixed platform structures that are appropriate for shallow seafloors, like those located off of the East Coast and mid-Atlantic. However, floating platforms, which have yet to be deployed commercially, will likely need to anchor to the deeper seafloor if deployed off of the West Coast. To analyze the employment and economic potential for floating offshore wind along the West Coast, the Bureau of Ocean Energy Management (BOEM) has commissioned the National Renewable Energy Laboratory (NREL) to analyze two hypothetical, large-scale deployment scenarios for California: 16more » GW of offshore wind by 2050 (Scenario A) and 10 GW of offshore wind by 2050 (Scenario B). The results of this analysis can be used to better understand the general scales of economic opportunities that could result from offshore wind development. Results show total state gross domestic product (GDP) impacts of $16.2 billion in Scenario B or $39.7 billion in Scenario A for construction; and $3.5 billion in Scenario B or $7.9 billion in Scenario A for the operations phases.« less

Ice interaction with offshore structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cammaert, A.B.; Muggeridge, D.B.

1988-01-01

Oil platforms and other offshore structures being built in the arctic regions must be able to withstand icebergs, ice islands, and pack ice. This reference explain the effect ice has on offshore structures and demonstrates design and construction methods that allow such structures to survive in harsh, ice-ridden environments. It analyzes the characteristics of sea ice as well as dynamic ice forces on structures. Techniques for ice modeling and field testing facilitate the design and construction of sturdy, offshore constructions. Computer programs included.

A Comprehensive Structural Study of Offshore Wind Turbine Foundation and Non-Model Based Damage Detection using Effective Mass with Application to Small Components/ Cables and a Truss Wind Turbine Tower

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Scott A.

This research has two areas of focus. The first area is to investigate offshore wind turbine (OWT) designs, for use in the Maryland offshore wind area (MOWA), using intensive modeling techniques. The second focus area is to investigate a way to detect damage in wind turbine towers and small electrical components.

2014–2015 Offshore Wind Technologies Market Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Aaron; Stehly, Tyler; Musial, Walter

2015-09-30

This report provides data and analysis to assess the status of the U.S. offshore wind industry through June 30, 2015. It builds on the foundation laid by the Navigant Consortium, which produced three market reports between 2012 and 2014. The report summarizes domestic and global market developments, technology trends, and economic data to help U.S. offshore wind industry stakeholders, including policymakers, regulators, developers, financiers, and supply chain participants, to identify barriers and opportunities.

NREL/University of Delaware Offshore Wind R&D Collaboration: Cooperative Research and Development Final Report, CRADA Number CRD-10-393

DOE Office of Scientific and Technical Information (OSTI.GOV)

Musial, Walt

2015-11-12

Specifically, the work under this CRADA includes, but is not limited to, the development of test procedures for an offshore test site in Delaware waters; testing of installed offshore wind turbines; performance monitoring of those turbines; and a program of research and development on offshore wind turbine blades, components, coatings, foundations, installation and construction of bottom-fixed structures, environmental impacts, policies, and more generally on means to enhance the reliability, facilitate permitting, and reduce costs for offshore wind turbines. This work will be conducted both at NREL's National Wind Technology Center and participant facilities, as well as the established offshore windmore » test sites.« less

Regulation and policy working group

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-03-01

The potential environmental impact of offshore platform disposal can be illustrated by both the numbers of platforms and the complexity of their abandonment options. Some 7,000 platforms are in place worldwide. In the US, approximately a quarter of the platforms are more than 25 years old and in sight of their end of service. In addition, 22,000 miles of pipeline are located on the Outer Continental Shelf (OCS) in the United States. There are more offshore platforms in the U.S. Gulf of Mexico than in any other single area in the world. It is estimated that between October 1995 andmore » December 2000, approximately 665 of the nearly 3,800 existing structures will be removed. Couple this with the mammoth size, the vagaries of the ocean, and the levels of sometimes conflicting international and federal laws, and the magnitude of the challenge to protect the environment becomes clear. The Offshore International Newsletter (11/06/95) stated, {open_quotes}In three of the last four years, annual Gulf of Mexico platform removals have exceeded installations, a trend that will likely continue.{close_quotes} Between 100 and 150 platforms have been removed from the OCS each year for the past six or seven years. As increasing numbers of wells, pipelines, and platforms are decommissioned and disposed of, it is important that the relevant techniques, policies, and regulations be discussed and evaluated. The goal of this workshop is to facilitate and document this discussion in an open, objective, and inclusive way. Since U.S. practices and policies provide precedents for other countries, international participation is encouraged and anticipated.« less

Study on load-bearing characteristics of a new pile group foundation for an offshore wind turbine.

PubMed

Lang, Ruiqing; Liu, Run; Lian, Jijian; Ding, Hongyan

2014-01-01

Because offshore wind turbines are high-rise structures, they transfer large horizontal loads and moments to their foundations. One of the keys to designing a foundation is determining the sensitivities and laws affecting its load-bearing capacity. In this study, this procedure was carried out for a new high-rise cap pile group foundation adapted to the loading characteristics of offshore wind turbines. The sensitivities of influential factors affecting the bearing properties were determined using an orthogonal test. Through a combination of numerical simulations and model tests, the effects of the inclination angle, length, diameter, and number of side piles on the vertical bearing capacity, horizontal bearing capacity, and bending bearing capacity were determined. The results indicate that an increase in the inclination angle of the side piles will increase the vertical bearing capacity, horizontal bearing capacity, and bending bearing capacity. An increase in the length of the side piles will increase the vertical bearing capacity and bending bearing capacity. When the length of the side piles is close to the central pile, the increase is more apparent. Finally, increasing the number of piles will increase the horizontal bearing capacity; however, the growth rate is small because of the pile group effect.

Study on Load-Bearing Characteristics of a New Pile Group Foundation for an Offshore Wind Turbine

PubMed Central

Liu, Run; Lian, Jijian; Ding, Hongyan

2014-01-01

Because offshore wind turbines are high-rise structures, they transfer large horizontal loads and moments to their foundations. One of the keys to designing a foundation is determining the sensitivities and laws affecting its load-bearing capacity. In this study, this procedure was carried out for a new high-rise cap pile group foundation adapted to the loading characteristics of offshore wind turbines. The sensitivities of influential factors affecting the bearing properties were determined using an orthogonal test. Through a combination of numerical simulations and model tests, the effects of the inclination angle, length, diameter, and number of side piles on the vertical bearing capacity, horizontal bearing capacity, and bending bearing capacity were determined. The results indicate that an increase in the inclination angle of the side piles will increase the vertical bearing capacity, horizontal bearing capacity, and bending bearing capacity. An increase in the length of the side piles will increase the vertical bearing capacity and bending bearing capacity. When the length of the side piles is close to the central pile, the increase is more apparent. Finally, increasing the number of piles will increase the horizontal bearing capacity; however, the growth rate is small because of the pile group effect. PMID:25250375

Offshore Wind Energy Resource Assessment for Alaska

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doubrawa Moreira, Paula; Scott, George N.; Musial, Walter D.

This report quantifies Alaska's offshore wind resource capacity while focusing on its unique nature. It is a supplement to the existing U.S. Offshore Wind Resource Assessment, which evaluated the offshore wind resource for all other U.S. states. Together, these reports provide the foundation for the nation's offshore wind value proposition. Both studies were developed by the National Renewable Energy Laboratory. The analysis presented herein represents the first quantitative evidence of the offshore wind energy potential of Alaska. The technical offshore wind resource area in Alaska is larger than the technical offshore resource area of all other coastal U.S. states combined.more » Despite the abundant wind resource available, significant challenges inhibit large-scale offshore wind deployment in Alaska, such as the remoteness of the resource, its distance from load centers, and the wealth of land available for onshore wind development. Throughout this report, the energy landscape of Alaska is reviewed and a resource assessment analysis is performed in terms of gross and technical offshore capacity and energy potential.« less

Screening of biosurfactant-producing bacteria from offshore oil and gas platforms in North Atlantic Canada.

PubMed

Cai, Qinhong; Zhang, Baiyu; Chen, Bing; Song, Xing; Zhu, Zhiwen; Cao, Tong

2015-05-01

From offshore oil and gas platforms in North Atlantic Canada, crude oil, formation water, drilling mud, treated produced water and seawater samples were collected for screening potential biosurfactant producers. In total, 59 biosurfactant producers belong to 4 genera, namely, Bacillus, Rhodococcus, Halomonas, and Pseudomonas were identified and characterized. Phytogenetic trees based on 16S ribosomal deoxyribonucleic acid (16S rDNA) were constructed with isolated strains plus their closely related strains and isolated strains with biosurfactant producers in the literature, respectively. The distributions of the isolates were site and medium specific. The richness, diversity, and evenness of biosurfactant producer communities in oil and gas platform samples have been analyzed. Diverse isolates were found with featured properties such as effective reduction of surface tension, producing biosurfactants at high rate and stabilization of water-in-oil or oil-in-water emulsion. The producers and their corresponding biosurfactants had promising potential in applications such as offshore oil spill control, enhancing oil recovery and soil washing treatment of petroleum hydrocarbon-contaminated sites.

H∞ memory feedback control with input limitation minimization for offshore jacket platform stabilization

NASA Astrophysics Data System (ADS)

Yang, Jia Sheng

2018-06-01

In this paper, we investigate a H∞ memory controller with input limitation minimization (HMCIM) for offshore jacket platforms stabilization. The main objective of this study is to reduce the control consumption as well as protect the actuator when satisfying the requirement of the system performance. First, we introduce a dynamic model of offshore platform with low order main modes based on mode reduction method in numerical analysis. Then, based on H∞ control theory and matrix inequality techniques, we develop a novel H∞ memory controller with input limitation. Furthermore, a non-convex optimization model to minimize input energy consumption is proposed. Since it is difficult to solve this non-convex optimization model by optimization algorithm, we use a relaxation method with matrix operations to transform this non-convex optimization model to be a convex optimization model. Thus, it could be solved by a standard convex optimization solver in MATLAB or CPLEX. Finally, several numerical examples are given to validate the proposed models and methods.

[Relationship between occupational stress and mental health in offshore oil platform workers].

PubMed

Wu, Hongtao; Xiao, Taiqin; Zou, Jianfang; Shan, Yongle; Li, Zijian

2014-02-01

To investigate the relationship between occupational stress and mental health in offshore oil platform workers and to provide a scientific basis for protection of their mental health. A total of 768 workers on offshore oil platform were surveyed with the Occupational Stress Inventory Revised Edition and Symptom Check List-90 (SCL-90). The total score of Occupational Role Questionnaire (ORQ) for the workers (160.27±24.63) was significantly lower than the national norm (166.52±27.01) (P < 0.01); the total score of Personal Strain Questionnaire (PSQ) (101.96±19.8) was significantly higher than the national norm (92.45±17.33) (P < 0.01). The total score of Personal Resource Questionnaire (PRQ) for the workers was not significantly different from the national norm (P > 0.05), but the items of recreation, social support, and rational/cognitive found significant difference (P < 0.05). The total score of SCL-90 was positively correlated with all items of ORQ and PSQ (P < 0.01) and negatively correlated with all items of PRQ (P < 0.01). The multiple stepwise regression analysis showed that current work seniority, education background, drinking, role overload, role insufficiency, role ambiguity, responsibility, physical environment, and rational/cognitive conduct impacted the score of SCL-90 (P < 0.05). The mental health of workers on offshore oil platform is related to occupational stress, and role overload, role ambiguity, physical environment, and rational/cognitive conduct, etc, are closely associated with the workers' mental health.

Environmental Impact of Offshore Gas Activities on the Benthic Environment: A Case Study

NASA Astrophysics Data System (ADS)

Punzo, E.; Gomiero, A.; Tassetti, A. N.; Strafella, P.; Santelli, A.; Salvalaggio, V.; Spagnolo, A.; Scarcella, G.; De Biasi, A. M.; Kozinkova, L.; Fabi, G.

2017-08-01

Multidisciplinary monitoring of the impact of offshore gas platforms on northern and central Adriatic marine ecosystems has been conducted since 1998. Beginning in 2006, 4-5 year investigations spanning the period before, during, and after rig installation have explored the effects of its construction and presence on macrozoobenthic communities, sediment, water quality, pollutant bioaccumulation, and fish assemblages. In this study, sediment samples collected at increasing distance from an offshore gas platform before, during and after its construction were subjected to chemical analysis and assessment of benthic communities. Ecological indices were calculated to evaluate the ecological status of the area. Ecotoxicological analysis of sediment was performed to establish whether pollutants are transferred to biota. The study applied a before-after control-impact design to assess the effects of rig construction and presence and provide reference data on the possible impacts of any further expansion of the gas extraction industry in the already heavily exploited Adriatic Sea. Only some of the metals investigated (barium, chromium, cadmium, and zinc) showed a different spatial and/or temporal distribution that may be platform-related. In the early phases, the sediment concentrations of polycyclic aromatic hydrocarbons were below the detection limit at all sites; they then became detectable, but without significant spatial differences. The present findings suggest that the environmental effects of offshore gas platforms may be difficult to quantify, interpret, and generalize, because they are influenced by numerous, often local, abiotic, and biotic variables in different and unpredictable ways.

Environmental Impact of Offshore Gas Activities on the Benthic Environment: A Case Study.

PubMed

Punzo, E; Gomiero, A; Tassetti, A N; Strafella, P; Santelli, A; Salvalaggio, V; Spagnolo, A; Scarcella, G; De Biasi, A M; Kozinkova, L; Fabi, G

2017-08-01

Multidisciplinary monitoring of the impact of offshore gas platforms on northern and central Adriatic marine ecosystems has been conducted since 1998. Beginning in 2006, 4-5 year investigations spanning the period before, during, and after rig installation have explored the effects of its construction and presence on macrozoobenthic communities, sediment, water quality, pollutant bioaccumulation, and fish assemblages. In this study, sediment samples collected at increasing distance from an offshore gas platform before, during and after its construction were subjected to chemical analysis and assessment of benthic communities. Ecological indices were calculated to evaluate the ecological status of the area. Ecotoxicological analysis of sediment was performed to establish whether pollutants are transferred to biota. The study applied a before-after control-impact design to assess the effects of rig construction and presence and provide reference data on the possible impacts of any further expansion of the gas extraction industry in the already heavily exploited Adriatic Sea. Only some of the metals investigated (barium, chromium, cadmium, and zinc) showed a different spatial and/or temporal distribution that may be platform-related. In the early phases, the sediment concentrations of polycyclic aromatic hydrocarbons were below the detection limit at all sites; they then became detectable, but without significant spatial differences. The present findings suggest that the environmental effects of offshore gas platforms may be difficult to quantify, interpret, and generalize, because they are influenced by numerous, often local, abiotic, and biotic variables in different and unpredictable ways.

Floating Offshore Wind in Oregon: Potential for Jobs and Economic Impacts from Two Future Scenarios

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jimenez, Tony; Keyser, David; Tegen, Suzanne

Construction of the first offshore wind power plant in the United States began in 2015, off the coast of Rhode Island, using fixed platform structures that are appropriate for shallow seafloors, like those located off of the East Coast and mid-Atlantic. However, floating platforms, which have yet to be deployed commercially, will likely need to anchor to the deeper seafloor if deployed off of the West Coast. To analyze the employment and economic potential for floating offshore wind along the West Coast, the Bureau of Ocean Energy Management (BOEM) commissioned the National Renewable Energy Laboratory (NREL) to analyze two hypothetical,more » large-scale deployment scenarios for Oregon: 5,500 megawatts (MW) of offshore wind deployment in Oregon by 2050 (Scenario A), and 2,900 MW of offshore wind by 2050 (Scenario B). These levels of deployment could power approximately 1,600,000 homes (Scenario A) or 870,000 homes (Scenario B). Offshore wind would contribute to economic development in Oregon in the near future, and more substantially in the long term, especially if equipment and labor are sourced from within the state. According to the analysis, over the 2020-2050 period, Oregon floating offshore wind facilities could support 65,000-97,000 job-years and add $6.8 billion-$9.9 billion to the state GDP (Scenario A).« less

Atmospheric metallic and arsenic pollution at an offshore drilling platform in the Bo Sea: A health risk assessment for the workers.

PubMed

Xu, Hong; Han, Suqin; Bi, Xiaohui; Zhao, Zhijing; Zhang, Lei; Yang, Wenjie; Zhang, Min; Chen, Jing; Wu, Jianhui; Zhang, Yufen; Feng, Yinchang

2016-03-05

To investigate the ambient metal pollution at the offshore drilling platform in the Bo Sea, which few studies have focused on, PM2.5 samples were collected and ten heavy metals, as well as As, were analyzed. High concentration levels of metals were observed, and the heavy metal pollution was quite serious compared to air quality standards and other marine areas. Back trajectories and wind dependent and PCA analyses showed that the marine sources included ship traffic emissions and corrosive stainless steels from the equipment at the platform as well as industrial emissions from stainless steel production and coal combustion sources, which were transported from the surrounding mainland. Both contributed greatly to the ambient metallic particles at the offshore platform. The Hazard Index values of the metals, which were much less than 1, the Carcinogenic Risk data, which were lower than the EPA's acceptable range, and the fact that the metal concentrations did not the exceed the permissible exposure limits of OSHA, indicated that the health risks from the ambient metallic particles for the oil-drilling workers were not significant. Copyright © 2015 Elsevier B.V. All rights reserved.

Predicting recreational fishing use of offshore petroleum platforms in the Central Gulf of Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gordon, W.R. Jr.

1987-01-01

This study is based on the premise that properly sited artificial reefs for optimal human recreational use, a predictive model based upon the marine travel patterns and behavior of marine recreational fishermen, is needed. This research used data gathered from a previous study that addressed the recreational fishing use of offshore oil and gas structures (Ditton and Auyong 1984); on-site data were also collected. The primary research objective was to generate a predictive model that can be applied to artificial-reef development efforts elsewhere. This study investigated the recreational-user patterns of selected petroleum platforms structures in the Central Gulf of Mexico.more » The petroleum structures offshore from the Louisiana coastline provide a unique research tool. Although intended to facilitate the exploration and recovery of hydrocarbons, petroleum platforms also serve as defacto artificial reefs, providing habitat for numerous species of fish and other marine life. Petroleum platforms were found to be the principal fishing destinations within the study area. On-site findings reveal that marine recreational fishermen were as mobile on water, as they are on land. On-site findings were used to assist in the development of a predictive model.« less

NREL Software Aids Offshore Wind Turbine Designs (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2013-10-01

NREL researchers are supporting offshore wind power development with computer models that allow detailed analyses of both fixed and floating offshore wind turbines. While existing computer-aided engineering (CAE) models can simulate the conditions and stresses that a land-based wind turbine experiences over its lifetime, offshore turbines require the additional considerations of variations in water depth, soil type, and wind and wave severity, which also necessitate the use of a variety of support-structure types. NREL's core wind CAE tool, FAST, models the additional effects of incident waves, sea currents, and the foundation dynamics of the support structures.

Oil rigs and offshore sport fishing in Louisiana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dugas, R.; Guillory, V.; Fischer, M.

Forty years ago, offshore sport fishing in Louisiana was almost nonexistent. Offshore oil drilling platforms are the primary cause of the present increase in sport fishing in this area. Algae and other organisms forming the first step in the food chain cluster around the subsurface structures of the rigs, attracting fish that seek food and shelter. Major game species frequenting these rigs are identified. (3 photos, 22 references, 2 tables)

NREL Supports Innovative Offshore Wind Energy Projects | News | NREL

Science.gov Websites

installation, operation, and maintenance methods for wind turbines located far from shore. Fishermen's Energy will also use the twisted-jacket foundation for the five 5-MW turbines it plans to install 3 miles off about offshore wind and investigate interactions between turbines. Principle Power will install five 6

Offshore marine constructions as propagators of moon jellyfish dispersal

NASA Astrophysics Data System (ADS)

Vodopivec, Martin; Peliz, Álvaro J.; Malej, Alenka

2017-08-01

We have studied the influence of offshore marine constructions on the moon jellyfish population in the Adriatic sea, where the newly set up substrates enable the formation of a new population based in the formerly unpopulated open waters. Our five-year long computer simulation uses a high resolution coupled bio-physical individual-based model to track the dispersal of the offspring from subpopulations originating from offshore and shore-based sources. According to our study, the platforms enhance connectivity between subpopulations of jellyfish polyps, help sustain existing shore-based subpopulations, contribute to jellyfish blooms in some areas, and play an important role in establishing connection with the rest of the Mediterranean, in addition to representing substantial amounts of available substrate. This is an aspect that is usually overlooked when evaluating the ecological impact of existing and future wind farms, oil and gas platforms, etc. Our approach could serve as a role model in future studies of ecological impacts of planned offshore constructions.

Radiation dose and risk to recreational fishermen from ingestion of fish caught near eight oil platforms in the Gulf of Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meinhold, A.F.; Holtzman, S.

1998-06-01

Offshore production of oil and gas is accompanied by a saline wastewater, called produced water. Produced water discharges to the Gulf of Mexico often contain elevated concentrations of radionuclides that occur naturally in the geologic reservoir along with the oil and gas. These radionuclides may accumulate in organisms that live near offshore oil and gas structures. Because recreational fishing in the Gulf of Mexico is concentrated near oil and gas platforms, there is the potential for increased risks to recreational fishermen from the ingestion of radionuclides in fish caught near produced water discharges. This analysis investigated the potential risk tomore » recreational fishermen from radium and lead-210 in offshore produced water discharged to the Gulf of Mexico.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The first controlled-temperature ice plug in the bend of an offshore gas trunkline has been carried out for Phillips Petroleum Co. Norway on its Norpipe A.S. platform in the German sector of the North Sea. The procedure was part of a subsea valve repair operation. The ice plug was successfully formed offshore and tested to a differential pressure of 1,450 psi. Repair of two valves required only 5 days during which time gas production was operating at close to 50--60% via the platform bypass, says the service company. The paper discusses the procedure.

1:50 Scale Testing of Three Floating Wind Turbines at MARIN and Numerical Model Validation Against Test Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dagher, Habib; Viselli, Anthony; Goupee, Andrew

The primary goal of the basin model test program discussed herein is to properly scale and accurately capture physical data of the rigid body motions, accelerations and loads for different floating wind turbine platform technologies. The intended use for this data is for performing comparisons with predictions from various aero-hydro-servo-elastic floating wind turbine simulators for calibration and validation. Of particular interest is validating the floating offshore wind turbine simulation capabilities of NREL’s FAST open-source simulation tool. Once the validation process is complete, coupled simulators such as FAST can be used with a much greater degree of confidence in design processesmore » for commercial development of floating offshore wind turbines. The test program subsequently described in this report was performed at MARIN (Maritime Research Institute Netherlands) in Wageningen, the Netherlands. The models considered consisted of the horizontal axis, NREL 5 MW Reference Wind Turbine (Jonkman et al., 2009) with a flexible tower affixed atop three distinct platforms: a tension leg platform (TLP), a spar-buoy modeled after the OC3 Hywind (Jonkman, 2010) and a semi-submersible. The three generic platform designs were intended to cover the spectrum of currently investigated concepts, each based on proven floating offshore structure technology. The models were tested under Froude scale wind and wave loads. The high-quality wind environments, unique to these tests, were realized in the offshore basin via a novel wind machine which exhibits negligible swirl and low turbulence intensity in the flow field. Recorded data from the floating wind turbine models included rotor torque and position, tower top and base forces and moments, mooring line tensions, six-axis platform motions and accelerations at key locations on the nacelle, tower, and platform. A large number of tests were performed ranging from simple free-decay tests to complex operating conditions with irregular sea states and dynamic winds.« less

Stabilized floating platforms

DOEpatents

Thomas, David G.

1976-01-01

The subject invention is directed to a floating platform for supporting nuclear reactors and the like at selected offshore sites. The platform is provided with a stabilizer mechanism which significantly reduces the effects of wave action upon the platform and which comprises a pair of relatively small floats attached by rigid booms to the platform at locations spaced therefrom for reducing wave pitch, acceleration, and the resonance period of the wave.

Design features of offshore oil production platforms influence their susceptibility to biocorrosion.

PubMed

Duncan, Kathleen E; Davidova, Irene A; Nunn, Heather S; Stamps, Blake W; Stevenson, Bradley S; Souquet, Pierre J; Suflita, Joseph M

2017-08-01

Offshore oil-producing platforms are designed for efficient and cost-effective separation of oil from water. However, design features and operating practices may create conditions that promote the proliferation and spread of biocorrosive microorganisms. The microbial communities and their potential for metal corrosion were characterized for three oil production platforms that varied in their oil-water separation processes, fluid recycling practices, and history of microbially influenced corrosion (MIC). Microbial diversity was evaluated by 16S rRNA gene sequencing, and numbers of total bacteria, archaea, and sulfate-reducing bacteria (SRB) were estimated by qPCR. The rates of 35 S sulfate reduction assay (SRA) were measured as a proxy for metal biocorrosion potential. A variety of microorganisms common to oil production facilities were found, but distinct communities were associated with the design of the platform and varied with different locations in the processing stream. Stagnant, lower temperature (<37 °C) sites in all platforms had more SRB and higher SRA compared to samples from sites with higher temperatures and flow rates. However, high (5 mmol L -1 ) levels of hydrogen sulfide and high numbers (10 7  mL -1 ) of SRB were found in only one platform. This platform alone contained large separation tanks with long retention times and recycled fluids from stagnant sites to the beginning of the oil separation train, thus promoting distribution of biocorrosive microorganisms. These findings tell us that tracking microbial sulfate-reducing activity and community composition on off-shore oil production platforms can be used to identify operational practices that inadvertently promote the proliferation, distribution, and activity of biocorrosive microorganisms.

Offshore Wind Research | Wind | NREL

Science.gov Websites

validation and certification. A photo of an offshore wind turbine with a yellow foundation floating in the wind turbine with three turbines and blue ocean in the background. Design Methods, Tools, and Standards Applying 35 years of wind turbine validation expertise, NREL has developed instrumentation for high

U.S. Wind Energy Manufacturing and Supply Chain: A Competitiveness Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fullenkamp, Patrick H; Holody, Diane S

The goal of the project was to develop a greater understanding of the key factors determining wind energy component manufacturing costs and pricing on a global basis in order to enhance the competitiveness of U.S. manufacturers, and to reduce installed systems cost. Multiple stakeholders including DOE, turbine OEMs, and large component manufactures will all benefit by better understanding the factors determining domestic competitiveness in the emerging offshore and next generation land-based wind industries. Major objectives of this project were to: 1. Carry out global cost and process comparisons for 5MW jacket foundations, blades, towers, and permanent magnet generators; 2. Assessmore » U.S. manufacturers’ competitiveness and potential for cost reduction; 3. Facilitate informed decision-making on investments in U.S. manufacturing; 4. Develop an industry scorecard representing the readiness of the U.S. manufacturers’ to produce components for the next generations of wind turbines, nominally 3MW land-based and 5MW offshore; 5. Disseminate results through the GLWN Wind Supply Chain GIS Map, a free website that is the most comprehensive public database of U.S. wind energy suppliers; 6. Identify areas and develop recommendations to DOE on potential R&D areas to target for increasing domestic manufacturing competitiveness, per DOE’s Clean Energy Manufacturing Initiative (CEMI). Lists of Deliverables 1. Cost Breakdown Competitive Analyses of four product categories: tower, jacket foundation, blade, and permanent magnet (PM) generator. The cost breakdown for each component includes a complete Bill of Materials with net weights; general process steps for labor; and burden adjusted by each manufacturer for their process categories of SGA (sales general and administrative), engineering, logistics cost to a common U.S. port, and profit. 2. Value Stream Map Competitiveness Analysis: A tool that illustrates both information and material flow from the point of getting a customer order at the manufacturing plant; to the orders being forwarded by the manufacturing plant to the material suppliers; to the material being received at the manufacturing plant and processed through the system; to the final product being shipped to the Customer. 3. Competitiveness Scorecard: GLWN developed a Wind Industry Supply Chain Scorecard that reflects U.S. component manufacturers’ readiness to supply the next generation wind turbines, 3MW and 5MW, for land-based and offshore applications. 4. Wind Supply Chain Database & Map: Expand the current GLWN GIS Wind Supply Chain Map to include offshore elements. This is an on-line, free access, wind supply chain map that provides a platform for identifying active and emerging suppliers for the land-based and offshore wind industry, including turbine component manufacturers and wind farm construction service suppliers.« less

30 CFR 250.907 - Where must I locate foundation boreholes?

Code of Federal Regulations, 2010 CFR

2010-07-01

... platforms and tension leg platforms, your maximum distance from any foundation pile to a soil boring must... throughout the anchor pattern to establish the soil profile suitable for foundation design purposes. ...

Offshore Wind Turbines - Estimated Noise from Offshore Wind Turbine, Monhegan Island, Maine: Environmental Effects of Offshore Wind Energy Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aker, Pamela M.; Jones, Anthony M.; Copping, Andrea E.

2010-11-23

Deep C Wind, a consortium headed by the University of Maine will test the first U.S. offshore wind platforms in 2012. In advance of final siting and permitting of the test turbines off Monhegan Island, residents of the island off Maine require reassurance that the noise levels from the test turbines will not disturb them. Pacific Northwest National Laboratory, at the request of the University of Maine, and with the support of the U.S. Department of Energy Wind Program, modeled the acoustic output of the planned test turbines.

30 CFR 250.911 - If my platform is subject to the Platform Verification Program, what must I do?

Code of Federal Regulations, 2011 CFR

2011-07-01

... installation for the Regional Supervisor's approval. You must include a project management timeline, Gantt... MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR...

IEA Wind Task 26: Offshore Wind Farm Baseline Documentation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smart, Gavin; Smith, Aaron; Warner, Ethan

This document has been produced to provide the definition and rationale for the Baseline Offshore Wind Farm established within IEA Wind Task 26--Cost of Wind Energy. The Baseline has been developed to provide a common starting point for country comparisons and sensitivity analysis on key offshore wind cost and value drivers. The baseline project reflects an approximate average of the characteristics of projects installed between 2012 and 2014, with the project life assumed to be 20 years. The baseline wind farm is located 40 kilometres (km) from construction and operations and maintenance (O&M) ports and from export cable landfall. Themore » wind farm consists of 100 4-megawatt (MW) wind turbines mounted on monopile foundations in an average water depth of 25 metres (m), connected by 33-kilovolt (kV) inter-array cables. The arrays are connected to a single offshore substation (33kV/220kV) mounted on a jacket foundation, with the substation connected via a single 220kV export cable to an onshore substation, 10km from landfall. The wind farm employs a port-based O&M strategy using crew-transfer vessels.« less

Earth Observations in Support of Offshore Wind Energy Management in the Euro-Atlantic Region

NASA Astrophysics Data System (ADS)

Liberato, M. L. R.

2017-12-01

Climate change is one of the most important challenges in the 21st century and the energy sector is a major contributor to GHG emissions. Therefore greater attention has been given to the evaluation of offshore wind energy potentials along coastal areas, as it is expected offshore wind energy to be more efficient and cost-effective in the near future. Europe is developing offshore sites for over two decades and has been growing at gigawatt levels in annual capacity. Portugal is among these countries, with the development of a 25MW WindFloat Atlantic wind farm project. The international scientific community has developed robust ability on the research of the climate system components and their interactions. Climate scientists have gained expertise in the observation and analysis of the climate system as well as on the improvement of model and predictive capabilities. Developments on climate science allow advancing our understanding and prediction of the variability and change of Earth's climate on all space and time scales, while improving skilful climate assessments and tools for dealing with future challenges of a warming planet. However the availability of greater datasets amplifies the complexity on manipulation, representation and consequent analysis and interpretation of such datasets. Today the challenge is to translate scientific understanding of the climate system into climate information for society and decision makers. Here we discuss the development of an integration tool for multidisciplinary research, which allows access, management, tailored pre-processing and visualization of datasets, crucial to foster research as a service to society. One application is the assessment and monitoring of renewable energy variability, such as wind or solar energy, at several time and space scales. We demonstrate the ability of the e-science platform for planning, monitoring and management of renewable energy, particularly offshore wind energy in the Euro-Atlantic region. Further we explore the automatization of processes using different domains and datasets, which facilitate further research in evaluating and understanding renewable energy variability. AcknowledgementsThis work is supported by Foundation for Science and Technology (FCT), Portugal, project UID/GEO/50019/2013 - Instituto Dom Luiz.

Turboexpanders with pressurized magnetic bearings for off-shore applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agahi, R.R.; Ershaghi, B.; Baudelocque, L.

1995-12-31

There are two primary parameters that encourage the use of magnetic bearings in turbomachinery: oil-free process and space requirements. For cryogenic processes such as hydrogen purification and ethylene plants, oil free process is the primary objective. In the case of off-shore platforms for oil and gas production, the occupied space and weight are of prime concern. In off-shore operations, the process gas density is usually higher than in normal process plants because the gas is untreated and at high pressure. High density process gas generates more windage loss and may also cause excessive radial load to journal bearings. The bearingmore » assembly design should be suitable for sour gas environments as well. Furthermore, the thrust bearing system should withstand process fluctuations which are more severe due to high pressure. In this paper, the authors explain their experience of designing a turboexpander-compressor with magnetic bearings for an off-shore oil production platform. They will present side load analysis and their solutions for heat dissipation and coping with process fluctuations.« less

30 CFR 250.915 - What are the CVA's primary responsibilities?

Code of Federal Regulations, 2010 CFR

2010-07-01

... OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Platforms and Structures... or organizations acting as CVAs must not function in any capacity that would create a conflict of... design, fabrication and installation of the platform. ...

Integration of offshore wind farms through high voltage direct current networks

NASA Astrophysics Data System (ADS)

Livermore, Luke

The integration of offshore wind farms through Multi Terminal DC (MTDC) networks into the GB network was investigated. The ability of Voltage Source Converter (VSC) High Voltage Direct Current (HVDC) to damp Subsynchronous Resonance (SSR) and ride through onshore AC faults was studied. Due to increased levels of wind generation in Scotland, substantial onshore and offshore reinforcements to the GB transmission network are proposed. Possible inland reinforcements include the use of series compensation through fixed capacitors. This potentially can lead to SSR. Offshore reinforcements are proposed by two HVDC links. In addition to its primary functions of bulk power transmission, a HVDC link can be used to provide damping against SSR, and this function has been modelled. Simulation studies have been carried out in PSCAD. In addition, a real-time hardware-in-the-loop HVDC test rig has been used to implement and validate the proposed damping scheme on an experimental platform. When faults occur within AC onshore networks, offshore MTDC networks are vulnerable to DC overvoltages, potentially damaging the DC plant and cables. Power reduction and power dissipation control systems were investigated to ride through onshore AC faults. These methods do not require dedicated fast communication systems. Simulations and laboratory experiments are carried out to evaluate the control systems, with the results from the two platforms compared..

Characteristics of produced water discharged to the Gulf of Mexico hypoxiczone.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veil, J. A.; Kimmell, T. A.; Rechner, A. C.

2005-08-24

Each summer, an area of low dissolved oxygen (the hypoxic zone) forms in the shallow nearshore Gulf of Mexico waters from the Mississippi River Delta westward to near the Texas/Louisiana border. Most scientists believe that the leading contributor to the hypoxic zone is input of nutrients (primarily nitrogen and phosphorus compounds) from the Mississippi and Atchafalaya Rivers. The nutrients stimulate growth of phytoplankton. As the phytoplankton subsequently die, they fall to the bottom waters where they are decomposed by microorganisms. The decomposition process consumes oxygen in the bottom waters to create hypoxic conditions. Sources other than the two rivers mentionedmore » above may also contribute significant quantities of oxygen-demanding pollutants. One very visible potential source is the hundreds of offshore oil and gas platforms located within or near the hypoxic zone. Many of these platforms discharge varying volumes of produced water. However, only limited data characterizing oxygen demand and nutrient concentration and loading from offshore produced water discharges have been collected. No comprehensive and coordinated oxygen demand data exist for produced water discharges in the Gulf of Mexico. This report describes the results of a program to sample 50 offshore oil and gas platforms located within the Gulf of Mexico hypoxic zone. The program was conducted in response to a requirement in the U.S. Environmental Protection Agency (EPA) general National Pollutant Discharge Elimination System (NPDES) permit for offshore oil and gas discharges. EPA requested information on the amount of oxygen-demanding substances contained in the produced water discharges. This information is needed as inputs to several water quality models that EPA intends to run to estimate the relative contributions of the produced water discharges to the occurrence of the hypoxic zone. Sixteen platforms were sampled 3 times each at approximately one-month intervals to give an estimate of temporal variability. An additional 34 platforms were sampled one time. The 50 sampled platforms were scattered throughout the hypoxic zone to give an estimate of spatial variability. Each platform was sampled for biochemical oxygen demand (BOD), total organic carbon (TOC), nitrogen (ammonia, nitrate, nitrite, and total Kjeldahl nitrogen [TKN]), and phosphorus (total phosphorus and orthophosphate). In addition to these parameters, each sample was monitored for pH, conductivity, salinity, and temperature. The sampling provided average platform concentrations for each parameter. Table ES-1 shows the mean, median, maximum, and minimum for the sampled parameters. For some of the parameters, the mean is considerably larger than the median, suggesting that one or a few data points are much higher than the rest of the points (outliers). Chapter 4 contains an extensive discussion of outliers and shows how the sample results change if outliers are deleted from consideration. A primary goal of this study is to estimate the mass loading (lb/day) of each of the oxygen-demanding pollutants from the 50 platforms sampled in the study. Loading is calculated by multiplying concentrations by the discharge volume and then by a conversion factor to allow units to match. The loadings calculated in this study of 50 platforms represent a produced water discharge volume of about 176,000 bbl/day. The total amount of produced water generated in the hypoxic zone during the year 2003 was estimated as 508,000 bbl/day. This volume is based on reports by operators to the Minerals Management Service each year. It reflects the volume of produced water that is generated from each lease, not the volume that is discharged from each platform. The mass loadings from offshore oil and gas discharges to the entire hypoxic zone were estimated by multiplying the 50-platform loadings by the ratio of total water generated to 50-platform discharge volume. The loadings estimated for the 50 platforms and for the entire hypoxic zone are shown in Table ES-2. These estimates and the sampling data from 50 platforms represent the most complete and comprehensive effort ever undertaken to characterize the amount and potential sources of the oxygen demand in offshore oil and gas produced water discharges.« less

Weathering the Storm: Developing a Spatial Data Infrastructure and Online Research Platform for Oil Spill Preparedness

NASA Astrophysics Data System (ADS)

Bauer, J. R.; Rose, K.; Romeo, L.; Barkhurst, A.; Nelson, J.; Duran-Sesin, R.; Vielma, J.

2016-12-01

Efforts to prepare for and reduce the risk of hazards, from both natural and anthropogenic sources, which threaten our oceans and coasts requires an understanding of the dynamics and interactions between the physical, ecological, and socio-economic systems. Understanding these coupled dynamics are essential as offshore oil & gas exploration and production continues to push into harsher, more extreme environments where risks and uncertainty increase. However, working with these large, complex data from various sources and scales to assess risks and potential impacts associated with offshore energy exploration and production poses several challenges to research. In order to address these challenges, an integrated assessment model (IAM) was developed at the Department of Energy's (DOE) National Energy Technology Laboratory (NETL) that combines spatial data infrastructure and an online research platform to manage, process, analyze, and share these large, multidimensional datasets, research products, and the tools and models used to evaluate risk and reduce uncertainty for the entire offshore system, from the subsurface, through the water column, to coastal ecosystems and communities. Here, we will discuss the spatial data infrastructure and online research platform, NETL's Energy Data eXchange (EDX), that underpin the offshore IAM, providing information on how the framework combines multidimensional spatial data and spatio-temporal tools to evaluate risks to the complex matrix of potential environmental, social, and economic impacts stemming from modeled offshore hazard scenarios, such as oil spills or hurricanes. In addition, we will discuss the online analytics, tools, and visualization methods integrated into this framework that support availability and access to data, as well as allow for the rapid analysis and effective communication of analytical results to aid a range of decision-making needs.

Historical Population Estimates For Several Fish Species At Offshore Oil and Gas Structures in the US Gulf of Mexico

NASA Astrophysics Data System (ADS)

Gitschlag, G.

2016-02-01

Population estimates were calculated for four fish species occurring at offshore oil and gas structures in water depths of 14-32 m off the Louisiana and upper Texas coasts in the US Gulf of Mexico. From 1993-1999 sampling was conducted at eight offshore platforms in conjunction with explosive salvage of the structures. To estimate fish population size prior to detonation of explosives, a fish mark-recapture study was conducted. Fish were captured on rod and reel using assorted hook sizes. Traps were occasionally used to supplement catches. Fish were tagged below the dorsal fin with plastic t-bar tags using tagging guns. Only fish that were alive and in good condition were released. Recapture sampling was conducted after explosives were detonated during salvage operations. Personnel operating from inflatable boats used dip nets to collect all dead fish that floated to the surface. Divers collected representative samples of dead fish that sank to the sea floor. Data provided estimates for red snapper (Lutjanus campechanus), Atlantic spadefish (Chaetodipterus faber), gray triggerfish (Balistes capriscus), and blue runner (Caranx crysos) at one or more of the eight platforms studied. At seven platforms, population size for red snapper was calculated at 503-1,943 with a 95% CI of 478. Abundance estimates for Atlantic spadefish at three platforms ranged from 1,432-1,782 with a 95% CI of 473. At three platforms, population size of gray triggerfish was 63-129 with a 95% CI of 82. Blue runner abundance at one platform was 558. Unlike the other three species which occur close to the platforms, blue runner range widely and recapture of this species was dependent on fish schools being in close proximity to the platform at the time explosives were detonated. Tag recapture was as high as 73% for red snapper at one structure studied.

Radionuclides, Metals, and Hydrocarbons in Oil and Gas Operational Discharges and Environmental Samples Associated with Offshore Production Facilities on the Texas/Louisiana Continental Shelf with an Environmental Assessment of Metals and Hydrocarbons.

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-06-01

This report presents concentrations of radionuclides, metals, and hydrocarbons in samples of produced water and produced sand from oil and gas production platforms located offshore Texas and Louisiana. concentrations in produced water discharge plume / receiving water, ambient seawater, sediment, interstitial water, and marine animal tissue samples collected in the vicinity of discharging platforms and reference sites distant from discharges are also reported and discussed. An environmental risk assessment is made on the basis of the concentration of metals and hydrocarbons determined in the samples.

Radionuclides, Metals, and Hydrocarbons in Oil and Gas Operational Discharges and Environmental Samples Associated with Offshore Production Facilities on the Texas/Louisiana Continental Shelf with an Environmental Assessment of Metals and Hydrocarbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Continental Shelf Associates, Inc.

1999-08-16

This report presents concentrations of radionuclides, metals, and hydrocarbons in samples of produced water and produced sand from oil and gas production platforms located offshore Texas and Louisiana. Concentrations in produced water discharge plume/receiving water, ambient seawater, sediment, interstitial water, and marine animal tissue samples collected in the vicinity of discharging platforms and reference sites distant from discharges are also reported and discussed. An environmental risk assessment is made on the basis of the concentrations of metals and hydrocarbons determined in the samples.

A simplified method in comparison with comprehensive interaction incremental dynamic analysis to assess seismic performance of jacket-type offshore platforms

NASA Astrophysics Data System (ADS)

Zolfaghari, M. R.; Ajamy, A.; Asgarian, B.

2015-12-01

The primary goal of seismic reassessment procedures in oil platform codes is to determine the reliability of a platform under extreme earthquake loading. Therefore, in this paper, a simplified method is proposed to assess seismic performance of existing jacket-type offshore platforms (JTOP) in regions ranging from near-elastic to global collapse. The simplified method curve exploits well agreement between static pushover (SPO) curve and the entire summarized interaction incremental dynamic analysis (CI-IDA) curve of the platform. Although the CI-IDA method offers better understanding and better modelling of the phenomenon, it is a time-consuming and challenging task. To overcome the challenges, the simplified procedure, a fast and accurate approach, is introduced based on SPO analysis. Then, an existing JTOP in the Persian Gulf is presented to illustrate the procedure, and finally a comparison is made between the simplified method and CI-IDA results. The simplified method is very informative and practical for current engineering purposes. It is able to predict seismic performance elasticity to global dynamic instability with reasonable accuracy and little computational effort.

[Reliability and validity of the Occupational Stress Scale for Chinese offshore oil platform workers].

PubMed

Chen, Wei-qing; Huang, Zi-hui; Yu, De-xin; Lin, Yan-zu; Ling, Zhi-ming; Tang, Ji-song

2003-02-01

To evaluate the validity and reliability of the Occupational Stress Scale (OSS) for Chinese offshore oil platform workers. A 51-item self-administered questionnaire developed in the light of Cooper's questionnaire and company's special situation was used to investigate 561 subjects. 51 occupational stress items relating to offshore oil production were subjected to factor analysis, and nine latent factors were identified, which explained 62.5% of the total variance. According to the contents described by the items included in each factor, they were respectively defined as: "the interface between job and family/social life (factor 1)", "career and achievement (factor 2)", "safety (factor 3)", "management problem and relationship with others at work (factor 4)", "physical factors of workplace (factor 5)", "platform living environment (factor 6)", "role in management (factor 7)", "ergonomics (factor 8)" and "organization structure (factor 9)". Significant difference in the score of five factors was observed among 12 different job categories by analysis of variance. After adjusting for potential confounding factors (age, educational level), hierarchical multiple regression analysis indicated that the score of the OSS was significantly and positively correlated with the poor mental health of the workers (P < 0.01). The consistent test between OSS and each factor showed that Cronbach's alpha were 0.72 - 0.91. The OSS is a valid and reliable tool for measuring occupational stress, and can be used to explore occupational stress and its influence on health and safety problems in offshore oil workers.

High-resolution onshore-offshore morpho-bathymetric records of modern chalk and granitic shore platforms in NW France

NASA Astrophysics Data System (ADS)

Duperret, Anne; Raimbault, Céline; Le Gall, Bernard; Authemayou, Christine; van Vliet-Lanoë, Brigitte; Regard, Vincent; Dromelet, Elsa; Vandycke, Sara

2016-07-01

Modern shore platforms developed on rocky coasts are key areas for understanding coastal erosion processes during the Holocene. This contribution offers a detailed picture of two contrasted shore-platform systems, based on new high-resolution shallow-water bathymetry, further coupled with aerial LiDAR topography. Merged land-sea digital elevation models were achieved on two distinct types of rocky coasts along the eastern English Channel in France (Picardy and Upper-Normandy: PUN) and in a NE Atlantic area (SW Brittany: SWB) in NW France. About the PUN case, submarine steps, identified as paleo-shorelines, parallel the actual coastline. Coastal erosive processes appear to be continuous and regular through time, since mid-Holocene at least. In SWB, there is a discrepancy between contemporary coastline orientation and a continuous step extending from inland to offshore, identified as a paleo-shoreline. This illustrates a polyphased and inherited shore platform edification, mainly controlled by tectonic processes.

2014-2015 Offshore Wind Technologies Market Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Aaron; Stehly, Tyler; Musial, Walter

2015-09-01

This report provides data and analysis to assess the status of the U.S. offshore wind industry through June 30, 2015. It builds on the foundation laid by the Navigant Consortium, which produced three market reports between 2012 and 2014. The report summarizes domestic and global market developments, technology trends, and economic data to help U.S. offshore wind industry stakeholders, including policymakers, regulators, developers, financiers, and supply chain participants, to identify barriers and opportunities. Title page contains link to associated data tables posted at http://www.nrel.gov/docs/fy15osti/64283_data_tables.xlsx.

The Role of Disturbance, Larval Supply, and Native Community on the Establishment of a Non-Native Species on Oil Platforms in the Santa Barbara Channel

NASA Astrophysics Data System (ADS)

Viola, S.; Page, M.; Miller, R. J.; Zaleski, S.; Doheny, B.; Dugan, J.; Schroeder, D. M.

2016-02-01

Disturbance facilitates the establishment of non-native species in a variety of ecosystems. In marine ecosystems, offshore structures, such as oil and gas platforms, provide hard substrate habitat that can be colonized by non-native species. Periodic platform cleaning and storm events are disturbances that remove the attached epibenthic community and may promote the establishment of non-native species. The non-native crustose bryozoan, Watersipora subtorquata (=W. subatra?), has colonized a number of oil platforms in the Santa Barbara Channel. In this study, we experimentally 1) tested the role of disturbance and water depth on the establishment of Watersipora on an offshore platform, 2) explored how larval supply might influence observed patterns, and 3) evaluated the importance of biotic interactions, specifically predation on Watersipora larvae. To attain these objectives, we 1) quantified Watersipora cover in cleared and undisturbed plots, 2) measured monthly variation in larval supply using settlement plates, and 3) deployed tethered live mussels and sealed mussel shells and compared recruitment to these two surfaces. Our results suggest that disturbance greatly enhances the establishment of Watersipora, but that this effect varies with depth and associated larval availability. Additionally, predation of larvae by native suspension feeders appears to limit the recruitment rate of Watersipora. Our findings on the factors influencing the establishment of Watersipora could inform decisions to manage the spread of non-native species to artificial and natural marine habitats, as well as decisions related to the maintenance of offshore structures as artificial reefs.

Bacterial diversity in water injection systems of Brazilian offshore oil platforms.

PubMed

Korenblum, Elisa; Valoni, Erika; Penna, Mônica; Seldin, Lucy

2010-01-01

Biogenic souring and microbial-influenced corrosion is a common scenario in water-flooded petroleum reservoirs. Water injection systems are continuously treated to control bacterial contamination, but some bacteria that cause souring and corrosion can persist even after different treatments have been applied. Our aim was to increase our knowledge of the bacterial communities that persist in the water injection systems of three offshore oil platforms in Brazil. To achieve this goal, we used a culture-independent molecular approach (16S ribosomal RNA gene clone libraries) to analyze seawater samples that had been subjected to different treatments. Phylogenetic analyses revealed that the bacterial communities from the different platforms were taxonomically different. A predominance of bacterial clones affiliated with Gammaproteobacteria, mostly belonging to the genus Marinobacter (60.7%), were observed in the platform A samples. Clones from platform B were mainly related to the genera Colwellia (37.9%) and Achromobacter (24.6%), whereas clones obtained from platform C were all related to unclassified bacteria. Canonical correspondence analyses showed that different treatments such as chlorination, deoxygenation, and biocide addition did not significantly influence the bacterial diversity in the platforms studied. Our results demonstrated that the injection water used in secondary oil recovery procedures contained potentially hazardous bacteria, which may ultimately cause souring and corrosion.

Impact of Offshore Wind Energy Plants on the Soil Mechanical Behaviour of Sandy Seafloors

NASA Astrophysics Data System (ADS)

Stark, Nina; Lambers-Huesmann, Maria; Zeiler, Manfred; Zoellner, Christian; Kopf, Achim

2010-05-01

Over the last decade, wind energy has become an important renewable energy source. Especially, the installation of offshore windfarms offers additional space and higher average wind speeds than the well-established windfarms onshore. Certainly, the construction of offshore wind turbines has an impact on the environment. In the framework of the Research at Alpha VEntus (RAVE) project in the German offshore wind energy farm Alpha Ventus (north of the island Borkum in water depths of about 30 m) a research plan to investigate the environmental impact had been put into place. An ongoing study focuses on the changes in soil mechanics of the seafloor close to the foundations and the development of scour. Here, we present results of the first geotechnical investigations after construction of the plants (ca. 1 - 6 months) compared to geotechnical measurements prior to construction. To study the soil mechanical behaviour of the sand, sediment samples from about thirty different positions were measured in the laboratory to deliver, e.g., grain size (0.063 - 0.3 mm), friction angles (~ 32°), unit weight (~ 19.9 kN/m³) and void ratios (~ 0.81). For acoustic visualisation, side-scan-sonar (towed and stationary) and multibeam-echosounders (hull mounted) were used. Data show a flat, homogenous seafloor prior to windmill erection, and scouring effects at and in the vicinity of the foundations afterwards. Geotechnical in-situ measurements were carried out using a standard dynamic Cone Penetration Testing lance covering the whole windfarm area excluding areas in a radius < 50 m from the installed windmills (due the accessibility with the required research vessel). In addition, the small free-fall penetrometer Nimrod was deployed at the same spots, and furthermore, in the areas close to the tripod foundations (down to a distance of ~ 5 m from the central pile). Before construction, CPT as well as Nimrod deployments confirm a flat, homogenous sandy area with tip resistance values ranging from 1200 - 1600 kPa (CPT with a mass of ~ 100 kg and an impact velocity of ~ 1 m/s) and quasi-static bearing capacities (qsbc.) mainly ranging from 39 - 69 kPa (Nimrod: mass of ~ 13 kg, impact velocity of ~ 8 m/s). There was no evidence for layering in results of both in-situ instruments. After construction, most of the positions show changes in sediment strength ranging from 10 % up to 100 % compared to the results prior to windmill construction. Extreme changes (> 50 %) occur above all close to the foundations. Furthermore, patterns of relatively soft zones (qsbc.: 50 - 80 kPa) and hard zones (qsbc. > 100 kPa) were mapped during the high-resolution surveys close to the foundation. Beside that, a very soft sediment layer (0.03 - 0.05 m) drapes most of the soft zones. This may be recently eroded and re-deposited sediment, whereas the hard zones may indicate areas of sediment erosion where looser material has been carried away. Reasons for sediment remobilization and changes in geotechnical properties may be scouring as a consequence of the changed hydrodynamics in the vicinity of the windmills. Besides first developments of scour, the side scan sonar results show relicts of the wind turbine erection (e.g., footprints of jack-up-platforms). First multibeam-echosounder measurements confirm sediment re-deposition due to scour in the lee of the main current direction and show traces of wind turbine erection equipment in the same areas where also the penetrometer measurements took place. In summary, a local impact of the wind turbines on the soil mechanical properties of the seafloor is attested from this initial post-erection survey. Future cruises (every 6 months) will complement those data, which will eventually allow us a comparison to, or even refinement of long-term scouring models.

Analytical and numerical investigation of bolted steel ring flange connection for offshore wind monopile foundations

NASA Astrophysics Data System (ADS)

Madsen, C. A.; Kragh-Poulsen, J.-C.; Thage, K. J.; Andreassen, M. J.

2017-12-01

The monopile foundation is the dominant solution for support of wind turbines in offshore wind farms. It is normally grouted to the transition piece which connects the foundation to the turbine. Currently, the bolted steel ring flange connection is investigated as an alternative. The monopile--transition piece connection has specific problems, such as out-of-verticality and installation damage from driving the MP into the seabed and it is not fully known how to design for these. This paper presents the status of the ongoing development work and an estimate of what still needs to be covered in order to use the connection in practice. This involves presentation of an analytical and non-linear FE analysis procedure for the monopile-transition piece connection composed of two L flanges connected with preloaded bolts. The connection is verified for ultimate and fatigue limit states based on an integrated load simulation carried out by the turbine manufacturer.

Pit bearing capacity effect on status of soil plug during pile driving in ocean engineering

NASA Astrophysics Data System (ADS)

Yan, Shu-Wang; Zhou, Qun-Hua; Liu, Run; Dong, Wei

2011-06-01

Foundation piles of the offshore oil platforms in the Bohai Bay are usually longer than 100 m with a diameter larger than 2 m. Driving such long and large-sized piles into the ground is a difficult task. It needs a comprehensive consider ation of the pile dimensions, soil properties and the hammer energy. Thoughtful drivability analysis has to be performed in the design stage. It has been shown that judging whether the soil column inside the pile is fully plugged, which makes the pile behave as close-ended, strongly influences the accuracy of drivability analysis. Engineering practice repeatedly indicates that the current methods widely used for soil plug judgment often give incorrect results, leading the designers to make a wrong decision. It has been found that this problem is caused by the ignorance of the bearing capacity provided by the soil surrounding the pile. Based on the Terzaghi's bearing capacity calculation method for deep foundation, a new approach for judging soil plug status is put forward, in which the surcharge effect has been considered and the dynamic effect coefficient is included. This approach has been applied to some practical engineering projects successfully, which may give more reasonable results than the currently used method does.

Data Modeling, Development, Installation and Operation of the ACEX Offshore Drilling Information System for the Mission Specific Platform Expedition to the Lomonosov Ridge, Arctic Ocean.

NASA Astrophysics Data System (ADS)

Conze, R.; Krysiak, F.; Wallrabe-Adams, H.; Graham, C. C.

2004-12-01

During August/September 2004, the Arctic Coring Expedition (ACEX) was used to trial a new Offshore Drilling Information System (OffshoreDIS). ACEX was the first Mission Specific Platform (MSP) expedition of the Integrated Ocean Drilling Programme (IODP), funded by the European Consortium for Ocean Research Drilling (ECORD). The British Geological Survey in conjunction with the University of Bremen and the European Petrophysics Consortium were the ECORD Science Operator (ESO) for ACEX. IODP MSP expeditions have very similar data management requirements and operate in similar working environments to the lake drilling projects conducted by the International Continental Scientific Drilling Program (ICDP), for example, the GLAD800, which has very restricted space on board and operates in difficult conditions. Both organizations require data capture and management systems that are mobile, flexible and that can be deployed quickly on small- to medium-sized drilling platforms for the initial gathering of data, and that can also be deployed onshore in laboratories where the bulk of the scientific work is conducted. ESO, therefore, decided that an adapted version of the existing Drilling Information System (DIS) used by ICDP projects would satisfy its requirements. Based on the existing DIS, an OffshoreDIS has been developed for MSP expeditions. The underlying data model is compatible with IODP(JANUS), the Bremen Core Repository, WDC-MARE/PANGAEA and the LacCore in Minneapolis. According to the specific expedition platform configuration and on-board workflow requirements for the Arctic, this data model, data pumps and user interfaces were adapted for the ACEX-OffshoreDIS. On the drill ship Vidar Viking the cores were catalogued and petrophysically logged using a GeoTek Multi-Sensor Core Logger System, while further initial measurements, lithological descriptions and biostratigraphic investigations were undertaken on the Oden, which provided laboratory facilities for the expedition. Onboard samples were registered in a corresponding sample archive on both vessels. The ACEX-OffshoreDIS used a local area network covering the two ships of the three icebreaker fleet by wireless LAN between the ships and partly wired LAN on the ships. A DIS-server was installed on each ship. These were synchronized by database replication and linked to a total of 10 client systems and label printers across both ships. The ACEX-OffshoreDIS will also be used for the scientific measurement and analysis phase of the expedition during the post-field operations `shore-party' in November 2004 at the Bremen Core Repository (BCR). The data management system employed in the Arctic will be reconfigured and deployed at the BCR. In addition, an eXtended DIS (XDIS) Web interface will be available. This will allow controlled sample distribution (core curation, sub-sampling) as well as sharing of data (registration, upload and download) with other laboratories which will be undertaking additional sampling and analyses. The OffshoreDIS data management system will be of long-term benefit to both IODP and ICDP, being deployed in forthcoming MSP offshore projects, ICDP lake projects and joint IODP-ICDP projects such as the New Jersey Coastal Plain Drilling Project.

26 CFR 1.638-1 - Continental Shelf areas.

Code of Federal Regulations, 2013 CFR

2013-04-01

... exploitation of oil and is physically present on an offshore oil drilling platform operated by employees of L... a foreign country, designs equipment for use on oil drilling platforms affixed to the continental... corporation, to engage in exploratory oil drilling activities on a leasehold held by Y Corporation. Such...

26 CFR 1.638-1 - Continental Shelf areas.

Code of Federal Regulations, 2014 CFR

2014-04-01

... exploitation of oil and is physically present on an offshore oil drilling platform operated by employees of L... a foreign country, designs equipment for use on oil drilling platforms affixed to the continental... corporation, to engage in exploratory oil drilling activities on a leasehold held by Y Corporation. Such...

26 CFR 1.638-1 - Continental Shelf areas.

Code of Federal Regulations, 2012 CFR

2012-04-01

... exploitation of oil and is physically present on an offshore oil drilling platform operated by employees of L... a foreign country, designs equipment for use on oil drilling platforms affixed to the continental... corporation, to engage in exploratory oil drilling activities on a leasehold held by Y Corporation. Such...

26 CFR 1.638-1 - Continental Shelf areas.

Code of Federal Regulations, 2011 CFR

2011-04-01

... exploitation of oil and is physically present on an offshore oil drilling platform operated by employees of L... a foreign country, designs equipment for use on oil drilling platforms affixed to the continental... corporation, to engage in exploratory oil drilling activities on a leasehold held by Y Corporation. Such...

Offshore platform structure intended to be installed in arctic waters, subjected to drifting icebergs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kure, G.; Jenssen, D.N.; Naesje, K.

1984-09-11

An offshore platform structure, particularly intended to be installed in waters where drifting iceberg frequently appear, the platform structure being intended to be founded in a sea bed and comprises a substructure, a superstructure rigidly affixed to the substructure and extending vertically up above the sea level supporting a deck superstructure at its upper end. The horizontal cross-sectional area of the substructure is substantially greater than tath of the superstructure. The substructure rigidly supports a fender structure, the fender structure comprising an outer peripherally arranged wall and an inner cylindrical wall the inner and outer wall being rigidly interconnected bymore » means of a plurality of vertical and/or horizontal partition walls, dividing the fender structure into a plurality of cells or compartlents. The fender structure is arranged in spaced relation with respect to the superstructure.« less

Drill cuttings mount formation study

NASA Astrophysics Data System (ADS)

Teh, Su Yean; Koh, Hock Lye

2014-07-01

Oil, Gas and Energy sector has been identified as an essential driving force in the Malaysian Economic Transformation Programs (ETP). Recently confirmed discovery of many offshore oil and gas deposits in Malaysian waters has ignited new confidence in this sector. However, this has also spurred intense interest on safeguarding the health and environment of coastal waters in Malaysia from adverse impact resulting from offshore oil and gas production operation. Offshore discharge of spent drilling mud and rock cuttings is the least expensive and simplest option to dispose of large volumes of drilling wastes. But this onsite offshore disposal may have adverse environmental impacts on the water column and the seabed. It may also pose occupational health hazards to the workers living in the offshore platforms. It is therefore important to model the transport and deposition of drilling mud and rock cuttings in the sea to enable proper assessment of their adverse impacts on the environment and the workers. Further, accumulation of drill particles on the seabed may impede proper operation of pipelines on the seabed. In this paper, we present an in-house application model TUNA-PT developed to cater to local oil and gas industry needs to simulate the dispersion and mount formation of drill cuttings by offshore oil and gas exploration and production platforms. Using available data on Malaysian coastal waters, simulation analyses project a pile formation on the seabed with a maximum height of about 1 m and pile radius of around 30 to 50 m. Simulated pile heights are not sensitive to the heights of release of the cuttings as the sensitivity has been mitigated by the depth of water.

Foundations of Wind Turbines as Stepping Stones for Non-Indigenous Species in the Southern North Sea

NASA Astrophysics Data System (ADS)

De Mesel, I.; Degraer, S.; Kerckhof, F.; Schön, I.; Martens, K.

2016-02-01

Since 2008, offshore wind farms have been constructed in the shallow waters (<50m) of the Southern North Sea. At present, hundreds of turbines are operational and many more are planned. A new habitat for benthos has been created, with vertical hard structures in the offshore environment, extending from the sandy seabed to the sea surface. Monitoring in Belgian waters focussed on the succession of the fouling community in the sub- and intertidal zone, with special attention to non-indigenous species (NIS). A Metridium senile-Jassa herdmani dominated community developed in the subtidal, and only few NIS were present (3 out of a total of 90 species observed). Their presence was however most striking in the intertidal zone, where we identified 17 obligate intertidal species with about half of them being non-indigenous. This study confirmed the hypothesis that the introduced hard substrata within offshore wind farms play an important role in the establishment and the expansion of the population of both indigenous and non-indigenous species. Foundations of wind turbines strengthen the strategic position of NIS in the southern North Sea. An ongoing study on the population genetics of a fouling species (Patella vulgata) will, in combination with dispersal modelling, elucidate the dispersal pattern and connectivity with neighbouring areas, and the role of the foundations as stepping stones.

[Work-related accidents on oil drilling platforms in the Campos Basin, Rio de Janeiro, Brazil].

PubMed

Freitas, C M; Souza, C A; Machado, J M; Porto, M F

2001-01-01

The offshore oil industry is characterized by complex systems in relation to technology and organization of work. Working conditions are hazardous, resulting in accidents and even occasional full-scale catastrophes. This article is the result of a study on work-related accidents in the offshore platforms in the Campos Basin, Rio de Janeiro State. The primary objective was to provide technical back-up for both workers' representative organizations and public authorities. As a methodology, we attempt to go beyond the immediate causes of accidents and emphasize underlying causes related to organizational and managerial aspects. The sources were used in such a way as to permit classification in relation to the type of incident, technological system, operation, and immediate and underlying causes. The results show the aggravation of safety conditions and the immediate need for public authorities and the offshore oil industry in Brazil to change the methods used to investigate accidents in order to identify the main causes in the organizational and managerial structure of companies.

First evaluation of foraminiferal metabarcoding for monitoring environmental impact from an offshore oil drilling site.

PubMed

Laroche, Olivier; Wood, Susanna A; Tremblay, Louis A; Ellis, Joanne I; Lejzerowicz, Franck; Pawlowski, Jan; Lear, Gavin; Atalah, Javier; Pochon, Xavier

2016-09-01

At present, environmental impacts from offshore oil and gas activities are partly determined by measuring changes in macrofauna diversity. Morphological identification of macrofauna is time-consuming, expensive and dependent on taxonomic expertise. In this study, we evaluated the applicability of using foraminiferal-specific metabarcoding for routine monitoring. Sediment samples were collected along distance gradients from two oil platforms off Taranaki (New Zealand) and their physico-chemical properties, foraminiferal environmental DNA/RNA, and macrofaunal composition analyzed. Macrofaunal and foraminiferal assemblages showed similar shifts along impact gradients, but responded differently to environmental perturbations. Macrofauna were affected by hypoxia, whereas sediment grain size appeared to drive shifts in foraminifera. We identified eight foraminiferal molecular operational taxonomic units that have potential to be used as bioindicator taxa. Our results show that metabarcoding represents an effective tool for assessing foraminiferal communities near offshore oil and gas platforms, and that it can be used to complement current monitoring techniques. Copyright © 2016 Elsevier Ltd. All rights reserved.

Offshore Hydrokinetic Energy Conversion for Onshore Power Generation

NASA Technical Reports Server (NTRS)

Jones, Jack A.; Chao, Yi

2009-01-01

Design comparisons have been performed for a number of different tidal energy systems, including a fully submerged, horizontal-axis electro-turbine system, similar to Verdant Tidal Turbines in New York's East River, a platform-based Marine Current Turbine, now operating in Northern Ireland's Strangford Narrows, and the Rotech Lunar Energy system, to be installed off the South Korean Coast. A fourth type of tidal energy system studied is a novel JPL/Caltech hydraulic energy transfer system that uses submerged turbine blades which are mechanically attached to adjacent high-pressure pumps, instead of to adjacent electrical turbines. The generated highpressure water streams are combined and transferred to an onshore hydroelectric plant by means of a closed-cycle pipeline. The hydraulic energy transfer system was found to be cost competitive, and it allows all electronics to be placed onshore, thus greatly reducing maintenance costs and corrosion problems. It also eliminates the expenses of conditioning and transferring multiple offshore power lines and of building offshore platforms embedded in the sea floor.

Biological effects of diethylene glycol (DEG) and produced waters (PWs) released from offshore activities: a multi-biomarker approach with the sea bass Dicentrarchus labrax.

PubMed

Stefania, Gorbi; Maura, Benedetti; Claudia, Virno Lamberti; Barbara, Pisanelli; Ginevra, Moltedo; Francesco, Regoli

2009-11-01

Diethylene glycol (DEG) is largely used during oil and gas exploitation by offshore platforms. The aim of this work was to investigate if this compound induces direct molecular/cellular effects in marine organisms, or indirectly modulate those of produced waters (PWs). Sea bass (Dicentrarchus labrax) were exposed to DEG dosed alone or in combination with PWs from an Adriatic platform. A wide array of analysed biomarkers included cytochrome P450-dependent enzymatic activity, bile metabolites, glutathione S-transferases, acetylcholinesterase, peroxisomal proliferation, antioxidant defences (catalase, glutathione reductase, glutathione peroxidases, glutathione), total oxyradical scavenging capacity, malondialdehyde and DNA integrity (single strand breaks and frequency of micronuclei). Results did not reveal marked effects of DEG, while PWs influenced the biotransformation system, the oxidative status and the onset of genotoxic damages. Co-exposures caused only limited differences of biomarker responses at some experimental conditions, overall suggesting a limited biological impact of DEG at levels normally deriving from offshore activities.

Proceedings: An international workshop on offshore lease abandonment and platform disposal: Technology, regulation, and environmental effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pulsipher, A.

This Proceedings volume includes papers prepared for an international workshop on lease abandonment and offshore platform disposal. The workshop was held April 15, 16, and 17, 1996, in New Orleans, Louisiana. Included in the volume are several plenary speeches and issue papers. prepared by six working groups, who discussed: Abandoning Wells; Abandoning Pipelines; Removing Facilities; Site Clearance; Habitat Management, Maintenance, and Planning; and Regulation and Policy. Also included are an introduction, an afterword (reprinted with the permission of its author, John Lohrenz), and, as Appendix C, the complete report of the National Research Council Marine Boards An Assessment of Techniquesmore » for Removing Fixed Offshore Structures, around which much of the discussion at the workshop was organized. Short biographies of many speakers, organizers, and chairpersons are included as Appendix A. Appendix B is a list of conference participants. Selected papers have been processes separately for inclusion in the Energy Science and Technology database.« less

Offshore oil platforms and fouling communities in the southern Arabian Gulf (Abu Dhabi).

PubMed

Stachowitsch, Michael; Kikinger, Reinhard; Herler, Jürgen; Zolda, Pamela; Geutebrück, Ernst

2002-09-01

This study examined the fouling organisms on the legs of offshore oil platforms at two sites in the southern Arabian Gulf (offshore Abu Dhabi, United Arab Emirates). 100% of the metal structures was colonized by encrusting organisms. Both the number of individuals and the total biomass tended to decrease with depth. The total weight of dead shells always exceeded that of living organisms. Sessile filter feeders dominated the biomass, whereas small mobile forms had the largest number of individuals. The biomass at the deeper platform (22 m) was dominated by bivalves, barnacles and bryozoans, while polychaetes and amphipods had the greatest number of individuals. Biomass values here ranged from 1 g/0.1 m2 at 20 m to 147 g/0.1 m2 at 5 m; the corresponding individual numbers were 266 (20 m) and 11,814 indiv./0.1 m2 (5 m). The results at the shallower platform (11 m) differed in several respects: barnacles clearly dominated over bivalves, and sponges exceeded byrozoans, while total individual numbers fell due to a decline in polychaete dominance. Biomass values here ranged from 84 g/0.1 m2 at 10 m to 153 g/0.1 m2 at 0 m; the corresponding individual numbers were 695 (10 m) and 3,125 indiv./0.1 m2 (0 m). The potential role of such fouling communities on artificial structures in the Gulf is discussed.

WindFloat Pacific Project, Final Scientific and Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banister, Kevin

2017-01-17

PPI’s WindFloat Pacific project (WFP) was an up to 30 MW floating offshore wind demonstration project proposed off the Coast of Oregon. The project was to be sited approximately 18 miles due west of Coos Bay, in over 1000 ft. of water, and is the first floating offshore wind array proposed in the United States, and the first offshore wind project of any kind proposed off the West Coast. PPI’s WindFloat, a semi-submersible foundation designed for high-capacity (6MW+) offshore wind turbines, is at the heart of the proposed project, and enables access to the world class wind resource at themore » project site and, equally, to other deep water, high wind resource areas around the country.« less

Noise Mitigation During Pile Driving Efficiently Reduces Disturbance of Marine Mammals.

PubMed

Nehls, Georg; Rose, Armin; Diederichs, Ansgar; Bellmann, Michael; Pehlke, Hendrik

2016-01-01

Acoustic monitoring of harbor porpoises (Phocoena phocoena L., 1758) indicated a strongly reduced disturbance by noise emitted by pile driving for offshore wind turbine foundations insulated by a big bubble curtain (BBC). This newly developed noise mitigation system was tested during construction of the offshore wind farm Borkum West II (North Sea). Because porpoise activity strongly corresponded to the sound level, operation of the new system under its most suitable configuration reduced the porpoise disturbance area by ~90%. Hence, for the first time, a positive effect of a noise mitigation system during offshore pile driving on an affected marine mammal species could be demonstrated.

Psychosocial burden among offshore drilling platform employees.

PubMed

Leszczyńska, Irena; Jeżewska, Maria

2010-01-01

Conditions of work on offshore drilling platforms are particularly hard due to extreme environmental situations created both by nature and technological processes. Oil drilling workers employed on the open sea are potentially exposed to permanently high stress. Apart from the obvious objective factors affecting drilling platform employees, a great role in the general work-related stress level is played by the working conditions and work-related psychosocial factors, defined according to Karask's concept as demands, control, and social support. A total of 184 drill platform workers were examined using objective and subjective research methods. The level of subjective stress among drilling platform workers is lower than the level of objective stress and the stress resulting from prognoses related with specificity of work in extremely hard conditions (audit). The examinations of drilling platform workers reveal a positive role of stress in psychological adaptation, being a special case of the "work ethos" and attachment to the firm. In such investigations of work-related stress on drilling platforms, which are very specific workplaces, a multi-aspect character, sociological and economic aspects, organizational culture conditions in the firm, and a tendency to conceal ailments and the stress experienced should be taken into account. It is important to apply measures referring to at least three different types of evidence (objective demands, subjective stress, health problems reported). Otherwise, the result reflecting work-related stress may not be objective and far from the truth.

Measurement and Analysis of Extreme Wave and Ice Actions in the Great Lakes for Offshore Wind Platform Design

DOE Office of Scientific and Technical Information (OSTI.GOV)

England, Tony; van Nieuwstadt, Lin; De Roo, Roger

This project, funded by the Department of Energy as DE-EE0005376, successfully measured wind-driven lake ice forces on an offshore structure in Lake Superior through one of the coldest winters in recent history. While offshore regions of the Great Lakes offer promising opportunities for harvesting wind energy, these massive bodies of freshwater also offer extreme and unique challenges. Among these challenges is the need to anticipate forces exerted on offshore structures by lake ice. The parameters of interest include the frequency, extent, and movement of lake ice, parameters that are routinely monitored via satellite, and ice thickness, a parameter that hasmore » been monitored at discrete locations over many years and is routinely modeled. Essential relationships for these data to be of use in the design of offshore structures and the primary objective of this project are measurements of maximum forces that lake ice of known thicknesses might exert on an offshore structure.« less

Postmortem analysis of sand grain crushing from pile interface using X-ray tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silva, I. Matias; Combe, Gaeel; Foray, Pierre

2013-06-18

Pile foundations of offshore platforms, wind and water turbines are typically subjected to a variety of cyclic loading paths due to their complex environment. While many studies focus on global pile behaviour, the soil-pile interface is explored here by a micromechanical study of the soil layer in contact with the pile surface. This work is devoted to the analysis of frozen post-mortem silica sand samples recovered at the pile interface following installation and cyclic loading tests in a calibration chamber using x-ray tomography. An experimental procedure developed for three dimensional (3D) snow imaging was adapted for the recovery of themore » in-situ sand samples to preserve their structure during tomography scans. 3D images at a pixel size of 7 {mu}m were then obtained using a cryogenic cell. Results confirm the presence of a shear band at the pile surface as well as void ratios changes in the direction of the pile's radius.« less

Some recent advances of intelligent health monitoring systems for civil infrastructures in HIT

NASA Astrophysics Data System (ADS)

Ou, Jinping

2005-06-01

The intelligent health monitoring systems more and more become a technique for ensuring the health and safety of civil infrastructures and also an important approach for research of the damage accumulation or even disaster evolving characteristics of civil infrastructures, and attracts prodigious research interests and active development interests of scientists and engineers since a great number of civil infrastructures are planning and building each year in mainland China. In this paper, some recent advances on research, development nad implementation of intelligent health monitoring systems for civil infrastructuresin mainland China, especially in Harbin Institute of Technology (HIT), P.R.China. The main contents include smart sensors such as optical fiber Bragg grating (OFBG) and polivinyllidene fluoride (PVDF) sensors, fatigue life gauges, self-sensing mortar and carbon fiber reinforced polymer (CFRP), wireless sensor networks and their implementation in practical infrastructures such as offshore platform structures, hydraulic engineering structures, large span bridges and large space structures. Finally, the relative research projects supported by the national foundation agencies of China are briefly introduced.

Analysis of offshore platforms lifting with fixed pile structure type (fixed platform) based on ASD89

NASA Astrophysics Data System (ADS)

Sugianto, Agus; Indriani, Andi Marini

2017-11-01

Platform construction GTS (Gathering Testing Sattelite) is offshore construction platform with fix pile structure type/fixed platform functioning to support the mining of petroleum exploitation. After construction fabrication process platform was moved to barges, then shipped to the installation site. Moving process is generally done by pull or push based on construction design determined when planning. But at the time of lifting equipment/cranes available in the work area then the moving process can be done by lifting so that moving activity can be implemented more quickly of work. This analysis moving process of GTS platform in a different way that is generally done to GTS platform types by lifting using problem is construction reinforcement required, so the construction can be moved by lifting with analyzing and checking structure working stress that occurs due to construction moving process by lifting AISC code standard and analysis using the SAP2000 structure analysis program. The analysis result showed that existing condition cannot be moved by lifting because stress ratio is above maximum allowable value that is 0.950 (AISC-ASD89). Overstress occurs on the member 295 and 324 with stress ratio value 0.97 and 0.95 so that it is required structural reinforcement. Box plate aplication at both members so that it produces stress ratio values 0.78 at the member 295 and stress ratio of 0.77 at the member 324. These results indicate that the construction have qualified structural reinforcement for being moved by lifting.

Review and Recommendations for the Interagency Ship Structure Committee’s Fiscal 1984 Research Program,

DTIC Science & Technology

1983-01-01

Daily. Proposal Evaluation Procedure Organizations interested in doing the work adverstised submit proposals and cost estimates. The USCG contracting...types of offshore structures. These structures have largely been fixed platforms for petroleum drilling and production, and mobile offshore drilling...structures and of those mobile drilling units that are bottom supported, such as jack-ups and submersibles. Structures which are held in place by anchors

Development of Decision Analysis Specifically for Arctic Offshore Drilling Islands.

DTIC Science & Technology

1985-12-01

the decision analysis method will - give tradeoffs between costs and design wave height, production and depth • :of water for an oil platform , etc...optimizing the type of platform that is best suited for a particular site has become an extremely difficult decision. Over fifty- one different types of...drilling and production platforms have been identified for the Arctic environment, with new concepts being developed - every year, Boslov et al (198j

Analysis of Earthquake Recordings Obtained from the Seafloor Earthquake Measurement System (SEMS) Instruments Deployed off the Coast of Southern California

USGS Publications Warehouse

Boore, D.M.; Smith, C.E.

1999-01-01

For more than 20 years, a program has been underway to obtain records of earthquake shaking on the seafloor at sites offshore of southern California, near oil platforms. The primary goal of the program is to obtain data that can help determine if ground motions at offshore sites are significantly different than those at onshore sites; if so, caution may be necessary in using onshore motions as the basis for the seismic design of oil platforms. We analyze data from eight earthquakes recorded at six offshore sites; these are the most important data recorded on these stations to date. Seven of the earthquakes were recorded at only one offshore station; the eighth event was recorded at two sites. The earthquakes range in magnitude from 4.7 to 6.1. Because of the scarcity of multiple recordings from any one event, most of the analysis is based on the ratio of spectra from vertical and horizontal components of motion. The results clearly show that the offshore motions have very low vertical motions compared to those from an average onshore site, particularly at short periods. Theoretical calculations find that the water layer has little effect on the horizontal components of motion but that it produces a strong spectral null on the vertical component at the resonant frequency of P waves in the water layer. The vertical-to-horizontal ratios for a few selected onshore sites underlain by relatively low shear-wave velocities are similar to the ratios from offshore sites for frequencies less than about one-half the water layer P-wave resonant frequency, suggesting that the shear-wave velocities beneath a site are more important than the water layer in determining the character of the ground motions at lower frequencies.

Venezuela offshore oil and gas production development: Past, present and future

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perez La Salvia, H.; Schwartz, E.; Contreras, M.

1995-12-01

This paper presents a short history of offshore oil and gas production in Venezuela starting in Lake Maracaibo in 1923. The main emphasis has been the results of the recent R and D and the exploratory offshore programs in areas like Orinoco Delta located in the Atlantic Ocean, Northeast and Northwest Venezuela in the Caribbean sea. In the R and D offshore program the main objectives were: (1) To establish the local environmental, oceanographical, geotechnical and seismicity conditions for the Venezuelan Continental Platform. (2) To give a technical support to the PDVSA Operating Affiliates during the exploratory programs including: (a)more » to develop accurate drilling vessel positioning systems; (b) evaluation of sea bottom geotechnical conditions for safely operating the jack-ups and drilling vessels involved in the exploratory wells and (c) to identify those areas which because of their special nature require further investigation to establish preliminary type of platforms required for the areas to be developed or to evaluate other solutions proposed by Foreign Consultant Engineering Companies to the PDVSA Operating Affiliated Companies. The main objective of PDVSA for the coming future will be to develop the North of Paria Gas Field through the initially named Christopher Columbus Project now Sucre Gas, S.A., a consortium conformed by LaGoven, S.A. Shell, Exxon and Mitsubishi. objective of this paper is to give an idea of the history of the Venezuelan Oil and Gas Offshore development giving emphasis to the results of the INTEVEP S.A. Red offshore program and to show some results of the particular characteristics of oceanographical, environmental, geotechnical and seismic conditions in the main areas evaluated during the exploratory program: Orinoco Delta, Gulf of Paria and North of Paria.« less

Mobile demersal megafauna at common offshore wind turbine foundations in the German Bight (North Sea) two years after deployment - increased production rate of Cancer pagurus.

PubMed

Krone, R; Dederer, G; Kanstinger, P; Krämer, P; Schneider, C; Schmalenbach, I

2017-02-01

Within the next decades the construction of thousands of different types of large wind turbine foundations in the North Sea will substantially increase the amount of habitat available to reef fauna. To gain first insights which effect these substantial changes in habitat structure and diversity might have on faunal stocks settling on hard substrata, we compared the mobile demersal megafauna associated with the common types of wind turbine foundations ('jacket', 'tripod' and 'monopile with scour protections of natural rock') in the southern German Bight, North Sea. Monopiles with scour protection were mostly colonized by typical reef fauna. They were inhabited by an average of about 5000 edible crabs Cancer pagurus (per foundation), which is more than twice as much as found at the foundation types without scour protection. Strong evidence was found that all three foundation types not only function as aggregation sites, but also as nursery grounds for C. pagurus. Assuming equal shares of the three foundation types in future wind farms, we project that about 27% of the local stock of C. pagurus might be produced on site. When, for example, comparing the existing fauna at 1000 ship wrecks and on the autochthonous soft substrate with those which probably will establish at the foundations of 5000 hypothetically realized wind turbines, it becomes clear that the German Bight in the future will provide new artificial reef habitats for another 320% crabs (C. pagurus) and 50% wrasse (Ctenolabrus rupestris) representing substrata-limited mobile demersal hard bottom species. Further research is urgently required in order to evaluate this overspill as it would be an important ecological effect of the recent offshore wind power development. Copyright © 2016 Elsevier Ltd. All rights reserved.

The SPOT Project (Potentially Triggerable Offshore Seismicity and Tsunamis): a First Appraisal of the Possible Impact of Oil and Gas Platforms on the Seismic and Tsunami Risks along the Italian Coasts

NASA Astrophysics Data System (ADS)

Basili, R.; Di Bucci, D.; Antoncecchi, I.; Ciccone, F.; Teofilo, G.; Argnani, A.; Rovere, M.; Ligi, M.; Coltelli, M.; Lorito, S.; Borzi, B.; Germagnoli, F.; Di Ludovico, M.; Lignola, G. P.; Prota, A.

2017-12-01

The majority of oil and gas production in Europe takes place offshore and Italy is one of the European countries with the longest coastlines facing these operations. Given the generally growing energy demand, and the increasing concern toward human-driven hazards, scientists are called to provide background information for helping ensure a safe energy supply. We here present the activities of the project SPOT, which is aimed to help Italian authorities comply with the application of the Safety of Offshore Oil and Gas Operations European Directive (2013/30/EU) and the ensuing Italian codes. We carry out a reconstruction of offshore geological structures to assess the existence of potentially seismogenic faults in the surroundings of off-shore platforms. This study is a propaedeutic step for the assessment of potentially triggered seismicity connected with operations on such platforms. The descriptive parameters (3D geometry and behavior) of the identified faults will be used to estimate their natural earthquake rates. The impact of these natural earthquakes along the coasts will then be modeled in terms of expected ground shaking and tsunamis. The tsunamis potentially generated by submarine landslides induced by earthquake shaking will also be analyzed. In turn, these models will be used to estimate potential human and economic losses in a multi-hazard approach to risk assessment. Wherever the combined earthquake and tsunami modeling indicates a relevant impact along the coasts, a more detailed analysis will be carried out, also involving the operators of the related platforms, to perform specific models which also take into account production and/or storage data. Activities with a consolidated background, such as those concerning the impact scenarios of earthquakes, and more innovative activities, such as those dedicated to build up the first vulnerability/fragility curves related to tsunamis for the Italian building stock, will be integrated within the project. The details of the project workflow, along with the preliminary results of the first leg of activities will be presented. The SPOT project has been conceived and funded by the Italian Ministry of Economic Development, with the technical support of the National Department of Civil Protection, following auspices of the Italian Major Risk Commission.

Geological history of the west Libyan offshore and adjoining regions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benniran, M.M.; Taleb, T.M.; McCrossan, R.G.

1988-08-01

The continental margin of the African plate north of Libya is separated from the Saharan platform to the south by a major Variscan fault system running along the coastline. The structural evolution of three sedimentary basins within the margin is discussed. The Jeffara basin, onshore western Libya-southern Tunisia, formed as a right-lateral pull-part late in the Variscan event. When the strike-slip motion ceased in the Late Permian, the basin continued to subside thermally. The Sabratah (Tripolitanian) basin, offshore western Libya-southern Tunisia, and the Benghazi basin in the Sirte rise were both formed as left-lateral pull-aparts in the Late Triassic-Early Jurassic.more » From the Middle Jurassic to the present they have subsided thermally. Onshore the lower Mesozoic is characterized by continental and nearshore clastics, separated by an evaporite sequence of Late Triassic-Early Jurassic age. Offshore this sequence is thought to grade northward into open marine carbonates. Uplift along the edge of the Saharan platform during the Early Cretaceous sourced coarse clastics, which grade northward into a thick sequence of shallow-water carbonates. Throughout the Late Cretaceous and early Tertiary, high-energy carbonates were deposited around the flanks of the Sabratah basin, grading into deeper-water, fine-grained clastics and carbonates toward the center of the basin. The late Tertiary succession is dominated by clastics derived from the growing Tellian Atlas to the northwest. During the Mesozoic and Tertiary a thick sequence of carbonates was deposited on the Pelagian platform to the north of the Sabratah basin. Periodically the platform was exposed subaerially.« less

Enrichment and shifts in macrobenthic assemblages in an offshore wind farm area in the Belgian part of the North Sea.

PubMed

Coates, Delphine A; Deschutter, Yana; Vincx, Magda; Vanaverbeke, Jan

2014-04-01

The growing development of offshore wind energy installations across the North Sea is producing new hard anthropogenic structures in the natural soft sediments, causing changes to the surrounding macrobenthos. The extent of modification in permeable sediments around a gravity based wind turbine in the Belgian part of the North Sea was investigated in the period 2011-2012, along four gradients (south-west, north-east, south-east, north-west). Sediment grain size significantly reduced from 427 μm at 200 m to 312 ± 3 μm at 15 m from the foundation along the south-west and north-west gradients. The organic matter content increased from 0.4 ± 0.01% at 100 m to 2.5 ± 0.9% at 15 m from the foundation. The observed changes in environmental characteristics triggered an increase in the macrobenthic density from 1390 ± 129 ind m⁻² at 200 m to 18 583 ± 6713 ind m⁻² at 15 m together with an enhanced diversity from 10 ± 2 at 200 m to 30 ± 5 species per sample at 15 m. Shifts in species dominance were also detected with a greater dominance of the ecosystem-engineer Lanice conchilega (16-25%) close to the foundation. This study suggests a viable prediction of the effects offshore wind farms could create to the naturally occurring macrobenthos on a large-scale. Copyright © 2013 Elsevier Ltd. All rights reserved.

Assessment of multi-phase movements in a gas-gathering pipeline and the relevance to on-line, real-time corrosion monitoring and inhibitor injection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, M.A.; Asperger, R.G.

1988-01-01

A study was conducted to determine the time required for aqueous fluid to travel 100 miles (160 km) from an offshore platform in the Gulf of Mexico to landfill. If this time is short, the corrosivity of the water at landfall may be used as the basis for setting the offshore corrosion inhibitor injection rates. But, for this particular system, the traveling time was found to be long, greater than 65 days. Therefore, the corrosivity as measured on-shore can not be used for online, real-time adjustments of the offshore, corrosion inhibitor chemical pumps.

The Feasibility of Wind and Solar Energy Application for Oil and Gas Offshore Platform

NASA Astrophysics Data System (ADS)

Tiong, Y. K.; Zahari, M. A.; Wong, S. F.; Dol, S. S.

2015-04-01

Renewable energy is an energy which is freely available in nature such as winds and solar energy. It plays a critical role in greening the energy sector as these sources of energy produce little or no pollution to environment. This paper will focus on capability of renewable energy (wind and solar) in generating power for offshore application. Data of wind speeds and solar irradiation that are available around SHELL Sabah Water Platform for every 10 minutes, 24 hours a day, for a period of one year are provided by SHELL Sarawak Sdn. Bhd. The suitable wind turbine and photovoltaic panel that are able to give a high output and higher reliability during operation period are selected by using the tabulated data. The highest power output generated using single wind energy application is equal to 492 kW while for solar energy application is equal to 20 kW. Using the calculated data, the feasibility of renewable energy is then determined based on the platform energy demand.

Use of high-resolution geophysical and geotechnical techniques for artificial reef site selection, west Cameron planning area, offshore Louisiana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pope, D.L.; Wagner, J.B.

1988-09-01

Before siting oil and gas platforms on the sea floor as artificial reefs offshore Louisiana, potentially hazardous and unstable geologic conditions must be identified and evaluated to assess their possible impacts on platform stability. Geologic and man-made features can be identified and assessed from high-resolution geophysical techniques (3.5-7.0 kHz echograms, single-channel seismic, and side-scan sonar). Such features include faults, diapirs, scarps, channels, gas seeps, irregular sea floor topography, mass wasting deposits (slumps, slides, and debris flows), pipelines, and other subsea marine equipment. Geotechnical techniques are utilized to determine lithologic and physical properties of the sediments for correlation with the geophysicalmore » data. These techniques are used to develop a series of geologic maps, cross sections, and pipeline and platform-location maps. Construction of echo-character maps from 3.5-kHz data provides an analysis of near-bottom sedimentation processes (turbidity currents and debris flows).« less

Monitoring compaction and compressibility changes in offshore chalk reservoirs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dean, G.; Hardy, R.; Eltvik, P.

1994-03-01

Some of the North Sea's largest and most important oil fields are in chalk reservoirs. In these fields, it is important to measure reservoir compaction and compressibility because compaction can result in platform subsidence. Also, compaction drive is a main drive mechanism in these fields, so an accurate reserves estimate cannot be made without first measuring compressibility. Estimating compaction and reserves is difficult because compressibility changes throughout field life. Installing of accurate, permanent downhole pressure gauges on offshore chalk fields makes it possible to use a new method to monitor compressibility -- measurement of reservoir pressure changes caused by themore » tide. This tidal-monitoring technique is an in-situ method that can greatly increase compressibility information. It can be used to estimate compressibility and to measure compressibility variation over time. This paper concentrates on application of the tidal-monitoring technique to North Sea chalk reservoirs. However, the method is applicable for any tidal offshore area and can be applied whenever necessary to monitor in-situ rock compressibility. One such application would be if platform subsidence was expected.« less

Regional Patterns in Invertebrate Assemblages on Offshore Oil Platforms Along the Pacific Outer Continental Shelf

NASA Astrophysics Data System (ADS)

Zaleski, S.; Page, H. M.; Miller, R. J.; Doheny, B.; Dugan, J. E.; Schroeder, D. M.

2016-02-01

Twenty-seven oil and gas platforms are arrayed offshore California from north of Point Conception south to San Pedro Bay (a coastline distance of >300 km). To test the hypothesis that variability in the structure of sessile invertebrate communities on the platforms is associated with regional differences in sea surface temperature, we sampled space-holding invertebrate taxa photographically on 23 platforms and compared the composition and cover of invertebrates among and within regions using multivariate analyses. To explore temporal variability in invertebrate assemblages, we also compared the cover and composition of invertebrates on a subset of platforms in the Santa Barbara Channel (SBC) where data were collected over ten years previously. The composition of invertebrate assemblages differed significantly among regions, and was driven by variation in the relative abundance of certain anemone, bryozoan, tubiferous annelid, sponge, and bivalve taxa. The presence of non-native bryozoan and anemone taxa on some platforms in the south (San Pedro Bay) and southeast SBC contributed to the distinction of these assemblages from the others. Comparison of survey data on the subset of platforms in the SBC surveyed over ten years apart revealed little change in the cover of major space-holding taxa (e.g., anemones Metridium, Corynactis) across platforms, although there was an increase in cover of the non-native bryozoan Watersipora subtorquata between surveys. The existence of geographical patterns in the composition of platform invertebrate assemblages suggests that these assemblages may be useful as barometers of short and longer-term environmental change. For biogeographic transition zones, such as the SBC, monitoring of platform invertebrate assemblages could permit an evaluation of the concept that these zones are particularly susceptible to shifts in the composition of marine species driven by ocean climate.

Offshore wind turbine foundation monitoring, extrapolating fatigue measurements from fleet leaders to the entire wind farm

NASA Astrophysics Data System (ADS)

Weijtens, Wout; Noppe, Nymfa; Verbelen, Tim; Iliopoulos, Alexandros; Devriendt, Christof

2016-09-01

The present contribution is part of the ongoing development of a fatigue assessment strategy driven purely on in-situ measurements on operational wind turbines. The primary objective is to estimate the remaining life time of existing wind farms and individual turbines by instrumenting part of the farm with a load monitoring setup. This load monitoring setup allows to measure interface loads and local stress histories. This contribution will briefly discuss how these load measurements can be translated into fatigue assessment of the instrumented turbine. However, due to different conditions at the wind farm, such as turbulence, differences in water depth and foundation design this turbine will not be fully representable for all turbines in the farm. In this paper we will use the load measurements on two offshore wind turbines in the Northwind offshore wind farm to discuss fatigue progression in an operational wind farm. By calculating the damage equivalent loads on the two turbines the fatigue progression is quantified for every 10 minute interval and can be analyzed against turbulence and site conditions. In future work these results will be used to predict the fatigue life progression in the entire farm.

Investigation on installation of offshore wind turbines

NASA Astrophysics Data System (ADS)

Wang, Wei; Bai, Yong

2010-06-01

Wind power has made rapid progress and should gain significance as an energy resource, given growing interest in renewable energy and clean energy. Offshore wind energy resources have attracted significant attention, as, compared with land-based wind energy resources, offshore wind energy resources are more promising candidates for development. Sea winds are generally stronger and more reliable and with improvements in technology, the sea has become a hot spot for new designs and installation methods for wind turbines. In the present paper, based on experience building offshore wind farms, recommended foundation styles have been examined. Furthermore, wave effects have been investigated. The split installation and overall installation have been illustrated. Methods appropriate when installing a small number of turbines as well as those useful when installing large numbers of turbines were analyzed. This investigation of installation methods for wind turbines should provide practical technical guidance for their installation.

Growth and demise of a Paleogene isolated carbonate platform of the Offshore Indus Basin, Pakistan: effects of regional and local controlling factors

NASA Astrophysics Data System (ADS)

Shahzad, Khurram; Betzler, Christian; Ahmed, Nadeem; Qayyum, Farrukh; Spezzaferri, Silvia; Qadir, Anwar

2018-03-01

Based on high-resolution seismic and well datasets, this paper examines the evolution and drowning history of a Paleocene-Eocene carbonate platform in the Offshore Indus Basin of Pakistan. This study uses the internal seismic architecture, well log data as well as the microfauna to reconstruct factors that governed the carbonate platform growth and demise. Carbonates dominated by larger benthic foraminifera assemblages permit constraining the ages of the major evolutionary steps and show that the depositional environment was tropical within oligotrophic conditions. With the aid of seismic stratigraphy, the carbonate platform edifice is resolved into seven seismic units which in turn are grouped into three packages that reflect its evolution from platform initiation, aggradation with escarpment formation and platform drowning. The carbonate factory initiated as mounds and patches on a Cretaceous-Paleocene volcanic complex. Further, the growth history of the platform includes distinct phases of intraplatform progradation, aggradation, backstepping and partial drownings. The youngest succession as late-stage buildup records a shift from benthic to pelagic deposition and marks the final drowning in the Early Eocene. The depositional trend of the platform, controlled by the continuing thermal subsidence associated with the cooling of volcanic margin lithosphere, was the major contributor of the accommodation space which supported the vertical accumulation of shallow water carbonate succession. Other factors such as eustatic changes and changes in the carbonate producers as a response to the Paleogene climatic perturbations played secondary roles in the development and drowning of these buildups.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karr, Dale G.; Yu, Bingbin; Sirnivas, Senu

To create long-term solutions for offshore wind turbines in a variety of environmental conditions, CAE tools are needed to model the design-driving loads that interact with an offshore wind turbine system during operation. This report describes our efforts in augmenting existing CAE tools used for offshore wind turbine analysis with a new module that can provide simulation capabilities for ice loading on the system. This augmentation was accomplished by creating an ice-loading module coupled to FAST8, the CAE tool maintained by the NREL for simulating land-based and offshore wind turbine dynamics. The new module includes both static and dynamic icemore » loading that can be applied during a dynamic simulation of the response of an offshore wind turbine. The ice forces can be prescribed, or influenced by the structure’s compliant response, or by the dynamics of both the structure and the ice floe. The new module covers ice failure modes of spalling, buckling, crushing, splitting, and bending. The supporting structure of wind turbines can be modeled as a vertical or sloping form at the waterline. The Inward Battered Guide Structure (IBGS) foundation designed by Keystone Engineering for the Great Lakes was used to study the ice models coupled to FAST8. The IBGS foundation ice loading simulations in FAST8 were compared to the baseline simulation case without ice loading. The ice conditions reflecting those from Lake Huron at Port Huron and Lake Michigan at North Manitou were studied under near rated wind speed of 12 m/s for the NREL 5-MW reference turbine. Simulations were performed on ice loading models 1 through 4 and ice model 6 with their respective sub-models. The purpose of ice model 5 is to investigate ice loading on sloping structures such as ice-cones on a monopile and is not suitable for multi-membered jacketed structures like the IBGS foundation. The key response parameters from the simulations, shear forces and moments from the tower base and IBGS foundation base, were compared. Ice models 1 and 6 do not significantly affect the tower fore-aft shear and moment. However, ice model 2 (dynamic analyses), model 3 (random ice loading), and model 4 (multiple ice failure zone loading) show increased effect on the tower fore-aft shear and moment with significant effect from ice model 3.1. In general ice loading creates large reaction forces and moments at the base of the IBGS foundation; the largest occurred in model 1.1 (steady creep ice indentation loading) followed by model 3.1 (random creep ice indentation loading). In general the power production from the ice loading cases had little deviation from the baseline case without ice loading. For ultimate limit state (ULS), ice model 1.1 ice and 3.1 appear to be the ice most critical models to consider at an early stage of design. Ice model 4 is an important tool for assessing structural fatigue.« less

30 CFR 250.406 - What additional safety measures must I take when I conduct drilling operations on a platform that...

Code of Federal Regulations, 2010 CFR

2010-07-01

... OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations General Requirements § 250.406 What additional safety measures must I take when I conduct drilling... when I conduct drilling operations on a platform that has producing wells or has other hydrocarbon flow...

30 CFR 250.406 - What additional safety measures must I take when I conduct drilling operations on a platform that...

Code of Federal Regulations, 2014 CFR

2014-07-01

... when I conduct drilling operations on a platform that has producing wells or has other hydrocarbon flow... OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations General Requirements § 250.406 What additional safety measures must I take...

30 CFR 250.406 - What additional safety measures must I take when I conduct drilling operations on a platform that...

Code of Federal Regulations, 2011 CFR

2011-07-01

... ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations General Requirements § 250.406 What additional safety measures... when I conduct drilling operations on a platform that has producing wells or has other hydrocarbon flow...

30 CFR 250.406 - What additional safety measures must I take when I conduct drilling operations on a platform that...

Code of Federal Regulations, 2013 CFR

2013-07-01

... when I conduct drilling operations on a platform that has producing wells or has other hydrocarbon flow... OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations General Requirements § 250.406 What additional safety measures must I take...

30 CFR 250.406 - What additional safety measures must I take when I conduct drilling operations on a platform that...

Code of Federal Regulations, 2012 CFR

2012-07-01

... when I conduct drilling operations on a platform that has producing wells or has other hydrocarbon flow... OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations General Requirements § 250.406 What additional safety measures must I take...

Offshore Wind Plant Balance-of-Station Cost Drivers and Sensitivities (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saur, G.; Maples, B.; Meadows, B.

2012-09-01

With Balance of System (BOS) costs contributing up to 70% of the installed capital cost, it is fundamental to understanding the BOS costs for offshore wind projects as well as potential cost trends for larger offshore turbines. NREL developed a BOS model using project cost estimates developed by GL Garrad Hassan. Aspects of BOS covered include engineering and permitting, ports and staging, transportation and installation, vessels, foundations, and electrical. The data introduce new scaling relationships for each BOS component to estimate cost as a function of turbine parameters and size, project parameters and size, and soil type. Based on themore » new BOS model, an analysis to understand the non-turbine costs associated with offshore turbine sizes ranging from 3 MW to 6 MW and offshore wind plant sizes ranging from 100 MW to 1000 MW has been conducted. This analysis establishes a more robust baseline cost estimate, identifies the largest cost components of offshore wind project BOS, and explores the sensitivity of the levelized cost of energy to permutations in each BOS cost element. This presentation shows results from the model that illustrates the potential impact of turbine size and project size on the cost of energy from US offshore wind plants.« less

Nighttime approaches to offshore installations in Brazil: Safety shortcomings experienced by helicopter pilots.

PubMed

Nascimento, Felipe A C; Majumdar, Arnab; Jarvis, Steve

2012-07-01

Accident rates for night sorties by helicopters traveling to offshore oil and gas platforms are at least five times higher than those during the daytime. Because pilots need to transition from automated flight to a manually flown night visual segment during arrival, the approach and landing phases cause great concern. Despite this, in Brazil, regulatory changes have been sought to allow for the execution of offshore night flights because of the rapid expansion of the petroleum industry. This study explores the factors that affect safety during night visual segments in Brazil using 28 semi-structured interviews with offshore helicopter pilots, followed by a template analysis of the narratives. The relationships among the factors suggest that flawed safety oversights, caused by a combination of lack of infrastructure for night flights offshore and declining training, currently favor spatial disorientation on the approach and near misses when close to the destination. Safety initiatives can be derived on the basis of these results. Copyright © 2012 Elsevier Ltd. All rights reserved.

Assessing the suitability of a remotely operated vehicle (ROV) to study the fish community associated with offshore gas platforms in the Ionian Sea: a comparative analysis with underwater visual censuses (UVCs)

NASA Astrophysics Data System (ADS)

Andaloro, Franco; Ferraro, Maria; Mostarda, Edoardo; Romeo, Teresa; Consoli, Pierpaolo

2013-06-01

The effectiveness of a remotely operated vehicle (ROV) to describe the fish communities of three gas platforms located offshore Crotone (Italy, Ionian Sea) was investigated by comparing its observations with underwater visual censuses (UVCs). The study was carried out at two depth layers (0-6 and 12-18 m). Moreover, the ROV was used to survey three deeper depth layers up to 76 m. Overall, the ROV surveys failed to give a truthful representation of the fish communities underestimating the number of species and their abundances as compared to UVCs. The main discrepancies in data regarded crypto-benthic and nekto-benthic species, whereas the ROV proved to be a suitable method to census low-mobile and abundant planktivorous species. The differences between the fish assemblage described by the ROV, with respect to the one depicted by UVC, should be considered in the light of the technical limits of the recording camera, whose resolution and field of vision is clearly lower than the diver's eye. In addition, video images did not allow for the acquisition of a correct estimate of the distance between the individuals and the platform structures. This led, almost certainly, to an under- or over-estimation of fish abundance as regards to the censused volume. In spite of this, as a result of its capacity to reach depths inaccessible to scuba divers and then to add complementary information, the ROV could be used jointly with UVCs, in studies having as their objective the description of the fish communities associated with offshore platforms.

Hydrodynamic analysis of floating platform for special purposes under complex water environment

NASA Astrophysics Data System (ADS)

Ma, Guang-ying; Yao, Yun-long

2018-03-01

This article studied a new floating offshore platform for special purposes, which was assembled by standard floating modules. By using ANSYS AQWA software, the hydrodynamic model of the platform was established. The time history responses of the platform motions and the cable tension forces were calculate under complex water environments, such as wind, wave, current and mooring. The results showed that the tension of the four cables are far less than the breaking tension of the cable, so that the cable will not break. This study can be referenced by the relevant researchers and engineers.

Development of a computer model to predict platform station keeping requirements in the Gulf of Mexico using remote sensing data

NASA Technical Reports Server (NTRS)

Barber, Bryan; Kahn, Laura; Wong, David

1990-01-01

Offshore operations such as oil drilling and radar monitoring require semisubmersible platforms to remain stationary at specific locations in the Gulf of Mexico. Ocean currents, wind, and waves in the Gulf of Mexico tend to move platforms away from their desired locations. A computer model was created to predict the station keeping requirements of a platform. The computer simulation uses remote sensing data from satellites and buoys as input. A background of the project, alternate approaches to the project, and the details of the simulation are presented.

Dynamic analysis of a 5-MW tripod offshore wind turbine by considering fluid-structure interaction

NASA Astrophysics Data System (ADS)

Zhang, Li-wei; Li, Xin

2017-10-01

Fixed offshore wind turbines usually have large underwater supporting structures. The fluid influences the dynamic characteristics of the structure system. The dynamic model of a 5-MW tripod offshore wind turbine considering the pile-soil system and fluid structure interaction (FSI) is established, and the structural modes in air and in water are obtained by use of ANSYS. By comparing low-order natural frequencies and mode shapes, the influence of sea water on the free vibration characteristics of offshore wind turbine is analyzed. On basis of the above work, seismic responses under excitation by El-Centro waves are calculated by the time-history analysis method. The results reveal that the dynamic responses such as the lateral displacement of the foundation and the section bending moment of the tubular piles increase substantially under the influence of the added-mass and hydrodynamic pressure of sea water. The method and conclusions presented in this paper can provide a theoretical reference for structure design and analysis of offshore wind turbines fixed in deep seawater.

Study on Vortex-Induced Motions of A New Type of Deep Draft Multi-Columns FDPSO

NASA Astrophysics Data System (ADS)

Gu, Jia-yang; Xie, Yu-lin; Zhao, Yuan; Li, Wen-juan; Tao, Yan-wu; Huang, Xiang-hong

2018-03-01

A numerical simulation and an experimental study on vortex-induced motion (VIM) of a new type of deep draft multi-columns floating drilling production, storage and offloading (FDPSO) are presented in this paper. The main dimension, the special variable cross-section column and the cabin arrangement of the octagonal pontoon are introduced based on the result. The numerical simulation is adapted to study the effects of current incidence angles and reduced velocities on this platform's sway motion response. The 300 m water depth equivalent truncated mooring system is adopted for the model tests. The model tests are carried out to check the reliability of numerical simulation. The results consist of surge, sway and yaw motions, as well as motion trajectories. The maximum sway amplitudes for different types of offshore platform is also studied. The main results show that the peak frequencies of sway motion under different current incidence angles and reduced velocities vary around the natural frequency. The analysis result of flow field indicates that the change of distribution of vortex in vertical presents significant influences on the VIM of platform. The trend of sway amplitude ratio curve of this new type FDPSO differs from the other types of platform. Under 45° current incidence angle, the sway amplitude of this new type of FDPSO is much smaller than those of other types of offshore platform at 4.4 ≤ V r ≤ 8.9. The typical `8' shape trajectory does not appear in the platform's motion trajectories.

Offshore Energy Mapping for Northeast Atlantic and Mediterranean: MARINA PLATFORM project

NASA Astrophysics Data System (ADS)

Kallos, G.; Galanis, G.; Spyrou, C.; Kalogeri, C.; Adam, A.; Athanasiadis, P.

2012-04-01

Deep offshore ocean energy mapping requires detailed modeling of the wind, wave, tidal and ocean circulation estimations. It requires also detailed mapping of the associated extremes. An important issue in such work is the co-generation of energy (generation of wind, wave, tides, currents) in order to design platforms on an efficient way. For example wind and wave fields exhibit significant phase differences and therefore the produced energy from both sources together requires special analysis. The other two sources namely tides and currents have different temporal scales from the previous two. Another important issue is related to the estimation of the environmental frequencies in order to avoid structural problems. These are issues studied at the framework of the FP7 project MARINA PLATFORM. The main objective of the project is to develop deep water structures that can exploit the energy from wind, wave, tidal and ocean current energy sources. In particular, a primary goal will be the establishment of a set of equitable and transparent criteria for the evaluation of multi-purpose platforms for marine renewable energy. Using these criteria, a novel system set of design and optimisation tools will be produced addressing new platform design, component engineering, risk assessment, spatial planning, platform-related grid connection concepts, all focussed on system integration and reducing costs. The University of Athens group is in charge for estimation and mapping of wind, wave, tidal and ocean current resources, estimate available energy potential, map extreme event characteristics and provide any additional environmental parameter required.

Floating Ocean Platform

DTIC Science & Technology

2003-08-15

floating structures create novel habitats for subtidal epibiota?, MARINE ECOLOGY -PROGRESS SERIES, 43-52 Mar. Ecol.- Prog. Ser., 2002 Vegueria, SFJ Godoy... ECOLOGICAL APPLICATIONS, 350-366 Ecol. Appl., 2000 Niedzwecki, JM van de Lindt, JW Gage, JH Teigen, PS, Design estimates of surface wave interaction with...The ecological effects beyond the offshore platform, Coastal Zone: Proceedings of the Symposium on Coastal and Ocean Management, v 2, n pt2, 1989, p

Numerical tools to predict the environmental loads for offshore structures under extreme weather conditions

NASA Astrophysics Data System (ADS)

Wu, Yanling

2018-05-01

In this paper, the extreme waves were generated using the open source computational fluid dynamic (CFD) tools — OpenFOAM and Waves2FOAM — using linear and nonlinear NewWave input. They were used to conduct the numerical simulation of the wave impact process. Numerical tools based on first-order (with and without stretching) and second-order NewWave are investigated. The simulation to predict force loading for the offshore platform under the extreme weather condition is implemented and compared.

Deadlines set for new U. K. offshore safety rules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-12-14

This paper reports on new U.K. offshore safety regulations-inspired by Lord Cullen's 1990 report spawned by the 1987 Piper Alpha platform accident which will take effect May 31, 1993, for new installations. The U.K. Health and Safety Executive (HSE) said its proposed regulations, required for operators or owners to gain HSE approval for each fixed or mobile installation, was put before Parliament Nov. 27. That gives opposition parties 40 days to call for debate and possible amendment before the proposals become law.

30 CFR 250.903 - What records must I keep?

Code of Federal Regulations, 2013 CFR

2013-07-01

... OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Platforms and Structures General... steel brackets, deck stiffeners and secondary braces or beams would not generally be considered primary...

30 CFR 250.903 - What records must I keep?

Code of Federal Regulations, 2014 CFR

2014-07-01

... OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Platforms and Structures General... steel brackets, deck stiffeners and secondary braces or beams would not generally be considered primary...

30 CFR 250.903 - What records must I keep?

Code of Federal Regulations, 2012 CFR

2012-07-01

... OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Platforms and Structures General... steel brackets, deck stiffeners and secondary braces or beams would not generally be considered primary...

Offshore submarine storage facility for highly chilled liquified gases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cook, S.F.

1982-12-28

Improvements in an offshore platform and submarine storage facility for highly chilled liquified gas, such as liquified natural gas, are disclosed. The improved facility includes an elongated, vertically oriented submerged anchoring frame to which one or more insulated storage tanks are moveably mounted so they can be positioned at a selected depth in the water. The double piston tank is constructed with improved seals to transfer ambient water pressure of the selected depth to the cryogenic liquified gas without intermixture. This transferred pressure at the depth selected aids in maintaining the liquified state of the stored liquified gas. Structural improvementsmore » to the tank facilitating ballasting, locking the double piston cylinders together and further facilitating surface access to the tank for inspection, repairs and removal, and structural improvements to the platform are disclosed.« less

Development of a Semi-submersible Barge for the installation of a TLP floating substructure. TLPWIND® case study

NASA Astrophysics Data System (ADS)

Amate, Juan; Sánchez, Gustavo D.; González, Gonzalo

2016-09-01

One of the biggest challenges to introduce Tension Leg Platform (TLP) technology into the Offshore Wind market are the Transport & Installation (T&I) stages, since most of TLPs are not self-stable as semisubmersible or SPAR platforms, and consequently requires additional means to perform these operations. This paper addresses this problem that has been overcome through the development of a Semi-submersible “Transport & Installation” Barge (SSB) for Iberdrola's TLPWIND® floating support structure. The Semi-submersible Barge has been designed both through the use of numerical models and an extensive basin testing campaign carried out at the University of Strathclyde facilities. This paper also includes an estimation of the duration in time to carry out the installation process of a Floating Offshore Wind Farm, comprising 100x5MW TLPWIND® units in different scenarios.

Full load estimation of an offshore wind turbine based on SCADA and accelerometer data

NASA Astrophysics Data System (ADS)

Noppe, N.; Iliopoulos, A.; Weijtjens, W.; Devriendt, C.

2016-09-01

As offshore wind farms (OWFs) grow older, the optimal use of the actual fatigue lifetime of an offshore wind turbine (OWT) and predominantly its foundation will get more important. In case of OWTs, both quasi-static wind/thrust loads and dynamic loads, as induced by turbulence, waves and the turbine's dynamics, contribute to its fatigue life progression. To estimate the remaining useful life of an OWT, the stresses acting on the fatigue critical locations within the structure should be monitored continuously. Unfortunately, in case of the most common monopile foundations these locations are often situated below sea-level and near the mud line and thus difficult or even impossible to access for existing OWTs. Actual strain measurements taken at accessible locations above the sea level show a correlation between thrust load and several SCADA parameters. Therefore a model is created to estimate the thrust load using SCADA data and strain measurements. Afterwards the thrust load acting on the OWT is estimated using the created model and SCADA data only. From this model the quasi static loads on the foundation can be estimated over the lifetime of the OWT. To estimate the contribution of the dynamic loads a modal decomposition and expansion based virtual sensing technique is applied. This method only uses acceleration measurements recorded at accessible locations on the tower. Superimposing both contributions leads to a so-called multi-band virtual sensing. The result is a method that allows to estimate the strain history at any location on the foundation and thus the full load, being a combination of both quasi-static and dynamic loads, acting on the entire structure. This approach is validated using data from an operating Belgian OWF. An initial good match between measured and predicted strains for a short period of time proofs the concept.

Assessing Fatigue and Ultimate Load Uncertainty in Floating Offshore Wind Turbines Due to Varying Simulation Length

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stewart, G.; Lackner, M.; Haid, L.

2013-07-01

With the push towards siting wind turbines farther offshore due to higher wind quality and less visibility, floating offshore wind turbines, which can be located in deep water, are becoming an economically attractive option. The International Electrotechnical Commission's (IEC) 61400-3 design standard covers fixed-bottom offshore wind turbines, but there are a number of new research questions that need to be answered to modify these standards so that they are applicable to floating wind turbines. One issue is the appropriate simulation length needed for floating turbines. This paper will discuss the results from a study assessing the impact of simulation lengthmore » on the ultimate and fatigue loads of the structure, and will address uncertainties associated with changing the simulation length for the analyzed floating platform. Recommendations of required simulation length based on load uncertainty will be made and compared to current simulation length requirements.« less

An Adaptive Coordinated Control for an Offshore Wind Farm Connected VSC Based Multi-Terminal DC Transmission System

NASA Astrophysics Data System (ADS)

Kumar, M. Ajay; Srikanth, N. V.

2015-01-01

The voltage source converter (VSC) based multiterminal high voltage direct current (MTDC) transmission system is an interesting technical option to integrate offshore wind farms with the onshore grid due to its unique performance characteristics and reduced power loss via extruded DC cables. In order to enhance the reliability and stability of the MTDC system, an adaptive neuro fuzzy inference system (ANFIS) based coordinated control design has been addressed in this paper. A four terminal VSC-MTDC system which consists of an offshore wind farm and oil platform is implemented in MATLAB/ SimPowerSystems software. The proposed model is tested under different fault scenarios along with the converter outage and simulation results show that the novel coordinated control design has great dynamic stabilities and also the VSC-MTDC system can supply AC voltage of good quality to offshore loads during the disturbances.

Providing emergency medical care to offshore oil and gas platforms in the Gulf of Mexico using telemedicine

NASA Astrophysics Data System (ADS)

Bouabene, Anis

2002-08-01

UTMB is developing with industrial partners the "24/7 telemedicine triage project" to provide emergency medical care to offshore oil and gas rigs and platforms in the Gulf of Mexico. The oil and gas industry is second only to the US department of defense in the number of employees stationed in remote areas. Providing medical care to such populations is logistically complex and expensive. In addition, emergency evacuation is often time-consuming and poses risks for both patients and medical crews. By utilizing high-resolution videoconferencing technology, through a satellite communication, patient visits will be conducted in real time and will provide more informed decisions about the need for more extensive treatment, thereby reducing unnecessary evacuations. In addition, patients who require evacuation will receive a higher standard of care while waiting for transport to a medical facility. UTMB physicians report that 39% of all patients from offshore facilities treated in the emergency department, could have been successfully treated through telemedicine without being evacuated to a hospital. The telemedicine project will employ standard procedures for medical triage, in which patients are directed to appropriate medical experts based on their symptoms or type of injury.

Colonisation of fish and crabs of wave energy foundations and the effects of manufactured holes - a field experiment.

PubMed

Langhamer, Olivia; Wilhelmsson, Dan

2009-10-01

Several Western European countries are planning for a significant development of offshore renewable energy along the European Atlantic Ocean coast, including many thousands of wave energy devices and wind turbines. There is an increasing interest in articulating the added values of the creation of artificial hard bottom habitats through the construction of offshore renewable energy devices, for the benefit of fisheries management and conservation. The Lysekil Project is a test park for wave power located about 100 km north of Gothenburg at the Swedish west coast. A wave energy device consists of a linear wave power generator attached to a foundation on the seabed, and connected by a wire to a buoy at the surface. Our field experiment examined the function of wave energy foundations as artificial reefs. In addition, potentials for enhancing the abundance of associated fish and crustaceans through manufactured holes of the foundations were also investigated. Assemblages of mobile organisms were examined by visual censuses in July and August 2007, 3 months after deployment of the foundations. Results generally show low densities of mobile organisms, but a significantly higher abundance of fish and crabs on the foundations compared to surrounding soft bottoms. Further, while fish numbers were not influenced by increased habitat complexity (holes), it had a significantly positive effect on quantities of edible crab (Cancer pagurus), on average leading to an almost five-fold increase in densities of this species. Densities of spiny starfish (Marthasterias glacialis) were negatively affected by the presence of holes, potentially due to increased predator abundance (e.g. C. pagurus). These results suggest a species-specific response to enhanced habitat complexity.

Holocene evolution of coastal chalk cliffs in Normandy (NW France) as evidenced by onshore-offshore high resolution geomorphology

NASA Astrophysics Data System (ADS)

Duguet, Timothée; Duperret, Anne; Costa, Stéphane; Regard, Vincent; Maillet, Grégoire

2017-04-01

Key words: erosion, rocky coast, cliffs, shore platform, watersheds, cosmogenic dating The chalk cliffs coastline extends to 120 km long in Normandy. It suffers from high erosion rates with a mean of about 0.15 m/y. The shore platforms extending from the cliff base to the sea, keep structural marks of the cliff erosion during long periods, i.e. the Holocene. Therefore it is essential to take an active interest in their morphology and their evolution to better understand cliff erosion timing. A land-sea Digital Elevation Model (DEM) has been produced for Mesnil-Val and Criel-sur-Mer sites (Seine Maritime), with the merge of topographic data (RGE alti, IGN) and shallow bathymetric data from three oceanographic Cruises, CROCOLIT-1 and 3 (Duperret, 2013) and SPLASHALIOT-2 (Maillet, 2014). Valleys that have more or less incised Turonian-Coniacian chalk cliffs occupy the landward part of study sites. The N130E V-shaped incised Mesnil-Val dry valley is elevated at 29 m high above the shore platform level, whereas the N175E Criel-sur-Mer flat valley, extending on 700 m wide and occupied by the Yères river, is directly connected to the shore platform. Offshore, the shore platform morphology varies from Criel-sur-Mer (North) to Mesnil-Val (South). Northern part of the study site is characterized by 1 km wide shore platform made of an overlay of flat steps controlled by normal faults. Southern part highlights a shore platform with a seaward edge located at about 500 m from the cliff face and strictly parallel oriented to the present-day coastline over a minimum distance of 5 km, without fracture control. The shore platform seaward edge is more or less steep and is always localized below the limit of the lowest tide level. Its origin could be related to the in-depth waves influence or to a past sea level stagnation. We aim to identify the origin of this seaward edge, using cosmogenic 10Be dating in order to develop a chalky shore platform evolution model. It is necessary to take into account detailed rock lithology and rock resistance, large and small-scale structural deformation and fractures occurrences versus the sea level variations during the Holocene. A numeric watersheds analysis has been performed inland to highlight the morphometric properties and the maturity status of each quaternary valley. They appear to be immature, even if their downstream areas demonstrate slopes varying between 0.5 and 2°. Paleo-rivers stopped to incise the chalk before reaching their equilibrium level base. We thus consider that the equilibrium point where the paleo-rivers and the past sea level were connected is located on the shore platform i.e. today located offshore. Therefore we project offshore the V-shaped valley base level, using Hack's law to estimate the paleo-coastline location. It will be correlated to the sea level fluctuations from the last interglacial period and to the Holocene shoreline recession rates known from the 10Be cosmogenic dating. References DUPERRET Anne (2013) CROCOLIT_LEG1 cruise, RV Haliotis, http://dx.doi.org/10.17600/13120080 DUPERRET Anne (2013) CROCOLIT_LEG3 cruise, RV Haliotis, http://dx.doi.org/10.17600/13120100 MAILLET Grégoire (2014) SPLASHALIOT-2 cruise, RV Haliotis, http://dx.doi.org/10.17600/14011800

Final Technical Report. DeepCwind Consortium Research Program. January 15, 2010 - March 31, 2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dagher, Habib; Viselli, Anthony; Goupee, Andrew

This is the final technical report for the U.S. Department of Energy-funded program, DE-0002981: DeepCwind Consortium Research Program. The project objective was the partial validation of coupled models and optimization of materials for offshore wind structures. The United States has a great opportunity to harness an indigenous abundant renewable energy resource: offshore wind. In 2010, the National Renewable Energy Laboratory (NREL) estimated there to be over 4,000 GW of potential offshore wind energy found within 50 nautical miles of the US coastlines (Musial and Ram, 2010). The US Energy Information Administration reported the total annual US electric energy generation inmore » 2010 was 4,120 billion kilowatt-hours (equivalent to 470 GW) (US EIA, 2011), slightly more than 10% of the potential offshore wind resource. In addition, deep water offshore wind is the dominant US ocean energy resource available comprising 75% of the total assessed ocean energy resource as compared to wave and tidal resources (Musial, 2008). Through these assessments it is clear offshore wind can be a major contributor to US energy supplies. The caveat to capturing offshore wind along many parts of the US coast is deep water. Nearly 60%, or 2,450 GW, of the estimated US offshore wind resource is located in water depths of 60 m or more (Musial and Ram, 2010). At water depths over 60 m building fixed offshore wind turbine foundations, such as those found in Europe, is likely economically infeasible (Musial et al., 2006). Therefore floating wind turbine technology is seen as the best option for extracting a majority of the US offshore wind energy resource. Volume 1 - Test Site; Volume 2 - Coupled Models; and Volume 3 - Composite Materials« less

Evaluating stress analysis and failure criteria for offshore structures for Pechora Sea conditions

NASA Astrophysics Data System (ADS)

Nesic, S.; Donskoy, Y.; Zolotukhin, A.

2017-12-01

Development of Arctic hydrocarbon resources has faced many challenges due to sensitive environmental conditions including low temperatures, ice cover and terrestrial permafrost and extreme seasonal variation in sunlight. Russian offshore field development in Arctic region is usually associated with annual ice cover, which can cause serious damage on the offshore platforms. The Pechora Sea has claimed as one of the most perspective oil and gas region of the Russian Arctic with seven discovered oil and gas fields and several dozens of structures. Our rough assessment, based on in-place hydrocarbon volumes and recovery factor evaluation concept, indicates that Pechora Sea alone has in-place volumes amounting to ca. 20 billion barrel oil equivalent (BOE). This quantity is enough to secure produced volumes by 2040 exceeding 3 billion BOE [1] that indicates huge resource potential of the region. The environmental conditions are primarily function of water dynamics and ice cover. The sea is covered by the ice for greatest part of the year. In this article, the ice load simulations were performed using explicit dynamic analysis system in ANSYS software to determine best shape and size of an offshore platform for the Pechora Sea ice conditions. Different gravity based structures (GBS) were analyzed: artificial island, hollow cylindrical and conical concrete structures and four-leg GBS. Relationships between the stress, deformations and time were analyzed and important observations from the simulation results were a basis for selecting the most preferable structures.

SEASAT demonstration experiments with the offshore oil, gas and mining industries

NASA Technical Reports Server (NTRS)

Mourad, A. G.; Robinson, A. C.; Balon, J. E.

1979-01-01

Despite its failure, SEASAT-1 acquired a reasonable volume of data that can be used by industrial participants on a non-real-time basis to prove the concept of microwave sensing of the world's oceans from a satellite platform. The amended version of 8 experimental plans are presented, along with a description of the satellite, its instruments, and the data available. Case studies are summarized for the following experiments: (1) Beaufort Sea oil, gas, and Arctic operations; (2) Labrador Sea oil, gas, and sea ice; (3) Gulf of Mexico pipelines; (4) U.S. East Coast offshore oil and gas; (5) worldwide offshore drilling and production operations; (6) Equatorial East Pacific Ocean mining; (7) Bering Sea ice project; and (8) North Sea oil and gas.

Task 1: Whole-body concentrations of elements in kelp bass (Paralabrax clathratus), kelp rockfish (Sebastes atrovirens), and Pacific sanddab (Citharichthys sordidus) from offshore oil platforms and natural areas in the Southern California Bight

USGS Publications Warehouse

Love, Milton S.

2009-01-01

Resource managers are concerned that offshore oil platforms in the Southern California Bight may be contributing to environmental contaminants accumulated by marine fishes. To examine this possibility, 18 kelp bass (Paralabrax clathratus), 80 kelp rockfish (Sebastes atrovirens), and 98 Pacific sanddab (Citharichthys sordidus) were collected from five offshore oil platforms and 10 natural areas during 2005-2006 for whole-body analysis of 63 elements. The natural areas, which served as reference sites, were assumed to be relatively uninfluenced by contaminants originating from platforms. Forty-two elements were excluded from statistical comparisons for one of three reasons: they consisted of major cations that were unlikely to accumulate to potentially toxic concentrations under ambient exposure conditions; they were not detected by the analytical procedures; or they were detected at concentrations too low to yield reliable quantitative measurements. The remaining 21 elements consisted of aluminum, arsenic, barium, cadmium, chromium, cobalt, copper, gallium, iron, lead, lithium, manganese, mercury, nickel, rubidium, selenium, strontium, tin, titanium, vanadium, and zinc. Statistical comparisons of these 21 elements indicated that none consistently exhibited higher concentrations at oil platforms than at natural areas. Eight comparisons yielded significant interaction effects between total length (TL) of the fish and the two habitat types (oil platforms and natural areas). This indicated that relations between certain elemental concentrations (i.e., copper, rubidium, selenium, tin, titanium, and vanadium) and habitat type varied by TL of affected fish species. To better understand these interactions, we examined elemental concentrations in very small and very large individuals of affected species. Although significant interactions were detected for rubidium, tin, and selenium in kelp rockfish, the concentrations of these elements did not differ significantly between oil platforms and natural areas over the TL range of sampled fish. However, for selenium, titanium, and vanadium in Pacific sanddab, small individuals (average TL, 13.0 cm) exhibited significantly lower concentrations at oil platforms than at natural areas, whereas large individuals (average TL, 27.5 cm) exhibited higher concentrations at oil platforms than at natural areas. For copper in Pacific sanddab, small individuals did not exhibit differences between oil platforms and natural areas, whereas large individuals exhibited significantly higher concentrations at oil platforms than at natural areas. On the other hand, for tin in Pacific sanddab, small individuals did not exhibit differences between oil platforms and natural areas, whereas large individuals exhibited significantly lower concentrations at oil platforms than at natural areas. Although concentrations of arsenic, cadmium, chromium, lead, mercury, and selenium in fishes from some platforms and natural areas equaled or exceeded literature-based toxicity thresholds for fish and fish-eating wildlife, studies are still needed to document evidence of toxicity from these elements. When estimates of elemental concentrations in skinless fillets were compared to risk-based consumption limits for humans, the concentrations of arsenic, cadmium, mercury, and tin in fish from a mix of oil platforms and natural areas were sufficiently elevated to suggest a need for further study of inorganic arsenic, cadmium, mercury, and tributyltin.

Storm wave buoy equipped with micromechanical inertial unit: Results of development and testing

NASA Astrophysics Data System (ADS)

Gryazin, D. G.; Staroselcev, L. P.; Belova, O. O.; Gleb, K. A.

2017-07-01

The article describes the results of developing a wave buoy to measure the statistical characteristics of waves and the characteristics of directional spectra of three-dimensional waves. The device is designed for long-term measurements lasting up to a season, which can help solve problems in forecasting waves and preventing emergencies from wave impact on offshore platforms, hydraulic structures, and other marine facilities. The measuring unit involves triads of micromechanical gyroscopes, accelerometers, and a three-component magnetometer. A description of the device, results of laboratory research of its characteristics, and bench and full-scale tests are offered. It is noted that to assess the performance characteristics, comparative tests of the Storm wave buoy were conducted with a standard string wave probe installed on an offshore platform. It is shown that the characteristics and capabilities of the wave buoy make it possible to oust foreign devices from the domestic market.

Floating Offshore WTG Integrated Load Analysis & Optimization Employing a Tuned Mass Damper

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodriguez Tsouroukdissian, Arturo; Lackner, Matt; Cross-Whiter, John

2015-09-25

Floating offshore wind turbines (FOWTs) present complex design challenges due to the coupled dynamics of the platform motion, mooring system, and turbine control systems, in response to wind and wave loading. This can lead to higher extreme and fatigue loads than a comparable fixed bottom or onshore system. Previous research[1] has shown the potential to reduced extreme and fatigue loads on FOWT using tuned mass dampers (TMD) for structural control. This project aims to reduce maximum loads using passive TMDs located at the tower top during extreme storm events, when grid supplied power for other controls systems may not bemore » available. The Alstom Haliade 6MW wind turbine is modelled on the Glosten Pelastar tension-leg platform (TLP). The primary objectives of this project are to provide a preliminary assessment of the load reduction potential of passive TMDs on real wind turbine and TLP designs.« less

Study on the influence of attitude angle on lidar wind measurement results

NASA Astrophysics Data System (ADS)

Han, Xiaochen; Dou, Peilin; Xue, Yangyang

2017-11-01

When carrying on wind profile measurement of offshore wind farm by shipborne Doppler lidar technique, the ship platform often produces motion response under the action of ocean environment load. In order to measure the performance of shipborne lidar, this paper takes two lidar wind measurement results as the research object, simulating the attitude of the ship in the ocean through the three degree of freedom platform, carrying on the synchronous observation test of the wind profile, giving an example of comparing the wind measurement data of two lidars, and carrying out the linear regression statistical analysis for all the experimental correlation data. The results show that the attitude angle will affect the precision of the lidar, The influence of attitude angle on the accuracy of lidar is uncertain. It is of great significance to the application of shipborne Doppler lidar wind measurement technology in the application of wind resources assessment in offshore wind power projects.

30 CFR 250.907 - Where must I locate foundation boreholes?

Code of Federal Regulations, 2011 CFR

2011-07-01

... foundation pile to a soil boring must not exceed 500 feet. (b) For deepwater floating platforms which utilize... necessary, other points throughout the anchor pattern to establish the soil profile suitable for foundation...

Risks to offshore installations in Europe due to natural hazards

NASA Astrophysics Data System (ADS)

Necci, Amos; Krausmann, Elisabeth

2017-04-01

Natural hazards, such as storms, earthquakes, or lightning are a major threat to industry. In particular, chemical plants, storage facilities, pipelines, and offshore oil and gas facilities are vulnerable to natural events which can cause hazardous materials releases and thereby endanger workers, the population and the environment. These technological accidents are commonly referred to as Natech accidents. Recent events have increased concerns about safety in the offshore oil and gas sector, and the need for improving knowledge on the matter has become evident. With those premises, we analyzed accidents, near misses and accident precursors at offshore facilities in Europe caused by natural events using both a statistical and a qualitative approach. For this purpose, we screened the World Offshore Accident Database (WOAD) to identify all incidents that featured natural events as causes or aggravating factors. A dataset of 1,085 global Natech events was built for the statistical analysis. Among those, a subset composed of 303 European records was selected. The results of the analysis showed that offshore Natech events in Europe are frequent; they resulted, however, in low consequences. The main threat to offshore facilities resulted from bad weather, such as strong winds and heavy seas. Storms can put intense loads on the structural parts of offshore installations, eventually exceeding design resistance specifications. Several incidents triggered by lightning strikes and earthquakes were also recorded. Substantial differences in terms of vulnerability, damage modality and consequences emerged between fixed and floating offshore structures. The main damage mode for floating structures was the failure of station keeping systems due to the rupture of mooring or anchors, mainly caused by adverse meteorological conditions. Most of the incidents at fixed offshore structures in Europe involved falling loads for both metal jacket and concrete base platforms due to storms. In contrast, in other parts of the world, and in particular in the Gulf of Mexico, tropical storms are likely to trigger severe direct damage to structures, resulting in platform capsizing, sinking or grounding. The in-depth analysis of the incident records also showed that the natural event was often just the triggering cause of the accident, which was frequently accompanied by contributing factors (e.g. corrosion, fatigue, wrong procedures, etc.). Under these circumstances, not only extreme storms, but also storms with moderate intensity can trigger incidents. Due to the high density of offshore structures and the unique environmental conditions promoting fatigue and corrosion, the North Sea is the area with the highest number of incidents recorded in Europe, as well as the area with the highest number of incidents at semi-submersible units in the world. About 4% of all reported global Natech events at offshore infrastructures involved casualties, and 2.6% for the European incident subset. Hazardous materials releases were documented for 21 events in Europe, resulting in fires and hydrocarbon spills polluting the sea. Furthermore, a surprisingly high number of severe events occurred during towing which highlights the impact of natural hazards on the safety of offshore transfer operations.

Gulf of Mexico and Caribbean Sea Data and Model Base Report

DTIC Science & Technology

1979-07-01

The source levels and spectral characteristics of merchant ships, drill rigs, and seismic profiling sources are reason- ably well known. Lacking...better data, fishing vessels are assumed to be 10 dB quieter than merchar• ships; production platforms are assumed to be similar to drill rigs, corrected...scope of the problem presented by production platforms, mobile drill rigs, and seismic profilers. 5. Impact on Exercise Planning Offshore oil industry

76 FR 7189 - Trunkline Gas Company, LLC; Notice of Request Under Blanket Authorization

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-09

... Ship Shoal T-27 Platform and appurtenant facilities located in Ship Shoal 274, Offshore Louisiana... as more fully set forth in the application, which is open to the public for inspection. The filing...

Where is the ideal location for a US East Coast offshore grid?

NASA Astrophysics Data System (ADS)

Dvorak, Michael J.; Stoutenburg, Eric D.; Archer, Cristina L.; Kempton, Willett; Jacobson, Mark Z.

2012-03-01

This paper identifies the location of an “ideal” offshore wind energy (OWE) grid on the U.S. East Coast that would (1) provide the highest overall and peak-time summer capacity factor, (2) use bottom-mounted turbine foundations (depth ≤50 m), (3) connect regional transmissions grids from New England to the Mid-Atlantic, and (4) have a smoothed power output, reduced hourly ramp rates and hours of zero power. Hourly, high-resolution mesoscale weather model data from 2006-2010 were used to approximate wind farm output. The offshore grid was located in the waters from Long Island, New York to the Georges Bank, ≈450 km east. Twelve candidate 500 MW wind farms were located randomly throughout that region. Four wind farms (2000 MW total capacity) were selected for their synergistic meteorological characteristics that reduced offshore grid variability. Sites likely to have sea breezes helped increase the grid capacity factor during peak time in the spring and summer months. Sites far offshore, dominated by powerful synoptic-scale storms, were included for their generally higher but more variable power output. By interconnecting all 4 farms via an offshore grid versus 4 individual interconnections, power was smoothed, the no-power events were reduced from 9% to 4%, and the combined capacity factor was 48% (gross). By interconnecting offshore wind energy farms ≈450 km apart, in regions with offshore wind energy resources driven by both synoptic-scale storms and mesoscale sea breezes, substantial reductions in low/no-power hours and hourly ramp rates can be made.

Job stress, mental health, and accidents among offshore workers in the oil and gas extraction industries.

PubMed

Cooper, C L; Sutherland, V J

1987-02-01

Psychosocial and occupational stressors among 194 male employees on drilling rig and production platform installations in the United Kingdom and Dutch sectors of the North Sea were studied. Mental well-being and job satisfaction were also assessed, with attention to the incidence of accidents offshore. This occupational group were found to be much less satisfied with their jobs than their onshore counterparts. Although overall mental well-being compared favorably with that of the general population, levels of anxiety were significantly higher. Multivariate analysis showed "relationships at work and at home" to be a strong predictor of both job dissatisfaction and mental ill-health. Type A coronary-prone behavior was also found to be a significant predictor of reduced mental well-being and increased accident rates offshore.

Satellite data relay and platform locating in oceanography. Report of the In Situ Ocean Science Working Group

NASA Technical Reports Server (NTRS)

Chase, R.; Cote, C.; Davis, R. E.; Dugan, J.; Frame, D. D.; Halpern, D.; Kerut, E.; Kirk, R.; Mcgoldrick, L.; Mcwilliams, J. C.

1983-01-01

The present and future use of satellites to locate offshore platforms and relay data from in situ sensors to shore was examined. A system of the ARGOS type will satisfy the increasing demand for oceanographic information through data relay and platform location. The improved ship navigation provided by the Global Positioning System (GPS) will allow direct observation of currents from underway ships. Ocean systems are described and demand estimates on satellite systems are determined. The capabilities of the ARGOS system is assessed, including anticipated demand in the next decade.

Do Offshore Wind Farms Influence Marine Primary Production?

NASA Astrophysics Data System (ADS)

Tweddle, J. F.; Murray, R. B. O.; Gubbins, M.; Scott, B. E.

2016-02-01

Primary producers (phytoplankton) form the basis of marine food-webs, supporting production of higher trophic levels, and act as a sink of CO2. We considered the impact of proposed large scale offshore wind farms in moderately deep waters (> 45 m) off the east coast of Scotland on rates of primary production. A 2 stage modelling process was used, employing state-of-the-art 3-D hydrographic models with the ability to capture flow at the spatial resolution of 10 m combined with 1-D vertical modelling using 7 years of local forcing data. Through influencing the strength of stratification via changes in current flow, large (100 m) modelled wind turbine foundations had a significant effect on primary producers, consistently reducing total annual primary production, although within the range of natural interannual variability. The percentage reduction was largest over submarine banks less than 54 m in depth, and was outside the range of natural interannual variability. Smaller (10 m) turbine foundations had no discernible effect on total annual primary production. The results indicate that smaller foundations should be favored as a mitigation measure, in terms of effects on primary production, and this type of analysis should be considered within sectoral planning and licensing processes for future renewable energy developments.

Pioneering offshore excellence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kent, R.P.; Grattan, L.

1996-11-01

Hibernia Management and Development Company Ltd. (HMDC) was formed in 1990 by a consortium of oil companies to develop their interests in the Hibernia and Avalon reservoirs offshore Newfoundland in a safe and environmentally responsible manner. The reservoirs are located 315km ESE of St. John`s in the North Atlantic. The water depth is about 80m. The entire Hibernia field is estimated to contain more than three billion barrels of oil in place and the owners development plan area is estimated to contain two billion barrels. Recoverable reserves are estimated to be approximately 615 million barrels. The Hibernia reservoir, the principlemore » reservoir, is located at an average depth of 3,700m. HMDC is building a large concrete gravity based structure (GBS) that which will support the platform drilling and processing facilities and living quarters for 280 personnel. In 1997 the platform will be towed to the production site and production will commence late 1997. Oil will be exported by a 2 km long pipeline to an offshore loading system. Dynamically positioned tankers will then take the oil to market. Average daily production is expected to plateau between 125,000 and 135,000 BOPD. It will be the first major development on the east coast of Canada and is located in an area that is prone to pack ice and icebergs.« less

The Development of a Finite Volume Method for Modeling Sound in Coastal Ocean Environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Long, Wen; Yang, Zhaoqing; Copping, Andrea E.

: As the rapid growth of marine renewable energy and off-shore wind energy, there have been concerns that the noises generated from construction and operation of the devices may interfere marine animals’ communication. In this research, a underwater sound model is developed to simulate sound prorogation generated by marine-hydrokinetic energy (MHK) devices or offshore wind (OSW) energy platforms. Finite volume and finite difference methods are developed to solve the 3D Helmholtz equation of sound propagation in the coastal environment. For finite volume method, the grid system consists of triangular grids in horizontal plane and sigma-layers in vertical dimension. A 3Dmore » sparse matrix solver with complex coefficients is formed for solving the resulting acoustic pressure field. The Complex Shifted Laplacian Preconditioner (CSLP) method is applied to efficiently solve the matrix system iteratively with MPI parallelization using a high performance cluster. The sound model is then coupled with the Finite Volume Community Ocean Model (FVCOM) for simulating sound propagation generated by human activities in a range-dependent setting, such as offshore wind energy platform constructions and tidal stream turbines. As a proof of concept, initial validation of the finite difference solver is presented for two coastal wedge problems. Validation of finite volume method will be reported separately.« less

Height system connection between island and mainland using a hydrodynamic model: a case study connecting the Dutch Wadden islands to the Amsterdam ordnance datum (NAP)

NASA Astrophysics Data System (ADS)

Slobbe, D. C.; Klees, R.; Verlaan, M.; Zijl, F.; Alberts, B.; Farahani, H. H.

2018-03-01

We present an efficient and flexible alternative method to connect islands and offshore tide gauges with the height system on land. The method uses a regional, high-resolution hydrodynamic model that provides total water levels. From the model, we obtain the differences in mean water level (MWL) between tide gauges at the mainland and at the islands or offshore platforms. Adding them to the MWL relative to the national height system at the mainland's tide gauges realizes a connection of the island and offshore platforms with the height system on the mainland. Numerical results are presented for the connection of the Dutch Wadden islands with the national height system (Normaal Amsterdams Peil, NAP). Several choices of the period over which the MWLs are computed are tested and validated. The best results were obtained when we computed the MWL only over the summer months of our 19-year simulation period. Based on this strategy, the percentage of connections for which the absolute differences between the observation- and model-derived MWL differences are ≤ 1 cm is about 34% (46 out of 135 possible leveling connections). In this case, for each Wadden island we can find several connections that allow the transfer of NAP with (sub-)centimeter accuracy.

Stress state reassessment of Romanian offshore structures taking into account corrosion influence

NASA Astrophysics Data System (ADS)

Joavină, R.; Zăgan, S.; Zăgan, R.; Popa, M.

2017-08-01

Progressive degradation analysis for extraction or exploration offshore structure, with appraisal of failure potential and the causes that can be correlated with the service age, depends on the various sources of uncertainty that require particular attention in design, construction and exploitation phases. Romanian self erecting platforms are spatial lattice structures consist of tubular steel joints, forming a continuous system with an infinite number of dynamic degrees of freedom. Reassessment of a structure at fixed intervals of time, recorrelation of initial design elements with the actual situation encountered in location and with structural behaviour represents a major asset in lowering vulnerabilities of offshore structure. This paper proposes a comparative reassessment of the stress state for an offshore structure Gloria type, when leaving the shipyard and at the end of that interval corresponding to capital revision, taking into account sectional changes due to marine environment corrosion. The calculation was done using Newmark integration method on a 3D model, asses of the dynamic loads was made through probabilistic spectral method.

Space Radar Image of Oil Slicks

NASA Image and Video Library

1999-04-15

This is a radar image of an offshore drilling field about 150 km 93 miles west of Bombay, India, in the Arabian Sea. The dark streaks are extensive oil slicks surrounding many of the drilling platforms, which appear as bright white spots.

Wildlife Densities and Habitat Use Across Temporal and Spatial Scales on the Mid-Atlantic Outer Continental Shelf. Final Report to the Department of Energy EERE Wind & Water Power Technologies Office

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, Kathryn A.; Stenhouse, Iain J.; Johnson, Sarah M.

The Mid-Atlantic Baseline Studies Project helped address environmental barriers to offshore wind energy development in the mid-Atlantic region by providing regulators, developers, and other stakeholders with comprehensive baseline ecological data and analyses. Project funders and collaborators from a range of academic institutions, non-governmental organizations, federal agencies, foundations, and private companies came together to study bird, sea turtle, and marine mammal distributions, densities, and movements on the mid-Atlantic Outer Continental Shelf between 2012 and 2014. Specific project activities and goals included the following: (1) Conduct standardized surveys to quantify bird, sea turtle, and marine mammal densities seasonally and annually throughout themore » study region and identify important habitat use or aggregation areas. (2) Develop statistical models to help understand the drivers of wildlife distribution and abundance patterns. (3) Use individual tracking data for several focal bird species to provide information on population connectivity and individual movements that is complementary to survey data. (4) Identify species that are likely to be exposed to offshore wind energy development activities in the mid-Atlantic study area. (5) Develop U.S.-based technological resources and assessment methods for future monitoring efforts, including a comparison of high resolution digital video aerial surveys to boat-based surveys. (6) Help meet data needs associated with National Environmental Policy Act (NEPA), Marine Mammal Protection Act, and Endangered Species Act requirements, by contributing several years of data and analysis towards future Environmental Impact Statements. This report consists of six parts: Project overview (executive summary and Chapters 1-2); Examining wildlife distributions and relative abundance from a digital video aerial survey platform (Chapters 3-6); Examining wildlife distributions and abundance using boat-based surveys (Chapters 7-12); Integrating data across survey platforms (Chapters 13-19); Individual movements and habitat use for focal bird species (Chapters 20-25); and Nocturnal avian migration monitoring (Chapters 26-27). Boat-based and digital video aerial surveys each had specific advantages and disadvantages, but were largely complementary (Chapters 1, 5, 13-14). Digital aerial surveys were particularly useful for covering offshore areas at broad scales, where general distributions of taxonomic groups were a priority; boat surveys could provide more detailed data on species identities and behaviors, but were more limited in geographic scope due to their slower survey pace. The mid-Atlantic study area was important for wintering and breeding taxa, and its location also made it a key migratory corridor. There was considerable variation in species composition and spatial patterns by season, largely driven by dynamic environmental conditions (Chapters 12, 15, and 20-22). Habitat gradients in nearshore waters, however, were reliable influences on productivity and patterns of species distributions and abundance. Areas within about 30-40 km of the coast offshore of the mouths of Chesapeake and Delaware Bays, as well as to the south of Delaware Bay along the coast, were consistent hotspots of abundance and species diversity, regardless of survey methodology or analytical approach (Chapters 2, 12, 17). Inter-annual variation was substantial, and the importance of certain environmental variables in predicting animal distributions indicates that these species may well respond to future environmental shifts brought about by anthropogenic effects and climatic change. This study is an important first step, however, towards understanding how bird, marine mammal, and sea turtle populations in the mid-Atlantic may be exposed to offshore wind energy development and other anthropogenic activities. The results of this study provide insight to help address environmental permitting requirements for current and future offshore development projects, and serve as a starting point for more site-specific studies, risk analyses, and evaluation of potential measures to avoid and minimize those risks.« less

Prediction of dynamic strains on a monopile offshore wind turbine using virtual sensors

NASA Astrophysics Data System (ADS)

Iliopoulos, A. N.; Weijtjens, W.; Van Hemelrijck, D.; Devriendt, C.

2015-07-01

The monitoring of the condition of the offshore wind turbine during its operational states offers the possibility of performing accurate assessments of the remaining life-time as well as supporting maintenance decisions during its entire life. The efficacy of structural monitoring in the case of the offshore wind turbine, though, is undermined by the practical limitations connected to the measurement system in terms of cost, weight and feasibility of sensor mounting (e.g. at muddline level 30m below the water level). This limitation is overcome by reconstructing the full-field response of the structure based on the limited number of measured accelerations and a calibrated Finite Element Model of the system. A modal decomposition and expansion approach is used for reconstructing the responses at all degrees of freedom of the finite element model. The paper will demonstrate the possibility to predict dynamic strains from acceleration measurements based on the aforementioned methodology. These virtual dynamic strains will then be evaluated and validated based on actual strain measurements obtained from a monitoring campaign on an offshore Vestas V90 3 MW wind turbine on a monopile foundation.

U.S. Balance-of-Station Cost Drivers and Sensitivities (Presentation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maples, B.

2012-10-01

With balance-of-system (BOS) costs contributing up to 70% of the installed capital cost, it is fundamental to understanding the BOS costs for offshore wind projects as well as potential cost trends for larger offshore turbines. NREL developed a BOS model using project cost estimates developed by GL Garrad Hassan. Aspects of BOS covered include engineering and permitting, ports and staging, transportation and installation, vessels, foundations, and electrical. The data introduce new scaling relationships for each BOS component to estimate cost as a function of turbine parameters and size, project parameters and size, and soil type. Based on the new BOSmore » model, an analysis to understand the non‐turbine costs has been conducted. This analysis establishes a more robust baseline cost estimate, identifies the largest cost components of offshore wind project BOS, and explores the sensitivity of the levelized cost of energy to permutations in each BOS cost element. This presentation shows results from the model that illustrates the potential impact of turbine size and project size on the cost of energy from U.S. offshore wind plants.« less

ASTER Views the Gulf of Mexico Oil Spill in Infrared May 1

NASA Image and Video Library

2010-05-04

NASA Terra spacecraft captured this image of the growing oil spill in the Gulf of Mexico on May 1, 2010. On April 20, 2010, an explosion destroyed the Deepwater Horizon oil platform operating offshore in the Gulf of Mexico.

The healthcare off-shoring industry in developing economies--institutional and economic foundations: an Indian case.

PubMed

Kshetri, Nir

2011-01-01

Industrialized world-based healthcare providers are increasingly off-shoring low-end healthcare services such as medical transcription, billing and insurance claims. High-skill medical jobs such as tele-imaging and tele-pathology are also being sub-contracted to developing countries. Despite its importance, little theory or research exists to explain what factors affect industry growth. The article's goals, therefore, are to examine economic processes associated with developing economies' shift from low- to high-value information technology enabled healthcare services, and to investigate how these differ in terms of legitimacy from regulative, normative and cognitive institutions in the sending country and how healthcare services differ from other services. This research is conceptual and theory-building. Broadly, its approach can be described as a positivistic epistemology. Anti off-shoring regulative, normative and cognitive pressures in the sending country are likely to be stronger in healthcare than in most business process outsourcing. Moreover, such pressures are likely to be stronger in high-value rather than in low-value healthcare off-shoring. The findings also indicate that off-shoring low-value healthcare services and emergent healthcare industries in a developing economy help accumulate implicit and tacit knowledge required for off-shoring high-value healthcare services. The approach lacks primary data and empirical documentation. The article helps in understanding industry drivers and its possible future direction. The findings help in understanding the lens through which various institutional actors in a sending country view healthcare service off-shoring. The article's value stems from its analytical context, mechanisms and processes associated with developing economies' shift to high-value healthcare off-shoring services.

Considerations in evaluating potential socioeconomic impacts of offshore platform decommissioning in California.

PubMed

Kruse, Sarah A; Bernstein, Brock; Scholz, Astrid J

2015-10-01

The 27 oil and gas platforms offshore southern California will eventually reach the end of their useful lifetimes (estimated between 2015 and 2030) and will be decommissioned. Current state and federal laws and regulations allow for alternative uses in lieu of the complete removal required in existing leases. Any decommissioning pathway will create a complex mix of costs, benefits, opportunities, and constraints for multiple user groups. To assist the California Natural Resources Agency in understanding these issues, we evaluated the potential socioeconomic impacts of the 2 most likely options: complete removal and partial removal of the structure to 85 feet below the waterline with the remaining structure left in place as an artificial reef-generally defined as a manmade structure with some properties that mimic a natural reef. We estimated impacts on commercial fishing, commercial shipping, recreational fishing, nonconsumptive boating, and nonconsumptive SCUBA diving. Available data supported quantitative estimates for some impacts, semiquantitative estimates for others, and only qualitative approximations of the direction of impact for still others. Even qualitative estimates of the direction of impacts and of user groups' likely preferred options have been useful to the public and decision makers and provided valuable input to the project's integrative decision model. Uncertainty surrounds even qualitative estimates of the likely direction of impact where interactions between multiple impacts could occur or where user groups include subsets that would experience the same option differently. In addition, we were unable to quantify effects on ecosystem value and on the larger regional ecosystem, because of data gaps on the population sizes and dynamics of key species and the uncertainty surrounding the contribution of platforms to available hard substrate and related natural populations offshore southern California. © 2015 SETAC.

Tectonic framework of Turkish sedimentary basins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yilmaz, P.O.

1988-08-01

Turkey's exploration potential primarily exists in seven onshore (Southeast Turkey platform, Tauride platform, Pontide platform, East Anatolian platform, Interior, Trace, and Adana) basins and four offshore (Black Sea, Marmara Sea, Aegean Sea, and Mediterranean Sea) regional basins formed during the Mesozoic and Tertiary. The Mesozoic basins are the onshore basins: Southeast Turkey, Tauride, Pontide, East Anatolian, and Interior basins. Due to their common tectonic heritage, the southeast Turkey and Tauride basins have similar source rocks, structural growth, trap size, and structural styles. In the north, another Mesozoic basin, the Pontide platform, has a much more complex history and very littlemore » in common with the southerly basins. The Pontide has two distinct parts; the west has Paleozoic continental basement and the east is underlain by island-arc basement of Jurassic age. The plays are in the upper Mesozoic rocks in the west Pontide. The remaining Mesozoic basins of the onshore Interior and East Anatolian basins are poorly known and very complex. Their source, reservoir, and seal are not clearly defined. The basins formed during several orogenic phases in mesozoic and Tertiary. The Cenozoic basins are the onshore Thrace and Adana basins, and all offshore regional basins formed during Miocene extension. Further complicating the onshore basins evolution is the superposition of Cenozoic basins and Mesozoic basins. The Thrace basin in the northwest and Adana basin in the south both originate from Tertiary extension over Tethyan basement and result in a similar source, reservoir, and seal. Local strike-slip movement along the North Anatolian fault modifies the Thrace basin structures, influencing its hydrocarbon potential.« less

Fire Protection Jacket

NASA Technical Reports Server (NTRS)

1991-01-01

NERAC, Inc., Tolland, CT, aided Paul Monroe Engineering, Orange, CA, in the development of their PC1200 Series Fire Protection Jacket that protects the oil conduit system on an offshore drilling platform from the intense hydrocarbon fires that cause buckling and could cause structural failure of the platform. The flame-proof jacketing, which can withstand temperatures of 2000 degrees Fahrenheit for four hours or more, was developed from a combination of ceramic cloth (similar to the ceramic in Space Shuttle tiles), and laminates used in space suits.

Montubi completes mile-long liquid ethylene pipeline project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1979-12-01

Montubi has completed the mile-long liquid ethylene pipeline project for Solvay S.p.A. at Vada, Italy, a line that extends 3.4 mi from an offshore unloading dock to an onshore gasification facility for Solvay's chemical plant at Rosignano. The 18 mo project included a mile-long 1750 ton jetty; one eight-leg main unloading platform; eight mooring dolphins plus four breasting dolphins; one small platform for firefighting pump units; and a concrete service road along the jetty.

30 CFR 250.901 - What industry standards must your platform meet?

Code of Federal Regulations, 2011 CFR

2011-07-01

...? 250.901 Section 250.901 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND... Constructing Fixed Offshore Platforms—Working Stress Design (incorporated by reference as specified in § 250... Stress Cracking Resistant Metallic Materials for Oilfield Equipment, (incorporated by reference as...

30 CFR 250.1628 - Design, installation, and operation of production systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

... mechanical and electrical systems to be installed was approved by registered professional engineers. After... Installation of Offshore Production Platform Piping Systems; (3) Electrical system information including a plan... Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as...

Sea loads on ships and offshore structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faltinsen, O.

1990-01-01

The book introduces the theory of the structural loading on ships and offshore structures caused by wind, waves and currents, and goes on to describe the applications of this theory in terms of real structures. The main topics described are linear-wave induced motions, loads on floating structures, numerical methods for ascertaining wave induced motions and loads, viscous wave loads and damping, stationkeeping and water impact and entry. The applications of the theoretical principles are introduced with extensive use of exercises and examples. Applications covered include conventional ships, barges, high speed marine vehicles, semisubmersibles, tension leg platforms, moored or dynamic positionedmore » ships, risers, buoys, fishing nets, jacket structures and gravity platforms. One aim of the book is to provide a physical understanding through simplified mathematical models. In this way one can develop analytical tools to evaluate results from test models, full scale trials or computer simulation, and learns which parameters represent the major contributions and influences on sea loads.« less

46 CFR 108.601 - Crane design.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Crane design. 108.601 Section 108.601 Shipping COAST... Cranes Cranes § 108.601 Crane design. (a) Each crane and crane foundation on a unit must be designed in accordance with the American Petroleum Institute Specification for Offshore Cranes, API Spec. 2C, Second...

46 CFR 108.601 - Crane design.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Crane design. 108.601 Section 108.601 Shipping COAST... Cranes Cranes § 108.601 Crane design. (a) Each crane and crane foundation on a unit must be designed in accordance with the American Petroleum Institute Specification for Offshore Cranes, API Spec. 2C, Second...

30 CFR 250.918 - What are the CVA's primary duties during the installation phase?

Code of Federal Regulations, 2010 CFR

2010-07-01

... INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Platforms and..., and review the towing records; (iii) Launching and uprighting operations; (iv) Submergence operations..., and when the independent monitoring activities were conducted; (2) Describe the CVA's activities...

Welder

ERIC Educational Resources Information Center

Tech Directions, 2013

2013-01-01

Welding is used to create many things, from cars, trucks, and motorcycles to rail cars, ships, aircraft, rockets, and space stations. Welding is huge in the construction industry, too. Skyscrapers, bridges, and highways would be impossible to build without welding, as would oil and natural-gas pipelines, offshore oil platforms, wind turbines, and…

30 CFR 250.1727 - What information must I include in my final application to remove a platform or other facility?

Code of Federal Regulations, 2010 CFR

2010-07-01

... MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER... are placing the explosives inside or outside of the pilings; (3) If you will use divers or acoustic...

Summer and winter plankton fish assemblages around offshore oil and gas platforms in south-eastern Australia

NASA Astrophysics Data System (ADS)

Neira, Francisco J.

2005-06-01

Opportunistic plankton surveys were conducted within a 5-nmi radius of nine offshore oil and gas platforms in Bass Strait, south-eastern Australia, in February 1998 and 1999 (summer) and August 1998 (winter). The 108 day-night samples collected alongside (vertical tows) and nearby (surface and oblique tows) platforms yielded 1526 larval and early juvenile fishes representing 55 taxa from 45 families. Epipelagic/mesopelagic taxa dominated the catches, whereas hard/soft habitat-associated taxa were uncommon. Carangidae (36.2%) and Myctophidae (31.5%) dominated in summer and winter, respectively. The most abundant taxon was Trachurus declivis (Carangidae, 35.1%), followed by Bovichtus angustifrons (Bovichtidae, 8.7%), Scomberesox saurus (Scomberesocidae, 3.7%), Centroberyx affinis (Berycidae, 3.0%) and Arripis trutta (Arripidae, 1.7%). Fish concentrations (nos. per 100 m 3) alongside platforms did not differ significantly between day and night across all surveys. Likewise, concentrations nearby platforms in February 1999, including those of T. declivis, did not vary significantly by tow type (surface vs. oblique) or day vs. night. The far greater diversity and abundance recorded in February 1999 are likely the result of upwelling conditions over the eastern Bass Strait shelf during the sampling period, and which were not detected in February 1998. In the absence of data on adult fishes associated with the Bass Strait platforms, and given the limited availability of reefs directly around the area, it could be argued that some of the taxa caught may originate from spawning around neighboring natural reefs, particularly those off the Gippsland coastline and the south-east corner of mainland Australia. However, the prime position of the platforms almost right in the center of a productivity "hotspot" would have a confounding effect on the potential source(s) of larval fishes in that region of south-eastern Australia. The role of platforms as potential de-facto reefs for juvenile fishes in Bass Strait, as well as spawning areas, is discussed based on the findings of this study, the first on early stages of fishes around oil and gas platforms in Australia.

Response spectrum method for extreme wave loading with higher order components of drag force

NASA Astrophysics Data System (ADS)

Reza, Tabeshpour Mohammad; Mani, Fatemi Dezfouli; Ali, Dastan Diznab Mohammad; Saied, Mohajernasab; Saied, Seif Mohammad

2017-03-01

Response spectra of fixed offshore structures impacted by extreme waves are investigated based on the higher order components of the nonlinear drag force. In this way, steel jacket platforms are simplified as a mass attached to a light cantilever cylinder and their corresponding deformation response spectra are estimated by utilizing a generalized single degree of freedom system. Based on the wave data recorded in the Persian Gulf region, extreme wave loading conditions corresponding to different return periods are exerted on the offshore structures. Accordingly, the effect of the higher order components of the drag force is considered and compared to the linearized state for different sea surface levels. When the fundamental period of the offshore structure is about one third of the main period of wave loading, the results indicate the linearized drag term is not capable of achieving a reliable deformation response spectrum.

Deployment and Evaluation of the Helicopter In-Flight Tracking System (HITS)

NASA Technical Reports Server (NTRS)

Daskalakis, Anastasios; Martone, Patrick

2004-01-01

The Gulf of Mexico airspace has two major operating regions: low altitude offshore (below 7,000 ft) and high altitude oceanic (above 18,000 ft). Both regions suffer significant inefficiencies due to the lack of continuous surveillance during Instrument Flight Rules operations. Provision of surveillance in the offshore region is hindered by its low-altitude nature, which makes coverage by conventional radars economically infeasible. Significant portions of the oceanic sectors are inaccessible to shore-based sensors, as they are beyond line-of-sight. Two emerging surveillance technologies were assessed that are relatively low cost and can be deployed on offshore platforms Wide Area Multilateration and Automatic Dependent Surveillance Broadcast. Performance criteria were formulated using existing FAA specifications. Three configurations were developed and deployed representative of systems serving full-size and reduced-sized domestic terminal areas and an en-route/oceanic region. These configurations were evaluated during nine flight test periods using fixed- and rotary-wing aircraft.

Low-smoke, halogenfree ship-offshore/onshore cables with improved flame retardance and fire resistance

NASA Astrophysics Data System (ADS)

Pedersen, J. R.; Holte, T. A.; Johansen, E.

Cables with improved fire resistance and flame retardance have been developed. They will continue to function at least 3 hours even at temperatures up to 1000 C and do not propagate fire when tested according to IEC 332 part 3 1982, category A. Made with halogenfree materials they give off no corrosive gases and very little visible smoke in cases of fire. Cables are made for power, signal and instrument installations in hospitals, high rise buildings, railroad cars, subways, on board ship, oil rigs and oil production platforms. The offshore cables are specially constructed to withstand the rugged climatic conditions in the North Sea area.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reggio, R.; Haun, R.

This paper reviews the engineering and design work along with the installation procedures for a Persian Gulf natural gas pipeline. OPMI Ltd., a joint venture of Offshore Pipelines, Inc., Houston, and Maritime Industrial Services Co., Ltd., United Arab Emirates (UAE), successfully completed this 57.4 mile, 16-inch gas export pipeline for Consolidated Transmissions Inc. The pipeline begins at a platform in the Mubarek field offshore Sharjah, UAE, and runs to a beach termination at the Dugas treatment plant, Jebel Ali, Dubai. The paper describes the site preparation required for installation of the pipeline along with the specific design of the pipelinemore » itself to deal with corrosion, welding processes, condensate dropout, and temperature gradients.« less

Review of technology for Arctic offshore oil and gas recovery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sackinger, W. M.

1980-08-01

The technical background briefing report is the first step in the preparation of a plan for engineering research oriented toward Arctic offshore oil and gas recovery. A five-year leasing schedule for the ice-prone waters of the Arctic offshore is presented, which also shows the projected dates of the lease sale for each area. The estimated peak production rates for these areas are given. There is considerable uncertainty for all these production estimates, since no exploratory drilling has yet taken place. A flow chart is presented which relates the special Arctic factors, such as ice and permafrost, to the normal petroleummore » production sequence. Some highlights from the chart and from the technical review are: (1) in many Arctic offshore locations the movement of sea ice causes major lateral forces on offshore structures, which are much greater than wave forces; (2) spray ice buildup on structures, ships and aircraft will be considerable, and must be prevented or accommodated with special designs; (3) the time available for summer exploratory drilling, and for deployment of permanent production structures, is limited by the return of the pack ice. This time may be extended by ice-breaking vessels in some cases; (4) during production, icebreaking workboats will service the offshore platforms in most areas throughout the year; (5) transportation of petroleum by icebreaking tankers from offshore tanker loading points is a highly probable situation, except in the Alaskan Beaufort; and (6) Arctic pipelines must contend with permafrost, making instrumentation necessary to detect subtle changes of the pipe before rupture occurs.« less

30 CFR 250.1004 - Safety equipment requirements for DOI pipelines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Pipelines and Pipeline Rights-of... a flow safety valve (FSV). (ii) For sulphur operations, incoming pipelines delivering gas to the power plant platform may be equipped with high- and low-pressure sensors (PSHL), which activate audible...

30 CFR 250.1004 - Safety equipment requirements for DOI pipelines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL... operations, incoming pipelines delivering gas to the power plant platform may be equipped with high- and low-pressure sensors (PSHL), which activate audible and visual alarms in lieu of requirements in paragraph (b...

A Crew Exposure Study. Volume I. Offshore.

DTIC Science & Technology

1982-03-15

in Percutaneous Penetra- tion in Man - Pesticides ," Archives of Environmental Health, Vol. 23, pp 208-211, 1971. 20. Bartek, M. J., et al., "Skin...OTO FI RCABNEISOS UT iA- 0 - . . -- • G. DISCHARGING OF HAZARDOUS WASTES FROM PLATFORMS 1. Middleditch, Brian S., Basile , Brenda, and Chang, Evelyn S

DISTINGUISHING CONTAMINANT FROM REEF EFFECTS ON MEIOFAUNA NEAR OFFSHORE HYDROCARBON PLATFORMS IN THE GULF OF MEXICO. (R825355)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

49 CFR 192.163 - Compressor stations: Design and construction.

Code of Federal Regulations, 2010 CFR

2010-10-01

... SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Design of... building. Except for a compressor building on a platform located offshore or in inland navigable waters, each main compressor building of a compressor station must be located on property under the control of...

30 CFR 250.203 - Where can wells be located under an EP, DPP, or DOCD?

Code of Federal Regulations, 2010 CFR

2010-07-01

... OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Plans and Information General... reservoir management; (e) Location of drilling units and platforms; (f) Extent and thickness of the reservoir; (g) Geologic and other reservoir characteristics; (h) Minimizing environmental risk; (i...

Electromagnetic sensors for monitoring of scour and deposition processes at bridges and offshore wind turbines

NASA Astrophysics Data System (ADS)

Michalis, Panagiotis; Tarantino, Alessandro; Judd, Martin

2014-05-01

Recent increases in precipitation have resulted in severe and frequent flooding incidents. This has put hydraulic structures at high risk of failure due to scour, with severe consequences to public safety and significant economic losses. Foundation scour is the leading cause of bridge failures and one of the main climate change impacts to highway and railway infrastructure. Scour action is also being considered as a major risk for offshore wind farm developments as it leads to excessive excavation of the surrounding seabed. Bed level conditions at underwater foundations are very difficult to evaluate, considering that scour holes are often re-filled by deposited loose material which is easily eroded during smaller scale events. An ability to gather information concerning the evolution of scouring will enable the validation of models derived from laboratory-based studies and the assessment of different engineering designs. Several efforts have focused on the development of instrumentation techniques to measure scour processes at foundations. However, they are not being used routinely due to numerous technical and cost issues; therefore, scour continues to be inspected visually. This research project presents a new sensing technique, designed to measure scour depth variation and sediment deposition around the foundations of bridges and offshore wind turbines, and to provide an early warning of an impending structural failure. The monitoring system consists of a probe with integrated electromagnetic sensors, designed to detect the change in the surrounding medium around the foundation structure. The probe is linked to a wireless network to enable remote data acquisition. A developed prototype and a commercial sensor were evaluated to quantify their capabilities to detect scour and sediment deposition processes. Finite element modelling was performed to define the optimum geometric characteristics of the prototype scour sensor based on models with various permittivity conditions. The experimental analysis was conducted using simulations and open channel flume tests in different sediment and temperature conditions. The density and salinity effects on the response of the sensors were also evaluated and reported herein. The obtained results indicate that the sensors are capable of exhibiting high sensitivity to scour and sediment deposition processes under the different tested environmental conditions. Saline water and temperature induced electrical conductivity changes were also found to have inevitable influences on the sensor signals. Based on this research, it is concluded that the proposed monitoring system has considerable potential for field applications that will contribute to improving the resilience and sustainability of hydraulic and marine structures.

Semi-active control of monopile offshore wind turbines under multi-hazards

NASA Astrophysics Data System (ADS)

Sun, C.

2018-01-01

The present paper studies the control of monopile offshore wind turbines subjected to multi-hazards consisting of wind, wave and earthquake. A Semi-active tuned mass damper (STMD) with tunable natural frequency and damping ratio is introduced to control the dynamic response. A new fully coupled analytical model of the monopile offshore wind turbine with an STMD is established. The aerodynamic, hydrodynamic and seismic loading models are derived. Soil effects and damage are considered. The National Renewable Energy Lab monopile 5 MW baseline wind turbine model is employed to examine the performance of the STMD. A passive tuned mass damper (TMD) is utilized for comparison. Through numerical simulation, it is found that before damage occurs, the wind and wave induced response is more dominant than the earthquake induced response. With damage presence in the tower and the foundation, the nacelle and the tower response is increased dramatically and the natural frequency is decreased considerably. As a result, the passive TMD with fixed parameters becomes off-tuned and loses its effectiveness. In comparison, the STMD retuned in real-time demonstrates consistent effectiveness in controlling the dynamic response of the monopile offshore wind turbines under multi-hazards and damage with a smaller stroke.

30 CFR 250.907 - Where must I locate foundation boreholes?

Code of Federal Regulations, 2014 CFR

2014-07-01

... soil boring must not exceed 500 feet. (b) For deepwater floating platforms which utilize catenary or..., other points throughout the anchor pattern to establish the soil profile suitable for foundation design...

30 CFR 250.907 - Where must I locate foundation boreholes?

Code of Federal Regulations, 2013 CFR

2013-07-01

... soil boring must not exceed 500 feet. (b) For deepwater floating platforms which utilize catenary or..., other points throughout the anchor pattern to establish the soil profile suitable for foundation design...

30 CFR 250.907 - Where must I locate foundation boreholes?

Code of Federal Regulations, 2012 CFR

2012-07-01

... soil boring must not exceed 500 feet. (b) For deepwater floating platforms which utilize catenary or..., other points throughout the anchor pattern to establish the soil profile suitable for foundation design...

An Indo-Pacific damselfish (Neopomacentrus cyanomos) in the Gulf of Mexico: origin and mode of introduction.

PubMed

Robertson, D Ross; Dominguez-Dominguez, Omar; Victor, Benjamin; Simoes, Nuno

2018-01-01

The Indo-West Pacific (IWP) coral-reef damselfish Neopomacentrus cyanomos is well established across the south-west Gulf of Mexico (SwGoMx). Comparisons of mtDNA sequences of the SwGoMx population with those from conspecifics from 16 sites scattered across its native geographic range show that the SwGoMx population is derived from two of four native lineages: one from the north-west Pacific Ocean, the other from the northern Indian Ocean. Three hypotheses address how this species was introduced to the SwGoMX: (1) aquarium release; (2) borne by cargo-ship; and (3) carried by offshore petroleum platform (petro-platform). The first is unlikely because this species rarely features in the aquarium trade, and " N. cyanomos " traded to the USA from the sole IWP source we are aware of are a misidentified congener, N. taeniurus . The second hypothesis is unlikely because shipping has not been associated with the introduction of alien damselfishes, there is little international shipping between the IWP and the SwGoMx, and voyages between those areas would be lengthy and along environmentally unfavorable routes. Various lines of evidence support the third hypothesis: (i) bio-fouled petro-platforms represent artificial reefs that can sustain large and diverse populations of tropical reef-fishes, including N. cyanomos in the SwGoMx; (ii) relocation of such platforms has been implicated in trans-oceanic introductions leading to establishment of non-native populations of such fishes; and (iii) genetic characteristics of the SwGoMx population indicate that it was established by a large and diverse group of founders drawn from the IWP regions where many petro-platforms currently in the SwGoMx and other Atlantic offshore oilfields originated.

An Indo-Pacific damselfish (Neopomacentrus cyanomos) in the Gulf of Mexico: origin and mode of introduction

PubMed Central

Dominguez-Dominguez, Omar; Victor, Benjamin; Simoes, Nuno

2018-01-01

The Indo-West Pacific (IWP) coral-reef damselfish Neopomacentrus cyanomos is well established across the south-west Gulf of Mexico (SwGoMx). Comparisons of mtDNA sequences of the SwGoMx population with those from conspecifics from 16 sites scattered across its native geographic range show that the SwGoMx population is derived from two of four native lineages: one from the north-west Pacific Ocean, the other from the northern Indian Ocean. Three hypotheses address how this species was introduced to the SwGoMX: (1) aquarium release; (2) borne by cargo-ship; and (3) carried by offshore petroleum platform (petro-platform). The first is unlikely because this species rarely features in the aquarium trade, and “N. cyanomos” traded to the USA from the sole IWP source we are aware of are a misidentified congener, N. taeniurus. The second hypothesis is unlikely because shipping has not been associated with the introduction of alien damselfishes, there is little international shipping between the IWP and the SwGoMx, and voyages between those areas would be lengthy and along environmentally unfavorable routes. Various lines of evidence support the third hypothesis: (i) bio-fouled petro-platforms represent artificial reefs that can sustain large and diverse populations of tropical reef-fishes, including N. cyanomos in the SwGoMx; (ii) relocation of such platforms has been implicated in trans-oceanic introductions leading to establishment of non-native populations of such fishes; and (iii) genetic characteristics of the SwGoMx population indicate that it was established by a large and diverse group of founders drawn from the IWP regions where many petro-platforms currently in the SwGoMx and other Atlantic offshore oilfields originated. PMID:29441235

Offshore Deterioration in the Mekong Delta, Vietnam

NASA Astrophysics Data System (ADS)

Stattegger, K.; Unverricht, D.; Heinrich, C.

2016-02-01

The interplay of river, tide and wave forcing controls shape and sedimentation at the front of the Mekong Delta. Specific hydro- and morphodynamic conditions in the western subaqueous part of the asymmetric Mekong Delta generate a sand ridge - channel system (SRCS) which is unique in subaqueous delta formation. This large-scale morphological element extends 130 km along the delta front consisting of two sand ridges and two erosional channels. Three different zones within SRCS can be distinguished. The eastern initial zone stretches along delta slope and inner shelf platform southwest of the Bassac river mouth, the largest and westernmost distributary of the Mekong Delta. In the central zone SRCS covers the outer part of the subaqueous delta platform with a pronounced sand-ridge and erosional channel morphology. Cross-sections of the SRCS reveal an asymmetric shape including steeper ridge flanks facing into offshore direction. Channels incise down to 18.2 m water depth (wd) and 10.5 down the ridge top at the outer subaqueous delta platform, respectively. Towards the west the sand ridges pinch out while the two channels merge into one and form a giant erosional scour of up to 33 m wd within the subaqueous delta platform. In the western zone, the channel gets shallower and vanishes along the south-western edge of the subaqueous delta platform around Ca Mau Cape. Sediment transport from the Mekong River nourishes the sand ridges. In contrast, tide and wind-driven currents cut the erosional channels, which act also as fine-sediment conveyor from eroding headlands to the distal part of the delta front that is 200 km apart of the Bassac river mouth. SRCS in the subaqueous Mekong Delta is a relevant indicator of delta-front instability and erosion.

46 CFR 108.601 - Crane design.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Crane design. 108.601 Section 108.601 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Cranes Cranes § 108.601 Crane design. (a) Each crane and crane foundation on a unit must be designed in accordance with the American Petroleum...

46 CFR 108.601 - Crane design.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Crane design. 108.601 Section 108.601 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Cranes Cranes § 108.601 Crane design. (a) Each crane and crane foundation on a unit must be designed in accordance with the American Petroleum...

Dynamics modeling and loads analysis of an offshore floating wind turbine

NASA Astrophysics Data System (ADS)

Jonkman, Jason Mark

The vast deepwater wind resource represents a potential to use offshore floating wind turbines to power much of the world with renewable energy. Many floating wind turbine concepts have been proposed, but dynamics models, which account for the wind inflow, aerodynamics, elasticity, and controls of the wind turbine, along with the incident waves, sea current, hydrodynamics, and platform and mooring dynamics of the floater, were needed to determine their technical and economic feasibility. This work presents the development of a comprehensive simulation tool for modeling the coupled dynamic response of offshore floating wind turbines, the verification of the simulation tool through model-to-model comparisons, and the application of the simulation tool to an integrated loads analysis for one of the promising system concepts. A fully coupled aero-hydro-servo-elastic simulation tool was developed with enough sophistication to address the limitations of previous frequency- and time-domain studies and to have the features required to perform loads analyses for a variety of wind turbine, support platform, and mooring system configurations. The simulation capability was tested using model-to-model comparisons. The favorable results of all of the verification exercises provided confidence to perform more thorough analyses. The simulation tool was then applied in a preliminary loads analysis of a wind turbine supported by a barge with catenary moorings. A barge platform was chosen because of its simplicity in design, fabrication, and installation. The loads analysis aimed to characterize the dynamic response and to identify potential loads and instabilities resulting from the dynamic couplings between the turbine and the floating barge in the presence of combined wind and wave excitation. The coupling between the wind turbine response and the barge-pitch motion, in particular, produced larger extreme loads in the floating turbine than experienced by an equivalent land-based turbine. Instabilities were also found in the system. The influence of conventional wind turbine blade-pitch control actions on the pitch damping of the floating turbine was also assessed. Design modifications for reducing the platform motions, improving the turbine response, and eliminating the instabilities are suggested. These suggestions are aimed at obtaining cost-effective designs that achieve favorable performance while maintaining structural integrity.

Persistent differences between coastal and offshore kelp forest communities in a warming Gulf of Maine

PubMed Central

Lamb, Robert W.

2018-01-01

Kelp forests provide important ecosystem services, yet coastal kelp communities are increasingly altered by anthropogenic impacts. Kelp forests in remote, offshore locations may provide an informative contrast due to reduced impacts from local stressors. We tested the hypothesis that shallow kelp assemblages (12–15 m depth) and associated fish and benthic communities in the coastal southwest Gulf of Maine (GOM) differed significantly from sites on Cashes Ledge, 145 km offshore by sampling five coastal and three offshore sites at 43.0 +/- 0.07° N latitude. Offshore sites on Cashes Ledge supported the greatest density (47.8 plants m2) and standing crop biomass (5.5 kg m2 fresh weight) of the foundation species Saccharina latissima kelp at this depth in the Western North Atlantic. Offshore densities of S. latissima were over 150 times greater than at coastal sites, with similar but lower magnitude trends for congeneric S. digitata. Despite these differences, S. latissima underwent a significant 36.2% decrease between 1987 and 2015 on Cashes Ledge, concurrent with a rapid warming of the GOM and invasion by the kelp-encrusting bryozoan Membranipora membranacea. In contrast to kelp, the invasive red alga Dasysiphonia japonica was significantly more abundant at coastal sites, suggesting light or dispersal limitation offshore. Spatial differences in fish abundance mirrored those of kelp, as the average biomass of all fish on Cashes Ledge was 305 times greater than at the coastal sites. Remote video censuses of cod (Gadus morhua), cunner (Tautaogolabrus adspersus), and pollock (Pollachius virens) corroborated these findings. Understory benthic communities also differed between regions, with greater abundance of sessile invertebrates offshore. Populations of kelp-consuming sea urchins Stronglyocentrotus droebachiensis, were virtually absent from Cashes Ledge while small urchins were abundant onshore, suggesting recruitment limitation offshore. Despite widespread warming of the GOM since 1987, extraordinary spatial differences in the abundance of primary producers (kelp), consumers (cod) and benthic communities between coastal and offshore sites have persisted. The shallow kelp forest communities offshore on Cashes Ledge represent an oasis of unusually high kelp and fish abundance in the region, and as such, comprise a persistent abundance hotspot that is functionally significant for sustained biological productivity of offshore regions of the Gulf of Maine. PMID:29298307

Persistent differences between coastal and offshore kelp forest communities in a warming Gulf of Maine.

PubMed

Witman, Jon D; Lamb, Robert W

2018-01-01

Kelp forests provide important ecosystem services, yet coastal kelp communities are increasingly altered by anthropogenic impacts. Kelp forests in remote, offshore locations may provide an informative contrast due to reduced impacts from local stressors. We tested the hypothesis that shallow kelp assemblages (12-15 m depth) and associated fish and benthic communities in the coastal southwest Gulf of Maine (GOM) differed significantly from sites on Cashes Ledge, 145 km offshore by sampling five coastal and three offshore sites at 43.0 +/- 0.07° N latitude. Offshore sites on Cashes Ledge supported the greatest density (47.8 plants m2) and standing crop biomass (5.5 kg m2 fresh weight) of the foundation species Saccharina latissima kelp at this depth in the Western North Atlantic. Offshore densities of S. latissima were over 150 times greater than at coastal sites, with similar but lower magnitude trends for congeneric S. digitata. Despite these differences, S. latissima underwent a significant 36.2% decrease between 1987 and 2015 on Cashes Ledge, concurrent with a rapid warming of the GOM and invasion by the kelp-encrusting bryozoan Membranipora membranacea. In contrast to kelp, the invasive red alga Dasysiphonia japonica was significantly more abundant at coastal sites, suggesting light or dispersal limitation offshore. Spatial differences in fish abundance mirrored those of kelp, as the average biomass of all fish on Cashes Ledge was 305 times greater than at the coastal sites. Remote video censuses of cod (Gadus morhua), cunner (Tautaogolabrus adspersus), and pollock (Pollachius virens) corroborated these findings. Understory benthic communities also differed between regions, with greater abundance of sessile invertebrates offshore. Populations of kelp-consuming sea urchins Stronglyocentrotus droebachiensis, were virtually absent from Cashes Ledge while small urchins were abundant onshore, suggesting recruitment limitation offshore. Despite widespread warming of the GOM since 1987, extraordinary spatial differences in the abundance of primary producers (kelp), consumers (cod) and benthic communities between coastal and offshore sites have persisted. The shallow kelp forest communities offshore on Cashes Ledge represent an oasis of unusually high kelp and fish abundance in the region, and as such, comprise a persistent abundance hotspot that is functionally significant for sustained biological productivity of offshore regions of the Gulf of Maine.

Whole-body concentrations of elements in three fish species from offshore oil platforms and natural areas in the Southern California Bight, USA

USGS Publications Warehouse

Love, Milton S.; Saiki, Michael K.; May, Thomas W.; Yee, Julie L.

2013-01-01

elements. Forty-two elements were excluded from statistical comparisons as they (1) consisted of major cations that were unlikely to accumulate to potentially toxic concentrations; (2) were not detected by the analytical procedures; or (3) were detected at concentrations too low to yield reliable quantitative measurements. The remaining 21 elements consisted of aluminum, arsenic, barium, cadmium, chromium, cobalt, copper, gallium, iron, lead, lithium, manganese, mercury, nickel, rubidium, selenium, strontium, tin, titanium, vanadium, and zinc. Statistical comparisons of these elements indicated that none consistently exhibited higher concentrations at oil platforms than at natural areas. However, the concentrations of copper, selenium, titanium, and vanadium in Pacific sanddab were unusual because small individuals exhibited either no differences between oil platforms and natural areas or significantly lower concentrations at oil platforms than at natural areas, whereas large individuals exhibited significantly higher concentrations at oil platforms than at natural areas.

Comparison of concentrations and profiles of polycyclic aromatic hydrocarbon metabolites in bile of fishes from offshore oil platforms and natural reefs along the California coast

USGS Publications Warehouse

Gale, Robert W.; Tanner, Michael J.; Love, Milton S.; Nishimoto, Mary M.; Schroeder, Donna M.

2012-01-01

To determine the environmental consequences of decommissioning offshore oil platforms on local and regional fish populations, contaminant loads in reproducing adults were investigated at seven platform sites and adjacent, natural sites. Specimens of three species (Pacific sanddab, Citharichthys sordidus; kelp rockfish, Sebastes atrovirens; and kelp bass, Paralabrax clathratus) residing at platforms and representing the regional background within the Santa Barbara Channel and within the San Pedro Basin were collected. Some of the most important contaminant classes related to oil operations are polycyclic aromatic hydrocarbons (PAHs) because of their potential toxicity and carcinogenicity. However, acute exposure cannot be related directly to PAH tissue concentrations because of rapid metabolism of the parent chemicals in fish; therefore, PAH metabolites in bile were measured, targeting free hydroxylated PAHs (OH-PAHs) liberated by enzymatic hydrolysis of the bound PAH glucuronides and sulfates. An ion-pairing method was developed for confirmatory analysis that targeted PAH glucuronides and sulfates. Concentrations of hydroxylated PAHs in all samples (76 fish from platforms and 64 fish from natural sites) were low, ranging from less than the limits of detection (5 to 120 nanograms per milliliter bile; 0.03 to 42 nanograms per milligram protein) to a maximum of 320 nanograms per milliliter bile (32 nanograms per milligram protein). A previously proposed dosimeter of PAH exposure in fish, 1-hydroxypyrene, was not detected at any platform site. Low concentrations of 1-hydroxypyrene were detected in 3 of 12 kelp rockfish collected from a natural reef site off Santa Barbara. The most prevalent OH-PAH, 2-hydroxyfluorene, was detected at low concentrations in seven fish of various species; of these, four were from two of the seven platform sites. The greatest concentrations of 2-hydroxyfluorene were found in three fish of various species from Platform Holly and were only about threefold above low, yet quantifiable, concentrations found in three fish from Horseshoe Reef, East Anacapa Island, and Coche Point natural sites; the mean concentrations among all sampling sites were not measurably different.

Mechanical and deformation analyses of pile foundation for supporting structure of off-shore wind turbine at Changhua coast in Taiwan

NASA Astrophysics Data System (ADS)

Wang, W. C.; Lin, D. G.

2015-12-01

This study investigates the bearing capacities and mechanical behaviors of pile foundation installed on the seabed of wind farm near Chang-Hua coast of western Taiwan for the supporting structure of offshore wind turbine. A series of three-dimensional (3-D) numerical modeling of pile foundation subjected to various types of combined loading were carried out using Plaix-3D finite element program to investigate the interactive behaviors between soil and pile. In the numerical modeling, pile diameter, pile length and pile spacing were selected as design parameters to inspect their effects on the bearing capacities and deformation behaviors of the pile foundation. For a specific design parameter combination, one can obtain the corresponding loading-displacement curve, various ultimate bearing capacities, V-H (Vertical-Horizontal combined loading) ultimate bearing capacity envelope, and p-ycurve of pile foundation. Numerical results indicate that: (1) Large displacement and plastic points at ultimate state mostly distribute and concentrate in the topsoil of seabed and around pile head. (2) The soil resistance on the soil-pile interface is ascending with the increases of depth, pile diameter and pile length. (3) The vertical and horizontal bearing capacities of pile group increase significantly with the increase of pile diameter. (4) The vertical and bending moment capacities of pile group increase greatly with the increase of pile length whereas the horizontal capacity is almost insensitive to pile length. (5) The bending moment of pile is highly influenced by the pile spacing. (6) For different design parameters, the shape of ultimate bearing capacity envelopes of pile group on V-H plane is similar while the envelopes will expand as the design parameters increase. For different loading levels of bending moment, the envelopes on V-H plane will contract gradually as the bending moment loading increasing.

Ocean Observing Public-Private Collaboration to Improve Tropical Storm and Hurricane Predictions in the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Perry, R.; Leung, P.; McCall, W.; Martin, K. M.; Howden, S. D.; Vandermeulen, R. A.; Kim, H. S. S.; Kirkpatrick, B. A.; Watson, S.; Smith, W.

2016-02-01

In 2008, Shell partnered with NOAA to explore opportunities for improving storm predictions in the Gulf of Mexico. Since, the collaboration has grown to include partners from Shell, NOAA National Data Buoy Center and National Center for Environmental Information, National Center for Environmental Prediction, University of Southern Mississippi, and the Gulf of Mexico Coastal Ocean Observing System. The partnership leverages complementary strengths of each collaborator to build a comprehensive and sustainable monitoring and data program to expand observing capacity and protect offshore assets and Gulf communities from storms and hurricanes. The program combines in situ and autonomous platforms with remote sensing and numerical modeling. Here we focus on profiling gliders and the benefits of a public-private partnership model for expanding regional ocean observing capacity. Shallow and deep gliders measure ocean temperature to derive ocean heat content (OHC), along with salinity, dissolved oxygen, fluorescence, and CDOM, in the central and eastern Gulf shelf and offshore. Since 2012, gliders have collected 4500+ vertical profiles and surveyed 5000+ nautical miles. Adaptive sampling and mission coordination with NCEP modelers provides specific datasets to assimilate into EMC's coupled HYCOM-HWRF model and 'connect-the-dots' between well-established Eulerian metocean measurements by obtaining (and validating) data between fixed stations (e.g. platform and buoy ADCPs) . Adaptive sampling combined with remote sensing provides satellite-derived OHC validation and the ability to sample productive coastal waters advected offshore by the Loop Current. Tracking coastal waters with remote sensing provides another verification of estimate Loop Current and eddy boundaries, as well as quantifying productivity and analyzing water quality on the Gulf coast, shelf break and offshore. Incorporating gliders demonstrates their value as tools to better protect offshore oil and gas assets and the greater Gulf coast communities from storms and hurricanes. Data collected under the collaboration, along with deployment of gliders, will have long-term benefits in helping to understand the ecological and environmental health of the Gulf by monitoring real-time annual and seasonal physical variability.

30 CFR 250.901 - What industry standards must your platform meet?

Code of Federal Regulations, 2014 CFR

2014-07-01

... Structures for Hurricane Conditions, (as incorporated by reference in § 250.198); (5) API Bulletin 2INT-EX, Interim Guidance for Assessment of Existing Offshore Structures for Hurricane Conditions, (as incorporated by reference in § 250.198); (6) API Bulletin 2INT-MET, Interim Guidance on Hurricane Conditions in...

30 CFR 250.901 - What industry standards must your platform meet?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Structures for Hurricane Conditions, (as incorporated by reference in § 250.198); (5) API Bulletin 2INT-EX, Interim Guidance for Assessment of Existing Offshore Structures for Hurricane Conditions, (as incorporated by reference in § 250.198); (6) API Bulletin 2INT-MET, Interim Guidance on Hurricane Conditions in...

30 CFR 250.901 - What industry standards must your platform meet?

Code of Federal Regulations, 2012 CFR

2012-07-01

... Structures for Hurricane Conditions, (as incorporated by reference in § 250.198); (5) API Bulletin 2INT-EX, Interim Guidance for Assessment of Existing Offshore Structures for Hurricane Conditions, (as incorporated by reference in § 250.198); (6) API Bulletin 2INT-MET, Interim Guidance on Hurricane Conditions in...

30 CFR 250.203 - Where can wells be located under an EP, DPP, or DOCD?

Code of Federal Regulations, 2011 CFR

2011-07-01

... ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL... that can be economically drilled for proper reservoir management; (e) Location of drilling units and platforms; (f) Extent and thickness of the reservoir; (g) Geologic and other reservoir characteristics; (h...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This paper reports on Amoco's Yombo offshore oil field development on Marine I permit which is well under way with installation of decks on two wellhead platforms. Initial production from the field has begun at about 6,000 bopd. With production estimated to be 40,000 bopd by early 1992, it will bring Congo's total production to more than 200,000 bopd.

Developing AN Emergency Response Model for Offshore Oil Spill Disaster Management Using Spatial Decision Support System (sdss)

NASA Astrophysics Data System (ADS)

Balogun, Abdul-Lateef; Matori, Abdul-Nasir; Wong Toh Kiak, Kelvin

2018-04-01

Environmental resources face severe risks during offshore oil spill disasters and Geographic Information System (GIS) Environmental Sensitivity Index (ESI) maps are increasingly being used as response tools to minimize the huge impacts of these spills. However, ESI maps are generally unable to independently harmonize the diverse preferences of the multiple stakeholders' involved in the response process, causing rancour and delay in response time. This paper's Spatial Decision Support System (SDSS) utilizes the Analytic Hierarchy Process (AHP) model to perform tradeoffs in determining the most significant resources to be secured considering the limited resources and time available to perform the response operation. The AHP approach is used to aggregate the diverse preferences of the stakeholders and reach a consensus. These preferences, represented as priority weights, are incorporated in a GIS platform to generate Environmental sensitivity risk (ESR) maps. The ESR maps provide a common operational platform and consistent situational awareness for the multiple parties involved in the emergency response operation thereby minimizing discord among the response teams and saving the most valuable resources.

An evaluation of oil spill responses for offshore oil production projects in Newfoundland and Labrador, Canada: Implications for seabird conservation.

PubMed

Fraser, Gail S; Racine, Vincent

2016-06-15

Seabirds are vulnerable to oil pollution, particularly in cold-water regions. We investigated the response of small spills (<7.95m(3)) at offshore production platforms in Newfoundland, a region recognized for seabird diversity and abundance. In three environmental assessments for oil production operations Environment Canada requested monitoring and mitigation of small spills potentially impacting seabird populations; suggestions supported by two independent reviews. An industry spill response plan states that operators would collect systematic observations on spills and deploy countermeasures where possible. Operators' spill reports were obtained under an Access to Information request. There were 220 daytime spills with sheens (out of 381 spills; 1997-2010). Of these, six reported time to oil dispersion and eleven the presence or absence of seabirds. Industry self-reporting has not permitted an evaluation of the impact of chronic oil spills on seabirds. We recommend that independent observers be placed on platforms to systematically collect data on spills and seabirds. Copyright © 2016 Elsevier Ltd. All rights reserved.

Coastal Erosion in a Coral Reef Island, Taiping Island, South China Sea

NASA Astrophysics Data System (ADS)

Su, S.; Ma, G.; Liang, M.; Chu, J.

2011-12-01

Reef flats surrounding islands are known to dissipate much offshore wave energy, and thereby protect beaches from erosion. Taiping Island, the largest coral reef islands of the Spratly Islands in the South China Sea, has been observed the shorelines erosion on the southwest coast over past decades. It is recognized that wave and current processes across coral reefs affect reef-island development and morphology. A number of studies suggest effects of climate changes, sea-level rise and storm-intensity increase, determine the magnitude of wave energy on the reef platform and will likely intensify the erosion. The topographical change in the local region, the southwest reef flat was dredged a channel for navigation, may be a significant factor in influencing current characteristics. Numerical modeling is used to describe both hydrodynamics and sediment dynamics because there are no field measurements available around the reef flat. Field observations off the island conducted in August 2004 and November 2005 provides offshore wave characteristics of the predominant wind seasons. Numerical simulations perform the spatial and temporal variation of waves and current patterns and coastal erosion potential on the reef platform.

An Aeroelastic Perspective of Floating Offshore Wind Turbine Wake Formation and Instability

NASA Astrophysics Data System (ADS)

Rodriguez, Steven N.; Jaworski, Justin W.

2015-11-01

The wake formation and wake stability of floating offshore wind turbines are investigated from an aeroelastic perspective. The aeroelastic model is composed of the Sebastian-Lackner free-vortex wake aerodynamic model coupled to the nonlinear Hodges-Dowell beam equations, which are extended to include the effects of blade profile asymmetry, higher-order torsional effects, and kinetic energy components associated with periodic rigid-body motions of floating platforms. Rigid-body platform motions are also assigned to the aerodynamic model as varying inflow conditions to emulate operational rotor-wake interactions. Careful attention is given to the wake formation within operational states where the ratio of inflow velocity to induced velocity is over 50%. These states are most susceptible to aerodynamic instabilities, and provide a range of states about which a wake stability analysis can be performed. In addition, the stability analysis used for the numerical framework is implemented into a standalone free-vortex wake aerodynamic model. Both aeroelastic and standalone aerodynamic results are compared to evaluate the level of impact that flexible blades have on the wake formation and wake stability.

Geologic evolution and sequence stratigraphy of the offshore Pelotas Basin, southeast Brazil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abreu, V.S.

1996-01-01

The Brazilian marginal basins have been studied since the beginning of the 70s. At least nine large basins are distributed along the entire Eastern continental margin. The sedimentary infill of these basins consists of lower Cretaceous (continental/lacustrine) rift section underlying marine upper Cretaceous (carbonate platforms) and marine upper Cretaceous/Tertiary sections, corresponding to the drift phase. The sedimentary deposits are a direct result of the Jurassic to lower Cretaceous break-up of the Pangea. This study will focus on the geologic evolution and sequence stratigraphic analysis of the Pelotas basin (offshore), located in the Southeast portion of the Brazilian continental margin betweenmore » 28[degrees] and 34[degrees] S, covering approximately 50,000 Km[sup 2]. During the early Cretaceous, when the break-up of the continent began in the south, thick basaltic layers were deposited in the Pelotas basin. These basalts form a thick and broad wedge of dipping seaward reflections interpreted as a transitional crust. During Albian to Turonian times, due to thermal subsidence, an extensive clastic/carbonate platform was developed, in an early drift stage. The sedimentation from the upper Cretaceous to Tertiary was characterized by a predominance of siliciclastics in the southeast margin, marking an accentuate deepening of the basin, showing several cycles related to eustatic fluctuations. Studies have addressed the problems of hydrocarbon exploration in deep water setting within a sequence stratigraphic framework. Thus Pelotas basin can provide a useful analogue for exploration efforts worldwide in offshore passive margins.« less

Geologic evolution and sequence stratigraphy of the offshore Pelotas Basin, southeast Brazil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abreu, V.S.

1996-12-31

The Brazilian marginal basins have been studied since the beginning of the 70s. At least nine large basins are distributed along the entire Eastern continental margin. The sedimentary infill of these basins consists of lower Cretaceous (continental/lacustrine) rift section underlying marine upper Cretaceous (carbonate platforms) and marine upper Cretaceous/Tertiary sections, corresponding to the drift phase. The sedimentary deposits are a direct result of the Jurassic to lower Cretaceous break-up of the Pangea. This study will focus on the geologic evolution and sequence stratigraphic analysis of the Pelotas basin (offshore), located in the Southeast portion of the Brazilian continental margin betweenmore » 28{degrees} and 34{degrees} S, covering approximately 50,000 Km{sup 2}. During the early Cretaceous, when the break-up of the continent began in the south, thick basaltic layers were deposited in the Pelotas basin. These basalts form a thick and broad wedge of dipping seaward reflections interpreted as a transitional crust. During Albian to Turonian times, due to thermal subsidence, an extensive clastic/carbonate platform was developed, in an early drift stage. The sedimentation from the upper Cretaceous to Tertiary was characterized by a predominance of siliciclastics in the southeast margin, marking an accentuate deepening of the basin, showing several cycles related to eustatic fluctuations. Studies have addressed the problems of hydrocarbon exploration in deep water setting within a sequence stratigraphic framework. Thus Pelotas basin can provide a useful analogue for exploration efforts worldwide in offshore passive margins.« less

Application of metal magnetic memory technology on defects detection of jack-up platform

NASA Astrophysics Data System (ADS)

Xu, Changhang; Cheng, Liping; Xie, Jing; Yin, Xiaokang; Chen, Guoming

2016-02-01

Metal magnetic memory test (MMMT), which is an effective way in evaluating early damages of ferrimagnets, can determine the existence of material stresses concentration and premature defects. As one of offshore oil exploration and development equipment, jack-up platform always generate stress concentration during its life-cycle due to complicated loading condition and the hash marine environment, which will decline the bearing capacity and cause serious consequences. The paper conducts in situ experiments of defects detection on some key structural components of jack-up platform using MMMT. The signals acquired by MMM-System are processed for feature extraction to evaluate the severity of structure stress concentration. The results show that the method presented in this paper based on MMMT can provide an effective and convenient way of defect detection and structural health monitoring for Jack-up Platform.

Unsteady aerodynamic analysis for offshore floating wind turbines under different wind conditions.

PubMed

Xu, B F; Wang, T G; Yuan, Y; Cao, J F

2015-02-28

A free-vortex wake (FVW) model is developed in this paper to analyse the unsteady aerodynamic performance of offshore floating wind turbines. A time-marching algorithm of third-order accuracy is applied in the FVW model. Owing to the complex floating platform motions, the blade inflow conditions and the positions of initial points of vortex filaments, which are different from the fixed wind turbine, are modified in the implemented model. A three-dimensional rotational effect model and a dynamic stall model are coupled into the FVW model to improve the aerodynamic performance prediction in the unsteady conditions. The effects of floating platform motions in the simulation model are validated by comparison between calculation and experiment for a small-scale rigid test wind turbine coupled with a floating tension leg platform (TLP). The dynamic inflow effect carried by the FVW method itself is confirmed and the results agree well with the experimental data of a pitching transient on another test turbine. Also, the flapping moment at the blade root in yaw on the same test turbine is calculated and compares well with the experimental data. Then, the aerodynamic performance is simulated in a yawed condition of steady wind and in an unyawed condition of turbulent wind, respectively, for a large-scale wind turbine coupled with the floating TLP motions, demonstrating obvious differences in rotor performance and blade loading from the fixed wind turbine. The non-dimensional magnitudes of loading changes due to the floating platform motions decrease from the blade root to the blade tip. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Unsteady aerodynamic analysis for offshore floating wind turbines under different wind conditions

PubMed Central

Xu, B. F.; Wang, T. G.; Yuan, Y.; Cao, J. F.

2015-01-01

A free-vortex wake (FVW) model is developed in this paper to analyse the unsteady aerodynamic performance of offshore floating wind turbines. A time-marching algorithm of third-order accuracy is applied in the FVW model. Owing to the complex floating platform motions, the blade inflow conditions and the positions of initial points of vortex filaments, which are different from the fixed wind turbine, are modified in the implemented model. A three-dimensional rotational effect model and a dynamic stall model are coupled into the FVW model to improve the aerodynamic performance prediction in the unsteady conditions. The effects of floating platform motions in the simulation model are validated by comparison between calculation and experiment for a small-scale rigid test wind turbine coupled with a floating tension leg platform (TLP). The dynamic inflow effect carried by the FVW method itself is confirmed and the results agree well with the experimental data of a pitching transient on another test turbine. Also, the flapping moment at the blade root in yaw on the same test turbine is calculated and compares well with the experimental data. Then, the aerodynamic performance is simulated in a yawed condition of steady wind and in an unyawed condition of turbulent wind, respectively, for a large-scale wind turbine coupled with the floating TLP motions, demonstrating obvious differences in rotor performance and blade loading from the fixed wind turbine. The non-dimensional magnitudes of loading changes due to the floating platform motions decrease from the blade root to the blade tip. PMID:25583859

A new submarine oil-water separation system

NASA Astrophysics Data System (ADS)

Cai, Wen-Bin; Liu, Bo-Hong

2017-12-01

In order to solve the oil field losses of environmental problems and economic benefit caused by the separation of lifting production liquid to offshore platforms in the current offshore oil production, from the most basic separation principle, a new oil-water separation system has been processed of adsorption and desorption on related materials, achieving high efficiency and separation of oil and water phases. And the submarine oil-water separation device has been designed. The main structure of the device consists of gas-solid phase separation device, period separating device and adsorption device that completed high efficiency separation of oil, gas and water under the adsorption and desorption principle, and the processing capacity of the device is calculated.

Aeroelastic impact of above-rated wave-induced structural motions on the near-wake stability of a floating offshore wind turbine rotor

NASA Astrophysics Data System (ADS)

Rodriguez, Steven; Jaworski, Justin

2017-11-01

The impact of above-rated wave-induced motions on the stability of floating offshore wind turbine near-wakes is studied numerically. The rotor near-wake is generated using a lifting-line free vortex wake method, which is strongly coupled to a finite element solver for kinematically nonlinear blade deformations. A synthetic time series of relatively high-amplitude/high-frequency representative of above-rated conditions of the NREL 5MW referece wind turbine is imposed on the rotor structure. To evaluate the impact of these above-rated conditions, a linear stability analysis is first performed on the near wake generated by a fixed-tower wind turbine configuration at above-rated inflow conditions. The platform motion is then introduced via synthetic time series, and a stability analysis is performed on the wake generated by the floating offshore wind turbine at the same above-rated inflow conditions. The stability trends (disturbance modes versus the divergence rate of vortex structures) of the two analyses are compared to identify the impact that above-rated wave-induced structural motions have on the stability of the floating offshore wind turbine wake.

Research on the influence of helical strakes on dynamic response of floating wind turbine platform

NASA Astrophysics Data System (ADS)

Ding, Qin-wei; Li, Chun

2017-04-01

The stability of platform structure is the paramount guarantee of the safe operation of the offshore floating wind turbine. The NREL 5MW floating wind turbine is established based on the OC3-Hywind Spar Buoy platform with the supplement of helical strakes for the purpose to analyze the impact of helical strakes on the dynamic response of the floating wind turbine Spar platform. The dynamic response of floating wind turbine Spar platform under wind, wave and current loading from the impact of number, height and pitch ratio of the helical strakes is analysed by the radiation and diffraction theory, the finite element method and orthogonal design method. The result reveals that the helical strakes can effectively inhibit the dynamic response of the platform but enlarge the wave exciting force; the best parameter combination is two pieces of helical strakes with the height of 15% D ( D is the diameter of the platform) and the pitch ratio of 5; the height of the helical strake and its pitch ratio have significant influence on pitch response.

Characterisation of impacts on the environment of an idealised offshore wind farm foundation, under waves and the combination of waves and currents

NASA Astrophysics Data System (ADS)

García-Hermosa, Isabel; Abcha, Nizar; Brossard, Jérôme; Bennis, Anne-Claire; Ezersky, Alexander; Gross, Marcus; Iglesias, Gregorio; Magar, Vanesa; Miles, Jon; Mouazé, Dominique; Perret, Gaële; Pinon, Grégory; Rivier, Aurélie; Rogan, Charlie; Simmonds, David

2015-04-01

Offshore wind technology is currently the most widespread and advanced source of marine renewable energy. Offshore wind farms populate waters through the North Sea and the English Channel. The UK and French governments devised deadlines to achieve percentages of electricity from renewable sources by 2020, these deadlines and the direct translation of land based wind farm technology to the offshore environment resulted in the rapid expansion of the offshore wind energy. New wind farms have been designed with a larger number of masts and are moving from shallow offshore banks to deeper waters and in order to produce more power the diameters of monopoles masts are becoming larger to support larger turbines. The three-partner EU INTERREG funded project OFELIA (http://www.interreg-ofelia.eu/) aims to establish a cross-channel (between the UK and France) research collaboration to improve understanding of the environmental impacts of offshore wind farm foundations. The objective of the present study is to characterise changes in the hydrodynamics and sea bed in the vicinity of an offshore wind farm mast and in the wake area under wave and wave-current conditions corresponding to events in the French wind farm site of Courseulles-sur-mer (offshore of Lower Normandy, in the English Channel). Experiments were carried out in two laboratory facilities: a wave flume of 35 m long, 0.9 m wide and 1.2 m in depth with regular and irregular waves (García-Hermosa et al., 2014); and a wave and current flume of 17 m long, 0.5 m wide and 0.4 m depth with regular waves, currents from 180° to the waves and a mobile bed (Gunnoo et al., 2014). Flow velocity measurements were taken with an Acoustic Dopple Velocimeter (ADV) at various points around the cylinder and Particle Image Velocitmetry (PIV) techniques were applied to larger areas upstream and downstream of the cylinder. During the assessment of waves and currents' effects on the bed evolution were assessed using a laser and camera system photographing the bed (Marin & Ezersky, 2007, and Jarno-Druaux et al., 2004). Velocity fields, and flow structures around the cylinder at low KC numbers (KC~1) were characterised and parameters such as vorticity, turbulent kinetic energy and bed shear stresses derived where possible. During the experiments vortex structures with a horizontal axis were observed in the vicinity of the cylinder and the bed even at low KC. The Keulegan-Carpenter number (KC) is defined as: KC = UmT- D, where Um is the bottom orbital velocity, T the peak period and D the pile diameter. As part of the project, the findings from the experiments fed into a regional numerical modelling (Rivier et al., 2014) to improve parametrisation of the representation of the within-cell processes (local to the mast). References García-Hermosa, M. I., Brossard, J., Cohen, Z., Perret, G. (2014). Experimental characterisation of wave induced flow fields due to an offshore wind farm mast. First International Conference on Renewable Energies Offshore (RENEW) Lisbon, Portugal. November 2014. Gunnoo, H., Abcha, N., Mouazé, D., Ezersky, A., García-Hermosa, M. I. (2014). Laboratory simulation of resonance amplification of the hydrodynamic fields in the vicinity of wind farm masts. Proceedings of the First International Conference on Renewable Energies Offshore (RENEW) Lisbon, Portugal. November 2014. Jarno-Druaux, A., Brossard, J., Marin, F. (2004). Dynamical evolution of ripples in a wave channel, European Journal of Mechanics B/Fluids 23: 695-708. Marin, F. and Ezersky, A. B. (2007). Formation dynamics of sand bedforms under solitons and bound states of solitons in a wave flume used in resonant mode. European Journal of Mechanics - B/Fluids, Elsevier, 2008, 27 (3), pp.251-267. Rivier, A., Bennis, A.-C., Pinon, G., Gross, M., Magar, V. (2014). Regional numerical modelling of offshore monopile wind turbine impacts on hydrodynamics and sediment transport. Proceeding of the 1st International Conference on Renewable Energies Offshore (RENEW) Lisbon, Portugal. November 2014.

The U.S. Department of Energy's Reference Facility for Offshore Renewable Energy (RFORE): A New Platform for Research and Development (Invited)

NASA Astrophysics Data System (ADS)

Shaw, W. J.

2013-12-01

Offshore renewable energy represents a significant but essentially untapped electricity resource for the U.S. Offshore wind energy is attractive for a number of reasons, including the feasibility of using much larger and more efficient wind turbines than is possible on land. In many offshore regions near large population centers, the diurnal maximum in wind energy production is also closely matched to the diurnal maximum in electricity demand, easing the balancing of generation and load. Currently, however, the cost of offshore wind energy is not competitive with other energy sources, including terrestrial wind. Two significant contributing reasons for this are the cost of offshore wind resource assessment and fundamental gaps in knowledge of the behavior of winds and turbulence in the layer of the atmosphere spanned by the sweep of the turbine rotor. Resource assessment, a necessary step in securing financing for a wind project, is conventionally carried out on land using meteorological towers erected for a year or more. Comparable towers offshore are an order of magnitude more expensive to install. New technologies that promise to reduce these costs, such as Doppler lidars mounted on buoys, are being developed, but these need to be validated in the environment in which they will be used. There is currently no facility in the U.S. that can carry out such validations offshore. Research needs include evaluation and improvement of hub-height wind forecasts from regional forecast models in the marine boundary layer, understanding of turbulence characteristics that affect turbine loads and wind plant efficiency, and development of accurate representations of sea surface roughness and atmospheric thermodynamic stability on hub height winds. In response to these needs for validation and research, the U.S. Department of Energy is developing the Reference Facility for Offshore Renewable Energy (RFORE). The RFORE will feature a meteorological tower with wind, temperature, humidity, and turbulence sensors at nominally eight levels to a maximum measurement height of at least 100 m. In addition, remote sensing systems for atmospheric dynamic and thermodynamic profiles, sea state measurements including wave spectra, and subsurface measurements of current, temperature, and salinity profiles will be measured. Eventually, measurements from the platform are anticipated to include monitoring of marine and avian life as well as bats. All data collected at the RFORE will be archived and made available to all interested users. The RFORE is currently planned to be built on the structure of the Chesapeake Light Tower, approximately 25 km east of Virginia Beach, Virginia. This development is an active collaboration among U.S. DOE headquarters staff, the National Renewable Energy Laboratory (NREL), and Pacific Northwest National Laboratory (PNNL). NREL will design, construct, and operate the facility. PNNL will develop the research agenda, including the data archive. This presentation emphasizes the measurement capabilities of the facility in the context of research applications, user access to the data through the archive, and plans for user engagement and research management of the facility.

On the predominance of unstable atmospheric conditions in the marine boundary layer offshore of the U.S. northeastern coast

DOE PAGES

Archer, Cristina L.; Colle, Brian A.; Veron, Dana L.; ...

2016-07-18

The marine boundary layer of the northeastern U.S. is studied with focus on wind speed, atmospheric stability, and turbulent kinetic energy (TKE), the three most relevant properties in the context of offshore wind power development. Two long-term observational data sets are analyzed. The first one consists of multilevel meteorological variables measured up to 60 m during 2003–2011 at the offshore Cape Wind tower, located near the center of the Nantucket Sound. The second data set comes from the 2013–2014 IMPOWR campaign (Improving the Modeling and Prediction of Offshore Wind Resources), in which wind and wave data were collected with newmore » instruments on the Cape Wind platform, in addition to meteorological data measured during 19 flight missions offshore of New York, Connecticut, Rhode Island, and Massachusetts. It is found that, in this region: (1) the offshore wind resource is remarkable, with monthly average wind speeds at 60 m exceeding 7 m s -1 all year round, highest winds in winter (10.1 m s -1) and lowest in summer (7.1 m s -1), and a distinct diurnal modulation, especially in summer; (2) the marine boundary layer is predominantly unstable (61% unstable vs. 21% neutral vs. 18% stable), meaning that mixing is strong, heat fluxes are positive, and the wind speed profile is often nonlogarithmic (~40% of the time); and (3) the shape of the wind speed profile (log versus nonlog) is an effective qualitative proxy for atmospheric stability, whereas TKE alone is not.« less

On the predominance of unstable atmospheric conditions in the marine boundary layer offshore of the U.S. northeastern coast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Archer, Cristina L.; Colle, Brian A.; Veron, Dana L.

The marine boundary layer of the northeastern U.S. is studied with focus on wind speed, atmospheric stability, and turbulent kinetic energy (TKE), the three most relevant properties in the context of offshore wind power development. Two long-term observational data sets are analyzed. The first one consists of multilevel meteorological variables measured up to 60 m during 2003–2011 at the offshore Cape Wind tower, located near the center of the Nantucket Sound. The second data set comes from the 2013–2014 IMPOWR campaign (Improving the Modeling and Prediction of Offshore Wind Resources), in which wind and wave data were collected with newmore » instruments on the Cape Wind platform, in addition to meteorological data measured during 19 flight missions offshore of New York, Connecticut, Rhode Island, and Massachusetts. It is found that, in this region: (1) the offshore wind resource is remarkable, with monthly average wind speeds at 60 m exceeding 7 m s -1 all year round, highest winds in winter (10.1 m s -1) and lowest in summer (7.1 m s -1), and a distinct diurnal modulation, especially in summer; (2) the marine boundary layer is predominantly unstable (61% unstable vs. 21% neutral vs. 18% stable), meaning that mixing is strong, heat fluxes are positive, and the wind speed profile is often nonlogarithmic (~40% of the time); and (3) the shape of the wind speed profile (log versus nonlog) is an effective qualitative proxy for atmospheric stability, whereas TKE alone is not.« less

Hurricane shuts down gulf activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koen, A.D.

1992-08-31

This paper reports that producers in the Gulf of Mexico and plant operators in South Louisiana last week were checking for damage wrought by Hurricane Andrew. In its wake Andrew left evacuated rigs and platforms in the gulf and shuttered plants across a wide swath of the Gulf Coast. Operations were beginning to return to normal late last week. Not all gulf operators, especially in the central gulf, expected to return to offshore facilities. And even producers able to book helicopters did not expect to be able to fully assess damage to all offshore installations before the weekend. MMS officialsmore » in Washington estimated that 37,500 offshore workers were evacuated from 700 oil and gas installations on the gulf's Outer Continental Shelf. Gulf oil and gas wells account for about 800,000 b/d of oil and one fourth of total U.S. gas production. MMS was awaiting an assessment of hurricane damage before estimating how soon and how much gulf oil and gas production would be restored.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knott, D.

Northwest Europe`s offshore operators have boosted their oil and gas production dramatically in recent years, and while the area is now mature, a steady stream of developments continues. In the boom days of the late 1970s and 1980s, a typical North Sea installation was a large platform, which occasionally a new pipeline or, more commonly, a tie-in to the area`s massive export grids. These days, now that technical developments have enabled operators to justify developments of smaller, once uneconomic, discoveries, it is pointless to talk of a typical offshore development. Northwest Europe`s offshore operators have learned that it is worthwhilemore » to rack their brains for the most economic development concepts. This creativity is reflected in recent development plans. While operators are now snatching up the small accumulations in and around the mature North Sea producing fields, they are also seeking develop frontier regions. The paper discusses development activities in UK, Ireland, Denmark and Greenland, and Norway in gas, oil, and gas condensate deposits.« less

From Apollo to Cognac

NASA Technical Reports Server (NTRS)

1980-01-01

Shell Oil Company started oil and gas production from a new offshore platform called Cognac located in the Gulf of Mexico. It is the world's tallest oil platform, slightly taller than the Empire State Building. The highly complex job of installing Cognac's support "jacket" under water more than a thousand feet deep was directed from a barge-based control center. To enable crews to practice in advance difficult tasks never before accomplished, Honeywell, adapting NASA's Apollo technology, developed a system for simulating the various underwater operations. In training sessions, displays and controls reacted exactly as they would in real operation.

Dynamic modal estimation using instrumental variables

NASA Technical Reports Server (NTRS)

Salzwedel, H.

1980-01-01

A method to determine the modes of dynamical systems is described. The inputs and outputs of a system are Fourier transformed and averaged to reduce the error level. An instrumental variable method that estimates modal parameters from multiple correlations between responses of single input, multiple output systems is applied to estimate aircraft, spacecraft, and off-shore platform modal parameters.

Direct-current converter for gas-discharge lamps

NASA Technical Reports Server (NTRS)

Lutus, P.

1980-01-01

Metal/halide and similar gas-discharge lamps are powered from low-voltage dc source using small efficient converter. Converter is useful whenever 60-cycle ac power is not available or where space and weight allocations are limited. Possible applications are offshore platforms, mobile homes, and emergency lighting. Design innovations give supply high reliability and efficiency up to 75 percent.

Implementation and performance test of cloud platform based on Hadoop

NASA Astrophysics Data System (ADS)

Xu, Jingxian; Guo, Jianhong; Ren, Chunlan

2018-01-01

Hadoop, as an open source project for the Apache foundation, is a distributed computing framework that deals with large amounts of data and has been widely used in the Internet industry. Therefore, it is meaningful to study the implementation of Hadoop platform and the performance of test platform. The purpose of this subject is to study the method of building Hadoop platform and to study the performance of test platform. This paper presents a method to implement Hadoop platform and a test platform performance method. Experimental results show that the proposed test performance method is effective and it can detect the performance of Hadoop platform.

Oil Industry Aids

NASA Technical Reports Server (NTRS)

1979-01-01

The accompanying photos show two types of offshore oil platforms used by Exxon Corporation. In the upper photo is a leg-supported gravity platform; the other structure is a "jackettype" platform, built in sections, towed to sea and assembled on-site. In construction of platforms like these, Exxon Production Research Company, Houston, Texas, conducts extensive structural investigations of decks, supporting members and other platform components, making use of the NASTRAN @ (NASA Structural Analysis) computer program. NASTRAN is a predictive tool which analyzes a computerized design and reports how the structure will react to a great many conditions it will encounter in its operational environment; in this case, NASTRAN studies the effects of waves, winds, ocean storms and other stress-inducing factors. NASTRAN allows Exxon Production Research to perform more complex and more detailed analysis than was possible with previous programs. The same program has also been used by Exxon Research and Engineering Company, Florham Park, New Jersey, in analysis of pressure vessels, turbine components and composite building boards.

DETAIL OVERHEAD VIEW OF SECONDARY ORE BIN. CONVEYOR PLATFORM,TRAM TRESTLE, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL OVERHEAD VIEW OF SECONDARY ORE BIN. CONVEYOR PLATFORM,TRAM TRESTLE, AND LOADING PLATFORM. LOOKING SOUTHWEST. THE HOLE IN THE ORE BIN FLOOR CAN BE SEEN, AND BALL MILL FOUNDATION AT LOWER LEFT CORNER. SEE CA-291-47(CT) FOR IDENTICAL COLOR TRANSPARENCY. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

DETAIL OVERHEAD VIEW OF SECONDARY ORE BIN, CONVEYOR PLATFORM TRAM ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL OVERHEAD VIEW OF SECONDARY ORE BIN, CONVEYOR PLATFORM TRAM TRESTLE, AND LOADING PLATFORM, LOOKING SOUTHWEST. THE HOLE IN THE ORE BIN FLOOR CAN BE SEEN, AND BALL MILL FOUNDATION AT LOWER LEFT CORNER. SEE CA-291-13 FOR IDENTICAL B&W NEGATIVE. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bech, H.; Haugsen, P.B.

The Norwegian Oil Company, Saga Petroleum a.s., is operator on two promising deep water blocks in the Norwegian sector of the North Sea. As a result, the company has introduced a new platform concept designed specifically for hostile and deep water areas. The platform idea is the result of a systematic innovation procedure. The first step was to analyze and describe the functions of the different structural elements on a general basis. Next was to analyze how these elements contributed to the total concept. The final development stage was to create a new solution. The resulting (hybrid platform design conceptmore » appears to offer a number of inherent deck layout and towout deck weight advantages). The concrete substructure is a lower unit consisting of a foundation with concrete skirts that will penetrate the soft soil in the seabed and a high concrete caisson extending up from the foundation, which is made up of seven cells with varying concrete thicknesses, terminating in domes. The upper steel platform section is a lattice-type jacket structure. There is a separate column for internal personnel access between the platform deck and the concrete caisson.« less

Waste management practices in the Gulf of Suez - Egypt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghzaly, S.M.; Binegar, J.S.

1996-12-31

The Gulf of Suez Petroleum Company (GUPCO) is the largest offshore oil producing company in Egypt. GUPCO currently produces 400,000 BOPD from over 350 wells supported by 87 offshore producing platforms. As a leader of the Egyptian petroleum industry, GUPCO established within its strategies and goals a separate category covering safety, health and Protection of the environment. This step was recognized and emphasized the importance of GUPCO`s role in protecting the Egyptian environment while producing oil and natural gas. This paper discusses the existing waste management practices of the Gulf of Suez Petroleum Company which were put into place tomore » protect the Egyptian environment in the Gulf of Suez-Egypt and GUPCO`s associated operations.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Childers, M.; Barnes, J.

The phased field development of the Lion and Panthere fields, offshore the Ivory Coast, includes a small floating production, storage, and offloading (FPSO) tanker with minimal processing capability as an early oil production system (EPS). For the long-term production scheme, the FPSO will be replaced by a converted jack up mobile offshore production system (MOPS) with full process equipment. The development also includes guyed-caisson well platforms, pipeline export for natural gas to fuel an onshore power plant, and a floating storage and offloading (FSO) tanker for oil export. Pipeline export for oil is a future possibility. This array of innovativemore » strategies and techniques seldom has been brought together in a single project. The paper describes the development plan, early oil, jack up MOPS, and transport and installation.« less

Collating science-based evidence to inform public opinion on the environmental effects of marine drilling platforms in the Mediterranean Sea.

PubMed

Mangano, M C; Sarà, G

2017-03-01

The use of rigorous methodologies to assess environmental, social and health impacts of specific interventions is crucial to disentangle the various components of environmental questions and to inform public opinion. The power of systematic maps relies on the capacity to summarise and organise the areas or relationships most studied, and to highlight key gaps in the evidence base. The recent Italian technical referendum (2016) - a public consultation inviting people to express their opinion by voting to change the rules on the length of licence duration and the decommissioning of offshore oil and gas platform drilling licences - inspired the creation of a systematic map of evidence to scope and quantify the effects of off-shore extraction platforms on Mediterranean marine ecosystems. The map was aimed as a useful model to standardise a "minimal informational threshold", which can inform public opinion at the beginning of any public consultation. Produced by synthesising scientific information, the map represents a reliable layer for any future sustainable strategy in the Mediterranean basin by: (i) providing a summary of the effects of marine gas and oil platforms on the Mediterranean marine ecosystem, (ii) describing the best known affected components on which the biggest monitoring efforts have been focused, and (iii) strengthening the science-policy nexus by offering a credible, salient and legitimate knowledge baseline to both public opinion and decision-makers. The map exercise highlights the knowledge gaps that need filling and taking into due consideration before future transnational and cross-border monitoring and management plans and activities can be addressed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Friction Stir Weld System for Welding and Weld Repair

NASA Technical Reports Server (NTRS)

Ding, R. Jeffrey (Inventor); Romine, Peter L. (Inventor); Oelgoetz, Peter A. (Inventor)

2001-01-01

A friction stir weld system for welding and weld repair has a base foundation unit connected to a hydraulically controlled elevation platform and a hydraulically adjustable pin tool. The base foundation unit may be fixably connected to a horizontal surface or may be connected to a mobile support in order to provide mobility to the friction stir welding system. The elevation platform may be utilized to raise and lower the adjustable pin tool about a particular axis. Additional components which may be necessary for the friction stir welding process include back plate tooling, fixturing and/or a roller mechanism.

Airborne Platforms for Emergency Communications and Reconnaissance in Domestic Disaster Response

DTIC Science & Technology

2010-04-01

primarily focused in the areas of tourism , port operations, and educational services. 3 Telecommunications are foundational in our nation’s...concerted effort to successfully integrate these airborne platforms into domestic disaster response operations must be undertaken, or we are doomed to

Performance of hydraulic fracturing and matrix acidizing in horizontal wellbores -- Offshore Qatar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwards, M.G.R.; Pongratz, R.

Considerable debate in the Middle East has centered upon what was previously felt to be two separate methods of enhancing revenues and daily production; hydraulic fracturing and horizontal drilling. In an effort to maximize return on investment, these two issues have been successfully combined in other areas of the world. In order to establish the suitability of this technology in this area, two horizontal wells with over 3,050m (10,000ft) of lateral section were drilled into the Cretaceous Kharaib formation, overlying the North Field, Offshore Qatar. A massive stimulation program was performed in order to evaluate the most feasible stimulation methodmore » from both a technical and economical perspective for further field development considerations.Three propped hydraulic fracturing treatments were performed using 183, 500kg (403, 700lb) of 20/40 mesh sand, and seventeen acid matrix treatments placing over 3,217,250l (850,000gals) of HCL into the lateral sections of both wells. This paper describes the performance, operation and logistical support required to complete this offshore operation with join a minimal time frame. The use of a mobile offshore jack-up platform, whereby a land based fracturing spread was placed onto the deck of a converted drilling rig is described.« less

Update on GPS-Acoustics Measurements on the Continental Slope of the Cascadia Subduction Zone

NASA Astrophysics Data System (ADS)

Chadwell, C. D.

2017-12-01

Land-based GPS measurements suggest the megathrust is locked offshore along the Cascadia Subduction Zone. However, land-based data alone lack geometric resolution to constrain the how the slip is distributed. GPS-Acoustic measurements can provide these constraints, but using traditional GPS-Acoustic approaches employing a ship is costly. Wave Gliders, a wave- and solar-powered, remotely-piloted sea surface platform, provide a low cost method for collecting GPS-A data. We have adapted GPS-Acoustic technology to the Wave Glider and in 2016 began annual measurements at three sites in the Cascadia Subduction Zone (CSZ). Here, we review positioning results collected during summer 2017 at two sites on the continental slope of the Cascadia Subduction Zone: One site is approximately 45 NM offshore central Oregon and the other approximately 50 NM offshore central Washington State. A third site is approximately 90 NM offshore central Oregon on the incoming Juan de Fuca plate. We will report on initial results of the GPS-A data collection and operational experiences of the missions in 2016 and 2017. Wave Glider based GPS-A measurement have the potential to significantly increase the number and frequency of measurements of strain accumulation in Cascadia Subduction Zone and elsewhere.

Light, Compact Pumper for Harbor Fires

NASA Technical Reports Server (NTRS)

Burns, R. A.

1983-01-01

Report describes development of new transportable water-pumping unit for fire-fighting. Compact, self-contained unit provides fire protection at coastal and inland ports and is lighter than standard firetruck pumper of same capacity. Used to fight fires in harbors, cities, forests, refineries, chemical plants, and offshore drilling platforms. Other possible applications include cleaning up oilspills, pumping out ships, and flood control pumping.

30 CFR 250.108 - What requirements must I follow for cranes and other material-handling equipment?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What requirements must I follow for cranes and... follow for cranes and other material-handling equipment? (a) All cranes installed on fixed platforms must... Maintenance of Offshore Cranes (API RP 2D), incorporated by reference as specified in 30 CFR 250.198. (b) All...

Interference evaluation between manifold and wet Christmas tree CP systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brasil, S.L.D.C.; Baptista, W.

2000-05-01

Offshore production wells are controlled by valves installed in the marine soil, called wet Christmas trees (WCTs). A manifold receives the production of several wells and transports it to the platform. The manifold is cathodically protected by Al anodes and the WCT by Zn anodes. A computer simulation was carried out to evaluate the interference between the equipment cathodic protection systems.

An Assessment of Wave and Wind Data for Use in Design of Tension Leg Platforms - U.S. Offshore Areas.

DTIC Science & Technology

1984-07-01

level crossing rate equations first developed by Rice are commonly employed, reference 4. If one assumes that the wave height variance spectrum is...wave photo was kindly furnished by Mr. Dillard Hammett of SEDCO, Inc. : "The photo was taken in November, 1982. The location was the Ekofisk Field

Novel Atmospheric and Sea State Modeling in Ocean Energy Applications

NASA Astrophysics Data System (ADS)

Kallos, George; Galanis, George; Kalogeri, Christina; Larsen, Xiaoli Guo

2013-04-01

The rapidly increasing use of renewable energy sources poses new challenges for the research and technological community today. The integration of the, usually, highly variable wind and wave energy amounts into the general grid, the optimization of energy transition and the forecast of extreme values that could lead to instabilities and failures of the system can be listed among them. In the present work, novel methodologies based on state of the art numerical wind/wave simulation systems and advanced statistical techniques addressing such type of problems are discussed. In particular, extremely high resolution modeling systems simulating the atmospheric and sea state conditions with spatial resolution of 100 meters or less and temporal discretization of a few seconds are utilized in order to simulate in the most detailed way the combined wind-wave energy potential at offshore sites. In addition, a statistical analysis based on a variety of mean and variation measures as well as univariate and bivariate probability distributions is used for the estimation of the variability of the power potential revealing the advantages of the use of combined forms of energy by offshore platforms able to produce wind and wave power simultaneously. The estimation and prediction of extreme wind/wave conditions - a critical issue both for site assessment and infrastructure maintenance - is also studied by means of the 50-year return period over areas with increased power potential. This work has been carried out within the framework of the FP7 project MARINA Platform (http://www.marina-platform.info/index.aspx).

30 CFR 250.905 - How do I get approval for the installation, modification, or repair of my platform?

Code of Federal Regulations, 2013 CFR

2013-07-01

... foundations; drilling, production, and pipeline risers and riser tensioning systems; turrets and turret-and... component design; pile foundations; drilling, production, and pipeline risers and riser tensioning systems... Loads imposed by jacket; decks; production components; drilling, production, and pipeline risers, and...

30 CFR 250.905 - How do I get approval for the installation, modification, or repair of my platform?

Code of Federal Regulations, 2014 CFR

2014-07-01

... foundations; drilling, production, and pipeline risers and riser tensioning systems; turrets and turret-and... component design; pile foundations; drilling, production, and pipeline risers and riser tensioning systems... Loads imposed by jacket; decks; production components; drilling, production, and pipeline risers, and...

Borehole Breakout Derived Constraints on Stress Regimes in the Santa Barbara Channel, Offshore Southern California

NASA Astrophysics Data System (ADS)

Pritchard, E. H.; Persaud, P.; Stock, J. M.

2017-12-01

The Santa Barbara Channel is an E-W trending marine basin that serves as the southern extension of the Western Transverse Ranges block. Several active, E-W trending en echelon fault systems exist beneath the Channel with both N and S dips. These control a series of tight, asymmetric anticlinal folds along the North Channel and Mid-Channel regions. Although controversial, recent models have suggested that these systems are capable of producing large magnitude, tsunamigenic earthquakes. Not controversial, however, is the fact that further knowledge of the stress regime related to these systems would greatly contribute to our understanding of a potential rupture along them. In this study, oriented 4-arm caliper well log data obtained from industry are used to determine the orientations of stress induced shear failures along well bore walls, called borehole breakouts, beneath two offshore drill platforms in the Santa Barbara Channel. Analysis of breakout orientations along 18 differently oriented, highly deviated wells allows for constraint of the current in situ stress regime beneath each of the platforms. The best-fit stress regime can then be used to inform the nature of slip along nearby faults, many of which are blind and display no surface indications of slip. At the Holly platform, located roughly 19 km west of Santa Barbara, and proximate to the Pitas Point, North Channel, and Red Mountain fault systems, lower hemisphere polar projections of breakout orientations in deviated well sections indicate a mainly thrust faulting stress regime, although a strike-slip component is not currently excluded. At the Gail platform, located midway between Ventura and Santa Cruz Island, and proximate to the Western Deep Fault, polar projections of breakouts indicate that a predominantly thrust faulting stress regime also exists beneath this platform. However, a few inconsistencies in the breakout orientations at each platform suggest variability in the stress regime, leading to the hypothesis that the stress field beneath these regions may change with depth, from a shallow degenerate-like thrust faulting stress state, with the horizontal principal stresses roughly equal in magnitude yet greater than the vertical principal stress (SH = Sh > Sv), to a deeper, less degenerate regime.

Effects of Second-Order Hydrodynamics on a Semisubmersible Floating Offshore Wind Turbine: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bayati, I.; Jonkman, J.; Robertson, A.

2014-07-01

The objective of this paper is to assess the second-order hydrodynamic effects on a semisubmersible floating offshore wind turbine. Second-order hydrodynamics induce loads and motions at the sum- and difference-frequencies of the incident waves. These effects have often been ignored in offshore wind analysis, under the assumption that they are significantly smaller than first-order effects. The sum- and difference-frequency loads can, however, excite eigenfrequencies of the system, leading to large oscillations that strain the mooring system or vibrations that cause fatigue damage to the structure. Observations of supposed second-order responses in wave-tank tests performed by the DeepCwind consortium at themore » MARIN offshore basin suggest that these effects might be more important than originally expected. These observations inspired interest in investigating how second-order excitation affects floating offshore wind turbines and whether second-order hydrodynamics should be included in offshore wind simulation tools like FAST in the future. In this work, the effects of second-order hydrodynamics on a floating semisubmersible offshore wind turbine are investigated. Because FAST is currently unable to account for second-order effects, a method to assess these effects was applied in which linearized properties of the floating wind system derived from FAST (including the 6x6 mass and stiffness matrices) are used by WAMIT to solve the first- and second-order hydrodynamics problems in the frequency domain. The method has been applied to the OC4-DeepCwind semisubmersible platform, supporting the NREL 5-MW baseline wind turbine. The loads and response of the system due to the second-order hydrodynamics are analysed and compared to first-order hydrodynamic loads and induced motions in the frequency domain. Further, the second-order loads and induced response data are compared to the loads and motions induced by aerodynamic loading as solved by FAST.« less

Subsea pipeline isolation systems: Reliability and costs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masheder, R.R.

1995-12-31

On the night of 6/7 July 1988 a major oil production platform known as Piper Alpha in the UK sector of the North Sea was destroyed by explosion and fire, with the loss of 167 lives. This led to the appointment of Lord Cullen, a senior Scottish Judge, to hold a Public Inquiry into the Piper Alpha Disaster. The Cullen Enquiry Report consisting of 23 chapters set out in 2 volumes, was published on 12 November 1990. One of the important conclusions drawn by Lord Cullen resulted in a recommendation for studies to be conducted to consider ways of improvingmore » the reliability and reducing the costs of SSIVs (Subsea Isolation Valves) so that it is more often reasonably practicable to install them. To address the Cullen recommendations, a joint industry study was conducted by UKOOA (United Kingdom Offshore Operators Association) and the HSE/OSD (Health and Safety Executive Offshore Safety Division) in conjunction with independent consultants. The results of the studies and the conclusions drawn by UKOOA Pipeline Valve Group and the HSE Offshore Safety Division are presented in this paper.« less

Simulation of a weather radar display for over-water airborne radar approaches

NASA Technical Reports Server (NTRS)

Clary, G. R.

1983-01-01

Airborne radar approach (ARA) concepts are being investigated as a part of NASA's Rotorcraft All-Weather Operations Research Program on advanced guidance and navigation methods. This research is being conducted using both piloted simulations and flight test evaluations. For the piloted simulations, a mathematical model of the airborne radar was developed for over-water ARAs to offshore platforms. This simulated flight scenario requires radar simulation of point targets, such as oil rigs and ships, distributed sea clutter, and transponder beacon replies. Radar theory, weather radar characteristics, and empirical data derived from in-flight radar photographs are combined to model a civil weather/mapping radar typical of those used in offshore rotorcraft operations. The resulting radar simulation is realistic and provides the needed simulation capability for ongoing ARA research.

Oil and Water Don't Mix: The Gulf Coast Oil Disaster as a Preschool Social Studies Lesson

ERIC Educational Resources Information Center

Kruse, Tricia

2010-01-01

On April 20, 2010, an offshore oil-drilling platform exploded, spilling millions of gallons of oil into the gulf. From Louisiana to the Gulf Coast of Florida the effects are being felt by fisherman, shrimpers, dive charters, and other hardworking folks who depend on the water for their livelihood. But there is another population in these coastal…

Real-time simulation of an airborne radar for overwater approaches

NASA Technical Reports Server (NTRS)

Karmarkar, J.; Clark, D.

1982-01-01

Software developed to provide a real time simulation of an airborne radar for overwater approaches to oil rig platforms is documented. The simulation is used to study advanced concepts for enhancement of airborne radar approaches (ARA) in order to reduce crew workload, improve approach tracking precision, and reduce weather minimums. ARA's are currently used for offshore helicopter operations to and from oil rigs.

78 FR 38031 - Application for Final Commitment for a Long-Term Loan or Financial Guarantee in Excess of $100...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-25

... Petroquimica Basica. Description of Items Being Exported: Drilling rigs, platform rentals, compressors, oil... U.S. goods and services from U.S. small businesses to be used in its oil and gas projects. Brief non...'s on- and off-shore oil and gas exploration and production areas. To the extent that Ex-Im Bank is...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jardinier, R.C.; Bouger, Y.; Boisard, P.

Two pre-drilling templates were successfully installed offshore from Congo in a water depth of 170 meters at the end of September 1993. They are the first structures to use the suction foundation concept on the continental shelf of Western Africa, although the same concept has been used by other operators especially in the North Sea. Docking of jackets over these templates is expected in spring 1995. A general description of the construction and installation of these templates is presented herein.

Cell Motility and Invasiveness of Neurofibromin-Deficient Neural Crest Cells and Malignant Triton Tumor Lines. Addendum

DTIC Science & Technology

2006-06-01

Tumor Foundation, Molecular Biology of NF1, NF2, and Schwannomatosis Meeting, poster presentation. "A mild mutator phenotype arises in NF1-associated...malignancies" June 2006: Children’s Tumor Foundation, Molecular Biology of NF1, NF2, and Schwannomatosis Meeting, platform presentation. “DNA

Meals on Wheels? A Decade of Megafaunal Visual and Acoustic Observations from Offshore Oil & Gas Rigs and Platforms in the North and Irish Seas.

PubMed

Todd, Victoria Louise Georgia; Warley, Jane Clare; Todd, Ian Boyer

2016-01-01

A decade of visual and acoustic detections of marine megafauna around offshore Oil & Gas (O&G) installations in the North and Irish Seas are presented. Marine megafauna activity was monitored visually and acoustically by Joint Nature Conservation Committee (JNCC) qualified and experienced Marine Mammal Observers (MMO) and Passive Acoustic Monitoring (PAM) Operators respectively, with real-time towed PAM in combination with industry standard software, PAMGuard. Monitoring was performed during routine O&G industrial operations for underwater noise mitigation purposes, and to ensure adherence to regulatory guidelines. Incidental sightings by off-effort MMOs and installation crew were also reported. Visual and acoustic monitoring spanned 55 non-consecutive days between 2004 and 2014. A total of 47 marine mammal sightings were recorded by MMOs on dedicated watch, and 10 incidental sightings of marine megafauna were reported over 10 years. Species included: harbour porpoise (Phocoena phocoena), Atlantic white-sided dolphin (Lagenorhynchus acutus), white beaked dolphin (Lagenorhynchus albirostris), common dolphin (Delphinus delphis), minke whale (Balaenoptera acutorostrata), common seal (Phoca vitulina), grey seal (Halichoerus grypus) and, basking shark (Cetorhinus maximus). Passive Acoustic Monitoring was conducted on two occasions in 2014; 160 PAM hours over 12 days recorded a total of 308 individual clicks identified as harbour porpoises. These appear to be the first such acoustic detections obtained from a North Sea drilling rig whilst using a typically configured hydrophone array designed for towing in combination with real-time PAMGuard software. This study provides evidence that marine megafauna are present around mobile and stationary offshore O&G installations during routine operational activities. On this basis, Environmental Impact Assessments (EIAs) for decommissioning O&G platforms should be carried-out on a case-by-case basis, and must include provisions for hitherto overlooked marine megafauna.

A database of archived drilling records of the drill cuttings piles at the North West Hutton oil platform.

PubMed

Marsh, Roy

2003-05-01

Drill cuttings piles are found underneath several hundred oil platforms in the North Sea, and are contaminated with hydrocarbons and chemical products. This study characterised the environmental risk posed by the cuttings pile at the North West Hutton (NWH) oil platform. Data on the drilling fluids and chemical products used over the platform's drilling history were transferred from archived well reports into a custom database, to which were added toxicological and safety data. Although the database contained many gaps, it established that only seven chemical products used at NWH were not in the lowest category of the Offshore Chemicals Notification Scheme, and were used in only small quantities. The study therefore supports the view that the main environmental risk posed by cuttings piles comes from hydrocarbon contamination. The (dated) well records could help future core sampling to be targeted at specific locations in the cuttings piles. Data from many platforms could also be pooled to determine generic 'discharge profiles.' Future study would benefit from the existence, in the public domain, of a standardised, 'legacy' database of chemical products.

Explosives remain preferred methods for platform abandonment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pulsipher, A.; Daniel, W. IV; Kiesler, J.E.

1996-05-06

Economics and safety concerns indicate that methods involving explosives remain the most practical and cost-effective means for abandoning oil and gas structures in the Gulf of Mexico. A decade has passed since 51 dead sea turtles, many endangered Kemp`s Ridleys, washed ashore on the Texas coast shortly after explosives helped remove several offshore platforms. Although no relationship between the explosions and the dead turtles was ever established, in response to widespread public concern, the US Minerals Management Service (MMS) and National Marine Fisheries Service (NMFS) implemented regulations limiting the size and timing of explosive charges. Also, more importantly, they requiredmore » that operators pay for observers to survey waters surrounding platforms scheduled for removal for 48 hr before any detonations. If observers spot sea turtles or marine mammals within the danger zone, the platform abandonment is delayed until the turtles leave or are removed. However, concern about the effects of explosives on marine life remains.« less

Seepage investigation using geophysical techniques at Coursier Lake Dam, B.C., Canada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sirles, P.

1997-10-01

Subsurface seepage flow at Coursier Lake Dam was identified by onshore and offshore self-potential surveys, and electrical resistivity profiles and soundings during a Deficiency Investigation by BChydro. For typical seepage investigations baseline geophysical data are collected at {open_quotes}low-pool{close_quotes} level and the measurements are repeated when high hydraulic gradient conditions exist. At Coursier Lake Dam a rather unanticipated outcome of the low-pool surveys was that significant seepage beneath the structure was detected. The low-pool results were conclusive enough that, when combined with visual inspection and observation of sinkholes on the embankment, an immediate restriction was placed on the pool elevation. Thus,more » because of the identified potential hazard, the remaining geophysical investigations were conducted under a {open_quotes}minimum-pool{close_quotes} reservoir level in order to complete the comparative study. Therefore, the dam was studied under low- and minimum-pool reservoir conditions in the spring and fall of 1993, respectively. Low-pool data indicated very high resistivities (3000 to 5000 ohm-m) throughout the embankment indicating a coarse-average grain size, probably unsaturated sands and gravels. Higher resistivities (>5000 ohm-m) were obtained within the foundation deposits along the downstream toe indicating a combination of lower moisture content, coarser average grain size and higher porosity than the embankment. These electrical data indicate the subsurface conditions in the embankment and the foundation to be conducive to seepage. Results from low-pool SP surveys, performed both on-shore and offshore, indicate a dispersed or sheet flow seepage occurring nearly 1100 feet upstream of the intake. Therefore, apparently the seepage source begins far upstream of the embankment within the foundation deposits.« less

Analysis of unsteady flow over Offshore Wind Turbine in combination with different types of foundations

NASA Astrophysics Data System (ADS)

Alesbe, Israa; Abdel-Maksoud, Moustafa; Aljabair, Sattar

2017-06-01

Environmental effects have an important influence on Offshore Wind Turbine (OWT) power generation efficiency and the structural stability of such turbines. In this study, we use an in-house Boundary Element (BEM)— panMARE code—to simulate the unsteady flow behavior of a full OWT with various combinations of aerodynamic and hydrodynamic loads in the time domain. This code is implemented to simulate potential flows for different applications and is based on a three-dimensional first-order panel method. Three different OWT configurations consisting of a generic 5 MW NREL rotor with three different types of foundations (Monopile, Tripod, and Jacket) are investigated. These three configurations are analyzed using the RANSE solver which is carried out using ANSYS CFX for validating the corresponding results. The simulations are performed under the same environmental atmospheric wind shear and rotor angular velocity, and the wave properties are wave height of 4 m and wave period of 7.16 s. In the present work, wave environmental effects were investigated firstly for the two solvers, and good agreement is achieved. Moreover, pressure distribution in each OWT case is presented, including detailed information about local flow fields. The time history of the forces at inflow direction and its moments around the mudline at each OWT part are presented in a dimensionless form with respect to the mean value of the last three loads and the moment amplitudes obtained from the BEM code, where the contribution of rotor force is lower in the tripod case and higher in the jacket case and the calculated hydrodynamic load that effect on jacket foundation type is lower than other two cases.

The offshore petroleum industry: The formative years, 1945-1962

NASA Astrophysics Data System (ADS)

Kreidler, Tai Deckner

1997-12-01

This dissertation is the first to examine the offshore oil industry that was born in the calm waters of the Gulf of Mexico. It describes the industry's origins and tracks its development as a consequence of a search for new oil frontiers. In addition, it elaborates how the oil industry moved into the marine province using available technology, and was driven by the economic urgency to compete and develop new territories. Enterprising drilling contractors and operators seized the offshore gamble, finding it possible to lower the economic and technological threshold by drawing directly from wartime research and surplus equipment. Though large oil companies had placed its indelible stamp upon the industry, the smaller, independent oil operators set the pace of early offshore development. As a technological frontier, offshore development depended upon creative and unconventional engineering. Unfamiliar marine conditions tested the imagination of oil industry engineering. The unorthodox methods of John Hayward of Barnsdall Oil and R. G. LeTourneau of LeTourneau, Inc. among others transformed the industry by blending petroleum and marine engineering. Grappling with alien marine conditions and lacking formal training, Hayward and LeTourneau merged a century of practical oil field knowledge and petroleum engineering with 2,000 years of shipbuilding experience. The Gulf of Mexico served as a fertile and protective environment for the development of a fledgling industry. With calm waters, lacking the tempestuous and stormy character of the Atlantic Ocean, with a gradual sea-floor slope and saturated with the highly productive salt dome reservoirs, the Gulf became the birth place of the modern offshore oil industry. Within its protective sphere, companies experimented and developed various technical and business adaptations. Operators used technology and business strategies that increased the opportunity for success. In addition, regional academic research institutes arose as a response to increasing work done for the offshore industry. Academic areas that developed included oceanography, physical oceanography, marine biology, marine geology, meteorology, and weather forecasting, During the formative era that ended in the late 1950s the industry had formed its technological and economic foundation in the Gulf, and stood poised to seize the initiative in the North Sea, the Middle East, the Far East, and Indonesia.

Gis-Based Wind Farm Site Selection Model Offshore Abu Dhabi Emirate, Uae

NASA Astrophysics Data System (ADS)

Saleous, N.; Issa, S.; Mazrouei, J. Al

2016-06-01

The United Arab Emirates (UAE) government has declared the increased use of alternative energy a strategic goal and has invested in identifying and developing various sources of such energy. This study aimed at assessing the viability of establishing wind farms offshore the Emirate of Abu Dhabi, UAE and to identify favourable sites for such farms using Geographic Information Systems (GIS) procedures and algorithms. Based on previous studies and on local requirements, a set of suitability criteria was developed including ocean currents, reserved areas, seabed topography, and wind speed. GIS layers were created and a weighted overlay GIS model based on the above mentioned criteria was built to identify suitable sites for hosting a new offshore wind energy farm. Results showed that most of Abu Dhabi offshore areas were unsuitable, largely due to the presence of restricted zones (marine protected areas, oil extraction platforms and oil pipelines in particular). However, some suitable sites could be identified, especially around Delma Island and North of Jabal Barakah in the Western Region. The environmental impact of potential wind farm locations and associated cables on the marine ecology was examined to ensure minimal disturbance to marine life. Further research is needed to specify wind mills characteristics that suit the study area especially with the presence of heavy traffic due to many oil production and shipping activities in the Arabian Gulf most of the year.

The Ocean Observatories Initiative: Getting Wet Behind the Ears

NASA Astrophysics Data System (ADS)

Given, H. K.; Banahan, S.

2007-12-01

The U.S. National Science Foundation's Ocean Observatories Initiative (OOI) is constructing an integrated network to provide the oceanographic research and education communities with continuous, interactive access to the oceans. The program will build permanent science-focused infrastructure that will enable geoscientists to simultaneously study multiple phenomena in the oceans over time scales from milliseconds to decades, and over spatial scales from sub-meter to global. An integrative computer architecture or cyberinfrastructure will allow researchers to communicate with and configure globally situated experiments in near-real time, forming virtual observatories by designing customized data streams readily incorporated into adaptive models. The project, approved for planning activities by the National Science Board in 2000, will undergo its Preliminary Design Review for readiness in December 2007 and is expected to receive the first installment of a total anticipated capital investment of $330M in 2008. Specific assets include autonomous platforms at high-latitude sites in the northern and southern hemispheres, a submarine ackbone cable spanning the seafloor of the Juan de Fuca tectonic plate, and moorings and mobile assets studying the coastal ocean continental shelf and slope in the Middle Atlantic Bight and offshore the Pacific Northwest. With its global dimension and unifying cyberinfrastructure, the OOI is expected to catalyze new understanding of the oceans in a way that ship-based measurements and experiments, with their shorter observation window and inherent limitations on power and bandwidth, are unable to accomplish.

Underwater Nondestructive Testing of Ship Hull Welds

DTIC Science & Technology

1979-09-01

Norske Veritas. 5. Alan Taylor , Underwater Testing, Marine rechnology (Germany) Dec 1971, pp. 251-2. 6. Ship Underwater Maintenance, Evaluation and Repair...11. Peters, V. "NDT for Offshore Drilling Platform Structure," Welding end Metal Fabricatior, Jul 1973, V. 41-7. 12. Taylor , A., "Underwater...N. Cordea, Chairman, Senior Staff MetalZlugiet, ARMCO INC., Middletown, OH Mr. W. C. Brayton , Aset. to Gener•l Manager, Bethlehem Steel Corp

Mobile Launch Platform (MLP) Environmental Assessment

DTIC Science & Technology

2004-06-28

Sometimes these winds are interrupted by cool seasonal storms with southerly winds; dry offshore storms with southeasterly winds, called Santa Ana...winds; coastal eddies during the warm season with southeasterly winds over the inner waters; and alternating land and sea breezes that occur closer to...mean temperature of 14 oC (58 oF). Total annual precipitation averages 21.3 centimeters (8.4 inches). The dry season ranges from May to September and

Full load shop testing of 18,000-hp gas turbine driven centrifugal compressor for offshore platform service: Evaluation of rotor dynamics performance

NASA Technical Reports Server (NTRS)

Kirk, R. G.; Simpson, M.

1985-01-01

The results for in-plant full load testing of a 13.4 MW (18000 HP) gas turbine driven centrifugal compressor are presented and compared to analytical predictions of compressor rotor stability. Unique problems from both oil seals and labyrinth gas seals were encountered during the testing. The successful resolution of these problems are summarized.

Environmental impacts of produced water and drilling waste discharges from the Norwegian offshore petroleum industry.

PubMed

Bakke, Torgeir; Klungsøyr, Jarle; Sanni, Steinar

2013-12-01

Operational discharges of produced water and drill cuttings from offshore oil and gas platforms are a continuous source of contaminants to continental shelf ecosystems. This paper reviews recent research on the biological effects of such discharges with focus on the Norwegian Continental Shelf. The greatest concern is linked to effects of produced water. Alkylphenols (AP) and polyaromatic hydrocarbons (PAH) from produced water accumulate in cod and blue mussel caged near outlets, but are rapidly metabolized in cod. APs, naphtenic acids, and PAHs may disturb reproductive functions, and affect several chemical, biochemical and genetic biomarkers. Toxic concentrations seem restricted to <2 km distance. At the peak of discharge of oil-contaminated cuttings fauna disturbance was found at more than 5 km from some platforms, but is now seldom detected beyond 500 m. Water-based cuttings may seriously affect biomarkers in filter feeding bivalves, and cause elevated sediment oxygen consumption and mortality in benthic fauna. Effects levels occur within 0.5-1 km distance. The stress is mainly physical. The risk of widespread, long term impact from the operational discharges on populations and the ecosystem is presently considered low, but this cannot be verified from the published literature. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Ocean products delivered by the Mercator Ocean Service Department

NASA Astrophysics Data System (ADS)

Crosnier, L.; Durand, E.; Soulat, F.; Messal, F.; Buarque, S.; Toumazou, V.; Landes, V.; Drevillon, M.; Lellouche, J.

2008-12-01

The newly created Service Department at Mercator Ocean is now offering various services for academic and private ocean applications. Mercator Ocean runs operationally ocean forecast systems for the Global and North Atlantic Ocean. These systems are based on an ocean general circulation model NEMO as well as on data assimilation of sea level anomalies, sea surface temperature and temperature and salinity vertical profiles. Three dimensional ocean fields of temperature, salinity and currents are updated and available weekly, including analysis and 2 weeks forecast fields. The Mercator Ocean service department is now offering a wide range of ocean derived products. This presentation will display some of the various products delivered in the framework of academic and private ocean applications: " Monitoring of the ocean current at the surface and at depth in several geographical areas for offshore oil platform, for offshore satellite launch platform, for transatlantic sailing or rowing boat races. " Monitoring of ocean climate indicators (Coral bleaching...) for marine reserve survey; " Monitoring of upwelling systems for fisheries; " Monitoring of the ocean heat content for tropical cyclone monitoring. " Monitoring of the ocean temperature/salinity and currents to guide research vessels during scientific cruises. The Mercator Ocean products catalogue will grow wider in the coming years, especially in the framework of the European GMES MyOcean project (FP7).

Concept design and coupled dynamic response analysis on 6-MW spar-type floating offshore wind turbine

NASA Astrophysics Data System (ADS)

Meng, Long; Zhou, Tao; He, Yan-ping; Zhao, Yong-sheng; Liu, Ya-dong

2017-10-01

Tower, Spar platform and mooring system are designed in the project based on a given 6-MW wind turbine. Under wind-induced only, wave-induced only and combined wind and wave induced loads, dynamic response is analyzed for a 6-MW Spar-type floating offshore wind turbine (FOWT) under operating conditions and parked conditions respectively. Comparison with a platform-fixed system (land-based system) of a 6-MW wind turbine is carried out as well. Results demonstrate that the maximal out-of-plane deflection of the blade of a Spar-type system is 3.1% larger than that of a land-based system; the maximum response value of the nacelle acceleration is 215% larger for all the designed load cases being considered; the ultimate tower base fore-aft bending moment of the Spar-type system is 92% larger than that of the land-based system in all of the Design Load Cases (DLCs) being considered; the fluctuations of the mooring tension is mainly wave-induced, and the safety factor of the mooring tension is adequate for the 6-MW FOWT. The results can provide relevant modifications to the initial design for the Spar-type system, the detailed design and model basin test of the 6-MW Spar-type system.

Late Quaternary uplift rate across the Shimokita peninsula, northeastern Japan forearc

NASA Astrophysics Data System (ADS)

Matsu'Ura, T.

2009-12-01

I estimated the late Quaternary uplift rate across the northeastern Japan forearc (Shimokita peninsula) by using the height distribution of MIS 5.5 marine terraces as determined from tephra and cryptotephra stratigraphy. The heights of inner-margins (shoreline angles) of the MIS 5.5 marine terrace surface were previously reported to be 43-45 m and 30 m around Shiriyazaki and Gamanosawa, respectively. These heights decrease westward and are possibly due to a west-dipping offshore fault. But in some places, the heights of terrace inner-margins are probably overestimated by thick sediments. I found the MIS 5.5 wave-cut platform which is overlain by gravels and loess deposits containing a basal Toya tephra horizon (MIS 5.4) at Shiriyazaki by boring. The MIS 5.5 wave-cut platform (paleo sea level) is about 25 m above sea level, nearly half of the reported height of the terrace inner-margin. My result shows that the late Quaternary uplift rate across the Shimokita peninsula should be reconsidered. Further studies are also required whether or not the intra-plate (offshore) fault is a factor of the forearc uplifting at the peninsula. This research project has been conducted under the research contract with Nuclear and Industrial Safety Agency (NISA).

Optimisation and evaluation of pre-design models for offshore wind turbines with jacket support structures and their influence on integrated load simulations

NASA Astrophysics Data System (ADS)

Schafhirt, S.; Kaufer, D.; Cheng, P. W.

2014-12-01

In recent years many advanced load simulation tools, allowing an aero-servo-hydroelastic analyses of an entire offshore wind turbine, have been developed and verified. Nowadays, even an offshore wind turbine with a complex support structure such as a jacket can be analysed. However, the computational effort rises significantly with an increasing level of details. This counts especially for offshore wind turbines with lattice support structures, since those models do naturally have a higher number of nodes and elements than simpler monopile structures. During the design process multiple load simulations are demanded to obtain an optimal solution. In the view of pre-design tasks it is crucial to apply load simulations which keep the simulation quality and the computational effort in balance. The paper will introduce a reference wind turbine model consisting of the REpower5M wind turbine and a jacket support structure with a high level of detail. In total twelve variations of this reference model are derived and presented. Main focus is to simplify the models of the support structure and the foundation. The reference model and the simplified models are simulated with the coupled simulation tool Flex5-Poseidon and analysed regarding frequencies, fatigue loads, and ultimate loads. A model has been found which reaches an adequate increase of simulation speed while holding the results in an acceptable range compared to the reference results.

How to install platforms in tidal deltaic areas: The 25-year experience of Total in Kalimantan (Indonesia)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quenelle, A.; Metz, R.; Poirier, D.

1994-12-31

Due to the extended work by TOTAL, since 1971, offshore and within the Mahakam delta (East Kalimantan), several installation and platform concepts have been used. The present paper only concerns the installations at Handil and Tambora sites located in the Mahakam delta (in-shore) where water depths are between 2 and 4 meters, water current is 2 knots max. and tide is 2 meters as an average. The experience gained by the company in this kind of job made it possible to recently install in a single piece large and heavy integrated decks (up to 2,600 t) with the optimum usemore » of local skills, non-sophisticated technology and at low costs. The following shows the historical and evolutive experience of TOTAL up to now in platform concepts in this area of the world and gives, by the way, some useful information for future work.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lepage, A.

Despite scheduling complications caused by annual monsoons, the Yadana project to bring offshore Myanmar gas ashore and into neighboring Thailand has met it first-gas target of July 1, 1998. The Yadana field is a dry-gas reservoir in the reef upper Birman limestone formation t 1,260 m and a pressure of 174 bara (approximately 2,500 psi). It extends nearly 7 km (west to east) and 10 km (south to north). The water-saturated reservoir gas contains mostly methane mixed with CO{sub 2} and N{sub 2}. No production of condensate is anticipated. The Yadana field contains certified gas reserves of 5.7 tcf, calculatedmore » on the basis of 2D and 3D seismic data-acquisition campaigns and of seven appraisal wells. The paper discusses early interest, development sequences, offshore platforms, the gas-export pipeline, safety, environmental steps, and schedule constraints.« less

Comparison of Hydrodynamic Load Predictions Between Engineering Models and Computational Fluid Dynamics for the OC4-DeepCwind Semi-Submersible: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benitz, M. A.; Schmidt, D. P.; Lackner, M. A.

Hydrodynamic loads on the platforms of floating offshore wind turbines are often predicted with computer-aided engineering tools that employ Morison's equation and/or potential-flow theory. This work compares results from one such tool, FAST, NREL's wind turbine computer-aided engineering tool, and the computational fluid dynamics package, OpenFOAM, for the OC4-DeepCwind semi-submersible analyzed in the International Energy Agency Wind Task 30 project. Load predictions from HydroDyn, the offshore hydrodynamics module of FAST, are compared with high-fidelity results from OpenFOAM. HydroDyn uses a combination of Morison's equations and potential flow to predict the hydrodynamic forces on the structure. The implications of the assumptionsmore » in HydroDyn are evaluated based on this code-to-code comparison.« less

East Kalimantan project recovers 200 MMscfd of associated gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nacouz, E.

1984-02-06

Bekapai and Handil fields were discovered in 1972 and 1974 and in the Mahakam offshore Permit, East Kalimantan (Fig. 1). They are operated by Total Indonesie in association with Inpex under a production sharing contract with Pertamina. Oil production of the fields is about 200,000 b/d. Associated gas, until the construction of the facilities described here, were flared. Associated gas production is about 200 MMscfd. The Bekapai field is 40 km offshore in 35 m of water. The Handil field, located in the delta of the Mahakam, has a gathering system and platformmounted central process area. After a first stagemore » of separation at the Bekapai production platform and the central process area of Handil, the production of both fields is sent through pipelines to Senipah terminal onshore for final separation, processing, and storage before shipment.« less

Coastal Ohio Wind Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gorsevski, Peter; Afjeh, Abdollah; Jamali, Mohsin

The Coastal Ohio Wind Project intends to address problems that impede deployment of wind turbines in the coastal and offshore regions of Northern Ohio. The project evaluates different wind turbine designs and the potential impact of offshore turbines on migratory and resident birds by developing multidisciplinary research, which involves wildlife biology, electrical and mechanical engineering, and geospatial science. Firstly, the project conducts cost and performance studies of two- and three-blade wind turbines using a turbine design suited for the Great Lakes. The numerical studies comprised an analysis and evaluation of the annual energy production of two- and three-blade wind turbinesmore » to determine the levelized cost of energy. This task also involved wind tunnel studies of model wind turbines to quantify the wake flow field of upwind and downwind wind turbine-tower arrangements. The experimental work included a study of a scaled model of an offshore wind turbine platform in a water tunnel. The levelized cost of energy work consisted of the development and application of a cost model to predict the cost of energy produced by a wind turbine system placed offshore. The analysis found that a floating two-blade wind turbine presents the most cost effective alternative for the Great Lakes. The load effects studies showed that the two-blade wind turbine model experiences less torque under all IEC Standard design load cases considered. Other load effects did not show this trend and depending on the design load cases, the two-bladed wind turbine showed higher or lower load effects. The experimental studies of the wake were conducted using smoke flow visualization and hot wire anemometry. Flow visualization studies showed that in the downwind turbine configuration the wake flow was insensitive to the presence of the blade and was very similar to that of the tower alone. On the other hand, in the upwind turbine configuration, increasing the rotor blade angle of attack reduced the wake size and enhanced the vortices in the flow downstream of the turbine-tower compared with the tower alone case. Mean and rms velocity distributions from hot wire anemometer data confirmed that in a downwind configuration, the wake of the tower dominates the flow, thus the flow fields of a tower alone and tower-turbine combinations are nearly the same. For the upwind configuration, the mean velocity shows a narrowing of the wake compared with the tower alone case. The downwind configuration wake persisted longer than that of an upwind configuration; however, it was not possible to quantify this difference because of the size limitation of the wind tunnel downstream of the test section. The water tunnel studies demonstrated that the scale model studies could be used to adequately produce accurate motions to model the motions of a wind turbine platform subject to large waves. It was found that the important factors that affect the platform is whether the platform is submerged or surface piercing. In the former, the loads on the platform will be relatively reduced whereas in the latter case, the structure pierces the wave free surface and gains stiffness and stability. The other important element that affects the movement of the platform is depth of the sea in which the wind turbine will be installed. Furthermore, the wildlife biology component evaluated migratory patterns by different monitoring systems consisting of marine radar, thermal IR camera and acoustic recorders. The types of radar used in the project are weather surveillance radar and marine radar. The weather surveillance radar (1988 Doppler), also known as Next Generation Radar (NEXRAD), provides a network of weather stations in the US. Data generated from this network were used to understand general migratory patterns, migratory stopover habitats, and other patterns caused by the effects of weather conditions. At a local scale our marine radar was used to complement the datasets from NEXRAD and to collect additional monitoring parameters such as passage rates, flight paths, flight directions, and flight altitudes of nocturnal migrating species. Our work focused on the design and development of custom built marine radar that used t-bar and parabolic dish antennas. The marine radar used in the project was Furuno (XANK250) which was coupled with a XIR3000B digitizing card from Russell Technologies for collection of the radar data. The radar data was processed by open source radR processing software using different computational techniques and methods. Additional data from thermal IR imaging cameras were collected to detect heat emitted from objects and provide information on movements of birds and bats, data which we used for different animal flight behavior analysis. Lastly, the data from the acoustic recorders were used to provide the number of bird calls for assessing patterns and peak passage rates during migration. The development of the geospatial database included collection of different data sources that are used to support offshore wind turbine development. Many different data sets were collected and organized using initial version of web-based repository software tools that can accommodate distribution of rectified pertinent data sets such as the lake depth, lake bottom engineering parameters, extent of ice, navigation pathways, wind speed, important bird habitats, fish efforts and other layers that are relevant for supporting robust offshore wind turbine developments. Additional geospatial products developed during the project included few different prototypes for offshore wind farm suitability which can involve different stakeholders and participants for solving complex planning problems and building consensus. Some of the prototypes include spatial decision support system (SDSS) for collaborative decision making, a web-based Participatory Geographic Information System (PGIS) framework for evaluating importance of different decision alternatives using different evaluation criteria, and an Android application for collection of field data using mobile and tablet devices . In summary, the simulations of two- and three-blade wind turbines suggested that two-bladed machines could produce comparable annual energy as the three-blade wind turbines but have a lighter tower top weight, which leads to lower cost of energy. In addition, the two-blade rotor configuration potentially costs 20% less than a three blade configuration that produces the same power at the same site. The cost model analysis predicted a potential cost savings of approximately 15% for offshore two-blade wind turbines. The foundation design for a wind turbine in Lake Erie is likely to be driven by ice loads based on the currently available ice data and ice mechanics models. Hence, for Lake Eire, the cost savings will be somewhat smaller than the other lakes in the Great Lakes. Considering the size of cranes and vessels currently available in the Great Lakes, the cost optimal wind turbine size should be 3 MW, not larger. The surveillance data from different monitoring systems suggested that bird and bat passage rates per hour were comparable during heavy migrations in both spring and fall seasons while passage rates were significantly correlated to wind directions and wind speeds. The altitude of migration was higher during heavy migrations and higher over water relative to over land. Notable portions of migration on some spring nights occurred parallel the shoreline, often moving perpendicular to southern winds. The birds approaching the Western basin have a higher propensity to cross than birds approaching the Central basin of Lake Erie and as such offshore turbine development might be a better option further east towards Cleveland than in the Western basin. The high stopover density was more strongly associated with migration volume the following night rather than the preceding night. The processed mean scalar wind speeds with temporal resolutions as fine as 10-minute intervals near turbine height showed that August is the month with the weakest winds while December is the month, which typically has the strongest winds. The ice data suggests that shallow western basin of Lake Erie has higher ice cover duration many times exceeding 90 days during some winters.« less

Numerical study of a novel procedure for installing the tower and Rotor Nacelle Assembly of offshore wind turbines based on the inverted pendulum principle

NASA Astrophysics Data System (ADS)

Guachamin Acero, Wilson; Gao, Zhen; Moan, Torgeir

2017-09-01

Current installation costs of offshore wind turbines (OWTs) are high and profit margins in the offshore wind energy sector are low, it is thus necessary to develop installation methods that are more efficient and practical. This paper presents a numerical study (based on a global response analysis of marine operations) of a novel procedure for installing the tower and Rotor Nacelle Assemblies (RNAs) on bottom-fixed foundations of OWTs. The installation procedure is based on the inverted pendulum principle. A cargo barge is used to transport the OWT assembly in a horizontal position to the site, and a medium-size Heavy Lift Vessel (HLV) is then employed to lift and up-end the OWT assembly using a special upending frame. The main advantage of this novel procedure is that the need for a huge HLV (in terms of lifting height and capacity) is eliminated. This novel method requires that the cargo barge is in the leeward side of the HLV (which can be positioned with the best heading) during the entire installation. This is to benefit from shielding effects of the HLV on the motions of the cargo barge, so the foundations need to be installed with a specific heading based on wave direction statistics of the site and a typical installation season. Following a systematic approach based on numerical simulations of actual operations, potential critical installation activities, corresponding critical events, and limiting (response) parameters are identified. In addition, operational limits for some of the limiting parameters are established in terms of allowable limits of sea states. Following a preliminary assessment of these operational limits, the duration of the entire operation, the equipment used, and weather- and water depth-sensitivity, this novel procedure is demonstrated to be viable.

Offshore sand resources for coastal erosion control in Louisiana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramsey, K.E.; Penland, S.; McBride, R.A.

1990-09-01

An inventory of existing geophysical data supplemented by more than 15,000 km of high-resolution seismic profiles and 400 vibracores collected cooperatively by the Louisiana Geological Survey and US Geological Survey since 1981 indicates that a wide range of aggregate minerals occurs on the continental shelf in a variety of depositional settings. The distribution of these deposits is controlled by the geometry of the preexisting fluvial and deltaic channel systems and the stratigraphic signature of the Holocene Transgression across these features. The geology of coastal and offshore Louisiana is tied to the depositional history of the Mississippi River. Offshore of themore » delta plain, five types of aggregate sources can be identified: inner shelf shoals, submerged barrier islands, tidal inlets, distributary channels, and barrier platforms. This paper describes the geology of offshore Louisiana, the available geophysical data sets, and the distribution of aggregate mineral resources. On the continental shelf of the Mississippi River delta plain, two extensive seismic survey grids have been developed by the Louisiana Geological Survey and US Geological Survey. The most prospective resources found are the huge sand bodies of Ship Shoal and associated distributaries, Cat Island Pass tidal channels and associated tidal deltas, and Barataria Pass/Grand Terre tidal channels and associated tidal deltas. East of the mouth of the Mississippi River are the Chandeleur Islands, where LGS identified seven major sand resource targets, truncated barrier-spit and tidal inlet deposits, submerged beach ridges, and distributaries associated with abandoned St. Bernard delta complexes. Abundant sand resources can be found in offshore Louisiana. Many of the sand bodies contain heavy minerals, but their concentration and distribution is unknown. Other potential sand resources not yet adequately explored include Sabine Bank, the Outer Shoal, and the St. Bernard shoal.« less

Tidally driven pore water exchange in offshore intertidal sandbanks: Part I. Field measurements

NASA Astrophysics Data System (ADS)

Gibbes, B.; Robinson, C.; Carey, H.; Li, L.; Lockington, D.

2008-08-01

In recent years blooms of the toxic marine cyanobacteria Lyngbya majuscula have been frequently observed in a system of offshore intertidal sandbanks in Moreton Bay, Australia. Past research suggests that these blooms are linked to the presence of bio-available forms of iron. Using hydraulic and pore water chemistry data collected from a shore normal transect at an offshore bloom site, the role of tidally driven exchange as a potential mechanism for delivery of bio-available iron across the sediment-water interface was examined. Field data revealed a residual pore water flow system in the sandbank, with seawater entering the upper sandbank platform and discharging through the bank edge. Upward flow and elevated near-surface dissolved Fe(II) concentrations (>20 μM Fe(II) at -0.05 m depth) were measured simultaneously in the discharge zones at the sandbank edge. The measured concentrations were more than four times greater than concentrations previously shown to stimulate L. majuscula growth. These results suggest that the tidally driven exchange mechanism might be capable of delivering dissolved Fe(II) to sites within offshore intertidal sandbanks where blooms of L. majuscula have been observed. While the source of the iron was not identified, potential candidates are discussed. These findings have implications for the current conceptual model for L. majuscula blooms in offshore intertidal sandbanks within Moreton Bay. Further investigations are required to fully understand the role of tidally driven exchange in controlling the export of bio-available iron to coastal waters at the field site. In particular there is a need to better assess the link between the pore water flows and the geochemical reactions that might occur along the flow path.

The Stuff of Legend, or Unpacking Cultural Baggage? Introducing First-Year English Literature and Humanities Students to Foundational Literary Texts

ERIC Educational Resources Information Center

Beyer, Charlotte

2013-01-01

This article explores teaching and learning perspectives in relation to a first-year English Literature module on foundational literary texts and considers the value of certain assessment modes. The essay discusses methodological and pedagogical questions and argues that the module provides a contextual platform from which first-year students are…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Munkejord, T.

This paper gives a summary of the Heidrun substructure including tethers and foundations. The focus will although be on the concrete substructure. The Heidrun Field is located in 345 m water depth in the northern part of the Haltenbanken area, approximately 100N miles from the west coast of mid-Norway. The field is developed by means of a concrete Tension Leg Platform (TLP) by Conoco Norway Inc. The TLP will be moored by 16 steel tethers, arranged in groups of four per corner, which secure the substructure (hull) to the concrete foundations. A general view of the TLP is shown. Themore » Heidrun TLP will be the northern most located platform in the North Sea when installed at Haltenbanken in 1995. Norwegian Contractors a.s (NC) is undertaking the Engineering, Procurement, Construction and Installation (EPCI) contract for the Heidrun TLP substructure. This comprises the complete delivery of the hull with two module support beams (MSB), including all mechanical outfitting. Furthermore, NC will perform all marine operations related to the substructure. For the concrete foundations NC has performed the detailed engineering work and has been responsible for the two to field and installation of the foundations.« less

Re-assessment of offshore structures using the revised HSE fatigue guidance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stacey, A.; Sharp, J.V.

1995-12-31

The re-assessment of existing North Sea structures is an increasingly important issue as the age of platforms increases. Over 50 from a total of approximately 180 fixed installations in the UK sector are now over 15 years old. Fatigue damage has been the main reason for repairs to North Sea structures and the risk of this continues. The fatigue guidance of the Offshore Safety Division of the Health and Safety Executive (HSE) has recently been revised and published. Fundamental changes have been made to this guidance with several new recommendations including joint classification, basic design S-N curves for welded joints,more » the thickness effect, the effects of environment and the treatment of low and high stress ranges. To quantify the effects of the new guidance on the fatigue life assessment of offshore strictures, the HSE commissioned a study which included a deep water and a shallow water fixed steel structure and a twin-pontoon semi-submersible. These structures are typical of those operating in the North Sea. These were re-assessed with respect to fatigue lives and the results compared with predictions based on the 1990 guidance. The results and general conclusions are presented in this paper.« less

Advanced Offshore Wind Turbine/Foundation Concept for the Great Lakes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Afjeh, Abdollah A.; Windpower, Nautica; Marrone, Joseph

2013-08-29

This project investigated a conceptual 2-bladed rotor wind turbine design and assessed its feasibility for installation in the Great Lakes. The levelized cost of energy was used for this purpose. A location in Lake Erie near the coast of Cleveland, Ohio was selected as the application site. The loading environment was defined using wind and wave data collected at a weather station in Lake Erie near Cleveland. In addition, the probability distributions of the annual significant wave height and wind speed were determined. A model of the dependence of the above two quantities was also developed and used in themore » study of wind turbine system loads. Loads from ice floes and ridges were also included.The NREL 5 MW 3-bladed rotor wind turbine concept was used as the baseline design. The proposed turbine design employs variable pitch blade control with tip-brakes and a teeter mechanism. The rotor diameter, rated power and the tower dimensions were selected to closely match those of the NREL 5 MW wind turbine.A semi-floating gravity base foundation was designed for this project primarily to adapt to regional logistical constraints to transport and install the gravity base foundation. This foundation consists of, from bottom to top, a base plate, a buoyancy chamber, a taper zone, a column (with ice cone), and a service platform. A compound upward-downward ice cone was selected to secure the foundation from moving because of ice impact.The turbine loads analysis was based on International ElectroTechnical Committee (IEC) Standard 61400-1, Class III winds. The NREL software FAST was the primary computational tool used in this study to determine all design load cases. An initial set of studies of the dynamics of wind turbines using Automatic Dynamic Analysis of Mechanical Systems (ADAMS) demonstrated that FAST and ADAMS load predictions were comparable. Because of its relative simplicity and short run times, FAST was selected for this study. For ice load calculations, a method was developed and implemented in FAST to extend its capability for ice load modeling.Both upwind and downwind 2-bladed rotor wind turbine designs were developed and studied. The new rotor blade uses a new twist angle distribution design and a new pitch control algorithm compared with the baseline model. The coning and tilt angles were selected for both the upwind and downwind configurations to maximize the annual energy production. The risk of blade-tower impact is greater for the downwind design, particularly under a power grid fault; however, this risk was effectively reduced by adjusting the tilt angle for the downwind configuration.« less

Experiments with bosonic atoms for quantum gas assembly

NASA Astrophysics Data System (ADS)

Brown, Mark; Lin, Yiheng; Lester, Brian; Kaufman, Adam; Ball, Randall; Brossard, Ludovic; Isaev, Leonid; Thiele, Tobias; Lewis-Swan, Robert; Schymik, Kai-Niklas; Rey, Ana Maria; Regal, Cindy

2017-04-01

Quantum gas assembly is a promising platform for preparing and observing neutral atom systems on the single-atom level. We have developed a toolbox that includes ground-state laser cooling, high-fidelity loading techniques, addressable spin control, and dynamic spatial control and coupling of atoms. Already, this platform has enabled us to pursue a number of experiments studying entanglement and interference of pairs of bosonic atoms. We discuss our recent work in probabilistically entangling neutral atoms via interference, measurement, and post-selection as well as our future pursuits of interesting spin-motion dynamics of larger arrays of atoms. This work was supported by the David and Lucile Packard Foundation, National Science Foundation Physics Frontier Centers, and the National Defense Science and Engineering Graduate Fellowships program.

Joint Offshore Wind Field Monitoring with Spaceborne SAR and Platform-Based Doppler LIDAR Measurements

NASA Astrophysics Data System (ADS)

Jacobsen, S.; Lehner, S.; Hieronimus, J.; Schneemann, J.; Kuhn, M.

2015-04-01

The increasing demand for renewable energy resources has promoted the construction of offshore wind farms e.g. in the North Sea. While the wind farm layout consists of an array of large turbines, the interrelation of wind turbine wakes with the remaining array is of substantial interest. The downstream spatial evolution of turbulent wind turbine wakes is very complex and depends on manifold parameters such as wind speed, wind direction and ambient atmospheric stability conditions. To complement and validate existing numerical models, corresponding observations are needed. While in-situ measurements with e.g. anemometers provide a time-series at the given location, the merits of ground-based and space- or airborne remote sensing techniques are indisputable in terms of spatial coverage. Active microwave devices, such as Scatterometer and Synthetic Aperture Radar (SAR), have proven their capabilities of providing sea surface wind measurements and particularly SAR images reveal wind variations at a high spatial resolution while retaining the large coverage area. Platform-based Doppler LiDAR can resolve wind fields with a high spatial coverage and repetition rates of seconds to minutes. In order to study the capabilities of both methods for the investigation of small scale wind field structures, we present a direct comparison of observations obtained by high resolution TerraSAR-X (TS-X) X-band SAR data and platform-based LiDAR devices at the North Sea wind farm alpha ventus. We furthermore compare the results with meteorological data from the COSMO-DE model run by the German Weather Service DWD. Our study indicates that the overall agreement between SAR and LiDAR wind fields is good and that under appropriate conditions small scale wind field variations compare significantly well.

Long-term changes in sediment barium inventories associated with drilling-related discharges in the Santa Maria Basin, California, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phillips, C.; Evans, J.; Hom, W.

1998-09-01

Nine-year (1986--1995) records of barium (Ba) concentrations in surficial, subsurface, and suspended sediments near offshore oil and gas platforms in the Santa Maria Basin, California, USA, were analyzed to evaluate temporal trends related to drilling activities. These trends provide important information on the long-term effects of drilling discharges on geochemical conditions. Drilling during the 1986 through 1989 (phase II) monitoring period resulted in significant changes in Ba concentrations in suspended particles and surficial sediments, whereas the relatively shorter 1993 through 1994 (phase III) drilling operations resulted in only minor increases in Ba concentrations in suspended sediments. Residual excess Ba wasmore » present in some sediments within 500 m of the platforms at concentrations up to an order of magnitude above background. These elevated levels probably were associated with cuttings particles deposited near the base of the platforms. Calculated excess Ba in sediments within 500 m of the platforms represented 6 to 11% of the total Ba discharged during the two drilling periods.« less

Fully vs. Sequentially Coupled Loads Analysis of Offshore Wind Turbines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Damiani, Rick; Wendt, Fabian; Musial, Walter

The design and analysis methods for offshore wind turbines must consider the aerodynamic and hydrodynamic loads and response of the entire system (turbine, tower, substructure, and foundation) coupled to the turbine control system dynamics. Whereas a fully coupled (turbine and support structure) modeling approach is more rigorous, intellectual property concerns can preclude this approach. In fact, turbine control system algorithms and turbine properties are strictly guarded and often not shared. In many cases, a partially coupled analysis using separate tools and an exchange of reduced sets of data via sequential coupling may be necessary. In the sequentially coupled approach, themore » turbine and substructure designers will independently determine and exchange an abridged model of their respective subsystems to be used in their partners' dynamic simulations. Although the ability to achieve design optimization is sacrificed to some degree with a sequentially coupled analysis method, the central question here is whether this approach can deliver the required safety and how the differences in the results from the fully coupled method could affect the design. This work summarizes the scope and preliminary results of a study conducted for the Bureau of Safety and Environmental Enforcement aimed at quantifying differences between these approaches through aero-hydro-servo-elastic simulations of two offshore wind turbines on a monopile and jacket substructure.« less

Air emissions assessment from offshore oil activities in Sonda de Campeche, Mexico.

PubMed

Schifter, I; González-Macías, C; Miranda, A; López-Salinas, E

2005-10-01

Air emission data from offshore oil platforms, gas and oil processing installations and contribution of marine activities at the Sonda de Campeche, located at the Gulf of Mexico, were compiled and integrated to facilitate the study of long range transport of pollutants into the region. From this important region, roughly 76% of the total Mexican oil and gas production is obtained. It was estimated that the total air emissions of all contaminants are approximately 821,000 tons per year. Hydrocarbons are the largest pollutant emissions with 277,590 tons per year, generated during flaring activities, and SOx in second place with 185,907 tons per year. Marine and aviation activities contribute with less than 2% of total emissions. Mass of pollutants emitted per barrel of petroleum produced calculated in this work, are in the range reported by similar oil companies.

Comparison of numerical hindcasted severe waves with Doppler radar measurements in the North Sea

NASA Astrophysics Data System (ADS)

Ponce de León, Sonia; Bettencourt, João H.; Dias, Frederic

2017-01-01

Severe sea states in the North Sea present a challenge to wave forecasting systems and a threat to offshore installations such as oil and gas platforms and offshore wind farms. Here, we study the ability of a third-generation spectral wave model to reproduce winter sea states in the North Sea. Measured and modeled time series of integral wave parameters and directional wave spectra are compared for a 12-day period in the winter of 2013-2014 when successive severe storms moved across the North Atlantic and the North Sea. Records were obtained from a Doppler radar and wave buoys. The hindcast was performed with the WAVEWATCH III model (Tolman 2014) with high spectral resolution both in frequency and direction. A good general agreement was obtained for integrated parameters, but discrepancies were found to occur in spectral shapes.

Natural Offshore Oil Seepage and Related Tarball Accumulation on the California Coastline - Santa Barbara Channel and the Southern Santa Maria Basin: Source Identification and Inventory

USGS Publications Warehouse

Lorenson, T.D.; Hostettler, Frances D.; Rosenbauer, Robert J.; Peters, Kenneth E.; Dougherty, Jennifer A.; Kvenvolden, Keith A.; Gutmacher, Christina E.; Wong, Florence L.; Normark, William R.

2009-01-01

Oil spillage from natural sources is very common in the waters of southern California. Active oil extraction and shipping is occurring concurrently within the region and it is of great interest to resource managers to be able to distinguish between natural seepage and anthropogenic oil spillage. The major goal of this study was to establish the geologic setting, sources, and ultimate dispersal of natural oil seeps in the offshore southern Santa Maria Basin and Santa Barbara Basins. Our surveys focused on likely areas of hydrocarbon seepage that are known to occur between Point Arguello and Ventura, California. Our approach was to 1) document the locations and geochemically fingerprint natural seep oils or tar; 2) geochemically fingerprint coastal tar residues and potential tar sources in this region, both onshore and offshore; 3) establish chemical correlations between offshore active seeps and coastal residues thus linking seep sources to oil residues; 4) measure the rate of natural seepage of individual seeps and attempt to assess regional natural oil and gas seepage rates; and 5) interpret the petroleum system history for the natural seeps. To document the location of sub-sea oil seeps, we first looked into previous studies within and near our survey area. We measured the concentration of methane gas in the water column in areas of reported seepage and found numerous gas plumes and measured high concentrations of methane in the water column. The result of this work showed that the seeps were widely distributed between Point Conception east to the vicinity of Coal Oil Point, and that they by in large occur within the 3-mile limit of California State waters. Subsequent cruises used sidescan and high resolution seismic to map the seafloor, from just south of Point Arguello, east to near Gaviota, California. The results of the methane survey guided the exploration of the area west of Point Conception east to Gaviota using a combination of seismic instruments. The seafloor was mapped by sidescan sonar, and numerous lines of high -resolution seismic surveys were conducted over areas of interest. Biomarker and stable carbon isotope ratios were used to infer the age, lithology, organic matter input, and depositional environment of the source rocks for 388 samples of produced crude oil, seep oil, and tarballs mainly from coastal California. These samples were used to construct a chemometric fingerprint (multivariate statistics) decision tree to classify 288 additional samples, including tarballs of unknown origin collected from Monterey and San Mateo County beaches after a storm in early 2007. A subset of 9 of 23 active offshore platform oils and one inactive platform oil representing a few oil reservoirs from the western Santa Barbara Channel were used in this analysis, and thus this model is not comprehensive and the findings are not conclusive. The platform oils included in this study are from west to east: Irene, Hildago, Harvest, Hermosa, Heritage, Harmony, Hondo, Holly, Platform A, and Hilda (now removed). The results identify three 'tribes' of 13C-rich oil samples inferred to originate from thermally mature equivalents of the clayey-siliceous, carbonaceous marl, and lower calcareous-siliceous members of the Monterey Formation. Tribe 1 contains four oil families having geochemical traits of clay-rich marine shale source rock deposited under suboxic conditions with substantial higher-plant input. Tribe 2 contains four oil families with intermediate traits, except for abundant 28,30-bisnorhopane, indicating suboxic to anoxic marine marl source rock with hemipelagic input. Tribe 3 contains five oil families with traits of distal marine carbonate source rock deposited under anoxic conditions with pelagic but little or no higher-plant input. Tribes 1 and 2 occur mainly south of Point Conception in paleogeographic settings where deep burial of the Monterey Formation source rock favored generation from all thre

When Networks Build a Platform Students Step up. Lumina Foundation Lesson. Spring 2010

ERIC Educational Resources Information Center

Brennan, Patricia L.

2010-01-01

For the people behind the Lumina Foundation for Education, the term "network" has particular meaning. In fact, largely as a result of their work in a national college awareness and action campaign called KnowHow2GO, they have come to define networks in a specific way--and they ask their KnowHow2GO grantees and partners to form networks…

Assessment of Ports for Offshore Wind Development in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elkinton, Chris; Blatiak, Alicia; Ameen, Hafsa

As offshore wind energy develops in the United States, port facilities will become strategic hubs in the offshore wind farm supply chain because all plant and transport logistics must transit through these facilities. Therefore, these facilities must provide suitable infrastructure to meet the specific requirements of the offshore wind industry. As a result, it is crucial that federal and state policy-makers and port authorities take effective action to position ports in the offshore wind value chain to take best advantage of their economic potential. The U.S. Department of Energy tasked the independent consultancy GL Garrad Hassan (GL GH) with carryingmore » out a review of the current capability of U.S. ports to support offshore wind project development and an assessment of the challenges and opportunities related to upgrading this capability to support the growth of as many as 54 gigawatts of offshore wind installed in U.S. waters by 2030. The GL GH report and the open-access web-based Ports Assessment Tool resulting from this study will aid decision-makers in making informed decisions regarding the choice of ports for specific offshore projects, and the types of investments that would be required to make individual port facilities suitable to serve offshore wind manufacturing, installation and/or operations. The offshore wind industry in the United States is still in its infancy and this study finds that additional port facilities capable of supporting offshore wind projects are needed to meet the anticipated project build-out by 2030; however, no significant barriers exist to prevent the development of such facilities. Furthermore, significant port capabilities are in place today with purpose-build port infrastructure currently being built. While there are currently no offshore wind farms operating in the United States, much of the infrastructure critical to the success of such projects does exist, albeit in the service of other industries. This conclusion is based on GL GH’s review of U.S. ports infrastructure and its readiness to support the development of proposed offshore wind projects in U.S. waters. Specific examples of facility costs and benefits are provided for five coastal regions (North Atlantic, South Atlantic, Gulf of Mexico, Great Lakes, and Pacific) around the country. GL GH began this study by identifying the logistical requirements of offshore wind ports to service offshore wind. This review was based on lessons learned through industry practice in Northern Europe. A web-based port readiness assessment tool was developed to allow a capability gap analysis to be conducted on existing port facilities based on the identified requirements. Cost models were added to the assessment tool, which allowed GL GH to estimate the total upgrade cost to a port over the period 2014-2030 based on a set of regional project build-out scenarios. Port fee information was gathered from each port allowing an estimate of the potential revenue to the port under this same set of scenarios. The comparison of these revenue and improvement cost figures provides an initial indication of the level of offshore wind port readiness. To facilitate a more in-depth infrastructure analysis, six ports from different geographic regions, with varied levels of interest and preparedness towards offshore wind, were evaluated by modeling a range of installation strategies and port use types to identify gaps in capability and potential opportunities for economic development. Commonalities, trends, and specific examples from these case studies are presented and provide a summary of the current state of offshore wind port readiness in the U.S. and also illustrate the direction some ports have chosen to take to prepare for offshore wind projects. For example, the land area required for wind turbine and foundation manufacturing is substantial, particularly due to the large size of offshore wind components. Also, the necessary bearing capacities of the quayside and storage area are typically greater for offshore wind components than for more conventional cargo handling. As a result, most U.S. ports will likely require soil strength improvements before they can fully support offshore wind project construction. As U.S. ports and offshore wind developers look to work together on specific projects, they will encounter synergies and challenges. The challenges they face will include identifying sources of funding for the facility improvements required, and addressing ports’ typical desire to engage in long-term partnerships on the order of 10-20 years. Early projects will especially feel these challenges as they set the precedent for these partnerships in the United States. This study seeks to provide information about gaps, costs, and opportunities to aid these discussions.« less

Characterizing Methane Emissions at Local Scales with a 20 Year Total Hydrocarbon Time Series, Imaging Spectrometry, and Web Facilitated Analysis

NASA Astrophysics Data System (ADS)

Bradley, Eliza Swan

Methane is an important greenhouse gas for which uncertainty in local emission strengths necessitates improved source characterizations. Although CH4 plume mapping did not motivate the NASA Airborne Visible InfraRed Imaging Spectrometer (AVIRIS) design and municipal air quality monitoring stations were not intended for studying marine geological seepage, these assets have capabilities that can make them viable for studying concentrated (high flux, highly heterogeneous) CH4 sources, such as the Coal Oil Point (COP) seep field (˜0.015 Tg CH4 yr-1) offshore Santa Barbara, California. Hourly total hydrocarbon (THC) data, spanning 1990 to 2008 from an air pollution station located near COP, were analyzed and showed geologic CH4 emissions as the dominant local source. A band ratio approach was developed and applied to high glint AVIRIS data over COP, resulting in local-scale mapping of natural atmospheric CH4 plumes. A Cluster-Tuned Matched Filter (CTMF) technique was applied to Gulf of Mexico AVIRIS data to detect CH4 venting from offshore platforms. Review of 744 platform-centered CTMF subsets was facilitated through a flexible PHP-based web portal. This dissertation demonstrates the value of investigating municipal air quality data and imaging spectrometry for gathering insight into concentrated methane source emissions and highlights how flexible web-based solutions can help facilitate remote sensing research.

Consciousness platform: the greatest mystery of all time.

PubMed

Deutsch, Sid

2010-01-01

This article is about the model for a very controversial edifice--the many-sided foundation for consciousness. What I refer to is, undoubtedly, the greatest mystery of all time--why do we have an awareness of our own existence? What is the evolutionary advantage of consciousness? Much of the material printed about consciousness has a religious flavor, with references to the human spirit and/or extrasensory perception, but I will have none of that here. In this study, consciousness is tied in with a platform, not a physical platform, of course, but a conceptual platform. This is because we are most comfortable imagining or visualizing an actual platform that has many connections to various parts of the brain, a sort of an old-fashioned telephone switchboard.

In Situ Mortality Experiments with Juvenile Sea Bass (Dicentrarchus labrax) in Relation to Impulsive Sound Levels Caused by Pile Driving of Windmill Foundations

PubMed Central

Debusschere, Elisabeth; De Coensel, Bert; Bajek, Aline; Botteldooren, Dick; Hostens, Kris; Vanaverbeke, Jan; Vandendriessche, Sofie; Van Ginderdeuren, Karl; Vincx, Magda; Degraer, Steven

2014-01-01

Impact assessments of offshore wind farm installations and operations on the marine fauna are performed in many countries. Yet, only limited quantitative data on the physiological impact of impulsive sounds on (juvenile) fishes during pile driving of offshore wind farm foundations are available. Our current knowledge on fish injury and mortality due to pile driving is mainly based on laboratory experiments, in which high-intensity pile driving sounds are generated inside acoustic chambers. To validate these lab results, an in situ field experiment was carried out on board of a pile driving vessel. Juvenile European sea bass (Dicentrarchus labrax) of 68 and 115 days post hatching were exposed to pile-driving sounds as close as 45 m from the actual pile driving activity. Fish were exposed to strikes with a sound exposure level between 181 and 188 dB re 1 µPa2.s. The number of strikes ranged from 1739 to 3067, resulting in a cumulative sound exposure level between 215 and 222 dB re 1 µPa2.s. Control treatments consisted of fish not exposed to pile driving sounds. No differences in immediate mortality were found between exposed and control fish groups. Also no differences were noted in the delayed mortality up to 14 days after exposure between both groups. Our in situ experiments largely confirm the mortality results of the lab experiments found in other studies. PMID:25275508

Study of technology of pile foundation construction of no.5 main pier of Shoujiang bridge in Wenchuan County

NASA Astrophysics Data System (ADS)

Huang, Xianbin; Liu, Chenyang; Chen, Chunyang; Wangren, Yahong; Xu, Jialin; Xian, Jin

2018-03-01

The group of pile foundation of no.5 pier in Shoujiang Bridge needs to overcome the big load of large span continuous steel structure. The length of single pile foundation is 77m and the diameter of single pile foundation is 250cm. It not only faces the flood in the upstream of Shoujiang river, the construction obstacles during summer rain period, but also the reservoir clearance activity of Zipingpu reservoir and the high water level in winter and other water level fluctuation that have huge impact on platform of pile foundation construction. This article introduces the preparation in aspect of personnel, material, equipment and so on of pile foundation construction, and also conduct intensive research on leveling the field, assaying pile location, the embedment of the steel casing, installing the drill, mixing mud, drilling, final hole inspection and clearance, steel cage construction, perfusing concrete under water.

Offshore remote sensing of the ocean by stereo vision systems

NASA Astrophysics Data System (ADS)

Gallego, Guillermo; Shih, Ping-Chang; Benetazzo, Alvise; Yezzi, Anthony; Fedele, Francesco

2014-05-01

In recent years, remote sensing imaging systems for the measurement of oceanic sea states have attracted renovated attention. Imaging technology is economical, non-invasive and enables a better understanding of the space-time dynamics of ocean waves over an area rather than at selected point locations of previous monitoring methods (buoys, wave gauges, etc.). We present recent progress in space-time measurement of ocean waves using stereo vision systems on offshore platforms, which focus on sea states with wavelengths in the range of 0.01 m to 1 m. Both traditional disparity-based systems and modern elevation-based ones are presented in a variational optimization framework: the main idea is to pose the stereoscopic reconstruction problem of the surface of the ocean in a variational setting and design an energy functional whose minimizer is the desired temporal sequence of wave heights. The functional combines photometric observations as well as spatial and temporal smoothness priors. Disparity methods estimate the disparity between images as an intermediate step toward retrieving the depth of the waves with respect to the cameras, whereas elevation methods estimate the ocean surface displacements directly in 3-D space. Both techniques are used to measure ocean waves from real data collected at offshore platforms in the Black Sea (Crimean Peninsula, Ukraine) and the Northern Adriatic Sea (Venice coast, Italy). Then, the statistical and spectral properties of the resulting oberved waves are analyzed. We show the advantages and disadvantages of the presented stereo vision systems and discuss furure lines of research to improve their performance in critical issues such as the robustness of the camera calibration in spite of undesired variations of the camera parameters or the processing time that it takes to retrieve ocean wave measurements from the stereo videos, which are very large datasets that need to be processed efficiently to be of practical usage. Multiresolution and short-time approaches would improve efficiency and scalability of the techniques so that wave displacements are obtained in feasible times.

Meals on Wheels? A Decade of Megafaunal Visual and Acoustic Observations from Offshore Oil & Gas Rigs and Platforms in the North and Irish Seas

PubMed Central

Todd, Victoria Louise Georgia; Todd, Ian Boyer

2016-01-01

A decade of visual and acoustic detections of marine megafauna around offshore Oil & Gas (O&G) installations in the North and Irish Seas are presented. Marine megafauna activity was monitored visually and acoustically by Joint Nature Conservation Committee (JNCC) qualified and experienced Marine Mammal Observers (MMO) and Passive Acoustic Monitoring (PAM) Operators respectively, with real-time towed PAM in combination with industry standard software, PAMGuard. Monitoring was performed during routine O&G industrial operations for underwater noise mitigation purposes, and to ensure adherence to regulatory guidelines. Incidental sightings by off-effort MMOs and installation crew were also reported. Visual and acoustic monitoring spanned 55 non-consecutive days between 2004 and 2014. A total of 47 marine mammal sightings were recorded by MMOs on dedicated watch, and 10 incidental sightings of marine megafauna were reported over 10 years. Species included: harbour porpoise (Phocoena phocoena), Atlantic white-sided dolphin (Lagenorhynchus acutus), white beaked dolphin (Lagenorhynchus albirostris), common dolphin (Delphinus delphis), minke whale (Balaenoptera acutorostrata), common seal (Phoca vitulina), grey seal (Halichoerus grypus) and, basking shark (Cetorhinus maximus). Passive Acoustic Monitoring was conducted on two occasions in 2014; 160 PAM hours over 12 days recorded a total of 308 individual clicks identified as harbour porpoises. These appear to be the first such acoustic detections obtained from a North Sea drilling rig whilst using a typically configured hydrophone array designed for towing in combination with real-time PAMGuard software. This study provides evidence that marine megafauna are present around mobile and stationary offshore O&G installations during routine operational activities. On this basis, Environmental Impact Assessments (EIAs) for decommissioning O&G platforms should be carried-out on a case-by-case basis, and must include provisions for hitherto overlooked marine megafauna. PMID:27078153

Onshore and offshore basins of northeast Libya: Their origin and hydrocarbon potential

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shegewi, O.M.

1992-01-01

A comprehensive data base of more than 3000 km of seismic lines, gravity and magnetic data, more than 30 subsurface well logs, and surface geology data were utilized to examine and interpret the sedimentary and tectonic history of the onshore and offshore parts of Northeast Libya and their hydrocarbon potential. The Dernah-Tobruk and Benghazi offshore basins form the northern parts of the study area. The Cyrenaica Stable Platform represents the southern parts. The Sirual Trough stretches E-W and opens into the Antelat Trough in the west. Between these elements is the uplifted areas of the Al Jabal Al Akhdar. Sixmore » principal tectonic phases were responsible for the formation and development of these structural elements: the pre-Mesozoic phase, the Triassic-Jurassic rifting phase, the Neocomian and the Aptian-Albian renewed rifting phases, the Late Cretaceous-Paleocene uplifting phase; and the Eocene-Middle Oligocene rifting phase. Oceanic crust of probable Aptian-Albian age is evident on the seismic lines north of the master fault marking the southern boundary of the rift separating the north African plate and Apulia. The western boundary of the Dernah High displayed clearly NE-SW strike-slip movement of these trajectories. Oceanic crust is also present west of the Dernah High. Positive gravity and magnetic anomalies traverse parallel to the boundary of this oceanic plate Mesogea. The prerequisites for commercial hydrocarbon production are present in abundance. Reservoirs ranging in age from Paleozoic clastics in the Cyrenaica Stable Platform to Mesozoic and Tertiary carbonates throughout the rest of the region. Several deep sites for the generation of hydrocarbons were also present, including the rifted northern parts of the Dernah-Tobruk basin, the Antelat Trough and the Cyrenaica Passive Margin. The Cretaceous and Tertiary section in the study area contain several potential seal rocks. Several potential trap types are also present.« less

Gulf of Mexico Air/Sea Interaction: Measurements and Initial Data Characterization

NASA Astrophysics Data System (ADS)

MacDonald, C.; Huang, C. H.; Roberts, P. T.; Bariteau, L.; Fairall, C. W.; Gibson, W.; Ray, A.

2011-12-01

Corporate, government, and university researchers collaborated to develop an atmospheric boundary layer environmental observations program on an offshore platform in the Gulf of Mexico. The primary goals of this project were to provide data to (1) improve our understanding of boundary layer processes and air-sea interaction over the Gulf of Mexico; (2) improve regional-scale meteorological and air quality modeling; and (3) provide a framework for advanced offshore measurements to support future needs such as emergency response, exploration and lease decisions, wind energy research and development, and meteorological and air quality forecasting. In October 2010, meteorological and oceanographic sensors were deployed for an extended period (approximately 12 months) on a Chevron service platform (ST 52B, 90.5W, 29N) to collect boundary layer and sea surface data sufficient to support these objectives. This project has significant importance given the large industrial presence in the Gulf, sizeable regional population nearby, and the recognized need for precise and timely pollutant forecasts. Observations from this project include surface meteorology; sodar marine boundary layer winds; microwave radiometer profiles of temperature, relative humidity, and liquid water; ceilometer cloud base heights; water temperature and current profiles; sea surface temperature; wave height statistics; downwelling solar and infrared radiation; and air-sea turbulent momentum and heat fluxes. This project resulted in the collection of an unprecedented set of boundary layer measurements over the Gulf of Mexico that capture the range of meteorological and oceanographic interactions and processes that occur over an entire year. This presentation will provide insight into the logistical and scientific issues associated with the deployment and operations of unique measurements in offshore areas and provide results from an initial data analysis of boundary layer processes over the Gulf of Mexico, with a special focus on the relationship among measured and modeled energy fluxes and other oceanographic and atmospheric conditions.

Barge-mounted treating plant to serve Prudhoe Bay injection program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1983-01-01

A barge-mounted Seawater Treating Plant (STP) which will serve the largest waterflood project on the North American continent is nearing completion at Daewoo Shipbuilding and Heavy Machinery Ltd. of Korea. The $150-million facility, the first such offshore plant ever built, will provide 2.2 million bpd of filtered, demineralized and warmed seawater under pressure for injection into the Prudhoe Bay, Alaska, oil field. It will be towed from Daewoo's Okpo, Korea, shipyard, in May with expected delivery to Alaska in July. The water output from the STP will maintain, when operational, the pressure necessary to continue the field's current production ofmore » 1.5 million bpd. The STP is being fabricated as a complete unit on its own integral hull. It will be positioned and set in a prepared offshore gravel foundation on the seabed by controlled ballasting. After its estimated service life of 25 years, the STP can be removed from the site by deballasting and towing. Construction requirements for the STP are discussed.« less

Spatial distribution and historical trends of heavy metals in the sediments of petroleum producing regions of the Beibu Gulf, China.

PubMed

Yang, Jichao; Wang, Weiguo; Zhao, Mengwei; Chen, Bin; Dada, Olusegun A; Chu, Zhihui

2015-02-15

The concentrations of As, Sb, Hg, Pb, Cd, and Ba in the surface and core sediments of the oil and gas producing region of the Beibu Gulf were measured by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Atomic Fluorescence Spectrometry (AFS), and the spatial distribution and historical trends of these elements are discussed. The results show that the concentrations of these elements are highest near the platforms. The results of Enrichment Factor (EF) and Potential Ecological Risk Index (PERI) also reveal significantly higher enrichment around the platforms, which imply that the offshore petroleum production was the cause of the unusual distribution and severe enrichment of these elements in the study area. The environment around the platforms was highly laden with toxic elements, thereby representing a very high ecological risk to the environment of the study area. Copyright © 2014 Elsevier Ltd. All rights reserved.

Architecture and evolution of an Early Permian carbonate complex on a tectonically active island in east-central California

USGS Publications Warehouse

Stevens, Calvin H.; Magginetti, Robert T.; Stone, Paul

2015-01-01

The newly named Upland Valley Limestone represents a carbonate complex that developed on and adjacent to a tectonically active island in east-central California during a brief interval of Early Permian (late Artinskian) time. This lithologically unique, relatively thin limestone unit lies within a thick sequence of predominantly siliciclastic rocks and is characterized by its high concentration of crinoidal debris, pronounced lateral changes in thickness and lithofacies, and a largely endemic fusulinid fauna. Most outcrops represent a carbonate platform and debris derived from it and shed downslope, but another group of outcrops represents one or possibly more isolated carbonate buildups that developed offshore from the platform. Tectonic activity in the area occurred before, probably during, and after deposition of this short-lived carbonate complex.

Single-indicator-based Multidimensional Sensing: Detection and Identification of Heavy Metal Ions and Understanding the Foundations from Experiment to Simulation

PubMed Central

Leng, Yumin; Qian, Sihua; Wang, Yuhui; Lu, Cheng; Ji, Xiaoxu; Lu, Zhiwen; Lin, Hengwei

2016-01-01

Multidimensional sensing offers advantages in accuracy, diversity and capability for the simultaneous detection and discrimination of multiple analytes, however, the previous reports usually require complicated synthesis/fabrication process and/or need a variety of techniques (or instruments) to acquire signals. Therefore, to take full advantages of this concept, simple designs are highly desirable. Herein, a novel concept is conceived to construct multidimensional sensing platforms based on a single indicator that has capability of showing diverse color/fluorescence responses with the addition of different analytes. Through extracting hidden information from these responses, such as red, green and blue (RGB) alterations, a triple-channel-based multidimensional sensing platform could consequently be fabricated, and the RGB alterations are further applicable to standard statistical methods. As a proof-of-concept study, a triple-channel sensing platform is fabricated solely using dithizone with assistance of cetyltrimethylammonium bromide (CTAB) for hyperchromicity and sensitization, which demonstrates superior capabilities in detection and identification of ten common heavy metal ions at their standard concentrations of wastewater-discharge of China. Moreover, this sensing platform exhibits promising applications in semi-quantitative and even quantitative analysis individuals of these heavy metal ions with high sensitivity as well. Finally, density functional theory calculations are performed to reveal the foundations for this analysis. PMID:27146105

Sleipner mishap jolts booming Norway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-09-02

This paper reports on Norway's buoyant offshore industry that was stunned when the concrete substructure for Sleipner natural gas field's main production platform sank in the Grandsfjord off Stavanger late last month. The accident, a blow to Norway's gas sales program in Europe, came with offshore activity in the Norwegian North Sea moving into a new boom period. Currently, 10 oil and gas fields are under development, and several projects are on the drawing board. Aker Oil and Gas, a leading offshore firm, says the country's construction industry will be working at capacity for the next 4 years. Norwegian oilmore » production has been hovering just below 2 million b/d since the beginning of this year, making Norway the North Sea's largest producer, a position formerly held by the U.K. Gas production averages about 3 bcfd. With European gas demand sharply increasing, Norway is under pressure to increase output from new fields in the mid to late 1990s. The Sleipner setback forces state owned Den norske stats oljeselskap AS (Statoil) to cast around for supplies. Sleipner was to have begun deliveries to a consortium of continental gas companies in October 1993. Statoil believes it can fill the gap from existing fields in Norwegian waters.« less

U. K. pressing campaign to improve offshore safety

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knott, D.

1994-02-14

The U.K. government is making progress in its campaign to improve the safety of personnel working offshore. The government's Health and Safety Executive (HSE) plans to assess and pass judgment on at lease one safety plan, called a safety case, from each U.K. North Sea operator as soon as possible. HSE has agreed with the industry on a list of 61 priority safety cases, known as exemplars. Feedback from exemplar assessment will help operators review safety management and assist in preparation or revision of future safety cases. It also will give HSE practice in assessing a range of case types.more » The requirement for a safety program is part of new U.K. offshore legislation designed to prevent another accident similar to the Piper Alpha platform fire and explosion of 1988. After the transition period it will be against the law to operate an oil and gas installation in British waters without an accepted safety case. Besides existing installations, safety cases are also required for new installations reaching design stage by May 31, 1993, the date safety case regulations went into force. The paper describes the Cullen report, companies' experiences with the new law, and the safety assessment progress so far.« less

Capacities of template-type platforms in the Gulf of Mexico during hurricane Andrew

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bea, R.G.; Loch, K.J.; Young, P.L.

1997-02-01

This paper details results from nonlinear analyses of the ultimate limit state performance characteristics of four Gulf of Mexico (GOM) platforms subjected to intense loadings from hurricane Andrew. These four platforms were located to the east of the track of hurricane Andrew, and were thus in the most intense portion of the storm (Smith, 1993). The nonlinear analyses are able to replicate details of the observed behavior of the four structures. This replication is very dependent on realistic characterization of the performance characteristics of the pile foundations and on accurate information on the as is condition of the platforms beforemore » the storm.« less

Mobile Landing Platform with Core Capability Set (MLP w/CCS): Combined Initial Operational Test and Evaluation and Live Fire Test and Evaluation Report

DTIC Science & Technology

2015-07-01

annex.   iii Self-defense testing was limited to structural test firing from each machine gun mount and an ammunition resupply drill. Robust self...provided in the classified annex. Self-   8 defense testing was limited to structural test firing from each machine gun mount and a single...Caliber Machine Gun Mount Structural Test Fire November 2014 San Diego, Offshore Ship Weapons Range Operating Independently       9 Section Three

International trends and issues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Curtis, C

The nineteen (19) position statements in this paper represent Mr. Curtis` best efforts to capture Greenpeace`s views on ocean disposal or dumping of wastes and other harmful substances, including offshore oil and gas platforms. These statements, though, have not been formally approved as Greenpeace policies, although a number of them have appeared in Greenpeace documents or public statements. For this document, {open_quotes}dumping{close_quotes} refers to any deliberate disposal at sea of wastes or other matter, consistent with the London Convention.

Multibrid technology - a significant step to multi-megawatt wind turbines

NASA Astrophysics Data System (ADS)

Siegfriedsen, S.; Böhmeke, G.

1998-12-01

To fulfil the significant economic potential for offshore wind energy, it is essential that the largest possible installations must be allowed to come into use. Infrastructure investments for foundations and energy transport are only slightly dependent on the size of the installation, so these costs become proportionally smaller as the installed power output increases. This article puts forward a technologically novel type of development for a drive train design, specifically introduced for a 5 MW installation. The concept is especially suited for offshore application and the components are designed for this purpose. The usual way of modifying onshore plants partially and using them in the sea has been left with the present proposals. The design comprises a single-stage planetary gear, into which the rotor bearing is integrated, and a generator rotating at slow speed. Both components are assembled into a compact unit and are characterized by low wear and complete enclosure. New solutions are also proposed for the cooling of the machinery and the yaw system, offering particular advantages in offshore application. The advantages of the new technology are brought out from system comparisons with both a conventional plant configuration with a multi-stage gear and a high-speed generator, and also a combination with a direct drive generator in the 1·5 MW class. A particular design solution, worked through for a 5 MW installation, is presented and described in detail. At 31 kg kW-1, the specific tower head mass achieves a value that has not previously been realized in this power output class. As a result of the advantages that are brought together by this technology, both investment and operating costs are lowered, particularly for offshore applications. Implementation of this technology can thus provide a further stimulus for progress in wind energy utilization. Copyright

Stochastic Seismic Inversion and Migration for Offshore Site Investigation in the Northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Son, J.; Medina-Cetina, Z.

2017-12-01

We discuss the comparison between deterministic and stochastic optimization approaches to the nonlinear geophysical full-waveform inverse problem, based on the seismic survey data from Mississippi Canyon in the Northern Gulf of Mexico. Since the subsea engineering and offshore construction projects actively require reliable ground models from various site investigations, the primary goal of this study is to reconstruct the accurate subsurface information of the soil and rock material profiles under the seafloor. The shallow sediment layers have naturally formed heterogeneous formations which may cause unwanted marine landslides or foundation failures of underwater infrastructure. We chose the quasi-Newton and simulated annealing as deterministic and stochastic optimization algorithms respectively. Seismic forward modeling based on finite difference method with absorbing boundary condition implements the iterative simulations in the inverse modeling. We briefly report on numerical experiments using a synthetic data as an offshore ground model which contains shallow artificial target profiles of geomaterials under the seafloor. We apply the seismic migration processing and generate Voronoi tessellation on two-dimensional space-domain to improve the computational efficiency of the imaging stratigraphical velocity model reconstruction. We then report on the detail of a field data implementation, which shows the complex geologic structures in the Northern Gulf of Mexico. Lastly, we compare the new inverted image of subsurface site profiles in the space-domain with the previously processed seismic image in the time-domain at the same location. Overall, stochastic optimization for seismic inversion with migration and Voronoi tessellation show significant promise to improve the subsurface imaging of ground models and improve the computational efficiency required for the full waveform inversion. We anticipate that by improving the inversion process of shallow layers from geophysical data will better support the offshore site investigation.

The Design of Individual Knowledge Sharing Platform Based on Blog for Online Information Literacy Education

NASA Astrophysics Data System (ADS)

Qun, Zeng; Xiaocheng, Zhong

Knowledge sharing means that an individual, team and organization share the knowledge with other members of the organization in the course of activities through the various ways. This paper analyzes the obstacle factors in knowledge sharing based on the technical point, and chooses the Blog technology to build a platform for improving knowledge sharing between individuals. The construction of the platform is an important foundation for information literacy education, and it also can be used to achieve online information literacy education. Finally, it gives a detailed analysis of its functions, advantages and disadvantages.

A holistic approach to SIM platform and its application to early-warning satellite system

NASA Astrophysics Data System (ADS)

Sun, Fuyu; Zhou, Jianping; Xu, Zheyao

2018-01-01

This study proposes a new simulation platform named Simulation Integrated Management (SIM) for the analysis of parallel and distributed systems. The platform eases the process of designing and testing both applications and architectures. The main characteristics of SIM are flexibility, scalability, and expandability. To improve the efficiency of project development, new models of early-warning satellite system were designed based on the SIM platform. Finally, through a series of experiments, the correctness of SIM platform and the aforementioned early-warning satellite models was validated, and the systematical analyses for the orbital determination precision of the ballistic missile during its entire flight process were presented, as well as the deviation of the launch/landing point. Furthermore, the causes of deviation and prevention methods will be fully explained. The simulation platform and the models will lay the foundations for further validations of autonomy technology in space attack-defense architecture research.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fischer, F.J.

As the petroleum industry has moved into deeper and deeper water for the recovery of oil and gas, weight-sensitive floating platforms have replaced stationary, bottom-founded structures. The cost penalty for weight or vertical tension supported by floaters such as tension leg platforms (TLPs) is in the range of $10--20/kg. Hence, there is considerable incentive to reduce the weight of equipment or structural members on these platforms and downward forces exerted on these platforms by production and export risers, and mooring lines. Thus, there are numerous opportunities for utilizing light-weight, high-strength composites. The offshore petroleum industry has acknowledged the desirable performancemore » characteristics of composites for some time but only recently has there been some optimism that composites could be cost-effective. For most, if not all perceived applications, advanced composites are not considered to be technically enabling for current water depths of interest, i.e., 600--1,200m. However, in a very real sense, they may be economically enabling. In particular, they may allow marginal prospects to be developed or may expedite field development subject to capital constraints. The paper discusses composite production risers, break-even costs and savings, and riser tensioners.« less

Applying the System Component and Operationally Relevant Evaluation (SCORE) Framework to Evaluate Advanced Military Technologies

DTIC Science & Technology

2010-03-01

and charac- terize the actions taken by the soldier (e.g., running, walking, climbing stairs ). Real-time image capture and exchange N The ability of...multimedia information sharing among soldiers in the field, two-way speech translation systems, and autonomous robotic platforms. Key words: Emerging...soldiers in the field, two-way speech translation systems, and autonomous robotic platforms. It has been the foundation for 10 technology evaluations

Capstone: A Geometry-Centric Platform to Enable Physics-Based Simulation and Design of Systems

DTIC Science & Technology

2015-10-05

foundation for the air-vehicle early design tool DaVinci being developed by CREATETM-AV project to enable development of associative models of air...CREATETM-AV solvers Kestrel [11] and Helios [16,17]. Furthermore, it is the foundation for the CREATETM-AV’s DaVinci [9] tool that provides a... Tools and Environments (CREATETM) program [6] aimed at developing a suite of high- performance physics-based computational tools addressing the needs

A Delay Vector Variance based Marker for an Output-Only Assessment of Structural Changes in Tension Leg Platforms

NASA Astrophysics Data System (ADS)

Jaksic, V.; Wright, C.; Mandic, D. P.; Murphy, J.; Pakrashi, V.

2015-07-01

Although aspects of power generation of many offshore renewable devices are well understood, their dynamic responses under high wind and wave conditions are still to be investigated to a great detail. Output only statistical markers are important for these offshore devices, since access to the device is limited and information about the exposure conditions and the true behaviour of the devices are generally partial, limited, and vague or even absent. The markers can summarise and characterise the behaviour of these devices from their dynamic response available as time series data. The behaviour may be linear or nonlinear and consequently a marker that can track the changes in structural situations can be quite important. These markers can then be helpful in assessing the current condition of the structure and can indicate possible intervention, monitoring or assessment. This paper considers a Delay Vector Variance based marker for changes in a tension leg platform tested in an ocean wave basin for structural changes brought about by single column dampers. The approach is based on dynamic outputs of the device alone and is based on the estimation of the nonlinearity of the output signal. The advantages of the selected marker and its response with changing structural properties are discussed. The marker is observed to be important for monitoring the as- deployed structural condition and is sensitive to changes in such conditions. Influence of exposure conditions of wave loading is also discussed in this study based only on experimental data.

Aerodynamic Simulation of the MARINTEK Braceless Semisubmersible Wave Tank Tests

NASA Astrophysics Data System (ADS)

Stewart, Gordon; Muskulus, Michael

2016-09-01

Model scale experiments of floating offshore wind turbines are important for both platform design for the industry as well as numerical model validation for the research community. An important consideration in the wave tank testing of offshore wind turbines are scaling effects, especially the tension between accurate scaling of both hydrodynamic and aerodynamic forces. The recent MARINTEK braceless semisubmersible wave tank experiment utilizes a novel aerodynamic force actuator to decouple the scaling of the aerodynamic forces. This actuator consists of an array of motors that pull on cables to provide aerodynamic forces that are calculated by a blade-element momentum code in real time as the experiment is conducted. This type of system has the advantage of supplying realistically scaled aerodynamic forces that include dynamic forces from platform motion, but does not provide the insights into the accuracy of the aerodynamic models that an actual model-scale rotor could provide. The modeling of this system presents an interesting challenge, as there are two ways to simulate the aerodynamics; either by using the turbulent wind fields as inputs to the aerodynamic model of the design code, or by surpassing the aerodynamic model and using the forces applied to the experimental turbine as direct inputs to the simulation. This paper investigates the best practices of modeling this type of novel aerodynamic actuator using a modified wind turbine simulation tool, and demonstrates that bypassing the dynamic aerodynamics solver of design codes can lead to erroneous results.

Potential Impacts of Offshore Wind Farms on North Sea Stratification

PubMed Central

Carpenter, Jeffrey R.; Merckelbach, Lucas; Callies, Ulrich; Clark, Suzanna; Gaslikova, Lidia; Baschek, Burkard

2016-01-01

Advances in offshore wind farm (OWF) technology have recently led to their construction in coastal waters that are deep enough to be seasonally stratified. As tidal currents move past the OWF foundation structures they generate a turbulent wake that will contribute to a mixing of the stratified water column. In this study we show that the mixing generated in this way may have a significant impact on the large-scale stratification of the German Bight region of the North Sea. This region is chosen as the focus of this study since the planning of OWFs is particularly widespread. Using a combination of idealised modelling and in situ measurements, we provide order-of-magnitude estimates of two important time scales that are key to understanding the impacts of OWFs: (i) a mixing time scale, describing how long a complete mixing of the stratification takes, and (ii) an advective time scale, quantifying for how long a water parcel is expected to undergo enhanced wind farm mixing. The results are especially sensitive to both the drag coefficient and type of foundation structure, as well as the evolution of the pycnocline under enhanced mixing conditions—both of which are not well known. With these limitations in mind, the results show that OWFs could impact the large-scale stratification, but only when they occupy extensive shelf regions. They are expected to have very little impact on large-scale stratification at the current capacity in the North Sea, but the impact could be significant in future large-scale development scenarios. PMID:27513754

Potential Impacts of Offshore Wind Farms on North Sea Stratification.

PubMed

Carpenter, Jeffrey R; Merckelbach, Lucas; Callies, Ulrich; Clark, Suzanna; Gaslikova, Lidia; Baschek, Burkard

2016-01-01

Advances in offshore wind farm (OWF) technology have recently led to their construction in coastal waters that are deep enough to be seasonally stratified. As tidal currents move past the OWF foundation structures they generate a turbulent wake that will contribute to a mixing of the stratified water column. In this study we show that the mixing generated in this way may have a significant impact on the large-scale stratification of the German Bight region of the North Sea. This region is chosen as the focus of this study since the planning of OWFs is particularly widespread. Using a combination of idealised modelling and in situ measurements, we provide order-of-magnitude estimates of two important time scales that are key to understanding the impacts of OWFs: (i) a mixing time scale, describing how long a complete mixing of the stratification takes, and (ii) an advective time scale, quantifying for how long a water parcel is expected to undergo enhanced wind farm mixing. The results are especially sensitive to both the drag coefficient and type of foundation structure, as well as the evolution of the pycnocline under enhanced mixing conditions-both of which are not well known. With these limitations in mind, the results show that OWFs could impact the large-scale stratification, but only when they occupy extensive shelf regions. They are expected to have very little impact on large-scale stratification at the current capacity in the North Sea, but the impact could be significant in future large-scale development scenarios.

Self-represented witnessing: the use of social media by asylum seekers in Australia’s offshore immigration detention centres

PubMed Central

Rae, Maria; Holman, Rosa; Nethery, Amy

2017-01-01

The act of witnessing connects audiences with distant suffering. But what happens when bearing witness becomes severely restricted? External parties, including the mainstream news media, are constrained from accessing Australia’s offshore immigration detention centres. The effect is that people seeking asylum are hidden from the public and excluded from national debates. Some detainees have adopted social media as a platform to communicate their stories of flight, and their experiences of immigration detention, to a wider audience. This article examines the ways in which social media, and particularly Facebook, has facilitated what we call self-represented witnessing. We analyse two public Facebook pages to assess how detainees use such social media networks to document their experiences, and we observe the interaction between detainees, other social media users and mainstream media. Significantly, these social media networks enable detained asylum seekers to conduct an unmediated form of self-represented witnessing that exposes human rights abuses and documents justice claims. PMID:29782576

Digital depth horizon compilations of the Alaskan North Slope and adjacent Arctic regions

USGS Publications Warehouse

Saltus, Richard W.; Bird, Kenneth J.

2003-01-01

Data have been digitized and combined to create four detailed depth horizon grids spanning the Alaskan North Slope and adjacent offshore areas. These map horizon compilations were created to aid in petroleum system modeling and related studies. Topography/bathymetry is extracted from a recent Arctic compilation of global onshore DEM and satellite altimetry and ship soundings offshore. The Lower Cretaceous Unconformity (LCU), the top of the Triassic Shublik Formation, and the pre-Carboniferous acoustic basement horizon grids are created from numerous seismic studies, drill hole information, and interpolation. These horizons were selected because they mark critical times in the geologic evolution of the region as it relates to petroleum. The various horizons clearly show the major tectonic elements of this region including the Brooks Range, Colville Trough, Barrow Arch, Hanna Trough, Chukchi Platform, Nuwuk Basin, Kaktovik Basin, and Canada Basin. The gridded data are available in a variety of data formats for use in regional studies.

Study and Test of a New Bundle-Structure Riser Stress Monitoring Sensor Based on FBG.

PubMed

Xu, Jian; Yang, Dexing; Qin, Chuan; Jiang, Yajun; Sheng, Leixiang; Jia, Xiangyun; Bai, Yang; Shen, Xiaohong; Wang, Haiyan; Deng, Xin; Xu, Liangbin; Jiang, Shiquan

2015-11-24

To meet the requirements of riser safety monitoring in offshore oil fields, a new Fiber Bragg Grating (FBG)-based bundle-structure riser stress monitoring sensor has been developed. In cooperation with many departments, a 49-day marine test in water depths of 1365 m and 1252 m was completed on the "HYSY-981" ocean oil drilling platform. No welding and pasting were used when the sensor was installed on risers. Therefore, the installation is convenient, reliable and harmless to risers. The continuous, reasonable, time-consistent data obtained indicates that the sensor worked normally under water. In all detailed working conditions, the test results show that the sensor can do well in reflecting stresses and bending moments both in and in magnitude. The measured maximum stress is 132.7 MPa, which is below the allowable stress. In drilling and testing conditions, the average riser stress was 86.6 MPa, which is within the range of the China National Offshore Oil Corporation (CNOOC) mechanical simulation results.

The effect of an oil drilling operation on the trace metal concentrations in offshore bottom sediments of the Campos Basin oil field, SE Brazil.

PubMed

Rezende, C E; Lacerda, L D; Ovalle, A R C; Souza, C M M; Gobo, A A R; Santos, D O

2002-07-01

The concentrations of Al, Fe, Mn, Zn, Cu, Pb, Ni, Cr, Ba, V, Sn and As in offshore bottom sediments from the Bacia de Campos oil field, SE Brazil, were measured at the beginning and at 7 months after completion of the drilling operation. Concentrations of Al, Fe, Ba, Cr, Ni and Zn were significantly higher closer to the drilling site compared to stations far from the site. Average concentrations of Al, Cu, and in particular of Ni, were significantly higher at the end of the drilling operation than at the beginning. Comparison between drilling area sediments with control sediments of the continental platform, however, showed no significant difference in trace metal concentrations. Under the operation conditions of this drilling event, the results show that while changes in some trace metal concentrations do occur during drilling operations, they are not significantly large to be distinguished from natural variability of the local background concentrations.

Study and Test of a New Bundle-Structure Riser Stress Monitoring Sensor Based on FBG

PubMed Central

Xu, Jian; Yang, Dexing; Qin, Chuan; Jiang, Yajun; Sheng, Leixiang; Jia, Xiangyun; Bai, Yang; Shen, Xiaohong; Wang, Haiyan; Deng, Xin; Xu, Liangbin; Jiang, Shiquan

2015-01-01

To meet the requirements of riser safety monitoring in offshore oil fields, a new Fiber Bragg Grating (FBG)-based bundle-structure riser stress monitoring sensor has been developed. In cooperation with many departments, a 49-day marine test in water depths of 1365 m and 1252 m was completed on the “HYSY-981” ocean oil drilling platform. No welding and pasting were used when the sensor was installed on risers. Therefore, the installation is convenient, reliable and harmless to risers. The continuous, reasonable, time-consistent data obtained indicates that the sensor worked normally under water. In all detailed working conditions, the test results show that the sensor can do well in reflecting stresses and bending moments both in and in magnitude. The measured maximum stress is 132.7 MPa, which is below the allowable stress. In drilling and testing conditions, the average riser stress was 86.6 MPa, which is within the range of the China National Offshore Oil Corporation (CNOOC) mechanical simulation results. PMID:26610517

Offshore killer whale tracking using multiple hydrophone arrays.

PubMed

Gassmann, Martin; Henderson, E Elizabeth; Wiggins, Sean M; Roch, Marie A; Hildebrand, John A

2013-11-01

To study delphinid near surface movements and behavior, two L-shaped hydrophone arrays and one vertical hydrophone line array were deployed at shallow depths (<125 m) from the floating instrument platform R/P FLIP, moored northwest of San Clemente Island in the Southern California Bight. A three-dimensional propagation-model based passive acoustic tracking method was developed and used to track a group of five offshore killer whales (Orcinus orca) using their emitted clicks. In addition, killer whale pulsed calls and high-frequency modulated (HFM) signals were localized using other standard techniques. Based on these tracks sound source levels for the killer whales were estimated. The peak to peak source levels for echolocation clicks vary between 170-205 dB re 1 μPa @ 1 m, for HFM calls between 185-193 dB re 1 μPa @ 1 m, and for pulsed calls between 146-158 dB re 1 μPa @ 1 m.

Self-represented witnessing: the use of social media by asylum seekers in Australia's offshore immigration detention centres.

PubMed

Rae, Maria; Holman, Rosa; Nethery, Amy

2018-05-01

The act of witnessing connects audiences with distant suffering. But what happens when bearing witness becomes severely restricted? External parties, including the mainstream news media, are constrained from accessing Australia's offshore immigration detention centres. The effect is that people seeking asylum are hidden from the public and excluded from national debates. Some detainees have adopted social media as a platform to communicate their stories of flight, and their experiences of immigration detention, to a wider audience. This article examines the ways in which social media, and particularly Facebook, has facilitated what we call self-represented witnessing. We analyse two public Facebook pages to assess how detainees use such social media networks to document their experiences, and we observe the interaction between detainees, other social media users and mainstream media. Significantly, these social media networks enable detained asylum seekers to conduct an unmediated form of self-represented witnessing that exposes human rights abuses and documents justice claims.

Positive organizational behavior and safety in the offshore oil industry: Exploring the determinants of positive safety climate.

PubMed

Hystad, Sigurd W; Bartone, Paul T; Eid, Jarle

2014-01-01

Much research has now documented the substantial influence of safety climate on a range of important outcomes in safety critical organizations, but there has been scant attention to the question of what factors might be responsible for positive or negative safety climate. The present paper draws from positive organizational behavior theory to test workplace and individual factors that may affect safety climate. Specifically, we explore the potential influence of authentic leadership style and psychological capital on safety climate and risk outcomes. Across two samples of offshore oil-workers and seafarers working on oil platform supply ships, structural equation modeling yielded results that support a model in which authentic leadership exerts a direct effect on safety climate, as well as an indirect effect via psychological capital. This study shows the importance of leadership qualities as well as psychological factors in shaping a positive work safety climate and lowering the risk of accidents.

Vega is first offshore development for Montedison

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1985-10-01

Montedison's Vega field, 15 miles off the southern tip of Sicily, has recoverable oil reserves of 400 million bbl. This is Montedison's first offshore development venture, although the operator has considerable onshore experience. It will be followed by a second field, the smaller Mila floating production system, also off Sicily. One platform will be placed on a template installed in 1983 with up to 18 pre-drilled wells in water depths of 480 ft. The field may hold up to 1 billion bbl of 16/sup 0/ crude, but geology is complex and heavily fractured. The template has 30 available drilling slots,more » and water injection is being considered. The Vega discovery well was drilled in 1980, with 5000 b/d tested from 1000-ft oil column in Strep-penosa shales. Subsequently five wells were drilled by the Glomar Biscay I semi. These wells were drilled to a depth of just over 8000 ft with a total deviation of 60/sup 0/. The template is the first in the Mediterranean.« less

Gulf of Mexico Helicopter Offshore System Technologies Engineering Needs Assessment

NASA Technical Reports Server (NTRS)

Koenke, Edmund J.; Carpenter, Elisabeth J.; Williams, Larry; Caiafa, Caesar

1999-01-01

The National Aeronautics and Space Administration (NASA), in partnership with the Federal Aviation Administration (FAA), is conducting a research and development program to modernize the National Airspace System (NAS). The mission of NASA's Advanced Air Transportation Technologies (AATT) project is to develop advanced Air Traffic Management (ATM) concepts and decision support tools for eventual deployment and implementation by the FAA and the private sector. One major objective of the NASA AATT project is to understand and promote the needs of all user classes. The Gulf of Mexico (GoMex) airspace has unique needs. A large number of helicopters operate in this area with only limited surveillance and sometimes-severe environmental conditions. Thunderstorms are the most frequent weather hazard during the spring, summer, and fall. In winter, reduced hours of daylight, low ceilings, strong winds, and icing conditions may restrict operations. Hurricanes impose the most severe weather hazard. The hurricane season, from June through October, normally requires at least one mass evacuation of all offshore platforms.

Positive organizational behavior and safety in the offshore oil industry: Exploring the determinants of positive safety climate

PubMed Central

Hystad, Sigurd W.; Bartone, Paul T.; Eid, Jarle

2013-01-01

Much research has now documented the substantial influence of safety climate on a range of important outcomes in safety critical organizations, but there has been scant attention to the question of what factors might be responsible for positive or negative safety climate. The present paper draws from positive organizational behavior theory to test workplace and individual factors that may affect safety climate. Specifically, we explore the potential influence of authentic leadership style and psychological capital on safety climate and risk outcomes. Across two samples of offshore oil-workers and seafarers working on oil platform supply ships, structural equation modeling yielded results that support a model in which authentic leadership exerts a direct effect on safety climate, as well as an indirect effect via psychological capital. This study shows the importance of leadership qualities as well as psychological factors in shaping a positive work safety climate and lowering the risk of accidents. PMID:24454524

Undersea fiber optic technology for the offshore community

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mariano, J.J.

The explosive growth in demand for global communications has been met by a rapid evolution in the undersea fiber-optic technology, which in just a few years has become the predominant method of communication across the world`s oceans and seas. As the scope of applications has become broader, the technology has become more diverse, and now comprises a range of products capable of providing economical, reliable service in any subsea environment, from ocean depths to coastal lagoons. In this paper, the authors discuss how undersea lightwave technology is being applied to meet the communication and production control needs of the offshoremore » oil and gas industry. They discuss the trends and technology developments that are changing the economics of undersea fiber-optic communication networks, as well as synergies in the offshore industry. They consider various applications for the industry and means of enhancing the profitability of platform operations through reduced downtime, reduced operating cost, and enhanced safety. Finally, they discuss extensions to exploratory drilling and land-based operations.« less

Statistical analysis on the signals monitoring multiphase flow patterns in pipeline-riser system

NASA Astrophysics Data System (ADS)

Ye, Jing; Guo, Liejin

2013-07-01

The signals monitoring petroleum transmission pipeline in offshore oil industry usually contain abundant information about the multiphase flow on flow assurance which includes the avoidance of most undesirable flow pattern. Therefore, extracting reliable features form these signals to analyze is an alternative way to examine the potential risks to oil platform. This paper is focused on characterizing multiphase flow patterns in pipeline-riser system that is often appeared in offshore oil industry and finding an objective criterion to describe the transition of flow patterns. Statistical analysis on pressure signal at the riser top is proposed, instead of normal prediction method based on inlet and outlet flow conditions which could not be easily determined during most situations. Besides, machine learning method (least square supported vector machine) is also performed to classify automatically the different flow patterns. The experiment results from a small-scale loop show that the proposed method is effective for analyzing the multiphase flow pattern.

Anomalous Near-Surface Low-Salinity Pulses off the Central Oregon Coast

PubMed Central

Mazzini, Piero L. F.; Risien, Craig M.; Barth, John A.; Pierce, Stephen D.; Erofeev, Anatoli; Dever, Edward P.; Kosro, P. Michael; Levine, Murray D.; Shearman, R. Kipp; Vardaro, Michael F.

2015-01-01

From mid-May to August 2011, extreme runoff in the Columbia River ranged from 14,000 to over 17,000 m3/s, more than two standard deviations above the mean for this period. The extreme runoff was the direct result of both melting of anomalously high snowpack and rainfall associated with the 2010–2011 La Niña. The effects of this increased freshwater discharge were observed off Newport, Oregon, 180 km south of the Columbia River mouth. Salinity values as low as 22, nine standard deviations below the climatological value for this period, were registered at the mid-shelf. Using a network of ocean observing sensors and platforms, it was possible to capture the onshore advection of the Columbia River plume from the mid-shelf, 20 km offshore, to the coast and eventually into Yaquina Bay (Newport) during a sustained wind reversal event. Increased freshwater delivery can influence coastal ocean ecosystems and delivery of offshore, river-influenced water may influence estuarine biogeochemistry. PMID:26607750

DOE Office of Scientific and Technical Information (OSTI.GOV)

Corbett, R.A

Another quality crude oil is available from the North Sea. Norway's Oseberg crude oil entered the export market on Dec. 1, 1988. This premium, low-sulfur crude oil is currently being produced at approximately 240,000 b/d from the Norwegian sector of the North Sea. Two platforms, operated by Den Norske Stats Oijeselskap A.S. (Statoil), are currently in production, with a third scheduled to go into production in 1991. Oseberg is a typical, low-sulfur North Sea crude oil that will provide a full range of high-quality, low-sulfur products. The naphtha cuts are of intermediate to paraffinic quality, making them suitable for gasolinemore » production. The Oseberg crude is stabilized at the offshore platform and then transported to the Sture terminal, north of Bergen, Norway. The terminal can handle crude oil tankers up to 300,000 DWT.« less

Quality assessment of geogrids used for subgrade treatment.

DOT National Transportation Integrated Search

2012-12-01

Geogrid reinforcements have been used by the Indiana Department of Transportation (INDOT) to construct stable subgrade foundations : and to provide a working platform for construction over weak and soft soils. Use of geogrid reinforcement in a paveme...

Western Continental Margin of India - Re-look using potential field data

NASA Astrophysics Data System (ADS)

Rajaram, M.; S P, A.

2008-05-01

The Western Continental Margin of India (WCMI) evolved as a result of rifting between India and Madagascar that took place during mid Cretaceous (~88Ma).The WCMI is equally important in terms of natural resources as well as research point of view. The major tectonic elements in the western offshore includes the Laxmi and Chagos- Laccadive ridge dividing the WCMI and the adjoining Arabian sea into two basins, Pratap Ridge, Alleppey platform etc. Different theories have been proposed for the evolution of each of these tectonic elements. In the current paper we look at geopotential data on the west coast of India and the western off-shore. The data sets utilized include Satellite derived High Resolution Free Air Gravity data over the off-shore, Bouguer data onland, Champ Satellite Magnetic data, published Marine Magnetic data collected by ONGC, NIO, ground magnetic data over west cost collected by IIG and available aeromagnetic data. From the free air gravity anomaly the structural details of the western offshore can be delineated. The Euler depths of FAG depict deep solutions associated with Pratap Ridge, Comorin Ridge, the west coast fault and the Laxmi Ridge. These may be associated with continental margin and continental fragments. From the aeromagnetic and marine magnetic data it is evident that the West Coast Fault is dissected at several places. The shallow circular feature associated with Bombay High is evident both on the FAG and the analytic signal derived from satellite Magnetic data. The crustal magnetic thickness from MF5 lithospheric model of the Champ appears to suggest that the continental crust extends up to the Chagos- Laccadive ridge. Based on the analysis of these geopotential data sets the various theories for the evolution of the WCMI will be evaluated and these results will be presented.

Calibration and validation of a spar-type floating offshore wind turbine model using the FAST dynamic simulation tool

DOE PAGES

Browning, J. R.; Jonkman, J.; Robertson, A.; ...

2014-12-16

In this study, high-quality computer simulations are required when designing floating wind turbines because of the complex dynamic responses that are inherent with a high number of degrees of freedom and variable metocean conditions. In 2007, the FAST wind turbine simulation tool, developed and maintained by the U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory (NREL), was expanded to include capabilities that are suitable for modeling floating offshore wind turbines. In an effort to validate FAST and other offshore wind energy modeling tools, DOE funded the DeepCwind project that tested three prototype floating wind turbines at 1/50 th scalemore » in a wave basin, including a semisubmersible, a tension-leg platform, and a spar buoy. This paper describes the use of the results of the spar wave basin tests to calibrate and validate the FAST offshore floating simulation tool, and presents some initial results of simulated dynamic responses of the spar to several combinations of wind and sea states. Wave basin tests with the spar attached to a scale model of the NREL 5-megawatt reference wind turbine were performed at the Maritime Research Institute Netherlands under the DeepCwind project. This project included free-decay tests, tests with steady or turbulent wind and still water (both periodic and irregular waves with no wind), and combined wind/wave tests. The resulting data from the 1/50th model was scaled using Froude scaling to full size and used to calibrate and validate a full-size simulated model in FAST. Results of the model calibration and validation include successes, subtleties, and limitations of both wave basin testing and FAST modeling capabilities.« less

Geodynamics and synchronous filling of rift-type basin evolved through compression tectonics

NASA Astrophysics Data System (ADS)

Papdimitriou, Nikolas; Nader, Fadi; Gorini, Christian; Deschamps, Remy

2016-04-01

The Levant Basin falls in the category of frontier basins, and is bounded by the Eratosthenes seamount to the West, the Nile cone delta to the south, Cyprus to the north and Lebanon to the east. The Levant Basin was initially a rift type basin, which is located at a major plate boundary since the Late Triassic. It evolved later on through compression tectonics. The post-rift phase prevailed since the Late Jurassic and is expressed by the gradual initiation of a passive margin. A thick infill, mostly of deep water sediments (about 12 km thick) is accounted for the Levant Basin. The post-rift sediments are pinching-out along the slope of the well preserved (and imaged) eastern margin of the Eratosthenes seamount, which is essentially made up of Mesozoic platform carbonates (about 5 km). Thus, the Eratosthenes carbonate platform was adjacent to the deep marine facies of the Levant Basin until the late Cretaceous/Cenozoic. At that time, both the Eratosthenes seamount and the Levant Basin became part of a foreland basin along the Cyprus Arc zone as a result of the collision of the African and Eurasian plates. The objective of this contribution is to investigate the timing and the mechanisms of flexural subsidence as well as the sedimentary filling of Levant Basin (through a source-to-sink approach) in a well-deformed tectonic region. The interpretation of twenty-four 2D seismic profiles coupled with the available ODP wells, offshore Cyprus, aims to define the primary reflectors and seismic packages. Then, concepts of seismic stratigraphy and sequence stratigraphy are applied to achieve a better understanding of the tectonostratigraphy and sedimentary architecture of the Eratosthenes seamount (as an isolated carbonate platform) and its surroundings. Recent offshore discoveries south of the Eratosthenes seamount (e.g., Zhor) have confirmed the presence of gas accumulations exceeding 30Tcf in subsalt Lower Miocene carbonate buildups, making out the understanding of the evolution of this new frontier hydrocarbon province of great importance.

Can reef islands keep up with sea level? Exploring the interplay between sea-level rise, sediment supply, and overwash processes

NASA Astrophysics Data System (ADS)

Lorenzo-Trueba, J.

2016-02-01

Coral reef islands are accumulations of carbonate sediment deposited subaerially atop coral reef platforms. We hypothesize that the long-term evolution of reef islands is primarily controlled by the interplay between sea-level rise, sediment supply, and sediment overwash. Reef islands are supplied with sediment from offshore, in the form of reworked coral skeletons that originate at the reef edge and are carried onto the reef platform by waves, as well as in situ production on the reef flat itself. However, the primary mechanism that allows reef islands to keep pace with sea level is storm overwash, which enables the vertical transport of sediment from the periphery to the top of the island. Given the current lack of understanding on how production and overwash processes interact, we have constructed a morphodynamic model to elucidate and quantify how reef islands may respond to sea-level rise and changes in sediment production. Model results demonstrate that even if reef islands can remain subaerial over the coming century, this will require significant deposition of sediment atop the island and, in many cases, the island is expected to roll considerably over itself; both of these morphologic changes will negatively affect homes and infrastructure atop these islands. The model also suggests that as reef islands approach the lagoon edge of the reef platform, shoreline erosion and island drowning can be enhanced as sediment overwashes into the lagoon. Interestingly, this situation can only be avoided if either a high offshore sediment supply bulwarks the island in place or the system undergoes similar rates of overwash sedimentation from both the ocean and the lagoon sides. The model also allows us to explore the potential for increased overwash with increased storminess, increases in sediment supply due to bleaching or disturbance, or reduction of sediment supply as a result of reduced calcification rates due to ocean acidification.

Impact of the slab dip change onto the deformation partitioning in the northern Lesser Antilles oblique subduction zone (Antigua-Virgin Islands)

NASA Astrophysics Data System (ADS)

Laurencin, Muriel; Marcaillou, Boris; Klingelhoefer, Frauke; Graindorge, David; Lebrun, Jean-Frédéric; Laigle, Mireille; Lallemand, Serge

2017-04-01

Marine geophysical cruises Antithesis (2013-2016) investigate the impact of the variations in interplate geometry onto margin tectonic deformation along the strongly oblique Lesser Antilles subduction zone. A striking features of this margin is the drastic increase in earthquake number from the quiet Barbuda-St Martin segment to the Virgin Islands platform. Wide-angle seismic data highlight a northward shallowing of the downgoing plate: in a 150 km distance from the deformation front, the slab dipping angle in the convergence direction decreases from 12° offshore of Antigua Island to 7° offshore of Virgin Islands. North-South wide-angle seismic line substantiates a drastic slab-dip change that likely causes this northward shallowing. This dip change is located beneath the southern tip of the Virgin Islands platform where the Anegada Passage entails the upper plate. Based on deep seismic lines and bathymetric data, the Anegada Passage is a 450 km long W-E trending set of pull-apart basins and strike-slip faults that extends from the Lesser Antilles accretionary prism to Puerto Rico. The newly observed sedimentary architecture within pull-apart Sombrero and Malliwana basins indicates a polyphased tectonic history. A past prominent NW-SE extensive to transtensive phase, possibly related to the Bahamas Bank collision, opened the Anegada Passage as previously published. Transpressive tectonic evidences indicate that these structures have been recently reactivated in an en-echelon sinistral strike-slip system. The interpreted strain ellipsoid is consistent with deformation partitioning. We propose that the slab northward shallowing increases the interplate coupling and the seismic activity beneath the Virgin Islands platform comparatively to the quiet Barbuda-St Martin segment. It is noteworthy that the major tectonic partitioning structure in the Lesser Antilles forearc is located above the slab dip change where the interplate seismic coupling increases.

Strain engineering of electronic and magnetic properties of Ga2S2 nanoribbons

NASA Astrophysics Data System (ADS)

Wang, Bao-Ji; Li, Xiao-Hua; Zhang, Li-Wei; Wang, Guo-Dong; Ke, San-Huang

2017-05-01

Not Available Project supported by the National Natural Science Foundation of China (Grant Nos. 11174220 and 11374226), the Key Scientific Research Project of the Henan Institutions of Higher Learning, China (Grant No. 16A140009), the Program for Innovative Research Team of Henan Polytechnic University, China (Grant Nos. T2015-3 and T2016-2), the Doctoral Foundation of Henan Polytechnic University, China (Grant No. B2015-46), and the High-performance Grid Computing Platform of Henan Polytechnic University, China.

Observation of high-resolution wind fields and offshore wind turbine wakes using TerraSAR-X imagery

NASA Astrophysics Data System (ADS)

Gies, Tobias; Jacobsen, Sven; Lehner, Susanne; Pleskachevsky, Andrey

2014-05-01

1. Introduction Numerous large-scale offshore wind farms have been built in European waters and play an important role in providing renewable energy. Therefore, knowledge of behavior of wakes, induced by large wind turbines and their impact on wind power output is important. The spatial variation of offshore wind turbine wake is very complex, depending on wind speed, wind direction, ambient atmospheric turbulence and atmospheric stability. In this study we demonstrate the application of X-band TerraSAR-X (TS-X) data with high spatial resolution for studies on wind turbine wakes in the near and far field of the offshore wind farm Alpha Ventus, located in the North Sea. Two cases which different weather conditions and different wake pattern as observed in the TS-X image are presented. 2. Methods The space-borne synthetic aperture radar (SAR) is a unique sensor that provides two-dimensional information on the ocean surface. Due to their high resolution, daylight and weather independency and global coverage, SARs are particularly suitable for many ocean and coastal applications. SAR images reveal wind variations on small scales and thus represent a valuable means in detailed wind-field analysis. The general principle of imaging turbine wakes is that the reduced wind speed downstream of offshore wind farms modulates the sea surface roughness, which in turn changes the Normalized Radar Cross Section (NRCS, denoted by σ0) in the SAR image and makes the wake visible. In this study we present two cases at the offshore wind farm Alpha Ventus to investigate turbine-induced wakes and the retrieved sea surface wind field. Using the wind streaks, visible in the TS-X image and the shadow behind the offshore wind farm, induced by turbine wake, the sea surface wind direction is derived and subsequently the sea surface wind speed is calculated using the latest generation of wind field algorithm XMOD2. 3. Case study alpha ventus Alpha Ventus is located approximately 45 km from the coast of Borkum, Germany, and consists of twelve 5-Megawatt wind power turbines. The retrieved results are validated by comparing with QuikSCAT measurements, the results of the German Weather Service (DWD) atmospheric model and in-situ measurements of wind speed and wind direction, obtained from the research platform FiNO1, installed 400 m west of Alpha Ventus. 4. Conclusion In the presented case study we quantify the wake characteristics of wake length, wake width, maximum velocity de?cit, wake merging and wake meandering. We show that SAR has the capability to map the sea surface two-dimensionally in high spatial resolution which provides a unique opportunity to observe spatial characteristics of offshore wind turbine wakes. The SAR derived information can support offshore wind farming with respect to optimal siting and design and help to estimate their effects on the environment.

Does EMF Emitted from In Situ Subsea Power Cables Affect the Composition of Deep Benthic Fish and Invertebrate Communities?

NASA Astrophysics Data System (ADS)

Bull, A. S.; Nishimoto, M.; Love, M.; Schroeder, D. M.

2016-02-01

A network of power cables is an important component of any offshore renewable energy generation facilities (e.g., wind and wave). The cables laid on the seafloor carry current that produces both electric and magnetic fields; the magnetic field, here called an electromagnetic field (EMF), is what is emitted from shielded cables. The cables, themselves, add hard, low-relief structure to what is typically soft-bottom habitat (mud or sand). Given that laboratory experiments show EMF can affect the behavior of some marine vertebrates and invertebrates, concern is raised over the potential ecological impacts of in situ power cables. Here we report an unusual comparative study of the effect of EMF emitted from in situ power cables on the fish and invertebrate communities of the deep coastal shelf environment. In the Santa Barbara Channel of southern California, subsea power cables, similar to those used in the offshore renewable energy industry, transmit electricity from shore to offshore oil and gas production platforms. A non-energized cable in the vicinity of energized cables afforded us the unusual opportunity to control for the effect of cable as hard, low relief habitat. We conducted three annual submersible surveys in October, 2012- 2014, at depths from 75 m to 210 m. We present results comparing observations along the energized and nonenergized cables and on the adjacent natural substrate.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colliat, J.L.; Boisard, P.; Andersen, K.

Shallow caisson foundations are considered as alternative anchors for permanent mooring of a process barge at an oil and gas field developed by ELF Congo in the Gulf of Guinea. The 12 mooring lines are scheduled to be installed on site in July 1995 and the process barge will be connected in 1996 for start of production. With a water depth of about 170m, this field will be the deepest one offshore Western Africa to date. The soils at the site consist of soft normally consolidated clays. The paper presents the results of a comparative study of potential anchor solutionsmore » for this production barge, including high capacity drag anchors, driven piles, and shallow caisson foundations installed by underpressure. This comparative study, including design, construction, and installation of the mooring system, has shown that the caisson foundations represent the best suited solution, technically as well as on an economical point of view, because of the following advantages: (1) vertical load capability, thus allowing to reduce the anchoring pattern, (2) once positioned on the seabed, the location of each anchor is fixed and known with accuracy, and (3) more simple and shorter installation procedure, since caisson anchors, as piles, do not require to be proof-loaded on site.« less

Intelligent Fasteners

NASA Technical Reports Server (NTRS)

1997-01-01

Under a Small Business Innovation Research contract from Marshall Space Flight Center, Ultrafast, Inc. developed the world's first, high-temperature resistant, "intelligent" fastener. NASA needed a critical-fastening appraisal and validation of spacecraft segments that are coupled together in space. The intelligent-bolt technology deletes the self-defeating procedure of having to untighten the fastener, and thus upset the joint, during inspection and maintenance. The Ultrafast solution yielded an innovation that is likely to revolutionize manufacturing assembly, particularly the automobile industry. Other areas of application range from aircraft, computers and fork-lifts to offshore platforms, buildings, and bridges.

Military Use of Offshore Platforms

DTIC Science & Technology

1979-04-09

a 31 foot cabin area. The S-61N is signifi-- cantly longer than the Navy’s SH-3. The S-61N can also carry external loads of more than 7,000 pounds. At...using two external fuel tanks . In order to accomplish an ocean surveillance or radar flood/hold down mission with the helicopter’s LN-66 radar, radar...slashed from the FY-78 DOD budget. The vans which have dUi’eady been completed together with some that are partially completed, are presently in storage at

Operational experience in underwater photogrammetry

NASA Astrophysics Data System (ADS)

Leatherdale, John D.; John Turner, D.

Underwater photogrammetry has become established as a cost-effective technique for inspection and maintenance of platforms and pipelines for the offshore oil industry. A commercial service based in Scotland operates in the North Sea, USA, Brazil, West Africa and Australia. 70 mm cameras and flash units are built for the purpose and analytical plotters and computer graphics systems are used for photogrammetric measurement and analysis of damage, corrosion, weld failures and redesign of underwater structures. Users are seeking simple, low-cost systems for photogrammetric analysis which their engineers can use themselves.

Shallow geology, sea-floor texture, and physiographic zones of Buzzards Bay, Massachusetts

USGS Publications Warehouse

Foster, David S.; Baldwin, Wayne E.; Barnhardt, Walter A.; Schwab, William C.; Ackerman, Seth D.; Andrews, Brian D.; Pendleton, Elizabeth A.

2015-01-07

Geologic, sediment texture, and physiographic zone maps characterize the sea floor of Buzzards Bay, Massachusetts. These maps were derived from interpretations of seismic-reflection profiles, high-resolution bathymetry, acoustic-backscatter intensity, bottom photographs, and surficial sediment samples. The interpretation of the seismic stratigraphy and mapping of glacial and Holocene marine units provided a foundation on which the surficial maps were created. This mapping is a result of a collaborative effort between the U.S. Geological Survey and the Massachusetts Office of Coastal Zone Management to characterize the surface and subsurface geologic framework offshore of Massachusetts.

Quaternion-Based Conversion Formulas for Kinematic Attitude of Floating Offshore Wind Turbines (FOWT)

NASA Astrophysics Data System (ADS)

Li, Yugang; Fu, Gaoyong

2018-01-01

A floater allowing large-angle motion supporting a large payload (wind turbine and nacelle) with large aerodynamic loads high above the water surface is a great challenge because of the raised center of gravity and large overturning moment. In this paper, the conversion formulas between Euler angles and quaternions were derived, the research offered an efficient methodology without singularity to compute large-angle rigid body rotations of a FOWT, which laid the foundation for quaternion-based attitude kinematic model introduced to describe the dynamic response of the FOWT system and further solution.

A caregiver support platform within the scope of an ambient assisted living ecosystem.

PubMed

Costa, Angelo; Novais, Paulo; Simoes, Ricardo

2014-03-20

The Ambient Assisted Living (AAL) area is in constant evolution, providing new technologies to users and enhancing the level of security and comfort that is ensured by house platforms. The Ambient Assisted Living for All (AAL4ALL) project aims to develop a new AAL concept, supported on a unified ecosystem and certification process that enables a heterogeneous environment. The concepts of Intelligent Environments, Ambient Intelligence, and the foundations of the Ambient Assisted Living are all presented in the framework of this project. In this work, we consider a specific platform developed in the scope of AAL4ALL, called UserAccess. The architecture of the platform and its role within the overall AAL4ALL concept, the implementation of the platform, and the available interfaces are presented. In addition, its feasibility is validated through a series of tests.

A Caregiver Support Platform within the Scope of an Ambient Assisted Living Ecosystem

PubMed Central

Costa, Angelo; Novais, Paulo; Simoes, Ricardo

2014-01-01

The Ambient Assisted Living (AAL) area is in constant evolution, providing new technologies to users and enhancing the level of security and comfort that is ensured by house platforms. The Ambient Assisted Living for All (AAL4ALL) project aims to develop a new AAL concept, supported on a unified ecosystem and certification process that enables a heterogeneous environment. The concepts of Intelligent Environments, Ambient Intelligence, and the foundations of the Ambient Assisted Living are all presented in the framework of this project. In this work, we consider a specific platform developed in the scope of AAL4ALL, called UserAccess. The architecture of the platform and its role within the overall AAL4ALL concept, the implementation of the platform, and the available interfaces are presented. In addition, its feasibility is validated through a series of tests. PMID:24658626

Lime Kiln Dust for Treated Subgrades : Technical Summary

DOT National Transportation Integrated Search

2017-11-01

Chemical and cementitious materials are often used to modify and stabilize the subgrade soils that serve as foundations for pavements. Improvement of the subgrade provides a better working platform for construction of the layers above and improves th...

Lime Kiln Dust for Treated Subgrades : Final Report

DOT National Transportation Integrated Search

2017-11-01

Chemical and cementitious materials are often used to modify and stabilize the subgrade soils that serve as foundations for pavements. Improvement of the subgrade provides a better working platform for construction of the layers above and improves th...

Analysis of Wave Fields induced by Offshore Pile Driving

NASA Astrophysics Data System (ADS)

Ruhnau, M.; Heitmann, K.; Lippert, T.; Lippert, S.; von Estorff, O.

2015-12-01

Impact pile driving is the common technique to install foundations for offshore wind turbines. With each hammer strike the steel pile - often exceeding 6 m in diameter and 80 m in length - radiates energy into the surrounding water and soil, until reaching its targeted penetration depth. Several European authorities introduced limitations regarding hydroacoustic emissions during the construction process to protect marine wildlife. Satisfying these regulations made the development and application of sound mitigation systems (e.g. bubble curtains or insulation screens) inevitable, which are commonly installed within the water column surrounding the pile or even the complete construction site. Last years' advances have led to a point, where the seismic energy tunneling the sound mitigation systems through the soil and radiating back towards the water column gains importance, as it confines the maximum achievable sound mitigation. From an engineering point of view, the challenge of deciding on an effective noise mitigation layout arises, which especially requires a good understanding of the soil-dependent wave field. From a geophysical point of view, the pile acts like a very unique line source, generating a characteristic wave field dominated by inclined wave fronts, diving as well as head waves. Monitoring the seismic arrivals while the pile penetration steadily increases enables to perform quasi-vertical seismic profiling. This work is based on datasets that have been collected within the frame of three comprehensive offshore measurement campaigns during pile driving and demonstrates the potential of seismic arrivals induced by pile driving for further soil characterization.

Geotechnical centrifuge under construction

NASA Astrophysics Data System (ADS)

Richman, Barbara T.

Modifications are underway at the National Aeronautics and Space Administration (NASA) Ames Research Center in California to transform a centrifuge used in the Apollo space program to the largest geotechnical centrifuge in the free world. The centrifuge, to be finished in August and opened next January, following check out and tuning, will enable geoscientists to model stratigraphic features down to 275 m below the earth's surface. Scientists will be able to model processes that are coupled with body force loading, including earthquake response of earth structures and soil structure interaction; rubbled-bed behavior during in situ coal gasification or in oil shale in situ retorts; behavior of frozen soil; frost heave; behavior of offshore structures; wave-seabed interactions; explosive cratering; and blast-induced liquefaction.The centrifuge will have a load capacity of 900-g-tons (short); that is, it will be able to carry a net soil load of 3 short tons to a centripetal acceleration of 300 times the acceleration caused by gravity. Modified for a total cost of $2.4 million, the centrifuge will have an arm with a 7.6-m radius and a swinging platform or bucket at its end that will be able to carry a payload container measuring 2.1×2.1 m. An additional future input of $500,000 would enable the purchase of a larger bucket that could accommodate a load of up to 20 tons, according to Charles Babendreier, program director for geotechnical engineering at the National Science Foundation. Additional cooling for the motor would also be required. The centrifuge has the capability of accelerating the 20-ton load to 100 g.

On the Use of Coupled Wind, Wave, and Current Fields in the Simulation of Loads on Bottom-Supported Offshore Wind Turbines during Hurricanes: March 2012 - September 2015

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Eungsoo; Manuel, Lance; Curcic, Milan

In the United States, potential offshore wind plant sites have been identified along the Atlantic seaboard and in the Gulf of Mexico. It is imperative that we define external conditions associated with hurricanes and severe winter storms and consider load cases for which wind turbines may need to be designed. We selected two hurricanes, Ike (2008) and Sandy (2012), and investigated the effect these tropical storms would have on bottom-supported offshore wind turbines that were hypothetically in or close to their path as they made landfall. For realistic turbine loads assessment, it is important that the coupled influences of themore » changing wind, wave, and current fields are simulated throughout the evolution of the hurricanes. We employed a coupled model--specifically, the University of Miami Coupled Model (UMCM)--that integrates atmospheric, wave, and ocean components to produce needed wind, wave, and current data. The wind data are used to generate appropriate vertical wind profiles and full wind velocity fields including turbulence; the current field over the water column is obtained by interpolated discrete output current data; and short-crested irregular second-order waves are simulated using output directional wave spectra from the coupled model. We studied two monopile-supported offshore wind turbines sited in 20 meters of water in the Gulf of Mexico to estimate loads during Hurricane Ike, and a jacket space-frame platform-supported offshore wind turbine sited in 50 meters of water in the mid-Atlantic region to estimate loads during Hurricane Sandy. In this report we discuss in detail how the simulated hurricane wind, wave, and current output data are used in turbine loads studies. In addition, important characteristics of the external conditions are studied, including the relative importance of swell versus wind seas, aerodynamic versus hydrodynamic forces, current velocity effects, yaw control options for the turbine, hydrodynamic drag versus inertia forces, and soil-structure interaction effects. A detailed framework is presented that explains how coupled inputs can be included in turbine loads studies during a hurricane. This framework can aid in future efforts aimed at developing offshore wind turbine design criteria and load cases related to hurricanes.« less

A novel ultrasonic phased array inspection system to NDT for offshore platform structures

NASA Astrophysics Data System (ADS)

Wang, Hua; Shan, Baohua; Wang, Xin; Ou, Jinping

2007-01-01

A novel ultrasonic phased array detection system is developed for nondestructive testing (NDT). The purpose of the system is to make acquisition of data in real-time from 64-element ultrasonic phased array transducer, and to enable real- time processing of the acquired data. The system is composed of five main parts: master unit, main board, eight transmit/receive units, a 64-element transducer and an external PC. The system can be used with 64 element transducers, excite 32 elements, receive and sample echo signals form 32 elements simultaneously at 62.5MHz with 8 bit precision. The external PC is used as the user interface showing the real time images and controls overall operation of the system through USB serial link. The use of Universal Serial Bus (USB) improves the transform speed and reduces hardware interface complexity. The program of the system is written in Visual C++.NET and is platform independent.

Sensor and Processing COI (Briefing Charts)

DTIC Science & Technology

2014-05-27

Persistent Surveillance • Target Detection, Recognition & ID at Standoff Ranges • Force/Platform/Sensor Protection • Target Tracking • Early Warning • BDA ...inhomogeneous and complex media is also a foundational challenge for President’s BRAIN initiative. 38 Explore Advanced Sensors And Processing

Four essays on offshore wind power potential, development, regulatory framework, and integration

NASA Astrophysics Data System (ADS)

Dhanju, Amardeep

Offshore wind power is an energy resource whose potential in the US has been recognized only recently. There is now growing interest among the coastal states to harness the resource, particularly in states adjacent to the Mid-Atlantic Bight where the shallow continental shelf allows installation of wind turbines using the existing foundation technology. But the promise of bountiful clean energy from offshore wind could be delayed or forestalled due to policy and regulatory challenges. This dissertation is an effort to identify and address some of the important challenges. Focusing on Delaware as a case study it calculates the extent of the wind resource; considers one means to facilitate resource development---the establishment of statewide and regional public power authorities; analyzes possible regulatory frameworks to manage the resource in state-controlled waters; and assesses the use of distributed storage to manage intermittent output from wind turbines. In order to cover a diversity of topics, this research uses a multi-paper format with four essays forming the body of work. The first essay lays out an accessible methodology to calculate offshore wind resource potential using publicly available data, and uses this methodology to access wind resources off Delaware. The assessment suggests a wind resource approximately four times the average electrical load in Delaware. The second essay examines the potential role of a power authority, a quasi-public institution, in lowering the cost of capital, reducing financial risk of developing and operating a wind farm, and enhancing regional collaboration on resource development and management issues. The analysis suggests that a power authority can lower the cost of offshore wind power by as much as 1/3, thereby preserving the ability to pursue cost-competitive development even if the current federal incentives are removed. The third essay addresses the existing regulatory void in state-controlled waters of Delaware. It outlines a regulatory framework touching on key elements such as the leasing system, length of tenure, and financial terms for allocating property rights. In addition, the framework also provides recommendations on environmental assessment that would be required prior to lease issuance. The fourth essay analyzes offshore wind power integration using electric thermal storage in housing units. It presents a model of wind generation, heating load and wind driven thermal storage to assess the potential of storage to buffer wind intermittency. The analysis suggests that thermal load matches the seasonal excess of offshore wind during winter months, and that electric thermal storage could provide significant temporal, spatial, and cost advantages for balancing output from offshore wind generation, while also converting a major residential load (space heating) now met by fossil fuels to low carbon energy resources. Together, the four essays provide new analyses of policy, regulatory, and system integration issues that could impede resource development, and also analyze and recommend strategies to manage these issues.

3D Numerical Simulation of the Wave and Current Loads on a Truss Foundation of the Offshore Wind Turbine During the Extreme Typhoon Event

NASA Astrophysics Data System (ADS)

Lin, C. W.; Wu, T. R.; Chuang, M. H.; Tsai, Y. L.

2015-12-01

The wind in Taiwan Strait is strong and stable which offers an opportunity to build offshore wind farms. However, frequently visited typhoons and strong ocean current require more attentions on the wave force and local scour around the foundation of the turbine piles. In this paper, we introduce an in-house, multi-phase CFD model, Splash3D, for solving the flow field with breaking wave, strong turbulent, and scour phenomena. Splash3D solves Navier-Stokes Equation with Large-Eddy Simulation (LES) for the fluid domain, and uses volume of fluid (VOF) with piecewise linear interface reconstruction (PLIC) method to describe the break free-surface. The waves were generated inside the computational domain by internal wave maker with a mass-source function. This function is designed to adequately simulate the wave condition under observed extreme events based on JONSWAP spectrum and dispersion relationship. Dirichlet velocity boundary condition is assigned at the upper stream boundary to induce the ocean current. At the downstream face, the sponge-layer method combined with pressure Dirichlet boundary condition is specified for dissipating waves and conducting current out of the domain. Numerical pressure gauges are uniformly set on the structure surface to obtain the force distribution on the structure. As for the local scour around the foundation, we developed Discontinuous Bi-viscous Model (DBM) for the development of the scour hole. Model validations were presented as well. The force distribution under observed irregular wave condition was extracted by the irregular-surface force extraction (ISFE) method, which provides a fast and elegant way to integrate the force acting on the surface of irregular structure. From the Simulation results, we found that the total force is mainly induced by the impinging waves, and the force from the ocean current is about 2 order of magnitude smaller than the wave force. We also found the dynamic pressure, wave height, and the projection area of the structure are the main factors to the total force. Detailed results and discussion are presented as well.

Interdisciplinary Analysis of Drought Communication Through Social Media Platforms and Risk Communication

NASA Astrophysics Data System (ADS)

Wygant, M.

2015-12-01

As droughts continue to impact businesses and communities throughout the United States, there needs to be a greater emphasis on drought communication through interdisciplinary approaches, risk communication, and digital platforms. The purpose of this research is to provide an overview of the current literature on communicating drought and suggests areas for further improvement. Specifically, this research focuses on communicating drought through social media platforms such as Facebook, Twitter, and Instagram. It also focuses on the conglomeration of theoretical frameworks within the realm of risk communication, to provide a strong foundation towards future drought communication. This research proposal provides a critical step to advocate for paradigmatic shifts within natural hazard communication.

Compartmental genomics in living cells revealed by single-cell nanobiopsy.

PubMed

Actis, Paolo; Maalouf, Michelle M; Kim, Hyunsung John; Lohith, Akshar; Vilozny, Boaz; Seger, R Adam; Pourmand, Nader

2014-01-28

The ability to study the molecular biology of living single cells in heterogeneous cell populations is essential for next generation analysis of cellular circuitry and function. Here, we developed a single-cell nanobiopsy platform based on scanning ion conductance microscopy (SICM) for continuous sampling of intracellular content from individual cells. The nanobiopsy platform uses electrowetting within a nanopipette to extract cellular material from living cells with minimal disruption of the cellular milieu. We demonstrate the subcellular resolution of the nanobiopsy platform by isolating small subpopulations of mitochondria from single living cells, and quantify mutant mitochondrial genomes in those single cells with high throughput sequencing technology. These findings may provide the foundation for dynamic subcellular genomic analysis.

Workshop report: developing a pediatric inflammatory bowel diseases network and data platform in Canada.

PubMed

Sherman, Philip M; Brown, Sally; Rose, Keeley; Murphy, Tim; Makarchuk, Mary-Jo; Paterson, William; Belanger, Paul

2012-08-01

The purpose of the workshop was to receive input from the Canadian pediatric inflammatory bowel diseases research community to develop a research funding opportunity for a Canadian pediatric inflammatory bowel diseases network and data platform supported by the Canadian Institutes for Health Research, in partnership with the Foundation for Children with Intestinal and Liver Disorders. Leaders from across the country came together, with the objectives of identifying the scientific goals for a Canadian pediatric inflammatory bowel disease network, the required infrastructure, and an appropriate governance structure needed to achieve such a network and data platform, as well as other elements needed to ensure the successful implementation of a network.

Study of lifting operation of a tripod foundation for offshore wind turbine

NASA Astrophysics Data System (ADS)

Zhu, H.; Li, L.; Ong, M. C.

2017-12-01

This study addresses numerical analysis of the installation of a tripod foundation using a heavy lift vessel (HLV). Limiting sea states are firstly predicted in the frequency domain based on crane tip vertical motions using linear transfer functions. Then, numerical modelling and simulations are carried out in the time domain to analyse the coupled dynamic system taking into consideration of the nonlinearities of the system. In time-domain analysis, two lifting phases are brought into focus, i.e., the lift-off and the lowering phases. For the lift-off phase, two scenarios are considered, i.e., lift-off from the own deck of the HLV and lift-off from a transport barge. Moreover, comparative studies using two types of installation vessels, a floating vessel and a Jack-up, are investigated for the lowering process. Critical responses including the motions of the tripod and the lift wire tensions are presented and compared under various environmental and loading conditions.

Seismic analysis of offshore wind turbines on bottom-fixed support structures.

PubMed

Alati, Natale; Failla, Giuseppe; Arena, Felice

2015-02-28

This study investigates the seismic response of a horizontal axis wind turbine on two bottom-fixed support structures for transitional water depths (30-60 m), a tripod and a jacket, both resting on pile foundations. Fully coupled, nonlinear time-domain simulations on full system models are carried out under combined wind-wave-earthquake loadings, for different load cases, considering fixed and flexible foundation models. It is shown that earthquake loading may cause a significant increase of stress resultant demands, even for moderate peak ground accelerations, and that fully coupled nonlinear time-domain simulations on full system models are essential to capture relevant information on the moment demand in the rotor blades, which cannot be predicted by analyses on simplified models allowed by existing standards. A comparison with some typical design load cases substantiates the need for an accurate seismic assessment in sites at risk from earthquakes. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Data Lakes and Data Visualization: An Innovative Approach to Address the Challenges of Access to Health Care in Mississippi.

PubMed

Krause, Denise D

2015-01-01

There are a variety of challenges to developing strategies to improve access to health care, but access to data is critical for effective evidence-based decision-making. Many agencies and organizations throughout Mississippi have been collecting quality health data for many years. However, those data have historically resided in data silos and have not been readily shared. A strategy was developed to build and coordinate infrastructure, capacity, tools, and resources to facilitate health workforce and population health planning throughout the state. Realizing data as the foundation upon which to build, the primary objective was to develop the capacity to collect, store, maintain, visualize, and analyze data from a variety of disparate sources -- with the ultimate goal of improving access to health care. Specific aims were to: 1) build a centralized data repository and scalable informatics platform, 2) develop a data management solution for this platform and then, 3) derive value from this platform by facilitating data visualization and analysis. A managed data lake was designed and constructed for health data from disparate sources throughout the state of Mississippi. A data management application was developed to log and track all data sources, maps and geographies, and data marts. With this informatics platform as a foundation, a variety of tools are used to visualize and analyze data. To illustrate, a web mapping application was developed to examine the health workforce geographically and attractive data visualizations and dynamic dashboards were created to facilitate health planning and research. Samples of data visualizations that aim to inform health planners and policymakers are presented. Many agencies and organizations throughout the state benefit from this platform. The overarching goal is that by providing timely, reliable information to stakeholders, Mississippians in general will experience improved access to quality care.

Geotechnical Engineering in US Elementary Schools

ERIC Educational Resources Information Center

Suescun-Florez, Eduardo; Iskander, Magued; Kapila, Vikram; Cain, Ryan

2013-01-01

This paper reports on the results of several geotechnical engineering-related science activities conducted with elementary-school students. Activities presented include soil permeability, contact stress, soil stratigraphy, shallow and deep foundations, and erosion in rivers. The permeability activity employed the LEGO NXT platform for data…

Tectonic structure and petroleum potential of TayabasBay southeast Luzon, Philippines

NASA Astrophysics Data System (ADS)

Bacud, Jaime; Moore, Aidan; Lee, Chao-Skiing

Tayabas Bay is one of four offshore Philippine areas where the Australian GeologicalSurvey Organization and the Philippine Department of Energy conducted a cooperative marine seismic, gravity, magnetic, bathymetry and geochemical survey. The project acquired new seismic data and reprocessed the 1983 World Bank seismic sections which were all integrated with previous oil company data. the absence of wells drilled offshore, interpretation of offshore seismic data was complemented by onshore well log information and stratigraphy of the Bondoc Peninsula. Geochemistry data, both offshore and onshore, were analyzed to confirm the presence of mature source rocks and hydrocarbon migration. A new seismic interpretation has revealed the structure of this tectonically active geologically complex area. A major structural feature interpreted in offshore Tayabas Bay was a N-NW-trending strike-slip fault which is believed to be a northern splay of the Sibuyan Sea Fault. The authors named this fault the Tayabas Bay Fault and due to its association with the Philippine Fault System the movement is assumed to be left-lateral. The present study suggested the presence of a prolific source rock in the Middle Miocene Vigo Formation and/or the Late Oligocene to Early Miocene Panaon Limestone. Oil and gas generation have been and are occurring in the Bondoc Sub-basin. Two groups of reservoirs were identified, the shelf carbonates beneath the Middle Miocene shales on the Marinduque Platform and the early Middle Miocene carbonates and basin-floor clastics near the base of the Vigo Formation. Carbonate reservoirs are believed to be present in traps formed when the Late Oligocene to Early Miocene carbonate reefs and shelf deposits of the Panaon Limestone were buried by the Middle Miocene shales. A later set of traps was formed and possibly superimposed by the intense deformation associated with the Philippine Fault System which has continued from the Late Pliocene up to the present. Evaluation for hydrocarbon reserves of several possible traps identified three significant leads, namely the Yuni Lead in the south, the Mulanay in the central area and the Mabio in the North.

Design of verification platform for wireless vision sensor networks

NASA Astrophysics Data System (ADS)

Ye, Juanjuan; Shang, Fei; Yu, Chuang

2017-08-01

At present, the majority of research for wireless vision sensor networks (WVSNs) still remains in the software simulation stage, and the verification platforms of WVSNs that available for use are very few. This situation seriously restricts the transformation from theory research of WVSNs to practical application. Therefore, it is necessary to study the construction of verification platform of WVSNs. This paper combines wireless transceiver module, visual information acquisition module and power acquisition module, designs a high-performance wireless vision sensor node whose core is ARM11 microprocessor and selects AODV as the routing protocol to set up a verification platform called AdvanWorks for WVSNs. Experiments show that the AdvanWorks can successfully achieve functions of image acquisition, coding, wireless transmission, and obtain the effective distance parameters between nodes, which lays a good foundation for the follow-up application of WVSNs.

Study on a new chaotic bitwise dynamical system and its FPGA implementation

NASA Astrophysics Data System (ADS)

Wang, Qian-Xue; Yu, Si-Min; Guyeux, C.; Bahi, J.; Fang, Xiao-Le

2015-06-01

In this paper, the structure of a new chaotic bitwise dynamical system (CBDS) is described. Compared to our previous research work, it uses various random bitwise operations instead of only one. The chaotic behavior of CBDS is mathematically proven according to the Devaney's definition, and its statistical properties are verified both for uniformity and by a comprehensive, reputed and stringent battery of tests called TestU01. Furthermore, a systematic methodology developing the parallel computations is proposed for FPGA platform-based realization of this CBDS. Experiments finally validate the proposed systematic methodology. Project supported by China Postdoctoral Science Foundation (Grant No. 2014M552175), the Scientific Research Foundation for the Returned Overseas Chinese Scholars, Chinese Education Ministry, the National Natural Science Foundation of China (Grant No. 61172023), and the Specialized Research Foundation of Doctoral Subjects of Chinese Education Ministry (Grant No. 20114420110003).

An Overview of Coral Community Development on Offshore Platforms in the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Sammarco, P. W.

2016-02-01

Oil platforms in the N. Gulf of Mexico (GOM) number 1,750, providing hard substratum for settlement of marine fauna, including corals, where little existed in shallow water prior to the 1940s. The introduction of hard substratum has facilitated the biogeographic expansion of Caribbean reef corals. We surveyed scleractinian corals, hermatypic and ahermatypic, on 48 platforms around the Flower Garden Banks (FGB) and across the continental shelf, from Corpus Christi, Texas to Mobile, Alabama, USA. We also assessed coral populations on platforms and the FGB for genetic affinities using AFLPs. The western limit for hermatypes was the shelf edge off Corpus Christi. The highest hermatypic densities occurred at the shelf edge, 200 km from shore in the north-central GOM. Mobile was the eastern limit for some hermatypic corals. Ahermatypes (i.e., Tubastraea coccinea, Oculina diffusa, Phyllangia americana) were absent inshore and in the north-central GOM. Species richness of hermatypic corals peaked near the FGB. Genetic analyses revealed high self-recognition and site fidelity on the platforms and the FGB in Madracis decactis, particularly in the eastern GOM. Platform populations exhibited a strong genetic affinity to those on the FGB, indicating that the FGB are the likely larval source for many corals on the platforms. There was little or no genetic affinity of coral populations across the mouth of the Mississippi River, although in T. coccinea (invasive species), cross-recognition between populations was higher between platforms on a given side. The Mississippi is a strong geographic barrier to east-west dispersal. Brooders were found to be more effective at colonizing patchy habitats at this meso-scale than broadcasters (Diploria strigosa and Montastraea cavernosa). Broadcaster recruits were rarely found, indicating less effective dispersal capabilities. Oil/gas platforms have facilitated the development of coral communities across the northern GOM.

Performance of a Single Liquid Column Damper for the Control of Dynamic Responses of a Tension Leg Platform

NASA Astrophysics Data System (ADS)

Jaksic, V.; Wright, C.; Chanayil, Afeef; Faruque Ali, Shaikh; Murphy, Jimmy; Pakrashi, Vikram

2015-07-01

Tuned liquid column dampers have been proved to be successful in mitigating the dynamic responses of civil infrastructure. There have been some recent applications of this concept on wind turbines and this passive control system can help to mitigate responses of offshore floating platforms and wave devices. The control of dynamic responses of these devices is important for reducing loads on structural elements and facilitating operations and maintenance (O&M) activities. This paper outlines the use of a tuned single liquid column damper for the control of a tension leg platform supported wind turbine. Theoretical studies were carried out and a scaled model was tested in a wave basin to assess the performance of the damper. The tests on the model presented in this paper correspond to a platform with a very low natural frequency for surge, sway and yaw motions. For practical purposes, it was not possible to tune the liquid damper exactly to this frequency. The consequent approach taken and the efficiency of such approach are presented in this paper. Responses to waves of a single frequency are investigated along with responses obtained from wave spectra characterising typical sea states. The extent of control is quantified using peak and root mean squared dynamic responses respectively. The tests present some guidelines and challenges for testing scaled devices in relation to including response control mechanisms. Additionally, the results provide a basis for dictating future research on tuned liquid column damper based control on floating platforms.

Electrocoagulation with polarity switch for fast oil removal from oil in water emulsions.

PubMed

Gobbi, Lorena C A; Nascimento, Izabela L; Muniz, Eduardo P; Rocha, Sandra M S; Porto, Paulo S S

2018-05-01

An electrocoagulation technique using a 3.5 L reactor, with aluminum electrodes in a monopolar arrangement with polarity switch at each 10 s was used to separate oil from synthetic oily water similar in oil concentration to produced water from offshore platforms. Up to 98% of oil removal was achieved after 20 min of processing. Processing time dependence of the oil removal and pH was measured and successfully adjusted to exponential models, indicating a pseudo first order behavior. Statistical analysis was used to prove that electrical conductivity and total solids depend significantly on the concentration of electrolyte (NaCl) in the medium. Oil removal depends mostly on the distance between the electrodes but is proportional to electrolyte concentration when initial pH is 8. Electrocoagulation with polarity switch maximizes the lifetime of the electrodes. The process reduced oil concentration to a value below that stipulated by law, proving it can be an efficient technology to minimize the offshore drilling impact in the environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

[What do we know about chemical hazards in offshore work?].

PubMed

Moen, Bente E; Steinsvåg, Kjersti; Bråveit, Magne

2004-10-21

Norway has been an oil-producing nation for more than thirty years and a large number of Norwegians have been or are working on oil rigs. There are several chemical substances present on the oil platforms, and these factors may influence workers' health. The international literature on offshore chemical exposure and health is summarised. The most important groups of chemical substances used on oil rigs are described: crude oil, production chemicals, asbestos and drilling chemicals. Different types of exposure during maintenance work are described as well. Very few exposure data are published. Acute, irritative health effects from chemical exposure are described, as well as chronic health effects like skin disorders and cancer. These workers seem to have a higher risk, that may be related to benzene exposure, of developing acute myelogenous leukemia. Physicians who are treating patients working in the oil industry are advised to be aware of possible adverse health effects from the work environment on the rigs. Further exposure studies and research in this area are highly recommended, as the literature is scarce.

Offshore multiphase meter nears acceptable accuracy level

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaisford, S.; Amdal, J.; Berentsen, H.

1993-05-17

Companies worldwide are looking for new production methods for offshore oil fields. In many areas, undeveloped smaller fields cannot bear the cost of dedicated production facilities. Multiphase transportation to existing production facilities can extend the distance over which unseparated oil, water, and gas streams can be transported, from a limit of several kilometers today to perhaps 200 km in the future. An encouraging multiphase meter test was sponsored by Saga Petroleum AS and carried out by Den norske stats oljeselskap AS (Statoil) on the Gullfaks B platform, Norwegian sector of the North Sea. The complete multiphase meter has two separatemore » meters. One is the composition meter for measuring the instantaneous volume or mass fractions of oil, water, and gas in the sensor. The other is a velocity meter for determining the speed of the mixture through the sensor. An instantaneous volume or mass production rate for each component is calculated by combining the outputs from the two meters. The paper describes the multiphase meter; measurements; limitations; the test setup; calibration; test results for the composition meter, velocity meter, and production rates; and future plans.« less

Analysis of seafloor change at Breton Island, Gosier Shoals, and surrounding waters, 1869–2014, Breton National Wildlife Refuge, Louisiana

USGS Publications Warehouse

Flocks, James G.; Terrano, Joseph F.

2016-08-01

Characterizing bathymetric change in coastal environments is an important component in understanding shoreline evolution, especially along barrier island platforms. Bathymetric change is a function of the regional sediment budget, long-term wave and current patterns, and episodic impact from high-energy events such as storms. Human modifications may also cause changes in seafloor elevation. This study, conducted by the U.S. Geological Survey in collaboration with the U.S. Fish and Wildlife Service, evaluates bathymetric and volumetric change and sediment characteristics around Breton Island and Gosier Shoals located offshore of the Mississippi River Delta in Louisiana. This area has been affected by significant storm events such as Hurricane Katrina in 2005. Sedimentation patterns at Breton Island and offshore have also been modified by the excavation of a shipping channel north of the island. Four time periods are considered that encompass these episodes and include long-term change and short-term storm recovery: 1869–2014, 1869–1920, 1920–2014, and 2007–2014. Finally, sediment characteristics are reported in the context of seafloor elevation.

The Sea Breeze in South-Iceland: Observations with an unmanned aircraft and numerical simulations

NASA Astrophysics Data System (ADS)

Opsanger Jonassen, Marius; Ólafsson, Haraldur; Rasol, Dubravka; Reuder, Joachim

2010-05-01

Sea breeze events, 19-20 July 2009, observed during the international field campaign MOSO, at the southcoast of Iceland, have been investigated using high resolution numerical simulations. Thanks to the use of a small unmanned aircraft system (UAS), SUMO, the wind and temperature aloft could be observed at a high resolution in both space and time. Simultaneously with the UAS operations, conventional platforms were used to obtain surface measurements. The observations show a distinct sea breeze circulation with an onset at around noon and a final decay around 19:00 UTC. At the maximum, the sea breeze layer reached a height of appr. 400 m, marked by a capping wind minimum. When compared to the flow aloft, the sea breeze layer was found to exhibit relatively low temperatures and an expected turn from an off-shore to an on-shore flow. Overall, the agreement between the observations and simulations are relatively good. The simulations suggest a horizontal extent of the circulation some 20-30 km off-shore, but only around 5 km on-shore.

Ergonomics, safety, and resilience in the helicopter offshore transportation system of Campos Basin.

PubMed

Gomes, José Orlando; Huber, Gilbert J; Borges, Marcos R S; de Carvalho, Paulo Victor R

2015-01-01

Air transportation of personnel to offshore oil platforms is one of the major hazards of this kind of endeavor. Pilot performance is a key factor in the safety of the transportation system. This study seeks to identify the ergonomic factors present in pilots' activities that may in some way compromise or enhance their performance, the constraints and affordances which they are subject to; and where possible to link these to their associated risk factors. Methodology adopted in this project studies work in its context. It is a merging of Activity Analysis (Guerin et al. 2001) of European tradition with Cognitive Task Analysis (CTA - www.ctaresource.com) articulated with the recent approaches to cognitive systems engineering developed by Professors David Woods and Erik Hollnagel. Fifty-five hours of field interviews provided the input for analysis. Sixteen ergonomic constraints were identified, some cognitive, some physical, all considered relevant by the research subjects and expert advisers. Although the safety record of the personnel transportation system studied is considered acceptable, there is low hanging fruit to be picked which can help improve the system's safety.

Satellite tree subsea completions permit marginal reserves production offshore East Kalimantan, Indonesia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bunnell, R.L.; Hawkins, J.G.

1983-05-01

The hydrocarbon-bearing sands in the fields offshore East Kalimantan were deposited in a deltaic environment and are complicated by faulting. This faulting results in small accumulations which cannot be economically exploited by conventional means. Three of these accumulations had been discovered in the Attaka Field in water depths of 160-190 feet. Even though the weather conditions are mild, conventional platforms were ruled out on economic grounds. An alternate method employing subsea completions was found to be economically viable. This subsea system is characterized by its ''off-the-shelf'' configuration and simplicity. To reduce the possibility of required well workovers, the wells aremore » single string, gravel packed completions. This project, then, is an example of a subsea completion system being chosen for marginal reserve development based on economic grounds. Additionally, these are the first subsea completions in Indonesia and yielded much information for use in designing, scheduling, and costing similar installations. The wells were all previously drilled and suspended exploratory wells, and the completion operations were performed from a floating vessel.« less

Biomarkers in Natural Fish Populations Indicate Adverse Biological Effects of Offshore Oil Production

PubMed Central

Balk, Lennart; Hylland, Ketil; Hansson, Tomas; Berntssen, Marc H. G.; Beyer, Jonny; Jonsson, Grete; Melbye, Alf; Grung, Merete; Torstensen, Bente E.; Børseth, Jan Fredrik; Skarphedinsdottir, Halldora; Klungsøyr, Jarle

2011-01-01

Background Despite the growing awareness of the necessity of a sustainable development, the global economy continues to depend largely on the consumption of non-renewable energy resources. One such energy resource is fossil oil extracted from the seabed at offshore oil platforms. This type of oil production causes continuous environmental pollution from drilling waste, discharge of large amounts of produced water, and accidental spills. Methods and principal findings Samples from natural populations of haddock (Melanogrammus aeglefinus) and Atlantic cod (Gadus morhua) in two North Sea areas with extensive oil production were investigated. Exposure to and uptake of polycyclic aromatic hydrocarbons (PAHs) were demonstrated, and biomarker analyses revealed adverse biological effects, including induction of biotransformation enzymes, oxidative stress, altered fatty acid composition, and genotoxicity. Genotoxicity was reflected by a hepatic DNA adduct pattern typical for exposure to a mixture of PAHs. Control material was collected from a North Sea area without oil production and from remote Icelandic waters. The difference between the two control areas indicates significant background pollution in the North Sea. Conclusion It is most remarkable to obtain biomarker responses in natural fish populations in the open sea that are similar to the biomarker responses in fish from highly polluted areas close to a point source. Risk assessment of various threats to the marine fish populations in the North Sea, such as overfishing, global warming, and eutrophication, should also take into account the ecologically relevant impact of offshore oil production. PMID:21625421

Biomarkers in natural fish populations indicate adverse biological effects of offshore oil production.

PubMed

Balk, Lennart; Hylland, Ketil; Hansson, Tomas; Berntssen, Marc H G; Beyer, Jonny; Jonsson, Grete; Melbye, Alf; Grung, Merete; Torstensen, Bente E; Børseth, Jan Fredrik; Skarphedinsdottir, Halldora; Klungsøyr, Jarle

2011-01-01

Despite the growing awareness of the necessity of a sustainable development, the global economy continues to depend largely on the consumption of non-renewable energy resources. One such energy resource is fossil oil extracted from the seabed at offshore oil platforms. This type of oil production causes continuous environmental pollution from drilling waste, discharge of large amounts of produced water, and accidental spills. Samples from natural populations of haddock (Melanogrammus aeglefinus) and Atlantic cod (Gadus morhua) in two North Sea areas with extensive oil production were investigated. Exposure to and uptake of polycyclic aromatic hydrocarbons (PAHs) were demonstrated, and biomarker analyses revealed adverse biological effects, including induction of biotransformation enzymes, oxidative stress, altered fatty acid composition, and genotoxicity. Genotoxicity was reflected by a hepatic DNA adduct pattern typical for exposure to a mixture of PAHs. Control material was collected from a North Sea area without oil production and from remote Icelandic waters. The difference between the two control areas indicates significant background pollution in the North Sea. It is most remarkable to obtain biomarker responses in natural fish populations in the open sea that are similar to the biomarker responses in fish from highly polluted areas close to a point source. Risk assessment of various threats to the marine fish populations in the North Sea, such as overfishing, global warming, and eutrophication, should also take into account the ecologically relevant impact of offshore oil production.

Intellectual Entrepreneurship as a Platform for Transforming Higher Education

ERIC Educational Resources Information Center

Beckman, Gary D.; Cherwitz, Richard A.

2008-01-01

The thesis of this article is that "Intellectual Entrepreneurship (IE)" provides an intellectually authentic philosophical foundation capable of sustaining cross-campus entrepreneurship education. Drawing upon initiatives begun at The University of Texas at Austin, we document how IE educates "citizen-scholars." Specifically,…

Postglacial Fringing-Reef to Barrier-Reef conversion on Tahiti links Darwin's reef types

NASA Astrophysics Data System (ADS)

Blanchon, Paul; Granados-Corea, Marian; Abbey, Elizabeth; Braga, Juan C.; Braithwaite, Colin; Kennedy, David M.; Spencer, Tom; Webster, Jody M.; Woodroffe, Colin D.

2014-05-01

In 1842 Charles Darwin claimed that vertical growth on a subsiding foundation caused fringing reefs to transform into barrier reefs then atolls. Yet historically no transition between reef types has been discovered and they are widely considered to develop independently from antecedent foundations during glacio-eustatic sea-level rise. Here we reconstruct reef development from cores recovered by IODP Expedition 310 to Tahiti, and show that a fringing reef retreated upslope during postglacial sea-level rise and transformed into a barrier reef when it encountered a Pleistocene reef-flat platform. The reef became stranded on the platform edge, creating a lagoon that isolated it from coastal sediment and facilitated a switch to a faster-growing coral assemblage dominated by acroporids. The switch increased the reef's accretion rate, allowing it to keep pace with rising sea level, and transform into a barrier reef. This retreat mechanism not only links Darwin's reef types, but explains the re-occupation of reefs during Pleistocene glacio-eustacy.

Data standards, sense and stability: Scratchpads, the ICZN and ZooBank

PubMed Central

Baker, Edward; Michel, Ellinor

2011-01-01

Abstract The International Commission of Zoological Nomenclature has used the Scratchpads platform (currently being developed and maintained by ViBRANT) as the foundation for its redesigned website and as a platform for engaging with its users. The existing Scratchpad tools, with extensions to provide additional functions, have allowed for a major transformation in presentation of linked nomenclatural tools. Continued development of the new website will act as a springboard for the ICZN to participate more fully in the wider community of biodiversity informatics. PMID:22207812

Determinants of health: a progressive political platform.

PubMed

Terris, M

1994-01-01

This paper is based on the statement in the Ottawa Charter for Health Promotion that "The fundamental conditions and resources for health are peace, shelter, education, food, income, a stable eco-system, sustainable resources, social justice and equity. Improvement in health requires a secure foundation in these basic prerequisites." It attempts to formulate a progressive political platform for a number of these prerequisites, offering a series of recommendations regarding education, employment, income, and housing, and urging that the proposed programs be funded by progressive taxation and major reductions in the military budget.

Sea Basing Platforms for the 21st Century - An Evaluation of Maritime Prepositioning Force (Future) [MPF(F)] and the Mobile Offshore Base (MOB) to Perform Sea Basing

DTIC Science & Technology

2004-01-01

Large, Medium Speed , Roll-On/Roll-Off (LMSR) ships . The BLA sea base ships share a common hull, a common propulsion plant, and internal design from...would have the propulsion capable of maintaining a speed of 25 knots. Cargo fuel is stored in either the centerline tanks or in the deep tanks in the...for the Marine Expeditionary Force (Forward) [MEF(FWD)]. The ships required a seaport to offload cargo , an airfield to be the aerial port of

Underwater noise from three types of offshore wind turbines: estimation of impact zones for harbor porpoises and harbor seals.

PubMed

Tougaard, Jakob; Henriksen, Oluf Damsgaard; Miller, Lee A

2009-06-01

Underwater noise was recorded from three different types of wind turbines in Denmark and Sweden (Middelgrunden, Vindeby, and Bockstigen-Valar) during normal operation. Wind turbine noise was only measurable above ambient noise at frequencies below 500 Hz. Total sound pressure level was in the range 109-127 dB re 1 microPa rms, measured at distances between 14 and 20 m from the foundations. The 1/3-octave noise levels were compared with audiograms of harbor seals and harbor porpoises. Maximum 1/3-octave levels were in the range 106-126 dB re 1 microPa rms. Maximum range of audibility was estimated under two extreme assumptions on transmission loss (3 and 9 dB per doubling of distance, respectively). Audibility was low for harbor porpoises extending 20-70 m from the foundation, whereas audibility for harbor seals ranged from less than 100 m to several kilometers. Behavioral reactions of porpoises to the noise appear unlikely except if they are very close to the foundations. However, behavioral reactions from seals cannot be excluded up to distances of a few hundred meters. It is unlikely that the noise reaches dangerous levels at any distance from the turbines and the noise is considered incapable of masking acoustic communication by seals and porpoises.

Compartmental Genomics in Living Cells Revealed by Single-Cell Nanobiopsy

PubMed Central

Actis, Paolo; Maalouf, Michelle; Kim, Hyunsung John; Lohith, Akshar; Vilozny, Boaz; Seger, R. Adam; Pourmand, Nader

2014-01-01

The ability to study the molecular biology of living single cells in heterogeneous cell populations is essential for next generation analysis of cellular circuitry and function. Here, we developed a single-cell nanobiopsy platform based on scanning ion conductance microscopy (SICM) for continuous sampling of intracellular content from individual cells. The nanobiopsy platform uses electrowetting within a nanopipette to extract cellular material from living cells with minimal disruption of the cellular milieu. We demonstrate the subcellular resolution of the nanobiopsy platform by isolating small subpopulations of mitochondria from single living cells, and quantify mutant mitochondrial genomes in those single cells with high throughput sequencing technology. These findings may provide the foundation for dynamic subcellular genomic analysis. PMID:24279711

Uplift Patterns in the Forearc of the Middle America Trench, Costa Rica: Implications for Mass Balance and Fore-arc Kinematics

NASA Astrophysics Data System (ADS)

Fisher, D. M.; Gardner, T. W.; Sak, P.; Marshall, J. S.; Protti, M.

2001-12-01

Uplift patterns along the Pacific Coast of Costa Rica provide insight into the balance of mass in the fore arc and depict an inner forearc that thickens nonuniformly at the expense of a subsiding margin wedge. Offshore, incoming seamounts and ridges on the subducting Cocos plate result in embayment of the trench axis and scarring that reflects downdropping of fault bounded blocks in the wake of subducting seamounts. The upper slope displays a regional unconformity that records late Tertiary subsidence and arcward displacement of the trench axis. Uplifted marine wavecut benches along the coast of Costa Rica, combined with analysis of fault populations, indicate that the inner fore arc has experienced a history that is in marked contrast to the subsidence and erosion observed in the margin wedge. Regionally, the inner forearc, from Osa to Nicaragua, has experienced uplift. One way to produce this regional uplift signal is movement on an out-of-sequence fault, or an active fault arcward of the frontal thrust. The longitudinal fault that marks the front of the Fila Costena may be an example of such a fault. Wood from a raised wavecut platform along this thrust front was radiocarbon dated at 5540 yrs. A balanced cross section of the Fila Costena indicates a detachment at a depth of ~ 2 km near the contact between upper slope sediments of the Terraba basin and the underlying basement of the margin wedge. This cross section also requires a >10 km of shortening accomplished by underthrusting of the outer fore arc. Crustal thickening by this mechanism could explain the dichotomy between uplift of the mountainous Fila Costena and Talamanca Ranges and subsidence of the slope apron offshore. Superimposed on this regional uplift of the Costa Rican coast is a pattern of faster uplift within fault-bounded blocks that lie inboard of incoming seamount chains. Offshore of Nicoya, the subducting plate displays two parallel ridges: a ridge coincident with the trace of the Coc-Naz- East Pacific Rise junction and a ridge defined by the Fisher Seamount chain. Inboard of both these bathymetric features there are raised wavecut benches and headlands that expose Tertiary upper slope sediments. Radiocarbon dates for these platforms indicate maximum uplift rates of ~ 6 mm yr-1 with slower uplift rates between these regions. The largest scar in the Costa Rican forearc is a trough oriented parallel to the Car-Coc relative plate motion vector that extends from the trench to near the coastline. Inboard of this scar is the Herradura block, a block that has experienceed more uplift than adjacent regions. A wavecut platform near the faulted margin of the Herradura block yields radiocarbon dates of 1010-1650 yrs and uplift rates of ~2.5 mm yr-1. The Osa Peninsula inboard of the Cocos Ridge records some of the fastest uplift rates measured in the Costa Rican fore arc based on marine sediments deposited around the margins of this peninsula and radiocarbon (AMS)-dated as 27000 to 49000 yrs. The most striking aspect of uplift patterns is that the local areas of fastest uplift in the forearc lie inboard of the areas with the most scarring and erosion in the margin wedge offshore. This pattern of uplift requires either underplating of seamounts beneath the inner forearc or enhanced shortening and crustal thickening inboard of subducting seamounts.

SAR observation and numerical modeling of tidal current wakes at the East China Sea offshore wind farm

NASA Astrophysics Data System (ADS)

Li, XiaoMing; Chi, Lequan; Chen, Xueen; Ren, YongZheng; Lehner, Susanne

2014-08-01

A TerraSAR-X (TS-X) Synthetic Aperture Radar (SAR) image acquired at the East China Sea offshore wind farm presents distinct wakes at a kilometer scale on the lee of the wind turbines. The presumption was that these wakes were caused by wind movement around turbine blades. However, wind analysis using spaceborne radiometer data, numerical weather prediction, and in situ measurements suggest that the prevailing wind direction did not align with the wakes. By analyzing measurement at the tidal gauge station and modeling of the tidal current field, these trailing wakes are interpreted to have formed when a strong tidal current impinged on the cylindrical monopiles of the wind turbines. A numerical simulation was further conducted to reproduce the tidal current wake under such conditions. Comparison of the simulated surface velocity in the wake region with the TS-X sea surface backscatter intensity shows a similar trend. Consequently, turbulence intensity (T.I.) of the tidal current wakes over multiple piles is studied using the TS-X observation. It is found that the T.I. has a logarithmic relation with distance. Furthermore, another case study showing wakes due to wind movement around turbine blades is presented to discuss the differences in the tidal current wakes and wind turbine wakes. The conclusion is drawn that small-scale wakes formed by interaction of the tidal current and the turbine piles could be also imaged by SAR when certain conditions are satisfied. The study is anticipated to draw more attentions to the impacts of offshore wind foundations on local hydrodynamic field.

The oil and gas industry of coastal Louisiana and its effects on land use and other socioeconomic patterns

USGS Publications Warehouse

Davis, Donald W.; Place, John L.

1983-01-01

Louisiana's coastal wetlands, alone with their well-drained urbanized strips, have been significantly affected by the oil and gas industry. Onshore, more than 6,300 exploratory wells and more than 21,000 development wells were drilled in Louisiana's eight southernmost parishes between 1937 and 1977. Nearly all those wells were in wetlands or inland water bodies. The wetlands, totaling more than 2 million hectares (ha), extend inland to roughly latitude 30? N, and are about 15 percent forested swamp and 85 percent nonforested marsh. Inland waters within the Louisiana coastal zone total more than 1 million ha. Nearly all these waters are quite shallow. More than 235,000 ha of this coastal area is used for major activities associated with the extraction of oil and gas. Production in the eight southern parishes peaked in 1970 to 120 million m3 of oil and 172 billion m 3 of gas. Connecting extensive onshore fields--and also servicing offshore fields--are intricate networks of canals for pipelines and maritime traffic related to the oil and gas industry. Offshore, more than 2,400 drilling and production platforms had been installed by May of 1981. Oil production from wells in both Federal and State waters off Louisiana peaked at 71 million m3 in 1972. Offshore gas production continues to increase, with 131 billion m3, in 1979. Since the early 1950's southern Louisiana's population has shifted from remote rural areas in the marshes to the more densely settled areas on the natural levees and beach ridges where employment is available in oil-field support industries and businesses. In 1975, in the 14 primary settlement clusters within the coastal wetlands, more than 3,600 advertised business activities were connected directly to the oil and gas industry. This compares to about 1,200 such activities in 1955, at the start of offshore development. These businesses are listed as water transportation, transportation equipment, pipelines, chemicals, special trade contractors, and petroleum refining, as well as actual oil and gas extraction. Area measurements of urban land uses reveal a major concentration of industry and transportation facilities along the navigable waterways. Ship and rig construction are important activities; of 148 fixed drilling platforms under construction in the United States in March 1981, 94 were being built in Louisiana to be barged out into the Gulf of Mexico and beyond. Of the 122 petroleum-industry support boats being built in the United States in 1976, 82 were in Louisiana shipyards; the worldwide total was estimated to be only about 200. In 1980, the Nation's marine con- tractors were building 129 logistic support vessels. Louisiana-based firms had 98 vessels under construction.

Review of potential impacts to sea turtles from underwater explosive removal of offshore structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Viada, Stephen T.; Hammer, Richard M.; Racca, Roberto

2008-05-15

The purpose of this study was to collect and synthesize existing information relevant to the explosive removal of offshore structures (EROS) in aquatic environments. Data sources were organized and summarized by topic - explosive removal methods, physics of underwater explosions, sea turtle resources, documented impacts to sea turtles, and mitigation of effects. Information was gathered via electronic database searches and literature source review. Bulk explosive charges are the most commonly used technique in EROS. While the physical principles of underwater detonations and the propagation of pressure and acoustic waves are well understood, there are significant gaps in the application ofmore » this knowledge. Impacts to sea turtles from explosive removal operations may range from non-injurious effects (e.g. acoustic annoyance; mild tactile detection or physical discomfort) to varying levels of injury (i.e. non-lethal and lethal injuries). Very little information exists regarding the impacts of underwater explosions on sea turtles. Effects of explosions on turtles often must be inferred from documented effects to other vertebrates with lungs or other gas-containing organs, such as mammals and most fishes. However, a cautious approach should be used when determining impacts to sea turtles based on extrapolations from other vertebrates. The discovery of beached sea turtles and bottlenose dolphins following an explosive platform removal event in 1986 prompted the initiation of formal consultation between the U.S. Department of the Interior, Minerals Management Service (MMS) and the National Marine Fisheries Service (NMFS), authorized through the Endangered Species Act Section 7, to determine a mechanism to minimize potential impacts to listed species. The initial consultation resulted in a requirement for oil and gas companies to obtain a permit (through separate consultations on a case-by-case basis) prior to using explosives in Federal waters. Because many offshore structure removal operations are similar, a 'generic' Incidental Take Statement was established by the NMFS that describes requirements to protect sea turtles when an operator's individual charge weights did not exceed 50 lb (23 kg). Requirements associated with the Incidental Take Permit were revised in 2003 and 2006 to accommodate advances in explosive charge technologies, removals of structures in deeper waters, and adequate protection of deep water marine mammal species in Gulf of Mexico waters. Generally, these requirements include pre- and post-detonation visual monitoring using standard surface and aerial survey methods for sea turtles and marine mammals, and, in some scenarios, passive acoustic survey methods for marine mammals within a specified radius from an offshore structure. The survey program has been successful in mitigating impacts to sea turtles associated with EROS. However, even with these protective measures in place, there have been observations of sea turtles affected by explosive platform removals.« less

Constellation Pharmacology: A new paradigm for drug discovery

PubMed Central

Schmidt, Eric W.; Olivera, Baldomero M.

2015-01-01

Constellation Pharmacology is a cell-based high-content phenotypic-screening platform that utilizes subtype-selective pharmacological agents to elucidate the cell-specific combinations (“constellations”) of key signaling proteins that define specific cell types. Heterogeneous populations of native cells, in which the different individual cell types have been identified and characterized, are the foundation for this screening platform. Constellation Pharmacology is useful for screening small molecules or for deconvoluting complex mixtures of biologically-active natural products. This platform has been used to purify natural products and discover their molecular mechanisms. In the on-going development of Constellation Pharmacology, there is a positive-feedback loop between the pharmacological characterization of cell types and screening for new drug candidates. As Constellation Pharmacology is used to discover compounds with novel targeting-selectivity profiles, those new compounds then further help to elucidate the constellations of specific cell types, thereby increasing the content of this high-content platform. PMID:25562646

Experimental investigation of the dynamic installation of a slip joint connection between the monopile and tower of an offshore wind turbine

NASA Astrophysics Data System (ADS)

Segeren, M. L. A.; Hermans, K. W.

2014-06-01

The failure of the traditional grouted connections of offshore wind turbines has led to the investigation of alternatives that provide a connection between the foundation pile and the turbine tower. An alternative to the traditional joint is a steel-to-steel connection also called a slip joint. To ensure a proper fit of the slip joint a dynamic installation of the joint is proposed. In this contribution, the effectiveness of harmonic excitation as an installation procedure is experimentally investigated using a 1:10 scaled model of the joint. During the dynamic installation test the applied static load, settlements and dynamic response of the joint are monitored using respectively load cells, taut wires and strain gauges placed both inside and outside the conical surfaces. The results show that settlement occurs only when applying a harmonic load at specific forcing frequencies. The settlement stabilizes to a certain level for each of the specific frequencies, indicating that a controlled way of installation is possible. The results show that it is essential to vibrate at specific frequencies and that a larger amplitude of the harmonic force does not automatically lead to additional settlement.

Optimization of monitoring and inspections in the life-cycle of wind turbines

NASA Astrophysics Data System (ADS)

Hanish Nithin, Anu; Omenzetter, Piotr

2016-04-01

The past decade has witnessed a surge in the offshore wind farm developments across the world. Although this form of cleaner and greener energy is beneficial and eco-friendly, the production of wind energy entails high life-cycle costs. The costs associated with inspections, monitoring and repairs of wind turbines are primary contributors to the high costs of electricity produced in this way and are disadvantageous in today's competitive economic environment. There is limited research being done in the probabilistic optimization of life-cycle costs of offshore wind turbines structures and their components. This paper proposes a framework for assessing the life cycle cost of wind turbine structures subject to damage and deterioration. The objective of the paper is to develop a mathematical probabilistic cost assessment framework which considers deterioration, inspection, monitoring, repair and maintenance models and their uncertainties. The uncertainties are etched in the accuracy and precision of the monitoring and inspection methods and can be considered through the probability of damage detection of each method. Schedules for inspection, monitoring and repair actions are demonstrated using a decision tree. Examples of a generalised deterioration process integrated with the cost analysis using a decision tree are shown for a wind turbine foundation structure.

Disentangling the control of tectonics, eustasy, trophic conditions and climate on shallow-marine carbonate production during the Aalenian-Oxfordian interval: From the western France platform to the western Tethyan domain

NASA Astrophysics Data System (ADS)

Andrieu, Simon; Brigaud, Benjamin; Barbarand, Jocelyn; Lasseur, Eric; Saucède, Thomas

2016-11-01

The objective of this work is to improve our understanding of the processes controlling changes in the architecture and facies of intracontinental carbonate platforms. We examined the facies and sequence stratigraphy of Aalenian to Oxfordian limestones of western France. Seventy-seven outcrop sections were studied and thirty-one sedimentary facies identified in five depositional environments ranging from lower offshore to backshore. Platform evolution was reconstructed along a 500 km cross-section. Twenty-two depositional sequences were identified on the entire western France platform and correlated with European third-order sequences at the biozone level, demonstrating that eustasy was the major factor controlling the cyclic trend of accommodation. The tectonic subsidence rate was computed from accommodation measurements from the Aalenian to the Oxfordian in key localities. Tectonism controlled the sedimentation rate and platform architecture at a longer time scale. Tectonic subsidence triggered the demise of carbonate production at the Bathonian/Callovian boundary while the uplift made possible the recovery of carbonate platform from Caen to Le Mans during the mid Oxfordian. Topography of the Paleozoic basement mainly controlled lateral variations of paleodepth within the western France platform until the mid Bathonian. A synthesis of carbonate production in the western Tethyan domain at that time was conducted. Stages of high carbonate production during the Bajocian/Bathonian and the middle to late Oxfordian are synchronous with low δ13C, high eccentricity intervals, and rather dry climate promoting (1) evaporation and carbonate supersaturation, and (2) oligotrophic conditions. Periods of low carbonate production during the Aalenian and from the middle Callovian to early Oxfordian correlate with high δ13C and low eccentricity intervals, characterized by wet climate and less oligotrophic conditions. Such conditions tend to diminish growth potential of carbonate platforms. This work highlights the importance of climate control on carbonate growth and demise at large scale in western Tethyan epicontinental seas.

Assessment by regional modelling of the impact of monopile foundations on the hydrodynamics and sediment transport: case of Courseulles-sur-Mer (France) wind farm

NASA Astrophysics Data System (ADS)

Rivier, Aurélie; Bennis, Anne-Claire; Pinon, Grégory; Magar, Vanesa; Gross, Markus

2015-04-01

Offshore monopile foundations of wind turbines modify hydrodynamics and sediment transport at local scale and also at regional scale. The aim of this work is to assess these changes and to parametrize them in a regional model. These modifications were previously evaluated using the regional circulation model MARS3D (Lazure and Dumas, 2008) in tests-cases (Rivier et al., 2014) using two approaches: in the first approach, monopiles are explicitly modelled in the mesh as dry cells and in the second approach a sub-grid parametrization which considers the drag force exerted by a monopile on the flow is used. The sub-grid parametrization is improved close to the bed in this paper by adding a drag force term in the momentum equations, source terms in the turbulence model and by increasing the bed shear stress at monopile location. Changes in hydrodynamics regime, especially near-bed, affect sediment transport regime and modifications due to monopiles on sediment dynamics is also investigated using the MARS3D sediment transport module (Le Hir et al., 2011) which solves the advection-diffusion equations. Test-cases are run using hydrodynamical conditions and sediment grain sizes typical from the area located off Courseulles-sur-Mer (Normandy, France) where an offshore wind farm is planned to be built. Velocity, turbulent kinetic energy and bed thickness changes due to the monopile simulated by both approaches are compared to each other and to experimental measurements made in a flume at the University of Caen or to published data (e.g. Roulund et al., 2005; Dargahi,1989). Then the model is applied in a real configuration on an area including the future offshore wind farm of Courseulles-sur-Mer. Four monopiles are represented in the model using both approaches and modifications of the hydrodynamics and sediment transport are assessed along a tidal cycle. Currents increase at the side edge of the monopile and decrease in front of and downstream the monopile. Turbulent kinetic energy strongly increase as expected upstream the monopile. Resuspension and erosion occurs around the monopile in locations where current speeds increase due to the monopile presence and sediments deposit downstream where the bed shear stress is lower. The pattern of bed erosion is modified depending of current velocity. References Dargahi, B. 1989. The turbulent flow field around a circular cylinder. Experiments in Fluids, 8(1-2), 1-12. Lazure, P. and Dumas, F. (2008). external-internal mode coupling for a 3D hydrodynamical model for applications at regional scale (MARS). Advances in Water Resources 31(2), 233-250. Le Hir, P., Cayocca, F. and Waeles, B. (2011). Dynamics of sand and mud mixtures: a multiprocess-based modelling strategy. Continental Shelf Research 31(10), 135-149. Rivier, A., Bennis, A.-C., Pinon, G., Gross, M. and Magar, V. (2014). Regional numerical modelling of offshore monopile wind turbine impacts on hydrodynamics and sediment transport. Proceeding of the 1st International Conference on Renewable Energies Offshore, November 2014, Lisbonne, Portugal. Roulund, A., Sumer, B. M., Fredsøe, J., & Michelsen, J. 2005. Numerical and experimental investigation of flow and scour around a circular pile. Journal of Fluid Mechanics, 534, 351-401.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Bingbin; Karr, Dale G.; Song, Huimin

It is a fact that developing offshore wind energy has become more and more serious worldwide in recent years. Many of the promising offshore wind farm locations are in cold regions that may have ice cover during wintertime. The challenge of possible ice loads on offshore wind turbines raises the demand of modeling capacity of dynamic wind turbine response under the joint action of ice, wind, wave, and current. The simulation software FAST is an open source computer-aided engineering (CAE) package maintained by the National Renewable Energy Laboratory. In this paper, a new module of FAST for assessing the dynamicmore » response of offshore wind turbines subjected to ice forcing is presented. In the ice module, several models are presented which involve both prescribed forcing and coupled response. For conditions in which the ice forcing is essentially decoupled from the structural response, ice forces are established from existing models for brittle and ductile ice failure. For conditions in which the ice failure and the structural response are coupled, such as lock-in conditions, a rate-dependent ice model is described, which is developed in conjunction with a new modularization framework for FAST. In this paper, analytical ice mechanics models are presented that incorporate ice floe forcing, deformation, and failure. For lower speeds, forces slowly build until the ice strength is reached and ice fails resulting in a quasi-static condition. For intermediate speeds, the ice failure can be coupled with the structural response and resulting in coinciding periods of the ice failure and the structural response. A third regime occurs at high speeds of encounter in which brittle fracturing of the ice feature occurs in a random pattern, which results in a random vibration excitation of the structure. An example wind turbine response is simulated under ice loading of each of the presented models. This module adds to FAST the capabilities for analyzing the response of wind turbines subjected to forces resulting from ice impact on the turbine support structure. The conditions considered in this module are specifically addressed in the International Organization for Standardization (ISO) standard 19906:2010 for arctic offshore structures design consideration. Special consideration of lock-in vibrations is required due to the detrimental effects of such response with regard to fatigue and foundation/soil response. Finally, the use of FAST for transient, time domain simulation with the new ice module is well suited for such analyses.« less

Oceanic Platform of the Canary Islands: an ocean testbed for ocean energy converters

NASA Astrophysics Data System (ADS)

González, Javier; Hernández-Brito, Joaquín.; Llinás, Octavio

2010-05-01

The Oceanic Platform of the Canary Islands (PLOCAN) is a Governmental Consortium aimed to build and operate an off-shore infrastructure to facilitate the deep sea research and speed up the technology associated. This Consortium is overseen by the Spanish Ministry of Science and Innovation and the Canarian Agency for Research and Innovation. The infrastructure consists of an oceanic platform located in an area with depths between 50-100 meters, close to the continental slope and four kilometers off the coast of Gran Canaria, in the archipelago of the Canary Islands. The process of construction will start during the first months of 2010 and is expected to be finished in mid-year 2011. PLOCAN serves five strategic lines: an integral observatory able to explore from the deep ocean to the atmosphere, an ocean technology testbed, a base for underwater vehicles, an innovation platform and a highly specialized training centre. Ocean energy is a suitable source to contribute the limited mix-energy conformed in the archipelago of the Canary Islands with a total population around 2 million people unequally distributed in seven islands. Islands of Gran Canaria and Tenerife support the 80% of the total population with 800.000 people each. PLOCAN will contribute to develop the ocean energy sector establishing a marine testbed allowing prototypes testing at sea under a meticulous monitoring network provided by the integral observatory, generating valuable information to developers. Reducing costs throughout an integral project management is an essential objective to be reach, providing services such as transportation, customs and administrative permits. Ocean surface for testing activities is around 8 km2 with a depth going from 50 to 100 meters, 4km off the coast. Selected areas for testing have off-shore wind power conditions around 500-600 W/m2 and wave power conditions around 6 kW/m in the East coast and 10 kW/m in the North coast. Marine currents in the Canary Islands are not particularly powerful with values around 40-50 cm/s. However a detailed assessment, based on field measurements, will be conducted in the near future with the aim to identify specific areas close to the coast with stronger currents which make suitable the deployment of marine current turbines. Although the base Platform is not still available, PLOCAN has already started the activity as an ocean testbed providing services to a wave energy converter patented by the Spanish company PIPO Systems. A scaled 1:5 prototype will be deployed during January 2010 and monitored for several months. Current facilities available include some ODAS buoys (temperature, salinity, pH, oxygen, turbidity, wind, etc.), wave rider buoy, current meter profilers (ADCP and electromagnetic), system for data management, remote operated vehicles (ROV), autonomous underwater vehicles (AUV), and an oceanographic vessel. Future facilities include high frequency radar for wave and current measurements and submarine electro-optical cables to connect the Platform with the energy converters and with the shore station.

Increasing Student Engagement in Math: The Use of Khan Academy in Chilean Classrooms

ERIC Educational Resources Information Center

Light, Daniel; Pierson, Elizabeth

2014-01-01

Khan Academy, an online platform offering educational videos and exercises in different content areas, has awakened intense interest among foundations, multilateral organizations, policy makers, and educators about how this tool can help meet the educational challenges facing countries around the world. With support from Intel, Education…

Open chemistry registry and mapping platform based on open source cheminformatics toolkits (ACS Fall meeting)

EPA Science Inventory

TheOpen PHACTS project (openphacts.org) is a European initiative, constituting a public–private partnership to enable easier, cheaper and faster drug discovery [1]. The project is supported by the Open PHACTS Foundation (www.openphactsfoundation.org) and funded by contributions f...

Using Social Media to Engage Students and Families

ERIC Educational Resources Information Center

Nielsen, Lisa

2014-01-01

Using social media in education requires putting some building blocks for success in place. A strong foundation for successful use of social networking in education starts by securing parent/guardian and student agreements. Social networking provides a powerful platform for learning and connecting. Facebook is not just for sharing status updates…

Renovating Home Furnishings, Home and Family Education: 2781.01.

ERIC Educational Resources Information Center

Linden, Janice

The course examines the tools, materials, and basic principles used in reupholstering furniture. Techniques involved in using equipment, dismantling furniture, constructing the foundation, making the muslin cover, planning and preparing the platform and covering, and attaching loose wood panels are some of the operations dealt with in the course.…

Bahamian Teachers' Perceptions of Inclusion as a Foundational Platform for Adult Education Programs

ERIC Educational Resources Information Center

Newton, Norrisa; Hunter-Johnson, Yvonne; Gardiner-Farquharson, Beulah L.; Cambridge, Janelle

2014-01-01

Despite the paradigm shift globally regarding the adoption of inclusive education, teachers still have varying preconceived misconceptions about its successful implementation and practices in the general education classroom. This qualitative study focused on teachers' perception of adapting inclusive education policies and procedures in The…

Incorporating a Product Archaeology Paradigm across the Mechanical Engineering Curriculum

ERIC Educational Resources Information Center

Moore-Russo, Deborah; Cormier, Phillip; Lewis, Kemper; Devendorf, Erich

2013-01-01

Historically, the teaching of design theory in an engineering curriculum has been relegated to a senior capstone design experience. Presently, however, engineering design concepts and courses can be found through the entirety of most engineering programs. Educators have recognized that engineering design provides a foundational platform that can…

"Coursera" Online Course: A Platform for English Teachers' Meaningful and Vibrant Professional Development

ERIC Educational Resources Information Center

Silvia, Arnis

2015-01-01

This article reports on English teachers' attitudes towards a professional development program run by "Coursera" ("coursera.org"). These teachers were participants of "Foundation of Teaching for Learning 1: Introduction" online course. Using a survey case study, the findings reveal that most of the participants…

The Role of Faulting on the Growth of a Carbonate Platform: Evidence from 3D Seismic Analysis and Section Restoration

NASA Astrophysics Data System (ADS)

Nur Fathiyah Jamaludin, Siti; Pubellier, Manuel; Prasad Ghosh, Deva; Menier, David; Pierson, Bernard

2014-05-01

Tectonics in addition to other environmental factors impacts the growth of carbonate platforms and plays an important role in shaping the internal architecture of the platforms. Detailed of faults and fractures development and healing in carbonate environment have not been explored sufficiently. Using 3D seismic and well data, we attempt to reconstruct the structural evolution of a Miocene carbonate platform in Central Luconia Province, offshore Malaysia. Luconia Province is located in the NW coast of Borneo and has become one of the largest carbonate factories in SE Asia. Seismic interpretations including seismic attribute analysis are applied to the carbonate platform to discern its sedimentology and structural details. Detailed seismic interpretations highlight the relationships of carbonate deposition with syn-depositional faulting. Branching conjugate faults are common in this carbonate platform and have become a template for reef growth, attesting lateral facies changes within the carbonate environments. Structural restoration was then appropriately performed on the interpreted seismic sections based on sequential restoration techniques, and provided images different from those of horizon flattening methods. This permits us to compensate faults' displacement, remove recent sediment layers and finally restore the older rock units prior to the fault motions. It allows prediction of platform evolution as a response to faulting before and after carbonate deposition and also enhances the pitfalls of interpretation. Once updated, the reconstructions allow unravelling of the un-seen geological features underneath the carbonate platform, such as paleo-structures and paleo-topography which in turn reflects the paleo-environment before deformations took place. Interestingly, sections balancing and restoration revealed the late-phase (Late Oligocene-Early Miocene) rifting of South China Sea, otherwise difficult to visualize on seismic sections. Later it is shown that this carbonate platform was possibly originated from two or more connected reef build-ups. The platform evolution in terms of tectonic influences on carbonate growth and development may serve as a case example for re-evaluation of pre-Late Miocene structures as a new potential target for hydrocarbon exploration in Central Luconia Province. Eventually, techniques used in this study might be of interest to oil and gas explorers in carbonate system.

Environmental controls on daytime net community calcification on a Red Sea reef flat

NASA Astrophysics Data System (ADS)

Bernstein, W. N.; Hughen, K. A.; Langdon, C.; McCorkle, D. C.; Lentz, S. J.

2016-06-01

Coral growth and carbonate accumulation form the foundation of the coral reef ecosystem. Changes in environmental conditions due to coastal development, climate change, and ocean acidification may pose a threat to net carbonate production in the near future. Controlled laboratory studies demonstrate that calcification by corals and coralline algae is sensitive to changes in aragonite saturation state (Ωa), as well as temperature, light, and nutrition. Studies also show that the dissolution rate of carbonate substrates is impacted by changes in carbonate chemistry. The sensitivity of coral reefs to these parameters must be confirmed and quantified in the natural environment in order to predict how coral reefs will respond to local and global changes, particularly ocean acidification. We estimated the daytime hourly net community metabolic rates, both net community calcification (NCC) and net community productivity (NCP), at Sheltered Reef, an offshore platform reef in the central Red Sea. Average NCC was 8 ± 3 mmol m-2 h-1 in December 2010 and 11 ± 1 mmol m-2 h-1 in May 2011, and NCP was 21 ± 7 mmol m-2 h-1 in December 2010 and 44 ± 4 mmol m-2 h-1 in May 2011. We also monitored a suite of physical and chemical properties to help relate the rates at Sheltered Reef to published rates from other sites. While previous research shows that short-term field studies investigating the NCC-Ωa relationship have differing results due to confounding factors, it is important to continue estimating NCC in different places, seasons, and years, in order to monitor changes in NCC versus Ω in space and time, and to ultimately resolve a broader understanding of this relationship.

Gravity study of Libya;Evaluation and Integration with Geological Data

NASA Astrophysics Data System (ADS)

Ben Suleman, abdunnur; Saheel, Ahmed

2016-04-01

Libya is located on the Mediterranean foreland of the African Shield and covers an area of approximately 1.8 million square kilometers. Since Early Paleozoic time, Libya has been a site of deposition of large sheets of continental clastics and several transgressions and regressions by the seas with consequent accumulations of a wide variety of sedimentary rocks. Several tectonic cycles affected the area and shaped the geological setting of the country. However, the regional geology and the structural framework have been highly influenced by the Caledonian, Hercynian, and Alpine tectonic events. As a result, a total of seven sedimentary basins, namely Ghadames, Murzuq, Al Kufra, Al Butnan, Sirt, and the Offshore Pelagian Basin, were developed and were separated by intervening uplifts and platforms ( Gargaf, Tibesti, Nafusah and Cyrenaica platform). Apart from Sirt and the offshore basins, all the above mentioned basins are active since Early Paleozoic time and received several thousand feet of sediments. The capability of providing regional information on the structure of sedimentary basins makes gravity mapping, in conjunction with geological information, potentially powerful tools. In this study we used gravity mapping as our primary tool of investigation however, we also used all available geological information to better understand the regional tectonics. The gravity dataset that were used in the Gravity compilation project of Libya is not homogenous. As a result, some irregularities, apparent spikes or misties, and large shifts were obtained and were taken into consideration. Evaluation of gravity Maps of Libya and their integration with geological data provide a better understanding of the role that gravity mapping plays in the geological exploration of sedimentary basins. Results confirm the known Sirt Basin regional tectonic elements and the possible presence of NW-SE lateral wrench tectonics, crossing Ajdabiya Trough at the center of Sirt Basin. The residual gravity map supports new interpretation of the Sirwal Trough in Northern Cyrenaica. Results also indicate shallow crust along the present day coast line of Al Jabal Al Akhdar, steeply dipping toward the offshore. The depo-center of Ghadames Basin cannot be precisely defined due to the lack of gravity coverage. However, Murzuq Basin is well defined regionally, in spite of gravity gaps which make the overall coverage in the southern basins inadequate for precise interpretation.

Radiorespirometric assays for the detection of biogenic sulfides from sulfate-reducing bacteria.

PubMed

de Queiroz, J C; de Melo Ferreira, A C; da Costa, A C A

2013-04-01

The detection of trace concentrations of biogenic sulfides can be carried out through radiorespirometric assays. The objective of this work was to improve the methodology for detection of H2 S in trace concentrations, to correlate with sulfate-reducing bacterial activity. Serial dilutions of synthetic sea water with a pure culture of Desulfovibrio alaskensis, a mixed anaerobic microbial culture and a natural saline sample from a petroleum offshore platform indicated that dilutions were followed, accordingly, by sulfate reduction. Tests performed indicated that increasing the time of incubation of a mixed anaerobic microbial culture contributed to an increase in the sulfate reduction rates, as well as the amount of carbon source and inoculum. The technique here developed proved to be a rapid test for the detection of biogenic sulfides, particularly those associated with corrosion products, being an useful tool for monitoring and controlling oil/water storage tanks, petroleum continental platforms and several types of reservoirs. © 2013 The Society for Applied Microbiology.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hurst, J.M.; Lapointe, P.A.; Nyein, U.K.

Three Oligocene-Miocene carbonate depositional morphologies commonly occur: shoals, reefs, and isolated platforms. Lenticular shoals (0-25 m thick, 1 km long) are stacked and intercalated with siliciclastic mudstones. Facies include trough/festoon cross-bedded benthic foram grainstones passing laterally and vertically into red-algal dominated graded-laminated beds, bioturbated silty calcareous mudstone, and siliciclastic sandy foram wackestone and packstone. The morphology and facies are hydrodynamically controlled. Pinnacle reefs (1-2 km[sup 2]) dominated by red-algae, branching corals, and large mollusks occur on structure or aligned within shelf mudstones. The latter location reflects low sedimentation rates and hydrodynamic control. Isolated platforms (up to 150 km[sup 2]) aremore » environmental mosaics of marginal path reefs and shoals, interior lagoons, and islands plus marginal slopes. Facies are similar to shoals and reefs except there are more muddy fabrics and less high-energy facies. They develop on tilted fault blocks or eroded submerged arcs in the offshore Gulf of Martaban, distal to the ancestral Irrawaddy delta.« less

From carbonate platform to euxinic sea - the collapse of an Early/Middle Devonian reef, Cantabrian Mountains (Spain)

NASA Astrophysics Data System (ADS)

Loevezijn, Gerard B. S. van; Raven, J. G. M.

2017-12-01

The Santa Lucía Formation represents the major phase in Devonian reef development of the Cantabrian Zone (Cantabrian Mountains, northwest Spain). In the present study the transition from the carbonate platform deposits of the Santa Lucía Formation to the overlying euxinic basinal deposits of the Huergas Formation is described. These transitional strata are connected to the Basal Choteč Event and represent a condensed sedimentation of micritic dark-grey and black limestones with an upward increase of dark shale intercalations with iron mineralisation surfaces and storm-induced brachiopod coquinas. The transitional beds are grouped into a new unit, the Cabornera Bed, which consists of limestone, limestone-shale and shale facies associations, representing a sediment-starved euxinic offshore area just below the storm wave base. Four stages in reef decline can be recognised: a reef stage, an oxygen-depleted, nutrient-rich stage, a siliciclastic-influx stage and a pelagic-siliciclastic stage. Additional geochemical and geophysical investigations are needed to verify the results presented herein.

Coupled Modeling of Hydrodynamics and Sound in Coastal Ocean for Renewable Ocean Energy Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Long, Wen; Jung, Ki Won; Yang, Zhaoqing

An underwater sound model was developed to simulate sound propagation from marine and hydrokinetic energy (MHK) devices or offshore wind (OSW) energy platforms. Finite difference methods were developed to solve the 3D Helmholtz equation for sound propagation in the coastal environment. A 3D sparse matrix solver with complex coefficients was formed for solving the resulting acoustic pressure field. The Complex Shifted Laplacian Preconditioner (CSLP) method was applied to solve the matrix system iteratively with MPI parallelization using a high performance cluster. The sound model was then coupled with the Finite Volume Community Ocean Model (FVCOM) for simulating sound propagation generatedmore » by human activities, such as construction of OSW turbines or tidal stream turbine operations, in a range-dependent setting. As a proof of concept, initial validation of the solver is presented for two coastal wedge problems. This sound model can be useful for evaluating impacts on marine mammals due to deployment of MHK devices and OSW energy platforms.« less

Monitoring the freely dissolved concentrations of polycyclic aromatic hydrocarbons (PAH) and alkylphenols (AP) around a Norwegian oil platform by holistic passive sampling.

PubMed

Harman, Christopher; Thomas, Kevin V; Tollefsen, Knut Erik; Meier, Sonnich; Bøyum, Olav; Grung, Merete

2009-11-01

In order to assess the environmental impact of aquatic discharges from the offshore oil industry, polar organic chemical integrative samplers (POCIS) and semipermeable membrane devices (SPMDs) were deployed around an oil platform and at reference locations in the North Sea. Exposure to polycyclic aromatic hydrocarbons (PAH) and alkylated phenols (AP) was determined from passive sampler accumulations using an empirical uptake model, the dissipation of performance reference compounds and adjusted laboratory derived sampling rates. Exposure was relatively similar within 1-2 km of the discharge point, with levels dominated by short chained C1-C3 AP isomers (19-51 ngL(-1)) and alkylated naphthalenes, phenanthrenes and dibenzothiophenes (NPD, 29-45 ngL(-1)). Exposure stations showed significant differences to reference sites for NPD, but not always for more hydrophobic PAH. These concentrations are several orders of magnitude lower than those reported to give both acute and sub-lethal effects, although their long term consequences are unknown.

Offshore sand-shoal development and evolution of Petit Bois Pass, Mississippi-Alabama Barrier Islands, Mississippi, USA

USGS Publications Warehouse

Flocks, James G.; Kelso, Kyle W.; Twichell, Gregory C.; Buster, Noreen A.; Baehr, John N.; Rosati, Julie D.; Wang, Ping; Roberts, Tiffany M.

2011-01-01

Assessment of recently collected geophysical and sediment-core data identifies an extensive shoal field located off Dauphin and Petit Bois Islands. The shoals are the product of Pleistocene fluvial deposition and Holocene marine-transgressive processes, and their position and orientation oblique to the modern shoreline has been stable over the past century. The underlying stratigraphy has also influenced the evolution of the barrier platform and inlets. Buried distributary channels bisect the platform, creating erosion hotspots that breach during intense and repeated storms. Inlet growth inhibits littoral transport, and over time, reduces the down-drift sand supply. These relations demonstrate the role of the antecedent geologic framework on morphologic evolution. This study is part of the USGS Northern Gulf of Mexico Ecosystem Change and Hazard Susceptibility Project and the USACE Mississippi Coastal Improvements Program. These projects produced a wealth of information regarding coastal geology, geomorphology, and physical resources; some of the initial results are presented here.

Modelling the hydrodynamic and morphosedimentary response of an beach-headland system (Algarve, Southern Portugal)

NASA Astrophysics Data System (ADS)

Horta, João; Oliveira, Sónia; Moura, Delminda

2015-04-01

Future behaviour of beaches within a headland-beach system is of fundamental interest on coastal evolution since they act as a buffer between the waves' attack and the cliffs backing them. The beaches at the cliffs' foot anchored between headlands are space-limited environments to morphosedimentary processes. Additionally, headlands and shore platforms are natural barriers to the alongshore drift. Several attempts to develop numerical expressions to characterize the stability of headland-beach systems have been made based mainly on linear parameters. However, in the sandy areas occur volumetric variations of greater magnitude that changes in the shoreline position in a tidal cycle. This work aims to quantify the balance between the incoming and the lost sediment in two embayed beaches in order to improve knowledge of the sedimentary dynamics of such environments and therefore the evolution of coastal landscapes. The study area is the Algarve coastal karstic landscapes, which raises challenging questions on morphosedimentary processes because it has dozens of stacks and cavities both in the surf zone and in the nearshore that interfere with the littoral current patterns. The field campaigns were performed during spring tide conditions in February and March, 2011. The nearshore wave climate and the current's velocity and direction were measured using respectively a non-vented Level TROLL 700 Pressure Transducer (PT) and an autonomously deployable electro-magnetic current meter (EMCM) Infinity-EM with a data logger. The offshore wave data used was acquired through the Portuguese Hydrographic Institute (IH) at the Faro buoy, located 50 km southeast from the study area. The topographic surveys were performed for a total area of about 1500 m2 using two Global Navigation Satellite System receptors (GPS Trimble R6 and GPS Trimble 5800) in real-time kinematic mode (RTK) with differential global positioning system (DGPS) providing centimetric accuracy. The altimetric values ranged between -2 and +6 m (mean sea level-msl). The automatic determination of the spatial characteristics of the beach morphology results from the GIS tools. The wave and current post processing was made using the STWAVE and Bouss-2D model software. Our results showed that: (i) the shore orientation is the major factor for the height of the waves approaching the coast (considering the same offshore climate) and thus to the wave energy input to transport sediment, (ii) the shore platforms which extend up to -7 m (msl) determine a very irregular pattern of the shoaling waves and distance of the breaking point from the shoreline, (iii) as a consequence of (ii) the rip currents in the surf zone show a very complex pattern and the direction of the sedimentary transport can be opposite to the direction of the incoming waves, (iv) the pattern of the rip currents is highly variable depending on the water depth, (v) the results obtained for volumetric balances showed a negative balance (erosion higher than accretion) at the smaller embayed beach and a positive balance (accretion higher than erosion) at the larger one. This work is a contribution to the PTDC/GEO-GEO/3981/2012 funded by the Portuguese Foundation for Science and Technology.

Multi-event behavior of El Golfo landslide (El Hierro Island, Canary Archipelago)

NASA Astrophysics Data System (ADS)

León, Ricardo; Biain, Ander; Urgeles, Roger; Somoza, Luis; Ferrer, Mercedes; García-Crespo, Jesús; Francisco Mediato, José; Galindo, Inés; Yepes, Jorge; Gimenez-Moreno, Julia

2017-04-01

Based on the re-interpretation of a vast onshore-offshore data set, a new morpho-structural characterization of the El Golfo giant landslide in the island of El Hierro (Canary Archipelago, Spain) is presented. Offshore multibeam echosounder data, chirp sub-bottom profiles, multichannel seismic reflection data and onshore information from water wells and galleries have been analyzed to determine the nature of the event. The subaerial headscarp shows a non-continuous arcuate profile formed by two nested semi-circular amphitheaters that extend offshore along a smooth chute, suggesting the occurrence of at least two large retrogressive events. Channels/gullies and escarpments developed along the submarine sector of the scar also indicate smaller-scale events and predominance of sediment bypass. At the base of submerged island, two subunits within the related submarine mass transport deposit (MTD) are identified on multichannel seismic reflection profiles confirming the multi-event nature of the landslide. The MTD, identified as a debris avalanche, has a total estimated volume of 318 km3: 84 km3 and 234 km3, for the lower and upper subunits respectively. Data from wells and galleries show abrasion platforms with beach deposits at sea-level (0 masl) formed after the landslide scar and buried by the El Golfo post-collapse infill lavas, suggesting an age at least older than 23.5-82.5 ka for the landslide. This work has been supported by the projects IGCP-640 S4SLIDE, High resolution seabed mapping EASME/EMFF/2016/005 and CTM2010-09496-E. Keywords: Submarine landslides, volcanic islands, debris avalanche, Canary Islands

Geologic control on the evolution of the inner shelf morphology offshore of the Mississippi barrier islands, northern Gulf of Mexico, USA

USGS Publications Warehouse

Flocks, James G.; Kindinger, Jack G.; Kelso, Kyle W.

2015-01-01

Between 2008 and 2013, high-resolution geophysical surveys were conducted around the Mississippi barrier islands and offshore. The sonar surveys included swath and single-beam bathymetry, sidescan, and chirp subbottom data collection. The geophysical data were groundtruthed using vibracore sediment collection. The results provide insight into the evolution of the inner shelf and the relationship between the near surface geologic framework and the morphology of the coastal zone. This study focuses on the buried Pleistocene fluvial deposits and late Holocene shore-oblique sand ridges offshore of Petit Bois Island and Petit Bois Pass. Prior to this study, the physical characteristics, evolution, and interrelationship of the ridges between both the shelf geology and the adjacent barrier island platform had not been evaluated. Numerous studies elsewhere along the coastal margin attribute shoal origin and sand-ridge evolution to hydrodynamic processes in shallow water (<20 m). Here we characterize the correlation between the geologic framework and surface morphology and demonstrate that the underlying stratigraphy must also be considered when developing an evolutionary conceptual model. It is important to understand this near surface, nearshore dynamic in order to understand how the stratigraphy influences the long-term response of the coastal zone to sea-level rise. The study also contributes to a growing body of work characterizing shore-oblique sand ridges which, along with the related geology, are recognized as increasingly important components to a nearshore framework whose origins and evolution must be understood and inventoried to effectively manage the coastal zone.

Geologic control on the evolution of the inner shelf morphology offshore of the Mississippi barrier islands, northern Gulf of Mexico, USA

NASA Astrophysics Data System (ADS)

Flocks, James G.; Kindinger, Jack L.; Kelso, Kyle W.

2015-06-01

Between 2008 and 2013, high-resolution geophysical surveys were conducted around the Mississippi barrier islands and offshore. The sonar surveys included swath and single-beam bathymetry, sidescan, and chirp subbottom data collection. The geophysical data were groundtruthed using vibracore sediment collection. The results provide insight into the evolution of the inner shelf and the relationship between the near surface geologic framework and the morphology of the coastal zone. This study focuses on the buried Pleistocene fluvial deposits and late Holocene shore-oblique sand ridges offshore of Petit Bois Island and Petit Bois Pass. Prior to this study, the physical characteristics, evolution, and interrelationship of the ridges between both the shelf geology and the adjacent barrier island platform had not been evaluated. Numerous studies elsewhere along the coastal margin attribute shoal origin and sand-ridge evolution to hydrodynamic processes in shallow water (<20 m). Here we characterize the correlation between the geologic framework and surface morphology and demonstrate that the underlying stratigraphy must also be considered when developing an evolutionary conceptual model. It is important to understand this near surface, nearshore dynamic in order to understand how the stratigraphy influences the long-term response of the coastal zone to sea-level rise. The study also contributes to a growing body of work characterizing shore-oblique sand ridges which, along with the related geology, are recognized as increasingly important components to a nearshore framework whose origins and evolution must be understood and inventoried to effectively manage the coastal zone.

Shallow geology, sea-floor texture, and physiographic zones of Vineyard and western Nantucket Sounds, Massachusetts

USGS Publications Warehouse

Baldwin, Wayne E.; Foster, David S.; Pendleton, Elizabeth A.; Barnhardt, Walter A.; Schwab, William C.; Andrews, Brian D.; Ackerman, Seth D.

2016-09-02

Geologic, sediment texture, and physiographic zone maps characterize the sea floor of Vineyard and western Nantucket Sounds, Massachusetts. These maps were derived from interpretations of seismic-reflection profiles, high-resolution bathymetry, acoustic-backscatter intensity, bottom photographs/video, and surficial sediment samples collected within the 494-square-kilometer study area. Interpretations of seismic stratigraphy and mapping of glacial and Holocene marine units provided a foundation on which the surficial maps were created. This mapping is a result of a collaborative effort between the U.S. Geological Survey and the Massachusetts Office of Coastal Zone Management to characterize the surface and subsurface geologic framework offshore of Massachusetts.

Earth observations taken during STS-81 mission

NASA Image and Video Library

1997-01-21

STS081-711-009 (12-22 Jan. 1997) --- As photographed with a 70mm handheld camera from the Earth-orbiting Space Shuttle Atlantis, this image provides a northeastward panorama of the Florida peninsula, the northern Bahamas and Cuba as well as a synoptic view of the northern Caribbean region. Lake Okeechobee and the urban region around Miami are the two key visual points in Florida. The turquoise shallow water platforms around the Florida Keys, the Bahamas, and south of Cuba contrast with the deep blue color of the deeper channels which separate Florida from Cuba and the Bahamas. Offshore breezes keep the coastal areas clear of clouds.

A system identification technique based on the random decrement signatures. Part 2: Experimental results

NASA Technical Reports Server (NTRS)

Bedewi, Nabih E.; Yang, Jackson C. S.

1987-01-01

Identification of the system parameters of a randomly excited structure may be treated using a variety of statistical techniques. Of all these techniques, the Random Decrement is unique in that it provides the homogeneous component of the system response. Using this quality, a system identification technique was developed based on a least-squares fit of the signatures to estimate the mass, damping, and stiffness matrices of a linear randomly excited system. The results of an experiment conducted on an offshore platform scale model to verify the validity of the technique and to demonstrate its application in damage detection are presented.

Sedimentology of Upper Cretaceous Coffee sands in north-central Mississippi

DOE Office of Scientific and Technical Information (OSTI.GOV)

Webb, E.J.

1984-09-01

The Upper Cretaceous Coffee Group within the Desha basin of Mississippi is composed of two major lithologies, a light to dark marlstone and a series of white, fine to medium-grained siltstones and sandstones. The two source areas for the sands are the Sharkey platform to the south and the southern Appalachians. The presence of hydrocarbons has been described at the outcrop and in subsurface cuttings and cores. Depositional environments in the shallow shelf consist of lagoons, barrier island bars, offshore bars, and surge channel deposits. Southwest regional dip of approximately 40 ft/mi (8 m/km) is reflected on all Upper Cretaceousmore » horizons.« less

Augmenting breath regulation using a mobile driven virtual reality therapy framework.

PubMed

Abushakra, Ahmad; Faezipour, Miad

2014-05-01

This paper presents a conceptual framework of a virtual reality therapy to assist individuals, especially lung cancer patients or those with breathing disorders to regulate their breath through real-time analysis of respiration movements using a smartphone. Virtual reality technology is an attractive means for medical simulations and treatment, particularly for patients with cancer. The theories, methodologies and approaches, and real-world dynamic contents for all the components of this virtual reality therapy (VRT) via a conceptual framework using the smartphone will be discussed. The architecture and technical aspects of the offshore platform of the virtual environment will also be presented.

Synthesis copolymer use to reduce pour point temperature of diamond crude oil

NASA Astrophysics Data System (ADS)

Than, Dao Viet; Chuong, Thai Hong; Tuy, Dao Quoc

2017-09-01

Diamond oil field is located in Block 01&02 Offshore Vietnam. Crude oil from Diamond Well Head Platform (WHP) is evacuated to FPSO via 20km 10" subsea flexible pipeline. The lowest seabed temperature in the field is 22°C, while the pour point temperature (PPT) of Diamond crude oil is very high (36°C) due to high paraffin content (25%). So studying to research a suitable Pour Point Depressant (PPD) for the crude oil is very important. The PPD must have ability to reduce pour point temperature of crude oil from 36°C to 21°C.

Regulation and policy: International trends and issues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Griffin, W S

As offshore oil and gas resources become exhausted, the associated production platforms and facilities will be decommissioned. The world-wide oil and gas industry is strictly regulated by global, regional and national guidelines which have been developed by governments to find the most responsible framework to perform the decommissioning. In the summer of 1995, the Brent Spar incident brought uncertainty to decommissioning world-wide. In June of 1995, a moratorium prohibiting sea disposal within the North East Atlantic was imposed by the Oslo Commission, and an unsuccessful attempt was made in December of 1995 to impose a world-wide moratorium on sea disposalmore » at the London Convention.« less

Airfoil family design for large offshore wind turbine blades

NASA Astrophysics Data System (ADS)

Méndez, B.; Munduate, X.; San Miguel, U.

2014-06-01

Wind turbine blades size has scaled-up during last years due to wind turbine platform increase especially for offshore applications. The EOLIA project 2007-2010 (Spanish Goverment funded project) was focused on the design of large offshore wind turbines for deep waters. The project was managed by ACCIONA Energia and the wind turbine technology was designed by ACCIONA Windpower. The project included the design of a wind turbine airfoil family especially conceived for large offshore wind turbine blades, in the order of 5MW machine. Large offshore wind turbines suffer high extreme loads due to their size, in addition the lack of noise restrictions allow higher tip speeds. Consequently, the airfoils presented in this work are designed for high Reynolds numbers with the main goal of reducing blade loads and mantainig power production. The new airfoil family was designed in collaboration with CENER (Spanish National Renewable Energy Centre). The airfoil family was designed using a evolutionary algorithm based optimization tool with different objectives, both aerodynamic and structural, coupled with an airfoil geometry generation tool. Force coefficients of the designed airfoil were obtained using the panel code XFOIL in which the boundary layer/inviscid flow coupling is ineracted via surface transpiration model. The desing methodology includes a novel technique to define the objective functions based on normalizing the functions using weight parameters created from data of airfoils used as reference. Four airfoils have been designed, here three of them will be presented, with relative thickness of 18%, 21%, 25%, which have been verified with the in-house CFD code, Wind Multi Block WMB, and later validated with wind tunnel experiments. Some of the objectives for the designed airfoils concern the aerodynamic behavior (high efficiency and lift, high tangential coefficient, insensitivity to rough conditions, etc.), others concern the geometry (good for structural design, compatibility for the different airfoil family members, etc.) and with the ultimate objective that the airfoils will reduce the blade loads. In this paper the whole airfoil design process and the main characteristics of the airfoil family are described. Some force coefficients for the design Reynolds number are also presented. The new designed airfoils have been studied with computational calculations (panel method code and CFD) and also in a wind tunnel experimental campaign. Some of these results will be also presented in this paper.

Data Lakes and Data Visualization: An Innovative Approach to Address the Challenges of Access to Health Care in Mississippi

PubMed Central

Krause, Denise D.

2015-01-01

Background: There are a variety of challenges to developing strategies to improve access to health care, but access to data is critical for effective evidence-based decision-making. Many agencies and organizations throughout Mississippi have been collecting quality health data for many years. However, those data have historically resided in data silos and have not been readily shared. A strategy was developed to build and coordinate infrastructure, capacity, tools, and resources to facilitate health workforce and population health planning throughout the state. Objective: Realizing data as the foundation upon which to build, the primary objective was to develop the capacity to collect, store, maintain, visualize, and analyze data from a variety of disparate sources -- with the ultimate goal of improving access to health care. Specific aims were to: 1) build a centralized data repository and scalable informatics platform, 2) develop a data management solution for this platform and then, 3) derive value from this platform by facilitating data visualization and analysis. Methods: A managed data lake was designed and constructed for health data from disparate sources throughout the state of Mississippi. A data management application was developed to log and track all data sources, maps and geographies, and data marts. With this informatics platform as a foundation, a variety of tools are used to visualize and analyze data. To illustrate, a web mapping application was developed to examine the health workforce geographically and attractive data visualizations and dynamic dashboards were created to facilitate health planning and research. Results: Samples of data visualizations that aim to inform health planners and policymakers are presented. Many agencies and organizations throughout the state benefit from this platform. Conclusion: The overarching goal is that by providing timely, reliable information to stakeholders, Mississippians in general will experience improved access to quality care. PMID:26834938

DARPA TRADES Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aguilo Valentin, Miguel Alejandro; Trujillo, Susie

During calendar year 2017, Sandia National Laboratories (SNL) made strides towards developing an open portable design platform rich in highperformance computing (HPC) enabled modeling, analysis and synthesis tools. The main focus was to lay the foundations of the core interfaces that will enable plug-n-play insertion of synthesis optimization technologies in the areas of modeling, analysis and synthesis.

Theoretical Foundations of "Competitive Team-Based Learning"

ERIC Educational Resources Information Center

Hosseini, Seyed Mohammad Hassan

2010-01-01

This paper serves as a platform to precisely substantiate the success of "Competitive Team-Based Learning" (CTBL) as an effective and rational educational approach. To that end, it brings to the fore part of the (didactic) theories and hypotheses which in one way or another delineate and confirm the mechanisms under which successful…

Impacts and Characteristics of Computer-Based Science Inquiry Learning Environments for Precollege Students

ERIC Educational Resources Information Center

Donnelly, Dermot F.; Linn, Marcia C.; Ludvigsen, Sten

2014-01-01

The National Science Foundation-sponsored report "Fostering Learning in the Networked World" called for "a common, open platform to support communities of developers and learners in ways that enable both to take advantage of advances in the learning sciences." We review research on science inquiry learning environments (ILEs)…

The W22 genome: a foundation for maize functional genomics and transposon biology

USDA-ARS?s Scientific Manuscript database

The maize W22 inbred has served as a platform for maize genetics since the mid twentieth century. To streamline maize genome analyses, we have sequenced and de novo assembled a W22 reference genome using small-read sequencing technologies. We show that significant structural heterogeneity exists in ...

GenePattern Notebooks for Cancer Research | Informatics Technology for Cancer Research (ITCR)

Cancer.gov

The goal is to use the GenePattern computational genomics platform, which has served the cancer community since 2004, as the foundation for a new electronic notebook environment to provide cancer research community a way to easily collaborate on, document, capture, and share their work, from conception through analysis to publication.

Real-time Environmental Monitoring from a Wind Farm Platform in the Texas Hypoxic Zone

NASA Astrophysics Data System (ADS)

Mullins, R. L.; Dimarco, S. F.; Walpert, J. N.; Guinasso, N. L.; Howard, M. K.

2009-12-01

Ocean observing systems (OOS) provide coastal managers with data for informed decision-making. OOS are designed to monitor oceanographic and atmospheric conditions from a variety of offshore platforms. In the summer of 2009, a multi-disciplinary system, the Galveston Instrument Garden for Environmental Monitoring (GIGEM), was deployed off the coast of Galveston, Texas (Location: 29o 08’ 29.654’’N, 94o 44’ 51.339’’W) to monitor coastal waters and provide real-time observations for investigating processes responsible for coastal Texas hypoxia. Hypoxia occurs in the Gulf of Mexico over the continental shelf and refers to low dissolved oxygen concentrations in the bottom waters caused by a combination of environmental and physical parameters. Events form rapidly, last for a few days to weeks, and commonly occur along the Louisiana and Texas coasts; however, little research has been conducted to investigate the processes responsible for Texas hypoxia formation. GIGEM was designed to study this problem by contributing real-time measurements to compare with historical coastal data series. Unlike most coastal OOS, GIGEM is installed on an experimental wind farm platform operated by Wind Energy System Technologies Inc. This platform is the first executed offshore wind energy lease in the United States. GIGEM is comprised of two components, the subsurface mooring and a nearby bottom package. The data telemetry system includes a unique design of underwater and surface inductive modems. GIGEM is the only coastal OOS currently collecting real-time environmental water quality measurements on the Texas shelf. The work presented describes: the obstacles and challenges associated with deploying GIGEM, the flow of information from the water column to the user, and how this type of OOS fulfills the societal goals for protecting coastal ecosystems and improving coastal weather and ocean predictions envisioned by the Integrated Ocean Observing System (IOOS). Data and analysis results include profiles of vertical water column, examining the role of stratification in the formation of coastal hypoxia, and the influence of storm events on water column stability recorded from GIGEM. The comparison of real-time data from GIGEM with historical data will be presented in a unique 4D visualization tool (Eonfusion, Myriax Pty. Ltd.) as a useful method for investigating coastal hypoxia. The GIGEM data sets will be fused with model and remotely sensed data from the Gulf of Mexico Coastal Observing System (GCOOS) data portal to show the data in broader context for use in decision support tools.

Geologic assessment of undiscovered oil and gas resources—Lower Cretaceous Albian to Upper Cretaceous Cenomanian carbonate rocks of the Fredericksburg and Washita Groups, United States Gulf of Mexico Coastal Plain and State Waters

USGS Publications Warehouse

Swanson, Sharon M.; Enomoto, Catherine B.; Dennen, Kristin O.; Valentine, Brett J.; Cahan, Steven M.

2017-02-10

In 2010, the U.S. Geological Survey (USGS) assessed Lower Cretaceous Albian to Upper Cretaceous Cenomanian carbonate rocks of the Fredericksburg and Washita Groups and their equivalent units for technically recoverable, undiscovered hydrocarbon resources underlying onshore lands and State Waters of the Gulf Coast region of the United States. This assessment was based on a geologic model that incorporates the Upper Jurassic-Cretaceous-Tertiary Composite Total Petroleum System (TPS) of the Gulf of Mexico basin; the TPS was defined previously by the USGS assessment team in the assessment of undiscovered hydrocarbon resources in Tertiary strata of the Gulf Coast region in 2007. One conventional assessment unit (AU), which extends from south Texas to the Florida panhandle, was defined: the Fredericksburg-Buda Carbonate Platform-Reef Gas and Oil AU. The assessed stratigraphic interval includes the Edwards Limestone of the Fredericksburg Group and the Georgetown and Buda Limestones of the Washita Group. The following factors were evaluated to define the AU and estimate oil and gas resources: potential source rocks, hydrocarbon migration, reservoir porosity and permeability, traps and seals, structural features, paleoenvironments (back-reef lagoon, reef, and fore-reef environments), and the potential for water washing of hydrocarbons near outcrop areas.In Texas and Louisiana, the downdip boundary of the AU was defined as a line that extends 10 miles downdip of the Lower Cretaceous shelf margin to include potential reef-talus hydrocarbon reservoirs. In Mississippi, Alabama, and the panhandle area of Florida, where the Lower Cretaceous shelf margin extends offshore, the downdip boundary was defined by the offshore boundary of State Waters. Updip boundaries of the AU were drawn based on the updip extent of carbonate rocks within the assessed interval, the presence of basin-margin fault zones, and the presence of producing wells. Other factors evaluated were the middle Cenomanian sea-level fall and erosion that removed large portions of platform and platform-margin carbonate sediments in the Washita Group of central Louisiana. The production history of discovered reservoirs and well data within the AU were examined to estimate the number and size of undiscovered oil and gas reservoirs within the AU. Using the USGS National Oil and Gas Assessment resource assessment methodology, mean volumes of 40 million barrels of oil, 622 billion cubic feet of gas, and 14 million barrels of natural gas liquids are the estimated technically recoverable undiscovered resources for the Fredericksburg-Buda Carbonate Platform-Reef Gas and Oil AU.

Parameterization of wind turbine impacts on hydrodynamics and sediment transport

NASA Astrophysics Data System (ADS)

Rivier, Aurélie; Bennis, Anne-Claire; Pinon, Grégory; Magar, Vanesa; Gross, Markus

2016-10-01

Monopile foundations of offshore wind turbines modify the hydrodynamics and sediment transport at local and regional scales. The aim of this work is to assess these modifications and to parameterize them in a regional model. In the present study, this is achieved through a regional circulation model, coupled with a sediment transport module, using two approaches. One approach is to explicitly model the monopiles in the mesh as dry cells, and the other is to parameterize them by adding a drag force term to the momentum and turbulence equations. Idealised cases are run using hydrodynamical conditions and sediment grain sizes typical from the area located off Courseulles-sur-Mer (Normandy, France), where an offshore windfarm is under planning, to assess the capacity of the model to reproduce the effect of the monopile on the environment. Then, the model is applied to a real configuration on an area including the future offshore windfarm of Courseulles-sur-Mer. Four monopiles are represented in the model using both approaches, and modifications of the hydrodynamics and sediment transport are assessed over a tidal cycle. In relation to local hydrodynamic effects, it is observed that currents increase at the side of the monopile and decrease in front of and downstream of the monopile. In relation to sediment transport effect, the results show that resuspension and erosion occur around the monopile in locations where the current speed increases due to the monopile presence, and sediments deposit downstream where the bed shear stress is lower. During the tidal cycle, wakes downstream of the monopile reach the following monopile and modify the velocity magnitude and suspended sediment concentration patterns around the second monopile.

Simulation of an offshore wind farm using fluid power for centralized electricity generation

NASA Astrophysics Data System (ADS)

Jarquin-Laguna, A.

2016-09-01

A centralized approach for electricity generation within a wind farm is explored through the use of fluid power technology. This concept considers a new way of generation, collection and transmission of wind energy inside a wind farm, in which electrical conversion does not occur during any intermediate conversion step before the energy has reached the offshore central platform. A numerical model was developed to capture the relevant physics from the dynamic interaction between different turbines coupled to a common hydraulic network and controller. This paper presents two examples of the time-domain simulation results for an hypothetical hydraulic wind farm subject to turbulent wind conditions. The performance and operational parameters of individual turbines are compared with those of a reference wind farm with conventional technology turbines, using the same wind farm layout and environmental conditions. For the presented case study, results indicate that the individual wind turbines are able to operate within operational limits with the current pressure control concept. Despite the stochastic turbulent wind input and wake effects, the hydraulic wind farm is able to produce electricity with reasonable performance in both below and above rated conditions.

User's guide: Minerals management service outer continental shelf activity database (moad). Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steiner, C.K.; Causley, M.C.; Yocke, M.A.

1994-04-01

The 1990 Clean Air Act Amendments require the Minerals Management Service (MMS) to conduct a research study to assess the potential onshore air quality impact from the development of outer continental shelf (OCS) petroleum resources in the Gulf of Mexico. The need for this study arises from concern about the cumulative impacts of current and future OCS emissions on ozone concentrations on nonattainment areas, particularly in Texas and Louisiana. To make quantitative assessments of these impacts, MMS has commissioned an air quality study which includes as a major component the development of a comprehensive emission inventory for photochemical grid modeling.more » The emission inventories prepared in this study include both onshore and offshore emissions. All relevant emissions from anthropogenic and biogenic sources are considered, with special attention focused on offshore anthropogenic sources, including OCS oil and gas production facilities, crew and supply vessels and helicopters serving OCS facilities, commercial shipping and fishing, recreational boating, intercoastal barge traffic and other sources located in the adjacent state waters. This document describes the database created during this study that contains the activity information collected for the development of the OCS platform, and crew/supply vessel and helicopter emission inventories.« less

Geriatric infrastructure, BRAC, and ecosystem service markets? End-of-life decisions for dams, roads, and offshore platforms (Invited)

NASA Astrophysics Data System (ADS)

Doyle, M. W.

2010-12-01

US infrastructure expanded dramatically in the mid-20th century, and now includes more than 79,000 dams, 15,000 miles of levees, 3.7 million miles of roads, 600,000 miles of sewer pipe, 500,000 onshore oil wells, and over 4,000 offshore oil platforms. Many structures have been in place for 50 years or more, and an increasing portion of national infrastructure is approaching or exceeding its originally intended design life. Bringing national infrastructure to acceptable levels would cost nearly 10% of the US annual GDP. Decommissioning infrastructure can decrease public spending and increase public safety while facilitating economic expansion and ecological restoration. While most infrastructure remains critical to the national economy, a substantial amount is obsolete or declining in importance. Over 11,000 dams are abandoned, and of nearly 400,000 miles of road on its lands, the U.S. Forest Service considers one-fourth non-essential and often non-functional. Removing obsolete infrastructure allows greater focus and funding on maintaining or improving infrastructure most critical to society. Moreover, a concerted program of infrastructure decommissioning promises significant long-term cost savings, and is a necessary step before more substantial, systematic changes are possible, like those needed to address the new energy sources and shifting climate. One key challenge for infrastructure reform is how to prioritize and implement such a widespread and politically-charged series of decisions. Two approaches are proposed for different scales. For small, private infrastructure, emerging state and federal ecosystem service markets can provide an economic impetus to push infrastructure removal. Ecosystem market mechanisms may also be most effective at identifying those projects with the greatest ecological bang for the buck. Examples where this approach has proved successful include dam removal for stream mitigation under the Clean Water Act, and levee decommissioning on the Missouri and Iowa Rivers for wildlife conservation areas. Programs that link offshore oil platform decommissioning to marine conservation areas are also notable examples of creative linkages between infrastructure and conservation efforts. For federal infrastructure, the forthcoming Water Resources Development Act (WRDA) should include a BRAC-like program. Faced with a number of aging military bases, the Department of Defense (DOD) began identifying installations it would rather close than maintain or modernize. Overcoming political hurdles was accomplished via the Base Realignment and Closure Commission (BRAC), a bi-partisan commission that buffered politicians by creating a slate of closures for Congress and the President to approve or scuttle in toto. From 1988-2005, BRACs closed > 125 military installations, saving > $50 billion. DOD advocated BRAC because it increased efficiency by focusing funding on those bases central to DODs mission, and removed base funding decisions from political influence. Regardless of the approach, society must develop approaches from which to base difficult end-of-life decisions for infrastructure. In most cases, removing obsolete infrastructure can allow focus on infrastructure that remains critical to society.

Design, Analysis, Hybrid Testing and Orientation Control of a Floating Platform with Counter-Rotating Vertical-Axis Wind Turbines

NASA Astrophysics Data System (ADS)

Kanner, Samuel Adam Chinman

The design and operation of two counter-rotating vertical-axis wind turbines on a floating, semi-submersible platform is studied. The technology, called the Multiple Integrated and Synchronized Turbines (MIST) platform has the potential to reduce the cost of offshore wind energy per unit of installed capacity. Attached to the platform are closely-spaced, counter-rotating turbines, which can achieve a higher power density per planform area because of synergistic interaction effects. The purpose of the research is to control the orientation of the platform and rotational speeds of the turbines by modifying the energy absorbed by each of the generators of the turbines. To analyze the various aspects of the platform and wind turbines, the analysis is drawn from the fields of hydrodynamics, electromagnetics, aerodynamics and control theory. To study the hydrodynamics of the floating platform in incident monochromatic waves, potential theory is utilized, taking into account the slow-drift yaw motion of the platform. Steady, second-order moments that are spatially dependent (i.e., dependent on the platform's yaw orientation relative to the incident waves) are given special attention since there are no natural restoring yaw moment. The aerodynamics of the counter-rotating turbines are studied in collaboration with researchers at the UC Berkeley Mathematics Department using a high-order, implicit, large-eddy simulation. An element flipping technique is utilized to extend the method to a domain with counter-rotating turbines and the effects from the closely-spaced turbines is compared with existing experimental data. Hybrid testing techniques on a model platform are utilized to prove the controllability of the platform in lieu of a wind-wave tank. A 1:82 model-scale floating platform is fabricated and tested at the UC Berkeley Physical-Model Testing Facility. The vertical-axis wind turbines are simulated by spinning, controllable actuators that can be updated in real-time of the model scale. Under certain wind and wave headings, it is possible to control the orientation of the platform in regular waves to maximize the power output from the turbines. A time-domain numerical simulation tool is able to confirm some of the experimental findings, taking into account the decoupled properties of the slow-drift hydrodynamics and wind turbine aerodynamics. Future platform designs are discussed, including the French-based, pre-commercial design from Nenuphar Wind, called the TwinFloat, which is closely related to concepts examined in the thesis.

GIS Application System Design Applied to Information Monitoring

NASA Astrophysics Data System (ADS)

Qun, Zhou; Yujin, Yuan; Yuena, Kang

Natural environment information management system involves on-line instrument monitoring, data communications, database establishment, information management software development and so on. Its core lies in collecting effective and reliable environmental information, increasing utilization rate and sharing degree of environment information by advanced information technology, and maximizingly providing timely and scientific foundation for environmental monitoring and management. This thesis adopts C# plug-in application development and uses a set of complete embedded GIS component libraries and tools libraries provided by GIS Engine to finish the core of plug-in GIS application framework, namely, the design and implementation of framework host program and each functional plug-in, as well as the design and implementation of plug-in GIS application framework platform. This thesis adopts the advantages of development technique of dynamic plug-in loading configuration, quickly establishes GIS application by visualized component collaborative modeling and realizes GIS application integration. The developed platform is applicable to any application integration related to GIS application (ESRI platform) and can be as basis development platform of GIS application development.

A versatile quantitation platform based on platinum nanoparticles incorporated volumetric bar-chart chip for highly sensitive assays.

PubMed

Wang, Yuzhen; Zhu, Guixian; Qi, Wenjin; Li, Ying; Song, Yujun

2016-11-15

Platinum nanoparticles incorporated volumetric bar-chart chip (PtNPs-V-Chip) is able to be used for point-of-care tests by providing quantitative and visualized readout without any assistance from instruments, data processing, or graphic plotting. To improve the sensitivity of PtNPs-V-Chip, hybridization chain reaction was employed in this quantitation platform for highly sensitive assays that can detect as low as 16 pM Ebola Virus DNA, 0.01ng/mL carcinoembryonic antigen (CEA), and the 10 HER2-expressing cancer cells. Based on this amplified strategy, a 100-fold decrease of detection limit was achieved for DNA by improving the number of platinum nanoparticle catalyst for the captured analyte. This quantitation platform can also distinguish single base mismatch of DNA hybridization and observe the concentration threshold of CEA. The new strategy lays the foundation for this quantitation platform to be applied in forensic analysis, biothreat detection, clinical diagnostics and drug screening. Copyright © 2016 Elsevier B.V. All rights reserved.

Surface-water radon-222 distribution along the west-central Florida shelf

USGS Publications Warehouse

Smith, C.G.; Robbins, L.L.

2012-01-01

In February 2009 and August 2009, the spatial distribution of radon-222 in surface water was mapped along the west-central Florida shelf as collaboration between the Response of Florida Shelf Ecosystems to Climate Change project and a U.S. Geological Survey Mendenhall Research Fellowship project. This report summarizes the surface distribution of radon-222 from two cruises and evaluates potential physical controls on radon-222 fluxes. Radon-222 is an inert gas produced overwhelmingly in sediment and has a short half-life of 3.8 days; activities in surface water ranged between 30 and 170 becquerels per cubic meter. Overall, radon-222 activities were enriched in nearshore surface waters relative to offshore waters. Dilution in offshore waters is expected to be the cause of the low offshore activities. While thermal stratification of the water column during the August survey may explain higher radon-222 activities relative to the February survey, radon-222 activity and integrated surface-water inventories decreased exponentially from the shoreline during both cruises. By estimating radon-222 evasion by wind from nearby buoy data and accounting for internal production from dissolved radium-226, its radiogenic long-lived parent, a simple one-dimensional model was implemented to determine the role that offshore mixing, benthic influx, and decay have on the distribution of excess radon-222 inventories along the west Florida shelf. For multiple statistically based boundary condition scenarios (first quartile, median, third quartile, and maximum radon-222 inshore of 5 kilometers), the cross-shelf mixing rates and average nearshore submarine groundwater discharge (SGD) rates varied from 100.38 to 10-3.4 square kilometers per day and 0.00 to 1.70 centimeters per day, respectively. This dataset and modeling provide the first attempt to assess cross-shelf mixing and SGD on such a large spatial scale. Such estimates help scale up SGD rates that are often made at 1- to 10-meter resolution to a coarser but more regionally applicable scale of 1- to 10-kilometer resolution. More stringent analyses and model evaluation are required, but results and analyses presented in this report provide the foundation for conducting a more rigorous statistical assessment.

Parametric study on the behavior of an innovative subsurface tension leg platform in ultra-deep water

NASA Astrophysics Data System (ADS)

Zhen, Xing-wei; Huang, Yi

2017-10-01

This study focuses on a new technology of Subsurface Tension Leg Platform (STLP), which utilizes the shallowwater rated well completion equipment and technology for the development of large oil and gas fields in ultra-deep water (UDW). Thus, the STLP concept offers attractive advantages over conventional field development concepts. STLP is basically a pre-installed Subsurface Sea-star Platform (SSP), which supports rigid risers and shallow-water rated well completion equipment. The paper details the results of the parametric study on the behavior of STLP at a water depth of 3000 m. At first, a general description of the STLP configuration and working principle is introduced. Then, the numerical models for the global analysis of the STLP in waves and current are presented. After that, extensive parametric studies are carried out with regarding to SSP/tethers system analysis, global dynamic analysis and riser interference analysis. Critical points are addressed on the mooring pattern and riser arrangement under the influence of ocean current, to ensure that the requirements on SSP stability and riser interference are well satisfied. Finally, conclusions and discussions are made. The results indicate that STLP is a competitive well and riser solution in up to 3000 m water depth for offshore petroleum production.

Control of NORM at Eugene Island 341-A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shuler, P.J.; Baudoin, D.A.; Weintritt, D.J.

1995-12-31

A field study at Eugene island 341-A, an offshore production platform in the Gulf of Mexico, was conducted to develop strategies for the cost-effective prevention of NORM (Naturally Occurring Radioactive Materials) deposits. The specific objectives of this study were to: (1) Determine the root cause for the NORM deposits at this facility, utilizing different diagnostic techniques. (2) Consider all engineering options that are designed to prevent NORM from forming. (3) Determine the most cost-effective engineering solution. An overall objective was to generalize the diagnostics and control methods developed for Eugene Island 341-A to other oil and gas production facilities, especiallymore » to platforms located in the Gulf of Mexico. This study determined that the NORM deposits found at Eugene Island 341-A stem from commingling incompatible produced waters at the surface. Wells completed in Sand Block A have a water containing a relatively high concentration of barium, while those formation brines in Sand Blocks B and C are high in sulfate. When these waters mix at the start of the fluid treatment facilities on the platform, barium sulfate forms. Radium that is present in the produced brines co-precipitates with the barium, thereby creating a radioactive barium sulfate scale deposit (NORM).« less