Science.gov

Sample records for offshore platforms

  1. Offshore platform cathodic protection retrofits

    SciTech Connect

    Turnipseed, S.P.

    1996-10-01

    Cathodic protection (CP) is the primary technique used for underwater corrosion control on the majority of offshore steel structures. Offshore platforms are often kept in service far beyond their original design life. Refurbishment of the CP system is required when adequate protection can no longer be maintained. Various offshore platform CP retrofit designs are discussed.

  2. Arctic offshore platform

    SciTech Connect

    Bhula, D.N.

    1984-01-24

    An offshore structure is disclosed for use in drilling and producing wells in arctic regions having a conical shaped lower portion that extends above the surface of the water and a cylindrical upper section. The conical portion is provided with a controlled stiffness outer surface for withstanding the loads produced by ice striking the structure. The stiffness properties of the outer shell and flexible members are designed to distribute the load and avoid high local loads on the inner parts of the structure.

  3. Offshore drilling platform protection device

    SciTech Connect

    Magill, J.M.

    1981-12-15

    A description is given of an offshore drilling platform protection device for use on an offshore oil well drilling vessel including a drilling platform supportable on a plurality of extendable legs wherein each leg is moved by a rack gear assembly. The rack gear assembly includes an otherwise exposed first gear which engages a second gear positioned in a housing having a rectangular corner opening through which the first gear extends, the protection device including first and second protective sections adapted for mounting over the first gear adjacent to the rectangular corner of the housing for the second gear, the first and second protective sections cooperating to provide an l-shaped opening which communicates with the opening at the second gear housing for protecting the first gear while allowing the first gear to mesh with the second gear.

  4. Caisson shield for arctic offshore production platform

    SciTech Connect

    Clinton, J. D.; Reusswig, G. H.

    1985-03-12

    A caisson shield for the protection of an offshore production platform and, more particularly, a caisson shield for use in an arctic environment for the protection of the offshore structure in iceberg-infested waters which is capable of absorbing the destructive forces of an impact produced by a large iceberg. The caisson shield consists of an essentially annular concrete structure encircling at least the submerged support section of the offshore production platform including vertically upstanding concentrically spaced, annular side walls, a horizontal slab base resting on the marine bottom on which the side walls are supported, and a slab top supported on the side walls, and including annularly spaced internal radial partition walls whereby the entire overall caisson shield structure provides a generally toroidal configuration incorporating a plurality of closed compartments. In one embodiment of the invention, located along the outer annular wall is a plurality of arcuate wall sections forming a series of arches and enclosed compartments between each arcuate wall section and the outer annular wall, which impart a ''scallop-like'' configuration to the outer circumference of the caisson shield. The ''scallop-like'' outer walls are capable of resisting and absorbing extremely high ice loads by being adapted to progressively crush the leading edge of an impacting iceberg and to thereby minimize the crush of the iceberg against the caisson shield before coming to rest against the shield.

  5. Personnel evacuation apparatus for an offshore platform

    SciTech Connect

    Hunter, A.F.

    1987-04-28

    An apparatus is described for evacuating personnel from an offshore platform in all weather conditions to a position on the ocean surface a safe distance from the platform the apparatus comprising: a boat launching ramp; flotation means; boat means adapted to be supported and launched by the ramp; means for releasably securing the boat means within the ramp means adjacent the entry end; means for releasing the latch means to permit the flotation means to move the launching ramp from its stowed position to a deployed position; and means for releasing the boat securing means, thereby permitting the boat means to slide down the ramp and be launched from the exit end of the ramp onto the surface of the ocean a safe distance from the platform.

  6. 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.

  7. Semi-submerged modular offshore platform

    SciTech Connect

    Huang, Y.T.

    1994-12-31

    A modular offshore platform which can be used in a deep sea oil exploration is introduced here. A hybrid of guyed tower and tension leg platforms will be studied. A double-layer dodecahedrous float will be stabilized by a series of guyed cables and clump weights that are anchored to the ocean floor. The platform is built on a dodecahedrous float, which can be fabricated onshore and transported to the job site by direct towing. Buoyancy of the dodecahedrous float will counteract the tremendous weight exerted on this offshore structure. With the help of the guy cables and clump weights anchored to the ocean floor, the structure can be column stabilized to a designated location ready for needed drilling operation. Dodecahedron is one of the natural crystal forms which can be built up by modular space components. It is an ideal structure for easy assembly in a hostile, physically restrictive sea environment. In this article only the major factors affecting the analysis is considered. Much more detailed considerations will be required in the final design, reflecting environmental forces in action, stresses during erection, and the fabrication details.

  8. Offshore platform structure for artic waters

    SciTech Connect

    Einstabland, T.

    1984-11-27

    An offshore platform structure of the gravity type intended to be installed on a sea bed in artic or corresponding waters. The platform structure comprises a substructure intended to be completely submerged and supported by the sea bed when in installed position, a superstructure extending up from the substructure and up above the sea bed and a deck superstructure supported by the superstructure above the sea level. A fender is provided intended to protect the superstructure against drifting ice and icebergs, the substructure being provided with a preferably horizontal top support slab supporting the fender, the fender being movably arranged on said support slab and comprising a preferably compartmented cylindrical ring-shaped body with a large weight resting preferably freely on the substructure, intended to be arranged apart from the superstructure when in normal position.

  9. Safety off-shore drilling and pumping platform

    SciTech Connect

    Cunningham, B.H.

    1983-07-26

    A safety off-shore drilling, pumping and storage platform for oilwells is provided, wherein the structure has a first funnel like structure which floats near the ocean floor connected by a long tube to a second floating funnel platform which floats on the surface of the water.

  10. Fire-resistant wellhead equipment for offshore platforms

    SciTech Connect

    Williams, M.R.; Keene, K.

    1984-02-01

    A new generation of fire-resistant wellhead equipment has been developed for offshore platforms. This paper presents the design concepts and principles of operation of this new equipment, and it describes the engineering approach taken during its development. These new wellheads and christmas trees have survived numerous laboratory fire tests which simulated offshore platform fire conditions. No leakage was permissible during the test burns nor during the subsequent cooldown periods. The laboratory fire test results confirmed the performance predicted by computer Finite Element Analysis and verified the design procedures employed. This new fire resistant wellhead equipment promises to significantly reduce the fire hazard associated with the production of oil and gas from offshore platform wells.

  11. Secondary capping beams for offshore drilling platforms

    SciTech Connect

    Albaugh, E. K.

    1985-08-13

    A pair of I-shaped elongated girders secured to, and extending outwardly from, the capping beams of a four pile platform, to form cantilever secondary capping beams which support modified self-contained drilling rigs of a size and weight normally installed on eight pile platforms. Rig modifications comprise separation of pump and engine packages, a pipe rack extension, and a novel skidding system.

  12. 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.

  13. 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.

  14. 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

  15. Outbreak of Hepatitis A on an Offshore Petroleum Platform, Alaska

    PubMed Central

    Kosatsky, Tom; Middaugh, John P.; Hall, David

    1988-01-01

    An outbreak of 8 cases of hepatitis A among the 36-member crew of an offshore Alaska petroleum production platform was linked to a previous outbreak in an urban day-care center. Transmission of hepatitis A on the platform related most plausibly to refrigerated food items contaminated by a cook with mild disease. Control efforts included identifying and treating contacts of case patients who had traveled far from the platform before becoming ill. Early serologic confirmation of diagnosed cases and rapid reporting to public health authorities are essential to prevent disease transmission. Timely investigation can limit the administration of immune globulin to persons at high risk of contracting the disease. PMID:3348024

  16. Cathodic protection on concrete offshore platforms

    SciTech Connect

    Heuze, B.

    1980-05-01

    Experience with five cathodically protected North Sea concrete platforms has demonstrated the value of interconnecting the concrete-reinforcement steel with cathodically protected metal items on the structure (rather than insulating the steel from them) as a means of bringing the entire structure under the protection of the corrosion-control system. Lessons learned from this experience point out the importance of the duct material in safeguarding the prestressing tendons, the limitations of cathodic protection in cases of coating cracking and disbondment, and the precautions to be taken against stray welding currents. An improved approach to corrosion prevention focuses on the design philosophy, the current required by the reinforcing bar and well casing, the corrosion protection inside piping shafts and risers, and the required monitoring systems.

  17. Standardization of Meteorological Data from FINO Offshore Platforms

    NASA Astrophysics Data System (ADS)

    Leiding, Tina; Bastigkeit, Ilona; Bégué, Friederike; Gates, Lydia; Herklotz, Kai; Müller, Stefan; Neumann, Thomas; Schwenk, Patrick; Senet, Christian; Tinz, Birger; Wilts, Friedrich

    2015-04-01

    In order to investigate conditions for offshore wind power generation in the German coastal waters, three research platforms were constructed in the North Sea (FINO1 and 3) and the Baltic Sea (FINO2). Measurement masts at each offshore platform are equipped with a range of meteorological sensors at heights of 30 to 100 m above sea level. Standardized analysis and interpretation of the data is necessary to compare the results of the different platforms and will improve the knowledge of the marine ambient conditions at the three locations. International Electrotechnical Commission Standards (IEC) cannot always be applied as some requirements are not applicable to offshore masts e.g. due to the wake of the structure. In the FINO-Wind project, therefore, a standardization method is developed. Recorded measurement data are checked automatically on the basis of a comprehensive quality control. The routine starts with a formal check, followed by climatological, temporal, repetition, and consistency checks. After successful completion of each sequence, the data are assigned standardized quality flags. By default, 10-minute data are processed. A special focus is on mast effects on the wind data of the three masts due to the different shapes of the construction (square or triangular shapes and different boom structures). These effects are investigated in comparison with wind tunnel measurements, LiDAR, Computational Fluid Dynamics calculations, and a 'uniform ambient flow mast correction' method. An adjustment for such effects will be applied to all wind data. The comparison of sensor equipment, its installation and orientation as well as of the mast constructions will lead to suggestions on how wind measurements at offshore platforms mast can be improved. The research project FINO-Wind is funded under the 'Wind Energy' initiative of the German Federal Ministry for the Economic Affairs and Energy for the period 2013 to 2015. For further information see www.dwd.de/fino-wind.

  18. Suppression of resonance of offshore platform in irregular waves

    SciTech Connect

    Ishida, H.; Komura, T.

    1994-12-31

    A theoretical solution of the vibration of offshore platforms due to irregular waves has been presented by using the equivalent linearized method. This solution has been verified by comparison with the experimental data from the viewpoint of time variation and the spectrum analysis. In the case of irregular waves as well as periodic waves, the resonance can be suppressed by bringing the resonance point close to the cancellation point.

  19. Ecology of Oil/Gas Platforms Offshore California

    SciTech Connect

    Allen, M.J.; Cowen, R.K.; Kauwling, R.J.; Mitchell, C.T.

    1987-02-01

    The report summarizes the ecology of fishes and attached epifauna that associate with offshore oil and gas platforms of California and an evaluation of actual and potential use of the platforms for mariculture. The attached invertebrate biota in the upper 35 m of the water column is dominated by bay (Mytilus edulis) or California (M. californianus) mussels, depending upon location and/or age of the structure, with other mollusks, barnacles and polychaetes being of secondary importance. The attached community may take up to five years to fully develop. The fish fauna at shallow (less than 45 m of water), nearshore platforms is dominated by surfperches and rockfishes; major species in this assemblage are about equally divided between those with relatively large mouths (which consume large organisms such as crabs and small fish) and those with relatively small mouths (which graze on small epifauna and planktonic organisms). The fish fauna may take two years to attain a relatively stable community structure. The fish fauna at nearshore platforms is similar to that at natural reefs and oil islands in the area, but is more diverse among common species. As opposed to these other structures, platforms lack fish which associated with algae.

  20. Evaluating alternatives for decommissioning California's offshore oil and gas platforms.

    PubMed

    Bernstein, Brock B

    2015-10-01

    This paper introduces a series of 6 additional papers in this issue that describe an in-depth analysis of options for decommissioning oil and gas platforms offshore southern California. Although current leases require lessees in both state and federal waters to completely remove all production facilities and restore the seafloor to its pre-platform condition, other options have emerged since these leases were signed. Laws and regulations in other jurisdictions (particularly in federal waters) have evolved to allow a number of other uses such as aquaculture, alternative energy production, and artificial reefing. In response, the California Natural Resources Agency initiated an effort to investigate the issues associated with these and other decommissioning alternatives. The papers in this series are the result of the second phase in this process, a broad investigation of the engineering, economic, and environmental costs and benefits of the most feasible and likely options. In addition to the project's final report, the authors produced an interactive mathematical decision model, PLATFORM, that enables users to explore the implications of different decommissioning projects and options, as well as the effects of different approaches to valuing the associated costs and benefits.

  1. Proceedings of the 25th annual offshore technology conference. Volume 2 - Platform and marine system design

    SciTech Connect

    Not Available

    1993-01-01

    This is volume 2 of a 4 volume set of conference proceedings dealing with offshore development of mineral resources. This particular conference centers around the design, construction, and installation of offshore platforms and underwater pipelines. It contains papers which discuss retrofitting of various types of platforms to meet current safety standards. It also discusses design criteria used to minimize wave motion in offshore platforms, moorings, and various types of support facilities. Papers also describe methods for welding joints in both platforms and pipelines. Many papers specifically address economic aspects of offshore development and the cost of complying with increasing safety regulations and standards. A few papers also deal directly with engineered safety systems as they apply to offshore platforms.

  2. Experiments on an offshore platform model by FBG sensors

    NASA Astrophysics Data System (ADS)

    Li, Dongsheng; Li, Hongnan; Ren, Liang; Sun, Li; Zhou, Jing

    2004-07-01

    Optical fiber sensors show superior potential for structural health monitoring of civil structures to ensure their structural integrity, durability and reliability. Apparent advantages of applying fiber optic sensors to a marine structure include fiber optic sensors" immunity of electromagnetic interference and electrical hazard when used near metallic elements over a long distance. The strains and accelerations of the newly proposed model of a single post jacket offshore platform were monitored by fiber Bragg grating (FBG) sensors. These FBG sensors were attached to the legs and the top of the platform model in parallel with electric strain gauges or traditional piezoelectric accelerometers, respectively. Experiments were conducted under a variety of loading conditions, including underwater base earthquake simulation dynamic tests and static loading tests. Underwater seismic shaking table was utilized to provide the appropriate excitations. The natural frequencies measured by the FBG accelerometer agree well with those measured by piezo-electrical accelerometers. The monitoring network shows the availability of applying different fiber optic sensors in long-distance structural health monitoring with frequency multiplexing technology. Finally, the existing problems of packaging, strain transferring ratio between the bare fiber and the host structure on which the fiber embedded, and installation and protection of fiber optic sensors are emphasized.

  3. Probability based earthquake load and resistance factor design criteria for offshore platforms

    SciTech Connect

    Bea, R.G.

    1996-12-31

    This paper describes a probability reliability based formulation to determine earthquake Load and Resistance Factor Design (LRFD) parameters for conventional, steel, pile supported, tubular membered platforms that is proposed as a basis for earthquake design criteria and guidelines for offshore platforms that are intended to have worldwide applicability. The formulation is illustrated with application to platforms located in five areas: offshore California, Venezuela (Rio Caribe), the East Coast of Canada, in the Caspian Sea (Azeri), and the Norwegian sector of the North Sea.

  4. Modeling and Simulation of Offshore Wind Power Platform for 5 MW Baseline NREL Turbine

    PubMed Central

    Roni Sahroni, Taufik

    2015-01-01

    This paper presents the modeling and simulation of offshore wind power platform for oil and gas companies. Wind energy has become the fastest growing renewable energy in the world and major gains in terms of energy generation are achievable when turbines are moved offshore. The objective of this project is to propose new design of an offshore wind power platform. Offshore wind turbine (OWT) is composed of three main structures comprising the rotor/blades, the tower nacelle, and the supporting structure. The modeling analysis was focused on the nacelle and supporting structure. The completed final design was analyzed using finite element modeling tool ANSYS to obtain the structure's response towards loading conditions and to ensure it complies with guidelines laid out by classification authority Det Norske Veritas. As a result, a new model of the offshore wind power platform for 5 MW Baseline NREL turbine was proposed. PMID:26550605

  5. Modeling and Simulation of Offshore Wind Power Platform for 5 MW Baseline NREL Turbine.

    PubMed

    Roni Sahroni, Taufik

    2015-01-01

    This paper presents the modeling and simulation of offshore wind power platform for oil and gas companies. Wind energy has become the fastest growing renewable energy in the world and major gains in terms of energy generation are achievable when turbines are moved offshore. The objective of this project is to propose new design of an offshore wind power platform. Offshore wind turbine (OWT) is composed of three main structures comprising the rotor/blades, the tower nacelle, and the supporting structure. The modeling analysis was focused on the nacelle and supporting structure. The completed final design was analyzed using finite element modeling tool ANSYS to obtain the structure's response towards loading conditions and to ensure it complies with guidelines laid out by classification authority Det Norske Veritas. As a result, a new model of the offshore wind power platform for 5 MW Baseline NREL turbine was proposed.

  6. Method for scale reduction in off-shore platforms

    SciTech Connect

    Ehlers, D.M.; Hopkins, D.N.

    1987-12-15

    A process for reducing scale formation wherein sea water, incompatible with connate water, is used as the flooding medium forming thereby a mixture with liquid hydrocarbonaceous fluids where the fluids are produced in off-shore platforms is described comprising: (a) producing the mixture of water and liquid hydrocarbonaceous fluids to the surface from the formation; (b) directing the mixture into a water/oil separator where the liquid hydrocarbonaceous fluids are substantially separated from the mixture and the remaining hydrocarbonaceous fluid is entrained in the form of oil droplets within the separated aqueous mixture; (c) removing the aqueous mixture with oil droplets therein from the water/oil separator and thereafter mixing the combination with additional sea water, or other aqueous solution having a similar concentration of sulfate ions, in a vessel containing a coalescing means which sea water upon contact with the connate water causes a precipitate to form thereby reducing the scale forming tendency of the water; and (d) collecting liquid hydrocarbons from step (b) and from the coalescing means, and disposing of the resultant water.

  7. Assembly of conductor guides for off-shore drilling platform

    SciTech Connect

    Campo, J. J.

    1985-12-31

    A conductor guide assembly for conductors of an off-shore well platform having a jacket with an interior pile for extending from a sea bed to above a water level which is over the sea bed. In accordance with one inventive feature, a first guide mechanism comprising a plurality of vertically spaced supports which hold the tubular conduits within the interior pile is assembled in a plurality of sections wherein the upper support of each section is provided with removable bolt-on units for supporting the first guide mechanism as successive sections are jointed thereto. In accordance with another inventive feature, a second guide mechanism comprises a pair of circular plates positioned to rotate within a lower deck opening and which are connected together and define a plurality of passages for receiving the plurality of conductors that extend in the interior pile. The connected plates are temporarily attached to the lower deck for transport so that the second guide mechanism can be detached and rotated to align the passages with the intended positions for the conductors whereafter the second guide mechanism is permanently attached to the lower deck. In accordance with another inventive feature, a third guide mechanism comprising a plurality of radially extending beams is supported on an upper deck. The second guide mechanism also has passages for access to the conductors and it too can be rotated into a position of alignment with the conductors and thereafter permanently fixed to the upper deck.

  8. New Modeling Tool Analyzes Floating Platform Concepts for Offshore Wind Turbines (Fact Sheet)

    SciTech Connect

    Not Available

    2011-02-01

    Researchers at the National Renewable Energy Laboratory (NREL) developed a new complex modeling and analysis tool capable of analyzing floating platform concepts for offshore wind turbines. The new modeling tool combines the computational methodologies used to analyze land-based wind turbines with the comprehensive hydrodynamic computer programs developed for offshore oil and gas industries. This new coupled dynamic simulation tool will enable the development of cost-effective offshore technologies capable of harvesting the rich offshore wind resources at water depths that cannot be reached using the current technology.

  9. 33 CFR 165.155 - Northville Industries Offshore Platform, Riverhead, Long Island, New York-safety zone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Offshore Platform of LPG vessels via Marine Safety Information Radio Broadcast. ... (LPG) vessel is moored at the Offshore Platform. The safety zone remains in effect until the LPG vessel... Platform, Riverhead, Long Island, New York-safety zone. 165.155 Section 165.155 Navigation and...

  10. Design of self-contained sensor for monitoring of deep-sea offshore platform

    NASA Astrophysics Data System (ADS)

    Song, Yang; Yu, Yan; Zhang, Chunwei; Dong, Weijie; Ou, Jinping

    2013-04-01

    Offshore platform, which is the base of the production and living in the sea, is the most important infrastructure for developing oil and gas resources. At present, there are almost 6500 offshore platforms servicing in the 53 countries' sea areas around the world, creating great wealth for the world. In general, offshore platforms may work for 20 years, however, offshore platforms are expensive, complex, bulky, and so many of them are on extended active duty. Because of offshore platforms servicing in the harsh marine environment for a long time, the marine environment have a great impact on the offshore platforms. Besides, with the impact and erosion of seawater, and material aging, the offshore platform is possible to be in unexpected situations when a badly sudden situation happens. Therefore, it is of great significance to monitor the marine environment and offshore platforms. The self-contained sensor for deep-sea offshore platform with its unique design, can not only effectively extend the working time of the sensor with the capability of converting vibration energy to electrical energy, but also simultaneously collect the data of acceleration, inclination, temperature and humidity of the deep sea, so that we can achieve the purpose of monitoring offshore platforms through analyzing the collected data. The self-contained sensor for monitoring of deep-sea offshore platform includes sensing unit, data collecting and storage unit, the energy supply unit. The sensing unit with multi-variables, consists of an accelerometer LIS344ALH, an inclinometer SCA103T and a temperature and humidity sensor SHT11; the data collecting and storage unit includes the MSP430 low-power MCU, large capacity memory, clock circuit and the communication interface, the communication interface includes USB interface, serial ports and wireless interface; in addition, the energy supply unit, converting vibration to electrical energy to power the overall system, includes the electromagnetic

  11. Earthquake alarm system for the Maui-A offshore platform, New Zealand

    SciTech Connect

    Tyler, R.G.; Beck, J.L.

    1983-02-01

    Situated in the Tasman Sea, the Maui A offshore gas production platform has an earthquake alarm system that gives immediate warning when the seismic accelerations reach half the platform's design level. The system monitors only the response of the lower modes of the platform, as these make the major contribution to the stresses in the structure. In order to reduce the risk of false alarms, a radio link with similar detectors on shore confirms that an earthquake has occurred.

  12. Computational methods. [Calculation of dynamic loading to offshore platforms

    SciTech Connect

    Maeda, H. . Inst. of Industrial Science)

    1993-02-01

    With regard to the computational methods for hydrodynamic forces, first identification of marine hydrodynamics in offshore technology is discussed. Then general computational methods, the state of the arts and uncertainty on flow problems in offshore technology in which developed, developing and undeveloped problems are categorized and future works follow. Marine hydrodynamics consists of water surface and underwater fluid dynamics. Marine hydrodynamics covers, not only hydro, but also aerodynamics such as wind load or current-wave-wind interaction, hydrodynamics such as cavitation, underwater noise, multi-phase flow such as two-phase flow in pipes or air bubble in water or surface and internal waves, and magneto-hydrodynamics such as propulsion due to super conductivity. Among them, two key words are focused on as the identification of marine hydrodynamics in offshore technology; they are free surface and vortex shedding.

  13. Cleaning of the ocean floor near offshore platforms in the Gulf coast

    SciTech Connect

    Fang, C.S.; Smith, S.A. Jr.

    1986-03-01

    For decades in offshore drilling, the drill cuttings were separated from the circulating drilling fluid by the shale shaker and hydrocyclone, and discharged to the ocean. The drilling fluid itself was discharged to the ocean intermittently to maintain its required properties during the drilling process. These discharges contain many environmentally undesirable chemicals, such as hydrocarbons chemical additives and heavy metals. As a result, the ocean floor near some of the offshore platforms in the Gulf of Mexico are covered by contaminated sediment. Ocean current is not as effective in washing out the discarded ocean muds as previously believed. An attempt was made to clean some of the offshore platforms in the Gulf of Mexico. The quantity and characteristics of the drilling discharges are estimated the technology used to clean the ocean floor near platforms is described, and advanced treatments for hydrocarbon removal, chemical oxidation and activated carbon adsorption, are discussed. 8 references.

  14. Analyzing the safety of removal sequences for piles of an offshore jacket platform

    NASA Astrophysics Data System (ADS)

    Pan, Xin-Ying; Zhang, Zhao-De

    2009-12-01

    An inevitable consequence of the development of the offshore petroleum industry is the eventual obsolescence of large offshore structures. Proper methods for removal of decommissioned offshore platforms are becoming an important topic that the oil and gas industry must pay increasing attention to. While removing sections from a decommissioned jacket platform, the stability of the remaining parts is critical. The jacket danger indices D σ and D s defined in this paper are very useful for analyzing the safety of any procedure planned for disassembling a jacket platform. The safest piles cutting sequence can be determined easily by comparing every column of D σ and D s or simply analyzing the figures of every row of D σ and D s .

  15. Model test of new floating offshore wind turbine platforms

    NASA Astrophysics Data System (ADS)

    Shin, Hyunkyoung; Dam, Pham Thanh; Jung, Kwang Jin; Song, inseob; Rim, Chaewhan; Chung, Taeyoung

    2013-06-01

    This paper presents the model test results of 3 new spar platforms which were developed based on the OC3-Hywind spar to support a 5-MW wind turbine. By changing the shape but keeping both volume and mass of OC3- Hywind spar platform, those platforms were expected to experience different hydrodynamic and hydrostatic loads. The scale models were built with a 1/128 scale ratio. The model tests were carried out in waves, including both rotating rotor effect and mean wind speed. The characteristic motions of the 3 new models were measured; Response Amplitude Operators (RAO) and significant motions were calculated and compared with those of OC3-Hywind.

  16. 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.

  17. 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

  18. Offshore underbalanced drilling system could revive field developments. Part 2: Making this valuable reservoir drilling/completion technique work on a conventional offshore drilling platform

    SciTech Connect

    Nessa, D.O.; Tangedahl, M.J.; Saponja, J.

    1997-10-01

    Part 1, presented in the July issue, discussed the emerging trend to move underbalanced drilling (UBD) operations into the offshore arena, following its successful application in many onshore areas. This concluding article delves into the details of applying UBD offshore. Starting with advantages the technique offers in many maturing or complex/marginal prospects, the UBD system for offshore platforms use is described. This involves conversion of the conventional rotary system, use of rotating diverters, design of the surface fluid separation system and the necessary gas (nitrogen or natural gas) injection system to lighten the fluid column. Commonly faced operational challenges for offshore UBD are listed along with recommended solutions.

  19. Crack detection in offshore platform structure based on structural intensity approach

    NASA Astrophysics Data System (ADS)

    Tian, Xiaojie; Liu, Guijie; Gao, Zhiming; Chen, Pengfei; Mu, Weilei

    2017-02-01

    Structural intensity approach is introduced to study the crack detection for offshore platform in the paper. The Line Spring Model (LSM) of surface crack is proposed based on plate crack structure, and thus the relationship between the additional angle, displacement and crack relative depth is achieved. Besides, the concept of appended structure-borne sound intensity is introduced. The expression of appended structural intensity for crack damage is derived. By observing the input energy, distribution, transmission and vibration performance of structure intensity, evidence is provided for detection of crack location. Vibration analysis is conducted on the whole platform under multi environment load. Using the structural intensity approach, the crack is detected on the key point easily. Moreover, the K-shape welded pipe point is detected using structural intensity approach, and the crack can be detected accurately. Therefore, development structural intensity approach would be extremely useful to spread out technologies that can be applied for offshore platform crack detection accurately.

  20. Impact of offshore gas platforms on the structural and functional biodiversity of nematodes.

    PubMed

    Fraschetti, S; Guarnieri, G; Gambi, C; Bevilacqua, S; Terlizzi, A; Danovaro, R

    2016-04-01

    The Mediterranean Sea hosts hundreds of offshore gas platforms, whose activity represents a potential threat to marine ecosystems. Evidence from several studies indicates that nematodes can be highly sensitive to changes in the environmental quality. Here, we investigated the response of nematode assemblages to the presence of offshore gas platforms (located in the central Mediterranean Sea) in terms of spatial heterogeneity, structural and functional diversity. Since the effect of the investigated offshore platforms on macrofaunal assemblages were previously assessed by Terlizzi et al. (2008), the study provided also the opportunity to compare the response of different benthic compartments to the same impact related to fossil fuel extraction on marine environments. The platforms had a significant impact on nematode assemblages up to 1000 m distance from the structure. The effects were evident in term of: a) more homogeneous spatial distribution of nematode assemblages, b) increased trophic diversity of deposit feeders and c) changes in life strategies with an increase of opportunistic species in sediments closer to the platforms. Such effects seemed to be related to the dimension of the platform structures, rather than to chemical pollution or changes in food availability. These findings suggest that the platforms exert a physical alteration of the surrounding environment that is reflected by altered structural and functional traits of nematode biodiversity. The use of nematodes for monitoring the effects of the platforms only partially matched with the results obtained using macrofauna, providing further insights on potential outcomes on the functional response of marine assemblages to fossil fuel extraction.

  1. 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.

  2. System and method for positioning an off-shore platform on a support

    SciTech Connect

    Ninet, J.L.

    1983-11-08

    An off-shore platform is floated on a barge. A support structure is fixed to the sea bed and including a plurality of upstanding piles with at least two of said piles having platform-receiving guide means at their upper ends. The platform includes a plurality of legs for fixing to corresponding ones of the piles with at least two of the legs being hollow and being provided with respective plungers slideably mounted therein for co-operating with said platform-receiving guide means. Each plunger is associated with a releasable fastening capable of holding the plunger fixed in its leg, and of releasing it suddenly on command to drop into engagement with said platform-receiving guide means. The releasable fastenings of at least two of the plungers are arranged to release simultaneously on a common command.

  3. 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

  4. An improved modal strain energy method for damage detection in offshore platform structures

    NASA Astrophysics Data System (ADS)

    Li, Yingchao; Wang, Shuqing; Zhang, Min; Zheng, Chunmei

    2016-06-01

    The development of robust damage detection methods for offshore structures is crucial to prevent catastrophes caused by structural failures. In this research, we developed an Improved Modal Strain Energy (IMSE) method for detecting damage in offshore platform structures based on a traditional modal strain energy method (the Stubbs index method). The most significant difference from the Stubbs index method was the application of modal frequencies. The goal was to improve the robustness of the traditional method. To demonstrate the effectiveness and practicality of the proposed IMSE method, both numerical and experimental studies were conducted for different damage scenarios using a jacket platform structure. The results demonstrated the effectiveness of the IMSE method in damage location when only limited, spatially incomplete, and noise-polluted modal data is available. Comparative studies showed that the IMSE index outperformed the Stubbs index and exhibited stronger robustness, confirming the superiority of the proposed approach.

  5. Grid Simulator for Testing a Wind Turbine on Offshore Floating Platform

    SciTech Connect

    Gevorgian, V.

    2012-02-01

    An important aspect of such offshore testing of a wind turbine floating platform is electrical loading of the wind turbine generator. An option of interconnecting the floating wind turbine with the onshore grid via submarine power cable is limited by many factors such as costs and associated environmental aspects (i.e., an expensive and lengthy sea floor study is needed for cable routing, burial, etc). It appears to be a more cost effective solution to implement a standalone grid simulator on a floating platform itself for electrical loading of the test wind turbine. Such a grid simulator must create a stable fault-resilient voltage and frequency bus (a micro grid) for continuous operation of the test wind turbine. In this report, several electrical topologies for an offshore grid simulator were analyzed and modeled.

  6. Gravity base of offshore production platform with ice-penetrating peripheral nose sections

    SciTech Connect

    Gerwick, B.C.; Price, E.B.; Taylor, T.P.

    1983-12-27

    A gravity base offshore production platform structure and, more particularly, a production platform for use in an arctic environment, including an encircling structure having a predetermined configuration the protection of the offshore structure in iceberg-infested waters which are capable of resisting the destructive forces of an impact produced by a large iceberg. The gravity base offshore production platform structure consists of a monolithic, massive concrete structure of a configuration providing a plurality or horizontal array of upright, mostly cylindrical compartments, which is supported on a concrete or slab foundation nesting on the marine floor. Generally, although not necessarily, the compartmented structure rises above the marine surface and is covered by a concrete slab or similar covering structure to thereby form closed compartments within the monolithic structure. The circumference of the concrete structure incorporates a plurality of ice-deflecting nose portions which are integrally formed with the wall structure of the exteriorly located compartments of the array, and are reinforced to withstand large iceberg forces upon impact. These reinforced nose portions impart either a ''scallop-like'' configuration to the circumference of the structure, or when in the shape of substantially pointed wall sections, a ''starpoint'' form capable of resisting and absorbing extremely high energy of large, fast moving and strong icebergs by progressively crushing the leading edge of an impacting iceberg.

  7. Emissions of methane from offshore oil and gas platforms in Southeast Asia

    PubMed Central

    Nara, Hideki; Tanimoto, Hiroshi; Tohjima, Yasunori; Mukai, Hitoshi; Nojiri, Yukihiro; Machida, Toshinobu

    2014-01-01

    Methane is a substantial contributor to climate change. It also contributes to maintaining the background levels of tropospheric ozone. Among a variety of CH4 sources, current estimates suggest that CH4 emissions from oil and gas processes account for approximately 20% of worldwide anthropogenic emissions. Here, we report on observational evidence of CH4 emissions from offshore oil and gas platforms in Southeast Asia, detected by a highly time-resolved spectroscopic monitoring technique deployed onboard cargo ships of opportunity. We often encountered CH4 plumes originating from operational flaring/venting and fugitive emissions off the coast of the Malay Peninsula and Borneo. Using night-light imagery from satellites, we discovered more offshore platforms in this region than are accounted for in the emission inventory. Our results demonstrate that current knowledge regarding CH4 emissions from offshore platforms in Southeast Asia has considerable uncertainty and therefore, emission inventories used for modeling and assessment need to be re-examined. PMID:25266041

  8. 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.

  9. 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

  10. 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.

  11. Infrared inspection applied to offshore platforms: Petrobras experience at Campos Basin

    NASA Astrophysics Data System (ADS)

    Verdini, Edson A.; Veratti, Attilio B.

    2002-03-01

    Bacia de Campos (Rio de Janeiro - Brazil) is one of the biggest offshore petroleum fields in the world today. In June 2001, Bacia de Campos, having more than 490 oil wells, 34 offshore platforms and 7 modified ships in operation, reached 1,3 million barrels/day. If compared to OPEP countries only nine of them got an average production higher than 1 million barrels/day in 2000, which means it can be placed on the 10th position in the rank of oil producers. In this context this work aims not only to show the results achieved within the introduction of thermographic inspections in offshore oil production (platforms and ships), but also the financial results (ROI - Return of Investment) considering the use of this particular technique. Bacia de Campos got a ROI around 7 million dollars in the last 4 years, which means a hundred times higher than the total cost of thermographic services in the same period. As far as we know this is one of the best results already reported in the world. We also present the methodology applied to analyze thermal anomalies in electrical components and data management software, including advanced Digital Reports sent via Internet.

  12. Vertical Structure of the Wind Speed Profile at the North Sea Offshore Measurement Platform FINO1

    NASA Astrophysics Data System (ADS)

    Kettle, A. J.

    2013-12-01

    The vertical wind speed profile in the lowest 100m of the marine atmospheric boundary layer has been characterized from data collected at the FINO1 offshore research platform in the German North Sea sector for 2005. Located in 30m of water, the platform has a dense vertical array of meteorological instrumentation to measure wind speed, air temperature, relative humidity, and atmospheric turbulence characteristics. Along measurements of the ocean temperature and surface waves, the platform is well-equipped to characterize wind properties in the near-surface boundary layer. Preliminary analysis reveals a high incidence of vertical wind speed profiles that deviate significantly from Monin-Obukhov similarity theory with wind speed inflections that suggest decoupled layers near the surface. The presentation shows how the properties of the vertical wind speed profile change mainly depending on the wind speed, wind direction, and time of year. The results are significant because there are few reports of inflections in the vertical wind speed profile over the ocean and there is an a priori assumption that the vertical wind speed profile varies smoothly according to similarity theory. There are possible consequences for the wind energy development in terms of understanding the forces acting on offshore wind turbines whose rotors sweep across heights 150-200m above the sea surface.

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

    SciTech Connect

    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 by 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.

  14. Intelligent system for start-up of a petroleum offshore platform.

    PubMed

    Campos, M C; Satuf, E; de Mesquita, M

    2001-01-01

    It is difficult to control and to manage the start-up of a petroleum offshore platform. In order to solve this problem an intelligent system can play an important role, since available qualitative operator and design knowledge can be easily implemented to assist the operator during start-up. This paper describes the integration of an expert system with a fuzzy controller applied to such a process. The intelligent system has many heuristic rules to implement the automation of the start-up procedures, like the opening of many on-off valves while simultaneously monitoring process variables. It also has a fuzzy controller to optimize the opening of the oil wells, in order to minimize the start-up time. This intelligent system is being implemented in the platform P-19 of Petrobras, the Brazilian oil company, in Campos Basin, Brazil. The prototype has been operating since October 1998.

  15. Rotary cyclone will improve oily water treatment and reduce space requirement/weight on offshore platforms

    SciTech Connect

    Gay, J.C.; Triponey, G.; Bezard, C.; Schummer, P.

    1987-01-01

    A rotary hydrocyclone was developed for the treatment of the produced oily water on offshore platforms. The main advantages of this type of equipment consist in: a few second residence time resulting in a dramatic reduction in weight and volume; higher efficiency when comparing with conventional settling tanks or static cyclones; insensitivity to the platform motion; large flexibility in flow rate and oil concentration in the treated water; low pressure drop requirement; easily adaptable to changing field operating conditions; modular conception facilitating the offshore installation; reduced maintenance and power consumption resulting in a low operating cost. This paper outlines the results of laboratory work conducted initially on a static hydrocylcone and on a rotary cyclone scale model, with the reasons for the differences in performance of the both types of equipment. A field test of a 2 x 25 m/sup 3//h industrial rotary cyclone skid is presented and the field performance analyzed. Finally main features of the industrial units are presented and a comparison with a conventional treatment is made.

  16. 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.

  17. Model Development and Loads Analysis of a Wind Turbine on a Floating Offshore Tension Leg Platform

    SciTech Connect

    Matha, D.; Fischer, T.; Kuhn, M.; Jonkman, J.

    2010-02-01

    This report presents results of the analysis of a 5-MW wind turbine located on a floating offshore tension leg platform (TLP) that was conducted using the fully coupled time-domain aero-hydro-servo-elastic design code FAST with AeroDyn and HydroDyn. Models in this code are of greater fidelity than most of the models that have been used to analyze floating turbines in the past--which have neglected important hydrodynamic and mooring system effects. The report provides a description of the development process of a TLP model, which is a modified version of a Massachusetts Institute of Technology design derived from a parametric linear frequency-domain optimization process. An extensive loads and stability analysis for ultimate and fatigue loads according to the procedure of the International Electrotechnical Commission offshore wind turbine design standard was performed with the verified TLP model. Response statistics, extreme event tables, fatigue lifetimes, and selected time histories of design-driving extreme events are analyzed and presented. Loads for the wind turbine on the TLP are compared to those of an equivalent land-based turbine in terms of load ratios. Major instabilities for the TLP are identified and described.

  18. 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.

  19. Frequency variation and sensor contribution assessment: Application to an offshore platform in the South China Sea

    NASA Astrophysics Data System (ADS)

    Liu, Fushun; Li, Huajun; Wang, Weiying; Li, Wei; Wang, Bin

    2015-02-01

    In this paper, a time-frequency and multiple-sensor assessment method is presented and then applied to an offshore platform in the South China Sea with the goal of providing a more suitable time duration of measured signals and evaluating each sensor's contribution to mode shapes of interest. By processing all measured signals simultaneously, a series of linear parameters are used to fit the measured signals. A moving window in overlapping steps along the time record of a non-stationary signal is used for time-frequency analysis while a series of amplitude matrices are obtained for all sliced segments. These segments are then used to evaluate each sensor's contribution to some mode(s) of interest. Compared with the short-time Fourier transform (STFT) or S-transform method, the frequencies used in this time-frequency analysis are shared by the sensors involved so that the variations in the results due to the characteristics of different sensors are avoided. In addition, the approach requires only a short-duration segment to obtain high-frequency resolution, which will improve the computing efficiency of modal analysis using measured seat est data. The proposed method could also be used to estimate damping ratios and each sensor's contribution to modes of interest based on the analysis of the series of amplitude matrices; this could be used to guide the installation of sensors in field tests of offshore structures. To demonstrate the proposed method with a time-frequency analysis, a numerical example of a synthesized signal with five segments, each with its owns different frequency componentsincluding a relatively weaker component, is constructed; numerical results from the analysis of this example signal indicate that the approach could yield a sharper image with a good computing efficiency. The second example simulates three signals that represent multiple measurements; this example is used to study each sensor

  20. Molecular Analysis of the Bacterial Communities in Crude Oil Samples from Two Brazilian Offshore Petroleum Platforms

    PubMed Central

    Korenblum, Elisa; Souza, Diogo Bastos; Penna, Monica; Seldin, Lucy

    2012-01-01

    Crude oil samples with high- and low-water content from two offshore platforms (PA and PB) in Campos Basin, Brazil, were assessed for bacterial communities by 16S rRNA gene-based clone libraries. RDP Classifier was used to analyze a total of 156 clones within four libraries obtained from two platforms. The clone sequences were mainly affiliated with Gammaproteobacteria (78.2% of the total clones); however, clones associated with Betaproteobacteria (10.9%), Alphaproteobacteria (9%), and Firmicutes (1.9%) were also identified. Pseudomonadaceae was the most common family affiliated with these clone sequences. The sequences were further analyzed by MOTHUR, yielding 81 operational taxonomic units (OTUs) grouped at 97% stringency. Richness estimators also calculated by MOTHUR indicated that oil samples with high-water content were the most diverse. Comparison of bacterial communities present in these four samples using LIBSHUFF and Principal Component Analysis (PCA) indicated that the water content significantly influenced the community structure only of crude oil obtained from PA. Differences between PA and PB libraries were observed, suggesting the importance of the oil field as a driver of community composition in this habitat. PMID:22319534

  1. Molecular analysis of the bacterial communities in crude oil samples from two brazilian offshore petroleum platforms.

    PubMed

    Korenblum, Elisa; Souza, Diogo Bastos; Penna, Monica; Seldin, Lucy

    2012-01-01

    Crude oil samples with high- and low-water content from two offshore platforms (PA and PB) in Campos Basin, Brazil, were assessed for bacterial communities by 16S rRNA gene-based clone libraries. RDP Classifier was used to analyze a total of 156 clones within four libraries obtained from two platforms. The clone sequences were mainly affiliated with Gammaproteobacteria (78.2% of the total clones); however, clones associated with Betaproteobacteria (10.9%), Alphaproteobacteria (9%), and Firmicutes (1.9%) were also identified. Pseudomonadaceae was the most common family affiliated with these clone sequences. The sequences were further analyzed by MOTHUR, yielding 81 operational taxonomic units (OTUs) grouped at 97% stringency. Richness estimators also calculated by MOTHUR indicated that oil samples with high-water content were the most diverse. Comparison of bacterial communities present in these four samples using LIBSHUFF and Principal Component Analysis (PCA) indicated that the water content significantly influenced the community structure only of crude oil obtained from PA. Differences between PA and PB libraries were observed, suggesting the importance of the oil field as a driver of community composition in this habitat.

  2. 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.

  3. 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. ?? 1996 NRC.

  4. The 2013 seismic sequence close to gas injection platform of the Castor project, offshore Spain

    NASA Astrophysics Data System (ADS)

    Cesca, Simone; Grigoli, Francesco; Heimann, Sebastian; Gonzalez, Alvaro; Buforn, Elisa; Maghsoudi, Samira; Blanch, Estefania; Dahm, Torsten

    2014-05-01

    A spatially localized seismic sequence has originated few tens of kilometres offshore the Mediterranean coast of Spain, starting on September 5, 2013, and lasting at least until October 2013. The sequence culminated in a maximal moment magnitude Mw 4.3 earthquake, on October 1, 2013. The epicentral region is located near the offshore platform of the Castor project, where gas is conducted through a pipeline from mainland and where it was recently injected in a depleted oil reservoir, at about 2 km depth. We analyse the temporal evolution of the seismic sequence and use full waveform techniques to derive absolute and relative locations, estimate depths and focal mechanisms for the largest events in the sequence (with magnitude mbLg larger than 3), and compare them to a previous event (April 8, 2012, mbLg 3.3) taking place in the same region prior to the gas injection. Moment tensor inversion results show that the overall seismicity in this sequence is characterized by oblique mechanisms with a normal fault component, with a 30° low-dip angle plane oriented NNE-SSW and a sub- vertical plane oriented NW-SE. The combined analysis of hypocentral location and focal mechanisms could indicate that the seismic sequence corresponds to rupture processes along sub- horizontal shallow surfaces, which could have been triggered by the gas injection in the reservoir,. An alternative scenario includes the iterated triggering of a system of steep faults oriented NW-SE, which were identified by prior marine seismics investigations. The most relevant seismogenic feature in the area is the Fosa de Amposta fault system, which includes different strands mapped at different distances to the coast, with a general NE-SW orientation, roughly parallel to the coastline. No significant known historical seismicity has involved this fault in the past. Our both scenarios exclude its activation, as its known orientation is inconsistent with focal mechanism results.

  5. 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.

  6. 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.

  7. 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.

  8. Measurement of naphthenic acids in the receiving waters around an offshore oil platform by passive sampling.

    PubMed

    Harman, Christopher; Langford, Katherine; Sundt, Rolf C; Brooks, Steven

    2014-09-01

    Polar organic chemical integrative samplers (POCIS) were deployed in the vicinity of an offshore oil installation and analyzed for naphthenic acids (NAs). The POCIS accumulated a range of mono- to tetracyclic NAs, with different degrees of alkylation, with monocyclic acids being the most abundant. Currently, POCIS or similar polar samplers may be the only way to measure exposure to NAs from offshore discharges in situ. In addition, they may be a valuable tool for monitoring similar organic acids in general.

  9. Numerical Investigation into the Performance of a Rarefaction Shock Wave Cutter for Offshore Oil-Gas Platform Removal

    SciTech Connect

    Morris, J P; Glenn, L A; Antoun, T H; Lomov, I N

    2001-06-14

    The phase change in iron at 13 GPa results in the formation of rarefaction shock waves upon release. The interaction of multiple rarefaction shock waves induces high tensile stresses within a narrow zone, causing smooth spall. This effect can be exploited to sever cylindrical cross-section pipes, such as those supporting decommissioned offshore oil and gas platforms, using a minimal amount of explosive. Consequently, costs can be reduced and environmental impact minimized. They discuss the numerical techniques used to simulate rarefaction shock waves and the damage to steel resulting from the interaction of multiple rarefaction shock waves.

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

    PubMed

    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.

  11. 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

  12. Sea ice forces and the state of technology of offshore arctic platforms

    SciTech Connect

    Utt, M.E.

    1985-01-01

    Hydrocarbon exploration and production operations in offshore arctic regions are in their infancy. The oil industry learned to operate in ice conditions in the relatively mild environment of Cook Inlet in the 1960's and in the Arctic offshore Canada in the 1970's. Presently, there is no production from the offshore Arctic, only a handful of exploration systems with the capability of operating year-round in shallow water; there are no year-round systems for deeper water. As drilling and production activities are extended into deeper water and more hostile ice conditions, the industry will learn more about the Arctic, and some of the opinions expressed in this paper will, no doubt, become of no more than historical interest.

  13. Integrated use of biomarkers in the mussel Mytilus galloprovincialis for assessing off-shore gas platforms in the Adriatic Sea: results of a two-year biomonitoring program.

    PubMed

    Gomiero, Alessio; Da Ros, Luisa; Nasci, Cristina; Meneghetti, Francesca; Spagnolo, Alessandra; Fabi, Gianna

    2011-11-01

    Despite a large number of gas platforms existing in the Adriatic Sea, which is a semi-enclosed basin characterized by a slow turnover rate and increasing industrial as well as other anthropogenic activities, the effects of these structures on the aquatic ecosystem require further investigation. Since 1998, multidisciplinary studies have been performed by CNR-ISMAR to comply with legislation and to support the development of protocols for the monitoring of offshore activities in the Adriatic Sea. The present study was developed to implement a biomonitoring plan to assess the ecotoxicological effects of the extraction activities of an off-shore gas platform. Biomarkers were evaluated in mussels collected from the platform in relation to physiological stress, DNA damage, cellular damage, oxidative stress and exposure effects. Organic contaminants and trace element bioaccumulation were also assessed in the soft body of the mussels to correlate bioaccumulation of pollutants with biomarker responses. The results indicate an absence of platform-related environmental stress.

  14. The qualification of advanced composite pipe for use in fire water deluge systems on open type offshore oil platforms

    SciTech Connect

    Lea, R.H.; Stubblefield, M.A.; Pang, S.S.

    1996-12-01

    Different types of FIBERBOND{reg_sign} pipe in the dry condition and with a butt and strap joint were subjected to a controlled fire for fire endurance evaluation. Testing adheres to a modification of the ASTM 1173-95 guideline, which simulates the development of an actual hydrocarbon fire. For a fire water deluge system, the pipe is in the dry condition approximately one to three minutes during an actual hydrocarbon fire. Preliminary testing shows that composite pipe is able to withstand this exposure to fire for the five minute duration of the test. This is achieved with modifying the chemical composition of the composite pipe and in some cases, adding an additional structural component to the overall pipe. Therefore, composite pipe could be used for the deluge fire system of an offshore oil platform.

  15. Survival analysis of deep-water floating offshore platforms: Critical axis

    SciTech Connect

    Falzarano, J.M.; Kota, R.S.

    1996-12-31

    This paper describes the global dynamics of a typical Column Stabilized Mobile Offshore Drilling Unit (CS-MODU) about its critical, approximately quartering axis. It is well known that short and wide (i.e., small L/B ratio) twin hull vessels such as CS-MODU`s have minimum righting moment about an approximately quartering axis. This paper attempts to answer the question of whether this is also a critical rotational motion axis. In order to answer this question, a comparative global transient dynamical systems analysis is undertaken which compares the vessels response at all heading angles.

  16. A multi-attribute decision analysis for decommissioning offshore oil and gas platforms.

    PubMed

    Henrion, Max; Bernstein, Brock; Swamy, Surya

    2015-10-01

    The 27 oil and gas platforms off the coast of southern California are reaching the end of their economic lives. Because their decommissioning involves large costs and potential environmental impacts, this became an issue of public controversy. As part of a larger policy analysis conducted for the State of California, we implemented a decision analysis as a software tool (PLATFORM) to clarify and evaluate decision strategies against a comprehensive set of objectives. Key options selected for in-depth analysis are complete platform removal and partial removal to 85 feet below the water line, with the remaining structure converted in place to an artificial reef to preserve the rich ecosystems supported by the platform's support structure. PLATFORM was instrumental in structuring and performing key analyses of the impacts of each option (e.g., on costs, fishery production, air emissions) and dramatically improved the team's productivity. Sensitivity analysis found that disagreement about preferences, especially about the relative importance of strict compliance with lease agreements, has much greater effects on the preferred option than does uncertainty about specific outcomes, such as decommissioning costs. It found a near-consensus of stakeholders in support of partial removal and "rigs-to-reefs" program. The project's results played a role in the decision to pass legislation enabling an expanded California "rigs-to-reefs" program that includes a mechanism for sharing cost savings between operators and the state.

  17. WHTSubmersible: a simulator for estimating transient circulation temperature in offshore wells with the semi-submersible platform

    NASA Astrophysics Data System (ADS)

    Song, Xun-cheng; Liu, Yong-wang; Guan, Zhi-chuan

    2015-10-01

    Offshore wellbore temperature field is significant to drilling fluids program, equipment selection, evaluations on potential risks caused by casing thermal stress, etc. This paper mainly describes the theoretical basis, module structure and field verification of the simulator WHTSubmersible. This computer program is a useful tool for estimating transient temperature distribution of circulating drilling fluid on semi-submersible platform. WHTSubmersible is based on a mathematical model which is developed to consider radial and axial two-dimensional heat exchange of the inner drill pipe, the annulus, the drill pipe wall, the sea water and the formation in the process of drilling fluid circulation. The solution of the discrete equations is based on finite volume method with an implicit scheme. This scheme serves to demonstrate the numerical solution procedure. Besides, the simulator also considers the heating generated by drilling fluid circulation friction, drill bit penetrating rocks, friction between the drill column and the borehole wall, and the temperature effect on thermal physical properties and rheology of the drilling fluid. These measures ensure more accurate results. The simulator has been programmed as a dynamic link library using Visual C++, the routine interface is simple, which can be connected with other computer programs conveniently. The simulator is validated with an actual well temperature filed developed on a semi-submersible platform in South China, and the error is less than 5 %.

  18. Numerical Prediction of Experimentally Observed Behavior of a Scale Model of an Offshore Wind Turbine Supported by a Tension-Leg Platform: Preprint

    SciTech Connect

    Prowell, I.; Robertson, A.; Jonkman, J.; Stewart, G. M.; Goupee, A. J.

    2013-01-01

    Realizing the critical importance the role physical experimental tests play in understanding the dynamics of floating offshore wind turbines, the DeepCwind consortium conducted a one-fiftieth-scale model test program where several floating wind platforms were subjected to a variety of wind and wave loading condition at the Maritime Research Institute Netherlands wave basin. This paper describes the observed behavior of a tension-leg platform, one of three platforms tested, and the systematic effort to predict the measured response with the FAST simulation tool using a model primarily based on consensus geometric and mass properties of the test specimen.

  19. Comparative immune responses of corals to stressors associated with offshore reef-based tourist platforms.

    PubMed

    van de Water, Jeroen A J M; Lamb, Joleah B; van Oppen, Madeleine J H; Willis, Bette L; Bourne, David G

    2015-01-01

    Unravelling the contributions of local anthropogenic and seasonal environmental factors in suppressing the coral immune system is important for prioritizing management actions at reefs exposed to high levels of human activities. Here, we monitor health of the model coral Acropora millepora adjacent to a high-use and an unused reef-based tourist platform, plus a nearby control site without a platform, over 7 months spanning a typical austral summer. Comparisons of temporal patterns in a range of biochemical and genetic immune parameters (Toll-like receptor signalling pathway, lectin-complement system, prophenoloxidase-activating system and green fluorescent protein-like proteins) among healthy, injured and diseased corals revealed that corals exhibit a diverse array of immune responses to environmental and anthropogenic stressors. In healthy corals at the control site, expression of genes involved in the Toll-like receptor signalling pathway (MAPK p38, MEKK1, cFos and ATF4/5) and complement system (C3 and Bf) was modulated by seasonal environmental factors in summer months. Corals at reef platform sites experienced additional stressors over the summer, as evidenced by increased expression of various immune genes, including MAPK p38 and MEKK1. Despite increased expression of immune genes, signs of white syndromes were detected in 31% of study corals near tourist platforms in the warmest summer month. Evidence that colonies developing disease showed reduced expression of genes involved in the complement pathway prior to disease onset suggests that their immune systems may have been compromised. Responses to disease and physical damage primarily involved the melanization cascade and GFP-like proteins, and appeared to be sufficient for recovery when summer heat stress subsided. Overall, seasonal and anthropogenic factors may have interacted synergistically to overwhelm the immune systems of corals near reef platforms, leading to increased disease prevalence in summer at

  20. Seismic Performance Evaluation of the Jacket Type Offshore Platforms through Incremental Dynamic Analysis considering Soil-Pile-Structure Interaction

    SciTech Connect

    Asgarian, Behrouz; Shokrgozar, Hamed R.; Talarposhti, Ali Shakeri

    2008-07-08

    Of great interest in Performance-Based Earthquake Engineering (PBEE) is the accurate estimation of the seismic performance of structures. A performance prediction and evaluation procedure is based on nonlinear dynamics and reliability theory. In this method, a full integration over the three key stochastic models is as follow: ground motion hazard curve, nonlinear dynamic displacement demand, and displacement capacity. Further, both epistemic and aleatory uncertainties are evaluated and carried through the analysis.In this paper, jacket and soil-pile system have been modeled using Finite Element program (OpenSees) and the incremental dynamic analysis (IDA) are performed to investigate nonlinear behavior of offshore platforms. The system demand is determined by performing time history response analyses of the jacket under a suite of FEMA/SAC uniform hazard ground motions. The system capacity in terms of the drift ratio against incipient collapse is generally difficult to predict since the structural response goes into nonlinear range before collapse. All the analyses are performed in two directions and the results are compared with each others. The confidence level of a jacket in each direction for a given hazard level is calculated using the procedure described.

  1. Seismic Performance Evaluation of the Jacket Type Offshore Platforms through Incremental Dynamic Analysis considering Soil-Pile-Structure Interaction

    NASA Astrophysics Data System (ADS)

    Asgarian, Behrouz; Shokrgozar, Hamed R.; Talarposhti, Ali Shakeri

    2008-07-01

    Of great interest in Performance-Based Earthquake Engineering (PBEE) is the accurate estimation of the seismic performance of structures. A performance prediction and evaluation procedure is based on nonlinear dynamics and reliability theory. In this method, a full integration over the three key stochastic models is as follow: ground motion hazard curve, nonlinear dynamic displacement demand, and displacement capacity. Further, both epistemic and aleatory uncertainties are evaluated and carried through the analysis. In this paper, jacket and soil-pile system have been modeled using Finite Element program (OpenSees) and the incremental dynamic analysis (IDA) are performed to investigate nonlinear behavior of offshore platforms. The system demand is determined by performing time history response analyses of the jacket under a suite of FEMA/SAC uniform hazard ground motions. The system capacity in terms of the drift ratio against incipient collapse is generally difficult to predict since the structural response goes into nonlinear range before collapse. All the analyses are performed in two directions and the results are compared with each others. The confidence level of a jacket in each direction for a given hazard level is calculated using the procedure described.

  2. Application of an elastic 2D tube-waveform tomography to estimate the shear modulus in the vicinity of the FINO3 offshore platform

    NASA Astrophysics Data System (ADS)

    Köhn, D.; Wilken, D.; Rabbel, W.

    2012-04-01

    The FINO3 project is aimed at the construction of an offshore research platform in the north-sea, hosting research projects dealing with offshore wind energy topics. As part of FINO3 our sub-project deals with the development of new seismic acquisition and inversion concepts for offshore-building foundation soil analysis. We are focussed on the determination of seismic parameters and structural information of the building plot of the platform. Possible changes of the shear modulus of the sediments in the vicinity of the FINO3 monopile due to mechanic loads on the platform are estimated by a tube-waveform tomography. The tube-waves are excited by a hammer blow at the internal wall of the FINO3 monopile above the water line. The tube-waves are propagating through the water column and the sediments and are measured in situ by hydrophones at the external wall of the monopile. Homogenous long wavelength starting models for the waveform tomography are estimated using simple 2D finite difference models. Possible shear-wave velocity starting models range from 150-300 m/s. The resolution of the tube-waveform tomography is estimated by simple chequerboard and random media models. Additionally first results of the data application in the vicinity of the monopile are presented.

  3. 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

  4. 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

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

    SciTech Connect

    England, Tony; van Nieuwstadt, Lin; De Roo, Roger; Karr, Dale; Lozenge, David; Meadows, Guy

    2016-05-30

    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 has 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.

  6. Utilisation of the GMES Sentinel satellites for off-shore platform oil spills and gas flaring monitoring

    NASA Astrophysics Data System (ADS)

    Di Erasmo, Daniele; Casadio, Stefano; Cardaci, Massimo; Del Frate, Fabio

    2013-04-01

    Oil spills and gas flaring are serious issues for ecosystem, economy and people working on the extraction sites. Oil spill is known. Gas Flaring is the disposal of poison waste gases generated in the oil extraction process. High volumes (every year gas flaring burns worldwide the equivalent of 25% of the overall gas burned in Europe), significantly contributing to the global carbon emission budget (0.5% of total, 2008). European and worldwide legislation pays an increasing attention to it. Our Sentinel1 and 3 SAR and SLSTR usage for this objective won the GMES Masters 2012 IDEAS Challenge. In this study, we use SAR and infrared/thermal (SLSTR) data to identify unexpected misbehaviours of oil platforms, like switch on of the flare and oil spill in the ocean. On one side, the detection and characterization of gas flaring is achieved by analysing the infrared/thermal radiances measured by the SLSTR instrument on-board SENTINEL-3. This technique has been developed and tested using the ENVISAT Along Track Scanning Radiometer (ATSR) dataset and proved to be adequate for long term monitoring of oil extraction for both off-shore and in-shore drilling stations. The spatial/temporal coverage provided by SENTINEL-3 will allow an unprecedented daily monitoring of the oil extraction platforms. On the other side, the detection of oil spills and ships can be performed using Synthetic Aperture Radar (SAR). Both for oil spills and ships, many techniques have been published in the dedicated literature and validated to make the process of detection from SAR automatic. The extension of these techniques to the future SENTINEL-1 data is feasible. The service is mainly addressed to governments (in charge of controlling respect of the rules), civil protection authorities (to promote prevention of pollution damages), oil companies (that want to prove their respect of rules and attention to the environment), and ONGs (involved in the monitoring of the environment). The methodology applied

  7. Model Development and Loads Analysis of an Offshore Wind Turbine on a Tension Leg Platform with a Comparison to Other Floating Turbine Concepts: April 2009

    SciTech Connect

    Matha, D.

    2010-02-01

    This report presents results of the analysis of a 5-MW wind turbine located on a floating offshore tension leg platform (TLP) that was conducted using the fully coupled time-domain aero-hydro-servo-elastic design code FAST with AeroDyn and HydroDyn. The report also provides a description of the development process of the TLP model. The model has been verified via comparisons to frequency-domain calculations. Important differences have been identified between the frequency-domain and time-domain simulations, and have generated implications for the conceptual design process. An extensive loads and stability analysis for ultimate and fatigue loads according to the procedure of the IEC 61400-3 offshore wind turbine design standard was performed with the verified TLP model. This report compares the loads for the wind turbine on the TLP to those of an equivalent land-based turbine. Major instabilities for the TLP are identified and described.

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. A Comparison of Platform Options for Deep-water Floating Offshore Vertical Axis Wind Turbines: An Initial Study.

    SciTech Connect

    Bull, Diana L; Fowler, Matthew; Goupee, Andrew

    2014-08-01

    This analysis utilizes a 5 - MW VAWT topside design envelope created by Sandia National Laborator ies to compare floating platform options fo r each turbine in the design space. The platform designs are based on two existing designs, the OC3 Hywind spar - buoy and Principal Power's WindFloat semi - submersible. These designs are scaled using Froude - scaling relationships to determine an appropriately sized spar - buoy and semi - submersible design for each topside. Both the physical size of the required platform as well as mooring configurations are considered. Results are compared with a comparable 5 - MW HAWT in order to identify potential differences in the platform and mooring sizing between the VAWT and HAWT . The study shows that there is potential for cost savings due to reduced platform size requirements for the VAWT.

  13. BM platform, B Field, Offshore Northwest Java: A case history of multi-disciplinary integration including 3D seismic, reservoir simulation and horizontal drilling

    SciTech Connect

    Cooke, D.; Aziz, A.; Baldauff, J.; Diswarin, N.

    1996-12-31

    This case history describes how a multidisciplinary team used a 3D survey and reservoir simulation to review and revise the development plans for the BM platform, located in the B Field, Offshore Northwest Java, Indonesia. The case history starts with the collection of necessary parophysical, geologic and production data. These data are input to a reservoir simulation which shows there should be no problems with the new platform. However, this initial simulation has known problems with contradicting input structure maps and fluid contacts. Hopefully, these problems can be addressed with a new 3D seismic survey - if the seismic data can be acquired, processed, interpreted and input to the simulation before drilling starts at the BM platform. The seismic acquisition could not be done with the traditional towed seismic streamer cables - instead stationary ocean bottom cables with dual geophone-hydrophone sensors were used. Processing of the seismic data was done in a way that allowed interpretation of the critical area even before acquisition of the entire survey was finished. The new 3D structure maps changed the MDT`s opinion of what reservoir and what areas contained the bulk of the oil reserves. Unfortunately, the new maps were not available until after the jacket was set but before the wells drilled. The NMT updated the simulation with the new 3D data, which led to changes in development well bottom hole locations and an ambitious horizontal well.

  14. Eighteenth annual offshore technology conference. Volume 1

    SciTech Connect

    Not Available

    1986-01-01

    These sixty papers were given at a conference on offshore technology. Topics covered include friction effects of driving piles into sea beds of various compositions, wave forces on offshore platforms, stability, materials testing of various components such as plates, legs, wellheads, pipe joints, and protection of offshore platforms against ice and collision with icebergs.

  15. 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

  16. 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

  17. Optimum geometry of tuned liquid column-gas damper for control of offshore jacket platform vibrations under seismic excitation

    NASA Astrophysics Data System (ADS)

    Mousavi, Seyed Amin; Zahrai, Seyed Mehdi; Bargi, Khosrow

    2012-12-01

    In this study, the effectiveness of a tuned liquid column-gas damper, TLCGD, on the suppression of seismicinduced vibrations of steel jacket platforms is evaluated. TLCGD is an interesting choice in the case of jacket platforms because it is possible to use the structural elements as the horizontal column of the TLCGD. The objective here is to find the optimum geometric parameters, namely orientation and configuration of vertical columns, length ratio, and area ratio of the TLCGD, considering nonlinear damping of the TLCGD and water-structure interaction between the jacket platform and sea water. The effects of different characteristics of ground motion such as PGA and frequency content on the optimum geometry are also investigated and it is observed that these features have some influence on the optimum area ratio. Finally it is observed that pulse arrangement of ground acceleration is one of the most important parameters affecting the efficiency of a TLCGD. In other words, it is found that the TLCGD's capability to reduce the RMS responses depends only on the frequency content of the ground acceleration, but its capability to reduce the maximum responses depends on both the frequency content and the pulse arrangement of the ground acceleration.

  18. Research on systematization and advancement of shipbuilding production management for flexible and agile response for high value offshore platform

    NASA Astrophysics Data System (ADS)

    Song, Young-Joo; Woo, Jong-Hun; Shin, Jong-Gye

    2011-09-01

    Recently, the speed of change related with enterprise management is getting faster than ever owing to the competition among companies, technique diffusion, shortening of product lifecycle, excessive supply of market. For the example, the compliance condition (such as delivery date, product quality, etc.) from the ship owner is getting complicated and the needs for the new product such as FPSO, FSRU are coming to fore. This paradigm shift emphasize the rapid response rather than the competitive price, flexibility and agility rather than effective and optimal perspective for the domestic shipbuilding company. So, domestic shipbuilding companies have to secure agile and flexible ship production environment that could respond change of market and requirements of customers in order to continue a competitive edge in the world market. In this paper, I'm going to define a standard shipbuilding production management system by investigating the environment of domestic major shipbuilding companies. Also, I'm going to propose a unified ship production management and system for the operation of unified management through detail analysis of the activities and the data flow of ship production management. And, the system functions for the strategic approach of ship production management are investigated through the business administration tools such as performance pyramid, VDT and BSC. Lastly, the research of applying strategic KPI to the digital shipyard as virtual execution platform is conducted.

  19. Offshore Wind Research (Fact Sheet)

    SciTech Connect

    Not Available

    2011-10-01

    This 2-page fact sheet describes NREL's offshore wind research and development efforts and capabilities. The National Renewable Energy Laboratory is internationally recognized for offshore wind energy research and development (R&D). Its experience and capabilities cover a wide spectrum of wind energy disciplines. NREL's offshore wind R&D efforts focus on critical areas that address the long-term needs of the offshore wind energy industry and the Department of Energy (DOE). R&D efforts include: (1) Developing offshore design tools and methods; (2) Collaborating with international partners; (3) Testing offshore systems and developing standards; (4) Conducting economic analyses; (5) Characterizing offshore wind resources; and (6) Identifying and mitigating offshore wind grid integration challenges and barriers. NREL has developed and maintains a robust, open-source, modular computer-aided engineering (CAE) tool, known as FAST. FAST's state-of-the-art capabilities provide full dynamic system simulation for a range of offshore wind systems. It models the coupled aerodynamic, hydrodynamic, control system, and structural response of offshore wind systems to support the development of innovative wind technologies that are reliable and cost effective. FAST also provides dynamic models of wind turbines on offshore fixed-bottom systems for shallow and transitional depths and floating-platform systems in deep water, thus enabling design innovation and risk reduction and facilitating higher performance designs that will meet DOE's cost of energy, reliability, and deployment objectives.

  20. High-Ti basalt from the Abrolhos platform, offshore Brazil 18/sup 0/S: implications for mantle metasomatism and heterogeneity, South Atlantic region

    SciTech Connect

    Fodor, R.V.; Ragland, J.P.

    1985-01-01

    Surface and core samples of the Abrolhos islands and platform (30,000 km/sup 2/), offshore Brazil 18/sup 0/S, yields 35-65 Ma mafic flows and hypabyssal and cumulate rocks. (a) Basalt has very high TiO/sub 2/ attended by high FeO* but not proportionate amounts of incompatible elements; extreme Ti is shown by TiO/sub 2/ 5% at FeO*/MgOapprox. 2.5; LREE enrichment, La/sub (n)/ 80-110, La/Yb/sub (n)/approx. 8.5, Zr/Nbapprox. 6, Zr/Y approx. 7 are those of P-type MORB. (b) Cpx is transitional, Fs/sub 14-23/Wo/sub 42-36/, TiO/sub 2/ 1-2%, Al/sub 2/O/sub 3/ 2-5%. (c) Cumulates are clinopyroxenite and wehrlite, with cpx compositions like those of the basalts. The unusually high Ti, several trace elements, and mineral compositions correspond to certain high-TiO/sub 2/ flows and dikes in neighboring Serra Geral CFB province. Age differences and approx. 2 x higher P, Ba, and Sr in Serra Geral point to Abrolhos representing (re-)melting of an enriched CFB source-area similar to that for Serra Geral CFB but differing in metasomatic phases such as ap, amph, and mica. Extensive fractionation of enriched tholeiites with major-element compositions of certain S. Atlantic basin basalts accounts for Abrolhos compositions except for extreme Ti. Cumulates attest to the chamber environment necessary for fractionation, but high Ti must reflect the mantle source. Because Abrolhos rocks have compositional links to both continental and oceanic magmatism that occurred since Gondwanaland rifting, source-regions for each may have been similar throughout South Atlantic history, but with notable anomalies, due in part to localized Fe-Ti metasomatism.

  1. 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

  2. Proceedings of the fifth international offshore mechanics and Arctic engineering (OMAE) symposium. Volume 4

    SciTech Connect

    Lunardini, V.J.; Wang, Y.S.; Ayorinde, O.A.; Sodhi, D.V.

    1986-01-01

    This book presents the papers given at a symposium on offshore platforms. Topics considered at the symposium included climates, Arctic regions, hydrate formation, the buckling of heated oil pipelines in frozen ground, icebergs, concretes, air cushion vehicles, mobile offshore drilling units, tanker ships, ice-induced dynamic loads, adfreeze forces on offshore platforms, and multiyear ice floe collision with a massive offshore structure.

  3. 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

  4. Offshore drilling and production structure

    SciTech Connect

    Crockett, R.K.; Palmer, H.E.; Stenning, D.G.

    1982-02-09

    The invention relates to an off-shore marine structure that provides an elevated support for a drilling and/or production platform. A structure comprised of three interlocking components is provided, the first component being a large foundation base installed on the sea bed; the second being a conical shaped support component which is engagable with the foundation base and which, releasably carries the third platform supporting component. In the preferred form, the platform supporting component comprises a centrally-disposed vertical column, means being provided to facilitate engagement of the column with the platform and the second component and to subsequently elevate the platform to an operating height above sea level.

  5. Ice interaction with offshore structures

    SciTech Connect

    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.

  6. Offshore and arctic frontiers -structures, ocean mining

    SciTech Connect

    Chung, J.S.

    1985-05-01

    The systematic development of offshore technology is discussed. Today, this technology enables the production of approximately 14 million barrels of oil per day, or 26% of oil production worldwide. The evolution in offshore structures is examined with emphasis on jacket and jackup platforms. Challenges are explored. Microprocessors, data-base management, and artificial intelligence are mentioned as having an impact on the offshore and arctic oil industry.

  7. Offshore medicine.

    PubMed

    Baker, D

    2001-03-01

    Offshore life can be refreshing for medics who are looking for a little change of pace; however, it is not for everyone. Working offshore can be the easiest or most boring job you'll ever have. It takes a specific type of medic to fit this mold. So, if you are considering a career in the offshore field, take all of the above into consideration. You are not just making a change in jobs, but a change in lifestyle. Once you become accustomed to this lifestyle, it will be hard to go back to the everyday hustle and bustle of the streets. For more information about working offshore, contact Acadian Contract Services at 800/259-333, or visit www.acadian.com.

  8. EMS offshore. A new horizon for paramedics.

    PubMed

    Mallard, A S

    1991-10-01

    The difficulty in getting medical aid to offshore drilling platforms can be a source of life-threatening delays. Recently, some companies have charted new waters by actually stationing EMS crews on their rigs.

  9. Toxicity evaluation of diethylene glycol and its combined effects with produced waters of off-shore gas platforms in the Adriatic Sea (Italy): bioassays with marine/estuarine species.

    PubMed

    Tornambè, Andrea; Manfra, Loredana; Mariani, Livia; Faraponova, Olga; Onorati, Fulvio; Savorelli, Federica; Cicero, Anna Maria; Virno Lamberti, Claudia; Magaletti, Erika

    2012-06-01

    Diethylene glycol (DEG) is commonly used to dehydrate natural gas in off-shore extraction plants and to prevent formation of gas hydrates. It may be released into the sea accidentally or in discharged produced waters (PWs). PWs samples from off-shore gas platforms in the Adriatic Sea (Italy) have been used in this study. The objectives of the study were: a) to evaluate the toxicity of DEG for marine organisms; b) to evaluate if a high DEG content in PWs may alter their toxicity; c) to verify whether the DEG threshold concentration established by the Italian legislation (3.5 g/l) for PWs discharged at sea is safe for marine environment. Ten different species (Vibrio fischeri, Phaeodactylum tricornutum, Dunaliella tertiolecta, Brachionus plicatilis, Artemia franciscana, Tigropus fulvus, Mytilus galloprovincialis, Crassostrea gigas, Tapes philippinarum and Dicentrarchus labrax) have been exposed to DEG; four of these species were also exposed to PWs in combination with DEG. The results showed that: a) DEG is not toxic at levels normally detected in Adriatic PWs; b) DEG in combination with PW showed mainly additive or synergistic effects; c) short-term bioassays showed that the DEG limit of 3.5 g/l could be acceptable.

  10. 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.

  11. 26th annual offshore technology conference, 1994 proceedings

    SciTech Connect

    Not Available

    1994-01-01

    This conference is the world's largest and most comprehensive technical conference and exhibition on offshore resource development. The four Proceedings volumes have been separated by major areas of interest, with relative sessions included in each volume. This Volume 3 contains information relative to offshore platforms and marine system designs. It describes both the installation and decommissioning of offshore platforms, retrofitting platforms to meet current safety standards, and technology assessments for both drilling and platform designs. Papers are also provided which describe maintenance and repair technologies for damages to platform.

  12. 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.

  13. Offshore Space Center (offshore launch site)

    NASA Technical Reports Server (NTRS)

    Harvey, D. G.

    1980-01-01

    Any activity requiring the development of the HLLV can benefit by operations from an offshore space center (OSC) since operating near the equator provides a twenty percent increase in payload in an ecliptic plan orbit. Some OSC concepts considered include a moored floating (semisubmersible) design, a stationary design supported by fixed piles, and a combination of these two. The facility supports: a 15,000 foot long, 300 foot wide runway, designed to accommodate a two staged winged launch vehicle, with a one million pound payload capacity to low earth orbit; an industrial area for HLLV maintenance; an airport terminal, control and operation center, and observation tower; liquid hydrogen and liquid oxygen production and storage, and fuel storage platforms; a power generation station, docks with an unloading area; two separate launch sites; and living accommodations for 10,000 people. Potential sites include the Paramount Seamount in the Pacific Ocean off the north coast of South America. Cost estimates are considered.

  14. Comparison of API & IEC Standards for Offshore Wind Turbine Applications in the U.S. Atlantic Ocean: Phase II; March 9, 2009 - September 9, 2009

    SciTech Connect

    Jha, A.; Dolan, D.; Gur, T.; Soyoz, S.; Alpdogan, C.

    2013-01-01

    This report compares two design guidelines for offshore wind turbines: Recommended Practice for Planning, Designing, and Constructing Fixed Offshore Platform Structures and the International Electrotechnical Commission 61400-3 Design Requirements for Offshore Wind Turbines.

  15. Smarter offshoring.

    PubMed

    Farrell, Diana

    2006-06-01

    During the past 15 years, companies have flocked to a handful of cities in India and Eastern Europe for offshore service functions. As a result, the most popular sites are now overheating: Demand for young professionals is outstripping supply, wages and turnover are soaring, and overburdened infrastructure systems are struggling to serve the explosive growth. The happy news is that the tight labor markets in the well-known hot spots are the exceptions, not the rule. Many attractive alternatives are emerging around the world. According to a McKinsey Global Institute study, more than 90% of the vast and rapidly growing pool of university-educated people suitable for work in multinationals are located outside the current hot spot cities. For instance, Morocco is now home to offshore centers for French and Spanish companies requiring fluent speakers of their home languages. Neighboring Tunisia has used its modern infrastructure, business-friendly regulations, and stable, low-cost workforce to attract companies such as Siemens and Wanadoo. Vietnam offers university graduates who have strong mathematics skills; speak French, English, German, or Russian; and do not demand high wages. The problems facing the hot spots, coupled with the emergence of many more countries able and willing to provide offshore services, mean that picking a site has become more complicated. In choosing a location, companies will have to focus less on low wages and much more on other ways that candidate cities can fulfill their business needs. They will have to be much more rigorous in articulating precisely what they require from an offshore location. That means evaluating their unique needs on a range of dimensions and understanding how alternative locations can meet those needs for the foreseeable future.

  16. Pioneering offshore excellence

    SciTech Connect

    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 principle 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.

  17. Fracture Control for Fixed Offshore Structures.

    DTIC Science & Technology

    1984-12-01

    CRA&I DTIC TAB Unannounced E Jfstification Avil a’idjor iv Listing of Acronyms and Symbols ABS American Bureau of Shipping API American Petroleum Institute API...the American Petroleum Institute which is the primary design guide for American fixed offshore structures (see reference listings) ASCE American...Planning, Designing, and Constructing Fixed Offshore Platforms," API RP-2A, Thirteenth Edition, published by the American Petroleum Institute , Washington

  18. 26th Annual offshore technology conference: 1994 Proceedings

    SciTech Connect

    Not Available

    1994-01-01

    This conference represents the world's largest and most comprehensive technical conference and exhibition on offshore resource development. The four proceedings volumes have been separated by major areas of interest with this volume containing papers relative to design of offshore platforms and marine riser systems. Papers deal with design, installation, fabrication, transport systems, mooring devices, repair methods, and development of satellite production facilities. Case histories on various offshore oil and gas fills are discussed along with economics of some applications and designs.

  19. Ecological investigations of petroleum production platforms in the central Gulf of Mexico: volume II. Final report 1978

    SciTech Connect

    Not Available

    1981-01-01

    Surveys of biofouling macroepibiota and fishes were made in June 1978 at four production platforms offshore Louisiana and were supplemented by limited observations made at an additional 15 platforms in August and September of 1978. Biofouling communities of nearshore platforms were dominated by barnacles in terms of biomass, whereas the communities on offshore platforms were dominated by bivalves. Primary production was largely restricted to surface zones of nearshore platforms but at some offshore platforms primary producers were abundant to depths of 30 m.

  20. Proceedings of the 6th international offshore mechanics and Arctic engineering symposium, Vol. 4

    SciTech Connect

    Lunardini, V.J.; Sinha, N.K.; Wang, Y.S.; Goff, R.D.

    1987-01-01

    This book presents the papers given at a conference on offshore platforms. Topics considered at the conference included spray ice islands, arctic structures and operations, arctic thermal and permafrost engineering, ice properties, offshore drilling, foundations, offshore exploration, crude oil storage facilities, thermosyphons, heat transfer, concretes, wave forces, and soil mechanics.

  1. Floating Ocean Platform

    DTIC Science & Technology

    2003-08-15

    water from the Bacia de Campos oil field offshore platforms, ENVIRONMENTAL FORENSICS , 115-123 Environ. Forensics , 2002 Bybee, K, Intelligent well...PORTILLO, H, JUVENILE TURTLES FOR MOSQUITO-CONTROL IN WATER STORAGE TANKS, JOURNAL OF MEDICAL ENTOMOLOGY , 943-946 J. Med. Entomol., 1993 LI, YS KAREEM

  2. Japan's builders study platforms

    SciTech Connect

    Burke, R.G.

    1984-07-05

    This paper discusses the developing role of Japan as a major supplier of offshore drilling and production equipment. Different firms are discussed along with their capacity. The marketing areas, work experience, and plans for designs are also included. There is special attention payed on the potential for developing Arctic platforms.

  3. Structural option design in JZ20-2 offshore project

    SciTech Connect

    Wang Lianqi

    1993-12-31

    In the JZ20-2 Project, ice and earthquakes are the main loads which determine the member sizes of offshore structures. UQ and W platforms are located at same field. The vertical loads of an UQ platform are about two times as much as a W platform, but structural steel weight used by two platforms is about the same. This paper describes the results to be acquired and how to determine reasonably the standard of ice load and the resistance to earthquakes with less stiffness and large mass. This paper presents some useful principles and enlightenment for offshore engineering.

  4. Management of offshore wastes in the United States.

    SciTech Connect

    Veil, J. A.

    1998-10-22

    During the process of finding and producing oil and gas in the offshore environment operators generate a variety of liquid and solid wastes. Some of these wastes are directly related to exploration and production activities (e.g., drilling wastes, produced water, treatment workover, and completion fluids) while other types of wastes are associated with human occupation of the offshore platforms (e.g., sanitary and domestic wastes, trash). Still other types of wastes can be considered generic industrial wastes (e.g., scrap metal and wood, wastes paints and chemicals, sand blasting residues). Finally, the offshore platforms themselves can be considered waste materials when their useful life span has been reached. Generally, offshore wastes are managed in one of three ways--onsite discharge, injection, or transportation to shore. This paper describes the regulatory requirements imposed by the government and the approaches used by offshore operators to manage and dispose of wastes in the US.

  5. Reasons for decision in the matter of Sable Offshore Energy Inc., application dated 9 June 1998 for approval of the plan, profile and book of reference respecting the detailed route of a subsea pipeline from the Thebaud platform to a landfall near Goldboro, Nova Scotia, and an onshore pipeline from the landfall point to the inlet of the gas processing plant located east of Goldboro, Nova Scotia: MH-4-98

    SciTech Connect

    1998-12-31

    The National Energy Board approved a natural gas pipeline to be built by the proponents of the Sable Offshore Energy Project within a specified 500-meter-wide corridor. The pipeline will run from an offshore platform near Sable Island to a gas plant on the Nova Scotia mainland. This report summarizes proceedings of hearings held to determine the detailed route of the pipeline within the specified corridor and to consider the most appropriate methods and timing of constructing the pipeline. Specific objections to the detailed route from holders of mineral rights licenses are noted and a Board decision on the detailed route is presented.

  6. Proceedings of the nineteenth annual offshore technology conference. Vol. 1

    SciTech Connect

    Not Available

    1987-01-01

    This book presents the papers given at a conference on offshore platforms. Topics considered at the conference included soil-structure interactions, foundations, hydrodynamics, remotely operated vehicles, wave forces, seismic surveys, morrings, marine risers, steel platform repairs, underwater welding, underwater inspections, wave equations, well completion, damping, anchors, field tests, mechanical vibrations, and hydraulic equipment.

  7. Designing Australia's North West Shelf offshore pipeline

    SciTech Connect

    Seymour, E.V.; Craze, D.J.; Ruinen, W.

    1984-05-07

    Design studies for the offshore pipeline system for the North West Shelf project in Australia commenced in the early 1970s. The trunkline from the North Rankin A platform to shore has recently been completed as the first part of the offshore pipeline system for the North West Shelf project. This pipeline originates from the platform in a water depth of 125 m (410 ft), enters the mouth of Mermaid Sound, and terminates just south of Withnell Bay on the Burrup Peninsula, on the North West coastline of Western Australia. The pipeline is 1,016 mm (40 in.) in diameter and 134.2 km (83.4 miles) long. It will operate in two-phase flow, bringing both gas and condensate to an onshore plant near its landfall. A slugcatcher has been constructed within the plant to receive liquidhydrocarbon slugs from the pipeline. The trunkline to shore will initially serve only the one offshore platform and operate at about 25% of its capacity to supply the Western Australian domestic gas market. The domestic gas plant on the Burrup Peninsula is being constructed by Woodside to produce pipeline-quality gas for delivery to the State Energy Commission and condensate for shipment by coastal tankers.

  8. Shallow waters require platform innovation

    SciTech Connect

    Not Available

    1984-11-01

    Conventional platform designs generally apply to production facilities for relatively shallow-water oil and gas fields and consequently do not attract much attention in the offshore industry. But although new designs relate largely to deeper waters, specific requirements of a particular field in shallow water may well force designers to search for unconventional designs to meet a need for lower costs and rapid development. A central production facility is planned offshore at the drilling location AWG-1, approximately 3 km offshore and in a water depth of about six meters. The choice is governed by the optimum interfield pipeline configuration available at the AWG-1 location, taking into account the other locations required for adequate subsea well coverage. The platform is described.

  9. Session: Offshore wind

    SciTech Connect

    Gaarde, Jette; Ram, Bonnie

    2004-09-01

    This session at the Wind Energy and Birds/Bats workshop consisted of two presentations. Due to time constraints, a discussion period was not possible. The session addressed the current state of offshore wind energy development. The first presentation ''Monitoring Program and Results: Horns Rev and Nysted'' by Jette Gaarde summarized selected environmental studies conducted to date at operating offshore wind turbine projects in Denmark and lessons from other offshore wind developments in Europe. Wildlife impacts studies from the Danish sites focused on birds, fish, and mammals. The second presentation ''What has the U.S. Wind Industry Learned from the European Example'' by Bonnie Ram provided an update on current permit applications for offshore wind developments in the U.S. as well as lessons that may be drawn from the European experience.

  10. Offshore Wind Energy

    SciTech Connect

    Strach-Sonsalla, Mareike; Stammler, Matthias; Wenske, Jan; Jonkman, Jason; Vorpahl, Fabian

    2016-07-27

    In 1991, the Vindeby Offshore Wind Farm, the first offshore wind farm in the world, started feeding electricity to the grid off the coast of Lolland, Denmark. Since then, offshore wind energy has developed from this early experiment to a multibillion dollar market and an important pillar of worldwide renewable energy production. Unit sizes grew from 450 kW at Vindeby to the 7.5 MW-class offshore wind turbines (OWT ) that are currently (by October 2014) in the prototyping phase. This chapter gives an overview of the state of the art in offshore wind turbine (OWT) technology and introduces the principles of modeling and simulating an OWT. The OWT components -- including the rotor, nacelle, support structure, control system, and power electronics -- are introduced, and current technological challenges are presented. The OWT system dynamics and the environment (wind and ocean waves) are described from the perspective of OWT modelers and designers. Finally, an outlook on future technology is provided. The descriptions in this chapter are focused on a single OWT -- more precisely, a horizontal-axis wind turbine -- as a dynamic system. Offshore wind farms and wind farm effects are not described in detail in this chapter, but an introduction and further references are given.

  11. Loads Analysis of a Floating Offshore Wind Turbine Using Fully Coupled Simulation: Preprint

    SciTech Connect

    Jonkman, J. M.; Buhl, M. L., Jr.

    2007-06-01

    This paper presents the use of fully coupled aero-hydro-servo-elastic simulation tools to perform a loads analysis of a 5-MW offshore wind turbine supported by a barge with moorings, one of many promising floating platform concepts.

  12. Challenges in Simulation of Aerodynamics, Hydrodynamics, and Mooring-Line Dynamics of Floating Offshore Wind Turbines

    SciTech Connect

    Matha, D.; Schlipf, M.; Cordle, A.; Pereira, R.; Jonkman, J.

    2011-10-01

    This paper presents the current major modeling challenges for floating offshore wind turbine design tools and describes aerodynamic and hydrodynamic effects due to rotor and platform motions and usage of non-slender support structures.

  13. Comparison of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polybrominated diphenylethers, and organochlorine pesticides in Pacific sanddab (Citharichthys sordidus) 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.

    2013-01-01

    Recently, the relative exposure of Pacific sanddab (Citharichthys sordidus) to polycyclic aromatic hydrocarbons (PAHs) at oil-production platforms was reported, indicating negligible exposure to PAHs and no discernible differences between exposures at platforms and nearby natural areas sites. In this report, the potential for chronic PAH exposure in fish is reported, by measurement of recalcitrant, higher molecular weight PAHs in tissues of fish previously investigated for PAH metabolites in bile. A total of 34 PAHs (20 PAHs, 11 alkylated PAHs, and 3 polycyclic aromatic thiophenes) were targeted. In addition, legacy contaminants—polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs),—and current contaminants, polybrominated diphenylethers (PBDEs) linked to endocrine disruption, were measured by gas chromatography with electron-capture or mass spectrometric detection, to form a more complete picture of the contaminant-related status of fishes at oil production platforms in the Southern California Bight. No hydrocarbon profiles or unresolved complex hydrocarbon background were found in fish from platforms and from natural areas, and concentrations of aliphatics were low less than 100 nanograms per gram (ng/g) per component]. Total-PAH concentrations in fish ranged from 15 to 37 ng/g at natural areas and from 8.7 to 22 ng/g at platforms. Profiles of PAHs were similar at all natural and platform sites, consisting mainly of naphthalene and methylnaphthalenes, phenanthrene, fluoranthene, and pyrene. Total-PCB concentrations (excluding non-ortho-chloro-substituted congeners) in fish were low, ranging from 7 to 22 ng/g at natural areas and from 10 to 35 ng/g at platforms. About 50 percent of the total-PCBs at all sites consisted of 11 congeners: 153 > 138/163/164 > 110 > 118 > 15 > 99 > 187 > 149 > 180. Most OCPs, except dichlorodiphenyltrichloroethane (DDT)-related compounds, were not detectable or were at concentrations of less than 1 ng/g in fish. p

  14. Getting offshoring right.

    PubMed

    Aron, Ravi; Singh, Jitendra V

    2005-12-01

    The prospect of offshoring and outsourcing business processes has captured the imagination of CEOs everywhere. In the past five years, a rising number of companies in North America and Europe have experimented with this strategy, hoping to reduce costs and gain strategic advantage. But many businesses have had mixed results. According to several studies, half the organizations that have shifted processes offshore have failed to generate the expected financial benefits. What's more, many of them have faced employee resistance and consumer dissatisfaction. Clearly, companies have to rethink how they formulate their offshoring strategies. A three-part methodology can help. First, companies need to prioritize their processes, ranking each based on two criteria: the value it creates for customers and the degree to which the company can capture some of that value. Companies will want to keep their core (highest-priority) processes in-house and consider outsourcing their commodity (low-priority) processes; critical (moderate-priority) processes are up for debate and must be considered carefully. Second, businesses should analyze all the risks that accompany offshoring and look systematically at their critical and commodity processes in terms of operational risk (the risk that processes won't operate smoothly after being offshored) and structural risk (the risk that relationships with service providers may not work as expected). Finally, companies should determine possible locations for their offshore efforts, as well as the organizational forms--such as captive centers and joint ventures--that those efforts might take. They can do so by examining each process's operational and structural risks side by side. This article outlines the tools that will help companies choose the right processes to offshore. It also describes a new organizational structure called the extended organization, in which companies specify the quality of services they want and work alongside providers

  15. Understanding Potential Climate Variability Impacts on the Offshore Energy Industry

    NASA Astrophysics Data System (ADS)

    Stear, J.

    2014-12-01

    Climate variability may have important implications for the offshore energy industry. Scenarios of increased storm activity and changes in sea level could require the retrofit of existing offshore platforms and coastal infrastructure, the decommissioning of facilities for which upgrade or relocation is not economically viable, and the development of new methods and equipment which are removed from or less sensitive to environmental loads. Over the past years the energy industry has been actively involved in collaborative research efforts with government and academia to identify the potential changes in the offshore operating environment, and corresponding risk implications. This presentation will review several of these efforts, and for several of the hypothetical climate variation scenarios, review the potential impacts on and possible mitigations for offshore and coastal energy infrastructure and operations.

  16. Arctic and offshore research: Technology status report

    SciTech Connect

    Not Available

    1988-01-01

    This report describes the state of technology relative to the production of oil and gas in the Arctic. It discusses the technical issues that warrant investigation, and focuses on the current Department of Energy supported activities. Major accomplishments during the last year include the following: The Arctic and Offshore Research Information System (AORIS) was planned with industry survey recommendations incorporated. It contains a directory of 85 Arctic databases, a bibliographic component of over 7,000 citations, and a data component of about 300 data sets on sea ice characteristics. Seven position, pressure, and temperature buoys were deployed on ice islands (up to 3 by 6 miles in size) drifting off Ellesmere Island. Ice island movement, as much as 340 miles southwest of the Ward Hunt Ice Shelf during the last 4 years, represents a potential hazard to Arctic offshore structures in the Alaskan Beaufort Sea. The redesigned Seafloor Earthquake Measurement System (SEMS II) was deployed near Shell's Ellen-Elly platforms, about 10 miles offshore of Long Beach, California. The SEMS monitored the July 1986 southern California earthquakes. This was the first time earthquakes were simultaneouslly monitored by sensors located on land, aboard offshore platforms, and beneath the seafloor. Sea spray ice bond shear strength to various structural and protective coatings has been determined. The polyethylene coating demonstrated the most potential for rapid shedding of spray ice by gravity loading. Measurements of temperatures and salinities were completed as part of a pilot test to (1) detect seasonal conditions at the water-seabed interface, and (2) determine how they influence permafrost growth in the coastal waters of the Beaufort Sea. The temperatures and computed freezing point data suggest that seasonal seabed freezing can occur most of the winter. 13 refs., 14 figs., 4 tabs.

  17. A costing model for offshore decommissioning in California.

    PubMed

    Bressler, Andrew; Bernstein, Brock B

    2015-10-01

    California's 27 offshore oil and gas platforms will reach the end of their useful lifetimes sometime in the near future and will require decommissioning. Although existing leases require complete removal of all platforms and associated infrastructure, the underlying laws and regulations have changed in recent years to allow a number of alternative uses after decommissioning. In particular, AB 2503, signed into law in September 2010, provides for a rigs-to-reefs program that allows the state to accept ownership of decommissioned platforms in federal waters. Decisions about whether to remove platforms completely or leave them in place as artificial reefs will depend in part on the relative cost of the 2 options. In this study, we describe the design and use of a mathematical decision model that provides detailed cost estimates of complete and partial removal (to 85 feet below the water line) for California's offshore platforms. The model, PLATFORM, is loaded with Bureau of Safety and Environmental Enforcement (BSEE) and Bureau of Ocean Energy Management (BOEM) costs for complete removal, along with costs for partial removal calculated for this study and estimates of the uncertainty associated with decommissioning cost estimates. PLATFORM allows users to define a wide range of decommissioning and costing scenarios (e.g., number of platforms, choice of heavy lift vessel, shell mound removal, reef enhancement). As a benchmark cost, complete removal of all 27 offshore platforms, grouped into the 7 decommissioning projects defined by the most recent federal cost estimates produced in 2010, would cost an estimated $1.09 billion, whereas partial removal of these platforms, grouped into the same set of projects, would cost $478 million, with avoided costs of $616 million (with minor rounding).

  18. Proceedings of the 15. international conference on offshore mechanics and arctic engineering -- OMAE 1996. Volume 1, Part A: Offshore technology

    SciTech Connect

    Chakrabarti, S.K.; Pontes, M.T.; Maeda, Hisaaki; Falzarano, J.; Schofield, P.; Morrison, D.

    1996-12-31

    The 57 papers in Part A of Volume 1 are arranged under the following topical sections: Ocean waves; Ship dynamics; Fixed offshore structures; Hydrodynamic forces; Structural mechanics; Hydroelastic and articulated structure; and Tension leg platforms. Most of the papers have been processed separately for inclusion on the data base.

  19. Energy from Offshore Wind: Preprint

    SciTech Connect

    Musial, W.; Butterfield, S.; Ram, B.

    2006-02-01

    This paper provides an overview of the nascent offshore wind energy industry including a status of the commercial offshore industry and the technologies that will be needed for full market development.

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

    SciTech Connect

    Jimenez, Tony; Keyser, David; Tegen, Suzanne

    2016-04-18

    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: 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.

  1. Offshore rectenna feasbility

    NASA Technical Reports Server (NTRS)

    Freeman, J. W.; Hervey, D.; Glaser, P.

    1980-01-01

    A preliminary study of the feasibility and cost of an offshore rectenna to serve the upper metropolitan east coast was performed. A candidate site at which to build a 5 GW rectenna was selected on the basis of proximity to load centers, avoidance of shipping lanes, sea floor terrain, and relocated conditions. Several types of support structures were selected for study based initially on the reference system rectenna concept of a wire mesh ground screen and dipoles each with its own rectifier and filter circuits. Possible secondary uses of an offshore rectenna were examined and are evaluated.

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

    SciTech Connect

    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.

  3. EPA moves to control offshore emissions

    SciTech Connect

    Not Available

    1991-12-09

    This paper reports that except for most of the Gulf Coast, the Environmental Protection Agency proposes to hold all U.S. offshore rigs and platforms within about 28 miles from shore to the same standards as onshore facilities. EPA estimated compliance will cost the oil industry $2.2 million/year for all sources on the Outer Continental Shelf. The rule, the first EPA has proposed to control air pollution from OCS operations, covers drilling and production off Alaska, the Pacific coast states, the Atlantic coast states, and the Florida Gulf Coast. It does not affect OCS areas off Texas, Louisiana, Mississippi, and Alabama.

  4. Offshore Wind Energy Systems

    ERIC Educational Resources Information Center

    Musgrove, P.

    1978-01-01

    Explores the possibility of installing offshore windmills to provide electricity and to save fuel for the United Kingdom. Favors their deployment in clusters to facilitate supervision and minimize cost. Discusses the power output and the cost involved and urges their quick development. (GA)

  5. U.K. offshore project employs new technologies

    SciTech Connect

    Moritis, G.

    1995-12-18

    The Liverpool Bay project, to produce oil and gas from four offshore fields in the British sector of the Irish Sea, includes a number recently developed technologies. GE Power Systems and GE Marine and Industrial Engines says that this project is the first to use its GE LM6000 aeroderivative gas turbine for power generation. On the Lennox platform, Cooper Cameron Corp.`s first platform spool tree was installed. Marine fouling protection of the platforms is provided by LEV Group`s proprietary ocean-powered marine growth preventers. All three technologies are described.

  6. 30 CFR 250.900 - What general requirements apply to all platforms?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... platforms? 250.900 Section 250.900 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Platforms and Structures General Requirements for Platforms § 250.900 What general requirements apply to all platforms? (a) You must...

  7. Offshore Essaouira basin: Geology and hydrocarbon potential

    SciTech Connect

    Jabour, H.; Ait Salem, A. )

    1991-03-01

    The study area lies in the offshore extension of the onshore Essaouria basin. The Mesozoic development of the Essaouira margin was largely controlled by Late Triassic to Mid-Jurassic rifting and subsequent opening of the Central Atlantic, with the evolution of a typical passive, opening of the Central Atlantic, with the evolution of a typical passive, continental margin. Diapiric salt structure recognized on seismic defines a Late Triassic-Early Jurassic salt basin in the offshore area initiated during early rifting. Subsidence and sea-level rise during Jurassic resulted in carbonate platform development. This was followed during Cretaceous and Tertiary time by the deposition of a prograding siliciclastic system. Only three wells have been drilled in this basin. Although drilled on poorly defined prospects, these wells encountered gas and oil shows. Fairly extensive seismic coverage of good quality data is now available. A study based on an integrated approach involving seismic facies definition and mapping, correlation with well data, identification of the principal control on sedimentation, and basin modeling in conjunction with source rock prediction and maturity modeling has been carried out. Results have shown that hydrocarbon potential in the offshore Essaouira basin has not yet been substantiated by drilling. Attractive structural and stratigraphic prospects exist in the shelf, shelf edge, and the slope, and await confirmation by drilling.

  8. PEaCH4 v.2.0: A modelling platform to predict early diagenetic processes in marine sediments with a focus on biogenic methane - Case study: Offshore Namibia

    NASA Astrophysics Data System (ADS)

    Arning, Esther T.; Häußler, Steffen; van Berk, Wolfgang; Schulz, Hans-Martin

    2016-07-01

    The modelling of early diagenetic processes in marine sediments is of interest in marine science, and in the oil and gas industry, here, especially with respect to methane occurrence and gas hydrate formation as resources. Early diagenesis in marine sediments evolves from a complex web of intertwining (bio)geochemical reactions. It comprises microbially catalysed reactions and inorganic mineral-water-gas interactions. A model that will describe and consider all of these reactions has to be complex. However, it should be user-friendly, as well as to be applicable for a broad community and not only for experts in the field of marine chemistry. The presented modelling platform PeaCH4 v.2.0 combines both aspects, and is Microsoft Excel©-based. The modelling tool is PHREEQC (version 2), a computer programme for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations. The conceptual PEaCH4 model is based on the conversion of sediment-bound degradable organic matter. PEaCH4 v.2.0 was developed to quantify and predict early diagenetic processes in marine sediments with the focus on biogenic methane formation and its phase behaviour, and allows carbon mass balancing. In regard to the irreversible degradation of organic matter, it comprises a "reaction model" and a "kinetic model" to predict methane formation. Both approaches differ in their calculations and outputs as the "kinetic model" considers the modelling time to integrate temperature dependent biogenic methane formation in its calculations, whereas the "reaction model" simply relies on default organic matter degradation. With regard to the inorganic mineral-water-gas interactions, which are triggered by irreversible degradation of organic matter, PEaCH4 v.2.0 is based on chemical equilibrium thermodynamics, appropriate mass-action laws, and their temperature dependent equilibrium constants. The programme is exemplarily presented with the example of upwelling sediments off Namibia

  9. Wind Energy: Offshore Permitting

    DTIC Science & Technology

    2008-05-01

    Technological advancements and tax incentives have driven a global expansion in the development of renewable energy resources. Wind energy , in...particular, is now often cited as the fastest growing commercial energy source in the world. Currently, all U.S. wind energy facilities are based on land...authority to permit and regulate offshore wind energy development within the zones of the oceans under its jurisdiction. The federal government and coastal

  10. On the instability of offshore foundations: theory and mechanism

    NASA Astrophysics Data System (ADS)

    Gao, FuPing; Li, JinHui; Qi, WenGang; Hu, Cun

    2015-12-01

    As the offshore engineering moving from shallow to deep waters, the foundation types for fixed and floating platforms have been gradually evolving to minimize engineering costs and structural risks in the harsh offshore environments. Particular focus of this paper is on the foundation instability and its failure mechanisms as well as the relevant theory advances for the prevailing foundation types in both shallow and deep water depths. Piles, spudcans, gravity bases, suction caissons, and plate anchors are detailed in this paper. The failure phenomena and mechanisms for each type of foundations are identified and summarized, respectively. The theoretical approaches along with sophisticated empirical solutions for the bearing capacity problems are then presented. The major challenges are from flow-structure-soil coupling processes, rigorous constitutive modeling of cyclic behaviors of marine sediments, and the spatial variability of soil properties for large-spreading structures. Further researches are suggested to reveal the instability mechanisms for underpinning the evolution of offshore foundations.

  11. Offshore technology aims for reduced costs, greater safety

    SciTech Connect

    Dempsey, P.

    1985-04-01

    OFFSHORE TECHNOLOGY continued to make headway last year, although dramatic breakthroughs were few and far between. Major oil companies have been spending heavily on acquisitions and the service companies, which historically have done much innovative work, have been forced to curtail their engineering budgets. The Weir hydraulic pump has been vetted for offshore service and a production model is being installed on a North Sea platform. A CO/sub 2/ fire-control system has been developed for both offshore and onshore applications, and Drilco's Trans-Wate pipe promises to extend drillstring life. And, perhaps most significantly, the Poseidon project is healthy and flourishing. If successful, Poseidon could cut development costs by more than half.

  12. Experimental Study on a Tuned-Mass Damper of Offshore for Vibration Reduction

    NASA Astrophysics Data System (ADS)

    Wu, Qiong; Zhao, Xilu; Zheng, Rencheng

    2016-09-01

    With the development of industry, oceanic oil production is one of the most important energy resources. Normally, offshore platform, located in the hostile environment, is easily subjected to unstable environmental loading, such as wind, wave, ice, and earthquake, and it becomes a critical problem to ensure the stability of offshore platform for safely engineering operations. In recent years, tuned-mass damper (TMD) technology has been adopted to reduce vibrations from wind and earthquake influences. Due to the complexity of earthquake excitations, most of researchers were focused on controlling response of structures under wind loads; however, less attention has been put on controlling earthquake response. Therefore, this study concentrates on the seismic reduction of offshore platform by application of a TMD system, and a comprehensively experimental study was processed to validate its effectiveness exposed to different earthquake. A 4-column offshore platform was built according to the actual size of approximately 1:200 ratios, and a TMD system was prepared for the experiment. By the different performance analyses, experimental results indicated that the proposed TMD system can effectively suppress the earthquake stimulus and keep the stability of offshore platform.

  13. NCEL (Naval Civil Engineering Lab.) Ocean Platforms Seminar.

    DTIC Science & Technology

    1983-11-01

    type platforms. Both Cerveza and the Cerveza Ligera platforms[ 7] were launched in one piece and installed in 935 ft and 925 ft of water respectively...6. Magnus Jacket Takes Heavy Honors, Offshore V 42, No. 5, pp 189, 191- 193, May 1982. 7. Tannahill, C. A, W. M. Isenhower, D. D. Engle, Cerveza - A

  14. Experiment study of the motion of the floating offshore turbine

    NASA Astrophysics Data System (ADS)

    Chuang, Tzu-Ching; Hsu, Wen-Yang; Yang, Ray-Yeng; Chen, Yang-Yi

    2016-04-01

    Recently the wind industry moved to offshore areas. The floating wind turbine combined the platform and the mooring system. This research focuses on studying the motion of the floating offshore turbine with a mooring system. The platform, which was developed by the Ship and Ocean Industries R&D Center, had been test in a wave-wind flume in the Tainan Hydraulics Laboratory by using a 1:50 Froude scaling model. In the experiment, the floating offshore turbine was placed in a water flume and exposed to periodic waves at frequencies ranging from 0.22 rad/s - 0.875 rad/s, the wave amplitude is about 2.5 meter, and with the different pretension of the mooring lines. The experiment includes the measurement of damping coefficient from the free decay test and the dynamic response in a sea state. This research compares the motion of the floating offshore turbine with the different pretension of the mooring lines, and the model provides comprehensive data for the operational, design, and survival seas states, as well as the calibration and improvement of the existing design and performance of numerical models.

  15. The Effects of Anthropogenic Structures on Habitat Connectivity and the Potential Spread of Non-Native Invertebrate Species in the Offshore Environment

    PubMed Central

    Simons, Rachel D.; Page, Henry M.; Zaleski, Susan; Miller, Robert; Dugan, Jenifer E.; Schroeder, Donna M.; Doheny, Brandon

    2016-01-01

    Offshore structures provide habitat that could facilitate species range expansions and the introduction of non-native species into new geographic areas. Surveys of assemblages of seven offshore oil and gas platforms in the Santa Barbara Channel revealed a change in distribution of the non-native sessile invertebrate Watersipora subtorquata, a bryozoan with a planktonic larval duration (PLD) of 24 hours or less, from one platform in 2001 to four platforms in 2013. We use a three-dimensional biophysical model to assess whether larval dispersal via currents from harbors to platforms and among platforms is a plausible mechanism to explain the change in distribution of Watersipora and to predict potential spread to other platforms in the future. Hull fouling is another possible mechanism to explain the change in distribution of Watersipora. We find that larval dispersal via currents could account for the increase in distribution of Watersipora from one to four platforms and that Watersipora is unlikely to spread from these four platforms to additional platforms through larval dispersal. Our results also suggest that larvae with PLDs of 24 hours or less released from offshore platforms can attain much greater dispersal distances than larvae with PLDs of 24 hours or less released from nearshore habitat. We hypothesize that the enhanced dispersal distance of larvae released from offshore platforms is driven by a combination of the offshore hydrodynamic environment, larval behavior, and larval release above the seafloor. PMID:27031827

  16. Four barges mobilized for job: Indian offshore pipeline work demands comprehensive coordination

    SciTech Connect

    Schmidt, J. )

    1994-02-01

    This paper describes the design, installation, and commissioning timeframe developed for the Oil and Natural Gas Commission of India. Offshore Hyundai International Inc. and Offshore Pipelines International have completed the installation of 47 pipelines, six platforms, and a single-point mooring system in the Arabian Sea. The coordination and work scheduling problems are described along with the engineered placement of the pipelines in an already congested area.

  17. Offshore outlook: the American Arctic

    SciTech Connect

    Jahns, M.O.

    1985-05-01

    Offshore areas in the American Arctic are highlighted and the development of the area is compared with other offshore areas where the required technology is more readily available. Principal areas are shown in which new concepts are being put to practice. Canada's east coast is examined. Several technological trends are reviewed to help operators accelerate the discovery and development of arctic petroleum reserves.

  18. Offshore Fish Community: Ecological Interactions

    EPA Science Inventory

    The offshore (>80 m) fish community of Lake Superior is made up of predominately native species. The most prominent species are deepwater sculpin, kiyi, cisco, siscowet lake trout, burbot, and the exotic sea lamprey. Bloater and shortjaw cisco are also found in the offshore zone...

  19. Fiber glass pipe effective for offshore water handling

    SciTech Connect

    Turnipseed, S.P.

    1995-07-03

    Excellent corrosion resistance, weight savings, ease of construction, and reduced maintenance make fiber glass pipe attractive for water-handling service on offshore platforms. This article covers guidelines for fiber glass pipe installations and presents a number of case histories from the industry and Chevron Corp. Applications include seawater treatment, water injection, sewage and drains, deluge fire water systems, hose reel fire water, seawater cooling, produced water, and potable water. The paper gives usage guidelines.

  20. Screw pumps move heavy California offshore crude effectively

    SciTech Connect

    Brennan, J.R. )

    1994-09-19

    Multiple-screw pumps are ideally suited for transporting and processing heavy crude and emulsions. The pumps have high-pressure capability and excellent operating efficiencies. Minimal space for treating equipment on a platform makes pumping heavy crude from offshore fields difficult. Water is difficult to separate from heavy crude and heavy crude also has a tendency to retain sediments/solids. The paper describes the original development of these pumps, their field expansion, and the supporting onshore facility.

  1. Effect of Second-Order Hydrodynamics on a Floating Offshore Wind Turbine

    SciTech Connect

    Roald, L.; Jonkman, J.; Robertson, A.

    2014-05-01

    The design of offshore floating wind turbines uses design codes that can simulate the entire coupled system behavior. At the present, most codes include only first-order hydrodynamics, which induce forces and motions varying with the same frequency as the incident waves. Effects due to second- and higher-order hydrodynamics are often ignored in the offshore industry, because the forces induced typically are smaller than the first-order forces. In this report, first- and second-order hydrodynamic analysis used in the offshore oil and gas industry is applied to two different wind turbine concepts--a spar and a tension leg platform.

  2. Ice-breaking off-shore drilling and production structure

    SciTech Connect

    Loire, R.

    1986-09-02

    An ice-breaking drilling and production structure is described for use with an off-shore vertically disposed well shaft and the like having one end extending downwardly toward a sea floor and having an opposite end extending upwardly to a point above sea level. The structure consists of: (a) a platform member having outer edges and a generally downwardly facing lower surface which slopes upwardly toward at least one outer edge thereof and adapted to be positioned on a shaft so that the sloping surface extends both above and below sea level; and (b) means for flexibly connecting the platform to a shaft in a manner which will allow the platform to lift and/or to tilt with respect to the shaft as ice moves under the sloping generally downwardly facing lower surface to transfer part of the weight of the platform to the ice and thereby break the same.

  3. Bahrain's offshore banking center

    SciTech Connect

    Gerakis, A.S.; Roncesvalles, O.

    1983-01-01

    The economic effects of Bahrain's schemes for licensing offshore banking units (OBUs) were the immediate response of major international banks and the financial services the banking center has rendered by improving regional money and exchange markets at a time when a Middle East link was needed to service the increasing demand for oil-wealth banking services. Bahrain's leadership also created a favorable climate. Aggressive competition from banks in Kuwait and Saudi Arabia have caused some friction, but informal supervision by the Bahrain Monetary Agency (BMA) should be able to avoid serious difficulty. Bahrain's success required a banking infrastructure, a free-enterprise system, a willingness to maintain banking standards, a country small enough to benefit directly from OBU income, and a gap in nearby competing centers. 39 references, 1 figure, 5 tables. (DCK)

  4. Offshore winds using remote sensing techniques

    NASA Astrophysics Data System (ADS)

    Peña, Alfredo; Bay Hasager, Charlotte; Gryning, Sven-Erik; Courtney, Michael; Antoniou, Ioannis; Mikkelsen, Torben; Sørensen, Paul

    2007-07-01

    Ground-based remote sensing instruments can observe winds at different levels in the atmosphere where the wind characteristics change with height: the range of heights where modern turbine rotors are operating. A six-month wind assessment campaign has been made with a LiDAR (Light Detection And Ranging) and a SoDAR (Sound Detection and Ranging) on the transformer/platform of the world's largest offshore wind farm located at the West coast of Denmark to evaluate their ability to observe offshore winds. The high homogeneity and low turbulence levels registered allow the comparison of LiDAR and SoDAR with measurements from cups on masts surrounding the wind farm showing good agreement for both the mean wind speed and the longitudinal component of turbulence. An extension of mean wind speed profiles from cup measurements on masts with LiDAR observations results in a good match for the free sectors at different wind speeds. The log-linear profile is fitted to the extended profiles (averaged over all stabilities and roughness lengths) and the deviations are small. Extended profiles of turbulence intensity are also shown for different wind speeds up to 161 m. Friction velocities and roughness lengths calculated from the fitted log-linear profile are compared with the Charnock model which seems to overestimate the sea roughness for the free sectors.

  5. Review of technology for Arctic offshore oil and gas recovery

    SciTech Connect

    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 petroleum 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.

  6. Lysimeter Platform

    NASA Astrophysics Data System (ADS)

    Klammler, Gernot; Murer, Erwin; Plieschnegger, Markus

    2014-05-01

    The existing European Lysimeter Platform (www.lysimeter.at/HP_EuLP) provides an overview of lysimeter types used in Europe and show details on equipment, research results and future perspectives of lysimeter facilities. However, this platform is not user-editable and has not been updated since 2008. Thus, the Lysimeter Research Group (www.lysimeter.at) intends to serve a new database based website called Lysimeter Platform, where existing information of the former European Lysimeter Platform will be transferred to the new Lysimeter Platform and, furthermore, registered users are able to create and edit sites where lysimeters, soil water samplers and soil hydrologic measuring profiles are operated. The Lysimeter Research Group is a scientific association and, therefore, the membership is free of charge. The new Lysimeter Platform contains general information of lysimeter sites worldwide (e.g., what is measured at which site) in a standardized form to get a quick but informative overview of the sites and can be linked to more detailed, already existing information provided by the site operators. Due to the standardized information in the database the Lysimeter Platform serves also as search-engine for soil water measurements and helps to find sites of interest and corresponding contact information worldwide. The Session "Estimation of soil-atmosphere and vadose zone water fluxes by use of precision lysimeter measurements" at the EGU General Assembly 2014 would be an excellent chance to present the idea and the concept of this new Lysimeter Platform to international site operators and scientists.

  7. Offshore exploration and platform siting by imaging Sonar

    SciTech Connect

    Feder, A.M.

    1986-03-17

    Sonar, an acronym for sonic azimuth and ranging (some say ''sonic detection and ranging''), is the name of a type of remote sensor that was developed in World War II for antisubmarine warfare purposes. The principles of the sensor system are simple in that it broadcasts a focused (shaped) sonic pulse through the water (transmission medium), then receives the echo of that pulse and processes this signal for its information content. Hence, Sonar system principles are highly analagous to those of radar. Post-World War II saw development of Sonar probes that provided some success in determining sea floor materials composition and condition (e.g., subbottom profilers). The major advance, however, was with the advent of digital computation systems. These permitted the coupling of Sonar azimuth and range components to provide ''x'' and ''y'' coordinates for each echo location, or ''z'' value. This advance is seeing a proliferation of different types of imaging Sonar systems and performances.

  8. Salvage and Demolition of Two Navy Offshore Platforms,

    DTIC Science & Technology

    1984-10-01

    SES-100B Trials SESTF JEFF Craft Tests AALC-ETU LACV-30 Army Coast Guard Sled USCG n Sea/Air Rescue USCG Data Buoy NORDA Voyageur Ops Army/Bell HADAPS...for Lighted Buoys Issued F. .. . . . 4 Date Event 2 Jan. 1984 Florida, Dept. of Natural Resources Approval 9 Feb. 1984 Commerce Business Daily

  9. Offshore search continues despite disappointments

    SciTech Connect

    Cornitius, T.

    1985-05-01

    Exploration drilling activity in Australia broke records onshore in 1984, but offshore it was a different story. A total of 373 wells were drilled, onshore and offshore, with 266 labeled as wildcats and appraisals. Out of 80 wells drilled offshore last year, 43 were exploratory compared with 49 in 1983; 48 were oil wells, seven were gas, and 25 were dusters. Offshore discoveries included the Talisman 1 off the coast of Western Australia, which tested around 6000 b/d, and Challis 1 in the Timor Sea, which flowed at 5000 b/d. The failure to establish Jabiru in the Timor Sea as a major oil province like Bass Strait was a major disappointment. However, the Challis 1 was a relief since it indicated the presence of a commercial field adjacent to Jabiru.

  10. 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.

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

    SciTech Connect

    Jimenez, Tony; Keyser, David; Tegen, Suzanne; Speer, Bethany

    2016-05-01

    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, 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).

  12. Hybrid offshore structure

    SciTech Connect

    Finn, L.D.; Maus, L.D.

    1986-09-09

    An articulated offshore structure is described for use in a body of water, the structure comprising: a substantially rigid lower section, the lower section extending upwardly from the bottom of the body of water to a pivot point located intermediate the bottom and the surface of the body of water; a compliant upper section extending upwardly from the pivot point to a position at or above the surface of the body of water; pivot means located proximate pivot point, the pivot means interposed between and connected to the lower section and upper section and adapted to permit the upper section to pivot laterally relative to the lower section; torsion means connected to the upper section and the lower section, the torsion means adapted to transmit torsional loads from the upper section to the lower section; the pivot means being positioned above the bottom of the body of water a distance of between about 10 percent and about 50 percent of the total depth of the body of water so as to substantially minimize the weight of the structure while maintaining the flexural vibration period of the structure at or below a preselected maximum flexural vibration period.

  13. Turboexpanders with pressurized magnetic bearings for off-shore applications

    SciTech Connect

    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 bearing 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.

  14. Liverpool Bay project. LM6000 gas turbines go offshore

    SciTech Connect

    Not Available

    1994-09-01

    Liverpool Bay - comprising the North coast of Wales and the North West coast of England - has become one of the few sites for oil and natural gas extraction in the Irish Sea. Hamilton Oil Company Ltd, together with three UK partners, is now engaged in setting up the Liverpool Bay project. Power supply for the whole offshore project will be on the 8500 t Douglas production platform deck, using two LM6000 gas turbine generating sets. During normal operation, one unit providing 42 MW nominal power will be kept in service with the second in standby. Should the power demand exceed the capacity of one set, additional power can be supplied by the one-megawatt diesel generators installed on the accommodation platform, or by putting the second LM6000 unit into service. The main power loads will be four compressor sets, also installed on the Douglas production platform deck, including two for gas injection and two for gas compression. 5 figs.

  15. [Lens platform].

    PubMed

    Łukaszewska-Smyk, Agnieszka; Kałuzny, Józef

    2010-01-01

    The lens platform defines lens structure and lens material. Evolution of lens comprises change in their shape, angulation of haptens and transition of three-piece lens into one-piece lens. The lens fall into two categories: rigid (PMMA) and soft (siliconic, acrylic, colameric). The main lens maaterials are polymers (hydrophilic and hydrophobic). The lens platform has an effect on biocompatibility, bioadhesion, stability of lens in capsule, degree of PCO evolution and sensitiveness to laser damages.

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

    PubMed Central

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

    2015-01-01

    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. PMID:25583870

  17. 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.

  18. Submerged tank aids platform stability

    SciTech Connect

    Compagnon, J.P.

    1985-05-01

    A new floating platform concept, proposed for the installation of a new lighthouse, 64 km off Ouessant Island, northwest France, in water 130 meters deep, is described. A series of model tests carried out in test tanks in 1983 demonstrated that this new concept is viable in the offshore business as an alternative for deep and rough seas. The key to the success of this design is primarily the location and shape of a large, submerged buoyancy tank - a floater sandwiched between a conventional rig topside and a rigid, vertically suspended counter-weight. The floater balanced by a counter-weight acts as a damper and minimizes the effect of most wave action. This configuration permits a considerable gain in structure weight, improves stability and allows the structure to support a very high deck load with or without storage facilities when used as a production platform.

  19. Offshore Wind Energy Market Overview (Presentation)

    SciTech Connect

    Baring-Gould, I.

    2013-07-01

    This presentation describes the current international market conditions regarding offshore wind, including the breakdown of installation costs, how to reduce costs, and the physical siting considerations considered when planning offshore wind construction. The presentation offers several examples of international existing and planned offshore wind farm sites and compares existing international offshore resources with U.S. resources. The presentation covers future offshore wind trends and cites some challenges that the United States must overcome before it will be able to fully develop offshore wind sites.

  20. Numerical experiments in ringing of offshore systems under viscous loads

    SciTech Connect

    Gurley, K.R.; Kareem, A.

    1996-12-31

    A phenomenon which has recently received much attention in offshore engineering is the ringing response of structures. This high frequency transient type response has been observed in nature, particularly in tension leg platforms (TLPs). Given the implications of this behavior on the fatigue life of tendons, it is important that it be considered for response analysis. Significant progress has been made in recent years in identifying the nonlinear mechanisms that induce ringing in complex offshore structural systems. This introductory study-uses a simple model to numerically demonstrates several of the more salient features that are commonly cited in current literature, and shows that viscous loads may result in inducing ringing type response of members under certain conditions. Ringing response in pitch due to viscous loading is simulated on a column piercing the surface, and the significant contributing force mechanisms are identified. System characteristics are altered to ameliorate the performance of these systems.

  1. Development of an oil spill forecast system for offshore China

    NASA Astrophysics Data System (ADS)

    Wang, Yonggang; Wei, Zexun; An, Wei

    2016-07-01

    An oil spill forecast system for offshore China was developed based on Visual C++. The oil spill forecast system includes an ocean environmental forecast model and an oil spill model. The ocean environmental forecast model was designed to include timesaving methods, and comprised a parametrical wind wave forecast model and a sea surface current forecast model. The oil spill model was based on the "particle method" and fulfills the prediction of oil particle behavior by considering the drifting, evaporation and emulsification processes. A specific database was embedded into the oil spill forecast system, which contained fundamental information, such as the properties of oil, reserve of emergency equipment and distribution of marine petroleum platform. The oil spill forecast system was successfully applied as part of an oil spill emergency exercise, and provides an operational service in the Research and Development Center for Offshore Oil Safety and Environmental Technology.

  2. DEROCS: A computer program to simulate offshore oil and natural gas development scenarios and onshore service base requirements

    USGS Publications Warehouse

    Marcus, Philip A.; Smith, E.T.; Robinson, S.R.; Wong, A.T.

    1977-01-01

    The FORTRAN IV (H) computer program, DEROCS, constructs Outer Continental Shelf (OCS) resource development scenarios and quantifies the requirements for and impacts of the operation of the onshore service bases necessary to support offshore oil and gas operations. The acronym DEROCS stands for 'Development of Energy Resources of the Outer Continental Shelf.' The user may specify the number, timing, and amounts of offshore oil and natural gas finds, onshore service base locations, and multiplier relationships between offshore development activities and onshore land, supply, labor and facility requirements. The program determines schedules of platform installation, development drilling, production from platforms, and well workover, and calculates on a yearly basis the requirements for and impacts of the operation of the onshore service bases demanded by offshore activities. We present two examples of program application.

  3. Basin development and petroleum potential of offshore Otway basin, Australia

    SciTech Connect

    Williamson, P.E.; O'Brien, G.W.; Swift, M.G.; Scherl, A.S.; Marlow, M.S.; Exon, N.F.; Falvey, D.A.; Lock, J.; Lockwood, K.

    1987-05-01

    The Bass Strait region in southeastern Australia contains three sedimentary basins, which are, from east to west, the Gippsland, Bass, and Otway basins. The offshore Gippsland basin is Australia's most prolific petroleum-producing province and supplies over 90% of the country's production. In contrast, exploration has been unsuccessful in the offshore portion of the Otway basin; 17 wells have been drilled, and although shows of oil and gas have been common, no commercial discoveries have been made. Many of these wells, drilled in the 1960s and 1970s, were sited using poor-quality seismic data and, as a consequence, were frequently off structure. Seismic data quality has, however, improved significantly in recent years. The present study by the Australian Bureau of Mineral Resources (BMR) involved the collection, in the offshore Otway basin, of 3700 km of high-quality, 48-channel seismic reflection data by the BMR research vessel R/V Rig Seismic. These data have been integrated with existing industry seismic data, well data, limited dredged material, and geohistory analyses in a framework study of basin development and hydrocarbon potential in this under-explored area. The offshore Otway basin extends 500 km along the southern coastline and is typically 50 km wide in water depths of less than 200 m. It contains up to 10 km of predominantly late Mesozoic to early Cenozoic sediments, which are overlain by a thin sequence of middle to late Tertiary shelf carbonates. It has been divided into three main structural elements: the Mussel Platform in the east, the central Voluta Trough, and the Crayfish Platform in the west. The basin was initiated at the end of the Jurassic as part of the Bassian rift. Up to 6 km of Lower Cretaceous sediments were deposited prior to breakup at the end of the Early Cretaceous and the onset of sea-floor spreading between Australia and Antarctica.

  4. Bill Would Allow Platforms as Artificial Reefs

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    A 17 September U.S. congressional hearing on environmental aspects of oil and gas development focused primarily on potentially beneficial, alternative usages of thousands of decommissioned offshore oil and gas platforms in the Gulf of Mexico, and elsewhere. These platforms and associated rigs would be permitted to be used as artificial reefs for corals and fish populations, mariculture sites, and scientific research stations, under the Rigs to Reef Act, House Resolution 2654. The bill, introduced by Rep. David Vitter (R-Louisiana), currently is in referral in the Resources and in the Ways and Means committees of the House of Representatives.

  5. Offshore Energy Knowledge Exchange Workshop Report

    SciTech Connect

    none,

    2012-04-12

    A report detailing the presentations and topics discussed at the Offshore Energy Knowledge Exchange Workshop, an event designed to bring together offshore energy industry representatives to share information, best practices, and lessons learned.

  6. Offshore wind farm layout optimization

    NASA Astrophysics Data System (ADS)

    Elkinton, Christopher Neil

    Offshore wind energy technology is maturing in Europe and is poised to make a significant contribution to the U.S. energy production portfolio. Building on the knowledge the wind industry has gained to date, this dissertation investigates the influences of different site conditions on offshore wind farm micrositing---the layout of individual turbines within the boundaries of a wind farm. For offshore wind farms, these conditions include, among others, the wind and wave climates, water depths, and soil conditions at the site. An analysis tool has been developed that is capable of estimating the cost of energy (COE) from offshore wind farms. For this analysis, the COE has been divided into several modeled components: major costs (e.g. turbines, electrical interconnection, maintenance, etc.), energy production, and energy losses. By treating these component models as functions of site-dependent parameters, the analysis tool can investigate the influence of these parameters on the COE. Some parameters result in simultaneous increases of both energy and cost. In these cases, the analysis tool was used to determine the value of the parameter that yielded the lowest COE and, thus, the best balance of cost and energy. The models have been validated and generally compare favorably with existing offshore wind farm data. The analysis technique was then paired with optimization algorithms to form a tool with which to design offshore wind farm layouts for which the COE was minimized. Greedy heuristic and genetic optimization algorithms have been tuned and implemented. The use of these two algorithms in series has been shown to produce the best, most consistent solutions. The influences of site conditions on the COE have been studied further by applying the analysis and optimization tools to the initial design of a small offshore wind farm near the town of Hull, Massachusetts. The results of an initial full-site analysis and optimization were used to constrain the boundaries of

  7. 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.

  8. China offshore has top priority

    SciTech Connect

    Cornitius, T.A.

    1983-11-01

    Joint venture development of offshore petroleum reserves has top priority in the mammoth effort to modernize the People's Republic of China. While the country works to overcome a critical shortage of skilled personnel, export of oil, coal, consumer goods, and metals will finance technological imports.

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

    SciTech Connect

    Speer, Bethany; Keyser, David; Tegen, Suzanne

    2016-04-18

    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: 16 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.

  10. OTEC Cold Water Pipe-Platform Subsystem Dynamic Interaction Validation

    SciTech Connect

    Varley, Robert; Halkyard, John; Johnson, Peter; Shi, Shan; Marinho, Thiago

    2014-05-09

    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 final 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.

  11. Offshore Code Comparison Collaboration, Continuation: Phase II Results of a Floating Semisubmersible Wind System: Preprint

    SciTech Connect

    Robertson, A.; Jonkman, J.; Musial, W.; Vorpahl, F.; Popko, W.

    2013-11-01

    Offshore wind turbines are designed and analyzed using comprehensive simulation tools that account for the coupled dynamics of the wind inflow, aerodynamics, elasticity, and controls of the turbine, along with the incident waves, sea current, hydrodynamics, and foundation dynamics of the support structure. The Offshore Code Comparison Collaboration (OC3), which operated under the International Energy Agency (IEA) Wind Task 23, was established to verify the accuracy of these simulation tools [1]. This work was then extended under the Offshore Code Comparison Collaboration, Continuation (OC4) project under IEA Wind Task 30 [2]. Both of these projects sought to verify the accuracy of offshore wind turbine dynamics simulation tools (or codes) through code-to-code comparison of simulated responses of various offshore structures. This paper describes the latest findings from Phase II of the OC4 project, which involved the analysis of a 5-MW turbine supported by a floating semisubmersible. Twenty-two different organizations from 11 different countries submitted results using 24 different simulation tools. The variety of organizations contributing to the project brought together expertise from both the offshore structure and wind energy communities. Twenty-one different load cases were examined, encompassing varying levels of model complexity and a variety of metocean conditions. Differences in the results demonstrate the importance and accuracy of the various modeling approaches used. Significant findings include the importance of mooring dynamics to the mooring loads, the role nonlinear hydrodynamic terms play in calculating drift forces for the platform motions, and the difference between global (at the platform level) and local (at the member level) modeling of viscous drag. The results from this project will help guide development and improvement efforts for these tools to ensure that they are providing the accurate information needed to support the design and

  12. National Offshore Wind Energy Grid Interconnection Study

    SciTech Connect

    Daniel, John P.; Liu, Shu; Ibanez, Eduardo; Pennock, Ken; Reed, Greg; Hanes, Spencer

    2014-07-30

    The National Offshore Wind Energy Grid Interconnection Study (NOWEGIS) considers the availability and potential impacts of interconnecting large amounts of offshore wind energy into the transmission system of the lower 48 contiguous United States. A total of 54GW of offshore wind was assumed to be the target for the analyses conducted. A variety of issues are considered including: the anticipated staging of offshore wind; the offshore wind resource availability; offshore wind energy power production profiles; offshore wind variability; present and potential technologies for collection and delivery of offshore wind energy to the onshore grid; potential impacts to existing utility systems most likely to receive large amounts of offshore wind; and regulatory influences on offshore wind development. The technologies considered the reliability of various high-voltage ac (HVAC) and high-voltage dc (HVDC) technology options and configurations. The utility system impacts of GW-scale integration of offshore wind are considered from an operational steady-state perspective and from a regional and national production cost perspective.

  13. Offshore environmental concerns mitigated by onshore-based, extended-reach drilling

    SciTech Connect

    1998-05-04

    Extended-reach drilling may alleviate California environmental concerns by targeting distant offshore plays using onshore localities adjacent to preexisting facilities. If successful, it may set a precedent for offshore development without the use of new offshore platforms, thereby reducing the risk of offshore spills. Politicians, environmentalists, and the industry will closely watch the Gaviota No. 7 well, an extended-reach well operated by Benton Oil and Gas Co. in partnership with Molino Energy Co. The companies aim to find sweet gas in the Gaviota structure, an anticline hemmed in by two faults, located abut 1 1/4 miles offshore in the Santa Barbara Channel. Frank Reiber, project manager for Benton, characterizes the technologies used in the Gaviota No. 7, as fairly routine. However, state officials hail this onshore-to-offshore technique as the only practical way to develop oil or gas in state waters, given the political and environmental constraints that have virtually closed all waters within the 3-mile limit for decades. The paper describes the drilling and production program.

  14. Effects of Second-Order Hydrodynamic Forces on Floating Offshore Wind Turbines

    SciTech Connect

    Duarte, T.; Sarmento, A. J. N. A.; Jonkman, J.

    2014-04-01

    Relative to first-order, second-order wave-excitation loads are known to cause significant motions and additional loads in offshore oil and gas platforms. The design of floating offshore wind turbines was partially inherited from the offshore oil and gas industry. Floating offshore wind concepts have been studied with powerful aero-hydro-servo-elastic tools; however, most of the existing work on floating offshore wind turbines has neglected the contribution of second-order wave-excitation loads. As a result, this paper presents a computationally efficient methodology to consider these loads within FAST, a wind turbine computer-aided engineering tool developed by the National Renewable Energy Laboratory. The method implemented was verified against the commercial OrcaFlex tool, with good agreement, and low computational time. A reference floating offshore wind turbine was studied under several wind and wave load conditions, including the effects of second-order slow-drift and sum-frequency loads. Preliminary results revealed that these loads excite the turbine's natural frequencies, namely the surge and pitch natural frequencies.

  15. 33 CFR 149.535 - What are the requirements for rotating beacons on platforms?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... rotating beacons on platforms? 149.535 Section 149.535 Navigation and Navigable Waters COAST GUARD... EQUIPMENT Aids to Navigation Lights on Platforms § 149.535 What are the requirements for rotating beacons on... rotating beacon that distinguishes the deepwater port from other surrounding offshore structures....

  16. 33 CFR 149.535 - What are the requirements for rotating beacons on platforms?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... rotating beacons on platforms? 149.535 Section 149.535 Navigation and Navigable Waters COAST GUARD... EQUIPMENT Aids to Navigation Lights on Platforms § 149.535 What are the requirements for rotating beacons on... rotating beacon that distinguishes the deepwater port from other surrounding offshore structures....

  17. 33 CFR 149.535 - What are the requirements for rotating beacons on platforms?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... rotating beacons on platforms? 149.535 Section 149.535 Navigation and Navigable Waters COAST GUARD... EQUIPMENT Aids to Navigation Lights on Platforms § 149.535 What are the requirements for rotating beacons on... rotating beacon that distinguishes the deepwater port from other surrounding offshore structures....

  18. Experiences in retrofitting sacrificial anodes in offshore Arabian Gulf

    SciTech Connect

    Kiefer, J.H.; Thomason, W.H.; Alansari, N.G.

    1998-12-31

    An analysis was made of the cathodic protection systems of fifteen (15) fixed offshore platforms. These steel template structures are located in the warm waters off the coast of the United Arab Emirates with water depth varying between 125 and 185 feet. The operator employs a systematic survey program to monitor the corrosion protection systems including the assessment of sacrificial anode depletion, and measurement of the anode and platform potentials. These data are used to design new anode retrofits for the older structures to extend the life of the CP systems. This paper presents an analysis of the field survey measurements, the method used to evaluate when new anodes are required, how many are needed, and where to locate retrofit anodes.

  19. Placement and retrieval barge for off-shore well drilling

    SciTech Connect

    Grace, F.J.

    1983-05-31

    A placement and retrieval modular barge arrangement for offshore well drilling equipment comprising at least two separable barge sections having an arrangement for being joined together, each barge section being made of a floatable hull having a deck capable of carrying thereon sections of a blow-out collar or other equipment, the barge having a central opening formed therein for surrounding a well drilling derrick when the barge sections are joined together, each barge section being provided with a radially movable platform arrangement slidably supported in the hull thereof, and an arrangement for actuating the platform arrangement to retract it to the confines of the central opening or extend it therefrom a distance sufficient to support a blow-out collar or other equipment during assembly or disassembly thereof.

  20. 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.

  1. Wind/Wave Misalignment in the Loads Analysis of a Floating Offshore Wind Turbine: Preprint

    SciTech Connect

    Barj, L.; Stewart, S.; Stewart, G.; Lackner, M.; Jonkman, J.; Robertson, A.

    2014-02-01

    Wind resources far from the shore and in deeper seas have encouraged the offshore wind industry to look into floating platforms. The International Electrotechnical Commission (IEC) is developing a new technical specification for the design of floating offshore wind turbines that extends existing design standards for land-based and fixed-bottom offshore wind turbines. The work summarized in this paper supports the development of best practices and simulation requirements in the loads analysis of floating offshore wind turbines by examining the impact of wind/wave misalignment on the system loads under normal operation. Simulations of the OC3-Hywind floating offshore wind turbine system under a wide range of wind speeds, significant wave heights, peak-spectral periods and wind/wave misalignments have been carried out with the aero-servo-hydro-elastic tool FAST [4]. The extreme and fatigue loads have been calculated for all the simulations. The extreme and fatigue loading as a function of wind/wave misalignment have been represented as load roses and a directional binning sensitivity study has been carried out. This study focused on identifying the number and type of wind/wave misalignment simulations needed to accurately capture the extreme and fatigue loads of the system in all possible metocean conditions considered, and for a down-selected set identified as the generic US East Coast site. For this axisymmetric platform, perpendicular wind and waves play an important role in the support structure and including these cases in the design loads analysis can improve the estimation of extreme and fatigue loads. However, most structural locations see their highest extreme and fatigue loads with aligned wind and waves. These results are specific to the spar type platform, but it is expected that the results presented here will be similar to other floating platforms.

  2. Geological history of the west Libyan offshore and adjoining regions

    SciTech Connect

    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. 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.

  3. How dangerous is offshore drilling

    SciTech Connect

    McIntosh, T.S.

    1981-08-01

    As concluded by the National Research Council, the frequency of injuries during oil and gas operations on the outer continental shelf is comparable to that in other industries such as mining, maritime service, and heavy construction. Although an area of concern, offshore safety is not easily improved by legislation or detailed regulation. The industry itself must be committed to providing the safest possible workplace for the job and the environment. At Zapata Off-Shore Co., for example, top management recognizes the value of safety-trained personnel in terms of not only decreased downtime and lower insurance costs but also improved crew morale and productivity. The key operatives of Zapata's program are the rig representatives who provide full-time, rig-based safety, training, administrative, and employee-relations assistance to the crews.

  4. Offshore sand resources for coastal erosion control in Louisiana

    SciTech Connect

    Ramsey, K.E.; Penland, S.; McBride, R.A. ); Suter, J.R. ); Williams, J. )

    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 the 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.

  5. Pipelaying in artic offshore waters

    SciTech Connect

    Langner, C. G.

    1985-11-19

    The present invention provides a method and apparatus for constructing pipelines in Arctic offshore waters by a directional drilling technique, thereby minimizing exposure to ice gouging and eliminating the hazards associated with unstable permafrost. A special drilling-pipe-line construction vessel is also provided which has a conical shape with reinforced outer walls to resist ice forces, which vessel includes means to install deep underground pipeline segments and means to connect and protect the pipe ends.

  6. Fatigue handbook: Offshore steel structures

    SciTech Connect

    Almarnaess, A.

    1985-01-01

    The contents of this book are: Overview of Offshore Steel Structures; Loads on Ocean Structures; Fracture Mechanics As a Tool in Fatigue Analysis; Basic Fatigue Properties of Welded Joints; Significance of Defects; Improving the Fatigue Strength of Welded Joints; Effects of Marine Environment and Cathodic Protection on Fatigue of Structural Steels Fatigue of Tubular Joints; Unstable Fracture; Fatigue Life Calculations; and Fatigue in Building Codes Background and Applications.

  7. Two offshore Australian crudes assayed

    SciTech Connect

    Rhodes, A.K.

    1994-05-09

    Two light, sweet crudes from offshore Australia have been assayed. Gippsland crude, also called Bass Strait, is produced off the coast of Victoria, in southeastern Australia. The 47 API, 0.09% sulfur crude was analyzed in mid-1993. Skua, a 42 API, 0.06 wt % sulfur crude, is produced in the Timor Sea. Data are given on the whole crude and fractions for both deposits. Both chemical and physical properties are listed.

  8. Offshore sand and gravel mining

    SciTech Connect

    Pandan, J.W.

    1983-05-01

    This paper reviews the status of mining offshore for sand and gravel on a world-wide basis. It discusses the technology for exploration and evaluation of sea floor mineral targets, as well as mining, transportation, and processing. Large operations in Japan and Europe are described, based upon personal observations of the author. The U.S. situation is outlined and opinions offered as to the outlook for the future.

  9. 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.

  10. Offshore oil: Correctness of perspective

    SciTech Connect

    Burns, R.F.

    1993-05-01

    Except for the Gulf of Mexico, the offshore oil industry has been virtually banned from the US Exclusive Economic Zone for ten years. The oil potential in Alaska's Arctic National Wildlife Refuge (ANWR) is also off limits. The Gulf of Mexico is the only place with prospects for future success and a number of companies both large and small are determined to move forward. The depressed price of oil does not encourage development but recently gas prices in the US have increased, making offshore gas development more feasible. Perhaps most significant is development and application of new technology and more intense management to make sure it works. The offshore oil companies and support industries have made significant technological advances, expending over and above the dollars paid in taxes, lease fees, and royalties. The ocean industries harbor a great reservoir of high technology knowledge. They have demonstrated the ability to successfully meet a vast array of challenges in exploring for, drilling, and producing oil and gas in extreme conditions. These facts beg the question as to the rational basis of each and every regulation and the ban on drilling.

  11. Explosives remain preferred methods for platform abandonment

    SciTech Connect

    Pulsipher, A.; Daniel, W. IV; Kiesler, J.E.; Mackey, V. III

    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 required 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.

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

    SciTech Connect

    Stewart, G.; Lackner, M.; Haid, L.; Matha, D.; Jonkman, J.; Robertson, A.

    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 length 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.

  13. 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

  14. 1991 worldwide offshore contractors and equipment directory

    SciTech Connect

    Not Available

    1991-01-01

    This book is the information source-book for the international offshore oil industry. Within this single convenient reference you'll find addresses, phone numbers, telex, fax and cable listings for more than 3,500 companies and their key personnel in the drilling, workover, construction, service/supply/manufacturers, geophysical, diving and transportation segments of the offshore industry. Along with this vital contact information, the authors include such pertinent data as rig specifications, ownership, an equipment index, a company index and a current survey of offshore production systems from Offshore Incorporating the Oilman.

  15. Research on foundation response of a tri-floater offshore wind turbine

    NASA Astrophysics Data System (ADS)

    Gao, Y. W.; Li, C.; Cheng, X.

    2013-12-01

    Platform structure is the basic guarantee for safety operation of offshore wind turbines. Based on the boundary element method and combined with multi-body dynamics, we analyzed motion response and wave force mechanism to the platform structure, and obtained the dynamic response and the wave force change of the platform structures in time domain. We also analyzed the motion response and wave force change of semi-submerged platform in surge, sway and heave also roll, pitch and yaw direction. The results show that in translational direction, the motion response is periodic variation under three different incident direction; in the translational direction response appear a periodic attenuation change, and in the direction of rotation, motion response mainly concentrated in the 0s to 50s; in time domain, 90° of incidence, platform force is largest, wave force are mainly concentrated in the 0s to 50s. The result is high reference value on offshore tension leg platform structural design and optimization.

  16. 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.

  17. 76 FR 39410 - National Offshore Safety Advisory Committee; Vacancies

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-06

    ..., of offshore mineral and oil operations including geophysical services; (b) One member representing construction of offshore exploration and recovery facilities; (c) One member representing employees of... the exploration for and the recovery of offshore mineral resources. Registered lobbyists are...

  18. NREL Computer Models Integrate Wind Turbines with Floating Platforms (Fact Sheet)

    SciTech Connect

    Not Available

    2011-07-01

    Far off the shores of energy-hungry coastal cities, powerful winds blow over the open ocean, where the water is too deep for today's seabed-mounted offshore wind turbines. For the United States to tap into these vast offshore wind energy resources, wind turbines must be mounted on floating platforms to be cost effective. Researchers at the National Renewable Energy Laboratory (NREL) are supporting that development with computer models that allow detailed analyses of such floating wind turbines.

  19. Risk perception and safety in the UK offshore oil and gas industry

    SciTech Connect

    Flin, R.H.; Mearns, K.; Gordon, R.P.E.; Fleming, M.T.

    1996-12-31

    This paper presents a selection of the final results from a study of risk perception and safety attitudes in workers on UKCS offshore oil and gas platforms, which was sponsored by the HSE Offshore Safety Division, Amerada Hess, British Gas, BP, Conoco, Elf Enterprise and Total Oil Marine. The study was designed in conjunction with Dr Rundmo of Trondheim University who was carrying out a matched survey with Norwegian offshore workers for the Norwegian Petroleum Directorate`. A representative sample of 622 UKCS workers on six production platforms were surveyed about their job characteristics, perceived risks, safety attitudes, safety satisfaction, accidents and injuries and the Safety Case. The results indicate that the relative feelings of safety in relation to major hazards (e.g. explosion, blow-out) are aligned with QRA calculations. In general, the workforce feel safe but are aware of the hazards in their environment. Further analyses and statistical modelling indicates that organizational factors (e.g. management commitment to safety, safety attitudes) have the greatest direct effect on workers perception of risk and their satisfaction with safety measures. The British and Norwegian data sets are now being merged and preliminary findings will be mentioned. To explore the emerging issues further, a new study on human factors in UK offshore safety has just been launched with the support of OSD, OCA and six operating and contractor companies. A brief outline will be presented.

  20. 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..

  1. Seismic assessment for offshore pipelines

    SciTech Connect

    Bruschi, R.; Gudmestad, O.T.; Blaker, F.; Nadim, F.

    1995-12-31

    An international consensus on seismic design criteria for onshore pipelines has been established during the last thirty years. The need to assess seismic design for offshore pipelines has not been similarly recognized. In this paper, the geotechnical hazard for a pipeline routed across steep slopes and irregular terrains affected by earthquakes, is discussed. The integrity of both natural and artificial load bearing supports is assessed.d The response of the pipeline to direct excitation from soil or through discontinuous, sparsely distributed natural or artificial supports, is commented.

  2. The effects of second-order hydrodynamics on a semisubmersible floating offshore wind turbine

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    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 a floating 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 the Maritime Research Institute Netherlands (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 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 was applied to the Offshore Code Comparison Collaboration Continuation OC4-DeepCwind semisubmersible platform, supporting the National Renewable Energy Laboratory's 5-MW baseline wind turbine. In this paper, the loads and response of the system caused by the second-order hydrodynamics are analysed and compared to the first-order hydrodynamic loads and induced motions in the frequency domain. Further, the second-order loads

  3. The Characterization of Microearthquakes in Offshore Area of Northeastern South Korea from Multidisciplinary Data Set

    NASA Astrophysics Data System (ADS)

    Cho, H. M.; Che, I. Y.; Kim, G.

    2015-12-01

    A number of small earthquakes in offshore Gangneung-Sokcho-Goseong area of northeastern South Korea has been identified and the hypocenters of these events are relocated by double-difference algorithm using multidisciplinary data set. Korea Institute of Geoscience and Mineral Resources (KIGAM) lists 845 events for the period Jan. 2010 - Jun. 2015 with local magnitude up to 3.3. Peer review shows that the offshore events can be grouped into a number of small clusters, whereas onshore events are relatively few and unevenly distributed. It appears to have little relationship between the location of offshore event clusters and the direction of main onshore faults running NNE - SSW. In this study, we focus on the small events occurred in the area of N37°45´-38°35´ and E128°30´ - 129°20´. The Korea Integrated Seismic System (KISS) network operated by KIGAM and 5 temporary stations with Guralp CMG-40T short-period seismometers placed along the east coast of South Korea record the seismic energy generated from small events. The 137 events recorded from May to October 2014, ranging in local magnitude from 0.4 to 2.3, are already relocated using 1849 direct P-wave traveltimes identified from 29 stations. Relocation produced two major clusters in offshore Goseong (cluster 1) and Yangyang (cluster 2) province. The waveforms of relocated events in cluster 1 and 2 are similar to those from explosion in waters rather than earthquake, and spectrum analysis shows energy concentration on low frequencies below 10 Hz. We are combining the multidisciplinary data set from land based broadband and short-period seismometers, Guralp OBS system deployed in July this year, accelerometer and hydrophone array mounted on the offshore platforms of the underwater seismic observatory in the north of the study area. The integration of seismic and hydro-acoustic data in offshore supplements uneven azimuthal coverage and gives improved characterization of offshore seismic activity.

  4. Effect of Second-Order Hydrodynamics on Floating Offshore Wind Turbines: Preprint

    SciTech Connect

    Roald, L.; Jonkman, J.; Robertson, A,; Chokani, N.

    2013-07-01

    Offshore winds are generally stronger and more consistent than winds on land, making the offshore environment attractive for wind energy development. A large part of the offshore wind resource is however located in deep water, where floating turbines are the only economical way of harvesting the energy. The design of offshore floating wind turbines relies on the use of modeling tools that can simulate the entire coupled system behavior. At present, most of these tools include only first-order hydrodynamic theory. However, observations of supposed second-order hydrodynamic responses in wave-tank tests performed by the DeepCwind consortium suggest that second-order effects might be critical. In this paper, the methodology used by the oil and gas industry has been modified to apply to the analysis of floating wind turbines, and is used to assess the effect of second-order hydrodynamics on floating offshore wind turbines. The method relies on combined use of the frequency-domain tool WAMIT and the time-domain tool FAST. The proposed assessment method has been applied to two different floating wind concepts, a spar and a tension-leg-platform (TLP), both supporting the NREL 5-MW baseline wind turbine. Results showing the hydrodynamic forces and motion response for these systems are presented and analysed, and compared to aerodynamic effects.

  5. 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.

  6. Domestic Options to Offshore Oil and Gas.

    ERIC Educational Resources Information Center

    Kash, Don E.

    1983-01-01

    The continuing controversey over offshore oil/gas has given impetus to searching for domestic energy alternatives. The need for and types of several alternative sources are discussed. Indicates that the United States needs to pursue both offshore and other domestic liquid-fuel sources if it is to avoid becoming increasingly dependent on imports.…

  7. U.S. Offshore Wind Port Readiness

    SciTech Connect

    C. Elkinton, A. Blatiak, H. Ameen

    2013-10-13

    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.

  8. Structural features offshore northern Taiwan

    NASA Astrophysics Data System (ADS)

    Yicheng Yang, Eason; Liu, Char-Shine; Chang, Jih-Hsin; Chiu, Chien-Hsuan

    2016-04-01

    The area offshore northern Taiwan is the place where East China Sea Shelf extends into the Southern Okinawa Trough, and where pre-Pleistocene arc-continental collision had occurred. Comparison between fault distribution in the area with previously published results suggests that the fault distribution and regional structural framework are still controversial. Using marine multichannel seismic reflection data collected in 3 marine geophysical survey cruises, we remapped the fault distribution in the northern offshore area of Taiwan. By analyzing all the seismic profiles using the KINGDOM suite (a seismic interpretation software), a new fault distribution map is presented, and a subsurface unconformity PRSB (Pliocene reflection sequence boundary) is identified. Six major NE-SW trending high-angle normal faults cut the PRSB can be traced to the fault systems on land northernmost Taiwan. These normal faults are located between the Southern Okinawa Trough and the East China Sea continental shelf basin, and have been suggested to be reactivated from pre-existing reverse faults. The offsets of fault ramps in PRSB increase toward southeast. The isopach map of the study area compiled shows that sediment strata overlying PRSB thin toward northwest.

  9. Offshore Wind Market and Economic Analysis

    SciTech Connect

    Hamilton, Bruce Duncan

    2014-08-27

    This report is the third annual assessment of the U.S. offshore wind market. It includes the following major sections: Section 1: key data on developments in the offshore wind technology sector and the global development of offshore wind projects, with a particular focus on progress in the United States; Section 2: analysis of policy developments at the federal and state levels that have been effective in advancing offshore wind deployment in the United States; Section 3: analysis of actual and projected economic impact, including regional development and job creation; Section 4: analysis of developments in relevant sectors of the economy with the potential to affect offshore wind deployment in the United States

  10. Underbalanced drilling benefits now available offshore

    SciTech Connect

    Vozniak, J.P.; Cuthbertson, B.; Nessa, D.O.

    1997-05-01

    Offshore underbalanced drilling (UBD) is a reality. Applications in older, partially depleted fields and new fields are being considered. However, low productivity reservoirs and fields with sub normal pressures causing drilling problems are currently the main targets for offshore UBD. With proper planning and the correct technique, both jointed pipe and coiled tubing UBD drilling operations have been carried out offshore with success. The main concerns for offshore UBD have been altered drilling practices and surface production system operation. These issues have been examined and equipment has been designed and tested to address them. Environmental, safety and health issues are paramount and have been studied carefully. Detailed well planning, engineering, and flow modeling have proven critical for successful offshore UBD operations. Examples are given from oil and gas fields.

  11. The environmental issues of platform decommissioning

    SciTech Connect

    Susani, L.

    1996-12-31

    This paper provides a review of the environmental impacts of offshore platform disposal, based on past activities and technical and research studies. Environmental impacts are considered in relation to four main decommissioning options. The most significant effects stem from explosive cutting, sediment resuspension and release of contamination during initial production shut-down, well purging and removal of the jacket structure from the seabed. Any decommissioning option that minimizes movement of structures and avoids explosive cutting must therefore be viewed as preferable from an ecological viewpoint. Complete removal is preferred on the grounds of energy conservation, fisheries and navigational safety, and controlled disposal of potential contaminants.

  12. Marine riser protector for use on offshore oil drilling rigs in icy waters

    SciTech Connect

    Yashima, N.

    1985-03-19

    An apparatus for protecting a marine riser extending downwardly from a platform of an offshore station above a sea level toward a sea bottom. A tubular protector is removably mounted on the underside of the platform in surrounding relation to the marine riser in the vicinity of the sea level. According to another embodiment, a tubular protector has an upper portion in the shape of a truncated cone for contact with ice floes and a lower portion shaped as a grid-like truncated cone flaring downwardly for diverting ice floes away from the tubular protector.

  13. 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.

  14. Offshore Wind Energy Systems Engineering Curriculum Development

    SciTech Connect

    McGowan, Jon G.; Manwell, James F.; Lackner, Matthew A.

    2012-12-31

    Utility-scale electricity produced from offshore wind farms has the potential to contribute significantly to the energy production of the United States. In order for the U.S. to rapidly develop these abundant resources, knowledgeable scientists and engineers with sound understanding of offshore wind energy systems are critical. This report summarizes the development of an upper-level engineering course in "Offshore Wind Energy Systems Engineering." This course is designed to provide students with a comprehensive knowledge of both the technical challenges of offshore wind energy and the practical regulatory, permitting, and planning aspects of developing offshore wind farms in the U.S. This course was offered on a pilot basis in 2011 at the University of Massachusetts and the National Renewable Energy Laboratory (NREL), TU Delft, and GL Garrad Hassan have reviewed its content. As summarized in this report, the course consists of 17 separate topic areas emphasizing appropriate engineering fundamentals as well as development, planning, and regulatory issues. In addition to the course summary, the report gives the details of a public Internet site where references and related course material can be obtained. This course will fill a pressing need for the education and training of the U.S. workforce in this critically important area. Fundamentally, this course will be unique due to two attributes: an emphasis on the engineering and technical aspects of offshore wind energy systems, and a focus on offshore wind energy issues specific to the United States.

  15. NREL Offshore Balance-of-System Model

    SciTech Connect

    Maness, Michael; Maples, Benjamin; Smith, Aaron

    2017-01-01

    The U.S. Department of Energy (DOE) has investigated the potential for 20% of nationwide electricity demand to be generated from wind by 2030 and, more recently, 35% by 2050. Achieving this level of wind power generation may require the development and deployment of offshore wind technologies. DOE (2008) has indicated that reaching these 2030 and 2050 scenarios could result in approximately 10% and 20%, respectively, of wind energy generation to come from offshore resources. By the end of 2013, 6.5 gigawatts of offshore wind were installed globally. The first U.S. project, the Block Island Wind Farm off the coast of Rhode Island, has recently begun operations. One of the major reasons that offshore wind development in the United States is lagging behind global trends is the high capital expenditures required. An understanding of the costs and associated drivers of building a commercial-scale offshore wind plant in the United States will inform future research and help U.S. investors feel more confident in offshore wind development. In an effort to explain these costs, the National Renewable Energy Laboratory has developed the Offshore Balance-of-System model.

  16. Offshore Fish Community: Ecological Interactions | Science ...

    EPA Pesticide Factsheets

    The offshore (>80 m) fish community of Lake Superior is made up of predominately native species. The most prominent species are deepwater sculpin, kiyi, cisco, siscowet lake trout, burbot, and the exotic sea lamprey. Bloater and shortjaw cisco are also found in the offshore zone. Bloater is abundant in the offshore zone but appears restricted to depths shallower than 150 m (Selgeby and Hoff 1996; Stockwell et al. 2010), although it occuppied greater depths several decades ago (Dryer 1966; Peck 1977). Shortjaw is relatively rare in the offshore zone (Hoff and Todd 2004; Gorman and Hoff 2009; Gorman and Todd 2007). Lake whitefish is also known to frequent bathymetric depths >100 m (Yule et al. 2008b). In this chapter, we develop a conceptual model of the offshore food web based on data collected during 2001-2005 and on inferences from species interactions known for the nearshore fish community. We then develop a framework for examination of energy and nutrient movements within the pelagic and benthic habitats of the offshore zone and across the offshore and nearshore zones. To document research results.

  17. A practical approach to fire hazard analysis for offshore structures.

    PubMed

    Krueger, Joel; Smith, Duncan

    2003-11-14

    Offshore quantitative risk assessments (QRA) have historically been complex and costly. For large offshore design projects, the level of detail required for a QRA is often not available until well into the detailed design phase of the project. In these cases, the QRA may be unable to provide timely hazard understanding. As a result, the risk reduction measures identified often come too late to allow for cost effective changes to be implemented. This forces project management to make a number of difficult or costly decisions. This paper demonstrates how a scenario-based approached to fire risk assessment can be effectively applied early in a project's development. The scenario or design basis fire approach calculates the consequence of a select number of credible fire scenarios, determines the potential impact on the platform process equipment, structural members, egress routes, safety systems, and determines the effectiveness of potential options for mitigation. The early provision of hazard data allows the project team to select an optimum design that is safe and will meet corporate or regulatory risk criteria later in the project cycle. The focus of this paper is on the application of the scenario-based approach to gas jet fires. This paper draws on recent experience in the Gulf of Mexico (GOM) and other areas to outline an approach to fire hazard analysis and fire hazard management for deep-water structures. The methods presented will include discussions from the recent June 2002 International Workshop for Fire Loading and Response.

  18. Plastic optical fibre sensor for damage detection in offshore structures

    NASA Astrophysics Data System (ADS)

    Kuang, K. S. C.; Koh, C. G.

    2009-12-01

    It is important to ensure the safe and reliable use of massive engineering structures such as offshore platforms, including all aspects of safety and design code compliance. Although routine inspection is an integral part of the safety protocol in operating and maintaining these structures, regular assessment of the effectiveness and efficiency of existing safety evaluation methods is clearly desired in view of emerging technologies for structural health monitoring of engineering structures. The recent advancement in plastic optical fibre (POF) materials and processing render POF sensors an attractive alternative to glass-based optical fibre sensors as they offer much greater being flexibility, high resistance to fracture and hence the ease in their handling and installation. In this paper, some preliminary results demonstrating the use of plastic optical fibre sensors for damage detection and structural health monitoring for offshore and marine-related applications will be summarized. In this study, POF will be used for crack detection in tubular steel specimens in conjunction with a high-resolution photon-counting optical time-domain reflectrometry (v-OTDR). Although the use of OTDR technique is an established method in the telecommunication industry, this study is new in that it is now possible, with the availability of v-OTDR and graded-index perfluorinated POF, to detect and locate the crack position in the host structure to within 10 cm accuracy or better. It will also be shown that this technique could readily be configured to monitor crack growth in steel tubular members.

  19. Plastic optical fibre sensor for damage detection in offshore structures

    NASA Astrophysics Data System (ADS)

    Kuang, K. S. C.; Koh, C. G.

    2010-03-01

    It is important to ensure the safe and reliable use of massive engineering structures such as offshore platforms, including all aspects of safety and design code compliance. Although routine inspection is an integral part of the safety protocol in operating and maintaining these structures, regular assessment of the effectiveness and efficiency of existing safety evaluation methods is clearly desired in view of emerging technologies for structural health monitoring of engineering structures. The recent advancement in plastic optical fibre (POF) materials and processing render POF sensors an attractive alternative to glass-based optical fibre sensors as they offer much greater being flexibility, high resistance to fracture and hence the ease in their handling and installation. In this paper, some preliminary results demonstrating the use of plastic optical fibre sensors for damage detection and structural health monitoring for offshore and marine-related applications will be summarized. In this study, POF will be used for crack detection in tubular steel specimens in conjunction with a high-resolution photon-counting optical time-domain reflectrometry (v-OTDR). Although the use of OTDR technique is an established method in the telecommunication industry, this study is new in that it is now possible, with the availability of v-OTDR and graded-index perfluorinated POF, to detect and locate the crack position in the host structure to within 10 cm accuracy or better. It will also be shown that this technique could readily be configured to monitor crack growth in steel tubular members.

  20. U. K. pressing campaign to improve offshore safety

    SciTech Connect

    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. 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.

  1. Undersea fiber optic technology for the offshore community

    SciTech Connect

    Mariano, J.J.

    1994-12-31

    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 offshore 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.

  2. Geology of offshore central California

    SciTech Connect

    McCulloch, D.S.; Lewis, S.D.

    1988-03-01

    The offshore central California margin records Mesozoic and Cenozoic events attributable to continental and oceanic plate interactions. Terranes, some carried thousands of kilometers northward on the Kula and/or Farallon plates, were accreted to North America by late Eocene. Following accretion to North America, terranes along the margin were silvered and redistributed by strike-slip motion along the San Andreas and related faults. During Oligocene global low sea level, much of the coastal margin was subareal and erosion stripped Upper Cretaceous and Eocene strata from elevated basement blocks. These basement blocks subsequently subsided along large-displacement near-coastal faults, and shallow-water marine upper Oligocene and/or lower Miocene volcanics on the present shelf were covered by hemipelagic sediment at bathyal to mid-bathyal depths. This subsidence coincided with tectonism and significant changes in water depth elsewhere around the Pacific margin, and may have been related to a change in Pacific and North American plate relative motion that produced transtensional motion along the California margin. Transtension may have initiated both rupture and volcanism along the San Andreas fault system at about 23 Ma and wrench tectonic deformation on the shelf. During the late Miocene, growing structural highs on the shelf edge formed elongate shelf basins. A compressional component in Pacific and North America plate relative motion, which began between 5 and 3 Ma, produced strike-parallel folds and compressional faults that now dominate the structural grain of the offshore basins. Continued compressive deformation along coastal California is documented by active thrust faults, rapid coastal uplift, and earthquake focal mechanism solutions indicative of northeast-southwest compression.

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

    SciTech Connect

    Perez La Salvia, H.; Schwartz, E.; Contreras, M.; Rodriguez, J.I.; Febres, G.; Gajardo, E.

    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) 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.

  4. Current and future offshore activities in Canada

    SciTech Connect

    Hnatiuk, J.

    1987-06-01

    The development of innovative exploratory drilling systems for Canada's harsh Arctic offshore areas over the past decade and future activity in these areas, including possible production concepts, are discussed. The results can be applied in other Arctic areas of the world, including offshore Alaska. This operating experience will advance technology and serve as a basis for the design of Arctic offshore production and transportation systems. Unique technology has been developed and successfully used in the discovery of major accumulations of hyrodcarbons. Continued technological advances are anticipated to have widespread Arctic applications in both exploratory and production operations.

  5. Offshore drilling to increase in 1984

    SciTech Connect

    Not Available

    1984-05-01

    A mid-year report presents a worldwide overview of offshore drilling operations. The Gulf of Mexico and the North Sea are posting substantial gains as companies rush to drill the millions of acres acquired in those sectors both last year and in previous offerings. The Middle East, Latin America and the Asia/Pacific offshore theaters will see only slight increases. The Mediterranean and African regions are expected to sustain declines. A region-by-region summary of the 1984 offshore forecast is presented showing exploration and appraisal activities, as well as development for all of these areas.

  6. Certification of offshore mooring steel wire ropes

    SciTech Connect

    Lohne, P.W.

    1996-12-31

    The trend to produce oil in increasingly deeper water has led to the development of floating production solutions for the exploitation of the energy resources in these areas. It is a fact that steel wire ropes have been used and are being proposed as line segments in the majority of the mooring systems of these units/ships. This paper specifies requirements for the materials, design, manufacture and testing of large diameter offshore mooring steel wire ropes and may serve as a technical reference document in contractual matters between the purchaser and the manufacturer. Typical applications covered are permanently moored floating production systems (FPS), offshore loading systems and mobile offshore units.

  7. Offshore drilling, construction: Fortunes tied to stable gas prices

    SciTech Connect

    Pagano, S.S.; Marsh, T.

    1993-01-01

    Significantly improved US natural gas prices fueled an upswing in offshore drilling in the Gulf of Mexico in late 1992. Stabilized gas prices will be necessary to support both the off-shore drilling and construction markets in 1993 and beyond. The article discusses both these segments in detail: offshore drilling and offshore construction.

  8. 76 FR 11503 - National Offshore Safety Advisory Committee; Vacancies

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-02

    ... offshore supply vessels or other vessels, of offshore mineral and oil operations including geophysical; (b... environmental interests; and, (e) One person representing enterprises specializing in offshore drilling. To be... SECURITY Coast Guard National Offshore Safety Advisory Committee; Vacancies AGENCY: Coast Guard,...

  9. Decision framework for platform decommissioning in California.

    PubMed

    Bernstein, Brock B

    2015-10-01

    This article describes the overall decision framework for eventual decisions about decommissioning the 27 operating oil and gas platforms offshore southern California. These platforms will eventually reach the end of their useful lifetimes (estimated between 2015 and 2030, although specific dates have not been determined). Current law and regulations allow for alternative uses in lieu of the complete removal required in existing leases. To prepare for eventual decommissioning, the California Natural Resources Agency initiated an in-depth process to identify and investigate issues surrounding possible decommissioning alternatives. The detailed evaluation of alternatives focused on 2-complete removal and artificial reefing that included partial removal to 85 feet below the waterline. These were selected after a comparison of the technical and economic feasibility of several potential alternatives, availability of a legal framework for implementation, degree of interest from proponents, and relative acceptance by state and federal decision makers. Despite California's history of offshore oil and gas production, only 7 decommissioning projects have been completed and these were all relatively small and close to shore. In contrast, nearly 30% of the California platforms are in water depths (as much as 1200 feet) that exceed any decommissioning project anywhere in the world. Most earlier projects considered an artificial reefing alternative but none were implemented and all platforms were completely removed. Future decisions about decommissioning must grapple with a more complex decision context involving greater technological and logistical challenges and cost, a wider range of viable options, tradeoffs among environmental impacts and benefits, and an intricate maze of laws, regulations, and authorities. The specific engineering differences between complete and partial removal provide an explicit basis for a thorough evaluation of their respective impacts.

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

    SciTech Connect

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

  11. Feasibility of Floating Platform Systems for Wind Turbines: Preprint

    SciTech Connect

    Musial, W.; Butterfield, S.; Boone, A.

    2003-11-01

    This paper provides a general technical description of several types of floating platforms for wind turbines. Platform topologies are classified into multiple- or single-turbine floaters and by mooring method. Platforms using catenary mooring systems are contrasted to vertical mooring systems and the advantages and disadvantages are discussed. Specific anchor types are described in detail. A rough cost comparison is performed for two different platform architectures using a generic 5-MW wind turbine. One platform is a Dutch study of a tri-floater platform using a catenary mooring system, and the other is a mono-column tension-leg platform developed at the National Renewable Energy Laboratory. Cost estimates showed that single unit production cost is $7.1 M for the Dutch tri-floater, and $6.5 M for the NREL TLP concept. However, value engineering, multiple unit series production, and platform/turbine system optimization can lower the unit platform costs to $4.26 M and $2.88 M, respectively, with significant potential to reduce cost further with system optimization. These foundation costs are within the range necessary to bring the cost of energy down to the DOE target range of $0.05/kWh for large-scale deployment of offshore floating wind turbines.

  12. Brent spar experience haunts N. Sea platform abandonments

    SciTech Connect

    Knott, D.

    1996-06-03

    This paper reviews the environmental conflicts that oil and gas industry officials have recently encountered in their attempts to abandon offshore platforms. It reviews the various governmental policies which are in effect in the North Sea area and the effect these policies have had on removal or deepsea disposal of these facilities. It provides a prospectus of soon to be abandoned facilities in the North Sea countries and a summary of removal operations in recent history.

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

    SciTech Connect

    Lohoefener, R.; Hoggard, W.; Mullin, K.; Roden, C.; Rogers, C.

    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 ranged 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.

  14. First comparison of LES of an offshore wind turbine wake with dual-Doppler lidar measurement in the offshore wind farm "alpha ventus"

    NASA Astrophysics Data System (ADS)

    Vollmer, L.; Trabucchi, D.; Witha, B.; van Dooren, M.; Trujillo, J. J.; Schneemann, J.; Kühn, M.

    2014-12-01

    The planning of offshore wind farms is still tainted with high risks due to unknown power losses and a higher level of fatigue loads due to wake effects. Recently, Large Eddy Simulations (LES) are more and more used for simulating offshore wind turbine wakes as they resolve the atmospheric turbulence as well as the wake turbulence.However, for an application of LES wind fields to assess offshore wind farm flow a proper validation with measured data is necessary.Several methods have been investigated at the University of Oldenburg to compare LES wind fields and lidar measurements. In this study we apply one of these methods to validate wake simulations of a single wake of a 5MW wind turbine in the German offshore wind farm "alpha ventus" with processed dual-Doppler lidar measurements in the same wind farm.The simulations are performed with the LES model PALM, which has been enhanced by two different approaches of actuator models to simulate the wake of single wind turbines and the interaction of wakes in wind farms. Effects of tower and nacelle are regarded as well as simple turbine control mechanisms. The simulations are initialized with comparable atmospheric conditions as during the time of lidar operation by using measurements from the adjacent meteorological mast FINO 1.Plan Position Indicator (PPI) measurements have been performed with two long-range wind lidars installed at different opposing platforms at the border of the wind farm. A Cartesian grid was overlapped to the scanned region and a dual-Doppler algorithm was applied in order to estimate the horizontal stationary wind field on the grid nodes. To our knowledge, the presented study is one of the first validations of LES wake simulations with lidar measurements and first which validates offshore LES wake simulations with 2D lidar data.

  15. 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

  16. Offshore oil in the Alaskan Arctic

    NASA Technical Reports Server (NTRS)

    Weeks, W. F.; Weller, G.

    1984-01-01

    Oil and gas deposits in the Alaskan Arctic are estimated to contain up to 40 percent of the remaining undiscovered crude oil and oil-equivalent natural gas within U.S. jurisdiction. Most (65 to 70 percent) of these estimated reserves are believed to occuur offshore beneath the shallow, ice-covered seas of the Alaskan continental shelf. Offshore recovery operations for such areas are far from routine, with the primary problems associated with the presence of ice. Some problems that must be resolved if efficient, cost-effective, environmentally safe, year-round offshore production is to be achieved include the accurate estimation of ice forces on offshore structures, the proper placement of pipelines beneath ice-produced gouges in the sea floor, and the cleanup of oil spills in pack ice areas.

  17. Offshore oil in the alaskan arctic.

    PubMed

    Weeks, W F; Weller, G

    1984-07-27

    Oil and gas deposits in the Alaskan Arctic are estimated to contain up to 40 percent of the remaining undiscovered crude oil and oil-equivalent nature gas within U.S. jurisdiction. Most (65 to 70 percent) of these estimated reserves are believed to occur offshore beneath the shallow, ice-covered seas, of the Alaskan continental shelf. Offshore recovery operations for such areas are far from routine, with the primary problems associated with the presence of ice. Some problems that must be resolved if efficient, cost-effective, environmentally safe, year-round offshore production is to be achieved include the accurate estimation of ice forces on offshore structures, the proper placement of pipelines beneath ice-produced gouges in the sea floor, and the cleanup of oil spills in pack ice areas.

  18. Civil engineering in the Arctic offshore

    SciTech Connect

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

    1985-01-01

    This book presents the current state of practice and theory in the civil engineering aspects of offshore development in the Arctic. It also covers the emerging concepts and requirements, research and development needs, and a critique of present undergraduate programmes.

  19. Engineering Challenges for Floating Offshore Wind Turbines

    SciTech Connect

    Butterfield, S.; Musial, W.; Jonkman, J.; Sclavounos, P.

    2007-09-01

    The major objective of this paper is to survey the technical challenges that must be overcome to develop deepwater offshore wind energy technologies and to provide a framework from which the first-order economics can be assessed.

  20. 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.

  1. New perspectives in offshore wind energy

    PubMed Central

    Failla, Giuseppe; Arena, Felice

    2015-01-01

    The design of offshore wind turbines is one of the most fascinating challenges in renewable energy. Meeting the objective of increasing power production with reduced installation and maintenance costs requires a multi-disciplinary approach, bringing together expertise in different fields of engineering. The purpose of this theme issue is to offer a broad perspective on some crucial aspects of offshore wind turbines design, discussing the state of the art and presenting recent theoretical and experimental studies. PMID:25583869

  2. New perspectives in offshore wind energy.

    PubMed

    Failla, Giuseppe; Arena, Felice

    2015-02-28

    The design of offshore wind turbines is one of the most fascinating challenges in renewable energy. Meeting the objective of increasing power production with reduced installation and maintenance costs requires a multi-disciplinary approach, bringing together expertise in different fields of engineering. The purpose of this theme issue is to offer a broad perspective on some crucial aspects of offshore wind turbines design, discussing the state of the art and presenting recent theoretical and experimental studies.

  3. Arctic offshore drilling: a new challenge

    SciTech Connect

    Wetmore, S.B.

    1985-11-01

    The arctic offshore environment provides the drilling industry with its greatest challenge yet. Problems due to sea ice, high wind, extreme cold and poor bottom soil have required the design of special structures appropriate only for arctic offshore drilling. The challenge lies not just in the obvious factors of temperature and ice, but also the basic physics of ice problems are not well understood. The arctic environment and the petroleum industry are discussed.

  4. 2014 Offshore Wind Market and Economic Analysis

    SciTech Connect

    Hamilton, Bruce

    2014-08-25

    The objective of this report is to provide a comprehensive annual assessment of the U.S. offshore wind market.This 3rd annual report focuses on new developments that have occurred in 2014. The report provides stakeholders with a reliable and consistent data source addressing entry barriers and U.S. competitiveness in the offshore wind market. Available for download are both the full report and the report's underlying data.

  5. Arctic and offshore research. Technology status report

    SciTech Connect

    Not Available

    1985-10-01

    DOE's Morgantown Energy Technology Center (METC) and the DOE Fossil Energy Office of Oil, Gas, and Shale Technology are performing the following activities in Arctic and Offshore Research (AOR): (1) AOR Energy-Related Technology Data Base Development; (2) AOR seminars and workshops; (3) Arctic and Offshore Energy Research Coordination; (4) Arctic and Offshore Research which includes analysis of ice island generation, and prediction of drift paths; field and laboratory determination of (1) the engineering properties of multiyear ice, and (2) the interaction of multiyear ice with offshore structures; analysis of ice gouging in deep water (150 to 210 feet) in the Arctic Ocean, and numerical simulation modeling of the gouging process; analysis of the location and origin of the ice-ridging shear zone; analysis of sea-ice thickness using airborne radar sensing techniques; improvement of permafrost detection techniques, and analysis of permafrost characteristics; investigation of the effects of ice accretion and corrosion on offshore structures; measurements of seismic acceleration and velocity for analyzing vibration in and stability of off-shore structures; detection of oil spills that occur below the Arctic ice pack; analysis of the effects of frost heave and corrosion on pipelines; (5) Advanced Recovery Technologies; and (6) Subice Systems Development. Current activities include determining the Arctic bibliographic data base and initiating most of the research described above (except multiyear ice properties, pipeline research, and subice systems development). 10 refs., 15 figs., 3 tabs.

  6. Nonlinear coupled dynamics analysis of a truss spar platform

    NASA Astrophysics Data System (ADS)

    Li, Cheng-xi; Zhang, Jun

    2016-12-01

    Accurate prediction of the offshore structure motion response and associate mooring line tension is important in both technical applications and scientific research. In our study, a truss spar platform, operated in Gulf of Mexico, is numerically simulated and analyzed by an in-house numerical code `COUPLE'. Both the platform motion responses and associated mooring line tension are calculated and investigated through a time domain nonlinear coupled dynamic analysis. Satisfactory agreement between the simulation and corresponding field measurements is in general reached, indicating that the numerical code can be used to conduct the time-domain analysis of a truss spar interacting with its mooring and riser system. Based on the comparison between linear and nonlinear results, the relative importance of nonlinearity in predicting the platform motion response and mooring line tensions is assessed and presented. Through the coupled and quasi-static analysis, the importance of the dynamic coupling effect between the platform hull and the mooring/riser system in predicting the mooring line tension and platform motions is quantified. These results may provide essential information pertaining to facilitate the numerical simulation and design of the large scale offshore structures.

  7. Fitness to work: a comparison of European guidelines in the offshore wind industry.

    PubMed

    Preisser, Alexandra Marita; McDonough, Rosalie Victoria; Harth, Volker

    2016-01-01

    Occupational medicine must be able to meet the challenges of rapidly changing technologies and innovations, including the implementation of health and safety standards for physically and psychologically demanding work environments. One such challenge is presented by the offshore wind industry. Here, the demand for "Fitness to Work" regulations for potential employees is justified. An appropriate evaluation has to consider the two aspects "fit for task" and "fit for location and conditions". Guidelines for the fitness testing of offshore employees have been created by various national organisations. The guidelines of the industry organisations of the United Kingdom (Oil & Gas UK) and the Netherlands (NOGEPA), as well as the Norwegian Directorate of Health, were developed for employees of offshore oil and gas platforms. In Germany, however, a medical guideline for fitness testing specific to workers in the offshore wind industry has recently been created. Such recommendations should be made on the basis of accident statistics and rescue reports, but there are only limited data available. In this paper, we present, compare and discuss the content and features of the various guidelines, as well as their recommendations for medical assessment.

  8. Problems unique to offshore measurement

    SciTech Connect

    Young, J.G.

    1995-12-01

    Most of us have arrived at this meeting in some kind of company provided transportation. This is supplied in order for us to do our assigned jobs. These may be trucks, or cars, or even helicopters, and maybe boats. All who are involved in the offshore industry know that transportation is the cost costly of all. The helicopter bill for our company is a bill which costs us somewhere in the 9 million dollar range. Since this costs us so much, we are constantly looking at ways to reduce this. The helicopters we use cost us $510.00 a flying hour plus $28,000.00 a month for lease. These helicopters fly in the neighborhood of 140 miles per hour. You can quickly see how fast the cost can climb. We have two technicians, along with a pilot, and approx. 400 lbs of test gear and spare parts. You have to carry all you think you will need for the day`s activities because it`s a long and costly trip to go pick up some gasket material or an orifice plate.

  9. Norwegian Offshore Stratigraphic Lexicon (NORLEX)

    NASA Astrophysics Data System (ADS)

    Gradstein, Felix M.; Hammer, Oyvind; Brunstad, Harald; Charnock, Mike; Hellem, Terje; Sigve Lervik, Kjell; Anthonissen, Erik

    2010-05-01

    The Norwegian Offshore Stratigraphic Lexicon (NORLEX) provides a relational stratigraphic database for the North Sea, Norwegian Sea, Barents Sea and Svalbard. Both regional lithostratigraphy and biostratigraphy are being substantially updated, following guidelines laid out in the International Stratigraphic Guide. The main body of information developed is available as a petroleum consortium (oracle-style) database, and the new lithostratigraphic definitions as a public domain (paper) document. NORLEX is presented as a browsing website via the internet at http://www.nhm.uio.no/norlex. Seismic cross-sections, core photographs, well logs, field outcrops, microfossil occurrences and other vital attributes are relationally cross-linked. In addition, there are menus for instantly finding updated formation and member tops or microfossil events in all wells, plus a map contouring routine for unit thicknesses and depths. Several new initiatives will expand data and user coverage: 1. Overhaul of Mesozoic stratigraphy, especially Triassic and Cretaceous, in the Barents Sea. 2. Coverage of East Greenland 3. Linkage to UK and Belgium and The Netherlands surface and subsurface stratigraphy 4. Creation of a Sequence Stratigraphic Framework for specific regions. 5. A national microfossil atlas to support zonations 6. Tight linkage to the basin datapacks in TimeScaleCreator Pro, as developed for Australia, New Zealand, Brasil, Gulf of Mexico, Canada and Russia. NORLEX may thus evolve to become STRATLEX, covering many basin regions.

  10. Medical evacuations from offshore structures.

    PubMed

    Norman, J N; Ballantine, B N; Brebner, J A; Brown, B; Gauld, S J; Mawdsley, J; Roythorne, C; Valentine, M J; Wilcock, S E

    1988-09-01

    A retrospective study was carried out on medical evacuations from the installations of four major oil or gas producing companies, or both, operating offshore on the United Kingdom continental shelf. The study covered 1976-84 during which 2162 evacuations were recorded. Of these, 137 (7.7%) required the use of a chartered helicopter. In the earlier years of the study there were substantially more injuries sustained than episodes of illness recorded but from 1980 onwards the cases of illness equalled those of injury. Using the International Classification of Diseases, the digestive system was responsible for most evacuations for illness and of those, about half (115 evacuations) were for dental problems. Suspected fractures were responsible for about one third of those evacuated for an injury but injuries of hands and eye conditions were particularly common, accounting for 25% of all evacuations. As the age of the evacuee increased the proportion of evacuations for injury decreased and that for illness increased. The mean age for evacuation for injury was 28.3 years and for illness 34.4 years. Few evacuations were required for those aged over 45.

  11. Offshore oil and the coastline

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    A radical, accelerated 5-year plan to offer 875 million acres (of which 20 million could actually be leased for oil and gas extraction purposes) on the outer continental shelf (OCS) could result in the release of large volumes of drilling wastes and spillage (Environ. Sci. Tech., Nov. 1981). The actual leasing, under the 5-year plan proposed by Secretary of the Interior James G. Watt, could amount to 4-5 million acres per year—about 10 times as much, on the average, as had been leased over the past 25 years. Regulations on the environmental effects may be less complicated yet more effective in that impact statements will cover large areas instead of the tract-by-tract statements now required. A number of the new offshore leasing areas, for example, the Alaska Coast (Cook Inlet, Beaufort Bay, Gulf of Alaska), the Blake Plateau and Baltimore Canyon, and the Georges Bank, are extremely valuable in terms of renewable resources and potentially fragile in terms of environmental conditions. Fishing interests in these areas have produced considerable controversy over the planned sale of petroleum rights.

  12. 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.

    2014-11-01

    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.

  13. Calibration and Validation of a Spar-Type Floating Offshore Wind Turbine Model using the FAST Dynamic Simulation Tool: Preprint

    SciTech Connect

    Browning, J. R.; Jonkman, J.; Robertson, A.; Goupee, A. J.

    2012-11-01

    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 1/50th scale 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.

  14. Submarine landslides hazard offshore Israel

    NASA Astrophysics Data System (ADS)

    Katz, Oded

    2016-04-01

    Submarine landslides pose significant natural hazards. They can damage seafloor infrastructure, such as that used to recover oil and gas or seafloor telecommunication cables, and even generate tsunamis. We recently mapped 447 submarine landslides across the east Mediterranean continental slope, offshore Israel (hereafter the studied area). The mapped landslides are found at water depths of 130 m to 1,000 m and their volume ranges 10-5 - 100 km3. Landslide scars are typically related to a critical slope angle of >4° . Landslides at the northern part of the studied area are spatially associated with fault scarps and are smaller than the ones on the southern part. In this work we evaluate the potential hazard to population and to on- and off- shore facilities posed by submarine landslides across the studied area. We integrate three independent probabilities: (1) the probability for a landslide event of a given volume, based on the size distribution of the mapped landslides; (2) the probability for a landslide event in a given time, based on the reoccurrence time of triggering earthquakes with M >7, and on a 50,000 years general time frame derived from submarine landslides identified across the Mediterranean Sea; (3) the probability for a landslide event in a given area, based on the distribution of slopes exceeding the critical angle. Overall, the fraction of potentially destructive landslides (size > 0.1 km3) is small, 0.05. Thus, considering typical planning time scales of less than 100 years, the calculated hazard is only moderate. The small fraction of landslides with tsunamogenic potential (size > 1 km3), suggests that the hazard for landslide-induced tsunamis along the open slope part of the studied area is small. Landslides in the southern part of the studied area are larger and thus present a somewhat bigger potential source of tsunami waves.

  15. 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.

  16. 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.

  17. Offshore oil gas trends in ROVs tooling

    SciTech Connect

    Jacobson, J.R. )

    1994-04-01

    The ROVs that operate in today's offshore environment bear little or no resemblance to those which first began supporting the oil and gas work requirements less than 15 years ago. In that short span of time, an explosion of subsea technology has occurred, rendering older equipment obsolete and expanding subsea remote intervention capabilities beyond the horizon of intervention tasks originally envisioned. Today's offshore work ROVs employ the latest in robotics, fiver optics, acoustics, video, and computer technologies, and routinely achieve better than 90 percent operational availability. Leading offshore ROV operations companies have demonstrated less than 1 percent down-time over thousands of hours of operation. As the offshore oil and gas market evolves, the ever-expanding capabilities of the work ROV plays a major role in shaping the operational concepts employed in subsea oil and gas field exploration, development, and production. This paper explores the capabilities of available ROV systems in use offshore today, the economic trends driving ROV technology development, and the new trends in the employment of ROVs and their associated sensors and tooling systems.

  18. Operational management of offshore energy assets

    NASA Astrophysics Data System (ADS)

    Kolios, A. J.; Martinez Luengo, M.

    2016-02-01

    Energy assets and especially those deployed offshore are subject to a variety of harsh operational and environmental conditions which lead to deterioration of their performance and structural capacity over time. The aim of reduction of CAPEX in new installations shifts focus to operational management to monitor and assess performance of critical assets ensuring their fitness for service throughout their service life and also to provide appropriate and effective information towards requalification or other end of life scenarios, optimizing the OPEX. Over the last decades, the offshore oil & gas industry has developed and applied various approaches in operational management of assets through Structural Health and Condition Monitoring (SHM/CM) systems which can be, at a certain level, transferable to offshore renewable installations. This paper aims to highlight the key differences between offshore oil & gas and renewable energy assets from a structural integrity and reliability perspective, provide a comprehensive overview of different approaches that are available and applicable, and distinguish the benefits of such systems in the efficient operation of offshore energy assets.

  19. A framework for offshore vendor capability development

    NASA Astrophysics Data System (ADS)

    Yusuf Wibisono, Yogi; Govindaraju, Rajesri; Irianto, Dradjad; Sudirman, Iman

    2016-02-01

    Offshore outsourcing is a common practice conducted by companies, especially in developed countries, by relocating one or more their business processes to other companies abroad, especially in developing countries. This practice grows rapidly owing to the ease of accessing qualified vendors with a lower cost. Vendors in developing countries compete more intensely to acquire offshore projects. Indonesia is still below India, China, Malaysia as main global offshore destinations. Vendor capability is among other factors that contribute to the inability of Indonesian vendor in competing with other companies in the global market. Therefore, it is essential to study how to increase the vendor's capability in Indonesia, in the context of global offshore outsourcing. Previous studies on the vendor's capability mainly focus on capabilities without considering the dynamic of capabilities due to the environmental changes. In order to be able to compete with competitors and maintain the competitive advantage, it is necessary for vendors to develop their capabilities continuously. The purpose of this study is to develop a framework that describes offshore vendor capability development along the client-vendor relationship stages. The framework consists of three main components, i.e. the stages of client-vendor relationship, the success of each stage, and the capabilities of vendor at each stage.

  20. New OBS network deployment offshore Ireland

    NASA Astrophysics Data System (ADS)

    Le Pape, Florian; Bean, Chris; Craig, David; Jousset, Philippe; Horan, Clare; Hogg, Colin; Donne, Sarah; McCann, Hannah; Möllhoff, Martin; Kirk, Henning; Ploetz, Aline

    2016-04-01

    With the presence of the stormy NE Atlantic, Ireland is ideally located to investigate further our understanding of ocean generated microseisms and use noise correlation methods to develop seismic imaging in marine environments as well as time-lapse monitoring. In order to study the microseismic activity offshore Ireland, 10 Broad Band Ocean Bottom Seismographs (OBSs) units including hydrophones have been deployed in January 2016 across the shelf offshore Donegal and out into the Rockall Trough. This survey represents the first Broadband passive study in this part of the NE Atlantic. The instruments will be recovered in August 2016 providing 8 months worth of data to study microseisms but also the offshore seismic activity in the area. One of the main goal of the survey is to investigate the spatial and temporal distributions of dominant microseism source regions, close to the microseism sources. Additionally we will study the coupling of seismic and acoustic signals at the sea bed and its evolution in both the deep water and continental shelf areas. Furthermore, the survey also aims to investigate further the relationship between sea state conditions (e.g. wave height, period), seafloor pressure variations and seismic data recorded on both land and seafloor. Finally, the deployed OBS network is also the first ever attempt to closely monitor local offshore earthquakes in Ireland. Ireland seismicity although relatively low can reduce slope stability and poses the possibility of triggering large offshore landslides and local tsunamis.

  1. The industrial RB211-24 gas engine: initial experience in service offshore

    SciTech Connect

    Soinne, P.E.

    1983-01-01

    The Industrial RB211 gas engine is derived from the RB211 turbofan aero engine which in its various marks powers all Lockheed Tristars and a proportion of Boeing 747 airliners. The design and development programme of the industrial engine commenced in 1972. It arose out of an earlier feasibility study for a second generation marine propulsion engine. The industrial programme was specifically aimed at the production of a gas-fuelled base load machine for gas pumping and transmission applications. The engine was designated the Industrial RB211-22, being derived from the RB211-22 aero engine, the single mark of engine available at that time. The first field trials gas generator entered service in late 1974 in a transmission pipeline gas pumping application in Canada. Since then the RB211-22 engine has accumulated over 140,000 hours of operation in twelve onshore installations. Design and development of an uprated version of the engine began in early 1976. This was designated RB211-24, since it utilized the improved turbine technology of the RB211-524 aero engine introduced for the Boeing 747 and later versions of Tristar. With offshore applications in mind, the validation of improved corrosion resistant turbine materials was an integral part of the development programme. In consequence of this, the engine was available for both offshore and onshore applications as released for production. The first RB211-24 engines entered service in late 1980 in offshore applications on the Leman AK platform and another North Sea Gas production platform. There are now a total of fifteen RB211-24 installations which have accumulated over 53,000 hours of operation both onshore and offshore.

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

    NASA Astrophysics Data System (ADS)

    Archer, Cristina L.; Colle, Brian A.; Veron, Dana L.; Veron, Fabrice; Sienkiewicz, Matthew J.

    2016-08-01

    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 new 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.

  3. Current and future offshore activities in Canada

    SciTech Connect

    Hnatiuk, J.

    1984-05-01

    The development of innovative exploratory drilling systems for Canada's harsh Arctic offshore areas over the past decade is described. Future activity in these areas, including possible production concepts, is also discussed. The results of the experience in Canadian waters can be applied in other Arctic areas of the world including offshore Alaska. This operating experience will serve to further advance the drilling technology and will serve as a basis for the design of Arctic offshore production and transportation systems. Artificial islands, first commenced in 1972, are still being constructed but with improved designs and equipment. A step forward has been the use of subsea berms on which concrete or steel segmented caissons have been placed. Integrated-type steel caissons have also been adapted for placement on subsea berms, one of which is half of a crude oil tanker and a second, a purpose-built steel caisson to be placed this summer.

  4. Solar power satellite offshore rectenna study

    NASA Astrophysics Data System (ADS)

    1980-05-01

    Offshore rectennas are feasible and cost competitive with land rectennas but the type of rectenna suitable for offshore use is quite different from that specified in the present reference system. A nonground plane design minimizes the weight and greatly reduces the number of costly support towers. This perferred design is an antenna array consisting of individually encapsulated dipoles with reflectors or tagis supported on feed wires. Such a 5 GW rectenna could be built at a 50 m water depth site to withstand hurricane, winter storm, and icing conditions for a one time cost of $5.7 billion. Subsequent units would be about 1.3 less expensive. More benign and more shallow water sites would result in substantially lower costs. The major advantage of an offshore rectenna is the removal of microwave radiation from populated areas.

  5. Federal offshore statistics: leasing - exploration - production - revenue

    SciTech Connect

    Essertier, E.P.

    1984-01-01

    Federal Offshore Statistics is a numerical record of what has happened since Congress gave authority to the Secretary of the Interior in 1953 to lease the Federal portion of the Continental Shelf for oil and gas. The publication updates and augments the first Federal Offshore Statistics, published in December 1983. It also extends a statistical series published annually from 1969 until 1981 by the US Geological Survey (USGS) under the title Outer Continental Shelf Statistics. The USGS collected royalties and supervised operation and production of minerals on the Outer Continental Shelf (OCS) until the Minerals Management Service (MMS) took over these functions in 1982. Statistics are presented under the following topics: (1) highlights, (2) leasing, (3) exploration and development, (4) production and revenue, (5) federal offshore production by ranking operator, 1983, (6) reserves and undiscovered recoverable resources, and (7) oil pollution in the world's oceans.

  6. Solar power satellite offshore rectenna study

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Offshore rectennas are feasible and cost competitive with land rectennas but the type of rectenna suitable for offshore use is quite different from that specified in the present reference system. A nonground plane design minimizes the weight and greatly reduces the number of costly support towers. This perferred design is an antenna array consisting of individually encapsulated dipoles with reflectors or tagis supported on feed wires. Such a 5 GW rectenna could be built at a 50 m water depth site to withstand hurricane, winter storm, and icing conditions for a one time cost of $5.7 billion. Subsequent units would be about 1.3 less expensive. More benign and more shallow water sites would result in substantially lower costs. The major advantage of an offshore rectenna is the removal of microwave radiation from populated areas.

  7. Federal Offshore Statistics, 1993. Leasing, exploration, production, and revenue as of December 31, 1993

    SciTech Connect

    Francois, D.K.

    1994-12-31

    This document contains statistical data on the following: federal offshore lands; offshore leasing activity and status; offshore development activity; offshore production of crude oil and natural gas; federal offshore oil and natural gas sales volume and royalties; revenue from federal offshore leases; disbursement of federal offshore revenue; reserves and resource estimates of offshore oil and natural gas; oil pollution in US and international waters; and international activities and marine minerals. A glossary is included.

  8. The 1911 Quadrant offshore Namibia; Exploration in a virgin basin

    SciTech Connect

    Holtar, E.; Forsberg, A.

    1995-08-01

    As a result of the first licensing round in independent Namibia, the Namibian authorities in 1992 awarded five offshore licenses to five different companies or groups of companies. License no. 001 was awarded in 1992 to a group consisting of three Norwegian oil companies, Norsk Hydro, Saga Petroleum and Statoil, with Hydro as the operator. Somewhat later Bow Valley Energy (now Talisman Energy) farmed in. Since 1992 a seismic survey of 7200 km has been acquired over the license area that covers 11.619 sq. Km of the Walvis Basin. This basin was undrilled until the 1911/15-1 well was finished at a depth of 4586mRKB in early 1994. The sedimentary succession of the 1911/15-1 well reflects a depositional history that postdates the Neocorman Etendeka plateau basalts found onshore Namibia. After the onset of the drift phase in late Hauterivian times, the Walvis Basin subsided and eventually a marine transgression took place. Shallow marine platform sedimentation then prevailed until an Albian tectonic event resulted in complex block faulting and the formation of several sub basins. Subsequent volcanic activity created a series of volcanic centres localized on the Walvis Ridge bathymetric feature. In early Late Cretaceous the Southern African craton was uplifted relative to the shelf, leading to the formation of large scale westward prograding wedges. Later sedimentation largely followed the evolution of a passive continental margin, responding to relative sealevel changes and paleoclimate. A stratigraphic breakdown of the Northern Namibian offshore is proposed, and compared to South African and Angolan nomenclature.

  9. National Offshore Wind Energy Grid Interconnection Study Executive Summary

    SciTech Connect

    Daniel, John P.; Liu, Shu; Ibanez, Eduardo; Pennock, Ken; Reed, Gregory; Hanes, Spencer

    2014-07-30

    The National Offshore Wind Energy Grid Interconnection Study (NOWEGIS) considers the availability and potential impacts of interconnecting large amounts of offshore wind energy into the transmission system of the lower 48 contiguous United States.

  10. Strengthening America's Energy Security with Offshore Wind (Fact Sheet)

    SciTech Connect

    Not Available

    2012-02-01

    This fact sheet describes the current state of the offshore wind industry in the United States and the offshore wind research and development activities conducted the U.S. Department of Energy Wind and Water Power Program.

  11. 75 FR 80064 - National Offshore Safety Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-21

    ... oil and gas offshore industry. The purpose of this meeting is to review and discuss reports and... other concerns affecting the offshore oil and gas industry and assists the Coast Guard in formulating...

  12. 76 FR 3919 - National Offshore Safety Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-21

    ... safety of operations and other matters affecting the oil and gas offshore industry. The purpose of this... Coast Guard on safety and other concerns affecting the offshore oil and gas industry and assists...

  13. National Offshore Wind Energy Grid Interconnection Study Full Report

    SciTech Connect

    Daniel, John P.; Liu, Shu; Ibanez, Eduardo; Pennock, Ken; Reed, Gregory; Hanes, Spencer

    2014-07-30

    The National Offshore Wind Energy Grid Interconnection Study (NOWEGIS) considers the availability and potential impacts of interconnecting large amounts of offshore wind energy into the transmission system of the lower 48 contiguous United States.

  14. Effects of wave induced motion on power generation of offshore floating wind farms

    NASA Astrophysics Data System (ADS)

    Shoele, Kourosh

    2014-11-01

    Wind power has been the world's fastest growing energy source for more than a decade. There is a continuous effort to study the potentials of offshore floating wind farms in producing electricity. One of the major technical challenges in studying the performance of offshore floating wind farms is the hydrodynamic and aerodynamic interactions between individual turbines. In this study, a novel approach is presented to study the hydrodynamic interaction between group of floating wind turbines and determine how wave induced motion of the platforms modifies the power generation of the farm. In particular, exact analytical models are presented to solve the hydrodynamic diffraction and radiation problem of a group of floating wind turbine platforms, to model the aerodynamic interaction between turbines, and to quantify the nonlinear dynamic of the mooring lines used to stabilize the floating platforms through connecting them to the seabed. The overall performance of the farm with different configuration and at different wind and wave conditions are investigated and the effects of the sea state condition as well as the distance between the turbines in the farm on the low frequency temporal variation of the power output are discussed.

  15. Regional method to assess offshore slope stability.

    USGS Publications Warehouse

    Lee, H.J.; Edwards, B.D.

    1986-01-01

    The slope stability of some offshore environments can be evaluated by using only conventional acoustic profiling and short-core sampling, followed by laboratory consolidation and strength testing. The test results are synthesized by using normalized-parameter techniques. The normalized data are then used to calculate the critical earthquake acceleration factors or the wave heights needed to initiate failure. These process-related parameters provide a quantitative measure of the relative stability for locations from which short cores were obtained. The method is most applicable to offshore environments of gentle relief and simple subsurface structure and is not considered a substitute for subsequent site-specific analysis. -from ASCE Publications Information

  16. Offshore Wind Power Integration in severely fluctuating Wind Conditions

    NASA Astrophysics Data System (ADS)

    von Bremen, L.

    2010-09-01

    Strong power fluctuations from offshore wind farms that are induced by wind speed fluctuations pose a severe problem to the save integration of offshore wind power into the power supply system. Experience at the first large-scale offshore wind farm Horns Rev showed that spatial smoothing of power fluctuations within a single wind farm is significantly smaller than onshore results suggest when distributed wind farms of 160 MW altogether are connected to a single point of common-coupling. Wind power gradients larger than 10% of the rated capacity within 5 minutes require large amount of regulation power that is very expensive for the grid operator. It must be noted that a wind speed change of only 0.5m/s result in a wind power change of 10% (within the range of 9-11 m/s where the wind power curve is steepest). Hence, it is very important for the grid operator to know if strong fluctuations are likely or not. Observed weather conditions at the German wind energy research platform FINO1 in the German bight are used to quantify wind fluctuations. With a standard power curve these wind fluctuations are transfered to wind power. The aim is to predict the probability of exceedence of certain wind power gradients that occur in a time interval of e.g. 12 hours. During 2006 and 2009 the distribution of wind power fluctuations looks very similar giving hope that distinct atmospheric processes can be determined that act as a trigger. Most often high wind power fluctuations occur in a range of wind speeds between 9-12 m/s as can be expected from the shape of the wind power curve. A cluster analysis of the 500 hPa geopotential height to detect predominant weather regimes shows that high fluctuations are more likely in north-western flow. It is shown that most often high fluctuations occur in non-stable atmospheric stratification. The description of stratification by means of the vertical gradient of the virtual potential temperature is chosen to be indicative for convection, i

  17. Geomechanical Performance of Hydrate-Bearing Sediment in Offshore Environments

    SciTech Connect

    Stephen Holditch; Tad Patzek; Jonny Rutqvist; George Moridis; Richard Plumb

    2008-03-31

    The objective of this multi-year, multi-institutional research project was to develop the knowledge base and quantitative predictive capability for the description of geomechanical performance of hydrate-bearing sediments (hereafter referred to as HBS) in oceanic environments. The focus was on the determination of the envelope of hydrate stability under conditions typical of those related to the construction and operation of offshore platforms. We have developed a robust numerical simulator of hydrate behavior in geologic media by coupling a reservoir model with a commercial geomechanical code. We also investigated the geomechanical behavior of oceanic HBS using pore-scale models (conceptual and mathematical) of fluid flow, stress analysis, and damage propagation. The objective of the UC Berkeley work was to develop a grain-scale model of hydrate-bearing sediments. Hydrate dissociation alters the strength of HBS. In particular, transformation of hydrate clusters into gas and liquid water weakens the skeleton and, simultaneously, reduces the effective stress by increasing the pore pressure. The large-scale objective of the study is evaluation of geomechanical stability of offshore oil and gas production infrastructure. At Lawrence Berkeley National Laboratory (LBNL), we have developed the numerical model TOUGH + Hydrate + FLAC3D to evaluate how the formation and disassociation of hydrates in seafloor sediments affects seafloor stability. Several technical papers were published using results from this model. LBNL also developed laboratory equipment and methods to produce realistic laboratory samples of sediments containing gas hydrates so that mechanical properties could be measured in the laboratory. These properties are required to run TOUGH + Hydrate + FLAC3D to evaluate seafloor stability issues. At Texas A&M University we performed a detailed literature review to determine what gas hydrate formation properties had been measured and reported in the literature. We

  18. Cyrenaican platform: structure, stratigraphy, and exploration play concepts

    SciTech Connect

    Ross, C.M.; Zegaar, M.N.

    1985-02-01

    The structural and stratigraphic history of the Cyrenaican platform of eastern Libya is closely related to that of both the Sirte basin and the Western Desert of Egypt. At the end of the Paleozoic Hercynian orogeny, this area comprised the eastern end of the Sirte arch, the precursor of the Sirte basin. When the arch collapsed in the mid-Cretaceous, initiating the Sirte basin, the Cyrenaican area remained relatively high. A northwest-southeast trending high, the Gabboub arch, formed on the platform in the early Mesozoic, dividing the region into three areas: the high itself, a deep on the southwestern flank related to the Sirte basin, and a deep on the northeastern flank, which plunges into the offshore and appears to relate to the downwarped offshore area of the Western Desert of Egypt. Sediments of every age, except Triassic, are found in Cyrenaica. Paleozoic sediments are composed primarily of quartzitic sandstones and shales with lesser amounts of limestone, dolomites, and anhydrites. Mesozoic sediments are a mixture of clastics and carbonates. Cenozoic sediments are predominantly limestones, dolomites, and anhydrites with some sandstones and shales. Environments of deposition range from continental to deep marine. The Cyrenaican area has not been heavily explored and, until recently, no commercial hydrocarbons were found. Drilling on surface structures of some of the first wells in Libya resulted in one Devonian gas well. A reported 5600 BOPD Cretaceous discovery offshore Benghazi in mid-1984 demonstrates that hydrocarbon potential exists where thick sediments have been preserved.

  19. Floor Plans Engine Removal Platform, Hold Down Arm Platform, ...

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

    Floor Plans - Engine Removal Platform, Hold Down Arm Platform, Hydraulic Equipment Platforms, Isometric Cutaway of Engine Removal Platform, Isometric Cutaway of Hold Down Arm Platform, Isometric Cutaway of Hydraulic Platforms and Engine Support System Access - Marshall Space Flight Center, Saturn V S-IC Static Test Facility, West Test Area, Huntsville, Madison County, AL

  20. United States Offshore Wind Resource Assessment

    NASA Astrophysics Data System (ADS)

    Schwartz, M.; Haymes, S.; Heimiller, D.

    2008-12-01

    The utilization of the offshore wind resource will be necessary if the United States is to meet the goal of having 20% of its electricity generated by wind power because many of the electrical load centers in the country are located along the coastlines. The United States Department of Energy, through its National Renewable Energy Laboratory (NREL), has supported an ongoing project to assess the wind resource for the offshore regions of the contiguous United States including the Great Lakes. Final offshore maps with a horizontal resolution of 200 meters (m) have been completed for Texas, Louisiana, Georgia, northern New England, and the Great Lakes. The ocean wind resource maps extend from the coastline to 50 nautical miles (nm) offshore. The Great Lake maps show the resource for all of the individual lakes. These maps depict the wind resource at 50 m above the water as classes of wind power density. Class 1 represents the lowest available wind resource, while Class 7 is the highest resource. Areas with Class 5 and higher wind resource can be economical for offshore project development. As offshore wind turbine technology improves, areas with Class 4 and higher resource should become economically viable. The wind resource maps are generated using output from a modified numerical weather prediction model combined with a wind flow model. The preliminary modeling is performed by AWS Truewind under subcontract to NREL. The preliminary model estimates are sent to NREL to be validated. NREL validates the preliminary estimates by comparing 50 m model data to available measurements that are extrapolated to 50 m. The validation results are used to modify the preliminary map and produce the final resource map. The sources of offshore wind measurement data include buoys, automated stations, lighthouses, and satellite- derived ocean wind speed data. The wind electric potential is represented as Megawatts (MW) of potential installed capacity and is based on the square

  1. 46 CFR 111.105-33 - Mobile offshore drilling units.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Mobile offshore drilling units. 111.105-33 Section 111... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-33 Mobile offshore drilling units. (a) Applicability. This section applies to each mobile offshore drilling unit. (b) Definitions. As used in...

  2. 46 CFR 111.105-33 - Mobile offshore drilling units.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Mobile offshore drilling units. 111.105-33 Section 111... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-33 Mobile offshore drilling units. (a) Applicability. This section applies to each mobile offshore drilling unit. (b) Definitions. As used in...

  3. 46 CFR 111.105-33 - Mobile offshore drilling units.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Mobile offshore drilling units. 111.105-33 Section 111... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-33 Mobile offshore drilling units. (a) Applicability. This section applies to each mobile offshore drilling unit. (b) Definitions. As used in...

  4. 77 FR 26562 - Mobile Offshore Drilling Unit Dynamic Positioning Guidance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-04

    ... SECURITY Coast Guard Mobile Offshore Drilling Unit Dynamic Positioning Guidance AGENCY: Coast Guard, DHS... procedures on a Mobile Offshore Drilling Unit. We received comments both as submissions to the docket and at... damage. This is particularly true for Mobile Offshore Drilling Units (MODUs), where a loss of...

  5. 46 CFR 15.520 - Mobile offshore drilling units.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Mobile offshore drilling units. 15.520 Section 15.520... REQUIREMENTS Manning Requirements; Inspected Vessels § 15.520 Mobile offshore drilling units. (a) The requirements in this section for mobile offshore drilling units (MODUs) supplement other requirements in...

  6. 46 CFR 15.520 - Mobile offshore drilling units.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Mobile offshore drilling units. 15.520 Section 15.520... REQUIREMENTS Manning Requirements; Inspected Vessels § 15.520 Mobile offshore drilling units. (a) The requirements in this section for mobile offshore drilling units (MODUs) supplement other requirements in...

  7. 46 CFR 15.520 - Mobile offshore drilling units.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Mobile offshore drilling units. 15.520 Section 15.520... REQUIREMENTS Manning Requirements; Inspected Vessels § 15.520 Mobile offshore drilling units. (a) The requirements in this section for mobile offshore drilling units (MODUs) supplement other requirements in...

  8. 46 CFR 111.105-33 - Mobile offshore drilling units.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Mobile offshore drilling units. 111.105-33 Section 111... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-33 Mobile offshore drilling units. (a) Applicability. This section applies to each mobile offshore drilling unit. (b) Definitions. As used in...

  9. 46 CFR 15.520 - Mobile offshore drilling units.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Mobile offshore drilling units. 15.520 Section 15.520... REQUIREMENTS Manning Requirements; Inspected Vessels § 15.520 Mobile offshore drilling units. (a) The requirements in this section for mobile offshore drilling units (MODUs) supplement other requirements in...

  10. 47 CFR 22.1007 - Channels for offshore radiotelephone systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... CARRIER SERVICES PUBLIC MOBILE SERVICES Offshore Radiotelephone Service § 22.1007 Channels for offshore... located in the specified geographical zones that provide offshore radiotelephone service. All channels... and/or airborne mobile) as indicated, for voice-grade general communications and private line...

  11. 47 CFR 22.1007 - Channels for offshore radiotelephone systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CARRIER SERVICES PUBLIC MOBILE SERVICES Offshore Radiotelephone Service § 22.1007 Channels for offshore... located in the specified geographical zones that provide offshore radiotelephone service. All channels... and/or airborne mobile) as indicated, for voice-grade general communications and private line...

  12. 78 FR 18618 - National Offshore Safety Advisory Committee; Vacancies

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-27

    ... offshore drilling; (c) One member representing companies, organizations, enterprises or similar entities... entities engaged in offshore oil exploration and production on the Outer Continental Shelf of Alaska. To be... SECURITY Coast Guard National Offshore Safety Advisory Committee; Vacancies AGENCY: United States...

  13. 77 FR 17491 - National Offshore Safety Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-26

    ... SECURITY Coast Guard National Offshore Safety Advisory Committee AGENCY: United States Coast Guard.... SUMMARY: The National Offshore Safety Advisory Committee (NOSAC) will meet on April 11 and 12, 2012, in... affecting the oil and gas offshore industry. These meetings are open to the public. DATES: NOSAC will...

  14. 76 FR 62817 - National Offshore Safety Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-11

    ... SECURITY Coast Guard National Offshore Safety Advisory Committee AGENCY: United States Coast Guard. ACTION: Committee Management; Notice of Federal Advisory Committee Meeting. SUMMARY: The National Offshore Safety... related to safety of operations and other matters affecting the oil and gas offshore industry. The...

  15. Boundary Spanning in Offshored Information Systems Development Projects

    ERIC Educational Resources Information Center

    Krishnan, Poornima

    2010-01-01

    Recent growth in offshore outsourcing of information systems (IS) services is accompanied by managing the offshore projects successfully. Much of the project failures can be attributed to geographic and organizational boundaries which create differences in culture, language, work patterns, and decision making processes among the offshore project…

  16. International Offshore Students' Perceptions of Virtual Office Hours

    ERIC Educational Resources Information Center

    Wdowik, Steven; Michael, Kathy

    2013-01-01

    Purpose: The main aim of this study is to gauge international offshore students' perceptions of virtual office hours (VOH) to consult with their offshore unit coordinators in Australia. Design/methodology/approach: This paper employs a quantitative and qualitative approach where data was sourced from three offshore campuses over a 12-month period…

  17. Lake Michigan Offshore Wind Feasibility Assessment

    SciTech Connect

    Boezaart, Arnold; Edmonson, James; Standridge, Charles; Pervez, Nahid; Desai, Neel; Williams, Bruce; Clark, Aaron; Zeitler, David; Kendall, Scott; Biddanda, Bopi; Steinman, Alan; Klatt, Brian; Gehring, J. L.; Walter, K.; Nordman, Erik E.

    2014-06-30

    The purpose of this project was to conduct the first comprehensive offshore wind assessment over Lake Michigan and to advance the body of knowledge needed to support future commercial wind energy development on the Great Lakes. The project involved evaluation and selection of emerging wind measurement technology and the permitting, installation and operation of the first mid-lake wind assessment meteorological (MET) facilities in Michigan’s Great Lakes. In addition, the project provided the first opportunity to deploy and field test floating LIDAR and Laser Wind Sensor (LWS) technology, and important research related equipment key to the sitting and permitting of future offshore wind energy development in accordance with public participation guidelines established by the Michigan Great Lakes Wind Council (GLOW). The project created opportunities for public dialogue and community education about offshore wind resource management and continued the dialogue to foster Great Lake wind resource utilization consistent with the focus of the GLOW Council. The technology proved to be effective, affordable, mobile, and the methods of data measurement accurate. The public benefited from a substantial increase in knowledge of the wind resources over Lake Michigan and gained insights about the potential environmental impacts of offshore wind turbine placements in the future. The unique first ever hub height wind resource assessment using LWS technology over water and development of related research data along with the permitting, sitting, and deployment of the WindSentinel MET buoy has captured public attention and has helped to increase awareness of the potential of future offshore wind energy development on the Great Lakes. Specifically, this project supported the acquisition and operation of a WindSentinel (WS) MET wind assessment buoy, and associated research for 549 days over multiple years at three locations on Lake Michigan. Four research objectives were defined for the

  18. Offshore Investments by Colleges Draw Scrutiny

    ERIC Educational Resources Information Center

    Fain, Paul; Wolverton, Brad

    2007-01-01

    Billions of dollars in untaxed, offshore investments by college endowments could be subject to taxation under a proposal being considered by the leaders of the U.S. Senate Finance Committee. The proposed change, which targets hedge funds, a popular investing strategy for many colleges, would affect the largest college endowments, including those…

  19. 31 CFR 587.406 - Offshore transactions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 587.406 Section 587.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FEDERAL REPUBLIC OF YUGOSLAVIA (SERBIA...

  20. Risk analysis for Arctic offshore operations

    SciTech Connect

    Slomski, S.; Vivatrat, V.

    1986-04-01

    Offshore exploration for hydrocarbons is being conducted in the near-shore regions of the Beaufort Sea. This activity is expected to be intensified and expanded into the deeper portions of the Beaufort, as well as into the Chukchi Sea. The ice conditions in the Beaufort Sea are very variable, particularly in the deeper water regions. This variability greatly influences the probability of success or failure of an offshore operation. For example, a summer exploratory program conducted from a floating drilling unit may require a period of 60 to 100 days on station. The success of such a program depends on: (a) the time when the winter ice conditions deteriorate sufficiently for the drilling unit to move on station; (b) the number of summer invasions by the arctic ice pack, forcing the drilling unit to abandon station; (c) the rate at which first-year ice grows to the ice thickness limit of the supporting icebreakers; and (d) the extent of arctic pack expansion during the fall and early winter. In general, the ice conditions are so variable that, even with good planning, the change of failure of an offshore operation will not be negligible. Contingency planning for such events is therefore necessary. This paper presents a risk analysis procedure which can greatly benefit the planning of an offshore operation. A floating drilling program and a towing and installation operation for a fixed structure are considered to illustrate the procedure.

  1. 31 CFR 543.406 - Offshore transactions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 543.406 Section 543.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY CôTE D'IVOIRE SANCTIONS...

  2. Accord near for offshore California oil shipments

    SciTech Connect

    Not Available

    1993-02-15

    There are faint glimmers of hope again for offshore California operators. After more than a decade of often bitter strife over offshore oil and gas development and transportation issues, state officials and oil producers may be moving toward compromise solutions. One such solution may be forthcoming on offshore development. But the real change came with the turnabout of the California Coastal Commission (CCC), which last month approved a permit for interim tankering of crude from Point Arguello oil field in the Santa Barbara Channel to Los Angeles. The dispute over how to ship offshore California crude to market has dragged on since before Point Arguelo development plans were unveiled. The project's status has become a flashpoint in the U.S. debate over resource use and environmental concerns. The controversy flared anew in the wake of the 1989 Exxon Valdez tanker spill off Alaska, when CCC voided a Santa Barbara County permit for interim tankering, a move project operator Chevron Corp. linked to the Exxon Valdez accident. Faced with litigation, the state's economic devastation, and acrimonious debate over transporting California crude, Gov. Pete Wilson and other agencies approved the CCC permit. But there's a catch: A permanent pipeline must be built to handle full production within 3 years. The paper discusses permit concerns, the turnaround decision, the anger of environmental groups, and pipeline proposals.

  3. 31 CFR 537.406 - Offshore transactions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Offshore transactions. 537.406 Section 537.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BURMESE SANCTIONS REGULATIONS Interpretations §...

  4. 31 CFR 542.406 - Offshore transactions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Offshore transactions. 542.406 Section 542.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY SYRIAN SANCTIONS REGULATIONS Interpretations §...

  5. 31 CFR 542.406 - Offshore transactions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Offshore transactions. 542.406 Section 542.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY SYRIAN SANCTIONS REGULATIONS Interpretations §...

  6. 31 CFR 542.406 - Offshore transactions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 542.406 Section 542.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY SYRIAN SANCTIONS REGULATIONS...

  7. 31 CFR 542.406 - Offshore transactions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Offshore transactions. 542.406 Section 542.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY SYRIAN SANCTIONS REGULATIONS Interpretations §...

  8. Planning and evaluation parameters for offshore complexes

    NASA Technical Reports Server (NTRS)

    Sincoff, M. Z. (Editor); Dajani, J. S. (Editor)

    1976-01-01

    Issues are presented for consideration in the planning and design of offshore artificial complexes. The construction of such complexes, their social, economic, and ecological impacts, and the legal-political-institutional environments within which their development could occur, are discussed. Planning, design, and construction of near-shore complexes located off the Mid-Atlantic coast of the United States is emphasized.

  9. Cut drydocking costs for offshore rigs

    SciTech Connect

    Albaugh, E.K.

    1985-07-01

    Heavy-lift transport vessels (HLVs) can provide an economic alternative to the conventional shipyard approach of drydocking mobile offshore rigs for regulatory body inspections and/or repairs. Contractors now can drydock rigs in areas of the world where conventional drydocks are unavailable. This article discusses pros and cons of conventional shipyard drydocking and the HLV approach.

  10. Solar power satellite offshore rectenna study

    NASA Astrophysics Data System (ADS)

    1980-11-01

    It was found that an offshore rectenna is feasible and cost competitive with land rectennas but that the type of rectenna which is suitable for offshore use is quite different from that specified in the present reference system. The result is a nonground plane design which minimizes the weight and greatly reduces the number of costly support towers. This preferred design is an antenna array consisting of individually encapsulated dipoles with reflectors supported on feed wires. Such a 5 GW rectenna could be built at a 50 m water depth site to withstand hurricane and icing conditions for a one time cost of 5.7 billion dollars. Subsequent units would be about 1/3 less expensive. The east coast site chosen for this study represents an extreme case of severe environmental conditions. More benign and more shallow water sites would result in lower costs. Secondary uses such as mariculture appear practical with only minor impact on the rectenna design. The potential advantages of an offshore rectenna, such as no land requirements, removal of microwave radiation from populated areas and minimal impact on the local geopolitics argue strongly that further investigation of the offshore rectenna should be vigorously pursued.

  11. Offshore blowouts, data for risk assessment

    SciTech Connect

    Holand, P.

    1995-12-31

    Blowouts are, besides gas leakages, the major contributor to the total risk for offshore installations. Therefore, the blowout risk is always included in Quantitative Risk Analyses (QRAs) of offshore installations in the Norwegian Sector of the North Sea. SINTEF Offshore Blowout Database has existed since 1984 (until 1990 it was called Marintek`s blowout database). In 1990 the responsibility of the database was transferred to SINTEF Safety and Reliability. Throughout these years the database has been used for assessing blowout risk associated to development and operation of fields offshore Norway. Six oil companies and two consultants are presently sponsoring the database. These companies are using the database when performing risk analyses. During the past three years the database has been subjected to a thorough quality improvement, both with respect to the user interface, and most important, regarding the blowout data included in the database. What is unique with this database, besides the high quality of blowout descriptions, is first that the blowout causes are categorized related to loss of primary and secondary barriers. Secondly that the user interface makes it possible to establish searches to withdraw information regarding any blowout type subjected for specific searches.

  12. 31 CFR 548.406 - Offshore transactions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Offshore transactions. 548.406 Section 548.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BELARUS SANCTIONS REGULATIONS Interpretations §...

  13. 31 CFR 548.406 - Offshore transactions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Offshore transactions. 548.406 Section 548.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BELARUS SANCTIONS REGULATIONS Interpretations §...

  14. 31 CFR 548.406 - Offshore transactions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Offshore transactions. 548.406 Section 548.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BELARUS SANCTIONS REGULATIONS Interpretations §...

  15. 31 CFR 548.406 - Offshore transactions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 548.406 Section 548.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BELARUS SANCTIONS REGULATIONS...

  16. 31 CFR 548.406 - Offshore transactions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Offshore transactions. 548.406 Section 548.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BELARUS SANCTIONS REGULATIONS Interpretations §...

  17. 31 CFR 593.406 - Offshore transactions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Offshore transactions. 593.406 Section 593.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FORMER LIBERIAN REGIME OF CHARLES...

  18. Human Rights, Academic Freedom, and Offshore Academics

    ERIC Educational Resources Information Center

    Ross, Andrew

    2011-01-01

    Despite the carnage wrought on higher education by the Great Recession, evidence persists that the sector is still host to a speculator psychology. One example is the unabated stampede to set up branches and programs overseas. Colleges have many reasons to go offshore: (1) to reduce costs; (2) to build their "brands" in "emerging…

  19. Solar power satellite offshore rectenna study

    NASA Technical Reports Server (NTRS)

    1980-01-01

    It was found that an offshore rectenna is feasible and cost competitive with land rectennas but that the type of rectenna which is suitable for offshore use is quite different from that specified in the present reference system. The result is a nonground plane design which minimizes the weight and greatly reduces the number of costly support towers. This preferred design is an antenna array consisting of individually encapsulated dipoles with reflectors supported on feed wires. Such a 5 GW rectenna could be built at a 50 m water depth site to withstand hurricane and icing conditions for a one time cost of 5.7 billion dollars. Subsequent units would be about 1/3 less expensive. The east coast site chosen for this study represents an extreme case of severe environmental conditions. More benign and more shallow water sites would result in lower costs. Secondary uses such as mariculture appear practical with only minor impact on the rectenna design. The potential advantages of an offshore rectenna, such as no land requirements, removal of microwave radiation from populated areas and minimal impact on the local geopolitics argue strongly that further investigation of the offshore rectenna should be vigorously pursued.

  20. 31 CFR 537.406 - Offshore transactions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Offshore transactions. 537.406 Section 537.406 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BURMESE SANCTIONS REGULATIONS Interpretations §...

  1. Platform switching and bone platform switching.

    PubMed

    Carinci, Francesco; Brunelli, Giorgio; Danza, Matteo

    2009-01-01

    Bone platform switching involves an inward bone ring in the coronal part of the implant that is in continuity with the alveolar bone crest. Bone platform switching is obtained by using a dental fixture with a reverse conical neck. A retrospective study was performed to evaluate the effectiveness of conventional vs reverse conical neck implants. In the period between May 2004 and November 2007, 86 patients (55 females and 31 males; median age, 53 years) were operated and 234 implants were inserted: 40 and 194 were conventional vs reverse conical neck implants, respectively. Kaplan-Meier algorithm and Cox regression were used to detect those variables associated with the clinical outcome. No differences in survival and success rates were detected between conventional vs reverse conical neck implants alone or in combination with any of the studied variables. Although bone platform switching leads to several advantages, no statistical difference in alveolar crest resorption is detected in comparison with reverse conical neck implants. We suppose that the proximity of the implant abutment junction to the alveolar crestal bone gives no protection against the microflora contained in the micrograph. Additional studies on larger series and a combination of platform switching and bone platform switching could lead to improved clinical outcomes.

  2. Mapping Seabird Sensitivity to Offshore Wind Farms

    PubMed Central

    Bradbury, Gareth; Trinder, Mark; Furness, Bob; Banks, Alex N.; Caldow, Richard W. G.; Hume, Duncan

    2014-01-01

    We present a Geographic Information System (GIS) tool, SeaMaST (Seabird Mapping and Sensitivity Tool), to provide evidence on the use of sea areas by seabirds and inshore waterbirds in English territorial waters, mapping their relative sensitivity to offshore wind farms. SeaMaST is a freely available evidence source for use by all connected to the offshore wind industry and will assist statutory agencies in assessing potential risks to seabird populations from planned developments. Data were compiled from offshore boat and aerial observer surveys spanning the period 1979–2012. The data were analysed using distance analysis and Density Surface Modelling to produce predicted bird densities across a grid covering English territorial waters at a resolution of 3 km×3 km. Coefficients of Variation were estimated for each grid cell density, as an indication of confidence in predictions. Offshore wind farm sensitivity scores were compiled for seabird species using English territorial waters. The comparative risks to each species of collision with turbines and displacement from operational turbines were reviewed and scored separately, and the scores were multiplied by the bird density estimates to produce relative sensitivity maps. The sensitivity maps reflected well the amassed distributions of the most sensitive species. SeaMaST is an important new tool for assessing potential impacts on seabird populations from offshore development at a time when multiple large areas of development are proposed which overlap with many seabird species’ ranges. It will inform marine spatial planning as well as identifying priority areas of sea usage by marine birds. Example SeaMaST outputs are presented. PMID:25210739

  3. Mapping seabird sensitivity to offshore wind farms.

    PubMed

    Bradbury, Gareth; Trinder, Mark; Furness, Bob; Banks, Alex N; Caldow, Richard W G; Hume, Duncan

    2014-01-01

    We present a Geographic Information System (GIS) tool, SeaMaST (Seabird Mapping and Sensitivity Tool), to provide evidence on the use of sea areas by seabirds and inshore waterbirds in English territorial waters, mapping their relative sensitivity to offshore wind farms. SeaMaST is a freely available evidence source for use by all connected to the offshore wind industry and will assist statutory agencies in assessing potential risks to seabird populations from planned developments. Data were compiled from offshore boat and aerial observer surveys spanning the period 1979-2012. The data were analysed using distance analysis and Density Surface Modelling to produce predicted bird densities across a grid covering English territorial waters at a resolution of 3 km×3 km. Coefficients of Variation were estimated for each grid cell density, as an indication of confidence in predictions. Offshore wind farm sensitivity scores were compiled for seabird species using English territorial waters. The comparative risks to each species of collision with turbines and displacement from operational turbines were reviewed and scored separately, and the scores were multiplied by the bird density estimates to produce relative sensitivity maps. The sensitivity maps reflected well the amassed distributions of the most sensitive species. SeaMaST is an important new tool for assessing potential impacts on seabird populations from offshore development at a time when multiple large areas of development are proposed which overlap with many seabird species' ranges. It will inform marine spatial planning as well as identifying priority areas of sea usage by marine birds. Example SeaMaST outputs are presented.

  4. Quantitative Comparison of the Responses of Three Floating Platforms

    SciTech Connect

    Jonkman, J.; Matha, D.

    2010-03-01

    This report presents a comprehensive dynamic-response analysis of three offshore floating wind turbine concepts. Models were composed of one 5-MW turbine supported on land and three 5-MW turbines located offshore on a tension leg platform, a spar buoy, and a barge. A loads and stability analysis adhering to the procedures of international design standards was performed for each model using the fully coupled time-domain aero-hydro-servo-elastic design code FAST with AeroDyn and HydroDyn. The concepts are compared based on the calculated ultimate loads, fatigue loads, and instabilities. The results of this analysis will help resolve the fundamental design trade-offs between the floating-system concepts.

  5. Omnidirectional holonomic platforms

    SciTech Connect

    Pin, F.G.; Killough, S.M.

    1994-06-01

    This paper presents the concepts for a new family of wheeled platforms which feature full omnidirectionality with simultaneous and independently controlled rotational and translational motion capabilities. The authors first present the orthogonal-wheels concept and the two major wheel assemblies on which these platforms are based. They then describe how a combination of these assemblies with appropriate control can be used to generate an omnidirectional capability for mobile robot platforms. The design and control of two prototype platforms are then presented and their respective characteristics with respect to rotational and translational motion control are discussed.

  6. 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.

  7. Offshore Socotra, Republic of Yemen: Potential for a new hydrocarbon province?

    SciTech Connect

    Richardson, S.M.; Bott, W.F.; Birse, T.C.R.

    1995-08-01

    A new plate reconstruction has enabled the Island of Socotra, currently located in the Gulf of Aden adjacent to the Somalian coast, to be confidently restored to its original spatial position, adjacent to the southern Omani coastline. New studies integrated with these plate reconstructions, have confirmed the presence of an untested Mesozoic graben, which trends across the Socotra platform. Fieldwork carried out in the region now enables a SE extension of the prolific Lower Cretaceous Qishn `play` (delinated in the Masilah Basin, onshore Yemen) to be postulated offshore into the Gulf of Aden. Following the award of offshore acreage adjacent to the Island of Socotra, exploration studies have confirmed the presence of the Qishn `play` both on the Island of Socotra, and offshore in the one available basin-margin control well. This work has also identified two additional plays: the Shuabia-equivalent carbonates, which are prolific producing reservoirs in central Oman; and the Permo-Triassic clastics, which may provide a new reservoir target for the region. Fieldwork has also identified Jurassic siliclastics outcropping on the Island, which may provide further reservoir potential. Ongoing multidisciplinary studies, integrating the results of a detailed geophysical interpretation with high resolution structural-stratigraphic studies, have confirmed the presence of large structures within an undrilled Mesozoic rift-basin, which will be tested during 1995.

  8. Stability analysis of offshore wind farm and marine current farm

    NASA Astrophysics Data System (ADS)

    Shawon, Mohammad Hasanuzzaman

    Renewable energy has been playing an important role to meet power demand and 'Green Energy' market is getting bigger platform all over the world in the last few years. Due to massive increase in the prices of fossil fuels along with global warming issues, energy harvesting from renewable energy sources has received considerable interest, nowadays, where extensive researches are going on to ensure optimum use of renewable sources. In order to meet the increasing demand of electricity and power, integration of renewable energy is getting highest priorities around the world. Wind is one of the most top growing renewable energy resources and wind power market penetration is expected to reach 3.35 percent by 2013 from its present market of about 240 GW. A wind energy system is the most environmental friendly, cost effective and safe among all renewable energy resources available. Another promising form of renewable energy is ocean energy which covers 70 % of the earth. Ocean energy can be tapped from waves, tides and thermal elements. Offshore Wind farm (OWF) has already become very popular for large scale wind power integration with the onshore grid. Recently, marine current farm (MCF) is also showing good potential to become mainstream energy sources and already successfully commissioned in United Kingdom. However, squirrel cage induction generator (SCIG) has the stability problem similar to synchronous generator especially during fault location to restore the electromagnetic torque. Series dynamic braking resistor (SDBR) has been known as a useful mean to stabilize fixed speed wind generator system. On the other hand, doubly fed induction generator (DFIG) has the capability of coupling the control of active and reactive power and to provide necessary reactive power demand during grid fault conditions. Series dynamic braking resistor (SDBR) can also be employed with DFIG to limit the rotor over current. An integration of wind and tidal energy represents a new

  9. The offshore basement of Perú: Evidence for different igneous and metamorphic domains in the forearc

    NASA Astrophysics Data System (ADS)

    Romero, Darwin; Valencia, Kiko; Alarcón, Pedro; Peña, Daniel; Ramos, Victor A.

    2013-03-01

    As a result of new studies carried out in the offshore of Perú during the exploration and hydrocarbon evaluation of the forearc basins, new U-Pb SHRIMP and TIMS in zircons and some Ar-Ar data were obtained in the metamorphic and igneous basement. The understanding of this basement was critical to evaluate different hypotheses that have been proposed for the tectonic evolution of pre-Andean crust of Perú. Recent research performed in the basement rocks of the Marañón Massif in northern Perú, claimed that west of this area was a basement-free region in the Paleozoic, where the arc and forearc were developed in a mafic quasi-oceanic crust. However, petrographic studies and new preliminary ages indicate, for the first time, the nature and age of this sialic basement. Reconnaissance studies were performed in several offshore islands, as the Las Hormigas de Afuera Island west of Lima, and Macabí and Lobera islands along the edge of the continental platform. These data were complemented with the studies of some cutting samples obtained in recent exploration wells in northern Perú. The results of the present work show two large crustal domains in the Peruvian offshore forearc. A northern domain contains late Paleozoic igneous rocks that appear to be the southern offshore continuation of the Amotape-Tahuin block, which is interpreted as the southernmost remnant of the Laurentia Alleghenian orogen. The central offshore domain, known as the Paracas High, corresponds to the outer shelf high of previous studies. It contains orthogneisses of Grenville-age, probably recrystallized during an Ordovician magmatic episode. The new results show that the central offshore of Perú is an extension of the Grenville-age basement affected by Famatinian, early Paleozoic magmatism, well exposed in the southern domain in the Arequipa Massif along the coast of southern Perú.

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

    SciTech Connect

    Rodriguez Tsouroukdissian, Arturo; Lackner, Matt; Cross-Whiter, John; Ackers, Ben; Arora, Dhiraj; Park, Semiung

    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 be 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.

  11. How important is subsidence in evaluating high frequency cycles in the interior of isolated carbonate platforms?

    SciTech Connect

    Lomando, A.J.; Ginsburg, R.

    1995-08-01

    Differential regional subsidence can play a strong role in determining facies composition of adjacent isolated platforms. In the majority of platform oil & gas fields, reservoir architecture is dominated by the composition and stratial geometries in the platform interiors rather than the platform rims. Most work to develop analogues from modern reef-rimmed isolated platforms has focused on the platform margins where reef growths rates are capable of keeping pace with the Holocene sea level rise plus tectonic subsidence. We have focused on platform interiors where accumulation rate and style may be more sensitive to accommodation space generated by regional passive margin subsidence. The Belize platforms are located on a series of parallel ridges which extend progressively eastward, farther from the regional subsidence hingeline near the coast. Greater regional subsidence is reflected in the open, deeper, patch reef and sand rich platform interiors in the outermost platform (Lighthouse and Glovers Platform) in comparison to the mud-dominated interior within the innermost platform (Turneffe), which has filled up due to lesser subsidence rate. The facies response to a portion of a single eustatic cycle produces a {open_quotes}keep-up{close_quotes} transgressive systems tract appearance at Lighthouse and Glovers but a {open_quotes}choked-up{close_quotes} high stand or regressive systems tract appearance within Turneffe. Chinchorro Bank, offshore Yucatan, is a special case where subsidence changes along the length of the platforms. The entire windward margin has a well developed reef system which has uniformly kept pace with the Holocene transgression. The northern platform interior contains a patch reef/sand rich character similar to Lighthouse Platform whereas the southern platform interior is {open_quotes}drowning{close_quotes} due to subsidence along a series of northwest trending faults which downstep southward.

  12. Evaluation of the reliability of a conventional platform installed in South Pass Block 47 of the Mississippi River delta

    SciTech Connect

    Bea, R.G.

    1996-12-31

    In August 1995, the Energy Development Corporation (EDC) installed a conventional drilling and production platform in South Pass Block 47 (SP 47). Due to its proximity to the delta of the Mississippi River, this platform will be subject to the environmental forces developed by hurricanes and movements of the sea floor. This paper summarizes results from probability based study of the reliability characteristics of a conventional platform installed in SP 47. Bases for evaluation of the acceptability of the reliability of the platform are developed. This paper shows how reliability methods can be used to help improve the efficiency of offshore platforms. Application of traditional engineering approaches indicated the need for a mudslide resistant platform. Given that a mudslide resistant platform was required, then the gas reserves could not have been developed.

  13. Active motion and load control of floating offshore wind turbines

    NASA Astrophysics Data System (ADS)

    Jalili, Kaveh

    The research in this thesis is focused on stabilization and load reduction of floating offshore wind turbine (FOWT) structures for both the fore-aft (pitch) and side-to-side (roll) directions. Based on the Tuned Mass Damper (TMD) and Active Vane concepts recently proposed, two composite actuation schemes are investigated. The first scheme is to apply the horizontal vane and vertical vane to platform pitch and roll, respectively, resulting in the so-called Double Vane Actuation (DVA) scheme. The second scheme is the combination of the TMD based pitch control and active vertical vane based roll control, resulting in the so-called Hybrid Actuation (HA) scheme. Simulation results of DVA show great reductions of motions and loads in the fore-aft and side-to-side directions. Performance of HA is investigated by extensive simulations based on the IEC61400-3 standard and results show significant and consistent motions and loads reductions in both FA and SS directions.

  14. 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.

  15. 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.

  16. A nondestructive test contribution to the safety of offshore cranes

    SciTech Connect

    Hands, G.; Bourgeors-Jacquet, P.

    1995-10-01

    Non-Destructive Testing (NDT) plays a vital role in safety as well as in economics of manufacturing. This paper shows an example of how NDT has been successfully used offshore in Europe for a number of years, inspecting slewing bearings. Slewing bearings are the bearings that support among other things cranes and earth-moving equipment. These bearings carry a very heavy slow moving unbalanced axial-load. Due to the extreme environment and the very heavy and unbalanced loading supported by the bearings, particularly on oil exploration and production platforms in the North Sea, some bearings have failed catastrophically. In order to minimize the dangers, authorities have stipulated that slewing bearings for cranes employed in the North Sea are to be periodically inspected. The normal life-restricting failure mode of slewing bearings is spalling of the raceways. This is the rolling contact surface of the bearing breaking-up under the very heavy loads imposed upon it. The developed ultrasonic testing technique, apart from detecting and monitoring cracks in the stressed areas of the bearing, is also able to monitor the initiation and growth of any spalling on the main raceways of the bearings, thus enabling better planning on maintenance and replacements. This paper describes the development of the ultrasonic testing system.

  17. New technology emphasizes international offshore effort

    SciTech Connect

    1997-07-01

    While the offshore industry is focusing its major development efforts on the deeper waters of the US Gulf, West Africa and Brazil, technology has not stood still in the world`s many other established and frontier offshore development areas. These selected items drawn from contributions by UK companies and a major joint-venture development in Eastern Canada emphasize this effort. Included here are: (1) announcement of a major six-field, 3 Tcf gas development off Nova Scotia`s Sable Island and award of two drilling contracts; (2) a comprehensive study of mobile production units in the UK by Smith Rea Energy Analysts; (3) four applications of an option to high-pressure swivels on an FPSO with multiple subsea inlet lines; (4) a contract to supply a DC bus drive for 17 ESPs on Texaco`s Captain field; and (5) review of an environmental study of the Falkland Islands in preparation for exploration activity.

  18. Perspectives of offshore geothermal energy in Italy

    NASA Astrophysics Data System (ADS)

    Armani, F. B.; Paltrinieri, D.

    2013-06-01

    Italy is the first European and world's fifth largest producer of geothermal energy for power generation which actually accounts for less than 2% of the total electricity production of the country. In this paper after a brief introduction to the basic elements of high-enthalpy geothermal systems, we discuss the potentialities represented by the submarine volcanoes of the South Tyrrhenian Sea. In particular we focus on Marsili Seamount which, according to the literature data, can be considered as a possible first offshore geothermal field; then we give a summary of the related exploitation pilot project that may lead to the realization of a 200MWe prototype power plant. Finally we discuss some economic aspects and the development perspectives of the offshore geothermal resource taking into account the Italian energy framework and Europe 2020 renewable energy target.

  19. Locating Microseism Sources in Offshore Southern California

    NASA Astrophysics Data System (ADS)

    Tian, X.; Clayton, R. W.

    2007-12-01

    We use the broadband stations from the S. California network to locate the apparent origin of secondary microseisms energy (5-8 Hz band). The procedure is to grid the offshore region and using each grid point as the source point, predict the response of a Rayleigh wave at each station. These predicted waveforms are then correlated with the data over a time window that is typically a 1/2 hour in length and composited at the grid point. The length of the time window controls a tradeoff between the spatial-temporal resolution of the sources and the robustness on the image. The procedure is valid for multiple sources. This results show that during periods of high microseism activity the sources are distinct at several locations in a region approximately 50-100 km offshore. For an 11/09/2002 Southern Ocean storm, for example, two zones parallel to each other and perpendicular to the coast are imaged.

  20. The impact of wakes on power output at large offshore wind farms

    NASA Astrophysics Data System (ADS)

    Barthelmie, R. J.; Frandsen, S.; Hansen, K.; Schepers, G.; Rados, K.; Schlez, W.; Cabezon, D.; Jensen, L.; Neckelmann, S.

    2010-12-01

    The size of planned offshore wind farms is in the range 100 MW to 1 GW requiring tens to hundreds of wind turbines typically arranged in a large array. As wind farms offshore increase in size, one of the research challenges is to model interactions between the individual turbines, the atmosphere and neighbouring turbines to accurately predict power output before wind farm construction in addition to evaluation during the operation phase. The aim of the research described (part of the UpWind project) is to improve wind farm modelling and address the issue of providing more accurate power output predictions accounting for wind turbine wakes. DONG Energy and Vattenfall have allowed data from a number of cases studies to be used in this project. Detailed case studies of power losses due to wakes at the large wind farms at Nysted and Horns Rev have been analysed and are presented. A focus of the data analysis has been to understand the importance of turbulence and atmospheric stability at these offshore sites. It is evident that the magnitude of wake losses is primarily driven by wind speed but that signals from turbine spacing, turbulence and atmospheric stability can be determined. The case studies are simulated with a range of wind farm and computational fluid dynamics (CFD) models. The UpWind project presents a unique platform for model evaluation because the co-operation of a number of groups means that more models can be evaluated on standardised cases. Results shown indicate power losses due to wakes can be modelled, provided that the standard models are subject to some modifications. We also present some of the first full simulations of large offshore wind farms using CFD. Despite this progress, wake modelling of large wind farms is still subject to an unacceptably high degree of uncertainty requiring further work to understand the physical flow processes within and downwind of large wind farms.

  1. Protective riser-conductor for offshore structures

    SciTech Connect

    Rutherford, D. A.; Albers, G. P.

    1985-07-09

    A protective sleeve for fitting about the periphery of the leg of an offshore structure. The sleeve comprises means for carrying and enclosing a plurality of conductors. It further includes one or more inner rings; an outer jacket is fixedly spaced from the rings to define longitudinal passages within which the respective conductors are fixedly positioned. The sleeve is capable of deflecting packed ice and floating objects which represent possible sources of damage to the structure or to conductors.

  2. Mobile offshore structure for arctic exploratory drilling

    SciTech Connect

    Hale, D. R.; Orndorff Jr., J. A.; Owen, W. A.

    1985-04-23

    An offshore exploratory drilling floatable structure ballastable to rest on a sea floor but to extend above water level when so supported and adapted to withstand arctic ice loads, comprising a substantially vertical wall capable of withstanding arctic ice loads; a structural load bearing bottom rigidly connected to a lower portion of the wall; and a floatable vertically displaceable load bearing structural deck inside the wall.

  3. Automatic welding comes of age. [Offshore

    SciTech Connect

    Turner, D.L. Jr.

    1981-07-01

    Automatic pipe welding systems today fall into three main categories: gas metal arc welding, gas-tungsten arc welding, and flash-butt welding. The first automatic welding devices used offshore were the CRC and H.C. Price systems. Both use gas metal arc welding with a consumable steel filler wire. The recently developed McDermott flash-butt welding system is described. (DLC)

  4. Department of Defense Offshore Military Activities Program

    DTIC Science & Technology

    1987-03-16

    joint use of offshore areas for military and mineral exploration or developmental purposes. (See enclosure 2.) In carrying out negotiations with elements...that from time to time and from place to place the requirements for mineral exploration /development and defense related activities may conflict. In...area, certain defense- related activities on the OCS may be irreconcilable with mineral exploration / development and will, under the procedures

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

    SciTech Connect

    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 between 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.

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

    SciTech Connect

    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 between 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.

  7. The Seismic Reliability of Offshore Structures Based on Nonlinear Time History Analyses

    SciTech Connect

    Hosseini, Mahmood; Karimiyani, Somayyeh; Ghafooripour, Amin; Jabbarzadeh, Mohammad Javad

    2008-07-08

    Regarding the past earthquakes damages to offshore structures, as vital structures in the oil and gas industries, it is important that their seismic design is performed by very high reliability. Accepting the Nonlinear Time History Analyses (NLTHA) as the most reliable seismic analysis method, in this paper an offshore platform of jacket type with the height of 304 feet, having a deck of 96 feet by 94 feet, and weighing 290 million pounds has been studied. At first, some Push-Over Analyses (POA) have been preformed to recognize the more critical members of the jacket, based on the range of their plastic deformations. Then NLTHA have been performed by using the 3-components accelerograms of 100 earthquakes, covering a wide range of frequency content, and normalized to three Peak Ground Acceleration (PGA) levels of 0.3 g, 0.65 g, and 1.0 g. By using the results of NLTHA the damage and rupture probabilities of critical member have been studied to assess the reliability of the jacket structure. Regarding that different structural members of the jacket have different effects on the stability of the platform, an 'importance factor' has been considered for each critical member based on its location and orientation in the structure, and then the reliability of the whole structure has been obtained by combining the reliability of the critical members, each having its specific importance factor.

  8. The Seismic Reliability of Offshore Structures Based on Nonlinear Time History Analyses

    NASA Astrophysics Data System (ADS)

    Hosseini, Mahmood; Karimiyani, Somayyeh; Ghafooripour, Amin; Jabbarzadeh, Mohammad Javad

    2008-07-01

    Regarding the past earthquakes damages to offshore structures, as vital structures in the oil and gas industries, it is important that their seismic design is performed by very high reliability. Accepting the Nonlinear Time History Analyses (NLTHA) as the most reliable seismic analysis method, in this paper an offshore platform of jacket type with the height of 304 feet, having a deck of 96 feet by 94 feet, and weighing 290 million pounds has been studied. At first, some Push-Over Analyses (POA) have been preformed to recognize the more critical members of the jacket, based on the range of their plastic deformations. Then NLTHA have been performed by using the 3-components accelerograms of 100 earthquakes, covering a wide range of frequency content, and normalized to three Peak Ground Acceleration (PGA) levels of 0.3 g, 0.65 g, and 1.0 g. By using the results of NLTHA the damage and rupture probabilities of critical member have been studied to assess the reliability of the jacket structure. Regarding that different structural members of the jacket have different effects on the stability of the platform, an "importance factor" has been considered for each critical member based on its location and orientation in the structure, and then the reliability of the whole structure has been obtained by combining the reliability of the critical members, each having its specific importance factor.

  9. Innovative Offshore Wind Plant Design Study

    SciTech Connect

    Hurley, William L.; Nordstrom, Charles J.; Morrison, Brent J.

    2013-12-18

    Technological advancements in the Glosten PelaStar floating wind turbine system have led to projected cost of energy (COE) reductions from today’s best-in-class offshore wind systems. The PelaStar system is projected to deliver a COE that is 35% lower than that delivered by the current offshore wind plants. Several technology developments have been achieved that directly target significant cost of energy reductions. These include: Application of state-of-the-art steel construction materials and methods, including fatigue-resistant welding techniques and technologies, to reduce hull steel weight; Advancements in synthetic fiber tendon design for the mooring system, which are made possible by laboratory analysis of full-scale sub-rope specimens; Investigations into selected anchor technologies to improve anchor installation methods; Refinement of the installation method, specifically through development of the PelaStar Support Barge design. Together, these technology developments drive down the capital cost and operating cost of offshore wind plants and enable access to superb wind resources in deep water locations. These technology developments also reduce the uncertainty of the PelaStar system costs, which increases confidence in the projected COE reductions.

  10. View from second floor platform looking up at subsequent platforms. ...

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

    View from second floor platform looking up at subsequent platforms. Note the Shuttle assembly outlined by the platform edges. - Marshall Space Flight Center, Saturn V Dynamic Test Facility, East Test Area, Huntsville, Madison County, AL

  11. Floor Plans Rolling Platform, Tech Systems Platform, and Load ...

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

    Floor Plans - Rolling Platform, Tech Systems Platform, and Load Platform Plans - Marshall Space Flight Center, F-1 Engine Static Test Stand, On Route 565 between Huntsville and Decatur, Huntsville, Madison County, AL

  12. Preliminary evaluation of the Minerals Management Service`s offshore modeling system: A long-range modeling alternative

    SciTech Connect

    Capuano, M.E.; Kienzle, M.A.; Steorts, W.L.

    1994-12-31

    The Department of the Interior, Minerals Management Service (MMS) has recently adopted an alternative modeling capability for tracking pollutant releases from offshore platforms in the Central and Western Gulf of Mexico. The new modeling system provides transport and diffusion capabilities well beyond the existing straight-line Gaussian models (OCD, Offshore and Coastal Dispersion Model and E.P.A.`s SCREEN Model), which are limited by design to a maximum 50 km range. The new model, {open_quotes}SLAM{close_quotes} (Short-range Layered Atmospheric Model), is part of the Offshore Modeling System, which provides a well integrated modeling capability supported by a fully automated dial-up data service. The Offshore Modeling System executes on a Sun SPARCStation 2 at the MMS in New Orleans. All weather observations are provided through WSI Corporation and are ingested by the model`s preprocessor which builds validated model input files. A typical model simulation takes less than 60 minutes from start to finish as compared to the very time-intensive model preparation required by current regulatory models.

  13. Global Software Development with Cloud Platforms

    NASA Astrophysics Data System (ADS)

    Yara, Pavan; Ramachandran, Ramaseshan; Balasubramanian, Gayathri; Muthuswamy, Karthik; Chandrasekar, Divya

    Offshore and outsourced distributed software development models and processes are facing challenges, previously unknown, with respect to computing capacity, bandwidth, storage, security, complexity, reliability, and business uncertainty. Clouds promise to address these challenges by adopting recent advances in virtualization, parallel and distributed systems, utility computing, and software services. In this paper, we envision a cloud-based platform that addresses some of these core problems. We outline a generic cloud architecture, its design and our first implementation results for three cloud forms - a compute cloud, a storage cloud and a cloud-based software service- in the context of global distributed software development (GSD). Our ”compute cloud” provides computational services such as continuous code integration and a compile server farm, ”storage cloud” offers storage (block or file-based) services with an on-line virtual storage service, whereas the on-line virtual labs represent a useful cloud service. We note some of the use cases for clouds in GSD, the lessons learned with our prototypes and identify challenges that must be conquered before realizing the full business benefits. We believe that in the future, software practitioners will focus more on these cloud computing platforms and see clouds as a means to supporting a ecosystem of clients, developers and other key stakeholders.

  14. Summary of Conclusions and Recommendations Drawn from the DeepCWind Scaled Floating Offshore Wind System Test Campaign: Preprint

    SciTech Connect

    Robertson, A. N.; Jonkman, J. M.; Masciola, M. D.; Molta, P.; Goupee, A. J.; Coulling, A. J.; Prowell, I.; Browning, J.

    2013-07-01

    The DeepCwind consortium is a group of universities, national labs, and companies funded under a research initiative by the U.S. Department of Energy (DOE) to support the research and development of floating offshore wind power. The two main objectives of the project are to better understand the complex dynamic behavior of floating offshore wind systems and to create experimental data for use in validating the tools used in modeling these systems. In support of these objectives, the DeepCwind consortium conducted a model test campaign in 2011 of three generic floating wind systems, a tension-leg platform (TLP), a spar-buoy (spar), and a semisubmersible (semi). Each of the three platforms was designed to support a 1/50th-scale model of a 5 MW wind turbine and was tested under a variety of wind/wave conditions. The focus of this paper is to summarize the work done by consortium members in analyzing the data obtained from the test campaign and its use for validating the offshore wind modeling tool, FAST.

  15. Ladder attachment platform

    DOEpatents

    Swygert,; Richard, W [Springfield, SC

    2012-08-28

    A ladder attachment platform is provided that includes a base for attachment to a ladder that has first and second side rails and a plurality of rungs that extend between in a lateral direction. Also included is a user platform for having a user stand thereon that is carried by the base. The user platform may be positioned with respect to the ladder so that it is not located between a first plane that extends through the first side rail and is perpendicular to the lateral direction and a second plane that extends through the second side rail and is perpendicular to the lateral direction.

  16. Offshore Code Comparison Collaboration (OC3) for IEA Wind Task 23 Offshore Wind Technology and Deployment

    SciTech Connect

    Jonkman, J.; Musial, W.

    2010-12-01

    This final report for IEA Wind Task 23, Offshore Wind Energy Technology and Deployment, is made up of two separate reports, Subtask 1: Experience with Critical Deployment Issues and Subtask 2: Offshore Code Comparison Collaborative (OC3). Subtask 1 discusses ecological issues and regulation, electrical system integration, external conditions, and key conclusions for Subtask 1. Subtask 2 included here, is the larger of the two volumes and contains five chapters that cover background information and objectives of Subtask 2 and results from each of the four phases of the project.

  17. Dolomitization by ground-water flow systems in carbonate platforms

    SciTech Connect

    Simms, M.

    1984-09-01

    Dolomite occurs throughout the subsurface of modern carbonate platforms such as the Bahamas. Groundwater flow systems must be responsible for delivery of reactants needed for dolomitization. Reflux, freshwater lens flows, and thermal convection are large-scale flow systems that may be widespread in active platforms. The author has evaluated some aspects of the dynamics and characteristics of these processes with ground-water flow theory and by scaled sandbox experiments. Reflux is not restricted to hypersaline brines, but can occur with bankwaters of only slightly elevated salinity such as those found on the Bahama Banks today (42%). The lack of evaporites in a stratigraphic section, therefore, does not rule out the possibility that reflux may have operated. Flows associated with freshwater lenses include flow in the lens, in the mixing zone, and in the seawater beneath and offshore of the lens. Upward transfer of seawater through the platform margins occurs when surrounding cold ocean water migrates into the platform and is heated. This type of thermal convection (Kohout convection) has been studied by Francis Kohout in south Florida. The ranges of mass flux of magnesium in these processes are all comparable and are all sufficient to account for young dolomites beneath modern platforms. Each process yields dolomitized zones of characteristic shape and location and perhaps may be distinguishable in ancient rocks. The concepts presented here may have application to exploration for dolomite reservoirs in the Gulf Coast and elsewhere.

  18. Coiled tubing deployed ESP on the Auk platform

    SciTech Connect

    Stewart, D.W.; Watkins, P.; Holtslag, R.J.; Hudson, A.; Wee, P.Y.; McCleery, B.

    1996-12-31

    In March 1995, what is believed to be the world`s first offshore coiled tubing deployed electrical submersible pump (ESP) was successfully commissioned in well AA-03S1 on Shell U.K. Exploration and Production (Shell Expro) Auk platform in the United Kingdom`s Central North Sea. The ESP provides a new and important method of artificial lift for the 21 year old Auk platform, which hitherto had relied upon downhole hydraulic jet pumps to lift approximately half of the platform`s oil production. The coiled tubing deployment proved the viability of performing future workovers with or without the assistance or indeed the presence of a drilling package. The novel completion design successfully catered to the wide variety of customer requirements; Well Engineering for a rigless workover, Petroleum Engineering for reservoir access and Facilities Engineering for a specified flowline height. The experience gained during this project will be a valuable input in determining the future artificial lift strategy for this platform and for other prospects in terms of performance, reliability and operating costs.

  19. Assessing the Party Platforms.

    ERIC Educational Resources Information Center

    Farrell, Patrick J.

    1980-01-01

    From the perspective of a Catholic educator, the author examines the education planks of the 1980 Democratic and Republican Party platforms, particularly those planks relating to private education and tuition tax credits. (SJL)

  20. Operational Impacts of Large Deployments of Offshore Wind (Poster)

    SciTech Connect

    Ibanez, E.; Heaney, M.

    2014-10-01

    The potential operational impact of deploying 54 GW of offshore wind in the United States was examined. The capacity was not evenly distributed; instead, it was concentrated in regions with better wind quality and close to load centers (Table 1). A statistical analysis of offshore wind power time series was used to assess the effect on the power system. The behavior of offshore wind resembled that of onshore wind, despite the former presenting higher capacity factors, more consistent power output across seasons, and higher variability levels. Thus, methods developed to manage onshore wind variability can be extended and applied to offshore wind.

  1. ARM for Platform Application

    NASA Astrophysics Data System (ADS)

    Patte, Mathieu; Poupat, Jean-Luc; Le Meur, Patrick

    2015-09-01

    The activities described in this paper are part of the CNES R&T “Study of a Cortex-R ARM based architecture” performed by Airbus DS Space System & Electronics in 2014. With the support of CNES, Airbus DS has performed the porting of a representative space application software on an ARM based demonstration platform. This paper presents the platform itself, the activities performed at software level and the first results on this evaluation study.

  2. Building Community Web Platform

    NASA Astrophysics Data System (ADS)

    Ohmukai, Ikki; Matsuo, Yutaka; Matsumura, Naohiro; Takeda, Hideaki

    In this paper we propose Web-based communication environment called ``Community Web Platform''. Our platform provides an easy way to exchange personal knowledge among people with lightweight metadata such like RSS and FOAF. We investigate the nature of ``personal trustness'' on the environment since it is one and only measure for evaluating subjective information and knowledge. We also discuss how to develop and maintain Community Web applications from our exrerience.

  3. National Community Solar Platform

    SciTech Connect

    Rupert, Bart

    2016-06-30

    This project was created to provide a National Community Solar Platform (NCSP) portal known as Community Solar Hub, that is available to any entity or individual who wants to develop community solar. This has been done by providing a comprehensive portal to make CEC’s solutions, and other proven community solar solutions, externally available for everyone to access – making the process easy through proven platforms to protect subscribers, developers and utilities. The successful completion of this project provides these tools via a web platform and integration APIs, a wide spectrum of community solar projects included in the platform, multiple groups of customers (utilities, EPCs, and advocates) using the platform to develop community solar, and open access to anyone interested in community solar. CEC’s Incubator project includes web-based informational resources, integrated systems for project information and billing systems, and engagement with customers and users by community solar experts. The combined effort externalizes much of Clean Energy Collective’s industry-leading expertise, allowing third parties to develop community solar without duplicating expensive start-up efforts. The availability of this platform creates community solar projects that are cheaper to build and cheaper to participate in, furthering the goals of DOE’s SunShot Initiative. Final SF 425 Final SF 428 Final DOE F 2050.11 Final Report Narrative

  4. National Offshore Wind Strategy: Facilitating the Development of the Offshore Wind Industry in the United States

    SciTech Connect

    Patrick Gilman; Maurer, Ben; Feinberg, Luke; Duerr, Alana; Peterson, Lauren; Musial, Walt; Beiter, Phillipp; Golladay, Jennifer; Stromberg, Jessica; Johnson, Isis; Boren, Doug; Moore, Annette

    2016-09-01

    The U.S. Department of Energy, through its Wind Energy Technologies Office, and U.S. Department of the Interior, through its Bureau of Ocean Energy Management, have jointly produced this updated national strategy to facilitate the responsible development of offshore wind energy in the United States.

  5. Offshore Benin, a classic passive margin

    SciTech Connect

    Mathalone, J.M.P. )

    1991-03-01

    Offshore Benin comprises a narrow east-west continental shelf, some 30 km wide. A sharp shelf break running parallel to the coast borders the shelf, whereupon water depths rapidly increase to over 7000 ft. The area lies within the Dahomey Embayment, one of a series of Cretaceous and younger basins lining the coast of Africa that owe their inception to the Late Mesozoic break-up of the Gondwanaland Continent. The basin extends some 100 km inland, but sedimentary section is thin onshore compared to a maximum of 20,000 ft of sediment offshore. Initial sedimentation in this basin was of Neocomian alluvial and lacustrine clastics. These were deposited in east-west-trending narrow half-grabens associated with the initial break up of the South American and African continents. They are covered unconformably by more extensive Albian and Cenomanian transgressive clastics and shallow marine Turonian sandstones which are the main reservoir at Seme, Benin's only oilfield. The Senonian section offshore comprises passive margin deep sea clastic sediments prograding southwards. Very large proximal deep sea channels up to 2500 ft thick are developed in this interval. These channels are associated with excellent petroleum source rocks, averaging 4-5% oil-prone organic carbon, and form the main exploration target in the area when configured in a trap morphology. Seismic data quality is excellent in the region allowing detailed examination of the relationships between the rifted section and later units. In addition, these data illustrate clearly both internal and external morphology of the Senonian proximal deep sea channels.

  6. Cathodic protection retrofit of an offshore pipeline

    SciTech Connect

    Winters, R.H.; Holk, A.C.

    1997-09-01

    The cathodic protection anodes and corrosion coating on two 8-inch (203.2 mm) outside diameter (O.D.) offshore pipelines were damaged during deep water ({minus}380 feet, {minus}116 m) installation. In-situ methods for deep water inspection and repair of the pipelines` cathodic protection and coating systems were developed and performed. Methods are described in which underwater anode retrofits were performed and friction welding technology was used to re-attach anode leads. Standard procedures for underwater pipeline coating repair and remediation of damaged line pipe are provided.

  7. Calculator program helps set offshore design criteria

    SciTech Connect

    Tran, V.B.

    1983-01-10

    Describes a new program for the Hewlett-Packard HP 41C (or HP-41C) hand-held programmable calculator which predicts the design criteria for building offshore facilities. Points out that the ''wind and wave'' (WIWA) program can quickly provide the calculations necessary for proper design involving wind forces, wave forces, and stress acting on the hydrostatic pressure case of a submerged system. Presents a flow diagram of the program and the program listing. Explains the equations used as the basis of the program.

  8. 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.

  9. Dynamic analysis of offshore structures with non-zero initial conditions in the frequency domain

    NASA Astrophysics Data System (ADS)

    Liu, Fushun; Lu, Hongchao; Li, Huajun

    2016-03-01

    The state of non-zero conditions is typically treated as fact when considering the dynamic analysis of offshore structures. This article extends a newly proposed method [1] to manage the non-zero initial conditions of offshore structures in the frequency domain, including new studies on original environmental loads reconstruction, response comparisons with the commercial software ANSYS, and a demonstration using an experimental cantilever beam. The original environmental loads, such as waves, currents, and winds, that act on a structure are decomposed into multiple complex exponential components are represented by a series of poles and corresponding residues. Counter to the traditional frequency-domain method, the non-zero initial conditions of offshore structures could be solved in the frequency domain. Compared with reference [1], an improvement reported in this article is that practical issues, including the choice of model order and central-processing-unit (CPU) time consumption, are further studied when applying this new method to offshore structures. To investigate the feasibility of the representation of initial environmental loads by their poles and corresponding residues, a measured random wave force collected from a column experiment at the Lab of Ocean University of China is used, decomposed, reconstructed and then compared with the original wave force; then, a numerical offshore platform is used to study the performance of the proposed method in detail. The numerical results of this study indicate that (1) a short duration of environmental loads are required to obtain their constitutive poles and residues, which implies good computational efficiency; and (2) the proposed method has a similar computational efficiency to traditional methods due to the use of the inverse Fourier transform technique. To better understand the performance, of time consumption and accuracy of the proposed method, the commercial software ANSYS is used to determine responses

  10. Transactional Network Platform: Applications

    SciTech Connect

    Katipamula, Srinivas; Lutes, Robert G.; Ngo, Hung; Underhill, Ronald M.

    2013-10-31

    In FY13, Pacific Northwest National Laboratory (PNNL) with funding from the Department of Energy’s (DOE’s) Building Technologies Office (BTO) designed, prototyped and tested a transactional network platform to support energy, operational and financial transactions between any networked entities (equipment, organizations, buildings, grid, etc.). Initially, in FY13, the concept demonstrated transactions between packaged rooftop air conditioners and heat pump units (RTUs) and the electric grid using applications or "agents" that reside on the platform, on the equipment, on a local building controller or in the Cloud. The transactional network project is a multi-lab effort with Oakridge National Laboratory (ORNL) and Lawrence Berkeley National Laboratory (LBNL) also contributing to the effort. PNNL coordinated the project and also was responsible for the development of the transactional network (TN) platform and three different applications associated with RTUs. This document describes two applications or "agents" in details, and also summarizes the platform. The TN platform details are described in another companion document.

  11. Probabilistic analysis of local ice pressures. [Calculation of ice load and impact effects on offshore platforms

    SciTech Connect

    Jordaan, I.J.; Brown, P.W. ); Maes, M.A.; Hermans, I.P. . Dept. of Mathematics and Statistics)

    1993-02-01

    Extensive work in recent years has been carried out on the calculation of global ice loads on a probabilistic basis. An analysis method is presented for local ice pressures, which yields values of pressure for specific values of exceedance probability. In developing this method, particular attention has been paid to problems of exposure (length, position and number of impacts), as well as the area of exposure (area within area versus nominal contact area). The solution has been formulated for a series of discrete impacts, e.g., rams by a vessel, or a series of periods of continuous interactions. Data for the MV CANMAR Kigoriak and USCGC Polar Sea were ranked and curves were fitted through the tail of probability plots for three panel sizes. This allowed determination of exceedance probabilities of the design coefficients for pressure as a junction of area. The method developed was then applied to an example for a ship based on the data and expected number of rams per year. Formulas useful in the design of structures in ice are presented.

  12. Scour Caused by Extreme Waves and Currents near Offshore Gravitational Platforms

    NASA Astrophysics Data System (ADS)

    Shchemelinin, Leonid; Belyaev, Nikolay; Lebedev, Vladimir; Nudner, Igor; Semenov, Konstantin; Pelinovsky, Efim; Maximov, Vasily

    2014-05-01

    A soil scour problem is very important by operation of the gravity based structures (GBS). Strong scour may lead to loss of stability of the structure and cause technological disaster. In connection with this, it is necessary to assess and minimize the possibility of scour. Here we present the results of physical modeling of bed scour near the GBS with flat bottoms, close to the square and rectangular. The results of measurements of the bottom deformation caused by extreme waves and currents are given. The experiments were conducted in enclosure of model basin (40 x 6.2 m), within the work area (12x 6.2 m) with the model bottom and GBS. The work area was a broad crested weir. The bottom was formed by fine sand with a mean particle diameter of 0.22 mm. The wind waves were created by portable beam-type wave maker (the length of the beam was 6.1 m) mounted on the bottom of the basin. The modeling of the current was performed using standard centrifugal pump through pipes and valves. The wave impact was carried out using a single stationary vacuum wavemaker. The soil scour modeling was performed according to Froude number in the self-similar area of the Reynolds numbers. The modeling scale was 1:60. The optical measurements system of the surfaces (OMSS) was used to evaluate the bed deformation. The 3-D maps of the bottom after the end of the tests and drying of the model were given using the OMSS. The contactless acoustic measurement system has been applied for measuring of the bottom change during the large-amplitude wave action on the GBS model at discrete points. The results are used for the preparation of recommendations for the protection against scour.

  13. Floating substructure flexibility of large-volume 10MW offshore wind turbine platforms in dynamic calculations

    NASA Astrophysics Data System (ADS)

    Borg, Michael; Melchior Hansen, Anders; Bredmose, Henrik

    2016-09-01

    Designing floating substructures for the next generation of 10MW and larger wind turbines has introduced new challenges in capturing relevant physical effects in dynamic simulation tools. In achieving technically and economically optimal floating substructures, structural flexibility may increase to the extent that it becomes relevant to include in addition to the standard rigid body substructure modes which are typically described through linear radiation-diffraction theory. This paper describes a method for the inclusion of substructural flexibility in aero-hydro-servo-elastic dynamic simulations for large-volume substructures, including wave-structure interactions, to form the basis of deriving sectional loads and stresses within the substructure. The method is applied to a case study to illustrate the implementation and relevance. It is found that the flexible mode is significantly excited in an extreme event, indicating an increase in predicted substructure internal loads.

  14. 75 FR 47311 - National Offshore Safety Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-05

    ... SECURITY Coast Guard National Offshore Safety Advisory Committee AGENCY: Coast Guard, DHS. ACTION: Notice of open teleconference meeting. SUMMARY: The National Offshore Safety Advisory Committee (NOSAC) will meet by teleconference to discuss items related to safety of operations and other matters affecting...

  15. 46 CFR 15.520 - Mobile offshore drilling units (MODUs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Mobile offshore drilling units (MODUs). 15.520 Section 15.520 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MANNING REQUIREMENTS Manning Requirements; Inspected Vessels § 15.520 Mobile offshore drilling...

  16. 2016 Offshore Wind Energy Resource Assessment for the United States

    SciTech Connect

    Musial, Walt; Heimiller, Donna; Beiter, Philipp; Scott, George; Draxl, Caroline

    2016-09-01

    This report, the 2016 Offshore Wind Energy Resource Assessment for the United States, was developed by the National Renewable Energy Laboratory, and updates a previous national resource assessment study, and refines and reaffirms that the available wind resource is sufficient for offshore wind to be a large-scale contributor to the nation's electric energy supply.

  17. International Collaboration on Offshore Wind Energy Under IEA Annex XXIII

    SciTech Connect

    Musial, W.; Butterfield, S.; Lemming, J.

    2005-11-01

    This paper defines the purpose of IEA Annex XXIII, the International Collaboration on Offshore Wind Energy. This international collaboration through the International Energy Agency (IEA) is an efficient forum from which to advance the technical and environmental experiences collected from existing offshore wind energy projects, as well as the research necessary to advance future technology for deep-water wind energy technology.

  18. Offshore Oil: Environmental Impacts on Land and Sea

    ERIC Educational Resources Information Center

    Baldwin, Pamela L.

    1974-01-01

    Presents a counter position to that provided in SE 512 127 in which the author emphasizes that there are too many problems yet to be solved (related to offshore oil development) to proceed with full-scale development of offshore oil drilling. (PEB)

  19. 2014-2015 Offshore Wind Technologies Market Report

    SciTech Connect

    Smith, Aaron

    2015-11-18

    This presentation provides an overview of progress toward offshore wind cost reduction in Europe and implications for the U.S. market. The presentation covers an overview of offshore wind developments, economic and performance trends, empirical evidence of LCOE reduction, and challenges and opportunities in the U.S. market.

  20. Wind Resource Mapping for United States Offshore Areas: Preprint

    SciTech Connect

    Elliott, D.; Schwartz, M.

    2006-06-01

    The U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) is producing validated wind resource maps for priority offshore regions of the United States. This report describes the methodology used to validate the maps and to build a Geographic Information Systems (GIS) database to classify the offshore wind resource by state, water depth, distance from shore, and administrative unit.

  1. 76 FR 77223 - Enbridge Offshore Pipelines (UTOS); Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Enbridge Offshore Pipelines (UTOS); Notice of Filing Take notice that on November 30, 2011, Enbridge Offshore Pipelines (UTOS) submitted a request for a waiver of the...

  2. 26th Annual offshore technology conference: 1994 Proceedings

    SciTech Connect

    Not Available

    1994-01-01

    This conference is the world's largest and most comprehensive technical conference and exhibition on offshore resource development. This conference is divided into four volumes with this volume containing conference papers relative to offshore drilling and well completion information. Papers also deal with construction specifications for marine risers and pipelines, along with any relevant installation and performance information.

  3. Flying in, Flying out: Offshore Teaching in Higher Education

    ERIC Educational Resources Information Center

    Seah, Wee Tiong; Edwards, Julie

    2006-01-01

    This paper discusses the relatively new phenomenon of university education faculties offering offshore education. The analogy, "flying in, flying out" captures the intensity of such offshore experiences for visiting academics, and contrasts their professional experiences against expatriate academics. This paper reports on case studies of…

  4. The sea bottom temperature offshore southwestern Taiwan

    NASA Astrophysics Data System (ADS)

    Chiang, H.; Shyu, C.; Peng, Y.; Chang, H.; Chen, S.; Chung, S.; Wang, Y.

    2012-12-01

    The sea bottom temperature (SBT) is important to apply to the heat flow estimation by BSR. Also the SBT may response the fluid migration near subsurface. Here we present 150 measurements of SBT offshore southwestern Taiwan where abundant gas hydrates has been evaluated. The SBT data were acquired by the heat probe with high resolution up to 0.0001°C. Thermal gradients were determined from several temperature sensors installed in different depth in the heat probe and then the SBT could be calculated by extrapolation. The results show that the SBT are between 2.23 and 10.14°C in water depth within the range of 409 to 3248 meters. Basically, the SBT is inversely hyperbolic proportional to the water depth for those 132 measurements the water depth are shallower than 2650 meters. The product of SBT and water depth has an average of 4419 m-°C and a standard deviation of 402 m-°C. However the SBT of others 18 measurements in the deep water region are scattered without any significant trend. Some measurements near mud diapirs in the shallow water have high anomaly SBT. It is suggested that the fluid from deep underground may migrate along the fractures or faults related to the movements of the mud volume.; The sea bottom temperature offshore southwestern Taiwan

  5. Gladden Pull-Apart Basin, offshore Belize

    SciTech Connect

    Morrice, S. )

    1993-02-01

    The junction of the American and Caribbean plates in Belize has created a complex structural setting for oil and gas exploration. Recent seismic offshore Belize has been used to identify three structural provinces, from west to east: a shallow thrust zone, a narrow upthrown wrench faulted zone and a deeper extensional basin, named the Gladden Pull-Apart Basin. Hydrocarbon leakage from recent fault movement appears to have depleted the shallow structures to the west, but the pull-apart basin has a thick sequence of low-frequency clay-dominated sealing rocks with the potential to preserve hydrocarbon accumulations in Cretaceous carbonate banks. These buried carbonate are of the same age and depositional environment of Mexico's Golden Lane/Tabasco Reforma carbonate banks which are world class giant fields. The Belize and Mexican carbonate banks are within the same Cretaceous depositional basin, the Peten Basin. Seismic interpretations in offshore Belize have been integrated with gravity and magnetic surveys. This provides additional support for the deep extensional basin. The location of the thick Cretaceous carbonate banks is better interpreted with the integration of these three geophysical tools. Airborne geochemical surveys were used to detect the presence of oil seeps on the east and west basin margins.

  6. Optimization of monopiles for offshore wind turbines.

    PubMed

    Kallehave, Dan; Byrne, Byron W; LeBlanc Thilsted, Christian; Mikkelsen, Kristian Kousgaard

    2015-02-28

    The offshore wind industry currently relies on subsidy schemes to be competitive with fossil-fuel-based energy sources. For the wind industry to survive, it is vital that costs are significantly reduced for future projects. This can be partly achieved by introducing new technologies and partly through optimization of existing technologies and design methods. One of the areas where costs can be reduced is in the support structure, where better designs, cheaper fabrication and quicker installation might all be possible. The prevailing support structure design is the monopile structure, where the simple design is well suited to mass-fabrication, and the installation approach, based on conventional impact driving, is relatively low-risk and robust for most soil conditions. The range of application of the monopile for future wind farms can be extended by using more accurate engineering design methods, specifically tailored to offshore wind industry design. This paper describes how state-of-the-art optimization approaches are applied to the design of current wind farms and monopile support structures and identifies the main drivers where more accurate engineering methods could impact on a next generation of highly optimized monopiles.

  7. Thermometric well testing on the Vietnam offshore

    SciTech Connect

    San, T.N.; Shtyrlin, V.F.; Vakhitov, G.G.; Loi, L.M.; Listengarten, L.; Hien, D.L.

    1994-12-31

    It is impossible to control and adjust an oil and gas field development without determining the flow intervals of production wells. For that it is preferable to get production profiles by using the downhole flowmeter. There are, however, some main restrictions for wide-spread application of them on the offshore of Vietnam as follows: the flowmeter spinner velocity cannot indicate correctly in the open hole wells having a nonuniform diameter; it is unable to carry out in the case when the tubing shoe is lower than top formation on 300--500m. In this paper, the authors present a summary of temperature profile method to determine the flowing and intaking intervals of wells drilled in basement of the White Tiger Field on Vietnam offshore. For the last 2 years more than 30 wells were surveyed by this method in the above mentioned conditions. This paper presents the theory and practice of well temperature profile surveys, the concrete examples of data interpretation using the software Oiltest.

  8. CFD Experiments for Wind-Turbine-Platform Seakeeping Models and Flow Physics

    NASA Astrophysics Data System (ADS)

    Dunbar, Alexander; Paterson, Eric; Craven, Brent; Brasseur, James

    2013-11-01

    As part of the Penn State ``Cyber Wind Facility,'' we describe the development and application of a tightly-coupled CFD/6-DOF solver in OpenFOAM for the simulation of offshore floating wind turbine platforms. We highlight the tightly-coupled computational framework and validation of the solver via a comparison with benchmark experimental measurements. The validated CFD/6-DOF solver is then applied to the OC4 DeepCwind semisubmersible for the prediction of platform motion due to wind and wave loading. Supported by the US Department of Energy.

  9. Coniacian-Turonian Carbonates of the Miskar Field, offshore Tunisia

    SciTech Connect

    Knott, I.; Moody, R.; Sandman, R.

    1995-08-01

    The R1 and R1 Superior Carbonates of the Miskar Field, offshore Tunisia are of Coniacian-Turonian age. These ages are constrained by several biostratigraphic events including a rapid increase in ostracod diversity at the base of the overlying Aleg Formation and the occurrence of several diagnostic benthonic foraminifera including Rotalia algeriana. The indication is that the R1 and R1 Superior Carbonates are the lateral equivalents, in part, of the Douleb Formation which is a known reservoir, onshore Tunisia. During the Coniacian-Turonian the area of the Miskar Field was subject to regional extension with the opening of several major North-South trending fractures. These culminate in the contemporaneous outpouring of submarine serpentinized volcanics during deposition of the R1 Superior/Aleg Formation. The R1 lithologies are deposited in a shallow water regime and consist of rudist buildup and debraic carbonates overlain by lagoonal facies in the North with an increase in beach/sabkha facies to the South. The indication is for a shallowing upward sequence and a general progradation of lithofacies northwards across a tilted block. In contrast the R1 Superior is indicative of a flooding event with relative sea-level changes reflected in variations of both lithofacies and biofacies. Overall the lithofacies are dominated by calcispheric/bioclastic wackestone-packstones probably deposited in a mid-platform setting. The diagenetic history of the R1 is the more complex of the two carbonate sequences reflecting several phases of fluid movement through the constituent lithologies. Original depositional characteristics and subsequent diagenetic meditation result in the development of highly variable reservoir properties.

  10. Offshore deck to substructure mating system and method

    SciTech Connect

    Datta, B.N.; Baldwin, R.L.; Allen, J.D.

    1993-06-15

    An offshore platform, in combination, a deck for installation to be supported by a substructure is described including a plurality of upstanding column members, said deck including a corresponding plurality of depending legs, the improvement characterized by: at least one of said legs including a stabbing tip assembly for engagement with a corresponding column member, said stabbing tip assembly comprising an outer body for engagement with said column member to transfer permanent weight of said deck to said column member, a generally vertically movable locating pin disposed in said body for movement to stab into receiver means including means forming a receptacle on said column member for locating said dock with respect to said column member, and resilient means supported by said body for accommodating lateral and vertically-imposed loads acting between said column member and said leg during placement of said deck on said substructure to minimize the imposition of peak forces on said deck and said substructure; said receiver means comprising a generally cylindrical receiver shoe forming said receptacle, said shoe comprising part of a jack assembly supported on said column member and said shoe being operable to be moved to a position to permit contact of said leg with said column member to provide supporting relationship therebetween; and said jack assembly comprising a generally cylindrical body member supported on said column member and forming a chamber with said shoe for receiving particulate material to support said shoe in a first position for receiving said locating pin, said shoe being movable to a second position in response to removing said particulate material from said chamber to permit movement of said leg into engagement with said body member.

  11. Platforms for antibiotic discovery.

    PubMed

    Lewis, Kim

    2013-05-01

    The spread of resistant bacteria, leading to untreatable infections, is a major public health threat but the pace of antibiotic discovery to combat these pathogens has slowed down. Most antibiotics were originally isolated by screening soil-derived actinomycetes during the golden era of antibiotic discovery in the 1940s to 1960s. However, diminishing returns from this discovery platform led to its collapse, and efforts to create a new platform based on target-focused screening of large libraries of synthetic compounds failed, in part owing to the lack of penetration of such compounds through the bacterial envelope. This article considers strategies to re-establish viable platforms for antibiotic discovery. These include investigating untapped natural product sources such as uncultured bacteria, establishing rules of compound penetration to enable the development of synthetic antibiotics, developing species-specific antibiotics and identifying prodrugs that have the potential to eradicate dormant persisters, which are often responsible for hard-to-treat infections.

  12. R & D on Offshore Wind Power Generation System in Japan

    NASA Astrophysics Data System (ADS)

    Oishi, Kazuhito; Fukumoto, Yukinari

    Offshore wind energy has been widely exploited in Europe. Having a long coastline, the offshore wind energy will be the one of the important solutions for the increase of renewable energy in Japan. However, due to the difference in wind and marine condition between Japan and Europe, the safety, the environmental impact and the economical feasibility of the offshore wind power generation system have to be investigated in Japan. According to the data observed offshore, the wind speed is enough higher than that on land and the wind energy is economically feasible. In order to utilize the energy, the design method of the foundation against very high waves in typhoon storm should be established. For shallow offshore coastal area, gravity foundation type has been improved by hydraulic experiment. Additionally, for deeper ocean, floating types such as semi-submersible float and spar-buoy have been researched.

  13. The Personal Motion Platform

    NASA Technical Reports Server (NTRS)

    Park, Brian Vandellyn

    1993-01-01

    The Neutral Body Posture experienced in microgravity creates a biomechanical equilibrium by enabling the internal forces within the body to find their own balance. A patented reclining chair based on this posture provides a minimal stress environment for interfacing with computer systems for extended periods. When the chair is mounted on a 3 or 6 axis motion platform, a generic motion simulator for simulated digital environments is created. The Personal Motion Platform provides motional feedback to the occupant in synchronization with their movements inside the digital world which enhances the simulation experience. Existing HMD based simulation systems can be integrated to the turnkey system. Future developments are discussed.

  14. Manipulator mounted transfer platform

    DOEpatents

    Dobbins, James C.; Hoover, Mark A.; May, Kay W.; Ross, Maurice J.

    1990-01-01

    A transfer platform for the conveyance of objects by a manipulator includes a bed frame and saddle clamp secured along an edge of the bed frame and adapted so as to secure the bed frame to a horizontal crosspiece of the manipulator. The platform may thus move with the manipulator in a reciprocal linear path defined by a guide rail. A bed insert may be provided for the support of conveyed objects and a lifting bail may be provided to permit the manipulator arm to install the bed frame upon the crosspiece under remote control.

  15. Proceedings of the 15. international conference on offshore mechanics and arctic engineering -- OMAE 1996. Volume 1, Part B: Offshore technology

    SciTech Connect

    Chakrabarti, S.K.; Pontes, M.T.; Maeda, Hisaaki; Falzarano, J.; Schofield, P.; Morrison, D.

    1996-12-31

    The 49 papers contained in Part B of Volume 1 are arranged under the following topical sections: Computational hydrodynamics; Floating and moored systems; Ocean energy technology; Hydrodynamic design of offshore structures; Design and operation of offshore structures; and Risers and cables. Most of the papers have been processed separately for inclusion on the data base.

  16. Education Platforms for America

    ERIC Educational Resources Information Center

    District Administration, 2012

    2012-01-01

    What is at stake for K12 education in next month's presidential election? Both President Barack Obama (Democratic Party) and Gov. Mitt Romney (Republican Party) say improving education will be a top priority in their administrations, but their policies and initiatives would likely be quite different. While political platforms rarely offer detailed…

  17. Evolution and hydrocarbon potential of offshore Pinar Del Rio area, Southern Gulf of Mexico

    SciTech Connect

    Tenreyro-Perez, R.; Lopez-Rivera, J.G.; Fernandez-Carmona, J.; Lopez-Quintero, J.O.

    1996-09-01

    The evolution of Southeast Gulf of Mexico comprises three main periods: pre-orogenic, syn-orogenic and post-orogenic. During pre-orogenic time, from Lower Jurassic to Campanian, the stages are the rift of Pangaea and the thermal subsidence (or drift). In drift stage two domains interacted in the space; the carbonate platforms (Bahamas, Yucatan, Organos and others), and the deepwater basins. These fluctuations were dictated by the differential subsidence and horizontal displacements of basement blocks as well as by the eustatic movements of the ocean. The Organos platform, for example, was entirely drowned since Upper Jurassic and the sedimentation continued in deepwater environment. The collision between Great Antilles Volcanic Arc and the continental margins since Upper Cretaceous modeled the Cuban orogen. Here, the southern facies thrusted over the northern section with simultaneous strike-slip movements. The interaction suddenly ceased in Eocene. The source rock levels are considerably more frequent in the deepwater domain than in the platforms. The Lower and Upper Jurassic as well as Lower and Middle Cretaceous horizons contain very high levels of organic matter. The offshore seismic shows the transition from the thrusted belt to the foreland basin with a typical triangle zone configuration. Reservoirs are expected in the Cretaceous section covered by seals conformed by early foreland basin sediments of Upper Cretaceous-Paleocene age. Foothill structures has a great potential for hydrocarbon exploration.

  18. Geospatial characteristics of Florida's coastal and offshore environments: Administrative and political boundaries and offshore sand resources

    USGS Publications Warehouse

    Demopoulos, Amanda W.J.; Foster, Ann M.; Jones, Michal L.; Gualtieri, Daniel J.

    2011-01-01

    The Geospatial Characteristics Geopdf of Florida's Coastal and Offshore Environments is a comprehensive collection of geospatial data describing the political and natural resources of Florida. This interactive map provides spatial information on bathymetry, sand resources, military areas, marine protected areas, cultural resources, locations of submerged cables, and shipping routes. The map should be useful to coastal resource managers and others interested in the administrative and political boundaries of Florida's coastal and offshore region. In particular, as oil and gas explorations continue to expand, the map may be used to explore information regarding sensitive areas and resources in the State of Florida. Users of this geospatial database will find that they have access to synthesized information in a variety of scientific disciplines concerning Florida's coastal zone. This powerful tool provides a one-stop assembly of data that can be tailored to fit the needs of many natural resource managers.

  19. Mobile Platform for Large Structures

    NASA Technical Reports Server (NTRS)

    Wesselski, C. J.; Schneider, W. C.

    1987-01-01

    Proposed platform moves forward and in reverse, turns left and right, and changes planes. Mobile-platform concept proposed to move remote manipulators, workers, or other loads over truss panels on large structures. Platform moves at constant speed so does not cause swinging motion in hanging loads and overstress remote-manipulator arms. Transferred around corners to adjacent panels. Platform rides on sprocketed guide pins extending from structure at truss joints. Set of orthogonal tracks under platform slides on pins, which have enlarged heads to interlock with tracks. At least three tracks engage at least three pins at any position on panel so platform adequately and stably supported.

  20. On the Offshore Advection of Boundary-Layer Structures and the Influence on Offshore Wind Conditions

    NASA Astrophysics Data System (ADS)

    Dörenkämper, Martin; Optis, Michael; Monahan, Adam; Steinfeld, Gerald

    2015-06-01

    The coastal discontinuity imposes strong signals to the atmospheric conditions over the sea that are important for wind-energy potential. Here, we provide a comprehensive investigation of the influence of the land-sea transition on wind conditions in the Baltic Sea using data from an offshore meteorological tower, data from a wind farm, and mesoscale model simulations. Results show a strong induced stable stratification when warm inland air flows over a colder sea. This stratification demonstrates a strong diurnal pattern and is most pronounced in spring when the land-sea temperature difference is greatest. The strength of the induced stratification is proportional to this parameter and inversely proportional to fetch. Extended periods of stable stratification lead to increased influence of inertial oscillations and increased frequency of low-level jets. Furthermore, heterogeneity in land-surface roughness along the coastline is found to produce pronounced horizontal streaks of reduced wind speeds that under stable stratification are advected several tens of kilometres over the sea. The intensity and length of the streaks dampen as atmospheric stability decreases. Increasing sea surface roughness leads to a deformation of these streaks with increasing fetch. Slight changes in wind direction shift the path of these advective streaks, which when passing through an offshore wind farm are found to produce large fluctuations in wind power. Implications of these coastline effects on the accurate modelling and forecasting of offshore wind conditions, as well as damage risk to the turbine, are discussed.

  1. Underwater wet welding consumables for offshore applications

    SciTech Connect

    Sanchez-Osio, A.; Liu, S.; Olson, D.L.; Ibarra, S.

    1993-12-31

    The use of underwater wet welding for offshore repairs has been limited mainly because of porosity in the resulting welds. With appropriate consumable design, however, it is possible to enhance weld metal toughness through microstructural refinement and to reduce porosity. New titanium and boron based consumables have been developed with which high toughness acicular ferrite can be produced in underwater wet welds. Titanium, by means of oxide formation, promoted an increase in weld metal acicular ferrite, while boron additions decreased the amount of grain boundary ferrite, further improving the microstructure. Porosity reduction was possible through the addition of calcium carbonate at approximately 13 wt. % in the coating. However, weld metal decarburization also resulted with the addition.

  2. Offshore wind farm electrical cable layout optimization

    NASA Astrophysics Data System (ADS)

    Pillai, A. C.; Chick, J.; Johanning, L.; Khorasanchi, M.; de Laleu, V.

    2015-12-01

    This article explores an automated approach for the efficient placement of substations and the design of an inter-array electrical collection network for an offshore wind farm through the minimization of the cost. To accomplish this, the problem is represented as a number of sub-problems that are solved in series using a combination of heuristic algorithms. The overall problem is first solved by clustering the turbines to generate valid substation positions. From this, a navigational mesh pathfinding algorithm based on Delaunay triangulation is applied to identify valid cable paths, which are then used in a mixed-integer linear programming problem to solve for a constrained capacitated minimum spanning tree considering all realistic constraints. The final tree that is produced represents the solution to the inter-array cable problem. This method is applied to a planned wind farm to illustrate the suitability of the approach and the resulting layout that is generated.

  3. Recent advances in offshore pipeline technology

    SciTech Connect

    Bruschi, R.; Vitali, L.

    1994-12-31

    Since the pioneering construction of the TRANSMED pipeline system across the Sicily Channel in the early 80`s, offshore pipeline technology has been progressing towards more and more difficult environments. Now the projects envisaged for the 90`s are venturing far beyond the challenges of the recent past. The scope of this paper is to present the recent research efforts aimed at tackling the main design aspects of the new challenges. Particular attention will be given to the experiences and achievements on the last few years in transmission pipelines across the European Continental Shelf, e.g. in the Central and Southern North Sea and across the Mediterranean Sea. Technologies, tools and purpose developed criteria will be discussed. The performance of current operating pipeline systems will be reviewed and incentives to rationalize design criteria and guidelines will be illustrated.

  4. Troll, Haltenpipe showcase offshore pipelay advances

    SciTech Connect

    Blaker, F.; Gjertveit, E.; Breivik, J.

    1996-07-29

    Pipelines installed on the Norwegian continental shelf represent current offshore pipeline installation technology for pipe size (up to 40 in.), water depth (to 540 m) distance between pigging stations (up to 800 km), and complex seabed intervention and landfall construction. Furthermore, the number of deepwater pipelines worldwide has triggered significant advances in the development of pipeline repair. The Troll oil pipeline and Haltenpipe projects faced technical challenges: irregular seabed, conditions requiring highly accurate mapping, careful routing, free-span design, seabed preparation works, and special low-tension lay techniques. The two projects, therefore, have in many ways benefited from each other and been run practically as one large integrated project. The paper describes the design, route preparation, and installation for both pipelines.

  5. Storage of carbon dioxide in offshore sediments.

    PubMed

    Schrag, Daniel P

    2009-09-25

    The battle to reduce greenhouse gas emissions and prevent the most dangerous consequences of climate change will be waged across multiple fronts, including efforts to increase energy efficiency; efforts to deploy nonfossil fuel sources, including renewable and nuclear energy; and investment in adaptation to reduce the impacts of the climate change that will occur regardless of the actions we take. But with more than 80% of the world's energy coming from fossil fuel, winning the battle also requires capturing CO2 from large stationary sources and storing that CO2 in geologic repositories. Offshore geological repositories have received relatively little attention as potential CO2 storage sites, despite their having a number of important advantages over onshore sites, and should be considered more closely.

  6. Offshore structure and method of sinking same

    SciTech Connect

    Fern, D. T.

    1985-02-05

    An offshore structure and a method of skinking it to the sea bed. In accordance with one aspect of this invention, the structure is sunk asymmetrically by first sinking a first end portion thereof and then sinking the other end portion. The first end portion is sunk by ballasting it while the other end portion is closed to ballast. The structure is provided with sufficient water plane area while sinking each end portion to maintain stability during the sinking process. In accordance with another aspect of this invention, at least two spaced-apart piles are provided at the end corresponding to the first end portion to absorb the force of impact with the sea bed and to maintain a skirt on the structure out of contact with the sea bed until both ends of the structure have been sunk to the sea bed.

  7. Quantifying the hurricane catastrophe risk to offshore wind power.

    PubMed

    Rose, Stephen; Jaramillo, Paulina; Small, Mitchell J; Apt, Jay

    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. We present a method to estimate the catastrophe risk to offshore wind power using simulated hurricanes. Using this method, we estimate the fraction of offshore wind power simultaneously offline and the cumulative damage in a region. In Texas, the most vulnerable region we studied, 10% of offshore wind power could be offline simultaneously because of hurricane damage with a 100-year return period and 6% could be destroyed in any 10-year period. We also estimate the risks to single wind farms in four representative locations; we find the risks are significant but lower than those estimated in previously published results. 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.

  8. Offshore based WARP{trademark} Power Spar buoys for multi-megawatt wind power plants

    SciTech Connect

    Weisbrich, A.L.; Rhodes, A.F.

    1998-12-31

    Since the earliest use of wind as a stationary power source, major consideration and effort has gone into the selection of a location with relatively high wind speed as well as proximity to the place of energy demand. As wind speed increases, collectible energy from the wind increases by the third power. That is, in a location with 20% higher wind speed, it is possible to generate 73% more power. If 50% higher wind velocity is available, 300% more power and energy can be generated. In the ideal, an offshore wind power plant should be easily and relatively inexpensively constructed, and economically sited in any depth water. In addition to these characteristics, if the typically excellent offshore winds could be amplified by as much as 50% to 80% and captured by low cost, highly reliable aircraft propeller sized wind turbines, substantial cost effectiveness and practicality would result. ENECO`s Wind amplified Rotor Platform (WARP{trademark}) Power Spar buoy system design appears to have the features needed to achieve these objectives and is proposed for test and commercialization.

  9. Applying a New Event Detection Algorithm to an Ocean Bottom Seismometer Dataset Recorded Offshore Southern California

    NASA Astrophysics Data System (ADS)

    Bishop, J.; Kohler, M. D.; Bunn, J.; Chandy, K. M.

    2015-12-01

    A number of active southern California offshore faults are capable of M>6 earthquakes, and the only permanent Southern California Seismic Network stations that can contribute to ongoing, small-magnitude earthquake detection and location are those located on the coastline and islands. To obtain a more detailed picture of the seismicity of the region, an array of 34 ocean bottom seismometers (OBSs) was deployed to record continuous waveform data off the coast of Southern California for 12 months (2010-2011) as part of the ALBACORE (Asthenospheric and Lithospheric Broadband Architecture from the California Offshore Region Experiment) project. To obtain a local event catalog based on OBS data, we make use of a newly developed data processing platform based on Python. The data processing procedure comprises a multi-step analysis that starts with the identification of significant signals above the time-adjusted noise floor for each sensor. This is followed by a time-dependent statistical estimate of the likelihood of an earthquake based on the aggregated signals in the array. For periods with elevated event likelihood, an adaptive grid-fitting procedure is used that yields candidate earthquake hypocenters with confidence estimates that best match the observed sensor signals. The results are validated with synthetic travel times and manual picks. Using results from ALBACORE, we have created a more complete view of active faulting in the California Borderland.

  10. Time Dependent Fluid Occurrence Offshore Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, L.

    2010-12-01

    Time Dependent Fluid Occurrence Offshore Taiwan Liwen Chenab, Wu-Cheng Chia, Char-Shine Liuc (mma@earth.sinica.edu.tw)(wchi@gate.sinica.edu.tw) ; aInstitute of Earth Sciences, Academia Sinica, Taipei, Taiwan bInstitute of Geosciences, National Taiwan University, Taipei, Taiwan ; cInstitute of Oceanography, National Taiwan University, Taipei, Taiwan Earthquake-induced groundwater flows have been observed recently. Such fluid flow might temporarily change the temperature field in the crust. Here we used seismically detected gas hydrate under seafloor to study the temperature fields at a few hundred meters subbottom depth before, and after the 2006 Henchuan earthquake (Mw7.0). We used the hydrate-related bottom-simulating-reflector (BSR) in seismic profiles to study the effects of gas/fluid migration on the BSR attributes. We have conducted two seismic experiments before and after the earthquake across the same transects near the hypocenter of the earthquake using similar air gun arrays and streamers. By analyzing this unique dataset, we found enhanced BSR reflectivity in average after the earthquake (~0.03), but the Sea-floor reflectivity is very similar (~0.5). We also found changed amplitudes versus offset (AVO) in the dataset (the gradient of reflection coefficient versus the angles was ~-0.34). We interpret these results as a consequence of earthquake-induced gas and fluid migration, bringing the gases underneath the BSR, thus the enhanced reflection coefficients. Next we will explore new methods to use the BSR as a flow meter. Using time-dependent seismic attribute analyses across transects before and after a large earthquake, we found strong evidences of earthquake-related fluid migrations and possibly associated temperature perturbations. This is among the first studies to document such feature in the offshore region.

  11. Beyond offshoring: assess your company's global potential.

    PubMed

    Farrell, Diana

    2004-12-01

    In the past few years, companies have become aware that they can slash costs by offshoring: moving jobs to lower-wage locations. But this practice is just the tip of the iceberg in terms of how globalization can transform industries, according to research by the McKinsey Global Institute (MGI). The institute's yearlong study suggests that by streamlining their production processes and supply chains globally, rather than just nationally or regionally, companies can lower their costs-as we've seen in the consumer-electronics and PC industries. Companies can save as much as 70% of their total costs through globalization--50% from offshoring, 5% from training and business-task redesign, and 15% from process improvements. But they don't have to stop there. The cost reductions make it possible to lower prices and expand into new markets, attracting whole new classes of customers. To date, however, few businesses have recognized the full scope of performance improvements that globalization makes possible, much less developed sound strategies for capturing those opportunities. In this article, Diana Farrell, director of MGI, offers a step-by-step approach to doing both things. Among her suggestions: Assess where your industry falls along the globalization spectrum, because not all sectors of the economy face the same challenges and opportunities at the same time. Also, pay attention to production, regulatory, and organizational barriers to globalization. If any of these can be changed, size up the cost-saving (and revenue-generating) opportunities that will emerge for your company as a result of those changes. Farrell also defines the five stages of globalization-market entry, product specialization, value chain disaggregation, value chain reengineering, and the creation of new markets-and notes the different levers for cutting costs and creating value that companies can use in each phase.

  12. Offshore Deformation Front in Miaoli Area

    NASA Astrophysics Data System (ADS)

    Chiang, P.; Gwo-shyn, S.

    2015-12-01

    Taiwan is located at the junction of the Eurasian Plate and the Philippine Sea Plate. It's because arc-continent collision occurs in the western Taiwan, resulting in the orogeny has formed a fold-and-thrust belt, developing a series of thrusts aligned in north-south direction. The thrust faults, locating in the central island, are the oldest and have almost inactive. Westward to the island, the faults become younger, dipping angles are smaller, and motions were stronger. On the west side, the foot of the Taiwan Western Foothill is considered the youngest thrust faults located along west Taiwan. Scholars recognized them as so-called the deformation front, and they also believed that the deformation front is located in between the compressive terrain uplifted area and the extensional subsidence area. Therefore, this front line is on the boundary of two different tectonic zones. This study investigates the trace of the deformation front in Miaoli area. Previous studies suggested that the west side of Miaoli collision zone should be fault-bounded, and is located in the seabed. However, in the geological map, there is no geologic evidence that appears on land and so-called active faults related with this deformation front. In the near coast seafloor, according to the reflection earthquakes data from the Institute of Oceanography of NTU, we can only see the offshore strata have been uplifted, and the data also shows that seabed is only covered by thin layer of sediments. This study indicates that in offshore place within three kilometers, shallow formations show a special layer of slime which was extruded to be corrugated transversely. Accordingly, we believe that this slime layer should be pressurized and filled with muddy water. Such features should be further investigated with other geological and geophysical survey data to check if they belong to the structural product of the deformation front.

  13. 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.

  14. The cost effective use of pultruded composite mud-mats in offshore structures

    SciTech Connect

    Porcari, A.M.; Spessa, A.

    1993-12-31

    This paper describes the development and application of pultruded fiber-reinforced plastic mud-mats used as primary load-bearing structural components in the construction of the offshore platform ``Garibaldi C``, recently installed by AGIP S.p.A. in the Adriatic sea. The pultruded composite elements were used as an alternative to traditional steel structures. The mechanical and functional performance of the composite mud-mats are the same. The cost advantages are coming from weight savings, from the necessity of a lower number of aluminum anodes, from the construction procedures used in the yard and from the installation of the jacket performed with a lifting vessel of a lower class. The solutions of particular problems connected with the design and construction of composite mud-mats, as well as cost advantages, are illustrated and discussed.

  15. Three-point flanged skid for turbomachinery off-shore installation

    SciTech Connect

    Bartolozzi, S.; Cianferoni, G.; Generosi, S.

    1996-12-31

    One of the most important aspects to be considered in offshore installation of turbomachinery is the interface between the machine skid and the main structure. The whole structural design must be such that under the most severe static and dynamic loads machine alignment is maintained to acceptable levels whether the rotating machinery is installed in a module or directly on the platform deck. Two structural solutions achieve the above conditions; the multipoint skid, typically used the main structural stiffness permitting, and the three point skid that is used whenever the main structure displacements are too high for conventional baseplates. Three-point skids are being used increasingly because they can withstand displacement of their supporting deck without being affected by additional stresses or misalignment. This article describes a coupled skid arrangement, its geometrical characteristics and the relevant finite-element method of verification, as well as two projects in which it has been successfully applied.

  16. Mobility platform coupling device and method for coupling mobility platforms

    DOEpatents

    Shirey, David L.; Hayward, David R.; Buttz, James H.

    2002-01-01

    A coupling device for connecting a first mobility platform to a second mobility platform in tandem. An example mobility platform is a robot. The coupling device has a loose link mode for normal steering conditions and a locking position, tight link mode for navigation across difficult terrain and across obstacles, for traversing chasms, and for navigating with a reduced footprint in tight steering conditions.

  17. Evolution of the central Walvis Basin / offshore NW Namibia - balancing onshore erosion and offshore sedimentation

    NASA Astrophysics Data System (ADS)

    Henk, A.; Kukulus, M.; Junker, R.

    2003-04-01

    Rifting and break-up of Gondwana in the Late Jurassic / Early Cretaceous led to formation of the South Atlantic. One of the associated passive margins, the Walvis Basin in NW Namibia, is used as a case study to investigate the mass and process balances which link uplift and erosion onshore to contemporaneous subsidence and sedimentation offshore. One of the main objectives of the project is to gain quantitative insights into the feedback mechanisms between surface processes and lithospheric processes during passive margin evolution. Modeling concentrates on a traverse across the central Walvis Basin and adjacent onshore areas. Mass balancing requires a reconstruction of the denudation history and the volumes eroded onshore as well as a quantification of the contemporaneous sedimentary record preserved offshore. In the offshore parts of the study area, seismic sections and well data are available to constrain the post-rift evolution of the Walvis basin. However, as none of the exploration wells has yet reached syn-rift deposits, the early margin evolution has to remain speculative. In the onshore part of the traverse, field evidence and published apatite fission track data are used to reconstruct the erosion history. Comparison of the eroded and deposited volumes and masses, respectively, reveals a misfit of about 50 %, i.e. only half of the sediments observed offshore can be attributed to nearby source areas onshore. This result is supported by provenance analysis on cuttings from an offshore well which indicate that a substantial part of the detritus was derived from sources to the south and transported to the central Walvis Basin by coast-parallel currents. Sediment supply rates derived from reconstruction of the onshore erosion history and subsidence rates based on lithospheric cooling models together with global sea level changes are then used to model quantitatively deposition and stratigraphic architectures of the post-rift succession in the central Walvis

  18. Offshore asphaltene and wax deposition: Problems/solutions

    SciTech Connect

    Leontaritis, K.J. |

    1996-05-01

    Many production facilities around the world suffer from either asphaltene or wax deposition. Such problems seriously threaten economic production from many offshore reservoirs due to the high cost of remedial measures. Offshore facilities are especially susceptible to such deposition for a number of reasons. This article presents ideas and methodologies on how to predict, diagnose, prevent, or mitigate problems caused by organic deposition in offshore production facilities. In one facility where these ideas were put to use, despite the debilitating magnitude of the problems, the field has been produced for more than 14 years with minimum environmental impact. Principal conclusions developed are discussed in this paper.

  19. Assessment of Offshore Wind System Design, Safety, and Operation Standards

    SciTech Connect

    Sirnivas, S.; Musial, W.; Bailey, B.; Filippelli, M.

    2014-01-01

    This report is a deliverable for a project sponsored by the U.S. Department of Energy (DOE) entitled National Offshore Wind Energy Resource and Design Data Campaign -- Analysis and Collaboration (contract number DE-EE0005372; prime contractor -- AWS Truepower). The project objective is to supplement, facilitate, and enhance ongoing multiagency efforts to develop an integrated national offshore wind energy data network. The results of this initiative are intended to 1) produce a comprehensive definition of relevant met-ocean resource assets and needs and design standards, and 2) provide a basis for recommendations for meeting offshore wind energy industry data and design certification requirements.

  20. Evaluation of offshore penetration tests at El Palito refinery, Venezuela

    SciTech Connect

    Rodriguez, J.I.; Simone, A.; Tichatscheck, C.; Boggess, R.

    1995-12-01

    Data from an offshore study in the western part of Venezuela are presented in terms of the penetration test data and liquefaction evaluation. Two types of penetration test were performed (SPT and DCPT) and the results of each are compared. This was made possible by the comparison testing performed at two different locations where the separation between boreholes with different penetration tests was small enough to allow direct comparison of the results. To the authors` knowledge, this is the first time that dynamic cone measurements have been made in an offshore environment. Comments in relation to the evaluation of liquefaction resistance based on the results of the offshore penetration testing are made.

  1. California State Waters Map Series: offshore of San Francisco, California

    USGS Publications Warehouse

    Cochrane, Guy R.; Johnson, Samuel Y.; Dartnell, Peter; Greene, H. Gary; Erdey, Mercedes D.; Golden, Nadine E.; Hartwell, Stephen R.; Endris, Charles A.; Manson, Michael W.; Sliter, Ray W.; Kvitek, Rikk G.; Watt, Janet Tilden; Ross, Stephanie L.; Bruns, Terry R.; Cochrane, Guy R.; Cochran, Susan A.

    2015-01-01

    Circulation over the continental shelf in the Offshore of San Francisco map area is dominated by the southward-flowing California Current, an eastern limb of the North Pacific Gyre that flows from Oregon to Baja California. At its midpoint offshore of central California, the California Current transports subarctic surface waters southeastward, about 150 to 1,300 km from shore. Seasonal northwesterly winds that are, in part, responsible for the California Current, generate coastal upwelling. Ocean temperatures offshore of central California have increased over the past 50 years, driving an ecosystem shift from the productive subarctic regime towards a depopulated subtropical environment.

  2. NREL Software Aids Offshore Wind Turbine Designs (Fact Sheet)

    SciTech Connect

    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.

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

    SciTech Connect

    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. Six 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.

  4. OGC Collaborative Platform undercover

    NASA Astrophysics Data System (ADS)

    Buehler, G.; Arctur, D. K.; Bermudez, L. E.

    2012-12-01

    The mission of the Open Geospatial Consortium (OGC) is to serve as a global forum for the collaboration of developers and users of spatial data products and services, and to advance the development of international standards for geospatial interoperability. The OGC coordinates with over 400 institutions in the development of geospatial standards. OGC has a dedicated staff supported by a Collaborative Web Platform to enable sophisticated and successful coordination among its members. Since its origins in the early 1990s, the OGC Collaborative Web Platform has evolved organically to be the collaboration hub for standards development in the exchange of geospatial and related types of information, among a global network of thousands of technical, scientific and management professionals spanning numerous disparate application domains. This presentation describes the structure of this collaboration hub, the relationships enabled (both among and beyond OGC members), and how this network fits in a broader ecosystem of technology development and information standards organizations.

  5. Common tester platform concept.

    SciTech Connect

    Hurst, Michael James

    2008-05-01

    This report summarizes the results of a case study on the doctrine of a common tester platform, a concept of a standardized platform that can be applicable across the broad spectrum of testing requirements throughout the various stages of a weapons program, as well as across the various weapons programs. The common tester concept strives to define an affordable, next-generation design that will meet testing requirements with the flexibility to grow and expand; supporting the initial development stages of a weapons program through to the final production and surveillance stages. This report discusses a concept investing key leveraging technologies and operational concepts combined with prototype tester-development experiences and practical lessons learned gleaned from past weapons programs.

  6. Secure Sensor Platform

    SciTech Connect

    Troy Ross, Barry Schoeneman

    2010-08-25

    The Secure Sensor Platform (SSP) software provides a framework of functionality to support the development of low-power autonomous sensors for nuclear safeguards. This framework provides four primary functional blocks of capabilities required to implement autonomous sensors. The capabilities are: communications, security, power management, and cryptography. Utilizing this framework establishes a common set of functional capabilities for seamless interoperability of any sensor based upon the SSP concept.

  7. HPC - Platforms Penta Chart

    SciTech Connect

    Trujillo, Angelina Michelle

    2015-10-08

    Strategy, Planning, Acquiring- very large scale computing platforms come and go and planning for immensely scalable machines often precedes actual procurement by 3 years. Procurement can be another year or more. Integration- After Acquisition, machines must be integrated into the computing environments at LANL. Connection to scalable storage via large scale storage networking, assuring correct and secure operations. Management and Utilization – Ongoing operations, maintenance, and trouble shooting of the hardware and systems software at massive scale is required.

  8. "Platform switching": serendipity.

    PubMed

    Kalavathy, N; Sridevi, J; Gehlot, Roshni; Kumar, Santosh

    2014-01-01

    Implant dentistry is the latest developing field in terms of clinical techniques, research, material science and oral rehabilitation. Extensive work is being done to improve the designing of implants in order to achieve better esthetics and function. The main drawback with respect to implant restoration is achieving good osseointegration along with satisfactory stress distribution, which in turn will improve the prognosis of implant prosthesis by reducing the crestal bone loss. Many concepts have been developed with reference to surface coating of implants, surgical techniques for implant placement, immediate and delayed loading, platform switching concept, etc. This article has made an attempt to review the concept of platform switching was in fact revealed accidentally due to the nonavailability of the abutment appropriate to the size of the implant placed. A few aspect of platform switching, an upcoming idea to reduce crestal bone loss have been covered. The various methods used for locating and preparing the data were done through textbooks, Google search and related articles.

  9. The Prodiguer Messaging Platform

    NASA Astrophysics Data System (ADS)

    Greenslade, Mark; Denvil, Sebastien; Raciazek, Jerome; Carenton, Nicolas; Levavasseur, Guillame

    2014-05-01

    CONVERGENCE is a French multi-partner national project designed to gather HPC and informatics expertise to innovate in the context of running French climate models with differing grids and at differing resolutions. Efficient and reliable execution of these models and the management and dissemination of model output (data and meta-data) are just some of the complexities that CONVERGENCE aims to resolve. The Institut Pierre Simon Laplace (IPSL) is responsible for running climate simulations upon a set of heterogenous HPC environments within France. With heterogeneity comes added complexity in terms of simulation instrumentation and control. Obtaining a global perspective upon the state of all simulations running upon all HPC environments has hitherto been problematic. In this presentation we detail how, within the context of CONVERGENCE, the implementation of the Prodiguer messaging platform resolves complexity and permits the development of real-time applications such as: 1. a simulation monitoring dashboard; 2. a simulation metrics visualizer; 3. an automated simulation runtime notifier; 4. an automated output data & meta-data publishing pipeline; The Prodiguer messaging platform leverages a widely used open source message broker software called RabbitMQ. RabbitMQ itself implements the Advanced Message Queue Protocol (AMPQ). Hence it will be demonstrated that the Prodiguer messaging platform is built upon both open source and open standards.

  10. North Sea platforms revamped

    SciTech Connect

    O'Hare, J.

    1999-12-01

    Many of the early North Sea platforms are reaching their end-of-field life. Most are still equipped with their original drilling package. In a few cases the package has either been removed or decommissioned. The early installations were designed for much simpler and less demanding wells than the horizontal, extended-reach or designer wells common today. Extended-reach wells now can be drilled realistically from ageing platforms, without incurring massive capital expenditure. This can be achieved using the existing drilling package to the limit of its capabilities and supplementing where necessary with relatively minor upgrades or the use of temporary equipment. Drilling even a few more wells from existing platforms not only prolongs field life, it enables any surplus processing capacity to be made available to develop near-field potential with extended-reach drilling (ERD) or by tying back subsea satellite wells, or for processing third-party fluids. The paper describes well design, surface equipment, mud pumps, shakers and solids control equipment, drill cuttings disposal systems, derrick and hoisting system, top drive and drillstring, downhole equipment, well planning, casing wear, logistics, rig preparations, and ERD vs. subsea tie-backs.

  11. The Prodiguer Messaging Platform

    NASA Astrophysics Data System (ADS)

    Denvil, S.; Greenslade, M. A.; Carenton, N.; Levavasseur, G.; Raciazek, J.

    2015-12-01

    CONVERGENCE is a French multi-partner national project designed to gather HPC and informatics expertise to innovate in the context of running French global climate models with differing grids and at differing resolutions. Efficient and reliable execution of these models and the management and dissemination of model output are some of the complexities that CONVERGENCE aims to resolve.At any one moment in time, researchers affiliated with the Institut Pierre Simon Laplace (IPSL) climate modeling group, are running hundreds of global climate simulations. These simulations execute upon a heterogeneous set of French High Performance Computing (HPC) environments. The IPSL's simulation execution runtime libIGCM (library for IPSL Global Climate Modeling group) has recently been enhanced so as to support hitherto impossible realtime use cases such as simulation monitoring, data publication, metrics collection, simulation control, visualizations … etc. At the core of this enhancement is Prodiguer: an AMQP (Advanced Message Queue Protocol) based event driven asynchronous distributed messaging platform. libIGCM now dispatches copious amounts of information, in the form of messages, to the platform for remote processing by Prodiguer software agents at IPSL servers in Paris. Such processing takes several forms: Persisting message content to database(s); Launching rollback jobs upon simulation failure; Notifying downstream applications; Automation of visualization pipelines; We will describe and/or demonstrate the platform's: Technical implementation; Inherent ease of scalability; Inherent adaptiveness in respect to supervising simulations; Web portal receiving simulation notifications in realtime.

  12. 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.

  13. Model test of an inverted conical cylinder floating offshore wind turbine moored by a spring-tensioned-leg

    NASA Astrophysics Data System (ADS)

    Shin, Hyunkyoung; Cho, Sangrai; Jung, Kwangjin

    2014-03-01

    A new 5-MW floating offshore wind turbine moored by a spring-tensioned-leg was proposed for installa­tion in about 50m water depth. Its substructure is a platform of the inverted conical cylinder type with massive ballast weight plate at the bottom. A 1:128 scale model was built for the preliminary engineering development. The model tests in waves and wind were carried out to estimate motion characteristics of this platform in the Ocean Engineering Wide Tank of the University of Ulsan. Its motions were measured and the RAOs were compared. The proposed floating off­shore wind turbine showed a good stability and decent responses in waves, wind and operation of the wind turbine.

  14. Mapping Active Faults and Tectonic Geomorphology offshore central California

    NASA Astrophysics Data System (ADS)

    Johnson, S. Y.; Watt, J. T.; Hart, P. E.; Sliter, R. W.; Wong, F. L.

    2009-12-01

    In June 2008, and July 2009, the USGS conducted two high-resolution, marine, seismic-reflection surveys across the continental shelf and upper slope between Piedras Blancas and Point Sal, central California, in order to better characterize regional earthquake sources. More than 1,300 km of single-channel seismic data were acquired aboard the USGS R/V Parke Snavely using a 500-joule mini-sparker source fired at a 0.5-second shot interval and recorded with a 15-meter streamer. Most tracklines were run perpendicular to the coast at 800-meter spacing, extending from the nearshore (~ 10-15 m water depth) to as far as 20 km offshore. Sub-bottom imaging varies with substrate, ranging from outstanding (100 to 150 m of penetration) in inferred Quaternary shallow marine, shelf and upper slope deposits to poor (0 to 10 m) in the Mesozoic basement rocks. Marine magnetic data were collected simultaneously on this survey, and both data sets are being integrated with new aeromagnetic data, publicly available industry seismic-reflection data, onshore geology, seismicity, and high-resolution bathymetry. Goals of the study are to map geology, structure, and sediment distribution; to document fault location, length, segmentation, shallow geometry and structure; and to identify possible sampling targets for constraining fault slip rates, earthquake recurrence, and tsunami hazard potential. The structure and tectonic geomorphology of the >100-km-long, right-lateral, Hosgri fault zone and its connections to the Los Osos, Pecho, Oceano and other northwest-trending inboard faults are the focus of this ongoing work. The Hosgri fault forms the eastern margin of the offshore Santa Maria basin and coincides in places with the outer edge of the narrow (5- to 15-km-wide), structurally complex continental shelf. The Hosgri is imaged as a relatively continuous, vertical fault zone that extends upward to the seafloor; varies significantly and rapidly along strike; and incorporates numerous

  15. 12. OFFSHORE VIEW OF PIER, LOOKING EAST, SHOWING LIFEGUARD TOWER ...

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

    12. OFFSHORE VIEW OF PIER, LOOKING EAST, SHOWING LIFEGUARD TOWER AND 2ND TEE (CENTER), REFUGE BAY (RIGHT) - Huntington Beach Municipal Pier, Pacific Coast Highway at Main Street, Huntington Beach, Orange County, CA

  16. 14. OFFSHORE VIEW OF PIER, LOOKING SOUTHEAST, SHOWING (LEFTRIGHT) PUMPHOUSE, ...

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

    14. OFFSHORE VIEW OF PIER, LOOKING SOUTHEAST, SHOWING (LEFT-RIGHT) PUMPHOUSE, TACKLE BOX, RESTROOMS ON 3RD TEE - Huntington Beach Municipal Pier, Pacific Coast Highway at Main Street, Huntington Beach, Orange County, CA

  17. The offshore drilling contract--operator and contractor perspectives

    SciTech Connect

    Rankin, M.D.; Richardson, D.R.

    1983-02-01

    This paper reports the results of a survey conducted as a means of accessing the factors which most often constitute points of conflict between operators and drilling contractors during offshore drilling contract negotiations.

  18. 46 CFR 131.320 - Safety orientation for offshore workers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... informing each offshore worker of— (1) In general terms, emergency and evacuation procedures; (2) Locations of emergency exits and of embarkation areas for survival craft; (3) Locations of stowage...

  19. A wind chart to characterize potential offshore wind energy sites

    NASA Astrophysics Data System (ADS)

    del Jesus, F.; Menéndez, M.; Guanche, R.; Losada, I. J.

    2014-10-01

    Offshore wind industry needs to improve wind assessment in order to decrease the uncertainty associated to wind resource and its influence on financial requirements. Here, several features related to offshore wind resource assessment are discussed, such as input wind data, estimation of long-term and extreme wind statistics, the wind profile and climate variations. This work proposes an analytical method to characterize wind resource. Final product is a wind chart containing useful wind information that can be applied to any offshore sites. Using long-term time series of meteorological variables (e.g. wind speed and direction at different heights), the methodology is applied to five pilot sites in different countries along European Atlantic corridor and it is used to describe and compare offshore wind behavior.

  20. Use of a mobile diving support vessel, Offshore California

    SciTech Connect

    Carroll, J.P.

    1983-03-01

    The Blue Dolphin is a converted workboat with a one-atmosphere manipulator bell diving system. It provides diving support for Chevron's offshore drilling program. This support includes underwater inspection, repair and salvage.

  1. “Open Hatch” Tour of Offshore Wind Buoy

    SciTech Connect

    Zayas, Jose

    2015-09-18

    Wind and Water Power Technologies Office Director, Jose Zayas gives a behind the scenes tour of the AXYS WindSentinel research buoy, which uses high-tech instruments to measure conditions for potential offshore wind energy development.

  2. Review of potential impacts to sea turtles from underwater explosive removal of offshore structures

    SciTech Connect

    Viada, Stephen T. Hammer, Richard M. Racca, Roberto Hannay, David Thompson, M. John Balcom, Brian J. Phillips, Neal W.

    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 of 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

  3. Epifauna dynamics at an offshore foundation--implications of future wind power farming in the North Sea.

    PubMed

    Krone, Roland; Gutow, Lars; Joschko, Tanja J; Schröder, Alexander

    2013-04-01

    In the light of the introduction of thousands of large offshore wind power foundations into the North Sea within the next decades, this manuscript focuses on the biofouling processes and likely reef effects. The study explores the macrozoobenthos (biofouling) colonization at an offshore platform which is comparable to offshore wind turbine foundations. A total of 183 single samples were taken and the parameters water depth and time were considered comparing biofouling masses and communities. The blue mussel Mytilus edulis, Anthozoa and the Amphipoda Jassa spp. were the dominant species. The community from the 1 m zone and those from the 5 and 20-28 m zones can clearly be differentiated. The 10 m zone community represents the transition between the M. edulis dominated 1 m and 5 m zones and the Anthozoa dominated 20-28 m zone. In the future offshore wind farms, thousands of wind turbine foundations will provide habitat for a hard bottom fauna which is otherwise restricted to the sparse rocky habitats scattered within extensive sedimentary soft bottoms of the German Bight. However, offshore wind power foundations cannot be considered natural rock equivalents as they selectively increase certain natural hard bottom species. The surface of the construction (1280 m²) was covered by an average of 4300 kg biomass. This foundation concentrates on its footprint area (1024 m²) 35 times more macrozoobenthos biomass than the same area of soft bottom in the German exclusive economic zone (0.12 kg m(-2)), functioning as a biomass hotspot. Concerning the temporal biomass variation, we assume that at least 2700 kg biomass was exported on a yearly basis. 345 × 10(4) single mussel shells of different sizes were produced during the study period. It is anticipated that the M. edulis abundance will increase in the North Sea due to the expansion of the offshore wind farm development. This will result in the enhanced production of secondary hard substrate (mussel shells

  4. Offshore Renewable Energy Installations: Impact on Navigation and Marine Safety

    DTIC Science & Technology

    2011-01-01

    To reduce our dependence on foreign energy supplies, alternative or renewable energy sources are being pursued. These sources exploit a wide range of...technologies: solar photovoltaics or power plants; hydroelectricity (dams); ocean thermal energy conversion facilities; and offshore renewable energy installations...to affect marine navigation and safety, and although no offshore renewable energy installations presently exist in U.S. waters, several are

  5. Offshore Wind Balance-of-System Cost Modeling

    SciTech Connect

    Maness, Michael; Stehly, Tyler; Maples, Ben; Mone, Christopher

    2015-09-29

    Offshore wind balance-of-system (BOS) costs contribute up to 70% of installed capital costs. Thus, it is imperative to understand the impact of these costs on project economics as well as potential cost trends for new offshore wind technology developments. As a result, the National Renewable Energy Laboratory (NREL) developed and recently updated a BOS techno-economic model using project cost estimates created from wind energy industry sources.

  6. Evaluation of offshore stocking of Lake Trout in Lake Ontario

    USGS Publications Warehouse

    Lantry, B.F.; O'Gorman, R.; Strang, T.G.; Lantry, J.R.; Connerton, M.J.; Schanger, T.

    2011-01-01

    Restoration stocking of hatchery-reared lake trout Salvelinus namaycush has occurred in Lake Ontario since 1973. In U.S. waters, fish stocked through 1990 survived well and built a large adult population. Survival of yearlings stocked from shore declined during 1990–1995, and adult numbers fell during 1998–2005. Offshore stocking of lake trout was initiated in the late 1990s in response to its successful mitigation of predation losses to double-crested cormorants Phalacrocorax auritus and the results of earlier studies that suggested it would enhance survival in some cases. The current study was designed to test the relative effectiveness of three stocking methods at a time when poststocking survival for lake trout was quite low and losses due to fish predators was a suspected factor. The stocking methods tested during 2000–2002 included May offshore, May onshore, and June onshore. Visual observations during nearshore stockings and hydroacoustic observations of offshore stockings indicated that release methods were not a direct cause of fish mortality. Experimental stockings were replicated for 3 years at one site in the southwest and for 2 years at one site in the southeast. Offshore releases used a landing craft to transport hatchery trucks from 3 to 6 km offshore out to 55–60-m-deep water. For the southwest site, offshore stocking significantly enhanced poststocking survival. Among the three methods, survival ratios were 1.74 : 1.00 : 1.02 (May offshore : May onshore : June onshore). Although not statistically significant owing to the small samples, the trends were similar for the southeast site, with survival ratios of 1.67 : 1.00 : 0.72. Consistent trends across years and sites indicated that offshore stocking of yearling lake trout during 2000–2002 provided nearly a twofold enhancement in survival; however, this increase does not appear to be great enough to achieve the 12-fold enhancement necessary to return population abundance to restoration

  7. 2014–2015 Offshore Wind Technologies Market Report

    SciTech Connect

    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.

  8. 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

  9. 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.

  10. A Crew Exposure Study. Volume 1. Offshore

    DTIC Science & Technology

    1984-06-01

    level contour I maps were generated for seven platforms and two rigs. Personal noise dosimetry data ’ were collected during drilling and tripping...limits. Noise dosimetry data were interpreted relative to the exposure guidelines in USCG Navigation and Vessel Inspection Circular (NVC 12-82). The... dosimetry data. Finally, this report could not have been pro- duced without the skill and patience of Mrs. Dorothy Endicott who typed the report

  11. Tertiary evolution of the northeastern Venezuela offshore

    NASA Astrophysics Data System (ADS)

    Ysaccis B., Raul

    1998-12-01

    On the northeastern offshore Venezuela, the pre-Tertiary basement consists of a deeply subducted accretionary complex of a Cretaceous island arc system that formed far to the west of its present location. The internal structure of this basement consists of metamorphic nappes that involve passive margin sequences, as well as oceanic (ophiolitic) elements. The Tertiary evolution of the northeastern Venezuela offshore is dominated by Paleogene (Middle Eocene-Oligocene) extension and Neogene transtension, interrupted by Oligocene to Middle Miocene inversions. The Paleogene extension is mainly an arc-normal extension associated with a retreating subduction boundary. It is limited to the La Tortuga and the La Blanquilla Basins and the southeastern Margarita and Caracolito subbasins. All of these basins are farther north of and not directly tied to the El Pilar fault system. On a reconstruction, these Paleogene extensional systems were located to the north of the present day Maracaibo Basin. By early Miocene the leading edge of the now overall transpressional system had migrated to a position to the north of the Ensenada de Barcelona. This relative to South America eastward migration is responsible for the Margarita strike-slip fault and the major inversions that began during the Oligocene and lasted into the Middle Miocene. The Bocono-El Pilar-Casanay-Warm Springs and the La Tortuga-Coche-North Coast fault systems are exclusively Neogene with major transtension occurring during the Late Miocene to Recent and act independently from the earlier Paleogene extensional system. They are responsible for the large Neogene transtensional basins of the area: the Cariaco trough, the Northern Tuy-Cariaco and the Paria sub-basins, and the Gulf of Paria Basin. This latest phase is characterized by strain-partitioning into strike slip faults, a transtensional northern domain and a transpressional southern domain that is responsible for the decollement tectonics and/or inversions of the

  12. Conceptual Model of Offshore Wind Environmental Risk Evaluation System

    SciTech Connect

    Anderson, Richard M.; Copping, Andrea E.; Van Cleve, Frances B.; Unwin, Stephen D.; Hamilton, Erin L.

    2010-06-01

    In this report we describe the development of the Environmental Risk Evaluation System (ERES), a risk-informed analytical process for estimating the environmental risks associated with the construction and operation of offshore wind energy generation projects. The development of ERES for offshore wind is closely allied to a concurrent process undertaken to examine environmental effects of marine and hydrokinetic (MHK) energy generation, although specific risk-relevant attributes will differ between the MHK and offshore wind domains. During FY10, a conceptual design of ERES for offshore wind will be developed. The offshore wind ERES mockup described in this report will provide a preview of the functionality of a fully developed risk evaluation system that will use risk assessment techniques to determine priority stressors on aquatic organisms and environments from specific technology aspects, identify key uncertainties underlying high-risk issues, compile a wide-range of data types in an innovative and flexible data organizing scheme, and inform planning and decision processes with a transparent and technically robust decision-support tool. A fully functional version of ERES for offshore wind will be developed in a subsequent phase of the project.

  13. The Geohazards Exploitation Platform

    NASA Astrophysics Data System (ADS)

    Laur, Henri; Casu, Francesco; Bally, Philippe; Caumont, Hervé; Pinto, Salvatore

    2016-04-01

    The Geohazards Exploitation Platform, or Geohazards TEP (GEP), is an ESA originated R&D activity of the EO ground segment to demonstrate the benefit of new technologies for large scale processing of EO data. This encompasses on-demand processing for specific user needs, systematic processing to address common information needs of the geohazards community, and integration of newly developed processors for scientists and other expert users. The platform supports the geohazards community's objectives as defined in the context of the International Forum on Satellite EO and Geohazards organised by ESA and GEO in Santorini in 2012. The GEP is a follow on to the Supersites Exploitation Platform (SSEP) an ESA initiative to support the Geohazards Supersites & Natural Laboratories initiative (GSNL). Today the GEP allows to exploit 70+ Terabyte of ERS and ENVISAT archive and the Copernicus Sentinel-1 data available on line. The platform has already engaged 22 European early adopters in a validation activity initiated in March 2015. Since September, this validation has reached 29 single user projects. Each project is concerned with either integrating an application, running on demand processing or systematically generating a product collection using an application available in the platform. The users primarily include 15 geoscience centres and universities based in Europe: British Geological Survey (UK), University of Leeds (UK), University College London (UK), ETH University of Zurich (CH), INGV (IT), CNR-IREA and CNR-IRPI (IT), University of L'Aquila (IT), NOA (GR), Univ. Blaise Pascal & CNRS (FR), Ecole Normale Supérieure (FR), ISTERRE / University of Grenoble-Alpes (FR). In addition, there are users from Africa and North America with the University of Rabat (MA) and the University of Miami (US). Furthermore two space agencies and four private companies are involved: the German Space Research Centre DLR (DE), the European Space Agency (ESA), Altamira Information (ES

  14. Permeability of the South Ellwood Fault, Offshore Santa Barbara, California

    NASA Astrophysics Data System (ADS)

    Boles, J. R.; Horner, S.; Garven, G.

    2009-12-01

    Natural methane migrates from faulted and fractured siliceous Miocene-age shale hydrocarbon reservoirs to the seabed of the Santa Barbara channel in southern California. At one locality near Platform Holly, about 2 km offshore, where seepage is monitored from two steel and concrete tents on the seabed (area~1860 m2), seepage rate can be related to wells producing 1 km beneath the tents. A new well, perforated at 914 m (3000 ft) beneath the collection tents, directly affects the seepage into the tents. When the well is shut down, seepage production rates increase at a constant rate of 45.3 m3 day/day (1.6 MCF/day/day) to 31.2 m3 day/day (1.1 MCF/day/day) over shutdown periods ranging from 21 days in 2003 to 45 days in 2005, respectively. Using seismic and well data, a fault with about 60 m (200 ft) of throw has been identified running along the crest of the South Ellwood anticline. Using these changes in flow rate, the estimated pressure differences between the seep tent and the perforation intervals in the well, we have calculated the permeability with respect to gas for the 914 m fracture/fault flow path, assuming steady Darcian flow, to be about 3.0E-14 m2 (30 millidarcys, md). In another well, no longer in production, we observe tidal-cycle pressure variations indicating communication with the seabed and anomalous pressure build up that indicates influx of about 5 m3 (25 barrels) of seawater per day. Chemical and isotopic analysis confirms seawater mixing into the reservoir. Using an estimated fault volume of 6.3E+05 m3, we calculate a permeability of 1.9E-14 m2 (19 md) from the Darcy equation (Boles and Horner, 2003) for this well. These two permeability estimates, calculated by different methods, are remarkably similar and indicate that large fault conduits can have permeability of 10’s of md over kilometer length scales. Note: MCF= thousand cubic feet

  15. Geomechanical Performance of Hydrate-Bearing Sediments in Offshore Environments

    SciTech Connect

    Stephen A. Holditch

    2006-12-31

    The main objective of this study is to develop the necessary knowledge base and quantitative predictive capability for the description of geomechanical performance of hydrate bearing sediments (hereafter referred to as HBS) in oceanic environments. The focus is on the determination of the envelope of hydrate stability under conditions typical of those related to the construction and operation of offshore platforms. To achieve this objective, we have developed a robust numerical simulator of hydrate behavior in geologic media by coupling a reservoir model with a commercial geomechanical code. To be sure our geomechanical modeling is realistic, we are also investigating the geomechanical behavior of oceanic HBS using pore-scale models (conceptual and mathematical) of fluid flow, stress analysis, and damage propagation. In Phase II of the project, we will review all published core data and generate additional core data to verify the models. To generate data for our models, we are using data from the literature and we will be conducting laboratory studies in 2007 that generate data to (1) evaluate the conceptual pore-scale models, (2) calibrate the mathematical models, (3) determine dominant relations and critical parameters defining the geomechanical behavior of HBS, and (4) establish relationships between the geomechanical status of HBS and the corresponding geophysical signature. The milestones for Phase I of this project are given as follows: Literature survey on typical sediments containing gas hydrates in the ocean (TAMU); Recommendations on how to create typical sediments in the laboratory (TAMU); Demonstrate that typical sediments can be created in a repeatable manner in the laboratory and gas hydrates can be created in the pore space (TAMU); Develop a conceptual pore-scale model based on available data and reports (UCB); Test the developed pore-scale concepts on simple configurations and verify the results against known measurements and observations (UCB

  16. Assessment of economic impact of offshore and coastal discharge requirements on present and future operations in the Gulf of Mexico. Final report

    SciTech Connect

    Lindsey, R.

    1996-06-01

    The high potential costs of compliance associated with new effluent guidelines for offshore and coastal oil and gas operations could significantly affect the economics of finding, developing, and producing oil and gas in the Gulf of Mexico. This report characterizes the potential economic impacts of alternative treatment and discharge regulations for produced water on reserves and production in Gulf of Mexico coastal, territorial and outer continental shelf (OCS) waters, quantifying the impacts of both recent regulatory changes and possible more stringent requirements. The treatment technologies capable of meeting these requirements are characterized in terms of cost, performance, and applicability to coastal and offshore situations. As part of this analysis, an extensive database was constructed that includes oil and gas production forecasts by field, data on existing platforms, and the current treatment methods in place for produced water treatment and disposal on offshore facilities. This work provides the first comprehensive evaluation of the impacts of alternative regulatory requirements for produced water management and disposal in coastal and offshore areas of the Gulf of Mexico.

  17. PAH assessment in the main Brazilian offshore oil and gas production area using semi-permeable membrane devices (SPMD) and transplanted bivalves

    NASA Astrophysics Data System (ADS)

    André Lourenço, Rafael; Francisco de Oliveira, Fábio; Haddad Nudi, Adriana; Rebello Wagener, Ângela de Luca; Guadalupe Meniconi, Maria de Fátima; Francioni, Eleine

    2015-06-01

    The Campos Basin is Brazil's main oil and gas production area. In 2013, more than 50 million cubic meters of produced water (PW) was discharged into these offshore waters. Despite the large volumes of PW that are discharged in the Campos Basin each day, the ecological concern of the chemicals in the PW are not completely understood. Polycyclic aromatic hydrocarbons (PAH) are the most important contributors to the ecological hazards that are posed by discharged PW. This study aimed to evaluate the potential bioaccumulation of PAH using transplanted bivalves (Nodipecten nodosus) and semi-permeable membrane devices (SPMD). The study was conducted in two platforms that discharge PW (P19 and P40). Another platform that does not discharge PW (P25) was investigated for comparison with the obtained results. Time-integrated hydrocarbon concentrations using SPMD and transplanted bivalves were estimated from the seawater near the three platforms. The bioaccumulation of the PAH in the transplanted bivalves at platforms P19 and P40 were up to fivefold greater than the bioaccumulation of the PAH at platform P25. The lowest PAH concentrations were estimated for platform P25 (4.3-6.2 ng L-1), and the highest PAH concentrations were estimated for platform P19 (9.2-37.3 ng L-1). Both techniques were effective for determining the bioavailability of the PAH and for providing time-integrated hydrocarbon concentrations regarding oil and gas production activities.

  18. The EOS polar platform

    NASA Technical Reports Server (NTRS)

    Soffen, Gerald; Hobish, Mitchell K.

    1990-01-01

    An overview of NASA's Earth Observing System (EOS) is presented. The EOS will be part of the Mission to Planet Earth that will include a series of flight and scientific experiments. The initial polar-orbiting platform, EOS-A, will carry a suite of instruments designed to examine earth system processes at and near the planet's surface, and the interactions between various subsystems. Some of the instruments that will provide specialized data for geologists, meteorologists, biochemists, biologists, and physicists are described. Thus, EOS will provide an opportunity for technologists and scientists to examine the earth to a level of detail not previously attainable.

  19. Integrated fire analysis: Application to offshore cases

    SciTech Connect

    Saubestre, V.; Khalfi, J.P.; Paygnard, J.C.

    1995-12-31

    Evaluating thermal loads from different fire scenarios and then response of the structure to these loads covers several fields. It is also difficult and time consuming to implement. Interfaces are necessary between the heat calculation, transient propagation and structural analysis software packages. Nevertheless, it is necessary to design structures to accommodate heat loads in order to meet safety requirements or functional specification. Elf, along with several operators and organizations, have sponsored a research project on this topic. The project, managed by SINTEF NBL (Norwegian Fire Research Laboratory), has delivered an integrated fire analysis software package which can be used to address design-to-fire-related issues in various contexts. The core modules of the integrated package are robust, well validated analysis tools. This paper describes some benefits (technical or cost related) of using an integrated approach to assess the response of a structure to thermal loads. Three examples are described: consequence of an accidental scenario on the living quarters in an offshore complex, necessity for the reinforcement of a flareboom following a change in process, evaluation of the amount of insulation needed for a topside process primary structure. The paper focuses on the importance for the operator to have a practical tool which can lead to substantial cost saving while reducing the uncertainty linked to safety issues.

  20. AORIS. Arctic & Offshore Technical Data System

    SciTech Connect

    Pastoria, G.A.

    1990-05-01

    AORIS is a computerized information system to assist the technology and planning community in the development of Arctic oil and gas resources. In general, AORIS is geographically dependent and, where possible, site specific. The main topics are sea ice, geotechnology, oceanography, meteorology, and Arctic engineering, as they relate to such offshore oil and gas activities as exploration, production, storage, and transportation. AORIS consists of a directory component that identifies 85 Arctic energy-related databases and tells how to access them; a bibliographic/management information system or bibliographic component containing over 8,000 references and abstracts on Arctic energy-related research; and a scientific and engineering information system, or data component, containing over 800 data sets, in both tabular and graphical formats, on sea ice characteristics taken from the bibliographic citations. AORIS also contains much of the so-called grey literature, i.e., data and/or locations of Arctic data collected, but never published. The three components are linked so the user may easily move from one component to another. A generic information system is provided to allow users to create their own information systems. The generic programs have the same query and updating features as AORIS, except that there is no directory component.

  1. Data warehouse manages offshore project information

    SciTech Connect

    1998-05-04

    A data warehouse adopted from the POSC/Caesar data model will manage the life-cycle information for the offshore Norway Aasgard project. The Aasgard project comprises the Midgard, Smorbukk, and Smorbukk South fields, which lie in 780--985 ft of water. A semisubmersible production facility will handle gas exports, scheduled to begin in 2000. Statoil estimates that recoverable reserves in the fields are 7.5 tcf of gas and 780 million bbl of oil. Notia software components include: the Intergraph asset and information management (AIM) product; the P/C PDM and P/C RDL models; a data mapping, translation, and import toolkit; the application programming interface (API); and query and browser clients. Intergraph describes AIM, with its object management framework (OMF) from metaphase technology, as the engine upon which Notia is based. The P/C PDM defines the data terminology and structure. A dictionary of standard petrochemical data items, the P/C RDL, defines the various activities, materials, components, and relationships among these items. The API allows users to develop additional functionality, and the toolkit provides resources for translating and mapping data from existing sources into a neutral format so that administrators can prepopulate the data warehouse. A worldwide web browser client allows users to query the data warehouse and display results in a variety of configurable formats, including virtual data sheets.

  2. The significance of gas for offshore operations

    NASA Astrophysics Data System (ADS)

    Sills, G. C.; Wheeler, S. J.

    1992-10-01

    The purpose of this paper is to present an overview of the physical behaviour of a seabed containing undissolved gas in the light of laboratory simulations undertaken at Oxford, Belfast and Sheffield Universities. This physical behaviour is significant for offshore operations in several ways. Gas may exist in high pressure pockets, trapped beneath low permeability clays, which form a blow out hazard during drilling. In fine-grained soils, it exists in voids distributed through the soil, at pressures only a little greater than te ambient water pressure. In this condition, it is unlikely to induced casastrophic failure, but will affect the foundation behaviour through changes in compressibility and strength. In sands, gas may be present in pores between particles, replacing water but not affecting the soil structure. There are common features in all these cases, in that the gas-water interaction occurs through surface tension, acting in menisci whose curvature is affected by the soil particle sizes, shapes and packing. These menisci determine the differences between gas and water pressure that may exist in the soil. Results are presented to show that the compressibility and undrained shear strength of a fine-grained soil are reduced by the presence of gas in a predictable manner, with a similar conclusion for the undrained strength of a gassy sand.

  3. Exploration and development offshore southern Vietnam

    SciTech Connect

    Ferguson, A.M. )

    1996-01-01

    In Vietnam, the major focus of the oil and gas industry is on the Nam Con Son and Cuu Long Basins in the southern offshore area. Major licensing first occurred here in the early 1970s. Some exploration was also undertaken by foreign companies in the early 1980s. In 1981, the Soviet Union undertook to assist Vietnam with the development of oil and gas. Vietsovpetro, a joint venture between the then Soviet Oil and Gas Ministry and the Vietnam Oil and Gas Corporation was formed. Most of Vietsovpetro's efforts have been to develop the Bach Ho field in the Cuu Long Basin. This now produces [approximately]130000 bopd. The most recent large scale licensing round occurred in 1992, and, at present, there are over thirty foreign companies active in these Basins' blocks . The first phase of exploration is ending and successes in the Nam Con Son Basin include the BP-led Lan Tay/Lan Do gas discoveries and Pedco's gas discoveries. Mitsubishi's and Petronas' oil discoveries in the Cuu Long Basin have attracted much attention also. The Dai Hung oil field (BHP-operated) has been producing since late 1994. Certain blocks are being appraised, and exploration work is also continuing. Areas of the Cuu Long Basin that were part of Vietsovpetro's acreage, but which may soon be re-licensed, have generated keen interest. The presence of an active upstream industry - exploring, appraising, developing and producing - indicates the emergence of Vietnam as an important East Asian oil and gas player.

  4. Near real time monitoring of platform sourced pollution using TerraSAR-X over the North Sea.

    PubMed

    Singha, Suman; Velotto, Domenico; Lehner, Susanne

    2014-09-15

    Continuous operational monitoring by means of remote sensing contributes significantly towards less occurrence of oil spills over European waters however, operational activities show regular occurrence of accidental and deliberate oil spills over the North Sea, particularly from offshore platform installations. Since the areas covered by oil spills are usually large and scattered over the North Sea, satellite remote sensing particularly Synthetic Aperture Radar (SAR) represents an effective tool for operational oil spill detection. This paper describes the development of a semi-automated approach for oil spill detection, optimized for near real time offshore platform sourced pollution monitoring context. Eight feature parameters are extracted from each segmented dark spot. The classification algorithm is based on artificial neural network. An initial evaluation of this methodology has been carried out on 156 TerraSAR-X images. Wind and current history information also have been analyzed for particular cases in order to evaluate their influences on spill trajectory.

  5. Investigation of a FAST-OrcaFlex Coupling Module for Integrating Turbine and Mooring Dynamics of Offshore Floating Wind Turbines: Preprint

    SciTech Connect

    Masciola, M.; Robertson, A.; Jonkman, J.; Driscoll, F.

    2011-10-01

    To enable offshore floating wind turbine design, the following are required: accurate modeling of the wind turbine structural dynamics, aerodynamics, platform hydrodynamics, a mooring system, and control algorithms. Mooring and anchor design can appreciably affect the dynamic response of offshore wind platforms that are subject to environmental loads. From an engineering perspective, system behavior and line loads must be studied well to ensure the overall design is fit for the intended purpose. FAST (Fatigue, Aerodynamics, Structures and Turbulence) is a comprehensive simulation tool used for modeling land-based and offshore wind turbines. In the case of a floating turbine, continuous cable theory is used to emulate mooring line dynamics. Higher modeling fidelity can be gained through the use of finite element mooring theory. This can be achieved through the FASTlink coupling module, which couples FAST with OrcaFlex, a commercial simulation tool used for modeling mooring line dynamics. In this application, FAST is responsible for capturing the aerodynamic loads and flexure of the wind turbine and its tower, and OrcaFlex models the mooring line and hydrodynamic effects below the water surface. This paper investigates the accuracy and stability of the FAST/OrcaFlex coupling operation.

  6. U.S. Offshore Wind Manufacturing and Supply Chain Development

    SciTech Connect

    Hamilton, Bruce Duncan

    2013-02-22

    The objective of the report is to provide an assessment of the domestic supply chain and manufacturing infrastructure supporting the U.S. offshore wind market. The report provides baseline information and develops a strategy for future development of the supply chain required to support projected offshore wind deployment levels. A brief description of each of the key chapters includes: » Chapter 1: Offshore Wind Plant Costs and Anticipated Technology Advancements. Determines the cost breakdown of offshore wind plants and identifies technical trends and anticipated advancements in offshore wind manufacturing and construction. » Chapter 2: Potential Supply Chain Requirements and Opportunities. Provides an organized, analytical approach to identifying and bounding the uncertainties associated with a future U.S. offshore wind market. It projects potential component-level supply chain needs under three demand scenarios and identifies key supply chain challenges and opportunities facing the future U.S. market as well as current suppliers of the nation’s land-based wind market. » Chapter 3: Strategy for Future Development. Evaluates the gap or competitive advantage of adding manufacturing capacity in the U.S. vs. overseas, and evaluates examples of policies that have been successful . » Chapter 4: Pathways for Market Entry. Identifies technical and business pathways for market entry by potential suppliers of large-scale offshore turbine components and technical services. The report is intended for use by the following industry stakeholder groups: (a) Industry participants who seek baseline cost and supplier information for key component segments and the overall U.S. offshore wind market (Chapters 1 and 2). The component-level requirements and opportunities presented in Section 2.3 will be particularly useful in identifying market sizes, competition, and risks for the various component segments. (b) Federal, state, and local policymakers and economic development

  7. 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.

  8. Carbonate shelf edge off southern Australia: A prograding open-platform margin

    NASA Astrophysics Data System (ADS)

    James, Noel P.; von der Borch, Christopher C.

    1991-10-01

    The southern continental margin of Australia is an extensive shelf that has been a site of cool-water carbonate deposition since Eocene time. The platform has no rim and is swept by high-energy waves and swells throughout the year. The shelf is deep (40 to 100 m) and typified by bryozoan-rich sediments. The shelf margin is a gentle incline that becomes progressively steeper seaward, except where it laps down onto offshore terraces. The edge of the Eucla Platform in the Great Australian Bight is used to illustrate that the margin is a series of extensive prograding clinoforms. Progradation is interpreted to be the result of off-shelf sediment transport and in-place carbonate production by actively growing deep-water bryozoa and sponges. This area is a potential model for ancient high-energy platform margins during geologic periods when large skeletal reef-building metazoans were scarce.

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

    SciTech Connect

    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 to 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.

  10. Cots Correlator Platform

    NASA Astrophysics Data System (ADS)

    Schaaf, Kjeld; Overeem, Ruud

    2004-06-01

    Moore’s law is best exploited by using consumer market hardware. In particular, the gaming industry pushes the limit of processor performance thus reducing the cost per raw flop even faster than Moore’s law predicts. Next to the cost benefits of Common-Of-The-Shelf (COTS) processing resources, there is a rapidly growing experience pool in cluster based processing. The typical Beowulf cluster of PC’s supercomputers are well known. Multiple examples exists of specialised cluster computers based on more advanced server nodes or even gaming stations. All these cluster machines build upon the same knowledge about cluster software management, scheduling, middleware libraries and mathematical libraries. In this study, we have integrated COTS processing resources and cluster nodes into a very high performance processing platform suitable for streaming data applications, in particular to implement a correlator. The required processing power for the correlator in modern radio telescopes is in the range of the larger supercomputers, which motivates the usage of supercomputer technology. Raw processing power is provided by graphical processors and is combined with an Infiniband host bus adapter with integrated data stream handling logic. With this processing platform a scalable correlator can be built with continuously growing processing power at consumer market prices.

  11. Platform for Action: update.

    PubMed

    1995-01-01

    The Center for Women's Global Leadership (CWGL) has collaborated in the preparation of amendments and strategies designed to withstand the challenges being posed to the Platform for Action of the Fourth World Conference on Women. Specific challenges include the inappropriate use of the word "universal" to modify "human rights." This implies that some human rights are less than universal. The strategy proposed is to accept the use of the word "universal" in this context only when it affirms principles of universality contained in the Vienna Programme of Action and not where its use would restrict the rights to which women are entitled. A second concern is over the use of the word "equity" rather than "equality" when referring to gender relations. The use of these terms will be carefully monitored to insure that "equity" not be used to undermine the principle of gender equality. The third concern is the efforts of some governments to hinder the integration of women's human rights throughout the UN system. Such efforts will be opposed. Fourth, the CWGL will seek the inclusion of language which recognizes the barriers that different groups of women face when trying to secure their rights. Finally, the CWGL will propose inclusion of language recognizing and protecting sexual orientation rights. The CWGL is also going to work to translate the abstract language of the Platform for Action into political organizing potential to insure that governments will follow through on their agreements.

  12. Open systems storage platforms

    NASA Technical Reports Server (NTRS)

    Collins, Kirby

    1992-01-01

    The building blocks for an open storage system includes a system platform, a selection of storage devices and interfaces, system software, and storage applications CONVEX storage systems are based on the DS Series Data Server systems. These systems are a variant of the C3200 supercomputer with expanded I/O capabilities. These systems support a variety of medium and high speed interfaces to networks and peripherals. System software is provided in the form of ConvexOS, a POSIX compliant derivative of 4.3BSD UNIX. Storage applications include products such as UNITREE and EMASS. With the DS Series of storage systems, Convex has developed a set of products which provide open system solutions for storage management applications. The systems are highly modular, assembled from off the shelf components with industry standard interfaces. The C Series system architecture provides a stable base, with the performance and reliability of a general purpose platform. This combination of a proven system architecture with a variety of choices in peripherals and application software allows wide flexibility in configurations, and delivers the benefits of open systems to the mass storage world.

  13. Geological characterization of selected offshore sand resources on the OCS, offshore Alabama, for beach nourishment

    USGS Publications Warehouse

    Davies, David J.; Parker, Steven J.; Smith, W. Everett

    1993-01-01

    Most Alabama Gulf and estuarine shoreline is undergoing long-term erosion; threatened shorelines will need programs of replenishment and maintenance if they are to be even temporarily stabilized. Highest priority beach replenishment areas include eastern Dauphin Island; west of Perdido Pass; and west of the inlet at Little Lagoon. There are no appropriate local onshore sand sources available for any such large scale program. Sediments in the Federal waters of the EEZ were evaluated for possible sources of sand for beach nourishment. Six lithofacies were delineated based on sediment characterization, spatial framework, and environment of deposition; of these, two (Clean Sands and Graded Shelly Sands) were deemed to have highest potential as beach nourishment sources. Five offshore target areas were delineated as potential sand sources. Criteria included sand aesthetics, estimated sand volume, and sand distributions. Preliminary environmental analyses included impacts of offshore sand dredging on shelf circulation; on economic activities; and on local benthic biota. Dredging may not significantly alter background wave regimes; however, data are insufficient to model effects of major storms on a modified shelf morphology. Dredging would avoid areas of current economic activity. There would like be little long-term impact on benthic biota in the target areas. Additional work will be required to confirm or refute these preliminary findings.

  14. Geosynchronous platform definition study. Volume 5: Geosynchronous platform synthesis

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The development is described of the platform configurations, support subsystems, mission equipment, and servicing concepts. A common support module is developed; subsystem concepts are traded off; data relay, TDRS, earth observational, astro-physics, and advanced navigation and traffic control mission equipment concepts are postulated; and ancillary equipment required for delivery and on-orbit servicing interfaces with geosynchronous platforms is grossly defined. The general approach was to develop a platform concept capable of evolving through three on-orbit servicing modes: remote, EVA, and shirtsleeve. The definition of the equipment is to the assembly level. Weight, power, and volumetric data are compiled for all the platforms.

  15. Shelf mounted ocean thermal energy conversion platform, revised preliminary report

    NASA Astrophysics Data System (ADS)

    1984-03-01

    This report relates model tests of a generic Ocean Thermal Energy Conversion (OTEC) platform. The objective of these tests is to aid in the evaluation of new OTEC designs and to present a data base for design purposes. The test plant has been designed to provide a data base for comparison with current and projected analytical tools as well as comparisons of results from one model configuration to another. The new conceptual OTEC designs are different from the typical offshore (jacket type) structure which is quite transparent to waves. The major difference is the addition of large submerged power production modules to the frame. These proposed modules offer a large surface area to obstruct the flow and thereby increase the global wave forces acting on the structure.

  16. Sensitivity Analysis of Offshore Wind Cost of Energy (Poster)

    SciTech Connect

    Dykes, K.; Ning, A.; Graf, P.; Scott, G.; Damiami, R.; Hand, M.; Meadows, R.; Musial, W.; Moriarty, P.; Veers, P.

    2012-10-01

    No matter the source, offshore wind energy plant cost estimates are significantly higher than for land-based projects. For instance, a National Renewable Energy Laboratory (NREL) review on the 2010 cost of wind energy found baseline cost estimates for onshore wind energy systems to be 71 dollars per megawatt-hour ($/MWh), versus 225 $/MWh for offshore systems. There are many ways that innovation can be used to reduce the high costs of offshore wind energy. However, the use of such innovation impacts the cost of energy because of the highly coupled nature of the system. For example, the deployment of multimegawatt turbines can reduce the number of turbines, thereby reducing the operation and maintenance (O&M) costs associated with vessel acquisition and use. On the other hand, larger turbines may require more specialized vessels and infrastructure to perform the same operations, which could result in higher costs. To better understand the full impact of a design decision on offshore wind energy system performance and cost, a system analysis approach is needed. In 2011-2012, NREL began development of a wind energy systems engineering software tool to support offshore wind energy system analysis. The tool combines engineering and cost models to represent an entire offshore wind energy plant and to perform system cost sensitivity analysis and optimization. Initial results were collected by applying the tool to conduct a sensitivity analysis on a baseline offshore wind energy system using 5-MW and 6-MW NREL reference turbines. Results included information on rotor diameter, hub height, power rating, and maximum allowable tip speeds.

  17. Terminology Guideline for Classifying Offshore Wind Energy Resources

    SciTech Connect

    Beiter, Philipp; Musial, Walt

    2016-09-01

    The purpose of this guideline is to establish a clear and consistent vocabulary for conveying offshore wind resource potential and to interpret this vocabulary in terms that are familiar to the oil and gas (O&G) industry. This involves clarifying and refining existing definitions of offshore wind energy resource classes. The terminology developed in this guideline represents one of several possible sets of vocabulary that may differ with respect to their purpose, data availability, and comprehensiveness. It was customized to correspond with established offshore wind practices and existing renewable energy industry terminology (e.g. DOE 2013, Brown et al. 2015) while conforming to established fossil resource classification as best as possible. The developers of the guideline recognize the fundamental differences that exist between fossil and renewable energy resources with respect to availability, accessibility, lifetime, and quality. Any quantitative comparison between fossil and renewable energy resources, including offshore wind, is therefore limited. For instance, O&G resources are finite and there may be significant uncertainty associated with the amount of the resource. In contrast, aboveground renewable resources, such as offshore wind, do not generally deplete over time but can vary significantly subhourly, daily, seasonally, and annually. The intent of this guideline is to make these differences transparent and develop an offshore wind resource classification that conforms to established fossil resource classifications where possible. This guideline also provides methods to quantitatively compare certain offshore wind energy resources to O&G resource classes for specific applications. Finally, this guideline identifies areas where analogies to established O&G terminology may be inappropriate or subject to misinterpretation.

  18. 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.

  19. 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.

  20. 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.