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1

Stratigraphic architecture and evolution of the continental slope system in offshore Hainan, northern South China Sea  

E-print Network

of continental margins constrain the features of the continental shelf-slope system (Einsele, 2000). Two distinctStratigraphic architecture and evolution of the continental slope system in offshore Hainan the evolution of the stratigraphic architecture of two siliciclastic northern South China Sea continental slope

Müller, Dietmar

2

Numeric stratigraphic modeling: Testing sequence Numeric stratigraphic modeling: Testing sequence stratigraphic concepts using high resolution geologic examples  

Microsoft Academic Search

Numeric simulations based on integrated data sets enhance our understanding of depositional geometry and facilitate quantification of depositional processes. Numeric values tested against well-constrained geologic data sets can then be used in iterations testing each variable, and in predicting lithofacies distributions under various depositional scenarios using the principles of sequence stratigraphic analysis. The stratigraphic modeling software provides a broad spectrum

J. M. Armentrout; L. S. Smith-Rouch; S. A. Bowman

1996-01-01

3

Numeric stratigraphic modeling: Testing sequence Numeric stratigraphic modeling: Testing sequence stratigraphic concepts using high resolution geologic examples  

SciTech Connect

Numeric simulations based on integrated data sets enhance our understanding of depositional geometry and facilitate quantification of depositional processes. Numeric values tested against well-constrained geologic data sets can then be used in iterations testing each variable, and in predicting lithofacies distributions under various depositional scenarios using the principles of sequence stratigraphic analysis. The stratigraphic modeling software provides a broad spectrum of techniques for modeling and testing elements of the petroleum system. Using well-constrained geologic examples, variations in depositional geometry and lithofacies distributions between different tectonic settings (passive vs. active margin) and climate regimes (hothouse vs. icehouse) can provide insight to potential source rock and reservoir rock distribution, maturation timing, migration pathways, and trap formation. Two data sets are used to illustrate such variations: both include a seismic reflection profile calibrated by multiple wells. The first is a Pennsylvanian mixed carbonate-siliciclastic system in the Paradox basin, and the second a Pliocene-Pleistocene siliciclastic system in the Gulf of Mexico. Numeric simulations result in geometry and facies distributions consistent with those interpreted using the integrated stratigraphic analysis of the calibrated seismic profiles. An exception occurs in the Gulf of Mexico study where the simulated sediment thickness from 3.8 to 1.6 Ma within an upper slope minibasin was less than that mapped using a regional seismic grid. Regional depositional patterns demonstrate that this extra thickness was probably sourced from out of the plane of the modeled transect, illustrating the necessity for three-dimensional constraints on two-dimensional modeling.

Armentrout, J.M.; Smith-Rouch, L.S. [Mobil Exploration and Producing Technical Center, Dallas, TX (United States); Bowman, S.A. [Marco Polo Software, Inc., Houston, TX (United States)

1996-08-01

4

Structural and stratigraphic evolution of the East Georges Bank Basin, offshore Nova Scotia, Canada  

SciTech Connect

The East Georges Bank Basin is located offshore Nova Scotia on the southeastern Canadian continental shelf. The basin covers 2.5 million ac and is one of the last undrilled basins in North America. The geological interpretation is almost entirely based on 16,000 km of seismic data over the basin. Pertinent well control is limited to 10 wells on the US portion of the Georges Bank (West Georges Bank Basin) and two wells on the Scotian shelf. Seismic-stratigraphic analysis of this data has led to a structural and stratigraphic model for the basin. The basin formed during the Triassic when the landmass of Pange began separating along rift zones. A prominent Paleozoic basement high, the Yarmouth Arch separated the East Georges Bank Basin from the West Georges Bank Basin and had a dominant influence on sedimentation until the Middle Jurassic. Early synrift sequences consist of lacustrine clastics and shales. Marine incursions began in the late Triassic resulting in massive salt deposits that reflect the restricted extent of the basin and the arid Triassic and Early Jurassic climate. Further continental separation during the Early Jurassic resulted in deposition of carbonates and evaporites followed by Middle Jurassic continental shelf carbonates and deltaic sands. During the Middle Jurassic, major growth faulting and halokinesis was initiated by progradation of the deltaic sands. Post Middle Jurassic continental spreading in combination with changing climatic conditions resulted in a steady decline of carbonate sedimentation and dominance of clastic deposition throughout the remaining history of the basin.

Carswell, A.B. (Esso Canada Resources Ltd., Calgary, Alberta (Canada)); Koning, T. (Texaco Canada Petroleum, Inc., Calgary, Alberta (Canada)); Hibbs, D.C. (Conoco Canada Ltd., Calgary, Alberta (Canada))

1990-05-01

5

Ultrasonic thickness testing of aging offshore structures  

E-print Network

The objectives of this thesis concern the use of ultrasonic thickness (UT) testing for use in the offshore industry. Evidence from prior studies conducted at Texas A&M University suggests that the corrosion on the surface of offshore structural...

Ellison, Brian Kirk

2012-06-07

6

Tectono-stratigraphic signature of multiphased rifting on divergent margins (deep-offshore southwest Iberia, North Atlantic)  

NASA Astrophysics Data System (ADS)

Regional 2D multichannel seismic, borehole, dredge and outcrop data, together with burial models for strata in southwest Iberia, are used to investigate the tectono-stratigraphic signature of multiphased rifting on divergent margins. Our burial model reveals that Mesozoic extension occurred during three main phases, each comprising distinct subsidence pulses separated by short-lived periods of crustal uplift. The importance of the three phases varies across discrete sectors of the margin, each one revealing similar depositional architectures and associated tectonic systems tracts: 1) the Rift Initiation phase, characterized by incipient subsidence and overall aggradation/progradation over a basal unconformity, 2) the Rift Climax phase, which marks maxima of tectonic subsidence and is characterized by retrogradation-progradation, and 3) the Late Rift phase, recording the progradational infill of the basin and the effects of eustasy. The Rift Initiation systems tracts comprise Sinemurian and late Callovian-early Oxfordian strata. Marine units in the Pliensbachian and Late Oxfordian-Kimmeridgian represent the Rift Climax phase, a period marked by the development of Maximum Flooding Surfaces. Late Rift deposits were identified in the Rhaetian-Hettangian, Toarcian-Bathonian and Kimmeridgian-Berriasian. The results of this work are important to the economic exploration of deep-offshore rift basins, as they reveal that sequence stratigraphy can be used to predict sedimentary facies distribution in more distal segments of such basins. Significantly, this work recognizes that multiple tectonic-stratigraphic (rift) cycles can occur on deep-offshore rift basins, from the onset of rift-related extension until continental break-up, a character that contrast to what is known from deep-sea drilling data from the distal margin of Northwest Iberia.

Pereira, Ricardo; Alves, Tiago M.

2012-08-01

7

Stratigraphic and structural analysis of the Neogene sediments of the offshore portion of the Salina del Istmo Basin, southeastern Mexico  

NASA Astrophysics Data System (ADS)

Southeastern Mexico has been affected by regional and local tectonic events. Regional tectonic events are the Gulf of Mexico opening and the lateral movement of micro-plates on the Pacific margin. The local tectonic events are related to salt tectonics. Autochthonous Jurassic salt serves as the detachment level for the main compressional event in the late Miocene. Jurassic salt was allochthonously emplaced in the late Miocene, then partially displaced by a huge quantity of terrigenous sediments during the Plio-Pleistocene. This research is a study of the main geological processes that have influenced the structural and stratigraphic evolution of the Neogene sediments in the offshore portion of the Salina del Istmo basin known as the Marbella area. Owing to data availability, the project was divided into regional and local studies. The regional study is based on 2D multi-channel seismic reflection data, and the local study is based on a 3D seismic streamer survey. Structural analysis in the regional study permits the recognition of four buried fold belts (Agua Dulce, Catemaco, Marbella, and Marbella Norte) trending roughly NE. These fold belts are the result of tectonic convergence in the pacific margin during late Miocene. The Agua Dulce and Marbella Norte fold belts are separated by an enormous salt withdrawal basin called the Pescadores basin. The Pescadores basin is bounded on the north by a spectacular stepped, counter-regional structure. Beyond the Pescadores basin, a salt mini-basin area is recognized in the upper continental slope. Another important structural element is the Sal Somera canopy in the southern part of the study area. Sedimentation-rate analysis, based on isochore mapping in the local study area, indicates that from SB-2.4 to SB-2.6 Ma, deposition rate peaked with a maximum of 7.5 mm/yr. Regional and local structural restorations show that, in general, the maximum allochthonous salt mobilization was during the Plio-Pleistocene because of the huge quantity of sediments that the Chiapas massif and the Sierra de Chiapas supplied to the basin. A geohistory plot indicates rapid basin deepening at 2.4 to 2.6 Ma, which is attributed to a major influx of sediments and allochthonous salt evacuation.

Gomez-Cabrera, Pedro Tomas

2003-10-01

8

A preliminary guidebook for identifying stratigraphic contacts at the Nevada Test Site  

SciTech Connect

Lithologic variation, regional depositional trends, and the lack of written guidelines have resulted in inconsistencies in the recognition of stratigraphic contacts in drill holes at the Nevada Test Site (NTS). Stratigraphic identification, based on mineralogy of discrete samples, can be augmented by geophysical logs and downhole movies to more accurately and consistently locate contacts between units. Criteria are established for locating the base of the Pahute Mesa ash-flow tuff, the top of the Ammonia Tanks ash-flow tuff, the top of the Ammonia Tanks bedded tuff, and the top and the base of the Rainier Mesa Tuff.

Pawloski, G.A.; McKague, H.L.; Wagoner, J.L. [Lawrence Livermore National Lab., CA (United States); McKinnis, W.B. [Lawrence Livermore National Lab., Mercury, NV (United States)

1992-01-01

9

Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Coring operations, core sedimentology, and lithostratigraphy  

Microsoft Academic Search

In February 2007, BP Exploration (Alaska), the U.S. Department of Energy, and the U.S. Geological Survey completed the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well (Mount Elbert well) in the Milne Point Unit on the Alaska North Slope. The program achieved its primary goals of validating the pre-drill estimates of gas hydrate occurrence and thickness based on 3-D seismic

Kelly Rose; Ray Boswell; Timothy Collett

2011-01-01

10

Tectonic reconstructions of the southwestern Great Basin: Stratigraphic tests of structural models  

SciTech Connect

Accurate paleogeographic reconstruction of the tectonically dismembered southwestern Great Basin is in large part dependent on the validity of the Wernicke et al. (1988) and Snow and Wernicke (1989) correlations of Mesozoic (pre-Tertiary) contractile deformational features. In order to independently assess these structurally based models and their predictions, carefully chosen stratigraphic data were used as tests. In the northern Death Valley region, sediment dispersal trends in two regionally developed facies of the Lower Cambrian Wood Canyon Formation and Zabriskie Quartzite suggest that otherwise uniformly northwest-directed paleocurrent indicators have undergone vertical axis rotations comparable in direction and magnitude to those predicted for anti-clockwise rotation of the Grapevine Mountains structural block. In the central Death Valley region, stratigraphic differences in upper plate rocks in the proposed Tucki Mountain-northern Nopah Range pierce point prevent the adjacent juxtaposition of those rocks but are permissive of such a correlation. Finally, in the southern Death Valley region, the Levy and Christie-Blick (1989) pre-Mesozoic reconstruction results in overlap of range blocks and juxtaposition of disparate facies in the Proterozoic Pahrump Group rocks. This implies that the Cenozoic deformational vector displacement paths, determined for elsewhere in the southern Great Basin, are not applicable to southern Death Valley and must be reassessed.

Prave, A.R. (City College of New York, NY (United States). Dept. of Earth and Atmospheric Sciences); Snow, J.K. (California Inst. of Technology, Pasadena, CA (United States). Division of Geology and Planetary Sciences)

1993-04-01

11

Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Overview of scientific and technical program  

USGS Publications Warehouse

The Mount Elbert Gas Hydrate Stratigraphic Test Well was drilled within the Alaska North Slope (ANS) Milne Point Unit (MPU) from February 3 to 19, 2007. The well was conducted as part of a Cooperative Research Agreement (CRA) project co-sponsored since 2001 by BP Exploration (Alaska), Inc. (BPXA) and the U.S. Department of Energy (DOE) in collaboration with the U.S. Geological Survey (USGS) to help determine whether ANS gas hydrate can become a technically and commercially viable gas resource. Early in the effort, regional reservoir characterization and reservoir simulation modeling studies indicated that up to 0.34 trillion cubic meters (tcm; 12 trillion cubic feet, tcf) gas may be technically recoverable from 0.92 tcm (33 tcf) gas-in-place within the Eileen gas hydrate accumulation near industry infrastructure within ANS MPU, Prudhoe Bay Unit (PBU), and Kuparuk River Unit (KRU) areas. To further constrain these estimates and to enable the selection of a test site for further data acquisition, the USGS reprocessed and interpreted MPU 3D seismic data provided by BPXA to delineate 14 prospects containing significant highly-saturated gas hydrate-bearing sand reservoirs. The "Mount Elbert" site was selected to drill a stratigraphic test well to acquire a full suite of wireline log, core, and formation pressure test data. Drilling results and data interpretation confirmed pre-drill predictions and thus increased confidence in both the prospect interpretation methods and in the wider ANS gas hydrate resource estimates. The interpreted data from the Mount Elbert well provide insight into and reduce uncertainty of key gas hydrate-bearing reservoir properties, enable further refinement and validation of the numerical simulation of the production potential of both MPU and broader ANS gas hydrate resources, and help determine viability of potential field sites for future extended term production testing. Drilling and data acquisition operations demonstrated that gas hydrate scientific research programs can be safely, effectively, and efficiently conducted within ANS infrastructure. The program success resulted in a technical team recommendation to project management to drill and complete a long-term production test within the area of existing ANS infrastructure. If approved by stakeholders, this long-term test would build on prior arctic research efforts to better constrain the potential gas rates and volumes that could be produced from gas hydrate-bearing sand reservoirs. ?? 2010 Elsevier Ltd.

Hunter, R. B.; Collett, T. S.; Boswell, R.; Anderson, B. J.; Digert, S. A.; Pospisil, G.; Baker, R.; Weeks, M.

2011-01-01

12

Selected stratigraphic contacts for drill holes in LANL use areas of Yucca Flat, NTS (Nevada Test Site)  

Microsoft Academic Search

This report is a compilation of selected stratigraphic contacts in drill holes of Yucca Flat, Nevada Test Site (NTS), used by the Los Alamos National Laboratory (LANL). This is the product of an ongoing effort to establish and maintain the most up-to-date database of formation tops in LANL use areas of Yucca Flat. Several changes have been made to the

S. L. Jr. Drellack; A. P. Cavazos

1987-01-01

13

Self-bored pressuremeter testing in the Arctic offshore  

SciTech Connect

Self-bored pressuremeter (SBP) tests are an important part of site investigations for gravity base structure (GBS) foundations. This applies in particular when such structures are expected to experience significant lateral loads, as most arctic structures are. The SBP data is used for both serviceability state analysis and for providing fundamental information on undisturbed soil behaviour. SBP testing has been carried out offshore for Gulf Canada Resources Inc. (GCRI) during the past two years (1982-1983 arctic open water seasons). Testing has been carried out in a variety of soil conditions across the GCRI land interest on the Canadian continental shelf in the Beaufort Sea. The paper outlines the equipment used, operational successes and difficulties, and presents productivity data. Techniques and equipment for improving productivity are outlined. Experience with SBP operations has shown that the SBP is no more difficult to use offshore than the electric static cone penetrometer (CPT). One result in particular of the SBP testing stands out; the in-situ geostatic stress ratio (K /SUB o/ ) has been found to be not a unique function of past overburden history. This result is discussed in the geological context. It appears prudent to regard K /SUB o/ as an independent variable for engineering purposes.

Hughes, J.M.O.; Jefferies, M.G.; Morris, D.L.

1984-05-01

14

Stratigraphic modeling of sedimentary basins  

SciTech Connect

A two-dimensional stratigraphic forward model has been successfully applied and calibrated in clastic, carbonate, and mixed clastic/carbonate regimes. Primary input parameters are subsidence, sea level, volume of clastics, and carbonate growth potential. Program output includes sequence geometries, facies distribution lithology distribution, chronostratigraphic plots, burial history plots, thermal and maturity histories, and crossplots. The program may be used to predict reservoir distribution, to constrain interpretations of well and seismic data, to rapidly test exploration scenarios in frontier basins, and to evaluate the fundamental controls on observed basin stratigraphy. Applications to data sets from Main Pass (US Gulf Coast), Offshore Sarawak (Malaysia), Rub'al Khali basin (Oman), Paris basin (France), and Baltimore Canyon (US East Coast) demonstrate that the program can be used to simulate stratigraphy on a basin-wide scale as well as on the scale of individual prospects.

Aigner, T. (Shell Research B. V., Rijswijk (Netherlands)); Lawrence, D.T. (Shell Development Co., Houston, TX (USA))

1990-11-01

15

Selected stratigraphic contacts for drill holes in LANL (Los Alamos National Laboratory) use areas of Yucca Flat, NTS (Nevada Test Site)  

Microsoft Academic Search

This report is a compilation of selected stratigraphic contacts in drill holes in areas of Yucca Flat, Nevada Test Site (NTS), used by the Los Alamos National Laboratory (LANL). Data presented for each drill hole includes the following: (1) hole name; (2) total depth (TD) of drill hole at completion of drilling; (3) depth below surface to selected stratigraphic contacts;

S. L. Jr. Drellack; A. P. Cavazos

1986-01-01

16

Pore fluid geochemistry from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope  

USGS Publications Warehouse

The BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well was drilled and cored from 606.5 to 760.1. m on the North Slope of Alaska, to evaluate the occurrence, distribution and formation of gas hydrate in sediments below the base of the ice-bearing permafrost. Both the dissolved chloride and the isotopic composition of the water co-vary in the gas hydrate-bearing zones, consistent with gas hydrate dissociation during core recovery, and they provide independent indicators to constrain the zone of gas hydrate occurrence. Analyses of chloride and water isotope data indicate that an observed increase in salinity towards the top of the cored section reflects the presence of residual fluids from ion exclusion during ice formation at the base of the permafrost layer. These salinity changes are the main factor controlling major and minor ion distributions in the Mount Elbert Well. The resulting background chloride can be simulated with a one-dimensional diffusion model, and the results suggest that the ion exclusion at the top of the cored section reflects deepening of the permafrost layer following the last glaciation (???100 kyr), consistent with published thermal models. Gas hydrate saturation values estimated from dissolved chloride agree with estimates based on logging data when the gas hydrate occupies more than 20% of the pore space; the correlation is less robust at lower saturation values. The highest gas hydrate concentrations at the Mount Elbert Well are clearly associated with coarse-grained sedimentary sections, as expected from theoretical calculations and field observations in marine and other arctic sediment cores. ?? 2009 Elsevier Ltd.

Torres, M.E.; Collett, T.S.; Rose, K.K.; Sample, J.C.; Agena, W.F.; Rosenbaum, E.J.

2011-01-01

17

Environmentally safe burner for offshore well testing operations  

SciTech Connect

One of the problems that occurs during offshore well testing has been the discharge of unburned hydrocarbon emissions into the air and sea that leave deposits of oily slicks or {open_quotes}sheen{close_quotes} on the water surface. This residue results from inefficient flaring operations and can have adverse effects on marine environment. This paper will discuss a new burner that has been developed to address the environmentally unfriendly fallout conditions that have occurred from crude oil disposal during traditional well testing operations. To support a broad range of applications, the design criteria for this burner included not only the capability to perform fallout free in the wide range of conditions expected during well testing but also to be simple to operate, have a compact lightweight design with a stable pilot and igniter system, provide clean startup, and require low oil pressure. Burner performance is significantly affected by fuel oil properties and its atomization characteristics. The paper will include an overview of these topics and their relationship to the combustion process, how these topics were addressed in the development of the design, and the testing that was performed by an independent Norwegian environmental testing company to verify the burner`s efficiency. The burner designed to these specifications includes an array of atomizers, uniquely placed to improve flame turbulence and air ingestion important to efficient combustion. Engineering tests performed with 18 degree API crude oil were fallout free and smokeless, and tests performed by the independent environmental testing company verified that the new burner design performed with 99.9 percent efficiency as a burning disposal system.

Young, T.M.

1996-11-01

18

Physical properties of sediment from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope  

USGS Publications Warehouse

This study characterizes cored and logged sedimentary strata from the February 2007 BP Exploration Alaska, Department of Energy, U.S. Geological Survey (BPXA-DOE-USGS) Mount Elbert Gas Hydrate Stratigraphic Test Well on the Alaska North Slope (ANS). The physical-properties program analyzed core samples recovered from the well, and in conjunction with downhole geophysical logs, produced an extensive dataset including grain size, water content, porosity, grain density, bulk density, permeability, X-ray diffraction (XRD) mineralogy, nuclear magnetic resonance (NMR), and petrography.This study documents the physical property interrelationships in the well and demonstrates their correlation with the occurrence of gas hydrate. Gas hydrate (GH) occurs in three unconsolidated, coarse silt to fine sand intervals within the Paleocene and Eocene beds of the Sagavanirktok Formation: Unit D-GH (614.4. m-627.9. m); unit C-GH1 (649.8. m-660.8. m); and unit C-GH2 (663.2. m-666.3. m). These intervals are overlain by fine to coarse silt intervals with greater clay content. A deeper interval (unit B) is similar lithologically to the gas-hydrate-bearing strata; however, it is water-saturated and contains no hydrate.In this system it appears that high sediment permeability (k) is critical to the formation of concentrated hydrate deposits. Intervals D-GH and C-GH1 have average "plug" intrinsic permeability to nitrogen values of 1700 mD and 675 mD, respectively. These values are in strong contrast with those of the overlying, gas-hydrate-free sediments, which have k values of 5.7. mD and 49 mD, respectively, and thus would have provided effective seals to trap free gas. The relation between permeability and porosity critically influences the occurrence of GH. For example, an average increase of 4% in porosity increases permeability by an order of magnitude, but the presence of a second fluid (e.g., methane from dissociating gas hydrate) in the reservoir reduces permeability by more than an order of magnitude. ?? 2010.

Winters, W.; Walker, M.; Hunter, R.; Collett, T.; Boswell, R.; Rose, K.; Waite, W.; Torres, M.; Patil, S.; Dandekar, A.

2011-01-01

19

Physical properties of sediment from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope  

USGS Publications Warehouse

This study characterizes cored and logged sedimentary strata from the February 2007 BP Exploration Alaska, Department of Energy, U.S. Geological Survey (BPXA-DOE-USGS) Mount Elbert Gas Hydrate Stratigraphic Test Well on the Alaska North Slope (ANS). The physical-properties program analyzed core samples recovered from the well, and in conjunction with downhole geophysical logs, produced an extensive dataset including grain size, water content, porosity, grain density, bulk density, permeability, X-ray diffraction (XRD) mineralogy, nuclear magnetic resonance (NMR), and petrography. This study documents the physical property interrelationships in the well and demonstrates their correlation with the occurrence of gas hydrate. Gas hydrate (GH) occurs in three unconsolidated, coarse silt to fine sand intervals within the Paleocene and Eocene beds of the Sagavanirktok Formation: Unit D-GH (614.4 m-627.9 m); unit C-GH1 (649.8 m-660.8 m); and unit C-GH2 (663.2 m-666.3 m). These intervals are overlain by fine to coarse silt intervals with greater clay content. A deeper interval (unit B) is similar lithologically to the gas-hydrate-bearing strata; however, it is water-saturated and contains no hydrate. In this system it appears that high sediment permeability (k) is critical to the formation of concentrated hydrate deposits. Intervals D-GH and C-GH1 have average "plug" intrinsic permeability to nitrogen values of 1700 mD and 675 mD, respectively. These values are in strong contrast with those of the overlying, gas-hydrate-free sediments, which have k values of 5.7 mD and 49 mD, respectively, and thus would have provided effective seals to trap free gas. The relation between permeability and porosity critically influences the occurrence of GH. For example, an average increase of 4% in porosity increases permeability by an order of magnitude, but the presence of a second fluid (e.g., methane from dissociating gas hydrate) in the reservoir reduces permeability by more than an order of magnitude.

Winters, William J.; Walker, Michael; Hunter, Robert; Collett, Timothy S.; Boswell, Ray M.; Rose, Kelly K.; Waite, William F.; Torres, Marta; Patil, Shirish; Dandekar, Abhijit

2011-01-01

20

Test evaluates high-volume ESP application offshore Mexico  

SciTech Connect

An electric submersible pump (ESP) test, although shorter than hoped for, indicated that artificial lift with ESPs had potential for replacing gas-lift operations, offshore Mexico. Petroleos Mexicanos (Pemex) recently preformed this test of a high-volume (10,000 b/d) ESP in the Akal reservoir of the Cantarell field, northeast Marina Region in the Gulf of Mexico. In the Marine Region, gas lift is the main artificial lift method; however, to maintain production on gas lift, sweetened gas requirements for the Akal reservoir would have to increase by about 30 MMscfd. The ESP design was complex because the pump would have to handle 20--40% of free gas at its intake. Installed in September 1996, the ESP had to be pulled from the well in November 1997 because of an electrical short. Actual operating time was about 7 months. The paper describes test objectives, pump environment, pump design, downhole equipment, surface equipment, operating history, production history, and an analysis.

Almazo, S.G. [Pemex, Villahermosa (Mexico); Riling, G. [Cealc, Bartlesville, OK (United States)

1998-02-16

21

Automatic picking and attribute mapping for a quick evaluation of the potential of turbiditic sands and stratigraphic traps in frontier areas. An example from the deep offshore of the Niger Delta  

SciTech Connect

Most interpretation teams involved in the exploration of Nigeria's deep offshore have been faced with a major challenge: (1) how to scan through a large volume of 3D data in a drastically short time frame... (2) with the captive of understanding the depositional pattern of slope fan and basin floor fan turbidites to identify mostly stratigraphic traps... (3) in an environment almost devoid of reference wells and calibration. A traditional approach was likely to miss both the deadlines and the sensitivity required for the sedimentological aspects of the study. Elfs answer was to rely extensively on the advanced functionalities of the SISMAGE (TM) workstation, in order to quickly generate time and seismic attribute maps which could then be interpreted in terms of structure and sedimentology. Two critical aspects were particularly well handled by the workstation: (1) the reliability of the extrapolation process from a loose grid of manually picked lines, and (2) the generation of seismic attribute maps relative not only to surfaces (e.g. sequence boundaries), but also to whole intervals through statistical calculation. In a second stage, the interpreters were able to focus on the most prospective areas and to move on to prospect generation, with the help of AVO studies. This approach is illustrated through an example from the deep offshore of the Niger delta.

Montagnier, P.; Rossi, T. (Elf Nigeria, Lagos (Nigeria)); Clergeat, B.; Dall'astam, W.F. (Elf Aquitaine Production, Paris (France))

1996-01-01

22

Automatic picking and attribute mapping for a quick evaluation of the potential of turbiditic sands and stratigraphic traps in frontier areas. An example from the deep offshore of the Niger Delta  

SciTech Connect

Most interpretation teams involved in the exploration of Nigeria`s deep offshore have been faced with a major challenge: (1) how to scan through a large volume of 3D data in a drastically short time frame... (2) with the captive of understanding the depositional pattern of slope fan and basin floor fan turbidites to identify mostly stratigraphic traps... (3) in an environment almost devoid of reference wells and calibration. A traditional approach was likely to miss both the deadlines and the sensitivity required for the sedimentological aspects of the study. Elfs answer was to rely extensively on the advanced functionalities of the SISMAGE (TM) workstation, in order to quickly generate time and seismic attribute maps which could then be interpreted in terms of structure and sedimentology. Two critical aspects were particularly well handled by the workstation: (1) the reliability of the extrapolation process from a loose grid of manually picked lines, and (2) the generation of seismic attribute maps relative not only to surfaces (e.g. sequence boundaries), but also to whole intervals through statistical calculation. In a second stage, the interpreters were able to focus on the most prospective areas and to move on to prospect generation, with the help of AVO studies. This approach is illustrated through an example from the deep offshore of the Niger delta.

Montagnier, P.; Rossi, T. [Elf Nigeria, Lagos (Nigeria); Clergeat, B.; Dall`astam, W.F. [Elf Aquitaine Production, Paris (France)

1996-12-31

23

Cenozoic synthem stratigraphic architecture of the SE Brazilian shelf and its global eustatic context: evidence from the Pelotas Basin (offshore Brazil)  

NASA Astrophysics Data System (ADS)

The Pelotas Basin, located on the SE Brazilian shelf, has evolved since the Aptian. Stratigraphical data from the basin can be used for delineation of the unconformity-bounded units (synthems) on the shelf, which is a first step towards a full understanding of its stratigraphic architecture, evolution, and hydrocarbon potential. Hiatuses in the Cenozoic succession of the Pelotas Basin are established with both biostratigraphic (planktonic foraminifers and calcareous nannofossils) and isotopic (87Sr/86Sr) data. The seven recognised hiatuses are dated respectively as (1) Palaeocene (Danian- Thanetian), (2) Palaeocene/Eocene boundary (Thanetian-Ypresian), (3) Eocene (Ypresian-Lutetian), (4) Eocene-Oligocene (Lutetian-Rupelian), (5) early-late Oligocene (Rupelian-Chattian), (6) early Miocene (Aquitanian-Burdigalian), and (7) middle-late Miocene (Serravallian-Tortonian). These intervals between the hiatuses are correlated with those of the Santos and Campos Basins north from the Pelotas Basin. The breaks in sedimentation that these basins have in common occurred (1) at the Palaeocene-Eocene and (2) Eocene-Oligocene transitions, (3) in the early Miocene, and (4) in the middle-late Miocene. These main unconformities outline five synthems on the SE Brazilian shelf, viz. the SEBS-1 (Palaeocene), SEBS-2 (Eocene), SEBS-3 (Oligocene), SEBS-4 (early-middle Miocene) and SEBS-5 (late Miocene-Holocene). The above unconformities are correlated with those established in the Cenozoic sedimentary successions of different regions such as Western Siberia, Arabia, NW and NE Africa, peninsular India, S Australia, the Gulf of Mexico, NW Europe, and South Africa. The only regional unconformity, near the Oligocene/Miocene boundary, coincides with the nearly-global sedimentation break. The latter was resulted from a climatic event, i.e., the `Mi-1 glaciation'. Thus, a eustatic origin is supposed for this regional unconformity. The other regional unconformities also correspond to global sea-level falls (probably with an exception for the Palaeocene/Eocene surface), which suggests that global eustatic movements controlled the development of the regional synthem architecture.

de Santana dos Anjos Zerfass, Geise; Ruban, Dmitry A.; Chemale, Farid, Jr.; Zerfass, Henrique

2013-12-01

24

Characterizing Structural and Stratigraphic Heterogeneities in a Faulted Aquifer Using Pump Tests with an Array of Westbay Multilevel Monitoring Wells  

NASA Astrophysics Data System (ADS)

We are developing and assessing field testing and analysis methodologies for quantitative characterization of aquifer heterogenities using data measured in an array of multilevel monitoring wells (MLW) during pumping and recovery well tests. We have developed a unique field laboratory to determine the permeability field in a 20m by 40m by 70m volume in the fault partitioned, siliciclastic Hickory aquifer system in central Texas. The site incorporates both stratigraphic variations and a normal fault system that partially offsets the aquifer and impedes cross-fault flow. We constructed a high-resolution geologic model of the site based upon 1050 m of core and a suite of geophysical logs from eleven, closely spaced (3-10m), continuously cored boreholes to depths of 125 m. Westbay multilevel monitoring systems installed in eight holes provide 94 hydraulically isolated measurement zones and 25 injection zones. A good geologic model is critical to proper installation of the MLW. Packers are positioned at all significant fault piercements and selected, laterally extensive, clay-rich strata. Packers in adjacent MLW bracket selected hydrostratigraphic intervals. Pump tests utilized two, uncased, fully penetrating irrigation wells that straddle the fault system and are in close proximity (7 to 65 m) to the MLW. Pumping and recovery transient pressure histories were measured in 85 zones using pressure transducers with a resolution of 55 Pa (0.008 psi). The hydraulic response is that of an anisotropic, unconfined aquifer. The transient pressure histories vary significantly from zone to zone in a single MLW as well as between adjacent MLW. Derivative plots are especially useful for differentiating details of pressure histories. Based on the geologic model, the derivative curve of a zone reflects its absolute vertical position, vertical stratigraphic position, and proximity to either a fault or significant stratigraphic heterogeneity. Additional forward modeling is needed to assist qualitative interpretation of response curves. Prior geologic knowledge appears critical. Quantitative interpretation of the transient pressure histories requires utilizing a numerical aquifer response model coupled with a geophysical inversion algorithm.

Johnson, B.; Zhurina, E. N.

2001-12-01

25

Amplitude distribution analysis of acoustic emission during fatigue testing of steels used in offshore structures  

Microsoft Academic Search

An analysis of amplitude distribution of acoustic emission (AE) signals during fatigue testing of low-strength, low carbon steel specimens used extensively in the fabrication of off-shore structures was carried out. The test results show three different amplitude distribution patterns which coincide with the three stages of fatigue reported in the literature. A statistical analysis showed that the statistical parameters like

R. Visweswaran; M. Manoharan; G. Jothinathan; O. Prabhakar

1985-01-01

26

Quantitative stratigraphic inversion  

NASA Astrophysics Data System (ADS)

We develop a methodology for systematic inversion of quantitative stratigraphic models. Quantitative stratigraphic modeling predicts stratigraphy using numerical simulations of geologic processes. Stratigraphic inversion methodically searches the parameter space in order to detect models which best represent the observed stratigraphy. Model parameters include sea-level change, tectonic subsidence, sediment input rate, and transport coefficients. We successfully performed a fully automated process based stratigraphic inversion of a geologically complex synthetic model. Several one and two parameter inversions were used to investigate the coupling of process parameters. Source location and transport coefficient below base level indicated significant coupling, while the rest of the parameters showed only minimal coupling. The influence of different observable data on the inversion was also tested. The inversion results using misfit based on sparse, but time dependent sample points proved to be better than the misfit based on the final stratigraphy only, even when sampled densely. We tested several inversion schemes on the topography dataset obtained from the eXperimental EarthScape facility simulation. The clustering of model parameters in most of the inversion experiments showed the likelihood of obtaining a reasonable number of compatible models. We also observed the need for several different dillusion-coefficient parameterizations to emulate different erosional and depositional processes. The excellent result of the piecewise inversion, which used different parameterizations for different time intervals, demonstrate the need for development or incorporation of time-variant parameterizations of the diffusion coefficients. We also present new methods for applying boundary condition on simulation of diffusion processes using the finite-difference method. It is based on the straightforward idea that solutions at the boundaries are smooth. The new scheme achieves high accuracy when the initial conditions are non vanishing at the boundaries, a case which is poorly handled by previous methods. Along with the ease in implementation, the new method does not require any additional computation or memory.

Sharma, Arvind Kumar

27

Investigation of gas hydrate-bearing sandstone reservoirs at the "Mount Elbert" stratigraphic test well, Milne Point, Alaska  

SciTech Connect

In February 2007, the U.S. Department of Energy, BP Exploration (Alaska), Inc., and the U.S. Geological Survey conducted an extensive data collection effort at the "Mount Elbert #1" gas hydrates stratigraphic test well on the Alaska North Slope (ANS). The 22-day field program acquired significant gas hydrate-bearing reservoir data, including a full suite of open-hole well logs, over 500 feet of continuous core, and open-hole formation pressure response tests. Hole conditions, and therefore log data quality, were excellent due largely to the use of chilled oil-based drilling fluids. The logging program confirmed the existence of approximately 30 m of gashydrate saturated, fine-grained sand reservoir. Gas hydrate saturations were observed to range from 60% to 75% largely as a function of reservoir quality. Continuous wire-line coring operations (the first conducted on the ANS) achieved 85% recovery through 153 meters of section, providing more than 250 subsamples for analysis. The "Mount Elbert" data collection program culminated with open-hole tests of reservoir flow and pressure responses, as well as gas and water sample collection, using Schlumberger's Modular Formation Dynamics Tester (MDT) wireline tool. Four such tests, ranging from six to twelve hours duration, were conducted. This field program demonstrated the ability to safely and efficiently conduct a research-level openhole data acquisition program in shallow, sub-permafrost sediments. The program also demonstrated the soundness of the program's pre-drill gas hydrate characterization methods and increased confidence in gas hydrate resource assessment methodologies for the ANS.

Boswell, R.M.; Hunter, R. (ASRC Energy Services, Anchorage, AK); Collett, T. (USGS, Denver, CO); Digert, S. (BP Exploration (Alaska) Inc., Anchorage, AK); Hancock, S. (RPS Energy Canada, Calgary, Alberta, Canada); Weeks, M. (BP Exploration (Alaska) Inc., Anchorage, AK); Mt. Elbert Science Team

2008-01-01

28

The characteristics of gas hydrates recovered from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope  

USGS Publications Warehouse

Systematic analyses have been carried out on two gas hydrate-bearing sediment core samples, HYPV4, which was preserved by CH4 gas pressurization, and HYLN7, which was preserved in liquid-nitrogen, recovered from the BPXA-DOE-USGS Mount Elbert Stratigraphic Test Well. Gas hydrate in the studied core samples was found by observation to have developed in sediment pores, and the distribution of hydrate saturation in the cores imply that gas hydrate had experienced stepwise dissociation before it was stabilized by either liquid nitrogen or pressurizing gas. The gas hydrates were determined to be structure Type I hydrate with hydration numbers of approximately 6.1 by instrumentation methods such as powder X-ray diffraction, Raman spectroscopy and solid state 13C NMR. The hydrate gas composition was predominantly methane, and isotopic analysis showed that the methane was of thermogenic origin (mean ??13C=-48.6??? and ??D=-248??? for sample HYLN7). Isotopic analysis of methane from sample HYPV4 revealed secondary hydrate formation from the pressurizing methane gas during storage. ?? 2010 Elsevier Ltd.

Lu, H.; Lorenson, T.D.; Moudrakovski, I.L.; Ripmeester, J.A.; Collett, T.S.; Hunter, R.B.; Ratcliffe, C.I.

2011-01-01

29

Examination of core samples from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Effects of retrieval and preservation  

Microsoft Academic Search

Collecting and preserving undamaged core samples containing gas hydrates from depth is difficult because of the pressure and temperature changes encountered upon retrieval. Hydrate-bearing core samples were collected at the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well in February 2007. Coring was performed while using a custom oil-based drilling mud, and the cores were retrieved by a wireline. The

Timothy J. Kneafsey; Hailong Lu; William Winters; Ray Boswell; Robert Hunter; Timothy S. Collett

2011-01-01

30

Secondary Craters as Stratigraphic Markers: GIS-Based Program Development and Performance Testing Using the Secondaries of Zunil Crater, Mars  

NASA Astrophysics Data System (ADS)

The pervasive occurrence of secondary crater chains across multiple geologic terrains on planetary surfaces elevates their potential utility as stratigraphic markers. However, current approaches that link secondaries to their parent (source) craters are qualitative and vulnerable to over-simplification. Herein, we present the developmental status and operational performance of a GIS-based computer program that analyzes the spatial relationship of secondary craters with potential parent craters. Once provided a vector point file and limited set of user-defined control parameters, the current program attempts to identify crater clusters using nearest-neighbor analysis, directional distributions of statistical clusters, and great circles that extend along the major axis of each statistical cluster beginning at its center. The number and density of great circle intersections are then used to model the location of a parent crater. Control parameters can be dynamically changed to examine multiple ejection-trajectory-impact scenarios. To control and calibrate the program, we used the spatial locations of >22,000 secondaries (mapped using THEMIS VIS images) interpreted to have been sourced from Zunil, a 10.1-km-diameter, Late Amazonian-age crater located in Elysium Planitia, Mars. Mapped points served as input for multiple program iterations, each of which calculated and displayed the effects that different cluster characteristics, ejection velocities, and angular rotations have on the modeled location of the parent crater. We also estimated variance in the modeled parent crater location based on human and automated cluster identification. Results indicate: (1) optimized parameters identify the source as a point located 1.6 kilometers from Zunil’s center; (2) distance between modeled source location and Zunil’s center decreases with increasing cluster ellipticity; (3) human- and auto-identified cluster analyses identify comparable source locations but use contrasting parameters; (4) inclusion of rotational velocities to account for the Coriolis effect has varying effects on accurately correlating modeled and actual source location; and (5) some mapped secondaries do not appear to source from Zunil crater. Current and ongoing performance tests will help to refine the current GIS-program and to develop optimized methods for its use as an analytical tool for assessing stratigraphy and impact dynamics on Mars and other planetary bodies.

Nava, R. A.; Skinner, J. A.

2009-12-01

31

An Empirical Investigation of Client Managers’ Responsibilities in Managing Offshore Outsourcing of Software-Testing Projects  

Microsoft Academic Search

Despite an increase in the offshore outsourcing of in- formation technology (IT) projects, little research has been carried out to identify issues that client managers (CMs) encounter when managing projects with offshore vendors. Also research on how CMs' responsibilities change to effectively manage offshore out- sourcing relationships has received little attention. We conducted a case study of an offshore outsourcing

Radhika P. Jain; Robin S. Poston; Judith C. Simon

2011-01-01

32

Extensional tectonics, halokinesis, eustacy in the Norwegian Central Graben, North Sea: A testing ground for sequence and seismic stratigraphic principles  

SciTech Connect

The Norwegian Central Graben is a mature hydrocarbon province with proven reserves within the Upper Jurassic succession. Several phases of extensional tectonics ranging from the Permo-Triassic to the Upper Jurassic, and a thick mobile salt section, serve to complicate a clear regional understanding of the area. A full integration of structural interpretation, seismic and sequence stratigraphic principles, biostratigraphy and core studies is required to achieve a realistic interpretation and predict Upper Jurassic facies distributions within this complex area. Utilizing some 30 wells, regional seismic data and biostratigraphy, candidate sequence boundaries and regionally correlatable flooding surfaces (e.g. Eudoxus), have been identified. Horizon flattening on these surfaces has allowed the recognition of thickening-away reflection geometries adjacent to salt features and divergent geometries into graben boundary faults. This facilitates the identification of the dominant local or regional controls on accommodation space creation. Detailed seismic facies analysis was then used to reveal the relative expansion or suppression of depositional systems tracts as a response to either regional or local structural controls. It was subsequently possible to place these systems within a biostratigraphically constrained regional framework. Mapping the base Zechstein, base Jurassic and base Cretaceous horizons has provided a map view of the active faults and slopes controlling sediment transport at any given time. This provided the third dimension essential in depicting the spatial distribution of depositional systems, and is a crucial component of any sequence stratigraphic interpretation. A regional picture of the progressive evolution of this complex area has been thus been derived, and the effect of both regional and local controls on sequence stratigraphic expressions has been determined.

Spencer, P.A. [Oxford Brookes Univ. (United Kingdom); Prosser, S.D. [Saga Petroleum a.s., Sandvika (Norway)

1996-12-31

33

Extensional tectonics, halokinesis, eustacy in the Norwegian Central Graben, North Sea: A testing ground for sequence and seismic stratigraphic principles  

SciTech Connect

The Norwegian Central Graben is a mature hydrocarbon province with proven reserves within the Upper Jurassic succession. Several phases of extensional tectonics ranging from the Permo-Triassic to the Upper Jurassic, and a thick mobile salt section, serve to complicate a clear regional understanding of the area. A full integration of structural interpretation, seismic and sequence stratigraphic principles, biostratigraphy and core studies is required to achieve a realistic interpretation and predict Upper Jurassic facies distributions within this complex area. Utilizing some 30 wells, regional seismic data and biostratigraphy, candidate sequence boundaries and regionally correlatable flooding surfaces (e.g. Eudoxus), have been identified. Horizon flattening on these surfaces has allowed the recognition of thickening-away reflection geometries adjacent to salt features and divergent geometries into graben boundary faults. This facilitates the identification of the dominant local or regional controls on accommodation space creation. Detailed seismic facies analysis was then used to reveal the relative expansion or suppression of depositional systems tracts as a response to either regional or local structural controls. It was subsequently possible to place these systems within a biostratigraphically constrained regional framework. Mapping the base Zechstein, base Jurassic and base Cretaceous horizons has provided a map view of the active faults and slopes controlling sediment transport at any given time. This provided the third dimension essential in depicting the spatial distribution of depositional systems, and is a crucial component of any sequence stratigraphic interpretation. A regional picture of the progressive evolution of this complex area has been thus been derived, and the effect of both regional and local controls on sequence stratigraphic expressions has been determined.

Spencer, P.A. (Oxford Brookes Univ. (United Kingdom)); Prosser, S.D. (Saga Petroleum a.s., Sandvika (Norway))

1996-01-01

34

Sentinel Hill Core Test 1: Facies Descriptions and Stratigraphic Reinterpretations of the Prince Creek and Schrader Bluff Formations, North Slope, Alaska  

USGS Publications Warehouse

The Sentinel Hill Core Test 1 well penetrated an intertonguing sequence of (1) the marine Schrader Bluff Formation in the depth intervals 950?1,180 ft and 690?751 ft, which consists of shoreface and offshore deposits that accumulated along a storm-dominated, barred shoreline; and (2) the nonmarine Prince Creek Formation in the depth intervals 751?950 ft and surface to 690 ft, which consists of fluvial channel, crevasse splay, backswamp, and ash fall deposits. The strata range in age from early Campanian to early Maastrichtian. An erosional contact at a depth of 690 ft at the base of the upper unit of the Prince Creek Formation is interpreted as a major regional sequence boundary, and the overlying conglomeratic fluvial channel deposits are interpreted to have accumulated in a paleovalley. In its more proximal reaches along the Colville River, channels of this paleovalley cut down 75 ft into the lowermost Prince Creek Formation and the uppermost Schrader Bluff Formation. Farther offshore, the equivalent surface to the aforementioned paleovalley appears to be a subtle discontinuity between middle and lower Schrader Bluff Formation shelfal marine strata. Still farther offshore, the equivalent paleovalley surface is interpreted as a marine mass-wasting surface that locally cuts through the lowermost Schrader Bluff Formation and into the underlying Seabee Formation.

Flores, Romeo M.; Stricker, Gary D.; Decker, Paul L.; Myers, Mark D.

2007-01-01

35

LOOP: first US offshore terminal will be tested in April or May  

SciTech Connect

In April or May a specially trained mooring master will board a supertanker 24 miles off Lafourche Parish Louisiana, to begin the first offloading test from a US offshore terminal. The vessel will be guided shoreward for 5 miles and positioned at one of three SALM (Single Anchor Leg Mooring) buoys. The tanker will be moored only by bowlines, permitting it to weathervane into prevaling wind and waves while it offloads into the LOOP (Louisiana Offshore Oil Port) terminal. The $630,000,000 facility is constructed in 110-ft water in Grand Isle Block 59, approximately 19 miles offshore. The terminal is the first serious US effort to build a facility capable of handling supertankers and gain the economics of scale the large-volume ships offer. The components of LOOP are discussed and the mooring systems are explained. LOOP will handle six different designations of crude imports; use of the specific caverns for segregation is important. The Clovelly facility is an underground tank farm. Crude will move in and out of the caverns via brine displacement. Crude pumped into a cavity will displace brine to the surface storage reservoir. Typically, oil leaving the Clovelly Salt Dome will head northwest through the 48 inch diameter LOCAP pipe line connecting the dome with the St. James terminal of Capline. From St. James, the crude either will be piped to refineries in Louisiana or sent up the Capline system. Because of Capline and adjacent crude pipe lines, LOOP imports are connected with approximately 25% of the nation's refinery capacity. (DP)

Not Available

1980-11-01

36

Brief: Offshore North Sea case histories of the environmentally friendly testing vessel, the Crystal Sea  

SciTech Connect

One problem during offshore well-test operations, stimulations, and routine workovers are discharges into the air and sea while flaring. These procedures are usually performed by mobile drilling rigs with no storage capacity, and thus, hydrocarbons sequestered must be burned off from the rig flare booms. Another major problem has been the inability of the flare to operate at high flow rates. Because the burning process slows the pace of a test, restricting full flow testing, valuable well information is lost. Flaring of hydrocarbons also represents an economic loss. In the case of oil rigs, for example, flaring not only emits CO{sub 2} into the atmosphere but also burns off usable oil. The Crystal Sea well-test vessel was designed to address the problems inherent to flaring and, at the same time, provide cost efficiency by salvaging usable oil during well testing. The success of her initial two jobs on the Statfjord North satellite field in the Norwegian sector of the North Sea confirms that sale of the salvaged oil normally lost during the flaring process could generate sufficient economic return to pay for the vessel. In addition, with its capability to receive products at twice the flow rate of conventional methods, the increased accuracy of the technical information obtained from the well test further enhances its value for improved reservoir management.

Tjelta, O.; Ashwell, C.; Hilmarsen, G.; Taylor, R.W.

1996-04-01

37

Case study of preliminary cyclic load evaluation and triaxial soil testing in offshore wind farm planning  

NASA Astrophysics Data System (ADS)

In 2020 Germany aims to produce 20% of its electrical power trough renewable energy sources. Assigned Offshore Wind farms in the German exclusive economic zone of the North- and the Baltic Sea are important step toward a fulfilment of this goal. However the save erecting of 5-6 MW wind power plants (total construction size: > 200m) in water depth of around 40 m is related to unprecedented technical, logistical and financial challenges. With an intended lifetime expectation of 50 years for the foundations, construction materials and the soils around the foundation are subject to high and continued stresses from self-weight, waves, wind and current. These stresses are not only static, but have also a significant cyclic component. An estimated 250 million cyclic load changes may lead to an accumulation of plastic deformation in the soil that potentially may affect operability or lifespan of the plant. During a preliminary geotechnical site survey of one of the largest (~150 km2) offshore wind project sites within the German Bight (~45 km North off the island Juist) a total of 16 drill cores with in situ cone penetration data and a total sample length of ~800 m where recovered. Preliminary foundation designs and static self weight and lateral load calculations were used to design a cycling triaxial lab testing program on discrete natural soil samples. Individual tests were performed by foundation type and at vertical and lateral load maxima to evaluate the long-term soil behaviour under cyclic load. Tests have been performed on granular, cohesive and intermediate natural soils. Following an introduction to the unique MARUM triaxial apparatus and testing conditions, the cyclic triaxial test results are shown and explained. Furthermore cyclic shear strength and stiffness are compared to their static counterparts. Unique soil behaviour like abrupt partial failure, pore pressure response and unexpected in part load independent cyclic deformation behaviour is discussed and compared to literature results. The shown case study is intended to demonstrate a feasible procedure for evaluating cyclic loads, designing test procedures, presenting results and interpreting data in a so far unregulated field without common standards. The presented data has been produced within the framework of germanwind, a science industry partnership including RWE-Innogy, ENOVA and MARUM.

Otto, Daniel; Ossig, Benjamin; Kreiter, Stefan; Kouery, Saed; Moerz, Tobias

2010-05-01

38

Offshore northern sea case histories of the environmentally friendly testing vessel, the ``Crystal Sea``  

SciTech Connect

One of the problems that surfaces during offshore well test operations, stimulations, and routine workovers has been the discharges that are made into the air and sea, and in particular, the possible formation of dioxins during the combustion process. Since these operations and tests have normally been performed by mobile drilling rigs that do not have storage capacity, oil and gas sequestered during performance of the procedures are burned off from the rig flarebooms. Another major problem during well testing has been the incapability of the flare to operate at high flow rates. Since the burning process slows down the pace of a test and does not allow the well to be tested under full flow, valuable information about the well cannot be determined. In light of the economic and regulatory changes occurring in today`s oil and gas industry, the justification for development of a cost-effective, environmentally-safe alternative to flaring hydrocarbons was certainly indicated. This paper will discuss the well test vessel, ``Crystal Sea,`` and the initial two jobs on the Statfjord North Satellite Field in the Norwegian sector of the North Sea. The success of these jobs confirms that the Crystal Sea can provide an alternative to flaring that reduces the degree of pollutants discharged from oil rigs, and at the same time, can salvage the usable oil. The sale of the salvaged oil, which would normally be lost during the flaring process, often can generate sufficient economic return to pay for the vessel. ``Crystal Sea`` is capable of receiving products at approximately twice the flow rate as is possible with conventional surface test equipment from a rig. This increased flow rate not only improves the accuracy of the technical information obtained from the well test but also provides valuable tools for improved reservoir management.

Tjelta, O.; Ashwell, C.; Hilmarsen, G.; Taylor, R.W.

1995-12-01

39

Characterizing Structural and Stratigraphic Heterogeneities in a Faulted Aquifer Using Pump Tests with an Array of Westbay Multilevel Monitoring Wells  

Microsoft Academic Search

We are developing and assessing field testing and analysis methodologies for quantitative characterization of aquifer heterogenities using data measured in an array of multilevel monitoring wells (MLW) during pumping and recovery well tests. We have developed a unique field laboratory to determine the permeability field in a 20m by 40m by 70m volume in the fault partitioned, siliciclastic Hickory aquifer

B. Johnson; E. N. Zhurina

2001-01-01

40

Teaching with Stratigraphic Profiles  

ERIC Educational Resources Information Center

Presents two exercises modeled after the ice age puzzle described in the ESCP textbook, including formation of terminal moraines and kettle lakes and intersection of normal faults with gold-quartz veins. Indicates that the stratigraphic profiles are usable in teaching earth science, geography, general science, and topographic problems. (CC)

Stefanich, Greg P.

1974-01-01

41

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

SciTech Connect

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.

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

2013-07-01

42

Identification of third-order (approx. 10{sup 6} yrs) and fourth-order (approx. 10{sup 5}/10{sup 4} yrs) stratigraphic cycles in the South Addition, West Cameron Lease Area, Louisiana offshore  

SciTech Connect

In the highly explored South Addition of the West Cameron Lease Area, Louisiana offshore, interpretation of a six-mile ({approx}10 km) seismic section across a single intraslope basin yielded 20 sediment packages. Several interpretive tools were necessary. Seismic stratigraphy indicated that the shallower zone was an outer shelf marked by 8 major sea level oscillations. In the portion between 1 and 3 seconds, seismic stratigraphy and paleontology led to the interpretation of depositional environments such as upper slope, and paleobathymetrically deeper intervals with descent through the section. The intraslope basin, while small, may be viewed as a micro-continental margin. Each sea level oscillation cycle apparently made a distinct progradational unit, decipherable in the seismic data. Fourth order cycles have been provisionally interpreted, throughout most of the entire 3.7 second section. Such precision is possible only in explored basins with excellent seismic data. The sequence thickness showed a seven-fold variability, from 0.08 to 0.58 seconds. The shallower section, deposited along an outer shelf, has an average individual sequence thickness of 0.13 seconds. Individual seismic sequences in the deeper section, interpreted to have been deposited on an upper slope, have average thicknesses of 0.25 seconds. The thinner sequences of the shallower section are compatible with the notion that the outer shelf was a bypass zone during a glacial epoch. The thicker sequences of the deeper section are the result of deposition onto an aggrading upper slope within an intraslope basin during a highstand.

Lowrie, A.; Meeks, P. [Specialty Office Services, Waveland, MS (United States); Hoffman, K. [Dynamics Graphics, Houston, TX (United States)

1996-09-01

43

Examination of core samples from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Effects of retrieval and preservation  

USGS Publications Warehouse

Collecting and preserving undamaged core samples containing gas hydrates from depth is difficult because of the pressure and temperature changes encountered upon retrieval. Hydrate-bearing core samples were collected at the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well in February 2007. Coring was performed while using a custom oil-based drilling mud, and the cores were retrieved by a wireline. The samples were characterized and subsampled at the surface under ambient winter arctic conditions. Samples thought to be hydrate bearing were preserved either by immersion in liquid nitrogen (LN), or by storage under methane pressure at ambient arctic conditions, and later depressurized and immersed in LN. Eleven core samples from hydrate-bearing zones were scanned using x-ray computed tomography to examine core structure and homogeneity. Features observed include radial fractures, spalling-type fractures, and reduced density near the periphery. These features were induced during sample collection, handling, and preservation. Isotopic analysis of the methane from hydrate in an initially LN-preserved core and a pressure-preserved core indicate that secondary hydrate formation occurred throughout the pressurized core, whereas none occurred in the LN-preserved core, however no hydrate was found near the periphery of the LN-preserved core. To replicate some aspects of the preservation methods, natural and laboratory-made saturated porous media samples were frozen in a variety of ways, with radial fractures observed in some LN-frozen sands, and needle-like ice crystals forming in slowly frozen clay-rich sediments. Suggestions for hydrate-bearing core preservation are presented.

Kneafsey, T.J.; Lu, H.; Winters, W.; Boswell, R.; Hunter, R.; Collett, T.S.

2011-01-01

44

High-resolution well-log derived dielectric properties of gas-hydrate-bearing sediments, Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope  

USGS Publications Warehouse

A dielectric logging tool, electromagnetic propagation tool (EPT), was deployed in 2007 in the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well (Mount Elbert Well), North Slope, Alaska. The measured dielectric properties in the Mount Elbert well, combined with density log measurements, result in a vertical high-resolution (cm-scale) estimate of gas hydrate saturation. Two hydrate-bearing sand reservoirs about 20 m thick were identified using the EPT log and exhibited gas-hydrate saturation estimates ranging from 45% to 85%. In hydrate-bearing zones where variation of hole size and oil-based mud invasion are minimal, EPT-based gas hydrate saturation estimates on average agree well with lower vertical resolution estimates from the nuclear magnetic resonance logs; however, saturation and porosity estimates based on EPT logs are not reliable in intervals with substantial variations in borehole diameter and oil-based invasion.EPT log interpretation reveals many thin-bedded layers at various depths, both above and below the thick continuous hydrate occurrences, which range from 30-cm to about 1-m thick. Such thin layers are not indicated in other well logs, or from the visual observation of core, with the exception of the image log recorded by the oil-base microimager. We also observe that EPT dielectric measurements can be used to accurately detect fine-scale changes in lithology and pore fluid properties of hydrate-bearing sediments where variation of hole size is minimal. EPT measurements may thus provide high-resolution in-situ hydrate saturation estimates for comparison and calibration with laboratory analysis. ?? 2010 Elsevier Ltd.

Sun, Y.; Goldberg, D.; Collett, T.; Hunter, R.

2011-01-01

45

Research on smart control tests of ice-induced vibration control of offshore platform  

Microsoft Academic Search

This paper proposes a smart control system to reduce ice-induced motions in the offshore jacket platform structure subjected to ice-induced vibration. Magnetorheological (MR) dampers are applied as smart control devices and the control input determination is based on a clipped-optimal control algorithm which uses absolute displacement and acceleration feedback. The performance of this method is studied experimentally by means of

Jigang Zhang; Bin Wu

2010-01-01

46

Offshore structures  

SciTech Connect

This monograph provides a comprehensive coverage of the engineering concepts and design of offshore structures for the exploration for and production of offshore oil. Although offshore structural engineering is a relatively new field, the literature contains thousands of papers and a few books addressing various aspects of the discipline. The purpose of this treatise is to offer a general conspectus and a state-of-the-art picture, with emphasis on pragmatic engineering applications, to all those associated with offshore structural design, research, and development.

Reddy, D.V.; Arockiasamy, M. (Florida Atlantic Univ., Boca Raton, FL (United States))

1991-01-01

47

Offshore Technology  

NSDL National Science Digital Library

Offshore Technology is a Web site specifically geared for the offshore oil and gas industry. The highlight of the site is the Industry Projects link, which gives information about offshore drilling projects from around the world. Sites are categorized geographically and include description of the project, information on the geology of the area, drilling history of the site, wellhead platform, pipeline information, and much more. Other links on the main page include an A to Z listing of contractors and suppliers, exhibition and conference information, and other helpful resources for the offshore drilling professional and researcher.

48

Offshore Wind Research (Fact Sheet)  

SciTech Connect

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.

Not Available

2011-10-01

49

Stratigraphic and Paleomagnetic Comparisons of Mesoproterozoic Strata and Sills from the Belt Basin, NW Montana, USA, and NW Anabar Shield, Russia: Testing a Precambrian Plate Reconstruction  

NASA Astrophysics Data System (ADS)

Mesoproterozoic sedimentary strata and mafic sills overlie Archean and Paleoproterozoic basement rocks with profound unconformity in NW Montana and along the NW margin of the Anabar Shield in northern Siberia. The two localities plot adjacent to one another on a Precambrian plate reconstruction proposed by Sears and Price (2003) that places the NE margin of the Siberian craton against the SW margin of the North American craton. The plate reconstruction predicts that these strata occupied contiguous parts of an intracratonic basin prior to late Neoproterozoic breakup of Rodinia. Here we show that the Mesoproterozoic stratigraphic sequences, sedimentary structures, and lithologies of the NW Anabar margin closely match the Neihart, Chamberlain, and Newland formations of the Little Belt Mountains of Montana. They may predate opening of the Belt Supergroup rift basin at ca. 1500 Ma, when a major mafic magmatic episode occurred in both regions. Preliminary paleomagnetic data from the Siberian section will be compared with the Laurentian APWP to evaluate the reconstruction.

Sears, J. W.; Pavlov, V.; Veselovskiy, R.; Khudoley, A.

2008-12-01

50

Stratigraphic Architecture of Table Rock, Boise, Idaho  

NSDL National Science Digital Library

In the GEOS 315 â Sedimentology and Stratigraphy course at Boise State University, students conduct field research over a period of 4-5 weeks at Table Rock, a prominent sandstone plateau and popular hiking destination above Boise, ID. Table Rock is composed primarily of nearshore lacustrine sediments deposited along the margins of Mio-Pliocene Lake Idaho. In addition to measuring and correlating stratigraphic sections to describe the facies architecture, students are required to formulate and test an original hypothesis. The primary assessment criteria are field notes, a 4-page research proposal, and a poster presentation summarizing their research results.

Matson, Sam

51

The scientific objectives and program of the Japanese offshore methane hydrate production test  

NASA Astrophysics Data System (ADS)

A gas production attempt from deepwater marine methane hydrate deposits is planned in early 2013 in the AT1 site in the north slope Daini-Atsumi Knoll in the Eastern Nankai Trough. The scientific goal of this production test is to understand the behavior of methane hydrate dissociation under an in-situ condition. The program includes one to several weeks of gas flow by applying depressurization technique. Drilling operations for the production test started in February 2012 at the test location, and two monitoring boreholes and part of production well have been drilled and completed. Reservoir characterization study is an essential part of the science program. For this purpose, intensive geophysical logging and coring programs are included in the drilling program. The logging data were mainly obtained from a hole named AT1-MC. The well was drilled with LWD tools, wireline logging suits were run subsequently. Also pressure-preserved cores were recovered from methane hydrate-concentrated and overburden sections in a dedicated borehole (AT1-C). To keep the pressure and temperature of cores under gas hydrate stability condition all the time, pressure core analysis and transfer system (PCATS) was used. Also the PCATS-triaxial device that can make mechanical and physical property measurements possible under tri-axial effective stress conditions was utilized. The physical, hydraulic and mechanical properties obtained from core and log data will be used for modeling works, and given to the numerical simulator MH21-HYDRES for methane hydrate production modeling as input parameters for forward analysis and inversion (history matching) to understand the in-situ processes. The monitoring of the methane hydrate dissociation processes is another important subject. The two monitoring holes have temperature sensors to detect temperature drop and recovery due to gas hydrate dissociation and heat transfer. Also, one of the monitoring holes is kept re-accessible to allow cased-hole geophysical logging before and after the production test. A geophone array in an ocean bottom cable (OBC) will be deployed for a multi-component and time-lapse seismic survey on the seafloor. During the flow test, water and gas production rates, downhole temperature and pressure will be monitored. Comparison between actual well response and computed value from the numerical model will correct and improve our knowledge about reservoir characters and forecast of long-term productivity. JOGMEC, AIST and related scientists and engineers analyze the data to make unseen underground processes visible.;

Yamamoto, K.; Fujii, T.; Noguchi, S.; Nagao, J.

2012-12-01

52

Monitoring the Methane Hydrate Dissociation by the Offshore Methane Hydrate Production Tests using Multi-component Seismic  

NASA Astrophysics Data System (ADS)

We developed a new OBC (Ocean Bottom Cable), named as 'DSS' (Deep-sea Seismic System). The sensor has 3-component accelerometer and a hydrophone applicable for four-component (4C) seismic survey. Using the DSS, the methane hydrate dissociation zone will be tried to be monitored at the water depth of around 1000m during JOGMEC offshore methane hydrate production test in early 2013. Before the DSS, we had developed the RSCS (Real-time Seismic Cable System) with 3-component gimbaled geophones, and carried out a reflection seismic survey in the Nankai Trough in 2006. Referring this successful survey, we improved the RSCS to the DSS. The receiver size is reduced to 2/3 and the receiver case has a protective metallic exterior and the cable is protected with steel-screened armouring, allowing burial usage using ROV for sub-seabed deployment at the water depth up to 2000m. It will realize a unique survey style that leaves the system on the seabed between pre-test baseline survey and post-test repeated surveys, which might be up to 6 months. The fixed location of the receiver is very important for time-lapse monitoring survey. The DSS has totally 36 sensors and the sensor spacing is 26.5m. The total length is about 1km. We carried out the pre-test baseline survey between off Atsumi and Shima-peninsula in August, 2012.We located the DSS close to the production test well. The nearest sensor is 63m apart from the well. A newly developed real-time 3-D laying simulation system consisting of ADCP (Acoustic Doppler Current Profiler), transponders attached to the DSS, and real-time 3-D plotting system for transponder locations have been adopted. After we laid the cable, we buried the DSS using ROV (Remotely Operated Vehicle). The baseline survey included 2D/3D seismic surveys with shooting vessel and cable laying/observation ship. The resultant 2D section and 3D volume shows the good quality to delineate the methane hydrate concentrated zone. After the baseline survey, we have left the DSS on seafloor until the first monitoring survey scheduled in April 2013, because the fixed location of the sensors is essential for time-lapse monitoring survey.

Asakawa, Eiichi; Hayashi, Tsutomu; Tsukahara, Hitoshi; Takahashi, Hiroo; Saeki, Tatsuo

2013-04-01

53

Geologic evolution of a Pliocene-Pleistocene salt-withdrawal minibasin: Eugene Island Block 330, offshore Louisiana  

Microsoft Academic Search

The spatial and temporal distributions of reservoir sands are documented within the context of an evolving Plicoene-Pleistocene salt-withdrawal shelf minibasin. The Eugene Island Block 330 field, a giant oil and gas field in offshore Louisiana, is contained within the minibasin. Based on the stratigraphic and structural analyses, we present a sequence-stratigraphic and tectonic-stratigraphic model for reservoir prediction in complex shelf

L. L. Alexander; P. B. Flemings

1995-01-01

54

A Risk Analysis Methodology to Address Human and Organizational Factors in Offshore Drilling Safety: With an Emphasis on Negative Pressure Test  

NASA Astrophysics Data System (ADS)

According to the final Presidential National Commission report on the BP Deepwater Horizon (DWH) blowout, there is need to "integrate more sophisticated risk assessment and risk management practices" in the oil industry. Reviewing the literature of the offshore drilling industry indicates that most of the developed risk analysis methodologies do not fully and more importantly, systematically address the contribution of Human and Organizational Factors (HOFs) in accident causation. This is while results of a comprehensive study, from 1988 to 2005, of more than 600 well-documented major failures in offshore structures show that approximately 80% of those failures were due to HOFs. In addition, lack of safety culture, as an issue related to HOFs, have been identified as a common contributing cause of many accidents in this industry. This dissertation introduces an integrated risk analysis methodology to systematically assess the critical role of human and organizational factors in offshore drilling safety. The proposed methodology in this research focuses on a specific procedure called Negative Pressure Test (NPT), as the primary method to ascertain well integrity during offshore drilling, and analyzes the contributing causes of misinterpreting such a critical test. In addition, the case study of the BP Deepwater Horizon accident and their conducted NPT is discussed. The risk analysis methodology in this dissertation consists of three different approaches and their integration constitutes the big picture of my whole methodology. The first approach is the comparative analysis of a "standard" NPT, which is proposed by the author, with the test conducted by the DWH crew. This analysis contributes to identifying the involved discrepancies between the two test procedures. The second approach is a conceptual risk assessment framework to analyze the causal factors of the identified mismatches in the previous step, as the main contributors of negative pressure test misinterpretation. Finally, a rational decision making model is introduced to quantify a section of the developed conceptual framework in the previous step and analyze the impact of different decision making biases on negative pressure test results. Along with the corroborating findings of previous studies, the analysis of the developed conceptual framework in this paper indicates that organizational factors are root causes of accumulated errors and questionable decisions made by personnel or management. Further analysis of this framework identifies procedural issues, economic pressure, and personnel management issues as the organizational factors with the highest influence on misinterpreting a negative pressure test. It is noteworthy that the captured organizational factors in the introduced conceptual framework are not only specific to the scope of the NPT. Most of these organizational factors have been identified as not only the common contributing causes of other offshore drilling accidents but also accidents in other oil and gas related operations as well as high-risk operations in other industries. In addition, the proposed rational decision making model in this research introduces a quantitative structure for analysis of the results of a conducted NPT. This model provides a structure and some parametric derived formulas to determine a cut-off point value, which assists personnel in accepting or rejecting an implemented negative pressure test. Moreover, it enables analysts to assess different decision making biases involved in the process of interpreting a conducted negative pressure test as well as the root organizational factors of those biases. In general, although the proposed integrated research methodology in this dissertation is developed for the risk assessment of human and organizational factors contributions in negative pressure test misinterpretation, it can be generalized and be potentially useful for other well control situations, both offshore and onshore; e.g. fracking. In addition, this methodology can be applied for the analysis

Tabibzadeh, Maryam

55

Recognition of a thin stratigraphic trap by seismic reflection character analysis  

Microsoft Academic Search

The Cretaceous Cardium Formation, Alberta, Canada, which produces oil and gas from thin stratigraphic traps comprising coastal and offshore shelf sand-ridge deposits, appears as railroad tracks on seismic sections. Ninety-seven seismic lines were examined over a 10,000 km² area. Here, the Cardium is divided into the Cardium Sand and the overlying Cardium Zone, both of which are 15-50 m thick.

R. M. Slatt; K. Lighty; J. Robinson

1985-01-01

56

Sequence-Stratigraphic Analysis of the Regional Observation Monitoring Program (ROMP) 29A Test Corehole and Its Relation to Carbonate Porosity and Regional Transmissivity in the Floridan Aquifer System, Highlands County, Florida  

USGS Publications Warehouse

An analysis was made to describe and interpret the lithology of a part of the Upper Floridan aquifer penetrated by the Regional Observation Monitoring Program (ROMP) 29A test corehole in Highlands County, Florida. This information was integrated into a one-dimensional hydrostratigraphic model that delineates candidate flow zones and confining units in the context of sequence stratigraphy. Results from this test corehole will serve as a starting point to build a robust three-dimensional sequence-stratigraphic framework of the Floridan aquifer system. The ROMP 29A test corehole penetrated the Avon Park Formation, Ocala Limestone, Suwannee Limestone, and Hawthorn Group of middle Eocene to Pliocene age. The part of the Avon Park Formation penetrated in the ROMP 29A test corehole contains two composite depositional sequences. A transgressive systems tract and a highstand systems tract were interpreted for the upper composite sequence; however, only a highstand systems tract was interpreted for the lower composite sequence of the deeper Avon Park stratigraphic section. The composite depositional sequences are composed of at least five high-frequency depositional sequences. These sequences contain high-frequency cycle sets that are an amalgamation of vertically stacked high-frequency cycles. Three types of high-frequency cycles have been identified in the Avon Park Formation: peritidal, shallow subtidal, and deeper subtidal high-frequency cycles. The vertical distribution of carbonate-rock diffuse flow zones within the Avon Park Formation is heterogeneous. Porous vuggy intervals are less than 10 feet, and most are much thinner. The volumetric arrangement of the diffuse flow zones shows that most occur in the highstand systems tract of the lower composite sequence of the Avon Park Formation as compared to the upper composite sequence, which contains both a backstepping transgressive systems tract and a prograding highstand systems tract. Although the porous and permeable layers are not thick, some intervals may exhibit lateral continuity because of their deposition on a broad low-relief ramp. A thick interval of thin vuggy zones and open faults forms thin conduit flow zones mixed with relatively thicker carbonate-rock diffuse flow zones between a depth of 1,070 and 1,244 feet below land surface (bottom of the test corehole). This interval is the most transmissive part of the Avon Park Formation penetrated in the ROMP 29A test corehole and is included in the highstand systems tract of the lower composite sequence. The Ocala Limestone is considered to be a semiconfining unit and contains three depositional sequences penetrated by the ROMP 29A test corehole. Deposited within deeper subtidal depositional cycles, no zones of enhanced porosity and permeability are expected in the Ocala Limestone. A thin erosional remnant of the shallow marine Suwannee Limestone overlies the Ocala Limestone, and permeability seems to be comparatively low because moldic porosity is poorly connected. Rocks that comprise the lower Hawthorn Group, Suwannee Limestone, and Ocala Limestone form a permeable upper zone of the Upper Floridan aquifer, and rocks of the lower Ocala Limestone and Avon Park Formation form a permeable lower zone of the Upper Floridan aquifer. On the basis of a preliminary analysis of transmissivity estimates for wells located north of Lake Okeechobee, spatial relations among groups of relatively high and low transmissivity values within the upper zone are evident. Upper zone transmissivity is generally less than 10,000 feet squared per day in areas located south of a line that extends through Charlotte, Sarasota, DeSoto, Highlands, Polk, Osceola, Okeechobee, and St. Lucie Counties. Transmissivity patterns within the lower zone of the Avon Park Formation cannot be regionally assessed because insufficient data over a wide areal extent have not been compiled.

Ward, W. C.; Cunningham, K. J.; Renken, R. A.; Wacker, M. A.; Carlson, J. I.

2003-01-01

57

Summary of hydrologic testing in Tertiary limestone aquifer, Tenneco offshore exploratory well--Atlantic OCS, lease-block 427 (Jacksonville NH 17-5)  

USGS Publications Warehouse

A summary of hydrologic testing in an offshore oil-test well (LB427) drilled for Tenneco, Inc., 55 miles east of Fernandina Beach, Florida, is presented. The interval tested (1,050 to 1,070 feet below sea level) is in a calcarenite that is equivalent to the Ocala Limestone (late Eocene) of onshore Florida and South Georgia. At this site the Ocala forms the highly productive Tertiary limestone aquifer system of the southeastern United States. Pressure-head measurements indicate an equivalent freshwater head of 24 to 29 feet above sea level. These pressure-head measurements and an earlier one made in the nearby JOIDES J- I hole are the only hydraulic head determinations to date in the offshore extensions of any of the aquifers underlying the Atlantic coastal plain. A drill-stem test recovered water samples containing about 7,000 milligrams per liter chloride. However, seawater used in the drilling process apparently contaminated the samples and the formation water is considered slightly fresher. The head and salinity data from the Tenneco well suggest that the sampled interval lies in the transition zone between fresh and seawater in the limestone aquifer. These data, when viewed with similar data from JOIDES J-I, show the transition zone to slope very slightly landward. The interface position is probably intermediate between a position compatible with present-day heads and a position compatible with predevelopment heads.

Johnston, Richard H.; Bush, Peter W.; Krause, Richard E.; Miller, James A.; Sprinkle, Craig L.

1982-01-01

58

X-ray CT Observations of Methane Hydrate Distribution Changes over Time in a Natural Sediment Core from the BPX-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well  

SciTech Connect

When maintained under hydrate-stable conditions, methane hydrate in laboratory samples is often considered a stable and immobile solid material. Currently, there do not appear to be any studies in which the long-term redistribution of hydrates in sediments has been investigated in the laboratory. These observations are important because if the location of hydrate in a sample were to change over time (e.g. by dissociating at one location and reforming at another), the properties of the sample that depend on hydrate saturation and pore space occupancy would also change. Observations of hydrate redistribution under stable conditions are also important in understanding natural hydrate deposits, as these may also change over time. The processes by which solid hydrate can move include dissociation, hydrate-former and water migration in the gas and liquid phases, and hydrate formation. Chemical potential gradients induced by temperature, pressure, and pore water or host sediment chemistry can drive these processes. A series of tests were performed on a formerly natural methane-hydrate-bearing core sample from the BPX-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well, in order to observe hydrate formation and morphology within this natural sediment, and changes over time using X-ray computed tomography (CT). Long-term observations (over several weeks) of methane hydrate in natural sediments were made to investigate spatial changes in hydrate saturation in the core. During the test sequence, mild buffered thermal and pressure oscillations occurred within the sample in response to laboratory temperature changes. These oscillations were small in magnitude, and conditions were maintained well within the hydrate stability zone.

Kneafsey, T.J.; Rees, E.V.L.

2010-03-01

59

Lower Pleistocene to present structural deformation and sequence stratigraphy of the continental shelf, offshore Eel River Basin, northern California  

Microsoft Academic Search

Seismic stratigraphic sequences and deformational features are mapped beneath the continental shelf of the offshore Eel River Basin of northern California, using a closely spaced, high-resolution multichannel seismic grid. Geometries of sequences and morphologies of bounding unconformities reflect competing tectonic and glacioeustatic influences, producing shifting sedimentation patterns in the offshore basin during the last ?1 Myr. Estimated timing of unconformity

Robert L Burger; Craig S Fulthorpe; James A Austin; Sean P. S Gulick

2002-01-01

60

Latest Quaternary stratigraphic framework of the Mississippi River delta region  

USGS Publications Warehouse

Previous researchers separated the uppermost Quaternary stratigraphy of the Mississippi River delta region into two major lithofacies. The stratigraphically lower of these, "substratum," primarily consists of coarse-grained sediment deposited within lowstand-incised stream valleys. Relatively finer-grained "topstratum" overlies substratum; above interfluves, topstratum directly overlies weathered late Pleistocene sediments. However, the onshore to offshore distribution and architecture of these lithofacies was not well constrained. This study integrates published and unpublished lithostratigraphic data with high-resolution seismic profiles from the continental shelf to aid in mapping the regional distribution of major substratum deposits and thickness of topstratum sediments. A transgressive sand sheet commonly marks the base of the topstratum deposits, providing a stratigraphic marker to aid in regional lithostratigraphic correlations. Radiocarbondated deposits and boreholes tied to oxygen isotope chronologies provide chronostratigraphic control. Excellent correlation between these multiple datasets has been found to exist, enabling construction of regional isopachous and structural elevation maps and cross sections detailing elements of the Late Quaternary stratigraphy.

Kulp, Mark; Howell, Paul; Adiau, Sandra; Penland, Shea; Kindinger, Jack; Williams, S. Jeffress

2002-01-01

61

Design, manufacturing and tests of first cryogen-free MgB2 prototype coils for offshore wind generators  

NASA Astrophysics Data System (ADS)

Although renewable sector has started to take advantage of the offshore wind energy recently, the development is very intense. Turbines reliability, size, and cost are key aspects for the wind industry, especially in marine locations. A superconducting generator will allow a significant reduction in terms of weight and size, but cost and reliability are two aspects to deal with. MgB2 wire is presented as one promising option to be used in superconducting coils for wind generators. This work shows the experimental results in first cryogen-free MgB2 prototype coils, designed according to specific requirements of TECNALIA's wind generator concept.

Sarmiento, G.; Sanz, S.; Pujana, A.; Merino, J. M.; Iturbe, R.; Apiñaniz, S.; Nardelli, D.; Marino, I.

2014-05-01

62

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

SciTech Connect

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.

Richardson, S.M.; Bott, W.F.; Birse, T.C.R. [British Gas Exploration & Production Ltd., Reading (United Kingdom)

1995-08-01

63

Singularity analysis: a tool for extracting lithologic and stratigraphic content from seismic data  

E-print Network

In this work, we test an amplitude-independent method of seisimic data analysis designed to extract lithologic information about stratigraphic horizons. We apply the method of singularity characterization in an attempt to ...

Lyons, William J.

2001-01-01

64

Problems in offshore measurement  

SciTech Connect

Problems associated with offshore measurement are discussed here. There is no substitute for the human element on offshore platforms. Most problems in offshore measurement do have solutions. The sooner the problem is recognized and corrected can depend on how frequently a station can be visited. Advanced planning, good design, safe work practices and a realistic approach are the only solutions to offshore measurement problems. Good work practices, with well trained personnel can avert many problems and offer smooth safe operations.

Bitterly, D.G.

1984-04-01

65

MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND FARM SITES  

E-print Network

MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND important for offshore wind energy utilisation are discussed and tested: Four models for the surface of wind energy utilisation at least in Europe will come from offshore sites. The first large offshore wind

Heinemann, Detlev

66

BIOMODULE: a Java program to help model and interpret the stratigraphic record  

NASA Astrophysics Data System (ADS)

A combination of a stratigraphic simulation package (STRATA) and an evolutionary-ecological model (BIOSTRAT) can be used to simulate the distribution of species within a sequence stratigraphic framework. BIOMODULE is an extension of this model approach in that it facilitates the visualization and interpretation of those simulations and their input data. Environmental factors (e.g., sea-level changes or sedimentation rates) and ecological factors (preferred water depth, depth tolerance, abundance) that determine the spatial and temporal distribution of species are easily and quickly investigated. In addition, BIOMODULE can be used to compile the stratigraphic first and last appearances of those species and export them into available graphic correlation software packages (Conop9 and GraphCor). This can be used to test the graphic correlation technique and investigate its accuracy and precision under a range of different conditions (e.g., different stratigraphic architectures and sampling densities) since the true correlation of the different sections is already known.

Herrmann, Achim D.; Patzkowsky, Mark E.; Holland, Steven M.

2003-02-01

67

Offshoring, immigration, and the native wage distribution  

Microsoft Academic Search

This paper presents a simple model that examines the impact of offshoring and immigration on wages and tests these predictions using U.S. state-industry-year panel data. According to the model, the productivity effect causes offshoring to have a more positive impact on low-skilled wages than immigration, but this gap decreases with the workers' skill level. The empirical results confirm both of

William W. Olney

2012-01-01

68

Offshore wind energy prospects  

Microsoft Academic Search

In last two years offshore wind energy is becoming a focal point of national and non national organizations particularly after the limitations of fossil fuel consumption, adopted by many developed countries after Kyoto conference at the end of 1997 on global climate change. North Europe is particularly interested in offshore for the limited land areas still available, due to the

Gaetano Gaudiosi

1999-01-01

69

Structure of Offshore Flow  

Microsoft Academic Search

The horizontal and vertical structure of the mean flow and turbulent fluxes are examined using aircraft observations taken near a barrier island on the east coast of the United States during offshore flow periods. The spatial structure is strongly influenced by the surface roughness and surface temperature discontinuities at the coast. With offshore flow of warm air over cool water,

Dean Vickers; L. Mahrt; Jielun Sun; Tim Crawford

2001-01-01

70

Sequence stratigraphic interpretations in a continental strike-slip Basin - Southern Dead Sea, Israel  

SciTech Connect

Sequence stratigraphic interpretations of subsurface data from the Southern Dead Sea have been integrated with computer modeling of the stratigraphy, demonstrating that the sedimentary fill was controlled by extremely high rates of subsidence (1000 m/MY), salt tectonics, multiple sediment sources, and lake-level fluctuations. The southern part of the basin is underlain by half-grabens and full-grabens. A northwest-southeast directed shear zone (5-6 km wide) closes the basin to the north, while the large Amaziahu growth fault, developed by gravity sliding and salt-withdrawal, separates the basin into two segments. Fan deltas entered the basin at its southern and northern ends, while salt and lacustrine offshore sediments accumulated in its interior. The southern and northern lacustrine systems interfinger in a mixing zone which changed position as a function of lake-level variations. The advance of the northern system was accompanied by lake level falls, while lake-level rises favored an influx from the southern system. The northern sedimentary system gradually became more dominant. The stratigraphic simulation revealed that the lake-level falls paralleled those of the Mediterranean sea, but with a slight (0.3-0.4 MY) delay. Combined stratigraphic and thermal maturation modeling suggests that sediments in the deepest part of the basin are currently within the oil generation window. Significant pinch-out zones flanking the Mount Sedom diapir, buried fan delta complexes, and the peculiar interfingering, zones may be important exploration targets.

Csato, I.; Kendall, C.

1996-12-31

71

Subsurface sequence stratigraphic correlation using well logs  

NSDL National Science Digital Library

Students are given hard copies of a subsurface section containing gamma and resistivity logs of nine closely-spaced (well distance varies from 1 to 3 km) wells from Delaware Basin, southeast New Mexico for an interval of ~ 200 m clastic succession of Morrow sandstone of Pennsylvanian age. Core sedimentology of one of these wells is also provided. Students' task is to correlate the well logs to generate a stratigraphic cross-section of the area using sequence stratigraphic approach. As the data are from Delaware Basin, southeast New Mexico, student should first gather the knowledge of regional setting of the basin, with a particular emphasis to the paleo-eustasy. (Clue: in Delaware Basin, Morrow sandstones deposited in a low accommodation settings with high-amplitude fluctuations of sea-level.) When correlating the well logs students should start with the well which has lithological information. Students should try to correlate the mudstones first. The two most prominent sequence stratigraphic surfaces with comparatively higher correlation-length are 'sequence boundary' produced by pronounced fall of sea-level, and 'maximum flooding surface' generated at the time of highest stand of sea-level. Students should pay particular attention to incised-valley-fill deposits. After completing the correlation, students should check whether their correlation satisfy our prevailing ideas of sequence stratigraphy and stratal packaging. Student should prepare a brief description of overall depositional environments and sea-level history of the area substantiating their subsurface correlation. By doing this exercise, students will learn how to apply sequence stratigraphic principles in interpreting subsurface data, particularly from well logs.

Gani, M. R.

72

Stratigraphic turnover on west Africa margin page 1 Early Oligocene stratigraphic turnover on west Africa continental margin: a signature of  

E-print Network

Stratigraphic turnover on west Africa margin page 1 Early Oligocene stratigraphic turnover on west and evolution of the west African margin: The continental margin of west Africa resulted from the Neocomian profiles across #12;Stratigraphic turnover on west Africa margin page 2 the west African continental margin

Demouchy, Sylvie

73

A nearshore–offshore trend in acritarch distribution from the Early–Middle Ordovician of the Yangtze Platform, South China  

Microsoft Academic Search

The stratigraphical interval of the late Early Ordovician Didymograptus deflexus and the early Middle Ordovician Azygograptus suecicus graptolite Biozones was investigated from seven sections from the upper Yangtze Platform, southern China. These are located on different parts of the platform, between the nearshore environments of the Kunming area, Yunnan Province, and the offshore carbonate shelf of the Yichang area, Hubei

Jun Li; Thomas Servais; Kui Yan; Huaicheng Zhu

2004-01-01

74

Methane hydrate pore saturation evaluation from geophysical logging and pressure core analysis, at the first offshore production test site in the eastern Nankai Trough, Japan  

NASA Astrophysics Data System (ADS)

On March 2013, the first offshore production test form methane hydrate (MH) concentrated zone (MHCZ) was conducted by the Research Consortium for Methane Hydrate Resource Development in Japan (MH21) at the AT1 site located in the north-western slope of Daini-Atsumi Knoll in the eastern Nankai Trough, Japan. Before the production test, extensive geophysical logging and pressure coring using Hybrid Pressure Coring System were conducted in 2012 at monitoring well (AT1-MC) and coring well (AT1-C), in order to obtain basic information for the MH reservoir characterization. MH pore saturation (Sh) is one of the important basic parameters not only for reservoir characterization, but also the resource assessment. However, precise evaluation of Sh from geophysical logging is still challenging technical issue. The MHCZ confirmed by the geophysical logging at AT1-MC has a turbidite assemblage (from several tens of centimeters to a few meters) with 60 m of gross thickness; it is composed of lobe/sheet type sequences in the upper part, and relatively thick channel sand sequences in the lower part. In this study, the Sh evaluated from geophysical logging data were compared with those evaluated from pressure core analysis. Resistivity logs and nuclear magnetic resonance (NMR) log were used for the Sh evaluation by geophysical logging. Standard Archie equation was applied for Sh evaluation from resistivity log, while density magnetic resonance (DMR) method was used for Sh evaluation from NMR log. The Sh from pressure core samples were evaluated using the amount of dissociated gas volume, together with core sample bulk volume, measured porosity, net sand intervals, and assumed methane solubility in pore water. In the upper part of the MHCZ, Sh estimated from resistivity log showed distinct difference in value between sand and mud layers, compared to Sh from NMR log. Resistivity log has higher vertical resolution than NMR log, so it is favorable for these kinds of thin bed evaluation. In this part, 50 to 80% of Sh was observed in sandy layer, which showed fairly good agreement with core derived Sh. On the other hand, lower part of the MHCZ, Sh estimated from both resistivity and NMR log showed higher background value and relatively smoother curve than upper part. In this part, 50 to 80% of Sh was observed in sandy layer, which was also showed good agreement with core derived Sh. This study was conducted by the Research Consortium for Methane Hydrate Resource Development in Japan (MH21).

Fujii, T.; Suzuki, K.; Takayama, T.; Konno, Y.; Yoneda, J.; Egawa, K.; Ito, T.; Nagao, J.

2013-12-01

75

American Association of Stratigraphic Palynologists, Inc. (AASP)  

NSDL National Science Digital Library

The American Association of Stratigraphic Palynologists, Inc. (AASP) was established in 1967 "to promote the science of palynology in academia and industry." Visitors can discover scholarship opportunities and awards. The Biographies and Histories of Palynology link offers a growing collection of materials about many of the prominent scientists in the field of palynology, which is the branch of science concerned with the study of pollen, spores, and similar palynomorphs, living and fossil. By viewing a Microsoft PowerPoint presentation, students can learn about the science of palynology. Researchers can find information on a variety of conferences and meetings as well as on the publications produced by AASP.

76

Europa's Northern Trailing Hemisphere: Lineament Stratigraphic Framework  

NASA Technical Reports Server (NTRS)

Knowledge of the global distribution of Europan geologic units in time and space is a necessary step for the synthesis of the results of the Galileo mission and in preparation for future exploration (namely, by JIMO) of the satellite. We have initiated the production of the first Global Geological Map of Europa. As a base map, we use the recently published global photomosaic of Europa (U.S.G.S. Map I-2757) and additional Galileo SSI images at their original resolution. The map is being produced entirely on GIS format for analysis and combination with other datasets [1]. One of the main objectives of this project is to establish a global stratigraphic framework for Europa. In the absence of a well-developed cratering record, this goal will be achieved using the satellite s global network of lineaments (ridges, ridge complexes and bands; cf. [2]). Here we present the preliminary stratigraphic framework synthesized from the sequence of lineaments derived for the northern trailing hemisphere of Europa (Figure 1, below), and we discuss its significance and some emerging implications.

Figueredo, P. H.; Hare, T.; Ricq, E.; Strom, K.; Greeley, R.; Tanaka, K.; Senske, D.

2004-01-01

77

Exploration concept and characteristic of the dinarides stratigraphic and structural model in the Croatian offshore area  

SciTech Connect

The Dinarides Mesozoic carbonate platform constitutes an extensive paleogeographic unit of the Neo-Tethys platform system. Despite a large sedimentary complex within the platform displaying good hydrocarbon potential, no economic oil accumulations have as yet been discovered. A detailed study of the latest seismic and well data from the Kornati block and other relevant areas suggests, however, that a modified exploration scenario, based on the following elements, could be proposed: (1) Systematic lateral distribution of potential petroliferous facies between the Istrian-Dalmatian marginal zones and the central zone of the external Dinarides. Also, evidence of regular facies changes during platform evolution. (2) Paleotectonic control of varying depositional environments. These range from extremely restricted (anoxic) conditions, to high-energy zones on the platform margins and the edges of intraplatform basins and lagoons. (3) A link between the structural style of the final platform carbonates and the underlying Permian-Triassic halokinetic deposits. This relationship occurred during the Apulia microplate collision and shearing. (4) Differential platform subsidence and burial of potential source rock during platform evolution. Also, post-platform flysch and Molasse sedimentation. (5) Rotational displacement of potential hydrocarbon reservoirs away from the conventional target of exploratory drilling. An acceptance of the above-mentioned elements, particularly the rotation concept, could contribute toward developing a more effective exploration strategy. This should involve seismostratigraphic and other refined exploration methods in many zones of the Neo-Tethys carbonate platform system characterized by similar rotational displacement.

Grandic, S. (Western Geophysical, Isleworth, Middlesex (United Kingdom)); Susterciv, M.; Balas, E. (Ina-Naftaplin, Zagreb (Croatia))

1993-09-01

78

Selected stratigraphic contacts for drill holes in LANL use areas of Yucca Flat, NTS  

Microsoft Academic Search

This report is a compilation of selected stratigraphic contacts in drill holes of Yucca Flat, Nevada Test Site (NTS), used by the Los Alamos National Laboratory (LANL). This is the product of an ongoing effort to establish and maintain the most up-to-date database of formation tops in LANL use areas of Yucca Flat. Figure 1 is an index map showing

Drellack; S. L. Jr

1988-01-01

79

“Slicing the Value Chain” Internationally: Empirical Evidence on the Offshoring Strategy by French Firms  

Microsoft Academic Search

This paper analyzes the offshoring strategy from an empirical view. It focuses on a set of models, extracts a set of testable hypothesises and creates a suitable set of variable to test their validity. This analysis is based on a data set from French manufacturing firms that provides detailed information on the offshoring strategy. The choice of offshoring modes is

Liza Jabbour

80

Photoresponses of larval Atlantic menhaden ( Brevoortia tyrannus Latrobe) in offshore and estuarine waters: implications for transport  

Microsoft Academic Search

This study tested the hypothesis that Atlantic menhaden (Brevoortia tyrannus Latrobe) larvae have separate behaviors in offshore and estuarine waters that are evoked by chemical cues in these waters. Atlantic menhaden spawn offshore, and larvae are transported shoreward where they metamorphose after entering estuaries. Field studies suggest that during the day larvae are at moderate depths offshore and less abundant

Richard B. Forward; John S. Burke; Daniel Rittschof; James M. Welch

1996-01-01

81

Energy from Offshore Wind: Preprint  

SciTech Connect

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.

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

2006-02-01

82

Sequence stratigraphic controls on reservoir characterization and architecture: case study of the Messinian Abu Madi incised-valley fill, Egypt  

NASA Astrophysics Data System (ADS)

Understanding sequence stratigraphy architecture in the incised-valley is a crucial step to understanding the effect of relative sea level changes on reservoir characterization and architecture. This paper presents a sequence stratigraphic framework of the incised-valley strata within the late Messinian Abu Madi Formation based on seismic and borehole data. Analysis of sand-body distribution reveals that fluvial channel sandstones in the Abu Madi Formation in the Baltim Fields, offshore Nile Delta, Egypt, are not randomly distributed but are predictable in their spatial and stratigraphic position. Elucidation of the distribution of sandstones in the Abu Madi incised-valley fill within a sequence stratigraphic framework allows a better understanding of their characterization and architecture during burial. Strata of the Abu Madi Formation are interpreted to comprise two sequences, which are the most complex stratigraphically; their deposits comprise a complex incised valley fill. The lower sequence (SQ1) consists of a thick incised valley-fill of a Lowstand Systems Tract (LST1)) overlain by a Transgressive Systems Tract (TST1) and Highstand Systems Tract (HST1). The upper sequence (SQ2) contains channel-fill and is interpreted as a LST2 which has a thin sandstone channel deposits. Above this, channel-fill sandstone and related strata with tidal influence delineates the base of TST2, which is overlain by a HST2. Gas reservoirs of the Abu Madi Formation (present-day depth ˜3552 m), the Baltim Fields, Egypt, consist of fluvial lowstand systems tract (LST) sandstones deposited in an incised valley. LST sandstones have a wide range of porosity (15 to 28%) and permeability (1 to 5080mD), which reflect both depositional facies and diagenetic controls. This work demonstrates the value of constraining and evaluating the impact of sequence stratigraphic distribution on reservoir characterization and architecture in incised-valley deposits, and thus has an important impact on reservoir quality evolution in hydrocarbon exploration in such settings.

Abdel-Fattah, Mohamed I.; Slatt, Roger M.

2013-12-01

83

High-Alloy Materials for Offshore Applications  

Microsoft Academic Search

High-alloy materials possessing good corrosion resistance in hot, sour brines are being seriously considered for offshore applications. These alloys are available in a wide range of strength levels which can be attained by the methods of cold working or precipitation hardening. Results of testing INCONEL alloys 625 and 718 and INCOLOY alloys 825 and 925 for resistance to general corrosion,

T. F. Lemke; J. A. Harris

1983-01-01

84

GENERAL GEOLOGY OF THE MID-TERTIARY BLOCK 889 FIELD AREA, OFFSHORE MUSTANG ISLAND, TEXAS  

Microsoft Academic Search

The structural and stratigraphic architecture of the Block 889 field area, offshore Mustang Island, Texas, was defined by the integration of 3-D seismic, wireline logs, and engineering data. The area has produced 145 Bcf (billion cubic feet) of gas and 3 MMbbl (million barrels) of con- densate since the mid-1960's. Shale-withdrawal controlled the structural evolution of the area. Three growth

Ramón H. Treviño; Robert G. Loucks; L. Frank Brown; Randy L. Remington

85

Stratigraphic data for wells at and near the Idaho National Engineering Laboratory, Idaho  

SciTech Connect

A stratigraphic data base containing 230 stratigraphic units in 333 wells was constructed for deposits that make up the unsaturated zone and the Snake River Plain aquifer at and near INEL in eastern Idaho. Stratigraphic units, which were identified and correlated using data from numerous outcrops, 26 continuous cores, and 328 natural-gamma logs available in Dec. 1993, include 121 basalt-flow groups, 102 sedimentary interbeds, 6 andesite-flow groups, and 1 rhyolite dome. By volume, basalt flows make up about 90% of the deposits underlying most of this 890 mi{sup 2} area. Basalt, sediment, andesite, and rhyolite were identified from outcrops and cores that were selectively evaluated. Stratigraphic units were correlated using these data and natural-gamma logs. Best correlations were for basalt and sediment at Test Area North, the Naval Reactors Area, the Test Reactor Area, ICPP, and the Radioactive Waste Management Complex (RWMC), where most cores and 2/3 of the logs were obtained. Correlations range from good at the RWMC to uncertain the eastern half of the study area. A computer diskette containing the data is included.

Anderson, S.R.; Ackerman, D.J.; Liszewski, M.J. [Geological Survey, Washington, DC (United States); Frieburger, R.M. [EG and G Idaho, Inc., Idaho Falls, ID (United States)

1996-05-01

86

Tectonic and stratigraphic evolution of the tectonic and stratigraphic evolution of the Tjörnes Fracture Zone, Northern Iceland  

E-print Network

To explain the offshore distribution of pockmarks, one hasDistribution and Seafloor Morphology in Skjálfandi Bay 3.1 ABSTRACT Geophysical data collected offshoreOffshore pockmarks occur in a well-defined band determined by the interplay of the distribution

Fenwick, Rebecca Ann

2010-01-01

87

Offshore Wind Geoff Sharples  

E-print Network

energy capture · Get to beYer resource · Reduce opera?ons cost · Increase turbine the blades bigger? · How big will turbines get? #12;Offshore Resource is Good #12 risk averse U?li?es are risk averse Human customers demand cheap

Kammen, Daniel M.

88

Offshore Wind Energy Systems  

ERIC Educational Resources Information Center

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)

Musgrove, P.

1978-01-01

89

Offshore Renewable Energy Solutions  

E-print Network

and maximising energy extraction. Offshore understanding Our long track record working with the oil and gas and fisheries data. We also work collaboratively, with cross-cutting project teams, innovators in the supply chain and a range of international academic and industry players. Trusted advisors As scientific

90

The state of offshore  

SciTech Connect

In this book, the author explains the factors behind state involvement in offshore petroleum activities. From his analysis of government workings in Great Britain and Norway, he concludes that state intervention is determined by complex interactions among government officials, economic interests, and environmental pressures.

Nelson, B.F.

1991-01-01

91

Offshore space center (offshore launch site)  

SciTech Connect

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.

Harvey, D.G.

1980-07-01

92

Stratigraphic evolution of paleozoic erathem, northern Florida  

SciTech Connect

Unmetamorphosed Paleozoic sedimentary and volcanic rocks have been drilled in numerous wells throughout northern Florida and southern Georgia, in what is today a gently folded and block-faulted relict continental fragment of northwest Africa and northeast South America. Stratigraphic and lithologic equivalents of these North American Paleozoic units are prolific hydrocarbon producers in North Africa. The northern Florida Paleozoic sediments were deposited on Pan-African and Cadoman basement. Widespread continental glaciation from late Precambrian to Early Cambrian introduced a thick sequence of fine-grained marine sandstones (glacial flour), which overlie medium to coarse-grained glaciofluvial sandstones. Basinward of the sand shelf, the accretion of a volcanic island arc complex began during the Ordovician. A fluctuating transgression, accompanying a major glacial minimum, brought open-marine, graptolitic, black shales onto the sand shelf, producing an interbedded shoreface-shelf sand and black shale section during the Middle and Late Ordovician. At the Ordovician-Silurian boundary, renewed continental glaciation lowered sea level, producing a widespread unconformity. A Late Silurian major marine transgression returned black, graptolitic, highly organic shales onto the sand shelf. Devonian deltaic sands from Avalonia(.) to the north and the craton to the south closed the Paleozoic sedimentary record of northern Florida.

Coleman, J.L. Jr.

1985-02-01

93

Impact of lithosphere deformation on stratigraphic architecture of passive margin basins.  

NASA Astrophysics Data System (ADS)

The aim of this study is to revise our view of the long-term stratigraphic trends of passive margins to include the impact of the coupling between the lithosphere deformation and the surface processes. To do this, we developed a new numerical procedure simulating interactions between lithosphere deformation and (un)loading effects of surface processes (erosion/sedimentation) in 3D with a special attention to the stratigraphic architecture of the associated sedimentary basins. We first simulate the syn-rift phase of lithosphere stretching by thermo-mechanical modeling. We then use the resulting lithosphere geometry as input of a 3D flexural modeling including coupling with surface processes to simulate the post-rift evolution of the margin. We then use the resulting accumulation and subsidence histories as input of the stratigraphic simulation to model the detailed stratigraphic architecture of the basin. We tested this procedure using synthetic examples of lithosphere stretching based on different rheologies of the lithosphere (i.e. strength of the lower crust) in the cases of narrow or ultrawide rifting. We determined the stratigraphic expression of the conjugate margins and show that they differ in terms of long-term stratigraphic trends, erosion/accumulation and lithological distribution in space and time. In all cases, uplift/subisdence rates decrease with time while the flexure wavelength increases as isotherms are re-equilibrated. Some areas show displacement inversion over time from uplift to subsidence (or vice-versa). As expected, the amplitude of vertical motion of the wide margin cases is very limited with respect to the narrow margin case. Vertical motions are very asymetric on conjugate margins. Accordingly, the stratigraphic architectures and the sedimentation/erosion patterns of the conjugate simulated margins are significantly different mostly because the duration and length of progradation and retrogradation differ. We evaluated the sensitivity of the simulations to parameters controlling (i) the lithosphere deformation, (ii) the continental drainage erosivity (climate) or (iii) erodability (lithology) as well as (iv) base level (eustasy).

Rouby, Delphine; Huismans, Ritske; Braun, Jean; Robin, Cécile; Granjeon, Didier

2014-05-01

94

Electrokinetic improvement of offshore foundations  

NASA Astrophysics Data System (ADS)

Offshore and near-shore structures for energy exploration and production, harbour work and other facilities are often situated on very soft marine clay deposits that have shear strengths of a few kilopascals. The design of foundations embedded in these soft deposits often poses a challenge for geotechnical engineers, i.e., to satisfy the bearing capacity requirement, while at the same time minimizing the embedment depth and dimensions of the foundation due to cost considerations. The present study investigates the possibility of using electrokinetics to strengthen the soil adjacent to skirted foundations embedded in soft marine deposits and, thus, to improve the load carrying capacity of the foundations. The innovative feature of this approach as compared to soil improvement methods commonly adopted in practice is that the focus of strengthening is on the interface between the soil and embedded foundation, in terms of enhancement of adhesion and cementation. The thesis presents a summary of the method and results of a series of electrokinetic tests conducted on natural and simulated marine clays in small-scale and large-scale laboratory testing facilities. Steel plates and steel cylinders are used to simulate skirted foundations. A low dc voltage is applied via steel electrodes installed around the foundation models. The effects of electrokinetics are evaluated through changes in the geotechnical properties of the soil and load carrying capacities of the foundation model after treatment. The results demonstrate that the load carrying capacity of the skirted foundation model and the undrained shear strength of the adjacent soil increase by a factor of three after electrokinetic treatment. The clay adheres strongly to the inside and outside walls of the foundation model, indicating bonding occurs between the soil and steel after treatment. The treatment increases the soil undrained modulus and also induces a preconsolidation pressure of the remoulded clay, thereby reducing potential settlement of the foundation. The new technology described in this thesis has potential application in offshore engineering for increasing the load carrying capacity of skirted foundations installed in soft clayey sediments, as well as for rehabilitation of existing offshore structures.

Micic, Silvana

95

Efficient high-permeability fracturing offshore  

SciTech Connect

Offshore operators can more efficiently and effectively perform high-permeability and conventional hydraulic fracture treatments by blending treatment slurries under microprocessor control, adding undiluted acid on-the-fly, and altering sand concentrations and other slurry properties instantaneously. A two-skid system has been designed with these considerations in mind. The system, which can be shipped efficiently in ISO containers, has been tested on fluids up to 210-cp viscosity and can step or ramp sand concentrations up to a maximum of 20 lb/gal. All additives, including acid treatments, are added on-the-fly; leftover additives and acids may be stored for future jobs. The system may be applied in most conditions, including offshore wells requiring conventional or high-permeability fracture treatments and certain land-based wells in remote areas where a compact skid is needed. Three significant benefits have resulted from using the compact-skid system: offshore operators have been able to ship the skid system at 20% of shipping costs of non-ISO equipment; on-the-fly mixing has prevented material waste associated with batch-mixing; and volumes pumped on actual jobs have closely matched job designs. Data have been collected from several Gulf of Mexico jobs run with the two-part skid system that has been designed for conducting hydraulic fracture treatments from offshore rigs.

Phillipi, M.; Farabee, M.

1996-12-31

96

The offshore-ring: A new system design for the open ocean aquaculture of macroalgae  

Microsoft Academic Search

Mass culture of benthic macroalgae under rough offshore conditions in the North Sea requires rigid culture support systems that cannot only withstand rough weather conditions but can also be effectively handled while at the same time retain the cultured species. Various carrier constructions and different mooring systems were tested. Laminaria saccharina grew on all of these carriers with initially high

Bela Hieronymus Buck; Cornelia Maria Buchholz

2004-01-01

97

Frequency Domain Load Calculation for Offshore Wind Turbines (TURBU Offshore)  

Microsoft Academic Search

The design of offshore wind turbines requires to assess a huge amount of different sea-states and wind conditions. Therefor the calculational efficiency of a comb ined time\\/frequency domain approach is attractive. This was the reason for the development of the frequency domain tool TURBU Offshore. In addition, such a tool is very feasible for parameter studies; the dynamics of large

T. G. van Engelen

98

Offshore~WMEP - Monitoring offshore wind energy use  

Microsoft Academic Search

Offshore wind energy use is commonly suggested to play an important role in future electricity supply. However, long-term experience with thousands of onshore wind turbines explicitly hint on possible barriers for a save, efficient, economic and user friendly supply relying on offshore wind energy. A national German programme shall on the one hand support the wind energy branch improving technology

P. Lyding; S. Faulstich; B. Hahn; D. Callies

99

Offshoring, Immigration and the Domestic Wage Distribution: Evidence from the U.S. States 2000-05  

Microsoft Academic Search

While workers in developed countries have become increasingly concerned about the impact of offshoring and immigration on domestic wages, the available evidence on the link between offshoring, immigration, and wages remains ambiguous. This paper presents a simple model that identifies the impact of offshoring and immigration on native wages and tests these predictions using U.S. state-industry level data. Highlighting the

William W. Olney

100

Improved thermoplastic materials for offshore flexible pipes  

SciTech Connect

Long-term aging tests representative of field operating conditions have been conducted on various thermoplastic materials proposed for the inner tube of flexible pipes for offshore drilling and production applications. In particular, experimental data are provided about the changes of the mechanical properties of selected thermoplastic materials owing to optimized formulation when the pipes are exposed over time to crude oil in the presence of gas and water.

Dawans, F.; Jarrin, J.; Hardy, J.

1988-08-01

101

Security Issues with Offshore Outsourcing  

Microsoft Academic Search

Offshore coding is booming throughout North America and Europe, with Gartner group predicting that by 2004 80% of US companies will consider outsourcing critical services to foreign-based developers. But as this offshore outsourcing trend accelerates, concerns that enterprises are exposing themselves to undue risk of cyber-terrorism and industrial property theft are increasing.

Philip Hunter

2003-01-01

102

Pioneering offshore excellence  

SciTech Connect

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.

Kent, R.P.; Grattan, L.

1996-11-01

103

Floating offshore structure  

SciTech Connect

A floating offshore structure which is moored at a fixed position on the sea by means of mooring hawsers and anchors connected to the ends thereof respectively for conducting a submarine excavating operation from a deck of the structure. The structure includes a moorage hull part provided with a vertical through-hole formed therein for receiving an excavating drill pipe and the mooring hawsers and a movable hull part connected to the moorage hull part so as to be rotatable within a horizontal plane. The movable hull part is constituted as a hull defining the outer wall of the floating offshore structure and connected with the moorage hull part by inserting it into a moorage hull part receiving hole formed at a position closer to the bow thereof. The movable hull part has near its water plane a horizontal section with a substantially oval shape formed by a fore draft part in a substantially circular or polygonal shape, with the moorage hull part receiving hole as a center and an after draft part taperingly projecting aft from the fore draft part.

Oshima, M.; Narita, H.; Tabuchi, H.; Yashima, N.

1985-05-28

104

Offshore sand resources for coastal erosion control in Louisiana  

SciTech Connect

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.

Ramsey, K.E.; Penland, S.; McBride, R.A. (Louisiana Geological Survey, Baton Rouge (USA)); Suter, J.R. (Exxon Production Research, Houston, TX (USA)); Williams, J. (Geological Survey, Reston, VA (USA))

1990-09-01

105

Structure, stratigraphy and petroleum geology of the south east Nam Con Son Basin, offshore Vietnam  

SciTech Connect

Recent exploration of the south east Nam Con Son Basin, offshore Vietnam, by BP in alliance with Statoil has involved acquisition of new seismic and well data. These new data have allowed re-evaluation of the tectono-stratigraphic development and petroleum geology, and have provided additional constraints on the regional tectonic evolution. The offshore Vietnamese basins have evolved in response to the complex relative motions of Indochina, Peninsular Malaysia, Borneo and the South China Sea during the Cenozoic. On the regional scale these motions have been accommodated by strike-slip fault development, rifting and contraction. In the Nam Con Son Basin these motions have interacted in different ways from the Palaeogene to recent. Two rifting episodes are recognized; a Palaeogene phase dominated by E-W trending extensional faults, and a Miocene phase dominated by N-S to NE-SW trending faults. The structural evolution is complicated by a pulse of mild contraction during the Middle Miocene. The sedimentary fill of the basin evolves from continental fluvio-lacustrine in the Palaeogene through to fully marine following the second phase of rifting in the Miocene. This pulsed structural and stratigraphic evolution has resulted in basinwide deposition of source, reservoir and seal facies, and produced a variety of potential trapping styles. This paper describes the hydrocarbon habitat of the south east Nam Con Son Basin within the context of the regional tectono-stratigraphic model.

Fraser, A.J.; Matthews, S.J.; Lowe, S.; Todd, S.P.; Simon, P. Peel, F.J. (BP Exploration Operating Co., Ltd., Uxbridge (United Kingdom))

1996-01-01

106

Structure, stratigraphy and petroleum geology of the south east Nam Con Son Basin, offshore Vietnam  

SciTech Connect

Recent exploration of the south east Nam Con Son Basin, offshore Vietnam, by BP in alliance with Statoil has involved acquisition of new seismic and well data. These new data have allowed re-evaluation of the tectono-stratigraphic development and petroleum geology, and have provided additional constraints on the regional tectonic evolution. The offshore Vietnamese basins have evolved in response to the complex relative motions of Indochina, Peninsular Malaysia, Borneo and the South China Sea during the Cenozoic. On the regional scale these motions have been accommodated by strike-slip fault development, rifting and contraction. In the Nam Con Son Basin these motions have interacted in different ways from the Palaeogene to recent. Two rifting episodes are recognized; a Palaeogene phase dominated by E-W trending extensional faults, and a Miocene phase dominated by N-S to NE-SW trending faults. The structural evolution is complicated by a pulse of mild contraction during the Middle Miocene. The sedimentary fill of the basin evolves from continental fluvio-lacustrine in the Palaeogene through to fully marine following the second phase of rifting in the Miocene. This pulsed structural and stratigraphic evolution has resulted in basinwide deposition of source, reservoir and seal facies, and produced a variety of potential trapping styles. This paper describes the hydrocarbon habitat of the south east Nam Con Son Basin within the context of the regional tectono-stratigraphic model.

Fraser, A.J.; Matthews, S.J.; Lowe, S.; Todd, S.P.; Simon, P. Peel, F.J. [BP Exploration Operating Co., Ltd., Uxbridge (United Kingdom)

1996-12-31

107

OUTSHORE Maturity Model: Assistance for Software Offshore Outsourcing Decisions  

NASA Astrophysics Data System (ADS)

Offshore outsourcing software development (OOSD) is increasingly being used by the Software Industry. OOSD is a specific variant of Geographically Distributed Software Developmentdistributed software development (GDSD). Compared to the traditional mode of software development (i.e., in-house) GDSD is more edgy and puts at risk the attainment of the expected results. Although the failure of an offshore outsourcing software project may be caused by a variety of factors, one major complication is geographical distance. Consequently we argue that risk avoidance in outshore software development should be undertaken well in advance of the development launch. This could be done by testing the offshore outsourcing relevance of each software project and then the offshore outsourcing company involved. With this in mind we have developed the OUTSHORE Maturity Modeloutshore maturity model - OMM.

Mäkiö, Juho; Betz, Stafanie; Oberweis, Andreas

108

Evaluation of offshore stocking of Lake Trout in Lake Ontario  

USGS Publications Warehouse

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 targets.

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

2011-01-01

109

LWD borehole images/dips aid offshore California evaluation  

SciTech Connect

Quantitative, fullbore, azimuthal resistivity images of the borehole wall, acquired while drilling, can reveal large-scale structural bedding, fractures, faults, unconformities and other useful geologic events. While these images cannot resolve fine structural features or stratigraphic details, they can help identify those intervals requiring higher resolution wireline logging after drilling, and can be used to calculate general structural dips prior to wireline image/dipmeter runs. These images and dips have proven useful for time-critical drilling decisions and for subsequent geological interpretation and formation evaluation. This article presents discussions on: data acquisition at the bit with the Resistivity-at-the-Bit (RAB) tool, including tool functions and depth control, specific benefits derived from while-drilling resistivity images in two offshore California wells, and a favorable RAB outlook including a new RAB method for calculating high angle dips.

Young, R.A. [Schlumberger Wireline and Testing, Montrouge (France); Lovell, J.R.; Rosthal, R.A.; Buffington, L.; Arceneaux, C. Jr.

1996-04-01

110

Petroleum Systems of South Kara Basin: 3D stratigraphic simulation and basin modeling results  

NASA Astrophysics Data System (ADS)

Petroleum systems of South Kara Basin are still poorly studied and hydrocarbon resource estimates vary depending on geological models and understanding of the basin evolution. The main purpose of the regional studies of South Kara Basin was to produce a consistent model, which would be able to explain the existence of the fields discovered in the area as well as to determine the most favorable hydrocarbon accumulation zones in the study area for further exploration. In the study 3D stratigraphic simulation and basin modeling of South Kara Basin was carried out. The stratigraphic simulation results, along with geological, geophysical and geochemical data for the inland areas of Yamal and Gydan peninsulas and South Kara islands enabled to predict the lithological composition and distribution of source rocks, reservoirs and seals in the Kara Sea offshore area. Based on the basin modeling results hydrocarbon accumulations may occur in the reservoir facies of the wide stratigraphic range from Jurrasic to Cretaceous. The main source for the hydrocarbons, accumulated in the South Kara Basin Neocomian and Cenomanian reservoirs are the J3-K1 (the northward extension of Bazhenov Formation and its analogs of West Siberia), as well as J1 and probably J2 shales with predominantly marine type of kerogen (type II). Thermal and burial history restorations show that Lower Cretaceous (Aptian-Albian) sediments enriched with terrigenous organic matter (kerogen of type III) and containing coaly layers could not produce the hydrocarbon volumes to fill the giant Rusanovskoye and Leningradskoye gas-condensate fields as the K1 source rocks are not mature enough. The modeling results, in particular, suggest that the geologic conditions in the South Kara Basin are favorable for further discoveries of giant fields. Although gas accumulations are predominating in the basin, oil-and-gascondensate fields (not a pure oil fields though) with sufficient part of liquid hydrocarbons might be present in particular areas where the source rocks maturation was favorable. Further refining of the model will be possible as soon as new exploration wells will be drilled and new geological, geochemical and seismic data acquired.

Malysheva, S.; Vasilyev, V.; Verzhbitsky, V.; Ananyev, V.; Murzin, R.; Komissarov, D.; Kosenkova, N.; Roslov, Yu.

2012-04-01

111

Bahrain's offshore banking center  

SciTech Connect

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)

Gerakis, A.S.; Roncesvalles, O.

1983-01-01

112

Proceedings of the fifth international offshore mechanics and Arctic engineering (OMAE) symposium. Volume 3  

SciTech Connect

This book presents the paper given at a symposium on offshore platforms. Topics considered at the symposium included tension leg platforms, tether damage, mechanical vibrations, seismic effects, guyed towers, nonlinear characteristics, wave forces, jack-up drilling units, design, impact strength, barges, hoists, remotely-controlled underwater vehicles, buckle initiation in damaged subsea pipelines, flexible marine risers, offshore cables, hydrodynamics, fatigue properties of mooring chains, underwater inspection systems, offshore accidents, quality assurance, safety, deep water gravity platforms, reinforced concrete, foundations, and leak testing.

Chung, J.S.; Yoshida, K.; Sparks, C.P.; Tsahalis, D.T.

1986-01-01

113

The Future of Offshore Wind Energy  

E-print Network

energy prices · Increasing demand for energy and RECs · Aging fleet of coal and nuclear plants not easily-wide economic development: Delaware as offshore staging hub · Stable prices · Clean energy · Meet RPS obligation1 The Future of Offshore Wind Energy #12;2 #12;3 Offshore Wind Works · Offshore wind parks: 28

Firestone, Jeremy

114

Stratigraphic correlation with X-ray powder patterns  

E-print Network

STRATIGRAPHIC CORRELATION MITH X-RAY PONDER PATTERNS John B. Singletary A Thesis Submitted to the Graduate School Agricultural and Mechanical College of Texas in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE MA... JOR SUBJECT: PHYSICS 1951 STRATIGRAPHIC CORRELATION WITH X-RAY POW13ER PATTERHS A Thesis o i O 0 U Z o g I John B ~ Singletary Approved as to Style and Content by ~ y: e~ irman o t tee LIST OF FIGURES 1. Bragg Reflection Condition...

Singletary, John B

2012-06-07

115

Arctic and offshore research: Technology status report  

SciTech Connect

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.

Not Available

1988-01-01

116

Stratigraphic and structural synthesis of the New England Orogen  

Microsoft Academic Search

It is difficult to determine the ages of thick stratigraphic units in different parts of the Tablelands Complex in New England, because of a scarcity of fossils and the effects of superposed deformations. Many problems disappear if it is assumed that the Silverwood Group is in part Lower Permian and that its Ordovician and Devonian fossils are in olistoliths derived

R. J. Korsch; H. J. Harrington

1981-01-01

117

New Approaches to field-based analysis of stratigraphic sections  

NSDL National Science Digital Library

The project involves measurement of stratigraphic sections in the field and completion of a report that summarizes the nature of the section and a variety of interpretations. It includes data collection, separate interpretations of depositional processes and paleoenvironments, use of cut slabs and thin sections, and the use of mock expert "consulting" sessions with groups of students.

Myrow, Paul

118

Paleoclimate controls on stratigraphic repetition of chemical and siliciclastic rocks  

Microsoft Academic Search

Climate is a primary control on sediment flux from continental sources into sedimentary systems. In warm climates, siliciclastic input is greatest under highly seasonal rainfall. Nonseasonal conditions favor formation of end member chemical rocks; perennially wet climates are conductive to coal formation, whereas dry climates produce carbonates and\\/or evaporites. Stratigraphic repetition of siliciclastic and chemical rocks therefore appears to be

C. Blaine Cecil

1990-01-01

119

Harmony field, Clarke County, Mississippi: a true stratigraphic trap  

Microsoft Academic Search

Harmony field in Clarke County, Mississippi, has produced approximately 2 million bbl of oil since its discovery in 1968. Production has been from oolitic grainstones in the upper Jurasic Smackover Formation. The trappng mechanism at Harmony field is a complex stratigraphic trap. Porous oolitic grainstones pinch out updip into tight carbonates and anhydrite. Structure contour maps on top of the

R. B. Lieber; M. C. Carothers

1983-01-01

120

Alabama Ferry field: study of a lower Cretaceous stratigraphic trap  

Microsoft Academic Search

Since discovery in September 1983, nearly 200 wells have extended Alabama Ferry field to a surface area of approximately 70 mi². Located primarily in southeastern Leon County, east Texas, Alabama Ferry is oil productive from stratigraphically trapped carbonate reservoirs in the Lower Cretaceous upper Glen Rose D interval. Deposition within the field was the end result of a very large

1988-01-01

121

Offshore industry executives meet  

SciTech Connect

The future of the Gulf of Mexico is tied to the overall future of oil/gas on the international market as it relates to the US. Conquering this last frontier, possibly only through development of technology, was one of the themes covered in the 21st Annual Meeting of the National Ocean Industries Association held in early April, 1993 in Washington, D.C. Oil is the major source for foreign exchange but there are major uncertainties in predicting the future. The swing (imports vs. exports) is two million barrels per day. The big oil users (heavy industry) have reduced consumption. The last big uncertainty is the environmental policies of the West. Development of resources in the Gulf was the third record year in a row in 1992. The potential for hydrocarbon discoveries is significant, a substantial number of new fields have been made and significant discoveries are likely to continue. More than 100 trillion cubic feet of natural gas lies undiscovered offshore - 35% of undiscovered domestic resources. The oil potential exceeds nine billion barrels, more than any other basin except Alaska.

Burns, R.F.

1993-05-01

122

Structure for offshore exploitation  

SciTech Connect

A structure is disclosed for use in exploiting arctic offshore areas where floating ice masses may be present. The structure is comprised of a floating hull having ice-breaking capabilities which is moored by a plurality of mooring means which extend vertically from a moonpool in the hull to the marine bottom directly under the hull. The mooring means comprises flexible lines, e.g. nylon, steel, or the like or rigid conduits, e.g. drill pipe. Means are provided within the moonpool for tensioning the mooring means to thereby draw the hull downward to a position below its normal buoyant position thereby substantially eliminating vertical heaving of the hull. When an ice mass contacts the hull, tension on the mooring means is relaxed to thereby allow the hull to rock upward against the ice thereby generating the forces necessary for the ice-breaking operation. Due to the present mooring means, the hull moves only a relatively short lateral distance in breaking an approaching ice mass. This is important in floating drilling operations. Further, if repair or replacement of a mooring means is required, this can be accomplished even when ice surrounds the hull since the mooring means are anchored directly below the hull and are easily accessible through the moonpool.

Gerwick, B.C. Jr.; Hatcher, S.J.

1984-02-28

123

Combination offshore drilling rig  

SciTech Connect

An offshore drilling rig is described for use in drilling into a formation below a body of water comprising a barge hull having a drilling slot extending inwardly from the peripheral boundary of the barge hull, means for supporting the barge hull in a position above the water, a cantilever structure mounted on the barge hull and movable horizontally with respect to such barge hull, the cantilever structure being so located relative to the drilling slot as to be movable horizontally into a position in vertical alignment with the drilling slot, a derrick and drilling machinery mounted to the cantilever structure and movable into a position above the drilling slot whereby well drilling operations may be conducted through the drilling slot, the cantilever structure also being movable horizontally to a position which locates the derrick and the drilling machinery outboard of the peripheral boundary of the barge hull, whereby a drilling operations may be conducted outside of the peripheral boundary of the barge hull, means mounted on the barge hull for moving the cantilever structure horizontally to different positions relative to the barge hull.

Lorenz, D.B.; Laid, J.S. II

1986-07-29

124

Reassessment of offshore platforms  

SciTech Connect

Data from Hurricane Andrew demonstrated that the systems and procedures in place for evacuating offshore workers and minimizing oil spills and environmental damage functioned as planned. While the vast majority of the platforms survived the storm with no damage, a few of the older platforms (installed prior to 1972) either collapsed or suffered severe damage. The collapsed platforms were designed with insufficient deck height to clear the storm waves. In recent years, the API RP 2A has introduced guidance for minimum air gap, minimum structures, platform inspection and platform reuse. These provisions, coupled with natural attribution of the older platforms, will significantly improve the performance of platforms in the future. The reliability of NDT techniques to detect major structural defects should be improved through continued research. While flooded member detection is used by several operators as a screening tool to detect major defects underwater, its reliability is not always good and further research is needed in this area. Another area of high priority research is related to the use of Remotely Operated Vehicles (ROV) to perform underwater inspection of structures. 51 refs., 7 figs.

Nair, V.V.D.; Kuhn, J.M. (Mobil Research and Development Corporation, Dallas, TX (United States))

1993-05-01

125

Keeping earnings offshore  

SciTech Connect

Two IRS designations determine the taxation status for non-U.S. projects. For developers, understanding these designations is an important business concern. A PFIC (passive foreign investment company) is something to avoid. A CFC (controlled foreign corporation) may be good or bad, depending on the circumstances. These are lables that the US tax authorities put on certain foreign corporations. Anyone working on projects in other countries should be able to recognize them, not only because they may defeat his objective of keeping money offshore, but also because there are additional consequences from operating through a foreign corporation that the Internal Revenue Service (IRS) has labeled a PFIC or CFC. Return on investment may be lower than expected, and the developer may need to be more careful than otherwise not to pledge the stock of the foreign corporation as security for borrowing by the parent company in the United States or take other actions that might be viewed as putting income or assets of the foreign corporation to use here.

Martin, K.; Malkani, S. (Chadbourne Parke, Washington, DC (United States))

1994-04-01

126

MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND FARM SITES  

E-print Network

MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND.Lange@uni-oldenburg.de (2) Wind Energy Department, Risø National Laboratory, P.O. Box 49, DK-4000 Roskilde, Denmark ABSTRACT for conditions important for offshore wind energy utilisation are compared and tested: Four models

Heinemann, Detlev

127

SUBSPACE-BASED DETECTION OF FATIGUE DAMAGE ON JACKET SUPPORT STRUCTURES OF OFFSHORE WIND TURBINES  

E-print Network

SUBSPACE-BASED DETECTION OF FATIGUE DAMAGE ON JACKET SUPPORT STRUCTURES OF OFFSHORE WIND TURBINES structures of wind energy turbines. Based on results of an experimental fatigue test on a steel frame damage in real size structural components of offshore wind turbines. KEYWORDS : Damage detection

Paris-Sud XI, Université de

128

Stratigraphic Identification and Correlation of Basalt Aquifers Using Geophysical and Chemical Techniques.  

National Technical Information Service (NTIS)

Using geophysical data, Crosby and Anderson (1971) made stratigraphic correlations and identified the major aquifers in wells in the vicinity of Pullman, Washington. The current report describes the results of the most recent efforts to relate stratigraph...

B. A. Siems

1974-01-01

129

Late quarternary glacioeustatic sea-level fluctuations: What are the sedimentologic processes and stratigraphic responses on continental margins  

SciTech Connect

Published stable isotope data from deep-sea sediments clearly show that the earth's climatic cycles have oscillated through at least 10 major glacial and interglacial episodes during the last million years. These high-frequency, orbitally-forced events should have resulted in major glacioeustatic sea-level fluctuations on the continental margins with dramatic sedimentologic effects and stratigraphic responses. However, such high-frequency events have proven difficult to resolve. Are they too short-lived to be recorded, to complex to decipher, or have traditional stratigraphic tools not been adequate to recognize them in continental margin sequences A detailed, multidisciplinary study of various continental margins is necessary to test the sensitivity of sedimentologic systems and response in stratigraphic records. This study must utilize (1) high-resolution event stratigraphy to define the depositional and erosional sediment sequences; (2) sediment analyses to delineate depositional environments and characterize lithofacies of specific system tracts; and (3) biostratigraphic and geochronologic analyses to place the depositional sequences in time. Integration of these data sets will (4) determine the resolving power of sequence stratigraphy; (5) develop working stratal models for recognizing short-pulsed, glacioeustatic sea-level events within the stratigraphic record; and (6) define a chronostratigraphy of changing paleoclimatic and paleoceanographic events operating on continental margin systems during the late Quaternary.

Riggs, S.R. (East Carolina Univ., Greenville, NC (United States)); Snyder, S.W. (North Carolina Univ., Raleigh (United States)); Hine, A.C. (Univ. of South Florida, St. Petersburg (United States))

1990-01-09

130

Aluminium alloys for offshore drilling systems  

SciTech Connect

This paper presents the experience gained in the USSR (now CIS) over many years in the use of Aluminum Drill Pipe (ADP). The main advantages of aluminum over steel for drill pipe applications are discussed. Methods of fabricating aluminum pipes with steel tool joints are explained. The problems of abrasion and corrosion resistance are presented. Recent experience testing ADP after exposure to the offshore environment have shown negligible reduction in fatigue life. It is now considered possible to design a slimline riser in aluminum for water depths of 3--4 kilometers.

Fine, G.M.; Basovich, V.S.; Pisarnitsky, A.D. [Superdeep Co. Zapolyarny, Murmansk (Russian Federation); Jemetz, B.V.; Mazurova, L.D. [VNIITNEFT, Samara (Russian Federation); Gelfgat, M.Ya. [Aquatic Co., Moscow (Russian Federation)

1995-12-31

131

High-alloy materials for offshore applications  

SciTech Connect

High-alloy materials possessing good corrosion resistance in hot, sour brines are being seriously considered for offshore applications. These alloys are available in a wide range of strength levels which can be attained by the methods of cold working or precipitation hardening. Results of testing INCONEL alloys 625 and 718 and INCOLOY alloys 825 and 925 for resistance to general corrosion, hydrogen embrittlement, and stress-corrosion cracking (SCC) are presented. This paper also contrasts the range of mechanical properties available in precipitation-hardened materials with properties of cold-worked alloys.

Lemke, T.F.; Harris, J.A.

1983-05-01

132

Stratigraphic architectures spotted in southern Melas Chasma, Valles Marineris, Mars  

NASA Astrophysics Data System (ADS)

The distribution in space and time of liquid water on Mars is relevant to astrobiology and astroclimatology. To date, most orbital observations that attest to past fluvial and lacustrine activity on Mars have been dedicated to surficial landforms (i.e., drainage networks and depositional fans). Here we report an unprecedented identification of typical stratigraphic architectures made in Mars Global Surveyor Mars Orbiter Camera images of layered material in southern Melas Chasma. A particular set of strata is arranged in three depositional sequences bounded by stratigraphic unconformities. The sequences show spectacular steeply inclined clinoforms, and a broad channel-like depression. There are the same complex stratal patterns in Valles Marineris on Mars as there are in terrestrial deposits. Insights into these three-dimensional deposit geometries are used to tentatively isolate specific depositional processes and point to ancient subaqueous settings. Findings in southern Melas indicate a very attractive spot to which the search for ancient habitable environments on Mars could be directed.

Dromart, Gilles; Quantin, Cathy; Broucke, Olivier

2007-04-01

133

Stratigraphic studies: Part A: basalt stratigraphy of southern Mare Serenitatis  

USGS Publications Warehouse

Mare Serenitatis has long been noted for its conspicuous dark border (fig. 29-1). The Apollo 17 metric photographs traverse this border in southern Mare Serenitatis and show clearly superposition relationships among the mare and mare-related stratigraphic units. These photographs, together with full-Moon photographs, albedo measurements, and color information (table 29-I), provide the basis for a revised stratigraphic framework for these presumedly basaltic rocks (figs. 29-2 and 29-3). In contrast to most previous studies, we conclude that the darker units are older than lighter ones. Similar conclusions have been reached by Bryan and Adams (part C of sec. 30) and Boyce and Dial (part C of this section). The relatively light-colored central part of Mare Serenitatis is thought to represent the youngest basalt in the region; a very dark unit that includes the Apollo 17 landing site is one of the oldest.

Howard, K.A.; Carr, M.H.; Muehlberger, W.R.

1973-01-01

134

Stratigraphic record of Holocene coseismic subsidence, Padang, West Sumatra  

NASA Astrophysics Data System (ADS)

Stratigraphic evidence is found for two coseismic subsidence events that underlie a floodplain 20 km south of Padang, West Sumatra along the Mentawai segment (0.5°S-0.3°S) of the Sunda subduction zone. Each earthquake is marked by a sharp soil-mud contact that represents a sudden change from mangrove to tidal flat. The earthquakes occurred about 4000 and 3000 cal years B.P. based on radiocarbon ages of detrital plant fragments and seeds. The absence of younger paleoseismic evidence suggests that late Holocene relative sea level fall left the floodplain too high for an earthquake to lower it into the intertidal zone. Our results point to a brief, few thousand year window of preservation of subsidence events in tidal-wetland stratigraphic sequences, a result that is generally applicable to other emergent coastlines of West Sumatra.

Dura, Tina; Rubin, Charles M.; Kelsey, Harvey M.; Horton, Benjamin P.; Hawkes, Andrea; Vane, Christopher H.; Daryono, Mudrik; Pre, Candace Grand; Ladinsky, Tyler; Bradley, Sarah

2011-11-01

135

Biozones, stratigraphic log correlation, and corresponding interpretation of paleoenvironments.  

NSDL National Science Digital Library

The 50-minute group-based activity for hundreds of students starts by constructing bio-zones for a given set of fossil ranges. Results are reviewed using a sequence of clicker questions to discuss the optimal biostratigraphic decisions, the necessary types of thinking, and how to articulate a concise yet complete textual description of corresponding biozones. A set of stratigraphic logs is then used to interpret changes in depositional environment across space and time. Students also decide (and justify decisions) on the optimal choice of fossils for use when interpreting variations in depositional environment. The final result is an interpreted geologic section based on stratigraphic and biostratigraphic data. This interpretive exercise is only three weeks into a first course on Earth and life through time, so guidance is provided using carefully designed question sequences posed using "clicker" (personal response system) and/or for individual or whole class discussion.

Jones, Francis

136

Paleoclimate controls on stratigraphic repetition of chemical and siliciclastic rocks  

SciTech Connect

Climate is a primary control on sediment flux from continental sources into sedimentary systems. In warm climates, siliciclastic input is greatest under highly seasonal rainfall. Nonseasonal conditions favor formation of end member chemical rocks; perennially wet climates are conductive to coal formation, whereas dry climates produce carbonates and/or evaporites. Stratigraphic repetition of siliciclastic and chemical rocks therefore appears to be related to paleoclimate cycles as well as to transgressive-regressive events and tectonics.

Cecil, C.B. (Geological Survey, Reston, VA (USA))

1990-06-01

137

Algal stromatolites: use in stratigraphic correlation and paleocurrent determination.  

PubMed

Algal stromatolites are used for detailed rock-stratigraphic correlation for a distance of 160 kilometers in the Pethei Formation, of Aphebian (Precambrian) age, in the Northwest Territories, Canada. Laterally linked stromatolites are initiated by the draping of successive laminations over intraclasts or other irregularities in the bedding surface. Stromatolite shapes and orientations are related to paleocurrent direction determined from associated sedimentary structures. Thus stromatolite geometry is at least in part environmentally controlled. PMID:17770426

Hoffman, P

1967-09-01

138

Offshore wind farm layout optimization  

NASA Astrophysics Data System (ADS)

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 the farm. A more thorough optimization highlighted the features of the area that would result in a minimized COE. The results showed reasonable layout designs and COE estimates that are consistent with existing offshore wind farms.

Elkinton, Christopher Neil

139

High-resolution records of location and stratigraphic provenance from the rare earth element composition of fossil bones  

NASA Astrophysics Data System (ADS)

Bone apatite acts as a natural, timed sampling device, scavenging trace elements from local pore waters over timescales of ca. 1-50 ka. The rare earth element (REE) and U/Th composition of fossil bones reflects associated pore water compositions during the period of recrystallisation. The REE composition of fossil bones is controlled by partitioning of REE between pore waters and particle surfaces, and the REE composition of fossil bones reflects the REE composition of pore waters which vary spatially and temporally. Light REE are preferentially sorped onto particle surfaces, thus the high La/Yb values seen in many bones from coastal marine and aeolian environments are best explained by release of REE from light REE-enriched particles to local pore waters and subsequent immobilisation in recrystallising bones. The REE compositions of bones recovered from pedogenically altered diatomite sediments of the Olorgesailie Formation of southern Kenya vary over spatial scales of less than 10 m. Location accounts for 48% of the observed variation in bone chemistry and bones recovered from eight discrete excavations within the same time-equivalent stratigraphic layer can be assigned to their excavation location with >70% accuracy based on a discriminant analysis of REE, U, and Th composition. Despite this within-layer variation, bones recovered from different stratigraphic horizons within the Olorgesailie Formation can also be distinguished on the basis of their trace element composition. Bones recovered from four stratigraphic horizons spanning ca. 0.5 million years were assigned to their correct stratigraphic layer with >90% accuracy. Where sedimentological conditions are favourable, the trace element composition of fossil bone may be used to test stratigraphic provenance and burial location in excavated bone with a temporal resolution of <10 ka and a spatial resolution of <10 m. The trace element composition of fossil bone may also be used to investigate the accumulation history of vertebrate assemblages and to reconstruct pore water variability across land surfaces.

Trueman, C. N.; Behrensmeyer, A. K.; Potts, R.; Tuross, N.

2006-09-01

140

CHRONOS's Paleontological-Stratigraphic Interval Construction and Analysis Tool (PSICAT)  

NASA Astrophysics Data System (ADS)

The Paleontological-Stratigraphic Interval Construction and Analysis Tool (PSICAT) is a Java-based graphical editing tool for creating and viewing stratigraphic column diagrams from drill cores and outcrops. It is customized to the task of working with stratigraphic columns and captures data digitally as you draw and edit the diagram. The data and diagrams are captured in open formats, and integration with the CHRONOS system (www.chronos.org) will allow the user to easily upload their data and diagrams into CHRONOS. Because the data and diagrams are stored in CHRONOS, they will be accessible to anyone, anywhere, at any time. PSICAT is designed with a modular, plug-in-based architecture that will allow it to support a wide variety of functionality, tasks, and geoscientific communities. PSICAT is currently being developed for use by the ANDRILL project (http://www.andrill.org) on their upcoming drilling expeditions in Antarctica, but a general community version will be also available. PSICAT will allow unprecedented communication between Antarctica-based scientists and shore-based scientists, potentially allowing shore-based scientists to interact in almost real time with on-ice operations and data collection.

Reed, J. A.; Cervato, C.; Fielding, C. R.; Fils, D.

2005-12-01

141

Paleomagnetic constrains in the reconstruction of the recent stratigraphic evolution of the Po delta  

NASA Astrophysics Data System (ADS)

The delta and prodelta deposits are characterized by a complex stratigraphic architecture that can be approached with several multidisciplinary tools. We present an example from the Po delta system characterized by alternating phases of rapid advance and abandonment of its multiple deltaic lobes that has been investigated through: (1) a review of historical cartography extending back several centuries; (2) integrated surveys of VHR seismic profiles recorded offshore of the modern delta from water depths as shallow as 5 m to the toe of the prodelta in about 30 m; and (3) sedimentological and geochronological data from precisely positioned sediment cores. Within this well known stratigraphic framework we have acquired seismic data and sediment cores in the area of the post roman Po delta system. However a precise dating of the recent evolution of depositional delta lobes is difficult because of the lack of suitable dating methods. To constrain the emplacement timing of the Renaissance lobes a paleomagnetic studies was carried out on a sedimentary sequence representing a seismic facies well correlated in the cores by whole core magnetic susceptibility profile. Forty eight samples were collected from a core section (RER96-1) characterized by a fine grained lithology suitable for paleomagnetic investigations. The characteristic remanent magnetization (ChRM) of the sediments has been obtained by applying an AF cleaning between 10 and 30 millitesla. The results have been compared with the directions recorded by the historical lavas of the Etna and Vesuvius. The combination of the trends observed in the declination and inclination suggests that the results can be compatible with the directions of the secular variation of the earth magnetic field occurring during the XVII century. This allow to date the sismic unit as representative of the beginning of the new delta following the Porto Viro avulsion made by the Venice Republic in 1604 AD. This delta history reflects the forcing of high-frequency climate change, autocyclic avulsions, and anthropogenic factors, acting on variable, but typically short, time scales. By using multidisciplinary methods of investigation is possible to detect the sedimentary response forced by anthropic impact at centennial/decadal time scale.

Correggiari, Annamaria; Vigliotti, Luigi; Remia, Alessandro; Perini, Luisa; Calabrese, Lorenzo; Luciani, Paolo

2014-05-01

142

Current facts about offshore wind farms  

Microsoft Academic Search

This paper reviews offshore wind projects with a wide perspective. The current situation of the offshore wind market is presented, pointing out the countries leading the process in terms of installed capacity and in terms of technological leadership. Feasibility studies of alternative offshore wind farms (OWFs) are interesting not only in relation to the business but in relation to the

A. Madariaga; S. Ceballos

2012-01-01

143

The politics and economics of offshore outsourcing  

Microsoft Academic Search

This paper reviews the political uproar over offshore outsourcing connected with the release of the Economic Report of the President (ERP) in February 2004, examines the differing ways in which economists and non-economists talk about offshore outsourcing, and assesses the empirical evidence on the importance of offshore outsourcing in accounting for the weak labor market from 2001 to 2004. Even

N. Gregory Mankiw; Phillip Swagel

2006-01-01

144

Offshoring in the New Global Political Economy  

Microsoft Academic Search

abstract? This essay challenges claims by economists and management scholars that ‘offshoring’ is simply another form of trade with mutual benefits. I argue that reducing wages through offshoring leads to wealth creation for shareholders but not necessarily for countries and employees, and that many displaced workers have difficulty ‘trading up’ to higher skilled jobs. Offshoring is a new phenomenon that

David L. Levy

2005-01-01

145

Offshore Scientific and Technical Publications: 1985 Annual  

Microsoft Academic Search

The Minerals Management Service (MMS) established a scientific and technical publications program for Offshore Minerals Management in 1984. The objective of the program is to make the investigative findings of the Offshore Program available to the public. The Technical Publications Unit (TIP) within the Office of Offshore Information and Publications operates this program. The TPU has assigned series designations and

Bajusz

1988-01-01

146

Offshore QRA and the ALARP principle  

Microsoft Academic Search

A discussion is presented of the use of QRA within a requirement, of the UK offshore safety case regime, to demonstrate that risks from offshore major accidents are ALARP. General considerations are given to uncertainties in failure and incident data, assumptions and consequence methodologies within the analysis element of offshore QRA. The validity of risk results arising from the analysis

Stan Schofield

1998-01-01

147

European offshore oil and gas, 1985  

SciTech Connect

This book discusses the offshore industry, and provides information on every aspect of European offshore activity from basic geological facts to today's licensing and taxation regimes to field by field analysis of exploration and developments. It also contains a directory of European companies supplying services and equipment to offshore industry.

Not Available

1985-01-01

148

17 CFR 230.904 - Offshore resales.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Offshore resales. 230.904 Section...Act of 1933 § 230.904 Offshore resales. (a) An...offer or sale are made in an offshore transaction; (2) No...prior to the expiration of the distribution compliance period...

2013-04-01

149

17 CFR 230.904 - Offshore resales.  

Code of Federal Regulations, 2012 CFR

... 2012-04-01 false Offshore resales. 230.904 Section...Act of 1933 § 230.904 Offshore resales. (a) An...offer or sale are made in an offshore transaction; (2) No...prior to the expiration of the distribution compliance period...

2012-04-01

150

17 CFR 230.904 - Offshore resales.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Offshore resales. 230.904 Section...Act of 1933 § 230.904 Offshore resales. (a) An...offer or sale are made in an offshore transaction; (2) No...prior to the expiration of the distribution compliance period...

2010-04-01

151

17 CFR 230.904 - Offshore resales.  

... 2014-04-01 false Offshore resales. 230.904 Section...Act of 1933 § 230.904 Offshore resales. (a) An...offer or sale are made in an offshore transaction; (2) No...prior to the expiration of the distribution compliance period...

2014-04-01

152

17 CFR 230.904 - Offshore resales.  

Code of Federal Regulations, 2011 CFR

... 2011-04-01 false Offshore resales. 230.904 Section...Act of 1933 § 230.904 Offshore resales. (a) An...offer or sale are made in an offshore transaction; (2) No...prior to the expiration of the distribution compliance period...

2011-04-01

153

Linearized Dynamic Stability of Barges for Transportation of Offshore Structure  

Microsoft Academic Search

A method to evaluate dynamic stability of towed barges for transportation of offshore structure has been described. The general condition occurs when the barge is being towed in a restricted (narrow) and shallow canal. A state-of-the-art approach of the linearized formulation of this physical problem is adopted. The solution to the problem and a scheme to test dynamic stability are

P. Mukhopadhyay

1984-01-01

154

Neogene stratigraphic relationships within the Nam Con Son Basin, offshore Vietnam resulting from tectonics, eustasy, and sediment flux  

E-print Network

The South China Sea is a region of significant importance in terms of the records of SE Asian tectonics, including Tibetan Plateau uplift, and the onset and evolution of the East Asian monsoon. The Mekong River has been a dominant sediment source...

Wright, Christine M.

2009-05-15

155

Transfer terminal for offshore production  

SciTech Connect

A mooring station and transfer terminal for offshore hydrocarbon production is provided, comprising a coaxial riser linking underwater production and safety manifolds to surface lines. An underwater connector and quick release means are provided to facilitate rapid connection and disconnection of the riser pipes.

Arnaudeau, M.

1983-02-01

156

Deep water offshore jacket removal  

SciTech Connect

After an oil or gas field is no longer economically exploitable, the offshore structure is no longer of any use. This means that a solution must be found for the platform abandonment. There are two options to choose from: leave the platform in place or remove the platform. In this paper the second option is further investigated.

Herel, E.C.P. van; Wijninckx, A. [HeereMac VOF, Leiden (Netherlands); Wardenier, J. [Delft Univ. of Technology (Netherlands)

1995-12-31

157

Re-Regulating Offshore Finance?  

Microsoft Academic Search

This article explores global efforts to regulate offshore finance in the wake of international concern about the effects of so-called harmful tax competition, as well as money laundering and terrorist financing (the latter a relatively new category since September 11, 2001). In the mid-1990s, a number of multilateral organizations, from the Organization for Economic Cooperation and Development (OECD) to the

B. Maurer

2008-01-01

158

Offshore oil: Correctness of perspective  

Microsoft Academic Search

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

1993-01-01

159

Towers for Offshore Wind Turbines  

Microsoft Academic Search

Increasing energy demand coupled with pollution free production of energy has found a viable solution in wind energy. Land based windmills have been utilized for power generation for more than two thousand years. In modern times wind generated power has become popular in many countries. Offshore wind turbines are being used in a number of countries to tap the energy

V. J. Kurian; S. P. Narayanan; C. Ganapathy

2010-01-01

160

Stratigraphic Controls on Seawater Intrusion, and Implications for Ground-Water Management, Dominguez Gap Area of Los Angeles, California  

Microsoft Academic Search

Development of ground water in coastal Los Angeles in the 20th century led to extensive water-level declines and associated seawater intrusion. The U.S. Geological Survey (USGS) has developed a solute-transport model to quantitatively test the hydraulic implications of a sequence-stratigraphic model and to assess the possible effects of alternative management strategies. The transport modeling was conducted using SUTRA, a finite-element,

A. J. Siade; T. Nishikawa; E. G. Reichard

2007-01-01

161

P-wave velocity features of methane hydrate-bearing turbidity sediments sampled by a pressure core tool, from the first offshore production test site in the eastern Nankai Trough, Japan  

NASA Astrophysics Data System (ADS)

Turbidite sediments around the production test site at Daini-Atsumi knoll were deposited under channel and lobe environments of a submarine fan. Changes in physical properties of the sediments are likely caused by differences in the depositional environments. In addition, methane hydrate (MH) crystals growing among sediment grains alter the sediment's original physical properties. Thus, distinguishing between hydrate-bearing sediment and hydrate-free sediment based only on physical property changes measured during downhole logging can be difficult. To more precisely analyze sediment properties, core samples of MH-bearing sediments were taken at the first offshore MH production test site. Samples were collected using a wireline hybrid pressure coring system (Hybrid PCS), which retains downhole pressure, thereby preventing dissociation of MH in the sampled cores. Nondestructive, high-pressure analyses were conducted in both the 2012 summer drilling campaign and a 2013 winter laboratory study in Sapporo. To handle Hybrid PCS cores during the pressure coring campaign in the summer of 2012, a pressure core analysis and transfer system (PCATS) was installed on the research vessel Chikyu (Yamamoto et al., 2012). PCATS P-wave velocity measurements were made at in situ water pressure without causing any core destruction or MH dissociation. In January 2013, Georgia Tech (GT), USGS, AIST, and JOGMEC researchers used pressure core characterization tools (PCCTs) developed by GT to re-measure the P-wave velocity of the MH-bearing sediments at high pressure and low, non-freezing temperature. In the PCATS analysis, results showed a difference of more than 1,200 m/s in P-wave velocities between the MH-bearing sandy and muddy layers. This difference in P-wave velocities was confirmed by PCCTs measurements. P-wave velocities within the turbidite interval tend to decrease upward with the textural grading of the turbidite. Our result implies that MH concentration, which is related to the pore size of sediments, tends to be highest in coarser layers, enhancing the P-wave velocity change through the turbidite. Acknowledgement Authors would like to express thanks to Geotek for their assistance during the 2012 pressure core operation/analysis. This research is conducted as a part of MH21 research and the authors would like to express their sincere appreciation to MH21 and the Ministry of Economy, Trade and Industry for disclosure permission for this research.

Suzuki, K.; Santamarina, C. J.; Waite, W. F.; Winters, W. J.; Ito, T.; Nakatsuka, Y.; Konno, Y.; Yoneda, J.; Kida, M.; Jin, Y.; Egawa, K.; Fujii, T.; Nagao, J.

2013-12-01

162

Automatic fine-tuning and wind simulation at the Offshore Technology Research Center (OTRC)  

E-print Network

A method for developing an automatic fine-tuning controller for matching a specification in the frequency domain is developed for the wind simulation equipment at the Offshore Technology Research Center (OTRC). A test signal synthesis method...

Miller, Mark Alan

2012-06-07

163

Fossil preservation and the stratigraphic ranges of taxa.  

PubMed

The incompleteness of the fossil record hinders the inference of evolutionary rates and patterns. Here, we derive relationships among true taxonomic durations, preservation probability, and observed taxonomic ranges. We use these relationships to estimate original distributions of taxonomic durations, preservation probability, and completeness (proportion of taxa preserved), given only the observed ranges. No data on occurrences within the ranges of taxa are required. When preservation is random and the original distribution of durations is exponential, the inference of durations, preservability, and completeness is exact. However, reasonable approximations are possible given non-exponential duration distributions and temporal and taxonomic variation in preservability. Thus, the approaches we describe have great potential in studies of taphonomy, evolutionary rates and patterns, and genealogy. Analyses of Upper Cambrian-Lower Ordovician trilobite species, Paleozoic crinoid genera, Jurassic bivalve species, and Cenozoic mammal species yield the following results: (1) The preservation probability inferred from stratigraphic ranges alone agrees with that inferred from the analysis of stratigraphic gaps when data on the latter are available. (2) Whereas median durations based on simple tabulations of observed ranges are biased by stratigraphic resolution, our estimates of median duration, extinction rate, and completeness are not biased.(3) The shorter geologic ranges of mammalian species relative to those of bivalves cannot be attributed to a difference in preservation potential. However, we cannot rule out the contribution of taxonomic practice to this difference. (4) In the groups studied, completeness (proportion of species [trilobites, bivalves, mammals] or genera [crinoids] preserved) ranges from 60% to 90%. The higher estimates of completeness at smaller geographic scales support previous suggestions that the incompleteness of the fossil record reflects loss of fossiliferous rock more than failure of species to enter the fossil record in the first place. PMID:11539203

Foote, M; Raup, D M

1996-01-01

164

Fossil preservation and the stratigraphic ranges of taxa  

NASA Technical Reports Server (NTRS)

The incompleteness of the fossil record hinders the inference of evolutionary rates and patterns. Here, we derive relationships among true taxonomic durations, preservation probability, and observed taxonomic ranges. We use these relationships to estimate original distributions of taxonomic durations, preservation probability, and completeness (proportion of taxa preserved), given only the observed ranges. No data on occurrences within the ranges of taxa are required. When preservation is random and the original distribution of durations is exponential, the inference of durations, preservability, and completeness is exact. However, reasonable approximations are possible given non-exponential duration distributions and temporal and taxonomic variation in preservability. Thus, the approaches we describe have great potential in studies of taphonomy, evolutionary rates and patterns, and genealogy. Analyses of Upper Cambrian-Lower Ordovician trilobite species, Paleozoic crinoid genera, Jurassic bivalve species, and Cenozoic mammal species yield the following results: (1) The preservation probability inferred from stratigraphic ranges alone agrees with that inferred from the analysis of stratigraphic gaps when data on the latter are available. (2) Whereas median durations based on simple tabulations of observed ranges are biased by stratigraphic resolution, our estimates of median duration, extinction rate, and completeness are not biased.(3) The shorter geologic ranges of mammalian species relative to those of bivalves cannot be attributed to a difference in preservation potential. However, we cannot rule out the contribution of taxonomic practice to this difference. (4) In the groups studied, completeness (proportion of species [trilobites, bivalves, mammals] or genera [crinoids] preserved) ranges from 60% to 90%. The higher estimates of completeness at smaller geographic scales support previous suggestions that the incompleteness of the fossil record reflects loss of fossiliferous rock more than failure of species to enter the fossil record in the first place.

Foote, M.; Raup, D. M.

1996-01-01

165

Offshore Renewable Energy R&D (Fact Sheet)  

SciTech Connect

This fact sheet describes the offshore renewable energy R&D efforts at NREL's NWTC. As the United States increases its efforts to tap the domestic energy sources needed to diversify its energy portfolio and secure its energy supply, more attention is being focused on the rich renewable resources located offshore. Offshore renewable energy sources include offshore wind, waves, tidal currents, ocean and river currents, and ocean thermal gradients. According to a report published by the National Renewable Energy Laboratory (NREL) in 2010,1 U.S. offshore wind resources have a gross potential generating capacity four times greater than the nation's present electric capacity, and the Electric Power Research Institute estimates that the nation's ocean energy resources could ultimately supply at least 10% of its electric supply. For more than 30 years, NREL has advanced the science of renewable energy while building the capabilities to guide rapid deployment of commercial applications. Since 1993, NREL's National Wind Technology Center (NWTC) has been the nation's premier wind energy research facility, specializing in the advancement of wind technologies that range in size from a kilowatt to several megawatts. For more than 8 years, the NWTC has been an international leader in the field of offshore floating wind system analysis. Today, researchers at the NWTC are taking their decades of experience and extensive capabilities and applying them to help industry develop cost-effective hydrokinetic systems that convert the kinetic energy in water to provide power for our nation's heavily populated coastal regions. The center's capabilities and experience cover a wide spectrum of wind and water energy engineering disciplines, including atmospheric and ocean fluid mechanics, aerodynamics; aeroacoustics, hydrodynamics, structural dynamics, control systems, electrical systems, and testing.

Not Available

2011-10-01

166

Classification of offshore mass movements  

SciTech Connect

More than 100 offshore mass-movement deposits have been studied in Holocene and Pleistocene sediments. The processes can be divided into three main types: slides/slumps, plastic flows, and turbidity currents, of which 13 main varieties have been recognized. The three types are differentiated mainly by motion, architecture, and shape of failure surface. For slides, the morphology of deposits can usually be linked to a process, but for plastic flows and turbidity currents, information about the motion is mainly provided by the sedimentary record. A static classification based on these features is given, and is related to a dynamic classification system to try to underline the morphological transformation of an offshore event from initiation to deposition.

Mulder, T. [Inst. Francais de Recherches pour l`Exploitation de la Mer, Plouzane (France). Dept. de Geosciences Marines]|[Ecole Nationale Superieure de Geologie, Vandeuvre-les-Nancy (France). Lab. de Geomecanique; Cochonat, P. [Inst. Francais de Recherches pour l`Exploitation de la Mer, Plouzane (France). Dept. de Geosciences Marines

1996-01-01

167

Huntington Beach offshore Parcel 14  

Microsoft Academic Search

Parcel 14 of the Huntington Beach Oil Field (California) is located down the west plunge of a large east-west-trending asymmetrical anticlinal structure. This offshore structure extends from the shore westward approximately 3 miles. The south flank of the anticline is steep-dipping with known dips up to 65°. The north flank has an average dip of 10$. Faulting is minor on

1966-01-01

168

Testable Requirements for Offshore Outsourcing  

Microsoft Academic Search

Given that software offshore outsourcing is a business relationship, we assume that a contract is required in order to define\\u000a what services are requested from a contracted entity and how these services are to be delivered to the satisfaction of the\\u000a contractor. We first argue that, at the heart of the quality assurance facets of such a contract, we must

Jean-pierre Corriveau

2007-01-01

169

OFFSHORE DISTRIBUTION OF HYDRACTINIA ECHINATA  

Microsoft Academic Search

ABSTRAcr New distributional records for this hydroid are listed from 81 offshore locations along the Middle Atlantic region and from Georges Bank, off MassachusettS. The species was commonly found living on the shells of ani· mals having some degree of mobility-sea scallops (Pltlco­ pecten magelllln;cus), and gastropod shells inhabited by pagurid crabs. The bottom substrate for these animals is

ARTHUR S. MERRILL

170

The 1911 Quadrant offshore Namibia; Exploration in a virgin basin  

SciTech Connect

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.

Holtar, E.; Forsberg, A.

1995-08-01

171

Offshore oil: Correctness of perspective  

SciTech Connect

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.

Burns, R.F.

1993-05-01

172

High resolution sequence stratigraphic concepts applied to geostatistical modeling  

SciTech Connect

Lithofacies simulations using a high resolution 3D grid allow to enhance the geometries of internal heterogeneities of reservoirs. In this study the series simulated were the Ness formation, part of the Brent reservoir in the Dunbar field located in the Viking graben of the North Sea. Simulations results have been used to build the reservoir layering supporting the 3D grid used for reservoir engineering, and also used as a frame to study the effects of secondary diagenetic processes on petrophysical properties. The method used is based on a geostatistical study and integrates the following data: a geological model using sequence stratigraphic concepts to define lithofacies sequences and associated bounding surfaces, well data (cores and logs) used as database for geostatistical analysis and simulations, seismic data: a 3D seismic survey has been used to define the internal surfaces bounding the units, outcrop data: The Mesa Verde formation (Colorado, USA) has been used as an outcrop analog to calibrate geostatistical parameters for the simulations (horizontal range of the variograms). This study illustrates the capacity to use high resolution sequence stratigraphic concepts to improve the simulations of reservoirs when the lack of subsurface information reduce the accuracy of geostatistical analysis.

Desaubliaux, G. [Institut Francais du Petrole, Rueil Malmaison (France); De Lestang, A.P. [Beicip-Franlab, Rueil Malmaison (France); Eschard, R. [Institut Francais du Petrole, Rueil Malmaison (France)] [and others

1995-08-01

173

Harmony field, Clarke County, Mississippi: a true stratigraphic trap  

SciTech Connect

Harmony field in Clarke County, Mississippi, has produced approximately 2 million bbl of oil since its discovery in 1968. Production has been from oolitic grainstones in the upper Jurasic Smackover Formation. The trappng mechanism at Harmony field is a complex stratigraphic trap. Porous oolitic grainstones pinch out updip into tight carbonates and anhydrite. Structure contour maps on top of the Smackover Formation indicate a low relief structural nose associated with the field. Additional structure maps contoured at the top of the Haynesville anhydrite, approximately 500 ft (150 m) above the top of the Smackover, reveal only regional southwesterly dip. An isopach map of the interval between the two structural markers shows a thinning of Haynesville section coincident with the field area. Evidence suggests, therefore, that the porous Smackover in Harmony field was deposited with depositional relief above the surrounding sediments. This relief had been completely masked by the time the Haynesville anhydrite was deposited. Stratigraphic and structural cross sections using the Haynesville anhydrite as datum indicate the Smackover in Harmony field consists of not one, but multiple, thin olitic zones which are productive in various portions of the field. These zones grade laterally as well as updip into nonporous anhydritic carbonates. The Smackover Formation is often considered to be a chronolithologic unit. In the Harmony field area it is a lithostratigraphic unit, i.e. a unit defined not by time but by a particular rock type, in this case a porous limestone.

Lieber, R.B.; Carothers, M.C.

1983-09-01

174

On balanced and unbalanced accommodation\\/peat accumulation ratios in the Cretaceous coals from Gates Formation, Western Canada, and their sequence-stratigraphic significance  

Microsoft Academic Search

Coal composition was investigated by means of photometric and maceral analyses on closely spaced lithotype-based strip samples over the full thickness of several paralic coal seams from the Cretaceous Gates Formation of the Western Canadian Sedimentary Basin. The aim of this investigation was to test various methods of identifying accommodation trends in coal and use them to refine sequence-stratigraphic interpretation

C Diessel; R Boyd; J Wadsworth; D Leckie; G Chalmers

2000-01-01

175

Offshore petroleum security: Analysis of offshore security threats, target attractiveness, and the international legal framework for the protection and security of offshore petroleum installations.  

E-print Network

??The offshore petroleum industry is of critical importance to the global economy. Offshore petroleum installations are considered elements of critical national infrastructure in many nation-States… (more)

Kashubsky, Mikhail

2011-01-01

176

Integrated onshore-offshore investigation of a Mediterranean layered coastal aquifer.  

PubMed

Most of the Mediterranean coastal porous aquifers are intensively exploited. Because of climatic and anthropogenic effects, understanding the physical and geological controls on groundwater distribution and flow dynamics in such aquifers is crucial. This study presents the results of a structural investigation of a system located along the coastline of the Gulf of Lions (NW Mediterranean). A key aspect of this study relies on an onshore-offshore integrated approach combining outcrops, seismic profiles, and borehole data analysis. This multidisciplinary approach provides constraints on pore-fluid salinity distribution and stratigraphic organization, which are crucial in assessing the modes of groundwater/seawater exchanges. Onshore, Lower Pliocene deposits dip gently seaward. They are unconformably overlain by Holocene clays in the lagoons. Offshore the Pliocene deposits either outcrop at the seabed or are buried below nonconsolidated sands infilling paleo-valleys. Beneath the lido, the groundwater salinity distribution consists of salty pore water, overlying fresher pore water. Active circulation of groundwater masses is inferred from the geophysical results. In particular, offshore outcrops and paleo-valleys may play an important role in salt water intrusion. PMID:23163402

Lofi, Johanna; Pezard, Philippe; Bouchette, Frédéric; Raynal, Olivier; Sabatier, Pierre; Denchik, Nataliya; Levannier, Arnaud; Dezileau, Laurent; Certain, Raphaël

2013-01-01

177

Venusian extended ejecta deposits as time-stratigraphic markers  

NASA Technical Reports Server (NTRS)

Use of impact crater ejects at time-stratigraphic markers was established during lunar geologic mapping efforts. The basic premise is that the deposition of impact ejecta, either by itself or mixed with impact-excavated material, is superimposed on a surface. The deposit becomes an observable, mappable unit produced in a single instant in geologic time. Up to two-thirds of Venus craters exhibit extended ejecta deposits. A reconnaissance survey of 336 craters (about 40 percent of the total population) was conducted. About half the craters examined were located in and around the Beta-Atla-Themis region, and half were spread over the western hemisphere of the planet. The survey was conducted using primarily C1-MIDR images. The preliminary survey shows: (1) of the 336 craters, 223 were found to have extended ejecta deposits. This proportion is higher than that found in other Venus crater databases by up to a factor of 2. (2) 53 percent of all extended ejecta craters were unambiguously superimposed on all volcanic and tectonic units. Crater Annia Faustina's associated parabolic ejecta deposit is clearly superimposed on volcanic flows coming from Gula Mons to the west. Parabola material from Faustina has covered the lava flows, smoothing the surface and reducing its specific backscatter cross section. The stratigraphy implies that the parabola material is the youngest observable unit in the region. (3) 12 percent of extended ejecta deposits are superimposed by volcanic materials. Crater Hwangcini has extended ejecta that has been covered by volcanic flows from a dome field to the northwest, implying that the volcanic units were emplaced subsequent to the ejecta deposit and are the youngest units in the locality. (4) It is difficult to determine the stratigraphic relationships of the remaining extended ejecta deposits in SAR at C1-MIDR resolution. Examination of higher resolution images and application of the other Magellan datasets in systematic manner should resolve most of the ambiguous cases. Results from the preliminary survey indicate that extended ejecta deposits are effective time-statigraphic markers for the localities. If stratigraphic relationships between the deposits and surrounding units are studied on a case-by-case basis over the whole planet, they should provide useful constraints on Venus history and development of the surface through time. The continuation of the research will expand the study to include the entire crater population and the Magellan emissivity, altimetry, reflectivity, and rms slope datasets.

Izenberg, Noam R.

1992-01-01

178

OWL representation of the geologic timescale implementing stratigraphic best practice  

NASA Astrophysics Data System (ADS)

The geologic timescale is a cornerstone of the earth sciences. Versions are available from many sources, with the following being of particular interest: (i) The official International Stratigraphic Chart (ISC) is maintained by the International Commission for Stratigraphy (ICS), following principles developed over the last 40 years. ICS provides the data underlying the chart as part of a specialized software package, and the chart itself as a PDF using the standard colours; (ii) ITC Enschede has developed a representation of the timescale as a thesaurus in SKOS, used in a Web Map Service delivery system; (iii) JPL's SWEET ontology includes a geologic timescale. This takes full advantage of the capabilities of OWL. However, each of these has limitations - The ISC falls down because of incompatibility with web technologies; - While SKOS supports multilingual labelling, SKOS does not adequately support timescale semantics, in particular since it does not include ordering relationships; - The SWEET version (as of version 2) is not fully aligned to the model used by ICS, in particular not recognizing the role of the Global Boundary Stratotype Sections and Point (GSSP). Furthermore, it is distributed as static documents, rather than through a dynamic API using SPARQL. The representation presented in this paper overcomes all of these limitations as follows: - the timescale model is formulated as an OWL ontology - the ontology is directly derived from the UML representation of the ICS best practice proposed by Cox & Richard [2005], and subsequently included as the Geologic Timescale package in GeoSciML (http://www.geosciml.org); this includes links to GSSPs as per the ICS process - key properties in the ontology are also asserted to be subProperties of SKOS properties (topConcept and broader/narrower relations) in order to support SKOS-based queries; SKOS labelling is used to support multi-lingual naming and synonyms - the International Stratigraphic Chart is implemented as a set of instances of classes from the ontology, and published through a SPARQL end-point - the elements of the Stratigraphic chart are linked to the corresponding elements in SWEET (Raskin et al., 2011) and DBpedia to support traceability between different commonly accessed representations. The ontology builds on standard geospatial information models, including the Observations and Measurements model (ISO 19156), and GeoSciML. This allows the ages given in the chart to be linked to the evidence basis found in the associated GeoSciML features.

Cox, S. J.

2011-12-01

179

Accommodation and supply—a dual control on stratigraphic sequences  

NASA Astrophysics Data System (ADS)

It is widely accepted that both eustatic and tectonically controlled regional changes of sea level have contributed to the record of stratigraphic sequences. I suggest that environmental change be added as a third, autonomous control. Sedimentologic principles clearly indicate that sequences and their systems tracts are controlled by the interplay of two rates —the rate of change in accommodation (space available for sedimentation) and the rate of sediment supply. Sea level has direct control on accommodation, but its influence on sediment supply is remote and easily overshadowed by environmental factors. For instance, the record of the most recent sea-level rise is a transgressive systems tract where supply is low; it is a prograding highstand systems tract in deltas where the supply is high. Examples of sequence boundaries generated by changes in sediment supply include tectonically driven shifts in sediment input into basins, changes in ocean currents, pulsating supply from failure of submarine slopes and drowning of carbonate platforms by environmental stress. Furthermore, the stratigraphic sequences in fluviatile continental basins are physically removed from sea-level induced changes in accommodation and must have formed by changes in the rate and pattern of supply. Subaerial exposure of marine sediments at the sequence boundary is a most important criterion for recognizing sea level cycles as opposed to supply cycles. Other criteria include downstepping of shelf breaks and characteristic patterns in the spacing of time lines within sequences. Some third-order cycles (ca. 0.5-3 Ma duration) meet these criteria, others do not. Cycle-stacking patterns and the shifting facies belts on cratons indicate that many second- and third-order cycles lack pronounced exposure unconformities and represent gradual changes superimposed on more rapid, shorter oscillations. Seismic data yield poor images of these gradational changes because they lack resolution. Seismic models of outcrops show that near the limits of resolution, the seismic tool tends to portray rapid changes in facies and bed thickness, i.e. lateral variations in supply, as unconformities. Seismic unconformities do not necessarily correspond to unconformities in outcrop. The succession of stratigraphic sequences is best considered a composite record of sea-level and environmental change. Separating the various controls requires carefully planned experiments. Work on the oxygen-isotope curve—another proxy for sea level—has set an example in this respect.

Schlager, Wolfgang

1993-07-01

180

Stratigraphical distribution of the Ordovician conodont Erraticodon Dzik in Argentina  

NASA Astrophysics Data System (ADS)

Three different species of the Ordovician genus Erraticodon Dzik are described and illustrated. Erraticodon patu Cooper is reported from the Lower-Midde Ordovician strata of the Acoite and Alto del Cóndor formations. E. cf. Erraticodon balticus and Erraticodon hexianensis from Middle Ordovician carbonate deposits of the San Juan Formation are analyzed and compared to specimens of these species from Australia, China, Newfoundland, and Baltica. E. patu and E. hexianensis are recorded for first time in the San Juan Formation of Precordillera. The elements of E. cf. E. balticus resemble closely E. balticus Dzik but lack the important denticle on the posterior process of the S elements. An evaluation of the stratigraphic occurrences of these species relative to those of key Lower and Middle Ordovician conodont species such as Trapezognathus diprion Lindström, Oepikodus intermedius Serpagli, Baltoniodus triangularis (Lindström), Baltoniodus navis Lindström, Yangtzeplacognathus crassus (Chen and Zhang) and Eoplacognathus pseudoplanus (Viira) indicates they value for biostratigraphic correlation.

Heredia, S.; Carlorosi, J.; Mestre, A.; Soria, T.

2013-08-01

181

Geologic mapping and stratigraphic investigations of the lunar crater Tycho  

NASA Astrophysics Data System (ADS)

We produced a new geologic map and studied important stratigraphic relationships for Tycho crater. This crater is ~102 km in diameter and is located in the southern highlands on the nearside of the Moon. We used high-resolution Lunar Reconnaissance Orbiter Camera (LROC) and Selenological and Engineering Explorer (SELENE) Terrain Camera (TC) images for detailed mapping, stratigraphic investigations, and dating of geologic units with crater size-frequency distribution (CFSD) measurements. In addition, we used Clementine FeO and TiO2 maps [1] and Moon Mineralogy Mapper (M3) [2] data to investigate the mineralogy. CSFD measurements at young lunar craters are important for helping us better understand the impact rate over the last billion years [3]. Melt pools dated with CSFDs on LROC Narrow Angle Camera (NAC) images, show model ages between 24.2 ± 5.6 Ma and 80.0 ± 14.7 Ma, whereas our model age for the ejecta blanket is 119 ± 12 Ma. The apparent absolute model ages measured for melt pools at Tycho are younger than the ejecta blanket. However, the impact melt and ejecta blanket should have formed at about the same time [4]. One interpretation of the discrepancies between the model ages of the melt pools and the ejecta blanket is that they have different target properties, i.e., the melt pools could be less porous and stronger [3,5]. Alternatively, self-secondary cratering might cause differences in CSFDs [6]. Our detailed geological map shows the distribution of melt pools in the study area. In particular, it shows a large coherent melt sheet within the crater, melt pools and flows along the terraced crater rim, and melt pools on the continuous ejecta blanket. The mapped distribution of melt pools is consistent with an oblique impact of the Tycho impactor from the southwest, as proposed by [7,8]. In addition to the distribution, we will also present results of the volume of melt pools associated with Tycho.

Krüger, T.; Hiesinger, H.; van der Bogert, C. H.

2012-04-01

182

A synthetic stratigraphic model of foreland basin development  

NASA Astrophysics Data System (ADS)

The processes of erosion and deposition must be included in foreland basin models to predict correctly basin geometry and stratigraphy. We present a synthetic stratigraphic model of the development of nonmarine foreland basins that predicts progressive geometry, topography, and facies patterns. In the model, steady crustal shortening occurs according to a wedge-thickening model, erosion and deposition follow a diffusive process, and the lithosphere is compensated elastically. Erosion and deposition are controlled by the transport coefficients ? of the diffusion equation. For a range of thrust velocities and lithospheric rigidities, transport coefficients are of order 102-103 m2/yr in the mountain belt; these values are much higher than those derived from the study of scarp degradation. In the sedimentary basin, transport coefficients of order 104 m2/yr are appropriate and are compatible with previous studies of fluvial and deltaic deposition. Rapid thrusting results in a narrow underfilled basin, while slow thrusting results in a wide overfilled basin. In addition, by varying the erosional and depositional transport coefficients while holding other parameters constant, we generate both overfilled and underfilled basins. These results suggest that changes in the rate of thrust loading, the climate, or the source rock lithology can create stratigraphic signatures that have been interpreted to record viscoelastic relaxation of the lithosphere. Clearly, to understand either the long-term behavior of the lithosphere or to interpret orogenic history from preserved foreland strata, the manner in which a basin was filled must be considered. We apply the model to the evolution of the modern sub-Andean foreland and find that an erosional transport coefficient of 3000 m2/yr and a depositional transport coefficient of 20,000 m2/yr successfully predict the observed basin geometry.

Flemings, Peter B.; Jordan, Teresa E.

1989-04-01

183

Cenozoic stratigraphic evolution, North Sea and Labrador Sea  

SciTech Connect

The authors are studying Cenozoic correlation patterns, burial trends, and subsidence history of the Central North Sea, Labrador, and Orphan basins. The authors objectives are (1) to detail intraregional mid-high latitude biozonations using noise filtering and probabilistic zonation techniques; (2) to detail paleobathymetric trends from basin margins to centers; (3) to apply this knowledge to model basin evolution, in the perspective of the evolving North Atlantic Ocean; (4) to evaluate causes for the occurrence of major hiatuses and rapid changes of subsidence; and (5) to relate rapid changes in sedimentation in the last few millions of years to model observed undercompaction trends. Cenozoic microfossil assemblages in these basins are similar, related to similarities in sedimentary and paleoeceanographic conditions. In more basinal wells, flysch-type agglutinated foraminiferal assemblages occur, also known from Carpathians, Trinidad, and Moroccan foredeeps. Over 90% of agglutinated taxa are common between these basins, although local stratigraphic ranges vary sufficiently to rely on the concept of average ranges, rather than total ones for correlations. Cenozoic stratigraphic resolution in the North Sea and Labrador basins generally is in 3-5-Ma units. and paleobathymetric zonations define a minimum of five niches, from inner shelf to middle slope regimes. Significant hiatuses occurred in the late Eocene through the Miocene, particularly in northern Labrador and northern North Sea. Subsidence in the Labrador/Grand Banks passive margin half grabens was strongly influenced by Labrador Sea opening between anomalies 34 (Campanian) and 13 (early Oligocene), when subsidence exceeded sedimentation and bathyal conditions prevailed along the margin. Thermally induced subsidence in the central North Sea grabens was considerable in the late Paleocene, when the Norwegian Sea started to open.

Gradstein, F.M.; Grant, A.C.; Mudford, B.S. (Bedford Institute of Oceanography, Dartmouth, Nova Scotia (Canada)); Berggren, W.A. (Woods Hole Oceanographic Institute, MA (USA)); Kaminski, M.A. (Dalhousie Univ., Halifax, Nova Scotia (Canada)); D'Lorio, M.A. (Canada Centre for Remote Sensing, Nepean, Ontario (Canada)); Cloetingh, S. (Free Univ., Amsterdam (Netherlands)); Griffiths, C.M. (Univ. of Trondheim (Norway))

1990-05-01

184

46 CFR 15.520 - Mobile offshore drilling units.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Mobile offshore drilling units. 15.520...Requirements; Inspected Vessels § 15.520 Mobile offshore drilling units. (a) The requirements in this section for mobile offshore drilling units (MODUs)...

2010-10-01

185

75 FR 47311 - National Offshore Safety Advisory Committee  

Federal Register 2010, 2011, 2012, 2013

...affecting the oil and gas offshore industry. This meeting will...other concerns affecting the offshore oil and gas industry and assists...and possible action on the Offshore Supply Vessels (OSV's...2010. Written material for distribution to Committee members...

2010-08-05

186

Bundled pipe speeds offshore laying  

SciTech Connect

Technology which allows pipelines to be installed in bundles is expediting pipelay operations in the North Sea. This paper reports how the piggyback system was recently used on 60 km of North Sea gas pipelines for three major projects. For 7 years the practice of installing two or more pipelines in one operation has become an established practice for North Sea offshore oil and gas projects. The technique, commonly referred to as a piggyback operation, reduces installation costs, improves operation reliability, and cuts maintenance time.

Brockbank, J. (Avon Industrial Polymers Ltd., Melksham, Wiltshire (GB))

1990-05-07

187

Seismic Structure of the Continental Margin Offshore French Guiana and North-Eastern Brazil  

NASA Astrophysics Data System (ADS)

During November/December 2003 we carried out a marine geophysical survey of the continental margin offshore French Guiana and north-eastern Brazil onboard RRS Discovery. The survey comprised 1800 line km of coincident multi-channel seismic (MCS) reflection and wide-angle seismic refraction data which were acquired along 3 'transects' of the margin. In addition, more than 3000 line km of underway gravity and magnetic anomaly data were acquired. Preliminary processing of the MCS data has revealed the main stratigraphic units and the nature of the underlying basement at the margin. Up to 4 stratigraphic units have been identified, the uppermost of which is separated from lower units by an angular unconformity. We interpret the unconformity as of mid-Miocene age that corresponds to a major influx of sediment to the margin associated with uplift in the Bolivian Andes and the development of the Amazon deep-sea fan. The lower units beneath the fan offshore north-eastern Brazil comprise of gently landward-dipping reflectors that we interpret as post-rift sediments. Beneath the Demerara plateau offshore French Guinea, however, there is evidence of more steeply dipping reflectors that we attribute to Early Cretaceous and older syn-rift sediments. Basement has been imaged along each transect, most clearly beneath the middle and lower Amazon fan and the deep-water to the north of the Demerara plateau where we interpret it to be of oceanic-type. Preliminary processing of the wide-angle data recorded by ocean bottom instruments deployed at 10 km interval along each transect reveal high velocity arrivals at source-receiver offsets greater that 200 km. Ray-modelling indicate that primary intra-crustal first arrivals originate at major discontinuities within the stratigraphic column. Additional wide-angle land recording data contain arrivals at offsets greater than 400 km. We discuss here the results of the new seismic data, especially as they relate to the early opening history the Equatorial Atlantic and the structure and evolution of both its rift- and transform-type margins.

Greenroyd, C.; Rodger, M.; Peirce, C.; Watts, A. B.; Hobbs, R.

2004-12-01

188

Late Quaternary incised-valley fill of the Yangtze delta (China): its stratigraphic framework and evolution  

Microsoft Academic Search

A Late Quaternary stratigraphic framework of the Yangtze delta, China, has been established based on the analysis and correlation of over 600 cores. Thirty cores were drilled and analyzed during this study, and the rest were collected from numerous publications. The Late Quaternary stratigraphic framework of the Yangtze delta consists of incised-valley fill and two interfluvial sequences. The incised valley

Congxian Li; Ping Wang; Heping Sun; Jiaqiang Zhang; Daidu Fan; Bing Deng

2002-01-01

189

Tectono-stratigraphic history of the southern Junggar basin: seismic profiling evidences  

E-print Network

1 / 17 Tectono-stratigraphic history of the southern Junggar basin: seismic profiling evidences Institute of Petroleum Exploration and Development-Northwest, Lanzhou 730020, China Correspondence details-86-25 -89680700 Running title: Tectono-stratigraphic history of the southern Junggar basin insu-00852430,version1

Paris-Sud XI, Université de

190

Annual Logging Symposium, June 21-24, 2009 COMMON STRATIGRAPHIC FRAMEWORK TO SIMULATE  

E-print Network

in The Woodlands, Texas, United States, June 21-24, 2009. ABSTRACT We introduce the concept of common stratigraphicSPWLA 50th Annual Logging Symposium, June 21-24, 2009 1 COMMON STRATIGRAPHIC FRAMEWORK TO SIMULATE applicable) of individual layers are populated from logs and/or core-log correlations to construct the static

Torres-Verdín, Carlos

191

Domestic Options to Offshore Oil and Gas.  

ERIC Educational Resources Information Center

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.…

Kash, Don E.

1983-01-01

192

Offshore Wind Turbines: Some Technical Challenges  

E-print Network

1 Offshore Wind Turbines: Some Technical Challenges Prof. Guy Houlsby FREng Oxford University House engineers concerned with installation of offshore wind turbines. The author is Professor of Civil solved, a DTI and EPSRC-sponsored research programme on foundations for wind turbines will be briefly

Houlsby, Guy T.

193

Expanders do payouts offshore North Sea  

Microsoft Academic Search

Rich associated gas may be beneficially processed offshore, to yield high value condensate to be spiked into the crude, whilst still producing gas with an acceptable nett calorific value. Actual turbo expander operating experience on the Occidental Piper North Sea Platform has demonstrated that expanders are reliable offshore. This paper, describes both the process and mechanical aspects that affect the

J. Barnwell; W. Wong

1984-01-01

194

Cost of Offshore Wind Energy Charlene Nalubega  

E-print Network

Cost of Offshore Wind Energy water as well as on land based wind farms. The specific offshore wind energy case under consideration kilowatt Hour will be determined. Wind Energy has been around for a very long time. It started as out

Mountziaris, T. J.

195

Coupled Passive Margin Stratigraphic Evolution and Fluid Flow  

NASA Astrophysics Data System (ADS)

Continental margin processes are strongly influenced by patterns of overpressure and fluid flow within basin sediments. These patterns effect consolidation, slope stability, and the transport of heat and solutes. Numerous processes generate overpressure, but in many passive margins rapid deposition is thought to be a dominant mechanism, producing a two-way coupling between sedimentary processes and fluid flow. We study this coupling using a fully 2D margin-scale coupled stratigraphic evolution and fluid flow model. The sedimentary process model describes transport of sand and mud through coastal plain, shoreface, shelf, slope, fan, and rise depositional environments, as well as migration of internal boundaries between environments. The fluid flow model uses the finite element method (FEM) to solve for fluid flow on a dynamic grid. We explore the effects of 2D coupling for various basin geometries, sea-level histories, and sediment influx rates. We find that on a margin-scale, deposition tends to be localized in depocenters, which are initiated by sediment flux divergence across depositional environment boundaries (e.g. shoreline, shelf-break). Over timescales relevant to pore-pressure evolution, these boundaries and their associated clinoforms migrate in response to sedimentation and relative sea level change, resulting in complex dynamic patterns of overpressure. Although in some regions fluid flow is quasi-1D (vertical and forced only by local deposition), in many regions fluid flow is strongly 2D. Complex flow results from heterogeneous stratigraphy, with strong contrasts in sand and mud permeability determining preferential flow paths. On regional scales, confined horizontal sandy units, such as buried turbidite fan complexes, act as fluid flow conduits, inducing flow anisotropy. On smaller scales, interbedded sandy and muddy deposits produce anisotropic effective permeabilities with preferential horizontal flow. The complex dynamic geometries inherent to margin stratigraphic evolution have heretofore prevented effective margin-scale modeling coupled 2D stratigraphic-hydrologic system, but our computational approach introduces two innovations. A dynamic meshing technique allows for rapid meshing of arbitrary deposits while maintaining bounds on FEM conditioning and error. And a hierarchical mesh structure, which aggregates sediment layers into mesh nodes into finite elements, embeds sub-grid dynamics into the FEM model via layer averaged anisotropic permeabilities. Our results show that in regions of homogeneous lithology, quasi-1D numerical or asymptotic approximations are applicable, but that in regions with complex stratigraphy, strong anisotropy effects cannot be ignored. Our meshing and FEM approach is general and easily adapted for use with any sedimentary or backstripping model, and models including more grain sizes or processes have an even greater potential for complex 2D fluid flow. Hence our results demonstrate the viability and necessity of including 2D effects in continental margin fluid flow models.

Wolinsky, M. A.; Pratson, L. F.

2004-12-01

196

Brookian stratigraphic plays in the National Petroleum Reserve - Alaska (NPRA)  

USGS Publications Warehouse

The Brookian megasequence in the National Petroleum Reserve in Alaska (NPRA) includes bottomset and clinoform seismic facies of the Torok Formation (mostly Albian age) and generally coeval, topset seismic facies of the uppermost Torok Formation and the Nanushuk Group. These strata are part of a composite total petroleum system involving hydrocarbons expelled from three stratigraphic intervals of source rocks, the Lower Cretaceous gamma-ray zone (GRZ), the Lower Jurassic Kingak Shale, and the Triassic Shublik Formation. The potential for undiscovered oil and gas resources in the Brookian megasequence in NPRA was assessed by defining five plays (assessment units), one in the topset seismic facies and four in the bottomset-clinoform seismic facies. The Brookian Topset Play is estimated to contain between 60 (95-percent probability) and 465 (5-percent probability) million barrels of technically recoverable oil, with a mean (expected value) of 239 million barrels. The Brookian Topset Play is estimated to contain between 0 (95-percent probability) and 679 (5-percent probability) billion cubic feet of technically recoverable, nonassociated natural gas, with a mean (expected value) of 192 billion cubic feet. The Brookian Clinoform North Play, which extends across northern NPRA, is estimated to contain between 538 (95-percent probability) and 2,257 (5-percent probability) million barrels of technically recoverable oil, with a mean (expected value) of 1,306 million barrels. The Brookian Clinoform North Play is estimated to contain between 0 (95-percent probability) and 1,969 (5-percent probability) billion cubic feet of technically recoverable, nonassociated natural gas, with a mean (expected value) of 674 billion cubic feet. The Brookian Clinoform Central Play, which extends across central NPRA, is estimated to contain between 299 (95-percent probability) and 1,849 (5-percent probability) million barrels of technically recoverable oil, with a mean (expected value) of 973 million barrels. The Brookian Clinoform Central Play is estimated to contain between 1,806 (95-percent probability) and 10,076 (5-percent probability) billion cubic feet of technically recoverable, nonassociated natural gas, with a mean (expected value) of 5,405 billion cubic feet. The Brookian Clinoform South-Shallow Play is estimated to contain between 0 (95-percent probability) and 1,254 (5-percent probability) million barrels of technically recoverable oil, with a mean (expected value) of 508 million barrels. The Brookian Clinoform South-Shallow Play is estimated to contain between 0 (95-percent probability) and 5,809 (5-percent probability) billion cubic feet of technically recoverable, nonassociated natural gas, with a mean (expected value) of 2,405 billion cubic feet. The Brookian Clinoform South-Deep Play is estimated to contain between 0 (95-percent probability) and 8,796 (5-percent probability) billion cubic feet of technically recoverable, nonassociated natural gas, with a mean (expected value) of 3,788 billion cubic feet. No technically recoverable oil is assessed in the Brookian Clinoform South-Deep Play, as it lies at depths that are entirely in the gas window. Among the Brookian stratigraphic plays in NPRA, the Brookian Clinoform North Play and the Brookian Clinoform Central Play are most likely to be objectives of exploration activity in the near-term future because they are estimated to contain multiple oil accumulations larger than 128 million barrels technically recoverable oil, and because some of those accumulations may occur near existing infrastructure in the eastern parts of the plays. The other Brookian stratigraphic plays are not likely to be the focus of exploration activity because they are estimated to contain maximum accumulation sizes that are smaller, but they may be an objective of satellite exploration if infrastructure is extended into the play areas. The total volumes of natural gas estimated to occur in B

Houseknecht, David W.

2003-01-01

197

Stratigraphic records of paleogeography and global change from two late Proterozoic basins  

NASA Astrophysics Data System (ADS)

As sediments and volcanic deposits accumulate on Earth's surface, they record information about Earth's climate, the motion of continents, and the evolution of the biosphere. Through the study of ancient stratigraphic sequences, we can gain a window into our planet's varied, and sometimes tumultuous, past. In this dissertation, I employ a combination of field observations, magnetic data, and chemostratigraphic data in the Keweenawan Mid-continent Rift of North America and the Amadeus Basin of Central Australia to study the paleogeography and paleoclimate during and after the transition between the Mesoproterozoic (1.7 to 1.0 billion-years ago) and Neoproterozoic Eras (1.0 to 0.54 billion-years ago). The supercontinent Rodinia formed at the boundary between the Eras and broke apart throughout the Neoproterozoic. Basins that developed as Rodinia rifted apart record large changes in the biogeochemical cycling of carbon and sulfur, the waxing and waning of low-latitude ice sheets, and the progressive oxygenation of the atmosphere that facilitated the evolution of animals. I report high-resolution paleomagnetic data in stratigraphic context from Mamainse Point, Ontario---the most complete succession in the 1.1 billion-year-old Mid-continent Rift. The results demonstrate that previous suggestions of large non-dipolar geomagnetic field components at the time stemmed from low temporal resolution across geomagnetic reversals during a period of rapid plate motion. This result strengthens the framework for evaluating records of tectonics and climate across the Mesoproterozoic/Neoproterozoic boundary. Rock magnetic experiments on Mamainse Point lavas, paired with electron microscopy, demonstrate that a component of the magnetization in oxidized flows that is antiparallel to the characteristic remanence is a result of martite self-reversal. This component is the best resolved natural example of the experimentally observed self-reversal that accompanies the maghemite to hematite transition. This result allows the magnetizations of the lavas to be fully interpreted, and also suggests that this self-reversal phenomena may be more widespread than currently recognized---with its identification in this study being greatly aided by stratigraphic context during a period when North America was moving rapidly towards the equator. Stratigraphic and stable isotope work on the Neoproterozoic Bitter Springs Formation of the Amadeus Basin demonstrates that the negative carbon isotope values of the "Bitter Springs Stage" are tightly consistent in carbonate rocks across more than 400 km. In addition to being present in the isotopic composition of the carbonate, organic carbon isotope values shift sympathetically into and out of the stage thereby supporting the interpretation that the stage is a record of primary changes to the carbon cycle. The stage is bound by sequence boundaries that provide evidence for changes in sea-level and climate. Previous work on correlative stratigraphy from the Akademikerbreen Group of East Svalbard (Maloof et al., 2006), revealed changes in relative sea-level and paleomagnetic directions that have were interpreted to have resulted from a pair of large-scale true polar wander events. In an effort to further test this hypothesis, and to remedy a lack of paleogeographic constraints for north Australia in the early Neoproterozoic, I present paleomagnetic data from more than 630 paleomagnetic samples of carbonates, siltstones and basalt flows from the Bitter Springs Formation. A new reliable pole from post-Bitter Springs Stage siltstones provides strong support for a recently published hypothesis that there was relative rotation between north and south+west Australia in the late Neoproterozoic (Li and Evans, 2011), and for the long-standing hypothesis that Australia and Laurentia were cotravelers in Rodinia into the mid-Neoproterozoic Era. The difference between the paleomagnetic poles of syn-Bitter Springs Stage carbonates and post-Bitter Springs Stage siltstones is likely a result of a Cambrian remagnetization of

Swanson-Hysell, Nicholas L.

198

Tephrochronology offshore Ischia Island, Tyrrhenian sea, Italy  

NASA Astrophysics Data System (ADS)

This work presents the analytical results of a tephrochronological study carried out on 12 gravity cores collected offshore southern Ischia island down to a maximum depth of 1238 m. The more distal site (core C1071) is located few kilometers to the west of the "Banco delle Sirene" seamount, not far from the Magnaghi and Dohrn canyons. The composite succession records at least the last ca. 40 kyrs of marine sedimentation as deduced by 14C AMS dating and tephrostratigraphy. This is consistent with the attribution, on the basis of the calcareous nannofossil assemblages, to the Emiliania huxleyi Acme Zone (Rio et al., 1990) in the latest Pleistocene-Holocene time interval. Eight primary tephra layers were recognised and analysed. They are generally represented by coarse to fine ash alternating with a number of volcaniclastic turbidites along the whole succession. The glass fraction was geochemically characterised through SEM-EDS analyses and shows clear affinities with products erupted during significant explosive events occurred in the Campania Plain, Ischia and Procida islands during the last 40 kyrs. Four ash layers were correlated with several eruptions occurred on Ischia island between the Middle Ages and Roman times and at ~ cal. 17 ka B.P. Deposits related to explosive activity occurred on Procida island were also found and dated at ~23 cal ka. Among the most ancient tephra layers, the best preserved horizon, 30 cm thick, is represented by the flegrean products of the Campanian Ignimbrite event (39 ka; De Vivo et al., 2001) the marine signature of which is known as C13 tephra in the Tyrrhenian (Thon-That et al., 2001). The peculiar composition and stratigraphic position of two other main marker tephras recognised in the succession, allowed us to correlate them with the still poorly known Schiava (36 ka B.P.; Paterne and Guichard, 1993; Sulpizio et al., 2003) and Codola (~33. cal ka B.P.; this work) fall-out products which occur as 7-5 cm-thick pumice layers at the coring site. The definition of the source area of these two major events is still a matter of debate. However, the Somma-Vesuvius complex reasonably sourced the Schiava deposits while a Campi Flegrei provenance for the Codola deposits cannot be ruled out (Di Vito et al., 2008). These latters, known as C10 tephra in the Tyrrhenian and Adriatic sea (Paterne et al., 1988; Giaccio et al., 2008), in particular, represent reliable regional markers for the whole central Mediterranean area. References De Vivo, B., Rolandi, G., Gans, P.B., Calvert, A., Bohrson,W.A., Spera, F.J., Belkin, H.E., 2001. New constraints on the pyroclastic eruptive history of the Campanian volcanic Plain (Italy). Mineralogy and Petrology 73, 47-65. Di Vito,M.A., Sulpizio, R., Zanchetta, G., D'Orazio, M., 2008. The late Pleistocene pyroclastic deposits of the Campanian Plain: newinsights into the explosive activity of Neapolitan volcanoes. J. Volcanol. Geotherm. Res.177, 19-48. Giaccio, B., Isaia, R., Fedele, F.G., Di Canzio, E., Hoffecker, J., Ronchitelli, A., Sinitsyn, A., Anikovich, M., Lisitsyn, S.N., 2008. The Campanian Ignimbrite and Codola tephra layers: two temporal/stratigraphic markers for the Early Upper Palaeloithic in southern Italy and eastern Europe. J. Volcanol. Geotherm. Res. 177, 210-228. Paterne M., Guichard F. & Labeyrie J., 1988. Explosive activity of the south Italian volcanoes during the past 80.000 years as determined by marine tephrochronology. J. Volcanol. Geother. Res. 34, 153-172. Paterne, M., Guichard, F., 1993. Triggering of volcanic pluses in the Campanian area, south Italy, by periodic deep magma in.ux. Journal of Geophysical Research 98 (B2), 1861-1873. Rio, D., Raffi, I., Villa, G., 1990. Pliocene-Pleistocene calcareous nannofossil distribution patterns in the western Mediterranean. In: Kastens, K.A. (Ed.), Proceedings of the Ocean Drilling Program. Scientific Results, vol. 107. Ocean Drilling Program, College Station, TX, pp. 513-533. Sulpizio, R., Zanchetta, G., Paterne, M., Siani, G., 2003. A review of tephrostratigraphy in central and south

Insinga, Donatella; Sulpizio, Roberto; de Alteriis, Giovanni; Morabito, Simona; Morra, Vincenzo; Sprovieri, Mario; di Benedetto, Claudia; Lubritto, Carmine; Zanchetta, Giovanni

2010-05-01

199

Rupture lengths and temporal history of significant earthquakes on the offshore and north coast segments of the Northern San Andreas Fault based on turbidite stratigraphy  

NASA Astrophysics Data System (ADS)

74 piston, gravity and jumbo Kasten cores were collected from channel and canyon systems draining the northern California continental margin to investigate the record of periodic Holocene turbidites for possible connection to large magnitude earthquakes on the adjacent Northern San Andreas Fault. Poorly known channel systems were mapped with multibeam sonar to define pathways and channel confluences. Cores sampled all major and many minor channel systems extending from Cape Mendocino to just north of Monterey Bay. Sampling both along and across channels was done and particular attention was paid to channel confluences, as these areas afford opportunities to test for synchronous triggering of turbidity currents. While at sea, all cores were scanned using a GEOTEK multisensor core logger (MSCL), which collects high-resolution photography, P-wave velocity, gamma-ray density, and magnetic susceptibility data from the unsplit cores. Lithology was logged visually, and cores were later imaged with X-radiography. We use 14C ages, relative dating tests at channel confluences, and stratigraphic correlation using physical properties to determine whether turbidites deposited in separate channel systems are correlative, implying they were triggered by a common event. These tests can, in most cases, separate earthquake-triggered turbidity currents from other possible sources. The late Holocene turbidite record off northern California passes these tests for synchronous triggering, and can be correlated with multiple proxies from site to site between Noyo Channel and the latitude of San Francisco. Preliminary comparisons of our event ages with existing and in progress work at onshore coastal sites show good correlation, further circumstantial evidence that the offshore record is primarily earthquake generated. During the last ˜ 2800 yr, 15 turbidites are recognized, including the great 1906 earthquake. Their chronology establishes an average repeat time of ˜ 200 yr, similar to the onshore value of ˜ 230 yr. Along-strike correlation suggests that at least 8 of the youngest 10 of these events ruptured the 320 km distance from the Mendocino Triple Junction to near San Francisco.

Goldfinger, Chris; Morey, Ann E.; Nelson, C. Hans; Gutiérrez-Pastor, Julia; Johnson, Joel E.; Karabanov, Eugene; Chaytor, Jason; Eriksson, Andrew; Shipboard Scientific Party

2007-02-01

200

Eolian paleotopographic highs as stratigraphic traps: origin and distinction  

SciTech Connect

Significant hydrocarbon accumulations occur where eolian paleotopographic highs are preserved beneath transgressive marine deposits. Paleotopographic highs can represent erosional remnants of an unconformity, or partly preserved eolian dunes, or combinations of both. Paleotopography reflects the extent of modification undergone by eolian units prior to or during transgression. Modification varies between extremes of (1) destruction - where eolian deposits are deeply eroded and the former dunal profile is lost, and (2) preservation - where dunes and interdune areas are preserved nearly intact. The extent of modification that occurs during transgression is controlled primarily by (1) the energy of the transgressing sea, (2) the speed of transgression, and (3) the abundance of sand-stabilizing early cements or plants. High-energy seas destroy dunes through persistent erosion by tides and waves and by initiating dune collapse and mass flowage of dune sands. Preservation occurs where quiescent seas flood interdune areas and create shallow to periodically emergent marine environments, such as interdune sabkhas or tidal flats. Gradual filling of interdune areas with shallow marine sediments can fortify and preserve adjacent dunes. These varied processes that interact between marine and eolian environments to create different types of topography are exemplified in ancient eolian-marine sequences of the Western Interior of North America, and preserved Holocene dunes of coastal Australia. Different types of eolian highs can be recognized by analysis of bounding surfaces in outcrop or core. An understanding of eolian-marine processes and environments that create topography allows for prediction of areas of potential stratigraphic traps.

Eschner, T.B.; Kocurek, G.A.

1985-02-01

201

Relative Age-dating -- Discovery of Important Stratigraphic Principles  

NSDL National Science Digital Library

When piecing together the geologic history of the Earth, geologists rely on several key relative age-dating principles that allow us to determine the relative ages of rocks and the timing of significant geologic events. In a typical Historical Geology class or textbook, instructors/authors briefly discuss the important early researchers in the geological sciences, and then give the name of the stratigraphic principle, useful for relative age-dating of rocks and events, that these 17th and 18th century scientists are credited with discovering. After the instructor/author defines these principles, students are usually shown several examples so they can see how the principle can be applied. But why not start with the examples and let students discover these principles for themselves? Students are split into small groups which each work to discover a different relative age-dating principle. The groups are shown photos and given handouts with drawings of rock outcrops illustrating the various principles. These handouts include worksheets for which they must answer a series of prompts that help lead them to the discovery of their relative age-dating principle. Groups must also invent a name for their principle, and select a spokesperson who will present the group's results to the rest of the class.

Steinberg, Roger

202

The ocean-continent transition zones: Stratigraphic and paleoecosystem studies  

SciTech Connect

The author uses the Cenozoic of the Russian Pacific coast, drawing particularly on his 30-year experience with the molluscan faunas, as the source of examples of the ways that regional and global changes in the inorganic world affect the living world, as reflected in the stratigraphic and paleontologic record. The shelf ecosystem, despite its relative stability, shows periods of rapid change, reflecting both migration and accelerated evolution. The shelf ecosystem of the boreal belt evolved during Cenozoic time in an environment of changing paleoclimatic and paleogeographic phenomena. In spite of all their complexity and the considerable stressed nature of situations during individual moments in geological time, the ecosystem displayed a relative stability. The composition and structure of biotic communities, judging by the mollusks, changed with a definite trend (since Oligocene time, mainly on the species level), with gradual replacement through time of some forms by others, and with an increase in the percentage of Holocene species. This linear process was complicated by moments when the process accelerated. The problems encountered require wider discussion. The observed patterns of development of abiotic and biotic phenomena in this region, with its definite cyclicity and synchroneity, may be valuable in deciphering such patterns in other regions of the globe. The trends seen in the evolution of the biotic communities during Cenozoic time may also provide a basis for predicting the development of shelf ecosystems in the forthcoming decades and centuries. 46 refs., 2 figs., 2 tabs.

Gladenkov, Yu.B. (Inst. of Geology, Moscow (Russian Federation))

1993-03-01

203

The Cook Mountain problem: Stratigraphic reality and semantic confusion  

SciTech Connect

Historical inconsistency as to what constitutes the Cook Mountain Formation illustrates the semantic confusion resulting from extending surface-derived stratigraphic names into the subsurface without a full understanding of basin architecture. At the surface, the Cook Mountain Formation consists of fossilerous marine shale, glaucony and marl, and marginal-marine sandstone and shale between the nonmarine Sparta Formation sandstones below and the nonmarine Yegua Formation sandstones and lignitic shales above. Fossils are abundant, including the benthic foraminifer Ceratobulimina eximia. As subsurface exploration began, the first occurrence of Ceratobulimina eximia {open_quotes}Cerat{close_quotes} was used as the top of the marine {open_quotes}Cook Mountain Shale{close_quotes} below the Yegua section. Downdip, the overlying Yegua was found to become a sequence of marine shales and marginal-marine sandstones, the lower part of which yielded {open_quotes}Cerat{close_quotes}. Because of this, the lower sandstones were called {open_quotes}Cook Mountain{close_quotes} in many fields. At the Yegua shelf margin, {open_quotes}Cerat{close_quotes} is absent. Different exploration teams have used their own definitions for {open_quotes}Cook Mountain{close_quotes}, leading to substantial confusion.

Ewing, T.E. [Frontera Exploration Consultants, San Antonio, TX (United States); [Venus Oil Co., San Antonio, TX (United States)

1994-12-31

204

Current and future offshore activities in Canada  

SciTech Connect

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.

Hnatiuk, J.

1987-06-01

205

Quantifying the hurricane risk to offshore wind turbines  

E-print Network

Quantifying the hurricane risk to offshore wind turbines Stephen Rosea , Paulina Jaramilloa,1 GW will be required from shallow offshore turbines. Hurricanes are a potential risk to these turbines be destroyed by hurricanes in an offshore wind farm. We apply this model to estimate the risk to offshore wind

Jaramillo, Paulina

206

Hydroacoustic Monitoring of Fish Communities in Offshore Wind Farms  

E-print Network

#12;Hydroacoustic Monitoring of Fish Communities in Offshore Wind Farms Annual Report 2004 Horns .......................................................................................................................... 22 #12;Hydroacoustic monitoring of fish communities in offshore wind farms Page I Horns Rev Offshore Rev Offshore Wind Farm Published: May 2005 Prepared by: Christian B. Hvidt Lars Brünner Frank Reier

207

Offshoring: General Equilibrium Effects on Wages, Production and Trade  

Microsoft Academic Search

A simple model of offshoring, which depicts offshoring as ?shadow migration,? permits straightforward derivation of necessary and sufficient conditions for the effects on wages, prices, production and trade. We show that offshoring requires modification of the four classic international trade theorems, so econometricians who ignore offshoring might reject the Heckscher-Ohlin theorem when a properly specified version held in the data.

Richard E. Baldwin; Frédéric Robert-Nicoud

2007-01-01

208

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

NASA Astrophysics Data System (ADS)

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

Kreidler, Tai Deckner

1997-12-01

209

Tectonic evolution of the offshore Sarawak and Sabah Basins, Northwest Borneo  

SciTech Connect

The offshore Sarawak and Sabah Basins, northwest Borneo, contain up to 12 km of Oligocene to Holocene sediments. On the basis of marked different structural styles and stratigraphy, these basins can be divided into 13 tectono-stratigraphic provinces. Many of these, e.g., Balingian southwest Luconia, central Luconia, Baram delta, inboard belt, and outboard belt, are proven hydrocarbon provinces. Stratigraphically, these provinces generally become younger toward the northwest and/or northeast, with the older provinces overlying unconformably the Paleogene Rajang Group deep-marine sediments in the south. There is a great variation in structural styles. However, general structural trends can be recognized in that the older provinces in the southeast, e.g., Balingian, updip part of Baram delta, Rajang Group fold and thrust belt, inboard belt, and outboard belt, have been subjected to strong compressional tectonics, whereas the younger provinces in the northwest, e.g., central Luconia, north Luconia, southwest Luconia, and the central part of the Baram delta, have undergone predominantly extensional tectonics. The tectonic evolution of these provinces from late Eocene to Holocene, relative to the postulated subduction zones and major tectonic lineations recognized in the region, are discussed.

Hazebroek, H.; Tan, D.; Swinburn, P. (Sarawak Shell Berhad (Malaysia))

1994-07-01

210

Offshore medicine: Medical care of employees in the offshore oil industry  

SciTech Connect

This book is specifically designed to help the doctor who has to provide medical care for the expanding offshore oil industry. It describes the pattern of work offshore and the medical problems which it generates. The special features of offshore medical care are described along with the training of medics, the design of hospital facilities, and the provision of back-up services to cope with them. These are special chapters on diving, hygiene, and catering, dentistry, and legal aspects.

Cox, R.A.F.

1987-01-01

211

simulated service Thermal shock Testing  

E-print Network

conditions to evaluate mechanical and thermal integrity of insulation materials in real timeKeywords simulated service Testing Thermal shock Testing Cathodic disbondment Flexibility Testing for offshore Insulation and Corrosion Protection systems Simulated service insulation test samples being set up

Chapman, Clark R.

212

31 CFR 585.408 - Offshore transactions.  

Code of Federal Regulations, 2010 CFR

...THE TREASURY FEDERAL REPUBLIC OF YUGOSLAVIA (SERBIA AND MONTENEGRO) AND BOSNIAN SERB-CONTROLLED AREAS OF THE REPUBLIC OF BOSNIA AND HERZEGOVINA SANCTIONS REGULATIONS Interpretations § 585.408 Offshore transactions. (a) The...

2010-07-01

213

Future characteristics of Offshore Support Vessels  

E-print Network

The objective of this thesis is to examine trends in Offshore Support Vessel (OSV) design and determine the future characteristics of OSVs based on industry insight and supply chain models. Specifically, this thesis focuses ...

Rose, Robin Sebastian Koske

2011-01-01

214

Offshore oil in the alaskan arctic.  

PubMed

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. PMID:17813239

Weeks, W F; Weller, G

1984-07-27

215

31 CFR 588.406 - Offshore transactions.  

Code of Federal Regulations, 2013 CFR

... Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY WESTERN BALKANS STABILIZATION REGULATIONS Interpretations § 588.406 Offshore transactions. The prohibitions in §...

2013-07-01

216

31 CFR 588.406 - Offshore transactions.  

... Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY WESTERN BALKANS STABILIZATION REGULATIONS Interpretations § 588.406 Offshore transactions. The prohibitions in §...

2014-07-01

217

Offshore oil in the Alaskan Arctic  

NASA Technical Reports Server (NTRS)

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.

Weeks, W. F.; Weller, G.

1984-01-01

218

31 CFR 547.406 - Offshore transactions.  

Code of Federal Regulations, 2013 CFR

...Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY DEMOCRATIC REPUBLIC OF THE CONGO SANCTIONS REGULATIONS Interpretations § 547.406 Offshore transactions. The...

2013-07-01

219

31 CFR 547.406 - Offshore transactions.  

Code of Federal Regulations, 2011 CFR

...Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY DEMOCRATIC REPUBLIC OF THE CONGO SANCTIONS REGULATIONS Interpretations § 547.406 Offshore transactions. The...

2011-07-01

220

31 CFR 547.406 - Offshore transactions.  

Code of Federal Regulations, 2012 CFR

...Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY DEMOCRATIC REPUBLIC OF THE CONGO SANCTIONS REGULATIONS Interpretations § 547.406 Offshore transactions. The...

2012-07-01

221

31 CFR 547.406 - Offshore transactions.  

...Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY DEMOCRATIC REPUBLIC OF THE CONGO SANCTIONS REGULATIONS Interpretations § 547.406 Offshore transactions. The...

2014-07-01

222

31 CFR 547.406 - Offshore transactions.  

Code of Federal Regulations, 2010 CFR

...Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY DEMOCRATIC REPUBLIC OF THE CONGO SANCTIONS REGULATIONS Interpretations § 547.406 Offshore transactions. The...

2010-07-01

223

System architecture of offshore oil production systems  

E-print Network

This thesis presents an approach to applying Systems Architecture methods to the development of large, complex, commercial systems, particularly offshore oil and gas productions systems. The aim of this research was to ...

Keller, James (James Thomas)

2008-01-01

224

Expanders do payouts offshore North Sea  

SciTech Connect

Rich associated gas may be beneficially processed offshore, to yield high value condensate to be spiked into the crude, whilst still producing gas with an acceptable nett calorific value. Actual turbo expander operating experience on the Occidental Piper North Sea Platform has demonstrated that expanders are reliable offshore. This paper, describes both the process and mechanical aspects that affect the choice of an expander system for an offshore application. For a given typical rich associated gas, three process options are compared, Joule-Thompson expansion, external refrigeration and a turbo expander system. The process study illustrates that a turbo expander system is comparable for the offshore situation with the other two options. The paper also describes the mechanical features that should be incorporated into the specification of an expander for use on a platform topsides.

Barnwell, J.; Wong, W.

1984-02-01

225

Outsourcing, offshoring and the US office market  

E-print Network

There is intense debate among industry analysts and scholars over potential job losses caused by offshoring. The real estate industry has been grappling to understanding the implications of these numbers, as some have ...

Topolewski, Tanya M., 1969-

2004-01-01

226

Offshore Oil in the Alaskan Arctic  

Microsoft Academic Search

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 occur offshore beneath the shallow, ice-covered seas of the Alaskan continental shelf. Offshore recovery operations for such areas are

G. Weller

1984-01-01

227

Grid Integration of Offshore Wind Farms  

Microsoft Academic Search

\\u000a Offshore wind farms tend to become bigger and far from the onshore point of connection. The developers and the system operators\\u000a are facing a number of technical, economical, and environmental challenges in transmitting the bulk power developed at these\\u000a offshore wind farms over long distances. In this Chapter, some of these issues are discussed, giving emphasis to the basic\\u000a system

Lie Xu

228

Corrosion control survey methods for offshore pipelines  

SciTech Connect

Construction, operation, and maintenance of offshore pipelines and other facilities are expensive. The consequences of an offshore corrosion failure can be devastating. For these reasons, cathodic protection (CP) has become a universally applied technique for mitigating corrosion. Marine pipelines are typically provided with CP by bracelet anodes of zinc or aluminum. Impressed current systems at platforms or onshore are also used as well as hybrid systems that use a combination of the two. In this paper survey techniques are described and evaluated.

Weldon, C.P.; Kroon, D. (Corrpro Co. Inc., North, Spring, TX (US))

1992-02-01

229

Stratigraphic Controls on Seawater Intrusion, and Implications for Ground-Water Management, Dominguez Gap Area of Los Angeles, California  

NASA Astrophysics Data System (ADS)

Development of ground water in coastal Los Angeles in the 20th century led to extensive water-level declines and associated seawater intrusion. The U.S. Geological Survey (USGS) has developed a solute-transport model to quantitatively test the hydraulic implications of a sequence-stratigraphic model and to assess the possible effects of alternative management strategies. The transport modeling was conducted using SUTRA, a finite-element, density-dependent, ground-water flow and solute-transport model. The SUTRA configuration for this case is two dimensional and considers flow and transport along an approximate flow line extending from the Pacific Ocean through the Dominguez Gap area of coastal Los Angeles. The lithologic representation is based on a stratigraphic cross section developed by Ponti and others (2007) http://pubs.usgs.gov/of/2007/1013/. The transient-state simulation period is from 1850 to 2004. Trial-and-error model calibration was conducted using the measured water levels and chloride (Cl) concentrations at nine wells along the cross section. The results from the calibrated model indicate that faulting can provide the main pathway for downward transport of seawater by juxtaposing low permeability layers with high permeability layers; prior stratigraphic models for the region did not recognize this fault system. Three 20- year management scenarios were considered: (1) status quo, that is, no change in water-management strategies; (2) installation of a slurry wall; and (3) raising inland water levels through increased injection or decreased pumpage. Scenario 1 resulted in increasing Cl concentrations. Scenario 2 slowed Cl migration; however, this did not reverse seawater intrusion. Scenario 3 reversed seawater intrusion, but there remained Cl in the deeper regions that will be removed only by dilution over time.

Siade, A. J.; Nishikawa, T.; Reichard, E. G.

2007-12-01

230

Stratigraphic controls on seawater intrusion and implications for groundwater management, Dominguez Gap area of Los Angeles, California, USA  

USGS Publications Warehouse

Groundwater pumping has led to extensive water-level declines and seawater intrusion in coastal Los Angeles, California (USA). A SUTRA-based solute-transport model was developed to test the hydraulic implications of a sequence-stratigraphic model of the Dominguez Gap area and to assess the effects of water-management scenarios. The model is two-dimensional, vertical and follows an approximate flow line extending from the Pacific Ocean through the Dominguez Gap area. Results indicate that a newly identified fault system can provide a pathway for transport of seawater and that a stratigraphic boundary located between the Bent Spring and Upper Wilmington sequences may control the vertical movement of seawater. Three 50-year water-management scenarios were considered: (1) no change in water-management practices; (2) installation of a slurry wall; and (3) raising inland water levels to 7.6 m above sea level. Scenario 3 was the most effective by reversing seawater intrusion. The effects of an instantaneous 1-m sea-level rise were also tested using water-management scenarios 1 and 3. Results from two 100-year simulations indicate that a 1-m sea-level rise may accelerate seawater intrusion for scenario 1; however, scenario 3 remains effective for controlling seawater intrusion. ?? Springer-Verlag 2009.

Nishikawa, T.; Siade, A.J.; Reichard, E.G.; Ponti, D.J.; Canales, A.G.; Johnson, T.A.

2009-01-01

231

Stratigraphic controls on seawater intrusion and implications for groundwater management, Dominguez Gap area of Los Angeles, California, USA  

NASA Astrophysics Data System (ADS)

Groundwater pumping has led to extensive water-level declines and seawater intrusion in coastal Los Angeles, California (USA). A SUTRA-based solute-transport model was developed to test the hydraulic implications of a sequence-stratigraphic model of the Dominguez Gap area and to assess the effects of water-management scenarios. The model is two-dimensional, vertical and follows an approximate flow line extending from the Pacific Ocean through the Dominguez Gap area. Results indicate that a newly identified fault system can provide a pathway for transport of seawater and that a stratigraphic boundary located between the Bent Spring and Upper Wilmington sequences may control the vertical movement of seawater. Three 50-year water-management scenarios were considered: (1) no change in water-management practices; (2) installation of a slurry wall; and (3) raising inland water levels to 7.6 m above sea level. Scenario 3 was the most effective by reversing seawater intrusion. The effects of an instantaneous 1-m sea-level rise were also tested using water-management scenarios 1 and 3. Results from two 100-year simulations indicate that a 1-m sea-level rise may accelerate seawater intrusion for scenario 1; however, scenario 3 remains effective for controlling seawater intrusion.

Nishikawa, Tracy; Siade, A. J.; Reichard, E. G.; Ponti, D. J.; Canales, A. G.; Johnson, T. A.

2009-11-01

232

Stratigraphic evidence for an early Holocene earthquake in Aceh, Indonesia  

NASA Astrophysics Data System (ADS)

The Holocene stratigraphy of the coastal plain of the Aceh Province of Sumatra contains 6 m of sediment with three regionally consistent buried soils above pre-Quaternary bedrock or pre-Holocene unconsolidated sediment. Litho-, bio-, and chronostratigraphic analyses of the lower buried soil reveals a rapid change in relative sea-level caused by coseismic subsidence during an early Holocene megathrust earthquake. Evidence for paleoseismic subsidence is preserved as a buried mangrove soil, dominated by a pollen assemblage of Rhizophora and/or Bruguiera/Ceriops taxa. The soil is abruptly overlain by a thin tsunami sand. The sand contains mixed pollen and abraded foraminiferal assemblages of both offshore and onshore environments. The tsunami sand grades upward into mud that contains both well-preserved foraminifera of intertidal origin and individuals of the gastropod Cerithidea cingulata. Radiocarbon ages from the pre- and post-seismic sedimentary sequences constrain the paleoearthquake to 6500-7000 cal. yrs. BP. We use micro-and macrofossil data to determine the local paleoenvironment before and after the earthquake. We estimate coseismic subsidence to be 0.45 ± 0.30 m, which is comparable to the 0.6 m of subsidence observed during the 2004 Aceh-Andaman earthquake on Aceh's west coast.

Grand Pre, Candace A.; Horton, Benjamin P.; Kelsey, Harvey M.; Rubin, Charles M.; Hawkes, Andrea D.; Daryono, Mudrik R.; Rosenberg, Gary; Culver, Stephen J.

2012-10-01

233

Linking sedimentological, stratigraphic and diagenetic processes to understand unconventional reservoirs: the Upper Jurassic Vaca  

E-print Network

Linking sedimentological, stratigraphic and diagenetic processes to understand unconventional as to the scale of sedimentological variability within mudstone successions, and how related diagenetic alteration by Profs Taylor and Flint, to document the scale of sedimentological and diagenetic variability

Henderson, Gideon

234

A stratigraphic framework for Late Jurassic Early Cretaceous gas-bearing strata  

E-print Network

A stratigraphic framework for Late Jurassic­ Early Cretaceous gas-bearing strata (Monteith Formation) in the subsurface of northwest Alberta Abstract The entire Late Jurassic­Early Cretaceous stratal

235

Arctic and offshore research. Technology status report  

SciTech Connect

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.

Not Available

1985-10-01

236

Structure, stratigraphy, and hydrocarbons offshore southern Kalimantan, Indonesia  

SciTech Connect

Offshore southern Kalimantan (Borneo), Indonesia, the Sunda Shelf is bounded on the south by the east-west-trending Java-Madura foreland basin and on the north by outcrops of the granitic core of Kalimantan. Major northeast-southwest-trending faults created a basin and ridge province which controlled sedimentation at least until early Miocene time. Just above the unconformity, the oldest pre-CD Limestone clastic strata are fluviatile and lacustrine, the remainder consisting largely of shallow-marine, calcareous shale with interbeds of fine-grained, quartzose sandstone. A flood of terrigenous detritus - Kudjung unit 3 - resulted from post-CD Limestone uplift, and is more widely distributed. Unit 3 consists largely of fluviatile sandstone interbedded with shale and mudstone, grading upward to marine clastics with a few thin limestones near the top. The resulting Kudjing unit 2 is largely a shallow-basinal deposit, comprising thin, micritic limestones interbedded with calcareous shale and mudstone. Infilling of the basins was nearly complete by the end of Kudjing unit 1 deposition. Eastern equivalents of Kudjing units 1 and 2 are known as the Berai limestone interval (comprising bank, reefal, basinal, and open-marine limestones, and marl). Of the three oil fields in the area, two are shut in, but one has produced nearly 100 million bbl. Gas shows were recorded in most wells of the area, but the maximum flow was 1.8 MMcf methane/day, although larger flows with high percentages of carbon dioxide and nitrogen were reported. Fine-grained clastic strata of unit 3 are continuous with those farther south, where geochemical data indicate good source and hydrocarbon-generating potential. Sandstones with reservoir capability are present in the clastic intervals, and several carbonate facies have sporadically developed porosity. A variety of structural and stratigraphic traps is present. 20 figures, 1 table.

Bishop, W.F.

1980-01-01

237

Structural and stratigraphic evolution of Shira Mountains, central Ucayali Basin, Peru?  

E-print Network

STRUCTURAL AND STRATIGRAPHIC EVOLUTION OF SHIRA MOUNTAINS, CENTRAL UCAYALI BASIN, PERÚ A Thesis by JAIME ORLANDO SANCHEZ ALVAREZ Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 2007 Major Subject: Geology STRUCTURAL AND STRATIGRAPHIC EVOLUTION OF SHIRA MOUNTAINS, CENTRAL UCAYALI BASIN, PERÚ A Thesis by JAIME ORLANDO SANCHEZ ALVAREZ Submitted...

Sanchez Alvarez, Jaime Orlando

2008-10-10

238

Hydrodynamic effect on oil accumulation in a stratigraphic trap, Kitty Field, Powder River Basin, Wyoming  

E-print Network

HYDRODYNAMIC EFFECT ON OIL ACCUMULATION IN A STRATIGRAPHIC TRAP, KITTY FIELD, POWDER RIVER BASIN, WYOMING A Thesis by GREGORY MARTIN LARBERG "I Submitted to the Graduate College of Texas A8M University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE August 1976 Major Subject: Geology HYDRODYNAMIC EFFECT ON OIL ACCUMULATION IN A STRATIGRAPHIC TRAP, KITTY FIELD, POWDER RIVER BASIN, WYOMING A Thesis by GREGORY MARTIN LARBERG Approved as to style...

Larberg, Gregory Martin

2012-06-07

239

Stratigraphic boundary problems: Permian and Triassic of West Pakistan. Edited by Bernhard Kummel and Curt Teichert  

E-print Network

encompass this bound- ary in marine facies. Unfortunately, such stratigraphic sections are ex- tremely rare and, until quite recently, detailed stratigraphic and paleonto- logic investigations were nonexistent. In a worldwide review the search... Member, Mianwali Formation, Salt Range, West Pakistan 177 Bernhard Kummel Early Triassic Marine Ostracodes from the Salt Range and Surghar Range, West Pakistan 193 I. G. Sohn Uppermost Permian and Lower Triassic Conodonts of the Salt Range and Trans...

1970-01-01

240

A revised stratigraphic framework for later Cenozoic sequences in the northeastern Mediterranean region  

Microsoft Academic Search

This study describes the lithostratigraphic character of mid-Cenozoic (Oligocene-Pliocene) sequences in different parts of the northeastern Mediterranean area and offers a detailed stratigraphic correlation for this region. The sequences concerned are drawn from the Camardi area (south-central Anatolia), the Adana Basin, the Misis Mountains and the Kyrenia Range (northern Cyprus) and the submerged Florence Rise (west of Cyprus). The stratigraphic

Cengiz Yetis; Gilbert Kelling; Sungu L. Gökçen; Francois Baroz

1995-01-01

241

A revised stratigraphic framework for Later Cenozoic sequences in the northeastern Mediterranean region  

Microsoft Academic Search

This study describes the lithostratigraphic character of mid-Cenozoic (Oligocene–Pliocene) sequences in different parts of the northeastern Mediterranean area and offers a detailed stratigraphic correlation for this region. The sequences concerned are drawn from the Camardi area (south–central Anatolia), the Adana Basin, the Misis Mountains and the Kyrenia Range (northern Cyprus) and the submerged Florence Rise (west of Cyprus). The stratigraphic

Cengiz Yetis; Gilbert Kelling; Sungu L. Gökçen; Francois Baroz

1995-01-01

242

Building a Local Stratigraphic Column: A research-based assignment for an introductory course  

NSDL National Science Digital Library

Students build a stratigraphic column for a pre-selected area through the compilation of a series of individual research projects. Students are required to conduct introductory field research as well as a literature search to become "experts" on a selected stratigraphic unit. In addition to a final report, students will present their information at an outcrop on an end-of-semester field trip.

Hargrave, Jennifer

243

Application of the boundary-element method to offshore cathodic protection modeling  

Microsoft Academic Search

This paper deals with the main aspects of the calculation of current and potential distributions and summarizes some results obtained on different systems using a computer program based on the boundary-element method. Model results are compared to literature data for well-known geometries, and to experimental data obtained both in laboratory testing with a suitable cell and infield testing on offshore

P. Cicognani; F. Gasparoni; B. Mazza; T. Pastore

1990-01-01

244

Sedimentary facies and stratigraphic architecture in coarse-grained deltas: Anatomy of the Cenozoic Camaná Formation, southern Peru (16°25?S to 17°15?S)  

NASA Astrophysics Data System (ADS)

In the external forearc of southern Peru (Arequipa region), the sedimentary facies and the stratigraphic architecture of the Cenozoic Camaná Formation are presented in the context of tectono-eustatic controls. The Camaná Formation is defined as ?500 m thick coarse-grained deltaic complex that accumulated in a fault-bounded elongated depression extending from the Coastal Cordillera in the east to the offshore Mollendo Basin in the west and likely up to the Peruvian Trench. Based on the analysis of facies associations, we propose a refined stratigraphic scheme of the Camaná Basin fill. The Camaná Formation was formerly divided into the Camaná “A” and Camaná “B” units (CamA and CamB, respectively). We reinterpret the stratigraphic position and the timing of the CamA to CamB boundary, and define three sub-units for CamA, i.e. sub-units A1, A2, and A3. Each depositional unit shows individual stacking patterns, which are linked with particular shoreline trajectories through time. Strata of A1 form the basal succession of the Camaná Formation and consist of distributary channels and mouth bars, unconformably overlain by beds of A2. A2 consists of delta front deposits arranged in voluminous clinothems that reflect a progradational downstepping complex. A3 consists of delta front sandstones to prodelta siltstones arranged in retrogradational onlapping geometry. A pebbly intercalation in proximal onlapping A3 deposits is interpreted to reflect pulses of uplift in the hinterland. The overlying CamB unit is characterized by a thick alternation of fluvio-deltaic conglomerates and sand bars. The ages of the individual units of the Camaná Formation are not yet well defined. Based on the available information and stratigraphic correlations we tentatively assign A1 to the Late Oligocene, A2 to the Early Miocene, A3 to the late Early Miocene to early Middle Miocene, and CamB to the Late Miocene to? early Pliocene. The sub-units A1 and A2 represent a regressive systems tract, where the shoreline was forced to migrate seaward. This scenario differs from the Early Miocene eustatic sea-level rise suggesting that significant tectonic uplift along the Coastal Cordillera controlled the high sediment influx during A2 deposition. The sub-unit A3 represents a transgressive systems tract, triggering landward migration of the shoreline. This scenario is well in line with the global sea-level chart suggesting that A3 has been deposited during a phase of eustatic sea-level rise with minor tectonic activity. The fluvial deposits of CamB reflect an increased sediment flux due to uplift of the hinterland. The observed stratigraphic patterns support predominant tectonic control on sedimentation in the Camaná Basin and the established stratigraphic framework provides an essential baseline for future correlations of the Cenozoic sedimentation in the forearc area of the Central Andes.

Alván, Aldo; von Eynatten, Hilmar

2014-10-01

245

78 FR 43003 - Proposed Collection; Comment Request on Information Collection Tools Relating to the Offshore...  

Federal Register 2010, 2011, 2012, 2013

...Relating to the Offshore Voluntary Disclosure Program (OVDP) AGENCY...comments concerning the Offshore Voluntary Disclosure Program (OVDP). DATES...requirements: Title: Offshore Voluntary Disclosure Program (OVDP). OMB...

2013-07-18

246

Concerted Action for Offshore Wind Energy Deployment (COD): Grid Integration of Offshore Wind Farms  

Microsoft Academic Search

The objective of the European Concerted Action on Offshore Wind Energy Deployment (COD) is to speed up the responsible deployment of offshore wind energy in the EU by early identification and possibly to remove not explicitly technical barriers: legal, administrative, policy, environmental and grid infrastructure planning issues. The COD is carried out by eight sea- bordering member states, represented by

Achim Woyte; Helen Snodin; Paul Gardner; Ruud de Bruijne

247

Offshore remobilization processes and deposits in low-energy temperate-water carbonate-ramp systems: Examples from the Neogene basins of the Betic Cordillera (SE Spain)  

NASA Astrophysics Data System (ADS)

General facies models developed for modern and ancient Mediterranean temperate-water carbonates in the last two decades have shown that the style of deposition on outer-ramp, slope, and basin environments in low-energy areas such as the Mediterranean Sea differs overall from that of high-energy open-ocean areas, given the wider variety of smaller-scale topographic and hydrodynamic conditions in the former setting. However, these depositional models generally lack relevant information about sedimentary processes, transport mechanisms and controlling factors on offshore sediment redeposition, which are potential sources of information for sequence stratigraphic, palaeoclimate and exploration studies. Several examples from the Neogene Betic basins of the western Mediterranean region have been selected to integrate the processes and controlling factors on the offshore sediment transport and the resulting deposits. Additional published data from other Mediterranean localities have also been considered.

Puga-Bernabéu, Ángel; Martín, José M.; Braga, Juan C.; Aguirre, Julio

2014-05-01

248

Sanaga Sud field - Offshore Cameroon, west Africa  

SciTech Connect

The Sanaga Sud field, offshore Cameroon, is located just northwest of the coastal town of Kribi in the northern part of the Douala basin. The discovery well, Sanaga Sud A-1, was drilled in 1979 to test an apparent horst block that contained a prominent horizontal seismic amplitude. The Douala basin is one of a series of passive margin basins located along the coastline of central and southern Africa, and formed during the rifting of Africa and South America during the Early Cretaceous. Drilling results showed that the amplitude was a gas/water contact. Two appraisal wells, SSA-2 and SSA-3, were drilled in 1981. All three wells tested gas and condensate. Total recoverable hydrocarbons for the field are estimated to be approximately 1 tcf of gas. The trap in this field is composed of tilted and rotated fault blocks composed of interbedded Aptian to Albian sandstones, siltstones, and shales. The fault blocks were truncated by erosion (breakup unconformity) and later buried by a considerable thickness of onlapping Upper Cretaceous and Tertiary shale. The late Albian erosional unconformity forms the top of the trap over most of the field. Geochemical studies indicate a Lower Cretaceous source for the hydrocarbons. The gross pay thickness averages 250 m with an average porosity of 23% and an average permeability of 142 md. Reservoir lithologies range from well-sorted, massive sandstones to poorly sorted fine sandstones and siltstones containing shaly laminations that are carbonaceous and micaceous. The field is located predominantly in Block PH-38, but part of the field is in the Londji concession. Mobil Producing Cameroon, Inc., is the operator of PH-38 and Total Exploration and Production Cameroon is the operator of the Londji concession.

Pauken, R.J. (Mobil New Exploration Ventures Co., Dallas, TX (USA))

1990-09-01

249

Offshore oil gas trends in ROVs tooling  

SciTech Connect

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.

Jacobson, J.R. (Perry Tritech Inc., Jupiter, FL (United States))

1994-04-01

250

Beaufortian stratigraphic plays in the National Petroleum Reserve - Alaska (NPRA)  

USGS Publications Warehouse

The Beaufortian megasequence in the National Petroleum Reserve in Alaska (NPRA) includes Jurassic through lower Cretaceous (Neocomian) strata of the Kingak Shale and the overlying pebble shale unit. These strata are part of a composite total petroleum system involving hydrocarbons expelled from source rocks in three stratigraphic intervals, the Lower Jurassic part of the Kingak Shale, the Triassic Shublik Formation, and the Lower Cretaceous gamma-ray zone (GRZ) and associated strata. The potential for undiscovered oil and gas resources in the Beaufortian megasequence in NPRA was assessed by defining eight plays (assessment units), two in lower Cretaceous (Neocomian) topset seismic facies, four in Upper Jurassic topset seismic facies, one in Lower Jurassic topset seismic facies, and one in Jurassic through lower Cretaceous (Neocomian) clinoform seismic facies. The Beaufortian Cretaceous Topset North Play is estimated to contain between 0 (95-percent probability) and 239 (5-percent probability) million barrels of technically recoverable oil, with a mean (expected value) of 103 million barrels. The Beaufortian Cretaceous Topset North Play is estimated to contain between 0 (95-percent probability) and 1,162 (5-percent probability) billion cubic feet of technically recoverable, nonassociated natural gas, with a mean (expected value) of 405 billion cubic feet. The Beaufortian Cretaceous Topset South Play is estimated to contain between 635 (95-percent probability) and 4,004 (5-percent probability) billion cubic feet of technically recoverable, nonassociated natural gas, with a mean (expected value) of 2,130 billion cubic feet. No technically recoverable oil is assessed in the Beaufortian Cretaceous Topset South Play, as it lies at depths that are entirely in the gas window. The Beaufortian Upper Jurassic Topset Northeast Play is estimated to contain between 2,744 (95-percent probability) and 8,086 (5-percent probability) million barrels of technically recoverable oil, with a mean (expected value) of 5,176 million barrels. No technically recoverable gas is assessed in the Beaufortian Upper Jurassic Topset Northeast Play. The Beaufortian Upper Jurassic Topset Northwest Play is estimated to contain between 733 (95-percent probability) and 3,312 (5-percent probability) million barrels of technically recoverable oil, with a mean (expected value) of 1,859 million barrels. No technically recoverable gas is assessed in the Beaufortian Upper Jurassic Topset Northwest Play. The Beaufortian Upper Jurassic Topset Southeast Play is estimated to contain between 2,053 (95-percent probability) and 9,030 (5-percent probability) billion cubic feet of technically recoverable, nonassociated natural gas, with a mean (expected value) of 5,137 billion cubic feet. No technically recoverable oil is assessed in the Beaufortian Upper Jurassic Topset Southeast Play, as it lies at depths that are entirely in the gas window. The Beaufortian Upper Jurassic Topset Southwest Play is estimated to contain between 2,008 (95-percent probability) and 9,265 (5-percent probability) billion cubic feet of technically recoverable, nonassociated natural gas, with a mean (expected value) of 5,220 billion cubic feet. No technically recoverable oil is assessed in the Beaufortian Upper Jurassic Topset Southwest Play, as it lies at depths that are entirely in the gas window. The Beaufortian Lower Jurassic Topset Play is estimated to contain between 0 (95-percent probability) and 210 (5-percent probability) million barrels of technically recoverable oil, with a mean (expected value) of 83 million barrels. The Beaufortian Lower Jurassic Topset Play is estimated to contain between 0 (95-percent probability) and 1,915 (5-percent probability) billion cubic feet of technically recoverable, nonassociated natural gas, with a mean (expected value) of 793 billion cubic feet. The Beaufortian Clinoform Play is estimated to contain between 0 (95-percent probability)

Houseknecht, David W.

2003-01-01

251

10 CFR 150.7 - Persons in offshore waters not exempt.  

...2014-01-01 false Persons in offshore waters not exempt. 150.7 Section 150...IN AGREEMENT STATES AND IN OFFSHORE WATERS UNDER SECTION 274 Continued Commission Regulatory Authority in Offshore Waters § 150.7 Persons in offshore...

2014-01-01

252

Solar power satellite offshore rectenna study  

NASA Technical Reports Server (NTRS)

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.

1980-01-01

253

Current and future offshore activities in Canada  

SciTech Connect

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.

Hnatiuk, J.

1984-05-01

254

Investigation on installation of offshore wind turbines  

NASA Astrophysics Data System (ADS)

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

Wang, Wei; Bai, Yong

2010-06-01

255

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

SciTech Connect

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.

Francois, D.K.

1994-12-31

256

Improving offshore communication by choosing the right coordination  

E-print Network

, organizational, and stakeholder distances influence negatively the communication and knowledge exchangeImproving offshore communication by choosing the right coordination strategy Matthias Fabriek;Improving offshore communication by choosing the right coordination strategy Page 2 of 92 ABSTRACT

Utrecht, Universiteit

257

FEED-IN TARIFFS AND OFFSHORE WIND POWER DEVELOPMENT  

E-print Network

FEED-IN TARIFFS AND OFFSHORE WIND POWER DEVELOPMENT Prepared by Jon Lilley, Blaise Sheridan, Dawn........................................................................................................................ 28 #12; 3 Feed-in Tariffs and Offshore Wind Power Development Prepared Pursuant to DOE Grant Em

Firestone, Jeremy

258

75 FR 30845 - National Offshore Safety Advisory Committee  

Federal Register 2010, 2011, 2012, 2013

...Guard [USCG-2010-0453] National Offshore Safety Advisory Committee AGENCY: Coast...teleconference meeting of the National Offshore Safety Advisory Committee (NOSAC) to...June 17, 2010. Written material for distribution to Committee members should reach...

2010-06-02

259

FBG sensors for the measurement of the dynamic response of offshore oil platform model  

NASA Astrophysics Data System (ADS)

The dynamic response of offshore oil platform under seismic excitation is the coupling response of liquid and solid vibration. In recent years, the computation of dynamic responses and design of offshore platform have attracted the attention of many researchers. This paper presents a shaking table test of offshore oil platform model scaled down an actual one. Fiber Bragg grating is a new measurement technology with its superior ability of explosion proof, immunity to electromagnetic interference and high accuracy. In this paper, FBG sensors are used to monitor the dynamic response of offshore oil platform model on line. Ten FBG sensors are installed, one of which is temperature sensor, two of which are acceleration sensors and the others of which are strain sensors. One FBG accelerometer is placed on the surface of the shaking table; and another one is placed on the top surface of the offshore oil platform model. FBG strain sensors are placed on the key parts of the platform model. Some traditional strain gauges are installed in parallel with FBG strain sensors. In this experiment, electromagnetic interference of strain gauge is very big, while the FBG strain sensor has not this phenomenon. Based on the experiments results, it can be concluded that FBG sensor is superior to strain gauge.

Sun, Li; Li, Hongnan; Jin, Qiao

2005-05-01

260

3D stratigraphic forward modelling of Shu'aiba Platform stratigraphy in the Bu Hasa Field, Abu Dhabi, United Arab Emirates.  

NASA Astrophysics Data System (ADS)

This paper presents the results of three dimensional sequence stratigraphic forward modelling of the Aptian age Shu'aiba Formation from Abu Dhabi, United Arab Emirates (UAE). The Shu'aiba Formation lies within the uppermost part of the Lower Cretaceous Thamama Group and forms one of the most prolific hydrocarbon reservoir intervals of the Middle East with production dating back to the 1960's. The Shu'aiba Formation developed as a series of laterally-extensive shallow-water carbonate platforms in an epeiric sea that extended over the northern margin of the African-Arabian Plate. This shallow sea was bounded by the Arabian Shield to the west and the passive margin with the Neo-Tethys Ocean towards the north and east (Droste, 2010). The exposed Arabian Shield acted as a source of siliciclastic sediments to westernmost regions, however, more offshore areas were dominated by shallow-water carbonate deposition. Carbonate production was variously dominated by Lithocodium-Baccinella, orbitolinid foraminifera and rudist bivalves depending on local conditions. While there have been numerous studies of this important stratigraphic interval (for examples see van Buchem et al., 2010), there has been little attempt to simulate the sequence stratigraphic development of the formation. During the present study modelling was undertaken utilising the CARBONATE-3D stratigraphic forward modelling software (Warrlich et al., 2008; Warrlich et al., 2002)) thus allowing for the control of a diverse range of internal and external parameters on carbonate sequence development. This study focuses on platform development in the onshore Bu Hasa Field - the first giant oilfield to produce from the Shu'aiba Formation in Abu Dhabi. The carbonates of the Bu Hasa field were deposited on the southwest slope of the intra-shelf Bab Basin, siliciclastic content is minor. Initially these carbonates were algal dominated with rudist mounds becoming increasingly important over time (Alsharhan, 1987). Numerous simulations were undertaken, employing different sea level curves, platform geometries, etc. in order to accurately constrain and compare simulated facies geometries with those hypothesised from subsurface correlations. An initial low-angle ramp geometry was later overprinted by the development of localised relief through faulting and salt diapirism. Areas of bathymetric relief became sites of enhanced carbonate development with over-production resulting in aggradational geometries rapidly evolving to progradational systems. Several different regional, global and composite relative sea level curves were employed in the simulations in order to produce stratigraphic geometries comparable to those reported from previous studies. We conclude that none of the published sea level curves produce facies geometries directly analogous to those hypothesised from the sub-surface. We infer that this disparity primarily results from previous models lacking sufficient accommodation space and employing unrealistic carbonate production rates.

Hu, J.; Lokier, S. W.

2012-04-01

261

Offshore Wind Farm Layout Optimization (OWFLO) Project: Preliminary Results  

Microsoft Academic Search

Optimizing the layout of an offshore wind farm presents a significant engineering challenge. Most of the optimization literature to date has focused on land-based wind farms, rather than on offshore farms. Typically, energy production is the metric by which a candidate layout is evaluated. The Offshore Wind Farm Layout Optimization (OWFLO) project instead uses the levelized production cost as the

Christopher N. Elkinton; James F. Manwell; Jon G. McGowan

262

Offshore wind energy systems for the U.K  

Microsoft Academic Search

Some of the more important factors affecting the design of offshore wind energy systems are discussed. It is shown that power densities in offshore winds are attractively high, of the order of 300 kW\\/linear meter (perpendicular to the wind direction). The economics of offshore operation strongly favors the use of large wind turbines (about 100 m diameter) and a low

P. J. Musgrove

1979-01-01

263

Method and apparatus for positioning an offshore platform jacket  

Microsoft Academic Search

A method is described of positioning an offshore platform jacket comprising the steps of: loading and securing the platform jacket onto a tension leg barge; towing the tension leg barge to a predetermined offshore location; laying anchors on the floor of the ocean at the predetermined offshore location; attaching lines between the anchors and the tension leg barge to position

Oksuzler

1987-01-01

264

POWER - A METHODOLOGY FOR PREDICTING OFFSHORE WIND ENERGY RESOURCES  

Microsoft Academic Search

An accurate estimate of the long-term wind speed is essential to site an offshore wind farm effectively. Unfortunately measured wind speed data at potential offshore wind farm sites are currently sparse. A major European Commission funded project called 'Predicting Offshore Wind Energy Resources\\

G M Watson; J A Halliday; J P Palutikof; T Holt; R J Barthelmie; J P Coelingh; L Folkerts; G F M Wiegerinck; E J van Zuylen; J W Cleijne; G C S Hommel

265

Offshore Series Wind Turbine Variable Hub heights & rotor diameters  

E-print Network

3.6MW Offshore Series Wind Turbine GE Energy #12;Feature Variable Hub heights & rotor diameters harmonious function within the local grid Allows wind turbines to stay on line generating power, even during-savings feature, considering the rigors of offshore power generation. The 3.6 MW offshore wind turbine also

Firestone, Jeremy

266

Risk-based inspection planning optimisation of offshore wind turbines  

Microsoft Academic Search

Wind industry is substantially propelled and the future scenarios designate offshore locations as important sites for energy production. With this development, offshore wind farms represent a feasible option to accomplish the needed energy, bringing with it technical and economical challenges. Inspection and maintenance (I&M) costs for offshore sites are much larger than for onshore ones, making the choice of suitable

José G. Rangel-Ramírez; John D. Sørensen

2010-01-01

267

Seabed instability simplified model and application in offshore wind turbine  

Microsoft Academic Search

The offshore wind power is increasingly developed, it is essential to study the design technology of the offshore wind turbine foundation, which is crucial to reduce the construction cost of the offshore wind farm. In the design of marine pile foundations, the evaluation of wave-induced seabed stability is quite significant. Based on the mechanical properties of seabed, this article firstly

Zhang Yong-li; Li Jie

2009-01-01

268

Risk-based inspection planning optimisation of offshore wind turbines  

Microsoft Academic Search

Wind industry is substantially propelled and the future scenarios designate offshore locations as important sites for energy production. With this development, offshore wind farms represent a feasible option to accomplish the needed energy, bringing with it technical and economical challenges. Inspection and maintenance (I&M) costs for offshore sites are much larger than for onshore ones, making the choice of suitable

José G. Rangel-Ramírez; John D. Sørensen

2012-01-01

269

ForPeerReview PUBLIC ACCEPTANCE OF OFFSHORE WIND POWER  

E-print Network

ForPeerReview PUBLIC ACCEPTANCE OF OFFSHORE WIND POWER PROJECTS IN THE UNITED STATES Journal: Wind, Andrew; Minerals Management Service Keywords: offshore wind power, public opinion, social acceptancePeerReview 1 PUBLIC ACCEPTANCE OF OFFSHORE WIND POWER PROJECTS IN THE UNITED STATES Jeremy Firestone*, Willett

Firestone, Jeremy

270

Are offshore power plants realistic. [Alternative to nuclear power plants  

Microsoft Academic Search

Offshore fossil-fueled electric power plants offer a positive alternative to nuclear proliferation, a viable technology for providing electricity to coastal cities. Such plants combine new technology from the offshore oil industry with efficient power generation techniques, are cheaper than nuclear plants, and could burn coal or solid waste or a mixture of both. Offshore power plants could utilize ocean water

Adler

1976-01-01

271

Evolution and Reduction of Scour around Offshore Wind Turbines  

Microsoft Academic Search

Evolution and Reduction of Scour around Offshore Wind Turbines In response to growing socio-economic and environmental demands, electricity generation through offshore wind turbine farms is a fast growing sector of the renewable energy market. Considerable numbers of offshore wind farms exist in the shallow continental shelf seas of the North-West Europe, with many more in the planning stages. Wind energy

David McGovern; Suzana Ilic

2010-01-01

272

76 FR 3919 - National Offshore Safety Advisory Committee  

Federal Register 2010, 2011, 2012, 2013

...affecting the oil and gas offshore industry. The purpose of...other concerns affecting the offshore oil and gas industry and assists...recommendations for standards for Offshore Supply Vessels with an International...2011. Written material for distribution to Committee members...

2011-01-21

273

75 FR 80064 - National Offshore Safety Advisory Committee  

Federal Register 2010, 2011, 2012, 2013

...affecting the oil and gas offshore industry. The purpose of...other concerns affecting the offshore oil and gas industry and assists...recommendations for standards for Offshore Supply Vessels with a gross...2011. Written material for distribution to Committee members...

2010-12-21

274

Offshore Aquaculture: The Frontier of Redefining Oceanic Property  

Microsoft Academic Search

Over the past decade, offshore aquaculture has gained significant momentum as a global and, in particular, a U.S. seafood development strategy. Issues surrounding property rights, environmental impacts, and the social desirability of offshore aquaculture are inadequately addressed by policymakers and aquaculture specialists. This review essay describes offshore aquaculture's place in the development of industrial fish farming and the policy issues

Michael Skladany; Rebecca Clausen; Ben Belton

2007-01-01

275

Stratigraphic framework and petroleum potential of Northeastern Baltimore Canyon Trough, Mid-Atlantic Outer Continental Shelf  

SciTech Connect

Geologic data from 29 wells in the Baltimore Canyon Trough were released to the public as of 1982, and provide sufficient information for establishing Upper Jurassic through Cenozoic rock-stratigraphic units. The oldest rocks penetrated by exploratory wells are of Late Jurassic age and are correlative to the Scotian Shelf Mohawk, Mic Mac, and Abenaki Formations. The Mohawk(.) sandstone and Mic Mac shale equivalents in the Baltimore Canyon Trough represent lower delta plain to predominantly prodelta environments, and the Abenaki-equivalent limestone represents a shelfmargin carbonate buildup. A destructional phase of the delta is represented by the Naskapi equivalents a calcareous shale. Stratigraphic traps may be present in the Baltimore Canyon Trough Upper Jurassic and Lower Cretaceous deltaic sandstones and shelf-margin carbonates. The deltaic units contain channel and distributary-mouth-bar sandstones, which may be potential reservoirs. The Abenaki stratigraphic-reef trend provides another potential target.

Libby-French, J.

1984-01-01

276

Stratigraphic relations and hydrologic properties of the Paintbrush Tuff (PTn) hydrologic unit, Yucca Mountain, Nevada  

SciTech Connect

Yucca Mountain is being investigated as a potential site for a high- level nuclear waste repository. The intent of this study was to clarify stratigraphic relations within the Paintbrush Tuff (PTn) unit at Yucca Mountain in order to better understand vertical and lateral variations in hydrologic properties as they relate to the lithologic character of these rocks. This report defines informal stratigraphic units within the PTn interval, demonstrates their lateral continuity in the Yucca Mountain region, describes later and vertical variations within them, and characterizes their hydrologic properties and importance to numerical flow and transport models. We present tables summarizing the depth to stratigraphic contacts in cored borehole studies, and unit descriptions and correlations in 10 measured sections.

Moyer, T.C.; Geslin, J.K. [Science Applications International Corp., Golden, CO (United States); Flint, L.E. [U.S. Geological Survey, Yucca Mountain Project, Mercury, NV (United States)

1996-08-01

277

Probability distributions of wave heights in bimodal seas in an offshore basin  

Microsoft Academic Search

This study aims at assessing the adequacy for describing bimodal sea states of different non-linear probability distributions that have been developed for single sea states. It is based on data collected at an offshore test basin. The measurements represent three bimodal sea states with individual unidirectional wave systems propagating at 60?, 90? and 120? from each other. The wave spectra

Petya G. Petrova; C. Guedes Soares

2009-01-01

278

Stratigraphic evidence from the Appalachian Basin for continuation of the Taconian orogeny into Early Silurian time  

NASA Astrophysics Data System (ADS)

Traditional interpretations of the Appalachian Basin during Silurian time suggest a period of tectonic stability between Taconian and Acadian orogenies. However, recent interpretations of evidence from deformation and igneous sources in the northern Appalachians indicate Silurian tectonism centered on and near the St. Lawrence promontory and that this tectonism probably effected sedimentation in parts of the Appalachian Basin during much of Silurian time. Of special interest is the tectonism that extended from latest Ordovician into Early Silurian time and the nature of its relationships with known orogenic events. Although evidence and interpretations from deformation and igneous sources have become increasingly well established, there has been little support from the stratigraphic record. Now, however, criteria based on the implications of flexural models, namely the nature and distribution of unconformities, the presence of flexural stratigraphic sequences, and the distribution in time and space of dark-shale-filled foreland basins, provide stratigraphic evidence from the Appalachian Basin that supports Early Silurian (Medinan; early Llandoverian) tectonism related to Taconian orogeny. In particular, the distribution and local angularity of the Ordovician-Silurian or Cherokee unconformity suggest major tectonic influence and a latest Ordovician to Early Silurian inception for that tectonism. An overlying flexural stratigraphic sequence represented by the Lower Silurian Medina Group and the presence of a dark-shale-filled foreland basin reflected by the Power Glen-lower Cabot Head shales support interpretations of flexural subsidence related to deformational loading. Moreover, the distribution in space and time of the foreland basin containing these shales indicates that the basin is more likely a continuation of the northwestwardly shifting trend of earlier Taconian basins than that of later Salinic basins. Although the kinematic regime may be different from that of earlier Taconian tectophases, the stratigraphic evidence supports a northeastward extension of the Taconian orogeny into present-day eastern Canada during Early Silurian time and illustrates the usefulness of flexure-based stratigraphic interpretations in understanding the timing and extent of some orogenies.

Ettensohn, Frank R.; Brett, Carlton E.

2002-01-01

279

A simple high-precision Jacob's staff design for the high-resolution stratigrapher  

USGS Publications Warehouse

The new generation of high-resolution stratigraphic research depends upon detailed bed-by-bed analysis to enhance regional correlation potential. The standard Jacob's staff is not an efficient and precise tool for measuring thin-bedded strata. The high-precision Jacob's staff design presented and illustrated in this paper meets the qualifications required of such an instrument. The prototype of this simple design consists of a sliding bracket that holds a Brunton-type compass at right angles to a ruled-off staff. This instrument provides rapid and accurate measurement of both thick- or thin-bedded sequences, thus decreasing field time and increasing stratigraphic precision. -Author

Elder, W.P.

1989-01-01

280

CABFAC/USGS, a FORTRAN program for Q-mode factor analysis of stratigraphically ordered samples  

USGS Publications Warehouse

This program is a revision of the CABFAC program of Kovan and Imbrie (1971) which incorporates the following improvements: each factor is plotted against depth on the printer; samples are ordered stratigraphically by the program, so that input data need not be ordered stratigraphically; an option has been added to transform all variables to zero means before calculating the cosine-theta matrix; and all subroutines are variable-dimensioned, so that the size of .the program may be changed by simply altering the main program.

Adams, David P.

1976-01-01

281

Highwave off-shore energy hose  

Microsoft Academic Search

Many inshore wave energy collectors (WEC) concepts use wave energy to push water ashore to process it for energy conversion with turbines. An artificial reef design of floating HPDE pipe can be built in a harbor and installed offshore of the breaking waves in the near shore. The portable reef designed to mitigate shore erosion can serve as the shuttle

Gary Ross; A. Michael Weaver; Chris O'Connor

2011-01-01

282

Offshore Wind Power Farm Environmental Impact Assessment  

E-print Network

Horns Rev Offshore Wind Power Farm Environmental Impact Assessment on Water Quality #12;Prepared Design ApS 04.05.2000 #12;Bio/consult Side 3 Horns Rev. Environmental Impact Assessment. Water Quality ................................................................................................................................. 12 4.2. WATER QUALITY

283

Risk analysis for Arctic offshore operations  

SciTech Connect

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.

Slomski, S.; Vivatrat, V.

1986-04-01

284

Barge hull for offshore drilling rigs  

Microsoft Academic Search

An improved barge hull for offshore drilling rigs is disclosed. The invention comprises a channel in the bottom of a barge hull extending from the bottom of said barge hull to the back of said barge hull for directing the flow of water under said barge hull to the back of said barge hull in order to disrupt the relative

1984-01-01

285

Large enigmatic crater structures offshore southern California  

Microsoft Academic Search

Digital mosaics of swath and conventional bathymetry data reveal large, distinct near-circular crater structures in the Inner Continental Borderland offshore southern California. Two have maximum crater diameters that exceed 30 km and a third has a crater diameter of approximately 12 km. All three features exhibit the morphology of large complex craters (raised outer rim, ring moat and central uplift)

Mark R. Legg; Craig Nicholson; Chris Goldfinger; Randall Milstein; Marc J. Kamerling

2004-01-01

286

Solar power satellite offshore rectenna study  

NASA Technical Reports Server (NTRS)

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.

1980-01-01

287

Competitive Bidding for Offshore Petroleum Leases  

Microsoft Academic Search

This paper develops a formal model of competitive bidding to analyze some aspects of the federal offshore oil leasing system. The lease sales of interest are often characterized by small numbers of auction participants and by high levels of uncertainty regarding the true values of the leases offered. The model suggests that these circumstances may lead to the capture of

Douglas K. Reece

1978-01-01

288

Offshore oil and gas pipeline technology  

Microsoft Academic Search

This volume is a ''total-systems'' approach to offshore pipeline design, operation, and maintenance. The volume comprises 17 contributed sections reviewing the most important developments in the field over the last few years. The contributors are all internationally recognized experts, and the papers present a broad yet complete review of all aspects of pipeline integrity. Although each topic is treated in

Mare

1985-01-01

289

Wave Models for Offshore Wind Turbines  

Microsoft Academic Search

In the design of wind turbines—onshore or offshore—the prediction of extreme loads as- sociated with a target (long) return period requires statistical extrapolation from available loads data. The data required for such extrapolation are obtained by stochastic time- domain simulation of the inflow turbulence and of the turbine response. Prediction of accurate loads depends on assumptions made in the simulation

Puneet Agarwal; Lance Manuely

2008-01-01

290

Agile methods handling offshore software development issues  

Microsoft Academic Search

Agile methods have emerged as a new set of software development processes and practices, that cater requirements change by delivering the software in multiple small releases, increasing the client confidence and enables him\\/her to communicate the business requirements change at higher pace. On the other hand, technology world is switching to offshore software development rapidly due to global economic reasons.

M. F. Nisar; Tahir Hameed

2004-01-01

291

Offshore wind resource assessment through satellite images  

E-print Network

, Morten Nielsen, Sara Pryor Wind Energy Department European Geosciences Union (EGU) Nice, France, 25 angle Coefficients depend on radar incidence angle and wind speed OCEAN SEA BOTTOM CMOD4 Stoffelen et al1 Slide no. 4 Offshore wind resource assessment through satellite images Charlotte Bay Hasager

292

Human Rights, Academic Freedom, and Offshore Academics  

ERIC Educational Resources Information Center

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 markets"; and (3)…

Ross, Andrew

2011-01-01

293

Arctic offshore oil and gas technology  

SciTech Connect

This technical background briefing report is intended to assist in planning engineering research oriented toward Arctic offshore oil and gas recovery. The current five-year leasing schedule for the ice-prone waters of the Arctic offshore has been illustrated in Figure E-1. In Figure E-2 and Table I, the estimated reserves for these areas are given, based on National Petroleum Council estimates (December 1981). In view of the world petroleum situation since 1973, the probability of successful exploration and production from some areas of the Arctic offshore, at some time in the foreseeable future, is very high. The flow chart in Figure E-3 relates the special Arctic factors, such as ice and permafrost, to the normal petroleum production sequence. Other current technological frontiers are identified in the final section of this report. All of the subjects mentioned there should be advanced, to extract Arctic offshore oil and gas in an optimized and economic manner. Fortunately, the required technology is within reach. With the coordinated efforts of industry and government, and the allocation of sufficient resources in a timely manner, all of these technical advances can be accomplished in the decade ahead. 231 references, 134 figures, 1 table.

Sackinger, W.M.

1982-11-01

294

Offshore Investments by Colleges Draw Scrutiny  

ERIC Educational Resources Information Center

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…

Fain, Paul; Wolverton, Brad

2007-01-01

295

Sea loads on ships and offshore structures  

Microsoft Academic Search

The book introduces the theory of the structural loading on ships and offshore structures caused by wind, waves and currents, and goes on to describe the applications of this theory in terms of real structures. The main topics described are linear-wave induced motions, loads on floating structures, numerical methods for ascertaining wave induced motions and loads, viscous wave loads and

O. M. Faltinsen

1990-01-01

296

Probability distributions for offshore wind speeds  

Microsoft Academic Search

In planning offshore wind farms, short-term wind speeds play a central role in estimating various engineering parameters, such as power output, extreme wind load, and fatigue load. Lacking wind speed time series of sufficient length, the probability distribution of wind speed serves as the primary substitute for data when estimating design parameters. It is common practice to model short-term wind

Eugene C. Morgan; Matthew Lackner; Richard M. Vogel; Laurie G. Baise

2011-01-01

297

Offshore mussel aquaculture: new or just renewed?  

Microsoft Academic Search

The increase on the demand for marine products and the decrease of the wild marine population has led to the culturing of several marine species. Within the molluscs the mussel is the second largest product by volume of marine aquaculture. Mussels are an ideal species for culture in the open ocean, referred to as offshore aquaculture. Several different systems are

T. Lado-Insua; F. J. Ocampo; K. Moran

2009-01-01

298

Gas Production From a Cold, Stratigraphically Bounded Hydrate Deposit at the Mount Elbert Site, North Slope, Alaska  

SciTech Connect

As part of an effort to identify suitable targets for a planned long-term field test, we investigate by means of numerical simulation the gas production potential from unit D, a stratigraphically bounded (Class 3) permafrost-associated hydrate occurrence penetrated in the ount Elbert well on North Slope, Alaska. This shallow, low-pressure deposit has high porosities, high intrinsic permeabilities and high hydrate saturations. It has a low temperature because of its proximity to the overlying permafrost. The simulation results indicate that vertical ells operating at a constant bottomhole pressure would produce at very low rates for a very long period. Horizontal wells increase gas production by almost two orders of magnitude, but production remains low. Sensitivity analysis indicates that the initial deposit temperature is y the far the most important factor determining production performance (and the most effective criterion for target selection) because it controls the sensible heat available to fuel dissociation.

Moridis, G.J.; Silpngarmlert, S.; Reagan, M. T.; Collett, T.S.; Zhang, K.

2009-09-01

299

Comparative structural reconstruction of the post-breakup succession in conjugated salt and salt-free basins offshore South-America and South-Africa  

NASA Astrophysics Data System (ADS)

This project focuses on the post-breakup tectono-stratigraphic development of large offshore basins along the South American and African continental margins that record strongly varying post-rift sedimentary successions. The northernmost segment of the South Atlantic rift and salt basins is characterized by a pronounced asymmetry, with the Brazilian margin comprising narrower and deeper rift basins with less salt in comparison to the Congo-Gabon conjugate margin. Another important observation is that multiple phases of uplift and subsidence are recorded after the break-up of the southern South Atlantic on both sides of the Florianopolis-Walvis Ridge volcanic complex, features that are regarded as atypical when compared to published examples of other post-breakup margin successions. In this study we show a regional comparison between the large basins offshore southern Brazil (Espirito Santo Basin, Campos Basin, Santos Basin, Pelotas Basin) and southwest Africa (Lower Congo Basin, Kwanza Basin, Namibe Basin, Walvis Basin, etc). A sequential reconstruction of tectonic and stratigraphic elements of representative geological transects provides a comprehensive basin-to-basin documentation of the influence of key geological parameters controlling ocean and continental margin development. These include the subsidence development through time, sediment input, flux and storage patterns, salt vs. non-salt systems, carbonate-rich vs. clastics-dominated successions and finally major tectonic and magmatic events. Data from the salt basins indicate that salt-related tectonic deformation is amongst the prime controls for the non-uniform post-rift margin development.

Strozyk, Frank; Back, Stefan; Kukla, Peter

2013-04-01

300

Mapping Seabird Sensitivity to Offshore Wind Farms  

PubMed Central

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

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

2014-01-01

301

North Blowhorn Creek oil field - a stratigraphic trap in Black Warrior basin of Alabama  

Microsoft Academic Search

The Black Warrior basin of northwestern Alabama contains shallow oil and gas prospects. To date more than 1000 wells have been drilled in the region and more than 90 petroleum fields and pools have been discovered. Mississippian sandstone reservoirs are the most productive horizons for hydrocarbons in the basin, and the Carter sandstone is the most prolific. Identification of stratigraphic

B. L. Bearden; E. A. Mancini; P. R. Reeves

1984-01-01

302

Stratigraphic framework and petroleum potential of northeastern Baltimore Canyon Trough, mid-Atlantic outer Continental Shelf  

Microsoft Academic Search

Geologic data from 29 wells in the Baltimore Canyon Trough were released to the public as of 1982, and provide sufficient information for establishing Upper Jurasic through Cenozoic rock-stratigraphic units. Most of the units are lithologically similar to formations on the Scotian Shelf and are, therefore, considered in this study to be the Scotian Shelf homotaxial equivalents. The Mohawk(.) sandstone

Libby-French

1984-01-01

303

Stratigraphic framework and petroleum potential of Northeastern Baltimore Canyon Trough, Mid-Atlantic Outer Continental Shelf  

Microsoft Academic Search

Geologic data from 29 wells in the Baltimore Canyon Trough were released to the public as of 1982, and provide sufficient information for establishing Upper Jurassic through Cenozoic rock-stratigraphic units. The oldest rocks penetrated by exploratory wells are of Late Jurassic age and are correlative to the Scotian Shelf Mohawk, Mic Mac, and Abenaki Formations. The Mohawk(.) sandstone and Mic

Libby-French

1984-01-01

304

Integration of the stratigraphic aspects of very large sea-floor databases using information processing  

USGS Publications Warehouse

Information-processing methods are described that integrate the stratigraphic aspects of large and diverse collections of sea-floor sample data. They efficiently convert common types of sea-floor data into database and GIS (geographical information system) tables, visual core logs, stratigraphic fence diagrams and sophisticated stratigraphic statistics. The input data are held in structured documents, essentially written core logs that are particularly efficient to create from raw input datasets. Techniques are described that permit efficient construction of regional databases consisting of hundreds of cores. The sedimentological observations in each core are located by their downhole depths (metres below sea floor - mbsf) and also by a verbal term that describes the sample 'situation' - a special fraction of the sediment or position in the core. The main processing creates a separate output event for each instance of top, bottom and situation, assigning top-base mbsf values from numeric or, where possible, from word-based relative locational information such as 'core catcher' in reference to sampler device, and recovery or penetration length. The processing outputs represent the sub-bottom as a sparse matrix of over 20 sediment properties of interest, such as grain size, porosity and colour. They can be plotted in a range of core-log programs including an in-built facility that better suits the requirements of sea-floor data. Finally, a suite of stratigraphic statistics are computed, including volumetric grades, overburdens, thicknesses and degrees of layering. ?? The Geological Society of London 2006.

Jenkins, C.; Flocks, J.; Kulp, M.

2006-01-01

305

Limitations on stratigraphic analyses due to incomplete age control and their relevance to sedimentary paleomagnetism  

Microsoft Academic Search

A major limitation in the analysis of physical quantities measured from a stratigraphic core is incomplete knowledge of the depth to age relationship for the core. Records derived from diverse locations are often compared or combined to construct records that represent a global signal. Time series analysis of individual or combined records is commonly employed to seek quasi-periodic components or

D. G. McMillan; C. G. Constable; R. L. Parker

2002-01-01

306

Stratigraphy of small shield volcanoes on Venus: Criteria for determining stratigraphic relationships and assessment of relative  

E-print Network

Stratigraphy of small shield volcanoes on Venus: Criteria for determining stratigraphic than about 20 km, are common and sometimes very abundant features on the plains of Venus. Typically plains of Venus. Did the eruption style of small shields occur repeatedly throughout the visible part

Head III, James William

307

Seismic stratigraphy and stratigraphic modelling of the South-eastern German Molasse Basin  

SciTech Connect

Although the German Molasse Basin can be regarded as a mature hydrocarbon province, no regional sequence stratigraphic analysis has been carried out so far. We have studied seismic lines and well data from the region between the Isar and Inn rivers (SE Germany) that have been generously supplied by German oil companies (DEE, BEB, Mobil, RWE-DEA and Wintershall). Initial work indicates that five major seismic sequences within three main depositional cycles are developed. The Alpine thrust belt to the south serves as the primary sediment source in the foreland basin. However, sedimentary infill mainly took place parallel to the basin axis. Our analysis suggests that the stratigraphic development of the Molasse Basin was mainly controlled by eustatic sea-level changes which caused the shoreline to shift in the W-E direction. The shifting of the depocenter axis in a N-S direction was controlled by the tectonic evolution of the thrust belt. The sea-level curve determined by seismic stratigraphy and well-derived subsidence curves have been used as input parameters for stratigraphic modelling, using the programs GeoMOD and PHIL. Basin-fill simulations with PHIL are in good agreement with the main features of the sequence stratigraphy and the distribution of the systems tracts observed in the study area. The qualitative sea-level curve for the German Molasse Basin derived from the seismostratigraphic analysis could be quantified by the stratigraphic exercises.

Aigner, T.; Jin, J.; Luterbacher, P. [Univerisitaet Tuebingen (Germany)

1995-08-01

308

The Cretaceous-Paleogene boundary section of Gorgo a Cerbara: an integrated stratigraphical study  

Microsoft Academic Search

An integrated stratigraphical study has been performed at the Cretaceous-Paleogene transition section of Gorgo a Cerbara in North Umbria (Italy). A magnetostratigraphy for the section was established which was correlated to biostratigraphy with calcareous nannofossils and stable isotope stratigraphy. The nearly 30 m long section of Cerbara is built up of typical Scaglia Rossa limestones and marly limestones. Magnetostratigraphic results

Christine LATAL

2004-01-01

309

NANNOFOSSIL SUBDIVISION AND STRATIGRAPHIC RANGE OF THE EMINE FLYSCH FORMATION IN EAST BALKAN, EAST BULGARIA  

Microsoft Academic Search

The Campanian-Paleocene turbidite sequence known as Emine Flysch Formation is widely exposed in the East Balkan, East Bulgaria. Its boundaries and different stratigraphic levels have been described in many outcrops, but complete sequence of the unit is still not established due to great thickness and folded zones in different levels of the unit. A nannofossil zonation was applied here in

D. Sinnyovsky

2004-01-01

310

The role of climate in stratigraphic patterns exhibited by late Palaeozoic rocks exposed in Kansas  

Microsoft Academic Search

Late Palaeozoic “cyclothems” of the midcontinental U.S. cannot be represented by a single ideal facies sequence. Rather, they encompass a wide range of cycle types depending on their stratigraphic position. The exposed Late Palaeozoic (Pennsylvanian and Permian) rocks of Kansas, as compiled by Zeller (1968), can be divided into nine major lithofacies. These lithofacies were ordered based on their times

R. R. West; A. W. Archer; K. B. Miller

1997-01-01

311

Beyond stratigraphic noise: Unraveling the evolution of stratified assemblages in faunalturbated sites  

Microsoft Academic Search

This study explores the stratigraphic evolution of archaeological assemblages in faunaltur- bated sites. These sites are sometimes described as having limited archaeological value because of varying degrees of occupation mixing. It is argued here that the vertical distribution of assemblages is predictable in faunalturbated contexts. Understanding this vertical evolution may lead to a better assessment of the archaeological potential of

Eugène Morin

2006-01-01

312

Inorganic geochemistry of Devonian shales in southern West Virginia: geographic and stratigraphic trends  

SciTech Connect

Samples of cuttings from twenty-one wells and a core from a single well in southern West Virginia were analyzed for major and minor elements: silicon, aluminum, iron, magnesium, calcium, sodium, titanium, phosphorus, manganese, sulfur, zinc, and strontium. Stratigraphic and geographic controls on elemental abundances were studied through canonical correlations, factor analyses, and trend surface analyses. The most abundant elements, silicon and aluminum, show gradual trends through the stratigraphic column of most wells, with silicon increasing and aluminum decreasing up-section. Other elements such as calcium, sulfur, and titanium change abruptly in abundance at certain stratigraphic boundaries. Important geographic trends run east-west: for instance, one can see an increase in sulfur and a decrease in titanium to the west; and a decrease in silicon from the east to the central part of the study area, then an increase further west. Although observed vertical trends in detrital minerals and geographic patterns in elemental abundances agree with the accepted view of a prograding delta complex during Late Devonian time, geographically-local, time restricted depositional processes influenced elemental percentages in subsets of the wells and the stratigraphic intervals studied. The black shales of lower Huron age do not represent simply a return of depositional conditions present in the earlier Rhinestreet time; nor do the gray shales of the Ohio Shale represent the same environmental conditions as the Big White Slate.

Hohn, M.E.; Neal, D.W.; Renton, J.J.

1980-04-01

313

ROSSMAP; Regional Seismic Stratigraphic Correlations in the Victoria Land Basin and the Timing of Rifting Episodes  

Microsoft Academic Search

ROSSMAP aims to produce a new series of digital seismic stratigraphic and structural maps for the Ross Sea region, and develop reconstructions of past sedimentary volumes and paleo-bathymetry that will be used in numerical models to help identify tectonic and climate feedbacks. In particular, ROSSMAP will define targets for future drilling initiatives in the Ross Sea region, and provide a

B. W. Davy; S. A. Henrys; T. J. Wilson; C. R. Fielding; R. H. Levy

2010-01-01

314

Structural and stratigraphic analyses along the western margin of the Salton  

E-print Network

ABSTRACT Structural and stratigraphic analyses along the western margin of the Salton Trough show fault zones (the San Andreas fault and the West Salton detachment fault) to a network of dextral faults- ate, the older West Salton detachment fault, and Cretaceous mylonitic rocks below the detachment

Dorsey, Becky

315

Stratigraphic modeling of foreland basins: Interpreting thrust deformation and lithosphere rheology  

Microsoft Academic Search

The authors incorporate the processes of erosion and deposition in a numerical model to predict the stratal geometries and facies patterns produced during episodic thrusting in a nonmarine foreland basin. The resultant stratigraphic record is characterized by a stairstepped facies package in which each retrogradation of facies (toward the thrust) marks the onset of a thrusting event. The retrogradation of

Peter B. Flemings; Teresa E. Jordan

1990-01-01

316

STRATIGRAPHIC RECORD OF TRIASSIC-JURASSIC COLLISIONAL TECTONICS IN THE BLUE MOUNTAINS PROVINCE,  

E-print Network

STRATIGRAPHIC RECORD OF TRIASSIC-JURASSIC COLLISIONAL TECTONICS IN THE BLUE MOUNTAINS PROVINCE in the Blue Mountains province (BMP) of northeastern Oregon preserve a well studied record of Triassic­Jurassic to Early Jurassic deposits that change up section from (1a) older volcanic and volcaniclastic deposits

Dorsey, Becky

317

Deep burial dolomitization driven by plate collision: Evidence from strontium-isotopes of Jurassic Arab IV dolomites from offshore Qatar  

SciTech Connect

The use of strontium-isotope ratios of dolomites to constrain timing and mechanism of diagenesis has been investigated on Jurassic Arab IV dolomites from offshore Qatar. Reservoir quality is determined by two types of dolomites, which were differentiated geochemically (cathodoluminescence, fluid inclusions, and carbon and oxygen stable isotopes): (1) stratigraphically concordant sucrosic dolomites with high porosity formed during early near-surface diagenesis (Jurassic) and (2) stratigraphically discordant cylindrical bodies of massive, porosity-destroying dolomites formed late during deep burial diagenesis (Eocene-Pliocene). Detailed Sr-isotope analysis of dolomites from the Arab IV confirms an Early Jurassic age of the sucrosic, high porosity dolomites ({sup 87}Sr/{sup 86}SR = 0.70707 for NBS 987 = 0.71024) with magnesium and strontium being derived from Jurassic seawater. Late Tertiary compressional orogeny of the Zagros belt to the north is proposed to have caused large-scale squeezing of fluids from the pore system of sedimentary rocks. A regional deep fluid flow system developed dissolving infra-Cambrian evaporites upflow and causing large-scale deep burial dolomitization downflow.

Vahrenkamp, V.C.; Taylor, S.R. (Shell Research, Rijswijk (Netherlands))

1991-03-01

318

Divergent evolutionary processes associated with colonization of offshore islands.  

PubMed

Oceanic islands have been a test ground for evolutionary theory, but here, we focus on the possibilities for evolutionary study created by offshore islands. These can be colonized through various means and by a wide range of species, including those with low dispersal capabilities. We use morphology, modern and ancient sequences of cytochrome b (cytb) and microsatellite genotypes to examine colonization history and evolutionary change associated with occupation of the Orkney archipelago by the common vole (Microtus arvalis), a species found in continental Europe but not in Britain. Among possible colonization scenarios, our results are most consistent with human introduction at least 5100 bp (confirmed by radiocarbon dating). We used approximate Bayesian computation of population history to infer the coast of Belgium as the possible source and estimated the evolutionary timescale using a Bayesian coalescent approach. We showed substantial morphological divergence of the island populations, including a size increase presumably driven by selection and reduced microsatellite variation likely reflecting founder events and genetic drift. More surprisingly, our results suggest that a recent and widespread cytb replacement event in the continental source area purged cytb variation there, whereas the ancestral diversity is largely retained in the colonized islands as a genetic 'ark'. The replacement event in the continental M. arvalis was probably triggered by anthropogenic causes (land-use change). Our studies illustrate that small offshore islands can act as field laboratories for studying various evolutionary processes over relatively short timescales, informing about the mainland source area as well as the island. PMID:23998800

Martínková, Natália; Barnett, Ross; Cucchi, Thomas; Struchen, Rahel; Pascal, Marine; Pascal, Michel; Fischer, Martin C; Higham, Thomas; Brace, Selina; Ho, Simon Y W; Quéré, Jean-Pierre; O'Higgins, Paul; Excoffier, Laurent; Heckel, Gerald; Hoelzel, A Rus; Dobney, Keith M; Searle, Jeremy B

2013-10-01

319

Post-glacial sea-level history for SW Ireland (Bantry Bay) based on offshore evidence  

NASA Astrophysics Data System (ADS)

In recent years, progress in remote sensing techniques has helped to constrain the advance and retreat phases of the British-Irish Ice Sheet during and after the Last Glacial Maximum (LGM), both on- and offshore. However, little evidence has been collected to study the pattern of relative sea-level (RSL) change immediately after ice sheet retreat. Glacio-isostatic adjustment (GIA) models suggest a complex RSL pattern around Ireland, influenced by local and regional isostatic movements. Unfortunately, such models are poorly constrained for periods during which RSL was significantly lower than present, particularly the Late Pleistocene and Early Holocene, owing to the paucity of accurate observational data offshore. This poster presents post-LGM stratigraphic evidence from Bantry Bay (SW Ireland), one of seven areas targeted around the Irish Sea as part of a larger NERC funded project which aims to provide the first field data on the depth and age of the RSL minimum since deglaciation in the Irish Sea Basin. Data examined consists of: multibeam bathymetry and backscatter, pinger sub-bottom and vibrocores (25 sites). Notable features on the multibeam are a bluff line in the outer bay with a maximum height of 10 m in water depths of c. -80 m which forms the western edge of a large sediment lobe. The south-western boundary of this lobe is marked by a series of long (up to 22 km), parallel ridges at depths between -96 m and -131 m, with iceberg scouring evident on the offshore margin. Six seismo-stratigraphic units are interpreted from the pinger data, the most prominent of which can be traced from the inner part of the Bay to the inshore edge of the ridges. This unit sits on an erosional surface, is characterised by a turbid acoustic signature and is identified as alternating sand and clay layers with some traces of organic material and gas. Equal amounts of marine and estuarine foraminifera are present within this unit, whilst the underlying unit has a higher percentage of brackish species and the overlying unit becomes predominantly marine. Based on this evidence, we suggest that the erosional surface represents the transgressive surface, underlying intertidal sediments. Mapping the extent of this surface reveals a maximum depth of -75 m offshore, rising gradually to a depth of -30 m in the inner Bay, a profile remarkably similar to the modelled sea-level curve for the area. The long parallel ridges are interpreted to represent ice-marginal, submarine moraine ridges associated with ice retreat, behind which a glacio-marine delta formed, resulting in the large sediment lobe imaged at the mouth of Bantry Bay. Foraminifera from the proposed transgressive surface have been submitted for radiocarbon dating. Once available, these results will be used for fine-tuning the Earth and ice model parameters in the GIA model. Such adjustments could have important implications for modelled RSL curves around the Irish Sea basin.

Plets, R. M.; Callard, L.; Cooper, A.; Long, A. J.; Belknap, D. F.; Edwards, R.; Jackson, D.; Kelley, J. T.; Long, D.; Milne, G. A.; Monteys, X.; Quinn, R.

2013-12-01

320

Paraffin deposition in offshore oil production  

E-print Network

PARAFFIN DEPOSITION IN OFFSHORE OIL PRODUCTION A Thesis by G E R A L D M A S O N E L P H I N G S T O N E J R . Submitted to the Office of Graduate Studies of Texas A & M Univers i ty in part ial fulfillment of the requirements for the degree... of M A S T E R O F S C I E N C E May 1995 Major Subject: Chemica l Engineering PARAFFIN DEPOSITION IN OFFSHORE OIL PRODUCTION A Thesis by G E R A L D M A S O N E L P H I N G S T O N E J R . Submitted to Texas A & M University in part ial...

Elphingstone, Gerald Mason

2012-06-07

321

New technology emphasizes international offshore effort  

SciTech Connect

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.

NONE

1997-07-01

322

Perspectives of offshore geothermal energy in Italy  

NASA Astrophysics Data System (ADS)

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.

Armani, F. B.; Paltrinieri, D.

2013-06-01

323

Barge hull for offshore drilling rigs  

SciTech Connect

An improved barge hull for offshore drilling rigs is disclosed. The invention comprises a channel in the bottom of a barge hull extending from the bottom of said barge hull to the back of said barge hull for directing the flow of water under said barge hull to the back of said barge hull in order to disrupt the relative hydrodynamic stability of a body of water immediately behind said barge hull and thereby decrease the towing resistance of said barge hull.

Lorenz, D.B.

1984-06-19

324

Offshore drilling boom expanding in Alaska  

SciTech Connect

A fleet of six drilling vessels moved into the Bering Sea in 1984, starting the biggest offshore drilling boom in Alaska's history. Despite the lack of discoveries most of the activity is centered on the Navarin Basin, which is regarded as the most promising of the Bering Sea basins. Assuming there are commercial discoveries, development of the Navarin riserves appears feasible through evolution of North Sea and Cook Inlet platform technology.

Not Available

1985-01-01

325

Offshore distributional patterns of Hawaiian fish larvae  

Microsoft Academic Search

An analysis of ichthyoplankton samples based on relative abundance reveals pronounced inshore\\/offshore distributional gradients for most Hawaiian fish larvae. Larvae of pelagic bay species are found almost exclusively in semi-enclosed bays and estuaries. Larvae of pelagic neritic species are more or less uniformly distributed with distance from shore. The larvae of reef species with non-pelagic eggs are most abundant close

J. M. Leis; J. M. Miller

1976-01-01

326

Application of the boundary-element method to offshore cathodic protection modeling  

SciTech Connect

This paper deals with the main aspects of the calculation of current and potential distributions and summarizes some results obtained on different systems using a computer program based on the boundary-element method. Model results are compared to literature data for well-known geometries, and to experimental data obtained both in laboratory testing with a suitable cell and infield testing on offshore structures (in particular platform nodes). The good predictive capability of computer modeling is shown.

Cicognani, P. (Snamprogetti SpA, 61032 Fano PS (IT)); Gasparoni, F. (Tecnomare SpA, 30124 Venezia (IT)); Mazza, B.; Pastore, T. (Dipartimento di Chimica Fisica Applicata, Politecnico di Milano, 20133 Milano (IT))

1990-06-01

327

Caisson shield for arctic offshore production platform  

SciTech Connect

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.

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

1985-03-12

328

High resolution sequence stratigraphic and reservoir characterization studies of D-07, D-08 and E-01 sands, Block 2 Meren field, offshore Niger Delta  

E-print Network

. The dominant lithofacies are (1) locally calcite-cemented highly-bioturbated, fine-grained sandstones, (middle to lower shoreface facies); (2) cross-bedded, fine- to medium-grained well-sorted sandstones (upper shoreface facies); (3) horizontal to sub...

Esan, Adegbenga Oluwafemi

2004-09-30

329

The wind speed profile at offshore wind farm sites Bernhard Lange(1)  

E-print Network

The wind speed profile at offshore wind farm sites Bernhard Lange(1) , Søren E. Larsen(2) , Jørgen feasibility of offshore wind power utilisation depends on the favourable wind conditions offshore compared in Europe will come from offshore sites. The first large offshore wind farms are #12;currently being built

Heinemann, Detlev

330

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

SciTech Connect

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.

Jonkman, J.; Musial, W.

2010-12-01

331

A Brief History of the New England Offshore Fisheries  

E-print Network

A Brief History of the New England Offshore Fisheries By Albert C. Jensen UNITED STATES DEPARTMENT BERIE. onald L. :'.lcK rnan, Dir dor A Brief History of the New England Offshore Fisheries By ALBER T C · · · · · · · · · · 0 · 0 · · · · · · · · · · 111 12 14 #12;A Brief History of the New England Offshore Fisheries

332

Development and application of oil-spill risk assessment model for offshore pipeline  

NASA Astrophysics Data System (ADS)

To the potential oil-spill risk caused by offshore pipeline more attention has been paid after the Dalian oil spill incident from oil-pipeline explosion. Since then an issue about how to prevent and control the sudden oil-spill from the offshore pipeline has been raised. In this paper, we proposed an optimized model to analyze the main causes (probability) of spill and the consequence with the fuzzy comprehensive assessment model. Considering the complicated assessment process for oil-spill, the assessment factor system involving the spill probability and consequence was established based on the operative manual and statistic leakage/damage data of offshore pipeline in order to estimate the integrated spill risk score automatically. The evaluated factors of spill probability could be grouped into five aspects: corrosion, fatigue, national damage, third party, and operational fault; the consequence evaluated factors of spill included hazard of oil and impact-controlling capability. With some modifications based on experts' opinions, each of the evaluated factors in our work was developed with a relative weight and evaluation criterion. A test example for an offshore pipeline in the Bohai waters was described to show how the model can be used for an actual case in more detail. By using the oil-spill risk assessment model, it is easy to determine the risk level associated with the ongoing activity and management level and hence to take the risk mitigation action immediately.

Lu, Yan; Wang, Jia; Wei, Wenpu; Yang, Yong; An, Wei

2014-06-01

333

The tectono-stratigraphic evolution of basement highs in hyper extended deep-water rifted margins : the example of the Briançonnais domain in the Alps and comparisons with modern analogues  

NASA Astrophysics Data System (ADS)

The discovery of hydrocarbon systems in hyper-extended deep-water rifted margins, in conjunction with technical developments, expanded the hydrocarbon exploration into domains that are yet little investigated. The increasing number of high-quality reflection and refraction seismic surveys and drill hole data show that deep-water rifted margins are very different from proximal rifted margins. The new data show evidence for a polyphase rift evolution resulting in complex rift architectures with variable amounts of magmatic addition and local mantle exhumation that cannot be predicted by classical rift models. Thus, understanding the thermal structure, subsidence history, depositional environment and sedimentary architecture is a prerequisite to apply the "play elements" in these yet little investigated domains, which is essential to evaluate the survivability of syn- to post-rift petroleum systems. Although a big progress was made in the understanding of deep water rifted margins in the last 5 years, there are still many fundamental questions that remain open and ask for further research on this topic. One open scientific question is related to the tectono-sedimentary evolution and subsidence history of basement highs in deep water rifted margins. Péron-Pinvidic and Manatschal (2010) showed that different types of basement highs can be distinguished in rifted margins. These highs include micro-continents, continental ribbons, H-blocks and extensional allochthons. Mapping these highs and properly define their stratigraphic and tectonic evolution provide important insights into the tectonic evolution of rifted margins. However, these blocks are often at deep-water and sealed by thick post-rift sediments. Therefore access to direct observations requires expensive drillings. An alternative way to study these blocks is to use field analogues. One of which is the Briançonnais domain in the Alps. To achieve our goal we propose to review the existing structural, stratigraphic and age data from the whole Briançonnais domain (from Liguria/Italy, across the French Alps to Grisons in Switzerland). We propose to construct key tectonic sections across the Briançonnais domain. These data will form the basis to discuss the rift-related tectono-stratigraphic and subsidence evolution and to constrain the along and across strike stratigraphic architecture of the Briançonnais. These observations will be compared with that of seismically imaged basement highs in deep-water rifted margins (e.g. outer high in Campos or Santos). In our presentation we will show results of our preliminary works on the Briançonnais domain in the French Alps and a comparisons with seismically imaged basement highs imaged offshore Newfoundland.

Haupert, Isabelle; Manatschal, Gianreto; Unternehr, Patrick; Decarlis, Alessandro

2013-04-01

334

The Y-3 tephra: A Last Glacial stratigraphic marker for the central Mediterranean basin  

NASA Astrophysics Data System (ADS)

The paper reviews the existing data on the Y-3 tephra layer, first recognised in the Ionian Sea (Mediterranean basin). The collection and collation of old and new data on distal tephra occurrences in terrestrial, marine and lacustrine successions indicate that the Y-3 layer is dispersed over a wide area of the central Mediterranean basin. The peculiar homogeneous chemical composition of this layer makes its recognition rather straightforward and permits it being distinguished from other stratigraphically adjacent tephras. The best age estimate for the Y-3 layer of ca 30-31 cal ka BP, its peculiar stratigraphic position close to the Marine Isotope Stage 3/2 transition or Heinrich Event 3 onset, as well as its wide dispersion makes this layer an important marker to link and date late Pleistocene terrestrial and marine archives of the central Mediterranean basin.

Zanchetta, G.; Sulpizio, R.; Giaccio, B.; Siani, G.; Paterne, M.; Wulf, S.; D'Orazio, M.

2008-10-01

335

The stratigraphic sequence of volcanic and sedimentary units in the north polar region of Mars  

NASA Technical Reports Server (NTRS)

Based on photogeologic mapping of Viking orbiter images of Mars, four distinct informal stratigraphic units are defined for the region north of 70 degrees N latitude. They are: (a) bulbous plains, (b) mantled plains, (c) dune deposits, and (d) layered deposits/perennial ice. Background information on the Martian polar caps is provided from telescopic observation, Mariner mission results, and Viking mission results (August 1976-November 1978). A description, and an interpretation and distribution of the stratigraphic units are presented. Surface winds, which were determined from dune orientations, and discussed and implications for the source of circumpolar dune materials are delineated. A list of the Viking Orbiter imagery used in the research, the computer programs for crater size frequency distributions, and the crater size frequency data are presented.

Botts, M. E.

1980-01-01

336

Stratigraphic Subdivision of the Transvaal Dolomite from ERTS imagery. [South Africa  

NASA Technical Reports Server (NTRS)

ERTS imagery has revealed the presence of broad stratigraphic subdivisions in the previously undifferentiated Transvaal Dolomite of the western Tranvaal, Republic of South Africa. While detailed field mapping in areas of good outcrop, as well as borehole logging has recently led to the recognition of a stratigraphy in the Transvaal Dolomite of the central Transvaal, poor outcrop in the western Transvaal has to date prevented this. The ERTS-imagery, however, clearly reveals the presence of six, and in the far west seven, distinct stratigraphic zones extending along strike for a distance of at least 200 km. The investigation clearly demonstrates the potential applications of ERTS-imagery in geological studies, even in a country where the geology is supposedly well known.

Grootenboer, J.; Eriksson, K.; Truswell, J.

1974-01-01

337

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

SciTech Connect

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.

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

2012-11-01

338

Stratigraphic and interregional changes in Pennsylvanian coal-swamp vegetation: Environmental inferences  

Microsoft Academic Search

Phillips, T.L., Peppers, R.A. and DiMichele, W.A,, 1985. Stratigraphic and interregional changes in Pennsylvanian coal-swamp vegetation: Environmental inferences. In: T.L. Phillips and C.B. Cecil (Editors), Paleoclimatic Controls on Coal Resources of the Pennsylvanian System of North America. Int. J. Coal Geol., 5: 43—109. Quantitative analysis of Pennsylvanian coal-swamp vegetation provides a means of in- ferring organization and structure of communities.

TOM L. PHILLIPS; RUSSEL A. PEPPERS; WILLIAM A. DIMICHELE

1985-01-01

339

Neogene stratigraphic architecture and tectonic evolution of Wanganui, King Country, and eastern Taranaki Basins, New Zealand  

Microsoft Academic Search

Analysis of the stratigraphic architecture of the fills of Wanganui, King Country, and eastern Taranaki Basins reveals the occurrence of five 2nd order Late Paleocene and Neogene sequences of tectonic origin. The oldest is the late Eocene?Oligocene Te Kuiti Sequence, followed by the early?early Miocene (Otaian) Mahoenui Sequence, followed by the late?early Miocene (Altonian) Mokau Sequence, all three in King

Peter J. J. Kamp; Adam J. Vonk; Kyle J. Bland; Rochelle J. Hansen; Austin J. W. Hendy; Avon P. McIntyre; Melodie Ngatai; Stuart J. Cartwright; Shaun Hayton; Campbell S. Nelson

2004-01-01

340

Haynesville and Bossier mudrocks: A facies and sequence Stratigraphic investigation, East Texas and Louisiana, USA  

Microsoft Academic Search

Upper Jurassic Haynesville and Bossier shale-gas plays of the northwestern Gulf of Mexico (GOM) Basin produce from organic-rich, marine transgressive to highstand mudrocks within mixed carbonate-clastic depositional systems. Modern wireline-log suites from ?200 deep wells were used for detailed correlations, and 10 + cores throughout the upper Kimmeridgian to lower Tithonian basin were incorporated into detailed facies, stratigraphic, and lithologic analyses. The

Ursula Hammes; Gregory Frébourg

341

Computer program for stratigraphic correlation of Devonian shales in Appalachian basin  

SciTech Connect

A computer program has been written to perform graphic and computational functions related to stratigraphic correlation. Stratigraphic information is retrieved from a data base and used to interpolate formation tops between wells. A stratigraphic cross section can then be drawn on a graphics terminal. Kriging is employed in the interpolation to control smoothing. The user can stipulate which wells are included in the cross section, or ask for wells near a specific location or near a specific well. The cross section and other output from the program can be used to determine pay zones that were not correctly interpreted by a driller, to confirm a stratigrapher's correlations, and to find anomalous information in the data base. Estimated tops can be stored in the data base from within the program. Additional graphic activities include drawing a map of well locations and a graphic comparison of a strip log drawn from user-entered driller's lithologic tops and the interpolated tops. The driller's tops and interpolated tops can be matched by the program. The user can choose to turn off the graphics and just interpolate tops for each well on a list provided by the user. If some tops are known in a well, these can be used to interpolate the remaining tops. The base of the Berea Sandstone is commonly used. Accuracy of the interpolations increases as more known tops are used. The program is written in FORTRAN, and uses PLOT 10 Graphical Kernal System. It runs on a VAX 11/750. A Tektronix 4207 color terminal is needed unless the user opts for no graphics.

Timberlake, K.; Hohn, M.; Kite, S.; Behling, M.C.

1988-08-01

342

Stratigraphic framework and petroleum potential of northeastern Baltimore Canyon Trough, mid-Atlantic outer Continental Shelf  

SciTech Connect

Geologic data from 29 wells in the Baltimore Canyon Trough were released to the public as of 1982, and provide sufficient information for establishing Upper Jurasic through Cenozoic rock-stratigraphic units. Most of the units are lithologically similar to formations on the Scotian Shelf and are, therefore, considered in this study to be the Scotian Shelf homotaxial equivalents. The Mohawk(.) sandstone and Mic Mac shale equivalents in the Baltimore Canyon Trough represent lower delta plain to predominantly prodelta environments, and the Abenaki-equivalent limestone represents a shelf margin carbonate buildup. Inundation by the sea was incomplete, however, and channel and distributary-mouth-bar sands (Logan Canyon equivalent) were deposited. A final marine transgression began during the Late Cretaceous and resulted in the deposition of mudstone, which is considered equivalent to the Scotian Shelf Dawson Canyon Formation. Although both basins exhibit an upward increase in sand content, the Scotian Shelf Cenozoic strata are more sandy than those in the Baltimore Canyon Trough. Stratigraphic traps may be present in the Baltimore Canyon Trough Upper Jurassic and Lower Cretaceous deltaic sandstones and shelf-margin carbonates. The deltaic units contain channel and distributary-mount-bar sandstones, which may be potential reservoirs. Seals may be formed by lateral and vertical contacts against the prodelta, interdistributary bay, and marine shales. The Abenaki stratigraphic-reef trend provides another potential target. Source rocks, reservoir rocks, and traps may be associated with the trend, but its potential can only be defined by future drilling. 16 figures, 2 tables.

Libby-French, J.

1984-01-01

343

Examination of spaceborne imaging spectroscopy data utility for stratigraphic and lithologic mapping  

NASA Astrophysics Data System (ADS)

Due to the increasing development of image spectroscopy techniques, airborne and spaceborne hyperspectral images have in recent years become readily available for use in geological applications. One of the prominent advantages of imaging spectroscopy is its high spectral resolution, producing detailed spectral information in each pixel. The current study aims at exploring the feasibility of the Earth-Observing-1 Hyperion imaging spectrometer to map the geology arena over the Dana Geology National Park, Jordan. After overcoming the common preprocessing difficulties (e.g., smile effect), a classification scheme of two levels was applied. The first level resulted in a stratigraphic classification product of eleven classes and the second level in a lithologic classification product of six classes. The overall accuracy of the stratigraphic product was 57%, while that of the lithologic product was 79%. Mismatches in classification were mostly related to terrestrial cover of the lower topography formation by rock and sand debris. In addition, low accuracy values can be attributed to Hyperion's high sensitivity, leading to recognition of different mineral compositions as different classes within a rock formation, while the conventional geology-stratigraphic map generalizes these different classes into one formation. The methods practiced in the current research can advance the Hyperion's classification capabilities and therefore can be applied in different geological settings and additional disciplines such as penology, agriculture, ecology, forestry, urban, and other environmental studies.

Dadon, Alon; Ben-Dor, Eyal; Beyth, Michael; Karnieli, Arnon

2011-01-01

344

Revised Cretaceous and Tertiary stratigraphic nomenclature in the Colville Basin, Northern Alaska  

USGS Publications Warehouse

A revised stratigraphic nomenclature is proposed for Cretaceous and Tertiary geologic units of the central and western North Slope of Alaska. This revised nomenclature is a simplified and broadly applicable scheme suitable for a suite of digital geologic quadrangle maps being prepared jointly by the U.S. Geological Survey and the Alaska Department of Natural Resources, Division of Geological and Geophysical Surveys and Division of Oil and Gas. This revised nomenclature scheme is a simplification of a complex stratigraphic terminology that developed piecemeal during five decades of geologic investigations of the North Slope. It is based on helicopter-supported geologic field investigations incorporating information from high-resolution aerial photography, satellite imagery, paleontology, reflection seismic records, and sequence stratigraphic concepts. This revised nomenclature proposes the abandonment of the Colville Group; demotion of the Nanushuk Group to formation status; abandonment of six formations (Kukpowruk, Tuktu, Grandstand, Corwin, Chandler, and Ninuluk); revision of four formations (Sagavanirktok, Prince Creek, Schrader Bluff, and Seabee); elevation of the Tuluvak Tongue of the Prince Creek Formation to formation status; revision of two members (Franklin Bluffs Member and Sagwon Member of the Sagavanirktok Formation); abandonment of eight members or tongues (Kogosukruk, Rogers Creek, Barrow Trail, Sentinel Hill, Ayiyak, Shale Wall, Niakogon, and Killik); and definition of one new member (White Hills Member of the Sagavanirktok Formation).

Mull, Charles G.; Houseknecht, David W.; Bird, Kenneth J.

2003-01-01

345

33 CFR 100.728 - Special Local Regulations; Hurricane Offshore Classic, St. Petersburg, FL.  

... false Special Local Regulations; Hurricane Offshore Classic, St. Petersburg...100.728 Special Local Regulations; Hurricane Offshore Classic, St. Petersburg...All vessel traffic, not involved in the Hurricane Offshore Classic, entering...

2014-07-01

346

46 CFR 2.10-130 - Fees for examination of foreign mobile offshore drilling units.  

Code of Federal Regulations, 2010 CFR

... false Fees for examination of foreign mobile offshore drilling units. 2.10-130...10-130 Fees for examination of foreign mobile offshore drilling units. Each foreign mobile offshore drilling unit must pay:...

2010-10-01

347

46 CFR 11.468 - Officer endorsements for mobile offshore drilling units.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Officer endorsements for mobile offshore drilling units. 11.468...11.468 Officer endorsements for mobile offshore drilling units. Officer endorsements for service on mobile offshore drilling units...

2010-10-01

348

Toward Visualization and Analysis of Traceability Relationships in Distributed and Offshore Software  

E-print Network

Toward Visualization and Analysis of Traceability Relationships in Distributed and Offshore Relationships, Dependencies, Visualization, Distributed and Global Software Development, Offshore Software@ics.uci.edu Abstract. Offshore software development projects provoke new issues to the collaborative endeavor

Redmiles, David F.

349

Survey report of offshore wind conditions in prospect of offshore wind energy conversion systems in Japan  

Microsoft Academic Search

Wind energy is viewed as a promising new energy resource in its pure, clean, and inexhaustible nature. Because of less disturbed, stable and strong wind conditions, coastal areas are considered to be suitable for constructing wind energy systems. Moreover, it is said that offshore wind conditions are better than inshore wind conditions for power generation. However, actual measured reports of

K. Nishi; S. Shiraishi; M. Hamano; Y. Umeki; H. Kume

2004-01-01

350

Offshore installation and maintenance of submersible pumps  

SciTech Connect

Pertamina/IIAPCO operates a large offshore production complex in the Southeast Sumatra Contract Area of Indonesia. The use of submersible centrifugal electric pumps both for artificial lift and for pipeline transfer of produced fluids has played an important role in the success enjoyed by this contract area during its 10-year producing life. This paper describes the conditions and considerations contributing to the initial selection and eventual standardized use of these pumps by the company. Also included are a discussion of operational experience gained and a summary of the submersible pumps' performance record.

Verdina, G.G.

1983-01-01

351

Flow line riser for offshore structure  

SciTech Connect

Riser for an offshore marine platform which includes facilities to receive, treat, and/or store hydrocarbon fluid from a plurality of dispersed submerged wells. The riser includes means to accommodate a plurality of conduits between the platform deck and the floor of the body of water. As a rigid, or non-rigid conduit is pulled downwardly through the riser, it engages a deflecting shoe. The latter deflects the pulled conduit into a direction away from the platform and along the ocean floor, whereby it can readily engage a pipeline, or attach to one of the dispersed wells.

Knowles, J. P.; Mitchell, S. D.; Wheeler, S.

1985-05-28

352

Modelling wake and boundary-layer interactions for EfficieNt Development of Offshore Windfarms (ENDOW)  

NASA Astrophysics Data System (ADS)

The objective of the ENDOW project was to evaluate, enhance and interface wake and boundary-layer models for utilisation offshore. This resulted in a significant advance in the state of the art in both wake and marine boundary layer models leading to improved prediction of wind speed and turbulence profiles within large offshore wind farms. The model hierarchy formed the basis of design tools for use by wind energy developers and turbine manufacturers to optimise power output from offshore wind farms through minimised wake effects and optimal grid connections. The design tools were built onto existing regional scale models and wind farm design software which was developed with EU funding and is in use currently by wind energy developers. Part of the design tool evaluation included the issues of computational feasibility and ease of use (in addition to scientific and technical aspects). The project utilised databases from existing offshore wind farms (Vindeby and Bockstigen) to undertake the first comprehensive evaluation of offshore wake model performance. The six wake models vary in complexity from empirical solutions to the most advanced models based on solutions of the Navier-Stokes equations using eddy viscosity, k-epsilon or DES (detached eddy simulation) turbulence closure. The performance of the models was evaluated in comparison with measurements under a number of different wind speed, stability and turbulence conditions and the same criteria were applied for evaluation of model performance for predicting multiple wakes. Following this evaluation most of the models were enhanced with new parameterisations giving improved performance. Parallel research included comparison of a local-scale stability/roughness model with a mesoscale model focusing on boundary-layer development within and over a large offshore wind farm, and particularly the influence of large scale thermal flows. An experiment was also conducted to examine vertical wind speed profiles to hub-height and beyond in near-wake conditions and wake dispersion using SODAR to assist in model development and testing. Evaluation of the six wake models performance at different wake distances was based on this dataset. The paper will present the results of the project which concludes in February 2003. Final comparisons of the models will be given together with the results from the design tools for offshore wind farms.

Barthelmie, R.; Endow Partners

2003-04-01

353

Late Quaternary megaturbidites of the Indus Fan: Origin and stratigraphic significance  

E-print Network

-to-sink" systems of the Quaternary and extends over 106 km2 offshore. It is characterized by a complex tectonic.g., incised valley formation) on the timing of sedimentary transfer and sediment distribution at the basin their depositional patterns and their evolution through time. Large mud-rich fans are typically associated

Nicolas, Chamot-Rooke

354

Limitations on stratigraphic analyses due to incomplete age control and their relevance to sedimentary paleomagnetism  

NASA Astrophysics Data System (ADS)

A major limitation in the analysis of physical quantities measured from a stratigraphic core is incomplete knowledge of the depth to age relationship for the core. Records derived from diverse locations are often compared or combined to construct records that represent a global signal. Time series analysis of individual or combined records is commonly employed to seek quasi-periodic components or characterize the timescales of relevant physical processes. Assumptions that are frequently made in the approximation of depth to age relationships can have a dramatic and harmful effect on the spectral content of records from stratigraphic cores. A common procedure for estimating ages in a set of samples from a stratigraphic core is to assign, based on complementary data, the ages at a number of depths (tie points) and then assume a uniform accumulation rate between the tie points. Imprecisely dated or misidentified tie points and naturally varying accumulation rates give rise to discrepancies between the inferred and the actual ages of a sample. We develop a statistical model for age uncertainties in stratigraphic cores that treats the true, but in practice unknown, ages of core samples as random variables. For inaccuracies in the ages of tie points, we draw the error from a zero-mean normal distribution. For a variable accumulation rate, we require the actual ages of a sequence of samples to be monotonically increasing and the age errors to have the form of a Brownian bridge. That is, the errors are zero at the tie points. The actual ages are modeled by integrating a piecewise constant, randomly varying accumulation rate. In each case, our analysis yields closed form expressions for the expected value and variance of resulting errors in age at any depth in the core. By Monte Carlo simulation with plausible parameters, we find that age errors across a paleomagnetic record due to misdated tie points are likely of the same order as the tie point discrepancies. Those due to accumulation rate variations can be as large as 30 kyr, but are probably less than 10 kyr. We provide a method by which error estimates like these can be made for similar stratigraphic dating problems and apply our statistical model to an idealized marine sedimentary paleomagnetic record. Both types of errors severely degrade the spectral content of the inferred record. We quantify these effects using realistic tie point ages, their uncertainties and depositional parameters.

McMillan, D. G.; Constable, C. G.; Parker, R. L.

2002-08-01

355

Preliminary stratigraphic and paleomagnetic results from Neogene basins across the Anatolian Plateau (Turkey).  

NASA Astrophysics Data System (ADS)

An integrated paleomagnetic and stratigraphic study on Neogene basins across the Anatolian Plateau was carried out. This study is developed within the VAMP (Vertical Anatolian Movement Project), an interdisciplinary project aimed to the recent tectonic evolution of the central Anatolian Plateau. The studied areas are located in southern Turkey (Adana, Mut and Ermenek basins) and in northern Turkey (Kazan, Çankiri, Kastamonu, Boyabat and Sinop basins). For paleomagnetic analyses we sampled 1062 standard cylindrical samples from 13 stratigraphic sections, and 746 samples for paleontological analysis were taken from the same sections. AMS (Anisotropy of Magnetic Susceptibility), magnetic mineralogy and paleomagnetic polarity data are presented together with the results of the integrated stratigraphic analyses. In the Southern Turkey basins preliminary results show the diffuse presence of authigenic iron sulphides, together with magnetite, as main magnetic carriers. In these sections the iron-sulphides Characteristic Natural Magnetization (ChRM) component is characterized by inconsistent polarity record, suggesting that iron-sulphides have a late diagenetic origin. Conversely, magnetite bearing sediments show more reliable results in term of magnetic polarity interpretations. Preliminary stratigraphic and paleomagnetic results from the southern margin of the plateau allow us both to refine the stratigraphy for the late Miocene of the Adana Basin and to better constrain the age of the youngest marine deposits of the Mut and Ermenek basins. In the late Miocene of the Adana Basin evidence of the Messinian salinity crisis led to a new stratigraphic framework specially for the Messinian-Pliocene interval. Thick fluvial conglomerates from the uppermost Messinian deposits of the Adana Basin, which could be linked to the activation of the southern margin of the plateau, allow us to constrain at about 5.4 Ma the uplift of the central Anatolian Plateau. On the other hand, the preliminary results of the micropaleontological analyses carried out on the higher marine deposits sampled in the northern part of the Ermenek Basin (Basyayla section, 1840 m a.s.l.) point to a post-Tortonian age for the plateau uplift. The age of the basins at the northern margin of the plateau are very poor constrained, except for that basins containing vertebrate-bearing continental deposits. However, from a palaeogeographic point of view, our preliminary data suggest a possible Tortonian connection between the Çankiri Basin and the Paratethyan realm. This presentation was supported by the EUROCORE programme TOPO-EUROPE of the European Science Foundation.

Lucifora, Stella; Cifelli, Francesca; Mazzini, Ilaria; Cosentino, Domenico; Mattei, Massimo; Cipollari, Paola; Gliozzi, Elsa; Palolo Cavinato, Gian

2010-05-01

356

Sedimentological indicators of paleoenvironments and siliciclastic stratigraphic sequences in some Miocene deposits of the Calvert Cliffs, southern Maryland  

USGS Publications Warehouse

Middle Miocene siliciclastic deposits comprising the Calvert Cliffs section at the Baltimore Gas and Electric Company's (BG&E) nuclear power plant site in southern Maryland were analyzed in terms of lithostratigraphy, sedimentary structures, and granulometric parameters, to interprete paleo-environments within a sequence-stratigraphic framework. In terms of sequence-stratigraphic models, the BG&E section can be interpreted as consisting of two genetic stratigraphic sequences (Galloway model), namely, a shelf sequence and an overlying deltaic sequence. Using the Exxon model, the section consists of two third-order (1-5 m.y. duration) depositional sequences. The stratigraphic sequences of the BG&E section reflect both relatively short-term eustatic transgressive events, as well as a long-term regressive trend with associated local deltation and coastal progradation. The regression probably signified a regional basinward shift of depocenters within the Salisbury embayment during Miocene time. -from Author

Shideler, G.L.

1994-01-01

357

Core Description, Stratigraphic Correlation, and Mapping: A capstone project for an undergraduate course in Sedimentary Geology  

NSDL National Science Digital Library

This project is intended as a long-term (3 weeks1 month) lab exercise near the end of a combined Stratigraphy/Sedimentology course. The project utilizes real world data provided by CONSOL Energy of Pittsburgh, PA, and the West Virginia Geological and Economic Survey. This project has been assigned once and is being revised. Instructions have been left somewhat vague in an attempt to force students into discovering some of the more mechanical details of this process themselves. By the latter third of the course, students have described sedimentary rocks in detail and have constructed vertical sections of rock at several outcrops around campus. The course is moving from Sedimentology/Petrology into Stratigraphy. This project is designed to illustrate the basic principles of lithostratigraphy, which are covered concurrently in the lecture portion of the class. The project 'unfurls' over several weeks. If students are provided with the entire project at one time they generally get overwhelmed, so the project is presented piecemeal, allowing the students to expand the project as they complete one section. Step 1: Core description 40 feet of core from the Conemaugh Group of southwestern Pennsylvania is made available to the students. They must describe the core, define lithologic units, identify specific sedimentary structures, and construct a stratigraphic column. (Students struggle with detail versus efficiency of completion, given one full lab period (3 hours) and a week to complete the assignment, many students will get lost in the detail) The goal is to build familiarity with the type of data available to geologists as they go about constructing maps for resource estimates. Additionally, the lithologies present in this core will be similar to those described in the geologist and drilling logs necessary to complete the next step. Each step is evaluated independently in this step concern is primarily with identification of basic lithologies (coal, sandstone, shale, limestone). Step 2: construction of strip logs for 25 core holes in northern West Virginia. Students are provided with a location map, logs for 25 holes, and elevation data. They must construct strip logs suitable for correlation, deciding upon scale and detail of presentation. Students are provided with a CD including the location map and a .pdf for each drill record. The logs vary between the simplicity of driller data (60' of "blue" shale) and the detail of geologist descriptions, students must balance the detail and simplicity. Additionally, students were faced with "long" logs (i.e. greater than 500') and "short" logs (i.e. less than 100'). This turned out to be extremely difficult, some students got very lost, producing long detailed logs that left them without much time for the last two steps. Students are again provided with a week to construct the strip logs, including the lab time for the week. Strip logs are evaluated for detail, accuracy, and utility (in many cases too much detail can be as confusing as too little). Step 3: construction of stratigraphic cross sections. The first time this project was assigned, there was little guidance provided to students beyond "choosing logs that covered the largest stratigraphic interval." This exceeded the grasp of most students so additional guidance will be provided in the next iteration of this project. A generalized stratigraphic column illustrating the basic characteristics of the Monongahela and Conemaugh groups will be provided to assist students with recognition of the basic formations. Students will be required to construct a stratigraphic cross section through selected wells on the west side of the project area. This cross section will demonstrate the use of marker beds and the lateral continuity of stratigraphic units. The second cross section will run east-west onto the western flank of the Chestnut Ridge anticline. The datum for this cross section will be surface elevation. This cross section will illustrate the problems of stratigraphic correlation when combined with geological structures. The rock becomes consistently older as one proceeds towards the axis of the anticline. The prominent red beds and the absence of coals, in the eastern portion of the map area indicate the presence of the Chestnut Ridge Anticline. Evaluation of the cross sections will be based upon the accuracy of the correlations. Students are allowed a week to produce cross sections (including lab). The stratigraphic cross section should accurately delineate the Redstone, Pittsburgh, and Sewickley coals. These occur in sequence and are fairly easy to identify. Successful completion of the east-west cross section will require identification of the approximate stratigraphic position of the Monongahela-Conemaugh contact. Step 4: construction of isopach maps. Students are then required to identify specific coal and sandstone units within their cross sections, correlate those across the map region and construct isopach maps of those units. This requires that the students now extend what they have learned from the previous three weeks, extend those correlations to the core holes not included in the basic stratigraphic analysis. The thickness of the coal and sandstone should be identified and isopach maps constructed. The first iteration of this project produced problems similar to those encountered in step 3. Better guidance and evaluation of the cross sections and allowing students less input on the choice of stratigraphic units to isopach should reduce the confusion. Step 5: (optional) Interpretation and report writing : the first iteration of this project was running concurrently with a term paper. Instead of two separate projects, an interpretive report will be required. This is still in the planning stage and has not been assigned to students.

Matchen, David L.

358

Morpho-bathymetric and seismic-stratigraphic investigation in the Messina Straits (Southern Italy). The search for geomorphic and stratigraphic evidence of shallow seismogenic faults  

NASA Astrophysics Data System (ADS)

The 28 December, 1908 Reggio Calabria and Messina earthquake was one of the strongest (Mw 7.1) ever occurred in Italy, and was also followed by a tsunami that severely impacted the coasts of the Messina Straits. Although most workers agree that its epicentre locates in the Messina Straits, the source fault has never been detected; a century long question is therefore pending on the source of both the 1908 earthquake and tsunami. Within the ongoing debate on this question, little attention has been given, in recent time, to insights from very high resolution morpho-bathymetric data, particularly as regarding the question on whether a submarine landslides may had been the cause of the tsunami. We aim at filling this gap by presenting the results of a detailed geomorphic analysis in the area of the Messina Straits, integrated with high-resolution MC seismic profiles recently acquired during Cruise M86/2 on board R/V Meteor. The primary morpho-structural feature in this area is the axial channel of the Messina Canyon, toward which inflow several tributary canyons that incise the steep continental slope on the Calabrian and Sicilian margins. These canyons deeply cut into a very narrow continental shelf and merge laterally forming a continuous erosional margin rimming the Messina Straits. This giant, composite canyon environment is the locus of intense erosional and mass failure processes that superimpose on active tectonic deformation, resulting in a complex geomorphology that hinders the distinction between tectonic and sedimentary features. Based on detailed morpho-bathymetric and seismic-stratigraphic analysis, we discuss on the evidence of possible geomorphic and stratigraphic expression of tectonic deformation compatible with the 1908 Mw 7.1 earthquake.

Ridente, Domenico; Latino Chiocci, Francesco; Martorelli, Eleonora; Sposato, Andrea; Krastel, Sebastian; Gross, Felix; Lili, Fu; Schulten, Irena

2013-04-01

359

COST REDUCTION PROSPECTS FOR THE OFFSHORE WIND ENERGY SECTOR  

Microsoft Academic Search

The economics of offshore wind energy are (currently) less favorable than for onshore wind energy and there is a strong need for significant cost reductions in order to become competitive with fossil fuel sources. As about 70% part of the electricity cost is determined by the initial investment costs, we explored the ranges of possible cost reductions of offshore wind

M. Junginger

360

New Horizons for Offshore Wind Energy: Shifting Paradigms and Challenges  

Microsoft Academic Search

The placing of wind turbines offshore is likely to lead to developments of the technology as far-reaching as those which turned the crude onshore machines of the early 1980s into the elegant giants of today. This article discusses the acute need of development of offshore wind energy converting systems. The development of different design techniques and the economics of these

T. S. BHATTI; D. P. KOTHARI

2005-01-01

361

Assessment of off-shore wind farms in Malaysia  

Microsoft Academic Search

A lot of attention is being paid to wind energy due to the focus on renewable energy. Malaysia is situated in the equatorial region and its climate is governed by the monsoons. Wind resource in Malaysia varies from one location to another. Wind speed is better offshore compared to onshore, so more contribution by offshore wind powers in terms of

S. Mekhilef; D. Chandrasegaran

2011-01-01

362

Offshore wind farms in Italy: the Sicily case  

Microsoft Academic Search

Today in the research for new energies, the wind rep resents a powerful source of energy, especially if used offshore. Because of the high initial investments, it is necessary to study the feasibility of the pot ential project. For Italy, the best places set up offshore wind far m are in Sardinia and Sicily. The studies carried out by Project

Cecilia Camporeale

2006-01-01

363

Offshore oil and gas: global resource knowledge and technological change  

Microsoft Academic Search

It is argued that the contribution of technological change to the offshore oil and gas industry's progress is under-researched. As a prelude this theme, the changing geography of known offshore oil and gas resources is reviewed. Significant, and largely technologically dependent, developments are identified in terms of the industry's global spread, its extension into deep and ultradeep waters and its

David Pinder

2001-01-01

364

Structural monitoring of offshore platforms using impulse and relaxation response  

Microsoft Academic Search

Monitoring offshore platforms, long span bridges, high rise buildings, TV towers and other similar structures is essential for ensuring their safety in service. Continuous monitoring assumes even greater significance in the case of offshore platforms, which are highly susceptible to damage due to the corrosive environment and the continuous action of waves. Also, since a major part of the structure

Lalu Mangal; V. G Idichandy; C Ganapathy

2001-01-01

365

Integrated Multidisciplinary Constrained Optimization of Offshore Support Structures  

E-print Network

Integrated Multidisciplinary Constrained Optimization of Offshore Support Structures Rad Haghi1 structure more positively. Previous studies show the advantages of the integrated design with either limited.haghi@siemens.com Abstract. In the current offshore wind turbine support structure design method, the tower and foundation

Papalambros, Panos

366

Bank secrecy, illicit money and offshore financial centers  

Microsoft Academic Search

This paper discusses the effects of pressure policies on offshore financial centers as well as their ability to enforce the compliance of those centers with anti-money laundering regulations. Offshore banks can be encouraged to comply with rigorous monitoring of an investor's identity and the origin of his\\/her funds when pressure creates a sufficiently high risk of reputational harm to the

Pierre M. Picard; Patrice Pieretti

2011-01-01

367

Bank secrecy, illicit money and offshore financial centers  

Microsoft Academic Search

This paper discusses the effects of pressure policies on offshore financial centers as well as their ability to enforce the compliance of those centers with anti-money laundering regulations. Offshore banks can be encouraged to comply with rigorous monitoring of an investor's identity and the origin of his\\/her funds when pressure creates a sufficiently high risk of reputational harm to the

Pierre PICARD; Patrice PIERETTI

2010-01-01

368

DISCIPLINER LES CENTRES FINANCIERS OFFSHORE : INCITATION PAR LA PRESSION INTERNATIONALE  

Microsoft Academic Search

Since Offshore Financial Centers (OFCs) generally provide bank secrecy to foreign investors they are likely to attract criminal money. Recently however, academic writings have pointed to the fact that OFCs might have beneficial economic effects. In this context, we address the question whether pressure exerted by international organizations on offshore financial centers may be effective enough to enforce compliance with

Arnaud BOURGAIN; Patrice PIERETTI

2007-01-01

369

Northwest Sumatra and Offshore Islands Field Survey after the December  

E-print Network

Northwest Sumatra and Offshore Islands Field Survey after the December 2004 Indian Ocean Tsunami on the west coast of northern and central Sumatra and offshore islands 3­4 months after the 26 December 2004 Islands, and included 22 sites in Aceh province in Sumatra and on Simeulue Island, Nias Island, the Banyak

370

Quantifying the Benefits of Combining Offshore Wind and Wave Energy  

Microsoft Academic Search

For many locations the offshore wind resource and the wave energy resource are collocated, which suggests a natural synergy if both technologies are combined into one offshore marine renewable energy plant. Initial meteorological assessments of the western coast of the United States suggest only a weak correlation in power levels of wind and wave energy at any given hour associated

E. Stoutenburg; M. Z. Jacobson

2009-01-01

371

Offshoring and Transfer of Intellectual Property Gio Wiederhold  

E-print Network

deals well with issues of job loss and job creation, its title: "Globalization and Offshoring that participates in offshoring. Many enterprises, involved in the creation and use of software, are similarly cases, the destination for valuable IP is a Controlled Foreign Corporation (CFC), owned and controlled

Wiederhold, Gio

372

Design of support structures for offshore wind turbines  

Microsoft Academic Search

To meet growing energy demands, the Kyoto protocol and the much desired diversification of supply, wind energy has become a mainstream source of energy in the EU. Cost wise it is already competing with gas fired electricity. In the last decade wind moved offshore to accommodate even more wind power. The offshore wind resource is more abundant and of a

J. van der Tempel

2006-01-01

373

Offshore oil and gas occupational accidents—What is important?  

Microsoft Academic Search

Occupational accidents continue to present a problem to industry in general and the offshore oil and gas business in particular. To address this concern, a quantitative model capable of predicting occupational accident frequency in the offshore petroleum industry is being developed. The model offers a means to optimise safety spending, thereby maximising benefits to personnel and the organisation. As input

Daryl Attwood; Faisal Khan; Brian Veitch

2006-01-01

374

Experience of executing fixed price off-shored agile project  

Microsoft Academic Search

Organizations delivering offshore software development services have traditionally focused on CMMI framework to deliver quality software. With agile methodologies gaining more wide spread acceptance, such organizations cannot stay away from them. There are concerns about combining agile methodologies with offshoring. There are also concerns about mismatch of agile methodologies with CMMI framework. In this paper we have looked at the

Udayan Banerjee; Eswaran Narasimhan; N. Kanakalata

2011-01-01

375

Improvement of Offshore Wind Resource Modeling in the Mid-  

E-print Network

Improvement of Offshore Wind Resource Modeling in the Mid- Atlantic Bight Wind Energy Symposium Sienkiewicz , Chris Hughes 26 February 2013 #12;Improving Atmospheric Models for Offshore Wind Resource Mapping and Prediction Using LIDAR, Aircraft, and In-Ocean Observations Dr. Brian A. Colle Stony Brook

Firestone, Jeremy

376

E2I EPRI Assessment Offshore Wave Energy Conversion Devices  

E-print Network

, government/industry, public/private collaborative program to assess and demonstrate the feasibilityE2I EPRI Assessment Offshore Wave Energy Conversion Devices Report: E2I EPRI WP ­ 004 ­ US ­ Rev 1 #12;E2I EPRI Assessment - Offshore Wave Energy Conversion Devices Table of Contents Introduction

377

Globalization and Offshoring of Software Moshe Y. Vardi  

E-print Network

Globalization and Offshoring of Software Moshe Y. Vardi Rice University #12;Whoosh . . . · 1992, Europeans 2 #12;Early Decisions · Co-chairs: Mayadas+Vardi. Editor: Aspray · Global perspective · Secondary-Home Points · Offshoring is just a symptom, the issue is globalization. · We enabled it. Now we have to live

Vardi, Moshe Y.

378

Panel 2A: offshore oil and gas technology assessment  

SciTech Connect

The status of offshore oil and natural gas technology is reviewed, particularly as it pertains to deepwater and Arctic frontier areas of the U.S. Outer Continental Shelf. Offshore platforms, pipelines, tanker loading systems, and subsea support systems are discussed. Research and development activities of the petroleum industry, the U.S. Government, and the governments around the North Sea are briefly discussed.

Crooke, R.C.; Otteman, L.G.

1984-01-01

379

On the Modelling of a Floating Offshore Wind Turbine  

Microsoft Academic Search

The location of wind turbines on floating structures offshore would allow an immense resource to be tapped without the drawbacks large developments can have on public opinion. There are, however, potentially significant technical and cost drawbacks. This article describes the theory and results of research work aimed at developing analytical tools for evaluating the performance of floating offshore wind farms.

Andrew R. Henderson; Minoo H. Patel

2003-01-01

380

Challenges in Predicting Power Output from Offshore Wind Farms  

E-print Network

Challenges in Predicting Power Output from Offshore Wind Farms R. J. Barthelmie1 and S. C. Pryor2 an offshore wind farm, accurate assessment of the wind resource/power output from the wind farm is a necessity. Accurately predicting the power output requires an estimate of the wind resource over the lifetime

Pryor, Sara C.

381

Offshore Wind Power Experiences, Potential and Key Issues for  

E-print Network

Offshore Wind Power Experiences, Potential and Key Issues for Deployment Jørgen Lemming, Poul Erik-Erik Clausen Title: Offshore Wind Power Experiences, Potential and Key Issues for Deployment Division: VEA, SYS Risø-R-1673(EN) January 2008 Abstract: Wind power has been growing at spectacular rates. Today

382

International Collaboration on Offshore Wind Energy Under IEA Annex XXIII  

SciTech Connect

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.

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

2005-11-01

383

Maintenance strategies for deep-sea offshore wind turbines  

Microsoft Academic Search

Purpose – The objective of this paper is to outline a framework that guides the development of sound maintenance strategies and policies for deep-sea offshore wind turbines. Design\\/methodology\\/approach – An important challenge with offshore wind energy production is to reduce the high operation and maintenance costs. To decrease complexity, and structure the maintenance strategy developing process, systems engineering principles are

Ingrid Bouwer Utne

2010-01-01

384

47 CFR 22.1007 - Channels for offshore radiotelephone systems.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Channels for offshore radiotelephone...Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED...Service § 22.1007 Channels for offshore radiotelephone...operating on interstitial channels must be used only for voice grade general communications or to provide for...

2010-10-01

385

Wind Resource Mapping for United States Offshore Areas: Preprint  

SciTech Connect

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.

Elliott, D.; Schwartz, M.

2006-06-01

386

Riser and wellhead monitoring for improved offshore drilling operations  

E-print Network

Riser and wellhead monitoring for improved offshore drilling operations Gullik A. Jensen, Ph ­ Offshore drilling with riser ­ On the riser and the riser joints ­ On damage and consequences · Operational behaviour · Redundant system to secure stable, reliable data access · Online data distribution to the rig

Nørvåg, Kjetil

387

A Risk Assessment Model for Offshoring Using CMMI Quantitative Approach  

Microsoft Academic Search

Risk analysis and assessment obviously provides valuable insights to offshoring projects to identify and evaluate the magnitude of risks associated with the activities and the work products being considered. In offshoring software industry, successful execution of risk analysis drastically relies on strong software process skills and management skills to resolve the differences in cultures, languages, time zones, and development which

Morakot Choetkiertikul; Thanwadee Sunetnanta

2010-01-01

388

Contribution of offshore petroleum deposits to marine food chain  

Microsoft Academic Search

Petroleum production out of offshore petroleum deposits often coincides with abundant fisheries in the world. Superposition of marine microorganism concentration distribution and offshore petroleum field distribution from various data in the literature provides to prove this coincidence. Sakhalin Island coastal regions, North Sea, Gulf of Mexico, etc. are chosen for the superpositions. Significant conformity is observed between the plankton concentration

S. Mori

2009-01-01

389

Bedout: A Possible End-Permian Impact Crater Offshore of  

E-print Network

Bedout: A Possible End-Permian Impact Crater Offshore of Northwestern Australia L. Becker,1 * R. J, and spherulitic glass. The distribution of glass and shocked minerals over hundreds of meters of core material") High offshore of northwest- ern Australia might be the central uplift of a large end-Permian impact

Basu, Asish R.

390

DISTRIBUTED OPTIMIZATION AND CONTROL OF OFFSHORE OIL PRODUCTION: THE INTELLIGENT  

E-print Network

DISTRIBUTED OPTIMIZATION AND CONTROL OF OFFSHORE OIL PRODUCTION: THE INTELLIGENT PLATFORM Michael R to distributed optimization and control of offshore oil production systems. The model incorporates a complex. The proposed distributed controller network can be seen as a special case of a Multi Agent System (MAS

Foss, Bjarne A.

391

Influence of Subsea Cables on Offshore Power Distribution Systems  

Microsoft Academic Search

Subsea cable applications for the offshore power distribution systems create technical challenges in the system design, operation and maintenance. Harmonic parallel resonance introduced by subsea cables is one of the main concerns. In this paper, parallel resonance is investigated for an offshore distribution system with lengthy subsea cables on four interconnected platforms. Variable frequency drives are the dominant loads on

Xiaodong Liang; William Jackson

2008-01-01

392

Influence of Subsea Cables on Offshore Power Distribution Systems  

Microsoft Academic Search

Subsea cable applications for the offshore power distribution systems create technical challenges in the system design, operation, and maintenance. Harmonic parallel resonance introduced by subsea cables is one of the main concerns. In this paper, parallel resonance is investigated for an offshore distribution system with lengthy subsea cables on four interconnected platforms. Variable frequency drives (VFDs) are the dominant loads

Xiaodong Liang; William Michael Jackson

2009-01-01

393

The sea bottom temperature offshore southwestern Taiwan  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

394

Modal strain energy based structural damage localization for offshore platform using simulated and measured data  

NASA Astrophysics Data System (ADS)

Modal strain energy based methods for damage detection have received much attention. However, most of published articles use numerical methods and some studies conduct modal tests with simple 1D or 2D structures to verify the damage detection algorithms. Only a few studies utilize modal testing data from 3D frame structures. Few studies conduct performance comparisons between two different modal strain energy based methods. The objective of this paper is to investigate and compare the effectiveness of a traditional modal strain energy method (Stubbs index) and a recently developed modal strain energy decomposition (MSED) method for damage localization, for such a purpose both simulated and measured data from an offshore platform model being used. Particularly, the mode shapes used in the damage localization are identified and synthesized from only two measurements of one damage scenario because of the limited number of sensors. The two methods were first briefly reviewed. Next, using a 3D offshore platform model, the damage detection algorithms were implemented with different levels of damage severities for both single damage and multiple damage cases. Finally, a physical model of an offshore steel platform was constructed for modal testing and for validating the applicability. Results indicate that the MSED method outperforms the Stubbs index method for structural damage detection.

Wang, Shuqing; Liu, Fushun; Zhang, Min

2014-06-01

395

Management of offshore wastes in the United States.  

SciTech Connect

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.

Veil, J. A.

1998-10-22

396

R & D on Offshore Wind Power Generation System in Japan  

NASA Astrophysics Data System (ADS)

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.

Oishi, Kazuhito; Fukumoto, Yukinari

397

Testing  

MedlinePLUS

... mutation, and must be identified through further testing. Prenatal Testing Prenatal testing is used to determine if a fetus has ... used: In amniocentesis , the most common form of prenatal testing, a very fine needle is inserted into the ...

398

OMAE 1995 -- Proceedings of the 14. international conference on offshore mechanics and arctic engineering. Volume 1, Part B: Offshore technology  

SciTech Connect

This conference proceeding represents the second part of the volume of papers related to offshore technology as it relates to design of offshore structures, jacket and floating structures, tension leg platforms, mooring systems, risers, and cables. It also contains papers relating to structural and geotechnical mechanics. Separate abstracts were prepared for 48 papers in this report for inclusion in the information retrieval system.

Chakrabarti, S.K. [ed.] [Chicago Bridge and Iron Technical Services, Plainfield, IL (United States); Gudmestad, O.T. [ed.] [Statoil, Stavanger (Norway); Sparks, C. [ed.] [Inst. Francais du Petrole, Rueil-Malmaison (France); Morrison, D.G. [ed.] [Shell E and P Technology Co., Houston, TX (United States)

1995-12-31

399

Copyright 1999, Offshore Technology Conference This paper was prepared for presentation at the 1999 Offshore Technology Conference held in  

E-print Network

Offshore Technology Conference held in Houston, Texas, 3­6 May 1999. This paper was selected in the development of marginal fields. Whilst pile design procedures evolved smoothly from onshore experience and theory, design of shallow foundation systems has had to be re-examined in light of the intense offshore

Byrne, Byron

400

Numerical modeling and Hardware-in-the-Loop simulation of undersea networks, ocean observatories and offshore communications backbones  

Microsoft Academic Search

This paper discusses the importance of taking a systems engineering approach when designing undersea networks, ocean observatories and offshore communications backbones. A design that utilizes modular components and systems, and places diligence in modeling and testing communications, power and data bandwidth requirements is essential for sustained operation and economic feasibility. An example is the modular seafloor communications network described -

Andrew M. Clark; Donna M. Kocak; Ken Martindale; Adrian Woodroffe

2009-01-01

401

Rupture lengths and temporal history of significant earthquakes on the offshore and north coast segments of the Northern San Andreas  

E-print Network

Rupture lengths and temporal history of significant earthquakes on the offshore and north coast Andreas Fault. Poorly known channel systems were mapped with multibeam sonar to define pathways was paid to channel confluences, as these areas afford opportunities to test for synchronous triggering

Goldfinger, Chris

402

COMPARATIVE TOXICITY OF OFFSHORE AND OIL-ADDED DRILLING MUDS TO LARVAE OF THE GRASS SHRIMP 'PALAEMONETES INTERMEDIUS'  

EPA Science Inventory

Offshore drilling fluids (muds) varied widely in their toxicity to grass shrimp (Palaemonetes intermedius) larvae. The 96-hr LC50S for the eleven drilling muds tested ranged from 142 to >100,000 ppm (microliters/L). There was a significant correlation between oil content of the d...

403

The Deccan tholeiite lavas and dykes of Ghatkopar-Powai area, Mumbai, Panvel flexure zone: Geochemistry, stratigraphic status, and tectonic significance  

NASA Astrophysics Data System (ADS)

Mumbai City, situated on the western Indian coast, is well known for exposures of late-stage Deccan pillow basalts and spilites, pyroclastic rocks, rhyolite lavas, and trachyte intrusions. These rock units, and a little-studied sequence of tholeiitic flows and dykes in the eastern part of Mumbai City, constitute the west-dipping limb of a regional tectonic structure called the Panvel flexure. Here we present field, petrographic, major and trace element and Sr-Nd isotopic data on these tholeiitic flows and dykes, best exposed in the Ghatkopar-Powai area. The flows closely resemble the Mahabaleshwar Formation of the thick Western Ghats sequence to the east, in Sr-Nd isotopic ratios and multielement patterns, but have other geochemical characteristics (e.g., incompatible trace element ratios) unlike the Mahabaleshwar or any other Formation. The flows may have originated from a nearby eruptive center, possibly offshore of Mumbai. Two dykes resemble the Ambenali Formation of the Western Ghats in all geochemical characteristics, though they may not represent feeders of the Ambenali Formation lavas. Most dykes are distinct from any of the Western Ghats stratigraphic units. Some show partial (e.g., Sr-Nd isotopic) similarities to the Mahabaleshwar Formation, and these include several dykes with unusual, concave-downward REE patterns suggesting residual amphibole and thus a lithospheric source. The flows and dykes are inferred to have undergone little or no contamination, by lower continental crust. Most dykes are almost vertical, suggesting emplacement after the formation of the Panvel flexure, and indicate considerable east-west lithospheric extension during this late but magmatically vigorous stage of Deccan volcanism.

Sheth, Hetu C.; Zellmer, Georg F.; Demonterova, Elena I.; Ivanov, Alexei V.; Kumar, Rohit; Patel, Rakesh Kumar

2014-04-01

404

A study of cyclic pressuremeter testing for offshore applications  

E-print Network

with reasonable accuracy for any given pressure by multiplying the strain by a constant which depends only on the number of cycles. The use of the results is discussed briefly, especially with respect to the design of piles subjected to cyclic lateral loads... Data Corrections Cyclic Pressuremeter Data 39 44 45 CHAPTER VI. ANALYSIS OF RESULTS 47 Introduction . ~ ~ . ~ ~ ~ . ~ ~ ~ ~ ~ ~ ~ Discussion of Cyclic Loads Shear Modulus Degradation Deformation Model and Shear Modulus Model Factors...

Riner, Kenneth Byard

2012-06-07

405

Seismic depth-domain stratigraphic classification of the Golan Heights, central Dead Sea Fault  

NASA Astrophysics Data System (ADS)

A set of twenty five 2-D seismic profiles acquired over the Golan Heights basaltic plateau, central Dead Sea Fault segment, was processed and analyzed in the depth domain. The data were processed by the Pre-Stack Depth Migration techniques and, despite the thick basaltic layer entirely covering the plateau, shows surprisingly good quality. The study presents stratigraphic identification of eleven seismic markers recognized on the output depth-domain sections and their correlation with the adjacent Syrian, Jordanian and Israeli stratigraphic columns. Based on this regional correlation, the deep-seated structure and stratigraphic column underlying the extensive basaltic cover are addressed through structural mapping and isopach calculations, as well as through compilation of regional geological cross-sections. Results of the depth-domain seismic interpretation suggest that the Golan Heights covers a structural depression in which more than 8500 m of Late Proterozoic to Neogene sedimentary succession has accumulated, amid the Jordanian Highlands and the Mt. Hermon Anticline. The Infracambrian-Paleozoic succession attains a thickness of 3000-3500 m, while as much as 1500 m of this figure is attributed to the Late Proterozoic Saramuj Formation. The Mesozoic succession, outlined by the significant northward and north-western thickening of the Triassic and Jurassic successions, attains a cumulative thickness of 5 km in the Northern Golan. The Senonian-Cenozoic succession outlines the syncline nature of the Golan Plateau, attaining a thickness of 1.5-2 km at the central parts of the plateau. The estimated thickness of the Plio-Pleistocene basalt flows that cover the study area locally exceeds 1000 m. Two fault strands of the Dead Sea Fault System are recognized in the subsurface of the plateau: the Sheikh-Ali and Shamir Faults. The strands are interpreted beneath the basalt cover, extending into the plateau at a considerable distance from their surface expression next to the Arabian-Sinai plate boundary frontier, exhibiting various styles of deformation.

Meiler, Miki; Reshef, Moshe; Shulman, Haim

2011-10-01

406

Stratigraphic Cyclicity and Depositional Timescales at the Gale Crater MSL Landing Site  

NASA Astrophysics Data System (ADS)

Gale crater, recently selected as the field site for the Mars Science Laboratory rover, presents a new opportunity to probe the history and habitability of the Martian surface. The crater hosts a diverse suite of geologic materials several kilometers in thickness. Among the central challenges will be the interpretation of this extensive stratigraphic record within a poorly-constrained chronological framework. One potential constraint lies in the recent discovery of sedimentary deposits on Mars which have been found to contain regularly cyclic bedding at 1--10 meter scales. Although cyclic sedimentary deposits were initially recognized in the Arabia Terra region of Mars, Gale crater is among the best examples elsewhere on the planet where we have documented their occurrence. With evidence including multiple scales of repeating stratigraphy at Becquerel crater, we have previously drawn a link between these patterns and known oscillations in the planetary obliquity. This correlation provides an avenue to establish a relative geochronology for portions of the stratigraphic record at Gale. Using stereo image and topographic data from the HiRISE instrument, we have more closely evaluated the occurrence of periodic bedding within the Gale crater mound. The clearest example found to date is located near the top of the exposed section, a potential longer-term exploration target for the rover. This section spans several hundred meters of continuous regularly spaced strata. We further examine potential instances of repetitive bedding lower in the stratigraphy, more easily targeted over the course of the mission. Along with power spectral techniques to evaluate the periodicity of exposed bedding, we statistically assess our proposed astrochronological timescales given the lack of observed interbedded craters. The identification of specific orbital signals within the rock record at Gale would help in determining depositional mechanisms while providing a temporal calibration for stratigraphic units observed by the rover.

Lewis, K. W.; Aharonson, O.

2011-12-01

407

Surface Reservoir Characterization and Stratigraphic Studies Using Rock Magnetism and EPR in Venezuela: A Review  

NASA Astrophysics Data System (ADS)

During the last years, the Paleomagnetic and Rock Magnetic Laboratory at the Simon Bolivar University has incorporated studies of rock magnetism and non conventional techniques in geophysics (as Electronic Paramagnetic Resonance or EPR) to solve diverse problems at the Venezuelan oil industry. Particularly, surface reservoir characterization and EPR-Magnetostratigraphic studies have been performed. At some Venezuelan oil fields (Guafita, La Victoria and Furrial) rock magnetic properties studies (e.g. Magnetic Susceptibility (MS)), extractable organic matter (EOM) and organic matter free radical concentration (OMFRC obtained via EPR) analysis have been applied trying to identified, at shallow levels, the "oil magnetic signature" of subjacent reservoirs. The results obtained in non consolidated samples from the first 1500 m of producers and non producers wells, show the existence of MS, EOM and OMFRC anomalies at shallow levels that are associated with an underlying reservoir and/or oil migration. Authigenic spherical aggregates of submicronic FE-rich magnetic crystals, observed by Scanning Electron Microscopy (SEM), are responsible for the detected MS anomalies. These studies allowed to establish a set of criteria (i.e. EPR, EOM and SEM) in order to link, with a minimum uncertainty, near-surface MS anomalies with the underlying reservoir. We have also explored the application of EPR, combined with petrographic, MS analysis, Qn and S-ratios, to characterize stratigraphic facies and identifying depositional environments at various sections in southwestern Venezuela. The different paramagnetic species that have been identified (e.g. manganese, free radicals and different Fe forms) together with the rock magnetic parameters, seem to give valuable information regarding the lithological characteristics of the studied sections. According to our results, as manganese content is related with the redox conditions, it can be used as a paleoenvironmental change index in stratigraphic columns with large lithological contrasts. For stratigraphic sections that present similar lithologies, the presence and concentration of distinct Fe species could be useful to characterize different depositional environments. The results obtained indicates that this kind of integrated analysis can be used as powerful tool for stratigraphic and environmental studies.

Aldana, M.; Diaz, M.; Costanzo-Alvarez, V.

2007-05-01

408

Large-scale stratigraphic architecture, eustatic variation, and unsteady tectonism: A theoretical evaluation  

NASA Astrophysics Data System (ADS)

We incorporate a process-based depositional model with basin subsidence models to predict stratigraphic records. This allows us to investigate the importance of subsidence geometry on coastal stratigraphy and thus to characterize and compare the stratigraphic architecture of two categories of tectonic basins. The models demonstrate that the correlation of stratigraphic sequences to eustatic cycles is not the same in passive margin basins as in foreland basins and that in a foreland basin, the record of episodic tectonism is distinct from that of eustatic sea level change. In the model, sediment transport is approximated by slope-controlled diffusion; nonmarine transport is treated as more efficient diffusion than marine transport. Three different subsidence and sediment supply models are examined: a simple passive margin basin, a simple foreland basin, and then a foreland basin for which vertical motions are driven by thrust shortening that is compensated flexurally and for which sediment supply is related to relief. Predicted passive margin stratigraphies, for cases of varying eustatic sea level, are similar to those of natural basins and include progradational packages and subaerial unconformities, which are used to define sequence boundaries that form during sea level fall. We explore the timing relationships between stratigraphic features and a sinusoidal sea level history, showing that the phase relationship depends on subsidence, sediment flux, efficiency of sediment transport, and period and amplitude of sea level. When the basic geometry of the basin is inverted, placing the sediment supply on the side with maximum subsidence as is the case in foreland basins, the sequence character changes markedly: subaerial erosion does not generate unconformities. In the models of a dynamic foreland basin, sediment supply and subsidence are linked to the structure of the flanking thrust belt and are not necessarily constant. For steady thrusting and variable sea level, unconformities that define sequence boundaries form only on the distal or forebulge side of the basin, and the ages of the sequence boundaries correlate to limes of rising sea level. In cases of constant sea level but variable thrusting, subaerial unconformities are cut locally on both the proximal margin of the basin and the distal margin of the basin, yet the ages of the proximal margin and distal margin unconformities are out of phase in the tectonic cycle: erosion is most pronounced during quiescence on the proximal side and during thrusting on the distal side.

Jordan, T. E.; Flemings, P. B.

1991-04-01

409

Stratigraphic context and direct dating of the Neandertal mandible from Cova del Gegant (Sitges, Barcelona).  

PubMed

Stratigraphic study of the Cova del Gegant's sedimentary fill revealed different cycles of accumulation of typical interior cave and delta facies. A precise chronology for these deposits, the faunal remains and stone tools contained therein was obtained by radiocarbon, U-Th and OSL. Our results indicate that the Upper Pleistocene archaeological sequence dates between 49.3 +/- 1.8 ka BP, the U-Th age of the overlying flowstone, and 60.0 +/- 3.9 ka BP, the OSL age of the basal deposits. We have also directly dated the site's Neandertal mandible to 52.3 +/- 2.3 ka by U-Th. PMID:20570316

Daura, J; Sanz, M; Pike, A W G; Subirà, M E; Fornós, J J; Fullola, J M; Julià, R; Zilhão, J

2010-07-01

410

Simplified stratigraphic cross sections of the Eocene Green River Formation in the Piceance Basin, northwestern Colorado  

USGS Publications Warehouse

Thirteen stratigraphic cross sections of the Eocene Green River Formation in the Piceance Basin of northwestern Colorado are presented in this report. Originally published in a much larger and more detailed form by Self and others (2010), they are shown here in simplified, page-size versions that are easily accessed and used for presentation purposes. Modifications to the original versions include the elimination of the detailed lithologic columns and oil-yield histograms from Fischer assay data and the addition of ground-surface lines to give the depth of the various oil shale units shown on the cross section.

Dietrich, John D.; Johnson, Ronald C.

2013-01-01

411

Lake Tapps tephra: An early Pleistocene stratigraphic marker in the Puget Lowland, Washington  

USGS Publications Warehouse

The rhyolitic Lake Tapps tephra was deposited about 1.0 myr ago, shortly after culmination of the early phase of the Salmon Springs Glaciation in the Puget Lowland. It is contained within sediments that were deposited in ponds or lakes in front of the reteating glacier. An herb-dominated tundra existed in the southern Puget Lowland at that time. Lake Tapps tephra is most likely the product of an eruption that in part was phreatomagmatic. It forms an early Pleistocene stratigraphic marker across the southern sector of the Puget Lowland and provides a link between Puget lobe sediments of the Cordilleran Ice Sheet and sediments deposited by Olympic alpine glaciers. ?? 1987.

Westgate, J.A.; Easterbrook, D.J.; Naeser, N.D.; Carson, R.J.

1987-01-01

412

Three years' experience with the offshore self-boring pressuremeter ''PAM''  

SciTech Connect

The Offshore Self-Boring Pressuremeter (PAM) has been developed by the Institut Francais du Petrole for geotechnical investigations in water depths up to 1000 meters. The PAM was first presented at the 1981 OTC. It mainly consists of a seabed frame from which a self-boring pressuremeter probe is operated. To date, the PAM has totaled nearly 450 meters of borehole depth and more than 200 pressuremeter tests. Investigations have been performed in a wide variety of soil types. The latest deepwater campaign was carried out successfully in the Mediterranean at a water depth of 625 meters. Extensive geotechnical information is obtained from a PAM boring operation. The use of the pressuremeter method for offshore investigations and foundation designing should open up very interesting prospects.

Brucy, F.; Fay, J.B.; LeTirant, P.

1984-05-01

413

EARTHQUAKE HAZARDS IN THE OFFSHORE ENVIRONMENT.  

USGS Publications Warehouse

This report discusses earthquake effects and potential hazards in the marine environment, describes and illustrates methods for the evaluation of earthquake hazards, and briefly reviews strategies for mitigating hazards. The report is broadly directed toward engineers, scientists, and others engaged in developing offshore resources. The continental shelves have become a major frontier in the search for new petroleum resources. Much of the current exploration is in areas of moderate to high earthquake activity. If the resources in these areas are to be developed economically and safely, potential earthquake hazards must be identified and mitigated both in planning and regulating activities and in designing, constructing, and operating facilities. Geologic earthquake effects that can be hazardous to marine facilities and operations include surface faulting, tectonic uplift and subsidence, seismic shaking, sea-floor failures, turbidity currents, and tsunamis.

Page, Robert A.; Basham, Peter W.

1985-01-01

414

Meren field water injection project offshore Nigeria  

SciTech Connect

The Meren Water Injection Project, which is one of the largest in West Africa in terms of injection volume, secondary reserves to be recovered and cost, is located in the Meren field offshore Nigeria. This study presents an updated comprehensive plan to deplete 7 reservoir units in sands that have been producing under solution gas drive and gravity segregation with minimal water influx. The reservoir units contain ca 80% of the original oil-in-place in Meren field. Detailed studies have been undertaken to evaluate the performances of the 7 reservoirs with a view to developing a secondary recovery plan which has been brought into reality. Injection was to start in mid-1982 but was delayed until mid-1983. The effect of the delay and the changing of injector locations on recovery and cost is discussed.

Adetoba, L.A.

1984-04-01

415

Storage of Carbon Dioxide in Offshore Sediments  

NASA Astrophysics Data System (ADS)

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.

Schrag, Daniel P.

2009-09-01

416

Time Dependent Fluid Occurrence Offshore Taiwan  

NASA Astrophysics Data System (ADS)

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.

Chen, L.

2010-12-01

417

Snow stratigraphic heterogeneity within ground-based passive microwave radiometer footprints: implications for emission modelling  

NASA Astrophysics Data System (ADS)

Remote sensing of snow mass remains a challenging area of research. Scattering of electromagnetic radiation is sensitive to snow mass, but is also affected by contrasts in the dielectric properties of the snow. Although the argument that errors from simple algorithms average out at large scales has been used to justify current retrieval methods, it is not obvious why this should be the case. This hypothesis needs to be tested more rigorously. A ground-based field experiment was carried out to assess the impact of sub-footprint snow heterogeneity on microwave brightness temperature, in Churchill, Canada in winter in early 2010. Passive microwave measurements of snow were made using sled-mounted radiometers at 75cm intervals over a 5m transect. Measurements were made at horizontal and vertical polarizations at frequencies of 19 and 37 GHz. Snow beneath the radiometer footprints was subsequently excavated, creating a snow trench wall along the centrepoints of adjacent footprints. The trench wall was carefully smoothed and photographed with a near-infrared camera in order to determine the positions of stratigraphic snow layer boundaries. Three one-dimensional vertical profiles of snowpack properties (density and snow specific surface area) were taken at 75cm, 185cm and 355cm from the left hand side of the trench. These profile measurements were used to derive snow density and grain size for each of the layers identified from the NIR image. Microwave brightness temperatures for the 2-dimensional map of snow properties was simulated with the Helsinki University of Technology (HUT) model at 1cm intervals horizontally across the trench. Where each of five ice lenses was identified in the snow stratigraphy, a decrease in brightness temperature was simulated. However, the median brightness temperature simulated across the trench was substantially higher than the observations, of the order of tens of Kelvin, dependent on frequency and polarization. In order to understand and quantify possible sources of error in the simulations, a number of experiments were carried out to investigate the sensitivity of the brightness temperature to: 1) uncertainties in field observations, 2) representation of ice lenses, 3) model layering structure, and 4) near-infrared derived grain size representing snow grain size at microwave wavelengths. Field measurement error made little difference to the simulated brightness temperature, nor did the representation of ice lenses as crusts of high density snow. As the number of layers in the snow was reduced to 3, 2, or 1, the simulated brightness temperature increased slightly. However, scaling of snow grain size had a dramatic effect on the simulated brightness temperatures, reducing the median bias of the simulations to within measurement error for the statistically different brightness temperature distributions. This indicated that further investigation is required to define what is meant by the microwave grain size, and how this relates to the grain size that is used in the microwave emission model.

Sandells, M.; Rutter, N.; Derksen, C.; Langlois, A.; Lemmetyinen, J.; Montpetit, B.; Pulliainen, J. T.; Royer, A.; Toose, P.

2012-12-01

418

Effects of mass-wasting on the stratigraphic architecture of a fjord-valley fill: Correlation of onshore, shear-wave seismic and marine seismic data at Trondheim, Norway  

NASA Astrophysics Data System (ADS)

A combined record of onshore, high-resolution, shear-wave seismic and marine, P-wave seismic data shows the near-shore stratigraphic organisation of a fjord-valley fill at Trondheim, central Norway. The overall stratigraphy shows a typical fjord-valley fill of up to 160 m in thickness that is composed of glaciomarine and fjord-marine sediments overlain by deltaic deposits which, in the onshore section, are draped by an anthropogenic fill. An interval characterised by low shear-wave velocities below the onshore, anthropogenic fills is shown by sampled drillings to comprise part clay and part organic deposits. The seismic record reveals evidence of recurrent mass-wasting events that include landslide debris, turbidite deposits and channel features. A chronological framework for the stratigraphy is provided by existing radiocarbon dates for local deglaciation and mass-wasting events. The combined onshore-offshore datasets document the Lateglacial to Holocene development of an emerging fjord and delta system affected by major, mass-wasting events. The architectural development of the younger part of the stratigraphy is interpreted as particularly affected by two, known mass-wasting events each involving several million m3 of debris. A thick layer of debris from a 3500 cal yr event probably resulted in a blockage of the subaqueous channels, diversion of turbidity currents and deposition of lateral accretion packages, whereby local fjord sedimentation temporarily increased. A 2200 cal yr event resulted in a sudden reorganisation of the distributary system whereby distal delta sedimentation abruptly shifted north- to northeastwards to an area temporarily subjected to marine erosion during fall of relative sea level. The study adds to the understanding of landslides and low-stiffness zones in the area of importance for near-shore geohazard assessment. The study also provides insight into the stratigraphic variability of fjord-valley fills, and highlights the interplay between fjord marine sedimentation, marine abrasion, delta progradation and mass wasting during late stages of fjord filling.

Hansen, Louise; L'Heureux, Jean-Sébastien; Sauvin, Guillaume; Polom, Ulrich; Lecomte, Isabelle; Vanneste, Maarten; Longva, Oddvar; Krawczyk, Charlotte M.

2013-05-01

419

Experiments on an offshore platform model by FBG sensors  

NASA Astrophysics Data System (ADS)

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.

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

2004-07-01

420

Basin Analysis and Petroleum System Characterisation of Western Bredasdorp Basin, Southern Offshore of South Africa: Insights from a 3d Crust-Scale Basin Model - (Phase 1)  

NASA Astrophysics Data System (ADS)

In recent years, construction of 3D geological models and their subsequent upscaling for reservoir simulation has become an important tool within the oil industry for managing hydrocarbon reservoirs and increasing recovery rate. Incorporating petroleum system elements (i.e. source, reservoir and trap) into these models is a relatively new concept that seems very promising to play/prospect risk assessment and reservoir characterisation alike. However, yet to be fully integrated into this multi-disciplinary modelling approach are the qualitative and quantitative impacts of crust-scale basin dynamics on the observed basin-fill architecture and geometries. The focus of this study i.e. Western Bredasdorp Basin constitutes the extreme western section of the larger Bredasdorp sub-basin, which is the westernmost depocentre of the four southern Africa offshore sub-basins (others being Pletmos, Gamtoos and Algoa). These basins, which appear to be initiated by volcanically influenced continental rifting and break-up related to passive margin evolution (during the Mid-Late Jurassic to latest Valanginian), remain previously unstudied for crust-scale basin margin evolution, and particularly in terms of relating deep crustal processes to depo-system reconstruction and petroleum system evolution. Seismic interpretation of 42 2D seismic-reflection profiles forms the basis for maps of 6 stratigraphic horizons which record the syn-rift to post-rift (i.e. early drift and late drift to present-day seafloor) successions. In addition to this established seismic markers, high quality seismic profiles have shown evidence for a pre-rift sequence (i.e. older than Late Jurassic >130 Ma). The first goal of this study is the construction of a 3D gravity-constrained, crust-scale basin model from integration of seismics, well data and cores. This basin model is constructed using GMS (in-house GFZ Geo-Modelling Software) while testing its consistency with the gravity field is performed using IGMAS+ (Interactive Gravity and Magnetic Assistant System; Götze et al., 2010 and Schmidt et al., 2011). The ensuing model will be applied to predict the present-day deep crustal configuration and thermal field characteristics of the basin. Thereafter, 3D volumetric backstripping analysis will be performed to predict basin subsidence mechanisms (i.e. tectonic, thermal and sediment load) through time as well as to estimate paleo-water depths for paleogeographic reconstruction. The information gathered from crust-scale basin dynamics will be subsequently used at the petroleum system modelling stage to holistically assess the hydrocarbon potential of the basin in terms of source rock maturity and hydrocarbon generation, migration, timing and accumulation.

Sonibare, W. A.; Scheck-Wenderoth, M.; Sippel, J.; Mikeš, D.

2012-04-01

421

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

SciTech Connect

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.

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

2014-01-01

422

Medical support by a team of doctors to offshore paramedics.  

PubMed

The experience of one team of doctors supporting offshore paramedics in the North Sea is described. During 1985 all cases for which radio advice from a doctor was sought by offshore paramedics and all cases referred for examination by a doctor were analysed. Of the 743 cases 528 (71%) were referred for examination by a doctor and for 215 (29%) the offshore paramedics sought radio advice only. Injury formed the largest category of disorder for both groups of cases. The majority of patients referred for examination were seen in the doctor's surgery and following examination over half were cared for at home by their own general practitioner. PMID:3694575

Phillips, J C

1987-04-01

423

READINESS AND MINDSET FOR IT OFFSHORING: INSIGHTS FROM BANKING AND INSURANCE ORGANIZATIONS  

Microsoft Academic Search

In this research we examine the IT offshore outsourcing (offshoring) practice of a number of leading finance and insurance organizations in the Netherlands. In particular, we investigate the readiness (the state, condition or quality of being ready) and mindset (habits, opinions which affect a person's attitudes) of the organizations for IT offshoring. We examine IT offshoring practice from the process

Mehmet N. Aydin; Jos van Hillegersberg

424

75 FR 418 - Certificate of Alternative Compliance for the Offshore Supply Vessel KELLY ANN CANDIES  

Federal Register 2010, 2011, 2012, 2013

...for the Offshore Supply Vessel KELLY ANN CANDIES AGENCY: Coast Guard, DHS. ACTION...for the offshore supply vessel KELLY ANN CANDIES as required by 33 U.S.C. 1605(c...Purpose The offshore supply vessel KELLY ANN CANDIES will be used for offshore supply...

2010-01-05

425

Offshoring and the global distribution of work: Implications for task interdependence theory and practice  

Microsoft Academic Search

A recent Offshoring Research Network (ORN) global survey of offshoring shows that since 2004 management concerns about operational issues on achieving the benefits of offshoring have increased significantly. In this paper we examine inter-task interdependence, a key operational determinant of inter-site interaction and communications in offshoring. We analyze existing theories of interdependence to examine the extent to which they provide

Kuldeep Kumar; Paul C van Fenema; Mary Ann von Glinow

426

Offshoring and the global distribution of work: Implications for task interdependence theory and practice  

Microsoft Academic Search

A recent Offshoring Research Network (ORN) global survey of offshoring shows that since 2004 management concerns about operational issues on achieving the benefits of offshoring have increased significantly. In this paper we examine inter-task interdependence, a key operational determinant of inter-site interaction and communications in offshoring. We analyze existing theories of interdependence to examine the extent to which they provide

Kuldeep Kumar; Paul C van Fenema; Mary Ann von Glinow

2009-01-01

427

Trace element geochemistry: New technology for stratigraphic correlations and formation evaluation  

SciTech Connect

New technology based on the trace element chemistry of rocks is being developed as a tool for mapping subsurface formations in oilfields. This technology can be used to map rock formations in areas where traditional techniques are inconclusive. Trace element geochemistry complements and enhances conventional tools such as biostratigraphy, petrology, and log analysis. Applications cover a broad array of topics including stratigraphic correlations, interpretation of well log responses, age dating, and investigations of reservoir rock properties. Current work is focusing on identifying trace element fingerprints that uniquely mark specific subsurface horizons. There is convincing evidence that trace element fingerprints retain their relative stratigraphic position even though the original mineralogy of the rock has been extensively altered. This means that many of the trace elements associated with specific subsurface rock strata remain in place and are simply transferred from the original mineral to a new (alteration product) mineral. The immobility of these elements is an important geochemical feature because virtually all of the rocks encountered in the petroleum industry are altered to some extent. The ability to {open_quotes}see through{close_quotes} alteration events and obtain information about the original rock is a key advantage of trace element geochemistry techniques.

Lord, C.J. [Phillips Petroleum Company, Bartlesville, OK (United States)

1995-09-01

428

Stratigraphic and laterial variations of source rock attributes of the Pematang Formation, Central Sumatra  

SciTech Connect

The Pematang Formation of the Central Sumatra basin has been shown to be the primary, if not the only, source for the basin's 10+ billion bbl of recoverable oil. This lacustrine unit, which is restricted to a series of Paleogene half grabens, typifies the variability present in many rift source rock systems. Differences in organic facies occur both stratigraphically and laterally as a result of a series of complex interactions. The stratigraphic controls on organic facies within the Pematang appear to be (1) the challenging relationship between subsidence and sedimentation, (2) long-term climate trends influencing both lake level and regional vegetation patterns, and (3) the evolution of the lake basins' nutrient pool. These controls result in an increase in both the level of organic enrichment and oil-proneness toward the top of the unit. Superimposed on this pattern are changes in organic matter content and character caused by short-term climatic oscillations. The lateral controls on organic facies can be examined at two different scales: basinal and subbasinal. Basinal variations can be related to (1) different relative subsidence rates among the various subbasins and (2) variations in lake-water chemistry as a result of the nature of the paleodrainage basin. On a subbasinal scale, organic facies appear to be controlled by (1) hydrodynamic processes and circulation and (2) variations in water depth. These lateral variations are manifested in the level of organic enrichment, the proportions of oil- and gas-prone kerogen, and variations in oil composition.

Katz, B.J. (Texaco Inc., Houston, TX (United States))

1994-07-01

429

Neoproterozoic-Cambrian stratigraphic framework of the Anti-Atlas and Ouzellagh promontory (High Atlas), Morocco  

NASA Astrophysics Data System (ADS)

In the last two decades, great progress has been made in the geochronological, chrono- and chemostratigraphic control of the Neoproterozoic and Cambrian from the Anti-Atlas Ranges and the Ouzellagh promontory (High Atlas). As a result, the Neoproterozoic is lithostratigraphically subdivided into: (i) the Lkest-Taghdout Group (broadly interpreted at c. 800-690 Ma) representative of rift-to-passive margin conditions on the northern West African craton; (ii) the Iriri (c. 760-740 Ma), Bou Azzer (c. 762-697 Ma) and Saghro (c. 760?-610 Ma) groups, the overlying Anezi, Bou Salda, Dadès and Tiddiline formations localized in fault-grabens, and the Ouarzazate Supergroup (c. 615-548 Ma), which form a succession of volcanosedimentary complexes recording the onset of the Pan-African orogeny and its aftermath; and (iii) the Taroudant (the Ediacaran-Cambrian boundary lying in the Tifnout Member of the Adoudou Formation), Tata, Feijas Internes and Tabanite groups that have recorded development of the late Ediacaran-Cambrian Atlas Rift. Recent discussions of Moroccan strata to select new global GSSPs by the International Subcommissions on Ediacaran and Cambrian Stratigraphy have raised the stratigraphic interest in this region. A revised and updated stratigraphic framework is proposed here to assist the tasks of both subcommissions and to fuel future discussions focused on different geological aspects of the Neoproterozoic-Cambrian time span.

Álvaro, J. Javier; Benziane, Fouad; Thomas, Robert; Walsh, Gregory J.; Yazidi, Abdelaziz

2014-10-01

430

Stratigraphic analysis of the Sterkfontein StW 573 Australopithecus skeleton and implications for its age.  

PubMed

StW 573, Little Foot, is the most complete Australopithecus skeleton yet discovered, with many of its bones found in their correct anatomical position. Since the discovery of the in situ skeleton in the Silberberg Grotto in 1997, several teams have attempted to date the fossil. This appeared a simple process because several flowstones are inter-bedded in the breccia above and below StW 573. Dating of these flowstones, using U-Pb (uranium-lead) isotope decay techniques, gave younger results than expected from the fauna and stratigraphic position, around 2.2 Ma (millions of years). Our recent stratigraphic, micromorphological and geochemical studies revealed that the stratigraphy is much more complicated than was previously thought, with localized post-depositional processes leading to the creation of voids within the breccia around the skeleton. These voids were then filled by multiple generations of flowstone growth. The research we present here demonstrates that the proposed dates based on the flowstone deposition can give only a minimum age for StW 573 and that the flowstone formation came after, and probably long after, the breccia deposition. If one takes account of the long evolution of these karst fillings, StW 573 appears to be significantly older than 2.2 Ma. PMID:24698198

Bruxelles, Laurent; Clarke, Ronald J; Maire, Richard; Ortega, Richard; Stratford, Dominic

2014-05-01

431

Cambrian-Ordovician Knox production in Ohio: Three case studies of structural-stratigraphic traps  

USGS Publications Warehouse

The Knox Dolomite (Cambrian-Ordovician) in Ohio consists of a mixed carbonate-siliciclastic sequence deposited in a tidal-flat to shallow-marine environment along a broad continental shelf. Knox hydrocarbon production occurs in porous sandstone and dolomite reservoirs in the Copper Ridge dolomite, Rose Run sandstone, and Beekmantown dolomite. In Ohio, historical Knox exploration and development have been focused on paleogeomorphic traps within the prolific Morrow Consolidated field, and more recently, within and adjacent to the Rose Run subcrop. Although these paleogeomorphic traps have yielded significant Knox production, structural and stratigraphic traps are being largely ignored. Three Knox-producing pools demonstrate structural and stratigraphic traps: the Birmingham-Erie pool in southern Erie and southwestern Lorain counties, the South Canaan pool in northern Wayne County, and the East Randolph pool in south-central Portage County. Enhanced porosity and permeability from fractures, as evident in the East Randolph pool, are also an underexplored mechanism for Knox hydrocarbon accumulation. An estimated 800 bcf of gas from undiscovered Knox resources makes the Knox one of the most attractive plays in the Appalachian basin.

Riley, R. A.; Wicks, J.; Thomas, J.

2002-01-01

432

Recognition of eustatic versus tectonic signatures in the carbonate sequence stratigraphic record  

SciTech Connect

In the process of building sequence stratigraphic models it has become apparent that both eustatic and tectonic signatures can be recognized in the sequence stratigraphic record. Tectonics, active during deposition, modify the shelf to basin profile to leave a signature of increased or decreased rates of subsidence or uplift, or by quiescence. Subsidence or uplift may increase, decrease, or stop, and start again in short amounts of time. Tectonics can dramatically control the positioning of high to low quality reservoir rock. Eustatic sea level rise and fall may be synchronous or out of phase with tectonic events on the cycle, set, or sequence scale. On the sequence scale, if subsidence rates increased dramatically eustatic sea level rise and fall would deposit less complete shallowing-upward cycles in a transgressive systems tract. As subsidence slowed eustatic sea level would deposit complete cycles, containing exposure surfaces, in a highstand systems tract. If the basement is broken into discrete blocks, individual blocks may adjust differentially. One block may subside while an adjacent block may be quiescent or slowly uplifting. If one block abruptly subsides adjacent to a block that did not, cycles in the subsiding block thicken to form a wedge. As subsidence slowed and became more uniform, cycles across the same area will be of equal thickness. If subsidence stopped entirely, subaerial exposure would create an unconformity. Blocks slowly uplifting during deposition would receive thinner cycles across that block or the cycles would onlap onto it, and appear as a bulge in the shelf to basin profile.

Lindsay, R.F. [Chevron U.S.A. Production Co., Midland, TX (United States)

1996-12-31

433

Recognition of eustatic versus tectonic signatures in the carbonate sequence stratigraphic record  

SciTech Connect

In the process of building sequence stratigraphic models it has become apparent that both eustatic and tectonic signatures can be recognized in the sequence stratigraphic record. Tectonics, active during deposition, modify the shelf to basin profile to leave a signature of increased or decreased rates of subsidence or uplift, or by quiescence. Subsidence or uplift may increase, decrease, or stop, and start again in short amounts of time. Tectonics can dramatically control the positioning of high to low quality reservoir rock. Eustatic sea level rise and fall may be synchronous or out of phase with tectonic events on the cycle, set, or sequence scale. On the sequence scale, if subsidence rates increased dramatically eustatic sea level rise and fall would deposit less complete shallowing-upward cycles in a transgressive systems tract. As subsidence slowed eustatic sea level would deposit complete cycles, containing exposure surfaces, in a highstand systems tract. If the basement is broken into discrete blocks, individual blocks may adjust differentially. One block may subside while an adjacent block may be quiescent or slowly uplifting. If one block abruptly subsides adjacent to a block that did not, cycles in the subsiding block thicken to form a wedge. As subsidence slowed and became more uniform, cycles across the same area will be of equal thickness. If subsidence stopped entirely, subaerial exposure would create an unconformity. Blocks slowly uplifting during deposition would receive thinner cycles across that block or the cycles would onlap onto it, and appear as a bulge in the shelf to basin profile.

Lindsay, R.F. (Chevron U.S.A. Production Co., Midland, TX (United States))

1996-01-01

434

Late Cretaceous radiolarians of the genera Cuboctostylus Bragina and Hexacromyum Haeckel: Their stratigraphic and paleobiogeographical distribution  

NASA Astrophysics Data System (ADS)

Recently, representatives of the genus Cuboctostylus Bragina (order Entactinaria) were included in the Upper Cretaceous radiolarian regional stratigraphic scale of Sakhalin. The Late Cretaceous species Hexacromyum pergamenti Bragina (order Spumellaria) has morphological similarity to representatives of the genus Cuboctostylus. Peculiar features of H. pergamenti internal structure are considered. Collections of Upper Cretaceous radiolarians from southern Cyprus, Serbia, northern Turkey, Crimean Mountains, East European Platform, northwestern Kamchatka, eastern slope of the Sredinnyi Range in Kamchatka, and Shikotan Island (Lesser Kurile Range) were used for the analysis of the taxonomic composition of Late Cretaceous representatives of the genera Cuboctostylus Bragina and Hexacromyum Haeckel as well as their stratigraphic and paleobiogeographic distribution. It is established that Cuboctostylus is distributed from tropical to south boreal realms. This genus is shown to exist through almost the entire Late Cretaceous: from the middle Cenomanian to initial Maastrichtian. Hexacromyum Haeckel populated both the south boreal realm and marginal areas of the Tethys Ocean in the Late Cretaceous. The new data presented may be used for distant interregional correlations. Cuboctostylus stellatus sp. nov. and several other Cuboctostylus taxa identified in open nomenclature are described; some morphological features of Hexacromyum pergamenti are specified.

Bragina, L. G.

2013-01-01

435

Stratigraphic division and depositional processes for the Mesozoic basin in Northern South China Sea  

NASA Astrophysics Data System (ADS)

This paper divided the age of Mesozoic strata in the Northern South China Sea into epochs by the stratigraphic correlation between land and sea areas. A Mesozoic stratigraphic profile from South China to the northern continental slope of the South China Sea was constructed by ground and seismic surveys. The depositional process was illustrated by the chronostratigraphic framework of the Mesozoic basin, and the oil and gas exploration prospect was discussed. Results indicate that the depositional process from the initial transgression in the Late Triassic to the Mesozoic maximum flooding event that occurred in the Early Jurassic period formed a continuous transgression when the depositional environment varied from littoral to semi-closed gulf and shelf. After this maximum flooding event, a continuous marine regressive process developed, including seawater withdrawal from the South China epicontinental region at the end of the Early Jurassic period, seawater withdrawal to the outer shelf of the Northern South China Sea at the end of the Early Cretaceous period, and seawater withdrawal to the slope trough at the end of the Cretaceous period. Research achievement not only connects major Mesozoic geological events but also specifies the time nodes of such events. Thus, an investigation of this event is significant to the Mesozoic tectonic evolution study of the South China Sea and Paleo-Pacific Ocean.

Xu, Guo-Qiang; Wu, Shi-Hu; Zhang, Li; Li, Xiao-Gang; Yi, Hai; Lei, Lei; Xu, Xun

2013-12-01

436

Global Snow Mass Measurements and the Effect of Stratigraphic Detail on Inversion of Microwave Brightness Temperatures  

NASA Astrophysics Data System (ADS)

Snow provides large seasonal storage of freshwater, and information about the distribution of snow mass as snow water equivalent (SWE) is important for hydrological planning and detecting climate change impacts. Large regional disagreements remain between estimates from reanalyses, remote sensing and modelling. Assimilating passive microwave information improves SWE estimates in many regions, but the assimilation must account for how microwave scattering depends on snow stratigraphy. Physical snow models can estimate snow stratigraphy, but users must consider the computational expense of model complexity versus acceptable errors. Using data from the National Aeronautics and Space Administration Cold Land Processes Experiment and the Helsinki University of Technology microwave emission model of layered snowpacks, it is shown that simulations of the brightness temperature difference between 19 and 37 GHz vertically polarised microwaves are consistent with advanced microwave scanning radiometer-earth observing system and special sensor microwave imager retrievals once known stratigraphic information is used. Simulated brightness temperature differences for an individual snow profile depend on the provided stratigraphic detail. Relative to a profile defined at the 10-cm resolution of density and temperature measurements, the error introduced by simplification to a single layer of average properties increases approximately linearly with snow mass. If this brightness temperature error is converted into SWE using a traditional retrieval method, then it is equivalent to ±13 mm SWE (7 % of total) at a depth of 100 cm. This error is reduced to ±5.6 mm SWE (3 % of total) for a two-layer model.

Richardson, Mark; Davenport, Ian; Gurney, Robert

2014-05-01

437

Radiolarian biostratigraphic data from the Casiguran Ophiolite, Northern Sierra Madre, Luzon, Philippines: Stratigraphic and tectonic implications  

NASA Astrophysics Data System (ADS)

Results from the first detailed radiolarian biostratigraphic study conducted in Luzon are reported. The data were obtained from cherts associated with the Casiguran Ophiolite, a dismembered ophiolite mass consisting of serpentinized peridotites, gabbros, dolerite dikes and pillow basalts exposed along the eastern coast of the Northern Sierra Madre, Luzon, Philippines. Cherts and limestone interbeds conformably overlie the ophiolite. The radiolarian assemblages from the cherts constrain the stratigraphic range of the cherts to the Lower Cretaceous (upper Barremian-lower Aptian to Albian). This new biostratigraphic result is in contrast with the Upper Cretaceous stratigraphic range previously reported in the region. Radiolarian biostratigraphic results from the Casiguran Ophiolite provide additional evidence for the existence of Mesozoic oceanic substratum upon which Luzon and neighboring regions within the Philippine archipelago were likely built. Interestingly, the result closely resembles those reported for the ophiolite in southeastern Luzon as well as the oceanic crust of the Huatung Basin situated east of Taiwan and the ophiolites in eastern Indonesia. In light of this, along with previously gathered geochemical data from the ophiolites, a common provenance is being looked into for these crust-upper mantle sequences in the western Pacific region.

Queano, Karlo L.; Marquez, Edanjarlo J.; Aitchison, Jonathan C.; Ali, Jason R.

2013-03-01

438

Stratigraphic and structural evolution of the Selenga Delta Accommodation Zone, Lake Baikal Rift, Siberia  

USGS Publications Warehouse

Seismic reflection profiles from the Lake Baikal Rift reveal extensive details about the sediment thickness, structural geometry and history of extensional deformation and syn-rift sedimentation in this classic continental rift. The Selenga River is the largest single source of terrigenous input into Lake Baikal, and its large delta sits astride the major accommodation zone between the Central and South basins of the lake. Incorporating one of the world's largest lacustrine deltas, this depositional system is a classic example of the influence of rift basin structural segmentation on a major continental drainage. More than 3700?km of deep basin-scale multi-channel seismic reflection (MCS) data were acquired during the 1989 Russian and the 1992 Russian–American field programs. The seismic data image most of the sedimentary section, including pre-rift basement in several localities. The MCS data reveal that the broad bathymetric saddle between these two major half-graben basins is underlain by a complex of severely deformed basement blocks, and is not simply a consequence of long-term deltaic deposition. Maximum sediment thickness is estimated to be more than 9?km in some areas around the Selenga Delta. Detailed stratigraphic analyses of the Selenga area MCS data suggest that modes of deposition have shifted markedly during the history of the delta. The present mode of gravity- and mass-flow sedimentation that dominates the northern and southern parts of the modern delta, as well as the pronounced bathymetric relief in the area, are relatively recent developments in the history of the Lake Baikal Rift. Several episodes of major delta progradation, each extending far across the modern rift, can be documented in the MCS data. The stratigraphic framework defined by these prograding deltaic sequences can be used to constrain the structural as well as depositional evolution of this part of the Baikal Rift. An age model has been established for this stratigraphy, by tying the delta sequences to the site of the Baikal Drilling Project 1993 Drill Hole. Although the drill hole is only 100?m deep, and the base of the cores is only ?670?ka in age, ages were extrapolated to deeper stratigraphic intervals using the Reflection-Seismic-Radiocarbon method of Cohen et al. (1993). The deep prograding delta sequences now observed in the MCS data probably formed in response to major fluctuations in sediment supply, rather than in response to shifts in lake level. This stratigraphic framework and age model suggest that the deep delta packages developed at intervals of approximately 400?ka and may have formed as a consequence of climate changes affiliated with the northern hemisphere glaciations. The stratigraphic analysis also suggests that the Selenga Basin and Syncline developed as a distinct depocentre only during the past ?2–3