Sample records for offshore stratigraphic test

  1. Norwegian Offshore Stratigraphic Lexicon (NORLEX)

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

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

  2. Sequence stratigraphic framework of Neogene strata in offshore Nigeria

    SciTech Connect

    Pacht, J.A. [Seis Strat Services, Inc., Sugar Land, TX (United States); Bowen, B.E.; Hall, D.J. [Excalibur Consulting, Houston, TX (United States)] [and others

    1996-08-01

    The western portion of the Nigerian continental margin (Dahomey Basin) exhibits stable to moderately unstable progradation. Systems tracts are similar to those described by Vail for stable progradational margins. In contrast, strata off the central and eastern portions of the Nigerian coast (Niger Delta Complex) exhibit highly unstable progradation, and systems tracts are similar to those in Neogene strata of the offshore Gulf of Mexico. Lowstand basin floor fans in both areas are defined by a well-developed upper reflection. This reflection downlaps along the sequence boundary or abuts against the downthrown side of a growth fault surface. Most lower lowstand (slope fan) strata exhibit discontinuous to semi-continuous subparallel reflections. However, this systems tract also contains channel complexes characterized by chaotic bedding with small bright spots and less common large channels, which exhibit concave-upward reflections. In the western portion of the study area, lower lowstand deposits commonly pinch out on the slope. Deposition occurred largely from point sources. In contrast, contemporaneous shallow-water facies are developed in lower lowstand systems tracts in the Niger Delta Complex. Deposition occurred along a line source. Large amplitude anomalies in the upper lowstand (prograding wedge) suggest well-developed sheet sands occur in shallow-water and deep-water in the Niger Delta complex. However, in the Dahomey Basin there is little evidence of deep-water sands in this interval. The transgressive and highstand systems tracts are usually very thin in outer shelf to basin floor strata in both areas. Both the Dahomey Basin and Niger Delta Complex exhibit different stratigraphic geometries, and therefore, require different exploration strategies.

  3. Seismic-stratigraphic analysis of Miocene system, offshore Texas - models and implications

    SciTech Connect

    Riese, W.C.; Hill, W.A.; Rosen, R.N.

    1989-03-01

    The application of traditional seismic-stratigraphic models to the Miocene System offshore Texas was tested and found to be inadequate for the description of this section. Although the basic principles inherent to the application of seismic stratigraphy are useful, there are significant deviations from the model geometries of system tracts in the Miocene System. The most significant of these discrepancies is the apparent absence of lowstand wedges and shelf-margin wedges. Problems with applying the traditional seismic stratigraphic models and geometries to the interpretation of this section have been recognized by others, and alternative ramp and growth-fault models have been suggested. These, too, appear to be inadequately for interpretation of this section: the ramp model fails to account adequately for outer neritic bathymetries in apparent outer-shelf settings during lowstands; the growth-fault model fails to adequately explain downthrown expansion of predominantly shale intervals. The alternatives proposed postulate a fundamental difference in global, or at least basinal, water budgets for Miocene time relative to the Pleistocene or Holocene: eustatic levels in the Gulf of Mexico during the Miocene were apparently several hundred feet higher than during the Pleistocene and therefore erosion of the shelf during lowstands was minimal. The authors may also infer that surface gradients on the Texas shelf were steep during the Miocene and there was no pronounced continental shelf-slope break. Without such a break there is no steep surface against which to onlap the updip reaches of shelf-margin wedges or lowstand wedges, thus accounting for the absence of these geometries in their seismic data. this accounts for the presence of depositional fans in outer neritic, apparently shelfal settings during lowstands.

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

    SciTech Connect

    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

    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.

  5. Seismic stratigraphic analysis of the Punta del Este basin, offshore Uruguay, South America

    SciTech Connect

    Stoakes, F.A.; Campbell, C.V. (Stoakes Campbell Geoconsulting Ltd., Calgary, Alberta (Canada)); Cass, R. (Arvec Consulting Ltd., Calgary, Alberta (Canada)); Ucha, N. (ANCAP, Montivideo (Uruguay))

    1991-02-01

    The Punta del Este part of the greater Salado basin is relatively unexplored with only two wells having been drilled, both in the updip part of the basin. These two wells have contributed some understanding of the stratigraphic succession but have failed to adequately assess the basin's true hydrocarbon potential. This paper constitutes one of the first detailed, comprehensive published accounts of this basin and is a prerequisite for future exploration in the area. In this paper, the authors give the results and major conclusions of a regional seismic stratigraphic analysis of the Punta del Este basin, offshore Uruguay. This paper is one of the first detailed, comprehensive published accounts of the tectonic and sedimentary evolution of this basin. The study area covers approximately 15,000 km{sup 2} (5,790 mi{sup 2}) of the continental shelf, from the shoreline to the 200-m (655-ft) shelf isobath.

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

    SciTech Connect

    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

    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.

  7. Sequence stratigraphic applications to deep-water exploration in the Makassar Strait, offshore East Kalimantan, Indonesia

    SciTech Connect

    Malacek, S.J.; Reaves, C.M.; Atmadja, W.S.; Widiantara, K.O. (Mobil Oil Indonesia, Jakarta (Indonesia))

    1994-07-01

    A sequence stratigraphic study was conducted to help evaluate the exploration potential of the Makassar PSC, offshore East Kalimantan, Indonesia. The PSC is on the present-day slope in water depths of 500-3000 ft and borders the large oil and gas fields of the Mahakam delta. The study provided important insights on reservoir distribution, trapping style, and seismic hydrocarbon indicators. Lowstand deposition on a slope modified by growth faulting and shale diapirism controlled reservoir distribution within the prospective late Miocene section. Three major lowstand intervals can be seismically defined and tied to deep-water sands in nearby wells where log character and biostratigraphic data support the seismic system tract interpretation. The three intervals appear to correlate with third-order global lowstand events and are consistent with existing sequence stratigraphic schemes for the shelf and upper slope in the Makassar area. Seismic mapping delineated lowstand features, including incised valleys and intraslope to basin-floor thicks. Regional information on positions of middle-late Miocene delta lobes and shelf edges, helped complete the picture for sand sources, transport routes, and depocenters.

  8. Stratigraphic contacts from drillholes at the Nevada Test Site

    SciTech Connect

    Wagoner, J.L.; Richardson, W.

    1986-07-07

    This report is a compilation of stratigraphic contacts and several other parameters from drillholes at the Nevada Test Site. No post-shot holes are included. These data are stored in the LLNL Containment Program databases. This document should be used as a guideline only, since the accuracy of the data depends completely upon its source. The stratigraphic contacts for holes drilled before BANEBERRY are questionable because the contacts were determined mainly by using cuttings without the luxury of a full suite of geophysical logs or downhole photography. The contacts for post-BANEBERRY holes are probably correct to within 1 m.

  9. Revisiting the Tectono-Stratigraphic Evolution of the Eastern Mediterranean Offshore Levant and Nile Delta

    NASA Astrophysics Data System (ADS)

    Al-Balushi, Abdulaziz; Fraser, Alastair; A-L Jackson, Christopher; Bell, Rebecca; Kusznir, Nick

    2015-04-01

    Although the Eastern Mediterranean has become the focus for increased oil and gas exploration following significant discoveries in the pre-Messinian succession offshore Egypt and the Levant Margin, understanding its tectono-stratigraphic evolution is the first and most important step towards building reliable geological models that underpin petroleum play assessment. The Eastern Mediterranean Basin has evolved through a complex and poorly understood tectonic history. Disagreement within the scientific community relates to the age of rifting, the orientation of the crustal stretching direction and the type of crust underlying the Levant Basin and, by proxy, the magnitude of stretching. We present, for the first time, an interpretation of deep (i.e. 12-20 sec TWT) regional 2D seismic lines covering the entire Levant Basin. We have interpreted nine seismic surfaces (from top basement to seabed) from which depth and isopach maps for key surfaces and intervals have been generated. To constrain the rifting age, we have used a reverse subsidence modelling technique and restored the Middle Jurassic and the Late Cretaceous basin geometry along a NW-trending seismic profile from the Levant Basin. The restorations, for a specific rifting age, that meet geological constraints on water depth that are obtained from well data and seismic stratigraphy, are considered as viable solutions. The type of crust that underlies the Levant Margin has been inferred from the magnitude of the lithospheric stretching derived from gravity inversion and crustal thinning. Our interpretation of top basement and the Middle Jurassic depth-structure maps suggests that rifting in the Levant Basin led to the development of two main depocentres; in the northern Levant and the southern Levant, in the vicinity of the Nile Delta. These depocentres are separated by a series of NE-trending, fault- bound structural highs (i.e. Jonah and Leviathan). The orientation of the faults suggests they formed in response to NW-SE extension, which is further supported by the observation of a NW-SE-striking transform fault along the north-western Egyptian Margin. Reverse subsidence modelling indicates that rifting ages between 200 Ma and 176 Ma are required to restore the Middle Jurassic and the Upper Cretaceous surfaces to match the geological constraints on Middle Jurassic and Late Cretaceous palaeo-water depths. This predicted rifting age is in partial agreement with the rifting ages proposed by Gardosh et al. (2010) and Longacre et al. (2007) models. However, it disagrees with the rifting ages proposed by other models (i.e. Dercourt et al., 1986; Stampfli et al., 1991; Robertson, 1998; Garfunkel, 1998,2004). High values of lithospheric stretching (Beta > 5) are predicted by gravity inversion and crustal thinning in northern Levant which suggests that sea floor spreading is very likely to have occurred following rifting. We believe that a remnant of the Neo-Tethys Ocean is preserved because of the collision of the continental Eratosthenes Seamount with the Cyprus Arc, which locked up the subduction process.

  10. The Offshore New Harbor (ONH) Seismic Expedition: Revealing the Stratigraphic History in the Southern McMurdo Sound Region, Ross Sea, Antarctica from the Greenhouse to Icehouse Worlds

    Microsoft Academic Search

    S. F. Pekar; M. A. Speece; G. S. Wilson; D. A. Sunwall; K. J. Tinto

    2010-01-01

    In the austral spring 2008, the ANDRILL (ANtarctic geological DRILLing) Program's Offshore New Harbor Expedition successfully collected over 48 km of multi-channel seismic (MCS) data to investigate the stratigraphic and tectonic history of westernmost Southern McMurdo Sound during the Greenhouse World (Eocene) and the start of the Icehouse World (Oligocene). This survey represents an important step for identifying future drilling

  11. Seismic stratigraphic record of transpression and uplift on the Romanche transform margin, offshore Ghana

    Microsoft Academic Search

    Kodjopa Attoh; Larry Brown; Jingru Guo; Joel Heanlein

    2004-01-01

    Recently, available multi-channel seismic reflection data from offshore Ghana have been reprocessed to probe the eastern Romanche Fracture Zone (RFZ) of the Equatorial Atlantic and the sedimentary basins of the paleotransform margin. The RFZ terminates landward in a submarine canyon, up to 2 km deep and >50 km wide, variably filled with submarine fans and projects landward into a Neoproterozoic

  12. Stratigraphic development during the Late Pleistocene and Holocene offshore of the Yellow River delta, Bohai Sea

    Microsoft Academic Search

    Jian Liu; Yoshiki Saito; Hong Wang; Liangyong Zhou; Zigeng Yang

    2009-01-01

    A 61-m-long sediment core (HB-1) and 690 km of high-resolution seismic profiles from offshore of the Yellow River delta, Bohai Sea, were analyzed to document the stratigraphy and sea-level changes during the Late Pleistocene and Holocene. Accelerator mass spectrometry C-14 dating and analyses of benthic foraminifera, ostracods, the mineral composition, and sedimentary characteristics were performed for core HB-1, and seven

  13. Seismic stratigraphic record of transpression and uplift on the Romanche transform margin, offshore Ghana

    NASA Astrophysics Data System (ADS)

    Attoh, Kodjopa; Brown, Larry; Guo, Jingru; Heanlein, Joel

    2004-01-01

    Recently, available multi-channel seismic reflection data from offshore Ghana have been reprocessed to probe the eastern Romanche Fracture Zone (RFZ) of the Equatorial Atlantic and the sedimentary basins of the paleotransform margin. The RFZ terminates landward in a submarine canyon, up to 2 km deep and >50 km wide, variably filled with submarine fans and projects landward into a Neoproterozoic dextral shear zone. By contrast, the RFZ to the southwest is represented by an ENE submarine escarpment juxtaposing continental and oceanic crusts. Three major sedimentary sequences representing pre-, syn- and post-rift strata have been identified from the seismic profiles and calibrated with chronostratigraphic data from oil exploration wells. The pre-rift sequence consists largely of Paleozoic strata ranging in age from Devonian to Carboniferous. The overlying syn-rift sequence, which was deposited during the intracontinental shearing stage, consists of Aptian to Albian silicilastic strata with distinct continental facies. The seismic sections provide some of the clearest images yet of: (i) folding associated with transform displacement, and (ii) southwest increasing subaerial erosion and stratal discordance. We attribute lateral variation in erosion to crustal thickening associated with folding and to transient thermal effect of ridge-transform interaction which is predicted to produce westward increasing uplift on this margin.

  14. Sequence Stratigraphic Analysis for Delineating the Sedimentation Characteristic and Modeling of Nidoco Area, Off-Shore Nile Delta, Egypt

    NASA Astrophysics Data System (ADS)

    Nasr El Deen, Ahmed; Abu El-Ata, Ahmed; El-Gendy, Nader

    2014-05-01

    The Egyptian Nile Delta has recognized over the different human civilizations, as the source of life/ basket of wheat. In the recent time, the Nile Delta revealed another hidden treasure that hidden below the Mediterranean Sea within its sediments. This treasure reflects a number of giant gas reservoirs that require only the suitable technology and the assured ideas to commence injecting gas into the industrial veins of the growing Egyptian economy. The current study is aiming to discuss the Messinian Prospectivity of the concerned area, which is located in the offshore of the Nile Delta, about 25 Km from the Mediterranean Sea shoreline. An integrated exploration approach applied for a selected area, using a variety of subsurface borehole geologic and log data of the selected wells distributed in the study area, as well as biostratigraphic data. The well data comprise well markers, and electric logs (e.g. gamma ray, density, neutron and sonic logs), where the geological data represented by litho-stratigraphic information, as well as ditch samples analysis of the studied interval. Biostratigraphic data include biozones, benthonic to planktonic ratios, nannofossils and foraminiferal data. Different methods and techniques were applied by using different softwares such as Petrel and Interactive petrophysical software. Four missing times were identified intra-Pleistocene, Late Pliocene, Late Pliocene-Early Pliocene and Messinian. It has concluded that, the depositional environments ranged from shallow marine to middle nerritic and may reach upper bathyal toward the northern part of the study area. The top of Abu Madi Formation dated with the calcareous nannofossils zone NN12a, while the base dated with NN11c, and its age varied from 5.2 Ma to 5.7 Ma. The maximum flooding surface is dated with the calcareous nannofossils zone NN13 and the planktonic foraminiferal zone SN18 at 5 Ma (the acme presence of the Sphaeroidinellopsis sp.). From the utility of wireline logs for sequence stratigraphy using the different log tools for lithological interpretation and their impact upon the reflection characteristics and sequence stratigraphic interpretation, it is concluded the parasequence sets, system tracts, surface boundaries and their distribution within each well and their control on the sand distribution within each formation. In the present work, the Late Miocene (Messinian) and the Early Pliocene (Zanclian) pay-zones are the only rock units, that have integrated wireline logs approach, so it can be divided into 4 sequences; UM-1, UM-2A, UM-2B and LZ-1.

  15. The Role of Sequence Stratigraphic Analysis in the Messinian crisis at Baltim Area, Off-Shore Nile Delta, Egypt

    NASA Astrophysics Data System (ADS)

    Nasr El-Deen Badawy, A. M.; Abu El-Ata, A. S.; El-Gendy, N. H.

    2013-12-01

    The Egyptian Nile Delta has recognized over the different human civilizations, as the source of life/ basket of wheat. In the recent time, the Nile Delta revealed another hidden treasure that hidden below the Mediterranean Sea within its sediments. This treasure reflects a number of giant gas reservoirs that require only the suitable technology and the assured ideas to commence injecting gas into the industrial veins of the growing Egyptian economy. The current study is aiming to discuss the Messinian Prospectivity of the concerned area, which is located in the offshore of the Nile Delta, about 25 Km from the Mediterranean Sea shoreline. An integrated exploration approach applied for a selected area, using a variety of subsurface borehole geologic and log data of the selected wells distributed in the study area, as well as biostratigraphic data. The well data comprise well markers, and electric logs (e.g. gamma ray, density, neutron and sonic logs), where the geological data represented by litho-stratigraphic information, as well as ditch samples analysis of the studied interval. Biostratigraphic data include biozones, benthonic to planktonic ratios, nannofossils and foraminiferal data. Different methods and techniques were applied by using different softwares such as Petrel and Interactive petrophysical software. Four missing times were identified intra-Pleistocene, Late Pliocene, Late Pliocene-Early Pliocene and Messinian. It has concluded that, the depositional environments ranged from shallow marine to middle nerritic and may reach upper bathyal toward the northern part of the study area. The top of Abu Madi Formation dated with the calcareous nannofossils zone NN12a, while the base dated with NN11c, and its age varied from 5.2 Ma to 5.7 Ma. The maximum flooding surface is dated with the calcareous nannofossils zone NN13 and the planktonic foraminiferal zone SN18 at 5 Ma (the acme presence of the Sphaeroidinellopsis sp.). From the utility of wireline logs for sequence stratigraphy using the different log tools for lithological interpretation and their impact upon the reflection characteristics and sequence stratigraphic interpretation, it is concluded the parasequence sets, system tracts, surface boundaries and their distribution within each well and their control on the sand distribution within each formation. In the present work, the Late Miocene (Messinian) and the Early Pliocene (Zanclian) pay-zones are the only rock units, that have integrated wireline logs approach, so it can be divided into 4 sequences; UM-1, UM-2A, UM-2B and LZ-1.

  16. Stratigraphic development during the Late Pleistocene and Holocene offshore of the Yellow River delta, Bohai Sea

    NASA Astrophysics Data System (ADS)

    Liu, Jian; Saito, Yoshiki; Wang, Hong; Zhou, Liangyong; Yang, Zigeng

    2009-10-01

    A 61-m-long sediment core (HB-1) and 690 km of high-resolution seismic profiles from offshore of the Yellow River delta, Bohai Sea, were analyzed to document the stratigraphy and sea-level changes during the Late Pleistocene and Holocene. Accelerator mass spectrometry 14C dating and analyses of benthic foraminifera, ostracods, the mineral composition, and sedimentary characteristics were performed for core HB-1, and seven depositional units (DU 1-DU 7 in descending order) were identified. The seismic reflection data were interpreted in light of the sedimentological data of the core and correlated with other well-studied cores obtained previously in the Bohai Sea area. Seven seismic units (SU 1 to SU 7 in descending order) were distinguished and interpreted as follows: SU 7 corresponds to marine facies in Marine Isotopic Stage (MIS) 5; SU 6, to terrestrial facies in MIS 4; SU 5 and SU 4, to alternating terrestrial and marine facies (DU 7-DU 5) in MIS 3; SU 3, to terrestrial facies (DU 4) in MIS 2; SU 2, to Holocene marine facies (DU 3 and DU 2); and SU 1, to modern Yellow River delta sediments deposited since 1855 (DU 1). The sedimentary facies from DU 7 to DU 5 reflect sea-level fluctuations during MIS 3, and the boundary between DU 5 and DU 6, which coincides with that between SU 4 and SU 5, is a distinctive, laterally continuous, undulating erosion surface, with up to ˜20 m of relief. This surface reflects subaerial exposure between transgressions during MIS 3. Estimated sea levels during MIS 3 ranged from -35 ± 5 to -60 ± 5 m or lower, with short-term fluctuations of ˜20 m. Sedimentary environments in the Bohai Sea area were governed mainly by eustatic sea-level changes and the Bohai Strait topography, which controls the entry of sea water into the Bohai Sea area. The mineral composition of the sediment core suggests that the Yellow River did not discharge into the Bohai Sea, or at least did not influence the study area significantly, during parts of MIS 3 and MIS 2 to the early Holocene (˜11-8.5 cal kyr BP).

  17. Ultrasonic thickness testing of aging offshore structures

    E-print Network

    Ellison, Brian Kirk

    1999-01-01

    August 1999 Major Subject: Civil Engineering ULTRASONIC THICKNESS TESTING OF AGING OFFSHORE STRUCTURES A Thesis by BRIAN KIRK ELLISON Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... as series to show the longitudinal thickness variations. Averages among all rays and all rings were also plotted. For Member 01 (R), they are shown in Figs. 2. 7 to 2. 10. 0. 350 0. 340 0. 330 @ 0. 320 EQ 0. 310 Q 0. 300 ~o 0. 290 Z 0. 260 0. 270...

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

    E-print Network

    Wright, Christine M.

    2009-05-15

    in the East Nam Con Son Basin. Age constraints were assigned to key stratigraphic horizons by correlating sequence boundaries with published sea level curves. Accommodation in the study area is controlled by shelf -edge compaction, rift-related thermal...

  19. Selected stratigraphic data for drill holes located in Frenchman Flat, Nevada Test Site. Rev. 1

    SciTech Connect

    Drellack, S.L. Jr.

    1997-02-01

    Stratigraphic data are presented in tabular form for 72 holes drilled in Frenchman Flat, Nevada Test Site, between 1950 and 1993. Three pairs of data presentations are included for each hole: depth to formation tops, formation thicknesses, and formation elevations are presented in both field (English) and metric units. Also included for each hole, where available, are various construction data (hole depth, hole diameter, surface location coordinates) and certain information of hydrogeologic significance (depth to water level, top of zeolitization). The event name is given for holes associated with a particular nuclear test. An extensive set of footnotes is included, which indicates data sources and provides other information. The body of the report describes the stratigraphic setting of Frenchman Flat, gives drill-hole naming conventions and database terminology, and provides other background and reference material.

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

    Microsoft Academic Search

    Kelly Rose; Ray Boswell; Timothy Collett

    2011-01-01

    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

  1. Neogene and Quaternary geology of a stratigraphic test hole on Horn Island, Mississippi Sound

    USGS Publications Warehouse

    Gohn, Gregory S.; Brewster-Wingard, G. Lynn; Cronin, Thomas M.; Edwards, Lucy E.; Gibson, Thomas G.; Rubin, Meyer; Willard, Debra A.

    1996-01-01

    During April and May, 1991, the U.S. Geological Survey (USGS) drilled a 510-ft-deep, continuously cored, stratigraphic test hole on Horn Island, Mississippi Sound, as part of a field study of the Neogene and Quaternary geology of the Mississippi coastal area. The USGS drilled two new holes at the Horn Island site. The first hole was continuously cored to a depth of 510 ft; coring stopped at this depth due to mechanical problems. To facilitate geophysical logging, an unsampled second hole was drilled to a depth of 519 ft at the same location.

  2. Simulation and Laboratory Tests of Ice Induced Offshore Structure Vibrations

    Microsoft Academic Search

    Justin Hovland

    This paper describes the dynamic testing of an offshore oil platform laboratory model outfitted with rubber-steel isolators and its accompanying computer model in ANSYS. Three different input excitation signals were used: harmonic sine waves, random ice loads, and fixed ice loads. The ice loads were composed of triangular force impulses and were designed to replicate a realistic loading situation for

  3. The Offshore New Harbor (ONH) Seismic Expedition: Revealing the Stratigraphic History in the Southern McMurdo Sound Region, Ross Sea, Antarctica from the Greenhouse to Icehouse Worlds

    NASA Astrophysics Data System (ADS)

    Pekar, S. F.; Speece, M. A.; Wilson, G. S.; Sunwall, D. A.; Tinto, K. J.

    2010-12-01

    In the austral spring 2008, the ANDRILL (ANtarctic geological DRILLing) Program’s Offshore New Harbor Expedition successfully collected over 48 km of multi-channel seismic (MCS) data to investigate the stratigraphic and tectonic history of westernmost Southern McMurdo Sound during the Greenhouse World (Eocene) and the start of the Icehouse World (Oligocene). This survey represents an important step for identifying future drilling targets for ANDRILL, which is a multinational program, with the aim to recover stratigraphic intervals for interpreting Antarctica’s climate and glacial history over the past 50 million years. The goal of the Offshore New Harbor Project is to recover proximal archives from two widely recognized but unresolved time intervals regarding Antarctica’s history: 1) the mid-Paleogene cryospheric development on Antarctica; and 2) the abrupt climate shift across the Eocene/Oligocene transition. The ONH seismic survey used methods successfully employed by previous ANDRILL’s surveys in Southern McMurdo Sound (2005) and in Mackay Sea Valley (2007), which included deploying a Generator Injector (G.I.) airgun through holes drilled through the ice and a 1.5 km long streamer that used 60 gimbled geophones to measure the returning reflected seismic energy. Processing of the seismic data was successfully able to remove the bottom water multiple, permitting deeper seismic reflectors to be identified for the first time in this area. Since one of the two seismic lines crossed close to the previously drilled CIROS-1, correlation was possible between the seismic reflectors and the entire stratigraphic section at CIROS-1, which has been dated as old as Late Eocene (~37 Ma). Additionally, seismic and gravity data indicated that a thick sedimentary wedge of up to 5 km lie immediately east of CIROS-1. With the Devonian Beacon Sandstone Formation having been observed to be no thicker than 2 km on land, an additional 3 km of Cenozoic sediments may lie below and down dip of CIROS-1. The Oligocene strata are characterized by a clinoformal geometry, with reflectors down lapping onto the two prominent reflectors that correspond to the Eocene / Oligocene Boundary and the “mid” Oligocene hiatus recognized in the CIROS-1 borehole. These new data support the idea that substantial Eocene and Oligocene strata can be recovered by drilling east of the location of the CIROS-1 borehole. The upper units imaged below the base of CIROS-1 represent the potential for future drilling objectives for the ANDRILL Program. Additionally, reflectors that contained trough-like shapes were interpreted as representing incised valleys, which were most likely cut by ice streams. These valleys provide prima facie documentation of when the ice sheet extended beyond the present-day coastline. These reflectors were correlated to CIROS-1 as well as the ANDRILL AND-2A borehole, providing ages on the timing of major ice stream advances of the East Antarctic Ice Sheet in the western Ross Sea area.

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

    USGS Publications Warehouse

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

    2011-01-01

    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.

  5. Downhole well log and core montages from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    Microsoft Academic Search

    T. S. Collett; R. E. Lewis; W. J. Winters; M. W. Lee; K. K. Rose; R. M. Boswell

    2011-01-01

    The BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well was an integral part of an ongoing project to determine the future energy resource potential of gas hydrates on the Alaska North Slope. As part of this effort, the Mount Elbert well included an advanced downhole geophysical logging program. Because gas hydrate is unstable at ground surface pressure and temperature conditions,

  6. Regional long-term production modeling from a single well test, Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    Microsoft Academic Search

    Brian J. Anderson; Masanori Kurihara; Mark D. White; George J. Moridis; Scott J. Wilson; Mehran Pooladi-Darvish; Manohar Gaddipati; Yoshihiro Masuda; Timothy S. Collett; Robert B. Hunter; Hideo Narita; Kelly K. Rose; Ray Boswell

    2011-01-01

    Following the results from the open-hole formation pressure response test in the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well (Mount Elbert well) using Schlumberger's Modular Dynamics Formation Tester (MDT) wireline tool, the International Methane Hydrate Reservoir Simulator Code Comparison project performed long-term reservoir simulations on three different model reservoirs. These descriptions were based on 1) the Mount Elbert gas

  7. Formation pressure testing at the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Operational summary, history matching, and interpretations

    Microsoft Academic Search

    Brian Anderson; Steve Hancock; Scott Wilson; Christopher Enger; Timothy Collett; Ray Boswell; Robert Hunter

    2011-01-01

    In February 2007, the U.S. Department of Energy, BP Exploration (Alaska), and the U.S. Geological Survey, collected open-hole pressure-response data, as well as gas and water sample collection, in a gas hydrate reservoir (the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well) using Schlumberger's Modular Dynamics Formation Tester (MDT) wireline tool. Four such MDT tests, ranging from six to twelve

  8. Testing the impact of stratigraphic uncertainty on spectral analyses of sedimentary time series

    NASA Astrophysics Data System (ADS)

    Martinez, Mathieu; Kotov, Sergey; De Vleeschouwer, David; Pas, Damien; Vahlenkamp, Maximilian

    2015-04-01

    Spectral analysis has become a key tool for identifying the imprint of astronomical forcing on sedimentary records. In a next step, the identified cycles often contribute to the construction of a precise Geological Time Scale and to an in-depth understanding of past climate changes. Most of spectral analyses (Fast Fourier Transforms, the Multi-Taper Method…) require a constant sample step. Unfortunately, an equally spaced geological data series is, in practice, nearly impossible to obtain from field sedimentary series. Usually, there is a 10% uncertainty on the field measurements of the stratigraphic thickness within sedimentary series. Hence, important uncertainties exist in the actual position of each sample. Another source of uncertainty are errors in a time-space model. In this study, we explore the impact that the stratigraphic uncertainty on the sample position has on the result of spectral analyses. To simulate this uncertainty, we developed a model based on Monte Carlo randomisation of the distance between each successive point. In this way, the stratigraphic order of the data points is not affected after implementing this model. The application of this model to a theoretical sinusoid series and to several real sedimentary series shows that uncertainties in the actual position of samples can highly reduce the spectral powers of the frequencies ranging from the Nyquist Frequency up to 1/10 of the Nyquist Frequency. We then demonstrate that the precise reconstruction of the Milankovitch cycles in the sedimentary record requires a higher sampling density than previously suggested with, at least, 10 samples per thinnest cycle to be detected, i.e. 10 samples per precession cycle.

  9. 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

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

    1996-12-31

    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.

  10. 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

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

    1996-01-01

    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.

  11. 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

    Esan, Adegbenga Oluwafemi

    2004-09-30

    Meren field, located offshore Niger Delta, is one of the most prolific oil-producing fields in the Niger Delta. The upper Miocene D-07, D-08 and E-01 oil sands comprise a series of stacked hydrocarbon reservoirs in Block 2 of Meren field...

  12. 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

    Esan, Adegbenga Oluwafemi

    2004-09-30

    Meren field, located offshore Niger Delta, is one of the most prolific oil-producing fields in the Niger Delta. The upper Miocene D-07, D-08 and E-01 oil sands comprise a series of stacked hydrocarbon reservoirs in Block ...

  13. Gas-Charged Sediments Within the Hyblean Plateu Seismo-Stratigraphic Sequence and Associated Likely Shallow Mud-Volacanoes Seafloor Features Offshore Southern Sicily (Sicily Channel - Mediterranean Sea)

    Microsoft Academic Search

    A. Savini; C. Tessarolo; C. Corselli

    2007-01-01

    A shallow province of small-scale likely mud-volcanoes (MVs) seafloor features was recently discovered few miles offshore south-eastern Sicily (Holland et al., 2003) over the Hyblean-Malta plateau (Sicily-channel - Mediterranean sea), on an area whose surface might be over 100 square km and in a bathymetric range comprised between -100 and -200m. Such discovery promoted the National multidisciplinary programm MESC (Mud

  14. Sour-gas sweetening during offshore drillsteam tests; A case history

    SciTech Connect

    Casselman, R.L. (Columbia Gas Development Corp., Houston, TX (US))

    1990-03-01

    This case history details the use of a sour-gas sweetener on two exploratory well drillstem tests (DST's) offshore California. Also included is a brief description of the process and comments on future plans. This case history is intended to show that the process can be applied effectively in a sour-gas offshore DST. It shows performance on each of the exploratory wells and explains the solutions initiated to mitigate problems incurred in subsequent DST's.

  15. Downhole well log and core montages from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    USGS Publications Warehouse

    Collett, T.S.; Lewis, R.E.; Winters, W.J.; Lee, M.W.; Rose, K.K.; Boswell, R.M.

    2011-01-01

    The BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well was an integral part of an ongoing project to determine the future energy resource potential of gas hydrates on the Alaska North Slope. As part of this effort, the Mount Elbert well included an advanced downhole geophysical logging program. Because gas hydrate is unstable at ground surface pressure and temperature conditions, a major emphasis was placed on the downhole-logging program to determine the occurrence of gas hydrates and the in-situ physical properties of the sediments. In support of this effort, well-log and core data montages have been compiled which include downhole log and core-data obtained from the gas-hydrate-bearing sedimentary section in the Mount Elbert well. Also shown are numerous reservoir parameters, including gas-hydrate saturation and sediment porosity log traces calculated from available downhole well log and core data. ?? 2010.

  16. FIELD TEST KIT FOR CHARACTERIZING OIL-BRINE EFFLUENTS FROM OFFSHORE DRILLING PLATFORMS

    EPA Science Inventory

    This research program was initiated to evaluate test methods for characterizing oil-brine effluents from offshore oil production platforms and to package and deliver a field test kit for on-site oil-brine analyses. After an initial laboratory evaluation and selection of test meth...

  17. Testing Stratigraphic Integrity of Upper and Middle Paleolithic Deposits in Vindija Cave (Croatia): A Chipped Stone Refitting Analysis

    E-print Network

    Bruner, Kale

    2009-05-12

    refitting of the chipped stone assemblage within and between all stratigraphic levels at Vindija Cave was carried out and five percent of the assemblage was successfully refit. The vertical distribution of refitting artifacts throughout the Upper and Middle...

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

    SciTech Connect

    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

    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.

  19. Gas-Charged Sediments Within the Hyblean Plateu Seismo-Stratigraphic Sequence and Associated Likely Shallow Mud-Volacanoes Seafloor Features Offshore Southern Sicily (Sicily Channel - Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Savini, A.; Tessarolo, C.; Corselli, C.

    2007-12-01

    A shallow province of small-scale likely mud-volcanoes (MVs) seafloor features was recently discovered few miles offshore south-eastern Sicily (Holland et al., 2003) over the Hyblean-Malta plateau (Sicily-channel - Mediterranean sea), on an area whose surface might be over 100 square km and in a bathymetric range comprised between -100 and -200m. Such discovery promoted the National multidisciplinary programm MESC (Mud volcanoes Ecosystem study - Sicily Channel) aimed to provide a detailed acoustic mapping of the area (Savini et al., 2006) and focused water and sediment samples to study the ecosystem response to such geological phenomena. The main data set thus collected, during three different cruises carried out by the Italian R/V UNIVERSITATIS by mean of acoustic survey techniques, including new multibeam bathymetric data, side- scan sonar mosaics, a dense network of chirp-sonar profiles and focused multi-tip sparker profiles, is here presented. The detailed seafloor topography and the side scan sonar mosaic well show the occurrence of a field of more than 100 small scale conical and sub-conical seabed features, few meters high. Their morphologies, their strong acoustic scattering and the presence over them of distinct gas plumes, are foremost distinctive proprieties that liken them to MVs. Such filed consists of single and composite MVs arranged on the seafloor in two main different styles: 1) several conical features 50 - 200m in diameter, preferentially aligned along the isobaths 2) numerous close-set small cones no more than 10m in diameter, settled within well defined, flat, elongated areas (the largest one reaches 2000m in its long axis and 500m in its short axis) rising up to 10m from the seafloor. The acoustic character of the sediments in the chirp and sparker records indicates that such features are gas charged, because of the presence of numerous acoustic anomalies (i.e.: acoustic turbidity zones, wipe outs, gas pockets, enhanced reflectors...). In particular, the identified gas-related seafloor features are associated to sub- surface structures formed within a gas accumulative horizon covered by a variable thickness of sediments. This gas accumulative horizon has been found in association to a marked unconformity resembles the last trasgressive surface at the boundary between the Holocene and the Pleistocene sediments. Such gas-charged horizon has been used to map the depth of the free gas within the seafloor sediments. The depth of this "gas- front" is variable and domes up to the seafloor where MVs morphologies are found at the surface, often showing gas plumes (up to 20m high) at their top.

  20. Holocene earthquake record offshore Portugal (SW Iberia): Testing turbidite paleoseismology in a slow-convergence margin

    E-print Network

    Goldfinger, Chris

    Holocene earthquake record offshore Portugal (SW Iberia): Testing turbidite paleoseismology Georisorse C.N.R. ­ Universita` di Padova, 35137 Padova, Italy d Departament de Geodina`mica i Geofi Lisbon Earthquake and Tsunami and 1969 Horseshoe Earth- quake. Despite efforts to identify active

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

    SciTech Connect

    Gevorgian, V.

    2012-02-01

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

  2. A study of cyclic pressuremeter testing for offshore applications

    E-print Network

    Riner, Kenneth Byard

    1984-01-01

    tion IV 10 ? 13 Stiff to very stiff red clay with calcareous nodules and pockets, slickensided. 13 ? 20 Stiff to very stiff red clay, slicken- sided. Soil borings B-Sl and B-S2 are given in Figures 19 and 20. Cuttings encountered during cyclic... Compression Test + Minioture Vane Test l31 IO ? slickensided below lift 124 I I 9 ~ +w II8 FIC. 19: Boring ? S I ( Ift=02048m, itsf= 95. BkN/rrP, Ipcf=0. I57kMn ) TAMU Research and Extens(on Center 33 8ORING ? S2 DESCRIPTION OF MATER I AL O co...

  3. Use of formation pressure test results over a hydrate interval for long-term production forecasting at the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Implications of uncertainties

    Microsoft Academic Search

    Mehran Pooladi-Darvish; Huifang Hong

    2011-01-01

    In the first part of this paper, the pressure and temperature measurements obtained using Schlumberger's Modular Formation Dynamics Tester (MDT) conducted on the C2 interval in the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well (Mount Elbert Well) are history matched, with the following three objectives: (i) to obtain a better understanding of hydrate decomposition and its reformation as conditions

  4. Time series simulations of wideband spectra for fatigue tests of offshore structures

    SciTech Connect

    Lin, N.K.; Hartt, W.H.

    1984-12-01

    A time-series simulation method, based on the principle of time series modeling for dynamic systems, is used to reporduce a wide-band stress history from a prescribed stress spectral model for fatigue testing of offshore structures. The optimization procedures and stability of the time series model for the prescribed spectrum are presented and discussed. The optimization procedures are developed on the basis of the Levison-Durbin algorithm, which usually produces a stable time series model if the order of the time series model is even. An example is presented to demonstrate the applicability of the proposed method to long-time, high-cycle fatigue testing.

  5. Shaking table test and numerical analysis of offshore wind turbine tower systems controlled by TLCD

    NASA Astrophysics Data System (ADS)

    Chen, Jianbing; Liu, Youkun; Bai, Xueyuan

    2015-03-01

    A wind turbine system equipped with a tuned liquid column damper (TLCD) is comprehensively studied via shaking table tests using a 1/13-scaled model. The effects of wind and wave actions are considered by inputting response-equivalent accelerations on the shaking table. The test results show that the control effect of the TLCD system is significant in reducing the responses under both wind-wave equivalent loads and ground motions, but obviously varies for different inputs. Further, a blade-hub-tower integrated numerical model for the wind turbine system is established. The model is capable of considering the rotational effect of blades by combining Kane's equation with the finite element method. The responses of the wind tower equipped with TLCD devices are numerically obtained and compared to the test results, showing that under both controlled and uncontrolled conditions with and without blades' rotation, the corresponding responses exhibit good agreement. This demonstrates that the proposed numerical model performs well in capturing the wind-wave coupled response of the offshore wind turbine systems under control. Both numerical and experimental results show that the TLCD system can significantly reduce the structural response and thus improve the safety and serviceability of the offshore wind turbine tower systems. Additional issues that require further study are discussed.

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

    USGS Publications Warehouse

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

    2007-01-01

    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.

  7. Regional long-term production modeling from a single well test, Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    SciTech Connect

    Anderson, Brian; Kurihara, Masanori; White, Mark D.; Moridis, George J.; Wilson, Scott J.; Pooladi-Darvish, Mehran; Gaddipati, Manohar; Masuda, Yoshihiro; Collett, T. S.; Hunter, Robert B.; Narita, Hideo; Rose, Kelly K.; Boswell, Ray

    2011-02-02

    Following the results from the open-hole formation pressure response test in the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well (Mount Elbert well) using Schlumberger’s Modular Dynamics Formation Tester (MDT) wireline tool, the International Methane Hydrate Reservoir Simulator Code Comparison project performed long-term reservoir simulations on three different model reservoirs. These descriptions were based on 1) the Mount Elbert gas hydrate accumulation as delineated by an extensive history-matching exercise, 2) an estimation of the hydrate accumulation near the Prudhoe Bay L-pad, and 3) a reservoir that would be down-dip of the Prudhoe Bay L-pad and therefore warmer and deeper. All of these simulations were based, in part, on the results of the MDT results from the Mount Elbert Well. The comparison group’s consensus value for the initial perme- ability of the hydrate-filled reservoir (k = 0.12 mD) and the permeability model based on the MDT history match were used as the basis for subsequent simulations on the three regional scenarios. The simulation results of the five different simulation codes, CMG STARS, HydrateResSim, MH-21 HYDRES, STOMP-HYD, and TOUGHþHYDRATE exhibit good qualitative agreement and the variability of potential methane production rates from gas hydrate reservoirs is illustrated. As expected, the pre- dicted methane production rate increased with increasing in situ reservoir temperature; however, a significant delay in the onset of rapid hydrate dissociation is observed for a cold, homogeneous reservoir and it is found to be repeatable. The inclusion of reservoir heterogeneity in the description of this cold reservoir is shown to eliminate this delayed production. Overall, simulations utilized detailed information collected across the Mount Elbert reservoir either obtained or determined from geophysical well logs, including thickness (37 ft), porosity (35%), hydrate saturation (65%), intrinsic permeability (1000 mD), pore water salinity (5 ppt), and formation temperature (3.3–3.9 ?C). This paper presents the approach and results of extrapolating regional forward production modeling from history-matching efforts on the results from a single well test.

  8. Regional long-term production modeling from a single well test, Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    USGS Publications Warehouse

    Anderson, B.J.; Kurihara, M.; White, M.D.; Moridis, G.J.; Wilson, S.J.; Pooladi-Darvish, M.; Gaddipati, M.; Masuda, Y.; Collett, T.S.; Hunter, R.B.; Narita, H.; Rose, K.; Boswell, R.

    2011-01-01

    Following the results from the open-hole formation pressure response test in the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well (Mount Elbert well) using Schlumberger's Modular Dynamics Formation Tester (MDT) wireline tool, the International Methane Hydrate Reservoir Simulator Code Comparison project performed long-term reservoir simulations on three different model reservoirs. These descriptions were based on 1) the Mount Elbert gas hydrate accumulation as delineated by an extensive history-matching exercise, 2) an estimation of the hydrate accumulation near the Prudhoe Bay L-pad, and 3) a reservoir that would be down-dip of the Prudhoe Bay L-pad and therefore warmer and deeper. All of these simulations were based, in part, on the results of the MDT results from the Mount Elbert Well. The comparison group's consensus value for the initial permeability of the hydrate-filled reservoir (k = 0.12 mD) and the permeability model based on the MDT history match were used as the basis for subsequent simulations on the three regional scenarios. The simulation results of the five different simulation codes, CMG STARS, HydrateResSim, MH-21 HYDRES, STOMP-HYD, and TOUGH+HYDRATE exhibit good qualitative agreement and the variability of potential methane production rates from gas hydrate reservoirs is illustrated. As expected, the predicted methane production rate increased with increasing in situ reservoir temperature; however, a significant delay in the onset of rapid hydrate dissociation is observed for a cold, homogeneous reservoir and it is found to be repeatable. The inclusion of reservoir heterogeneity in the description of this cold reservoir is shown to eliminate this delayed production. Overall, simulations utilized detailed information collected across the Mount Elbert reservoir either obtained or determined from geophysical well logs, including thickness (37 ft), porosity (35%), hydrate saturation (65%), intrinsic permeability (1000 mD), pore water salinity (5 ppt), and formation temperature (3.3-3.9 ??C). This paper presents the approach and results of extrapolating regional forward production modeling from history-matching efforts on the results from a single well test. ?? 2010 Elsevier Ltd.

  9. Stratigraphic reference section for Georges Bank Basin--depositional model for New England passive margin

    SciTech Connect

    Poag, C.W.

    1982-08-01

    During 1976, the United States petroleum industry began the initial exploration of the Georges Bank basin, offshore Massachusetts, by drilling two deep Continental Offshore Stratigraphic Test (COST) wells: COST G-1 (16,071 ft; 4,899 m) and G-2 (21,874 ft; 6,667 m). The geologic data from these wells have been released to the public, and they provide the principal direct means of interpreting the geologic framework of the Georges Bank basin. This paper is an attempt to provide and to interpret in some detail the chronostratigraphy, lithostratigraphy, and paleoenvironments along a typical cross section of the basin. This section can be used to summarize the depositional history of the basin, to compare its geologic framework with that of other basins, to identify significant geologic problems, and to assist further research and exploration in the Georges Bank region.

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

    SciTech Connect

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

    1996-04-01

    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.

  11. Web-Based Integrated Precise Positioning System Design and Testing for Moving Platforms in Offshore Surveying

    Microsoft Academic Search

    Rahmi Nurhan CELIK

    2010-01-01

    SUMMARY Positions of points which are decided to drill exploration wells are defined after some feasibility studies in petroleum exploration activities carried out in offshore sea areas. For the wells that are planned to drill in the offshore sea areas, petroleum platforms (in shallow sea: jack-up platforms, in deep sea: semi-submersible, and in very deep sea: drillship) must be transported

  12. Teaching with Stratigraphic Profiles

    ERIC Educational Resources Information Center

    Stefanich, Greg P.

    1974-01-01

    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)

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

    SciTech Connect

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

    2013-07-01

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

  14. Data from stratigraphic test holes drilled at the U.S. Marine Corps Air Station, Cherry Point, North Carolina, 1994-2001, and periodic water levels, 2000-2003

    USGS Publications Warehouse

    Wrege, Beth M.; Jen, Philip S.

    2004-01-01

    Nine stratigraphic test holes, from 158 to 305 feet deep, were drilled at the U.S. Marine Corps Air Station at Cherry Point, North Carolina, between 1994 and 2001 by the U.S. Geological Survey. These test holes and subsequent wells provide information about the lithology, stratigraphy, and geology at the Marine Corps Air Station. In addition, ground-water-level data were collected at the Air Station through 2003. The U.S. Geological Survey also conducted high-resolution marine and land seismic surveys during this investigation. The ground-water-level data and locations of the seismic survey lines are included in this report. The stratigraphic data combined with the seismic data provide a basis for the delineation of paleochannels beneath the Air Station as well as information for the management of water resources at the Air Station.

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

    NASA Astrophysics Data System (ADS)

    Shin, Hyunkyoung; Cho, Sangrai; Jung, Kwangjin

    2014-03-01

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

  16. Analysis of core samples from the BPXA-DOE-USGS Mount Elbert gas hydrate stratigraphic test well: Insights into core disturbance and handling

    SciTech Connect

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

    2009-09-01

    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.

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

    SciTech Connect

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

    2011-06-01

    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.

  18. Tectonic-stratigraphic division and blind fold structures in Nansha Waters, South China Sea

    Microsoft Academic Search

    Pin Yan; Hailing Liu

    2004-01-01

    Extensive multiple-channel reflection seismic data have been collected in the Nansha (Spratley Islands) Waters, the southern margin of the South China Sea. Stratigraphic correlation is shown with focus on a comprehensive geophysiXcal survey line run from offshore NW Sabah to offshore SE Vietnam. According to the varying tectono-stratigraphy from southeast to northwest, five tectonic belts can be determined, i.e. the

  19. Seismic amplitude and coherency response of channel sand, offshore Louisiana, Gulf of Mexico

    E-print Network

    Fischer, Elena Mikhaylovna

    1999-01-01

    Geological drilling hazards are a major concern in the ics. drilling and development of offshore reservoirs. Some of these hazards may display high amplitudes on seismic profiles and some may be associated with stratigraphic features. Seismic...

  20. Seismic amplitude and coherency response of channel sand, offshore Louisiana, Gulf of Mexico 

    E-print Network

    Fischer, Elena Mikhaylovna

    1999-01-01

    Geological drilling hazards are a major concern in the ics. drilling and development of offshore reservoirs. Some of these hazards may display high amplitudes on seismic profiles and some may be associated with stratigraphic features. Seismic...

  1. Offshore Wind Research (Fact Sheet)

    SciTech Connect

    Not Available

    2011-10-01

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

  2. 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.

  3. Tribology offshore

    SciTech Connect

    Not Available

    1985-01-01

    The papers presented in this book deal with the performance and reliability of plant and materials in offshore engineering operations. The rigours of the North Sea environment have proved to be particularly strenuous for offshore equipment. The lessons learned in the last few years of exploration are relevant to offshore sites throughout the world. The topics covered include lifting gear, compressors, pumps, valves and seals, lubricants and lubrication, underwater equipment, friction and wear associated with the anchorage of rigs and platforms, sliding contract and condition monitoring offshore.

  4. 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)

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

    2008-12-01

    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.

  5. Stratigraphic statistical curvature analysis techniques

    SciTech Connect

    Bengtson, C.A.; Ziagos, J.P.

    1987-05-01

    SCAT applies statistical techniques to dipmeter data to identify patterns of bulk curvature, determine transverse and longitudinal structural directions, and reconstruct cross sections and contour maps. STRAT-SCAT applies the same concepts to geometric interpretation of multistoried unimodal, bimodal, or trough-type cross-bedding and also to seismic stratigraphy-scale stratigraphic structures. Structural dip, which comprises the bulk of dipmeter data, is related to beds that (statistically) were deposited with horizontal attitudes; stratigraphic dip is related to beds that were deposited with preferentially oriented nonhorizontal attitudes or to beds that assumed such attitudes because of differential compaction. Stratigraphic dip generates local zones of departure from structural dip on special SCAT plots. The RMS (root-mean-square) of apparent structural dip is greatest in the (structural) T-direction and least in the perpendicular L-direction; the RMS of stratigraphic dip (measured with respect to structural dip) is greatest in the stratigraphic T*-direction and least in the stratigraphic L*-direction. Multistoried, cross-bedding appears on T*-plots as local zones of either greater scatter or statistically significant departure of stratigraphic median dip from structural dip. In contrast, the L*-plot (except for trough-type cross-bedding) is sensitive to cross-bedding. Seismic stratigraphy-scale depositional sequences are identified on Mercator dip versus azimuth plots and polar tangent plots as secondary cylindrical-fold patterns imposed on global structural patterns. Progradational sequences generate local cycloid-type patterns on T*-plots, and compactional sequences generate local cycloid-type patterns on T*-plots, and compactional sequences generate local half-cusp patterns. Both features, however, show only structural dip on L*-plots.

  6. Stratigraphic Architecture of Table Rock, Boise, Idaho

    NSDL National Science Digital Library

    Sam Matson

    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.

  7. Field tests of six offshore oil containment booms. I. Final report

    Microsoft Academic Search

    P. R. Corpuz; R. A. Griffiths

    1978-01-01

    This report describes the test procedures and equipment used in testing six different oil containment booms in the Gulf of Mexico. Oil was not used. Each boom was evaluated for its seakeeping and logistic requirements for deployment and retrieval. Each boom was moored in a U shape, or catenary, configuration. This was done by establishing two sets of mooring buoys

  8. NaREC Offshore and Drivetrain Test Facility Collaboration: Cooperative Research and Development Final Report, CRADA Number CRD-04-140

    SciTech Connect

    Musial, W.

    2014-08-01

    The National Renewable Energy Laboratory (NREL) and the National Renewable Energy Centre (NaREC) in the United Kingdom (UK) have a mutual interest in collaborating in the development of full-scale offshore wind energy and drivetrain testing facilities. NREL and NaREC will work together to share resources and experiences in the development of future wind energy test facilities. This Cooperative Research and Development Agreement (CRADA) includes sharing of test protocols, infrastructure cost data, test plans, pro forma contracting instruments, and safe operating strategies. Furthermore, NREL and NaREC will exchange staff for training and development purposes.

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    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.

  10. Stratigraphic Modelling of Continental Rifting

    NASA Astrophysics Data System (ADS)

    Mondy, Luke; Duclaux, Guillaume; Salles, Tristan; Thomas, Charmaine; Rey, Patrice

    2013-04-01

    Interlinks between deformation and sedimentation have long been recognised as an important factor in the evolution of continental rifts and basins development. However, determining the relative impact of tectonic and climatic forcing on the dynamics of these systems remains a major challenge. This problem in part derives from a lack of modelling tools capable of simulated high detailed surface processes within a large scale (spatially and temporally) tectonic setting. To overcome this issue an innovative framework has been designed using two existing numerical forward modelling codes: Underworld, capable of simulating 3D self-consistent tectonic and thermal lithospheric processes, and Tellus, a forward stratigraphic and geomorphic modelling framework dedicated to simulating highly detailed surface dynamics. The coupling framework enables Tellus to use Underworld outputs as internal and boundary conditions, thereby simulating the stratigraphic and geomorphic evolution of a realistic, active tectonic setting. The resulting models can provide high-resolution data on the stratigraphic record, grain-size variations, sediment provenance, fluvial hydrometric, and landscape evolution. Here we illustrate a one-way coupling method between active tectonics and surface processes in an example of 3D oblique rifting. Our coupled model enables us to visualise the distribution of sediment sources and sinks, and their evolution through time. From this we can extract and analyse at each simulation timestep the stratigraphic record anywhere within the model domain. We find that even from a generic oblique rift model, complex fluvial-deltaic and basin filling dynamics emerge. By isolating the tectonic activity from landscape dynamics with this one-way coupling, we are able to investigate the influence of changes in climate or geomorphic parameters on the sedimentary and landscape record. These impacts can be quantified in part via model post-processing to derive both instantaneous and cumulative erosion/sedimentation.

  11. 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)

    Tabibzadeh, Maryam

    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

  12. Testing 8000 years of submarine paleoseismicity record offshore western Algeria : First evidence for irregular seismic cycles

    NASA Astrophysics Data System (ADS)

    Ratzov, G.; Cattaneo, A.; Babonneau, N.; Yelles, K.; Bracene, R.; Deverchere, J.

    2012-12-01

    It is commonly assumed that stress buildup along a given fault is proportional to the time elapsed since the previous earthquake. Although the resulting « seismic gap » hypothesis suits well for moderate magnitude earthquakes (Mw 4-5), large events (Mw>6) are hardly predictable and depict great variation in recurrence intervals. Models based on stress transfer and interactions between faults argue that an earthquake may promote or delay the occurrence of next earthquakes on adjacent faults by increasing or lowering the level of static stress. The Algerian margin is a Cenozoic passive margin presently inverted within the slow convergence between Africa and Eurasia plates (~3-6 mm/yr). The western margin experienced two large earthquakes in 1954 (Orléansville, M 6.7) and 1980 (El Asnam, M 7.3), supporting an interaction between the two faults. To get meaningful statistics of large earthquakes recurrence intervals over numerous seismic cycles, we conducted a submarine paleoseismicity investigation based on turbidite chronostratigraphy. As evidenced on the Cascadia subduction zone, synchronous turbidites accumulated over a large area and originated from independent sources are likely triggered by an earthquake. To test the method on a slowly convergent margin, we analyze turbidites from three sediment cores collected during the Maradja (2003) and Prisme (2007) cruises off the 1954-1980 source areas. We use X-ray radioscopy, XRF major elements counter, magnetic susceptibility, and grain-size distribution to accurately discriminate turbidites from hemipelagites. We date turbidites by calculating hemipelagic sedimentation rates obtained with radiocarbon ages, and interpolate the rates between turbidites. Finally, the age of events is compared with the only paleoseismic study available on land (El Asnam fault). Fourteen possible seismic events are identified by the counting and correlation of turbidites over the last 8 ka. Most events are correlated with the paleoseismic record of the El Asnam fault, but uncorrelated events suggest that other faults were active. Only the 1954 event (not the 1980) triggered a turbidity current, implying that the sediment buffer on the continental shelf could not be reloaded in 26 years, thus arguing for a minimum time resolution of our method. The new paleoseismic catalog shows a recurrence interval of 300-700 years for most events, but also a great interval of >1200 years without any major earthquake. This result suggests that the level of static stress may have drastically dropped as a result of three main events occurring within the 800 years prior the quiescence period.

  13. 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

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

    2003-01-01

    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.

  14. 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

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

    2010-03-01

    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.

  15. Stratigraphic and structural data for the Conasauga Group and the Rome Formation on the Copper Creek fault block near Oak Ridge, Tennessee: preliminary results from test borehole ORNL-JOY No. 2

    SciTech Connect

    Haase, C.S.; Walls, E.C.; Farmer, C.D.

    1985-06-01

    To resolve long-standing problems with the stratigraphy of the Conasauga Group and the Rome Formation on the Copper Creek fault block near Oak Ridge National Laboratory (ORNL), an 828.5-m-deep test borehole was drilled. Continuous rock core was recovered from the 17.7- to 828.5-m-deep interval; temperature, caliper, neutron, gamma-ray, and acoustic (velocity and televiewer) logs were obtained. The Conasauga Group at the study site is 572.4 m thick and comprises six formations that are - in descending stratigraphic order - Maynardville Limestone (98.8 m), Nolichucky Shale (167.9 m), Maryville Limestone (141.1 m), Rogersville Shale (39.6 m), Rutledge Limestone (30.8 m), and Pumpkin Valley Shale (94.2 m). The formations are lithologically complex, ranging from clastics that consist of shales, mudstones, and siltstones to carbonates that consist of micrites, wackestones, packstones, and conglomerates. The Rome Formation is 188.1 m thick and consists of variably bedded mudstones, siltstones, and sandstones. The Rome Formation thickness represents 88.1 m of relatively undeformed section and 100.0 m of highly deformed, jumbled, and partially repeated section. The bottom of the Rome Formation is marked by a tectonic disconformity that occurs within a 46-m-thick, intensely deformed interval caused by motion along the Copper Creek fault. Results from this study establish the stratigraphy and the lithology of the Conasauga Group and the Rome Formation near ORNL and, for the first time, allow for the unambiguous correlation of cores and geophysical logs from boreholes elsewhere in the ORNL vicinity. 45 refs., 26 figs., 2 tabs.

  16. Oil and gas exploration, offshore southern California

    Microsoft Academic Search

    Wallis

    1981-01-01

    Four local Tertiary basins comprise the regional Pacific Basin south of Point Conception: the San Diego trough and the offshore Los Angeles, Outer Banks, and Ventura-Santa Barbara Channel Basins. The San Diego trough has not been tested by deep wells. The offshore Los Angeles Basin produces oil and gas from Neogene sandstones in giant oil fields which extend on shore.

  17. Stratigraphic Relationships on Husband Hill, Mars

    NASA Astrophysics Data System (ADS)

    Cole, S. B.; Watters, W. A.; Squyres, S. W.

    2011-03-01

    We measure bedding plane orientations of outcrops on Cumberland Ridge in the Columbia Hills. Our measurements are consistent with the hypotheses that the outcrops (1) form a stratigraphic section, and (2) drape the Husband Hill edifice.

  18. Pliocene paleoenvironment evolution as interpreted from 3D-seismic data in the southern North Sea, Dutch offshore sector

    Microsoft Academic Search

    Gesa Kuhlmann; Theo E. Wong

    2008-01-01

    A high-resolution 3D-seismic survey from the Dutch offshore sector has been interpreted and subsequently correlated with existing regional seismo-stratigraphic concepts derived from conventional 2D-seismic data sets. The interpreted 13 seismic units have been related to a newly established chrono-stratigraphic framework [Kuhlmann et al., 2006a,b. Chronostratigraphy of Late Neogene sediments in the southern North Sea Basin and paleoenvironmental interpretations. Palaeogeography, Palaeoclimatology,

  19. Assessing offshore wind potential

    Microsoft Academic Search

    Adesoji Adelaja; Charles McKeown; Benjamin Calnin; Yohannes Hailu

    2012-01-01

    Quantifying wind potential is a pivotal initial step in developing and articulating a state’s policies and strategies for offshore wind industry development. This is particularly important in the Great Lakes States where lessons from other offshore environments are not directly applicable. This paper presents the framework developed for conducting a preliminary assessment of offshore wind potential. Information on lake bathymetry

  20. Offshore Wind Geoff Sharples

    E-print Network

    Kammen, Daniel M.

    States Cape Wind PPA at 18 c/kWh #12;The cycle of non-innova?on OffshoreOffshore Wind Geoff Sharples geoff@clearpathenergyllc.com #12;Frequently Unanswered Ques?ons · Why don't "they" build more offshore wind? · Why not make

  1. Some debatable problems of stratigraphic classification

    NASA Astrophysics Data System (ADS)

    Gladenkov, Yury

    2014-05-01

    Russian geologists perform large-scale geological mapping in Russia and abroad. Therefore we urge unification of legends of geological maps compiled in different countries. It seems important to continuously organize discussions on problems of stratigraphic classification. 1. The stratigraphic schools (conventionally called "European" and "American") define "stratigraphy" in different ways. The former prefers "single" stratigraphy that uses data proved by many methods. The latter divides stratigraphy into several independent stratigraphers (litho-, bio-, magneto- and others). Russian geologists classify stratigraphic units into general (chronostratigraphic) and special (in accordance with a method applied). 2. There exist different interpretations of chronostratigraphy. Some stratigraphers suppose that a chronostratigraphic unit corresponds to rock strata formed during a certain time interval (it is somewhat formalistic because a length of interval is frequently unspecified). Russian specialists emphasize the historical-geological background of chronostratigraphic units. Every stratigraphic unit (global and regional) reflects a stage of geological evolution of biosphere and stratisphere. 3. In the view of Russian stratigraphers, the main stratigraphic units may have different extent: a) global (stage), b) regional (regional stage,local zone), and c) local (suite). There is no such hierarchy in the ISG. 4. Russian specialists think that local "lithostratigraphic" units (formations) which may have diachronous boundaries are not chronostratigraphic ones in strict sense (actually they are lithological bodies). In this case "lithostratigraphy" can be considered as "prostratigraphy" and employed in initial studies of sequences. Therefore, a suite is a main local unit of the Russian Code and differs from a formation, although it is somewhat similar. It does not mean that lithostratigraphy is unnecessary. Usage of marker horizons, members and other bodies is of great help. Lithostratigraphy may be regarded as the start of geological mapping on scales of 1 : 10 000, 1 : 25 000 or 1 : 50 000, and lithostratigraphic subdivisions can be used as the mapping units because they practically have isochronic boundaries when we deal with geological mapping on these scales. 5. Russian geologists interpret a chronozone (defined with due account of the standard assemblage-zone) as a part of a stage. In opinion of other specialists, zones serve as correction markers. This gives rise to controversy where zonal scales are needed for the Phanerozoic or whether stage scales are sufficient. In the Russian Code a chronozone is referred to general stratigraphic units (less than a stage). 6. The popular GSSP "concept" may be is inadequate in the broad sense because stages remain "empty" and do not reflect geological events. The search of "golden spikes" can be useful as a part of comprehensive investigations of stratigraphic subdivisions. "Silver" and other type spike-markers can be used as well as recommended by event stratigraphy (Ager, 1973). 7. A new version of "International Stratigraphic Guide" should include not only recommendations but also alternative views. However the work must not be done in a hurry! In avoid bias representatives of interested countries should be involved. Finally, I would like to make two proposals. Proposal 1. A special symposium should be held during the second International Congress on Stratigraphy-2015 to review national stratigraphic codes (USA, Germany, Great Britain, China, Russia, Australia and other countries). This can provide better understanding of their similarities and dissimilarities and enable to realize how much they differ from each other. The review may show the present state of the stratigraphic classification and reveal both pressing and alleged problems of stratigraphy of the early XXI century. Proposal 2. It would be appropriate to prepare a special publication presenting briefly c

  2. Certification of offshore mooring steel wire ropes

    SciTech Connect

    Lohne, P.W. [Det Norske Veritas AS, Oslo (Norway)

    1996-12-31

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

  3. Knowledge-based stratigraphic well-log correlation 

    E-print Network

    Denton, Michael A.

    1990-01-01

    inspirational support. TABLE OF CONTENTS Page ABSTRACT nl DEDICATION ACKNOWLEDGEMENT TABLE OF CONTENTS LIST OF TABLES x1 LIST OF FIGURES xl1 CHAPTER I ? INTRODUCTION 1. 1 Well-Logs 1. 2 Stratigraphic Well-Log Correlation . 1. 3 Well-Log Correlation.... 3 LITHO Expert System 2. 5. 4 MUD Expert System 2. 5. 5 Expert Log Analysis System (ELAS) . . Chapter 2. 5. 6 WLAI Expert System 2. 5. 7 LOGIX Expert System 2. 5. 8 INTELLOG Expert System 2. 5. 9 Well Test Expert System Page CHAPTER III...

  4. Collapse of offshore pipelines: Seminar proceedings

    SciTech Connect

    Not Available

    1990-02-20

    In order to transfer the results of research on collapse of offshore pipelines sponsored by the Pipeline Research Committee, the Offshore Supervisory Committee held a one-day seminar, on February 20, 1990. Participants included experts from academia, offshore service company representatives, and natural gas and oil companies with offshore interests. Offshore pipeline construction has some significant problems not found in land pipeline construction. Among these are laying pipe over a laybarge stinger with a significant unsupported span to bottom, laying pipe from a reel barge, or pulling pipe through a J-tube to connect to an offshore platform. The latter two applications result in the pipe undergoing significant plastic deformation during the installation process, which could lead to failure of the pipe. Another unique offshore loading is from the water itself which exerts external pressure on the line during construction and operations. This external pressure may cause the pipe to collapse. There are many cases underwater where significant spans occur, such as the unsupported span from a laybarge, where the lateral loads from weight or current are carried by a combination of tension and large deflections rather than bending moments. This structural behavior is not accounted for in most piping design and analysis computer programs. The approach to address these problems has been theoretical work, small-scale testing and large-scale testing to verify the theories and small-scale tests. The seminar included the progress in understanding pipe buckling phenomena from its beginnings to the five years of PRC-sponsored work involving small-scale tests. The final and main portion of the seminar was devoted to the transfer of offshore pipeline design guidelines.

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

    Microsoft Academic Search

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

    2010-01-01

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

  6. Drilling and data acquisition programs for the methane hydrate offshore production test in the Eastern Nankai Trough

    NASA Astrophysics Data System (ADS)

    Yamamoto, K.; Fujii, T.

    2013-12-01

    Marine methane hydrates are a matter of scientific interests from various viewpoints such as a key player of global carbon cycle, effects on climate change, cause of seafloor instability, and a possible future energy resource. Under the Japanese national research program, the MH21 research consortium (Japan Oil, Gas and Metals National Corporation and National Institute of Advanced Industrial Science and Technology) has conducted survey operations and subsequent analyses of data and samples from methane hydrate-bearing sediments in the Eastern Nankai Trough. The goal of the project was a gas production test from a methane hydrate deposits in sandy intervals of Pleistocene turbidite sediments. The test location was set in Daini Atsumi Knoll that is a ridge between forearc basin and accretionary prism, and the sediments cover the flank of the knoll. The water depth at the test location is approximately 1000m, and 50m thick methane hydrate concentrated zone exists around 300m below seafloor. The main interest of the MH21 research team is to know physical (thermal, hydraulic, and mechanical) parameters of sediments that are necessary to understand gas hydrate dissociation processes during the production test. Core samples and geophysical logging data obtained during past surveys are utilized for this purpose. Sedimentation and tectono-geophysical conditions govern such material properties, so the samples were analyzed from those viewpoints, too. The first drilling at the location was done in 2004 with logging and coring operation including pressure-conserved core sampling. In 2011, shallow geotechnical survey holes were drilled in the area for geo-hazard assessment, and core samples were taken in the holes, along with some in-situ mechanical and hydraulic testings. In early 2012, a well construction operation for the gas production test was conducted with logging operations that contains neutron porosity data using pulse-neutron devices, magnetic resonance log, etc. A core sampling operation followed in the middle of 2012 using an improved pressure-coring tool and analysis devices. In the March of 2013, the gas production attempt was started using 'depressurization method,' in which liquid in the wellbore was removed by downhole pump to drawdown pore pressure in the formation. The test was accomplished with six day methane gas production. Gas flow rate from the single borehole by depressurization procedure (original 13.5MPa to 4.5MPa at the bottom of the borehole) could provid 20,000Sm3/day gas before the test was forced to terminate due to a sand production problem. An intensive monitoring program accompanied with the test, including two monitoring borehole for time-lapse cased-hole logging and temperature measurements. Moreover, multi-component and time-lapse seismic survey was done using an ocean bottom cable. The taken flow rate, pressure and temperature data, and gas, liquid and solid samples are under detailed analyses to understand the response of methane hydrates in the sediments against depressurization operation, and may provide knowledge of hydrogeology and thermodynamics information of the methane hydrate bearing strata. Some detailed study results are presented in this session and posters.

  7. Proceedings of the seventh international conference on offshore mechanics and Arctic engineering

    Microsoft Academic Search

    J. S. Chung; C. P. Sparks; J. N. Brekke; E. C. Clukey; T. R. Penney

    1988-01-01

    These proceedings collect papers given at a conference on offshore engineering. Topics include: fracture mechanics, vibration testing, wave energy converters, ocean thermal energy converters, underwater pipelines, offshore platforms, and design and installation of permanent mooring systems for tankers.

  8. Uncertainty in the age of fossils and the stratigraphic fit to phylogenies.

    PubMed

    Pol, Diego; Norell, Mark A

    2006-06-01

    The ages of first appearance of fossil taxa in the stratigraphic record are inherently associated to an interval of error or uncertainty, rather than being precise point estimates. Contrasting this temporal information with topologies of phylogenetic relationships is relevant to many aspects of evolutionary studies. Several indices have been proposed to compare the ages of first appearance of fossil taxa and phylogenies. For computing most of these indices, the ages of first appearance of fossil taxa are currently used as point estimates, ignoring their associated errors or uncertainties. The effect of age uncertainty on measures of stratigraphic fit to phylogenies is explored here for two indices based on the extension of ghost lineages (MSM* and GER). A solution based on randomization of the ages of terminal taxa is implemented, resulting in a range of possible values for measures of stratigraphic fit to phylogenies, rather than in a precise but arbitrary stratigraphic fit value. Sample cases show that ignoring the age uncertainty of fossil taxa can produce misleading results when comparing the stratigraphic fit of competing phylogenetic hypotheses. Empirical test cases of alternative phylogenies of two dinosaur groups are analyzed through the randomization procedure proposed here. PMID:16861213

  9. Offshore wind energy systems

    Microsoft Academic Search

    P. Musgrove

    1978-01-01

    Wind energy systems deployed in the shallow but windy waters of the southern North Sea have the potential to provide more than 20% of UK electricity needs. With existing experience of windmills, and of aircraft and offshore structures, such wind energy systems could be developed within a relatively short timescale. A preliminary assessment of the economics of offshore wind energy

  10. CONGRESSIONAL BRIEFING Offshore Wind

    E-print Network

    Firestone, Jeremy

    · Fishermen's Energy · Cape Wind · BVG Associates · Maryland Energy Administration · New Bedford (MA) MarineCONGRESSIONAL BRIEFING Offshore Wind Lessons Learned from Europe: Reducing Costs and Creating Jobs Thursday, June 12, 2014 Capitol Visitors Center, Room SVC 215 Enough offshore wind capacity to power six

  11. Quantifying the stratigraphic completeness of delta shoreline trajectories

    NASA Astrophysics Data System (ADS)

    Mahon, Robert C.; Shaw, John B.; Barnhart, Katherine R.; Hobley, Daniel E. J.; McElroy, Brandon

    2015-05-01

    Understanding the incomplete nature of the stratigraphic record is fundamental for interpreting stratigraphic sequences. Methods for quantifying stratigraphic completeness for one-dimensional stratigraphic columns, defined as the proportion of time intervals of some length that contain stratigraphy, are commonplace; however, quantitative assessments of completeness in higher dimensions are lacking. Here we present a metric for defining stratigraphic completeness of two-dimensional shoreline trajectories using topset-foreset rollover positions in dip-parallel sections and describe the preservation potential of a shoreline trajectory derived from the geometry of the delta surface profile and the kinematics of the geomorphic shoreline trajectory. Two end-member forward models are required to fully constrain the preservation potential of the shoreline dependent on whether or not a topset is eroded during base level fall. A laboratory fan-delta was constructed under nonsteady boundary conditions, and one-dimensional stratigraphic column and two-dimensional shoreline completeness curves were calculated. Results are consistent with the hypothesis derived from conservation of sediment mass that completeness over all timescales should increase given increasing dimensions of analysis. Stratigraphic trajectories and completeness curves determined from forward models using experimental geomorphic trajectories compare well to values from transects when subsampled to the equivalent stratigraphic resolution as observed in the actual preserved sequence. The concept of stratigraphic completeness applied to two-dimensional trajectory analysis and the end-member forward models presented here provide novel tools for a conceptual understanding of the nature of stratigraphic preservation at basin scales.

  12. Loss of genetic diversity in Harpacticoida near offshore platforms

    Microsoft Academic Search

    P. A. Montagna

    1996-01-01

    Offshore oil and gas production platforms can be a source of chronic stress that could lead to sublethal impacts on resident benthic organisms. In June 1993 and January 1994, genetic diversity of Harpacticoida (Copepoda) living proximal to operating, offshore platforms in the Gulf of Mexico was estimated to test if platforms are associated with strong selective pressures. Because harpacticoids have

  13. Applications for concrete offshore

    SciTech Connect

    Not Available

    1982-01-01

    The report collects and summarizes the various proposals for development offshore which have in common the use of concrete as the main structural material, and where possible, indicates their relative feasibility. A study encompassing such diverse schemes as offshore windmills, concrete LNG carriers, hydrocarbon production platforms and floating airports cannot be completely exhaustive on each subject, so references to sources of further information have been given wherever possible. Details of individual projects and proposals are included for Power plants, Hydrocarbon production platforms, Concrete ships, Storage systems and industrial plants, Subsea systems, Offshore islands, Coastal works and Other concrete structures.

  14. Servicing the offshore industry

    SciTech Connect

    NONE

    1997-03-01

    What factors are leading operators to using boat-based services vs. those that are rig-based for offshore completions, stimulations and workovers? What trends are companies experiencing in completion practices for the unconsolidated formations in the Gulf of Mexico? What are companies` most important specifications for well service boats operating near their offshore platforms? To answer these and other questions, Petroleum Engineering International asked those who should know -- the producing companies active in offshore operations in the Gulf of Mexico and worldwide.

  15. Regional method to assess offshore slope stability.

    USGS Publications Warehouse

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

    1986-01-01

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

  16. 3D Stratigraphic Modeling of Central Aachen

    NASA Astrophysics Data System (ADS)

    Dong, M.; Neukum, C.; Azzam, R.; Hu, H.

    2010-05-01

    Since 1980s, advanced computer hardware and software technologies, as well as multidisciplinary research have provided possibilities to develop advanced three dimensional (3D) simulation software for geosciences application. Some countries, such as USA1) and Canada2) 3), have built up regional 3D geological models based on archival geological data. Such models have played huge roles in engineering geology2), hydrogeology2) 3), geothermal industry1) and so on. In cooperating with the Municipality of Aachen, the Department of Engineering Geology of RWTH Aachen University have built up a computer-based 3D stratigraphic model of 50 meter' depth for the center of Aachen, which is a 5 km by 7 km geologically complex area. The uncorrelated data from multi-resources, discontinuous nature and unconformable connection of the units are main challenges for geological modeling in this area. The reliability of 3D geological models largely depends on the quality and quantity of data. Existing 1D and 2D geological data were collected, including 1) approximately 6970 borehole data of different depth compiled in Microsoft Access database and MapInfo database; 2) a Digital Elevation Model (DEM); 3) geological cross sections; and 4) stratigraphic maps in 1m, 2m and 5m depth. Since acquired data are of variable origins, they were managed step by step. The main processes are described below: 1) Typing errors of borehole data were identified and the corrected data were exported to Variowin2.2 to distinguish duplicate points; 2) The surface elevation of borehole data was compared to the DEM, and differences larger than 3m were eliminated. Moreover, where elevation data missed, it was read from the DEM; 3) Considerable data were collected from municipal constructions, such as residential buildings, factories, and roads. Therefore, many boreholes are spatially clustered, and only one or two representative points were picked out in such areas; After above procedures, 5839 boreholes with -x, -y, -z coordinates, down-hole depth, and stratigraphic information are available. 4) We grouped stratigraphic units into four main layers based on analysis of geological settings of the modeling area. The stratigraphic units extend from Quaternary, Cretaceous, Carboniferous to Devonian. In order to facilitate the determination of each unit boundaries, a series of standard code was used to integrate data with different descriptive attributes. 5) The Quaternary and Cretaceous units are characterized by subhorizontal layers. Kriging interpolation was processed to the borehole data in order to estimate data distribution and surface relief for the layers. 6) The Carboniferous and Devonian units are folded. The lack of software support, concerning simulating folds and the shallow depth of boreholes and cross sections constrained the determination of geological boundaries. A strategy of digitalizing the fold surfaces from cross sections and establishing them as inclined strata was followed. The modeling was simply subdivided into two steps. The first step consisted of importing data into the modeling software. The second step involved the construction of subhorizontal layers and folds, which were constrained by geological maps, cross sections and outcrops. The construction of the 3D stratigraphic model is of high relevance to further simulation and application, such as 1) lithological modeling; 2) answering simple questions such as "At which unit is the water table?" and calculating volume of groundwater storage during assessment of aquifer vulnerability to contamination; and 3) assigned by geotechnical properties in grids and providing them for user required application. Acknowledgements: Borehole data is kindly provided by the Municipality of Aachen. References: 1. Janet T. Watt, Jonathan M.G. Glen, David A. John and David A. Ponce (2007) Three-dimensional geologic model of the northern Nevada rift and the Beowawe geothermal system, north-central Nevada. Geosphere, v. 3; no. 6; p. 667-682 2. Martin Ross, Michel Parent and René Lefebvre (2005) 3D geologic

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

    E-print Network

    Heinemann, Detlev

    MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND for conditions important for offshore wind energy utilisation are compared and tested: Four models turbines more vulnerable for spatial and temporal wind speed variations. For typical offshore sites

  18. Virtual Reality techniques for planning the Offshore Felipe Carvalho, Alberto Raposo

    E-print Network

    Barbosa, Alberto

    the offshore platform robotizing. SimUEP-Robotics has an integrated Virtual Reality Engine specially tailored of real operation tests scenarios. Keywords--virtual reality; robot simulation;offshore platforms. I of offshore platforms will present high degree of automation. New design concepts consider the use of robotic

  19. Complex Stratigraphic Evolution of the Red Sea

    NASA Astrophysics Data System (ADS)

    Almalki, Khalid A.; Mahmud, Syed A.

    2015-04-01

    The Red Sea rift, separates the African and the Arabian continents, and is considered a type location of a juvenile rift-related small ocean. Geological studies and drilling programs date back to more than half a century yet very little is known about the stratigraphic evolution to the wider geological community. Following the arrival of the Afar plume at the late Oligocene (ca 30 Ma) the southern Red Sea underwent rapid extension culminating in extended continental crust or seafloor spreading, which stalled during the early Miocene at the central Red Sea due to either slowing of the convergence between Arabia and Eurasia or the onset of the Arabian plate passive margin collision with Eurasia. The mainland pan of the region was uplifted, resulting in the development of the Red Sea erosional escarpment. Shelf sedimentation (Middle-late Miocene to Pleistocene successions) then ensued and covered oceanic and continental crust. The present day spreading centre resumed in the southern Red Sea at 5 Ma and has been propagating northward until the present-day. However, detailed analysis of the basin shows a more complex pattern of basin development with late Oligocene succession restricted to the western Red Sea coast and the southern sectors. Well data suggest that up to 4 km of sediments exist in the southern Red Sea shallowing upward to the northern sector; 3 km or more of this section consists of Miocene evaporates, which contains intercalated anhydrite and shale horizons. These Miocene evaporates are overlain by Quaternary reefal limestone, and recent volcanic rocks restricted to the central axial trough zone of the Red Sea. In this study extensive well data that is well spread in the area was used to evaluate the stratigraphic architecture, build-ups, and local controls on deposition. Potential stratigraphic models have been developed. The distribution of stratigraphy in the Red Sea area yields complex correlation, with unique depositional characteristics in discrete zones within the Red Sea basin.

  20. Stratigraphic Paleobiology of the Taranto Area

    NASA Astrophysics Data System (ADS)

    Scarponi, Daniele; Angeletti, Lorenzo; Taviani, Marco; Huntley, John Warren; Amorosi, Alessandro; Negri, Alessandra; Battista Vai, Gian

    2015-04-01

    The area surrounding Taranto, Italy is chronostratigraphically very important, as it is one of the few areas in the world where Upper Pleistocene marine successions are well exposed, easily accessible, and relatively thick. Several outcrops in this area were investigated as suitable marine sections for defining the Late Pleistocene GSSP. At these locations, the late Pleistocene bathymetric history of the Taranto area was depicted using macrobenthic assemblages from a network of outcrops and cores. Outcrops at Pontile, Fronte, and Garitta, along with two cores drilled at Cimino and Cantoro were densely sampled to conduct quantitatively-derived paleobathymetric reconstructions. These deposits yielded relatively diverse mollusk associations (> 250 species and > 9.000 specimens distributed among 55 samples), dominated by extant mollusk species of known bathymetric distribution. Multiple analytical approaches were applied to the macrobenthic dataset in a comparative fashion: (i) direct calibration by weighted averaging of taxa with known preferred depth recovered in a sample, (ii) posteriori-calibrated ordination (DCA) using bathymetric data of key extant taxa. These analyses were conducted at both species and genus level. Regardless of the choice of the analytical method, mollusk assemblages yielded bathymetric trends congruent with previous qualitative and semi-quantitative paleoecological and stratigraphic analyses: the bathymetric range of sampled deposits is bracketed between 140 and 0 meters. Secondly, macrobenthos-derived proxies provided an improved characterization of the marine deposits in terms of sample bathymetry and by discriminating shallowing-upward (regressive) trends from deepening-upward (transgressive) tendencies. Thirdly, mollusk-derived bathymetric inferences suggest spatial bathymetric gradients that are coherent with the morphology of the study area. In conclusion, the results provided an improved characterization of coastal depositional facies in a sequence stratigraphic perspective, which is one of the primary research goals of Stratigraphic Paleobiology.

  1. Bedout basement rise, offshore northwestern Australia: evidence of an unshocked mafic volcanic hyaloclastite volcanic breccia

    Microsoft Academic Search

    A. Glikson

    2004-01-01

    Core samples from Bedout-1 (3035.8-3044.95 m.), Bedout basement rise, offshore northwestern Australia, were examined by optical microscopy, SEM, EDS and WDS spectrometry. At this stratigraphic depth level Becker et al. (2004) interpret cryptocrystalline alteration zones around and within plagioclase in terms of shock-induced transformation of feldspar into diaplectic maskelynite glass _u postulating a ~200 km-large impact structure and thereby an

  2. Geological evolution, regional perspectives and hydrocarbon potential of the northwest Phu Khanh Basin, offshore Central Vietnam

    Microsoft Academic Search

    Michael B. W. Fyhn; Lars H. Nielsen; Lars O. Boldreel; Le D. Thang; Jørgen Bojesen-Koefoed; Henrik I. Petersen; Nguyen T. Huyen; Nguyen A. Duc; Nguyen T. Dau; Anders Mathiesen; Ian Reid; Dang T. Huong; Hoang A. Tuan; Le V. Hien; Hans P. Nytoft; Ioannis Abatzis

    2009-01-01

    Seismic stratigraphic and structural analyses of the northwest Phu Khanh Basin, offshore Central Vietnam, based on 2-D seismic data, indicate that the initial rifting began during the latest Cretaceous? or Palaeogene controlled by left-lateral transtension along the East Vietnam Boundary Fault Zone (EVBFZ) and northwest–southeast directed extension east of the EVBFZ. Rifting stopped due to transpression during middle Oligocene times

  3. Tectonic-stratigraphic division and blind fold structures in Nansha Waters, South China Sea

    NASA Astrophysics Data System (ADS)

    Yan, Pin; Liu, Hailing

    2004-12-01

    Extensive multiple-channel reflection seismic data have been collected in the Nansha (Spratley Islands) Waters, the southern margin of the South China Sea. Stratigraphic correlation is shown with focus on a comprehensive geophysiXcal survey line run from offshore NW Sabah to offshore SE Vietnam. According to the varying tectono-stratigraphy from southeast to northwest, five tectonic belts can be determined, i.e. the Palawan-Borneo Nappe, Nansha Trough, Nanwei-Liyue Compressive Belt, Zheng'he Extensional Belt and the Circum-Southwest Subbasin Belt. In the Palawan-Borneo Nappe, Neogene-Quaternary deposits were highly upthrust northwestwards, resulting in a series of moderately to tightly folded anticlines separated by open synclines. The Nansha Trough was a narrow, deep-water belt filled with thick, undisturbed Neogene-Quaternary deposits. The Nanwei-Liyue Compressive Belt was dominated by strongly folded paleo-anticlines overlain by an undeformed sedimentary cap with a pronounced hiatus of Paleogene sediments. The Zheng'he Extensional Belt consisted of a rugged topography and Paleogene half-grabens bounded by listic faults. The major extensional faults were reactivated to cut through the overlying Neogene-Quaternary deposits. Over the Circum-Southwest Subbasin Belt, Neogene-Quaternary deposits draped on the largely subsided fault blocks related to the Late Oligocene-Mid-Miocene seafloor spreading. Based on the regional stratigraphic correlation, the prominent paleo-anticlines found within the Nanwei-Liyue Compressive Belt are deduced to consist of mainly Mesozoic marine sediments that were compressed in the Late Mesozoic Era. Therefore, the Nansha Microcontinent Block is shown to be a collision complex assembled during Late Mesozoic Era.

  4. High-Alloy Materials for Offshore Applications

    Microsoft Academic Search

    T. F. Lemke; J. A. Harris

    1983-01-01

    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,

  5. Lake Michigan Offshore Wind Feasibility Assessment

    SciTech Connect

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

    2014-06-30

    The purpose of this project was to conduct the first comprehensive offshore wind assessment over Lake Michigan and to advance the body of knowledge needed to support future commercial wind energy development on the Great Lakes. The project involved evaluation and selection of emerging wind measurement technology and the permitting, installation and operation of the first mid-lake wind assessment meteorological (MET) facilities in Michigan’s Great Lakes. In addition, the project provided the first opportunity to deploy and field test floating LIDAR and Laser Wind Sensor (LWS) technology, and important research related equipment key to the sitting and permitting of future offshore wind energy development in accordance with public participation guidelines established by the Michigan Great Lakes Wind Council (GLOW). The project created opportunities for public dialogue and community education about offshore wind resource management and continued the dialogue to foster Great Lake wind resource utilization consistent with the focus of the GLOW Council. The technology proved to be effective, affordable, mobile, and the methods of data measurement accurate. The public benefited from a substantial increase in knowledge of the wind resources over Lake Michigan and gained insights about the potential environmental impacts of offshore wind turbine placements in the future. The unique first ever hub height wind resource assessment using LWS technology over water and development of related research data along with the permitting, sitting, and deployment of the WindSentinel MET buoy has captured public attention and has helped to increase awareness of the potential of future offshore wind energy development on the Great Lakes. Specifically, this project supported the acquisition and operation of a WindSentinel (WS) MET wind assessment buoy, and associated research for 549 days over multiple years at three locations on Lake Michigan. Four research objectives were defined for the project including to: 1) test and validate floating LIDAR technology; 2) collect and access offshore wind data; 3) detect and measure bird and bat activity over Lake Michigan; 4) conduct an over water sound propagation study; 5) prepare and offer a college course on offshore energy, and; 6) collect other environmental, bathometric, and atmospheric data. Desk-top research was performed to select anchorage sites and to secure permits to deploy the buoy. The project also collected and analyzed data essential to wind industry investment decision-making including: deploying highly mobile floating equipment to gather offshore wind data; correlating offshore wind data with conventional on-shore MET tower data; and performing studies that can contribute to the advancement and deployment of offshore wind technologies. Related activities included: • Siting, permitting, and deploying an offshore floating MET facility; • Validating the accuracy of floating LWS using near shoreline cup anemometer MET instruments; • Assessment of laser pulse technology (LIDAR) capability to establish hub height measurement of wind conditions at multiple locations on Lake Michigan; • Utilizing an extended-season (9-10 month) strategy to collect hub height wind data and weather conditions on Lake Michigan; • Investigation of technology best suited for wireless data transmission from distant offshore structures; • Conducting field-validated sound propagation study for a hypothetical offshore wind farm from shoreline locations; • Identifying the presence or absence of bird and bat species near wind assessment facilities; • Identifying the presence or absence of benthic and pelagic species near wind assessment facilities; All proposed project activities were completed with the following major findings: • Floating Laser Wind Sensors are capable of high quality measurement and recordings of wind resources. The WindSentinel presented no significant operational or statistical limitations in recording wind data technology at a at a high confidence level as compared to traditional an

  6. Stratigraphic variations in oil-shale fracture properties

    NASA Astrophysics Data System (ADS)

    Young, C.; Patti, N. C.; Trent, B. C.

    1982-09-01

    The proper design and evaluation of in situ oil shale fracture and retorting experiments which require that both the extreme values and spatial distribution of the controlling rock properties be adequately known are discussed. The prediction, control and evaluation of explosive oil shale fracturing require a detailed knowledge of tensile strength behavior as a function of shale grade and stratigraphic position. Direct pull tensile tests, point load pinch tests, and four point bend fracture toughness tests are utilized to develop detailed logs of the relevant fracture properties for the 37 m thick Mahogany Zone section of the Green River Formation near Anvil Points, Colorado and for the rich, upper 13 m of the Tipton Member near Rock Springs, Wyoming. Statistical analyses were performed on these data and on Fischer assay oil yield data to establish the correlations between them. Data from both tensile strength and fracture energy tests correlate well with lithologic and oil yield characteristics of the Mahogany Zone shale while poor correlations were found for the Tipton shale.

  7. The geotechnical centrifuge in offshore engineering

    SciTech Connect

    Murff, J.D.

    1996-12-31

    One of the greatest needs in offshore geotechnical engineering is for large scale test measurements on which to calibrate design procedures. The geotechnical centrifuge offers at least a partial remedy. Because it allows one to properly simulate stresses, it is a legitimate, relatively inexpensive option to full scale field testing. As such it is a valuable technique and can be an excellent complement to laboratory tests, 1-g model tests and numerical analyses. However, it has not been widely used by industry even though the capability has existed for almost thirty years. This paper argues that this technology should gain acceptance beyond the research community. The paper presents an overview of centrifuge principles, philosophies of use, and limitations of the technique. For illustration, several actual applications of centrifuge testing for complex offshore problems are described. Results are shown to provide important insights into prototype behavior and to agree well with full scale measurements where these are available.

  8. Offshore platform cathodic protection retrofits

    SciTech Connect

    Turnipseed, S.P. [Chevron Research and Technology Co., Richmond, CA (United States)

    1996-10-01

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

  9. Offshore rectenna feasbility

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    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 using a numerical experimentation approach. To do this, we first simulated the syn-rift phase of lithosphere stretching by thermo-mechanical modeling. We then used the deformed 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 corresponding accumulation and subsidence histories as input of the stratigraphic model to simulate the detailed stratigraphic architecture of the basin. We tested this procedure using synthetic examples of lithosphere stretching based on end-members rheologies of the lithosphere (i.e. strength of the lower crust) for narrow or ultra-wide rifting modes. We determined the stratigraphic architecture of the basins of each conjugate margin using three grain-sizes (sand, silt, and clay) differing in their transport length. 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).

  11. Seismo and sequence stratigraphy of Cenozoic units of the Morondava Basin, offshore western Madagascar

    NASA Astrophysics Data System (ADS)

    Kaufmann, Dirk; Stollhofen, Harald; Klimke, Jennifer; Franke, Dieter

    2015-04-01

    The N-S trending Morondava Basin extends in width from western onshore Madagascar over about 350 km westwards to the offshore Davie Ridge in the Mozambique Channel. Although basin formation was initiated during Karoo times, the main basin evolution took place during Jurassic rifting and subsequent drifting until middle Cretaceous as a result of Gondwana breakup (Geiger et al., 2004). Contemporaneous to the separation of India and Madagascar widespread flood basalts were emplaced during the late Cretaceous (Storey et al., 1995). Present knowledge of the Morondava Basin is mainly based on outcrop studies, seismic surveys and borehole information (e.g. Geiger et al., 2004), gathered in western onshore Madagascar, although the fast majority of the basin, including its depocenter is located offshore in the Mozambique Channel, now at up to 3,500 m water depth. Almost all of the recent offshore studies of the Morondava Basin rely on industrial data but up to date publications of exploration results are generally rare and mostly anonymized. Our study aims to extend knowledge, particularly on the offshore seismic and sequence stratigraphy of the Morondava Basin. A key question is also to test the proposed tectonic stability of the Davie Ridge over the last 40 Ma. For this purpose 12 seismic profiles and bathymetric data, acquired in early 2014 by RV SONNE, are interpreted. Most of the profiles cover the distal deep marine areas of the northern Morondava Basin between the Davie Ridge and the shelf break of Madagascar. Top Cretaceous, Top Eocene, Top Oligocene, the Middle Miocene Unconformity and the Base Pliocene, are mapped as major seismic marker horizons. Especially shelf and slope sedimentary units are important resources to reconstruct the tectonostratigraphic basin evolution. At the continental slope diffuse to chaotic seismic pattern of Miocene and younger age are identified which are subdivided by laterally continuous, high frequency reflectors with a higher impedance contrast. Bounded by the Base Tertiary and the Base Pliocene these units can be used to develop and verify a sequence stratigraphic approach for the Cenozoic in the Morondava Basin. Prelimary results indicate that the major sedimentation at the continental slope moved after Early Pliocene significantly landwards. In general the thickness of post-Pliocene units increases to the east. Work in progress encompasses the application of seismo and sequence stratigraphic concept for Mesozoic sedimentary units and a correlation with other, potentially time-equivalent, basins in the area, such as the Mandawa Basin in northern Mozambique. References Geiger, M., Clark, D.N., und Mette, W., 2004, Reappraisal of the timing of the break-up of Gondwana based on sedimentological und seismic evidence from the Morondava Basin, SW Madagascar: Journal of African Earth Sciences, v. 38, p. 363-381. Storey, M., Mahoney, J. J., Saunders, A. D., Duncan, R. A., Kelley, S. P., und Coffin, M. F., 1995, Timing of Hot Spot--Related Volcanism und the Breakup of Madagascar und India: Science, v. 267, no. 5199, p. 852-855.

  12. The stratigraphic distribution of large marine vertebrates and shell beds in the Pliocene of Tuscany

    NASA Astrophysics Data System (ADS)

    Dominici, Stefano; Benvenuti, Marco; Danise, Silvia

    2015-04-01

    The record of 337 shark fossils, 142 cetaceans and 10 sea cows from the Pliocene of Tuscany, mostly from historical museum collections, is revised. The majority of these fossils are concentrated at a few geographic sites from separated hinterland basins, on the South-Western side of the Northern Apennines. To better understand the meaning of these concentrations, the sequence stratigraphic distribution of more recent findings of large marine vertebrates is reconstructed against a high-resolution framework based on sedimentary facies analysis. These remains are usually covered by, or included in mudstones deposited far from the coast (N=12), skeletons being usually articulated, slightly displaced, and often bioeroded. A minor part of better preserved articulated skeletons is associated with sandstones from deltaic paleonenvironments (N=2). Marine mammal and shark remains may be associated with laterally-continuous shell accumulations, a type of concentration occurring at maximum flooding surfaces, separating relatively coarse-grained facies from open marine mudstones. Shell beds were bulk-sampled at 66 locations from six basins, covering a wide range of sedimentary facies, and spanning a chronologic interval of about 2.5 million years. A dataset of 62,655 mollusc specimens belonging to 496 species formed the basis of a statistical study to reconstruct the structure of the benthic communities, and to estimate paleodepths from intertidal to upper bathyal settings. Mollusc associations closely mirror the distribution of sedimentary facies, allowing for a fine tuning of the sequence stratigraphic architecture. Merging paleogeographic, stratigraphic and paleoecologic data, we conclude that the more abundant and diverse accumulations of large vertebrates took place in settings under the influence of coastal upwelling. A modern analogue occurs today in the Ligurian Sea, on the Tuscan offshore, where abundant nutrients carried by deep-marine currents of Western origin, within an otherwise oligotrophic Mediterranean Sea, sustain a rich and diverse cetacean and shark, epipelagic and mesopelagic community. The modern steep bathymetric gradient was displaced towards the East during the Pliocene, before the latest phases of uplift of the Northern Apennines. An open marine, nutrient-rich ecosystem influenced hinterland basins during major transgressive pulses, leading to a higher productivity and the formation of laterally-continuos accumulations of biogenic hard parts. A comparison with the few available studies on the sequence-stratigraphic distribution of large marine vertebrates and shell beds suggests that a model integrating high-productivity and sea level rise, favouring bone bed and shell bed formation, can be applied at other settings, and other geologic intervals.

  13. Dynamics of offshore structures

    SciTech Connect

    Patel, M.H.

    1989-01-01

    This book is a text on ocean engineering integrating the areas of design, construction, installation and operation of fixed and floating offshore structures. Includes basic equations and theoretical results with emphasis on the fundamentals of oceanography, basic fluid mechanics, wave theory and hydrodynamics.

  14. Offshore Wind Energy Systems

    ERIC Educational Resources Information Center

    Musgrove, P.

    1978-01-01

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

  15. The state of offshore

    SciTech Connect

    Nelson, B.F.

    1991-01-01

    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.

  16. Economics of Developing Hot Stratigraphic Reservoirs

    SciTech Connect

    Greg Mines; Hillary Hanson; Rick Allis; Joseph Moore

    2014-09-01

    Stratigraphic geothermal reservoirs at 3 – 4 km depth in high heat-flow basins are capable of sustaining 100 MW-scale power plants at about 10 c/kWh. This paper examines the impacts on the levelized cost of electricity (LCOE) of reservoir depth and temperature, reservoir productivity, and drillhole/casing options. For a reservoir at 3 km depth with a moderate productivity index by hydrothermal reservoir standards (about 50 L/s/MPa, 5.6 gpm/psi), an LCOE of 10c/kWh requires the reservoir to be at about 200°C. This is the upper temperature limit for pumps. The calculations assume standard hydrothermal drilling costs, with the production interval completed with a 7 inch liner in an 8.5 inch hole. If a reservoir at 4 km depth has excellent permeability characteristics with a productivity index of 100 L/s/MPa (11.3 gpm/psi), then the LCOE is about 11 c/kWh assuming the temperature decline rate with development is not excessive (< 1%/y, with first thermal breakthrough delayed by about 10 years). Completing wells with modest horizontal legs (e.g. several hundred meters) may be important for improving well productivity because of the naturally high, sub-horizontal permeability in this type of reservoir. Reducing the injector/producer well ratio may also be cost-effective if the injectors are drilled as larger holes.

  17. Stratigraphic and structural interpretation of Willapa basin

    SciTech Connect

    Palmer, S.P.

    1989-04-01

    Willapa basin is a middle Eocene to Holocene depocenter in southwestern Washington and on the adjacent continental shelf. Surface geology, biostratigraphy, and seismic and well data have been used to develop a stratigraphic and structural interpretation of the basin. Middle Eocene deep-water sediments were deposited on convergent margin and accreted to North America prior to the early Miocene. Turbidite sandstones interpreted to be the lower to middle Miocene Astoria(.) Formation overlie this Eocene sequence in onshore wells. Distal turbidites of lower to middle Miocene age (Hoh assemblage) were thrust beneath the Eocene and Astoria(.) Formation rocks during the middle to upper Miocene. Upper Miocene bathyal shales and siltstones unconformably overlie the older rocks. This sequence was then unconformiably(.) covered by upper Miocene sandstones and siltstones deposited in a nearshore shelf environment. This extreme change in water depth is interpreted to be of tectonic origin. The occurrence of redeposited lower to middle Miocene deep-water fauna in the late Miocene shelf sequence is ascribed to erosion at the sea floor of mud diapirs rooted in Hoh assemblage rocks. Activation of these diapirs was probably associated with this tectonic uplift. Pliocene and Pleistocene conglomerates, sandstones, and siltstones were deposited in both marine and deltaic environments and are locally exhibited as an onlap sequence in marine seismic data. Diapiric growth has continued into the Holocene, resulting in both angular truncation of the Pliocene-Pleistocene sequence and diapiric breaching at the sea floor.

  18. Stratigraphic evolution of paleozoic erathem, northern Florida

    SciTech Connect

    Coleman, J.L. Jr.

    1985-02-01

    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.

  19. Tectono-stratigraphic terrane map of Alaska

    SciTech Connect

    Nokleberg, W.J.; Brew, D.A.; Grantz, A.; Plafker, G.; Moore, T.E.; Patton, W.W. Jr. (Geological Survey, Menlo Park, CA (United States)); Mollstalcup, E.J. (Geological Survey, Reston, VA (United States)); Miller, T.P. (Geological Survey, Anchorage, AK (United States))

    1993-04-01

    A new terrane map compelled at a scale of 2.5 million is a comprehensive portrayal of the major tectono-stratigraphic terranes, pre-accretionary plutonic rocks, faults or sutures that bound terranes, and younger overlap sedimentary , volcanic, and plutonic assemblages of Alaska. Terranes are divided by tectonic affinity into cratonal, passive continental margin, metamorphosed continental margin, continental margin arc, island arc, oceanic crust, sea mount, ophiolite, accretionary wedge, subduction zone, turbidite basin, and metamorphic environments. Overlap assemblages consist of sequences of sedimentary, volcanic, and plutonic rocks that link or weld together adjacent terranes after emplacement, and provide important constraints on the timing of tectonic juxtaposition. Groups of terranes and overlap assemblages, with similar tectonic environments and geologic histories, can be correlated within Alaska and into the adjacent Canadian Cordillera. These groups include: (1) highly deformed and metamorphosed continental margin terranes (Seward, Coldfoot, Ruby, Yukon-Tanana, Kootenay) that are interpreted either as displaced fragments of the North American or other continental margins; (2) ophiolite terranes (Angayucham, Tozitna, Inoko, Seventymile, Slide Mountain) that are interpreted as remnants of one or more major, long-lived, Paleozoic and early Mesozoic oceanic basins; (3) Jurassic and Early Cretaceous island arc terranes (Koyukuk, Togiak, Nyac) that are interpreted as remnants of a discontinuous, short-lived, Mesoxoic island arc system; and (4) the Late Jurassic and Early Cretaceous Kahiltna and Gravina-Nutzotin overlap assemblages that are interpreted as parts of a major arc and flysch sequence.

  20. Offshore space center (offshore launch site)

    SciTech Connect

    Harvey, D.G.

    1980-07-01

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

  1. Offshore Space Center (offshore launch site)

    NASA Technical Reports Server (NTRS)

    Harvey, D. G.

    1980-01-01

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

  2. Geological & Geophysical findings from seismic, well log and core data for marine gas hydrate deposits at the 1st offshore methane hydrate production test site in the eastern Nankai Trough, offshore Japan: An overview

    NASA Astrophysics Data System (ADS)

    Fujii, T.; Noguchi, S.; Takayama, T.; Suzuki, K.; Yamamoto, K.

    2012-12-01

    In order to evaluate productivity of gas from marine gas hydrate by the depressurization method, Japan Oil, Gas and Metals National Corporation is planning to conduct a full-scale production test in early 2013 at the AT1 site in the north slope of Daini-Atsumi Knoll in the eastern Nankai Trough, Japan. The test location was determined using the combination of detailed 3D seismic reflection pattern analysis, high-density velocity analysis, and P-impedance inversion analysis, which were calibrated using well log data obtained in 2004. At the AT1 site, one production well (AT1-P) and two monitoring wells (AT1-MC and MT1) were drilled from February to March 2012, followed by 1 coring well (AT1-C) from June to July 2012. An extensive logging program with logging while drilling (LWD) and wireline-logging tools, such as GeoVISION (resistivity image), EcoScope (neutron/density porosity, mineral spectroscopy etc.), SonicScanner (Advanced Sonic tool), CMR/ProVISION (Nuclear Magnetic Resonance Tools), XPT (formation pressure, fluid mobility), and IsolationScanner (ultrasonic cement evaluation tools) was conducted at AT1-MC well to evaluate physical reservoir properties of gas hydrate-bearing sediments, to determine production test interval in 2013, and to evaluate cement bonding. Methane hydrate concentrated zone (MHCZ) confirmed by the well logging at AT1-MC was thin turbidites (tens of centimeters to few meters) with 60 m of gross thickness, which is composed of lobe type sequences in the upper part of it and channel sand sequences in the lower part. The gross thickness of MHCZ in the well is thicker than previous wells in 2004 (A1, 45 m) located around 150 m northeast, indicating that the prediction given by seismic inversion analysis was reasonable. Well-to-well correlation between AT1-MC and MT1 wells within 40 m distance exhibited that lateral continuity of these sand layers (upper part of reservoir) are fairly good, which representing ideal reservoir for the production test. The XPT measurement results showed approximately 0.1 to several mD of water permeability in both the hydrate-bearing formation and seal formation, although there are some variations in measured values. However, the comparison of these results with permeability estimated by NMR log showed significant discrepancy (more than one order of difference), which suggests that it is necessary to have further investigation considering the difference in scale, measurement direction (Kh or Kv), and calibration methodology by pressure core data. In order to obtain basic reservoir/seal properties for the well log calibration within and above production test interval, pressure coring using Hybrid Pressure Coring System (Hybrid PCS) and also non-destructive core analysis onboard using Pressure Core Analysis and Transfer System (PCATS) were conducted for 60 m interval in AT1-C, which located about 10 m northeast of AT1-MC. Finally, integrated reservoir characterization based on well-log and pressure core data was conducted to predict and optimize the flow rate of upcoming production test.

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

    SciTech Connect

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

    2010-11-23

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

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

    Microsoft Academic Search

    Bela Hieronymus Buck; Cornelia Maria Buchholz

    2004-01-01

    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

  5. The Future of Offshore Wind Energy

    E-print Network

    Firestone, Jeremy

    in the waters around Europe #12;4 US Offshore Wind Projects Proposed Atlantic Ocean Gulf of Mexico Cape Wind1 The Future of Offshore Wind Energy #12;2 #12;3 Offshore Wind Works · Offshore wind parks: 28 in 10 countries · Operational since 1991 · Current installed capacity: 1,250 MW · Offshore wind parks

  6. Stratigraphic and structural characteristics of volcanic rocks in core hole USW G-4, Yucca Mountain, Nye County, Nevada

    Microsoft Academic Search

    R. W. Spengler; M. P. Chornack; D. C. Muller; J. E. Kibler

    1984-01-01

    Detailed stratigraphic and structural studies, performed in connection with the Nevada Nuclear Waste Storage Investigations program, have been in progress since 1978. The purpose of these studies is to characterize volcanic rocks underlying Yucca Mountain - a volcanic highland situated along the western boundary of the Nevada Test Site in southern Nye county, Nevada. Core hole USW G-4 was cored

  7. Including stratigraphic hierarchy information in geostatistical simulation: a demonstration study on analogs of alluvial sediments

    NASA Astrophysics Data System (ADS)

    Comunian, Alessandro; Felletti, Fabrizio; Giacobbo, Francesca; Giudici, Mauro; Bersezio, Riccardo

    2015-04-01

    When building a geostatistical model of the hydrofacies distribution in a volume block it is important to include all the relevant available information. Localised information about the observed hydrofacies (hard data) are routinely included in the simulation procedures. Non stationarities in the hydrofacies distribution can be handled by considering auxiliary (soft) data extracted, for example, from the results of geophysical surveys. This piece of information can be included as auxiliary data both in variogram based methods (i.e. co-Kriging) and in multiple-point statistics (MPS) methods. The latter methods allow to formalise some soft knowledge about the considered model of heterogeneity using a training image. However, including information related to the stratigraphic hierarchy in the training image is rarely straightforward. In this work, a methodology to include the information about the stratigraphic hierarchy in the simulation process is formalised and implemented in a MPS framework. The methodology is applied and tested by reconstructing two model blocks of alluvial sediments with an approximate volume of few cubic meters. The external faces of the blocks, exposed in a quarry, were thoroughly mapped and their stratigraphic hierarchy was interpreted in a previous study. The bi-dimensional (2D) maps extracted from the faces, which are used as training images and as hard data, present a vertical trend and complex stratigraphic architectures. The training images and the conditioning data are classified according to the proposed stratigraphic hierarchy, and the hydrofacies codes are grouped to allow a sequence of interleaved binary MPS simulation. Every step of the simulation sequence corresponds to a group of hydrofacies defined in the stratigraphic hierarchy. The blocks simulated with the proposed methodology are compared with blocks simulated with a standard MPS approach. The comparisons are performed on many realisations using connectivity indicators and transport simulations. The latter are performed with the Kolmogorov-Dmitriev method, which allows to investigate the transport behaviour at a spatial scale one order of magnitude bigger than the scale of the model blocks, using the transport properties statistics extracted from the results of particle tracking simulations on the model blocks. To allow a direct comparison with the observed facies maps, which are available in 2D only, all the aforementioned comparison are first performed in 2D and subsequently on the three-dimensional blocks.

  8. Wind energy's promise, offshore

    Microsoft Academic Search

    TERRI BOOKMAN

    2005-01-01

    In November 2001, Cape Wind Associates, a Boston-based energy development firm, began the permitting application process with the U.S. Army Corps of Engineers to build the first offshore wind farm in the United States. The historical context and significance of the application, and of its continuing review process, is profound. On a global level looms ever-increasing evidence and recognition of

  9. Advanced Offshore Oil Platforms

    Microsoft Academic Search

    Fred S. Ellers

    1982-01-01

    Four innovative offshore platforms that are designed to withstand 100-foot waves in waters 600-feet deep are described. These platforms are: (1) Stratfjord B Concrete Gravity-Base Platform; (2) Magnus Steel-Template-Jacket Platform; (3) Hutton Tension-Leg Platform; and (4) Block 280 Guyed Tower. The Statfjord B platform, designed in Norway, rests on four massive concrete columns with storage tanks at the base. It

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

    SciTech Connect

    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

    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.

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

    SciTech Connect

    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

    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.

  12. CWI stratigraphic nomenclature changes coming August 1, 2014 To keep up with current regional Paleozoic nomenclature, old stratigraphic unit designations in CWI will

    E-print Network

    Ciocan-Fontanine, Ionut

    regional Paleozoic nomenclature, old stratigraphic unit designations in CWI will be replaced.Lawrence-Tunnel City. For a thorough discussion of the new Paleozoic stratigraphic nomenclature see MGS RI-65 ( http

  13. Is more IT offshoring better?

    Microsoft Academic Search

    Ajay Bhalla; ManMohan S. Sodhi; Byung-Gak Son

    2008-01-01

    We explore the link between a company's performance and the extent of its offshoring of IT-enabled services, focusing on large western companies. Our performance measures comprise sales, profit as percentage of sales, profit\\/employee and sales\\/employee over 1999–2004. To measure offshoring, we consider the extent to which these companies have offshored: (1) software development and other IT-related development and maintenance, (2)

  14. Application of an Advanced Cost Model in the Different Design Phases of an Offshore Wind Turbine

    Microsoft Academic Search

    H. B. Hendriks; C. Lindenburg; H. J. T. Kooijman; H. B. Bulder; J. Bozelie; J. B. Madsen; R. Halfschepel; W. Molenaar; R. van den Berg; M. Zaaijer

    The goal of the Dutch Offshore Wind Energy Converter (DOWEC) consortium is to develop concepts and technology in order to make large scale offshore wind energy economically feasible. The overall DOWEC development comprises of the design, the construction, and the prototype testing. Onshore testing of a 3 MW research and development prototype is scheduled for the end of 2002. The

  15. OUTSHORE Maturity Model: Assistance for Software Offshore Outsourcing Decisions

    NASA Astrophysics Data System (ADS)

    Mäkiö, Juho; Betz, Stafanie; Oberweis, Andreas

    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.

  16. Middle and upper Miocene natural gas sands in onshore and offshore Alabama

    SciTech Connect

    Mink, R.M.; Mancini, E.A.; Bearden, B.L.; Smith, C.C.

    1988-09-01

    Thirty Miocene natural gas fields have been established in onshore and offshore Alabama since the discovery of Miocene gas in this area in 1979. These fields have produced over 16 bcf of natural gas from the middle Miocene Amos sand (24 fields) and upper Miocene Luce (3 fields), Escambia (1 field), and Meyer (3 fields) sands. Production from the Amos transgressive sands represents over 92% of the cumulative shallow Miocene natural gas produced in onshore and offshore Alabama. In addition, over 127 bcf of natural gas has been produced from upper Miocene sands in the Chandeleur area. The productive Miocene section in onshore and coastal Alabama is interpreted to present transgressive marine shelf and regressive shoreface sands. The middle Miocene Amos sand bars are the most productive reservoirs of natural gas in onshore and coastal Alabama, principally due to the porous and permeable nature of these transgressive sands and their stratigraphic relationship to the underlying basinal clays in this area. In offshore Alabama the upper Miocene sands become thicker and are generally more porous and permeable than their onshore equivalents. Because of their deeper burial depth in offshore Alabama, these upper Miocene sands are associated with marine clays that are thermally more mature. The combination of reservoir grade lithologies associated with moderately mature petroleum source rocks enhances the natural gas potential of the upper Miocene sands in offshore Alabama.

  17. Offshore~WMEP - Monitoring offshore wind energy use

    Microsoft Academic Search

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

    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

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

    Microsoft Academic Search

    T. G. van Engelen

    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

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

    SciTech Connect

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

    1986-01-01

    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.

  20. Towers for Offshore Wind Turbines

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

    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 from wind over the oceans and convert to electric energy. The advantages of offshore wind turbines as compared to land are that offshore winds flow at higher speed than onshore winds and the more available space. In some land based settings, for better efficiency, turbines are separated as much as 10 rotor diameters from each other. In offshore applications where only two wind directions are likely to predominate, the distances between the turbines arranged in a line can be shortened to as little as two or four rotor diameters. Today, more than a dozen offshore European wind facilities with turbine ratings of 450 kw to 3.6 MW exist offshore in very shallow waters of 5 to 12 m. Compared to onshore wind turbines, offshore wind turbines are bigger and the tower height in offshore are in the range of 60 to 80 m. The water depths in oceans where offshore turbines can be located are within 30 m. However as the distance from land increases, the costs of building and maintaining the turbines and transmitting the power back to shore also increase sharply. The objective of this paper is to review the parameters of design for the maximum efficiency of offshore wind turbines and to develop types offshore towers to support the wind turbines. The methodology of design of offshore towers to support the wind turbine would be given and the environmental loads for the design of the towers would be calculated for specific cases. The marine corrosion on the towers and the methods to control the corrosion also would be briefly presented. As the wind speeds tend to increase with distance from the shore, turbines build father offshore will be able to capture more wind energy. Currently two types of towers are considered. Cylindrical tubular structures and truss type structures. But truss type structures have less weight and flexibility in design. The construction of the offshore towers to harness the wind energy is also presented. The results will include the calculation of wind and wave forces on the tower and the design details for the tower.

  1. Lower Miocene sequence stratigraphy of Taishi Basin, offshore Western Taiwan

    SciTech Connect

    Ting, J.S. (Chinese Petroleum Corp., Taipei (Taiwan, Province of China)); Lee, T.Y. (National Taiwan Normal Univ., Taipei (Taiwan, Province of China))

    1994-07-01

    By applying sequence stratigraphic concepts to the lower Miocene sedimentary sections in Taishi Basin, offshore western Taiwan, it is possible to identify four third-order sequences from subsurface information. The overall depositional environment of these sequences is in a deltaic setting. Following the early Aquitanian flood (24.8 Ma), the basin experienced a long period of sea level highstand, which generated more than 400 m of highstand prograding units. In late Aquitanian time, a thick retrogradational package ([approximately]250 m) was developed in response to rising sea level. Sandy units are now the dominant sediment type in the Taishi Basin. Until the early middle Miocene (15-16 Ma), the basin was flooded and deposited with thick marine shale. This analysis shows that the lower Miocene sedimentary sequences in the Taishi Basin have a good correlation with the Haq et al. (1987) chart, which would imply a passive margin setting for the Taishi Basin in the early Miocene. The predictive nature of the sequence stratigraphic technique can help in redefining the hydrocarbon play concepts in this area.

  2. Floating offshore structure

    SciTech Connect

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

    1985-05-28

    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.

  3. Earthquake resistant design of offshore building structures

    Microsoft Academic Search

    M. Ozaki; S. Hayashi

    1978-01-01

    A proposed earthquake resistant design system for offshore building structures in Japan is introduced. Offshore building structures are defined as the fixed type offshore structures which are constantly utilized for the purpose of habitation, duty, work, operation, gathering, recreation, sightseeing, etc. In the first section, basic principles for the design of offshore building structures are introduced considering safety of human

  4. Application of nonmarine genetic sequence stratigraphic concepts to reservoir characterization in the fluvial-lacustrine Westbourne Formation, Eromanga basin, Australia

    SciTech Connect

    Hamilton, D.S.; Holtz, M.H.; Yeh, J. (Univ. of Texas, Austin, TX (United States)) (and others)

    1996-01-01

    A high-resolution sequence stratigraphic analysis of the Westbourne Formation identified five chronostratigraphic genetic units each separated by thin, but laterally extensive, shale markers interpreted as maximum lacustrine flooding surfaces. The flooding surfaces were primarily identified by their lateral persistence and high gamma-ray log response, but marked changes in bedding architecture across these surfaces also facilitated their identification. The changes in bedding architecture reflect reorganization of the depositional systems from one depositional episode to the next. The Westbourne Formation is interpreted as a series of fluvially-dominated lacustrine delta sequences. Although the genetic units generally display lobate to digitate sand body geometries, sediment transport directions between successive units is highly variable. The complex morphology of the distributary network and accompanying high degree of facies variability indicates shallow lacustrine sedimentation similar to that in the modern inland Niger River delta which provides a modern analog. Westbourne fluid flow trends were established by mapping water encroachment during field development, observing differential depletion in repeat formation test data, and monitoring production response to water shut-off workovers. The fluid flow trends emphasized the highly layered character of the Westbourne reservoirs and integrating these trends with the geologic architecture defined stratigraphic controls on Westbourne flow units. The stratigraphic framework proved essential for unraveling sediment transport patterns and thus, predicting reservoir sandstone distribution. The stratigraphic framework also provided the key to understanding water encroachment and pressure a depletion which, when combined with predicted sandstone geometries, identified several step-out drilling and recompletion opportunities.

  5. Application of nonmarine genetic sequence stratigraphic concepts to reservoir characterization in the fluvial-lacustrine Westbourne Formation, Eromanga basin, Australia

    SciTech Connect

    Hamilton, D.S.; Holtz, M.H.; Yeh, J. [Univ. of Texas, Austin, TX (United States)] [and others

    1996-12-31

    A high-resolution sequence stratigraphic analysis of the Westbourne Formation identified five chronostratigraphic genetic units each separated by thin, but laterally extensive, shale markers interpreted as maximum lacustrine flooding surfaces. The flooding surfaces were primarily identified by their lateral persistence and high gamma-ray log response, but marked changes in bedding architecture across these surfaces also facilitated their identification. The changes in bedding architecture reflect reorganization of the depositional systems from one depositional episode to the next. The Westbourne Formation is interpreted as a series of fluvially-dominated lacustrine delta sequences. Although the genetic units generally display lobate to digitate sand body geometries, sediment transport directions between successive units is highly variable. The complex morphology of the distributary network and accompanying high degree of facies variability indicates shallow lacustrine sedimentation similar to that in the modern inland Niger River delta which provides a modern analog. Westbourne fluid flow trends were established by mapping water encroachment during field development, observing differential depletion in repeat formation test data, and monitoring production response to water shut-off workovers. The fluid flow trends emphasized the highly layered character of the Westbourne reservoirs and integrating these trends with the geologic architecture defined stratigraphic controls on Westbourne flow units. The stratigraphic framework proved essential for unraveling sediment transport patterns and thus, predicting reservoir sandstone distribution. The stratigraphic framework also provided the key to understanding water encroachment and pressure a depletion which, when combined with predicted sandstone geometries, identified several step-out drilling and recompletion opportunities.

  6. Float pump offshore wave energy converters

    SciTech Connect

    Nielsen, K. [Danish Wave Power Aps, Virum (Denmark)

    1996-12-31

    This paper will describe the numerical design models developed by DWP and ES-Consult as part of the Off-shore Wave Energy Converter project OWEC-1 supported by the European Union under the JOULE initiative. Offshore Wave Power Plants composed of float pump systems, has been investigated. Modeling techniques required to provide reliable methods for the predicted hydrodynamic behavior of the floats, their performance has been assessed and standardized criteria and techniques for the design has been provided. The systems investigated and the numerical time domain models developed will be described. The DWP/ES-Consult design models include both heave and surge motion of the device motion. The hydrodynamics are based on the long wave approximation of wave exiting forces as well as nonlinear drag and lift-forces, limits for the buoyancy force and variation of added mass with submergence are included in the calculations. The numerical models developed by DWP/ES-Consult are intended as tools for the structural design. The results in medium waves are compared to more exact hydrodynamic models (heave only) developed at Chalmars University and at NTH norwegian Technical University. Results are compared to model tests and real sea measurements. The design of the float geometry`s and power takeoff has not been optimized. The scope has been to compare and provide tools and guidelines for time domain modeling of offshore wave energy converters as a basis for further optimization.

  7. New Approaches to field-based analysis of stratigraphic sections

    NSDL National Science Digital Library

    Paul Myrow

    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.

  8. Offshoring and Directed Technical Change

    E-print Network

    Acemoglu, Daron

    2012-11-24

    To study the short-run and long-run implications on wage inequality, we introduce directed technical change into a Ricardian model of offshoring. A unique final good is produced by combining a skilled and an unskilled ...

  9. Methane Seeps along Offshore Virginia

    USGS Multimedia Gallery

    Numerous distinct methane streams emanating from the seafloor at an upper slope (< 500 m water depth) cold seep site offshore Virginia. Image courtesy of NOAA Okeanos Explorer Program, 2013 Northeast U.S. Canyons Expedition....

  10. Problems unique to offshore measurement

    SciTech Connect

    Young, J.G. [ANR Pipeline Co., Lafayette, LA (United States)

    1995-12-01

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

  11. A study on the dynamic response of a semi-submersible floating offshore wind turbine system Part 1: A water tank test

    Microsoft Academic Search

    Takeshi Ishihara; Pham Van Phu; Hiroyuki Sukegawa; Kenji Shimada

    A new semi-submersible floating structure was proposed on which three wind turbine towers would be installed. This paper presented the dynamic behaviors of the 1\\/150 scaled rigid model experiments in a water tank. A free vibration test was conducted in still water to obtain the natural pe- riods for verifying the numerical model and modeling the damping ratio of the

  12. Visual Stratigraphic Correlation and Anaglyph 3-D Visualizations Using GigaPan Imagery: Examples from Western Kansas

    Microsoft Academic Search

    R. C. Schott

    2008-01-01

    GigaPan images of outcrop, quarry, and roadcut exposures have been captured and are being used to test the efficacy of a novel visual comparison technique in addressing issues of stratigraphic correlation of sub- units within the Upper Cretaceous Niobrara Formation in Rooks, Ellis, Gove, and Trego Counties in northwest Kansas. Through the use of side-by-side implementations of the web-based GigaPan

  13. High-alloy materials for offshore applications

    SciTech Connect

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

    1983-05-01

    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.

  14. Stratigraphical links between Miocene Alpine Foreland basin and Gulf of Lion Passive Margin during lowstands

    NASA Astrophysics Data System (ADS)

    Rubino, Jean-Loup; Gorini, Christian; Leroux, Estelle; Aslanian, Daniel; Rabineau, Marina; Parize, Olivier; Besson, David

    2015-04-01

    Miocene peri-alpine foreland basin is connected toward the south with the Gulf of Lion passive margin and is predominantly filled by marine shallow water molassic deposits ranging from lower Miocene to Pliocene in age. Nine to ten depositional sequences are recorded and partly preserved in this basin and can be traced into the post rift part of the Gulf of Lion. One of the most surprising feature of the stratigraphic infill is the total lack of lowstand deposits within the foreland basin ; All superimposed sequences only includes transgressive and highstand System Tracts separated by erosional sequence boundaries and the development of incised valley networks filled by tidal deposits during transgression; Besson et al. 2005. It means that the entire foreland basin in SE France is exposed during lowstand periods without any preservation of fluvial deposits. By place few forced regression wedges are preserved at the transition between the foreland and the passive margin, close to the present day coastline. To date no real lowstand wedges have never been reported in the offshore of the Gulf of Lion. A reinterpretation of the best old vintage 2D dip seismic profiles along the passive margin validates the idea that the foreland basin is entirely exposed as well as the proximal part of the passive margin; first because some incised valleys can be occasionally picked on the shelf and second mainly because well defined superimposed or juxtaposed prograding lowstand wedges with nicely defined clinoforms onlapping the sequence boundaries can be recognized on the distal part of the shelf from the Burdigalian to the Messinian. Their ages being constrains by the Calmar well calibration. Unfortunately, they can't be continuously mapped all along the shelf break because of the strong erosion related to the Messinian Unconformity and the associated huge sea level fall.So we have to explain why during the lowstands, exceptionally long fluvial valley networks (more than 300km) can be developed. The first observation shows that the subsidence rate at least in the marginal part of the foreland basin, close to the forebulge, along the Rhone Valley, is very low and never exceed 40m/My. Second, the water depth of the deeper shelf series doesn't go deeper than 70 - 80m with shallowest water depth in the thresholds separating sub-basins. Therefore eustatically driven Miocene sea level changes can probably be great enough during this stratigraphic interval (50 to 70m) to lead to the almost complete basin emergence. Finally fluvial over-incision could also be enhanced by tectonic uplift links to anticline growing or local diapirism.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    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.

  16. Offshore Wind Energy Market Overview (Presentation)

    SciTech Connect

    Baring-Gould, I.

    2013-07-01

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

  17. Reassessment of offshore platforms

    SciTech Connect

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

    1993-05-01

    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.

  18. Combination offshore drilling rig

    SciTech Connect

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

    1986-07-29

    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.

  19. Structure for offshore exploitation

    SciTech Connect

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

    1984-02-28

    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.

  20. Keeping earnings offshore

    SciTech Connect

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

    1994-04-01

    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.

  1. Stratigraphic and lithofacies computer modeling in three dimensions

    SciTech Connect

    Abry, C.G.

    1984-04-01

    A new computer method has been developed to create a three-dimensional lithostratigraphic model from well and seismic data. The model is constructed by interpolating and extrapolating lithofacies data in three dimensions, within a time-stratigraphic framework. Volumes as large as a sedimentary basin or as small as an oil or gas field can be accommodated. The modeling method involves rescaling of original data from a depth to a geologic time scale prior to interpolation, and inverse rescaling thereafter. Displays of the three-dimensional interpretation are in the form of structure contour maps and lithofacies maps representing any geologic time. Also serial cross sections are obtained, which show lithofacies arrangements such as layers, lenses, channels, pinch-outs, reefs, and facies variations. Volumes of all types of sediments are computed. This stratigraphic modeling technique is of interest to exploration and production geologists and geophysicists, because it provides a more complete interpretation than conventional mapping techniques.

  2. SAS program for quantitative stratigraphic correlation by principal components

    USGS Publications Warehouse

    Hohn, M.E.

    1985-01-01

    A SAS program is presented which constructs a composite section of stratigraphic events through principal components analysis. The variables in the analysis are stratigraphic sections and the observational units are range limits of taxa. The program standardizes data in each section, extracts eigenvectors, estimates missing range limits, and computes the composite section from scores of events on the first principal component. Provided is an option of several types of diagnostic plots; these help one to determine conservative range limits or unrealistic estimates of missing values. Inspection of the graphs and eigenvalues allow one to evaluate goodness of fit between the composite and measured data. The program is extended easily to the creation of a rank-order composite. ?? 1985.

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

    SciTech Connect

    Abreu, V.S. (Petrobras and Rice Univ., Houston, TX (United States))

    1996-01-01

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

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

    SciTech Connect

    Abreu, V.S. [Petrobras and Rice Univ., Houston, TX (United States)

    1996-12-31

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

  5. Coupled dynamic analysis of floating offshore wind farms 

    E-print Network

    Shim, Sangyun

    2009-05-15

    dynamic analysis of an offshore floating wind turbine system including blade-rotor dynamics and platform motions. As a test case, the TLP-type floater system with 3 blades of 70-m diameter designed by the National Renewable Energy Laboratory (NREL...

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

    SciTech Connect

    Not Available

    1987-01-01

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

  7. RTK GPS, Lidar & Augmented Reality Devices integrated for Stratigraphic Modeling

    Microsoft Academic Search

    2007-01-01

    Outcrop-based modeling of reservoir analogous strata has long been a preferred technique utilized to understand sub-surface, sub-seismic and interwell heterogeneity in the petroleum industry. Historically, the methodologies employed focused collecting field data such as photographs, measured stratigraphic sections, gps, lidar, etc. and be compiled in the laboratory for construction of a digital outcrop model. The objective of these studies is

  8. Stratigraphic correlation with X-ray powder patterns

    E-print Network

    Singletary, John B

    1951-01-01

    . Introduction II. Theory anc Technique of Analysis by the Powder Nethod A. :. -Ray Diffraction B. The Recording Geiger Counter Spectrometer . 8 C. Construction and Usc of Soller Collimators. 15 D. Sample Preparation and Procedure for Obtaining Powder... Pattern=. II J. Interpretation of' Results. A. Pr eparation of Logs B. Discuss'on of Logs 23 25 25 33 IV. Conclusions. 36 V. Acknowledgements VI. Bibliography 37 38 STRATIGRAPHIC CORRELATION WITH X-RAY POWDER PATTERNS I. INTROIKCTION...

  9. Paleoclimate controls on stratigraphic repetition of chemical and siliciclastic rocks

    SciTech Connect

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

    1990-06-01

    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.

  10. Burial depth and stratigraphic controls on shale diagenesis

    E-print Network

    Moore, David Wesley

    1983-01-01

    and support and especially her patience in typing this thesis. vii TABLE OF CONTENTS Page INTRODUCTION Regional Setting Wilcox Group Environments of Deposition Shale Diagenesis METHODS Materials Studied Sample Preparation Analytical Methods 16 I... and Pranks, 1979). Much work has been completed relating the effects of burial dia- ganesis to the diagenetic clay mineral composition of shales. Eow- ever, a detailed study of the relationship between stratigraphic location and shale diagenesis has...

  11. Comparison of Offshore Turbidite records and Lake Disturbance Events at the Latitude of Seattle, Washington

    NASA Astrophysics Data System (ADS)

    Galer, S.; Goldfinger, C.; Morey, A. E.; Black, B.; Romsos, C.; Beeson, J. W.; Erhardt, M.

    2014-12-01

    We are investigating the paleoseismic history of northern Washington using offshore turbidite cores and lake sediments collected from forearc lakes along a transect from offshore to Seattle, Washington. Additional offshore cores, ash determinations and heavy mineral analysis flesh out the turbidite stratigraphy off northern Washington, and support 3-5 proximal turbidites in northern Washington canyons (see Adams, 1990) in addition to the 19 regionally correlated beds. Onshore, we have cored multiple lakes including (west to east) Beaver, Leland, Tarboo, Hall, Sawyer, and Wapato, east of the Cascades, and collected multibeam bathymetry, backscatter and chirp subbottom data. These lakes are small (2-113 ha), 6-18 m deep, and are all kettle lakes except Beaver Lake (landslide-dammed) and Wapato Lake, a glacial scour. These lakes were selected for their limited outside sediment sources and low sensitivity to ground shaking. The sedimentology is mostly organic-rich gyttja. All lakes contain the Mazama ash based on its similar depth occurrence in previously published cores and new EMP analysis. Computed Tomography (CT) density, gamma density, and magnetic susceptibility (ms) data show there is more stratigraphic variability than is visually apparent. Low-energy disturbance events are apparent in the stratigraphy of all lakes (except Hall) as increases in clastics, density, and ms. The number of post Mazama disturbance events is similar to the number of expected great earthquakes found offshore and onshore, though definition of the boundaries of the lake events is much less clear. Initial radiocarbon results and preliminary correlations along this 185 km transect show strong similarities in stratigraphic records between these cores over the past ~7600 years, anchored by the Mazama tephra. Preliminary comparisons with offshore cores show a striking similarity in downcore variability in physical properties. Given the evidence for earthquake origin for the offshore cores, and the strong common signal across the lake transect, we suggest that the lake disturbance events are likely of earthquake origin, representing turbidites generated internally within each lake. Analysis continues with the goal of estimating slope stability and minimum levels of ground shaking required to destabilize lake margins.

  12. Submitted for Review Journal of Offshore Mechanics and Arctic Engineering, ASME PRACTICAL AIRGAP PREDICTION FOR OFFSHORE STRUCTURES

    E-print Network

    Sweetman, Bert

    Department Texas A&M University at Galveston 200 Seawolf Parkway Galveston, Texas 77553, USA sweetman increase in the water surface elevation caused incident waves interacting with an offshore structure extreme airgap events using model test data. Estimates of extreme airgap events based on this method

  13. Offshore Aquaculture in the United States

    E-print Network

    Offshore Aquaculture in the United States: Economic Considerations, Implications & Opportunities from: http://aquaculture.noaa.gov This document should be cited as follows: Rubino, Michael (editor). 2008. Offshore Aquaculture in the United States: Economic Considerations, Implications & Opportunities

  14. A Simple Model of Offshore Outsourcing,

    E-print Network

    Paris-Sud XI, Université de

    A Simple Model of Offshore Outsourcing, Technology Upgrading and Welfare Jaewon JUNG THEMA Simple Model of Offshore Outsourcing, Technology Upgrading and Welfare Jaewon Jung and Jean Mercenier in the North as making explicit offshore outsourcing decisions to cheap-labor economies. Globalization results

  15. The politics and economics of offshore outsourcing

    Microsoft Academic Search

    N. Gregory Mankiw; Phillip Swagel

    2006-01-01

    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

  16. Virtual workgroups in offshore systems development

    Microsoft Academic Search

    Sachidanandam Sakthivel

    2005-01-01

    The market for offshore systems development, motivated by lower costs in developing countries, is expected to increase and reach about $15 billion in the year 2007. Virtual workgroups supported by computer and communication technologies enable offshore systems development. This article discusses the limitations of using virtual work in offshore systems development, and describes development processes and management procedures amenable to

  17. European offshore oil and gas, 1985

    SciTech Connect

    Not Available

    1985-01-01

    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.

  18. Measuring safety climate on offshore installations

    Microsoft Academic Search

    Kathryn Mearns; Rhona Flin; Rachale Gordon; Mark Fleming

    1998-01-01

    The human and organizational factors affecting safety were examined on 10 offshore installations using the Offshore Safety Questionnaire. The questionnaire contained scales measuring work pressure and work clarity, job communication, safety behaviour, risk perception, satisfaction with safety measures and safety attitudes. A total of 722 UK offshore workers (33% response rate) from a range of occupations completed and returned the

  19. OFFSHORE ARCTIC PIPELINE OIL SPILL RISK ASSESSMENT

    Microsoft Academic Search

    A. Dinovitzer; R. Lazor; D. Hinnah

    2004-01-01

    While offshore arctic pipelines have been under consideration for more than 25 years, few have been built. Renewed interest in offshore arctic oil and gas has necessitated the design of pipelines capable of both overcoming the technical challenges of the arctic offshore environment and minimizing the risk to it. This paper describes a quantitative risk assessment completed by BMT Fleet

  20. Cost of Offshore Wind Energy Charlene Nalubega

    E-print Network

    Mountziaris, T. J.

    and Industrial Engineering The focus of my research is to estimate the cost of floating offshore wind turbines turbines in shallow water or in the target location, we will model a system where the wind turbine turbines have evolved to be offshore. Offshore wind turbines generate more electricity because

  1. Deep Structure of the Kwanza Basin, offshore Angola

    NASA Astrophysics Data System (ADS)

    von Nicolai, C.; Scheck-Wenderoth, M.; Lewerenz, B.; Clausen, L.

    2009-04-01

    Due to its specific rheological behaviour the presence of salt in the stratigraphic succession of passive continental margins strongly influences the structural evolution of the latter. Although it is known that salt tectonics are closely tied to regional deformation the interplay of both processes in the geological evolution of passive continental margins is still not well understood. In this study we present preliminary results from a project aiming to decipher the interaction of regional tectonics (i.e. subsidence, uplift) and internal deformation processes (= salt tectonic movements) in the South Atlantic Kwanza Basin by construction of a margin-wide, crustal-scale 3D structural model, and subsequent reconstruction of the deformation history. The Kwanza Basin offshore Angola formed during the Early Cretaceous opening of the South Atlantic. After continental break-up restricted marine conditions caused the precipitation of evaporites during the Aptian followed by carbonate and finally clastic deposition from the Albian to the present. Numerous salt structures of different maturation and styles document intense deformation of the Kwanza Basin since rifting. It thus provides an ideal site to study salt mobilisation processes and their relation with regional tectonics. A first simple 3D model of the Southern part of the basin providing insight into its present state configuration was constructed by the combination of structural and gravimetric modelling. 2D seismic reflection data was used to determine the structural setting and the configuration of the stratigraphic units in the sedimentary and upper crustal part of the basin, whereas its deep structure was constrained by gravity modelling. The resulting geological model suggests a strong segmentation of the continental crust of the Southern Kwanza Basin characterised by a chain of basement horsts and deep sedimentary troughs.

  2. Offshore Renewable Energy R&D (Fact Sheet)

    SciTech Connect

    Not Available

    2011-10-01

    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.

  3. Use of stratigraphic and lithofacies maps in hydrogeologic studies: Examples from the General Separations Area, Savannah River Site, S. C

    SciTech Connect

    Thayer, P.A. (Univ. of North Carolina, Wilmington, NC (United States). Dept. of Earth Sciences); Smits, A.D. (Science Applications International Corporation, Augusta, GA (United States)); Harris, M.K. (Westinghouse Savannah River Co., Aiken, SC (United States). Environmental Restoration Dept.)

    1993-03-01

    Stratigraphic and lithofacies maps are effective tools for assessing hydrologic properties of Tertiary aquifer and confining units in the 15mi[sup 2] General Separations Area (GSA) at the Savannah River Site, S.C. Pumping tests and laboratory permeability data indicate that the type, geometry, and spatial distribution of lithofacies are important factors controlling the lateral and vertical variability of hydraulic conductivity in unconsolidated terrigenous and carbonate sediments comprising aquifer and confining units. Lithofacies mapping is useful for predicting lateral permeability heterogeneity, particularly in areas where hydraulic data is sparse. The authors used detailed lithologic data from 186 coreholes to construct stratigraphic and lithofacies maps of aquifer and confining units, including: structure contour; isopach; isolith thickness of mud, sand, and carbonate; sand, mud, and carbonate percentage; number of sand and mud beds; sand-mud ratio; clastic ratio; lithofacies; and entropy lithofacies. Data from the stratigraphic and lithofacies maps are being integrated into a ground-water flow model for the GSA and have proved useful for generation of potentiometric surface maps, head difference maps, and contaminant plume maps.

  4. Visual Stratigraphic Correlation and Anaglyph 3-D Visualizations Using GigaPan Imagery: Examples from Western Kansas

    NASA Astrophysics Data System (ADS)

    Schott, R. C.

    2008-12-01

    GigaPan images of outcrop, quarry, and roadcut exposures have been captured and are being used to test the efficacy of a novel visual comparison technique in addressing issues of stratigraphic correlation of sub- units within the Upper Cretaceous Niobrara Formation in Rooks, Ellis, Gove, and Trego Counties in northwest Kansas. Through the use of side-by-side implementations of the web-based GigaPan Flash viewer, distinctive individual layers and stratigraphic sequences can be matched in a highly intuitive visual manner. Incorporating adequate quantitative measures of scale is a challenge that remains to be solved before high precision correlation can be done with GigaPan imagery, however semi-quantitative and qualitative preliminary results suggest that this device may become a powerful research tool. Application of the visual correlation technique to the teaching of stratigraphic correlation concepts in the classroom offers a novel and interactive way for students to experience the joy of discovery in a virtual field environment. A method for creating anaglyph GigaPan images with the current GigaPan robot will also be described; the resulting images represent another way to significantly enhance classroom-based virtual field experiences.

  5. A MATLAB®-based program for 3D visualization of stratigraphic setting and subsidence evolution of sedimentary basins: example application to the Vienna Basin

    NASA Astrophysics Data System (ADS)

    Lee, Eun Young; Novotny, Johannes; Wagreich, Michael

    2015-04-01

    In recent years, 3D visualization of sedimentary basins has become increasingly popular. Stratigraphic and structural mapping is highly important to understand the internal setting of sedimentary basins. And subsequent subsidence analysis provides significant insights for basin evolution. This study focused on developing a simple and user-friendly program which allows geologists to analyze and model sedimentary basin data. The developed program is aimed at stratigraphic and subsidence modelling of sedimentary basins from wells or stratigraphic profile data. This program is mainly based on two numerical methods; surface interpolation and subsidence analysis. For surface visualization four different interpolation techniques (Linear, Natural, Cubic Spline, and Thin-Plate Spline) are provided in this program. The subsidence analysis consists of decompaction and backstripping techniques. The numerical methods are computed in MATLAB® which is a multi-paradigm numerical computing environment used extensively in academic, research, and industrial fields. This program consists of five main processing steps; 1) setup (study area and stratigraphic units), 2) loading of well data, 3) stratigraphic modelling (depth distribution and isopach plots), 4) subsidence parameter input, and 5) subsidence modelling (subsided depth and subsidence rate plots). The graphical user interface intuitively guides users through all process stages and provides tools to analyse and export the results. Interpolation and subsidence results are cached to minimize redundant computations and improve the interactivity of the program. All 2D and 3D visualizations are created by using MATLAB plotting functions, which enables users to fine-tune the visualization results using the full range of available plot options in MATLAB. All functions of this program are illustrated with a case study of Miocene sediments in the Vienna Basin. The basin is an ideal place to test this program, because sufficient data is available to analyse and model stratigraphic setting and subsidence evolution of the basin. The study area covers approximately 1200 km2 including 110 data points in the central part of the Vienna Basin.

  6. Towers for Offshore Wind Turbines

    Microsoft Academic Search

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

    2010-01-01

    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

  7. Ultrasonic thickness testing of aging offshore structures 

    E-print Network

    Ellison, Brian Kirk

    1999-01-01

    research on the use of corrosion protection. New corrosion resistant membranes are sometimes placed on the members in the splash zone area. Pemex Exploration and Production has used a protective epoxy coating called "RE-32" in the Bay of Campeche... an environment in which oil and gas reserves can be developed and profitably produced. The collapse of oil prices in the 1980's has put tremendous pressure on producers to eliminate waste. Inspection and intervention programs have been heavily scrutinized...

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

    SciTech Connect

    Holtar, E.; Forsberg, A.

    1995-08-01

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

  9. Role of stratigraphic discontinuities in episodic development of paleogeography, Helderberg Group, Central Appalachians

    SciTech Connect

    Goodwin, P.W.; Anderson, E.J.

    1988-01-01

    The Lower Devonian Helderberg Group is segregated into paleogeographically significant packages by stratigraphic discontinuities at two scales. All stratigraphic sections are completely divisible into punctuated aggradational cycles (PACS) whose boundaries are synchronous stratigraphic discontinuities produced by rapid sea level rises that recurred at intervals of thousands or tens of thousands of years. Environmentally disjunct facies were superimposed basin-wide at each PAC boundary. Facies within PACs represent a continuous spectrum of paleoenvironments that coexisted and evolved through aggradation. At a larger scale, correlation of PACs reveals cryptic unconformities with a recurrence interval of hundreds of thousands of years. At these stratigraphic discontinuities, PACs are locally or regionally missing as a result of nondeposition or erosion associated with major sea level falls (and subsequent rises). Large basin-wide facies changes across these discontinuities indicate major reorganizations of paleogeography. Therefore, Helderbergian paleogeography developed episodically in response to allogenic stratigraphic events at two scales and two frequencies. Reorganization of the paleographic significance of these allogenic events emphasizes the need to distinguish between stratigraphic and sedimentologic processes in stratigraphic analysis. Facies architecture and paleogeographic patterns were determined by stratigraphic processes, not sedimentologic processes, and therefore require stratigraphic models for interpretation.

  10. Regional comparison of syn- and post-rift sequences in salt and salt-free basins offshore Brazil and Angola/Namibia, South Atlantic

    NASA Astrophysics Data System (ADS)

    Strozyk, Frank; Back, Stefan; Kukla, Peter

    2015-04-01

    The large South Atlantic basins offshore South America and Africa record a highly variable syn- to post-breakup tectono-stratigraphic development. The present-day diversity in the structural and sedimentary architecture of the conjugate margins offshore southern Brazil, Namibia and Angola reflects variations in the interplay of a number of controlling factors, of which the most important are i) the structural configuration of each margin segment at the time of break-up, ii) the post break-up geodynamic history including tectonics and magmatism, and iii) variations in the type, quantity and distribution of sediment input to the respective margin segment. Particularly the basins around the Rio Grande Rise - Walvis Ridge volcanic complex show a pronounced tectono-stratigraphic asymmetry both along the respective continental margin and across the Atlantic. Only a few attempts exist to establish a regional tectono-stratigraphic correlation framework across the South Atlantic Ocean, mainly because of the lack of data across entire margin segments and limited resolution of basin wide geophysics. Still unresolved issues particularly concern the explanation of the basin-specific geological evolution of respective margin segments along the same continental margin, as well as the correlation of conjugate basins and margin segments across the Atlantic Ocean. In our study we present interpretations and first-pass restorations of regional 2D seismic-reflectivity data from the large basins offshore Brazil (Pelotas Basin, Santos Basin, Campos Basin, Espirito Santo Basin), and offshore Namibia and Angola (Walvis Basin, Namibe Basin, Benguela Basin, Kwanza Basin), which represent four adjacent pairs of conjugate basins on both sides of the South Atlantic. Results are used to document and compare on a basin-scale the contrasting styles of rift and post-rift settings during and after the continental breakup.

  11. High resolution sequence stratigraphic concepts applied to geostatistical modeling

    SciTech Connect

    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

    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.

  12. Model study of shoreline changes due to a series of offshore breakwaters 

    E-print Network

    Cords, Donald Alan

    1986-01-01

    the desired shoreline changes or the time needed for the shoreline change to reach an equilibrium shape can be estimated. An extensive annotative bibliography on detached breakwaters was compiled by Lesnik (9) Shoreline changes have been monitored... due to local hydrographical and sedimentological circumstances. Fried tested fourteen alternatives of a series of six offshore breakwaters in the model. It was shown that the building schedule of the offshore breakwaters had a direct influence...

  13. Intraslope basin reservoirs deposited by gravity-driven processes: Ship shoal and ewing banks areas, offshore Louisiana

    SciTech Connect

    Armentrout, J.M.; Malecek, S.J.; Mathur, V.R. [Mobil Oil Corp., Dallas, TX (United States)] [and others

    1995-06-01

    Seismic facies and high-resolution biostratigraphic analysis provide a sequence stratigraphic framework for interpreting lateral distribution of sand-prone facies and reservoir connectivity in the Ship Shoal 351-358 to Ewing Bank 988 area, offshore Louisiana. The interval of interest is an isochron thick interpreted as a lowstand systems tract deposited at bathyal water depths within an intraslope-basin. This basin is approximately 50 kilometers from the age equivalent shelf/slope break. The D. pentaradiatus-D. brouweri sequence consists of the synclinal fill of a salt withdrawal basin forming an isochron thick that thins onto adjacent salt-cored structural highs. This isochron interval was subdivided into four seismic facies and each is calibrated with local well data. The seismic facies are: Facies (1) hummocky-mounded facies with an internal reflection character of discontinuous variable amplitude, calibrated to thick, flat-based blocky to fining-upward sandstones interpreted as local sheets deposited as channel-fed depositional lobes; Facies (3) clinoform-wedge facies are characterized by continuous, uniform amplitude reflections and are calibrated with mudstones interpreted as part of a downslope prograding complex that downlaps and onlaps the hummocky- mounded facies; and Facies (4) parallel-continuous facies of relatively uniform amplitude correlated with mudstones that drape the other three facies throughout the study area and are interpreted as hemipelagic mudstone. Mapped patterns of these seismic facies suggest a network of channel systems within a slope valley supplying sand by gravity-driven processes into a local salt withdrawal intraslope-basin. Following the above analysis, three wells and two side-tracks were drilled to further test the prospectivity of the area. Rock type and hydrocarbon predictions based on seismic facies analysis were confirmed by the wells.

  14. Geological history of the Flemish Pass Basin, offshore Newfoundland

    SciTech Connect

    Foster, D.G.; Robinson, A.G. (BP Exploration Operating Company Ltd., Uxbridge (United Kingdom))

    1993-04-01

    In this paper the authors present a seismic-stratigraphic interpretation of the Mesozoic and Tertiary geologic history of the Flemish Pass Basin, offshore Newfoundland, based on seismic data and data from seven wells that were integrated on the BP subsurface integrated interpretation system (SIIS). Four megasequences are identified. Megasequence 1 (MSI) is Triassic to lower Berriasian, and includes poorly known sediments associated with Triassic-Early Jurrasic rifting prior to spreading between the North African and American continents. The uppermost mappable unconformity-bounded unit within MSI contains major Kimmeridgian to Portlandian marine source rocks deposited in two east-west-trending subbasins in the Baccalieu and Gabriel areas. During the early Berrasian, pronounced rifting linked to the subsequent spreading of Iberia from the Grand Banks (Barremian-Aptian) led to regional deepening and deposition of clastic sediments (MS2) in two northeast-southwest-trending, fault-bounded subbasins in the Baccalieu and Gabriel areas. In the Aptian, Early Cretaceous subbasins were inverted due to strike-slip movement as extension assumed a northeast-southwest orientation prior to movement of Greenland/Europe away from Labrador (Albian). MS3 sediments fill northwest-southeast trending fault-bounded depocenters typically located on areas that had formed highs during Early Cretaceous. Postrift sedimentation continued from the Albian( ) to the present with Upper Cretaceous pelagic limestone and later clastic sediment deposition. 37 refs., 19 figs., 1 tab.

  15. Sea loads on ships and offshore structures

    SciTech Connect

    Faltinsen, O. (Norwegian Inst. of Technology (NO))

    1990-01-01

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

  16. Fatigue handbook: Offshore steel structures

    SciTech Connect

    Almarnaess, A.

    1985-01-01

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

  17. OWL representation of the geologic timescale implementing stratigraphic best practice

    NASA Astrophysics Data System (ADS)

    Cox, S. J.

    2011-12-01

    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.

  18. Offshore oil-spill occurrence rates

    Microsoft Academic Search

    Robert P. LaBelle; Cheryl M. Anderson

    1996-01-01

    The U.S. Minerals Management Service maintains statistics on the frequency of offshore oil spills associated with platforms, pipelines, and tanker traffic. Oil-spill occurrence rates have decreased slightly for U.S. offshore platforms, increased for U.S. offshore pipelines, and remained about the same for worldwide tankers (comparing rates calculated through 1992 to rates calculated through the mid-80s). Recently calculated rates are presented

  19. About Hercules Offshore Headquartered in Houston, Texas, Hercules Offshore serves the oil and

    E-print Network

    Fisher, Kathleen

    About Hercules Offshore Headquartered in Houston, Texas, Hercules Offshore serves the oil and gas industry with the largest fleet of mobile drilling platforms in the U.S. Gulf of Mexico, and the fourth exploration, drilling and related maintenance tasks. Hercules Offshore operates in key oil producing sites

  20. 46 CFR 126.170 - Carriage of offshore workers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...false Carriage of offshore workers. 126.170 Section 126...170 Carriage of offshore workers. (a) Offshore workers may be carried aboard an...meets the applicability and construction requirements of subpart...

  1. 46 CFR 15.520 - Mobile offshore drilling units.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false Mobile offshore drilling units. 15.520 Section 15...Vessels § 15.520 Mobile offshore drilling units. (a) The requirements in this section for mobile offshore drilling units (MODUs) supplement other...

  2. 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 Section 15...Vessels § 15.520 Mobile offshore drilling units. (a) The requirements in this section for mobile offshore drilling units (MODUs) supplement other...

  3. 46 CFR 15.520 - Mobile offshore drilling units.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false Mobile offshore drilling units. 15.520 Section 15...Vessels § 15.520 Mobile offshore drilling units. (a) The requirements in this section for mobile offshore drilling units (MODUs) supplement other...

  4. 46 CFR 15.520 - Mobile offshore drilling units.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 false Mobile offshore drilling units. 15.520 Section 15...Vessels § 15.520 Mobile offshore drilling units. (a) The requirements in this section for mobile offshore drilling units (MODUs) supplement other...

  5. Infauna Monitoring Horns Rev Offshore Wind Farm

    E-print Network

    #12;Infauna Monitoring Horns Rev Offshore Wind Farm Annual Status Report 2004 Published: 21 April-2004................................................. 48 Wind farm area (Turbine), Reference area (Ref

  6. Vessel movement influences offshore communications system design

    SciTech Connect

    Holcomb, S.R. [Brown and Root Inc., Houston, TX (United States); Burger, S.D. [Amoco Orient Production Co., Chiwan (China)

    1996-05-27

    Communications links for the Liuhua 11-1 oil production project, offshore China, required a system that would function with vessel movement under typhoon conditions of heavy rainfall and extreme wave action. The system includes a microwave path between two floating production facilities and a satellite connection between the offshore facilities and onshore China. The system provides multiple local-area-network (LAN) linkages, and voice with fax in English and Chinese. The satellite link has a geostabilized platform offshore and a China National Offshore Oil Corp. master earth station onshore. System operations started in mid-1995. This paper reviews the design and performance of this communications network.

  7. Chemical Contaminants as Stratigraphic Markers for the Anthropocene

    NASA Astrophysics Data System (ADS)

    Kruge, M. A.

    2012-12-01

    Thousands and even millions of years from now, widespread anthropogenic contaminants in sediments would likely persist, incorporated into the geological record. They would inadvertently preserve evidence of our present era (informally designated as the Anthropocene Epoch) characterized by large human populations engaged in intensive industrial and agricultural activities. Hypothetical geologists in the distant future would likely find unusually high concentrations of a wide variety of contaminants at stratigraphic levels corresponding to our present time, analogous to the iridium anomaly marking the bolide impact event at the close of the Cretaceous Period. These would include both organic and inorganic substances, such as industrially-derived heavy metals (e.g., Hg, Pb, Cr, Zn) and hydrocarbons, both petrogenic (derived directly from petroleum) and pyrogenic (combustion products). While there are natural sources for these materials, such as volcanic eruptions, wildfires, and oil seeps, their co-occurrence would provide a signature characteristic of human activity. Diagnostic assemblages of organic compounds would carry an anthropogenic imprint. The distribution of polycyclic aromatic hydrocarbons (PAHs) in a sediment sample could distinguish between natural and human sources. Stable isotopic signatures would provide additional evidence. Concentrations of contaminants in the sedimentary record would increase exponentially with increasing proximity to urban source areas, where at present billions of people are collectively consuming vast quantities of fossil fuels and generating large amounts of waste. Aolian and marine transport prior to deposition has been seen at present to globally redistribute detectable amounts of contaminants including Hg and PAHs, even at great distances from principal source areas. For organic contaminants, deposition in an anoxic sedimentary environment could insure their preservation, increasing the likelihood of their inclusion in the long-term stratigraphic record, establishing markers of the Anthropocene Epoch for millions of years to come.

  8. Regional geological framework and petroleum geology of Miocene sandstones in coastal and offshore Alabama

    SciTech Connect

    Mancini, E.A.; Bearden, B.L.; Mink, R.M.

    1987-05-01

    The Miocene natural gas trend of coastal and offshore Alabama is part of the regional Miocene oil and gas trend of the Gulf coastal area that extends from Texas into Alabama. The major Miocene productive area in Alabama is in southern Baldwin County and Mobile Bay. Since the discovery of Miocene gas in 1979, 28 natural gas fields have been established in coastal and offshore Alabama. The Miocene sandstones range in thickness from 10 to 200 ft, are very fine to coarse grained, are quartz rich, and have subangular to rounded and moderately to well-sorted quartz grains. The productive Miocene interval overlies upper Oligocene marine shelf deposits (Chickasawhay Limestone) and is overlain by Miocene fluvial clastics. The Miocene sandstones, which include the Amos, Escambia, Luce, and Meyer, are interpreted to represent a marine shelf-deltaic complex. A Miocene delta system prograded from the west in the area of offshore Louisiana-Mississippi into coastal and offshore Alabama. Reservoirs and potential reservoirs include highly constructive and highly destructive deltaic and marine shelf sandstones. Porosity in these sandstones is primary intergranular and generally ranges from 27 to 35%. Permeabilities may exceed 2000 md. Basinal Miocene marine clays and Oligocene marls are the probable petroleum source rocks. Petroleum traps are principally stratigraphic, typically involving lateral sandstone pinch-outs against regional dip. Seismic reflection is an excellent exploration tool for identifying potential Miocene fields. Miocene gas sands are best delineated with relative-amplitude seismic reflection data on which gas-charged sands are apparent as bright spots.

  9. Pacific offshore record of plinian arc volcanism in Central America: 1. Along-arc correlations

    NASA Astrophysics Data System (ADS)

    Kutterolf, S.; Freundt, A.; PeréZ, W.; MöRz, T.; Schacht, U.; Wehrmann, H.; Schmincke, H.-U.

    2008-02-01

    We collected 56 marine gravity cores from the Pacific seafloor offshore Central America which contain a total of 213 volcanic ash beds. Ash-layer correlations between cores and with their parental tephras on land use stratigraphic, lithologic, and compositional criteria. In particular, we make use of our newly built database of bulk-rock, mineral, and glass major and trace element compositions of plinian and similarly widespread tephras erupted since the Pleistocene along the Central American Volcanic Arc. We thus identify the distal ashes of 11 Nicaraguan, 8 El Salvadorian, 6 Guatemalan, and 1 Costa Rican eruptions. Relatively uniform pelagic sedimentation rates allow us to determine ages of 10 previously undated tephras by their relative position between ash layers of known age. Linking the marine and terrestrial records yields a tephrostratigraphic framework for the Central American volcanic arc from Costa Rica to Guatemala. This is a useful tool and prerequisite to understand the evolution of volcanism at a whole-arc scale.

  10. Petroleum geology of the deltaic sequence, Rio Del Rey basin, offshore Cameroon

    SciTech Connect

    Coughlin, R.M.; Bement, W.O.; Maloney, W.V. (Pecten International Company, Houston, TX (United States))

    1993-09-01

    The Rio Del Rey Basin of offshore Cameroon comprises the easternmost portion of the Niger delta complex. In the delta flank setting, the overall package is thinner and stratigraphic correlation simpler than in the depocenter to the west so the distribution of reservoirs and seals is well defined. Productive reservoirs are shallow, typically less than 2000 m, and mostly hydropressured to slightly overpressured. Reservoir properties generally are excellent and seismic bright-spot technology has played a major role in exploration and development efforts. Rio Del Rey is characterized by three main structural styles from north to south: (1) detachment-based growth faults, (2) highly faulted, mobile shale cored domes and ridges, and (3) toe thrusts and folds. Virtually all individual traps are fault dependent and lack of sufficient internal seals in sand-rich wave-dominated deltaic sequences can limit the objective window. Most fields are downthrown fault traps in which hanging-wall reservoirs are effectively sealed against older prodelta and marine shales. All large oil fields are located in the dome and ridge province and are potential analogs for similar structures now being explored on the upper slope off Nigeria. The best quality source rocks identified thus far are Paleocene to Eocene marine shales. Oil vs. gas distribution in the basin is a function of variations in the kerogen type, organic richness, and maturity of these source rocks. A significant quantity of the gas found to date in Rio Del Rey is biogenic in origin. The Cameroon charge model may aid in better understanding hydrocarbon distribution on offshore Nigeria, where the Miocene deltaic section is much thicker and potential Paleocene-Eocene source rocks likely are unpenetrated. The shallow deltaic play in Cameroon is relatively mature. Future exploration likely will focus on identifying deeper, nonbright-spot-supported opportunities including potential stratigraphic traps.

  11. Offshore wind resource assessment through satellite images

    E-print Network

    1 Slide no. 4 Offshore wind resource assessment through satellite images Charlotte Bay Hasager images for offshore wind ressource assessment in lieu of in-situ mast observations #12;4 Slide no 2001 i.e. prior to construction of the wind farm 19991019 Footprint averaging per scene #12;1 0 Slide

  12. Offshore Wind Turbines: Some Technical Challenges

    E-print Network

    Houlsby, Guy T.

    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

  13. Seepage in Vietnam — onshore and offshore examples

    Microsoft Academic Search

    J. J. Traynor; Chris Sladen

    1997-01-01

    Hydrocarbon seepages in Vietnam are generally linked to migration from Tertiary source rocks, and seeps are present both onshore and offshore.Residual oil can be observed at outcrop in breached traps within Tertiary sections and in exhumed ‘buried hill’ traps in pre-Tertiary rocks in the onshore Hanoi Basin. There is active oil seepage on the western margin of the offshore Phu

  14. 44 MArch 2006 Can offshore aquaculture

    E-print Network

    Miami, University of

    44 MArch 2006 Can offshore aquaculture of carnivorous fish be sustainable? Case studies from and pollution concerns sug- gest that major environmental benefits are to be gained by moving cage aquaculture development of offshore aquaculture through university-industry-government partnerships. Emerging technology

  15. Passive control of offshore jacket platforms

    Microsoft Academic Search

    K. C. Patil; R. S. Jangid

    2005-01-01

    The wave-induced dynamic force is one of the most important excitations to be dealt with in the design of offshore structures. In order to perform a reliable design of an offshore structure, it is important to obtain an exact evaluation of its dynamic response but also to examine the ways of reducing the response. This paper presents the response of

  16. Mari Voldsund Exergy analysis of offshore

    E-print Network

    Kjelstrup, Signe

    Mari Voldsund Exergy analysis of offshore oil and gas processing Doctoral thesis for the degree my contact persons, helping out both with administrative issues, and with matters concerning offshore on different types of North Sea platforms; (ii) identify and discuss improvement potentials for each case

  17. Preliminary seismic characterization of parts of the island of Gotland in preparation for a potential CO2 storage test site

    NASA Astrophysics Data System (ADS)

    Lydersen, Ida; Sopher, Daniel; Juhlin, Christopher

    2015-04-01

    Geological storage of CO2 is one of the available options to reduce CO2-emissions from large point sources. Previous work in the Baltic Sea Basin has inferred a large storage potential in several stratigraphic units. The most promising of these is the Faludden sandstone, exhibiting favorable reservoir properties and forming a regional stratigraphic trap. A potential location for a pilot CO2 injection site, to explore the suitability of the Faludden reservoir is onshore Gotland, Sweden. In this study onshore and offshore data have been digitized and interpreted, along with well data, to provide a detailed characterization of the Faludden reservoir below parts of Gotland. Maps and regional seismic profiles describing the extent and top structure of the Faludden sandstone are presented. The study area covers large parts of the island of Gotland, and extends about 50-70km offshore. The seismic data presented is part of a larger dataset acquired by Oljeprospektering AB (OPAB) between 1970 and 1990. The dataset is to this date largely unpublished, therefore re-processing and interpretation of these data provide improved insight into the subsurface of the study area. Two longer seismic profiles crossing Gotland ENE-WSW have been interpreted to give a large scale, regional control of the Faludden sandstone. A relatively tight grid of land seismic following the extent of the Faludden sandstone along the eastern coast to the southernmost point has been interpreted to better understand the actual distribution and geometry of the Faludden sandstone beneath Gotland. The maps from this study help to identify the most suitable area for a potential test injection site for CO2-storage, and to further the geological understanding of the area in general.

  18. [Offshore ecosystem health status assessment: a review].

    PubMed

    Dai, Ben-lin; Hua, Zu-lin; Mu, Fei-hu; Xu, Ning; He, Yu-long

    2013-04-01

    With the promotion of the concept of sustainable development, the issues of aquatic ecosystem health attract substantial attention, and considerable work has been carried out on the health assessment of waters, e. g. , rivers and lakes. However, the health assessment of offshore ecosystem is still at its exploratory stage. Based on the investigations on the related references at home and abroad, this paper analyzed the concepts of offshore ecosystem health assessment, summarized the main methods for the assessment, the principles for screening related indicators, and the research philosophy, and systematically listed the quantitative indices for the assessment. Aiming at the main existing issues in the researches of offshore ecosystem health, the future research directions about the offshore ecosystem health were suggested. It was considered that the concept and connotation analyses, the screening of assessment indicators, the choice of assessment scale, and the integration of assessment methods should be further strengthened to improve the assessment of offshore ecosystem health. PMID:23898680

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

    SciTech Connect

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

    1994-07-01

    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.

  20. Geological factors controlling gas volumes in Miocene carbonate buildups-offshore Sarawak

    SciTech Connect

    Smith, L.R. [Occidental international Exploration and Production Co., Bakersfield, CA (United States)

    1996-12-31

    Over 170 independent Miocene carbonate buildups are located within the Luconia Province of offshore Sarawak, Malaysia. They vary in size and shape from small isolated pinnacles through tabular to broad low relief platforms, distributed across nearly 10MM acres of the shallow Miocene shelf. Among the 70-odd buildups drilled to date, over half are gas-bearing. Discovered volumes exceeds 40 TCF of gas-in-place, with gas columns ranging from a few meters to greater than 500 m. Geological factors suspected of controlling the occurrence and volume of gas within each buildup include caprock, source, stratigraphic and structural variables. The source for gas is the (largely uncontrolled) Cycle I/II coastal plain sequence. In practice, only caprock and seismically-derived stratigraphic and structural factors provide sufficient geological/geophysical evidence to characterize and distinguish buildups at the prospect level. Useful caprock-related discriminators include clastictseismic facies, drape, and pore pressure - each reflecting the sealing capacity of the caprock as measured by the gas column height in the reservoir. Factors related to the gas-focusing effectiveness of bedding below the reservoir include the relief and structural configuration of the pre-carbonate section, the areal extent of the drainage area, and faulting. As prospect discriminators, these structural factors are limited by possible velocity distortions and poor seismic resolution beneath the carbonate section. Five gas accumulations discovered by Occidental since 1992 are compared to show the variety of discernible factors controlling their in-place volumes.

  1. Climate cyclicity revealed from X-ray CT images of deep offshore sediments

    NASA Astrophysics Data System (ADS)

    Grochau, M.; Muller, T. M.; Campos, E.; Clennell, B.; Gurevich, B.

    2009-04-01

    We present a methodology to assess climate variability by using X-ray computed tomography (CT) images along with laboratory velocity measurements and borehole logs and apply it to a specific stratigraphic interval in deep water Campos Basin, offshore Brazil. The higher resolution of sampling in the core data (extracted from 2.8km depth) overcomes the aliasing and smoothing effect of log-based measurements and enables the delineation of stratigraphic cycles. The mineralogy variation in these rocks, which we interpret as a response to astronomically-forced climatic cycles, leads to pronounced and rhythmic variations in physical properties. In addition, we observe a good correlation between X-ray CT value and ultrasonic velocity. We demonstrate that there is spatial cyclicity that cannot be revealed even using high resolution logs. The understanding of the cyclicity characteristics in the area under study allowed us to identify Milankovich cycles, which we interpret as precession cycles (19ky periodicity). We conclude that there is a potential for using X-ray CT tools combined with ultrasonic measurements to assess small scale rock physical properties from deeply buried sediments. Consequently, this new methodology broadens the spectrum of data to be used in paleo-climate studies.

  2. Newport-Inglewood-Carlsbad-Coronado Bank Fault System Nearshore Southern California: Testing models for Quaternary deformation

    NASA Astrophysics Data System (ADS)

    Bennett, J. T.; Sorlien, C. C.; Cormier, M.; Bauer, R. L.

    2011-12-01

    The San Andreas fault system is distributed across hundreds of kilometers in southern California. This transform system includes offshore faults along the shelf, slope and basin- comprising part of the Inner California Continental Borderland. Previously, offshore faults have been interpreted as being discontinuous and striking parallel to the coast between Long Beach and San Diego. Our recent work, based on several thousand kilometers of deep-penetration industry multi-channel seismic reflection data (MCS) as well as high resolution U.S. Geological Survey MCS, indicates that many of the offshore faults are more geometrically continuous than previously reported. Stratigraphic interpretations of MCS profiles included the ca. 1.8 Ma Top Lower Pico, which was correlated from wells located offshore Long Beach (Sorlien et. al. 2010). Based on this age constraint, four younger (Late) Quaternary unconformities are interpreted through the slope and basin. The right-lateral Newport-Inglewood fault continues offshore near Newport Beach. We map a single fault for 25 kilometers that continues to the southeast along the base of the slope. There, the Newport-Inglewood fault splits into the San Mateo-Carlsbad fault, which is mapped for 55 kilometers along the base of the slope to a sharp bend. This bend is the northern end of a right step-over of 10 kilometers to the Descanso fault and about 17 km to the Coronado Bank fault. We map these faults for 50 kilometers as they continue over the Mexican border. Both the San Mateo - Carlsbad with the Newport-Inglewood fault and the Coronado Bank with the Descanso fault are paired faults that form flower structures (positive and negative, respectively) in cross section. Preliminary kinematic models indicate ~1km of right-lateral slip since ~1.8 Ma at the north end of the step-over. We are modeling the slip on the southern segment to test our hypothesis for a kinematically continuous right-lateral fault system. We are correlating four younger Quaternary unconformities across portions of these faults to test whether the post- ~1.8 Ma deformation continues into late Quaternary. This will provide critical information for a meaningful assessment of the seismic hazards facing Newport beach through metropolitan San Diego.

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

    USGS Publications Warehouse

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

    2009-01-01

    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.

  4. The Marlin and Albacora giant fields, Campos Basin, offshore Brazil

    SciTech Connect

    De Souza, J.M.; Scarton, J.C.; Candido, A.; Cora, C.A.G. (Petrobras, Rio de Janeiro (Brazil))

    1990-09-01

    The Albacore and Marlim giant fields are located in the province of Campos basin, about 110 km (68 mi) offshore Cape Sao Tome, in water depths ranging from 200 m (656 ft) to 2,000 m (6562 ft). The Albacora field was discovered in September 1984 by the wildcat 1-RJS-297, drilled in 293 m (961 ft) of water. Subsequently, the wildcats 1-RJS-305 and 1-RJS-342 extended the field limits to deeper waters. The Albacora field is approximately 235 km{sup 2} (90 mi{sup 2}) in area, with an estimated volume of 4.5 billion bbl of oil in place. The Marlim field was discovered in February 1985 by the wildcat 1-RJS-219A, in a water depth of 853 m (2,800 ft). The Marlim field area is about 152 km{sup 2} (58 mi{sup 2}), and the latest estimate of oil in place is about 8.2 billion bbl. The Marlim complex encompasses Marlim field itself and the surrounding proved and potential areas known as East-of-, West-of-, and South-of-Marlim, respectively. The current estimated volume of oil in place in the Marlim complex is close to 13.9 billion bbl, with a total surface of about 350 km{sup 2} (135 mi{sup 2}). Oil production in the Albacora field comes from Lower Cretaceous (Albian) and Tertiary (Eocene, Oligocene, and Miocene) turbidite reservoirs. Oligocene turbidite sandstones are the potential reservoirs in the Marlim field. These deposits are genetically associated with sea level variations and are mainly composed of massive sandstones and, subordinately, of contourites. Both fields are structurally and stratigraphically controlled accumulations. Hydrocarbons are trapped in anticlines and/or faulted blocks associated with salt tectonics. Stratigraphic contributions result from sandstone bodies pinching out against shales and marls. The development of these fields has been supported by three-dimensional seismic data. The Albacora field is being gradually put on stream from shallower to deeper waters.

  5. Depositional model and stratigraphic architecture of rift climax Gilbert-type fan deltas (Gulf of Corinth, Greece)

    NASA Astrophysics Data System (ADS)

    Rohais, Sébastien; Eschard, Rémi; Guillocheau, François

    2008-10-01

    Facies, depositional model and stratigraphic architecture of Pleistocene giant Gilbert-type fan deltas are presented, based on outcrop data from the Derveni-Akrata region along the southern coast of the Gulf of Corinth, Greece. The common tripartite consisting of topset, foreset and bottomset [Gilbert, G.K., 1885. The topographic features of lake shores: Washington, D.C., United States Geol. Survey, 5th Annual Report, 69-123.] has been identified, as well as the most distal environment consisting of turbidites, and is organised in a repetitive pattern of four main systems tracts showing a clear facies and volumetric partitioning. The first systems tract (ST1) is characterised by the lack of topset beds and the development of a by-pass surface instead, thick foresets and bottomset beds, and thick well-developed turbiditic systems. This systems tract (ST1) is organised in an overall progradational pattern. The second systems tract (ST2) is characterised by a thin topset and almost no foreset equivalent. This systems tract is not always well-preserved and is organised in an overall retrograding trend with a landward shift in the position of the offlap break. The offshore is characterised by massive sandy turbidites. The third systems tract (ST3) is characterised by small-scale deltas prograding above the staked topsets of the giant Gilbert-type fan delta. Those small Gilbert-type fan deltas are generally organised in a pure progradation evolving to an aggradational-progradational pattern. In the distal setting of those small Gilbert-type fan deltas, almost no deposits are preserved on the remaining topography of the previous Gilbert-type fan delta. The fourth systems tract (ST4) is characterised by continuous vertically aggrading topsets that laterally pass into aggrading and prograding foresets. Bottomsets and distal turbiditic systems are starved. This fourth systems tract (ST4) is organised in an overall aggrading trend. These giant Gilbert-type fan deltas correspond to the Middle Group of the Corinth Rift infill and their stratigraphic development was strongly influenced by evolving rift structure. They record the migration of the depocenter from the rift shoulder to the rift axis in four main sequences from ca. 1.5 to 0.7 Ma, related to the migration of fault activity. It is worth noting that the maximum paleobathymetry was recorded during the final stage of the progradation of the Middle Group, suggesting that the rift climax was diachronous at the scale of the entire basin. The rapid (< 1 Ma) structural and sedimentological evolution, the migration of fault activity as well as the youth of the Corinth Rift, are probably exceptional factors allowing the characterisation of such diachronism.

  6. Late Pleistocene stratigraphy of IODP Site U1396 and compiled chronology offshore of south and south west Montserrat, Lesser Antilles

    NASA Astrophysics Data System (ADS)

    Wall-Palmer, Deborah; Coussens, Maya; Talling, Peter J.; Jutzeler, Martin; Cassidy, Michael; Marchant, Isabelle; Palmer, Martin R.; Watt, Sebastian F. L.; Smart, Christopher W.; Fisher, Jodie K.; Hart, Malcolm B.; Fraass, Andrew; Trofimovs, Jessica; Le Friant, Anne; Ishizuka, Osamu; Adachi, Tatsuya; Aljahdali, Mohammed; Boudon, Georges; Breitkreuz, Christoph; Endo, Daisuke; Fujinawa, Akihiko; Hatfield, Robert; Hornbach, Matthew J.; Kataoka, Kyoko; Lafuerza, Sara; Maeno, Fukashi; Manga, Michael; Martinez-Colon, Michael; McCanta, Molly; Morgan, Sally; Saito, Takeshi; Slagle, Angela L.; Stinton, Adam J.; Subramanyam, K. S. V.; Tamura, Yoshihiko; Villemant, Benoit; Wang, Fei

    2014-07-01

    sediments around volcanic islands contain an archive of volcaniclastic deposits, which can be used to reconstruct the volcanic history of an area. Such records hold many advantages over often incomplete terrestrial data sets. This includes the potential for precise and continuous dating of intervening sediment packages, which allow a correlatable and temporally constrained stratigraphic framework to be constructed across multiple marine sediment cores. Here we discuss a marine record of eruptive and mass-wasting events spanning ˜250 ka offshore of Montserrat, using new data from IODP Expedition 340, as well as previously collected cores. By using a combination of high-resolution oxygen isotope stratigraphy, AMS radiocarbon dating, biostratigraphy of foraminifera and calcareous nannofossils, and clast componentry, we identify five major events at Soufriere Hills volcano since 250 ka. Lateral correlations of these events across sediment cores collected offshore of the south and south west of Montserrat have improved our understanding of the timing, extent and associations between events in this area. Correlations reveal that powerful and potentially erosive density-currents traveled at least 33 km offshore and demonstrate that marine deposits, produced by eruption-fed and mass-wasting events on volcanic islands, are heterogeneous in their spatial distribution. Thus, multiple drilling/coring sites are needed to reconstruct the full chronostratigraphy of volcanic islands. This multidisciplinary study will be vital to interpreting the chaotic records of submarine landslides at other sites drilled during Expedition 340 and provides a framework that can be applied to the stratigraphic analysis of sediments surrounding other volcanic islands.

  7. Tephrochronology offshore Ischia Island, Tyrrhenian sea, Italy

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

    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

  8. Using borehole images to quantify reservoir quality and stratigraphic distribution

    SciTech Connect

    Roestenburg, J.W. (Schlumberger Geophysics Nusantara, Jakarta (Indonesia))

    1994-07-01

    Understanding the distribution of good-quality reservoir rock in a prospective formation is essential to improved reserves computation and maximized production. High-resolution borehole images provide a rapid and efficient method to evaluate reservoir quality over extended sequences. Microconductivity curves from images are evaluated using modal analysis on histograms to establish specific populations. These populations are assigned to electrofacies, which are discriminated using other logs and core data to generate a lithofacies column. Net pay, or sand counts, are computed based on the distribution of log-derived lithofacies. Reservoir distribution is based on the integration of structural and stratigraphic image analyses. This method is applied to two different reservoirs, the first example is of a well developed, valley-fill sequence comprising thick, stacked fluvial-deltaic channel sands. These sands are over 100 ft thick, have >20% porosity, and over 200 md permeability. The distribution and thickness of optimum quality reservoir is random, however. The second example is of multiple, small scale, depositional units between 3 in. and 24 in., which have 15% porosity with >500 md permeability. The net thickness and exact position of high-quality reservoir intervals is not apparent from standard logs, but becomes clear after image analysis.

  9. Upper Paleozoic stratigraphic sequences in the Western Interior, USA

    SciTech Connect

    Maughan, E.K.; Macke, D.L.

    1993-04-01

    Major depositional sequences in the upper Paleozoic (Mississippian through Permian) of the Western Interior reflect either tectonism, eustatic sea-level change, or both. The stratigraphic sequences approximate (1) the Lower Mississippian Lodgepole Limestone of the Madison Group, (2) the Lower and Upper Mississippian Mission Canyon Limestone in the Madison Group, (3) the Upper Mississippian Big Snowy Group, (4) the Lower and Middle Pennsylvanian Amsden Group, (5) the Middle Pennsylvanian and Lower Permian Minnelusa Group, and (6) the Middle and Upper Permian Park City Group. These upper Paleozoic sequences in the Western Interior seem to be intricately related to similar, third-order transgressive-regressive cycles in the Cordilleran region, but precise relationships of some sequence boundaries remain to be determined. Parasequence sets evidence minor eustatic oscillations within these six major Western Interior sequences. The widespread paraconformable contact between Permian and overlying Triassic strata on the Wyoming shelf indicates that this sequence boundary resulted primarily from eustatic marine regression. Overall, the upper Paleozoic sequences of the Western Interior were deposited in a stable epeirogenic framework that succeeded Devonian tectonism but were diastrophically affected again during the Pennsylvanian. The timing of these diastrophic events in the Western Interior seem to coincide with plate collision events along the eastern and southern margins of North America, but eustatic changes may be related to other causes.

  10. Horizontal drilling in the Austin Chalk: Stratigraphic factors

    SciTech Connect

    Durham, C.O. Jr. (Durham Geological Associates, Houston, TX (USA)); Bobigian, R.A. (Fleet Petroleum Partners, Houston, TX (USA))

    1990-05-01

    Horizontal drilling has renewed interest in the Austin chalk in south-central Texas. Large fields on opposite sides of the San Marcos arch Giddings to the northeast and Pearsall to the southwest were active with vertical drilling 10 years ago. Giddings' 4,500 Austin wells produced 209 million BO and 934 bcfg of gas through 1988; Pearsall's 1,440 wells produced 57 million BO and 35 bcfg of gas. Most vertical wells were completed, 20% were economic successes, 40% were marginal, 40% were uneconomic due to uneven areal distribution of near-vertical fractures and small faults, which provide reservoirs in otherwise tight chalk. Horizontal drilling, led by Amoco in Giddings and Oryx in Pearsall, enhances the chances of encountering the fractures by drilling perpendicular to the fracture trend. Horizontal drilling requires preselection of the stratigraphic horizon to be penetrated. One must understand the variable Austin stratigraphy to choose the zone with the most brittle character and best matrix porosity, both reduced by increased clay content. Chalk 130 ft thick on the San Marcos arch thickens to 600 to 800 ft in central Giddings field where middle marl separates lower and upper chalk Northeastward only lower chalk is preserved beneath a post-Austin submarine channel. The Austin thickens to 300-500 ft in Pearsall field where middle member ash beds separate lower and upper chalk inhibiting vertical reservoir communication. Locally, on the Pearsall arch, ash is missing, lower chalk thickens, and upper chalk thins.

  11. Basal Murphy belt and Chilhowee Group -- Sequence stratigraphic comparison

    SciTech Connect

    Aylor, J.G. Jr. (Florida State Univ., Tallahassee, FL (United States). Dept. of Geology)

    1994-03-01

    The lower Murphy belt in the central western Blue Ridge is interpreted to be correlative to the Early Cambrian Chilhowee Group of the westernmost Blue Ridge and Appalachian fold and thrust belt. Basal Murphy belt depositional sequence stratigraphy represents a second-order, type-2 transgressive systems tract initiated with deposition of lowstand turbidites of the Dean Formation. These transgressive deposits of the Nantahala and Brasstown Formations are interpreted as middle to outer continental shelf deposits. Cyclic and stacked third-order regressive, coarsening upwards sequences of the Nantahala Formation display an overall increase in feldspar content stratigraphically upsection. These transgressive siliciclastic deposits are interpreted to be conformably overlain by a carbonate highstand systems tract of the Murphy Marble. Palinspastic reconstruction indicates that the Nantahala and Brasstown Formations possibly represent a basinward extension of up to 3 km thick siliciclastic wedge. The wedge tapers to the southwest along the strike of the Murphy belt at 10[degree] and thins northwestward to 2 km in the Tennessee depocenter where it is represented by the Chilhowee Group. The Murphy belt basin is believed to represent a transitional rift-to-drift facies deposited on the lower plate of the southern Blue Ridge rift zone.

  12. Stratigraphic placement and age of modern humans from Kibish, Ethiopia.

    PubMed

    McDougall, Ian; Brown, Francis H; Fleagle, John G

    2005-02-17

    In 1967 the Kibish Formation in southern Ethiopia yielded hominid cranial remains identified as early anatomically modern humans, assigned to Homo sapiens. However, the provenance and age of the fossils have been much debated. Here we confirm that the Omo I and Omo II hominid fossils are from similar stratigraphic levels in Member I of the Kibish Formation, despite the view that Omo I is more modern in appearance than Omo II. 40Ar/39Ar ages on feldspar crystals from pumice clasts within a tuff in Member I below the hominid levels place an older limit of 198 +/- 14 kyr (weighted mean age 196 +/- 2 kyr) on the hominids. A younger age limit of 104 +/- 7 kyr is provided by feldspars from pumice clasts in a Member III tuff. Geological evidence indicates rapid deposition of each member of the Kibish Formation. Isotopic ages on the Kibish Formation correspond to ages of Mediterranean sapropels, which reflect increased flow of the Nile River, and necessarily increased flow of the Omo River. Thus the 40Ar/39Ar age measurements, together with the sapropel correlations, indicate that the hominid fossils have an age close to the older limit. Our preferred estimate of the age of the Kibish hominids is 195 +/- 5 kyr, making them the earliest well-dated anatomically modern humans yet described. PMID:15716951

  13. Applying high-resolution sequence stratigraphic tools to the Texas continental margin to fine-tune conventional sequence stratigraphic models and improve reservoir prediction

    SciTech Connect

    Anderson, J.A.; Banfield, L.A.; Eckles, B.J. (Rice Univ., Houston, TX (United States)) (and others)

    1996-01-01

    A regional sequence stratigraphic study of the Texas continental margin resulted in an improved understanding of Pleistocene-Holocene eustatic sea level fluctuations and their influence on depositional environments associated with several distinct systems: the Colorado/Brazos system, the Texas interfluve region, and the Rio Grande system. The dataset consists of approximately 7500 kilometers of high-resolution seismic profiloes, 200 borehole descriptions, and 12 sediment cores. The study involved analysis of three independent variables to better constrain Pleistocene-Holocene sea level history: coastal onlap derived from high-resolution seismic profiles; oxygen isotope data determined from selected sediment cores; and paleoenvironmental data developed from high-resolution micropaleontologic analyses. Combined lithologic data and seismic facies analysis is used to map the distribution of major depositional systems on the shelf during one complete glacial eustatic cycle. Our study provided anopportunity to fine tune conventional stratigraphic models with regard to the distribution of potential reservoirs relative to regionally mappable stratigraphic surfaces.

  14. Applying high-resolution sequence stratigraphic tools to the Texas continental margin to fine-tune conventional sequence stratigraphic models and improve reservoir prediction

    SciTech Connect

    Anderson, J.A.; Banfield, L.A.; Eckles, B.J. [Rice Univ., Houston, TX (United States)] [and others

    1996-12-31

    A regional sequence stratigraphic study of the Texas continental margin resulted in an improved understanding of Pleistocene-Holocene eustatic sea level fluctuations and their influence on depositional environments associated with several distinct systems: the Colorado/Brazos system, the Texas interfluve region, and the Rio Grande system. The dataset consists of approximately 7500 kilometers of high-resolution seismic profiloes, 200 borehole descriptions, and 12 sediment cores. The study involved analysis of three independent variables to better constrain Pleistocene-Holocene sea level history: coastal onlap derived from high-resolution seismic profiles; oxygen isotope data determined from selected sediment cores; and paleoenvironmental data developed from high-resolution micropaleontologic analyses. Combined lithologic data and seismic facies analysis is used to map the distribution of major depositional systems on the shelf during one complete glacial eustatic cycle. Our study provided anopportunity to fine tune conventional stratigraphic models with regard to the distribution of potential reservoirs relative to regionally mappable stratigraphic surfaces.

  15. 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)

    Alván, Aldo; von Eynatten, Hilmar

    2014-10-01

    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.

  16. Quantifying the hurricane risk to offshore wind turbines

    E-print Network

    Jaramillo, Paulina

    Quantifying the hurricane risk to offshore wind turbines Stephen Rosea , Paulina Jaramilloa,1. Turbine tower buckling has been observed in typhoons, but no offshore wind turbines have yet been built be destroyed by hurricanes in an offshore wind farm. We apply this model to estimate the risk to offshore wind

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

    E-print Network

    Massachusetts at Amherst, University of

    , electrical line losses, and turbine availability--with offshore wind farm component cost models present for offshore wind farm developers by creating an analysis tool that unites offshore turbineOffshore Wind Farm Layout Optimization (OWFLO) Project: Preliminary Results Christopher N. Elkinton

  18. Offshore maintenance reduces cost and downtime

    SciTech Connect

    Danahy, J.W.

    1983-08-01

    Maintenance is the single activity offshore that can have the most impact on productivity, safety, and downtime. Unfortunately, unless it is well organized, maintenance may be carried out according to unchanging and often unnecessary routines. Overly rigid maintenance procedures, that are viewed by crews as ''makework'' assignments, are not conducive to quality or to failure-proof operation of key rig systems. An alternate system of maintenance, which Keydril has adopted on all its rigs, is designed to circumvent the problems of crew attitude and at the same time provide an effective preventive program that simply and efficiently manages all of the rig's operational requirements. The program consists of detailed maintenance and test procedures which are based on frequency analyses of the operating profiles of each piece of machinery. Keydril calls the program an Engineered Approach to Maintenance. The heart of the engineered approach system is a color-coded visual display of maintenance requirement cards (T-cards). These cards assign and describe specific tasks according to an analysis of the operating history of the unit itself and analyses of similar equipment on other company rigs. The second part of the engineered system is the use of high-technology testing methods that can remotely analyze various operating parameters and give early warning of equipment wear prior to failure. The equipment on board Keydril's rigs must be used, and rig personnel have to know that it will always work at satisfactory performance levels. The engineered approach to maintenance provides that assurance.

  19. Stratigraphic analysis of Pennsylvania rocks using hierarchy of transgressive-regressive units

    NASA Astrophysics Data System (ADS)

    Busch, R. M.

    1984-06-01

    Pennsylvanian stratigraphic sequences is described, interpreted, and correlated using a hierarchy of six scales of allocyclic, time-stratigraphic, transgressive-regressive units (abbreviated T-R units are inferred to be the net result of deposition during eustatic cycles of sea level change. The T-R units can be correlated across both marine and nonmarine facies in the Appalachian Basin. This permits differentiation of allocyclic T-R units from autocyclic T-R units or fluvial autocyclic units. The precise correlations also provide a time-stratigraphic framework for very accurate paleogeographic reconstructions. Paleogeographic maps were constructed for successive fifth-order marine events of the Glenshaw Formation (Upper Pennsylvanian) of the Northern Appalachian Basin. The hierarchal T-R unit approach is useful for understanding and predicting the location of marine units, claystones, various types of stratigraphic breaks, and economic mineral deposits.

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

    E-print Network

    Henderson, Gideon

    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

  1. Sequence stratigraphic controls on synsedimentary cementation and preservation of dinosaur tracks: Example from the lower Cretaceous,

    E-print Network

    González, Luis A.

    Sequence stratigraphic controls on synsedimentary cementation and preservation of dinosaur tracks in the Upper Albian Dakota Formation of southeastern Nebraska contains the first dinosaur tracks; Diagenesis; Isotopes; Dinosaur tracks; Carbonate cements 1. Introduction The preservation of fossils

  2. Seismic definition of Lower Cretaceous delta, south Whale subbasin, offshore Newfoundland

    SciTech Connect

    Jayasinghe, N.R.; Stokes, R.E.

    1986-05-01

    Recognition of stratigraphic traps in areas where previous prospects were structural is a trend attributable partly to the availability of new, high-quality seismic data. In the South Whale subbasin, offshore Newfoundland, Canada, such a change in exploration philosophy is presently being evaluated. Exploratory drilling offshore eastern Canada began in 1966 in the South Whale subbasin. By the end of 1973, 13 wells were drilled in this subbasin; however, lack of success discouraged further drilling. These wells evaluated large, salt-related structures, well defined by seismic data. Although an adequate reservoir was encountered in a number of these wells, faulting associated with halokinesis may have resulted in petroleum migration out of the reservoir. Interpretation of recently acquired high-quality seismic data indicate a delta in the Lower Cretaceous Missisauga Formation in the study area. Seismic dip sections across the delta show a shingled progradation pattern suggesting a wave-dominated depositional environment. The delta comprises approximately 400 km/sup 2/, with closure in the eastern half. Data from wells in the area indicate that adequate source and sealing beds could be present. Furthermore, rocks of similar age in the nearby Avalon basin contain significant petroleum accumulations, the most notable being within the Hibernia oil field.

  3. 2-D synthetic seismic and log cross sections from stratigraphic forward models

    SciTech Connect

    Shuster, M.W. (KSEPL (Shell Research), Rijswijk (Netherlands)); Aigner, T. (Universitat Tubingen (Germany))

    1993-09-01

    In an effort to fully utilize deterministic stratigraphic forward modeling techniques in subsurface stratigraphic analysis, Shell has developed a computer interface to routinely create synthetic logs and one-dimensional and two-dimensional (2-D) seismic responses from 2-D stratigraphic simulations. Each 2-D stratigraphic model can contain up to 200 timelines defining age equivalent stratigraphic layers with laterally variable lithofacies and depths. Synthetic gamma-ray, density, and velocity responses are calculated for the simulated lithofacies using user-specified rock and fluid properties. Vertically incident synthetic seismograms are created using calculated reflection coefficients and user-defined input wavelets. Because the chronostratigraphy is know a priori, log correlations and the interpolated seismic geometries follow timelines exactly. The power of this technique as an aid in sequence stratigraphic interpretations is shown from three case studies: (1) a simulation of an idealized clastic system assuming constant clastic input and sinusoidal fourth- and third-order sea level variations, (2) simulations of the Permian mixed clastic-carbonate infill of the Midland basin, and (3) a detailed simulation of one third-order carbonate depositional sequence (lower-middle San Andres Formation) from the Northwest Shelf, Permian basin. Some general conclusions form these case studies include the following: (a) seismic and well log-defined topsets, forests, bottom-sets, and related event terminations can be unequivocally related to relative sea level fluctuations; (b) Exxon-type sequence boundaries are not necessarily seismically imageable and their identification on well logs is not straight forward; and (c) buildups and lateral variations in amplitude related to lithofacies variations can be modeled. Synthetic logs and seismic sections from stratigraphic forward models may be useful in constraining interpretations of subsurface data and in stratigraphic prediction.

  4. Three-dimensional seismic stratigraphic study of Minnelusa Formation, Powder River basin, Campbell County, Wyoming 

    E-print Network

    Walters, Donna Lynn

    1988-01-01

    THREE-DIMENSIONAL SEISMIC STRATIGRAPHIC STUDY OF MINNELUSA FORMATION, POWDER RIVER BASIN, CAMPBELL COUNTY, WYOMING A Thesis by DONNA LYNN WALTERS Submitted to the Office of Graduate Studies of Texas A8 M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 1988 Major Subject: Geophysics THREE-DIMENSIONAL SEISMIC STRATIGRAPHIC STUDY OF MINNELUSA FORMATION, POWDER RIVER BASIN, CAMPBELL COUNTY, WYOMING A Thesis by DONNA LYNN WALTERS Approved...

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

    E-print Network

    Larberg, Gregory Martin

    1976-01-01

    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...

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

    E-print Network

    Larberg, Gregory Martin

    1976-01-01

    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...

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

    NSDL National Science Digital Library

    Jennifer Hargrave

    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.

  8. 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)

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

    2014-05-01

    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.

  9. Cathodic protection of well casings offshore

    SciTech Connect

    Schremp, F.W.

    1982-08-01

    Wells completed from offshore platforms have unique cathodic protection (CP) problems because they are shorted electrically to the platforms. Thus, there is no convenient way to determine how much galvanic or impressed current flows in each well casing system. Also, most platforms are protected with sacrificial anodes, and the depth to which they protect well casings is unknown. Furthermore, there are no established protection criteria applicable to offshore well casings attached to platforms. This study was performed to investigate the effects of galvanic current and impressed current CP on an offshore platform and six wells, and some CP guidelines were established.

  10. Offshore drilling to increase in 1984

    SciTech Connect

    Not Available

    1984-05-01

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

  11. Image processing in offshore engineering

    SciTech Connect

    Rodriguez, M.V.R.; A. Oliveira, M. de; Almeida, M.E.T. de; Lorenzoni, C. [Petrobras-DEPRO, Rio de Janeiro (Brazil); Ferrante, A.J. [ISC Italia, Milano (Italy)

    1995-12-31

    The technological progress which has taken place during the last decade introduced a totally new outlook regarding the professional computational environment in general, and regarding the engineering profession in particular. During many years engineering computing was performed based on large computer centers, getting bigger and bigger all the time, going from mainframes to super computers, essentially producing numerical results on paper media. Lately, however, it has been realized that a much more productive computational environment can be implemented using an open architecture of client/server type, based on smaller lower cost equipment including workstations and PC`s, and considering engineering information in a broader sense. This papers reports briefly the experience of the Production Department of Petrobras in transforming its centralized, mainframe based, computational environment into a open distributed client/server computational environment, focusing on the problem of handling technical graphics information regarding its more than 70 fixed offshore platforms.

  12. Structure, stratigraphy, and hydrocarbons offshore southern Kalimantan, Indonesia

    SciTech Connect

    Bishop, W.F.

    1980-01-01

    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.

  13. Neogene sequence stratigraphy, Nam Con Son Basin, offshore Vietnam

    SciTech Connect

    McMillen, K.J. [Beaver Creek Tech. Co., Mason, TX (United States); Do Van Luu; Lee, E.K.; Hong, S.S. [PEDCO, Ho Chi Minh City (Viet Nam)

    1996-12-31

    An integrated well log, biostratigraphic, and seismic stratigraphic study of Miocene to Recent deltaic sediments deposited in the Nam Con Son Basin offshore from southern Vietnam shows the influence of eustacy and tectonics on sequence development. Sediments consist of Oligocene non-marine rift-basin fill (Cau Formation), early to middle Miocene tide-dominated delta plain to delta front sediments (TB 1.5 to TB 2.5, Due and Thong Formations), and late Miocene to Recent marine shelf sediments (TB. 2.6 to TB 3.1 0, Mang Cau, Nam Con Son, and Bien Dong Formations). Eustacy controlled the timing of key surfaces and sand distribution in the tectonically-quiet early Miocene. Tectonic effects on middle to late Miocene sequence development consist of thick transgressive systems tracts due to basin-wide subsidence and transgression, sand distribution in the basin center, and carbonate sedimentation on isolated fault blocks within the basin. Third-order sequence boundaries (SB) are identified by spore peaks, sand stacking patterns, and channel incision. In the basin center, widespread shale beds with coal occur above sequence boundaries followed by transgressive sandstone units. These TST sandstones merge toward the basin margin where they lie on older HST sandstones. Maximum flooding surfaces (MFS) have abundant marine microfossils and mangrove pollen, a change in sand stacking pattern, and often a strong seismic reflection with downlap. Fourth-order genetic-type sequences are also interpreted. The MFS is the easiest marker to identify and correlate on well logs. Fourth-order SB occur within these genetic units but are harder to identify and correlate.

  14. Neogene sequence stratigraphy, Nam Con Son Basin, offshore Vietnam

    SciTech Connect

    McMillen, K.J. (Beaver Creek Tech. Co., Mason, TX (United States)); Do Van Luu; Lee, E.K.; Hong, S.S. (PEDCO, Ho Chi Minh City (Viet Nam))

    1996-01-01

    An integrated well log, biostratigraphic, and seismic stratigraphic study of Miocene to Recent deltaic sediments deposited in the Nam Con Son Basin offshore from southern Vietnam shows the influence of eustacy and tectonics on sequence development. Sediments consist of Oligocene non-marine rift-basin fill (Cau Formation), early to middle Miocene tide-dominated delta plain to delta front sediments (TB 1.5 to TB 2.5, Due and Thong Formations), and late Miocene to Recent marine shelf sediments (TB. 2.6 to TB 3.1 0, Mang Cau, Nam Con Son, and Bien Dong Formations). Eustacy controlled the timing of key surfaces and sand distribution in the tectonically-quiet early Miocene. Tectonic effects on middle to late Miocene sequence development consist of thick transgressive systems tracts due to basin-wide subsidence and transgression, sand distribution in the basin center, and carbonate sedimentation on isolated fault blocks within the basin. Third-order sequence boundaries (SB) are identified by spore peaks, sand stacking patterns, and channel incision. In the basin center, widespread shale beds with coal occur above sequence boundaries followed by transgressive sandstone units. These TST sandstones merge toward the basin margin where they lie on older HST sandstones. Maximum flooding surfaces (MFS) have abundant marine microfossils and mangrove pollen, a change in sand stacking pattern, and often a strong seismic reflection with downlap. Fourth-order genetic-type sequences are also interpreted. The MFS is the easiest marker to identify and correlate on well logs. Fourth-order SB occur within these genetic units but are harder to identify and correlate.

  15. La Galite Archipelago (Tunisia, North Africa): Stratigraphic and petrographic revision and insights for geodynamic evolution of the Maghrebian Chain

    NASA Astrophysics Data System (ADS)

    Belayouni, Habib; Brunelli, Daniele; Clocchiatti, Roberto; Di Staso, Angelida; El Hassani, Iz-Eddine El Amrani; Guerrera, Francesco; Kassaa, Samia; Ouazaa, Nejia Laridhi; Martín, Manuel Martín; Serrano, Francisco; Tramontana, Mario

    2010-01-01

    The location of the La Galite Archipelago on the Internal/External Zones of the Maghrebian Chain holds strong interest for the reconstruction of the geodynamic evolution of the Mesomediterranean Microplate-Africa Plate Boundary Zone. New stratigraphic and petrographic data on sedimentary successions intruded upon by plutonic rocks enabled a better definition of the palaeogeographic and palaeotectonic evolutionary model of the area during the early-middle Miocene. The lower Miocene sedimentary units ( La Galite Flysch and Numidian-like Flysch) belong to the Mauritanian (internal) and Massylian (external) sub-Domains of the Maghrebian Chain, respectively. These deposits are related to a typical syn-orogenic deposition in the Maghrebian Flysch Basin Domain, successively backthrusted above the internal units. The backthrusting age is post-Burdigalian (probably Langhian-Serravallian) and the compressional phase represents the last stage in the building of the accretionary wedge of the Maghrebian orogen. These flysch units may be co-relatable to the similar well-known formations along the Maghrebian and Betic Chains. The emplacement of potassic peraluminous magmatism, caused local metamorphism in the Late Serravallian-Early Tortonian (14-10 Ma), after the last compressional phase (backthrusting), during an extensional tectonic event. This extensional phase is probably due to the opening of a slab break-off in the deep subduction system. La Galite Archipelago represents a portion of the Maghrebian Flysch Basin tectonically emplaced above the southern margin of the "Mesomediterranean Microplate" which separated the Piemontese-Ligurian Ocean from a southern oceanic branch of the Tethys (i.e. the Maghrebian Flysch Basin). The possible presence of an imbricate thrust system between La Galite Archipelago and northern Tunisia may be useful to exclude the petroleum exploration from the deformed sectors of the offshore area considered.

  16. Implications of Stratigraphic and Structural Data from the Bitter Spring Region, Southern Nevada

    NASA Astrophysics Data System (ADS)

    Donatelle, A.; Goeden, J.; Hannon, M.; Hickson, T.; Holter, S.; Johnson, T.; Lamb, M.; Lindberg, J.

    2004-05-01

    Deposition of the Tertiary Horse Spring Formation (HSF) in southern Nevada has been used to infer varying styles of extensional and strike-slip basin formation. Beard (1996) proposes an initial large contiguous basin of Rainbow Gardens age (ca. 26-18 Ma) that is subsequently broken up into sub-basins during Thumb time (16-14 Ma). A key locality to test this hypothesis is near the southern end of East and West Longwell Ridges, on the Bitter Spring USGS 1:24000 quadrangle (BSQ). However, the stratigraphic framework in this area is poorly defined. The BSQ is located west of the Overton arm of Lake Mead near the junction of the Las Vegas Valley Shear Zone and the Lake Mead Fault System. By mapping a portion of the quadrangle at 1:5000 scale, measuring detailed sections, and collecting ash samples from key localities, we investigated the structural and sedimentary framework of the area and have begun to clarify the stratigraphic relationships between members of the HSF. Faults fall into three categories: one set strikes north and dips moderately to the west; another strikes east-northeast and dips shallowly to the northwest; and the last strikes north and dips to the east. Many of these faults show an oblique sense of movement and may be related to movement on the White Basin (WBF) and Rodgers Spring Faults (Bohannon, 1983). A distinctive resistant limestone caps gypsiferous and clastic units on both sides of the north-south trending WBF. To the west of the WBF, this limestone is mapped as the Bitter Ridge Limestone Member of the HSF, whereas to the east it is mapped as the Thumb Member by Beard (unpub) and as the Rainbow Gardens Member by Bohannon (1983). We suspect that these limestones may be correlative; geochemical and petrographic fingerprinting of numerous ashes from our sections should allow correlation of these units across the WBF. In addition, sections from the east side of the WBF spaced over 1.5 km show conglomerate at the base, overlain by a sequence of red sandstone, gypsum, and carbonates (mainly oncolitic and peloidal limestone). These units show rapid lateral facies changes and thickness variation suggesting comparable changes in accommodation-space creation, possibly related to extensionally-induced subsidence. Paleocurrent data from the central portion of the mapping area indicate that flow was east- to southeast-directed, indicating that West Longwell Ridge may have been a topographic high during Thumb time. This interpretation is further supported by stratigraphic relationships near the basin margin, where conglomerate was deposited in buttress contact against Paleozoic limestones at the southern end of the ridge. Future work in this area includes continued mapping, Ar-Ar dating of ash mineral phases, and provenance analysis of sedimentary units.

  17. The effectiveness of 3-D marine systems as an exploration tool in the offshore Niger Delta

    SciTech Connect

    Idowu, A.O. (Nigerian National Petroleum Corp., Lagos (Nigeria))

    1993-09-01

    From inception in 1984, three-dimensional (3-D) marine surveys have been used widely for field development where commercial hydrocarbons were known to exist in Nigeria. The high-trace density and full 3-D migration provide a data set that allows detailed interpretation of complex geologic structures and, in many cases, provides good stratigraphic information as well. The result has been better placement of development wells, making field development more efficient and cost effective. Previous application of the 3-d method (i.e., reconaissance 3-D) as an exploration tool in 1987 has demonstrated its effectiveness for predrilling detailing of prospects in offshore Niger Delta in a situation where a large volume of seismic data were acquired at relatively reduced unit costs. The technique involves acquiring data along a line every 200 m spacing, while interpretation in 3-D data processing is applied for subsequent 3-D migration. Based on pattern recognition of events on the input traces, the links are established to allow traces to be formed between input locations by comparing several attributes of events on neighboring traces. A case history example from the offshore Niger delta shows that the collection costs for the reconnaissance 3-D method are comparable to two-dimensional detailing based on similar line kilometer and time duration for the survey. A trade-off between cost and technical specifications can be programmed by focusing on the geologic objective. The technique brings the advantage of 3-D methods, but not their costs, to the exploration phase of the search for petroleum, and it is highly recommended for exploration in frontier areas, particularly the deep offshore of the Niger Delta.

  18. Making up for Lost Time: Stratigraphic and Geochemical Implications of a Long-Lived Sturtian Glaciation

    NASA Astrophysics Data System (ADS)

    Macdonald, F. A.; Schmitz, M. D.; Condon, D. J.; Zhu, M.; Rooney, A. D.; Brandon, A. D.

    2014-12-01

    Geochronology provides a direct test of many models pertaining to the nature of Cryogenian climate change. Here we present new U-Pb and Re-Os geochronological constraints on Sturtian glacial deposits from Zambia, Arctic Alaska, Mongolia, South China, and throughout Laurentia. We present these new ages in stratigraphic, sedimentological and geochemical context to integrate data from other key localities, such as Namibia and Australia, and to construct a new age model for the Cryogenian Period. We find that there is no evidence for a global, pre-717 Ma glaciation. Instead, Sturtian glacial deposits appeared on all of these cratons by 717 Ma following widespread basaltic volcanism. We then review the nature and duration of the >50 Myr long Sturtian glacial epoch. In many localities, strata deposited during this interval are characterized by two massive diamictite units separated by diamictite-free, siliciclastic strata. These intervening clast-poor deposits are commonly interpreted to represent an interglacial period, however, alternatively they formed during a long-lived glaciation as newly rifted margins subsided and detached from the ice-grounding line. In the aftermath of the Sturtian glaciation, high sedimentation rates made up for lost time, and filled pent-up accommodation space, creating thick Cryogenian non-glacial interlude deposits on many margins. We discuss implications for geochemical cycles and the interpretation of carbon isotope anomalies.

  19. Outsourcing, offshoring and the US office market

    E-print Network

    Topolewski, Tanya M., 1969-

    2004-01-01

    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 ...

  20. 31 CFR 548.406 - Offshore transactions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BELARUS SANCTIONS REGULATIONS Interpretations § 548.406 Offshore transactions. The prohibitions in § 548.201 on...

  1. 31 CFR 548.406 - Offshore transactions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BELARUS SANCTIONS REGULATIONS Interpretations § 548.406 Offshore transactions. The prohibitions in § 548.201 on...

  2. 31 CFR 548.406 - Offshore transactions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BELARUS SANCTIONS REGULATIONS Interpretations § 548.406 Offshore transactions. The prohibitions in § 548.201 on...

  3. 31 CFR 548.406 - Offshore transactions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BELARUS SANCTIONS REGULATIONS Interpretations § 548.406 Offshore transactions. The prohibitions in § 548.201 on...

  4. 31 CFR 548.406 - Offshore transactions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BELARUS SANCTIONS REGULATIONS Interpretations § 548.406 Offshore transactions. The prohibitions in § 548.201 on...

  5. 31 CFR 595.407 - Offshore transactions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY TERRORISM SANCTIONS REGULATIONS Interpretations § 595.407 Offshore transactions. The prohibitions contained in §...

  6. Future characteristics of Offshore Support Vessels

    E-print Network

    Rose, Robin Sebastian Koske

    2011-01-01

    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 ...

  7. Offshore oil in the Alaskan Arctic

    NASA Technical Reports Server (NTRS)

    Weeks, W. F.; Weller, G.

    1984-01-01

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

  8. Engineering Challenges for Floating Offshore Wind Turbines

    SciTech Connect

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

    2007-09-01

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

  9. A Collaborative Environment for Offshore Engineering Simulations

    E-print Network

    Barbosa, Alberto

    , gallotti, rogerps, wagnerga}@tecgraf.puc-rio.br 2 CENPES/Petrobras ismaelh@petrobras.com.br Abstract of Petrobras, a large Brazilian governmental oil & gas company. For this article we have focused on Offshore

  10. 31 CFR 593.406 - Offshore transactions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FORMER LIBERIAN REGIME OF CHARLES TAYLOR SANCTIONS REGULATIONS Interpretations § 593.406 Offshore transactions. The prohibitions in § 593.201 on...

  11. 31 CFR 593.406 - Offshore transactions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FORMER LIBERIAN REGIME OF CHARLES TAYLOR SANCTIONS REGULATIONS Interpretations § 593.406 Offshore transactions. The prohibitions in § 593.201 on...

  12. EMS offshore. A new horizon for paramedics.

    PubMed

    Mallard, A S

    1991-10-01

    The difficulty in getting medical aid to offshore drilling platforms can be a source of life-threatening delays. Recently, some companies have charted new waters by actually stationing EMS crews on their rigs. PMID:10116023

  13. Visualization of vibration experienced in offshore platforms

    E-print Network

    Patrikalakis, Alexander Marinos Charles

    2010-01-01

    In this thesis, I design and evaluate methods to optimize the visualization of vortex-induced vibration (VIV) in marine risers. VIV is vibration experienced by marine risers in offshore drilling platforms due to ocean ...

  14. Paraffin deposition in offshore oil production 

    E-print Network

    Elphingstone, Gerald Mason

    1995-01-01

    The extreme environmental conditions typically encountered in offshore oil operations lead to a number of problems. Cool deep sea temperatures promote particle formation and deposition of paraffinic compounds. These solids can buildup inside...

  15. MAPPING STRATIGRAPHIC DISCONTINUITIES IN WEST CANDOR LAYERED DEPOSITS AND THE POTENTIAL FOR SEQUENCE STRATIGRAPHIC ANALYSIS. K. Thaisen, and J. Schieber, Depart-

    E-print Network

    Schieber, Juergen

    FOR SEQUENCE STRATIGRAPHIC ANALYSIS. K. Thaisen, and J. Schieber, Depart- ment of Geological Sciences, Indiana- ites that have been found on Earth and the data being collected by the Mars Exploration Rovers, all from the Mars Orbiter Camera (MOC), Mars Orbiter Laser Al- timeter (MOLA), and Thermal Imagery Emission

  16. Low-frequency Stoneley energy for stratigraphic evaluation

    SciTech Connect

    Hlaing, K.K.; Lemoy, C.; Maret, J.P.; Kremer, Y.; Borland, W.H.; Maw, M.

    1994-07-01

    Conventional sonic measurements of shear and compressional slowness are body waves that travel within the formation and are commonly used for petrophysical analysis of a well. Low-frequency Stoneley waves travel within the well bore and are traditionally used to interpret fractures and formation permeability, usually by analyzing the energy losses and, to a lesser extent, the slowness. The authors have found that Stoneley energy has been very useful in the identification of vuggy carbonate facies linked to paleokarstic surfaces in the Upper Burman limestone reservoir of Miocene age, in the YADANA gas deposit, offshore Myanmar. One good example is seen in well YAD-1 where the carbonate reservoir has been cored, allowing precise facies and porosity type determination. Matching Stoneley energy and core description show a striking correlation between loss of energy and vuggy carbonate facies due to karstic diagenetic processes, always in relation with reefal or near reefal facies. Accordingly, facies interpretation has tentatively been done in the deeper, noncored reservoir zone, where losses of energy are important and considered as indicating karstic influence and the specific environment.

  17. Stratigraphic evidence for an early Holocene earthquake in Aceh, Indonesia

    NASA Astrophysics Data System (ADS)

    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

    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.

  18. New perspectives in offshore wind energy

    PubMed Central

    Failla, Giuseppe; Arena, Felice

    2015-01-01

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

  19. New perspectives in offshore wind energy.

    PubMed

    Failla, Giuseppe; Arena, Felice

    2015-02-28

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

  20. Vega is first offshore development for Montedison

    SciTech Connect

    Not Available

    1985-10-01

    Montedison's Vega field, 15 miles off the southern tip of Sicily, has recoverable oil reserves of 400 million bbl. This is Montedison's first offshore development venture, although the operator has considerable onshore experience. It will be followed by a second field, the smaller Mila floating production system, also off Sicily. One platform will be placed on a template installed in 1983 with up to 18 pre-drilled wells in water depths of 480 ft. The field may hold up to 1 billion bbl of 16/sup 0/ crude, but geology is complex and heavily fractured. The template has 30 available drilling slots, and water injection is being considered. The Vega discovery well was drilled in 1980, with 5000 b/d tested from 1000-ft oil column in Strep-penosa shales. Subsequently five wells were drilled by the Glomar Biscay I semi. These wells were drilled to a depth of just over 8000 ft with a total deviation of 60/sup 0/. The template is the first in the Mediterranean.

  1. Leveraging 3D Wheeler Diagrams and relative time mapping in seismic data to improve stratigraphic interpretation: Application, Assumptions, and Sequence Stratigraphic Revelations

    NASA Astrophysics Data System (ADS)

    Goggin, L. R.

    2014-12-01

    Our understanding of subsurface stratigraphic relationships is guided by stratigraphic concepts that were developed using many varieties and scales of data including paleontological samples, cuttings and core, outcrop analogs, well logs, and seismic. Subsurface stratigraphic correlations are strongly influenced by the type, density, and distribution of the data available. The exploration geologist typically interprets 2D and 3D seismic reflections to define prospects and plays. In structurally simple areas, he or she often assumes that seismic reflectors mark depositional boundaries that are essentially time-synchronous events represented by a single wavelet character. In reality, seismic reflectors usually display spatial wavelet variability, seldom resolve individual beds and are the product of the amplitude expression of a range of lithologic changes that encompasses a range of geologic time and depositional processes. Our assumption that seismic reflections are time-synchronous can lead to errors in stratigraphic correlation that only become evident when our prediction of well or field performance is unrealized. To mitigate the potential for this correlation error, we must modify how we interpret seismic data. In this presentation we will focus on the concept of defining or approximating time-correlative surfaces in seismic data, leverage concepts of the Wheeler transform to place these seismic reflectors into the relative time domain and then examine the diachronous nature of these time-mapped surfaces in 3D. We will then explore how the 3D mapping of time-correlative surfaces fits sequence stratigraphic concepts and discuss whether this new approach requires us to change our interpretation paradigms.

  2. Two-dimensional synthetic seismic and log cross sections from stratigraphic forward models

    SciTech Connect

    Shuster, M.W. (KSEPL (Shell Research), Rijswijk (Netherlands) Shell Development Company, Houston, TX (United States)); Aigner, T. (Universitaet Tuebingen, Tuebingen (Germany))

    1994-03-01

    In an effort to fully use deterministic stratigraphic forward-modeling techniques in subsurface stratigraphic analysis, we developed a computer interface to routinely create synthetic logs and one-dimensional and two-dimensional (2-D) seismic responses from 2-D stratigraphic simulations. Each 2-D stratigraphic model can contain up to 200 timelines defining age-equivalent stratigraphic layers with laterally variable lithofacies and depths. Synthetic gamma ray, density and velocity responses are calculated for the simulated lithofacies using user-specified rock and fluid properties. Vertically incident synthetic seismograms are created using calculated reflection coefficients and user-defined input wavelets. The power of this technique as an aid in sequence stratigraphic interpretations is shown from three examples: (1) a simulation of an idealized clastic system assuming constant clastic input and sinusoidal fourth-order and third-order sea level variations, (2) a detailed simulation of one third-order carbonate depositional sequence (lower-middle San Andres Formation) from the Northwest shelf, Permian basin, and (3) simulations of the Permian mixed clastic-carbonate infill of the Midland basin. Some general conclusions from these examples include the following: (1) seismic and well log-defined topsets, foresets, bottomsets, and related event terminations can be directly related to relative sea level fluctuations, (2) Exxon-type sequence boundaries (i.e., unconformities) are not necessarily seismically imageable, and their identification on well logs is not straight-forward, and (3) lateral variations in amplitude related to lithofacies variations can be modeled. Synthetic logs and seismic sections from stratigraphic forward models such as these may be useful in constraining interpretations of subsurface data and thus aiding the prediction of reservoir and seal distribution. 19 refs., 13 figs., 2 tabs.

  3. The International Subcommission on Stratigraphic Classification of the International Commission on Stratigraphy: The Knowledge

    NASA Astrophysics Data System (ADS)

    Pratt, Brian

    2014-05-01

    The International Subcommission on Stratigraphic Classification (ISSC) was born in 1955 as an effort to promote awareness of stratigraphic principles and encourage worldwide standardization of stratigraphic approaches and terminology. The first major achievement of ISSC was the 1976 publication of the International Stratigraphic Guide. It was revised in 1994, with an abridged version appearing in 1999. These documents achieved their goals magnificently: cited innumerable times and forming the core of many national stratigraphic codes. As the discipline has evolved, particularly from technological advances and ocean drilling, new tools and methodologies have been developed and these have led to ever finer resolution of geological time and ever more exact correlation of stratigraphic units and events, thereby enhancing the understanding of the genesis of the geological record. Under the leadership of M. B. Cita, ISSC embarked in 2002 on a renewed initiative to disseminate to the global geological community these newer developments, and ultimately incorporate them into a third edition of the Guide. To this aim, traditional and new branches of stratigraphy are being treated: chemostratigraphy, cyclostratigraphy, magnetostratigraphy, lithostratigraphy, sequence stratigraphy, biostratigraphy, and chronostratigraphy. An open-access review paper is dedicated to each and published in Newsletters on Stratigraphy. The next edition of the Guide will be inclusive of all branches of stratigraphy and also embrace igneous and metamorphic rocks. It is envisaged that a textbook on stratigraphy based on these papers and the revised Guide could prove a timely contribution, especially to younger generations of practitioners, and aid global communication and understanding of stratigraphic principles and methods.

  4. Stratigraphic control of hot fluids on anthracitization, Lackawanna synclinorium, Pennsylvania

    NASA Astrophysics Data System (ADS)

    Harrison, Michael J.; Marshak, Stephen; Onasch, Charles M.

    2004-01-01

    The Lackawanna synclinorium of Pennsylvania contains abundant coal that was altered to anthracite rank during the Late Paleozoic Alleghanian orogeny. Why did the coal in the synclinorium undergo anthracitization? Two alternatives have been suggested. (1) The region was buried deeply during and/or after the Alleghanian orogeny and thus became hot in response to Earth's geothermal gradient; and (2) hot fluids migrating from the orogen toward the foreland carried heat into the coal and caused anthracitization. If the second hypothesis is correct, the region should contain evidence that hot fluids passed through the coal. Field observations, illite-crystallinity studies and fluid-inclusion analyses indicate that the coal-bearing Pottsville and Llewellyn Formations, and an underlying detachment fault, called the Pottchunk fault (at or slightly below the base of the Pottsville Formation), acted as a regional aquifer for the migration of hot fluids during the Alleghanian orogeny. The presence of quartz veins and the hydrothermal minerals tosudite and pyrophyllite in strata above the Pottchunk fault, and the apparent absence of an illite-crystallinity burial gradient in the underlying strata, suggest that fluids migrated through large pores in coarse-grained sandstones, through abundant fractures that developed in response to Alleghanian deformation, and along the Pottchunk fault. The quartz veins, tosudite and pyrophyllite mineralization do not occur below the Pottchunk fault (except at one locality), suggesting that fluid flow was greater above the fault, perhaps because fracturing accompanying deformation increased permeability of the fault's hanging wall. Fluid inclusions in the Pottsville and Llewellyn Formations indicate fluids achieved a minimum temperature of 270 °C at a depth of ˜3.1-8.5 km. Heat-flow calculations constrained by fluid-inclusion data show the heat carried by the migrating fluids through the coal-bearing strata was sufficient to elevate the rock temperature to anthracite-grade conditions (˜250 °C), assuming that the fluid event lasted about 1 year. Thus, deep burial (6-9 km) of the coal-bearing strata in the Lackawanna synclinorium was not required for anthracitization. Anthracitization was likely the result of stratigraphically controlled hot fluid migration through the coal-bearing strata at shallow depths (?5 km).

  5. Seismic paleoceanography and the stratigraphic signature of rapid climate changes

    NASA Astrophysics Data System (ADS)

    Berne, Serge; Sierro, Francisco Javier

    2015-04-01

    The term "seismic paleoceanography" was introduced in 2004 by R. Schneider, a former Chair of Images, during the EC-funded « Promess » project, for highlighting the importance of seismic data in paleoceanographic reconstructions during this particular project. The interest of seismic stratigraphy prior to drilling operations, such as those of the IODP, has long been recognized, and became a pre-requisite for the submission of scientific proposals. However, this kind of expedition generally relies on relatively low resolution, multi-channel seismic data where only the impact of major climate changes can be visualized. In contrast, a large proportion of the Images community, more familiar with the Marion Dufresne, mainly considers seismic data as a support for selecting the best coring sites. The large amount of shallow cores, borehole and seismic (at various frequencies) data available in the Gulf of Lions allows us to illustrate the importance of very high- and ultra high- resolution seismic data for tracking the signature of rapid climate changes. The flooding events associated to "Bond Cycles" (bundles of several Dansgaard-Oeschger cycles) during MIS 3- MIS 2, are an example of the interesting feedbacks between seismic interpretation and high-resolution paleoceanography. These events where first identified in the Gulf of Lions through the multi-proxy analysis of cores retrieved at site PRGL1-4 (Sierro et al., 2009). In return, the re-examination of seismic data allows us to identify a series of corresponding seismic bounding surfaces (characterized by toplap and onlap terminations) along the continental slope. In terms of seismic amplitudes, the seismic surface associated to the transition between Heinrich Stadial 4 and Interstadial 8 appears as the most pronounced event during the entire MIS3-MIS2, suggesting that the magnitude of the associated sea-level change was the most important of this interval. Even more subtle events, such as the Melt Water Pulse 19 ka, have a distinct seismic stratigraphic signature, in the form of a mappable transgressive parasequence. Once identified at a specific location, such distinct seismic signatures might become important guides in the selection of coring sites along margins that have not yet been cored extensively. Sierro, F. J. et al. (2009). Phase relationship between sea level and abrupt climate change." Quaternary Science Reviews 28(25-26): 2867-2881.

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

  7. Offshore structures: a book list. [80 references to offshore engineering and construction

    SciTech Connect

    Vance, M.

    1983-01-01

    The references in this bibliography are divided into the two classifications of ocean engineering and offshore structures. The first section deals with marine science and facilities in general; the latter is concerned with the construction, engineering, and maintenance of offshore structures. (DCK)

  8. Horns RevHorns Rev Offshore Wind FarmOffshore Wind Farm

    E-print Network

    Horns RevHorns Rev Offshore Wind FarmOffshore Wind Farm #12;Prepared for: ELSAM A/S, Overgade 45......................................................................................................6-1 Annex 6.1. Wind Farm Area. Spring 2001.............................................................................6-1 Annex 6.2. Wind Farm Area. Autumn 2001

  9. 75 FR 17755 - Certificate of Alternative Compliance for the Offshore Supply Vessel GULF TIGER

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-07

    ...maneuver within close proximity of offshore platforms. Due to the design of the...susceptible to damage from offshore platforms. The offshore supply vessel...maneuvering within close proximity to offshore platforms. In addition, the...

  10. Morphologic and stratigraphic evolution of muddy ebb-tidal deltas along a subsiding coast: Barataria Bay, Mississippi River delta

    USGS Publications Warehouse

    FitzGerald, D.M.; Kulp, M.; Penland, S.; Flocks, J.; Kindinger, J.

    2004-01-01

    The Barataria barrier coast formed between two major distributaries of the Mississippi River delta: the Plaquemines deltaic headland to the east and the Lafourche deltaic headland to the west. Rapid relative sea-level rise (1??03 cm year-1) and other erosional processes within Barataria Bay have led to substantial increases in the area of open water (> 775 km2 since 1956) and the attendant bay tidal prism. Historically, the increase in tidal discharge at inlets has produced larger channel cross-sections and prograding ebb-tidal deltas. For example, the ebb delta at Barataria Pass has built seaward > 2??2 km since the 1880s. Shoreline erosion and an increasing bay tidal prism also facilitated the formation of new inlets. Four major lithofacies characterize the Barataria coast ebb-tidal deltas and associated sedimentary environments. These include a proximal delta facies composed of massive to laminated, fine grey-brown to pale yellow sand and a distal delta facies consisting of thinly laminated, grey to pale yellow sand and silty sand with mud layers. The higher energy proximal delta deposits contain a greater percentage of sand (75-100%) compared with the distal delta sediments (60-80%). Associated sedimentary units include a nearshore facies consisting of horizontally laminated, fine to very fine grey sand with mud layers and an offshore facies that is composed of grey to dark grey, laminated sandy silt to silty clay. All facies coarsen upwards except the offshore facies, which fines upwards. An evolutionary model is presented for the stratigraphic development of the ebb-tidal deltas in a regime of increasing tidal energy resulting from coastal land loss and tidal prism growth. Ebb-tidal delta facies prograde over nearshore sediments, which interfinger with offshore facies. The seaward decrease in tidal current velocity of the ebb discharge produces a gradational contact between proximal and distal tidal delta facies. As the tidal discharge increases and the inlet grows in dimensions, the proximal and distal tidal delta facies prograde seawards. Owing to the relatively low gradient of the inner continental shelf, the ebb-tidal delta lithosome is presently no more than 5 m thick and is generally only 2-3 m in thickness. The ebb delta sediment is sourced from deepening of the inlet and the associated channels and from the longshore sediment transport system. The final stage in the model envisages erosion and segmentation of the barrier chain, leading to a decrease in tidal discharge through the former major inlets. This process ultimately results in fine-grained sedimentation seaward of the inlets and the encasement of the ebb-tidal delta lithosome in mud. The ebb-tidal deltas along the Barataria coast are distinguished from most other ebb deltas along sand-rich coasts by their muddy content and lack of large-scale stratification produced by channel cut-and-fills and bar migration. ?? 2004 International Association of Sedimentologists.

  11. Sanaga Sud field - Offshore Cameroon, west Africa

    SciTech Connect

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

    1990-09-01

    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.

  12. Preliminary stratigraphic and petrologic characterization of core samples from USW-G1, Yucca Mountain, Nevada

    SciTech Connect

    Waters, A.C.; Carroll, P.R. (eds.)

    1981-11-01

    Tuffs of the Nevada Test Site are currently under investigation to determine their potential for long-term storage of radioactive waste. As part of this program, hole USW-G1 was drilled to a depth of 6000 ft below the surface, in the central part of the Yucca Mountain area, Nevada Test Site, Nevada. Petrographic study of the USW-G1 core is presented in this report and shows the tuffs (which generally were variably welded ash flows) are partly recrystallized to a variety of secondary minerals. The important alteration products are zeolites (heulandite, clinoptilolite, mordenite and analcime), smectite clays with minor interstratified illite, albite, micas, potassium feldspar, and various forms of silica. Iijima`s zeolite zones I through IV of burial metamorphism can be recognized in the core. Zeolites are first observed at about the 1300-ft depth, and the high-temperature boundary of zeolite stability in this core occurs at about 4350 ft. Analcime persists, either metastably or as a retrograde mineral, deeper in the core. The oxidation state of Fe-Ti oxide minerals, through most of the core, increases as the degree of welding decreases, but towards the bottom of the hole, reducing conditions generally prevail. Four stratigraphic units transected by the core may be potentially favorable sites for a waste repository. These four units, in order of increasing depth in the core, are (1) the lower cooling unit of the Topopah Spring Member, (2) cooling unit II of the Bullfrog Member, (3) the upper part of the Tram tuff, and (4) the Lithic-rich tuff.

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

    SciTech Connect

    Francois, D.K.

    1994-12-31

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

  14. 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)

    Strozyk, Frank; Back, Stefan; Kukla, Peter

    2013-04-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Sun, Li; Li, Hongnan; Jin, Qiao

    2005-05-01

    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.

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

    SciTech Connect

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

    2013-07-01

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

  17. The Seabed Stability Zonation in Chinese Offshore

    NASA Astrophysics Data System (ADS)

    Du, J.

    2013-12-01

    There are abundant natural resources and energy in Chinese offshore continental shelf, and which should be the most development potential region now and in the future. But the seabed of Chinese offshore is often under the instable status caused by many factors which deeply affects the safety of marine development. Marine geohazards is an active one among the influence factors. The marine geohazards means the geological factors developed in the seabed surface and the strata below the seabed, such as fault, shallow gas, landslide, coastal erosion, buried river channel, sand wave and sand ridge, easily liquefied sand layer etc., which will cause damage to the human life and property. In this paper, the seabed stability were analyzed and divided it into five grades based on the marine geohazards evaluation result which made by fuzzy mathematic model. Firstly, by collecting the analyzing the marine geohazards which distributed on the seabed or under the seabed, the marine geohazards maps in Chinese offshore were made and the classification system of marine geohazards was established. Then, the evaluation index system of seabed stability was set which included the seismic peak acceleration, geomorphology, direct geohazards and restricted geohazards. And the weighted value of each indicator was calculated by using analytic hierarchy process. And, a group of appropriate number with normal distribution was selected to replace the membership grade function. Based on above, a fuzzy evaluation model for seabed stability is established. Using the maps of marine geohazards, geomorphology maps and seismic peak acceleration maps as data source, using the fuzzy matrix as calculated method, based on the principles of maximum membership grade of fuzzy mathematics, we get the evaluation result of Chinese offshore with 6' by 6' grid unit. The maximum membership grade should be taken as the stability level in each unit. Above all, the seabed stability of Chinese offshore is divided into five grades according to the maximum membership grade. In this paper, we defined 5 classes which respectively were basically stable, relatively stable, medium, relatively unstable and unstable. By using statistical analysis method, a stability zonation map of the Chinese offshore has been drawn based on the evaluation result of each unit. From the stability map, Chinese offshore seabed stability was divided into sixty sub-regions with 5 classes. And the unstable sub-regions were mainly located in the North-East of Liaodong Bay, north of Laizhou Bay, the shoal in north Jiangsu, north Taiwan offshore and around Nan'ao Islands of Guangdong. Most Chinese offshore seabed stability has been in the relatively stable status.

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

    SciTech Connect

    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

    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.

  19. Genetic differentiation between inshore and offshore Atlantic cod (Gadus morhua)

    E-print Network

    Ruzzante, Daniel E.

    Genetic differentiation between inshore and offshore Atlantic cod (Gadus morhua) off Newfoundland, and Sally V. Goddard Abstract: The genetic difference between inshore overwintering Atlantic cod (Gadus morhua) from Trinity Bay, Newfoundland, and offshore overwintering cod from the Grand Bank region

  20. Hard Bottom Substrate Monitoring Horns Rev Offshore Wind Farm

    E-print Network

    Hard Bottom Substrate Monitoring Horns Rev Offshore Wind Farm Annual Status Report 2003 #12;Hard Bottom Substrate Monitoring Horns Rev Offshore Wind Farm Annual Status Report 2003 Published: 14 May 2004

  1. FEED-IN TARIFFS AND OFFSHORE WIND POWER DEVELOPMENT

    E-print Network

    Firestone, Jeremy

    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

  2. E2I EPRI Assessment Offshore Wave Energy Conversion Devices

    E-print Network

    E2I 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 ............................................................................... 26 Appendix E - Orecon

  3. 46 CFR 15.520 - Mobile offshore drilling units (MODUs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 2014-10-01 2014-10-01 false Mobile offshore drilling units (MODUs). 15.520 Section 15.520 Shipping...Requirements; Inspected Vessels § 15.520 Mobile offshore drilling units (MODUs). (a) The requirements in this...

  4. Plastic Limit Analysis of Offshore Foundation and Anchor 

    E-print Network

    Chi, Chao-Ming

    2010-10-12

    This study presents the applications of plastic limit analysis to offshore foundations and anchors, including the drag embedment anchors (DEAs) for mobile offshore drilling units (MODU’s) and spudcan foundations for jack-up ...

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

    SciTech Connect

    Not Available

    2012-02-01

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

  6. Coupled Dynamic Analysis of Multiple Unit Floating Offshore Wind Turbine

    E-print Network

    Bae, Yoon Hyeok

    2013-04-23

    floating wind turbines, so the effects of such high-frequency excitations from the tower and blades need to be checked. 5 Another concept for floating offshore wind farms is the Multiple Unit Floating Offshore Wind Turbine (MUFOWT). This model...

  7. Ecological Issues Related to Decommissioning of California's Offshore Production Platforms

    E-print Network

    Carr, Mark H.

    Ecological Issues Related to Decommissioning of California's Offshore Production Platforms Report offshore oil production platforms to assess the current state of knowledge and identify a research agenda................................................................................................................ 8 II.A. Review of California platforms

  8. Hierarchical construction of stratigraphic elements in surface-based reservoir models

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Xu, S.; Mukerji, T.

    2013-12-01

    We present a surface-based simulation algorithm connecting stratigraphic hierarchy with surface-based reservoir models through statistical metrics. Geostatistical simulation algorithms provide tools for modeling spatial complexity and the resulting uncertainties for energy resource assessments. As a new family within a wide array of stochastic geological models, surface-based models and rule-based algorithms effectively represent stratigraphic responses to geological events in both time and space by assigning depositional and erosional surfaces with predefined geometries and rules. Recent advances in surface-based modeling focus on simulating morphological evolution of deep-water depositional systems and constraining models to available well and seismic data. However, especially in deep-water plays, scarce well data can only bring information about local stratal features rather than relatively general information such as hierarchy or organization, when these features are below seismic resolution. Without such information, surface-based models lack geological realism and may not be reliable even when conditioned to data. Our proposed surface-based simulation algorithm links stratigraphic hierarchy with surface-based reservoir modeling through spatial statistical tools. Ripley's K-function is used to quantitatively describe the stratigraphic distribution patterns of channel deposits. We also use the compensation index metric for quantifying the strength of compensational stacking in stratigraphic elements. These two metrics help us to extract information about sedimentary hierarchy and element organization from a set of experimental strata, and bridge physical tank experiments with numerical models. We utilize these two geostatistical metrics in conjunction with a surface-based simulation algorithm to 1) integrate clustering and compensational stacking patterns of channel deposits into reservoir modeling 2) make numerical models represent a stratigraphic hierarchical framework comparable to physical tank experiments 3) explore a means of imparting stochastic structures to models and improving geological realism. These models can be used to better assess subsurface spatial uncertainty.

  9. Testing

    MedlinePLUS

    ... curesma.org > learn about sma > causes & diagnoses > testing Testing An SMA diagnosis must be confirmed through genetic ... and must be identified through further testing. Prenatal Testing Prenatal testing is used to determine if a ...

  10. Inquiring into indicators and origin of catastrophic events at stratigraphic boundaries.

    PubMed

    Zhang, Q; Xu, D

    1996-01-01

    Since 1982, numerous indicators of catastrophic events have been observed at the main stratigraphic boundaries in China during the Phanerozoic, i.e. Precambrian-Cambrian, Permian-Triassic, Cretaceous-Tertiary as well as Ordovician-Silurian and Devonian-Carboniferous boundaries. These markers are boundary clay layer, microspherules, high Ir anomaly, mass extinction of organisms and impact of meteorite. We support the hypothesis of the extraterrestrial origin of catastrophic events and suggest that the events at different stratigraphic boundaries might be different in features and processes. PMID:12747349

  11. Stratigraphic Profiles for Selected Hanford Site Seismometer Stations and Other Locations

    SciTech Connect

    Last, George V.

    2014-02-01

    Stratigraphic profiles were constructed for eight selected Hanford Site seismometer stations, five Hanford Site facility reference locations, and seven regional three-component broadband seismometer stations. These profiles provide interpretations of the subsurface layers to support estimation of ground motions from past earthquakes, and the prediction of ground motions from future earthquakes. In most cases these profiles terminated at the top of the Wanapum Basalt, but at selected sites profiles were extended down to the top of the crystalline basement. The composite one-dimensional stratigraphic profiles were based primarily on previous interpretations from nearby boreholes, and in many cases the nearest deep borehole is located kilometers away.

  12. Multi-scale constraints of sediment source to sink systems in frontier basins: a forward stratigraphic modeling case study of the Levant region

    NASA Astrophysics Data System (ADS)

    Hawie, Nicolas; Deschamps, Remy; Granjeon, Didier; Nader, Fadi-Henri; Gorini, Christian; Müller, Carla; Montadert, Lucien; Baudin, François

    2015-04-01

    Recent scientific work underlined the presence of a thick Cenozoic infill in the Levant Basin reaching up to 12 km. Interestingly; restricted sedimentation was observed along the Levant margin in the Cenozoic. Since the Late Eocene successive regional geodynamic events affecting Afro-Arabia and Eurasia (collision and strike slip deformation)induced fast marginal uplifts. The initiation of local and long-lived regional drainage systems in the Oligo-Miocene period (e.g. Lebanon versus Nile) provoked a change in the depositional pattern along the Levant margin and basin. A shift from carbonate dominated environments into clastic rich systems has been observed. Through this communication we explore the importance of multi-scale constraints (i.e.,seismic, well and field data) in the quantification of the subsidence history, sediment transport and deposition of a Middle-Upper Miocene "multi-source" to sink system along the northernLevant frontier region. We prove through a comprehensive forward stratigraphic modeling workflow that the contribution to the infill of the northern Levant Basin (offshore Lebanon) is split in between proximal and more distal clastic sources as well as in situ carbonate/hemipelagic deposition. In a wider perspective this work falls under the umbrella of multi-disciplinary source to sink studies that investigate the impact of geodynamic events on basin/margin architectural evolutions, consequent sedimentary infill and thus on petroleum systems assessment.

  13. Exploration potential of offshore northern California basins

    SciTech Connect

    Bachman, S.B.; Crouch, J.K.

    1988-01-01

    A series of exploratory wells was drilled in the northern California offshore basins in the 1960s following leasing of federal tracts off northern California, Oregon, and Washington. The drilling, although encountering numerous oil shows, was considered at the time to indicate low prospectivity in an area that extended as far south as the offshore Santa Maria basin. However, subsequent major discoveries in this decade in the offshore Santa Maria basin, such as the Point Arguello field, indicate that these offshore basins may be highly prospective exploration targets. Many of the key features of Monterey production in central and southern California are also present in the offshore basins of northern California. A new 5-year leasing plan has scheduled leasing in the northern California OCS starting in early 1989. The first basins on the schedule, the Point Arena and Eel River basins, differ in some respects. The Point Arena basin is more typical of a Monterey basin, with the potential for fractured chert reservoirs and organic-rich sections, deep burial of basinal sections to enhance the generation of higher gravity oils, and complex folding and faulting. The Eel River basin is more clastic-rich in its gas-producing, onshore extension. Key questions in the Eel River basin include whether the offshore, more distal stratigraphy will include Monterey-like biogenic sediments, and whether the basin has oil potential in addition to its proven gas potential. The Outer Santa Cruz basin shares a similar stratigraphy, structure, and hydrocarbon potential with the Point Arena basin. The Santa Cruz-Bodega basin, also with a similar stratigraphy, may have less exploration potential because erosion has thinned the Monterey section in parts of the basin.

  14. An overview of offshore wind electric energy resources

    Microsoft Academic Search

    Hamed H. Aly; M. E. El-Hawary

    2010-01-01

    In this paper we review offshore wind energy for generating electricity at off-shore sites. In particular, we survey the impacts of offshore wind integration into the grid, various types of generators and their dynamic modeling, fault ride-through techniques used to improve generator and grid integration performance, the aggregated wind turbines modeling and finally highlight some stability and control issues.

  15. Offshore Series Wind Turbine Variable Hub heights & rotor diameters

    E-print Network

    Firestone, Jeremy

    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

  16. 47 CFR 22.1037 - Application requirements for offshore stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false Application requirements for offshore...CARRIER SERVICES PUBLIC MOBILE SERVICES Offshore...Service § 22.1037 Application requirements for offshore...days before filing the application: (1) The name...caused to any base or mobile station using the...

  17. 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

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

    Microsoft Academic Search

    Kazuhito Oishi; Yukinari Fukumoto

    2009-01-01

    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

  19. ForPeerReview PUBLIC ACCEPTANCE OF OFFSHORE WIND POWER

    E-print Network

    Firestone, Jeremy

    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

  20. Risk-based inspection planning optimisation of offshore wind turbines

    Microsoft Academic Search

    José G. Rangel-Ramírez; John D. Sørensen

    2010-01-01

    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

  1. Ris-R-1407(EN) Efficient Development of Offshore

    E-print Network

    the at- mosphere and wind turbines in offshore regimes. The objective of the ENDOW project the impact of thermal flows, roughness and orography on offshore wind speeds. The model hierarchy developed, Roskilde April 2003 #12;Abstract Europe has large offshore wind energy potential that is poised

  2. Risk-based inspection planning optimisation of offshore wind turbines

    Microsoft Academic Search

    José G. Rangel-Ramírez; John D. Sørensen

    2012-01-01

    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

  3. Seabed instability simplified model and application in offshore wind turbine

    Microsoft Academic Search

    Zhang Yong-li; Li Jie

    2009-01-01

    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

  4. Evolution and Reduction of Scour around Offshore Wind Turbines

    Microsoft Academic Search

    David McGovern; Suzana Ilic

    2010-01-01

    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

  5. Building the business case for diversity in offshoring

    Microsoft Academic Search

    Carine Peeters; Patricia Garcia-Prieto Sol

    2009-01-01

    Offshoring inevitably leads to increased cultural diversity in work relations. Most companies perceive this increased diversity as a risk, a problem that needs to be minimized or remedied for offshoring to succeed. Building on the business case for diversity management literature we propose an alternative positive view of cultural diversity in the context of offshore relationships. We suggest that the

  6. Energy Efficient Pump Control for an Offshore Oil Processing System

    E-print Network

    Yang, Zhenyu

    /gas to the onshore or nearby offshore processing platforms, and move the products from one processing facilityEnergy Efficient Pump Control for an Offshore Oil Processing System Zhenyu Yang Kian Soleiman Bo, Denmark. Abstract: The energy efficient control of a pump system for an offshore oil processing system

  7. A fuzzy approach to the lectotype optimization of offshore platforms

    Microsoft Academic Search

    S. Chen; G. Fu

    2003-01-01

    Lectotype optimization of offshore platforms is of particular importance in the concept design process. Lectotype optimization involves multiple objectives with uncertainty and so is a problem of multiple attribute decision making. To date, there have been few published works on this topic in the context of offshore engineering. This paper develops a framework and methodology for evaluation of offshore platform

  8. International Offshore Students' Perceptions of Virtual Office Hours

    ERIC Educational Resources Information Center

    Wdowik, Steven; Michael, Kathy

    2013-01-01

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

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

    SciTech Connect

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

    1991-03-01

    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.

  10. Exotic invertebrate species on offshore oil platforms

    Microsoft Academic Search

    Henry M. Page; J Enifer E. Dugan; Carolynn S. Culver; JC Hoesterey

    2006-01-01

    ABSTRACT: We report the presence,of 3 exotic invertebrate,species,inhabiting,offshore,oil and gas platforms on the Pacific offshore continental shelf (POeS) of central and southern California, USA. These exotic species,occur in high cover or density and may,negatively,affect populations,of native species on the platforms. Conspicuous,exotic species,(the bryozoan,Watersipora ?subtorquata and the anemone,Diadumene,sp.) were detected on 2 of 7 platforms,surveyed. An inconspicuous,exotic spe­ cies (the amphipod,Caprella

  11. Application of low density foam pigs offshore Brazil

    SciTech Connect

    Lima, P.C.R.; Alves, S.J. [Petrobras, Rio de Janeiro (Brazil)

    1995-12-31

    In complex offshore installations, such as in the Campos Basin, it is relatively common to encounter pipeline systems where conventional pigs can not be run due to several factors. Changing pipe diameters, and presence of wet X-mas trees and manifolds are the most troublesome ones. In this work a new successful concept of using low cost and low density foam pigs for both liquid removal in wet-gas pipelines, and paraffin removal in oil and multiphase flow pipelines, is presented. Experimental work conducted in a 4 in laboratory facility, including a small scale glass manifold and a 6 in steel manifold, proved these pigs to be very effective. The performance of almost all kind of flexible polyurethane foams manufactured in Brazil is evaluated. Three field tests are also reported. The first low density foam pig operation was performed on a 127 mile long, 16 in diameter wet-gas offshore pipeline where the foam pig showed even higher liquid removal efficiency than the conventional inflatable spheres. The second operation was performed on a 6 mile long, 12 in diameter multiphase production offshore pipeline, which has never been pigged during its 9 year operation, and resulted in the removal of approximately 200 tons of paraffin. Finally, the third successful case is the cleaning of a 2 mile long flexible flow line of a subsea completed satellite well, in which the foam pigs were sent through a 2.5 in gas lift line, through a wet x-mas tree, not designed to be pigged, and then back through the 4 in production flow line. In spite of the fact that this paper is focusing on condensate and paraffin removal in pipeline, the basic principles can be applied to several kinds of operations: general pipeline cleaning; products separation in pipeline; corrosion evaluation; chemical product application.

  12. Stratigraphic Record from the Antarctic Continental Margin and the Nature of Cenozoic Climate and Ice Volume Changes

    Microsoft Academic Search

    L. R. Bartek

    2001-01-01

    Ocean Drilling Program core and seismic stratigraphic analyses indicate that large ice sheets were present in Antarctica at least by early Paleogene time and expanded out over large areas of the continental margin by the Eocene. Seismic stratigraphic analysis shows that seismic facies similar to those produced in the Pleistocene are present throughout the Cenozoic continental margin strata in the

  13. Integrating age information from different localities for stratigraphic marker beds: discussion of the Eltville Tephra age (Western Europe)

    NASA Astrophysics Data System (ADS)

    Zeeden, Christian; Zens, Joerg; Lehmkuhl, Frank

    2015-04-01

    Stratigraphic marker beds are often used in geosciences for regional and global correlation. For various reasons dating those layers directly proves to be difficult sometimes. In such cases ages from above and below such a horizon represent minimum- and maximum-ages. If these ages are determined from more than one location, it is possible to combine these ages, test their consistency and finally derive an age in agreement with the findings from most localities. Several approaches to integrate the age information from different localities are discussed, resulting in combined ages consistent with both stratigraphy and most of the dating results. All approach rely on assumptions, most importantly the correctness of ages and their reported uncertainty. The Eltville Tephra originates from an unknown eruption in the Eifel volcanic field is an important maker bed in Rhine-Meuse Area nearby the boundary between the deposition of reworked and primary loess during the LGM (ca. 20 ka). The Eltville Tephra is usually imbedded in loess; dates from directly above and below come almost exclusively from luminescence dating. As different luminescence dating techniques were applied to samples over- and underlying the Eltville Tephra a systematic bias of the sum of these techniques seems unlikely, but may be present due to the fact that most ages are feldspar ages uncorrected for fading. The results of several statistical approaches to deal with ages from various localities are compared, and their chances and shortcomings using well understood artificial data are discussed. These are also used to obtain an integrated datum for the Eltville Tephra including a reproducible uncertainty. This has the potential to improve on existing dates for various other stratigraphic marker beds especially in the terrestrial realm, where often dates for (or around) correlative sediments are obtained from various localities.

  14. United States Offshore Wind Resource Assessment

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

    The utilization of the offshore wind resource will be necessary if the United States is to meet the goal of having 20% of its electricity generated by wind power because many of the electrical load centers in the country are located along the coastlines. The United States Department of Energy, through its National Renewable Energy Laboratory (NREL), has supported an ongoing project to assess the wind resource for the offshore regions of the contiguous United States including the Great Lakes. Final offshore maps with a horizontal resolution of 200 meters (m) have been completed for Texas, Louisiana, Georgia, northern New England, and the Great Lakes. The ocean wind resource maps extend from the coastline to 50 nautical miles (nm) offshore. The Great Lake maps show the resource for all of the individual lakes. These maps depict the wind resource at 50 m above the water as classes of wind power density. Class 1 represents the lowest available wind resource, while Class 7 is the highest resource. Areas with Class 5 and higher wind resource can be economical for offshore project development. As offshore wind turbine technology improves, areas with Class 4 and higher resource should become economically viable. The wind resource maps are generated using output from a modified numerical weather prediction model combined with a wind flow model. The preliminary modeling is performed by AWS Truewind under subcontract to NREL. The preliminary model estimates are sent to NREL to be validated. NREL validates the preliminary estimates by comparing 50 m model data to available measurements that are extrapolated to 50 m. The validation results are used to modify the preliminary map and produce the final resource map. The sources of offshore wind measurement data include buoys, automated stations, lighthouses, and satellite- derived ocean wind speed data. The wind electric potential is represented as Megawatts (MW) of potential installed capacity and is based on the square kilometers (sq. km) of Class 5 and higher wind resource found in a specific region. NREL uses a factor of 5 MW of installed capacity per sq. km of "windy water" for its raw electric potential calculations. NREL uses Geographic Information System data to break down the offshore wind potential by state, water depth, and distance from shore. The wind potential estimates are based on the updated maps, and on previous offshore resource information for regions where new maps are not available. The estimates are updated as new maps are completed. For example, the updated Texas offshore map shows almost 3000 sq. km of Class 5 resource within 10 nm of shore and nearly 2000 sq. km of Class 5 resource or 10,000 MW of potential installed capacity in water depths of less than 30 m. NREL plans to develop exclusion criteria to further refine the offshore wind potential

  15. Improving coastal wave hindcasts by combining offshore buoy observations with global wave models.

    NASA Astrophysics Data System (ADS)

    Crosby, S. C.; O'Reilly, W. C.; Guza, R. T.

    2014-12-01

    Waves conditions in southern California are sensitive to offshore wave directions. Due to blocking by coastal islands and refraction across complex bathymetry, a <10o difference in incident wave direction can dramatically change coastal wave energy. Directional wave buoys are fundamentally low-resolution instruments, while the directional bin widths of operational wind-wave models are coarse (e.g. 10o). Operational wind-wave models have useful prediction skill in the nearshore, however, wave buoy measurements, when combined with standard directional estimation techniques, are shown to provide significantly better hindcasts. Techniques to combine offshore global wave model predictions (NOAA's Wave Watch 3 hindcasts) and offshore buoy measurements are being developed. The skill of different combination methodologies as an offshore boundary condition is assessed using spectral ray-tracing methods to transform incident offshore swell-spectra to shallow water buoy locations. A nearly continuous 10 yr data set of approximately 14 buoys is used. Comparisons include standard bulk parameters (e.g. significant wave height, peak period), the frequency-dependent energy spectrum (needed for run-up estimation) and radiation stress component Sxy (needed for alongshore current and sediment transport estimation). Global wave model uncertainties are unknown, complicating the formulation of optimum assimilation constraints. Several plausible models for estimating offshore waves are tested. Future work includes assimilating nearshore buoy observations, with the long-term objective of accurate regional wave hindcasts using an efficient mix of global wave models and buoys. This work is supported by the California Department of Parks and Recreation, Division of Boating and Waterways Oceanography Program.

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

    SciTech Connect

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

    2014-07-01

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

  17. The Gulf of Mexico structural and stratigraphic structural synthesis project: Introduction and overview

    Microsoft Academic Search

    J. S. Watkins; W. R. Bryant; R. T. Buffler

    1996-01-01

    The Gulf of Mexico Structural and Stratigraphic Synthesis Project (GMS3) was organized in the fall of 1987. Its main objective was to map, by means of student research projects, the northern Gulf of Mexico. Included objectives were (1) provide realistic research for graduate students in geology and geophysics, (2) to produce high-quality results suitable for publication and (3) to produce

  18. GEOMORPHIC AND STRATIGRAPHIC ANALYSIS OF LAYERED DEPOSITS IN TERBY CRATER, MARS. S. A. Wilson1

    E-print Network

    Howard, Alan D.

    GEOMORPHIC AND STRATIGRAPHIC ANALYSIS OF LAYERED DEPOSITS IN TERBY CRATER, MARS. S. A. Wilson1, fan-like structures, sinuous channels, col- lapse pits, a massive landslide and viscous flow fea was examined. Data Analysis: A preliminary geographic map was generated using all currently released wide

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

    E-print Network

    Torres-Verdín, Carlos

    -base and water-base mud-filtrate invasion, thence validate dynamic petrophysical properties (e.g. permeability Torres-Verdín, Ankur Gandhi, Gbenga Alabi, and Malek Lemkecher, The University of Texas at Austin in The Woodlands, Texas, United States, June 21-24, 2009. ABSTRACT We introduce the concept of common stratigraphic

  20. Digital Outcrop Models: Applications of Terrestrial Scanning Lidar Technology in Stratigraphic Modeling

    Microsoft Academic Search

    J. A. Bellian; C. KERANS; D. C. JENNETTE

    2005-01-01

    Laser ranging is extremely accurate and efficient. Terres- trial scanning lidar (light detection and ranging) applied to outcrop stratigraphic mapping enables researchers to capture laser range data at a rate of thousands of individual X, Y, Z and laser-intensity points per second. These data, in conjunction with complementary remotely and directly sampled data, are used to conduct high-precision facies characterization

  1. Baskerville, C. A.; and Merguerian, Charles, 1983, Stratigraphic differentiation in the Manhattan Schist, New York City.

    E-print Network

    Merguerian, Charles

    Baskerville, C. A.; and Merguerian, Charles, 1983, Stratigraphic differentiation in the Manhattan Schist, New York City. The Manhattan Schist, named for its type locality, Manhattan Island, New York Counties, as part of the U.S. Geological Survey engineering geologic mapping program, divides the Manhattan

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

    SciTech Connect

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

    1980-04-01

    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.

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

    USGS Publications Warehouse

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

    2006-01-01

    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.

  4. The Purisima Formation is an important upper Miocene and Pliocene stratigraphic unit in central California, cropping

    E-print Network

    Laughlin, Robert B.

    Abstract The Purisima Formation is an important upper Miocene and Pliocene stratigraphic unit- sima Formation record a latest Miocene transgressive event, whereas the middle and upper parts that the Purisima Formation ranges in age from the latest Miocene (about 7 Ma) to the late Pliocene (about 2.6 Ma

  5. Stratigraphic condensation of marine transgressive records: Origin of major shell deposits in the Miocene of Maryland

    Microsoft Academic Search

    Susan M. Kidwell

    1989-01-01

    Cyclic stratigraphic sequences in shallow marine records are commonly charaterized by a condensed transgressive lag at the base of thicker, shallowing-upward facies. The standard actualistic model for these thin fossiliferous lags, by which most of the shelf is starved owing to coastal trapping of sediment and fossils are suspected of being reworked because of the association with an erosional ravinement,

  6. Late Cretaceous marine transgressions in Ecuador and northern Peru: a refined stratigraphic framework

    E-print Network

    Paris-Sud XI, Université de

    Late Cretaceous marine transgressions in Ecuador and northern Peru: a refined stratigraphic Peru and Ecuador has made it possible to recognize correlatable marine transgressions and to propose of a NNE-trending forearc basin, which extended from Paita in northwestern Peru to northern Ecuador

  7. Structural and stratigraphic controls on cave development in the Oak Ridge area, Tennessee

    SciTech Connect

    Rubin, P A; Lemiszki, P J

    1992-01-01

    The Oak Ridge Reservation (ORR) is located in the northwestern part of the Valley and Ridge province in east Tennessee. The Valley and Ridge province is the topographic expression of the southern Appalachian foreland fold-thrust belt, which formed during the late Paleozoic Alleghanian orogeny. In the Oak Ridge area, three major northwest verging thrust faults (Kingston, Whiteoak Mountain, and Copper Creek) imbricate and juxtapose carbonate and clastic stratigraphic units that range in age from the lower Cambrian to the lower Mississippian. The carbonate stratigraphic units range in thickness from 1278 to 1748 m and include the Maynardville Limestone in the Conasauga Group (hereby included as part of the Knox Group), the Knox Group, and the Chickamauga Group. Stratigraphic relationships and repetition of units by thrust faulting has produced three northeast striking and southeast dipping carbonate bands bounded to the northwest and southeast by noncarbonate units. Preliminary results indicate that within two of these carbonate bands, formations composed of mudstone and argillaceous limestone appear to further subdivide groundwater basins. Our efforts have focused on relating the stratigraphic and structural characteristics of these rock units with cave development in the region.

  8. Regional correlations in the South Caspian Sea -implications for stratigraphic nomenclature

    SciTech Connect

    Murphy, J. [Chevron, San Ramon, CA (United States)] Rukhsara, K. [State Oil Company, Baku (Kazakhstan)

    1995-08-01

    Regional Correlations in the South Caspian Sea - Implications for Stratigraphic Nomenclature Detailed sequence boundary correlations in the South Caspian sea have led to a better understanding of the relationships between stratigraphic units identified in wells throughout the basin. With the aid of synthetic seismograms, used to tie the logs to the seismic data, lithologic units have been identified seismically and have been mapped across the basin. The synthetic seismograms were created from pseudo-sonic logs which were transformed from resistivity logs with the Faust equation. Checkshots and VSP surveys supplied the velocity control. The sequence boundary correlations revealed substantial facies changes across the basin and led to the creation of a new stratigraphic correlation chart which relates local formation names to their time correlative boundaries. A recognition of these facies changes has led to a better understanding of the lithologic relationships within the basin, the depositional history of the basin, and the source and distribution of potential reservoir sands. Previous well log correlations, made primarily by matching tops of sand and shale sequences, frequently crossed sequence boundaries mapped from seismic data. Lithologic units, deposited under similar geologic conditions, often looked the same but were not time equivalent. Seismic sequence analyses have shown that tectonic movements, as evidenced by rising domes, created barriers to sediment distribution and led to pronounced thickness changes on opposite sides of a high. New log correlations, incorporating these concepts, are helping to unravel the complex structural and stratigraphic history of the South Caspian Sea.

  9. Paleozoic Sedimentary Basins and Volcanic-Arc Systems of Southern Mongolia: New Stratigraphic and Sedimentologic Constraints

    Microsoft Academic Search

    Melissa A. Lamb; Gombosuren Badarch

    1997-01-01

    Paleozoic rocks of southern Mongolia record an important part of the tectonic growth and amalgamation of central Asia, but have not been studied closely because of their remote location. New stratigraphic and sedimentologic data from 17 localities help constrain previous geological models and strongly suggest tectonic activity throughout much of the Paleozoic, with deposition occurring predominantly within basins associated with

  10. GEOLOGY, March 2011 259 The stratigraphic distribution of fossils reflects a combina-

    E-print Network

    Heim, Noel A.

    GEOLOGY, March 2011 259 ABSTRACT The stratigraphic distribution of fossils reflects a combina- tion of physical and biological factors. Although many studies have addressed the distribution of fossils the distribution of fossils within longer duration sedimentary succes- sions covering broad geographic regions

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

    E-print Network

    Head III, James William

    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

  12. Geophysical Prospecting, 2007, 55, 679684 Stratigraphic filtering and source penetration depth

    E-print Network

    van der Baan, Mirko

    Geophysical Prospecting, 2007, 55, 679­684 Stratigraphic filtering and source penetration depth and increased penetration depth. We show how this can be done with the help of a few statistical parameters with challenges. Multiple scattering in a layer with large velocity variations may prevent penetration of seismic

  13. Stratigraphic and structural evolution of the Blue Nile Basin, Northwestern Ethiopian Plateau

    Microsoft Academic Search

    N. D. S. GANI; M. G. Abdelsalam; S. Gera; M. R. Gani

    2009-01-01

    The Blue Nile Basin, situated in the Northwestern Ethiopian Plateau, contains ? 1400 m thick Mesozoic sedimentary section underlain by Neoproterozoic basement rocks and overlain by Early-Late Oligocene and Quaternary volcanic rocks. This study outlines the stratigraphic and structural evolution of the Blue Nile Basin based on field and remote sensing studies along the Gorge of the Nile. The Blue

  14. Testing.

    ERIC Educational Resources Information Center

    Killoran, James, Ed.

    1984-01-01

    This journal issue addresses the issue of testing in the social studies classroom. The first article, "The Role of Testing" (Bragaw), focuses on the need for tests to reflect the objectives of the study completed. The varying functions of pop quizzes, weekly tests, and unit tests are explored. "Testing Thinking Processes" (Killoran, Zimmer, and…

  15. SDAR 1.0 a New Quantitative Toolkit for Analyze Stratigraphic Data

    NASA Astrophysics Data System (ADS)

    Ortiz, John; Moreno, Carlos; Cardenas, Andres; Jaramillo, Carlos

    2015-04-01

    Since the foundation of stratigraphy geoscientists have recognized that data obtained from stratigraphic columns (SC), two dimensional schemes recording descriptions of both geological and paleontological features (e.g., thickness of rock packages, grain size, fossil and lithological components, and sedimentary structures), are key elements for establishing reliable hypotheses about the distribution in space and time of rock sequences, and ancient sedimentary environmental and paleobiological dynamics. Despite the tremendous advances on the way geoscientists store, plot, and quantitatively analyze sedimentological and paleontological data (e.g., Macrostrat [http://www.macrostrat.org/], Paleobiology Database [http://www.paleodb.org/], respectively), there is still a lack of computational methodologies designed to quantitatively examine data from a highly detailed SCs. Moreover, frequently the stratigraphic information is plotted "manually" using vector graphics editors (e.g., Corel Draw, Illustrator), however, this information although store on a digital format, cannot be used readily for any quantitative analysis. Therefore, any attempt to examine the stratigraphic data in an analytical fashion necessarily takes further steps. Given these issues, we have developed the sofware 'Stratigraphic Data Analysis in R' (SDAR), which stores in a database all sedimentological, stratigraphic, and paleontological information collected from a SC, allowing users to generate high-quality graphic plots (including one or multiple features stored in the database). SDAR also encompasses quantitative analyses helping users to quantify stratigraphic information (e.g. grain size, sorting and rounding, proportion of sand/shale). Finally, given that the SDAR analysis module, has been written in the open-source high-level computer language "R graphics/statistics language" [R Development Core Team, 2014], it is already loaded with many of the crucial features required to accomplish basic and complex tasks of statistical analysis (i.e., R language provide more than hundred spatial libraries that allow users to explore various Geostatistics and spatial analysis). Consequently, SDAR allows a deeper exploration of the stratigraphic data collected in the field, it will allow the geoscientific community in the near future to develop complex analyses related with the distribution in space and time of rock sequences, such as lithofacial correlations, by a multivariate comparison between empirical SCs with quantitative lithofacial models established from modern sedimentary environments.

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

    NASA Astrophysics Data System (ADS)

    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

    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.

  17. A New Architecture for Offshore Wind Farms

    Microsoft Academic Search

    Anish Prasai; Jung-Sik Yim; Deepak Divan; Ashish Bendre; Seung-Ki Sul

    2008-01-01

    Offshore wind farms using HVDC links can be positioned a large distance from shore, opening up new opportunities for wind generation. Conventional approaches using 60 Hz generators and transformers are not appropriate in such applications, as they are heavy and result in expensive and complex installation and maintenance issues. This paper proposes an alternative architecture for such wind farms, using

  18. A new architecture for offshore wind farms

    Microsoft Academic Search

    Anish Prasai; A. Bendre; Jung-Sik Yim; Seung-Ki Sul; D. Divan; Frank Kreikebaum

    2007-01-01

    Offshore wind farms using HVDC links can be positioned a large distance from shore, opening up new opportunities for wind generation. Conventional approaches using 60 hertz generators and transformers are not appropriate in such applications, as they are heavy and result in expensive and complex installation and maintenance issues. This paper proposes an alternative architecture for such wind farms, using

  19. Oceanic engineering and offshore energy production

    Microsoft Academic Search

    William M. Carey; Claude P Brancart

    2008-01-01

    The Annual Energy Outlook 2008 [1] prepared by Energy Information Administration of the United States Department of Energy projects the continued use of fossil fuels (liquids, coal and natural gas) with little emphasis on “Oceanic Energy Conversion” and marginal importance to “Offshore Wind Energy conversion.” However the potential energy available for conversion to electrical energy along the coastal United States

  20. Solar power satellite offshore rectenna study

    NASA Astrophysics Data System (ADS)

    1980-11-01

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

  1. Offshore maintenance reduces cost and downtime

    Microsoft Academic Search

    Danahy

    1983-01-01

    Maintenance is the single activity offshore that can have the most impact on productivity, safety, and downtime. Unfortunately, unless it is well organized, maintenance may be carried out according to unchanging and often unnecessary routines. Overly rigid maintenance procedures, that are viewed by crews as ''makework'' assignments, are not conducive to quality or to failure-proof operation of key rig systems.

  2. Rocky and Sandy Seafloor Offshore California

    USGS Multimedia Gallery

    Image of ripples in sand, next to a rocky surface on the seafloor 2.5 km (1.5 miles) offshore San Mateo County, California at a depth of 24.6 meters (81 feet). The two red dots in the image (from lasers mounted on the camera and used as reference points) are 15 cm (6 inches) apa...

  3. Nantucket Sound Offshore Wind Stakeholder Process

    Microsoft Academic Search

    Greg Watson; Fara Courtney

    2004-01-01

    In response to government efforts to promote renewable energy development, Cape Wind Associates proposed the first offshore wind farm in the United States. The plan has been met with both vehement opposition and ardent support. In response to an increasingly unproductive debate over the project, the Massachusetts Technology Collaborative (MTC), a quasi-state agency, held a series of stakeholder meetings to

  4. A heave compensation approach for offshore cranes

    Microsoft Academic Search

    Jörg Neupert; Tobias Mahl; Bertrand Haessig; Oliver Sawodny; Klaus Schneider

    2008-01-01

    Offshore installations during harsh sea conditions results in rigorous requirements in terms of safety and efficiency for the involved crane system. Hence a heave compensation system based on heave motion prediction and an inversion based control strategy is proposed. The control objective is to let the rope suspended payload track a desired reference trajectory in an earth fixed frame without

  5. Accord near for offshore California oil shipments

    SciTech Connect

    Not Available

    1993-02-15

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

  6. CHOOSING OFFSHORE PIPELINE ROUTES: PROBLEMS AND SOLUTIONS

    EPA Science Inventory

    The report discusses the environmental and fisheries problems associated with offshore pipelines. The report focuses on how these problems can be addressed during the pipeline planning and route selection process. Geologic hazards are highlighted as the major factors related to p...

  7. Planning and evaluation parameters for offshore complexes

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

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

  8. Environmental effects of offshore oil production

    Microsoft Academic Search

    Middleditch

    1981-01-01

    The Buccaneer Gas and Oil Field Study is the most comprehensive interdisciplinary ecological study to date of an offshore oil field operating under normal conditions. Involving nearly 30 individual research groups, the study focused on the effects of the oil field structures and on low-level chronic exposure of organisms to various discharges from the production platforms. Chapters cover a wide

  9. HYDRODYNAMIC LOADING ON SLENDER OFFSHORE WIND TURBINES

    Microsoft Academic Search

    A. R. Henderson; Garrad Hassan

    In the shallow seas that are the favoured locations for offshore wind farms, the limited water depths can result in highly non-linear waves. The determination of the design wave loads will involve selection of appropriate models of wave kinematics as well as force and structural dynamics models. Each selection will involve a compromise between accuracy and usability (speed, ease of

  10. Sea loads on ships and offshore structures

    Microsoft Academic Search

    O. M. Faltinsen

    1990-01-01

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

  11. Practical stochastic fatigue analysis of offshore platforms

    Microsoft Academic Search

    R. Skjong; H. O. Madsen

    1987-01-01

    A method for stochastic fatigue analysis of offshore platforms is presented. The method accounts for the nonlinearity in the drag loading term, and for the systematic deviation from a Gaussian process for a platform response. The method is based on an assumed form of the stress response process at a hot spot. A number of full scale measurements for elements

  12. Fatigue failure paths for offshore platform inspection

    Microsoft Academic Search

    Demir I. Karsan; Ashok Kumar

    1990-01-01

    A closed- form, reliability-based procedure is developed to identify fatigue failure paths of offshore structures and assess the notional probability of system failure through these paths. The procedure utilizes the Miners rule node fatigue failure reliability model developed by Wirsching. Effects of load redistribution following the fatigue failure of a node on the time to failure of remaining unfailed nodes

  13. 4-D stratigraphic architecture and 3-D reservoir zonation of the Mirado Formation, Cusiana Field, Colombia

    SciTech Connect

    Fajardo, A.A. (Ecopetrol, del Petroleo (Colombia)); Cross, T.A. (Colorado School of Mines, Golden, CO (United States))

    1996-01-01

    A high-resolution sequence stratigraphic study using 2300 feet of core calibrated with geophysical logs from 14 wells and 1800 measurements of porosity and permeability established the 4-D stratigraphy and 3-D reservoir zonation of the Mirador. Virtually all reservoir-quality facies are through cross-stratified sandstones which occur in channel facies successions in the lower Mirador, but in bay-head delta and estuarine channel facies successions in the upper Mirador. Petrophysical properties and the geometry, continuity and volume of reservoir-quality sandstones change regularly as function of their stratigraphic position. These vertical facies successions reflect increasing accommodation-to-sediment supply (A/S) ratio through each intermediate-term cycle. The upper long-term cycle comprises four intermediate-term, landward-stepping, symmetrical base-level cycles. These cycles consist of estuarine channel, bay-head to bay-fill facies successions. The transition from channel to bay-head to bay-fill facies successions represents an increase in A/S ratio, and the reverse transition indicates a decrease in A/S ratio. Sixteen reservoir zones were defined within the Cusiana field. Reservoirs within the upper and lower long-term cycles are separated by a continuous middle Mirador mudstone which creates two large reservoir divisions. At the second level of zonation, the reservoir compartments and fluid-flow retardants coincide with the intermediate-term stratigraphic cycles. A third level of reservoir compartmentalization follows the distribution of facies successions within the intermediate-term cycles. A strong stratigraphic control on reservoir properties occurs at the three scales of stratigraphic cyclicity. In all cases as A/S ratio increases, porosity and permeability decrease.

  14. 4-D stratigraphic architecture and 3-D reservoir zonation of the Mirado Formation, Cusiana Field, Colombia

    SciTech Connect

    Fajardo, A.A. [Ecopetrol, del Petroleo (Colombia); Cross, T.A. [Colorado School of Mines, Golden, CO (United States)

    1996-12-31

    A high-resolution sequence stratigraphic study using 2300 feet of core calibrated with geophysical logs from 14 wells and 1800 measurements of porosity and permeability established the 4-D stratigraphy and 3-D reservoir zonation of the Mirador. Virtually all reservoir-quality facies are through cross-stratified sandstones which occur in channel facies successions in the lower Mirador, but in bay-head delta and estuarine channel facies successions in the upper Mirador. Petrophysical properties and the geometry, continuity and volume of reservoir-quality sandstones change regularly as function of their stratigraphic position. These vertical facies successions reflect increasing accommodation-to-sediment supply (A/S) ratio through each intermediate-term cycle. The upper long-term cycle comprises four intermediate-term, landward-stepping, symmetrical base-level cycles. These cycles consist of estuarine channel, bay-head to bay-fill facies successions. The transition from channel to bay-head to bay-fill facies successions represents an increase in A/S ratio, and the reverse transition indicates a decrease in A/S ratio. Sixteen reservoir zones were defined within the Cusiana field. Reservoirs within the upper and lower long-term cycles are separated by a continuous middle Mirador mudstone which creates two large reservoir divisions. At the second level of zonation, the reservoir compartments and fluid-flow retardants coincide with the intermediate-term stratigraphic cycles. A third level of reservoir compartmentalization follows the distribution of facies successions within the intermediate-term cycles. A strong stratigraphic control on reservoir properties occurs at the three scales of stratigraphic cyclicity. In all cases as A/S ratio increases, porosity and permeability decrease.

  15. The Stratigraphic Expression of Submarine Channel-Lobe Transitions: An Outcrop Example from Southern Chile

    NASA Astrophysics Data System (ADS)

    Pemberton, Erin A. L.; Hubbard, Stephen M.; Fildani, Andrea; Romans, Brian; Kostic, Svetlana

    2015-04-01

    The stratigraphic expression of sediment-laden gravity flows transitioning from deep-sea submarine channel to less-confined fan lobe is poorly constrained, motivating investigation of outcropping channel-lobe transition zone and channel fills in the Magallanes Basin, southern Chile. We hypothesize that turbidity currents moving from a high-slope confined setting (channel) into a lower slope unconfined setting (lobe), expand laterally and, under the right conditions, undergo internal hydraulic jumps. The Cretaceous strata examined are characterized by a variety of architectural elements in close juxtaposition both laterally and stratigraphically, including: (a) low aspect ratio channelform bodies attributed to slope channel fill; (b) high aspect ratio channelform bodies interpreted as the deposits of weakly-confined turbidite channels; (c) lenticular sedimentary bodies considered to represent the infill of laterally amalgamated scours; (d) discontinuous channelform bodies representing isolated scour fills; and (e) cross-stratified positive relief sedimentary bodies, which record upslope migrating depositional barforms. The ephemeral nature of settings characterized by flow expansion (i.e., channel-lobe transition zone), as well as the propensity for scour and sediment bypass, yields extensive architectural variability in the stratigraphic record. Net-erosional and net-depositional cyclic steps play a fundamental role in the formation, filling, and maintenance phases of channel to lobe transition areas where high gradients support the development of densimetric Froude-supercritical turbidity currents; abrupt slope breaks can, under the right conditions, promote hydraulic jumps and possibly the spontaneous evolution of an erodible seabed into cyclic steps. Along these longitudinal profiles, both the formation of highly composite stratigraphic surfaces, as well as geomorphic surfaces, are passed into the rock record. This yields less repeated stratigraphic patterns than those reported from channel- or lobe- dominated units deposits up- or down- dip of expansion zones.

  16. Divergent evolutionary processes associated with colonization of offshore islands.

    PubMed

    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

    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

  17. Southern Mozambique basin: most promising hydrocarbon province offshore eat Africa

    SciTech Connect

    De Buyl, M.; Flores, G.

    1984-09-01

    Recent offshore acquisition of 12,800 km (8,000 mi) of seismic reflection data, with gravity and magnetic profiles encompassing the southern half of the Mozambique basin, reveals new facets of the subsurface geology. Integrated interpretation of these new geophysical data with old well information results in the development of depositional and tectonic models that positively establish the hydrocarbon potential of the basin. The recent comprehensive interpretation affords the following conclusions. (1) Significant oil shows accompany wet gas discoveries suggest that the South Mozambique basin is a mature province, as the hydrocarbon associations imply thermogenic processes. (2) Super-Karoo marine Jurassic sequences have been encountered in Nhamura-1 well onshore from the application of seismic stratigraphy and well correlation. (3) Steeply dipping reflectors truncated by the pre-Cretaceous unconformity testify to significant tectonic activity preceding the breakup of Gondwanaland. Hence, preconceived ideas about the depth of the economic basement and the absence of mature source rocks of pre-Cretaceous age should be revised. (4) Wildcats in the vicinity of ample structural closures have not been, in retrospect, optimally positioned nor drilled to sufficient depth to test the viability of prospects mapped along a major offshore extension of the East African rift system delineated by this new survey.

  18. Mapping seabird sensitivity to offshore wind farms.

    PubMed

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

    2014-01-01

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

  19. Bedout basement rise, offshore northwestern Australia: evidence of an unshocked mafic volcanic hyaloclastite volcanic breccia

    NASA Astrophysics Data System (ADS)

    Glikson, A.

    2004-12-01

    Core samples from Bedout-1 (3035.8-3044.95 m.), Bedout basement rise, offshore northwestern Australia, were examined by optical microscopy, SEM, EDS and WDS spectrometry. At this stratigraphic depth level Becker et al. (2004) interpret cryptocrystalline alteration zones around and within plagioclase in terms of shock-induced transformation of feldspar into diaplectic maskelynite glass _u postulating a ~200 km-large impact structure and thereby an impact connection of the Permian-Triassic boundary mass extinction. However, the breccia is dominated by fragments of microlitic basalt and ophitic-textured dolerite with well preserved igneous textures, showing no evidence of shock metamorphism. Euhedral pseudomorphs of chlorite and amphibole, probably after pyroxene, protrude into or are enveloped by euhedral albite-twinned calcic plagioclase (andesine to bytownite). Minor phases include euhedral ilmenite needles and subhedral magnetite grains. Plagioclase is altered by cryptocrystalline albite and microcrystalline albite-chlorite matrix along crystal boundaries, along twin lamella and within internal oscillatory crystal zones, consistent with burial metamorphosed hydrovolcanic basalts and spilites (e.g. Amstutz, 1974). The volcanic fragments are set within, and injected by, microcrystalline intergranular mesostasis of mixed mineral fragments and volcanic meta-glass. Becker et al. (2004) refer to the breccia in part as product of Mg-rich sediments (e.g. dolomites). However, apart from the pristine igneous textures of the breccia, the transition element levels (chlorite in dolerite fragment "C Ni 97-160 ppm; Co 75-152 ppm; Cu 69-204 ppm; mesostasis "C Ni 29-45 ppm; Co 18-52 ppm; Cu 26-110 ppm) are consistent with Fe-rich basalts but exceed common abundances in carbonates and marls (BVTP, 1981; Wedepohl, 1978). No shock metamorphic features, such as planar deformation features (PDF), are observed in the feldspar or in any other phases. No criteria for discriminating maskelynite and volcanic meta-glass are indicated by Becker et al. (2004). As PDF formation (10-35 GPa) necessarily precedes diaplectic transformation into maskelynite (35-45 GPa) (French, 1998), a presence of maskelynite is inconsistent with the absence of PDF in the plagioclase _u a phase prone to the development of shock effects (e.g. Mory, 2000). Little evidence exists for the hydrothermal activity which typically follows impact events. However, thanks to a partial development of a rim syncline-like structure in Triassic sediments around the Bedout rise, further testing of the origin of this remarkable structure is warranted. Amstutz, G.C., 1974, Spilites and Spilitic Rocks, Springer-Verlag, Berlin; Becker, L. et al., 2004, Science Express, 13.5.04; BVSP - Basaltic Volcanism Study Project, 1981, Pergamon; French, B.M., 1998, Traces of Catastrophe, Lunar and Planetary Contributions 954; Mory et al., 2000, Earth and Planetary Science, 177, 119-128; Wedepohl, K.H., Handbook of Geochemistry, Springer-Verlag, 1978.

  20. Exploring Challenges and Opportunities in Recognizing the Signature of Sea Level, Tectonic Subsidence, and Sediment Supply in the Stratigraphic Record: A Comparison of Field-based and Model-generated Data from Carbonate Sedimentary Records

    NASA Astrophysics Data System (ADS)

    Brady, M. E.; Oliver, D. L.; Bowie, C.

    2014-12-01

    Integrating field and model observations of marine carbonate strata, we investigate how distinct sedimentary basins respond to the same eustatic sea level history, specifically in terms of the preserved record of lithofacies and meter-scale depositional cycles. First, we compare two coeval Devonian sedimentary records characterized by different subsidence regimes (North American 'stable' cratonic interior vs. 'passive' continental margin) and rock accumulation rates (measured over m.y. time scales). Despite the greater potential for subaerial exposure due to minimal accommodation space, stratigraphic and petrographic analyses revealed the apparently significant role of suppressed subtidal sedimentation rates, along with submarine erosion and non-deposition, in limiting both the thickness and number of facies and cycles preserved in the cratonic record compared to the continental margin. To explore insights gained from the field, we use a previously-developed, one-dimensional forward model to generate stratigraphic columns. Knowing the true history underlying each model run, we can test the sensitivity of the resultant stratigraphy to variation in subsidence and sedimentation rates, while maintaining the same eustatic sea level curve. For the model conditions explored, 1) thicker component depositional units reflect higher sedimentation rates; 2) total stratigraphic thickness, numbers of units, and stratigraphic completeness reflect combinations of low enough sedimentation rates and high enough subsidence rates to maintain sufficient accommodation space; and 3) the preserved stratal patterns rarely faithfully record sea level history. The model results lead to new questions that can direct future field studies. Overall, this approach can inform similar investigations in other carbonate, siliciclastic and non-marine records, especially over stratigraphic scales finer than the temporal resolution typically afforded by numerical ages and correlation techniques.

  1. Correcting relative paleointensity records for variations in sediment composition: Results from a South Atlantic stratigraphic network

    NASA Astrophysics Data System (ADS)

    Hofmann, Daniela I.; Fabian, Karl

    2009-06-01

    Marine sediments record direction and intensity of the Earth's magnetic field by the alignment of magnetic particles during deposition. For determining relative paleointensity (RPI) from sediment records it is commonly assumed that their natural remanent magnetization (NRM) is proportional to the Earth's magnetic field during deposition, and also proportional to the concentration of remanence carriers in the sediment layer. However, little is known how varying sediment composition and environmental conditions during deposition influence the NRM. Here we try to identify and quantify such sedimentary influences for eight sediment series from the subtropical and subantarctic South Atlantic. The cores were recovered in a constraint area crossing the subtropical front (STF). They have widely different sediment lithologies, which can be divided into three lithologic groups. Due to their mutual proximity, they have experienced approximately the same magnetic field history, and differences in their RPI signals must be caused by their varying sediment composition and recording properties. Based on high resolution rock magnetic and compositional data from two previous studies it is possible to quantitatively test and compare the influences of different sediment properties upon the NRM. It is found that magnetic grain size, as measured by the magnetic parameter ARM/IRM, is most influential among the parameters tested. Weak to moderate reductive diagenesis, as measured by the parameter Fe/ ?, turns out to have minor impact. By comparing the sensitivity of different normalization procedures for RPI determination, it is found that induced remanent magnetization (IRM) is most robust. Based on an extended linear RPI theory, we can calculate a corrected RPI stack for the investigated cores. This correction improves the correlation with independent global paleointensity stacks in comparison to our previous uncorrected RPI stack (Hofmann, D., Fabian, K., 2007. Rock-magnetic properties and relative paleointensity stack for the last 300 ka based on a stratigraphic network from the subtropical and subantarctic South Atlantic. Earth Planet. Sci. Lett. 260, 297-312.). The ratio between corrected and uncorrected RPI stacks reveals a hidden global climate signal, which indicates that climatic variations in sediment composition are inevitably present in non-ideal sediment sequences.

  2. Internal waves in a large offshore storage tank

    SciTech Connect

    Chakrabarti, S.K. (Chicago Bridge and Iron Technical Services Co., Plainfield, IL (United States))

    1993-06-01

    The internal wave in a partially filled tank, or sloshing'' of liquid as it is commonly known, involves the transfer of liquid from one side of the storage tank to the other in the form of a wave. Sloshing is a natural period phenomenon. There are many natural periods in which the sloshing may be excited. Usually, the fundamental mode of motion is the most critical one. Simple calculations provide these natural periods for a rigid rectangular or circular cylindrical tank. If the storage tank is in motion, such as a liquid vessel on road or on rail, the force generated by this motion and the associated run-up may be severe. For an offshore storage tank, the liquid inside the tank is excited by the motion of the tank wall or bottom for an external agent, e.g., waves or earthquakes. In this case, the tank walls are deflected from the dynamic pressure distribution around its outside. Similarly, the waves induce a motion of the foundation of the structure. The purpose of this paper is to examine the sloshing phenomenon in waves due to the displacement of the wall as well as the displacement of the bottom of a gravity-based offshore oil storage tank. Simple analysis was made to predict the wave heights generated by the internal waves due to the translational and rotational motion of the cylindrical storage tank. A wave tank test was performed with the model of a shallow water oil storage tank. The storage tank wall was modeled for the stiffness following Froude-Cauchy similitude. In addition, the actual foundation on the seafloor was modeled in the test with springs. No attempt was, however, made to introduce the foundation (soil) damping into the model. The test data from regular waves generated in the wave tank were used to correlate the theory.

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

    SciTech Connect

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

    2012-11-01

    In 2007, the FAST wind turbine simulation tool, developed and maintained by the U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory (NREL), was expanded to include capabilities that are suitable for modeling floating offshore wind turbines. In an effort to validate FAST and other offshore wind energy modeling tools, DOE funded the DeepCwind project that tested three prototype floating wind turbines at 1/50th scale in a wave basin, including a semisubmersible, a tension-leg platform, and a spar buoy. This paper describes the use of the results of the spar wave basin tests to calibrate and validate the FAST offshore floating simulation tool, and presents some initial results of simulated dynamic responses of the spar to several combinations of wind and sea states.

  4. 46 CFR 131.565 - Monthly tests and inspections.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false Monthly tests and inspections. 131...GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Tests, Drills, and Inspections § 131.565 Monthly tests and...

  5. 46 CFR 131.565 - Monthly tests and inspections.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false Monthly tests and inspections. 131...GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Tests, Drills, and Inspections § 131.565 Monthly tests and...

  6. 46 CFR 131.565 - Monthly tests and inspections.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false Monthly tests and inspections. 131...GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Tests, Drills, and Inspections § 131.565 Monthly tests and...

  7. 46 CFR 131.565 - Monthly tests and inspections.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 false Monthly tests and inspections. 131...GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Tests, Drills, and Inspections § 131.565 Monthly tests and...

  8. 46 CFR 131.565 - Monthly tests and inspections.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 false Monthly tests and inspections. 131...GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Tests, Drills, and Inspections § 131.565 Monthly tests and...

  9. Comparison of anxiety prevalence among based and offshore National Iranian Drilling Company staff's children in Ahvaz, 2013

    PubMed Central

    Zargham-Boroujeni, Ali; Shahba, Zohre; Abedi, Heidarali

    2015-01-01

    Background: Anxiety is one of the most common psychological issues among all age groups including children. The main role of parents has been known to support their children. Being far away from a source of support has been shown to be a potential trigger for childhood anxiety. Periodical jobs, including offshore work, are among the main reasons for absence of one of the parents. Therefore, this study aims to assess anxiety in children of National Iranian Drilling Company offshore staff. Materials and Methods: In this historical cohort study, 160 students including 80 boys and 80 girls were selected through convenient random sampling from the schools of National Iranian Drilling Company. Data were collected using Revised Children's Manifest Anxiety Inventory (by Reynolds and Richmond), consisting 37 items and a demographic questionnaire. The collected data were statistically analyzed by t-test and logistic regression tests through SPSS software. Results: The mean anxiety score was 12.80 among offshore staff's children and 11.67 among the children of the based staff. The ratio of manifest anxiety among the offshore workers’ children was significantly more than the based ones’. Conclusions: Based on the findings, offshore fathers’ job affects the anxiety of the children. PMID:26097851

  10. Integration of offshore wind farms through high voltage direct current networks

    NASA Astrophysics Data System (ADS)

    Livermore, Luke

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

  11. The role of seismic in exploration of carbonate buildups in offshore Sarawak, Malaysia

    SciTech Connect

    Ng, T.S. (Petronas Carigali, Kuala Lumpur (Malaysia))

    1994-07-01

    The Luconia geological province offshore Sarawak is typical in that carbonates extensively developed mainly during the Miocene, and some 200 carbonate buildups have been seismically mapped. The seismic data of the early days were mainly used to define the carbonate structure. The present advancement of the seismic technology enables interpreters to confidently map the Miocene carbonate buildups and the Pliocene argillaceous top seals, which are characterized by low amplitude and monotonous reflectors. Furthermore, these high-frequency seismic data permit the identification of the pre-carbonate structural focusing and deep faults as hydrocarbon mitigation pathways, upper Miocene sandy thief beds, and intraformational shale as secondary top seal. The use of seismic data in the development of carbonate gas fields is not only confined to structural mapping but also to the stratigraphic interpretations. Both the vertical and lateral porosity variations of the carbonate reservoirs can be calibrated to seismic amplitude and acoustic impedance. The thickness of the reservoir indicates some relationships with the seismic isochron values. These techniques can be used in selecting optimum location for development wells.

  12. Seismic modeling for gas field development in offshore Niger Delta: A case history

    SciTech Connect

    Idowu, A.O. (Nigerian National Petroleum Corp., Lagos (Nigeria))

    1994-07-01

    In practice, seismic data has been used to map the geometry of events in the subsurface, mainly from reflection continuity and the character of reflection packages. Seismic modeling techniques are attempts to mathematically and geometrically represent the geology of the subsurface and to depict the interaction of the geology with a propagating seismic wave front. In the Niger delta, recent development in stratigraphic exploration has induced the examination of more subtle features of reflection, mainly polarity, amplitude, and waveform, to define the limits of seismic resolution and hence predict the geometry of the subsurface fluid and solid interfaces. The field being appraised for development in this study is located approximately 35 km offshore southeast of the Niger delta in a water depth ranging from 20 to 25 m, and the project involves a modeling evaluation of five sand units encountered at different levels in the subsurface. The sands being modeled occur within the Agbada Formation (Miocene age), an alternation sequence of transitional sands and shales characterized by high-amplitude, anomalous seismic events over the Nkop field. Structurally, the field is characterized by seaward facing, contemporaneous growth faults consisting mainly of a rollover anticline located in a regional fault couple, bounded to the north and south by a growth fault.

  13. Sequence stratigraphy of the Hith/Upper Arab formations offshore Abu Dhabi, U.A.E.

    SciTech Connect

    Azer, S.R.; Peebles, R.G.

    1995-11-01

    The Kimmeridgian Upper Arab zones A, B, and C, are prolific hydrocarbon bearing reservoirs in central and western Offshore Abu Dhabi (OAD). They were deposited in an arid climate which dominated the Arabian peninsula during Late Jurassic times. The Berriasian to Tithonian Hith Formation which overlies the Arab reservoirs constitute the cap rock, which just to the east of central OAD gradually pinches out and forms a N-S feather edge. The Hith and Upper Arab zones A, B, and C form 450 to over 600 feet of massive to interbedded anhydrites with varying proportions of limestones and dolomites in central and western OAD. The Arab Formation in OAD is a major regressive unit which was deposited on a broad carbonate platform and prograded eastwards into an open marine shelf environment. The objectives of this paper are to develop a sequence stratigraphic framework, emphasizing cyclicity, facies architecture and diagenesis. Core and well log data geared with various inorganic geochemical analyses from four wells are used to constrain the current uncertainties in age dating and integrate the diagenetic signatures in the patterns of relative sea level change which considerably control the formation of those parasequences. This effort will help in better understanding and possible prediction of porosity in such prospective reservoirs.

  14. Behavior of foundation clays supporting compliant offshore structures

    SciTech Connect

    Malek, A.M.; Baligh, M.M.; Germaine, J.T. (Massachusetts Inst. of Tech., Cambridge, MA (USA). Dept. of Civil Engineering); Azzouz, A.S. (College of Engrg. and Petroleum, Kuwait Univ., P.O. Box 5969 (KW))

    1989-05-01

    Piles supporting compliant offshore structures subject the foundation soils to large cyclic shear stresses superimposed on significant static (sustained) stresses. In order to investigate the behavior of foundation clays during critical undrained storm-loading conditions, an extensive experimental program involving K/sub o/-consolidated undrained cyclic direct simple shear tests was performed on normally consolidated samples of resedimented Boston blue clay. Results are presented in normalized format to allow generalizations and comparisons with other clays obeying normalized behavior. A simplified method is then proposed for predicting important aspects of shaft performance for a rigid rough cylindrical pile subjected to the combined static and undrained cyclic loading conditions imposed by tension leg platforms.

  15. Risk perception by offshore oil personnel during bad weather conditions.

    PubMed

    Rundmo, T; Sjöberg, L

    1998-02-01

    This article presents the results of analyses of employee subjective risk assessments caused by platform movements on an offshore oil installation in the Norwegian sector of the North Sea. The results are based on a self-completion questionnaire survey conducted among 179 respondents covering three shifts on the platform. The data collection was carried out during the spring of 1994. A minority expressed worry due to platform movements. A greater proportion of the personnel stated worry about the construction of the platform. The personnel were more unsafe when they assessed their own safety attitudes with regard to specific potentially hazardous consequences of platform movements. Two approaches aimed at modeling worry and concern caused by platform movements were tested. The models were the mental imagery approach and the rationalistic approach. The rationalistic and mental imagery models fitted equally well. Implications of the results for risk communication are discussed. PMID:9523449

  16. The Offshore East African Rift System

    NASA Astrophysics Data System (ADS)

    Franke, D.; Klimke, J.; Jokat, W.; Stollhofen, H.; Mahanjane, S.

    2014-12-01

    Numerous studies have addressed various aspects of the East African Rift system but surprisingly few on the offshore continuation of the south-eastern branch of the rift into the Mozambique Channel. The most prominent article has been published almost 30 years ago by Mougenot et al. (1986) and is based on vintage seismic data. Several studies investigating earthquakes and plate motions from GPS measurements reveal recent deformation along the offshore branch of the East African Rift system. Slip vectors from earthquakes data in Mozambique's offshore basins show a consistent NE direction. Fault plane solutions reveal ~ E-W extensional failure with focal depth clustering around 19 km and 40 km, respectively. Here, we present new evidence for neotectonic deformation derived from modern seismic reflection data and supported by additional geophysical data. The modern rift system obviously reactivates structures from the disintegration of eastern Gondwana. During the Jurassic/Cretaceous opening of the Somali and Mozambique Basins, Madagascar moved southwards along a major shear zone, to its present position. Since the Miocene, parts of the shear zone became reactivated and structurally overprinted by the East African rift system. The Kerimbas Graben offshore northern Mozambique is the most prominent manifestation of recent extensional deformation. Bathymetry data shows that it deepens northwards, with approximately 700 m downthrown on the eastern shoulder. The graben can be subdivided into four subbasins by crosscutting structural lineaments with a NW-SE trend. Together with the N-S striking graben-bounding faults, this resembles a conjugate fault system. In seismic reflection data normal faulting is distinct not only at the earthquake epicenters. The faults cut through the sedimentary successions and typically reach the seafloor, indicating ongoing recent deformation. Reference: Mougenot, D., Recq, M., Virlogeux, P., and Lepvrier, C., 1986, Seaward extension of the East African Rift: Nature, v. 321, p. 599-603

  17. Platforms will handle sour streams offshore India

    SciTech Connect

    NONE

    1997-07-21

    The recently installed Panna facilities, offshore the west coast of India, are designed to produce 50,000 b/d of highly paraffinic, sour oil, 180 MM-scfd of sour gas, and 100,000 bw/d. The field lies in about 154 ft of water. Enron Oil and Gas India Ltd. is operator. Enercon Engineering Inc., Houston, provided detailed design, procurement, and inspection services for the development that includes installation of six platforms and 22 pipelines.

  18. Cenozoic tectonics of the Caribbean: Structural and stratigraphic studies in Jamaica and Hispaniola

    NASA Astrophysics Data System (ADS)

    Mann, W. P.

    Structural and stratigraphic field studies in Jamaica and Hispaniola (Dominican Republic and Haiti) and synthesis of published data from surrounding areas refine previously proposed models for convergent and strike-slip plate interactions in the northern Caribbean. Specifically: (1) new data and regional stratigraphic analysis of major unconformities in the Greater Antilles supports the idea of two distinct arcs that terminated by collision at slightly different times in the latest Cretaceous and Paleogene; (2) field studies in the Port Maria area of northeastern Jamaica essentially complete mapping of the Wagwater Belt, a reactivated Paleogene graben and overlying sedimentary basin; and (3) the interpretation of satellite imagery and aerial photographs and field studies in the Enriquillo Valley and Sierra el Numero, Dominican Republic; the Culde-Sac Valley and southern peninsula of Haiti; and the Clydesdale area of eastern Jamaica.

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

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

    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.

  20. Using 3D visualization and seismic attributes to improve structural and stratigraphic resolution of reservoirs

    SciTech Connect

    Kerr, J. (Landmark Graphics Corp., Weybridge (United Kingdom)); Jones, G.L. (Landmark Graphics Corp., Houston, TX (United States))

    1996-01-01

    Recent advances in hardware and software have given the interpreter and engineer new ways to view 3D seismic data and well bore information. Recent papers have also highlighted the use of various statistics and seismic attributes. By combining new 3D rendering technologies with recent trends in seismic analysis, the interpreter can improve the structural and stratigraphic resolution of hydrocarbon reservoirs. This paper gives several examples using 3D visualization to better define both the structural and stratigraphic aspects of several different structural types from around the world. Statistics, 3D visualization techniques and rapid animation are used to show complex faulting and detailed channel systems. These systems would be difficult to map using either 2D or 3D data with conventional interpretation techniques.

  1. Using 3D visualization and seismic attributes to improve structural and stratigraphic resolution of reservoirs

    SciTech Connect

    Kerr, J. [Landmark Graphics Corp., Weybridge (United Kingdom); Jones, G.L. [Landmark Graphics Corp., Houston, TX (United States)

    1996-12-31

    Recent advances in hardware and software have given the interpreter and engineer new ways to view 3D seismic data and well bore information. Recent papers have also highlighted the use of various statistics and seismic attributes. By combining new 3D rendering technologies with recent trends in seismic analysis, the interpreter can improve the structural and stratigraphic resolution of hydrocarbon reservoirs. This paper gives several examples using 3D visualization to better define both the structural and stratigraphic aspects of several different structural types from around the world. Statistics, 3D visualization techniques and rapid animation are used to show complex faulting and detailed channel systems. These systems would be difficult to map using either 2D or 3D data with conventional interpretation techniques.

  2. Sequence stratigraphic and sedimentologic significance of biogenic structures from a late Paleozoic marginal- to open-marine reservoir, Morrow Sandstone, subsurface of southwest Kansas, USA

    USGS Publications Warehouse

    Buatois, L.A.; Mangano, M.G.; Alissa, A.; Carr, T.R.

    2002-01-01

    Integrated ichnologic, sedimentologic, and stratigraphic studies of cores and well logs from Lower Pennsylvanian oil and gas reservoirs (lower Morrow Sandstone, southwest Kansas) allow distinction between fluvio-estuarine and open marine deposits in the Gentzler and Arroyo fields. The fluvio-estuarine facies assemblage is composed of both interfluve and valley-fill deposits, encompassing a variety of depositional environments such as fluvial channel, interfluve paleosol, bay head delta, estuary bay, restricted tidal flat, intertidal channel, and estuary mouth. Deposition in a brackish-water estuarine valley is supported by the presence of a low diversity, opportunistic, impoverished marine ichnofaunal assemblage dominated by infaunal structures, representing an example of a mixed, depauperate Cruziana and Skolithos ichnofacies. Overall distribution of ichnofossils along the estuarine valley was mainly controlled by the salinity gradient, with other parameters, such as oxygenation, substrate and energy, acting at a more local scale. The lower Morrow estuarine system displays the classical tripartite division of wave-dominated estuaries (i.e. seaward-marine sand plug, fine-grained central bay, and sandy landward zone), but tidal action is also recorded. The estuarine valley displays a northwest-southeast trend, draining to the open sea in the southeast. Recognition of valley-fill sandstones in the lower Morrow has implications for reservoir characterization. While the open marine model predicts a "layer-cake" style of facies distribution as a consequence of strandline shoreline progradation, identification of valley-fill sequences points to more compartmentalized reservoirs, due to the heterogeneity created by valley incision and subsequent infill. The open-marine facies assemblage comprises upper, middle, and lower shoreface; offshore transition; offshore; and shelf deposits. In contrast to the estuarine assemblage, open marine ichnofaunas are characterized by a high diversity of biogenic structures representing the activity of a benthic fauna developed under normal salinity conditions. Trace fossil and facies analyses allow environmental subdivision of the shoreface-offshore successions and suggest deposition in a weakly storm-affected nearshore area. An onshore-offshore replacement of the Skolithos ichnofacies by the Cruziana ichnofacies is clearly displayed. The lower Morrow fluvio-estuarine valley was incised during a drop of sea level coincident with the Mississippian-Pennsylvanian transition, but was mostly filled during a subsequent transgression. The transgressive nature of the estuarine infill is further indicated by the upward replacement of depauperate brackish-water trace fossil assemblages by the open-marine Cruziana ichnofacies. Additional stratal surfaces of allostratigraphic significance identified within the estuary include the bayline surface, the tidal ravinement surface, the wave ravinement surface, and a basinwide flooding surface recording inundation of the valley interfluves. A younger sequence boundary within the lower Morrow is also recorded in the Gentzler field at the base of a forced regression shoreface, demarcated by the firmground Glossifungites ichnofacies, indicating a rapid basinward facies migration during a sea-level drop. Trace fossil models derived from the analysis of Mesozoic and Cenozoic reservoirs are generally applicable to the study of these late Paleozoic reservoirs. Pennsylvanian brackish-water facies differ ichnologically from their post-Paleozoic counterparts, however, in that they have: (1) lower trace fossil diversity, (2) lower degree of bioturbation, (3) scarcity of crustacean burrows, (4) absence of firmground suites, and (5) absence of ichnotaxa displaying specific architectures designed to protect the tracemaker from salinity fluctuations. Morrow open-marine ichnofaunas closely resemble their post-Paleozoic equivalents. ?? 2002 Elsevier Science B.V. All rights reserved.

  3. Smoke dispersion around complex offshore structure

    SciTech Connect

    Moros, A.; Webb, S.; Fells, C. [BP International, Sunbury-on-Thames (United Kingdom); Bonn, R. [BP Exploration, Aberdeen (United Kingdom)

    1994-12-31

    Fires on offshore installations can produce large quantities of smoke. Although it is important to know the fire behavior and its effects on the structures it is equally important to know the smoke behavior in and around the platform. High levels of smoke can affect the safety of the personnel. This work describes a comparison of a Computational Fluid Dynamics (CFD) model with field experiments conducted on a North Sea Platform. The purpose of the work is to use CFD to assess the smoke behavior on offshore platforms. To validate the model for such studies, a series of experiments were performed during which small amounts ({approximately}0.5 kg/s) of synthetic smoke were released at given locations on the platform. The resulting plume concentration was measured at four points around the platform-n using optical densitometers. During the experiments the wind field at different locations around the platform was also measured. The results of this validation indicate that simulation tools can be used to predict global smoke movement and concentrations in complex offshore structures to within the required accuracies. On average, the predicted wind flow is to within a factor of 2 of the measured values and in some areas to within 50%. The predicted concentrations are to within a factor of two of the measured values except one point where the predictions were an order of magnitude less than the measurements.

  4. Stratigraphical and palynological appraisal of the Late Quaternary mangrove deposits of the west coast of India

    Microsoft Academic Search

    K. P. N. Kumaran; K. M. Nair; Mahesh Shindikar; Ruta B. Limaye; D. Padmalal

    2005-01-01

    The organic deposits derived from the mangrove swamps form reliable stratigraphic markers within the Late Quaternary sequence of Kerala–Konkan Basin. Three generations of such deposits have been identified. The older one is dated to around 43,000–40,000 14C yr B.P., with a few dates beyond the range of radiocarbon. The younger ones date from the Middle Holocene to latest Pleistocene (10,760–4540

  5. Stratigraphic occurrences of iridium anomalies at four Cretaceous\\/Tertiary boundary sites in New Zealand

    Microsoft Academic Search

    Robert R. Brooks; C. Percy Strong; Julian Lee; Charles J. Orth; James S. Gilmore; Douglas E. Ryan; Jiri Holzbecher

    1986-01-01

    Three new iridium anomaly sites have been discovered in Cretaceous\\/Tertiary boundary sequences in New Zealand. These are at Needles Point, Chancet Rocks, and Waipara, where integrated iridium deposition values were 165, 211, and 7 ng\\/cm2, respectively. In contrast to the previously reported Woodside Creek stratigraphic sequence that had an iridium anomaly of 187 ng\\/cm2, a ferruginous boundary clay is absent

  6. 26th Annual offshore technology conference: 1994 Proceedings

    SciTech Connect

    Not Available

    1994-01-01

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

  7. Structural and tectonic setting of the Charleston, South Carolina, region: Evidence from the Tertiary stratigraphic record

    USGS Publications Warehouse

    Weems, R.E.; Lewis, W.C.

    2002-01-01

    Eleven upper Eocene through Pliocene stratigraphic units occur in the subsurface of the region surrounding Charleston, South Carolina. These units contain a wealth of information concerning the long-term tectonic and structural setting of that area. These stratigraphic units have a mosaic pattern of distribution, rather than a simple layered pattern, because deposition, erosion, and tectonic warping have interacted in a complex manner through time. By generating separate structure-contour maps for the base of each stratigraphic unit, an estimate of the original basal surface of each unit can be reconstructed over wide areas. Changes in sea level over geologic time generate patterns of deposition and erosion that are geographically unique for the time of each transgression. Such patterns fail to persist when compared sequentially over time. In some areas, however, there has been persistent, repetitive net downward of upward movement over the past 34 m.y. These repetitive patterns of persistent motion are most readily attributable to tectonism. The spatial pattern of these high and low areas is complex, but it appears to correlate well with known tectonic features of the region. This correlation suggests that the tectonic setting of the Charleston region is controlled by scissors-like compression on a crustal block located between the north-trending Adams Run fault and the northwest-trending Charleston fault. Tectonism is localized in the Charleston region because it lies within a discrete hinge zone that accommodates structural movement between the Cape Fear arch and the Southeast Georgia embayment.

  8. Spheroidal carbonaceous particles are a defining stratigraphic marker for the Anthropocene.

    PubMed

    Swindles, Graeme T; Watson, Elizabeth; Turner, T Edward; Galloway, Jennifer M; Hadlari, Thomas; Wheeler, Jane; Bacon, Karen L

    2015-01-01

    There has been recent debate over stratigraphic markers used to demarcate the Anthropocene from the Holocene Epoch. However, many of the proposed markers are found only in limited areas of the world or do not reflect human impacts on the environment. Here we show that spheroidal carbonaceous particles (SCPs), a distinct form of black carbon produced from burning fossil fuels in energy production and heavy industry, provide unambiguous stratigraphic markers of the human activities that have rapidly changed planet Earth over the last century. SCPs are found in terrestrial and marine sediments or ice cores in every continent, including remote areas such as the high Arctic and Antarctica. The rapid increase in SCPs mostly occurs in the mid-twentieth century and is contemporaneous with the 'Great Acceleration'. It therefore reflects the intensification of fossil fuel usage and can be traced across the globe. We integrate global records of SCPs and propose that the global rapid increase in SCPs in sedimentary records can be used to inform a Global Standard Stratigraphic Age for the Anthropocene. A high-resolution SCP sequence from a lake or peatland may provide the much-needed 'Golden Spike' (Global Boundary Stratotype Section and Point). PMID:26020614

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

    USGS Publications Warehouse

    Shideler, G.L.

    1994-01-01

    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

  10. 78 FR 34568 - Special Local Regulation; Heritage Coast Offshore Grand Prix, Tawas Bay; East Tawas, MI

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-10

    ...Regulation; Heritage Coast Offshore Grand Prix, Tawas Bay; East Tawas, MI AGENCY...after the Heritage Coast Offshore Grand Prix boat race. This special local regulation...Regulation; Heritage Coast Offshore Grand Prix, East Tawas, MI. (a) Regulated...

  11. 46 CFR 11.468 - Officer endorsements for mobile offshore drilling units.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Officer endorsements for mobile offshore drilling units. 11.468 Section 11.468...Officer endorsements for mobile offshore drilling units. Officer endorsements for service on mobile offshore drilling units (MODUs) authorize...

  12. 46 CFR 2.10-130 - Fees for examination of foreign mobile offshore drilling units.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...for examination of foreign mobile offshore drilling units. 2.10-130 Section 2.10-130...for examination of foreign mobile offshore drilling units. Each foreign mobile offshore drilling unit must pay: (a) For...

  13. 46 CFR 2.10-130 - Fees for examination of foreign mobile offshore drilling units.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...for examination of foreign mobile offshore drilling units. 2.10-130 Section 2.10-130...for examination of foreign mobile offshore drilling units. Each foreign mobile offshore drilling unit must pay: (a) For...

  14. 46 CFR 11.468 - Officer endorsements for mobile offshore drilling units.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Officer endorsements for mobile offshore drilling units. 11.468 Section 11.468...Officer endorsements for mobile offshore drilling units. Officer endorsements for service on mobile offshore drilling units (MODUs) authorize...

  15. 46 CFR 11.468 - Officer endorsements for mobile offshore drilling units.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Officer endorsements for mobile offshore drilling units. 11.468 Section 11.468...Officer endorsements for mobile offshore drilling units. Officer endorsements for service on mobile offshore drilling units (MODUs) authorize...

  16. 46 CFR 2.10-130 - Fees for examination of foreign mobile offshore drilling units.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...for examination of foreign mobile offshore drilling units. 2.10-130 Section 2.10-130...for examination of foreign mobile offshore drilling units. Each foreign mobile offshore drilling unit must pay: (a) For...

  17. 46 CFR 2.10-130 - Fees for examination of foreign mobile offshore drilling units.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...for examination of foreign mobile offshore drilling units. 2.10-130 Section 2.10-130...for examination of foreign mobile offshore drilling units. Each foreign mobile offshore drilling unit must pay: (a) For...

  18. 46 CFR 11.468 - Officer endorsements for mobile offshore drilling units.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Officer endorsements for mobile offshore drilling units. 11.468 Section 11.468...Officer endorsements for mobile offshore drilling units. Officer endorsements for service on mobile offshore drilling units (MODUs) authorize...

  19. 46 CFR 2.10-130 - Fees for examination of foreign mobile offshore drilling units.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...for examination of foreign mobile offshore drilling units. 2.10-130 Section 2.10-130...for examination of foreign mobile offshore drilling units. Each foreign mobile offshore drilling unit must pay: (a) For...

  20. 75 FR 29397 - National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-26

    ...Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling By the authority...Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling (the ``Commission...and mitigating the impact of, oil spills associated with offshore...

  1. Mooring Line Modelling and Design Optimization of Floating Offshore Wind Turbines

    E-print Network

    Victoria, University of

    Mooring Line Modelling and Design Optimization of Floating Offshore Wind Turbines by Matthew Thomas Mooring Line Modelling and Design Optimization of Floating Offshore Wind Turbines by Matthew Thomas Jair. Curran Crawford, Supervisor (Department of Mechanical Engineering) ABSTRACT Floating offshore wind

  2. 75 FR 12560 - Certificate of Alternative Compliance for the Offshore Supply Vessel BUMBLE BEE

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-16

    ...maneuver within close proximity of offshore platforms. Due to the design of the...susceptible to damage from offshore platforms. Locating the sidelights 12...maneuvering within close proximity to offshore platforms. In addition the forward...

  3. 75 FR 20372 - Certificate of Alternative Compliance for the Offshore Supply Vessel RIG RUNNER

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-19

    ...89, has been issued for the offshore supply vessel RIG RUNNER, O...maneuver within close proximity of offshore platforms. The forward masthead light...working in close proximity to offshore platforms. Furthermore the...

  4. 75 FR 418 - Certificate of Alternative Compliance for the Offshore Supply Vessel KELLY ANN CANDIES

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-05

    ...INFORMATION: Background and Purpose The offshore supply vessel KELLY ANN CANDIES will be used for offshore supply operations. Full compliance...to maneuver within close proximity of offshore platforms and conduct helicopter...

  5. 75 FR 32802 - Certificate of Alternative Compliance for the Offshore Supply Vessel ROSS CANDIES

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-09

    ...part 81, has been issued for the offshore supply vessel ROSS CANDIES, O...maneuver within close proximity of offshore platforms. The horizontal distance between...part 81, has been issued for the offshore supply vessel ROSS CANDIES,...

  6. 75 FR 36106 - Certificate of Alternative Compliance for the Offshore Supply Vessel SOUTHERN CROSS

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-24

    ...maneuver within close proximity to offshore platforms. Placing the aft masthead...susceptible to damage from offshore platforms. Locating the side lights...maneuvering within close proximity to offshore platforms. The Certificate of...

  7. 75 FR 32803 - Certificate of Alternative Compliance for the Offshore Supply Vessel JONCADE

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-09

    ...89, has been issued for the offshore supply vessel JONCADE, O...maneuver within close proximity of offshore platforms. The forward masthead light...working in close proximity to offshore platforms. Furthermore the...

  8. 75 FR 39956 - Certificate of Alternative Compliance for the Offshore Supply Vessel MARIE ELISE

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-13

    ...maneuver within close proximity to offshore platforms. Placing the aft masthead...susceptible to damage from offshore platforms. Locating the side lights...maneuvering within close proximity to offshore platforms. The Certificate of...

  9. 75 FR 29569 - Certificate of Alternative Compliance for the Offshore Supply Vessel JANSON R. GRAHAM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-26

    ...89, has been issued for the offshore supply vessel JANSON R. GRAHAM...maneuver within close proximity of offshore platforms. The forward masthead light...working in close proximity to offshore platforms. Additionally, the...

  10. About offshore resource assessment with floating lidars with special respect to turbulence and extreme events

    NASA Astrophysics Data System (ADS)

    Gottschall, J.; Wolken-Möhlmann, G.; Lange, B.

    2014-12-01

    Offshore resource assessment with lidars on floating platforms is a flexible and particularly cost-effective alternative to the conventional meteorological mast solution, that is considered as onshore state-of-the-art transferred to offshore sites, and may enable better and more complete wind resource assessments for the growing offshore wind sector. Wind lidar technology, and remote sensing in general, has already been proven to be a very promising technology for resource assessment and power performance testing onshore. For offshore applications and on floating platforms in particular, the motions from the floating base have to be considered in addition, affecting the wind measurements significantly and causing systematic measurement errors. We have studied the motions and the corresponding influences on lidar measurements generated by different possible offshore platforms – vessels or buoys – both in detailed simulations as well as first validation experiments. In addition to this, we have developed motion compensation algorithms that allow to correct the affected measurements and retrieve the undisturbed wind data. The motions considered and studied comprise rotations as well as translations in all six degrees of freedom. For the evaluation of the motion-affected and corrected wind data in this paper, special attention is paid to the measurement of turbulence as well as extreme wind events. The research question to be answered is if a lidar device placed on a floating platform is capable of measuring more or less the same statistics of extreme wind events as a fixed lidar device. Quantities to be investigated are: the turbulence intensity as well as the statistics of maximum wind speed values within a 10-min period, but also wind speed increments on different time scales. At this, obviously two issues are to be discussed – the influence of the lidar measurement principle on the recording of extreme wind events, and the additional impact of the superimposed motions of the floating platform.

  11. The outsourcing and offshoring competitive landscape and its uncertainties

    E-print Network

    Sultan, Ziad R. (Ziad Raymond)

    2005-01-01

    The outsourcing and offshoring competitive landscape is rapidly and constantly evolving, presenting new challenges and opportunities for providers and customers alike. Outsourcing providers are pressured to increase the ...

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

    SciTech Connect

    Ibanez, E.; Heaney, M.

    2014-10-01

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

  13. Rock Mechanical Characterization of an Offshore Mudrock from Haltenbanken, Mid-Norway

    Microsoft Academic Search

    T. Kvilhaug; E. Roaldset

    1998-01-01

    Summary   Rock mechanical tests and subsequent investigations in scanning electron microscopy (SEM) have been carried out on samples\\u000a retrieved from the Late Cretaceous Springar Fm offshore Mid-Norway. Mineralogical and petrophysical analyses pertinent to\\u000a this study have been conducted according to standard methods. The Springar Fm has a clay content of 45–50%, with smectite\\u000a rich mixed-layer illite\\/smectite as the dominating clay

  14. Time, Order, and Stratigraphy: Exploring the Effects of Missing Time in the Identification of Ordered Patterns in the Stratigraphic Record

    NASA Astrophysics Data System (ADS)

    Oliver, D. L.; Brady, M. E.

    2014-12-01

    Detection of cyclical drivers of stratigraphic patterns aids in the reconstruction of paleoenvironments and the identification of potential hydrocarbon reservoirs. Statistical analysis of lithofacies stacking patterns is a common approach, and often focuses on the question of whether the observed patterns can be distinguished from those generated by random processes, which offers the potential of extrapolation into a predictive framework. The observed sedimentary record can be fragmented by a variety of issues, such as covered sections in outcrop, broken sections on cores, dolomitization, or recording errors from geophysical equipment. This missing data represents unobserved time in the record, and understanding how this missing time affects our observations can enhance our ability to reconstruct a basin's history. Synthetic stratigraphic sections of known history are generated by Dougal, a previously developed 1-D carbonate forward numeric model, and used to explore the effects of cover, or fragmentation of the record, in the analysis of observed stratigraphic sections. Each synthetic stratigraphic section is covered in increments of 5% of the total thickness, and examined under a variety of styles ranging from a singular thick to numerous thin intervals. Covered intervals are distributed as clustered or evenly spaced across the whole stratigraphic section. Results indicate a general decrease in the degree of observed order in the stratigraphic columns as the proportion of cover increases. Within each increment, the style with a singular thick covered interval demonstrated the lowest degree of order, and the stratigraphic sections with two evenly spaced and equally thick covered intervals demonstrated the highest order. These results show how the proportional quantity and distribution of missing data can affect the identification of ordered patterns in the rock record. This work can provide guidelines for the analysis of covered intervals in stratigraphic sections.

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

    Microsoft Academic Search

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

    2009-01-01

    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 -

  16. OFF-SHORE WIND AND GRID-CONNECTED PV: HIGH PENETRATION PEAK SHAVING FOR NEW YORK CITY

    E-print Network

    Perez, Richard R.

    OFF-SHORE WIND AND GRID-CONNECTED PV: HIGH PENETRATION PEAK SHAVING FOR NEW YORK CITY Richard Perez-shore wind and PV generation using the city of New York as a test case. While wind generation is not known to be complementary. A recent study [1] demonstrated this synergy for bulk power generation in New York State

  17. Articulated stable offshore platforms: With buoys attached via universal joints, ASOP`S configuration minimizes transmission of forces, moments to the platform hull

    SciTech Connect

    Grinius, V.G. [Offshore Model Basin, Escondido, CA (United States); Mooney, J.B. [Consultant, Arlington, VA (United States); Mills, T.R.J. [McDermott Engineering Houston, Inc., TX (United States)

    1996-04-01

    Articulated stable offshore platforms (ASOP) are a vessel concept that can provide a very stable floating platform at sea. The concept lends itself to two distinct types of offshore platforms: (1) a system that can produce, store, and offload oil (FPSO) and (2) a mobile system that can be self-propelled and provide a stable platform for uses such as a floating production system (FPS) and/or any other commercial or military need that requires a very stable deck. An ASOP concept was originally developed in the early 1970s by Offshore Model Basin (OMB), then known as Offshore Technology Corp. Patents were granted in 1974 and 1975. A design for an oil storage and a self-propelled, highly mobile, exploratory drilling rig was among several of the concepts. There was extensive model testing performed on these designs, and the results were very favorable inasmuch as they showed an improvement when compared to similar use platforms.

  18. Towards Sustainable Offshore Outsourcing: An Empirical Study on Canadian Manufacturing Small and Medium Size

    E-print Network

    Towards Sustainable Offshore Outsourcing: An Empirical Study on Canadian Manufacturing Small Manufacturing small and medium size enterprises (SMEs) are increasingly jumping onto the offshore outsourcing

  19. First comparison of LES of an offshore wind turbine wake with dual-Doppler lidar measurements in a German offshore wind farm

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

    Large-Eddy Simulations (LES) are more and more used for simulating wind turbine wakes as they resolve the atmospheric as well as the wake turbulence. Considering the expenses and sparsity of offshore measurements, LES can provide valuable insights into the flow field in offshore wind farms. However, for an application of LES wind fields to assess offshore wind farm flow, a proper validation with measured data is necessary. Such a proper validation requires that the LES can closely reproduce the atmospheric conditions during the measurement. For this purpose, a representation of the large-scale features that drive the wind flow is required. Large-scale-forcing and nudging of the LES model PALM is tested with reanalysis data of the COSMO-DE model for a case study during one particular day in the beginning of 2014 at a German offshore wind farm. As wind and temperature profiles of the LES prove to follow the large-scale features closely, the wake of a single wind turbine is simulated with an advanced version of an actuator disc model. Measurement data is provided by processed dual-Doppler lidar measurements during the same day in the same wind farm. Several methods have been investigated at the University of Oldenburg to compare LES wind fields and lidar measurements. In this study a dual-Doppler algorithm was applied in order to estimate the horizontal stationary wind field. The raw data originate from Plan Position Indicator (PPI) measurements, which have been performed with two long-range wind lidars installed at different opposing platforms at the border of the wind farm.

  20. 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)

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

    2013-04-01

    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.

  1. 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)

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

    2013-05-01

    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.

  2. Optimizing safety by inherent offshore platform design

    SciTech Connect

    Mansfield, D.P. [AEA Technology, Risley (United Kingdom); Kletz, T.A. [Kletz (T.A.), Cheadle (United Kingdom); Al-Hassan, T. [HSE Offshore Safety Div., Bootle (United Kingdom)

    1996-12-31

    Following the Cullen Report into the Piper Alpha Disaster, UK Operators and the Health and Safety Executive Offshore Safety Division (OSD) have been working together to bring in a new safety regime, progressively replacing prescriptive requirements with goal setting regulations to enable a more integrated approach to hazard management. This is allowing the industry to be more flexible and specific about the way it manages hazards throughout the life of the installation. In particular it is encouraging a hazards based focus to design which is changing the way installations are designed and which would promote the use of inherently safer design. Conventional installation design often relies on standard specification engineered safety systems such as shutdown systems and water deluge to control hazards, with less attention paid to minimizing the hazards at source. These add-on safety systems can be expensive to install and maintain, and may only be effective in some circumstances. This paper reports on a pilot study sponsored by OSD, involving offshore operators and design contractors, to assess the status of inherent safety in offshore installation design in the UK and to encourage its further use spreading best practice and examples of the benefits of the approach. The paper outlines the key considerations for implementation of inherently safer design, and describes some of the benefits these can bring to the industry. It also highlights the role regulations, industry initiatives and guidance can play in promoting inherently safer design both now and in the future. The study`s findings suggest that awareness of the inherent safety principles is limited to some safety specialists and designers, but that the industry is beginning to recognize the role and benefits of inherent safety. As a result its principles are starting to appear in some design procedures and hazard management guides.

  3. Visual Simulation of Offshore Liquefied Natural Gas (LNG) Terminals

    E-print Network

    Standiford, Richard B.

    Visual Simulation of Offshore Liquefied Natural Gas (LNG) Terminals in a Decision-Making Context1, Berkeley. 3/ Liquified Natural Gas Act Stats, 1977, Chap. 855, Page 2506 (effective Sept. 17, 1977 potential offshore Liquified Natural Gas (LNG) sites and the types of terminals that might occupy those

  4. Quantifying Offshore Wind Resources from Satellite Wind Maps

    E-print Network

    Pryor, Sara C.

    through footprint area averaging per image. Secondly, these data are averaged in time to provide a local of the Horns Rev wind farm is quantified from satellite SAR images and compared with state-of-the-art wake; offshore wake #12;It is highly innovative to estimate the offshore wind resource based on satellite images

  5. Offshore spawning by the portunid crab Scylla serrata (Crustacea: Decapoda)

    Microsoft Academic Search

    B. J. Hill

    1994-01-01

    The portunid crabScylla serrata (Forskål) is shown to migrate offshore to spawn. Records of 447S. serrata caught as bycatch by trawlers in the tropical waters of northern Australia were analysed with respect to area, depth, distance offshore and month of capture as well as the sex and size of the crabs and whether the females were ovigerous. The crabs were

  6. Ris National Laboratory Satellite SAR applied in offshore wind

    E-print Network

    Risø National Laboratory Satellite SAR applied in offshore wind ressource mapping: possibilities is to quantify the regional offshore wind climate for wind energy application based on satellite SAR ·Study of 85 ERS-2 SAR scenes ·Using CMOD4 (Stoffelen and Anderson, 1997) Wind from SAR #12;Study site: Horns Rev

  7. OPTIMAL DEVELOPMENT PLANNING OF OFFSHORE OIL AND GAS FIELD

    E-print Network

    Grossmann, Ignacio E.

    , well drilling schedule and production profiles of oil, water and gas in each time period. The model canOPTIMAL DEVELOPMENT PLANNING OF OFFSHORE OIL AND GAS FIELD INFRASTRUCTURE UNDER COMPLEX FISCAL Pittsburgh, PA 15213 Abstract The optimal development planning of offshore oil and gas fields has received

  8. Anchoring systems for marine renewable energies offshore platforms

    Microsoft Academic Search

    R. Rodriguez; I. Gorrochategui; C. Vidal; R. Guanche; J. Canizal; J. A. Fraguela; V. Diaz

    2011-01-01

    At present no specific methodologies have been developed for the design of the anchoring systems of offshore moored platforms, individual and in farm configuration, for obtaining renewable energy. This paper presents a R&D project whose objective is to cover this lack of knowledge. The scope of the project involves several areas of scientific expertise such as Soil Mechanics, Hydrodynamics, Offshore

  9. Riser and wellhead monitoring for improved offshore drilling operations

    E-print Network

    Nørvåg, Kjetil

    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 Page 2 #12;The KONGSBERG Riser Management Systems (RMS) Integrity of drilling riser based on monitoring

  10. Dresser-Rand Offshore Baseplate Project Project Summary

    E-print Network

    Demirel, Melik C.

    the cost. The project focused on reevaluating the baseplate design using modern analysis toolsDresser-Rand Offshore Baseplate Project Project Summary Baseplates are utilized in offshore, with recent rises in material and manufacturing costs, there is a desire to minimize the excess and reduce

  11. EGG LOSS DURING INCUBATION FROM OFFSHORE NORTHERN LOBSTERS (DECAPODA: HOMARIDAE)

    E-print Network

    EGG LOSS DURING INCUBATION FROM OFFSHORE NORTHERN LOBSTERS (DECAPODA: HOMARIDAE) HERBERT C. PERKINS' ABSTRACT Egg loss during incubation from offshore northern lobsters, Homaru8 americanus Milne Edwards, was estimated by counting the eggs of 196 females. The lobsters were captured along the continental shelf off

  12. Offshore Heavy Oil in Campos Basin: The Petrobras Experience

    Microsoft Academic Search

    A. C. Capeleiro Pinto; C. C. M. Branco; J. S. de Matos; P. M. Vieira; S. da Silva Guedes; C. Pedroso Jr; A. C. Decnop Coelho; M. M. Ceciliano

    2003-01-01

    This paper was selected for presentation by an OTC Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper, as presented, have not been reviewed by the Offshore Technology Conference and are subject to correction by the author(s). The material, as presented, does not necessarily reflect any position of the Offshore Technology

  13. A critique of offshore liquefied natural gas (LNG) terminal policy

    Microsoft Academic Search

    William D. Whitmore; Vern K. Baxter; Shirley L. Laska

    2009-01-01

    The Maritime Transportation Security Act of 2002 amended the Deepwater Port Act of 1974 to permit the construction of offshore liquefied natural gas (LNG) terminals. Terminals with environmentally destructive open-loop regasification systems were quickly approved in the Gulf of Mexico. This study analyzed the political methods of the George W. Bush administration to determine how it developed offshore LNG. Findings

  14. DISCIPLINER LES CENTRES FINANCIERS OFFSHORE : INCITATION PAR LA PRESSION INTERNATIONALE

    Microsoft Academic Search

    Arnaud BOURGAIN; Patrice PIERETTI

    2007-01-01

    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

  15. Oil rigs and offshore sport fishing in Louisiana

    Microsoft Academic Search

    R. Dugas; V. Guillory; M. Fischer

    2009-01-01

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

  16. Oil rigs and offshore sport fishing in Louisiana

    Microsoft Academic Search

    R. Dugas; V. Guillory; M. Fischer

    1979-01-01

    The environmental effects of Louisiana's offshore oil platforms are discussed with regard to an increase in sport-fishing. The effects upon fish populations, species diversity, underwater habitats, and food chains from the offshore platforms are obtained from several summaries of studies undertaken between 1970-1979. (DS)

  17. Wave Models for Offshore Wind Turbines Puneet Agarwal

    E-print Network

    Manuel, Lance

    Wave Models for Offshore Wind Turbines Puneet Agarwal§ and Lance Manuely Department of Civil practice for modeling waves on offshore wind turbines is limited to the representation of linear irregular for the turbine and for the input wind/wave conditions. While for the wind, inflow turbu- lence models are fairly

  18. RELIABILITY COMPARISON MODELS FOR OFFSHORE WIND TURBINES (OWT)

    E-print Network

    Bernstein, Joseph B.

    RELIABILITY COMPARISON MODELS FOR OFFSHORE WIND TURBINES (OWT) Yizhou Lu, T. M. Delorm, A. Christou of survivor functions R(t) of drive-trains, after 1 year of operation, between Offshore Wind Turbine (OWT) vs (Types1-4a) - horizontal axis turbines (3-6 MW) were selected for reliability modelling & technology

  19. Foundation modelling to assess dynamic behaviour of offshore wind turbines

    Microsoft Academic Search

    M. B. Zaaijer

    2006-01-01

    The dynamic behaviour of wind turbines at offshore locations is more complex than that of both onshore wind turbines and offshore platforms used in the oil and gas industry. In order to reduce the computational burden, the work presented in this paper aims at simplification of the dynamic model of the foundation, while maintaining sufficient accuracy. A stiffness matrix at

  20. The Future of Offshore Wind Power is Built Onshore

    Microsoft Academic Search

    Esa Holttinen; Jarmo Huttunen; Ilari Silvola; Aleksi Lumijärvi

    Summary: The investment costs for the offshore wind farms are 30 to 100 % higher than onshore. High installation costs, weather constraints and environmental issues all add uncertainty to the viability of investments. Several new innova- tive installation methods have been suggested. Hollming Mechanical Engineering Division has a long tradition as a supplier for the offshore and shipbuilding industries. In

  1. The concept of self-maintained offshore wind turbines

    Microsoft Academic Search

    E. Echavarria; T. Tomiyama; G. J. W. van Bussel

    Summary The objective of on-going research on the concept of self-maintained offshore wind turbines is to develop a design methodology to increase the availability for offshore wind farms, by means of an intelligent maintenance system capable of responding to faults by reconfiguring the system or subsystems, without increasing service visits, economics, or complexity. The design methodology explained in the paper

  2. Maintenance strategies for deep-sea offshore wind turbines

    Microsoft Academic Search

    Ingrid Bouwer Utne

    2010-01-01

    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

  3. Taming Hurricanes With Arrays of Offshore Wind Turbines

    E-print Network

    Firestone, Jeremy

    Taming Hurricanes With Arrays of Offshore Wind Turbines Mark Z. Jacobson Cristina Archer, Willet #12;Representation of a vertically-resolved wind turbine in model Lines are model layers) or 50 m/s (destruction) speed. Can Walls of Offshore Wind Turbines Dissipate Hurricanes? #12;Katrina

  4. Design of support structures for offshore wind turbines

    Microsoft Academic Search

    J. van der Tempel

    2006-01-01

    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

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

    SciTech Connect

    Elliott, D.; Schwartz, M.

    2006-06-01

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

  6. Structural monitoring of offshore platforms using impulse and relaxation response

    Microsoft Academic Search

    Lalu Mangal; V. G Idichandy; C Ganapathy

    2001-01-01

    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

  7. Determination of human error probabilities for offshore platform musters

    Microsoft Academic Search

    Dino G. DiMattia; Faisal I. Khan; Paul R. Amyotte

    2005-01-01

    The focus of this work is on prediction of human error probabilities during the process of emergency musters on offshore oil and gas production platforms. Due to a lack of human error databases, and in particular human error data for offshore platform musters, an expert judgment technique, the Success Likelihood Index Methodology (SLIM), was adopted as a vehicle to predict

  8. Cathodic protection retrofit of an offshore pipeline

    SciTech Connect

    Winters, R.H.; Holk, A.C. [Tenneco Energy, Houston, TX (United States)

    1997-09-01

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

  9. Petroleum geology of the Norphlet formation (Upper Jurassic), S. W. and offshore Alabama

    SciTech Connect

    Mancini, E.A.; Mink, R.M.; Bearden, B.L.

    1984-07-16

    Recent successful gas test in the Norphlet formation (up to 26 million CF/day) at depths exceeding 20,500 ft in the Mobile Bay area demonstrate a high potential for hydrocarbon production in the Alabama offshore area. In addition, wells drilled in the upper Mobile Bay area could encounter gas condensate in the Norphlet formation; gas condensate is being produced from wells in Hatter's Pond field about 14 miles north of Mobile Bay and 45 miles north of the Lower Mobile Bay-Mary Ann field. With continued petroleum exploration, additional Norphlet petroleum fields should be discovered in southwestern and offshore Alabama in the years ahead. In light of the recent discoveries in Escambia County and in the lower Mobile Bay area, Mobile, Baldwin, and Escambia counties and Mobile Bay appear to be the most prospective hydrocarbon areas.

  10. 46 CFR 130.480 - Test procedure and operations manual.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS VESSEL CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.480 Test procedure and operations manual. (a) A procedure for tests...

  11. 46 CFR 130.480 - Test procedure and operations manual.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS VESSEL CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.480 Test procedure and operations manual. (a) A procedure for tests...

  12. 46 CFR 130.480 - Test procedure and operations manual.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS VESSEL CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.480 Test procedure and operations manual. (a) A procedure for tests...

  13. 46 CFR 130.480 - Test procedure and operations manual.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS VESSEL CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.480 Test procedure and operations manual. (a) A procedure for tests...

  14. 46 CFR 130.480 - Test procedure and operations manual.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS VESSEL CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.480 Test procedure and operations manual. (a) A procedure for tests...

  15. The potential role of offshore standby/rescue ships

    SciTech Connect

    McDonald, H.G.

    1985-01-01

    The loss of the drilling rig ''Sea Gem'' in 1966, in which thirteen people died, was perhaps the first occasion when a major accident connected with offshore explorations and production in the UK Sector of the North Sea resulted in multiple deaths. Since then, loss of life among offshore workers, either through major accidents or individuals falling overboard, has continued to occur throughout the various operational areas worldwide. One method of increasing the survival chances of maritime casualties associated with offshore installations is to ensure that a designated rescue vessel is always available to attempt a rescue. At present in the UK, Regulation 10 of the Offshore Installations (Emergency Producures) Regulations 1976, lays down that a standby vessel should be present within five miles of every manned offshore installation, ready to give assistance in an emergency, able to accommodate the entire crew of the installation, and provide aid for them all.

  16. Management of offshore wastes in the United States.

    SciTech Connect

    Veil, J. A.

    1998-10-22

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

  17. Depositional environments and source rock investigations of the Oligocene to Middle Miocene deposits in the Ardjuna Basin, offshore Northwest Java, Indonesia

    SciTech Connect

    Wu Chiahsin Charlie.

    1991-01-01

    Investigations of depositional environments, paleogeographic evolution, source rock potential/maturity, and petroleum generation, expulsion, migration and accumulation were performed on the Oligocene to Middle Miocene deposits in the Ardjuna Basin, offshore Northwest Java, using integrated geologic, seismic and geochemical approaches. The Oligocene to Middle Miocene sediments were deposited in a generally transgressive sequence. It is the most prospective stratigraphic unit for petroleum exploration in the Ardjuna Basin. The rocks comprise three Formations: Talang Akar, Baturaja and Cibulakan. Paleogeography of six stages within the study interval, showing the degree of marine transgression were mapped based on integrated biostratigraphic, paleoenvironmental, and seismic-stratigraphic data. The coals and carbonaceous shales deposited in the deltaic and nearshore environment of the Talang Akar Formation are petroleum source rocks for the waxy oils produced in the Ardjuna Basin. The organic matter contains predominantly vitrinite maceral and up to 30% exinite maceral. Source rock temperature, after calibration with vitrinite reflectance, provides an accurate quantitative measurement for predicting the level of thermal maturation. Two geochemical approaches were used and compared in petroleum resource assessment: petroleum yield (S1) method and genetic potential (S2) method. The oil generative kitchen, the Ardjuna depocenter, has the best opportunity for new oil discovery. This model has since been proved by subsequent drilling leading to several oil discoveries in the last two years.

  18. Stratigraphic hierarchy and cycle stacking, facies distribution, and Interwell-Scale heterogeneity: Grayburg Formation, New Mexico

    SciTech Connect

    Barnaby, R.J.; Ward, W. B. [Univ. of Texas, Austin, TX (United States)

    1996-12-31

    The Grayburg Formation (middle Guadaluplan) of southeastern New Mexico is a mixed carbonate-siliciclastic succession that represents predominantly shallow water sedimentation on the Northwest Shelf of the Delaware Basin. Exceptional Grayburg outcrops in the Brokeoff Mountains permit high-resolution correlation and mapping of interwell-scale facies complexity both along depositional dip and across strike. Three orders of stratigraphic hierarchy are recognized using vertical facies successions and transgressive-regressive relationships expressed along a dip cross section. This stratigraphic organization cannot be fully defined from a vertical section. Cycles (3-30 ft thick) are the smallest-scale, upward-shoaling facies successions that can be correlated across facies tracts and constitute the basic chronostratigraphic unit. Cycles are organized into transgressive-regressive cycle sets (15-40 ft thick). High-frequency sequences (100-160 ft thick) are unconformity-bound successions composed of 10 to 20 cycles arranged into transgressive and highstand systems tracts. One-dimensional cycle thickness stacking patterns do not reflect the long-term accommodation trends imposed by high-frequency sequences because most cycles did not fully aggrade to sea level. Interwell-scale heterogeneity (hundreds of ft) is high in transgressive ooid grainstones, which formed dip-elongate tidal channels and shoals. Highstand ooid grainstones formed strike-elongate shoals that are laterally continuous along dip and across strike (thousands of feet) due to stacking and amalgamation of grainstone bodies in an accommodation-limited highstand setting. The well-defined relationship between stratigraphic hierarchy and facies composition and heterogeneity can be used to improve correlations and better predict lateral dimensions of reservoir facies.

  19. Stratigraphic hierarchy and cycle stacking, facies distribution, and Interwell-Scale heterogeneity: Grayburg Formation, New Mexico

    SciTech Connect

    Barnaby, R.J.; Ward, W. B. (Univ. of Texas, Austin, TX (United States))

    1996-01-01

    The Grayburg Formation (middle Guadaluplan) of southeastern New Mexico is a mixed carbonate-siliciclastic succession that represents predominantly shallow water sedimentation on the Northwest Shelf of the Delaware Basin. Exceptional Grayburg outcrops in the Brokeoff Mountains permit high-resolution correlation and mapping of interwell-scale facies complexity both along depositional dip and across strike. Three orders of stratigraphic hierarchy are recognized using vertical facies successions and transgressive-regressive relationships expressed along a dip cross section. This stratigraphic organization cannot be fully defined from a vertical section. Cycles (3-30 ft thick) are the smallest-scale, upward-shoaling facies successions that can be correlated across facies tracts and constitute the basic chronostratigraphic unit. Cycles are organized into transgressive-regressive cycle sets (15-40 ft thick). High-frequency sequences (100-160 ft thick) are unconformity-bound successions composed of 10 to 20 cycles arranged into transgressive and highstand systems tracts. One-dimensional cycle thickness stacking patterns do not reflect the long-term accommodation trends imposed by high-frequency sequences because most cycles did not fully aggrade to sea level. Interwell-scale heterogeneity (hundreds of ft) is high in transgressive ooid grainstones, which formed dip-elongate tidal channels and shoals. Highstand ooid grainstones formed strike-elongate shoals that are laterally continuous along dip and across strike (thousands of feet) due to stacking and amalgamation of grainstone bodies in an accommodation-limited highstand setting. The well-defined relationship between stratigraphic hierarchy and facies composition and heterogeneity can be used to improve correlations and better predict lateral dimensions of reservoir facies.

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

    SciTech Connect

    Chakrabarti, S.K. [ed.] [Chicago Bridge and Iron Technical Services Co., Plainfield, IL (United States); Pontes, M.T. [ed.] [Inst. Nacional de Engenharia e Tecnologia Industrial, Lisbon (Portugal); Maeda, Hisaaki [ed.] [Univ. of Tokyo (Japan); Falzarano, J. [ed.] [Univ. of New Orleans, LA (United States); Schofield, P. [ed.] [W.S. Atkins, Surrey (United Kingdom); Morrison, D. [ed.] [Shell E and P Technology Co., Houston, TX (United States)

    1996-12-31

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

  1. Copyright 2000, Offshore Technology Conference This paper was prepared for presentation at the 2000 Offshore Technology Conference held in

    E-print Network

    Griffiths, Gwyn

    Offshore Technology Conference held in Houston, Texas, 1Ð4 May 2000. This paper was selected that flexibility was fundamental to the technology design. Hence for Autosub-1 there was no fixed sensor suiteCopyright 2000, Offshore Technology Conference This paper was prepared for presentation at the 2000

  2. A study of cyclic pressuremeter testing for offshore applications 

    E-print Network

    Riner, Kenneth Byard

    1984-01-01

    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... Influencing the Degradation Parameter Backbone Pressuremeter Curves Cyclic Shear Modulus Prediction Model Recommendations 47 47 48 60 65 71 77 81 vii TABLE OF CONTENTS (Continued) Page CHAPTER VII. POTENTIAL APPLICATIONS Application of Cyclic...

  3. Stratigraphic framework of Lower and Upper Cretaceous rocks in central and eastern Montana

    USGS Publications Warehouse

    Condon, Steven M.

    2000-01-01

    This study shows the lithology, thickness, distribution, and correlation of Lower and Upper Cretaceous rocks in central and eastern Montana. The described stratigraphic units range from the Aptian Kootenai Formation (oldest) to the Maastrichtian Hell Creek Formation (youngest). An included text report describes the units, and most formations or members are also represented by isopach maps. Structure contour maps of three horizons are also included. Correlations across the study area are shown on a series of cross sections. All text and illustrations are included as Adobe PDF files.

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

    USGS Publications Warehouse

    Dietrich, John D.; Johnson, Ronald C.

    2013-01-01

    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.

  5. Centrifuge modelling of fold—thrust structures in a tripartite stratigraphic succession

    NASA Astrophysics Data System (ADS)

    Dixon, John M.; Tirrul, Rein

    Analog models measuring 127 × 76 mm in plan were deformed at 2500-4000 g in a centrifuge. Scaled stratigraphic sequences were constructed of anisotropic multilayers with individual layers of Plasticine and silicone putty as thin as 40 ?m. The plasticine—silicone putty multilayers are analogs for interbedded competent carbonates and clastics, and incompetent pelites, given the model ratios of acceleration, 2500 g; length, 5 × 10 -6; specific gravity, 0.6; time 10 -10. Modelling of fold—thrust tectonics emphasizes the influence of stratigraphic succession on structural evolution. The models are constructed with a tripartite stratigraphic succession comprising basal and upper, well-laminated and incompetent units, and a middle, somewhat more isotropic and competent unit. The models deform by three mechanisms: layer-parallel shortening, folding and thrust faulting. They reproduce a number of fold—thrust relationships that have been observed in nature. Folds are typically periclinal, in en échelon arrays. Folds and thrusts are arcuate in plan, reflecting differential shortening. Fold attitudes grade from upright at high levels to overturned at deeper levels within a structural panel, reflecting drag against the basal décollement; fold axial surfaces and thrust faults are listric. While competent units may be offset by localized displacement on thrust faults, the discrete faults may die out both upwards and downwards into regions of ductile strain in less-competent units. Thrust faults appear to follow staircase trajectories through the strata, transecting incompetent units at shallow angles to bedding and competent units at steeper angles. However, the apparent staircase pattern results from propagation of a fault along a relatively straight trajectory through previously-folded strata. Foreland-verging thrusts are more common than back thrusts; the latter have steeper dips. The models suggest a mechanism of thrust-ramp nucleation following detachment folding: long-wavelength buckling of a competent unit can initiate localized strain (folding and layer-parallel shear) in an underlying incompetent unit, beneath the anticlines of the competent unit; thrust faults propagate up-section from these high-strain zones through the foreland-dipping limbs of buckle-folds in the competent unit. This mechanism may explain the commonly-observed spatial periodicity of thrust ramps. The model results bear similarities to natural fold—thrust belts in which the stratigraphic succession consists of three mechanical units, for example, the Asiak Foreland and Bear Creek Hills fold—thrust belts of the Slave Province, Northwest Territories, Canada.

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

    USGS Publications Warehouse

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

    1987-01-01

    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.

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

    PubMed

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

    2010-07-01

    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

  8. Gladden Pull-Apart Basin, offshore Belize

    SciTech Connect

    Morrice, S. (BNR Ltd., Denver, CO (United States))

    1993-02-01

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

  9. Stratigraphic sections showing coal correlations within the lower coal zone of the Paleocene Fort Union Formation, Fillmore Ranch and Seaverson Reservoir quadrangles, Carbon County, Wyoming

    SciTech Connect

    Honey, J.G.; Hettinger, R.D.

    1989-01-01

    Stratigraphic sections showing coal correlations within the lower coal zone of the Paleocene Fort Union Formation, Fillmore Ranch and Seaverson Reservoir quadrangles, Carbon County, Wyoming are presented.

  10. STATE-OF-THE-ART DESIGN STANDARD SPECIFIC DEVELOPED AND APPLICABLE FOR OFFSHORE WINDTURBINE STRUCTURES

    Microsoft Academic Search

    Tove Feld

    The wind energy industry requires cost-effective design for offshore wind turbine structures in order to make the projects economically viable. The newly issued DNV standard for Design of Offshore Wind Turbine Structures fills a gap within the offshore industry being specific developed and applicable for offshore wind turbine structures. It is based on DNVs experience from participation in more than

  11. Optimal Control of Offshore Indoor Climate Zhenyu Yang and Andrea Valente

    E-print Network

    Yang, Zhenyu

    indoor climate control is very critical to manned offshore platforms in terms of onboard staffs' comfort-and-gas offshore platform by employing some advanced control technique - Model Predictive Control (MPC). The Single for offshore platforms [2]. Even offshore HVAC standards are recent, like the ISO 15138 (2000) and Danish

  12. Experiments on an offshore platform model by FBG sensors

    NASA Astrophysics Data System (ADS)

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

    2004-07-01

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

  13. Single and dual lift analyses of offshore structures

    SciTech Connect

    Sekita, K.; Kimura, H.

    1984-02-01

    At offshore job sites today, decks are lifted onto jacket structures in relatively large, heavy sections. Since lifting operations are greatly affected by the motions of the derrick barge or the crane ship, it is necessary to evaluate the sling system in consideration of vessel motions in order to regulate lifting operations at the job site. This paper proposes a static analysis method for designing sling systems and describes the application of this method to dual-lift operations carried out by two derrick crane barges in Southeast Asian waters. This paper also presents the methods of analyzing the motions of a hoisted load caused by wave-induced vessel motions and resulting dynamic sling tensions in single- and dual-lift operations. Single-lift, unified analysis -- a method that considers the interaction between the barge and the hoisted load -- is discussed, and calculated results are compared with 1/75-scale model test results to clarify the conditions necessary for unified analysis. Finally, the results of transient motion analysis for a barge crawling while lifting a load are compared with model test results.

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

    PubMed

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

    2013-12-01

    The U.S. Department of Energy has estimated that over 50 GW of offshore wind power will be required for the United States to generate 20% of its electricity from wind. Developers are actively planning offshore wind farms along the U.S. Atlantic and Gulf coasts and several leases have been signed for offshore sites. These planned projects are in areas that are sometimes struck by hurricanes. We present a method to estimate the catastrophe risk to offshore wind power using simulated hurricanes. Using this method, we estimate the fraction of offshore wind power simultaneously offline and the cumulative damage in a region. In Texas, the most vulnerable region we studied, 10% of offshore wind power could be offline simultaneously because of hurricane damage with a 100-year return period and 6% could be destroyed in any 10-year period. We also estimate the risks to single wind farms in four representative locations; we find the risks are significant but lower than those estimated in previously published results. Much of the hurricane risk to offshore wind turbines can be mitigated by designing turbines for higher maximum wind speeds, ensuring that turbine nacelles can turn quickly to track the wind direction even when grid power is lost, and building in areas with lower risk. PMID:23763387

  15. Spheroidal carbonaceous fly ash particles provide a globally synchronous stratigraphic marker for the Anthropocene.

    PubMed

    Rose, Neil L

    2015-04-01

    Human impacts on Earth are now so great that they have led to the concept of a new geological epoch defined by this global human influence: the Anthropocene. While not universally accepted, the term is increasingly popular and widely used. However, even among proponents, there is considerable debate regarding when the epoch may have started, from coeval with the Holocene, through the Industrial Revolution, to the mid-20th century when unprecedented human activities resulted in exponential increases in population, resource consumption, and pollutant emission. Recently, this latter period, known as the Great Acceleration, appears to be becoming the more widely accepted start date. To define any start point, a global stratigraphic marker or Global Boundary Stratotype Section and Point (GSSP) is typically required. Here, spheroidal carbonaceous fly ash particles (SCPs), byproducts of industrial fossil-fuel combustion, are proposed as a primary marker for a GSSP at the time of the Great Acceleration. Data from over 75 lake sediment records show a global, synchronous, and dramatic increase in particle accumulation starting in c. 1950 driven by the increased demand for electricity and the introduction of fuel-oil combustion, in addition to coal, as a means to produce it. SCPs are morphologically distinct and solely anthropogenic in origin, providing an unambiguous marker. This is a clear signal of great stratigraphic utility representing a primary driving force for global anthropogenic change. PMID:25790111

  16. North African petroleum geology: regional structure and stratigraphic overview of a hydrocarbon-rich cratonic area

    SciTech Connect

    O'Connor, T.E.; Kanes, W.H.

    1985-02-01

    North Africa, including Sinai, contains some of the most important hydrocarbon-producing basins in the world. The North African Symposium is devoted to examining the exploration potential of the North African margin in light of the most recent and promising exploration discoveries. The geologic variety of the region is extraordinary and can challenge any exploration philosophy. Of primary interest are the Sirte basin of Libya, which has produced several billion barrels of oil, and the Gulf of Suez, a narrow, evaporite-capped trough with five fields that will produce more than 5 billion bbl. Both are extensional basins with minimal lateral movement and with good source rocks in direct proximity to reservoirs. Structural models of these basins give firm leads for future exploration. More difficult to evaluate are the Tethyan realm basins of the northern Sinai, and the Western Desert of Egypt, the Cyrenaican Platform of Libya, and the Tunisia-Sicily shelf area, where there are only limited subsurface data. These basins are extensional in origin also, but have been influenced by lateral tectonics. Favorable reservoirs exist, but source rocks have been a problem locally. Structural models with strong stratigraphic response offer several favorable play concepts. The Paleozoic Ghadames basin in Libya, Tunisia, and Algeria has the least complex structural history, and production appears to be limited to small structures. A series of stratigraphic models indicates additional areas with exploration potential. The Paleozoic megabasin of Morocco, with its downfaulted Triassic grabens, remains an untested but attractive area.

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    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.

  18. Eustatic control on synchronous stratigraphic development: cretaceous and eocene coastal basins along an active margin

    NASA Astrophysics Data System (ADS)

    May, Jeffrey A.; Yeo, Ross K.; Warme, John E.

    1984-07-01

    Field studies document an apparent eustatic control on facies patterns along a tectonically active margin. In the San Diego Embayment and northern Baja California, progradational-retrogradational shoreline sequences characterize Late Cretaceous and Eocene forearc stratigraphy. Extensive benthonic foraminifera and nannoplankton data provide control on the age and distribution of facies changes along these depositionally compact, bathymetrically steep-gradient margins. The complete stratigraphic package is arranged into three scales and patterns of depositional sequences. Timing and geometry of the two largest sequences provide relative sea-level curves that correlate exceptionally well with worldwide sea-level curves. The major depositional cycle is asymmetric, hundreds of meters thick, characterized by a thin basal retrogradational sequence overlain by a thick progradational sequence; each cycle correlates to a coastal-onlap "supercycle". Smaller scale stratigraphic rhythms, controlled by global "cycles" and "paracycles", compose depositional cycles. Local depostional pulses overprint these two larger order sequences of sedimentation. Coeval cycles and depositional rhythms in isolated coastal basins from Oregon to Baja California further indicate a primary eustatic control on sedimentation. Field-based facies analysis thus supports the use of the "Vail curve" or other coastal-onlap and global sea-level curves as a predictive tool in basin analysis.

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

    SciTech Connect

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

    1996-12-31

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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.