共查询到20条相似文献，搜索用时 15 毫秒
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A large-scale enigmatic mound structure (M1) has been discovered in middle Miocene strata of the Norwegian–Danish Basin, c. 10 km east and updip of the Central Graben. It is located about 1 km beneath the seabed and clearly resolved by a 3D seismic data set focused on the deeper, remobilised, sand-filled Siri Canyon. M1 comprises two culminations, up to 80 m high and up to 1400 m long, constituting a sediment volume of some 5.3 × 107 m3. It is characterized by a hard reflection at the top, a soft reflection at the base, differential compaction relative to the surrounding sediments, and 10 ms TWT velocity pull up of underlying reflections, indicating a relatively fast mound fill, attributed to the presence of sand within the mound. Internal seismic reflections are arranged in an asymmetric concentric pattern, suggesting a progressive aggradation to the NW, downstream to a mid-Miocene contour current system. Numerous elongated pockmarks occur in the upper Miocene succession close to the mound and indicate that the study area was influenced by gas expulsion in the mid- and late Miocene.The reflection configuration, velocity, dimensions, regional setting, and isolated location can best be explained by interpreting the mound as a giant sand volcano extruded >1 km upward from the Siri Canyon during the middle Miocene (c. 15 Ma). The likely causes of this remarkable structure include gas charge and lateral pressure transfer from the Central Graben along the Siri Canyon reservoir. While this is the first such structure described from this part of the North Sea, similar-aged sand extrudites have recently been inferred from seismic observations in the North Viking Graben, thus suggesting that the mid-Miocene was a time of widespread and intense sediment remobilization and fluid expulsion in the North Sea. 相似文献
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George Dellagiarino 《Marine Georesources & Geotechnology》2013,31(2-3):83-89
Since 1976, the Minerals Management Service (MMS) has administered its prelease geological and geophysical (G & G) data acquisition program through Title 30, Part 251, of the Code of Federal Regulations, which govern permitting, acquisitions, and data release. Leading indicators of offshore oil and gas activity are the number of permits issued to industry, associated mileage, and expenditures. Over the last 20 years, permit activity has indicated that most of the oil and gas surveying has been in the Gulf of Mexico, where 80 % of all permits have been issued, followed by Alaska (10 %), the Pacific (7 %), and the Atlantic (3 %). These statistics correlate with the dominant position of the central and western Gulf of Mexico areas in oil and gas activity. More than 95 % of all permits were issued for geophysical exploration, mostly for two-dimensional (2-D) common-depth-point (CDP) seismic data. However, over the last 10 years, permits for three-dimensional (3-D) seismic data have averaged 25 % of all geophysical permits and, by 1996, made up approximately half of all geophysical permits offshore-wide. Between 1976 and the early 1990s, industry shot approximately 500,000 linemiles of 2-D CDP data each year on the Outer Continental Shelf (OCS). Of that total, MMS acquired approximately50,000 line-miles annually. In the 1990s, parallel with industry, MMS increased its acquisition of 3-D seismic data in concert with the development and use of interactive workstations. The majority of 2-D and 3-D data have been acquired in the Gulf of Mexico by a ratio of 2:1 over Alaska, the next largest data inventory. With regard to MMS expenditures for G & G data, from 1976 through the 1980s, Alaska, having more offshore area than the other three regions combined, had the largest portion. However, in the 1900s, the vast majority of expenditures have been in the Gulf of Mexico. Over the years, permit totals, mileage acquired, and expenditures for data reflect trends of oil and gas pricing, limitations of offshore moratoria, and a shift of industry emphasis to foreign theaters. 相似文献
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George Dellagiarino 《Marine Georesources & Geotechnology》1999,17(2):83-89
Since 1976, the Minerals Management Service (MMS) has administered its prelease geological and geophysical (G & G) data acquisition program through Title 30, Part 251, of the Code of Federal Regulations, which govern permitting, acquisitions, and data release. Leading indicators of offshore oil and gas activity are the number of permits issued to industry, associated mileage, and expenditures. Over the last 20 years, permit activity has indicated that most of the oil and gas surveying has been in the Gulf of Mexico, where 80 % of all permits have been issued, followed by Alaska (10 %), the Pacific (7 %), and the Atlantic (3 %). These statistics correlate with the dominant position of the central and western Gulf of Mexico areas in oil and gas activity. More than 95 % of all permits were issued for geophysical exploration, mostly for two-dimensional (2-D) common-depth-point (CDP) seismic data. However, over the last 10 years, permits for three-dimensional (3-D) seismic data have averaged 25 % of all geophysical permits and, by 1996, made up approximately half of all geophysical permits offshore-wide. Between 1976 and the early 1990s, industry shot approximately 500,000 linemiles of 2-D CDP data each year on the Outer Continental Shelf (OCS). Of that total, MMS acquired approximately50,000 line-miles annually. In the 1990s, parallel with industry, MMS increased its acquisition of 3-D seismic data in concert with the development and use of interactive workstations. The majority of 2-D and 3-D data have been acquired in the Gulf of Mexico by a ratio of 2:1 over Alaska, the next largest data inventory. With regard to MMS expenditures for G & G data, from 1976 through the 1980s, Alaska, having more offshore area than the other three regions combined, had the largest portion. However, in the 1900s, the vast majority of expenditures have been in the Gulf of Mexico. Over the years, permit totals, mileage acquired, and expenditures for data reflect trends of oil and gas pricing, limitations of offshore moratoria, and a shift of industry emphasis to foreign theaters. 相似文献
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This paper is a discussion of Sælevik et al. (2009). Their comparison between block and granular model results is described in more detail, along with a discussion of five parameters which may be in general responsible for deviations between block and granular models. New small scale physical model tests have been performed to support some of the statements made. Finally, it is argued that the use of physical model testing based on simplified geometries are justified in practice and normally produce results that are considerably better than an order of magnitude. 相似文献
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