Science.gov (United States)

The first sediments to onlap the metamorphosed Precambrian Arabian shield were Infracambrian (Proterozoic) to Middle Cambrian carbonates, clastics, and evaporites. The oldest Arabian reservoir rocks occur in the Precambrian to lower Paleozoic Era Salt of the Huqf Group, which forms the Birba field of Oman. The Middle Cambrian sequence was followed by Late Cambrian through Early Permian marine sandstones and continental to littoral siltstones and variegated shales. The first commercial oil discovered in the Arabian Gulf region occurs in fluvial sands of the Ordovician to Permian Haima and Haushi Groups of the Marmul field in south Oman. These strata are also productive in other fields and are sealed by unconformable contact with the Al Khlata Formation or beneath shale of the Albian Nahr Umr Formation. The deeply buried kerogen sediments of the Huqf Group to the southeast are believed to be the source rocks for these fields of south Oman. The ...

Energy Technology Data Exchange (ETDEWEB)

The carbonate rocks of the Lower Ordovician Majiagou Formation represent important hydrocarbon reservoirs in the Ordos basin in the western part of the North China plate. Cores and thin sections from more than 60 wells were examined. The main reservoir in the Majiagou Formation consists of fine crystalline dolomite, which was altered by meteoric water during an extended subaerial exposure. Three phreatic zones have been identified in the Majiagou Formation in the northern part of the basin. Oxygen isotopes and fluid inclusion microthermometry data indicates that the porosity developed during the early karst event was considerably reduced by the late-stage, coarse crystalline calcite cements that appear to be related to hydrothermal fluids during deep burial. It was concluded that the main factors that determine the porosity and permeability of these carbonate reservoirs are dolomitization, karstification, and calcite cementation.

Energy Technology Data Exchange (ETDEWEB)

This paper discusses geology, coalfields, coal quality, seams and strata, coal reserves, mining methods, production, coal liquefaction, and research on spontaneous combustion and methane explosions.

Energy Technology Data Exchange (ETDEWEB)

The Cambro-Ordovician platform was formed along the margin of the old super-continent of Laurentia approximately 470 million years ago, and is a prolific producer of hydrocarbons. This presentation provided a geological review of the region as well as estimates of the amounts of oil in place. A simplified geological cross-section of the formation was presented, as well as a chart of the Anticosti Basin of western Newfoundland. Details of exploration wells targeting the Cambro-Ordovician carbonate platform and current west coast land holdings were provided. An outline of the area's petroleum system included details of source rock, reservoirs, traps and seals and migration and timing. Offshore prospects for the platform were estimated to be in the region of 100 to 200 million barrels. Onshore prospects were estimated to be in the region of 30 million to 150 million barrels. It was noted that limited coverage by onshore seismic data may ...

Energy Technology Data Exchange (ETDEWEB)

Lining shafts and placing them in a given strata needs extensive computation. Therefore, it is natural that the use of electronic computing and of numerical methods in this mining area started early. For shafts being sunk in non-stable water-bearing strata the deformations and stresses of the freezing wall are analysed. The complex system of an outer lining in the shaft sinking stage is designed with regard to the elastic support of the strata. In cases of strata-embedded systems the tubbing liner can be shaped as the loads require. Here analysis of safety against buckling is very important. If a sliding shaft is built as a composite construction, there are advantages in determining the distribution of the material by numerical methods. The analysis of stability is possible only by numerical methods and could not be solved otherwise. The Finite Element Method proves itself as a very general tool to ...

UK PubMed Central (United Kingdom)

BackgroundThe aim of this cohort study was to quantify the effect of alcohol in the risk of oral cancer in different strata of folate intake, controlling for known...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Since living things began their activities on the earth, the extermination of living things in large number on global scale occurred twice 230 million years ago (P-Tr boundary) and 65 million years ago (K-T boundary). As to the cause of exterminating living things in short period, there are volcano eruption theory, meteorite collision theory and so on, but still it is not decided. Therefore, as to the strata of P-Tr boundary in south-western part of China where it has been known the preservation of P-Tr strata is especially good, the existence of elements was measured by instrument neutron activation analysis and ICP-MS, and the state of change was examined. According to the results, the change occurred at the P-Tr boundary on the earth, and further, the possibility of meteorite collision by paying attention to Ir were examined. The samples, the neutron activation analysis, the ICP-MS and the results are reported. The distinction by ...

Energy Technology Data Exchange (ETDEWEB)

The studied coal bearing series has a parallel origin. The following facial complexes are isolated in its composition: lakes free of vegetation without coal interlayers; overgrown lakes of their margins which are poor in coals; swampy lakes, whose peat beds formed coal layers of shallow or moderate depth; channel sediments without coal layers and swamps from between channel spaces which created thick coal strata of high quality for which, however, a strong changeability in thickness is intrinsic. The coal strata are normally split towards the central parts of the lake basins and river channels. The coal presence of the suite is reduced along the section which is associated with the replacement of the lake swamp conditions of sedimentation by lake river conditions. A paleotectonic analysis established that the distribution of the zones richest in coal was controlled by consedimentational structural elements.

Energy Technology Data Exchange (ETDEWEB)

A chronology for Paleocene strata of the Hinton area of west-central Alberta was developed from the integration of a magnetostratigraphic and palynostratigraphic study of the upper Coalspur and middle to upper Paskapoo strata in the Coal Valley to Obed Mountain area. The study resulted in the compilation of a complete section of 1100 m of strata with a maximum sediment accumulation rate of 250 m/m.y. Four new informal biostratigraphic units were used to highlight stratigraphically useful bioevents not previously recognized in existing zonations. These strata range in age from magnetochron 29r to 24r and palynozones Wodehouseia spinata Zone, Aquilapollenites reticulatus Subzone through the Pistillipollenite mcgregorii Zone. The 3 intervals with the most rapid changes in the palynoflora were the earliest Paleocene; the transition from the early to middle Paleocene; and in the late Paleocene. Each ...

Energy Technology Data Exchange (ETDEWEB)

The Ordos Basin is a typical lapped basin, including three sequences of strata: early Paleozoic, late Paleozoic and Mesozoic, with a total thickness of 4000-6000m. Impermeable sealing beds are well developed at the top and base of the upper Paleozoic sequence, separating it from the Mesozoic and the lower Paleozoic strata to form an independent petroleum system. In this petroleum system, the source rocks are widely distributed coals and dark mudstones occurring in the Carboniferous-lower Permian coal measures, with a thickness of 10-15 and 40-60m, respectively. The reservoirs are mainly early Permian tight sandstones, mostly with a porosity of 4-8% and a permeability of 0.1-1.0x10{sup -3}{mu}m{sup 2}. The regional cap rock is a 100-150m thick mudstone in the upper Permian strata. The structural framework of the basin is a huge asymmetric syncline, dipping gently toward the east and north, and steeply toward the south and ...

Energy Technology Data Exchange (ETDEWEB)

Discusses design of unconventional pneumatic forms for construction of monolithic liners in mine roadways driven by drilling and blasting. The forms were developed for construction of the municipal subway in Leningrad. They were successfully tested in the Pavlogradugol' mines for construction of chambers situated at shaft bottom at depths of 420 m. The chambers were situated in unstable rock strata. A set of pneumatic forms consisted of 4 to 7 units, each 0.4 m thick and 1.2-2.2 m long. Air pressure was 0.03 MPa, installation time was about 20 min. Service life of pneumatic forms ranged from 3 to 4 years.

Energy Technology Data Exchange (ETDEWEB)

Over one-third of Canada's coal resources occurs in the southern Canadian Rocky Mountains, with major deposits in the Front Ranges, Inner Foothills and Outer Foothills. In the Front Ranges, deposits of metallurgical and thermal, high-volatile bituminous to semi-anthracite coal occur in the Late Jurassic-Early Cretaceous Mist Mountain Formation. In the Inner Foothills of northeastern British Columbia and west-central Alberta, resources of metallurgical and thermal medium- and low-volatile bituminous coal occur in Early Cretaceous strata of the Gething and Gates Formations. In the Outer Foothills resources of thermal, high-volatile bituminous coal occur in Late Cretaceous and Paleocene strata of the Belly River Coalspur and Paskapoo Formations. The major deposits of the Front Ranges and Inner Foothills accumulated within the coastal plains of the Fernie and Moosebar-Clearwater seas. Shorelines prograded to the north and northeast into a ...

Energy Technology Data Exchange (ETDEWEB)

This topical report is a compilation of characterizations by different disciplines of the Red River Formation in the southwest portion of the Williston Basin and the oil reservoirs which it contains in an area which straddles the state line between North Dakota and South Dakota. Goals of the report are to increase understanding of the reservoir rocks, oil-in-place, heterogeneity, and methods for improved recovery. The report is divided by discipline into five major sections: (1) geology, (2) petrography-petrophysical, (3) engineering, (4) case studies and (5) geophysical. Interwoven in these sections are results from demonstration wells which were drilled or selected for special testing to evaluate important concepts for field development and enhanced recovery. The Red River study area has been successfully explored with two-dimensional (2D) seismic. Improved reservoir characterization utilizing 3-dimensional (3D) and has been investigated for identification of structural and ...

British Library Electronic Table of Contents (United Kingdom)

The North-West Borneo Trough is bordered along its south-east margin by a melange wedge that has been the subject of disagreement with insufficient discussion. Offshore Palawan it has been interpreted as an accretionary prism that has been preserved in place when subduction ceased in the Middle Miocene. It is unconformably overlain by undeformed Upper Miocene to Holocene draping strata. Farther south-west along the Trough, the seismically identical melange wedge has been named a Major Thrust Sheet System, which was assumed to have been thrust as a nappe north-westwards over the autochthonous Dangerous Grounds terrane of attenuated continental crust of the South China Sea passive margin. The accretionary prism model is the simplest, resulting in interpretation of the North-West Borneo Troug...

Energy Technology Data Exchange (ETDEWEB)

Natural fractures and in situ stresses commonly dictate subsurface reservoir permeability and permeability anisotropy, as well as the effectiveness of stimulation techniques in low-permeability, natural gas reservoirs. This paper offers an initial prediction for the orientations of the fracture and stress systems in the tight gas reservoirs of the Frontier Formation, in the Green River basin of southwestern Wyoming. It builds on a previous report that addressed fractures and stresses in the western part of the basin and on ideas developed for the rest of the basin, using the principle that thrust faults are capable of affecting the stress magnitudes and orientations in little-deformed strata several hundreds of kilometers in front of a thrust. The prediction of subsurface stresses and natural fracture orientations is an undertaking that requires the willingness to revise models as definitive data are acquired during drilling. The predictions made in this paper are ...

Energy Technology Data Exchange (ETDEWEB)

In the early 1980s, a program was begun to evaluate the oil shale resources of the Albert Formation by undertaking a geological lithofacies study of the Albert strata in the Moncton Subbasin of southeastern New Brunswick. Most rock exposures of the Albert were examined from 1982-84 and additional field work was carried out in the summers of 1989 and 1990. In January 1989, 1,900 km of Vibroseis seismic reflection profiles shot from 1981-84 by Chevron Canada Resources Ltd. in the Moncton and Sackville subbasins became publicly available. This report gives the results of the geological investigations on the Albert Formation in the southeastern Moncton Subbasin and the integration of interpreted seismic reflection profiles to help resolve some of the geological problems encountered.

International Nuclear Information System (INIS)

Since high resolution sequence stratigraphy was introduced into China by DENG Hong-wen in 1995, it has been experienced two development stages in China which are the beginning stage of theory research and development of theory research and application, and the stage of theoretical maturity and widely application that is going into. It is proved by practices that high resolution sequence stratigraphy plays more and more important roles in the exploration and development of oil and gas in Chinese continental oil-bearing basin and the research field spreads to the exploration of coal mine, uranium mine and other strata deposits. However, the theory of high resolution sequence stratigraphy still has some shortages, it should be improved in many aspects. The authors point out that high resolution sequence stratigraphy should be characterized quantitatively and modelized by computer techniques. (authors)

British Library Electronic Table of Contents (United Kingdom)

The first member of the Qingshankou Formation recovered by CCSD-SK-Is borehole (China Cretaceous Continental Scientific Drilling-SongkeI-the south borehole) is 81.41 m long, and the recovery of cores is 100%. The age of the member is approximately Turonian. The sequence and process of lithology-lithofacies and cyclic stratigraphy were revealed by a detailed core description. 6 rock types (mudstone, dolomite, marl, limestone, ostracode limestone, and volcanic ash) comprise the sedimentary strata. Deposition occurred in a deep lake, including 6 sedimentary microfacies: mudstone, sandy turbidite, dolomite, marl, limestone, and volcanic ash microfacies. The first member of the Qingshankou Formation represents 81 meter-scale cycles (sixth-order cycle), 25 fifth-order cycles, 6 fourth-order cycl...

Energy Technology Data Exchange (ETDEWEB)

The paleogeography postulated from the distribution of Permian and Triassic sedimentary rocks in the Middle East is shown and related to the paleostructure of the region. The Middle East region as defined here includes the Arabian Peninsula, Iran, Iraq, SE Turkey, Syria, Lebanon, Jordan, West Jordan, and the Sinai Peninsula. Within the limits of the area included in this study, a relatively stable pre-Late Triassic tectonic regime can be recognized and distinguished from a succession of diastrophic events of the Late Triassic epoch, which caused marked changes in the types and distribution of facies. Excluding NE Iran, the Middle East was stable from Late Cambrian to Middle Triassic times, as it formed a part of the Arabian Massif and much of the Middle East Platform, which is a broad shelf bordering the positive Afro-Arabian Massif to the NE and east. The sediments of this platform have undergone no strong deformation and have been subjected only to epeirogenic movements which ...

Energy Technology Data Exchange (ETDEWEB)

The coal rank, coal distribution, and coalbed methane of four major coal zones in the Hinton and Grande Cache areas of Alberta were investigated. Coal rank in the study area ranges from subbituminous and high volatile C bituminous at surface for the Upper Cretaceous/Tertiary coal measures and semianthracite for the Lower Cretaceous Luscar Group in the Alberta Syncline. In the Rocky Mountain Foothills, maximum cumulative coal thicknesses occur in the Smoky River, Cadomin-Luscar, and Coal Valley coalfields. Cumulative coal thicknesses generally decrease east of the deformed belt; however, coal isopach maps indicate local cumulative coal thicknesses in excess of 25 m. A regional coalbed methane assessment for strata east of the deformed belt shows favorable coalbed methane adsorption capacities in Luscar Group coals. These coals occur, however, at depth levels [gt]2500 m. In contrast, Brazeau and Coalspur Formation coals occur at favorable depth levels ([lt] 1100 m) ...

Energy Technology Data Exchange (ETDEWEB)

The objective of the Coastal Habitat Injury Assessment study was to document and quantify injury to biota of the shallow subtidal, intertidal, and supratidal zones throughout the shoreline affected by oil or cleanup activity associated with the Exxon Valdez oil spill. The results of these studies were to be used to support the Trustee`s Type B Natural Resource Damage Assessment under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). A probability based stratified random sample of shoreline segments was selected with probability proportional to size from each of 15 strata (5 habitat types crossed with 3 levels of potential oil impact) based on those data available in July, 1989. Three study regions were used: Prince William Sound, Cook Inlet/Kenai Peninsula, and Kodiak/Alaska Peninsula. A Geographic Information System was utilized to combine oiling and habitat data and to select the probability sample of study sites. ...

Energy Technology Data Exchange (ETDEWEB)

As a parameter for execution control of confirming a bearing stratum, which is most important in a bored precast pile method, discussions were made on the relativity between the product AT'' of a load current value A'' in an electric motor driving an auger used to drill pit holes with an excavation time T'' and a value N,'' a result of the standard penetration test of the ground. As a result, although the relativity of the N'' value has some variance in the ground of diluvial clay, they correspond well to each other in other kinds of ground. In pile bearing strata in particular, they correspond very well to each other regardless of soil textures of the ground, proving clearly that the AT'' value can be used as an effective parameter for confirmation of and penetration into the bearing stratum. Therefore, tips of all the piles used in one construction site can ...

Energy Technology Data Exchange (ETDEWEB)

This thesis studied the petrology and sequence stratigraphy of the Hoadley barrier, a Glauconitic member in the Westerose field in Alberta. The unit contains gas reserves in an extensive northeast-southwest trending marine complex. A high resolution sequence stratigraphic model was used to understand the facies development of the unit and the diagenetic pathway of the strata. Six high frequency sequences were identified within the Glauconitic member. Each are separated from one another by surfaces of incision or subaerial exposure which sometimes coincide with a flooding surface and erosion. This thesis provided a petrographic characterization and depositional history of each of the 6 sequences. Reservoir quality is developed within the relatively quartz-rich foreshore facies of the G2B sandstones. The G3 chert litharenite to sublitharenite sandstones are excellent gas producers because of their coarser grain size and secondary porosity. The G4, G5 and G6 are ...

Energy Technology Data Exchange (ETDEWEB)

Preliminary field investigations suggest three detachments in the Sadlerochit and Shublik Mountains: (1) the Kingak Shale, (2) along the pre-Mississippian unconformity, and (3) within the pre-Mississippian basement. Thrust faults that cut the overlying Mississippian and younger section have horizontal displacements of 5-8 km and emplace pre-Mississippian rocks on Cretaceous strata. A large number of smaller thrust faults, responsible for deformation of the pre-Mississippian surface contribute to shortening. Structures involving the pre-Mississippian section trend east-west whereas earlier formed structures related to the Kingak Shale decollement trend east-northeast-to west-southwest. Possible exploration leads beneath the coastal plain include: (1) large, broad, basement involved structural culminations that may have subtle seismic expressions and (2) pre-Mississippian potential reservoirs thrust over Cretaceous source beds. Possible applications for regional ...

International Nuclear Information System (INIS)

Site studies for CANDU type NPP began in a careful manner since 1982 as a first part of the Nuclear Power Plant Romanian Program adopted by political and governmental authorities at the time. A team was charged to develop all packages of the necessary main studies. The first Romanian NPP CANDU 6 type reactor gone to erection on Cernavoda site, planned to have 5 units and, like Wolsong NPP, applied the same design for the nuclear island. For the BOP parts the ANSALDO-GE project was applied with a thorough concern about requirements raised by connection to NSP. The first mission of design and research multi-branch team was to adapt the NPP Cernavoda project having an open water cooling circuit 'once-through' to the new parameters of a close recirculation water cooling circuit. Also, the structural design was re-evaluated for the case of soft foundation strata instead of hard rock ones. The close recirculation water cooling circuit system was applied for PWR NPP type ...

Energy Technology Data Exchange (ETDEWEB)

The Pequop Mountains (PM), Wood Hills (WH) and East Humboldt Range (EHR), NE Nevada, provide evidence that the hinterland of the Sevier thrust belt experienced large-magnitude Mesozoic shortening ([>=]55 km) and crustal thickening ([>=] 30 km). These ranges expose a structurally continuous crustal cross section of unmetamorphosed to high pressure upper amphibolite facies Triassic to Precambrian miogeoclinal strata. This sequence lies structurally beneath unmetamorphosed extensional klippen that omit metamorphic grade and crustal section, but also repeat stratigraphic units. Because they repeat stratigraphic units, the underlying miogeoclinal section, or footwall, must have once lain beneath a thrust fault (herein named the Windermere thrust). The footwall of the Windermere thrust was exhumed by two generations of top-to-the-W-NW low-angle normal faults that are distinguished by whether they are depositionally overlapped by Eocene volcanic rocks or if they cut ...

Energy Technology Data Exchange (ETDEWEB)

Oil shale occurrences have been historically reported in the Cape Breton Island, northern mainland and southern mainland areas of Nova Scotia. Twelve of these occurrences were investigated for this study. Rocks from three of the areas gave oil yields of less than 25 litres per tonne (below oil shale grade) while the remainder gave oil yields greater than 25 litres per tonne (above oil shale grade). The rock types of oil shale grade include silicate-rich shale, carbonaceous shale locally transitional to coal, limy shale and petroliferous limestone associated with coal, silicate-rich shale and cannel shale associated with coal and silicate-rich shale, cannel shale and boghead shale associated with coal. The Stellarton Basin represents the province's largest oil shale resource with an estimated 825 x 10{sup 6} tonnes of oil shale and 168 x 10{sup 6} barrels of shale oil in situ. The Antigonish Basin represents the second largest oil shale resource in the province with an ...

Energy Technology Data Exchange (ETDEWEB)

Thirty-three measured sections of the Dinwoody Formation, including five from the literature, provide information on thickness, lithology, paleontology, and stratigraphic relations within the Wind River basin and immediately adjacent areas of Wyoming. Most of these sections are in Fremont County, and some lie within the Wind River Indian Reservation. The Dinwoody becomes progressively thinner eastward, from a maximum thickness of 54.6 m in the northwestern Wind River Mountains to zero near the Natrona County line. The formation is characterized by yellowish-weathering, gray siltstone and silty shale. Variable amounts of limestone, sandstone, gypsum, and claystone are also present. Marine bivalves, gastropods, brachiopods (Lingula), and conodonts are common in the western part of the study area, but are absent to the northeast in gypsiferous strata, and near the eastern limit of Dinwoody deposition. The Dinwoody in the Wind River Basin area was deposited ...

Energy Technology Data Exchange (ETDEWEB)

The basic feature in the functional ecology of any mire ecosystem is retardation of the effective decay of organic material resulting in a conspicuous accumulation of plant debris as peat overtime. The carbon accumulation process is slow, and climatic change may have an impact on the carbon cycle of peatlands, therefore, it has been of interest to study the rate of carbon accumulation by geological methods from dated peat strata. The approach is hampered by several facts. First, the mires vary enormously as to their vegetation and hydrology and hence their production and decay properties. It follows that a great number of study sites are needed. Second, the peat in mires expands both vertically and laterally, and this requires a spatial reconstruction of carbon accumulation within a mire basin. Third, simple geological methods cannot account for the actual rate of carbon accumulation in peat, and finally, an additional carbon sink in the mire ecosystems can be the ...

Energy Technology Data Exchange (ETDEWEB)

Utah oil fields have produced over 1.2 billion barrels (191 million m{sup 3}). However, the 13.7 million barrels (2.2 million m{sup 3}) of production in 2002 was the lowest level in over 40 years and continued the steady decline that began in the mid-1980s. The Utah Geological Survey believes this trend can be reversed by providing play portfolios for the major oil-producing provinces (Paradox Basin, Uinta Basin, and thrust belt) in Utah and adjacent areas in Colorado and Wyoming. Oil plays are geographic areas with petroleum potential caused by favorable combinations of source rock, migration paths, reservoir rock characteristics, and other factors. The play portfolios will include: descriptions and maps of the major oil plays by reservoir; production and reservoir data; case-study field evaluations; summaries of the state-of-the-art drilling, completion, and secondary/tertiary techniques for each play; locations of major oil pipelines; descriptions of reservoir outcrop analogs; and ...