摘要:

The offshore and onshore area of the Canadian Arctic Archipelago, 1.7 million sq km, is one of the most prospective frontier regions in Canada. The first onshore well was drilled at Winter Harbour in 1961, and the first offshore well was drilled from an ice‐strengthened island at Hecla in 1974. To date, more than 140 wells have been drilled, and 12.0 Tcf of recoverable gas have been discovered as well as a small amount of oil. The gas is largely Lower Jurassic, with smaller amounts in Triassic and Lower Cretaceous strata.The Canadian Arctic Archipelago is actually underlain by two prospective basins: the older Franklinian geosyncline, or basin, Cambrian through Devonian; and the younger Sverdrup successor basin, Late Mississippian through Middle Eocene. The principal orogenic events to affect the area were the Caledonian uplift (Devonian), the Ellesmerian orogeny, a compressive fold system was produced with décollement of the southern part of the Franklinian on the Ordovician Bay Fiord salt. Vertical uplift, with compression in the east, dominated the Eurekan orogeny.Objectives in the Franklinian basin include sub‐Bay Fiord (sub‐Ordovician) structures—mainly Lower Paleozoic carbonates and some terrigenous clastics; supra‐salt folds of the Parry Islands fold belt—Ordovician‐Devonian reefs and porous shelf carbonates; other Lower Paleozoic reef bodies; and porous Devonian clastics in the Parry Islands fold belt. Sverdrup basin objectives include mainly terrigenous clastic reservoirs in Pennsylvanian‐Cretaceous rocks, with structural (salt anticlines and diapirs; some folds in the east) and stratigraphic (pinchouts on the flanks of structures, and along the folds) possibilities. The greatest potential in the Sverdrup basin is in the central and western parts. Ultimate recovery of gas is estimated to be

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1981.tb00938.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The long Syrian Arc belt in the Middle East consists of tens of folds and monoclines with their associated faults. The structure of one monocline of this belt, the Hebron monocline in Israel, is analyzed by construction of accurate structural traverses, measurement of the internal strain of the rocks, and geological mapping. The surface structure indicates that three modes of monocline development, draping, buckling and kinking, operated in the Hebron monocline. The subsurface structure, which includes a steep reverse fault, is deduced through mechanical and tectonic models, and structural similarity with other monoclines in Israel.

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1981.tb00939.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The thermodynamic equilibria of petroleum hydrocarbons and the geographic and depth distributions of oil occurrences suggest that petroleum is formed at shallow depths and low temperatures. The currently prevailing theory of origin from kerogen is inconsistent with known data, especially in relation to the non‐marine oils of China.As an alternative, a hypothesis of origin by microbial diagenesis is proposed. Microbial activities are ubiquitous at depths of less than 2,800 m. Sedimentary organic matter is first transformed into microbial lipids which migrate, accumulate and are finally converted into petroleum at 50‐8Od̀C. The energy enrichment process is performed first by microbial activities and then by heat. This process is irreversible in strictly anaerobic conditions because anaerobes cannot utilize hydrocarbons.The dependence of the efficiency of primary migration upon the pore geometry of source rocks and upon the dimensions of microbial remains deserves emphasis.The diagenesis of carbonate sediments is characterised by the “openness” of the systems, and by the facility with which local dissolution and reprecipitation occur. If the deposition of a carbonate sediment is sufficiently rapid, and is followed by a quickly‐consolidated cover so as to prevent the supply of molecular oxygen for microbes, much pore space and hence pore water may be retained within the sediment, so that it becomes a possible source bed. The carbon and oxygen isotope compositions of carbonate minerals can be used as indicators to define both carbonate and clastic source beds.Volcanic hydrogen gas ascending into a sedimentary basin may increase the petroleum potential of the basin by supporting the growth of anaerobes which produce sourc

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1981.tb00940.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Phanerozoic deposits on the East‐European platform are represented by four megasequences: Lower Paleozoic, Middle‐Upper Paleozoic. Mesozoic and Cenozoic. Each megacycle includes several depositional cycles. A correlation may be established between the distribution of oil and gas source rocks and commercial production and the depositional and geotectonic megacycles and cycles. The formation of major gasfields (Orenburg, Shebelinka, Astrakhan and Vuktyl) during the periods of upward tectonic movement is discus

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1981.tb00941.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

This paper forms the third and concluding section of the second part of a detailed and rigorous geomechanical analysis of the stability of overpressured, gently‐sloping sediment layers presented in the Journal of Petroleum Geology,2,3, 1980 and3,2, and3,3, 1981. Parts II(a) and (b) considered stress equilibrium, related stress equations, types of overpressure, the representation of the stress state in Mohr space, and the plastic/elastic states of frictional materials in long fluid‐filled layers, together with numerical and analytical examinations of slip lines and considerations of plastic flow and slip.This concluding section introduces the effects of peak‐strength and liquefaction phenomena, together with a consideration of the behaviour of purely cohesive materials, and contains also the six important conclusions derived from this

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1981.tb00942.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1981.tb00943.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY