ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00399.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

This paper is a review of the standard stratigraphic column accepted by many workers for the Lower Cretaceous (Berriasian‐Aptian) of the Arabian Gulf. Type sections, synonymy and summary paleontological details are included. A historical introduction provides an explanation of the profusion of formational and member names. The observed fades variation in the region, both vertical and lateral, can best be understood in terms of the migration of predominantly shallow water carbonate facies‐belts across a shelf. Two, predominantly carbonate, cycles can be recognised, with the maximum development of the marginal clastic fades occurring within the upper cy

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00400.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

The location and geographic distribution of oil and gas reserves within a producing basin often indicate that a remarkable concentration of reserves has taken place in a small area. The concentration of reserves is the result of secondary hydrocarbon migration, itself governed by the basin‐wide regional structure which was present at the time of migration. These factors permit the definition of the most prospective areas of a new basin or play at an early stage in the exploration cycle. Basic geochemical data are required for the definition of critical details of the effective generative depocentre, and regional geological‐geophysical data are required to establish regional structures near particular source‐bed levels, or near top Basement as the deepest prospective level. Other data commonly utilized in the early stages of exploration, such as basin classification schemes, reservoir bed studies and tectonic analyses, are rather less important in forward basin evaluation.A particularly clear example of the importance of the regional basement structure in the concentration of oil reserves exists in the Powder River Basin, Wyoming, USA. Cumulative oil production here was over 1.9 B brls** in 1984 from more than 460 oilfields and pools. However, 1.5 B brls (79% of the basin output) were produced from only 22 fields (4.7% of the number of fields and pools in the basin). It is also remarkable that all 22 major oilfields in the Powder River Basin are located on positive Bouguer gravity anomalies, which are expressions of deep basement irregularities. Regional lateral oil migration in the Powder River Basin appears to have utilized routes resulting from Laramide deformation (Late Cretaceous ‐ Paleocene).The resultant basin structure was accentuated by regional structural‐topographic anomalies, which became sites of major structural and stratigraphic traps. In this case regional gravity maps seem to show sufficient details of the deep structure for the accurate definition of major exploration targets.The Powder River Basin is thus an excellent example of the importance of regional geological and geophysical reconnaissance data aimed at, and available for, the definition of major migration pathways at an early stage of hydrocarbon exploration. When combined with geochemical data, such an approach will become the basis for forward exploration in all kno

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00401.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

A number of commercial hydrocarbon accumulations, which include oil and gas, are now known in southern England. Investigations into the organic maturity and hydrocarbon potentials of sedimentary rocks in the area suggest that the Jurassic Lias, Oxford Clay and Kimmeridge Clay units are the most probable sources for these hydrocarbon accumulations. The Lias on the southern side of the Purbeck‐Isle of Wight Disturbance appears to be the main source of the Dorset oils (Wytch Farm and Kimmeridge Bay) on the bases of adequate maturity, n‐alkane distribution, alkane ratios and stable carbon and hydrogen isotope ratios. On the basis of organic maturity, the oil accumulations in the Weald and the adjacent Hampshire areas are considered to be composed of varying contributions of bitumen generated from the three Jurassic source formations.Application of the modified Lopatin method of basin modelling suggests the Lias in the Weald as the probable source for the natural gas deposit at Godley Bridge in Surrey and predicts a possible Liassic sourced wet‐gas field in the Dorset‐Isle of Wig

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00402.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Petrographical and geochemical studies of 135 core rock samples from Cretaceous formations at the Ain Zalah oilfield suggests that the carbonate rocks contain different percentages of dolomite and calcite.Dolomitisation, stylolisation and neomorphic processes were observed in these formations. This study suggests that the Upper Cretaceous formations were deposited in a deep‐sea environment under low‐energy conditions, while the Middle and Lower Cretaceous formations were deposited in a shallow‐marine environment associated with tidal conditions far from wave a

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00403.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Semilog plots of hydrocarbon ratios with depth for four wells in the offshore Niger Delta show that hydrocarbon expulsion has occurred at an interval shallower than the geochemically‐acceptedtop of the oil‐generative window (OGW), This shallow expulsion zone, which spans the maturation range 0.3‐0.6% RO, is related to the transformation of resinite‐ and sporiniterich organic matter to hydrocarbons. The deeper generation/expulsion zone (conventional OGW) has not released its generated hydrocarbons, presumably because of overpressure development.The critical hydrocarbon saturation at the onset of migration is 10–22 mg per gm organic carbon. Within the expulsion zone, expulsion efficiency varies considerably (10–81%; average 50%), and expulsion ceases when the hydrocarbon saturation falls 10–60% below the critical saturation level.The relative contribution of the paralic Agbada and marine, pro‐delta Akata source shales to the reservoired hydrocarbons in various areas of the delta depends on the present depth position of top supernormal pressure (Hsnp), relative to the top of the Akata Formation (Hak), and the top of the OGW (Hogw). Since the top of OGW must be above the top of the overpressure (HogwHogw: developed in the younger offshore and central onshore areas, with the Agbada constituting the major source rock;(b) Hogw

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00404.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

The unidirectional‐polycyclic evolution of crustal position, and the regimes of tectonic disturbance are the most important factors which determine the structure of Chinese petroliferous basins, and the habitat of oil and gas. Chinese basins can be differentiated into various prototypes in terms of historical stages and geodynamic mechanisms. If their complex and superimposed configurations are systematically investigated, an appraisal of the undiscovered oil and gas resources of China may be possibl

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00405.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

From a remote‐sensing study here reported, a block of Mesozoic sediments (about 160 km by 40 km) in the Arabian Peninsula appears to have been tilted, and the boundaries of the tilted rocks were seen to be bounded by lineaments detected on satellite imagery. Fieldwork has shown supporting evidence of increased dips, and the movement of the block was confirmed by carrying out a trend surface analysis of the positions of key horizons in water bore‐holes, and their outcrops at the surf

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00406.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Book reviewed in this article:Beginning with a bang “Practical seismic interpretation”, by M. E. Badley.Beginning with a bang “Seismic data processing: theory and practice”, by L. Hatton, M. H. Worthington and J. Makin.Beginning with a bang “An introduction to the theory of seismology”, by K. E. Bullen and B. A. Bolt.“Coalbed methane”“Coalbed methane resources of the United States”, AAPG Studies in Geology No. 17. Edited by C. T. Rightmire, G. E. Eddy and J. M. Kin.New Zealand's Sedimentary Basins “Cretaceous and Cenozoic sedimentary basins of the West Coast Region, South Island, New Zealand”, compiled by Simon NathanAustralian Basin Studies “Contributions to the geology and hydrocarbon potential of the Eromanga Basin”, edited by D. I. Gravestock, P. S. Moore and G. M. Pitt.Australian Basin Studies APEA Journal Technical PapersEtudes geologiques…“Geology: principles and methods”, by J. Dercourt and J. Paquet. 0 86010 484 2 Graham and TrotmanEtudes geologiques…“Histoire géothermique et diagenese organique” by P. RobertOil and gas databook “Oil and gas databook for developing countries: with special reference to the ACP countries” edited by Derek FeeMediterranean geochemistry “Geochemistry and Sedimentology of the Mediterranean Sea”, by E. M. Emelyanov and K. M. Shimkus.Also received…“Geologic Well‐Log Analysis — Third Edition”, by S. J. Pirson.Also received…“Open‐Hole Log Analysis and Formation Evaluation”, by R. M. Bateman.Also received…“Log Analysis of Subsurface Geology — Concepts and Computer Methods”, by J. H. Doveton.Also received… ISBN 0 8137 2205 5, Geological Society of America, 3300 Penrose PlaceMechanics of Geomaterials “Mechanics of Geomaterials: Rocks, Concrete, Soils”, Z. P. Bazant (Ed.).Britain's Caledonian rocks “Synthesis of the Caledonian Rocks of Britain”, Eds D. J. Fettes and A. L. Harris.“Methods for Analysis and Testing”, ISBN 0 47190998 X. Available from: John Wiley and Sons, Baffins LaneAlso received…“Fundamentals of Geophysical Data Processing, with Applications to Petroleum Prospecting”, by J. F. Claerbout.For the non‐expert…“The illustrated petroleum reference dictionary”, by R. D. Langenkamp (Editor).For the non‐expert…“Petroleum produ

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00408.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

The following highly‐topical contribution is concerned with the experimental deep‐drilling programme which has been initiated in the Siljan Ring in Sweden. Readers will recall that according to the theories of Professor Thomas Gold of Cornell University, which were first propounded in our January 1979 issue (1 (3) 3–19), deep‐seated abiogenic hydrocarbon gases may be encountered at this site, where a meteoric impact is believed to have produced a structure favourable for hydrocarbon accumulation. Dr Gibbs, however, here suggests an alternative, more conventional explanation for any hydrocarbon gases that may be found as drilling, which commenced in June 1986, pro

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00409.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY