ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1992.tb00862.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

The formation and evolution since the Sinian of the Tirim Basin, NW China, are introduced in this paper. on the basis of a study of stratigraphical and sedimentaty facies. and an analysis of structura1, features. Mechanisms of basin formation have varied throughout this time, caused by frequent tectonic movements along the southern margin of the Eurasian Plate. As regards petroleum geology. six structural units have been classified from a consideration of the distribution of major source‐rock sequences. An overall evaluation is made concerning hydrocarbon exploration in the individual structural units. Moreover, a general review is presented regarding source rocks, hydrocarbon reservoirs, trap structures, sealing layers and hydrocarbon generation, as well as possible recent exploration success

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1992.tb00863.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

A review of published data for the Palaeozoic of SE Turkey, together with facies distribution and palaeo‐fault maps derived from regional field data, are used to interpret the Palaeozoic tectonic history of the region.Intracratonic rifting events in the Early Cambrian and the Early Ordovician led to syn‐rift deposition within fault‐bounded basins. Marine transgressions across the region in the mid‐Cambrian and mid‐to‐Late Ordovician were probably influenced by regional thermal subsidence after each rifting event, in addition to (glacio‐)eustatic mechanisms. Marine transgressions in the Early Silurian and Early Carboniferous are thought to have been entirely eustatic in origin.Poorly‐constrained, Late Palaeozoic facies variations across the region can be related to uplift during the Caledonian and Hercynian orogenic episodes. Widespread tilting and erosion before the Cretaceous, which has removed much of the Late Palaeozoic record from this region, resulted from uplift at the edges of a major rift system which was initiated during the Triassic‐to‐Jurassic opening of the

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1992.tb00864.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Thick Permo‐Triassic sandstones occur in two basins in Northern Ireland. The sandstones are fluvio‐deltaic, including an oolitic facies, and are interbedded with mudrocks. They exhibit petrographic features which are typical of red beds and are widely found in the Permo‐Triassic elsewhere in the British Isles. The predominant cements are haematite, potassium feldspar. illite and carbonates. Gypsum, anhydrite and dolomite cements occur in the regions of deepest burial. which represent the basin centres. There was widespread leaching of carbonate/sulphate cements, but calcite is preserved in the oolitic facies and below the sub‐Cretaceous (chalk) unconformity. The dissolution of cements and framework grains was due to leaching by meteoric fluids. Precipitation of kaolinite in secondary pores, and subsequent illitization, represent fluctuations in the meteoric hydraulic head. Deep boreholes exhibit sandstone porosities which indicate that there may be significant reservoir potential where adequate seals and traps are

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1992.tb00865.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

The ratio of the concentration (barrels of oil equivalent/sq. km) of accumulated oil in the richest sedimentary basin to that in the poorest basin, among those basins containing “giant” and “super‐giant” fields, is more than 500 to 1. By contrast, the ratio of the richest to the poorest petroliferous basin in terms of average organic concentration may be less than 20 to 1. Such a large discrepancy between these two ratios suggests that organic concentration alone cannot account, for petroleum concentration in commercial reservoirs, because significant quantities of petroleum may be lost to the surface and be disseminated throughout the sedimentary sequence if the trapping conditions are not suitable. Most of this disseminated petroleum cannot be produced economically using present‐day technology.For a more accurate petroleum assessment, the Author stresses the importance of the efficiency of petroleum accumulation and preservation in commercial reservoirs: this may be evaluated as combining (a) the organic concentration of the source rock, (b) the duration of oil generation, (c) the thickness of the oil‐generating “window”, (d) the total geologic age involved, and (e) the fluid expulsion rate, and the presence or absence of undercompacted intervals.Other parameters, such as the trap, reservoir and cap rock, and also the types of organic matter in the source rock, may have a great influence on the efficiency of petroleum concentrations in commercial reservoirs. However, most of these factors are of local significance, and thus are more difficult to generalise than those mentioned above in the context of the global distribution and concentratio

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1992.tb00866.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Neogene sedimentany, strata in Hungary contain important mineral resourcs: pelitic rocks, deposited during the last major deltaic depositional cycle in the Pannonian Basin. are considered to be the principal sources of petroleum.The organic‐geochemical investigations presented in this paper show that these Neogene sediments not onlv constitute a good gas‐prone source. but are also a fair oil‐prone source. About 75% of disseminated rganic matter in these deltaic sediments was found to be gas‐prone kerogen (Type III), and more than 13% of the examined samples were oil‐prone, containing Type II kerogen. More than 10% of the sedinirnts contained mixtures of II and III kerogens.At the end of the Neogene highly oil‐prone, organic‐rich sediments (alginites) were deposited in small volcanic tuff rings which, formed during the, final episode of basaltic volcanism (3–5 ± 0.9 million yrs ago) in the Pannonian Basin. This depositional environment, together with the richness of the biological precursor materical, and the good preservation of algae, resulted in the formation of Types I and II kerogens. which have an excellent liquid hydrocarbon potential.The qunlity and quantity of organic matter deposited in the two main stages of the deltaic system are different. Thus, sediments deposited during the deep‐water stage were, found to be fair oil source rocks. As a consequence of the frequent lignite horizons. which illustrate the increasing importance of terrestrial conditions, the shallow‐water sequences constitute a gas‐prone source rock. with a high

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1992.tb00867.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Three discrete turbidite sandstone bodies form the Scapa Sandstone Member reservoir units within the limestone, marl and conglomerate sequence of the Early Cretaceous Valhall Formation in the Scapa field (UK North Sea Block 14/19). Eighteen palynological zones have been established for the Valhall Formation, designated as VA in the early Aptian through VR in the latest Ryazanian. Scapa reservoir sandstones are restricted to the late Hauterivian VF to early Valanginian VQ zones. Black, anoxic mudstones of the Fischschiefer Member form a widespread intra‐ early Aptian correlation marker at the base of zone VA in the upper Valhall Formation.The zonal scheme is based principally on dinocyst distribution, relative abundance and palynomorph associations. Additional micropalaeontological evidence from the top of the Valhall Formation to the top of the Scapa Sandstone Member (zones VA through VF) provides furthrr refinement.Vertical and lateral variations in the age and abundance of reworked palynomorphs reflect a multisource origin for the Scapa Sandstone Member and deposition via several individually distinct, but coalescing, fan systems. An understanding of sandstone distribution within the Valhall Formation has been determined by the integration of the palynological zonation with wireline log correlation. lithofacies studies and reservoir pressure dat

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1992.tb00868.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1992.tb00869.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Book reviewed in this article:“Diagenesis”. edited by I.A. Mcllreath and D.W. Morrow“Classic petroleum provinces”. edited by J

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1992.tb00870.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1992.tb00871.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY