ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1981.tb00529.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The Nahr Umr Formation is argued here to be in physical and possible chronological continuity with the exposed Rutbah Sandstone Formation of Western Iraq. This stratigraphic relation is postulated on the basis of subsurface mapping.The presently available information, i.e. lithofacies data, well logs, petroleum occurrences, and structural traps availability were evaluated in order to present a preliminary prospect evaluation. It appears that the Albian petroliferous belt coincides with: a marginal‐marine environment of deposition, a sand/shale ratio of>1<8, and a Cretaceous growth of structural trap

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1981.tb00530.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Up‐to‐date lithostratigraphic classifications of the Triassic detritals of the Upper Triassic and Lower Jurassic evaporitic series have been made in North‐Central Algeria. It is believed that the formation of the Lower Triassic fluvio‐deltaic deposits and the principal Upper Trias‐Lias evaporites may be explained in terms of plate tectonics. Correlation of the Triassic formations were found possible between the two different tectonic units known in Algeria. The Epihercynian and Pre‐cambrian platforms attained their main tectonic features after the Early Alpine “Post‐Liassic” orogenic movements; whereas the successive southerly migrations of the Equator during Later Triassic time led to the formation of several lagoons.To the E of the High Plateaux, a NE‐SW lagoonal basin probably existed in the central part of which salt accumulated, overlain by shales and anhydrites, whereasat the edges only anhydrites were deposited. In the NW of the Algerian Sahara‐studied area, open Tethys sea sedimentation partly prevailed and carbonate rocks were deposited during Late Triassic.Triassic‐Liassic diapirs of different ages of emplacement are known in N Algeria and are represented on the surface by saliferous shales and other associated rocks mainly produced by halotectonic processes. Precise photogeologic and seismic studies may reveal the presence of salt‐dome structures in areas of halokinetic piercing diapirs, as well as in other areas away from the direct effects of regional tectonics. No Triassic‐Liassic outcrops or diapirs are known on the Saharan platform, the Triassic basins having develo

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1981.tb00531.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

In order for the hydrodynamics of meteoric water to be an important trapping mechanism for hydrocarbon accumulations, it must have existed for a long geologic period extending from the time of secondary hydrocarbon migration and its accumulation to the present time. However, in most interior sedimentary basins, the present hydrodynamic patterns are considered to have been developed only a short while ago (geologically speaking), after the significant uplift and the associated erosional events which caused the present topographical relief. Most petroleum accumulations were probably formed a long time before the development of the present hydrodynamic flow patterns, and hence must be explained by different mechanisms that have been effective for a much longer geologic period.This paper also discusses other possible problems in applying the hydrodynamics concept to understanding the formation of petroleum accumulations, such as the lack of proper water passways and outlets in several basins, the difficulty of moving water through hydrocarbon‐saturated sections of a reservoir, and the difficulty of keeping significant salinity gradients in a reservoir where active water flow has taken plac

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1981.tb00532.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The evolution of the Earth's atmosphere has been explained by a diffusion model that obeys first order kinetics. By assuming that the same rate law governs the diffusion of petroleum compounds that are known to exist in the upper mantle, we find that 1.5 × 1015tons have diffused out during the past 3.1 billion years. If 0.1% of this primordial petroleum has undergone crustal migration and entrapment, deposits totalling 1.5 × 1012tons are now present in the Earth's crust. Assigning a 0.3 recovery factor, this is equivalent to about 3 trillion barrel

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1981.tb00533.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The following is a short note reporting preliminary experimental work designed to test the feasibility of simulating early diagenetic changes in Recent carbonates. Two experiments are reported; one lasted a period of 3 months and the other for a period of 6 months. In both cases, samples of Recent ooids, split from a single sample taken from the Schooner Cays tidal belt, off Eleuthera Island, Bahamas, were held in a constant temperature/pressure regime in the presence of standard sea water.

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1981.tb00534.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

This study reports aqueous solubilities of crude oil distillation fractions over the carbon number range C1‐C34as a function of: temperature (100° to 400° C), pressure (100 to 2,000 bars), NaCl concentration, and gas in solution (N2,CO2,CH4).Experimental parameters were designed so that conditions within a petroleum basin would be duplicated. Increases in temperature increased crude oil solubility, and the higher molecular weight species were affected more positively than lower molecular weight species. Increases in pressure or salinity decreased solubility. The presence of gas in solution increased the solubility of high molecular weight hydrocarbons (>C24)over all temperatures, and increased the solubility of lower molecular weight hydrocarbons at high temperatures (>180–260°C). Gas decreased the solubility of low molecular weight hydrocarbons at low temperatures.Hydrocarbon solute compositional changes were also examined as a function of the above parameters. At high temperatures, both increasing gas concentration and increasing temperature caused hydrocarbon solutes to become compositionally more similar and eventually identical to the original distillation fraction. The high molecular weight hydrocarbons and saturated hydrocarbons, especially the n‐paraffins, were taken into solution in progressively greater concentrations over the aromatic and low molecular weight hydrocarbons. Thus, the strong preferential uptake of low molecular weight and aromatic hydrocarbons into solution at lower temperatures was

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1981.tb00535.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.tb00536.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Book reviewed in this article:“Sedimentation in Oblique‐slip Mobile Zones”, Special Publication No. 4 of the International Association of Sedimentologists, Eds. P. F. Ballance and H. G. Reading.Geotectonics. by V. V. Beloussov.“Thrust and Nappe Tectonics”, Geological Society Special Publication No. 9, Eds. K. R. McClay and N. J.“Organic Geochemistry for Exploration Geologists” by D. Waples.“Economic Geology and Geotectonics”. Ed. D. H. Tarling.Giant Oil and Gas Fields of the Decade 1968–1978.

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1981.tb00537.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY