The coal-bearing strata of the Lower Cretaceous Mannville Group (Western Canadian Sedimentary Basin, South Central Alberta), PART 2: Factors controlling the composition of organic matter accumulations

Abstract Meso-Cenozoic sedimentary cover in the Middle Kura depression located between the Greater and Lesser Caucasus mountain structures contains numerous oil accumulations. According to studies in the Cretaceous and Paleogene strata, sedimentary organic matter is of mixed clastic-marine origin. Moderate amounts of organic matter have been recorded in the Eocene sediments (on average 0.70%), in the Upper and Lower Cretaceous average values made up 0.39% и 0.42%, respectively. Analysis of bitumoid composition suggests that in a number of areas bitumoids have experienced a widespread movement across the sedimentary strata. The results of measurements on isolated samples indicate that the Cretaceous strata have only advanced to the initial hard-coal stage of organic transformation (0.48-0.55%Ro). On vitrinite reflectance data the Eocene deposits in studied areas of the Middle Kura depression have reached initial (brown-coal) stage of catagenetic transformation (±0.48Ro%; est. paleotemperature of 85°C). Nonetheless, analysis of formation conditions of commercial HC accumulations found earlier in the Eocene strata allows considering them the most prospective in the Middle Kura depression.

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KEROGEN TYPES OF BAZHENOV FORMATION BASED ON PYROLYSIS DATA AND THEIR COMPARISON WITH OIL PARAMETERS

Oil and Gas Studies ◽

10.31660/0445-0108-2017-5-34-43 ◽

2017 ◽

pp. 34-43

Author(s):

E. E. Oksenoyd ◽

V. A. Volkov ◽

E. V. Oleynik ◽

G. P. Myasnikova

Keyword(s):

Organic Matter ◽

Lower Cretaceous ◽

Alternative Model ◽

Oil And Gas ◽

Upper Jurassic ◽

Gas Content ◽

Basin Modeling ◽

Bazhenov Formation ◽

Gas Bearing

Based on pyrolytic data (3 995 samples from 208 wells) organic matter types of Bazhenov Formation are identified in the central part of Western Siberian basin. Zones of kerogen types I, II, III and mixed I-II and II-III are mapped. Content of sulfur, paraffins, resins and asphaltenes, viscosity, density, temperature and gas content in oils from Upper Jurassic and Lower Cretaceous sediments (3 806 oil pools) are mapped. Oil gradations are identified and distributed. The alternative model of zones of kerogen II and IIS types is presented. The established distributions of organic matter types can be used in basin modeling and in assessment of oil-and-gas bearing prospects.

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New adherent foraminiferans from the Lower Cretaceous (Aptian) of south-central England

Journal of Micropalaeontology ◽

10.1144/jm.5.2.1 ◽

1986 ◽

Vol 5 (2) ◽

pp. 1-8 ◽

Cited By ~ 5

Author(s):

Mark A. Wilson

Keyword(s):

New Species ◽

Lower Cretaceous ◽

New Genus ◽

High Energy ◽

Junior Synonym ◽

New Genus And Species ◽

South Central ◽

Energy Environment ◽

Three New Species

Abstract. Three new species and one new genus of adherent foraminiferans have been found within bivalve borings in cobbles from the Faringdon Sponge-gravel (Upper Aptian) of south-central England. The new genus and species, Lapillincola faringdonensis is a uniserial textulariine with an initial planispiral coil and a multiple aperture. Lapillincola gen. nov. is a remarkable homeomorph of Arenonina Barnard, which was originally described as an agglutinated form. Arenonina is shown here to actually be calcareous and perforate, and thus a junior synonym of Rectocibicides Cushman & Ponton. Acruliammina parvispira sp. nov. is another uniserial textulariine with an initial coil. Bullopora ramosa sp. nov. is an adherent polymorphinid with a branching, irregular series of adherent chambers. These foraminiferans may have used the bivalve borings as spatial refuges from the abrasive, high energy environment of the Sponge-gravel.

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