«OIL AND GAS GEOLOGY» № 6/2015

 

CONTENTS

 

HYDROCARBON RESOURCES AND RESERVES

 

Shein V.S. Russian land and water areas oil-and-gas-geological zonation

 

In the article present principles of oil-and-gas-geological zonation are considered. The advantages of zonation based on geodynamic criteria are presented. The “Draft of the oil-andgas-
geological zonation map for land and water areas of Russia and adjacent regions” is proposed as well as the “Draft of the map of oil-and-gas-bearing, oil-and-gas-potential and presumably
oil-and-gas-bearing basins on the land and water areas of Russia and adjacent regions”. Traditional oil-and-gas-geological zonation is compared to the one based on geodynamic
criteria. Oil and gas promising areas in the East-European and Siberian plate basins are defined.

 

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METHODS OF OIL AND GAS DEPOSITS PROSPECTING

 

Polovinkin O.M. Features of lithofacial structure and oil and gas prospects of synrift oligocene deposits in the north-eastern flange of Southern Konshon basin

 

Synrift stage is a period of the formation of basic elements for oil and gas complexes. Clay sediments formed in depocentres and significantly enriched with organic matter might be source
rocks with certain temperature-pressure conditions, while detrital cones and organogenous structures might make reservoirs. Overlapping clays perform as shielding sediments. This sedimentation model is common for most rift-related basins and numerous results of well drilling confirm it. Based on the wave pattern of seismic data, drilling data for adjacent sectors and sedimentation model, the attempt to reconstruct synrift sedimentation conditions was conducted for the North-Eastern part of the Southern Konshon oil and gas basin.

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OIL AND GAS RESERVOIRS

 

Gorbunova A.O., Gavrilov S.S., Shaikhutdinov A.N., Dulkarnaev M.R., Shaikhutdinova G.Kh. Conceptual model of rocks formation for Vasiuganskaia suite in the area of Surgutskii arch and Northern-Vartovskaia megaterrace

 

The paper presents the results of complex sedimentologic research on the interval of J1 1 layer in the Surgutskii arch and the Northern-Vartovskaia megaterrace. The authors considered proces-ses and defined cycles and stages corresponding to different sedimentation conditions. In addition general directions of terrigenous material migrations were determined. With a new conceptual model of rocks formation developed, the formation and expansion regularities could be defined for unexplored areas. The investigation of structural regularities for Vasiuganskii horizon revealed factors affecting the spread of reservoirs with different reservoir properties.

 

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GEOPHYSICAL INVESTIGATIONS

 

Afanasenkov A.P., Volkov R.P., Yakovlev D.V. Heitened electric resistivity anomaly under perma-frost sediments layer as a new prospecting indicator for hydrocarbon deposit

 

Subpermafrost high resistive anomalies above oil and gas deposits were discovered by electrical prospecting in the western part of the Yenisei-Khatanga Trough. Magnetotelluric (MT) method was applied. Possible origins of anomalies are discussed. It is proposed to use observed phenomenon as new prospecting indicator for finding of oil and gas reservoirs in the northern part of the Western Siberia and in the Yenisei-Khatanga Trough.

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GEOCHEMICAL INVESTIGATIONS

 

Gottikh R.P., Pisotskii B.I., Mokhov A.V. Isotope-geochemical and geochemical characteristics of the naftides in cristalline rocks (at the example of the deposits on the Vietnam shelf and the northern flange of the Dnepr-Donezk aulacogen)

 

The paper presents the investigation on isotope-geochemical and geochemical features of oil in crystalline rocks on the Northern flange of the Dnepr-Donezk aulacogen (Iulievskaia) and in granitoids of the Vietnam Shelf (Belyi Tigr, Drakon). The presence of the elements affined to oxygen and sulfur in oil and isotope-geochemical data showed that inorganic components in oil could have different sources. Devonian alkaline-mafite and volcano-sedimentary rift base are presumed the source for recovered fluids of the Dneprovskii graben. As for the source of Vietnam Shelf fluids it could be mottled volcanogenic arc associations and its derivatives. The generation of the recovered fluid systems that are involved in oil formation and accumulation is based on tectonic factors which contribute to the formation of hydrothermal solutions of different composi-tion and oxidation-reduction potential in discontinuous fault zones. The formation mechanism is demonstrated at the example of streaky and peristreaky unbalanced mineral associations in granitoid metasomatic reservoirs. Actual materials show that naftidogenic processes are quite complicated and depend on many factors..

 

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HARD-TO-EXTRACT AND NON-TRADITIONAL HYDROCARBON SOURCES

 

Kharachinov V.V., Kulishkin N.M., Shlenkin S.I., Oliunin A.V. New approaches to the investigation of oil and gas potential for the pre-jurassic deposits in the West-Siberian oil and gas province

 

The structure of Paleozoic complexes of the Urmanskoe and the Archinskoe oil and gas conden-sate deposits in the Western Siberia was thoroughly investigated with present wells and seismic survey technology. Integrated analysis of the obtained data presents a new approach to the development of oil and gas potential for pre-Jurassic deposits in the West-Siberian oil and gas province.

 

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Zubkov M.Yu. Secondary reservoirs of tectonic-hydrothermal origin in the roof of the pre-Jurrasic complex in the West-Siberian plate and its forecast methods

 

Present concepts of reservoir formation mechanisms in the roof of pre-Jurassic complex are considered and the evidence for secondary (tectonic-hydrothermal) way of the reservoir formation
is provided in the article. The types of rocks referred to as potential productive where the formation is possible are distinguished. The method for hydrocarbon deposit forecast in the roof
of the pre-Jurassic complex is suggested based on the complex data on material composition of rocks contained in it, petrophysical investigations and seismic survey.

 

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Eder V.G., Zamirailova A.G, Zanin Yu.N. , Zigulskii I.A. Lithological structural features of the main types of the Bazhenov Formation sections

 

Upper Jurassic Bazhenov Formation sections were studied in the Salym, Kolpashev, Vakh, Nizhnevartovsk regions of the Western Siberia. Six section types were distinguished according
to the lithological composition, main rock types ratio (predominantly biogenic and allotigenic genesis), analysis of the thickness. Regions with the periodic clay material supply during Bazhe-nov Formation sedimentation (North-Nivagalskaya area), and also regions without sufficient clay material supply (area of Salym sections distribution, Niznevartovsk region) the regions where is was supplied at the last stage of sedimentation (south of the area between Ob and Irtysh) were
preliminary outlined. As the result of the analysis of the hemipelagic sediments composition and distribution in the Bazhenov Paleobasin, it was found that the higher thicknesses of this sediment type were accumulated in the Salym and surrounding territories. During the first stage of sedi-mentation in this region, siliceous biogenic sedimentation (radiolarian) prevails, on the last ones

– siliceous-carbonate (coccoliths, and less radiolaria). In the Niznevartovsk and Vakh regions, calcareous pack with coccoliths is absent.

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DISCUSSION

 

Petersilje V.I. Concerning the reserves of shaly oil deposits evaluation

 

The issues of the reservoir model substantiation and the parameters for shaly oil reserves esti-mation are presented in the paper. The approaches that suggest to use petrophysical and geochemical data for that purpose which were recently proposed in geological journals are examined.