The paper is devoted to the questions of the geological structure and oil and gas potential of deep-buried pre-Jurassic deposits and the foundation of the central regions of Western Siberia and the granitoid rocks of the Pre-Cenozoic crystalline basement of the Vietnam shelf. A possible mechanism for the formation of an oil field in the basement is proposed, and a model of the reservoir structure is developed. Geochemical features of subterranean oil sedimentary strata covering the protrusions of the crystalline basement of the West Siberian oil and gas basin (NSA) are considered. The study of hydrocarbon (HC) and trace elements (TE) naphthyde composition made it possible to conclude about two sources of oil generation: syngenetic, associated with the Paleozoic OM, and epigenetic, generated Jurassic and Triassic OM. The possible depths of the processes of HC generation are specified. A differentiated distribution of TE, in particular, vanadium and vanadylporphyrins in naphthides of this region of Western Siberia, was noted. A zone of minimum concentrations in the bitumen formations of the Bazhenov deposits of vanadium and metal porphyrins is singled out, which is probably due to the different warmth of the interior and the migration of bituminoids fr om the lower horizons to the upper horizons. This zone practically coincides with the prospective oil-bearing zone of the pre-Jurassic sediments based on the results of mathematical modeling carried out by us earlier and with the existing oil content of the Khanty-Mansi and Nyurol regions. The depths of probable detection of hydrocarbon accumulations in the regions of fluid-conducting faults in the foundation, for example, Shaimsky, wh ere the increase in catagenesis with depth occurs most intensively, amount up to 3200 m for oil and up to 4000 m for gas condensates. To increase the probability of revealing medium and large reserves of oil and gas in the formations of the basement of Western Siberia, by analogy with Vietnam, the choice of the location and depth of the project well becomes extremely important. Considering the extremely uneven structure of the strata and the distribution of the unconsolidated fissured-cavernous rocks with good filtration-capacitive properties (in it, it is also necessary to conduct seismic operations using advanced technology, using scattered waves, to map the zones of increased fracturing even at the pre-drilling stage.
References
1. Dmitrievskiy A.N., Shuster V.L., Punanova S.A., Doyurskiy kompleks Zapadnoy Sibiri – novyy etazh neftegazonosnosti. Problemy poiska, razvedki i osvoeniya mestorozhdeniy uglevodorodov (PreJurassic complex of Western Siberia — new floor petroleum potential. Problems prospecting, exploration and development of hydrocarbon deposits), Lambert Academic Publishing, 2012, 135 p.
2. Shuster V.L., Problemy neftegazonosnosti kristallicheskikh porod fundamenta (The problems of oil and gas potential of crystalline basement rocks), Moscow: Geoinformtsentr Publ., 2003, 48 p.
3. Khalimov Yu.E., Petroleum potential of granitoid basement reservoirs (In Russ.), Neftegazovaya geologiya. Teoriya i praktika, 2012, V. 7, no. 4, URL: http://www.ngtp.ru/rub/9/58_2012.pdf
4. Punanova S.A., About polygenic nature of the source of oil trace (In Russ.), Geokhimiya = Geochemistry, 2004, no. 8, pp. 893–907.
5. Phi Phi Manh Tung, Usloviya formirovaniya skopleniy uglevodorodov i otsenka perspektiv neftegazonosnosti v basseyne Yuzhnyy Konshon (shel'f Yuzhnogo V'etnama) (Conditions for formation of hydrocarbon accumulations and estimation of prospects for oil-and-gas-bearing capacity of the South-Konshon basin): thesis of candidate of geological and mineralogical science, Moscow, 2016.
6. Punanova S.A., Shuster V.L., Geological-geochemical conditions for oil and gas content availability of Pre-Jurassic deposits located on West-Siberian platform (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, 2012, no. 6, pp. 20–26.
7. Kiryukhina T.A., Ul'yanov G.V., Dzyublo A.D., Geochemical aspects of the gas and petroleum sector of the Jurassic and pre-Jurassic deposits in the north of Western Siberia and the adjacent shelf (In Russ.), Gazovaya promyshlennost' – GAS Industry of Russia, 2011, no. 7, pp. 66–70.
8. Fedorov Yu.N., Maslov A.V., Ronkin Yu.L., Lepikhina O.P., Mikroelementnaya kharakteristika syrykh neftey Shaimskogo i Sredneobskogo neftegazonosnykh rayonov Zapadnoy Sibiri: novye dannye. Degazatsiya (Trace elements characteristics of crude oils from Shaimskiy and Sredneobskiy oil and gas bearing regions of Western Siberia: new data. Degassing), Moscow: GEOS Publ., 2010, pp. 586–589.
9. Chakhmakhchev V.A., Punanova S.A., To the problem of diagnostics of oil reservoirs on the example of Bazhenov deposits of Western Siberia (In Russ.), Geokhimiya = Geochemistry, 1992, no. 1, pp. 99–109.
10. Kontorovich A.E., Fomin A.N., Krasavchikov V.O., Istomin A.V., Katagenez organicheskogo veshchestva mezozoyskikh i paleozoyskikh otlozheniy Zapadnoy Sibiri (The catagenesis of the organic matter of the Mesozoic and Paleozoic deposits of Western Siberia), Proceedings of International Scientific and Practical Conference “Litologicheskie i geokhimicheskie osnovy prognoza neftegazonosnosti” (Lithological and geochemical fundamentals for prediction oil and gas potential), St. Petersburg, Publ. of VNIGRI, 2008, pp. 68–77.
11. Stupakova A.V., Sokolov A.V., Soboleva E.V. et al., Geological survey and petroleum potential of Paleozoic deposits in the Western Siberia (In Russ.), Georesursy = Georesources, 2015, no. 2(61), pp. 63–75.
12. Shuster V.L., Punanova S.A., Probabilistic estimation of oil-and-gas prospects of hydrocarbon potential of a pre-Jurassic complex of Western Siberia by means of the geological and mathematical program “Choice” (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2014, no. 1, pp. 16–19.
13. Kremnev A.N. et al., Prediction of fracture-cavern type reservoirs by scattered seismic waves (In Russ.), Tekhnologii seysmorazvedki = Seismic technologies, 2008, no. 3, pp. 12–16.
14. Levyant V.B., Shuster V.L., Isolation in the foundation zone of fractured rock by seismic exploration 3D-methods (In Russ.), Geologiya nefti i gaza = The journal Oil and Gas Geology, 2002, no. 2, pp. 21–25.
