Перспективы газонефтеносности арктических областей Обь-Енисейского междуречья

Abstract

Despite lasting investigation of geological structure and oil-gas-bearing capacity of the Western-Siberian megaprovince (WSMP) and durational exploration of its hydrocarbon potential (1953-2015), some regions within the WSMP boundaries are not well-studied. First of all it corresponds with north-east, in particular with an arctic part of Ob-Yenisei interfluve Gydan and Yenisei-Khatanga areas. Worst of all the central regions of the interfluve are explored, as well as lower Neocomum and Jurassic horizons as a whole. An the article there is a brief analysis of stratigraphy, lithology, structural tectonics of upper and middle horizons of sedimentary cover over the range from Cainozoe up to middle Jurassic (Triassic has been unsealed only with single wells). Increase in sandiness of all lithologic-stratigraphic complexes in the direction from west to east, and all-around high carbon-saturation of Barrem-Apt profile are registered. For all the years of surveys within the framework of the interfluve 380 deep wells at 43 sites have been drilled, 27 hydrocarbon fields have been discovered, including one, probably, merely oil Pay-Yakha field, 5 gas-condensate-oil fields. Other fields are gas and gascondensate, including 24 in the boundaries of interfluve. Total discovered initial reserves of gas reached 3·1012 m3, of liquid hydrocarbon less than 0,2·109 t. According to modern views, the North-East of WSMP is an area of predominant gas accumulation. Authors together with V.A. Skorobogatov made qualitative assessment of oil-and-gas bearing outlooks for all arctic regions of Western Siberia from nearYamal continental shelf up to Yenisei river. Also potential hydrocarbon resources were calculated. They amount to 13,5·109 t of equivalent fuel (free gas of nearly 90 %). Some conclusions were done regarding a number and sizes of new hydrocarbon fields, which probably will be discovered in arctic part of Ob-Yenisei interfluve at WSMP.