Известия Томского политехнического университета: Инжиниринг георесурсов (May 2019)
Zonation schemes of Ust-Tym megadepression by density of shale oil resources of the Togur and Bazhenov source rock formations
Abstract
The relevance of the research is determined by the need of criteria and schemes development of evaluations of hard-to-recover reserves of the shale oil (accumulated in situ) of source rock formations for reproduction and expansion of resource base of hydrocarbon raw materials of the West Siberian petroleum province. The main aim of the research is to determine a complex of basic geological and geophysical data, a method and technology of regional and areal zonation of source rock depositions by density of shale oil resources, to conduct zonation of the Ust-Tym megadepression. The object of the research is Lower Jurassic Togur source rock and Upper Jurassic Bazhenov source rock depositions of the Mesozoic and Cenozoic section, opened with deep wells in the southeast of Western Siberia. The methods of the research. It is accepted that most of shale oil is localized where source rock depositions are/were in the main zone of oil formation and are more heated-up. Zonation method is based on the method of paleotemperature modeling that allows to reconstruct thermal history of source rock depositions, to allocate and map hot spots of oil generation according to geothermal criteria. Evaluation of the oil generation resources is defined by an integrated indicator which depends directly on time of source rock formation discovery in the main zone of oil formation and on its geotemperatures. The results. The authors demonstrated initial geological and geophysical data, methodological approach, scheme and results of zonation of Togur and Bazhenov formations of the Ust-Tym megadepression fulfilled for the first time by density of shale oil resources. The promising lands for shale oil of the Bazhenov formation are the zone of a threefold joint of the Sampatsky mesodeflection, Parabel megamonoklin and North-Parabel megamonoklin and the zone of a threefold joint of Negotsky mesodeflection, Aleksandrov arch and Karaminsky mesosaddle. The promising lands for shale oil of togur formation are shown in the zone of a joint of the central and southwest parts of the Ust-Tym megadepression with North-Parabel megamonoklin. Zonation reliability is confirmed by oil inflows when hydraulic fracturing Yu0 occurs in the Snezhnoe field and by drilling results of East-Paydugin № 1 appraisal well.
