Известия Томского политехнического университета: Инжиниринг георесурсов (May 2019)
Late quaternary permafrost as a factor of geothermal mode and realization of petrogenerative capacity of the bazhenov suite (Tomsk and Novosibirsk regions)
Abstract
The relevance of the research is caused by the need to develop the criteria and effective schemes of quantitative assessment of resources - prospects of petroleum of West Siberian petroleum province territories having unique late quaternary paleoclimate features. In the review of the problem of improving the technique to calculate the resources of hydrocarbons by the volume and genetic method the authors have determined the major paleoclimate factors: 1) the century course of temperatures on a terrestrial surface; 2) formation and degradation of Neo-Pleistocene thickness of permafrost rock; 3) late quaternary glacial covers. The main aim of the research is to define the influence of the second factor of a paleoclimate - Neo-Pleistocene permafrost thickness - on the settlement geothermal regime and extent of implementation of their generative potential of petromaternal deposits on the example of the Bazhenov suite of the southeast of Western Siberia. Object of researches is Bazhenov deposits of the Mesozoic and Cenozoic section, opened with deep wells in the southeast of Western Siberia (the Luginetskaya field of the Tomsk region, the Verkh-Tarsky field of the Novosibirsk region). The technique of researches is based on a method of paleotemperature modeling - the solution of the return and direct problems of a non-stationary geothermal in the conditions of sedimentation, on diversity paleotectonic and paleotemperature reconstructions, on the assessment of the reconstruction results compliance to the criteria of optimality of geophysics return problem solution, on the assessment of coherence degree of the settlement centers of oil generation with the established petroleum potential of mineral resources. Research results. It was ascertained that the accounting of Neo-Pleistocene permafrost with about 300 m power is necessary and it is preferable to apply the «local» (regional) century course of temperatures on a terrestrial surface to adequate recovery of thermal history of petromaternal deposits on еру lands of the southeast of Western Siberia. This allows considering more correctly the history of the main phase of oil formation, both without underestimating (to 25-30 %) the settlement of hydrocarbon resources obtained by the volume and genetic method. The conclusion is drawn that the interdisciplinary approach (petroleum geology, geophysics and a paleoclimatology) can provide the development of the resource efficient technology of searching and investigating hydrocarbons.
