Известия Томского политехнического университета: Инжиниринг георесурсов (Mar 2018)
Integrated assessment of paleoclimate factors of reconstructing thermal history of petromaternal Bazhenov suite in arctic regions of Western Siberia
Abstract
The relevance. The Arctic regions of Western Siberia have the unique paleoclimate features, the inversion tectonic history in Paleogene Neogene and the considerable variations of geochemical characteristics of petromaternal deposits. This causes the necessity to improve schemes and parameters of quantitative assessment of hydrocarbon resources by volume and genetic method based on paleoreconstruction of geotemperature mode of petromaternal deposits. The main aim of research is to estimate the impact of paleoclimate factors - temperature secular variation of the Earth surface and Neo-Pleistocene permafrost thickness, glacial sheets, in a complex with a factor of erosive processes, on the settlement geothermal mode of petromaternal of Bazhenov suite. Object of researches: Bazhenov deposits of Mesozoic and Cenozoic sections, opened deep wells on Arctic, Sredne-Yamal and Rostov areas (Yamal Peninsula). The method of research is based on original computer paleotemperature modeling considering the parameters of sedimentation history and the history of thermal properties of sedimentary thickness, including permafrost rocks and glaciers, without aprioristic data on sizes and the nature of a deep heat flow. Research results on identification and registration of denudation parameters in conjunction with the assessment of the role and taking into account the characteristics of paleoclimatic features allowed making the conclusions and recommendations. It is recommended to apply «Arctic» secular variation of temperature and take into account the dynamics of Neo-Pleistocene permafrost strata of about 300-600 meters when determining the hydrocarbon resources by the volumetric-genetic method in the territory of Arctic region. Calculation hydrocarbon resources may be understated by 40-50 % in case if not taking into account permafrost and paleoclimatic secular variation of temperatures. The authors have stated the tasks of forthcoming researches, including the estimate of the role of paleoclimatic factors in thermal history of Kiterbyut source formation and elaboration of formalized scenarios for identifying and estimating the interruptions in sedimentation and erosion according to the geothermic data.
