Analysis of Geological Factors That Influenced the Filling of Hydrocarbon Traps in the License Areas of the Uvat District of the Tyumen Region

摘要

The article presents the results of the analysis of geological factors that had a great influence on the occupancy of the Middle Jurassic traps with hydrocarbons.According to the results of the regional paleotectonic analysis,three major stages of restructuring of the structural plans of the sedimentary cover were revealed-in the Late Jurassic,in the Early Cretaceous,and at the boundary of the Cretaceous and Paleogene.Each tectonic stage was characterized by the appearance of new structural traps in sediments of the Middle Jurassic and by immersion to a certain depth of rocks of the Bazhenov formation.Based on the results of basin modeling,it was revealed that most of the Bazhenov formation in the Uvat territory did not manage to realize its oil-bearing potential.In the central and eastern regions of Uvat,the Bazhenov formation entered the"oil"'window only 65 million years ago(in the Paleogene).On the territory of Uvat in the Mesozoic period,lateral migration of hydrocarbons dominated.Due to the fact that the formation of the Jurassic structural plans took place in three tectonic stages,the formation of traps capable of accumulating oil and the lateral migration of hydrocarbons from the Bazhenov formation also occurred in stages.As a result,the combined influence of the lateral migration of hydrocarbons and the phased formation of local structures in different regions of Uvat led to the selective filling of Jurassic traps of hydrocarbons.