Seismostratigraphic characteristics, tectonic evolution, and petroleum potential of the northwestern part of the Kaimysovy petroliferous region

Abstract

Structural and isopach maps of seismogeologic megacomplexes were constructed on the basis of an integrated interpretation of seismic prospecting, GIS, and deep drilling data. The tectonic evolution of the northwestern part of the Kaimysovy arch and adjacent areas of the Yugan megadepression in the Mesozoic–Cenozoic was analyzed, and the main stages of formation of structures of different orders were established. An analysis of geological and geophysical data shows that the Larlomkiny and Pervomaiskoe–Vesennii swells have radically different formation histories despite their similar modern tectonic structure. The results of the investigations suggest that most of the local uplifts in the Bazhenovka Formation, in particular, the Larlomkiny structure bearing an Upper Jurassic oil pool, formed in the Neocomian due to the inherited growth of erosional-tectonic salients (ETS) of the pre-Jurassic basement, and then developed only slightly. The large tectonic structures of the first order—the Kaimysovy arch and the Yugan megadepression and the Pervomaiskoe–Vesennii swell—a big trap associated with one of the largest oil fields of southeastern West Siberia, completed their formation in the Cenozoic.