Oil and gas potential of the deep-lying Jurassic and pre‑Jurassic deposits of the North of Western Siberia in unconventional traps

Abstract

In-depth additional studies were carried out to assess oil and gas potential of deep-lying Jurassic and pre-Jurassic deposits of the northern territories of Western Siberia. As in previous work, the geological and mathematical program “Vybor” was used. Based on the first constructed series of model maps with probabilistic values of informative geochemical and geological parameters, the most promising both local and regional objects were selected. Increasing complexity of the traps structure with depth was noted. As a rule, from the Cretaceous deposits to the Jurassic and Paleozoic, the type of trap from the predominant anticline (in the Cretaceous) changes to a much more complex combined one, which requires special approaches (and new technologies) to identify and explore such objects. Studies based mainly on seismic data indicate rather high oil and gas content of both the Paleozoic and Triassic deposits, which have a platform occurence and large thicknesses, as well as crystalline basement formations. In this regard, unconventional combined traps of deep-lying deposits of the North of Western Siberia are of significant interest in terms of incremental oil and gas resources and reserves.

Impact of the Pai-Khoi-Altai Regional Strike-Slip Zone on Localization of Hydrocarbon Fields in the Pre-Jurassic Basement of the Central Part of West Siberian Oil and Gas Province

“…According to various authors, deep-seated tectonic processes led to leaching of feldspar from acidic rocks, karst formation in carbonate rocks, the development of caverns and fractures, and the leaching of minerals from basic lavas (basalts), resulting in the formation of porous and fractured reservoirs [21,34,35]. Traps in such rocks are typically located in structural highs of the basement (with more developed weathering crust), in areas of Triassic rock exposure on basement uplifts [7], and near fault disruptions that create collectors and tectonic-screened traps [36].…”