Identification of Local Petroleum Kitchen in the Southern Periphery of the West Siberian Oil and Gas Basin

The southern part of the West Siberian Basin is still underexplored due to insufficient drilling success in the 1970s and 1980s. The research focuses on core analysis from three wells drilled in the Prirakhtov oil field in 2011–2012, using various techniques to determine the lithological and geochemical properties of the Jurassic and Cretaceous sediments. The main identified source rock in this area is the Bazhenov Formation, which was previously classified as immature based on indirect assessment methods. However, the extensive direct geochemical studies identified kerogen type IIS intervals within the Bazhenov Formation, which, in fact, is in the oil window. Additionally, coals with high liptinite content were discovered within the Vasyugan and Tyumen Formations that could generate oil at low stages of catagenesis. These findings clearly indicate the presence of a local petroleum kitchen in the area. Thus, the obtained insights on the geochemical characteristics of the source rocks have the potential to greatly increase the estimate of oil potential in the region and could lead to further renewal of exploration works.