DISTRIBUTION REGULARITIES OF THE MAIN COMPONENTS AND TYPES OF ROCKS OF THE BAZHENOV FORMATION IN WEST SIBERIA

The distribution regularities of the main components and types of rocks of the Bazhenov Formation are investigated. It is one of the largest black shale formations in the world. The results of the lithological and geochemical study revealed that the brittlest rocks of the formation are widely distributed in the Central region and are considered as potential reservoirs: siliceous mudstones, kerogenic siliceous mudstones, carbonated radiolarites (limestones and dolomites). In the South-Eastern region, thicknesses of silicites are noticeably reduced; kerogen-clay-siliceous mudstones (similar in silica content to siliceous mudstones) prevail, which are also reservoirs in a number of areas. These types of rocks are practically not typical for the Northern and Southern regions. Detailed distribution maps of the main components of rocks for the lower, middle and upper parts, as well as for the Formation as a whole, were constructed. It was revealed that the highest concentrations of siliceous material are observed in the lower and to a lesser extent in the middle parts of the Bazhenov Formation section in the Central region. By the nature of distribution, composition and thickness of potential reservoirs, the Central region can be considered as a highly promising region in terms of development for hydrocarbon raw materials, the South-Eastern is medium-promising one, the Northern and Southern are low-promising ones.