The Pore Volume Structure in the Reservoir Intervals of the Bazhenov Formation, Priobskoye Field of Western Siberia

Abstract

This paper reports the data on the rock structure and reservoir properties of the Bazhenov Formation in the sections of three wells located in different structural zones of the Priobskoye field. The dynamic porosity of samples varies from 0.02 to 6.95% and the absolute gas permeability of the rocks reaches 1.364 mD. Reservoirs of the Bazhenov Formation are confined to silicite–radiolarites (their porosity is related to leaching of radiolarian shells), kerogen–clay–siliceous rock, and kerogen–clay silicite (the porosity is related to the free space between the clay–siliceous matrix and kerogen due to organic matter maturing). Secondary processes such as recrystallization of radiolarians and local warming influenced the formation of voids in these lithotypes.