Analysis of Hydrocarbon Saturation Nature in a Heterogeneous Reservoir as Exemplified in AC10 Formation of Priobskoe Field

The main factors affecting the nature of uneven hydrocarbon saturation of the AC10 formation reservoir at Priobskoye field located in Western Siberia are considered. The formation is characterized by extreme heterogeneity caused by macro- and microstructure, which is determined by the lithofacial and structural-morphological conditions of sedimentation. The formation is characterized by high variability of lithological-mineralogical composition and textural and structural features. To bring to light the nature of the uneven hydrocarbon saturation of the reservoir, the combined analysis of the findings obtained from the study of the size of capillary channels and pores, as well as the investigation of the degree of their filling with clay and carbonate material, was performed. The analysis has shown that the filler composition, its amount in the pore space, and the (core) hydrocarbon saturation collectively evened the AC10 formation electrical resistance in different saturation zones, which led to distortion of the hydrocarbon saturation of the reservoir as a whole.