Influence of formation conditions on reservoir thickness and reservoir properties

Abstract

Authors of the article identified the influence of sedimentation conditions on reservoir thickness and the patterns of change in reservoir properties of superviscous oil field from the following three zones of the sandstone sequence of the Sheshminsky horizon: Northern, Southern and Central identified by PJSC Tatneft and prepared for initial development. The following relationships have been investigated: open porosity relation with bitumen content (by weight and by volume), open porosity relation with carbonate content, open porosity relation with bulk density, carbonate content relation with bulk density, bitumen content (by weight and by volume) relation with carbonate content, and also bitumen content relation with their depth. The revealed patterns of changes in reservoir properties and bitumen content within the sandstone sequence can be the result of not only changing conditions of sedimentation, but also the result of post-sedimentation processes resulting in calcitization or redistribution of carbonate cement in the rock under the influence of aggressive products (oxidation, biodegradation) of oil deposits destruction.