Results of integrated lithofacies analysis for optimization of field development plan: updating geological structure of low-permeable Turonian formations in the Kharampursky oil and gas condensate field

Core studies and integrated interpretation of geological and geophysical information was carried out within the framework of Field Development Plan optimization for the Turonian pool in the Kharampursky oil and gas condensate field - one of the largest fields in the south-eastern part of the Yamal-Nenets Autonomous Okrug. These works allowed revealing the new regularities of the Gazsalinsky low-permeable reservoir bed formation, more precisely define its lithologic and mineralogical, and depositional model. It was found that distribution of rocks having different porosity and permeability within the study area was determined by the distance to shore line, paleotectonic features of the area evolution, and sea floor paleogeography, as well as secondary processes of sediments erosion, transportation, and redeposition by bottom, gravity, storm waves and wave currents. The authors propose a depositional model of Turonian formations that is determined by the so-called turbidity fans, which moved the fine-washed clastic material over immense distances (exceeding 100 km away from the shoreline). Existence of three largest fans contributed to the formation of proximal zones having better reservoir properties, which are clearly expressed in well logs; and the authors recommend them to be the priority development targets