ENHANCED OIL RECOVERY METHODS AT FIELDS OF YUGRA

The relevance. State Register of Reserves booked 482 fields of raw hydrocarbons (in the order of 12 billion tonnes of recoverable reserves) in Yugra. 273 fields are at production stage, 210 fields are at different stages of research. Current depletion of producing fields is 61 % and their current water cut is above 85 %. Modern stage is characterized by decreasing production rate virtually at all objects of oil recovery and increasing of hard to recover reserves component to 65-70 %. The main task for fuel and energy manufacturers of Yugra - the major base of raw hydrocarbon materials and recovery in Russia - is to stabilize oil production on the reached in 2018 level at 235-236 million tonnes per year. Solving of this problem is impossible without application of innovative enhanced oil recovery technologies. The main aim of the research is the efficiency analysis (from viewpoint of additional production) of tertiary technologies of enhanced oil recovery factor at fields of Yugra, which were introduced while operation. Object: peculiarities and field-geological results of enhanced oil recovery methods at fields of Yugra (2013-2019): physical and chemical, hydrodynamic, hydraulic fracturing, horizontal drilling, sidetracking, bottomhole treatment and other methods - well interventions operations for optimization of well stock work. Methods. Retrospective comparative analysis of performed enhanced oil recovery well operations and additional oil production: physical and chemical - 48016, hydrodynamic - 23374, hydraulic fracturing - 28454, horizontal drilling - 11225, sidetracking - 9010, bottomhole treatment - 44081, well interventions operations - 32123 operations. Results. Field-geological and statistical reporting data of Research and Analytical Center for the Rational Use of the Subsoil named after V.I. Shpilman and Department of Subsurface Management & Natural Resources of Khanty-Mansi Autonomous Okrug-Yugra was analyzed. A trend of stabilization of annual oil recovery is emerged in Yugra. Thereat, a fraction of additional oil production was increased from 9,4 % in 2013 to 16,0 % in 2019 due to application of enhanced oil recovery methods and well interventions operations. The major methods of intensification of production and enhanced oil recovery are physical and chemical, bottomhole treatment and hydrodynamic. The most effective methods, which provide additional production, are horizontal drilling, sidetracking and hydraulic fracturing. Application of enhanced oil recovery methods requires enhancement of scientific and technical explanation of optimal conditions of construction and operation of development systems. The fraction of hard to recover reserves of oil is about 60 % in average and for several companies is 75-80 %, for this reason today there is no alternative to development of tertiary enhanced oil recovery methods at the fields of Yugra.