Release:2017, Vol. 3. №3
About the authors:Alexander A. Pyatkov, Postgraduate Student, Department of Mechanics of Multiphase Systems, University of Tyumen; Laboratory Assistant with Higher Education, Tyumen Branch of Khristianovich Institute of Theoretical and Applied Mechanics of the Siberian Branch of the Russian Academy of Sciences; Researcher, Uni-CONCORD (Tyumen); firstname.lastname@example.org
Due to the depletion of light oil, fields with high-viscosity oil are more and more involved into the development. Reserves of heavy oil and bitumen make up about 70% of the total oil reserves. The oil recovery factor for these fields take very low values due to the large difference in the mobilities of the displacing and displaced agents. One of the technologies, allowing to increase oil recovery from such reservoirs, is the technology of hot water and steam injection into the reservoir. In the process of warming up of the reservoir, the viscosity of the oil is significantly reduced. This leads to the reduction of the difference in the mobilities of water and oil and, consequently, to the increase of oil recovery factor. Currently, the processes of oil recovery in sandstone fractured-porous reservoirs have been studied insufficiently, including the processes of non-isothermal waterflooding of such reservoirs.
This work presents the study of isothermal and non-isothermal filtration of high-viscosity oil in fractured-porous reservoir. A numerical experiment is conducted using proprietary reservoir simulator with the capability to model the fluid motion in conditions of non-isothermal processes and a solitary long cracks in the formation. In the simulation the unstructured grid (Voronoi polygons) is used. At the core of the simulator there is a mathematical model of filtration — the “black oil”. It is established that the efficacy of non-isothermal waterflooding in fractured-porous collector is strongly dependent on the configuration of the cracks. Despite a significant increase in oil production, the efficiency caused by producing hot water in the fissured-porous aquifer, in most examined cases, is lower than in isotropic porous layer. The analysis of the volumes of injection and extraction of hot water on the nearby wells allows determining the predominant direction and the size of cracks in the formation.