EOR Technologies for Permocarbonic Deposit of High-viscosity Oil in Usinskoye Oil Field - Experience and Prospect

Presented are the results of laboratory research and field tests of physicochemical technologies intended to improve oil recovery of high-viscosity oil deposits developed by steam injection. To increase the efficiency of thermal-steam and cyclic-steam stimulations we proposed to combine them with physicochemical methods using thermotropic gel-forming and oil-displacing systems: the gels increase reservoir coverage by steam injection and oil-displacing systems, which at thermal stimulation generate СО2 and alkaline buffer solution, promote decrease in oil viscosity and additional oil displacement. In 2007-2011 154 wells located on Permocarbonic deposit in Usinskoye oilfield were stimulated using IPC SB RAS IOR technologies. Daily increase in oil production rate ranged from 3 to 24 tons per well and additional oil production amounted to more than 2000 thousand tons. A complex technology of alternating injections of steam, thermotropic gel-forming and surfactant-based oil-displacing systems was shown to be promising to provide increased reservoir coverage with steam injection and oil after-washing.