Thermal steam stimulation (TSS) is considered the most effective of current methods for heavy-oil production. However, the method has problems with low coverage by steam injection and decreased efficiency at later stages of development. This paper presents the results of solving these problems by combining thermal steam and physicochemical stimulations and using “cold” technologies involving thermotropic gel-forming and oil-displacing systems.
In Russia, the amount of oil reserves considered difficult to recover is constantly increasing. Active reserves account for one-third of all prospected reserves, and the difficult-to-recover oil reserves account for 67%. High-viscosity oils are 13% of the difficult-to-recover oils, and low-permeability formations account for 36%. The amount of heavy and high-viscosity oil is several times greater than the amount of light and low-viscosity oil. Therefore, the development of the deposits of heavy and high-viscosity oils is given more attention. To develop heavy- and high-viscosity-oil reservoirs effectively and increase oil production, new, integrated enhanced-oil-recovery (EOR) technologies are necessary. The new technologies addressed here combine basic reservoir stimulation by water or steam injection and physicochemical methods, increasing reservoir coverage and oil-displacement factors and improving the development.
In recent years, thermal methods—oil displacement with steam, cyclic steam injection, and steam-assisted gravity drainage—have been the most widespread EOR methods used in heavy-oil fields. One can improve the efficiency of steam stimulation by combining it with physicochemical methods—in particular, using thermotropic gel-forming and oil-displacing systems—thereby increasing the reservoir coverage by steam injection and providing additional oil displacement....
Pilot Tests of New Enhanced-Oil-Recovery Technologies for Heavy-Oil Reservoirs
01 March 2016