EXPERIMENTAL INVESTIGATION ON THE EFFECT OF LOW SALINE WATER (LSW) DURING FAWAG-CO2 ON LIGHT OIL

Water flooding for a long time has been regarded as a secondary oil recovery method which can considerably increase oil production. However, even in this case, a significant amount of oil is still trapped in the reservoir. So far, to recover the remaining oil, various methods as tertiary recovery processes have been proposed. In the water flooding, it is usually pointed out that injection of low saline water change wetting properties of the reservoir during a water flood in a favorable way to improve oil recovery due to salinity.
In the tertiary recovery, several EOR methods such as continuous Gas Injection, Water Alternating Gas flooding (WAG), Simultaneous Water Alternating Gas flooding (SWAG), and Foam Assisted Water Alternating Gas (FAWAG) process have been studied. Among these methods due to high mobility control in the gas flow, FAWAG process has been found to be more feasible.
Hence, in this work based on the acceptable performance of the foregoing methods, FAWAG process is improved with low saline water. For this purpose, the oil recovery factor is compared between the application of formation water (high salinity brine) and low salinity brine during FAWAG-CO2. Type of surfactants to be used already finalized, only salinity of the brine is changing. However, several chemical screening tests will be conducted. Coreflooding will be done to determine the effect of low saline water during FAWAG on oil recovery.