Applying the Synergistic Effect of Chemically Low Salinity Water Flooding Assisted Fines Migration in Coated Micromodel

Summary One of the important subjects in enhanced oil recovery (EOR) is low salinity water (LSW) flooding and it has been performed as the secondary oil recovery. Many studies have reported that LSW flooding can increase recovery in sandstone and carbonate reservoirs. The main goal of this investigation is comparing the synergistic effect of polymer, water salinity and the presence of fines migration on final recovery which have rarely investigated before. A series of experiments have been done at high temperature (80 °C), including fluid-fluid interaction tests, rock-fluid interaction tests, and micromodel flooding tests. Six aqueous solutions that have been applied for EOR purposes include sea water (SW), ten times diluted sea water (LSW), SW+ hydrolyzed polyacrylamide (HPAM), LSW+HPAM, deionized water (DW), and DW+HPAM. The results show that the high concentration of cations caused the best efficiency in interfacial tension reduction by SW+HPAM. LSW+HPAM has the highest recovery due to the high performance of HPAM, suitable wettability alteration, and better emulsification. Moreover, it was observed in the sandstone coated micromodel flooding test that fine migration has a positive impact on recovery in the case of LSW+HPAM. However, in the case of DW+HPAM, recovery slightly dwindled due to the pore blocking.