experimental assessment of hybrid low salinity water and polymer flooding (lspf) for wettability alteration of oil-wet sandstones reservoirs

Low salinity water flooding (lswf) is one of the enhanced oil recovery (eor) methods that has recently received much attention. research studies show the fact that change of contact angle from the oil wet towards water wet can improve the production in the water injection process, depending on the rock/water/oil balance. therefore, in different oil reservoirs, the optimal salinity and composition of injected water can be different based on the crude oil/water/rock (cobr) system. as a result, it is necessary to consider recognizing the effect of salinity and optimal composition of injected water on the initial equilibrium water/oil/rock system. the main goal of this research is to investigate the effectiveness of hybrid low salinity and polymer on fluid/rock properties of specific oil/rock/brine system from southwest iran. in this study, the wettability behavior for several aqueous samples was identified by measuring the contact angle of crude oil on the quartz slides before and after contact with the brine and polymer solutions. from the experimental results, in the case of 2xcsw quartz surface shows a very strong oil wet behavior. even after adding polymer (500ppm and 1000ppm) the changes in contact angle were not significant. however, with reducing the salinity of water (sw), the change of contact angle was remarkable. for instance in the case of quartz/crude oil/sw+1000 ppm hpam the contact angle changed from about 175°, to the ultimate value of 130° after 60 hours.