화학공학소재연구정보센터
Energy & Fuels, Vol.34, No.5, 5715-5732, 2020
Low Salinity Polymer Flooding: Effect on Polymer Rheology, Injectivity, Retention, and Oil Recovery Efficiency
Synergism between different enhanced oil recovery (EOR) methods has always been a subject of paramount interest for oil industry as it led to the development of many successful EOR methods in the past. Low salinity water flooding is a recent development in the field of EOR, and polymer flooding is a conventional EOR technique that has been practiced for many decades. In this study, we have investigated the synergistic effects of low salinity water flooding and polymer flooding focusing on the effect of low salinity on polymer rheology, polymer solution injectivity, retention of polymer in the reservoir rock, and oil recovery efficiency of low salinity polymer flooding. The study is comprised of a multidimensional experimental approach including measurements of bulk rheology of polymer solutions prepared with brines of varying salinities, single phase displacement experiments for injectivity analyses, UV-visible and electron dispersive spectroscopy along with scanning electron microscopy for studying retention of polymer on the reservoir rock surface, and finally laboratory flooding experiments to demonstrate the oil recovery efficiency of low salinity polymer flooding synergy. The results obtained from this study show that low salinity water tremendously improves the polymer rheology that could greatly favor the oil recovery efficiency of the overall process. Low salinity water is also found to be a very impressive agent for improving displacement efficacy and the injectivity of a polymer solution. Finally, the results of enhanced oil recovery flooding experiments demonstrated that low salinity polymer flooding could significantly increase the oil recovery efficiency in comparison to either low salinity or conventional polymer flooding alone.