The wettability with Ca2+ brine in a tight oil reservoir with zeta potential

摘要

Based on Zetasizer Nano ZS instrumentation, the zeta potential with Ca2+ and tight oil reservoir were analyzed to study the abilities and microscopic mechanisms on reservoir characteristics of wettability. The results show that in the CaCl2 solution, Ca2+ can reduce the surface hydrophilicity of tight sandstone, thus change the reservoir wetting characteristics. While increasing pH can improve reservoir wettability and facilitate tight oil development. Ca2+ can change the structural characteristics of tight reservoirs and crude oil. This provides a theoretical basis for our study of low salinity water flooding and recovery ratio.