an investigation of various salts and ph's effect on fine migration in sandstone reservoirs

Low salinity water (lsw) injection and alkaline flooding are two common enhanced oil recovery (eor) methods. these methods although has a lot of advantages, could cause some formation damages. one of the main problems during lsw and alkaline flooding is fine migration. fine migration might reduce reservoir permeability or produce and damage well facilities. ionic strength and ph are two main factors that could control fine migration in these eor methods. in this paper, the effect of four salts nacl, kcl, cacl2, and mgcl2 was studied as an ion strength parameter on fine migration. also, four ph as 6.5, 8, 10, and 12 's effect on fine migration was investigated. the results showed that the presence of salts decreases the amount of fine migration in comparison with distilled water injection and also divalent salts have a better performance than monovalent salts. furthermore, studies on ph's effect indicate that the more injection fluid's ph, the more fine migration. zeta potential measurements prove that the potential of fine particles' surfaces increases by raising fluid ph. as a result, at the higher ph, the repulsive forces between fine particles is greater and more fine migrate.