Screening of Acidification Cleanup Additive by Core Flow Method

Adding cleanup additives to acid when Acidizing operations can increase the rate of spent acid in the back flow. But the acid reaction of acid rock contains large amounts of calcium, if not effective discharge of acid formation will create new and more serious blockage. Therefore, the cleanup additive should be not only compatible with the acid, but more importantly, with high levels of calcium combined with spent acid solution. At present, the literature studies for cleanup additive only estimate the compatibility with the acid, and the formula is determined by the main application effect with lower surface and interfacial tension and higher cleanup rate. The cleanup agent requires to be compatible with acid and spent acid in actual production, and spent acid discharge level requires to be improved after the reaction on the application effect, and it won't affect the permeability of rock formation, even may increase the permeability. The compatibility of various surface active agents with acid and spent acid solution is evaluated in this article. Through the core flow experiments and making comparative analysis, the non-fluorine surfactant cleanup additive formulations with good effect and low cost are screened out.