Study on Pretreatment Agent for Anti-Clogging in Polymer Flooding Wells

A surfactant containing sulfonic group was used as pretreatment agent before polymer flooding. It can form a mixed absorption layer with the polar substances of rock surface. So the wettability of rock surface can be changed to some extent, and plugging near borehole zones which was caused by polymer injection can be decreased. Compared with the effects of different wettability reversal agents on the saturated static adsorption of polymer on rock surface, a wettability reversal agent with the best effect was selected to be used as pretreatment agent for anti-clogging in polymer flooding wells. Core displacement experiment showed that the pretreatment agent can prevent the polymer adsorbing on rock surface effectively, and the plugging rate and injection pressure of polymer flooding were reduced by more than 20% and 50% respectively.