Development of Polymer Gel Plugging Removal Agent in Suizhong 361 Oilfield

Abstract

Suizhong 361 offshore oilfield has applied polymer gel to profile control operations. With the continuous injection of the polymer gel, packers had not been put down in the whole of profile job because of the special situation of offshore oilfield. It has resulted that the polymer gel not only blocked layer segments of high permeability, but also blocked the rest lays. This situation makes the subsequent construction impossible and fails to reach the purpose of profile control. Therefore an effective blocking remover is necessary to break down reservoirs and open the low permeability layers, so that the polymer gel will be continued injecting into the reservoirs for subsequent construction. The purpose of profile will be achieved. Based on the actual blocking situation of Suizhong 361 oilfield, as well as the blockage removing mechanism of plugging removal agent and the profile control mechanism of polymer gel, a new plugging removal agent formula has been developed by screening and optimizing the type and mass concentration of blocking removal agent. Research shows that degradation rate of the new formula has reached above 90%, which has an important practical significance for enhancing oil recovery and reducing the cost of oil production.