An Overview of Polymer Broken Down for Increasing Injectability in Polymer Flooding

Abstract

Abstract There are many reasons for the low fluid volume of oil wells and decreasing injectability of the polymer injection wells, such as the unreasonable process, the variations of the formation conditions, imperfect injection-production pattern, and improper production management, etc., and moreover, another important factor is the injected polymer and cross-linked polymer jamming in the near wellbore area and deep oil reservoir. According to the Statistical analysis of the 289 wells in Daqing Oilfield, there are two situations existing in polymer jamming which caused decreasing injectability, one is the shallow blocking, blockage radius within 3 meters, mainly caused by the polymer micelles, polymer floc, mechanical impurities, salt scale and iron sulfide, etc.; the second is the deep formation block, blockage radius around 10 meters, there are two factors resulting in this situation, which are, high viscosity caused near wellbore area jamming and polymer retention and adsorption in far wellbore zone. Aiming at these two situations, we have developed the polymer blockage remover and its supporting technology, which can efficiently remove blockage from polymer / cross-linked polymer, through this technology, the injection stop or under-injection can be solved to some extent, and the development effects of the polymer injection area have been improved.