Study On Branched Salt-resistant Polymer With Granular Core For Enhanced Oil Recovery

In this paper,according to the current situation of polymer flooding,such as temperature and inorganic salt ions easily leads to the viscosity degradation of polymer,combined with the requirements of seawater oilfield for the salt resistance of the polymer solution in seawater.Exploring some ways to improve the salt resistance of polymers.The idea of the article draws on the structure of hyperbranched polymer and polysaccharide-grafted core-shell polymer,and prepares a series of salt-resistant polymers with branched structure with nano-silica as the core.In the first part of the paper,the polymer was synthesized by low temperature-int-ermediate temperature method.The effects of several monomers(AMPS?DMAA?NVP?ACMO?DAC)with temperature and salt resistance on the apparent viscosity of the p olymer solution were investigated.The synthesis conditions of the polymer were optim ized by orthogonal test.The experimental results show polymer sample PASO have ex cellent performance.The second part,based on the preferred polymer formulation,expl ores the effect of different granules and initiating conditions on the viscosity of the pr oduct,branched structural polymers PASOA2 and PASOO1 show optimum tackifying a bility.The third part evaluates the temperature resistance,salt resistance,shear resistan ce,aging stability and flooding performance of the polymer solution.According to the experimental results,it is considered that all of the preferred three polymers have good salt resistance,the branched structural polymer exhibits better tackifying ability and higher viscosity retention ratio under harsh conditions than linear polymers.The viscosity retention rate of PASO in double seawater salinity water was 60%,the viscosity retention rate of PASOA2 and PASOO1 was 72% and 73% respectively.The results of the flooding experiments also showed that the performance of the branched polymer was better.The recovery rate of the PASO flooding after water flooding was 51%,the recovery of PASOA2 was 63%,and the recovery of PASOO1 was 72%.