Polymer Flooding Technology For High Permeability Heavy Oil Reservoirs Based On High Residual Resistance Coefficient

There are two ways to improve the mobility control capacity of polymer solution, one is to raise solution viscosity and another is improving residual resistance factor (RRF). In the process of exploiting high-permeability and heavy-oil reservoir by polymer flooding, constrained by the current economy and technology, the way of raising solution viscosity can’t get good effect of polymer flooding. Therefore, on the condition of high-permeability and heavy-oil, in order to decrease the demand of polymer viscosity increment capacity required by these reservoirs and to enlarge the field application of polymer flooding, we should improve the capacity of polymer solution building RRF.This paper has studied the solution properties and Percolation characteristics of different kinds of polymers in the high-permeability and heavy-oil reservoir in bohai oilfield and found that on condition of same solution viscosity, high molecular weight linear partially hydrolyzed polyacrylamide(HPAM) has good injectivity but it’s capacity of building flowing resistance is limited. the structure type polymer, for example hydrophobic associating polymer (MC-10) or dendritic polymer (SGC-32), can effectually decrease the permeabilty of high permeability porous media but have some problem of injectivity. After synthesizing the capacity of mobility control, we propose a new way of mobility control based on high RRF, it is to form a new combined polymer system by adding some light structure type polymers to the solution of HPAM.We also have compared the displacing characteristics of two ways of improving the viscosity and ability of building RRF. The results show that on condition of same polymer injection amount, improving RRF and combining with a certain degree of viscosity can have good performance of effectively mobility controling and displacement result. By the combined polymer system, the higher mobility control has effectually decreased water cut, delayed the rising of water cut during the subsequent water flooding, enlaged sweep volume and finally get better results of polymer flooding development.We also have studied the characteristic of mobility control by RS600 rheometer, AFM and ESEM. Finally, we have proposed a new scheme which is fit for the development of operating fluid for high-permeability and heavy-oil reservoir exploited by polymer flooding. It can lay a foundation for the application of polymer flooding to exploiting high-permeability and heavy-oil reservoir.