Abstract: The conventional water flooding of heavy oil reservoir development mainly faces the problems of high crude oil viscosity,strong reservoir heterogeneity and low recovery efficiency.Based on chemical flooding effect of ordinary heavy oil reservoir in Nan15-5# station of eastern area in Gudao oilfield,aiming at different crude oil viscosity conditions in Shengli oilfield,in combination with actual dynamic field status,the numerical simulation model of chemical flooding reservoir has been established.By collecting different viscosity of crude oil reservoir of high pressure physical properties,phase permeability curve,development of test data,the study of different crude oil viscosity on the water flooding,the chemical flooding development effect and the influence of injection-production capacity have been carried out.Taking raising the recovery factor and economic indicators into consideration,the underground crude oil viscosity is preliminarily determined to be 500 mPa·s.Under the condition of appropriate viscosity of crude oil,the application of chemical flooding technology can improve the oil recovery of heavy oil reservoir.