The Feasibility Research Of Polymer EOR On Target Oversea High-Temperature Reservoir

The polymer flooding development prospect is from normal temperature to high temperature,so the proper thermal tolerance polymer is the key of the influence on the polymer flooding effect.Aiming at an overseas high temperature reservoir as the research object,this paper screens out the polymer flooding agents according with the high temperature reservoir by lab experiments evaluation.Systematically research the feasibility of the polymer EOR on target reservoir by static evaluation and dynamic evaluation and optimize the polymer slug design.Then the target reservoir has been researched in two parts,rock properties and fluid properties,the result is that the target reservoir is suitable for the polymer flooding,for the absolute mineral content is low,the total acid number is high,the calcium and magnesium content on formation water is low.In polymer evaluation,proper polymer samples have been screened by the parameters such as physical-chemical property,shear resistance,thermal tolerance,thermal stability,the compatibility between reservoir and polymer,polymer flooding efficiency and the resistance factor and residual resistance factor.In the polymer thermal stability experiment,a trace of oxygen will decrease the polymer viscosity seriously.The experiment results by the modified oxygen removal equipment shows that the viscosity retention after 90 days is more than 80%.In the polymer compatibility experiment,the method of hydrodynamic characteristic size has been used,and the hydrodynamic characteristic size will increase as the polymer concentration increase,meanwhile,when the solution salinity decrease,the hydrodynamic characteristic size increase,and the polymer has good compatibility with the rock more than 800 mD.After screening the proper polymer agent,the polymer slug design has been optimized.In the polymer flooding slug design optimization part,when the slug size is 0.5PV,the slug concentration is 1500 ppm and the slug injection pattern is 2000ppm+1500ppm,the polymer flooding effect is the best and can reach 27.08%.