Experiment study on viscoelasticity of associative polymer solution under simulated reservoir conditions

In order to determine whether the viscoelasticity of associative polymer solution(APS) is better or not under real reservoir conditions,the effect of concentration and salinity on the viscoelasticity of APS is analyzed by simulating major reservoir conditions of Daqing Oilfield.The result shows that the effect is the same as it is on HPAM solution.However,the viscoelasticity of HPAM solution is produced differently from that of APS.That is,the viscoelasticity of HPAM solution is generated from the entanglement of molecular chains,while the viscoelasticity of APS is mainly causes by the association reactions between molecular chains.APS viscoelasticity is obvious under much lower concentration.It is much higher than that of HPAM solution within low and wide frequency range.It is revealed that APS has viscoelasticity when it flows in porous media with lower shear rate.That means the purpose of improving oil displacement efficiency can be realized relying on APS viscoelasticity with lower injection rate.