Adaptability evaluation of HPAM and hydrophobic associating polymer solution in the seventh region of Gudong oilfield

In order to solve the contradictions between the rheological behavior of polymer solution and its injectivity,the polymer is selected to suit the reservoir conditions of strong heterogeneity and unconsolidated reservoir structure,and flow experiments are carried out in the cores with different lengths.The pressure of different locations in the same core are measured,and evaluation method of polymer injectivity is established,and the injectivity of HPAM and hydrophobic associating polymer solution are evaluated;the produced fluid is taken out from outlet end of different cores to study distribution characteristics of polymer solution's resistance coefficient,residual resistance factor and viscosity in near wellbore area and deep reservoir.The experimental results show that,the rising rate of pressure gradient of injecting polymer HJ is 16.37 MPa·m-1·PV-1,and the stable value of pressure gradient is 5.68 MPa·m-1,both of them are less than the values of polymer DH5 and B4 with the same concentration.From the ability to improve the sweep efficiency and rheological behavior of polymer solution,the resistance coefficient,residual resistance factor and viscosity reserve rate of polymer DH5 is respectively 283.86、39.4 and 0.713,which are much larger than the values of polymer B4 and HJ with the same concentration.The evaluation result of polymer injectivity and distribution characteristics of rheological behavior shows that polymer HJ whose concentration is 1.8 g/L is better than polymer DH5 and B4 with the same concentration.