Experimental Study On Polymer Profile Control And Flooding In Low Permeability Sandstone Reservoir

In this paper,in view of the difficulties in waterflooding development of low permeability sandstone reservoir,by studying the mechanism of polymer flooding,and combining with the research status of polymer flooding technology,polymer rheology and polymer rheology in porous media at home and abroad,The rheological properties of polymer in porous media and the experiment of polymer flooding in laboratory were carried out.In this paper,polymer rheology and oil displacement experiments are carried out in one-dimensional physical model.In the experiments that affect the rheological properties of polymer solution,the core permeability is changed by changing the displacement times.Analysis of the conditions of injection rate and solution mass concentration to determine the influencing factors of rheological behavior of polymer solution in porous media The experimental results show that the apparent viscosity of polymer solution decreases with the increase of displacement times,and increases with the increase of core permeability and solution mass concentration.The design of these rheological properties of polymer solution for oil displacement is of great significance.In the oil displacement experiment,the distribution rule of residual oil in the core at different stages and the contribution of different pores to the recovery degree are tested by nuclear magnetic resonance(NMR)technique.The experimental results show that the oil recovery of high permeability core is higher than that of low permeability core,but the recovery of low permeability core is higher than that of high permeability core in polymer flooding and subsequent water flooding stage.The final recovery of core is higher than that of low permeability core.