Study On The Injection And Effective Of Polymer Flooding In Low Permeability Reservoirs

The average porosity of Wenxi San oil field was 16.4%,the permeability of which is 51×10-3 um2,in the process of waterflooding,most of the injected water is wasted via the advantageble channel of layer and the difference of water absorption is bigger on the layer profile,which leads to the low recovery degree in the low permeability layer.In his paper,different polymer samples are choosed to analyze the injection capability in cores,due to the good mobility control function of polymers.The injecton pressure,resistance factor and residual resistance factor are used to evaluate the transfusion feature of polymer samples in the porous media.Nextly,the basic property of ptimized polymer solution is analyzed.Lastly,the oil deplacement efficiency is evaluated by the physical model and numerical simulation.Real layer cores and man-made three-dimensional heterogeneous cores are used during the physical experiments.The process of numerical simulation is condcuted on the base of existing reservoir geology model.The primary influence factors of low permeability reservoir are optimized in combination of the advantageous polymer,which is used to anlyze the function feature and oil deplacement efficiency.On base of the analysis of physical and mathematical models,this paper concludes that the selected TDS-9 pilot products have good injectivity under the conditions of Wenxi San reservoir.The polymer solution has certain viscosity,stability,shearing resistance under the condition of Wenxi San oil reservoir.The polymer of DST-9 has good mobility control ability in cores.The increasment of oil recovery efficiency can reach 10%above on the base of water flooding.Via the numerical simulation,the polymer of DST-9 can decrease the water cut and improve the production of oil.The increasment of oil recovery efficiency can reach 7.17%.The decline of water cut can reach 13%.Per ton of polymer of DST-9 can produce 82 ton of oil more.