Experimental Study On Enhanced Oil Recovery By Strong ASP Flooding

The statistical data of injection pressure of wells in Daqing oilfield show that the injection pressure of three yuan composite system is close to the fracturing pressure of reservoir rock,which shows that the space of reserved pressure rise of subsequent EOR measures is very small.Therefore,in order to improve the efficiency of oil recovery measures,the actual pressure increase must be considered.Otherwise,the indoor through a large increase of injection pressure to achieve the expansion of the purpose,but the mine is difficult to meet the pressure rise requirements and even to inject difficult awkward situation.In this paper,the multiple injection system of strong base ASP flooding after EOR is studied,the multiple injection system of high concentration polymer solution,E-GLASS binary system,weak base system,cpam system,cationic gel system,microsphere system,reverse profile system are evaluated.the oil recovery,water content and injection pressure are evaluated.The results show that high concentration polymer solution,E-GLASS binary composite system," polymer gel +weak base ternary composite system" and " polymer gel + E-GLASS binary system" can further enhance oil recovery after the constant speed test,in which the technology of " polymer gel + E-GLASS binary system" is better.Under the experimental conditions of constant pressure,high concentration polymer flooding speed is low,the production duration is longer,the corresponding rate is higher,the technical and economic effect is worse.Compared with other constant pressure displacement methods," polymer gel + E-GLASS binary system" has higher yield,higher rate of producing fluid and better technical and economic results.In the strong base ternary composite system and subsequent enhanced oil recovery by oil displacement agent injection,due to the heterogeneity of the core,the initial and medium height pervious bed decreased,Pulmonary shunt fraction decreased,and medium-low permeability increased and Pulmonary shunt fraction increased.However,when the injection into the middle and late period,the number of medium-low permeability decreased,Pulmonary shunt fraction decreased,high pervious bed increased,Pulmonary shunt fraction increased,the " profile inversion" phenomenon,and then negative effect on the chemical flooding effect.