Experimental Study On Alternative Injection And Flooding Of CO₂ And ASP Flooding

As most oil fields in China gradually enter high water cuts and extra high water cuts,the use of water or polymer flooding alone is only around 35%,and there are also mount of oil reserves still underground.Therefore,most of oilfields have gradually adopted tertiary oil recovery technology in recent years.In the tertiary oil recovery process,tertiary oil recovery methods such as gas injection,chemical injection,microbial injection,and ultrasonic stimulation are widely used in oil fields,However,the use of any oil recovery technology alone has certain limitations.Therefore,how to effectively extract a large amount of remaining reserves remaining in the formation and increase economic efficiency has become an important issue in the oil industry.This paper introduces a new method that combines CO₂ and ASP flooding,two rapidly developing enhanced oil recovery technologies,and proposes a new model of CO₂/ASP flooding.Alternating injection combined with gas flooding can increase microscopic displacement efficiency and ASP flooding can increase macroscopic sweep efficiency.Alternating use of these two different forms of chemical agents can have good synergistic effects and form complementary advantages to optimize injection methods.To achieve enhanced oil recovery.Base on reading and analyzing numbers of literature studies,laboratory simulation experiments were conducted to investigate whether this method can significantly increase oil recovery.After reading and analyzing a lot of literature,the physical simulation experiments have been taken to discuss the feasibility of improving the oil recovery by this method..Results of the experiment:1.CO₂ and water alternating injection in the long core to improve the oil recovery of water drive from 38.96% to 67.90%.The recovery increased by 28.94 percent.2.ASP flooding system injected into long core to improve the oil recovery of water drive from 39.01% to 64.60%.The recovery increased by 25.59 percent.3.CO₂ flooding system injected into long core to improve the oil recovery of water drive from 39.01% to 72.84%.The recovery increased by 33.84 percent.The advantages are obviously superior to the CO₂ injection or the ASP flooding injection,the main reason is injection CO₂ can cause formation crude oil volume expansion,so that,some of the oil volume in the blind end voids expands into the permeation channels,the viscosity of crude oil in the permeation channels decreased and the ratio of crude oil utilization was increased.At the same time,because of the injection of the ASP,increased sweep volume,more void space is flows into the infiltration channels,the emulsification of ternary system drives out part of oil part of oil film.