Experimental Study On The Gas Channeling And Anti-gas Channeling During Foam Flooding

As the foam flooding has both high strength profile control ability and good displacement efficiency,it can not only protect the formation but also increase the sweep and displacement efficiency rapidly.Therefore,it is a widely-used technology with good development prospect.However,during the foam flooding,the gas channeling will be existed so that it will influence the oil recovery.Thus,it is crucial to study the mechanism and gas channeling laws during the flooding.It will provide theoretical basis for technology pilot test and large-scale application.In this paper,we estimate the integrated performance of the foam system through the laboratory experiments.The optimization concentration of foam agent is 0.5%.Under this condition,foam has a good performance of stability.It has a long half life period and better reservoir adaptability.Meanwhile,it has a low cost and high economic benefit.We study the gas channeling laws through the sand packs of both single and double cells.The results show that when the permeability is too high,there are large filtration paths in the porous medium.The size of foam can not match the filtration path,so the resistance factor of foam is lower.As a result,the foam can not form the efficient blockage.High foam agent concentration can cause a high strength of liquid film.The function of liquid film flowing can reduce the chance of gas channeling.Compared with the slug injection and gas/liquid injection,the foam from generator has a better quality and has less chance of gas channeling.The velocity of injection is lower,the chance of gas channeling is less.However,when the value of velocity is above the certain one,the blockage ability of foam becomes stable.Due to the increasing fluid mobility of gas phase and gas/liquid ratio,the resistance of foam in the porous medium is rising gradually.In order to define the gas channeling opportunity and degree,we bring up Ig,and define the value of 0.5 as the critical point.The gel foam has a better performance than the common foam.Therefore,it can be chosen the reasonable concentration of gel foam to reduce the chance of gas channeling during the oil field development.During the foam flooding,the gel foam can be injected to strength the blockage effect in order to provide guarantee for the oil recovery enhancement.