泡沫分流特性研究

为了研究泡沫在地层中的渗流特性,对气液在地层中不同注入顺序、气液注入过程中的产出规律进行了研究,分析了泡沫产生分流效应的并联管前缘流动理论,从而得到了泡沫在多孔介质中的分流特性;同时还研究了泡沫的封堵特性,通过泡沫注入实验数据分析,指出泡沫封堵存在叠加效应的认识有待商榷。研究表明:在非均质地层中,先注入气体或先注入发泡剂溶液,泡沫都可以产生分流效应;多段塞气液交替注入后,非均质地层流出的流体流速相同;分流率相同的实质是流度相同;泡沫有效封堵时,在高低渗地层的段塞式运移速度取决于孔隙,高低渗地层速度之比是孔隙度的反比。该研究对产生泡沫的现场注入气液顺序提供了指导,认识了泡沫在多孔介质中的流动本质,可指导现场泡沫调剖驱油的生产作业。下一步还需要深入研究泡沫深部调剖的方法和泡沫叠加效应。

Property study of foam divided-flow

In order to study the seepage property of foam in the formation, the different sequences of injecting gas and liquid into the formation and the production law of gas and liquid during injection are studied, furthermore, the flow theory of floam with divided flow at the front parallel pipe is analyzed. So the divided-flow property of foam in porous media is obtained. The foam blocking propertyis studied at the same time. Through analyzing the data got from the foam injection experiment, it is pointed out that the recognition that foam blocking may have superimposed effect is open to question. The study indicates that in non-homogeneous formation foam has divided-flow effect either by injecting gas first or by injecting foaming agent first. After injecting multi-block gas and liquid lternatively,the fluid flowing out from non-homogeneous formation flows at the same speed. The essence of the same divided-flow rate is the same flow speed. When the foam blocks effectively, the migration velocity of the gas-liquid slug in high and low permeability formation is subject to the pore; the ratio of the velocity in high and low permeability formation is the inverse ratio of porosity. The study providesguidance for field gas-liquid injection sequence producing foam, the essence of foam flow in porous media is recognized. This could be used to guide the profile medication and enhanced oil recovery of foam flooding on the site. Next further study needs to be conducted on the method of deep profile modification of foam flooding and the superimposed effect of foam.