Study On Influence Factors For Foam Stability And Plugging Capacity

Currently, the development of most oil and gas fields has entered the advanced stage, early stimulation resulted in an increase in the formation heterogeneity. Because of the role of profile control and oil displacement, foam be used in oil filed widely. But most of the important is the good performance of foam.Now.we have studied foam system has a stable capacity, but the law of the foam stability under harsh conditions still need to further strengthen and stabe foam system need to further improvement.At the base of searching literature home and abroad, summarizing the mechanism about foam stability and the factors that influence the foam stability. Through analysising of the characteristics of each type of surfactant and the law of mutual synergy, considering the cost of the surfactant and the type of use of the surfactant properties of different requirements, optimizing the best foam system for the low-salt reservoirs and high-salt reservoirs at 120℃.Foam stabilizer studied in different research methods. First, using conventional mixing method to study the effect HPMC on foam stability under diffent temperature and using rheometer to analyze the change of HPMC under high temperature, further analysising the influencing factors and mechanism of stable foam; A lot of experiments about sodium soil, sepiolite, attapulgite, kaolin, silica, calcium carbonate superfine on the foam stability and law of their respective interaction with the surface active agent under different conditions.Though analyzing their characters and contrasting micrograph,we found mechanism of their impact on the stability of the foam. Experimental results show that: sodium soil and sepiolite can choosed be foam stabilizer of system.In order to ensure the effect of the stabilizer, we conduct sodium soil and sepiolite to dispersion experiments and ultimately determine selecting 400 mesh 3% sodium soil as a foam stabilizer before plugging performance test of foam system. Injecting evaluation showed that foam added to the system with good soil sodium can easily injected in formation which permeability is greater than 1μm2. The single-core plugging experimental results show that the foam with sodium as stabilizer has better plugging capacity than foam and sodium. It showed that sodium has a good ability to stabilize the foam.