文摘
Aiming at the influence of temperature on foaming ability and blocking characteristics during steam injection, a study is carried out to establish a new evaluation method of foaming agents at variable temperatures in a heavy oil reservoir. The method synthetically considers the influence of temperature variation on the foaming ability, foam stability, and resistance factor by introducing some important parameters, such as the average foam comprehensive index, the average foam resistance factor, the weighted factor, and the comprehensive value of foam performance. In the laboratory, five foaming agents are quantificationally evaluated according to the method introduced in this article. The experimental results indicate that agent A, ZWF-1, is the optimum foaming agent in terms of the order of the dimensionless evaluation parameters. Aiming at an actual well group of an oilfield from China, the pilot test of foam profile control is implemented. The practice results show that the cumulative incremental oil production reaches 675.9 m3 within 3 1/2 months and the injection pressure largely increases after foam injection during steam flooding.