This paper describes the industrial pilot results of foam flooding for enhanced oil recovery. The results are explained by the laboratory results obtained.

Based on the experiences of the single well foam-flooding results on the Lao Jun Miao field in northwestern China, an industrial pilot foam-flooding operation was carried out in the middle of the reservoir in this field in October 1979. This pilot operation involved 18 production wells and 8 injection wells. The area of the pilot operation was 1.23 km2.

A response was obtained from a small number of the production wells, but no response was obtained from the other wells even two years later.

To analyze and explain the above-mentioned pilot results, the laboratory experiments were performed. The laboratory conditions were the same as those in the industrial pilot operation. The core sample was divided into two parts. One was swept by the conventional method, and the other was remained under its natural conditions. It was found that the precipitation occurred between the foaming agent and the water injected before the solution formed by foam with air. The amount of the precipitation depends on the concentration of the foaming agent and the salinity. The solubility of the foaming agent can be improved by adding SP-3 to the solution. The dispersion coefficient of the foaming agent (K1) between the crude oil and the formation water was equal to 1.5 in the presence of three phases. The K2 between the solid and the liquid present in four phases was greater than K1. The adsorption isotherm of the foaming agent did not correspond to that of Langmuir's model. It had a maximum value at the critical micelle concentration (C.M.C). The adsorption decreased in the presence of SP-3 and SP-6 in the foam solution.

In principle, it was found that the foam was no longer formed farther than 10 meters from the injection well.

The last part of this paper describes the results of simulation using a mathematical model. They correspond to the results of the industrial pilot and the laboratory results.

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