Air foam flooding method for reducing gas channeling for underground thickened oil exploitation and air foaming agent of foam flooding for reducing gas channeling for underground thickened oil exploitation

Abstract

The invention discloses an air foam flooding method for reducing gas channeling for underground thickened oil exploitation and a foaming agent of the foam flooding for reducing gas channeling for the underground thickened oil exploitation. The method comprises the following steps of S1, preparation work; S2, pre-injection; S3, slug injection, specifically, the slug injection are divided three groups in total, a slug combination 1 is repeated twice for 0.06PV air foam flooding and 0.04PV water flooding, a slug combination 2 is repeated for six times for 0.03PV air foam flooding and 0.03PV water flooding, and a slug combination 3 is repeated for four times for 0.05PV three-phase mixed foam flooding and 0.05PV water flooding; S4, post-injection; and S5, parameter adjustment, and the foaming agent is prepared from the following components of, in percentage by mass, 0.43%-0.46% of anionic surfactant, 0.32%-0.35% of ampholytic surfactant and the balance water. According to the air foam flooding method, the purpose of effectively reducing the gas channeling is achieved in a step-by-step injection mode, the nitrogen content is monitored in real time, the gas injection speed and the liquid injection speed are regulated and controlled, the plugging effect of air foam flooding is effectively improved on the premise that the gas channeling does not occur, and the profile control and displacement and the oil washing efficiency of the air foam flooding are greatly improved.

Description

technical field [0001] The invention relates to the technical field of air foam flooding in oil exploitation, in particular to an air foam flooding method and a foaming agent thereof for reducing gas channeling in downhole heavy oil development. Background technique [0002] As one of the very efficient tertiary oil recovery technologies, foam flooding technology has developed rapidly in recent years. After it is injected into oil-bearing formations, it can effectively improve the swept area of ​​water injection and oil washing efficiency, and reduce the surface active substances in it. The oil-water interfacial tension and the adjustment of the oil-water mobility ratio are of great significance to the prevention and control of water channeling and gas channeling. However, due to the poor fluidity of crude oil in oil production, it is difficult to achieve a good production effect by relying on the oil reservoir's own pressure production or general water injection development...

AI Technical Summary

Problems solved by technology

However, there is a certain gap between the pore seepage law of air foam flooding in the experiment and the actual formation state, and further research is needed to optimize the air foam flooding technology and solve the problems of gas channeling

[0004] The selection and application of foaming agent is the key to realize air foam flooding. Reasonable selection of foaming agent can effectively improve foaming performance and foaming stability. In actual production, different types of foaming agents or surfactants are usually compounded Form a mixed system to make up for the defects in the performance of a single foaming agent or surfactant to achieve better results. However, due to the relatively high interfacial tension between the foaming agent and crude oil, it has poor performance in oil washing, so It is necessary to study and improve the performance of the foaming agent to obtain a more stable foaming agent with higher oil washing efficiency

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