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.