Surig gas field is a typical "low-permeability, low-pressure, low-productivity" gas field, with rapid pressure decrease in gas wells after production, and serious fluid accumulation at the bottom of gas wells, which has a greater impact on natural gas extraction. In order to avoid the accumulation of fluids in the wellbore, the foam drainage process is commonly used in Sulige gas field, but due to the high content of light hydrocarbons and methanol in the gas field as well as the high mineralisation of formation water, and the implementation of downhole throttling in some of the gas wells, the actual application effect is not satisfactory. In response to the above problems, through data collection and experimental analysis, the water production characteristics and water quality characteristics of Su A block of Surig gas field were clarified, and it was believed that the formation water type of this block was CaCl2 type with high mineralisation. On this basis, the conventional performance evaluation and throughput effect experiments of the two in-use foaming agents were carried out, and it was found that the foaming power and liquid-carrying capacity of the two foaming agents were better at different concentrations and mineralisation degrees, and the mass fraction of 0.30% for both foaming agents when foaming was the optimal ratio in the process of draining and extracting gas from Sulige gas field Su A block.