Synthesis and Performance Evaluation of Temperature and Salt-Resistant Foam Drainage Agent XY-1

The production of the gas well continues to decline due to the prevailing accumulation of flowback fluid in the well. The flowback fluid can be carried out by agitation of the airflow at the bottom of the gas well after a foam drainage agent is added, thereby increasing the production of the gas well. The high temperature at the bottom of the well and the high salinity, pH, and methanol content of the flowback fluid will affect the foaming and foam stabilization performance of a foam drainage agent. To solve these problems, a betaine-type foam drainage agent XY-1 is synthesized by a two-step etherification and one-step quaternization method. The agent’s synthesis conditions were optimized, the best reaction temperature was 50 °C, the optimal feeding ratio of DED to CHPS-Na was 1:7, and the best reaction time was 8 h. The foaming and foam stabilization performance of the foam drainage agent were evaluated using the ross–miles method. The experimental results show that foam drainage agent XY-1 can effectively reduce the surface tension of pure water to less than 25mN/m and has good performance at 40 g/L salinity, 90 °C high temperature, and 15% condensate of methanol. Compared with foam drainage agent used on site, foam drainage agent XY-1 has better performance than foam drainage agent used on site.