Abstract: During the period of gas production,adding High Temperature Foam Drainage Agent (HTFDA) can reduce the surface tension of formation water and well-bore fluid density,improve the flowing state of water and gas,and finally achieve the goal of drainage and gas production.In this paper,the HTFDA,called YCH,which is compatible to the gas-water producing well in Yanchen Oilfield,is chosen by a serious of laboratory experiments.The practices proved that YCH,the HTFDA,ensure gas well discharge liquid continuously and production normally.