Analysis on Production Characteristics of water producing Gas Wells in Yan X well block

Abstract

In Yan X well block, which is a tight gas project, the gathering & transmission system is a low-pressure system, which may cause gas well liquid loading or even complete water flooding, resulting in failure of production. In this paper, the reservoir conditions, gas-liquid velocity, and drainage capacity of gas wells in different production stages are simulated, and coupling with the models proposed by Li Min, Turner and Gray, the mechanism of gas well liquid loading is analyzed. The results show that the downhole choke can be installed to reduce the gathering & transmission pipeline pressure and prevent hydrate ice blockage; however, with the decrease of reservoir pressure, the lower part of the choke is prone to liquid loading, so it is necessary to pull out the choke in time and cooperate with other processes of gas recovery by water drainage. Moreover, the velocity string can reduce the critical liquid carrying flow rate and thus keep the gas well in long-term stable production. The application in Well Y05 shows remarkable effect after installing downhole choke and velocity string. This technology is believed to effectively improve the ultimate recovery of tight gas in Yan X well block.