Applicable gas-water ratio experiment research for downhole throttle technique of production well in Suqiao gas storage

In order to determine the applicable gas-water ration production conditions in water-producing gas wells with downhole throttle in Suqiao gas storage, an air-water two phase choke test was conducted based on stimulated experiment well with depth of 930 m. through choke flow pattern watch window and real-time gathering data, the performance and characteristic of choke flow have been monitored and analyzed under various flow forms. The results showed that the desired production differential pressure for slug fluid flows through wellhole was greater than that for gas, and which resulted in that a large part of liquid fell back to bottom hole; pressures before and after chock, gas and water productions all had large fluctuation, meanwhile, the stability of chock flow was very poor. While the flow pattern was mist flow, those parameters changed slightly and choke flow became rather stable. So the applicable gas-water ration of water-producing gas wells with downhole throttle in Suqiao gas storage is 1800~2000 m3/m3 for slug transmitting to mist flow. Considering the effect of two-phase choke stability on tubing water drainage, the suitable condition for throttling downhole is mist flow, and the chock radius should not design too small for slug flow in large amount volume of gas well.