Optimization of coiled-tubing drainage gas recovery technology in tight gas field:

In this study, research progress on critical liquid-carrying theory was introduced and its applicable conditions were presented and analyzed. The design technique of coiled-tubing drainage gas recovery was proposed, including the design method and calculation formula of diameter of coiled tubing, strength, and installation of a gas well Christmas tree, along with running time. Based on the design method, coiled-tubing drainage gas recovery technology was used in SD block of Sulige gas field to solve the problem of gas effusion. The field test results show a good effect of smaller pressure difference and higher gas production rate when the coiled-tubing drainage gas recovery method is used.