The gas lifts is one of the most important drainage gas recovery technique.

Flowing bottomhole pressure(FBHP) on drainage gas recovery wells is obtained by calculating bottomhole pressure of pumping wells at home and abroad.

Calculation and analysis on efficiency of dewatering gas production system by pig gas-lift;

With petroleum development entering the later stage and increasing water production wells, the dewatering gas production technique has become an important means to reach the steady production in Chuanyu gasfield.

This paper elaborates the operating principle of the ESP and points out the application scope of the ESP in dewatering gas production as well as its features .

Aiming to the water producing situation in Weicheng gas field,this paper introduced the working principle,working require and testing results of the technique of gas recovery by water drainage.

Based on the minimum flow rate theory of unloading for gas wells, the improved Tuener model is applied to form a set of methods to optimize the foaming agents for gas recovery by water drainage with foam.

Among the common techniques of gas recovery by water drainage , the technique of gas recovery by water drainage with optimized tubing string is widely used at home because it is featured by simple operation and less cost.

Through investigation and analysis of gas lift in and broad, the evolution and up-to-date technical status of it are understood, which is helpful for the further development of this technique in our country.

This paper introduces the application of gas lift optimization technolo.

In China, gas lift is popularized in Zhongyuan, Tuha, Talimu, Sichuan, Nanhai and so on.