Abstract: The Jurassic gas reservoir in western Sichuan is a typical low-porosity and low-permeability sandstone gas reservoir, which produces a small amount of formation water during the development of the gas reservoir, and there is no obvious edge and bottom water or inter-layer water. With the continuous development of the gas field, the accumulation of fluid at the bottom of gas wells has intensified, resulting in rapidly decline of production and pressure, short stable production period and long low-pressure and low-production production time, and deliquification technology is a key factor for long-term stable gas production. Based on 25 years of research and practice, a set of diversified wellbore diagnostic techniques for water-producing gas wells is established and improved, based on flow-pressure measurements, echometer test and empirical methods, according to the law of gas well energy change, a differentiated foam drainage technology, supplemented by complementary gas lift deliquification and velocity strings artificial lift methods is formed, by the development of digital technology, a management system of "fine diagnosis + intelligent process integration" is proposed, intelligent supporting devices such as online diagnosis of fluid accumulation, cluster wells foaming and plunger lift device is developed. Through more than 1 200 gas wells application, it has effectively improved the effect of gas well drainage and production stabilization, and reduced the reduction of comprehensive decline of old wells, which has certain significance for the development of similar gas fields at home and abroad.

Key words: tight sandstone gas reservoir, foaming drainage, plunger lift, velocity strings, deliquification lift