Advances in the Research of Drainage Gas Recovery Process Technology for Water-Driven Gas Reservoirs
摘要
The gas–water relationship in water-driven gas reservoirs is complicated. In the middle and later stages of gas field development, it is common for gas wells to experience an increase in water production, leading to fluid accumulation in the wellbore. This phenomenon significantly limits gas field recovery rates and sustainable production. It also poses serious environmental and economic challenges. Domestic and international development practices have shown that drainage gas recovery technology, as a fundamental measure to improve recovery rates in such gas reservoirs, is critical to maintaining stable production, increasing yields, and extending the life cycle of gas fields. Aiming at the problems existing in the actual development process at present, starting from five types of conventional technology: foam drainage, plunger gas lift, velocity string, electric submersible pump and water plugging, combining two types of resumed production techniques, gas lift and coiled tubing for the serious liquid accumulation well. Comprehensively comparing and summarizing different technologies from the fundamental principles, equipment applicability, and gas field development practices. It identifies the measures applicable to the process for different gas well conditions, such as water production and pressure. On this basis, in view of the emerging composite process of gas reservoir development at home and abroad at present, it is proposed that the drainage gas recovery technology develops towards the trend of intelligence and digitalization. It has some guiding significance for the rational selection of extraction process and efficient development of gas reservoir with water in China.