Development of a plunger lift model for gas wells

Abstract

The use of plunger lift has proven to enhance the performance of gas wells with liquid production and extend the life of gas reservoirs. These wells often suffer from liquid loading problems which severely reduce gas production or kill the well requiring swabbing jobs or shut-in periods for pressure buildup. Unfortunately, the lack of a through understanding of plunger lift systems leads to disappointing results in actual applications. This study develops a plunger lift model that incorporates both the dynamic nature of the mechanical plunger system and the reservoir performance. The model takes advantage of previous work and incorporates frictional effects of the liquid slug and the expanding gas above and below the plunger. The model considers separator and flowline effects and includes modeling of the transient gas production after the slug has arrived at the surface. The model yields improved design and analysis of plunger lift installations for gas well applications. The study discusses relevant parameters in plunger lift operations including , shut-in and flowing times , liquid slug size, casing and tubing pressure , and tubing and flowline diameter. Recommendations for the optimization and design of plunger lift systems in gas wells are also discussed.