Abstract
Throughout the production life of a gas well its reservoir pressure declines and well becomes prone to liquid loading. The stationary liquid column in the wellbore exerts back pressure on the formation resulting in decrease or sometimes ceases the production. The overall outcome of this phenomenon is reduced recovery factor resulting in loss of reserves.
Increasing Liquid Gas Ratio (LGR), decreasing gas rates and velocities with decreasing reservoir pressure are the main factors contributing in liquid loading. Various methods have been used in the industry to de-liquefy gas wells and maintain production rates. One method to de-liq a gas well is down hole soap injection through 1/4" or 3/8" capillary string to reduce the effective density and surface tension of the produced liquids. This method is cheap and effective, no external source of energy is needed since it utilizes reservoir energy. Injected soap or foam must be selected according to the reservoir characteristics.
This paper shares the case studies of different wells having depleted reservoir pressures and liquid loading tendency. Foam Assisted Lift (FAL) was implemented on these wells as a de-liq technique, detailed study was carried out to observe their production behaviors and economic benefits from FAL. This work also incorporates the good and bad practices to ensure FAL is effectively de-liquefying a gas well to maximize production.
The different practices proposed in this study can be used as an analogy to ascertain soap injection is performing in the best way to attain incremental production from depleted gas wells with liquid loading problems.
