Abstract
In natural gas wells, gas production decreases due to the decline of reservoir pressure. The cause of this loss of gas production is liquid loading that occurs when water and condensate enter and remain in the bottom of the well. Foaming agents are frequently used to aid in the unloading of water and condensate accumulated in the production tubing. Fundamental surfactant properties of foamers have been measured and these have been successfully correlated to unloading performance. This provides a fundamental understanding of how foamers work and provides a rapid evaluation technique.