A binary surfactant mixture that can generate stable, high quality foam at insitu conditions has been developed in this study. This paper presents laboratory results of this surfactant system and discusses its application in the gas well production.
We have used Ross-Miles, Waring Blender and Drill-Aid methods to evaluate foamability, half life of foam volume decay, and foam stability. It was found that a mixture composed of THSP, a derivative of Tea Plant, and SDS (sodium dodecyl sulfate) is a desirable aqueous base surfactant foaming liquid. It presents much better foam performance than other surfactants used before. The effects of H2S, salts and surfactant concentrations, condensate and reservoir temperatures on the THSP-SDS mixture in foamability and foam stability are investigated. At insitu conditions, this surfactant mixture is only one that can be used to drain water out from the gas well, and therefore enhanced gas well productivity.
In this paper, we will present chemical compositions of the THSP-SDS, show all the laboratory data and test procedures, and illustrate field application results. Research findings in this work provide useful information for engineers involved in using foam drainage in gas well production.