Development and application of low-molecular-weight foam solvent

Most of existing foam solvents have higher moisture content and liquid-carrying amount which can not be well adapted to field construction in low pressure and low producing wells in Sulige gas field during foam drainage. In this paper, in view of the actual situation of the liquid loading in the bottom hole in low pressure and low producing wells in Sulige gas field, a low-molecular-weight foam solvent based on the experiment is developed, and the foam properties of the foam solvent is evaluated in laboratory by use of of Ross-Miles method and stirring method, and also the moisture content of different foam solvent during the process of liquid-carrying under the same experimental conditions is compared, then some Sulige gas wells are evaluated to confirm the effect of foam drainage on-site. Comprehensive studies have shown that the new type of low-molecular-weight foam solvent is low in moisture content and can control the liquid-carrying amount and reduce pressure gradient in the wellbore, and so it’s suitable for foam drainage operation in low pressure and low producing gas wells.