Well-washing and stimulation technology of gas extraction wells based on sodium pyrophosphate solution

Abstract

In order to promote drainage efficiency and gas production of gas extraction well, taking the construction of gas extraction well group in a coal mine area in Huaibei as an opportunity, a series of well cleaning processes with sodium pyrophosphate as clay dispersant to prepare the well wash fluid were designed and different application tests were carried out for each well in the form of group control between wells，and the actual influence of well-washing technology with sodium pyrophosphate solution on gas production was quantitatively and qualitatively evaluated, the set of optimal schemes has been selected. The study results indicate that the optimized well-washing scheme is much better than the conventional scheme, which can increase the maximum wellhead pressure up to 140%, the average wellhead pressure up to 142%, the maximum daily gas output up to 180%, and the average daily gas output up to 165%, the gas drainage data and the stimulation effect was improved remarkably.

Keywords

• gas extraction well
• cbm wells
• well-washing technology
• sodium pyrophosphate
• extraction effect