Completion technology of surface gas extraction wells

Extraction of coalbed gas in overlying mining-disturbed area of working face through surface wells can well resolve the difficult problems of gas drainage in coal seams with low permeability. However, the low ratio of successful well completion severely limits the application of the technology. Trough the study of the key factors influencing well completion such as well layout, well structure,gas drainage by well, extraction horizons, drilling technology and drilling management etc., by applying well completion technology for gas extraction trough surface wells in Xinji No.1 mine, all 12 wells for surface gas extraction have been successfully completed, providing guarantee for the successful application of gas extraction by surface wells.