The first horizontal fracturing well along the coal seam in the Huainan mining area undertaken by CCTEG Xi'an Research Institute successfully produced gas and ignited recently. This is a key step taken by the mining area in the advanced regional governance technology of major disasters, and is of great significance to promoting the development of the entire coalbed methane industry chain in the Huainan area.
The Huainan mining area is located in the Huaihe alluvial plain, where the coal seams are broken and soft, and the structure is complex. Under complex geological conditions, how to achieve efficient extraction of coalbed methane and liberate high-quality coal resources has become a problem that plagues many mines in the mining area. With the increase in mining depth, there are goafs and tunnels above the mining area, making the extraction of coalbed methane even more difficult.
In response to these problems faced by the mining area, CCTEG Xi'an Research Institute organized the coalbed methane project team to carry out targeted technical research and development work. The hydraulic pumping perforation-bridge plug joint perforation process, multi-cluster, horizontal two-wing + vertical downward perforation method, and large-diameter low-temperature soluble bridge plugs were used, which greatly reduced the amount of subsequent drilling and plugging work. At the same time, the dynamic control of the fracturing construction process was adopted to avoid the impact on the adjacent mining working face and the upper goaf, and quickly release the spray after the fracturing project was completed, with a return rate of more than 10%. At present, the daily gas production of the test well has exceeded 1,300 cubic meters.
The successful gas production of the test well marks a major breakthrough in the extraction of coalbed methane by horizontal well fracturing, and lays a solid foundation for the innovation of gas control mode and the improvement of deep resource exploitation technology in Huainan area.
