Recently, the project Research on Intelligent Targeted Drilling Technology for Soft and Broken Coal Seams in the Wuhai Mining Area and Engineering Demonstration, undertaken by China Shenhua’s Wuhai Energy, passed its final acceptance review. The project has not only effectively resolved technical challenges which long beset the industry but also injected a strong technological impetus for safe and efficient mining operation.
Coal seams in the Wuhai mining area are generally characterized as “broken, soft, and of low permeability”. Conventional hydraulic drilling techniques suffer from difficulties in hole formation and low trajectory control accuracy. Moreover, traditional operations lack real-time sensing of formation characteristics, relying on limited monitoring parameters and delayed data analysis, which leads to inefficient gas control and elevated risks.
To tackle these challenges, the project team conducted systematic research on pneumatic targeted drilling technology for soft and broken coal seams. They overcame several key technical hurdles, including precise coal-rock interface identification using azimuthal gamma-ray logging while drilling, multi-parameter monitoring and early warning systems while drilling, automated drilling rigs and auxiliary equipment, and a series of matched drilling tools. These innovations have significantly improved drilling trajectory control, hole completion rates, and coal-seam intersection rates, delivering a comprehensive intelligent solution for targeted drilling in soft and broken coal seams.
The project results were validated through a large-scale engineering demonstration at the Luotuoshan Coal Mine. The maximum drilling depth reached 651 meters, setting a new national record for underground pneumatic directional drilling in coal mines. The overall hole completion rate stood at 87.5%, with an average monthly rig efficiency of 2,060 meters. These outcomes have substantially increased gas extraction efficiency in soft and broken coal seams, effectively reduced gas disaster risks, and provided a solid foundation for mine safety. They have also significantly improved the economic returns and management performance of drilling operations, while offering a replicable and scalable technical model for other mining areas in China with similar geological conditions.
