Practice and Challenge of in-seam Directional Borehole over 2000 m in Coal Mines in China

Abstract

The gas in the coal seam is an important disaster-causing factor that affects and restricts the safe and efficient mining in coal mines. The use of directional drilling in the coal seam is the preferred method to reduce the gas content and pressure of the coal seam. In the past two decades, the directional drilling technology and equipment have been widely used in high-gas coal mine in China, and remarkable gas control effects have been achieved. In view of the need for gas control in super-long working face in China, it is proposed to use ZDY12000LD directional drill rig, BLY460/13 pump, survey system and supporting drilling tools to carry out directional drilling of in-seam over 2,000m, and to summarize and form the matching technology of directional drilling over 2,000m. It provides a new way to improve the construction capability of directional borehole in coal mines and explore a new mode for gas control in long working face.