Abstract:
Specialized drilling technology is a critical component of drilling technology system in underground coal mine. Its core lies in adopting specialized drilling method and equipment to address unique working conditions and achieve specific drilling objectives, playing a vital role in preventing major geological disasters and advancing geological transparency in underground coal mine. The typical application scenarios of specialized drilling technology are summarized, such as precise gas control in soft-fragmented coal seam, replacing tunnel with borehole for relieved gas drainage in roof, mine water detection and release, and grouting reinforcement of water-resisting layer.It delves into the key technical challenges encountered during implementation.Focusing on drilling equipment upgrade, innovative drilling method, and drilling parameter optimization, the study comprehensively reviews the current development status, critical technological advancements, and practical outcomes.The specialized drilling technology suitable for soft-fragmented coal seam, hard rock strata, and fractured and water sensitive strata are outlined, and the existing technical bottlenecks and challenges are identified.Given the evolving trends of diversified demand, equipment intelligence, and region-specific adaptation in underground specialized drilling technology, future research priorities are proposed: ① To enhance air directional drilling technology for soft-fragmented coal seam to improve formation adaptability and process compatibility. ② To advance high-efficiency drilling acceleration technology and tool for hard rock strata to boost rock-breaking efficiency and service life of impact drilling tool. ③ To overcome theoretical and technical barrier in pressure-controlled drilling under near-horizontal condition to strengthen borehole formation capability in fractured and water-sensitive strata of roof or floor. ④ To accelerate the improvement of the reliability and stability of intelligent drilling technology and equipment in underground coal mine, and promote the realization of the transformation of specialized drilling technology from equipment intelligence to engineering intelligence. ⑤ To research and constructe specialized drilling technology system of regional, mining area and mine, and promote their wide application and in-depth development in the coal mining industry.The study can provide an important reference for the technological innovation and efficiency improvement of drilling process in underground coal mine.