Research status and tendency on underground rotary drilling dynamics in coal mine

In view of the technical requirements of safe and efficient development of underground drilling in coal mine, the paper presents the composition and work characteristics of the technical system of underground rotary drilling in coal mine. The relevant main research achievements are analyzed and commented, which are drilling rig system dynamics, drill string dynamics and rock breaking of drill bit dynamics. Based on the characteristics of underground rotary drilling in coal mine, the results and problems of current rotary drilling dynamics are analyzed. It includes the establishment of integrated dynamic model of multi-technology system and working environment, the research way of drill string dynamics under complex alternating load and the problem of efficient rock breaking by PDC bit. The development direction of underground drilling dynamics is discussed in this paper. Firstly, multi-domain modeling and simulation of underground drilling system should be realized. The machinery, hydraulic, electrical, control, information and other model library of drilling rig needs to be established preliminarily. A system-level model is established for drilling parameters, mud pump pressure, control information perception and other specific construction applications in drilling construction, and a multidisciplinary coupling is formed to comprehensively analyze and predict the dynamic performance of drilling technology system. Secondly, we can try to analyze the dynamic characteristics of drilling object in virtual environment through semi-physical simulation test. Through the establishment of mathematical model, programming, interactive feedback and other technical processes in the computer operation, further obtained the power head torque, feed/pull force, mud pump pressure and other drilling system main parameters of the dynamic feedback. The research on underground rotary drilling dynamics in coal mine will be helpful to further improve the level of underground drilling technology and equipment design, and provide reference for safe and efficient intelligent drilling in coal mine.