Study on compound drilling tools of single bendingscrew motor and hydro hammer

In order to solve the problem of low efficiency of directional drilling in hard rock underground coal mine, the combination of single bending screw motor and hydro hammer is put forward, which has the characteristics of controlled trajectory and high efficiency of directional drilling in hard rock. This paper introduces the combination of the compound drilling tools and the principle of realizing the impact rotary directional drilling, and studies the concrete implementation methods, including the combination of drilling tools, the selection of tools, the matching of flow, the anti-vibration of the drilling measurement system and the design of special bit. The results show that the hydro hammer should be set up between the single curved screw motor and the bit. In order to meet the requirements of the low speed of the hydro hammer and the need of the bending angle of the single bending screw motor, a low speed and adjustable curved shell screw motor is made. According to the work displacement of different drilling tools, three kinds of flow matching methods are put forward. Based on the mechanism of rock breaking by compound drilling, a column-chip mixed type bit is designed. Finally, the possible problems are put forward, and some suggestions for solving the problems are given.