Design and experimental study of high speed and high torque drilling equipment in complex weak coal seam

Abstract

The drilling effect of complex and weak coal seams is of great significance for gas extraction in mines. A ZDY6000LR high-speed tracked drilling rig with high rotational speed, high power, and high torque performance was designed to address the problems of difficult slag removal, high accident rate, and hole formation during the drilling construction of complex and weak coal seams in Wangpo Coal Mine. The maximum torque was 6 000 N·m and the maximum speed was 400 r/min. The layout, power head, angle adjustment mechanism, feed body, and hydraulic system of the drilling rig were optimized to ensure that the problems such as sticking and collapsing during the drilling process can be effectively solved during the construction process. The ϕ95/ ϕ60.3 mm wide blade insert sealed auger rod with high strength and not easy to break teeth is developed and designed, and the ϕ113 mm, ϕ120 mm, ϕ133 mm triangular ladder PDC bits with high strength and low risk of broken teeth are also designed. The on-site industrial test at the 3206 working face of Wangpo Coal Mine has shown that this set of drilling equipment and drill assembly effectively solved the problems existing in the construction process such as slag discharge difficulty and top drilling of the jet hole, and improved the hole formation rate of the drilling, and the hole formation rate of the drilling above 100 meters was more than 70%, which provided an important support for the gas extraction of the coal seam of the mine.

Keywords

• complex weak coal seam
• high speed crawler drill
• plug and seal screw drill pipe
• gas extraction
• pore forming rate