Optimization Analysis of Key Parameters of Gas Drainage Drilling in Coal Seams Based on Screw Drills

To increase the efficiency of gas extraction drilling in coal seams, screw drilling tools used in petroleum-related operations were introduced instead of common bottomhole combination drilling tools. According to the Box–Behnken experimental design principle, the significance of three main construction factors on the drilling efficiency is: the flow rate  \(>\)  pump pressure  \(>\)  feed force. The optimized drilling parameters were used to conduct a field test in Wangzhuang coal mine of Shanxi Lu’an Group. The results showed that the drilling efficiency of screw drilling increased by 39.08% and the drilling slag discharge increased by 48.28% compared with the conventional rotary drilling technique, which significantly improved the construction efficiency of coal seam drilling and is expected to reduce the gas treatment cycle and cost of coal seams to a significant extent.