Experimental Study on Reflection Superiority of Multisensors Measurement-While-Drilling of Roof Bolter

The measurement-while-drilling (MWD) technology of roof bolter can reveal properties and structure of drilling medium through various monitoring indicators. Studying the reflection superiority of different indicators under certain basic conditions is of great significance for the indicator selection and development of on-site MWD instrumentation. So, in this study, relatively precise experiments are carried out to study the feedback effect of various parameters on different lithology under a certain Rotation rate, multi-sensors acquisition is adopted relying on two kinds of rocks and their combination. The MWD indicators of Propulsion speed, Torque, Thrust, and Vibration speeds in three directions of drill rig are analyzed, and the reflection superiority sequencing of the indicators is obtained. In addition, the influences of shallow drilling difficulty and deep drilling difficulty on the MWD indicators are also discussed to prompt precautions when applying the indicators. Results show that the Torque and Z-Vibration indicators can not only better reveal the rock strength, but also eliminate the influence of shallow and deep drilling difficult areas to some extent, which should be firstly selected. The revealed results lay a foundation for optimization indicators selection of roof bolter MWD method, the development of field instrumentation and site project design.