Research On Measurement-while-drilling Technology Of Borehole Trajectory In Underground Coal Mine

In the process of coal production,down-hole drilling is an essential project.On one hand,it is an important method of geologic prospecting in the production of coalmine.on the other hand,it is also guarantee to solve security problems.But the down-hole rotary drilling rig mostly widespread used does no thae the function of measuring the trajectory of the borehole.Therefore,current down-hole drilling is generally blind drilling based on experience.Although,MWD technology is a good method to solve the problem,it is mainly used in KM directional drilling at present.Thus,there is still no good solution to the measure mean of the trajectory of the bore hole of common drilling machine.In this study,based on the key technology of MWD,an Attitude and Heading Reference System(AHRS)of multi-sensor was established by the method of measuring the trajectory of the AHRS can be used to measure the footage and the attitude while drilling.The error in the AHRS can be controlled through modeling processing,which can improve the precision of the system without increasing the cost of the sensors.A set of measurement system was developed,consisting of measuring nipple,console and related software components.The system can accomplish measurement while drilling at any time,data exporting,3D graphing,and the data can be automatically drawn onto the CAD maps.A lot of ground tests and three underground tests testify that this system can adapt to the complex and harsh environment underground,and it can reach the accuracy required by the borehole positioning and trajectory measurement.