Retrievable Whipstock in Underground Coal Mine

A retrievable whipstock was developed for directional drilling construction in underground coal mine. The retrievable whipstock was composed of lean-iron, packer and fishing drill pipe. The structure performance characteristics, work principle and use method of this device were introduced, and it had been proved that the device had a good performance via the industrial test. The retrievable whipstock was applied in directional drilling construction of underground coal mine, so the technical problem could be solved that it was difficult to open a branch hole in the hard rock, and the drilling efficiency was improved greatly, which provided guarantee for coal mine safety and efficient production.