New Directional Drilling Technology in Underground Coal Mine

With the investigation on the technical status of the available directional drilling in underground coal mine and the new technologies in the petrol drilling area,the paper in detail stated the new technologies and development tendency of the directional drilling in the underground coal mine,including the measuring system with the drilling operation for the measurement of the drilling bit position,the downhole motor providing the power of the drilling bit,the brand-new rotary guide drilling system and other advanced technologies.Among them,the key technology of the measuring system with the drilling operation was the seal of the drilling rods and the seal between the connections of the permanent electric cables in the drilling rods on the premise to ensure the strength of the drilling rods.The key point to be solved for the downhole motor was the service life of the stator and the bearing of the motor.The measuring system with the drilling operation and the downhole motor are in a preliminary application stage in China coal mines and are needed to be well developed.The application of the rotary guide system in the underground mines would be a main development tendency.