Research Of Key Technology With Drilling Stem Fixed With Cable In Directional Drilling Under Coal Mine

When drilling the hole inside telecommunicates with the hole outside using special drill pipe, so the thesis researched the key technologies of the drilling communications, the major object of study is the relevant characteristics of drill pipe, including communications of the electrical characteristics and mechanical properties. Are as follows:â‘ In accordance with the structure of communication drill pipe, reference the distribution formula of the coaxial cable to calculating the parameters, obtain the RGLC expression of communication pipe, analyse the relationship between signal frequency and various electrical characteristics, research the speed of electromagnetic wave signal when transmitting through pipe , as well as the attenuation in some frequency phase . At last it establishes a general analysis ways under any conditions.â‘¡Through the circuit model of drill pipe , we can set up the transmission line equation for simulation analysis. These simulation results will provide an important reference to the entire communications system. In accordance with input threshold, we can determine the scope of transmission signal frequency.â‘¢Using finite element software ANSYS, we analyse and compare several forms of thread joint, then get the fluence of shoulder model,thread taper and tooth structure. Through the von Mises we can campare the output. At last analyse the main factors of sealing the drill pipe.