Design Of Ultrasonic Transmission System On Measurement Near By Drill Bit And Experimental Study

In recent years, the technology of down-hole drilling measurement and transmission becomes One of key technologies in drilling. Mud pulse,insulated lines,wireless and other modes of signal transmission have some restrict. So this paper is mostly about using ultrasonic transmission with signal.Design ultrasonic transmission system on measurement near by drill bit by means of theoretical analysis and experiment. This paper analyzes the ultrasound law of refraction, reflection and attenuation characteristic by the drill string, finds out a wave form of ultrasonic transmitting in drill pipe, and provides theory support for underside experiment. At the same time, according to require of underground signal transmission and space of instrument, choose compatible piezoelectricity material, develop configuration and size of a new ultrasonic transducer for experiment system, matching acoustic and electrical parameters, assure every parameter adapt to experiment requirement. Study characteristic of the transducer in experiment and choose proper signal form transmitting in drill string and its parameters. Research transmission characteristic of ultrasonic signal in drill pipe and mud motor, analyse ultrasonic attenuation in different drill tool. Design and optimize emitter circuit and receiving circuit, and design special transformer separately, which match ultrasonic transducer well, ensure that transducer woking in optimum condition. Experimentalize simulatively in room for ultrasonic transmission system on measurement near by drill bit,which validates ultrasonic as carrier to transmit signal that is feasibility,and these datas transmitted arrive at high precision. It is feasibility and stability that full suite of system testing in well.