Research On A Hydraulic Driving Mud Pulser

The mud pulser is a communication tool for downhole transmission of measurementwhile drilling and logging while drilling. Compared with other transmission technologies,mud pulse transmission technology has advantages of bigger transmission well depth, quickertransmission speed, better reliability and lower cost. Therefore, Mud pulse transmissiontechnology gains more and more attention and gradually dominates in MWD and LWD. Apositive mud pulser was designed based on hydraulic system in this paper. Further research onthe key technical problems was done when the pulser was devised.The type of the mud pulser was introduced and the latest researches and application ofthe mud pulser at home and aboard were discussed.The structure of a mud pulse was determined in this paper. Based on the integration themud pulser was designed and on the condition of high temperature and pressure the materialsof the key components were chosen.The structure of the piston pump was determined in this paper. The performance indexes,the main structural parameters and the piston assembly of the piston pump were computedand analyzed. The piston strength and the strength and stiffness of the cylinder were checked.The thermal deformation and leakage of the piston pairs and the response character of the portvalve were simulated.Based on the analysis of the mud pulse signal transmission process and occurrencemechanism, the composition and the working principle of hydraulic system of the mud pulserwere introduced. The mathematical model of the hydraulic system was constructed. The effectof hydraulic system on the pulse signal frequency of mud pulser was simulated with AMESimsoftware. The simulation results show, to a certain extent, the increase of the speed of thepiston pump, the diameter of damping hole and the spring stiffness of the main valve and thedecrease of the length of the center pipe can improve the pulse signal frequency of the mudpulser.