Design and Application of Downhole Drilling Mud Pulse Signal Transmission System

Abstract

Time-efficient measurement of undisturbed formation through measurement while drilling technology is an effective means to improve drilling efficiency in deep formations and increase the drilling-encounter ratio of reservoirs. Based on the application and development trend of existing downhole signal transmission technology, a pulse signal transmission system of downhole mud while drilling is designed. The system pulse generation device adopts the structure of a positive pulse generator, which is through the internal driving circuit and hydraulic circuit of the device to drive the valve head to move to generate a mud pulse signal while using the design of a limit switch to optimize the expansion spacing of the valve head so that the generated pulse signal amplitude is close. The system uses combined encoding as the encoding method, while the ground part of the system is designed to monitor and process the collected signals. Finally, the transmission capability and accuracy of the system are tested through field experiments, and the field results show that the system can work smoothly in the downhole environment to transmit downhole data to the wellhead with small errors, which meets the design requirements and field requirements. The field applications are carried out in several wells, such as the Shixi 105 well. The results show that the system has good downhole pulse signal transmission functions such as borehole inclination measurement, which helps to promote the development of existing drilling measurement technology.