Abstract:
With the goal of developing a high-performance rotary steerable drilling tool system,the design and performances analysis of the measurement and control system of Dynamic Point-the-Bit Rotary Steerable Drilling Tool(DPRSDT) were conducted. Based on a self-designed prototype of DPRSDT,the measurement and control system was designed,and its key technologies and properties were analyzed and validated by simulating the actual drilling conditions,which included the feasibility of the measurement and control scheme,the validity of the measuring signal processing and the control algorithm.Simulation results showed that the dynamic measurement error of tool face angle has been reduced by 84% by using a complementary filtering algorithm.Moreover,a four-closed-loop control system based on permanent magnet synchronous motor current loop,motor speed loop,stabilized platform to ground speed loop and stabilized platform position loop was proposed.In addition to satisfying the performance index of steerable drilling,the proposed control scheme could restrict the error of tool face angle within 5 degrees under the working condition of the stick-slip grade of 200%.It was shown that the dynamic measurement accuracy of tool face angle could be effectively improved by a complementary filtering algorithm,and the quick and stable control of the tool face angle could be accomplished by the four-closed-loop control system.The measurement and control performance indexes of the prototype satisfied the technical requirements of actual drilling engineering.