The Research On The MPD Control Technology Based On The PCS7

In order to improve the drilling efficiency of abnormal oil & gas fields and ensure the safe operation of the drilling process,MPD technologies have become more and more important.However,there is few research on MPD control technology.Also the traditional control schemes of the downhole pressure can hardly satisfy the requirements with the increasingly complex downhole conditions.For solving this problem,automatic control system is designed on the MPD experimental device,and then many control methods applied to the control system,such as fuzzy control,fuzzy PID control with dynamic adjustment factor and internal model control.,The specific research work about these advanced control algorithms are as follows:(1)Build automatic control system on the MPD experimental device.Design the hardware and software configuration and the OPC connection between Wincc and MATLAB.According to the process of controlled pressure drilling,the basic control functions are achieved.This may provide the foundation for the realization of advanced control algorithms on the MPD experimental device.(2)Design the IMC controller and simulation with internal model control effect,and then apply the internal model control algorithm in the MPD experimental device.Experimental results show that the internal model controller has better performance in controlling downhole pressure than the traditional control scheme.(3)Design MPD fuzzy control methods.This method first transfers the exact hole pressure to the fuzzy variable,and makes fuzzy corresponding output according to the fuzzy rule,then gets the final reasoning result clarity.Experimental results show that the fuzzy control can control downhole pressure effectively.(4)Design MPD Fuzzy PID control method.We use fuzzy control to dynamically optimize the control parameters of the PID controller,and then use nonlinear dynamic PID controller to control downhole pressure.Experimental results show that the fuzzy PID control has better control ability than PID controller.(5)Design the Fuzzy controller with adjustment factor.Based on the original fuzzy controller,dynamic adjustment factor is further considered.The fuzzy rules can be real-time adjusted based on the current value of the error,the experimental results show that it has satisfied control effectiveness of the downhole pressure.Overall,there are four kinds of controllers designed: internal model control,fuzzy control,fuzzy PID controller and fuzzy controller with dynamically factor in this paper.These controller are applied to the MPD experiment apparatus.In fact,these research work in this paper has great practical significance to improve the control effect of downhole pressure.