Study And Simulation On Dynamic Annular Pressure Control System

Based on the DAPC system theory and requirement of controlled pressure drilling technology, analyze the DAPC system theory , the necessary equipment and its control processes and principles in detail.Wellhead back pressure is generated by instaling a rotary control head (RCH) in conventional drilling to change exposure wellhead into closed. The drilling fluid return from the well flow through the throttle valve, the throttle valve can adjust pressure drop.DAPC system control the wellhead back pressure by controlling the throttle opening and fluid flow of drilling fluid,and control bottom hole pressure.DAPC system effectively control formation fluid invasion in the complex formation and reduce probability of the other well drilling problems occurrence, adapted to the narrow drilling window formation of less difference between pore and fracture pressure.According to the process of drilling processes and comparing the conventional drilling, study pressure and equipment control analysis when normal drilling, pipe connection and the occurrence of kick.The components of DAPC system back pressure throttling system were analyzed, and wellhead back pressure control loop have been described. According to the the mathematical model of throttle system, make the system Bode plot of system and analyze the stability and Rapid of system based on MATLAB software.Based on MATLAB / simulink module according to PID control and fuzzy PID control principle and the role of each parameter, and set up a simulation model. Based on the model of the control system under unit step system simulation, the PI control system, PID control, and Fuzzy PID control were compared and analyzed.