Simulation Of MPD Control System

Managed pressure drilling (MPD) is emerging as a powerful technology for precise control of wellbore pressure within tight bounds and high security. Many experts studied the dynamic control of bottom hole pressure and Proposed a lot of hydraulics model and control methods, In a real world application it is too complex to calculate the hydraulics models and For the control methods it is poor for momentary pressure variation, So it needs to further research on hydraulics model and control system.The paper studies the constant bottom hole managed pressure drilling(CBHP MPD) by developing the feedback control framework of Fuzzy control, Which is constituted by the real-time dynamic hydraulics model of MPD system and the fuzzy controller. So, it builds hydraulics model to calculate the bottom hole pressure by online calculation, this model can lower the complexity of hydraulics model.In addition, this paper studies the improved fuzzy control algorithm, this algorithm can adjust the bottom hole pressure.The hydraulics model is calculated the bottom hole pressure by online calculation, The fuzzy controller controls of bottom hole pressure via fuzzy control algorithm. According to the error of bottom hole pressure and the error difference, The feedback control framework utilizes the fuzzy controller to regulate the differential of the backpressure and choke flow rate and the mud pump flow rate, regulations then are inputed to the real-time dynamic hydraulics to calculate the bottom hole pressure, which feedback to the fuzzy controller for the next round of adjustment.The paper designs a fuzzy controller, a real-time hydraulics model and a simulation model of fuzzy feedback control framework to verify the effect of feedback control in Matlab, It simulates the variation of the bottom hole pressure when the bottom hole pressure by using the real-time hydraulics simulation model. The simulation model of the fuzzy feedback control framework is used to simulate the variation of bottom hole pressure and the control of relevant equipment (such as choke opening, Mud pump flow and choke flowrate) when some well drilling incidents is coming.Via the simulation of some well drilling incidents, It tests the online real-time hydraulics calculation and the nonlinear control of Fuzzy feedback control framework, Which show the strong performance. It has guiding significance for design, development and applying of the control system of MPD.