MPD控制系统仿真研究

发布时间：2018-09-15 19:12

【摘要】：MPD作为最近年来发展起来的钻井新技术,具有安全性高、井底压力控制精确、可有效解决窄安全钻井压力窗口问题,在国内外得到广泛的应用。很多学者对其水力学模型和自动控制模式进行了研究,提出了各种水力学模型和控制模式及算法,但是在实际应用中,这些研究存在着模型过于复杂；控制系统对瞬时突变反应慢,控制效果差等缺点,因此,有必要对水力学模型和控制系统进一步研究。本论文根据恒井底压力控压钻井控制过程和工艺的要求,构建了基于模糊控制的反馈控制框架,该控制框架的技术核心是MPD系统动态的实时水力学模型和模糊控制模型,为此,论文建立了基于在线计算的实时水力学模型,该模型可降低水力学模型的复杂程度,实时计算井底压力；此外,论文还研究了改进的模糊控制算法,通过模糊控制算法对井底压力进行调节。论文建立的反馈控制框架可使实时水力学模型与基于模糊控制算法的模糊控制器稳定、协调工作,根据井底压力设定值和实际值的偏差以及偏差的变化率,利用模糊控制算法调节节流流量和泥浆泵流量,将这些调控量输入到实时水力学模型中,计算井底压力,然后反馈到模糊控制器中,进行下一轮调节。为了应用和验证MPD反馈控制模型和算法,在Matlab环境下,设计了模糊控制器、实时水力学模型和模糊反馈控制框架的仿真模型。利用实时水力学仿真模型,仿真井底发生溢流后井底压力的变化；通过模糊反馈控制框架的仿真模型,仿真不同情况下,井底压力控制情况以及该过程中其它相关设备的调节情况(如节流阀开度,泥浆泵流量和节流流量)。通过仿真试验,该控制框架在实时水力学在线计算和MPD非线性控制方面都表现出良好的性能。本论文所建立的恒井底压力控压钻井反馈控制框架及相关理论模型和仿真模型,可提高MPD井底压力动态控制精度和响应速度,对控压钻井的控制系统的设计、开发和应用具有实用的指导意义。
[Abstract]:As a new drilling technology developed in recent years, MPD has high safety and accurate bottom hole pressure control. It can effectively solve the problem of narrow safe drilling pressure window, and has been widely used at home and abroad. Many scholars have studied its hydraulic model and automatic control model, and put forward a variety of hydraulic models and control models and algorithms. However, in practical applications, these models are too complex; Since the control system has the disadvantages of slow response to transient mutation and poor control effect, it is necessary to further study the hydraulic model and control system. According to the requirements of the control process and process of the constant bottom pressure controlled pressure drilling, a feedback control framework based on fuzzy control is constructed in this paper. The technical core of the control framework is the dynamic real-time hydraulics model and fuzzy control model of MPD system. In this paper, a real-time hydraulic model based on on-line calculation is established, which can reduce the complexity of hydraulic model and calculate the bottom hole pressure in real time. In addition, the improved fuzzy control algorithm is also studied. The bottom hole pressure is adjusted by fuzzy control algorithm. The feedback control framework established in this paper can make the real-time hydraulic model and fuzzy controller based on fuzzy control algorithm stable and coordinate, according to the deviation between the set and actual values of bottom hole pressure and the variation rate of deviation. Fuzzy control algorithm is used to adjust throttling flow rate and mud pump flow rate. These parameters are input into real time hydraulic model to calculate bottom hole pressure and then feed back to fuzzy controller for the next adjustment. In order to apply and verify the MPD feedback control model and algorithm, fuzzy controller, real-time hydraulics model and simulation model of fuzzy feedback control framework are designed in Matlab environment. By using the real-time hydraulic simulation model, the change of bottom hole pressure after overflow is simulated, and the simulation model of fuzzy feedback control framework is used to simulate the different conditions. Bottom hole pressure control and regulation of other related equipment during the process (e.g. throttle opening, mud pump flow and throttling flow). The simulation results show that the control framework has good performance in real-time hydraulics on-line calculation and MPD nonlinear control. The feedback control framework and related theoretical model and simulation model established in this paper can improve MPD bottom pressure dynamic control precision and response speed, and design the control system of controlled pressure drilling. Development and application are of practical significance.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE928

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