基于线性节流阀的MPD井筒压力调控方法

MPD wellbore pressure control method based on linear throttle valve

王果

WANG Guo

页岩油气富集机理与有效开发国家重点试验室 中国石油化工股份有限公司石油工程技术研究院

State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development, Beijing 102200, China SINOPEC Research Institute of Petroleum Engineering, Beijing 102200, China

针对MPD钻井影响压力调控精度的关键问题，从底层调控硬件到顶层测算模型及调控方法等进行了原创性研究。首先针对现有节流阀难以满足回压精细控制的难题，提出了过流面积轴向动态优化的压降线性调控新理念，并设计出在25%~85%的开度范围内压降随开度线性变化的节流阀；然后针对井筒压力难以准确测算、控制模型复杂等问题，建立了一种实时模型系数预测方法，实现了井底压力实时准确测算；最后结合回压快速调控实现了井筒压力串级控制，解决了井筒压力精细调控难题。开发了井筒压力调控模块，通过实验及应用验证了控制方法的效果，井底压力控制精度达到0.2 MPa。研究结果为井筒压力精细调控提供理论与技术支撑。

To address the key problems influencing the pressure control accuracy in the process of MPD, this paper carried out original researches from bottom-level control hardware to top-level calculation model and control method. Firstly, in view that existing throttle valves can hardly realize fine back pressure control, a new concept of linear pressure drop control of axial dynamic optimization of open area was put forward, and the throttle valve whose pressure drop varies linearly with the opening in the opening range of 25%-85% was designed. Then, in view that wellbore pressure can be hardly calculated accurately and the control model is complicated, a kind of real-time model coefficient prediction method was established to realize the real-time accurate calculation of bottom hole pressure. Finally, wellbore pressure serials control was realized by means of fast back pressure control, so as to solve the difficulty in the fine wellbore pressure control. Wellbore pressure control module was developed, and the control method was verified by virtue of experiment and application, which showed that the control accuracy of bottom hole pressure is up to 0.2 MPa. The research results provide theoretical and technical support for the fine wellbore pressure control.

10.13639/j.odpt.2021.02.010