控压钻井自动分流管汇系统设计与数值模拟研究

为解决精细控压钻井回压补偿系统价格高、占用井场面积大的问题，设计了一种用于控压钻井的自动分流管汇系统，用以替代现有精细控压钻井设备中的回压补偿系统。设计的自动分流管汇系统结构简单，适应能力强，具有钻井泵单泵工作模式、双泵工作模式和常规钻井大排量模式，可满足现有精细控压钻井各种工况的转换要求。根据质量守恒方程、动量守恒方程及节流阀开度的控制方式，建立了自动分流管汇系统的数学流动模型，并采用数值方法求解了数学流动模型。数学流动模型的计算结果和计算流体动力学模拟结果都表明，该自动分流管汇系统能将井口压力稳定控制在设定压力，能够满足精细控压钻井需求。 

Design and Numerical Simulation of an Automatic Diverter Manifold in Managed Pressure Drilling

Back-pressure compensation system in managed pressure drilling can be characterized by high cost and a large occupied drilling field site.Under such circumstances,an automatic diverting manifold system has been developed to replace the existing system.With its simple structure and high adaptability,the innovative automatic diverter manifold with different operation modes of single drilling pump,with dual pumps and large flow rates in conventional drilling operations which can satisfy the demands of different operation mode shifts in finely managed pressure drilling.A mathematical flow model for the innovative automatic diverter manifold system has been established based on mass conservation,momentum conservation and control over throttle valves,and the numerical flow method is used to solve the mathematical flow model.Both the fluid flow calculation results and computational fluid dynamics simulation results show that this automatic manifold system can control wellhead pressure within set pressure and meet the needs of fine pressure control drilling.