钻柱粘滑振动仿真和控制策略研究

在深井和超深井钻探过程中存在钻柱粘滑振动,不仅造成机械钻速降低,驱动能量浪费,而且会加速钻具的老化和失效,严重威胁钻井安全。以钻柱旋转系统为研究对象,建立转盘、BHA(Bottom-Hole Assembly)和钻头的二自由度钻柱系统扭转模型。该模型考虑了扭转刚度、粘滞阻尼和岩石钻头相互作用等高度非线性摩擦。通过MATLAB/Simulink仿真模块对该模型进行仿真试验,分析了实际钻井过程中钻柱产生的粘滑振动特性。为抑制钻柱的粘滑振动,设计1套基于PID控制策略的双闭环控制系统。该研究结论对工程实践中钻柱粘滑振动的抑制具有重要意义。

Research on Simulation and Control Strategy of Stick-slip Vibration with Drilling String

Stick-slip vibration, existing in deep and ultradeep wells exploration and development, not only causes mechanical drilling speed lowered and drive power wasted, but also speeds up the aging and failure of drilling tools, which seriously threaten the safety of drilling processes. Taking the system of rig rotation as the research object, a torsional model of the drilling-string system with two degrees of freedom including rotary table, BHA(Bottom-Hole Assembly), and the drill bit was established. The model took into account highly nonlinear friction such as torsional degrees of steel, stick damping, and rock-drill bit interaction. The system model was simulated by MATLAB and Simulink simulation modules, and the stick-slip vibration characteristic of the drilling string was analyzed in the actual drilling process. In order to suppress the stick-slip vibration of the drilling string, a control system of double closed-loop based with PID control strategy was designed. The research conclusion has important significance for the suppression of stick-slip vibration of drilling string in engineering practice.