基于波浪谱与钻井船RAO的钻井船运动模拟

Vessel Motion Simulation Based on Wave Spectrum and Drilling Vessel RAO

钻井船运动对深水钻井隔水管动力性能有重要影响。提出一种根据波浪谱和钻井船响应幅值算子(RAO)模拟钻井船随机运动的方法。为充分模拟钻井船运动,建立了包括钻井船平均偏移、不规则波浪导致瞬时波频运动和二阶波浪力导致的低频慢漂运动的钻井船运动模型。采用随机波浪模拟技术得到具有不同波高、周期与相位角的组成波序列。根据响应幅值算子(RAO)所定义的钻井船运动与不同频率的波浪之间的幅值比与相位差和钻井船运动数字模型,迭代产生随机波浪作用下钻井船运动,并基于MATLAB仿真平台实现了上述算法。

Drilling vessel motion has a large impact on dynamic behavior for deepwater drilling risers. Based on wave spectrum and drilling vessel Response Amplitude Operator （RAO）, an approach was put forward to simulate random motion of the drilling vessel. To adequately simulate vessel motion, a model was built which includes terms representing mean vessel offset from the wellhead, a long term drift motion modeling the response of the positioning system, and the instantaneous response of the vessel to irregular waves. The wave components with different wave height, period and initial phase angle were obtained using the techniques of random wave simulation. Then, according to the amplitude and phase of vessel motion relative to the wave for a particular wave frequency defined by the RAO and the numerical model of the drilling vessel motion, the vessel motion caused by irregular wave was generated iteratively. The algorithm mentioned above was implemented based on MATLAB simulation platform.