为了探究大质量、大刚度防喷器组(blowout preventers,BOPs)对深水钻井隔水管系统动态相应预测精度的影响,根据细长钻井隔水管与刚性防喷器组的结构特点,提出两者刚柔耦合的概念,采用能量法推导隔水管-防喷器组-水下井口系统的动能和势能,采用LAGRANGE方法建立耦合系统动力学理论模型,采用科学计算软件和Newmark-β直接积分法对动力学模型进行数值计算.以南海某深水钻井隔水管为例,开展基于耦合动力学模型的隔水管系统动态响应分析.结果表明,采用本文理论模型得到的隔水管不同位置的节点位移、单元弯矩、上部和下部挠性接头转角时程曲线、整体侧向位移包络线和弯矩包络线等与ABAQUS仿真结果均吻合良好,最大误差为 8.8%.此方法可为深水钻井隔水管和水下井口系统动态分析提供参考.
In order to explore the influence of large mass and stiffness blowout preventers(BOPs)on corresponding prediction accuracy of deepwater drilling riser system dynamics,this paper proposes the rigid-flexible coupling concept of riser and BOPs according to the structural characteristics of riser and BOPs,deriving the potential and kinetic energies of the riser-BOPs-subsea wellhead by the energy method.The theoretical model of the coupled system is established based on LAGRANGE,and the numerical calculation is conducted by employing the Newmark-β direct integration method based on science computation software.Taking the riser system of a deepwater well in the South China Sea as an example,the dynamic response analysis of the drilling riser based on the coupled dynamics model was carried out.The research showed that the established theoretical model and ABAQUS finite element model agreed well with each other in terms of time histories of nodes displacements and elements bending moments of three different positions along the risers,the upper and lower flex-joints rotation angles,as well as the global lateral dynamic displacement and bending moment envelopes of the deepwater risers,with the maximal error of 8.8%.This method could be used to provide references for dynamic analysis of deepwater drilling riser and subsea wellhead.