深水隔水管-防喷器组耦合系统动力学建模与仿真验证

Dynamic modeling and simulation verification of deepwater riser-BOP stack coupled system

在深水钻井过程中,隔水管与防喷器组系统是整个作业环节的重要一环。由于在作业过程中面临着诸多风险,因此,建立精确的隔水管-防喷器组耦合系统力学分析模型,准确分析其力学行为和性能,对指导钻井作业安全进行具有重要意义。目前大多只关注于对隔水管的独立建模而忽视防喷器组的潜在影响,这将导致所建模型与实际情况存在差异,使得隔水管系统的力学特性无法得到精确分析。提出了隔水管与防喷器组刚柔耦合概念,推导耦合系统动能、势能,采用拉格朗日方法建立理论模型,用Newmark-β直接积分法对动力学模型进行数值计算。采用ADAMS软件进行了仿真建模,开展不同工况条件下的动态响应对比分析。结果表明,理论模型得到的隔水管横向位移包络线、弯矩包络线、隔水管中部节点横向位移时程曲线和底部弯矩时程曲线与ADAMS仿真结果吻合良好,从而表明了该理论模型的重要性,可为我国隔水管的设计和分析提供参考和支持。

During deepwater drilling,riser and blowout preventer(BOP)stack system are an important part of the entire operation process.Due to many risks faced during operation process,to establish an accurate mechanical analysis model for a riser-BOP stack coupled system and correctly analyze its mechanical behavior and performance is of great significance for guiding the safety of drilling operation.At present,most studies only focus on independent modeling for riser and ignore potential impact of BOP stack to cause differences between the established model and the actual situation,and make it difficult to accurately analyze mechanical characteristics of riser system.Here,the concept of riser-BOP stack rigid-flexible coupled system was proposed,kinetic energy and potential energy of the couped system were derived,Lagrange method was used to establish the system’s theoretical dynamic model,Newmark-βdirect integration method was used to do numerical calculation and solve the dynamic model.Furthermore,the software ADAMS was used to establish a simulation model and perform dynamic response comparative analysis under different operating conditions.The results showed that lateral displacement envelope curve and bending moment envelope curve of riser obtained with the theoretical model as well as riser middle node’s lateral displacement time history curve and bottom bending moment time history curve agree well with ADAMS simulation results,the correctness of the derived theoretical model here is verified,it can provide reference and support for design and analysis of risers in China.