深水钻井隔水管张紧系统反冲控制仿真研究

隔水管张紧系统能够克服浮式平台/船升沉运动对隔水管的影响,为隔水管提供近于恒定的顶部张紧力,因此隔水管系统中存储大量能量。在隔水管底部总成与水下防喷器紧急脱离时,能量释放会产生反冲,若反冲得不到有效控制,会导致隔水管与平台碰撞或隔水管丢失等严重事故。为研究隔水管反冲的动态过程并验证反冲控制系统设计的合理性,对3658 m水深隔水管张紧系统搭建了仿真模型,针对紧急脱离工况进行模拟,设计了反冲控制算法。通过仿真得到张紧液缸运动曲线以及防反冲阀主阀的流量曲线。研究结果表明:在紧急脱离工况下,PLC以预编程模式控制防反冲阀主阀的节流速度,使系统在行程末端达到稳定状态;主阀开度控制曲线是隔水管反冲控制的主要影响因素,优化主阀开度曲线可优化反冲相应过程。研究结果对于深水钻井隔水管张紧系统的现场安全应用具有一定的指导作用。

Recoil Control Analysis of Deepwater Drilling Riser Tension System

The drilling riser tension system can mitigate the influence of the floating platform/ship heave motion on the riser and provide a nearly constant top tension force for the riser.Therefore,a large amount of energy is stored in the drilling riser system.During the emergency disconnection of bottom assembly of the riser and the BOP,the energy release will produce recoil.If the recoil cannot be effectively controlled,serious accidents such as collision of the riser with the platform or loss of the riser may occur.A simulation model was built for the 3658 m deep riser tensioning system in order to study the dynamic process of the riser recoil and verify the rationality of the design of the recoil control system.In order to simulate the emergency disconnection,a recoil control algorithm was designed.Through the simulation,the movement curve of the tension hydraulic cylinder and the flow curve of the main valve of the anti-recoil valve are obtained.The results of the study show that:under emergency disconnection conditions,the PLC controls the throttling speed of the main valve of the anti-recoil valve in a pre-programmed mode,so that the system reaches a stable state at the end of the stroke.The main valve opening curve is the main influencing factor,which can be used for optimizing the corresponding process of recoil.The study results have a certain guiding role for the field safety application of the riser tension system.