深水钻井隔水管法兰接头压溃安全分析研究

Safety Analysis of Flange Joint Collapse in Deep Water Drilling Risers

针对深水钻井隔水管法兰接头在深水钻井过程中承受着复杂恶劣的环境载荷,以及工作过程中产生的内外压差,有必要对深水钻井过程中法兰接头的工作受力情况进行深入研究。根据有限元原理,建立了法兰接头模型,利用有限元分析方法研究了不同外压载荷下的隔水管法兰接头无磨损以及磨损情况下的应力分布情况及临界压溃压力。分析结果表明,在螺栓预紧力载荷以及工作载荷情况下,法兰接头符合安全强度要求;对无磨损的法兰接头施加外压载荷,法兰接头受到的最大应力随着外压载荷的增加而增加,外压载荷增加到一定值时,上法兰接头辅助管道通道处的T型台处会产生应力集中;对磨损的法兰接头施加外压载荷,法兰接头的临界压溃压力随着磨损深度的增加而减小。

In deep water drilling,the flange joints of drilling risers are usually exposed to complex and harsh environmental loads while experiencing a high difference between internal and external pressure.Therefore,it is necessary to monitor the stress in these flange joints while drilling.In this study,a finite element model of a flange joint was developed for analyzing the stress distribution and critical collapse pressure of both a wear-free and a worn flange joint in a drilling riser under different external load conditions.The results showed that the flange joint satisfied the strength safety requirement under bolt preload and working load conditions.When applying an external load on a wear-free flange joint,the maximum stress inside the flange joint increased with increasing external load.Once the external load reached a certain threshold,a stress concentration formed on the T-shaped platform at the auxiliary pipeline junction in the upper flange joint.When applying an external load on a worn flange joint,the critical collapse pressure of the flange joint decreased with increasing depth of the wear.