The Design And Mechanical Analysis Of Safety Joint For Subsea Drilling Riser System

With the on-going of time,onshore drilling gradually turned to offshore drilling,and drilling riser become important equipment in oil industry.More and more people start to study the safety of drilling riser because its integrity ensures the drilling process.On behalf of the riser safety,this paper provides a new type of safety joint applying in drilling riser system comparing similar product abroad.Hence,the physical structure of safety joint is proposed.The mechanical analysis as well as hydrodynamic analysis is conducted respectively.Some paragraphs discussed the principle of design strategy by comparing different locations of safety joint.Also the scope of application had been restricted for designing a specialized safety joint.Account for compatibility,the couple head of safety joint used conventional design.The overall structure and the attachment structure was determined considering safety joint's functions.Besides,a three dimensional model was built in Solidworks for assessing the structure and its function.Furthermore,interference assessment also carried out.The mechanical analysis was conducted in ABAQUS.Safety joint was carefully examined to make sure function well while drilling.At a specified load,the main structure has good robust and the elastic bolts can break hence riser system is protected.The Southern China Sea condition was chosen as simulation condition.Thus,its current and wave can refer to existing data.The hydrodynamic analysis was done by OrcaFlex.Cases with or without safety joint were run as a comparison.The stress,moment and maximum effective tension of drilling riser were obtained.The maximum moment occurred at the top of upper riser and the maximum moment of bottom riser occurred near wellhead.Difference was found between riser system with and without safety joint.