Investigation Of Design And Analysis For Unbonded Flexible Pipe End Fiting Structural

Oil resources exploitation in China needs a large number of pipelines urgently, the unbonded flexible pipe is widely used for its flexible advantage. End fitting is important connection device of unbonded flexible pipe with the function of terminating all the pipe layers, sealing and venting all the gas chapped between the pipe layers. End fitting is composed of an upper flange, neck and body, while the body compromise anchoring, sealing and venting gas system. End fitting is the weakest component in the flexible pipe system which is easy to fail under functional and environmental load. Developing the design and analysis method independently is of great significance while the key technology is monopolized by foreign countries for a long period.This paper summarised the failure modes of the end fitting and put forward the end fitting design method and process based on the failure modes after investigating the application and research achievements of the end fitting at home and abroad. Considering leakage is the most seriously failure mode of the end fitting, this paper established the finite element model for the flexible pipe end fitting seal system based on software of ABAQUS and discussed the influence of several parameters on the seal system. To clarify the uncertainty in analysis based on software design, this paper proposed the experiment scheme for the end fitting seal system. At last, this paper introduced the design results for the "863" project of the end fitting combining with the conclusion of the previous chapters.The research of this paper is sponsored by national "863"program, and will be of great significance for the design of the end fitting in China.