Optimization Analysis And Performance Study Of Seal Structure For Deepwater Horizontal Clamp Connector

With the implementation of oil and gas resources exploitation into deep sea strategy,deepwater pipeline connection technology becomes the essential key technology.The horizontal clamp connector was one of the horizontal connection equipment of the underwater jumper.The horizontal clamp connector has the advantages of simple structure,low cost and so on.Accelerate research of horizontal clamp connection technology has great significance to the exploitation of marine resources.The horizontal clamp connector was impacted by deep water external pressure and internal pressure.Reasonable horizontal clamp connection scheme can make installation easy and reasonable sealing structure can make the seal reliable.The current horizontal connection method installation was complex and the sealing effect was limited.So it was urgent to put forward the installation convenient connection scheme and design reliable sealing structure.It was necessary to analyze the sealing performance under environmental loading.These studies are provided with great research value.To settle problem above,based on the research of the domestic and foreign horizontal clamp connector,this paper put forward a horizontal connection scheme that achieve the close and clamping with only single insertion torque wrench to realize.Based on the metal sealing mechanism,the H sealing ring with double seal function was designed.Through the establishment of the mechanical model of the seal structure,the preload force calculation of axial was carried out under preload and pressure condition.And the seal structure strength is checked.The contact pressure and equivalent stress were obtained through finite element simulation which established foundation for sealing optimization.The H sealing contact theory model was established based on Hertz contact theory.The contact pressure distribution,contact width and seal self-tightening coefficient were obtained by analysis which provide theoretical basis for optimal design.Spearman variable screening method was used to determine the variables with large correlation degree.The sealing cone angle and seal sphere radius R were taken as the optimal design variables.The maximum contact stress and minimum axial preload were taken as objective function based on multi-objective genetic algorithm.Then the sealing ring was optimized.The contact characteristics and self-tightening characteristics of sealing rings were studied by simulation of sealing contact.Verified that the sealing ring was reliable.The leakage rate model was established according to continuity equation and fluid motion equation through the basic theory of fluid flow and micro leakage channel of seal surface.The sealing evaluation standard of connector was established which was based on studied the static sealing parameter grade and underwater pipeline sealing requirements.The sealing evaluation standard provide basis for judging the sealing performance under external load.The different leakage modes of connectors subjected to tension,compression,bending and torsion were studied.The mechanical properties of the sealing structure under external load were studied by establishing the coordinate deformation equation of the connection system under tension.The ultimate tensile force,pressure,bending moment and torque load were derived.Connecting performance and hydrostatic pressure test of horizontal clamp connector prototype were studied.It was proved that sealing performance to meet the requirements and the installation of the connector was fast and convenient.The load test of tension,compression,bending and torsion was carried out by the external load test equipment.Compared with the theoretical analysis and experimental results,it was concluded that the connector can keep sealing performance in the limit load range.It was indicates that the connector has a certain bearing capacity.