Device Research On Backpack Clamp Of Ocean Jacket Cable Protection Pipes

With the vigorous exploitation of the world marine resources,ocean engineering is developing rapidly,which makes the ocean engineering cable needs expanding,and its related technology has put forward higher requirements,one important link is the research of submarine cable laying,protection and maintenance.When offshore oil field completed and put into production,new subsea pipelines and the new cable need to be established.Cable protection pipe clamp is used to fix cable protection pipe on the jacket.This topic comes from CNOOC Zhanjiang branch of Guangdong Scientific Research Project – “The development of backpack pipe clamp” and the national natural science fund – “bearing mechanism analysis and experimental study of large spreader for marine pile”.The purpose is to avoid the problem of traditional steel structure clamp splice,counterpoint,fastening difficulty when installed cable protection pipe under water,reduce the risk and workload of under water,finally,develop a new type of portable connecting riser clamp – “backpack clamp”,which solve the riser cable protection pipe difficult underwater installation problem.In this paper,the domestic and foreign development present situation of backpack clamp structure form and installation method was reviewed,and the related techniques of clamp device design were introduced.Drawing lessons from the abroad experience in the design of related products and combining with the actual conditions in China,the general design scheme of the backpack clamp device was put forward.For the reason that backpack clamp device works under water,environmental load of clamp device underwater installation need to be analyzed,and studied the influence factors of environmental load.The load characteristic of clamp device was determined by Morison equation which was a classical theory.According to the complex stress problem of tensioned and fastened backpack clamp device,clamp device underwater mechanics analysis model was established.The minimum tension pre-tightening force was determined.Finite element simulation and theoretical analysis method were used in strength analysis of clamp key components,stability analyze of the jacket and fatigue life analysis of fasteners.The engineering prototype of backpack clamp device was developed and the experimental device of backpack clamp device was designed.Backpack clamp structure stability and strength experiment and determination experiment of the coefficient of friction can judge the working reliability and verify the designing correctness of backpack clamp device at sea.12 sets backpack clamp products were manufactured and had been installed and used on undersea jacket successfully,which accumulated experience of marine engineering related technical.