Design And Optimization Of Remote Auxiliary Anode For In-service Submarine Pipelines

As the main way of oil and gas transportation,submarine pipelines play an important role in the offshore oil and gas development system.However,the submarine environment is very complicated,and the submarine pipelines are mostly carbon steel materials,which are prone to corrosion damage in seawater.Considering economy and operability,the main corrosion protection measures currently used are anticorrosive coatings on the pipe surface and a sacrificial anode cathodic protection system.However,as the years of pipeline use increase,the anti-corrosion coating is gradually destroyed and the sacrificial anode is consumed year by year,resulting in a positive shift in the surface potential of the pipeline.In order to achieve greater economic benefits,the submarine pipeline needs to be in service for more than the designed service life.In order to ensure the continued safe service of the pipeline,cathodic protection and life extension measures must be taken.The underwater replacement of the sacrificial anode anode is difficult to construct,and the cost is high,and there is a certain amount of pollution during the production and use of the sacrificial anode.The impressed current protection system has simple construction,adjustable protection current,and is an environmentally friendly device,which can be used in the life extension of submarine pipelines.The auxiliary anode is an important part of the impressed current protection system,and its working stability and reliability directly affect the stability of cathodic protection.After investigation,the form of auxiliary anode suitable for impressed current cathodic protection of submarine pipelines is remote,but the remote auxiliary anodes currently used in engineering at home and abroad have certain defects.The auxiliary anode is an important part of the impressed current protection system,and its working stability and reliability directly affect the stability of cathodic protection.After investigation,the form of auxiliary anode suitable for impressed current cathodic protection of submarine pipelines is remote,but the remote auxiliary anodes currently used in engineering at home and abroad have certain defects.This article mainly aims at the defects of the existing remote auxiliary anode,and designs and optimizes the remote auxiliary anode.The completed design mainly includes the material selection design of the auxiliary anode and the material selection design of the auxiliary anode base.Among them,the design of the auxiliary anode base includes the selection of the antisinking plate form,the structural design of the auxiliary anode protective cover,the design of the overall structure of the base,and the watertight design of key parts.The auxiliary anode is MMO anode,the protective cover is made of titanium steel,and the base is mainly in the form of FRP concrete composite column.Then test the watertight performance of the key parts of the structure,test the performance of the selected materials,and use ANSYS to numerically simulate the overall strength of the structure.The experimental results show that the selected materials meet the design requirements,the watertight performance of the key parts of the structure is good,and the strength of the structure meets the design requirements.Finally,the designed remote auxiliary anode device is assembled,and the device is used for actual sea test.The test results indicate that the equipment can work stably and protect the submarine pipeline in a real sea environment.The research results of this paper can provide references for the design of remote auxiliary anodes for submarine pipelines in service,and have certain engineering practical value.