Research On Detection And Evaluation Technology Of Corrosion Protection Status Of Submarine Pipeline

Submarine pipelines are a necessary part of the marine oil and gas resources development system.Corrosion protection measures using external corrosion protection layer and sacrificial anode are necessary and effective means to ensure the safety of submarine pipeline service and prolong its service period.The damage or aging state of the corrosion protection layer of submarine pipeline,the consumption state of sacrificial anode and the detection and evaluation of the corrosion protection state of pipeline are the important contents of the integrity management of submarine pipeline.Therefore,it is very important to regularly inspect and evaluate the corrosion protection state of submarine pipelines.Aiming at the detection and evaluation technology of corrosion protection condition of non-contact submarine pipeline which is convenient to detect,this paper makes the principle exposition and validity verification of the corrosion protection state detection technology of submarine pipeline based on the potential difference measurement of remote reference electrode,and puts forward the evaluation technology of corrosion protection state to this detection technology.By designing the corresponding research experiment to the distribution characteristics of electric field in the surrounding environment of submarine pipeline and demonstrating experiment to the detection technology,the distribution characteristics of the electric field around the pipeline are analyzed,and the validity of the detection technology is verified.At the same time,in order to ensure the smooth running of the test,a high precision Ag/AgX reference electrode is adopted,and an easy-to-operate potential detection device and a potential data acquisition and analysis program system based on C# are designed,which is easy to expand functions.On the basis of the experimental demonstration,this paper also compares the rationality and accuracy of the test results and numerical simulation results by means of boundary element numerical simulation technology,and on this basis,carries on the numerical simulation based on the actual submarine pipeline parameters,and gets the distribution characteristics of the surrounding environment electric field around the actual submarine pipeline,and further verifies that the effectiveness of the detection technology on the actual scale.On the basis of the test results and numerical simulation results,through the full analysis of the characteristics of the environmental potential distribution curve around the submarine pipeline and its correlation with the corrosion protection state,an evaluation technology of the corrosion protection state of the submarine pipeline based on the effectiveness of the protection potential of the submarine pipeline,the sacrificial anode state and the coating state is proposed.Through the evaluation results,the external corrosion protection state of the current submarine pipeline can be known timely,and the defective submarine pipeline corrosion protection system can be found and perfected accordingly to avoid corrosion damage to the pipeline.