Research On External Corrosion Repair Technology Of Long-Distance Oil And Gas Pipeline

Oil and gas are important strategic material in the in today’s world.Pipeline transportation of oil and gas has become the main transportation mode,because of its advantages,such as safety and stability,low operation and maintenance cost,and small loss.In recent years,due to the rapid increase of oil and gas consumption,pipeline transportation capacity is obviously insufficient in our country.In addition,oil and gas resources are widely distributed in China,and pipeline laying needs to pass through various terrain areas.The corrosion failure events of old pipelines in different environmental landforms are also increasing year by year.In order to ensure the transportation safety of oil and gas pipeline,and fully grasp its corrosion situation,the repair strategy is developed based on availability and operation and maintenance cost to repair the corroded parts evaluated as repairable.This paper mainly takes long oil pipelines as the research object,and researches the following aspects on the external corrosion repair and residual strength of pipelines.1.Taking pipeline repair technology as the research object,combined with the development status,summarized and analyzed the existing 8 different pipeline repair technology and its characteristics.2.The three-dimensional modeling of long-haul oil and gas pipeline was carried out,and the residual strength of the pipeline after carbon fiber repair was simulated by ANSYS software,and the effect of carbon fiber repair was verified by acoustic emission hydrostatic test.3.For the uniform corrosion of No.20 steel plate,the carbon fiber dressing technology and high energy pulse precision cold repair technology were used to repair the corrosion.To evaluate the safety performance of the cold-welded repaired specimens,samples were sampled and subjected to normal temperature tensile test,bending test,low temperature impact test and shear test.4.The simulated defects of API 5L X52 long-distance pipeline samples were repaired by high-energy pulse precision cold repair.For the repaired pipeline,the explosion test of the tubular sample was carried out by using the ultra-high pressure liquid pump,and the acoustic emission detection technology was used to collect the acoustic emission signal of the pipeline.Through comprehensive analysis of the test results,the highest pressure bearing capacity of the pipeline repaired by cold welding is very high,which can be used to repair the pipeline with high pressure bearing capacity requirements.In addition,high-energy pulse precision cold repair technology was applied to repair a petrochemical corrosion pipeline,and non-destructive testing was carried out after repair.No defects were found in the repair area,and the pipeline was successfully repaired.It is safe and reliable to use pulse cold welding technology to repair external corrosion defects of pipeline.