Cathodic Protection Detection and Influencing Factor Analysis of Directional Drilling Crossing Pipeline

Close interval potential method and polarization test piece method were used to detect the on-off potentials of the pipeline in the crossing section of directional drilling. Numerical simulation technology was also used to simulate and calculate the pipe section where the on-off potentials could not be measured, and the factors that affect the pipeline potential of the directional drilling crossing section were simulated and analyzed. The results showed that the cathodic protection potential attenuation of the pipeline crossing section of the directional drilling was small, the cathodic protection effect was good, and the actual measurement and simulation calculation results were consistent. Numerical simulation results showd that the greater the damage rate of the anti-corrosion layer of the crossing section of the pipeline, the more uneven the pipeline potential distribution, and the increase of the damage rate would cause the potential to shift positively, and the cathodic protection effect would decrease. When the overall performance of the pipeline anti-corrosion layer was good, the change of soil resistivity hardly caused the pipeline potential to change. When the quality of the anti-corrosion layer of the crossing section of the pipeline decreased, as the soil resistivity of the section increased, the unevenness of the pipeline potential distribution increased, the potential of the non-crossing section of the pipeline became negative, and the potential of the crossing section of the pipeline became positive. The buried depth of the crossing section pipeline had little effect on the overall potential distribution of the pipeline.