Measures to Solve the Effect of HVDC Grounding Electrode Current on Metal Pipelines

The DC current injected into the earth from the grounding electrodes of HVDC system could flow into the oil and gas pipelines through their grounding, lead to high pipe-to-soil potential. It is necessary to study the measures to solve the effect of DC current on metal pipelines. In this paper, the pipe-to-soil potential under field test is measured and calculated. Several measures on metal pipeline is discussed in a real case. It is found that the pipe segmental insulation and laying sacrificial anodes on pipe used jointly is effective to reduce the pipe-to-soil potential. Maintaining an effective safety distance of DC grounding electrode and metal pipeline is an important way to address the interaction.