Feasibility study of detecting gas leakage in buried pipeline based on resistivity method

Abstract

Urban gas pipe networks are mostly buried underground and it is hard to monitor, detect and locate the leakage area effectively. The primary structure of the soil could change before and after aeration, so the detection method of gas leakage based on resistivity method has some physical basis. Based on the theoretical research of the predecessors, corresponding geoelectric model is established by combining two typical gas leakage geological models to study the influences of testing device, leakage mode and leakage intensity on the distribution characteristics of gas leakage geoelectric field. Obtained by using forward and inverse numerical computation methods, the theoretical resistivity profile image is compared with the resistivity profile measured by outdoor gas leakage simulation experiment to evaluate comprehensively the feasibility and effectiveness of detecting gas leakage of buried pipelines based on resistivity differential characteristics. The research results show that resistivity method could describe the spatial distribution location effectively and the electrical resistivity has positive correlation with leakage pressure. And the pressure inside the pipeline also determines the migration path of the gas leakage, which diffuses outwards in the shape of “smoke ring” in high-pressure leakage.