PIPELINE REPLACEMENT FEASIBILITY STUDY: A METHODOLOGY FOR MINIMIZING SEISMIC AND CORROSION RISKS TO UNDERGROUND NATURAL GAS PIPELINES

Abstract

This report presents a methodology which a utility can use to fold mitigation for seismic hazards into its ongoing repair and replacement program. The methodology was developed specifically for buried pipeline components within the Southern California Gas Company (SoCalGas) system. Both transmissions and distribution pipeline systems are considered; however, suggested procedures differ, due in part to the importance and relative lack of redundancy (i.e., interconnectedness) for transmission pipe. In the past, the SoCalGas repair and replacement program focused on corrosion damage. The new methodology incorporates potential seismic damage as characterized by areas of potential ground failure. As part of this effort, a new procedure for estimating corrosion leakage rates in data-poor areas is proposed.