Satellite-Based Monitoring of Subsidence Ground Movement Impacting Pipeline Integrity

Ground movements due to a range of governing mechanisms are recognized to pose hazards to the operating integrity of pipelines in California. As part of an extensive technology management program, Southern California Gas Company (SoCalGas) is involved in the development and implementation of satellite-based monitoring of subsidence ground movements impacting pipeline integrity. By both hosting a Gas Technology Institute (GTI) and Pipeline Research Council International (PRCI) study and undertaking an internal study, SoCalGas is supporting the investigation of two aspects of this promising pipeline integrity management technology. The current project of monitoring ground subsidence due to oil production in the San Joaquin Valley utilizes synthetic aperture radar (SAR) to derive sub-centimeter ground movement measurements from February to September, 2001. The estimates of the subsidence derived from the SAR data are compared with GPS survey results taken at 65 monuments. In addition, archived SAR data from 1992 to 2000 are used to better estimate the movement that has occurred there over the past decade.