Management System for the Identification Risk, Qualification and Remediation of Geo-Hazards in Rocks and Residual Soils of the Camisea NG and NGL Pipelines

Abstract

An early identification of geo-hazards i.e. slides, fluvial erosion, eolic erosion, rainwater erosion among others and the subsequent mitigation and remediation of its effects on the Right of Way (ROW) and the pipelines, has prevented the occurrence of leaks in the Camisea NG and NGL Transportation System, which includes a 730 Km natural gas pipeline and a parallel 560 Km natural gas liquids pipeline, operated and maintained by Compan˜i´a de Gas del Amazonas (COGA). The Camisea Transportation System, traverse the Peruvian territory starting in Malvinas (Cusco). The NGL pipeline stops in Playa Loberi´a (Ica) and the NG pipeline stops in the City Gate, located in Luri´n (Lima). These pipelines traverse the Peruvian rainforest, the Andes Mountains and coastal areas. The intend of this paper is to describe the use of a Risk Matrix (RM) in order to calculate different risk levels for the prioritization of the geotechnical mitigation and stabilization works to be performed during the dry season of the Peruvian rainforest. The RM is a tool based on the so-called Safety Ratio, incorporating calculation parameters of the Security Factor used in the stability analysis of slopes. Once the work sites have been identified using the RM, the engineering design is performed, using geotechnical engineering techniques such as subsoil exploration, laboratory testing, mathematic modeling, designs and instrumentation. After the Geotechnical Engineering process has been completed, the Safety Ratio values estimated with the RM are replaced by Safety Factors. The paper concludes showing the benefits of the whole Risk Management System, which has been successfully applied in the first 200 Km of the ROW characterized by residual soils, slopes with more than 45° and 7000 mm in excess of rainfall per year.