Extreme Testing: Assessing CPM Leak Detection Systems on a Northern Oil Pipeline

Abstract

Pipelines in remote and ecologically sensitive regions pose special challenges for pipeline integrity monitoring. These challenges include difficulties of access, reliability issues of communication and instrumentation that may impact the leak detection technology applied in these regions. The selection, application and continuous testing of an appropriate technology to detect possible leaks are important to pipeline integrity monitoring. The paper reports theoretical assessment and extensive testing on an Enbridge subarctic liquid pipeline. It also reports the comprehensive cost-benefit analysis to guide the leak detection instrument design/configuration and the evaluation of the capabilities of alternative computational pipeline monitoring (CPM) technologies for leak detection. The selected test pipeline is an 869 kilometer (540 mile), NPS 12 inch pipeline that transports sweet crude through environmentally sensitive areas. This pipeline currently uses a real-time transient model (RTTM) style CPM as the leak detection system (LDS). The pipeline LDS is tested annually by a number of industry-recognized methodologies. These include fluid withdrawal tests, simulated leak tests and an API-1130 instrument adjustment approach. This pipeline is also assessed by API-1149 for its theoretical CPM leak detection sensitivity. A pilot project invited commercial CPM-style vendors to participate in an LDS test using data from fluid withdrawal and simulated leak tests. Five vendors responded and were included in the test suite. The paper describes the design and implementation of the test process. The results of the commercial systems are presented in aggregated form and the participating vendors remain anonymous. Performance assessment focuses on the LDS evaluation factors of sensitivity and accuracy. The paper concludes with a “lessons learned” review of issues associated with test design.