Oil and gas pipeline design, construction and integrity management programs are employed to prevent product releases. However, not all programs perform perfectly and pipeline operators are required by regulators to develop and maintain leak management programs including computational pipeline monitoring (CPM). The requirements for enhanced leak detection and management programs are being considered and a range of above ground, in ground and in pipe leak detection technologies are available and being evaluated.
To design a leak detection and management program or apply risk management to pipeline operations, the ability to link the leakage rate or total release volume over time to the pipeline operational conditions (e.g. product, pressure), defect type (e.g. corrosion, fatigue crack) and pipe size are essential. Being able to estimate leakage rate supports evaluation of release consequence and can be used in supporting operational responses when incidents occur and remedial action strategies.
While basic leak rate models exist, they have been demonstrated to over predict leak rates. Based on this understanding, we submitted a white paper to the US Department of Transportation, Pipeline and Hazardous Materials and Safety Administration (PHMSA) outlining a full-scale trail program and model development program to improve on the current state of practice and knowledge.
As a result, we have been awarded a research project valued at $750K by PHMSA with industry co-funding from the Colonial Pipeline Company. The project is focussed on the developing liquid pipeline physical trial data from testing at our facility in Ottawa, Canada to then use this data to validate enhanced modelling tools.
The investigation will consider through wall dent fatigue cracks, stress corrosion cracking, corrosion pits and weld seam defects experimentally. The modelling will consider both computational fluid dynamics to simulate leaks with the ultimate goals to developing simple analytical models that agree well with the physical trial data.
While this work will be intellectually and financially rewarding to us, it has caught the attention of the pipeline industry with the Pipeline Research Council International (PRCI) and its member pipeline operating companies. This project will provide a foundation building block to a PRCI Strategic Research Priority on leak detection and mitigation.