Outflow Analysis and Overland Spill Modeling (OSM) are fast becoming the go-to methods for liquid pipeline consequence modeling, in both the pipeline design phase, as well as leveraged in quantitative risk assessments, and management of High Consequence Areas (HCA) for operational pipelines. With a continued increased focus on environmental protection and safe operations of pipelines, the application of consequence modeling is equally growing in importance for both integrity management, and emergency response planning.
Although multiple models for outflow analysis and OSM exist, they follow the same core concepts: pipelines can travel through several geometrically different areas, usually involving changes in ground elevations. These ground elevation changes result in relative gravity difference between segments, which in turn causes differences in local pressure in the pipeline, leading to a variance in the total volume that would be released at any location along the pipeline if a failure occurred. Other operational parameters that affect outflow volumes include; valve placements and closure times, as well as leak detection methods. Changes in elevation and soil types also affect the trajectory of an overland spill, affecting the spreading and pooling, the depth of infiltration into soil, and the width of the lateral spread. Overland Spill Modeling can be used to determine the path of an overland spill and whether a liquid would intersect waterbodies, waterways or other HCAs. Further analysis can be done for Hydrological Transport Modeling by considering flow direction and connectivity between streams and waterbodies. Recently, Spill Modeling results have also been used to produce spill plume fires and radiation radius’.
Outflow Analysis is used to understand the potential volume that could be released at any location along the pipeline, and is incorporated in further Valve Optimization Analysis to determine the potential mitigations that can be applied to reduce outflow volumes, in particular near waterbodies, waterways or other HCAs. Valve Optimization Analysis is used in both the design and operational phases of a pipeline’s lifecycle. The analysis consists of iterative modeling of outflow volumes based on the theoretical placements of various types of valves along the pipeline. This assists operators with determining the optimal valve placements to achieve the most reduction in outflow volumes, keeping cost benefit analysis in mind.
Results of Outflow Analysis and Spill Modeling, provide operators with data driven intelligence when making risk-based decisions. With the industry moving towards a more quantitative risk assessment approach, Dynamic Risk assists operators through our IRAS solution, by incorporating detailed outflow release volumes in their risk algorithms to provide more accurate environmental consequence results. Analysis results are also used to support emergency response planning, in selecting and deploying better leak detection systems, and more effective placement of Emergency Restriction Flow Devices (ERFDs).
To learn more about how Dynamic Risk can support your organization with consequence modeling for liquids pipelines, please visit our website or contact Val directly.
About the Author:
Valeria is a Client Partnership Lead at Dynamic Risk, based out of the Calgary office. In her role, Val provides ongoing relationship management and leadership in identifying and providing value added business solutions in support of our clients’ strategic risk management programs. With 10 years of experience in the oil and gas sector, Val has a background in both financial and operational risk management, as well as emergency management. Val graduated with a B.Comm Degree in Finance and Risk Management from the University of Calgary, and holds her Canadian Risk Management Designation from the University of Toronto.
Val can be contacted directly at: firstname.lastname@example.org