Comprehensive and Site-Specific Consequence Assessments for Pipeline Releases

An undisclosed North American pipeline operator contracted RPS to perform a consequence assessment for accidental releases from two pipelines, one transporting highly volatile liquid (HVL) products (natural gas liquids) and the other a crude oil product, in nearby right of ways (ROWs). New development near those ROWs has changed the overall risk circumstances associated with operating these pipelines. RPS simulated overland transport of liquid hydrocarbons, atmospheric dispersion of harmful vapors, and thermal radiation from both pool and jet fires to help the operator understand the potential consequences from an accidental release to nearby populations. For releases of crude oil, RPS used the OILMAPLand model to asses overland transport pathways of full-bore ruptures at intervals along the current pipeline and alternative routes to determine all the possible pathways of release. Locations where crude oil was expected to form pools of oil on the land surface were identified, and the thermal radiation from pool fires were assessed. For releases of the HVL products, atmospheric dispersion modeling was performed, assuming an unignited release, to assess vapor concentrations exceeding explosive and human health related limits. Additionally, jet fire release simulations were performed, assuming an ignited release, to assess thermal radiation levels away from a rupture site.