Consequence Modeling for a Carbon Capture & Storage CO2 Transport Pipeline

Reducing carbon emissions is quickly becoming a priority to combat climate change, and carbon capture, utilization, and storage (CCUS) is a key strategy to help meet emission reduction goals. With the increase in CCUS operations, more pipelines will be built, or converted from transporting hydrocarbons, to transport CO₂.

As with any product transported by pipeline, there are risks associated with CO₂ transport. However, these risks are quite different from those of hydrocarbon products. The primary risk associated with a release of a large quantity of CO₂ is the displacement of oxygen that can cause an asphyxiation hazard. With this risk, it is necessary for pipeline operators to understand the potential consequences of an accidental loss of containment.

An undisclosed pipeline operator was considering converting an existing crude oil pipeline to transport CO₂ for the purposes of transporting captured carbon dioxide to a subsurface storage location. The pipeline traversed a large distance including both developed and rural areas.

Challenge

The first step for the operator was to assess the feasibility of this conversion, including gaining an understanding of the potential consequences if an accidental release were to occur and assessing potential mitigation options that may reduce those consequences.

They needed to understand the risk to sensitive receptors such as High Consequence Areas (HCAs) and how valve additions/changes would be able to help reduce the consequences of a CO₂ vapor release. They also needed an understanding of the sensitivity of the models to some of the assumptions that were made, such as leak sizes, pipeline operational conditions, and varying environmental conditions.

This information would then allow the operator to make an informed decision on if the risk was acceptable or not before proceeding with the project.