In a context of growing world economy and consumptions, an energy transition is needed to shift towards a low carbon emission system to contrast global warming and limit world average temperature increase below 1.5-degrees Celsius by 2050. It is expected that the transition will involve the transportation of large quantity of CO2 (either in gas or supercritical fluid state) from capture sites to storage sites via pipeline including subsea pipelines. Hazard assessment of this type of transport indicates that human life, assets, and the environment may be at risk during incidental gas or liquid releases. To assess the consequences of a sub-sea gas or liquid leak correctly, manage the related risk and define risk-mitigation strategies, it is important to understand the quantitative impact of the released plume. The risk assessment process for offshore pipeline system includes several stages. One of these is estimating the consequences for human health and environment due to accidental loss of containment events. An important step is to predict how the gas bubbles are dispersed in the ocean and if they survive all the way to the surface. The predicted surface flux can then be used as input to atmospheric dispersion calculations. Here we only consider the buoyant jets in the ocean. Realistic experiments to study the phenomena are very expensive and potentially dangerous, therefore bubble plumes have been studied via integral models in the past and CFD models in recent years, in order to perform a more reliable risk assessment.
Scope of the paper is to investigate the underwater plume behaviour of leakage of CO2 from offshore pipelines and to create a methodology to study CO2 dispersions through CFD analysis.