As discussed in earlier posts, risk can be defined as the product of consequence and likelihood. The consequence term in this equation is a mixture of aleatory and epistemic uncertainties. The likelihood term is a random aleatory chance factor. Recall that aleatory uncertainties are inherently random and cannot be reduced by technical work. Epistemic uncertainties can be determined and refined by increasing knowledge of the physical properties of the system.
With this in mind, we recommend a two-step approach for risk assessment. In Step 1, project teams evaluate the epistemic uncertainty in the factors impacting the project. In Step 2, the teams proceed to assess the chance that the assessment is correct and that unexpected events might occur. Both sets of data and judgments should be stored separately and summarized at critical stage gates in the project so that decision-makers can be fully informed.
Linking the FEPs to impacts is important for identifying hazards, estimating their potential impact on the project, and proposing a fit-for-purpose monitoring plan for detection and mitigation. This is particularly important for gauging whether the CO2 plume and the pressure front ahead of the plume are being properly contained in the intended reservoir and area of interest.