Storing carbon dioxide (CO2) in geological formations is a crucial method for mitigating climate change. As with any subsurface engineering operation, CO2 storage has inherent risks. The knowledge of the storage complex is limited as drilling, coring and logging wells is expensive and the spatial resolution of seismic data is limited. Leakage risks in CO2 storage complexes can arise due to the drilling processes (e.g. development of leakage paths due to formation damage along the wellbore) and the operation of the reservoir (e.g. permeability enhancement around faults, mainly due to reservoir pressure changes). Accurately simulating this problem at different scales is crucial to predict the consequences of CO2 injection and storage. However, this task can be challenging, particularly in the early stages of a storage project when knowledge of the storage reservoir is limited, and the cost of obtaining high-quality well logs, cores, and seismic data is high.

To address this issue, this study proposes a workflow for ultra-fast screening of storage capacity and leakage risks during injection and storage at the concept selection stage. In this contribution we present a portfolio of reduced complexity models that can serve as a middle ground. More specifically we present vertical equilibrium (VE) models, spill point analysis and flow diagnostics inspired approaches to obtain storage capacity and leakage risk with a higher level of confidence than estimates but less effort than full reservoir simulations. Specifically, we will discuss 3 workflows,

Realistic storage capacity estimation using seismic data.
Fault leakage risk assessment using VE – methods and application.
Wellbore leakage risk assessment
The fast workflow presented in this study provides a useful tool for identifying the uncertainties associated with key fault parameters, reservoir architecture, and other constitutive relations that affect the behavior of the storage reservoir and potential leakage outcomes. Overall, the proposed workflow provides a cost-effective and efficient method for screening storage capacity and fault leakage risk during CO2 injection and storage, helping to ensure safe and effective carbon storage.