Required Capabilities for Assessing Depleted and Deep Saline Reservoirs for Successful CCS Projects

Depleted and saline reservoir types are the main candidates to consider for any CCS-scenario. Both kinds of reservoir have fundamentally different risk profiles and degrees of uncertainty and each of them has a role to play in successful CO2 sequestration scenarios.

Depleted reservoirs provide a relatively rapid path to storage with significantly less uncertainty on containment and injectivity efficiency. However, the large number of well penetrations that reduce the performance uncertainty also increase the risk of potential leakage points.

In contrast, deep saline reservoirs will take longer to bring to project maturity but have by an order of magnitude more storage potential. Additionally, they will almost certainly support super-critical injection in dense phase making the project design much simpler to manage and monitor.

Successful long-term CO2 storage projects are likely to employ a combination of both types of reservoirs through a phased life-cycle where the use of a depleted reservoir enables early injection whilst an adjacent saline reservoir is brought ‘on stream’ later on.

The implementation of successful CO2 storage projects requires capabilities with strong adjacency to the oil and gas sector, supplemented with those specific to CO2 storage, requiring flexible and adaptable approaches to the upskilling of key staff.