World-class training for the modern energy industry

Fieldwork for CCS – Fluvio-aeolian Outcrops in the UK

calendar April 17, 2024

The requirement for Carbon Capture and Storage (CCS) remains as strong as ever, driven partly by the historical and continued use of fossil fuels as we move through the energy transition. Global progress in the deployment of CCS projects has been slow but is now accelerating and the UK continues to be at the forefront of this, with large-scale planned projects, such as the HyNet hub in NW England and the Teeside hub in NE England.

The injection of carbon dioxide (CO2) into subsurface rocks is not a new technique and has been adopted for more than 50 years, specifically in the process of CO2enhanced oil recovery, where CO2 is used to displace the oil with the CO2 remaining in the reservoir rock. The injection of CO2 into the saline aquifer above the Sleipner reservoir in the Norwegian sector of the North Sea has been underway since 1994. This is specifically done as a climate change mitigation tool and remains one of the bestcase studies we have of long-term CO2 injection as part of a designated CCS project.

Fluvio aeolian deposits of the Triassic Sherwood Sandstone Group at Budleigh Salterton Devon
Fluvio-aeolian deposits of the Triassic Sherwood Sandstone Group at Budleigh Salterton, Devon.

It is now known that we can store carbon dioxide in a variety of underground geological formations, including non-producing oil and gas reservoir rocks, saline aquifer rocks, layers of volcanic basalt and even coal beds. In the UK, both saline aquifer rocks (e.g. Bunter Sandstones in the Endurance storage site) and old hydrocarbon reservoir rocks (e.g. the Ormskirk Formation of the Hamilton field) are planned as CO2 storage sites. Sites that once held hydrocarbons have large amounts of data available to geologists and reservoir engineers to scrutinize when ascertaining, for example, the rock and reservoir properties (e.g. porosity and permeability) and potential seal risks for a planned CO2 injection project. The key factor is undoubtedly permeability of the reservoir rocks, as it will control injection rate and therefore how many wells are needed for CO2 injection and ultimately project costs.

Permian and Triassic sandstones in old oil and gas reservoirs are some of the main CO2 storage opportunities in the UK offshore. Leman, Bunter and Ormskirk sandstones preserve a variety of facies types, including aeolian sediments representing deposits laid down by the action of wind-blown sand in arid continental settings. Fluvial (river) and lacustrine (lake) deposits are also present in these formations, and understanding the subsurface arrangement and properties of these deposits is clearly of great importance for CO2 reservoir storage characterization.

Aeolian deposits in the Permian Hopeman Sandstone Hopeman
Aeolian deposits in the Permian, Hopeman Sandstone, Hopeman.

The value of observing and examining these rocks at outcrop in order to understand aspects such as rock properties, heterogeneity and connectivity etc., coupled with wider reservoir characterization themes for CO2 storage, cannot be underestimated. At GeoLogica, our portfolio of CCS courses continues to grow and is supported by a range of multi-disciplinary options that compliment these (e.g. clastic depositional systems, reservoir modelling for CO2 storage and re-purposing infrastructure).

We would like to highlight the value of field training and have three field courses available for in-house groups to explore CCS reservoir storage:

E550: Carbon Capture – Reservoir Storage and Risk Elements: Insights from the Field, NE England

Focus is placed on the assessment of reservoirs that have the potential for carbon storage in the subsurface with an emphasis on suitable prospects.

E556: Reservoir Characterization for Carbon Capture and Underground Storage, Devon and Dorset, UK

A field-based overview of CCS with a focus on widely exploited depositional environments and their associated heterogeneity.

E578: CCS Reservoir Geology at Outcrop: Rotliegend and Bunter/Sherwood Sandstones, Cumbria and NW Cheshire

A course that gives subsurface teams the opportunity to see at outcrop some of the rocks they are planning to use as CO2 storage sites in the UK.

The value of fieldwork cannot be underestimated, so for more information on these and our scheduled CCS courses, please visit our website or get in touch with us: info@geologicaworld.com