Call 1 – Storage

The project will three-dimensionally image hydraulically conductive features in the reservoir, caprock and overburden of an active CO₂ injection site: the Aquistore site, Canada. Our research will provide important information on potential migration pathways within the storage complex to inform future monitoring strategies at the Aquistore site and at future storage sites. We will monitor micro-seismic events prior to, and during, CO₂ injection using a three-component nanoseismic surface monitoring array which will complement data collected by the existing geophone network at the site. This analysis can be used to provide deep focussed monitoring information on permeability enhancement near the injection point. As injection continues it will also enable imaging of any flowing features within the caprock.

Main project funder category: UKCCSRC – Call 1
Funder name: UKCCSRC
Grant number: UKCCSRC-C1-19
Project fund amount: £74,000
Project date: Oct 2013 to Oct 2015
Lead institution: University of Strathclyde
Principal investigator(s): S.I. Pytharouli
Category: Storage/Monitoring
Primary research theme: Active and passive seismics

Fault risk remains a key parameter in evaluating the potential for trapping CO₂ in the subsurface, yet very little is known about the conditions under which CO₂ and CO₂/hydrocarbon mixtures are retained by faults. The project will investigate the roles and properties of faults in their capacity to retain CO₂. Natural and engineered accumulations of hydrocarbon and CO₂-hydrocarbon mixtures will be examined across a wide self-similar province (to minimize geological variability) to develop a knowledge base of fault flow properties. Fault geometries, orientations, seismic attributes, proven vertical trapping and lateral pressure retention values and column-heights will be documented. High-quality data-rich examples will be selected for analysis with established software tools to predict and calibrate CO₂ column height and pressure retention. Differences between prediction and observation will be reconciled by checking site-specific geology and optimising the petrophysical property values assigned to the faults, reservoir, seals and fluids (within realistic ranges) to produce an understandable pragmatic and calibrated fit. The fault properties knowledge-base and the newly calibrated tools will be applied to selected key reservoirs from the ETI UK Storage Assessment Project (UKSAP). This will provide improved and evidence-based assessment of storage in regional UK North Sea aquifers such as the Bunter Sandstone, Forties, Tay and Captain. These are some of the largest and promising early developments for storage and are vital to reducing storage costs via multi-user storage. The Bunter Sandstone has 8Gt CO₂ unrisked capacity – but only 1Gt may be considered viable because of fault risk. The Captain, Forties and Tay sandstones total 11.5Gt CO₂ unrisked capacity, of which only 1Gt may be currently considered viable. The impact of the research will be to upgrade parts of the UKSAP assessment and to assist the development of the large capacity element in these formations that does have perceived fault risk.

Project Outputs

• Fault Seal Controls on CO₂ Storage. Project update presented by John Williams at the UKCCSRC Cranfield Biannual Meeting, 22/04/2015
• Fault seal analysis of a natural CO₂ reservoir in the Southern North Sea, Energy Procedia Volume 63 (GHGT-12), 2014, p 3364-3370, J. MIocic, G. Johnson, S. Gilfillan

Main project funder category: UKCCSRC – Call 1
Funder name: UKCCSRC
Grant number: UKCCSRC-C1-14
Project fund amount: £232,000
Project date: Sep 2013 to Jan 2016
Lead institution: British Geological Survey
Principal investigator(s): J. Williams
Category: Storage
Primary research theme: Seals, faults and leakage pathways

We aim to de-risk the development of the major potential CO₂ storage reservoirs in the UK sector of the Northern and Central North Sea by developing our understanding of the geometry and properties of the overburden above the potential reservoirs (including their seals), and by developing an understanding of the likely hydraulic connectivity in the reservoirs, surrounding strata and overburden and hence the likely flow paths for CO₂ and formation brine within and between them. These reservoirs are some of the most widespread and internally hydraulically well-connected reservoirs on the UK Continental Shelf and appear to have excellent potential for high injectivity, large capacity without excessive pressure rise and, in some cases, good containment. Consequently, they promise to be of great significance if CCS becomes a major greenhouse gas mitigation technology in the UK.

Project Outputs

Glacistore bid – Scientific drilling for CO₂ Storage. Project update presented by Maxine Akhurst, BGS, at the UKCCSRC Cranfield Biannual Meeting, 22/04/2015.
CO₂ Storage in Paleogene and Neogene Hydrogeological systems of the North Sea: preparation of an IODP scientific drilling bid project update (presentation not available for publication). Project update presented by Sam Holloway, BGS, at the UKCCSRC Cambridge Biannual Meeting, 02/04/2013.

Main project funder category: UKCCSRC – Call 1
Funder name: UKCCSRC
Grant number: UKCCSRC-C1-30
Project fund amount: £290,000
Project date: Feb 2013 to May 2015
Lead institution: British Geological Survey
Principal investigator(s): M. Akhurst
Category: Storage/Appraisal & Site Evaluation
Primary research theme: Generic Techniques/Site Specific