In mid-2014, a review of some of the core analysis performed on rock material from the South West Hub (SW Hub) carbon capture and storage site was conducted.
There were still some key uncertainties remaining about the nature of the mechanisms, the causes of the identified fluid-rock interactions, and the extent to which they could impact on the future planning of the SW Hub injection testing. It was observed that the permeability of the Harvey-1 samples would decrease substantially (up to 60%) after undergoing a laboratory core-flooding procedure. Such results could have significant implications for the CO2 injectivity in the future injection wells at the SW Hub.
The overall objectives of this new work includes:
- the identification and characterisation of the mechanisms behind the previously observed petrophysical variations in the post-flood samples;
- characterisation of the in-situ geochemical reactions which may occur at the SW Hub;
- identify the extent of fines migration that occurs, and thus,
- estimation of the relative contribution of geochemical reaction changes versus fines migration as contributors to changes in porosity and permeability induced by flooding.