oa Regional Characterisation of the Triassic Bunter Sandstone: Implications for Reservoir Connectivity and Fluid Flow

The Bunter Sandstone Formation and correlative strata in the Dutch sector of the Southern North Sea are important candidate reservoirs for the geological storage of CO2 and will play a key role in the UK’s Net Zero Strategy. The formation and its equivalents comprise laterally variable continental red bed sequences deposited under arid to semi-arid conditions in a low-energy, ephemeral fluvial to aeolian-sabkha environment. However, there is notably little published information on its stratigraphy.

This project combines sedimentological analysis with SEM-derived automated mineralogy, petrography and porosity-permeability measurements in order to constrain how reservoir quality is controlled by changes in sedimentary environment of deposition, sandstone composition and diagenetic evolution, as well as to document its lateral and vertical heterogeneity. This data will be used to inform the assessment of CO2 injectivity and plume migration studies to ensure safe, long-term CO2 storage in the subsurface.

Particular focus has been placed on diagenetic sequences and cements. Sampling will has focussed principally on the Bunter Sandstone Formation and the correlative units of the Dutch sector. This project forms part of CASP’s Bunter Sandstone storage complex research theme