This project and resultant report provides sedimentological, geochemical and petrophysical data from the topmost Bunter Sandstone Formation / Lower Germanic Trias Group and the Haisborough Group / Upper Germanic Trias Group, derived from four offshore wells situated in the UK and Dutch sectors of the Southern North Sea. The four studied cored intervals offer unique insights on the facies, depositional environments and composition of these strata, which rarely have been cored. Combined with the data from reference well SM14 in North Yorkshire, issued in report BSSC.6, these data are a valuable asset for the assessment of the primary seal of the Bunter Sandstone CO₂ storage complex.

Main results: Detailed sedimentary logging of four cored sections – two from the Bunter Sandstone Formation to Haisborough Group transition (UK), and one each from the Lower and Upper Germanic Trias groups (NL) – allows for the recognition of twelve lithofacies. These are grouped into seven lithofacies associations representing seven depositional environments including terminal fluvial, claypan to sabhka, and salt lake to lagoonal settings.

Densely-spaced hand-held XRF measurements along three of the cores, together with QXRD and SEM-EDS analyses of core samples, allow for a compositional characterisation of the logged successions.

MICP analysis conducted on 21 samples enable supported CO₂ column heights to be calculated allowing a direct assessment of the primary seal effectiveness to carbon dioxide injection into the underlying Bunter Sandstone Formation.

Data delivery

The report spans 109 pages with 4 enclosures and comes with a 230-page appendix detailing sample petrography and SEM-EDS analyses. The report and supporting documents are provided in printed and electronic formats.

Completed: March 2025

Report details: Composition and sealing capacity of the Haisborough Group in the Southern North Sea

For further information, including licensing details, contact: [email protected]