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 is currently lacking provenance data, which can help to constrain several key factors for storage assessment including sediment routing patterns, lateral compositional and net-to-gross variability, and reservoir quality. The limited existing data suggests that the interval had a complex provenance involving widely spaced source regions and large sediment transport systems. This project will address this knowledge gap via a multi-proxy approach, whereby several provenance-sensitive parameters will be systematically analysed from a number of wells that penetrate the Bunter Sandstone Formation and equivalents across the UK and Dutch sectors.

Research programme

Sampling (every 10 m) of the Bunter Sandstone Formation will be undertaken on core from at least five wells from the UK sector, two wells from the Dutch offshore sector, and one UK onshore well. The same cores will be logged in detail as part of Project 4 (CASP.BSSC.4). An initial batch of conventional heavy mineral provenance analyses will guide the focus of more detailed work involving single grain analyses. The aim is to identify provenance changes throughout the formation and across the study region. Together with the findings of the other projects in this research theme, this will reveal how provenance has impacted reservoir quality.

Deliverables

Results will be delivered via an interim data release with associated presentation for client companies and a final technical report containing:

• Conventional heavy mineral data and provenance-sensitive index values
• Garnet and tourmaline geochemistry data
• Combined apatite U-Pb age and geochemistry data
• Zircon U-Pb age data

The data will be presented in tables and charts alongside core logs and used to refine the sediment transport path map in Figure 2. Sediment source regions will be proposed based on a comparison with data in the literature and the significance of provenance as a control on reservoir quality will be considered. It will conclude with a client workshop during which all data and interpretations will be presented and discussed.

Project duration

The project was launched at the beginning of July 2022 and has a planned duration of 25 months.

Contact(s): Adam Szulc for further information about this research and licensing options.