Abstract
Geological CO2 storage presents an opportunity for industrial innovation and revitalization by offsetting greenhouse gas emissions. Its deployment can help countries meet national “net zero” targets and address the multifaceted challenges of the climate crisis. Being a well-studied, data-rich, mature basin facing major industrial clusters located in northeastern England, the United Kingdom Southern North Sea has the potential to be a significant geological CO2 storage location. Numerous well-defined, periclinal and domal closures that host Lower Triassic Bunter Sandstone Formation reservoirs, sealed by Middle Triassic mudstones and evaporites, are prime storage targets. We present a critical geological evaluation of the Bunter Sandstone Formation closures in the Silverpit Basin of the Southern North Sea, based on closure depth, container size, and seal integrity. Integration of seismic well ties, the seismic interpretation of key stratigraphic horizons and their depth conversion using a seven-layer velocity model provides the basis for a new theoretical CO2 storage capacity model that incorporates volumetric calculations and CO2 phase and density based on depth and well-calibrated temperature data. The results enable the carbon storage potential of 11 closures to be risked, compared, and ranked. Three large (>1200 million tons of CO2 [MtCO2]) and six modest (8-300 MtCO2) Bunter Sandstone-bearing dry closures and two depleted gas fields have been identified, forming a geological CO2 storage portfolio for the Silverpit Basin. A further three closures were discounted due to shallow crestal depths and geological (fault-related) integrity concerns. This initial ranking process paves the way for site-specific studies that incorporate geological heterogeneity and nontechnical risks to geological CO2 storage, including well integrity concerns.
| Original language | English |
|---|---|
| Pages (from-to) | 1791-1825 |
| Number of pages | 35 |
| Journal | AAPG Bulletin |
| Volume | 106 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - Sept 2022 |
Bibliographical note
Acknowledgments:The work included in this paper forms part of a wider research project being undertaken by the Centre for Exploration Geoscience in the Institute of GeoEnergy Engineering at HWU to critically evaluate carbon storage sites as part of a road map for the United Kingdom Continental shelf (UKCS). Funding for the project has been provided by the Net Zero Technology Centre. The interpretations have drawn upon data made available through the Oil and Gas Authority’s National Data Repository that includes PGS’s Southern North Sea three-dimensional (3-D) MegaMerge volume and Western Geco’s Cavendish 3-D volume. We thank Dave Barlass, Matthew Masham, and Alex Ellwood for their support and WesternGeco for permission to show and publish data from their Cavendish 3-D speculative seismic survey. We thank Jo Bagguley of the Oil and Gas Authority for helpful comments regarding recent UKCS CCUS licenses and applications. Schlumberger is thanked for the donation of Petrel and Techlog software licenses, Esri is thanked for the donation of ArcGIS Pro software licenses, and Petrosys is thanked for the donation of Petrosys PRO software licenses to HWU, all of which have permitted the interpretation and analysis of seismic and wire-line log data to be undertaken.
Funding Information:
Several project development proposals have been published for the undertaking of CCUS in the SNSB through the 2010s. The White Rose project led by National Grid proposed the development of the saline aquifer Bunter Closure “Endurance” as a CCUS site as part of a £1 billion (approximately $1.4 billion) funding opportunity set by the United Kingdom government, which they later reneged on in 2015. Energy company E.ON had championed the depleted Hewett gas field as a CCUS site, conducting extensive front-end development research, but ultimately backed out of the project. Another project led by Pale Blue Dot, funded by the UK Department of Energy and Climate Change (now Department of Business, Energy, and Industrial Strategy) proposes the development of a BSF saline aquifer overlying the Carboniferous Schooner gas field (). These projects have yielded extensive publicly available legacy data that may benefit future developments. Recently, three CCUS licenses have been awarded in the Silverpit Basin. The first, awarded to the East Coast Cluster collaborative partnership, was given Track-1 status by the United Kingdom government, and seeks to develop the Endurance closure as a geological CO storage (GCS) site by the mid-2020s (). In May 2022, the North Sea Transition Authority announced that two further licensing rounds were both awarded to BP and Equinor, partially covering UKCS blocks 43 and 44 (Figure 2) (). Furthermore, a recent CCUS licensing round announcement offering 13 prospective license areas further demonstrates the drive to revitalize the UKCS as a CCUS hub (). 2
