Paper submitted to EAGE Annual 2026
Summary
The Greater Endurance area contains six prospective CO2 storage structures within 4 carbon storage licences (Figure 1) in the UK Southern North Sea. The first phase of the project, which will store 100 MtCO2 over 25 years within the Triassic Bunter saline sandstone reservoir at the Endurance structure, was sanctioned in December 2024 with the construction phase underway. Future storage capacity plans to utilise additional Bunter reservoir stores, are currently being appraised.
Legacy 3D seismic datasets available across the area, predominantly acquired in the 1990s, have several critical limitations for CCS site characterisation and development planning. These include gaps in 3D coverage, poor shallow imaging and sub-optimal resolution at reservoir level. Improved baseline datasets are also required for future 4D seismic monitoring of the stores during injection.
In 2022, NEP and TGS acquired a wide-tow quad-source 3D High Density (3DHD) streamer survey extending across the Endurance carbon store in licence CS001 and the prospective stores within the CS006 licence. The motivation for utilising a wide-tow multi-source 3D configuration was to obtain high resolution imaging for overburden integrity and reservoir characterization efficiently over large areas. The survey successfully delivered much higher near-offset fold than legacy hydrocarbon-focused surveys that had deeper imaging targets, improving imaging and resolution at all geological levels (Cooper, 2022, Widmaier et al., 2023, Tarasewicz, 2024).
In 2025, NEP and TGS, acquired a second 3DHD survey over Carbon Storage licence CS007, containing the prospective BC36 and BC37 stores. This paper outlines how this novel style of widetow quad-source acquisition has evolved from the 2022 to the 2025 configuration; details the relevant technical elements that allow for large-scale 3DHD surveys and suggests areas for future advancements.