Insight article
Integrated geophysical data to advance CCS projects
21 Feb 2025
- Two landmark decarbonisation schemes in the North and South of the UK, using new and existing infrastructure, to unlock a low carbon future through large-scale decarbonisation of hard-to-abate industries and replacement low carbon Hydrogen
- Innovative geophysical imaging solutions to support clients whose CCS strategy is using fields close to major industrial emitter hubs, repurposing existing infrastructure on depleted fields
- Very complex operating environments representative of CCS Hub environments
- Shearwater and XOCEAN partner to provide a multi-disciplinary, fully integrated data solution.
Background
Decarbonisation in the UK: Pioneering CCS and hydrogen solutions
The HyNet North West project is the UK’s foremost industrial decarbonisation project using hydrogen and carbon capture and storage (CCS) to reduce carbon emissions in industry, homes, and transport across northwest England and north Wales.
The project will store up to 10 Mtpa of captured CO₂ in the depleted Hamilton and Lennox gas fields in the Irish Sea. It will also integrate existing natural gas plants with carbon capture and storage (CCS) activities to produce low-carbon hydrogen for supply to industry, transport, and electricity generation in the region.
Delivered by a multi-partner consortium, the project operator will develop and operate the onshore-to-offshore transportation and storage of CO₂.
Meanwhile, Bacton Thames Net Zero (BTNZ) involves more than 10 entities working together to substantially decarbonise power and industrial processes in Norfolk and the Thames Estuary, near London.
The plan is to capture, transport, and store at least 10 Mtpa of carbon dioxide emitted from these regions into the Hewett depleted gas field off the coast of North Norfolk.
Watch: How We’re Advancing Carbon Capture and Storage at Hewett Field
The challenge
Data to delineate shallow geophysical targets in extremely complex operational contexts
The task was to acquire high-quality, high-resolution data, in an extremely complex operational context, to help the project operator delineate shallow geophysical targets in multiple identified storage sites.
Both Liverpool Bay and Hewett presented a challenge representative of many CCS Hub locations globally. The target sites, generally depleted fields, tend to be close to shore in water depths of 20 m and shallower.
Geophysical imaging for CCS requires focus on derisking the shallow overburden geology with high-resolution parameters for site characterisation and pre-injection imaging, and a future-proofed baseline monitor survey.
The data to mitigate CO₂ containment risk had to be acquired as efficiently as possible. Additional time constraints added to the complexity of both projects.
Shearwater provided high-quality seismic processing and processing services to support the NEP project and its Endurance offshore storage site, the UK’s first large-scale carbon storage facility.
By delivering accurate subsurface imaging, Shearwater’s expertise enables the safe and efficient development of storage sites, ensuring the long-term success of CCS initiatives.
The solution
Integrated bathy-morphological, hybrid seismic surveys
Liverpool Bay
An integrated data approach allows for contiguous imaging of the subsurface that would have otherwise been prevented if limited to any one single approach.
The areas closest to the shoreline in Liverpool Bay, for example, had post-critical angles that prevented imaging of the seabed. However, this lack of information was easily recovered using both OBN and sub-bottom profiler data.
For Liverpool Bay, Shearwater used towed streamer technology onboard SW Bly to maximise efficiencies, and then used a bespoke node solution in the shallowest sections to ensure full data imaging requirements could be delivered.
This hybrid approach demonstrates Shearwater’s versatility and operational excellence.
Bathymetric data was essential for safe navigation and de-risking the area geophysically and geomorphologically. Shearwater partnered with XOCEAN, using their innovative carbon-neutral unmanned surface vessels to provide multiple data measurements in an operationally efficient and safe manner.
These data measurements, including Multi Beam Echo Sounder, Sub Bottom Profiler, and Sound Velocity Profiles, enabled an integrated data solution to deliver more effective processing and imaging of the shallow faulting and target reservoirs.
This image shows how Shearwater was able to leverage a high tidal range to acquire streamer data over the Lennox field with the SW Bly as shallow as 7 m – shallower than the vessel’s minimum operating depth.
Placing a seismic vessel with towed equipment at a specific location at a specific time would typically see significant standby time waiting for ideal conditions. The acquisition strategy was able to further exploit a low-tide operating limit for the southern part of the Hamilton field, which was in water depths of 15–20 m. This limit was set by the Liverpool Port Authority to allow commercial shipping access to the port during high tide.
Lennox was acquired on high tide, Hamilton South on low tide, and Hamilton North efficiently while waiting for the next Lennox high tide.
The detailed planning added to an already challenging area featuring multiple wind farms, obstructions within the survey area, fishing community engagement, several other stakeholders, and high tidal currents—all to a tight permit deadline.
The bathymetry to enable the safe acquisition of both Hamilton and Lennox was acquired on a condensed timeline, which needed Shearwater and XOCEAN to quickly develop a close relationship to provide the right data in the right place in time for Shearwater to establish an acquisition plan.
Hewett
The Hewett field off the coast of Norfolk was an equally complex and challenging environment with additional hurdles.
For Hewett, Shearwater used the vessel SW Amundsen’s towed streamer multi-component technology in very shallow water up to just 10 m, with four obstructions to acquire around.
The coverage gaps were further minimised by innovative close-pass lines in-between the platforms, with the remaining gaps infilled using deployed nodes from the SW Vespucci. Coverage around the platforms was critical for site characterisation and pre-injection.
The image shows the SW Vespucci deploying Node On A Rope in early September, demonstrating safe operations late in the North Sea season. With a platform exclusion zone of 100m, the vessel was able to deploy nodes 101m from the platform.
To add to the complex operating environment, the survey started late in the North Sea season, with weather standby increased.
We were able to make the most of every good weather opportunity to maximise production, with minimal technical downtime. This was achieved by significant investment prior to the survey to ensure all in-sea equipment was fully operational.
Additional de-noise and de-multiple stages were added to the fast-track processing to verify high-quality data in a challenging environment.
Success of the project once again needed a coordinated effort with XOCEAN, who provided crucial updated water-bottom bathymetry, allowing safe navigation along the 10 m contour.
Simultaneous operations with rig decommissioning, fishing activity, and strong tidal currents up to 3.0 knots also meant the crews of the SW Amundsen and SW Vespucci had to have a strong plan, with contingency built in for flexibility.
Image of updated bathymetry clearly showing sand channels.
The result
High-quality data acquired safely and efficiently and delivering on technical expectations
Significant data uplift shows the benefit of a modern high-resolution dataset.
The acquired surveys will be fundamental to ensuring a successful and safe execution of a key client’s carbon capture and storage projects.
The combination of shallow waters (down to 2m), the huge variation of the mean sea level linked to the tides (8–9 m), and the shallow geophysical targets, together with the presence of numerous oil and gas infrastructure, wind farms, and fishing & marine traffic, make such offshore acquisition campaigns unique in their operational complexity.
The successful project deliveries led to Shearwater and XOCEAN formalising a collaboration partnership, promoting the value of the integrated data approach demonstrated for these projects.
This approach provides clients with a fully integrated, multi-disciplinary data solution combining modern high-resolution towed streamer and OBN 3D seismic data with bathymetric multi-beam echo sounder and sub-bottom profiler.
Carbon capture and storage is a strategic focus for Shearwater, and we are developing a fit-for-purpose acquisition toolkit specifically for this growing market.
Related articles
Seismic thinking for CCS – Unlocking the power of seismic technology
carbon capture and storage
Shearwater proud to support milestone CCS projects with advanced geophysical solutions
Shearwater awarded seismic survey for UK carbon capture and storage project
GET IN TOUCH
David Forecast, our storage solutions expert is here to help
