Project Colocate

Project Colocate, commissioned by The Crown Estate and Crown Estate Scotland and conducted by the University of Aberdeen, investigates the technical, geological, and operational feasibility of colocating offshore wind (OW) farms and carbon capture and storage (CCS) projects on the United Kingdom Continental Shelf (UKCS). The study focuses on the East Irish Sea (EIS) and Outer Moray Firth (OMF), two regions characterised by spatial competition among offshore wind, CCS, oil and gas and other marine stakeholders. The report identifies where OW and CCS interests overlap, mapping nine colocation sites in the EIS and several in the OMF, assessing their geological suitability for CCS, storage capacity, containment risks (including legacy wells and faults), the compatibility of monitoring, measurement and verification (MMV) technologies with wind farm installations and the potential for operational conflicts with current and future oil and gas projects. Towed-streamer seismic surveys conventionally used for high-resolution subsurface monitoring are largely incompatible with wind farm layouts due to collision risks and exclusion zones. Alternative MMV technologies, such as short streamer surveys, ‘spot’ seismic, ocean bottom nodes (OBN), distributed acoustic sensing (DAS), microseismicity and microgravity, are assessed for technical readiness, cost and operational constraints. Further research is needed into MMV technology development and legacy well risks. Colocation is likely to require significant technical and commercial compromise, via increased turbine spacing, holding open access corridors for drilling rigs and vessels, and the acceptance of partial MMV solutions. MMV plans should be adaptable to evolving technology and site-specific geological conditions. Legacy wells must be abandoned before CCS operations commence, maintaining access for future remediation if required while avoiding oil and gas drilling into CCS reservoirs in future. Colocation of OW and CCS may be feasible where spatial overlap is limited and legacy well risks are manageable. Where colocation overlaps already exist, and until operational efficiencies reduce the high cost of full OBN, advance acquisition of short streamer surveys can assure future CCS MMV using repeat sparse OBN. Nevertheless, the colocation of high-priority CCS sites with dense wind farm infrastructure remains highly challenging and the creation of new overlaps should be avoided wherever possible. Early stakeholder collaboration, co-ordinated spatial planning and enhanced regulatory alignment can optimise the use of limited offshore space. There is an opportunity for an integrated, cross-sector leasing and licensing framework to minimise colocation conflicts and decarbonisation delays while helping to assure the UK’s continued progress towards Net Zero.