Accelerating Well Intervention in the UKCS - The North Sea Transition Authority Viewpoint

Abstract The North Sea Transition Authority (NSTA) regulates, licenses and influences the oil and gas, carbon storage and offshore hydrogen industries in the UK. The NSTA gathers data from all UK Continental Shelf (UKCS) license holders through its annual stewardship survey, including information regarding well intervention work they have conducted. The data identifies trends, underlying themes, and common challenges across the UKCS and outlines how the NSTA assists operators in addressing these challenges. The NSTA analysed data from the survey to identify areas of success, growth, and improvement in well interventions and plug and abandonment (P&A) activities. The extensive wells data were filtered to focus on interventions performed on mechanically complete and operating wells, as well as mechanically complete and shut-in wells. The intervention types were categorised into four groups: Optimisation, Safeguarding, Restoration and Surveillance. As of end-2023, approximately 31% of the UKCS well stock was shut in or plugged. The NSTA emphasises the need to maintain and increase well intervention activity to preserve the skill set within the basin during the energy transition. The survey revealed operators carried out 443 well interventions in 2023, a 13% decrease on 2022 intervention levels (511) excluding plug and abonnement interventions. In response, the NSTA is collaborating closely with operators and the supply chain to thoroughly investigate well interventions. Notably, well P&A is expected to generate significant levels of activity in the near term. This is the first forensic examination of shut-in wells by the NSTA. The NSTA organised an event for operators and the supply chain to review the supplied data and explore opportunities to increase activity levels. The key actions identified are reducing costs for subsea interventions in the UKCS, benchmarking and fostering collaboration.