On the relevancy of systems thinking in permanent plug and abandonment regulations in Norway

More than 2500 production wells on the Norwegian Continental Shelf (NCS) will require permanent Plug and Abandonment (P&A) in the future. For this activity, the Norwegian regulations have, up to recently, adopted a principle of zero well leakage for perpetuity. This principle makes it appropriate to consider wells in isolation and ignore system effects, as any well leakage is unacceptable. The NORSOK D-010 issued in 2021 introduced a shift to this principle, by tolerating low-rate well leakage. Whether it is still appropriate to ignore the system effects has not yet been clarified. This article considers the relevancy and role of systems thinking in Norwegian P&A regulations, where Leveson's STAMP model is used as basis for the analysis. The system-wide effects investigated include well leakage in area perspectives, and whether feedback concerning well leakage is adequate for proper risk management. The analysis point to important system effects. Wells tend to cluster on the NCS, and certain clusters share characteristics associated with an elevated well leakage risk. We argue that a system's approach to P&A is required to properly manage the well leakage risk. The analysis indicates that feedback from well monitoring and well leakage detection fails to verify that the system operates properly, making identification of best technologies and best practices in P&A more difficult. A systems theoretical approach represents a way to strengthen current regulations.