This paper discusses principles of well barriers and how they have been applied to a large, diverse well inventory across multiple countries and fields. Well barrier principles are discussed with practical definitions and examples applied to typical well types. Then the work processes and lessons learned during implementation of these principles to a large collection of wells are reviewed. Implementation of well barrier principles has provided a common approach to viewing wells and has improved consistency in management of well risks.

Implementation of well barrier principles, and application to a large, diverse well population is early in industry adoption. The fundamental concepts of well barriers have been present in the literature since the publication of NORSOK D-010, version 3, in 2003. However, outside Norway uptake of these principles has been limited. As the industry recognizes the simplicity and broad applicability of the well barrier approach, work processes are being modified to align with these principles. Industry standards relating to well integrity, such as ISO 16530-2 (Well integrity for the operational phase), are using well barrier principles as a basis for design of specifications. This paper describes lessons learned while implementing this significant work process change.