Guest Editorial: Robust Well Barrier and Well Integrity Management

Abstract

Guest editorial There is an increased focus and emphasis on managing well integrity with smarter, more integrated and cost-efficient tools, systems, and solutions. The words “well integrity” and “digitalization” have become common buzzwords in the oil and gas industry. Many discussions have centered on combining these words to create better solutions to safeguard our wells. However, how do we measure well integrity in the most effective manner? And what do we measure well integrity against? To start with, we need a clearly defined yardstick or basis for measuring the integrity of our wells. We need to know what is in the well. Furthermore, we need a set of parameters to measure against. A principle objective is to define the well barriers and to visualize how to best safeguard our wells to reduce risk and avoid accidents. This can be done by using an integrated well integrity management system that includes—as a foundation—clear and consistent well barrier illustrations and tables containing information of each well barrier element. This is the logical starting point for creating and retaining well integrity. It is important to understand that the technical well barriers play a vital part in managing well integrity and reducing risk. Figuratively speaking, 90% of well integrity is about the technical well barriers, which have the capability and strength to contain pressure and hydrocarbons. The organizational, operational, and functional solutions are merely the “lubricants” in the “machinery” that help make the wheels turn in achieving and maintaining well integrity. Well barrier elements alone cannot hold anything in place. However, when these are placed together as a chain of components, they will form an envelope that can withstand the pressure. Two-Barrier Philosophy One of the principles that is applied to mitigate risk is the two-barrier philosophy, where you have a primary barrier, which is backed by a secondary barrier. NORSOK, the Norwegian organization that sets standards for the offshore exploration and production sector, defines well barriers as envelopes of one or several dependent well barrier elements that prevent fluids or gases from flowing unintentionally from the formation, into another formation or to surface. As part of the two-barrier philosophy, formation pressure is contained by a caprock. The moment the caprock is removed, it needs to be replaced with a primary barrier. This barrier will have to function inside and outside of any casing that is run in the well. A secondary barrier to support the primary barrier needs to be established. The secondary barrier envelope is independent of the primary barrier. This well barrier prevents flow from a breach of the primary barrier envelope (Fig. 1).