Cradle to grave: planning for all well decommissioning

Abstract

As the Australian offshore oil and gas sector continues to mature, there is an increasing level of activity in the final phase of the well lifecycle: well decommissioning (well abandonment). Several decommissioning projects are either already in progress or being planned in Australian waters. Since the 1960s, the eventual decommissioning of wells has been an expectation within the law. Whilst this fundamental obligation has not changed, the expectations for the management of offshore wells and equipment have changed for both the industry and regulators. In the meantime, the number of unused wells grew. In 2021, the National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) published a Decommissioning Compliance Strategy and Decommissioning Compliance Plan. From this, all wells will have been risk assessed and have accepted abandonment plans in place by the end of 2023, and all wells will be permanently abandoned within 3 years of cessation of well operation by the end of 2025. The industry has an immediate challenge catching up on the backlog of abandoning wells, some of which have been in an unused state for decades. Going forward, well abandonment should be actively considered throughout the well lifecycle, including design, construction and operation phases. This will enable decommissioning objectives to be achieved in a safe, timely and efficient manner. This paper will provide an overview of recent domestic and international developments related to well decommissioning, from a regulatory perspective, and the importance of proactive well decommissioning planning and collaboration.