Integrated team approach to decommissioning Environment Plan development

Abstract

The offshore oil and gas industry is facing a significant transition period in the coming decades due to the evolving energy market and aging oil and gas infrastructure. Industry has over 1000 offshore wells to plug and abandon, 57 fixed facilities and over 8000 km of subsea lines to decommission over the coming decades. Most of this significant portfolio is regulated by NOPSEMA (National Offshore Petroleum Safety and Environmental Management Authority) with the expectation that decommissioning involves the full removal of equipment as per Section 572 of the Offshore Petroleum and Greenhouse Gas Storage Act 2006 (Cth) (OPGGS Act). However, other options may be considered if the titleholder can demonstrate that an alternative decommissioning approach delivers equal or better environmental and safety outcomes compared to complete removal. Integration of environment and engineering functions primarily occurs during the process of developing an Environment Plan (EP) and, specifically, the process of identifying environmental hazards (Environmental Hazards Identification, ENVID) and mitigation measures. This paper proposes that improved stakeholder, regulatory, cost and environmental outcomes could be achieved through an earlier integrated approach to planning decommissioning activities. Specifically, co-designing an approach to decommissioning at the earliest stages would inform, for example, approvals strategy and equipment selection. This would ultimately result in improved outcomes without the application of mitigating control measures. The paper will discuss some of the current challenges and outline the value of early identification and understanding of key environmental values and sensitivities to ensure site-specific information is considered during planning stages, later streamlining EP development. A multi-disciplinary decommissioning team in the early stages of project development enhances problem-solving capabilities and ultimately improves environmental and safety outcomes.