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Concurrent 23. Presentation for: Safety zones and decommissioning in situ/artificial reefing in the Australian regulatory context: a net environmental benefit analysis-based comparative assessment (NEBA-CA) intergenerational value proposition

Nicholas A. Nelson A *
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A Montrose Environmental Solutions, 400 Northridge Road, Suite 400, Sandy Springs, GA 30350, USA.

* Correspondence to: nanelson@montrose-env.com

The APPEA Journal 62 - https://doi.org/10.1071/AJ21389
Published: 3 June 2022

Abstract

Presented on Thursday 19 May: Session 23

Australia’s oil and gas sector expects approximately 56 billion (AUD) to be expended for decommissioning costs over the next 50 years. The view of the National Offshore Petroleum Safety and Environmental Management Authority is that the designated decommissioning approach must provide equal or better environmental outcomes when compared to full removal of the infrastructure (considered the ‘best case’ expectation under current legislation) and meets as low as reasonably practicable (ALARP) levels of risk. Decommissioning alternatives are generally evaluated through a comparative multicriteria assessment approach, for example, a net environmental benefit analysis-based comparative assessment (NEBA-CA). Decommissioning options cover a range of possibilities, from full removal to leaving subsea structure in situ (in part or in whole). NEBA-CAs we have conducted suggest that some subsea structures are projected to generate significant ecological and social value over multiple generations to come. Thus, in these cases, management in situ can provide greater benefits to the public when compared to full removal. During operation, oil and gas assets typically incorporate a safety zone. If subsea structure is selected to be managed in situ, a question that arises is, should the safety zone be maintained or removed? Our experience indicates that if the safety zone is removed after decommissioning an asset that is left in situ, there may likely be a greater adverse impact on ecological and social values, depending upon the asset location. This abstract showcases the value of the use of safety zones to maximise environmental value while managing risk.

To access the presentation click the link on the right. To read the full paper click here

Keywords: artificial reef, exclusion zone, National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA), net environmental benefit analysis-based comparative assessment (NEBA-CA), oil and gas (O&G), Rigs-to-Reef, safety zone.

Nicholas (Nick) Nelson is a Scientist at Montrose Environmental Group. He earned a Bachelor of Arts degree in International Management with Minors in Applied Mathematics and Environmental Science from Franklin University Switzerland in 2018 and will graduate with a Master’s of Science degree in Biodiversity, Wildlife, and Ecosystem Health from the University of Edinburgh in 2023. He has conducted and co-authored multiple net environmental benefit analysis-based comparative assessments (NEBA-CAs) as applied to offshore oil and gas infrastructure decommissioning. Mr Nelson’s primary experience is in ecological service valuation using the Habitat Equivalency Analysis, Resource Equivalency Analysis, and commercial and personnel risk assessment. Mr Nelson has led and supported decommissioning projects in the North Sea, Gulf of Mexico, and Western Australia, and has experience conducting assessments in the regulatory climates associated with each.