Maximising gas production from late-life assets: a case study from the Snapper Field, Gippsland Basin
Hugo B. Burgin A * , Mohammad Bagheri A , Melanie Ryan A , Stewart Anderson A , Jianlin Wang A and Kieran Trump AA ExxonMobil Australia, Level 9, 664 Collins Street, Docklands, Vic. 3008, Australia.
The APPEA Journal 63 144-156 https://doi.org/10.1071/AJ22165
Submitted: 21 December 2022 Accepted: 11 February 2023 Published: 11 May 2023
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of APPEA.
Abstract
Discovered in 1968 and developed in 1981, the Snapper Field has supplied oil and gas to Australia’s eastern seaboard for over 40 years. The field consists of a broad northeast–southwest trending faulted anticline within the Eocene and Paleocene sands of the Latrobe Group. Reserves in 2023 are within the shallowest reservoir interval – the N-1 – which had an original gas in place of approximately 3.8 Tcf. Pressure and wireline log data acquired during exploration and development suggested that the Snapper Field was horizontally and vertically well connected, and it was expected that individual intervals within the N-1 reservoir would water-out sequentially from the bottom to the top of the reservoir during production. As a result, the risk of water over-running gas, and bypassed gas was considered to be low. Production and logging results in 2017 proved otherwise, prompting a period of renewed study from 2019 to 2022. This paper focusses on the culmination of this work effort: construction of a new static geological model and dynamic simulation model, which was built upon and expanded previous models completed prior to 2019. The insights from this study have demonstrated the importance of ongoing and regular reservoir surveillance and the significant value that the construction of new static and dynamic models can add to late-life oil and gas fields. This study showed a later end of field life than previous estimates and an increase in reserves by up to ~20% through the optimisation of future work-over programs. The Snapper Field is owned by ExxonMobil (50%) and Woodside Energy (50%) and is operated by ExxonMobil.
Keywords: gas production, Gippsland Basin, history match, late life assets, reserves recovery, reservoir management, reservoir model, Snapper Field.
Hugo B. Burgin is a Geoscientist at ExxonMobil Australia. He has a PhD and first-class honours degree from the Australian School of Petroleum, at the University of Adelaide. Hugo is currently working as the Production Engineer and Geoscientist for the Snapper Field. |
Dr Mohammad Bagheri has been working as a Reservoir Engineering Advisor with ExxonMobil Australia since 2021. He is a Reservoir Engineer with 20 years of oil and gas as well as CCUS experience in Australia, Europe, and the Middle East. Mohammad holds a PhD in Petroleum Engineering and has worked for Statoil, Schlumberger, British Gas, CarbonNet, Santos, and CO2CRC in both technical and management roles between 2003 and 2021. Mohammad is recognised as a Chartered Professional Engineer with Engineers Australia. He is a member of the Board of Professional Engineers of Queensland and certified by SPE as a Petroleum Professional. Mohammad has been the Program Chair for the Victorian and Tasmanian chapter of SPE since 2018. |
Melanie Ryan graduated from the University of Adelaide with a BSc (Hons) in Geology. She joined Esso Australia in 2001 and has worked in various development and production roles across Gippsland Basin, Malay Basin, North West Shelf, and Papua New Guinea. Melanie is currently working as the Supervisor for the Gippsland Basin Geoscience team. |
Stewart Anderson is a Petroleum Engineer with over 25 years of international experience in oil and gas. He holds a Bachelor’s degree in Engineering (Chemical) and Science from the University of Melbourne. Stewart has held a range of roles at ExxonMobil, Santos, Maersk Oil, Venture Production, Centrica, and EnQuest. He is currently the Production Engineering Lead at ExxonMobil Australia where he provides technical subsurface oversight for the Bass Strait assets, and mentors younger and less experienced team members. |
Jianlin Wang has BS and MS degrees in Civil Engineering from Tianjin University, China, and a PhD in Geomechanics from the University of Minnesota. He has been with ExxonMobil for ~16 years and has held a variety of technical and leadership positions globally in reservoir engineering. Jianlin’s experiences include R&D, enhanced oil recovery, reservoir simulation, production optimisation, and development of conventional, unconventional, heavy oil, and deep-water resources. He has had over 30 publications and 17 granted patents in his fields. Jianlin joined ExxonMobil Australia in 2022 as the Production Subsurface Supervisor, and prior to that he was the Reservoir Supervisor for Guyana development projects. |
Kieran Trump graduated from Curtin University, Western Australia, in 2017 with a BSc in Petroleum Engineering before completing a summer internship with Esso Australia, leading to Kieran joining the Esso team full time in 2018. Since joining the Esso team, Kieran has worked as a Production Surveillance Engineer and Reservoir Engineer across multiple offshore Gippsland Basin fields. Kieran is currently the Reservoir Engineer for the Turrum Field working on the development of a detailed simulation model as well as the Australian Reserves Coordinator. |
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