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Australian Energy Producers Journal Australian Energy Producers Journal Society
Journal of Australian Energy Producers
RESEARCH ARTICLE (Non peer reviewed)

Challenges and lessons learnt from Northern Territory (NT) Orphan Well project

Shaun Hingerty A *
+ Author Affiliations
- Author Affiliations

A Department of Industry, Tourism and Trade, Darwin, NT, Australia.

* Correspondence to: shaun.hingerty@nt.gov.au

The APPEA Journal 63 S192-S197 https://doi.org/10.1071/AJ22160
Accepted: 27 March 2023   Published: 11 May 2023

© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of APPEA.

Abstract

The Orphan Well project evolved from recommendations in the Final Report of the NT Hydraulic Fracturing Inquiry (HFI). The purpose was to assess wells that were drilled under petroleum permit or licence, and which had subsequently been surrendered by the titleholder and are now the responsibility of the NT Government. The project’s objective was to confirm the current status of these wells and to put forward recommendations for remedial works and/or monitoring for wells assessed to have an integrity risk. The assessment primarily focusses on the risk of fugitive methane gas. Two petroleum engineers were employed to undertake the project of assessing 113 orphan wells scattered over 1.4 million km2 of the NT. As it is a requirement to rehabilitate the land after petroleum activities have ceased, access to orphan wells is often not maintained; therefore, logistical consideration was undertaken. The project involved an initial desktop study of well history (construction) followed by a field site inspection. The drilling of these wells date back to the 1960s. These older wells can often have less detail in the well records including survey location, and being pre-GPS, may include location errors of several kilometres. Remote helicopter travel was used to undertake fieldwork and to locate these wells. The site inspections commenced in February 2022 and as at 31 December 2022 on ground field inspections were delivered to 96 wellsites. This paper provides insight as to how the Orphan Well team developed its processes in both desktop study and site investigations.

Keywords: fugitive methane gas, GPS, laser methane detector, magnetometer, Northern Territory, orphan wells, survey inaccuracy, well failure model, wellbore diagram.

Shaun Hingerty is currently employed by the Northern Territory Government in the role of Senior Orphan Wells Engineer. This project was initiated from the Northern Territory Hydraulic Fracturing Inquiry’s recommendation. Shaun has over 25 years of oil and gas industry experience in both Service Company and Operator affiliations. He has worked for companies such as Halliburton, Roc Oil and Bridgeport Energy, principally involved in drilling construction and life-cycle well operations in roles of engineering, supervision and management. Current interests include well integrity, repurposing of petroleum wells and geothermal. Shaun holds both a Bachelor and a Master's degree in Petroleum Engineering and is a Chartered Registered Engineer. He is an active member of Society of Petroleum Engineers and Engineers Australia.


References

Huddlestone-Holmes CR, Arjomand E, Kear J (2022) Long-term monitoring of decommissioned onshore gas wells. CSIRO Report EP2022-1246. (CSIRO: Australia)
| Crossref |

Pepper R, Anderson A, Ashworth P, Beck V, Hart B, Jones D, Priestly B, Ritchie D, Smith R (2018) Final Report of the Scientific Inquiry into Hydraulic Fracturing in the Northern Territory. Available at https://frackinginquiry.nt.gov.au/inquiry-reports/final-report

International Organization for Standardization (2017) Petroleum and natural gas industries — Well integrity — Part 1: Life cycle governance. ISO 16530-1. (International Organization for Standards)

Standards Norway (2021) NORSOK Standard D-010. Well integrity in drilling and well operations. Rev. 5, 5th edn. (Standards Norway)