Woollybutt Decommissioning Project - Field Management and Plug and Abandonment

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Activity name
Woollybutt Decommissioning Project - Field Management and Plug and Abandonment
Activity types
Drilling, Other survey
Submitted by
Eni Australia Limited
Submission date
Submission type
Revision (Change of Circumstances or Operations)
Titleholder to provide more information
Related documents
Link to previously accepted EP
Woollybutt Decommissioning - Field Management

Location map (click to enlarge)
Progress bar
Assessment with titleholder
Final decision
EP summary published
Activity started
Activity stopped
End of operation of EP
Activity events
Event Event date Next event* Next event due* Related documents
Submission of new EP 05/11/2018 NOPSEMA decision 05/12/2018 Not applicable
Not reasonably satisfied – opportunity to modify EP 03/12/2018 Titleholder action 01/02/2019 Decision notification (pdf 179 KB)
Extension of timeframe 10/12/2018 Titleholder action 02/04/2019 Not applicable
Extension of timeframe 22/03/2019 Titleholder action 12/04/2019 Not applicable
Extension of timeframe 12/04/2019 Titleholder action 29/04/2019 Not applicable
Resubmission of EP 29/04/2019 NOPSEMA decision 29/05/2019 Not applicable
Request for further information 29/05/2019 Titleholder action 19/06/2019 Not applicable
Extension of timeframe 20/06/2019 Titleholder action 17/07/2019 Not applicable

* The next event is based on NOPSEMA’s understanding and expectation of what may occur next in the assessment process. There are a number of other events that may occur, and events may happen sooner or later than expected. All events will be published in this table as and when they take place.

Activity description

The Woollybutt Field is located approximately 80 km off the northwest coast of Western Australia in Lease Area WA-25-L. The Field is approximately 25 km west of the Barrow Island Marine Management Area and Marine Park boundary, and more than 50 km south-west of the proposed Montebello Commonwealth Island Marine reserve.

The Woollybutt Field is presently shut-in. The scope of the EP covers passive field management activities and P&A activities (including well intervention) on four to seven wells within permit WA-25-L. Field management activities that may be undertaken in accordance with this EP include cathodic protection surveys and visual ROV inspections. The methods used by Eni are well understood and do not represent any novel techniques or equipment. ROV surveys will be conducted at least annually until the wells are plugged, and each survey is 3-7 days in duration. Only one project vessel will be in the Operational Area at any one time undertaking field management. Plug and abandonment will take approximately 20-30 days per well and will be completed within 5 years of EP acceptance. The well intervention of WB4 and WB1A may be completed prior to P&A and will take approximately 7-15 days. A maximum of three support vessels will be utilised to support the MODU during P&A activities. Only one project vessel will be in the Operational Area at any one time during well intervention activities. Project and support vessels will be selected based on the activity that will be undertaken. All vessels will be commercial vessels with a suitable survey class for activities in the Operational Area. All project vessels will run on marine diesel; no intermediate or heavy fuel oils will be used.

North West
Commonwealth waters adjacent to
Western Australia
Titles (or other instruments)
WA-25-L Opens in new window

Sashi Gajula

Decommissioning Coordinator

Eni Australia Ltd

226 Adelaide Terrace

PERTH  WA  6000

Telephone: +61 8 9320 1111

Email: eniaus.info@eni.com


*Where an environment plan was submitted or accepted prior to 28 February 2014 certain information is not published, in accordance with the Environment Regulations in place at that time. For accepted EPs, refer to the attached EP Summary for additional information.