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Timor Sea Wellhead Abandonment

Activity type Any other petroleum-related activity
Activity subtypes
Lifecycle Classification Decommissioning
Submitted by PTTEP Australasia (Ashmore Cartier) Pty Ltd
Submission date 04 May, 2022
Subtype Revision
Decision date 23 February, 2023
RMS ID 7005
Status Finalised
Outcome Accepted
Link to previously accepted EP 5234 - Timor Sea Wellhead Abandonment
Ryan Hartfield
Phone: 0439728555
Location map (click to enlarge)
Location map - Activity: Timor Sea Wellhead Abandonment (refer to description)

The titleholders undertaking this activity are PTTEP Australasia (Ashmore Cartier) Pty Ltd and PTTEP Australia Timor Sea Pty Ltd (collectively, PTTEP AA). PTTEP Australasia (Ashmore Cartier) Pty Ltd is the 100% titleholder of AC/RL12 and PTTEP Australia Timor Sea Pty Ltd is the 100% titleholder of AC/RL4. The title areas are located in a remote area of the Timor Sea, over 260 km northwest of the Kimberley coastline of Western Australia (WA), and approximately 640 km west of Darwin, Northern Territory (NT). The title areas are located in an area of shared jurisdiction with Indonesia called the Perth Treaty Area; as such the title areas and the petroleum activity covered by this EP are located outside of the Australian Exclusive Economic Zone (EEZ) and the Australian Fishing Zone (AFZ).

This EP revision covers the decommissioning of two permanently plugged wells, Oliver-2, located in permit area AC/RL12 and Tenacious West-1 ST1, located in permit area AC/RL4. These wellheads currently remain on the seabed and the wells are classified as having adequate barriers in place for permanent abandonment, as outlined in an accepted Well Operation Management Plan (WOMP; Revision 4, PTTEP Technical Document CORP-DR-D41-868269 (HQ202103848.1). Final abandonment reports have been accepted by the National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) for both wells. The scope of the EP revision covers the permanent abandonment of the two wellheads in situ. The wellheads were inspected by a dedicated ROV survey on 13/03/2022 and were observed to be intact, with no leaks observed and no sign of cuttings piles or debris on the surrounding seabed. The wells were documented to be almost completely covered in marine growth, creating a habitat for attracting numerous fish.

No on-the-water activities are proposed as part of this EP, and therefore the activity will be considered complete upon acceptance of the EP from NOPSEMA.

Other Details
Locations Ashmore Cartier
Commonwealth waters adjacent to ACI
Titles (or other instruments) AC/RL12
Current Documents (Finalised)
EP Document

Location map


Previous EP Documents (Under assessment)
EP Document

Location map