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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 30 April, 2020
Subtype New
Decision date 24 June, 2020
RMS ID 5234
Status Finalised
Outcome Accepted
Link to previously accepted EP
Ryan Hartfield
Phone: 0439728555
Location map (click to enlarge)
Location map - Activity: Timor Sea Well Suspension (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 covers the ongoing suspension of three wells, Oliver-1 ST1, Oliver-2 and Tenacious West-1 ST1. The wellheads are currently suspended on the seabed, isolated from the hydrocarbon zone and assessed as having adequate tested well barriers. The wells will continue to be suspended in petroleum title areas AC/RL12 and AC/RL4 until the wells are plugged and abandoned, which is scheduled to occur in 2022.

As part of this EP, a remotely operated vehicle (ROV) inspection of the three wells will be performed which will validate the current well barrier status and inform future permanent plug and abandonment plans for the wells. A boundary with a radius of 1 km from each well has been used to define the Operational Area in which the ROV inspection will take place. The ROV will be deployed from a vessel to locate the three wellheads and perform visual inspection and leak testing activities. ROV inspection surveys are anticipated to take between 2 and 6 hours per wellhead. This ROV inspection campaign will be carried out as soon as technically and practically possible, with the intention for this to be in performed in the first or second quarter (Q1/Q2) of 2021. The entire ROV inspection activity is expected to take approximately three days from arrival at the Operational Area.

Other Details
Locations Northern Territory
Commonwealth waters adjacent to ACI
Titles (or other instruments) AC/RL12
Current Documents (Under assessment)
EP Document

Location map