BTW Installation, Commissioning and Initial Operations
|Activity type||Significant modification of a petroleum pipeline|
|Submitted by||Esso Australia Resources Pty Ltd|
|Submission date||16 October, 2020|
|Status||Under assessment (with titleholder)|
|Link to previously accepted EP|
Phone: (03) 9261 0000
Esso has recently drilled and completed two subsea gas production wells in the West Barracouta (BTW) field in Production Licence VIC/L1 approximately 15km off the Gippsland coastline, south of Lakes Entrance in a water depth of 45m. At the completion of drilling the wells were suspended.
The BTW installation campaign includes:
• Installation of two subsea trees on the BTW wells.
• Laying a 6km long 12” flexible pipeline between the wells and the existing BTA450 pipeline to shore (Pipeline Licence VIC/PL1).
• Tie-in to the existing / operating BTA450 pipeline via a Hot Tap.
• Laying and trenching a control umbilical from the wells to the Barracouta (BTA) platform located in Production Licence VIC/PL2.
• Installation of associated subsea equipment including the Pipeline End Manifold (PLEM) and pipeline skid, Umbilical Termination Assembly (UTA) and jumpers and flying leads.
• Pre commissioning.
The installation activities will be undertaken by a Dive Support Vessel (DSV) utilising divers and remotely operated vehicles. The DSV will be operating in the BTA platform Petroleum Safety Zone (PSZ) when performing the hot tap operations and installing the umbilical to the platform. Activities around the BTW wells are located 6km distant from the platform and within the BTW PSZ. Diving operations will be supported by a Hyperbaric Rescue Vessel stationed outside the BTW PSZ. The activities will be undertaken in multiple stages and it is expected that the DSV will travel between the onshore supply base and BTW between each stage.
The earliest date of commencement of the installation campaign is late Q4 2020. Activities will be conducted 24 hours per day, seven days per week. It is expected to take approximately six weeks to complete the installation activity.
Following completion of the installation campaign the wells and pipeline will be commissioned and production will start-up. This revision is to address the commissioning and initial start-up stage, the installation activities were addressed in a previous submission that has already been accepted by NOPSEMA.