Green light for Eni’s Woollybutt environment plan

Italian oil and gas company Eni has received approval from Australian authorities for the environment plan for the Woollybutt field decommissioning project located offshore Western Australia. 

Eni submitted the revised environment plan for the Woollybutt field management and plug and abandonment to NOPSEMA in November 2018 and the plan was accepted last Friday.

The Woollybutt field is located approximately 80 km off the northwest coast of Western Australia in Lease Area WA-25-L. It 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 plug and abandonment activities (including well intervention) on four to seven wells within permit WA-25-L.

According to NOPSEMA, field management activities that may be undertaken in accordance with this EP include cathodic protection surveys and visual ROV inspections. 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.

Well intervention of WB4 will be completed using a Light Well Intervention Vessel prior to P&A and will take approximately 7-15 days. Only one project vessel will be in the operational area at any one time during well intervention activities.

Plug and abandonment will take approximately 20-30 days per well and will be completed within 5 years of EP acceptance. A maximum of three support vessels will be utilized to support the MODU during plug and abandonment activities.