Woodside is planning to decommission Calthorpe-1 exploration well. The wellhead is located in permit WA-59-L around 50 km north of Exmouth at a water depth of approximately 820 m and is proposed to be left in situ.
A Decommissioning Options Assessment was performed for the Calthorpe-1 well which compared removal of the wellhead to leaving it in situ. The assessment found that the leave in situ decommissioning option was preferred as it meets legislative requirements, is technically feasible, provides equal environmental outcomes, and has fewer health and safety risks when compared to removal. Impacts associated with the perpetual presence of the wellhead include long-term degradation of the wellhead material and potential displacement or interactions with current or future trawl fishers. These impacts and risks have been demonstrated as ALARP and acceptable in the EP.
The petroleum Activities Program will end on acceptance of this EP by NOPSEMA and the expected duration of the activity will be zero days.