Jadestone Energy has received approval from Australia’s offshore regulator for environmental plans covering wellhead removal work at the Montara oil field.
The National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) approved the plan on 22 April 2026. The clearance allows Jadestone Energy to proceed with removal activities for three wellheads, Montara-1, Montara-2, and Montara-3, within production license AC/L7.
The Montara field is located around 690 km west of Darwin in a water depth of about 80 m. It was discovered in 1988 through the Montara-1 exploration well. Montara-2 and Montara-3 were later drilled as appraisal wells in 1991 and 2002.
The three wells had previously been suspended and monitored annually using remotely operated vehicles. In 2021, both primary and secondary barriers were verified, and the wells were confirmed as plugged and abandoned under the well operations management plan accepted by NOPSEMA. A final abandonment report was submitted in September 2021.
The approved environmental plan covers ROV surveys before and after removal, marine growth cleaning and preparation of the wellhead areas. Jadestone Energy has included several possible cutting methods, including abrasive water jet cutting, diamond wire saw cutting or equivalent tools, and mechanical internal cutting.
Each wellhead removal is expected to take about two days. However, the plan allows around 14 days overall, including vessel mobilization, seabed surveys, removal work and demobilization, with flexibility for weather or equipment-related delays.
One vessel will be used for the operation and must be able to recover the subsea infrastructure to the deck. Dismantling and disposal are expected to be completed within 12 months after the wellheads reach the receiving port and waste management facility.
The wellheads are mainly made of mild steel, and most of the material is expected to be recycled or reused. The timing remains open because the work depends on suitable vessel availability. Where practical, Jadestone Energy plans to use a vessel already mobilized to the Montara field for other work.
The removal may take place at any point during the five-year validity period of the accepted environmental plan.
The wider Montara project, operated and owned by Jadestone Energy, includes the Montara, Skua and Swift/Swallow fields in the Timor Sea offshore Australia. Oil from the subsea wells is transported through subsea flowlines to an unmanned wellhead platform and then to the FPSO Montara Venture, which serves as the hub for the fields.
