The Success of Jadestone Energy’s Drilling Campaign in the Timor Sea

The analysis of a drilling campaign in the Timor Sea undertaken by Singapore’s Jadestone Energy has pointed to production rates exceeding previous estimates.

As reported by Jadestone, the Skua-11 well side-track (Skua-11ST) at the Montara field well has reached target depth, with analysis confirming the presence of over 900 meters of high-quality reservoir.

Since this is said to be more than double the reservoir section completed in any of the previous Skua wells, initial production rates are expected to exceed the previously disclosed estimates of 3,500 barrels per day (bbls/d).

T. Mitch Little, Jadestone’s Chief Executive Officer (CEO), said: “We look forward to Skua-11ST adding meaningful volumes to Group production once tied in, which will immediately reduce unit operating costs at Montara and extend field life by a year. This will add to our previously announced cost management initiatives that we intend to expand to other parts of the Group.”

Skua-11ST was the group’s main capital activity during 2025. As explained in Jadestone’s annual report, it had a dual objective of decommissioning the original Skua-11 well and drilling a sidetrack into the Skua structure up-dip of the original well path.

After arriving at the field in late March, the Valaris 247 jack-up rig started the drilling operations in April, which are now nearing completion. Once the rig is demobilized, the Skua-11ST well is expected to be brought onstream in early August 2025.

Originally planned to last 60 days, the drilling campaign ended up taking longer. This has caused the total capital cost of the Skua-11ST well to rise to $96-100 million, compared to the planned $70 million disclosed in May 2025.

Jadestone explained that several factors outside its control contributed to this, including weather and changes to the demobilization plan, which have added an estimated $13-14 million. Additionally, additional rig days were required, accounting for the rest of the incurred incremental cost.

Jadestone is the 100% owner and operator of the producing Montara project, located in production licenses AC/L7 and AC/L8 in the Timor Sea, approximately 630 kilometres offshore Western Australia, in a water depth of 77 meters.

Montara operations involve the production of oil using platform production wells for the Montara field and subsea wells for the Swift, Skua, and Swallow fields. The oil from the subsea wells is piped via subsea flowlines to an unmanned wellhead platform and then to a production storage and offloading (FPSO) facility, which acts as a hub for the Montara fields.