Amplitude Energy has taken final investment decision on the East Coast Supply Project (ECSP) offshore Victoria, sanctioning a three-field development targeting first gas in calendar 2028 and gross production of up to about 90 terajoules per day (TJ/d) through the Athena Gas Plant.

The sanctioned scope covers the Annie, Juliet and Artisan fields in the Otway Basin, which the company expects to sustain that production rate for at least four years from first gas. Annie and Artisan together hold an estimated 120-plus petajoules (PJ) of gross 2C contingent resources. One caveat applies: the scope remains subject to completion of Amplitude Energy's acquisition of Artisan.

The company puts point-forward development costs for its 50% share at $132.8 million (A$190 million) to A$210 million across fiscal 2027 and fiscal 2028. That estimate covers subsea infrastructure, modifications to the Athena plant, control system upgrades, pipeline re-lifing, approvals and project management, plus a potential subsea tie-in for Nestor. Most of the cost base sits in fixed-cost items or fixed-rate contracts, the company said, with subsea contracting outcomes in line with internal expectations. Funding will come from existing cash reserves and cash flow.

Nestor adds appraisal upside

The ECSP joint venture — Amplitude Energy and O.G. Energy — has sanctioned the Nestor exploration well, which will follow the Annie development well in the current Transocean Equinox campaign. Amplitude Energy's 50% share of Nestor drilling and completion costs is estimated at A$70–80 million. The well uses a "one touch" drilling and completion approach: if it makes a discovery, crews complete it during the same campaign, and Nestor could then be added to the ECSP scope.

The Nestor sanction pushed Amplitude Energy's fiscal 2027 capital expenditure guidance up to A$320–390 million, from A$250–310 million. The company said nothing else changed in its market guidance issued on 18 August 2026.

Drilling campaign progresses

Juliet-1 was completed and cleaned up on 27–28 September 2026 and is now being suspended for potential development. Gas samples from the well showed roughly 1% carbon dioxide and 2% nitrogen. The rig is due to move to Annie this week to spud the Annie-2 development well.

Amplitude Energy will update its reserves and resources statement after assessing whether the contingent volumes meet the criteria for reserves. Work on Juliet reserve estimates continues.

On the commercial side, the company holds agreements with EnergyAustralia and AGL covering 35 PJ of its share of ECSP production. The FID satisfies a key condition of those agreements — locking in supply for Australia's east coast market, where the development will connect discovered Otway Basin resources to existing Victorian infrastructure.

Managing director and CEO Jane Norman said: "Following the successful Juliet exploration result, we are pleased to have taken FID on the ECSP development phase, underpinned by Annie, Juliet and Artisan."

"AJA resources provide a very attractive base for the economics of the ECSP. Contracting outcomes and cost estimation work for FID provides greater visibility over expected development expenditure during FY27 and FY28," Norman said. "We are also excited to confirm the potential expansion of the ECSP via the Nestor well. The planned 'one touch' drilling and completion approach maximises capital efficiency by allowing the well to be completed during the current campaign if a discovery is made."

The FID narrows the Otway Basin focus for Amplitude Energy. In March, the company determined that the Isabella gas discovery in permit VIC/L24 was not commercially viable.

The watch items: completion of the Artisan acquisition, the Annie-2 development well now getting under way, and the Nestor exploration result — each one capable of reshaping the ECSP resource base before first gas in 2028.