3D Energi (ASX: TDO) has reported steady progress on drilling operations at the Essington-1 gas exploration well, located in the Otway Basin offshore Victoria.
The company confirmed that drilling reached a measured depth of 1,736 metres below rotary table (MDRT) and a true vertical depth subsea (TVDSS) of 1,704 metres after nine days of drilling.
Essington-1 lies within exploration permit VIC/P79, approximately 55 kilometres offshore from Port Campbell, Victoria.
The current 12¼-inch hole section is being drilled through the Paaratte Formation, and 3D Energi said that preparations are now underway to install 9⅝-inch casing ahead of drilling into the target reservoir intervals.
The company noted that the next stage of operations will see the drilling of an 8½-inch hole section through the Waarre C and Waarre A reservoir formations to a planned total depth of about 2,650 metres TVDSS.
Subject to operational factors such as weather and equipment performance, the full drilling campaign is expected to take around 32 days to reach total depth.
“At the time of this announcement, operations are running safely and smoothly, with no reported accidents or incidents,” 3D Energi stated.
The Essington-1 well was spudded on 1 November 2025 using the semi-submersible rig Transocean Equinox, which has previously operated in Norwegian and Australian waters.
Drilling is part of a broader Otway exploration programme designed to identify new gas resources to support Australia’s East Coast domestic gas market.
3D Energi holds a 20 per cent equity interest in the permit, with ConocoPhillips Australia holding 51 per cent and Korea National Oil Corporation (KNOC) owning the remaining 29 per cent.
ConocoPhillips serves as the operator of the project.
The partners’ combined effort reflects growing interest in exploring additional gas supply within the mature Otway Basin, which already supports several producing fields such as Casino, Henry, and Netherby operated by Beach Energy and Cooper Energy.
According to 3D Energi, Essington-1 targets a combined estimated mean prospective resource of 262 billion cubic feet (bcf) of gas across two formations.
The secondary target, Waarre C, lies at a depth of approximately 2,240 metres TVDSS and holds an estimated 76 bcf of potential gas with a 76 per cent chance of geological success.
The primary target, Waarre A, sits deeper at around 2,470 metres TVDSS and is estimated to contain about 186 bcf with a 68 per cent chance of success.
The Otway Basin, located along the southern margin of Australia, spans both onshore and offshore areas across Victoria and South Australia.
It has long been a key contributor to the country’s natural gas supply, with fields producing into the Otway Gas Plant near Port Campbell and the Iona underground gas storage facility.
The Australian Energy Market Operator (AEMO) has identified continued exploration in the basin as vital for offsetting declining output from legacy gas fields and supporting future supply security on the East Coast (AEMO, 2024 Gas Statement of Opportunities).
If successful, the Essington-1 well could strengthen 3D Energi’s portfolio and provide a significant boost to domestic gas supplies amid rising demand and tighter market conditions across southeastern Australia.
