ConocoPhillips (NYSE:COP, XETRA:YCP) and junior partner 3D Energi (ASX: TDO) say early results from the Charlemont-1 exploration/appraisal well in the offshore Otway Basin indicate gas may be present across the Waarre C, Waarre B and Waarre A sandstones.
Elevated gas readings and resistivity from logging are consistent with “probable hydrocarbon presence” in the three intervals.
Executive chairman Noel Newell said 3D was “incredibly excited” by the early indications, but that further work is needed to fully evaluate the gas and any accumulation size.
“We are incredibly excited by early indications consistent with gas presence in multiple Waarre reservoirs. Wireline logging will be critical in assessing the quality and extent of these indications, and the Company remains optimistic as it continues to plan to progress to the evaluation phase,” Newell said.
"The identification of probable hydrocarbons in the Waarre C is significant, as hydrocarbons were not anticipated in this zone prior to drilling. This outcome may have further positive implications for up-dip prospects along the Charlemont Trend, particularly those not currently supported by existing Direct Hydrocarbon Indicators (DHIs) on seismic. We will be evaluating this closely at the conclusion of the drilling program.
"The presence of gas across stacked Waarre sandstone reservoirs de-risks the up-dip prospects with DHIs in the Charlemont Trend, culminating with the La Bella discovery. If successfully appraised, this cluster could be among the largest gas pools in the Otway Basin.”
Shares in 3D were up 1.6% at 15.75 cents just before midday on the news.
Drilling ends short of planned depth after higher pressures
Charlemont-1 has been concluded before its planned total depth after encountering higher-than-anticipated formation pressures.
3D reported the well reached total depth at 2,753 metres (measured depth below Kelly bushing), around 70 metres into the Waarre A primary target, compared with a planned total depth of 2,862 metres.
Charlemont-1 was spudded at 7:15 pm AEDT on December 10, 2025 by the Transocean Equinox. Drilling was previously paused on entry to the Waarre C at 2,552 m (measured depth below rotary table) due to elevated pressures and gas shows, before re-commencing on January 2, 2026.
Wireline program under review
Further wireline logging is required to assess the nature and extent of any hydrocarbons in the Waarre B and Waarre A, and to determine possible connectivity with the Waarre C.
Scenarios for additional wireline logging operations are being evaluated.
Prospect chain links to La Bella discovery
Charlemont-1 is targeting the Charlemont B Prospect within permit VIC/P79, about 55 kilometres offshore from Port Campbell in around 110 metres of water.
Charlemont B sits near one end of a prospect chain that includes the La Bella gas discovery about 7 kilometres to the east, with intervening prospects showing a similar geophysical response.