ConocoPhillips Australia (COPA), a subsidiary of the U.S.-headquartered energy giant ConocoPhillips, has intersected gas in Waarre reservoirs during drilling activities at a well in the Otway Basin off the coast of Australia, with a semi-submersible rig owned by Transocean, an offshore drilling player.
Transocean’s Transocean Equinox semi-submersible drilling rig, which was tasked with search for more gas offshore Australia, spud the Charlemont-1 gas exploration well within VIC/P79 exploration permit in the Otway Basin offshore Victoria on December 10, 2025, encountering significant gas shows approximately 160 meters above the primary target (Waarre A) in the Waarre C on December 25, 2025.
A 7” liner was installed in the well after drilling was paused on entry to the Waarre C at 2,552 meters measured depth below rotary table (MDRT), following higher-than-anticipated formation pressures in conjunction with significant gas shows. Drilling into the Waarre C reservoir was restarted on the evening of January 2, 2026.
Elevated gas readings were recorded across the Waarre C sandstones, which coincide with elevated resistivity readings on wireline, consistent with probable hydrocarbon presence in the Waarre C sandstones, according to ConocoPhillips’ partner, 3D Energi , a Melbourne-based oil and gas exploration player whose subsidiary, TDO, has a 20% interest in both permits.
Charlemont-1 is targeting the Charlemont B prospect located approximately 55 kilometers offshore from Port Campbell, in water depths of approximately 110 meters. This is described as the penultimate prospect at one end of a prospect chain, with the La Bella gas discovery at the other, around 7 kilometers to the east.
ConocoPhillips’ partner claims that all intervening prospects, including Charlemont B, share similar geophysical response as La Bella. As a result, Charlemont-1 is perceived to have the potential to appraise the intervening prospects towards La Bella. However, further wireline logging is required to fully evaluate the nature and extent of the hydrocarbons.
Noel Newell , Executive Chairman of 3D Energi, commented: “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.
“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.”
As drilling proceeded, elevated gas readings were recorded across Waarre B sandstone intervals from 2,664 meters MDKB into the Waarre A primary target at 2,683 meters MDRT, and continued through the Waarre A to 2,753 meters MDKB. The company underlines that elevated gas readings in the Waarre B and Waarre A sandstones coincide with elevated resistivity on the LWD tool, consistent with probable hydrocarbon presence in both.
At 2,753 meters MDKB, the well intersected a zone with higher-than-anticipated formation pressures, reaching operational tolerances. 3D Energi confirms that drilling operations have been concluded prior to the planned total depth of 2,862 meters MDKB, with scenarios for further wireline logging operations being evaluated.
The firm elaborates that wireline logging is required to fully evaluate the nature and extent of any hydrocarbons in the Waarre B and Waarre A, and determine potential connectivity with the Waarre C. ConocoPhillips is the operator of this asset with a 51% stake, with partners, 3D Energi and Korea National Oil Company, holding the remaining 20% and 29% interests, respectively.
“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,” added Newell.