ConocoPhillips Australia (COPA), a subsidiary of the U.S.-headquartered energy giant ConocoPhillips, has completed its drilling program in the Otway Basin off the coast of Australia, with a semi-submersible rig owned by Transocean, an offshore drilling player. As a result, the rig has moved on to another assignment in Australian waters.
Transocean’s Transocean Equinox semi-submersible drilling rig, which was tasked with gas exploration offshore Australia, spud the Charlemont-1 gas exploration well within the VIC/P79 exploration permit in the Otway Basin offshore Victoria on December 10, 2025.
Drilling activities encountered significant gas shows approximately 160 meters above the primary target (Waarre A) in the Waarre C on December 25, 2025. In an update on January 21, 2026, ConocoPhillips confirmed the completion of the Otway exploration drilling program’s Phase 1.
Since the company was using the Transocean Equinox rig as part of an industry consortium, the semi-submersible has now been transferred to another operator in the Otway region. The exploration activities at Charlemont-1 were completed in mid-January, with the presence of natural gas detected in two reservoirs.
When exploration activities at Essington-1 were completed in early December 2025, gas was also discovered across two reservoirs. The anchors and mooring chains will remain in place at Charlemont-1, marked by surface buoys with navigation lights, until they are collected by mid-April at the latest.
However, all anchors and mooring chains at Essington-1 have been collected. The operator explains that further wells may be considered in the future under the approved environmental plan. According to ConocoPhillips, no decisions have been made at this stage regarding the progression to development.
While the campaign delivered encouraging outcomes at the Essington-1 well in November 2025, with indications placing the primary Waarre A target reservoir as a 62.6-meter gross hydrocarbon column, the secondary Waarre C target showed a further 33.2-meter gross hydrocarbon column as best estimates.
At the second well, Charlemont-1, the presence of natural gas was indicated in both the Waarre A and Waarre C from wireline logs. Further detailed analysis and evaluation are still required to determine the commercial viability of the results to inform any future development plans.
Since the firm believes that natural gas has a vital role in providing reliable and affordable energy as the nation transitions its energy systems, the company remains committed to supporting Australia’s domestic gas market, both through its work in unlocking potential new supply in the Otway Basin and its investments in APLNG, which supplies approximately 20% of the East Coast’s gas market demand.
Jan-Arne Johansen, President of ConocoPhillips Australia, commented: “These well results highlight the potential of the Otway Basin in supporting Australia’s future energy needs. The data gathered will be invaluable as we carefully evaluate next steps.
“We are committed to working with partners, regulators, and the community to responsibly assess and develop Australia’s natural gas resources to support domestic households and businesses, as well as the broader economy.”
ConocoPhillips Australia operates the Otway exploration drilling program and holds a 51% interest in the joint venture, alongside Korea National Oil Corporation (29%) and 3D Energi (20%).
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