An offshore gas exploration well operated by ConocoPhillips Australia has intersected unexpected gas in the Otway Basin off southeastern Australia, prompting a temporary pause in drilling while partners assess changes to the well design.
The Charlemont-1 exploration well, located in permit VIC/P79 offshore Victoria, encountered significant gas shows in the Waarre C reservoir around 160 meters above its primary target in the Waarre A formation, joint venture partner 3D Energi said in an operational update.
The well was spudded on December 10 using Transocean’s Transocean Equinox drilling rig. Drilling was halted on December 25 after higher-than-expected pressures were recorded at a depth of about 2,552 meters, with the operator now evaluating options to safely continue drilling toward the primary target.
Predrill assessments had not anticipated hydrocarbons at this shallower level, 3D Energi said.
The Charlemont-1 well is part of ConocoPhillips’ Otway exploration drilling program, which gained momentum last month after the operator confirmed a natural gas discovery at the nearby Essington-1 well - the basin’s first discovery since 2021.
Essington-1, drilled earlier in the same permit, encountered hydrocarbons in both the Waarre A and Waarre C reservoirs, with early analysis indicating gas-bearing sandstones in both formations. ConocoPhillips has said further technical work is assessing flow rates, recoverable resources and commercial potential.
“The Essington-1 well is the first discovery in the Otway since 2021 and is a promising start to ConocoPhillips’ exploration activities in the region,” said Jan-Arne Johansen, president of ConocoPhillips Australia, following the earlier discovery.
The Charlemont-1 well follows Essington-1 as the second exploration well in the permit, with drilling results now reinforcing interest in the Waarre reservoirs as potential contributors to future gas supply.
ConocoPhillips Australia operates VIC/P79 with a 51% interest, alongside Korea National Oil Company with 29% and 3D Energi with 20%.
Further updates on the Charlemont-1 well are expected once well design evaluations are completed.