Transocean rig hits gas pay in Australian waters

November 17, 2025, by Melisa Cavcic

ConocoPhillips Australia (COPA), a subsidiary of the U.S.-headquartered energy giant ConocoPhillips, has made a new gas discovery in the Otway Basin off the coast of Australia, with a semi-submersible rig owned by Transocean, an offshore drilling player.

Transocean Equinox rig; Source: Transocean

Following regulatory approvals for the Otway exploration drilling program, ConocoPhillips booked AHTS vessels from Sea1 Offshore, formerly Siem Offshore, and Transocean’s Transocean Equinox semi-submersible drilling rig to search for more gas offshore Australia.

The semi-submersible is working for COPA before returning for the second phase of Beach Energy’s activity, scheduled for H2 FY26. The rig began drilling the Essington-1 gas exploration well within the VIC/P79 exploration permit at the start of the month.

This well has intersected gas-bearing intervals in the Waarre C and Waarre A sandstones close to pre-drill predictions, according to ConocoPhillips’ partner, 3D Energi, a Melbourne-based oil and gas exploration player whose subsidiary, TDO, has a 20% interest in both permits.

COPA, which currently holds the remaining 80% stake, recently inked a deal to lower its stake to 51%, with Korea National Oil Corporation (KNOC) assuming a 29% interest.

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While a gross gas-bearing interval of 62.6 meters is interpreted on wireline logs in the primary Waarre A reservoir, comprising 58.5 meters of net pay, a gross gas-bearing interval of 33.2 meters is shown on wireline logs in the secondary Waarre C reservoir, entailing 31.5 meters of net pay.

ConocoPhillips’ partner claims that a clear gas gradient on pressure data provides additional evidence of movable gas; thus, Ora wireline formation testing will be conducted to obtain downhole gas samples and assess reservoir deliverability.

Located around 55 kilometers offshore from Port Campbell in water depths of approximately 100 meters, the well is expected to take approximately 32 days to drill to a planned total depth (TD) of 2,650 meters true vertical depth sub sea (TVDSS), subject to operational conditions.

Following the completion of the Essington-1 well, the rig is slated to spud the Charlemont-1 well. These drilling activities are said to be undertaken to deliver a new gas supply for Australia’s East Coast market.