Joint venture partners Santos and Australian Worldwide Exploration told the ASX that Casino would be a major long-term supply source to Australia’s gas markets once full production was achieved later this month.

Under the initial 12-year contract, up to 420 petajoules of gas will be delivered by the VIC/P44 joint venturers to TRUenergy from the Casino field and future possible near-field developments.

The gas will be piped from offshore into the Iona processing plant, where it will be sold and distributed by TRUenergy to customers in South Australia and the eastern states.

Santos managing director, John Ellice-Flint, said Casino was the company's second operated offshore resource project to start production ahead of schedule in the past nine months. It follows the Mutineer-Exeter oil field, which came onstream in April last year, three months ahead of schedule.

“The Casino gas project, [was]commissioned just a little over three years after discovery,” Ellice-Flint said.

“It provides further evidence that we have the expertise and ability in Australia to bring important resource projects successfully to completion within short cycle-times.”

AWE managing director Bruce Phillips said Casino was his company's first offshore production.

“We look forward to further exploration success in this highly regarded permit, along with the potential development of our recently discovered Henry gas field.”

The Casino gas field, which is the first commercial development in VIC/P44, is in about 70 metres of water, 30 kilometres offshore from Port Campbell .

The partners said the project’s gas development and transport facilities were specifically designed to minimise environmental and visual impact.

The gas will be transported from the subsea wellheads through a sea-floor pipeline that comes ashore via a directionally-drilled underground shore crossing, for processing at the existing Iona gas plant.

Meanwhile, as well as the successful drilling, completion and flow-test of two subsea wells at Casino last year, the joint venture participants said they were currently planning for the development of the adjacent Henry gas field, discovered in July.

Accelerated exploration drilling activity in adjacent prospects is also planned for this year, subject to drill rig availability, the partners said.

Participants in VIC P/44 are: Santos Limited (operator - 50%), Peedamullah Petroleum Pty Ltd (wholly-owned subsidiary of AWE – 25%), and Mittwell Energy Resources Pty Ltd (wholly-owned subsidiary of Mitsui – 25%).