Replacing him is the heir presumptive, British-born deputy managing director Nigel Hearne, who started with Chevron in Australia just four months ago.

Krzywosinski took over the business of running Chevron Australia from Colin Beckett in 2007, as Gorgon barrelled to final investment decision, and had overseen the engineering and development of one of the world's largest single LNG developments on the remote Barrow Island.

He is now leaving Chevron to take on a new position of vice president of engineering in Chevron's Energy Technology Company in Houston.

In his new role, Krzywosinski will have responsibility for facilities engineering as Chevron consolidates its ETC engineering department with its upstream engineering.

He leaves behind a Gorgon with one finished train and two under development, and hopefully that train will be working with repairs to the propane refrigerant circuit now well underway, and the separate Wheatstone development moving towards completion in 2017.

"Nigel's appointment reflects his strong downstream and upstream operating experience, combined with his proven record of leading large, complex operations, such as our Richmond refinery," Chevron Asia Pacific Exploration and Production president Steve Green said.

"He is well-qualified to position us for success as Australia commences operations at our world-class Gorgon and Wheatstone facilities."

Hearne joined Texaco in 1989 as a power engineer at the Pembroke Refinery in the United Kingdom.

He progressed through refinery positions of increasing responsibility, becoming operations manager at Pembroke before being appointed refinery business manager and later operations manager of the El Segundo refinery.

In 2010 he became vice president of strategy for Chevron's downstream strategy, technology and commercial Integration business unit.

In 2011, Hearne was named general manager of the Richmond Refinery, and in 2013 he named as vice president of the Appalachian/Michigan business unit, a role he held until late last year.

While living in Pittsburgh he was also a board member of the Center for Sustainable Shale Development.

When he left the US in January to come to Australia it was widely expected that he would take over once the first Gorgon train was switched on, a clear marker between the development and operations phase.

"What Roy and his team have achieved in developing Gorgon and Wheatstone is extraordinary," Green said.

"Gorgon, itself, represents the largest resource project in the history of Australia and the single largest capital investment in our company's history. These two projects will generate significant value for Australia and Chevron's shareholders for decades to come."

Krzywosinski joined Chevron in 1981 as a design and construction engineer, and moved up the ranks, working across the Pacific, in Papua New Guinea, Indonesia and Angola.