The Gorgon liquefied natural gas project in Western Australia, already the costliest in the world at $US54 billion, could face further delays to its completion schedule because of strikes called by workers at the offshore Barrow Island site.
Trade unions have threated strike action by September 4 if current negotiations on new work rosters are not successful.
The proposed industrial action is coordinated by three Australian unions and is the latest to affect LNG projects in Australia following stoppages at liquefaction plant construction ventures in Queensland last year.
The Gorgon LNG management-trade union talks revolve around demands for new rosters for construction workers at the site of the plant.
Chevron is already more than a year behind schedule and $17Bln over budget for the project, one of five major onshore LNG ventures under construction in Australia.
The Gorgon venture is about 95 percent complete and the strike threat comes at a time when about 7,000 workers are on site pushing to finish the project.
The first cargo was due to be shipped under the revised schedule by the end of 2015.
However, Chevron said recently that the risk of strikes combined with other factors meant the commercial start-up may not happen until early 2016.
Chevron is the operator of Gorgon with a 50 percent interest while Australian subsidiaries of Royal Dutch Shell and ExxonMobil each hold a 25 percent stake.
Other smaller stakes are held by the main cargo buyers, the Japanese utilities Osaka Gas, Tokyo Gas and Chubu Electric.
The facility comprises three Trains, a domestic gas plant and one of the world's largest carbon-dioxide injection systems.
The plant will produce around 15.6 million tonnes per annum from the three Trains when complete.
The current dispute has acquired more importance as workers will be required on site for several more years to come because of plans to expand the facility by building a fourth Train to take nameplate capacity up to 20.8 MTPA.
The project is named after the offshore Gorgon feed-gas field where the main feed-gas resources are coming from in the prolific Carnarvon Basin.
The trade unions are demanding more "family-friendly rosters". They want the current system changed from 26 days on, nine days off, to one of 20 days on and 10 days off.
The engineering and construction contractors employing the workers are mainly CB&I of the US and UK-listed Kentz.
The unions have now secured protection from the Australian Fair Work Commission that will allow the calling of stoppages of up to 24 hours without workers being fired.
