The project is now expected on stream in mid-2017.
Chevron Chief Executive Officer John Watson blamed the delay on the slow schedule of construction of the LNG plant modules in Malaysia.
Chevron still has an official cost of $29 billion for Wheatstone, but analysts now say the figure will be substantially more.
The ultimate cost of Chevron’s other LNG project in Western Australia, Gorgon-Jansz, is also expected to be higher than the last estimate of $54 billion. Gorgon-Jansz is scheduled to come on stream late this month or in March.
Chevron says of Wheatstone that hook-up and commissioning of the offshore platform is progressing and the pipeline to shore is ready for service. Final tie-in work is ongoing.
Six of the nine wells have been drilled and completed and will provide sufficient gas for the projects Train 1.
At the plant site near Onslow, the operations center and LNG loading jetty are complete and tank hydrotesting is continuing.
Despite the modules in Malaysia falling behind the initial schedule, Chevron says it has mitigated further delays and all modules for Train 1 are at the plant site. Piping and cable work is continuing.