Privately held Western Gas Corp. Pty. Ltd., Perth, has signed a memorandum of understanding with international service companies McDermott and Baker Hughes to be exclusive development partners for the Equus gas project offshore northwest Western Australia (OGJ Online, May 15, 2018).
As part of the agreement, the two service firms also were awarded a contract to support the planning phases of the development.
McDermott and Baker Hughes will coordinate with Western Gas to handle the pre-front end engineering design (pre-FEED) phase followed by the full FEED stage right up to a final investment decision, which Western Gas says is scheduled for late 2019.
Pre-FEED work should be completed by second-quarter 2019.
Once FID is achieved, McDermott and Baker Hughes are expected to undertake the engineering, procurement, construction, installation, and commissioning of the entire development under a separate contract.
The scope is comprehensive and covers reservoir evaluation, drilling and completions, subsea work, production facilities, an export pipeline, an LNG facility, and a domestic gas connection facility.
Western Gas says the plan is for a phased development, the first phase of which involves three production wells linked by subsea systems to a floating production, storage, and offloading vessel. Onboard facilities will include gas dehydration, condensate stripping, and gas compression.
Dry sales gas will be piped to a nearshore LNG production facility with a portion also piped to shore to link with the Western Australian gas grid. Gas supply in the initial stage is expected to be as much as 250 terajoules/day of gas with production to come on stream from 2023.
The project comprises eight main and three smaller gas-condensate fields within four permits and one retention lease (WA-390-P, WA-474-P, WA-518-P, WA-519-P, and WA-70-R), which have an independently certified resource in excess of 2 tcf of gas and 42 million bbl of condensate.
The fields are in the Carnarvon basin about 200 km northwest of Onslow and were discovered by Hess Corp. during 2008-12 in 1,000-1,200 m of water. The company drilled 16 wells that resulted in 14 successes in eight main fields. Hess planned an investment of about $6 billion (Aus.) to bring the project to fruition with a plan to feed the gas into the Woodside Petroleum Ltd.-led North West Shelf gas facilities on the Burrup Peninsula.
However, the project came off the boil in 2016 because of the downturn in world oil prices and the high capital costs of development in Australia.
The eight Equus group fields are Mentorc, Bravo, and Nimblefoot with Cretaceous-age reservoirs; Chester and Rimfire with Cretaceous-Triassic reservoirs; Glenloth and Briseals in Triassic sands; and the Glencoe discovery in the Jurassic. The three Cretaceous fields have the highest condensate-gas ratio of 40 bbl/MMcf.