Estimated reserves for Wheatstone and Julimar-Brunello fields offshore Western Australia have decreased following completion of reservoir studies based on 4D seismic, well performance, and well drilling results.
The downgrade is mentioned in the third quarter 2021 report of Woodside Petroleum, one of the members of the Chevron-operated Wheatstone LNG project.
Woodside said proved (1P) developed reserves moved down to 11.5 MMboe from 54.5 MMboe.
Proved total (1P) reserves declined to 112.6MMboe from 154.2MMboe, while proved plus probable (2P) developed reserves dropped to 26 MMboe from 86 MMboe and 2P total reserves to 168.4MMboe from 231.1MMboe.
The updated reserve estimate includes 2021 production to date of 11.8 MMboe.
As part of the reserves update, future phases of Wheatstone compression have been reclassified as undeveloped reserves from developed.
Woodside also said reserves for the nearby Julimar-Brunello project—which it operates as a segment of the total Wheatstone project—also have changed. It is now expected that about 44 MMboe of 1P and 62 MMboe of 2P reserves will be reclassified as developed reserves from undeveloped.
Best estimate contingent resources (2C) for Julimar-Brunello, however, have increased to 7.3 MMboe from 3.9 MMboe.
Woodside has a 65% interest in Julimar-Brunello with KUFPC holding 35%.
Woodside has a 13% non-operated interest in the Wheatstone project which includes the production platform, pipeline to shore, and shore-based LNG plant, but excludes Wheatstone and Iago fields and subsea infrastructure.
Other Wheatstone interest holders are Chevron (operator) with 64.1%, KUFPC 13.4%, Kyushu Electric Power Co. 1.5%, and PE Wheatstone 8%.
Wheatstone-Iago fields contribute 80% to the overall project. Julimar-Brunello contribute 20%.