Woodside Petroleum and its Browse Basin (SEN, 30/10) partners have now formally shifted tack and proposed using floating LNG technology to develop the massive gas reserves, offshore northwest Australia. A financial investment decision is now expected in mid-2015.

Reserves here are put at 440bcm and 417mmbbls of condensate.

This shift will result in a total re-arrangement of the development plan including the elimination of three deepwater wellhead platforms, an offshore central processing facility (cpf) on the shelf and twin 290km gas and condensate export pipelines.

While this decision - covering the Torosa, Brecknock and Calliancegas fields - will assuredly ruffle feathers in the Western Australian government which has continued to push for a land-based development, the new plan received an unexpected boost from the Australian Supreme Court.

The court ruled that the original approval by the Environmental Protection Authority for the onshore LNG plant, to be located at James Price Point, was unlawful. As a result of a number of conflicts of interest, the final EPA decision was made by just one board member and the court ruled that the then WA environment minister should not have granted the approval based on this decision.

Way forward

Woodside CEO Peter Coleman said last week that the development scenario will be phased - as was always the case - but is now likely to be based on three FLNG vessels, one on each of the three fields, being fed by a subsea production system, a concept identical to the one Shell is using at Prelude (30/7). In fact, SEN understands that each vessel would have a similar capacity (3.6mt/a) to the FLNG unit ordered by Shell or even slightly larger, although with a somewhat less complex topside due to the different chemical makeup of the gas.

Such a scheme will significantly reduce the original upfront capex of A$30bn, allowing the later phases of the development to be self-funding.

While the partners have yet to put a price tag on a revised development, Woodside told SEN that it expected the life-of-field savings to be 35-50%.

The original development scheme put forward by the original partners back in 2011 (28/17) proposed three tension leg platforms with partial processing plus seven subsea drill centres, all feeding a main processing platform in 80-120m. Between 50 and 90 wells were foreseen for the three fields with the furthest being more than 100km from the cpf.