Production Facilities

Domestic gas plant

Commissioned in 1984, the Karratha Gas Plant is one of the largest domestic gas plants in the southern hemisphere and consists of two parallel processing trains which together are capable of producing approximately 600 terajoules or 12,000 tonnes of domestic gas per day.

Natural gas is piped from offshore reserves at the North Rankin A, Goodwyn A and Angel platforms and the Cossack Pioneer FPSO through the Karratha trunkline where it is processed onshore into gas suitable for domestic sale.
Gas is delivered via the 1600km Dampier to Bunbury Natural Gas Pipeline which was completed in 1984 and transports gas to major industry users and more densely populated areas in Perth and Western Australia’s south-west.
The North West Shelf Venture currently provides about 65% of Western Australia's total gas production.

LNG plant

The Karratha Gas Plant has an annual LNG production capacity of 16.3 million tonnes and includes five LNG processing trains, four heavily insulated storage tanks each with a gross capacity of 65,000m3 and a dedicated LNG jetty with two loading berths. Trains 1, 2 and 3 each have an annual production capacity of 2.5 million tonnes while Trains 4 and 5 can produce up to 4.4 million tonnes.

Key elements of each LNG train include the sulphinol units, which remove carbon dioxide from the gas; dehydration units for the removal of water; a mercury removal unit; a scrub column, which removes the heavier gases; a liquefaction unit, which reduces the temperature of the gas from minus 35º C to minus 130º C; and two end flash vessels, where a reduction to atmospheric pressure leads to further cooling, achieving the cold temperature boiling point for methane of minus 161º C.

At this point, the gas condenses to a liquid at 1/600th of its gaseous volume and is stored before being piped to the LNG jetty for offloading onto purpose-built LNG carriers for transport to Japan, China and South Korea.

Condensate plant

Condensate is a very light crude oil which condenses from natural gas when it encounters normal atmospheric conditions. It is sold on the spot market, mainly to oil refineries in Australia and overseas, and is used as a feedstock for chemical plants and in the manufacture of automotive and aviation fuels.

The North West Shelf Venture’s condensate facilities include five stabiliser plants with a combined capacity of 130,000 barrels per day, four floating-roof storage tanks and six condensate loading and circulating pumps, condensate loading lines and loading arms. A sixth stabiliser train is currently under construction, and is expected to commence operation in the first half of 2009.

LPG plant

The LPG facilities consist of three fractionation trains, chilling facilities, two storage tanks and a ship-loading jetty for LPG and condensate.

Most of the LPG produced goes into a 52,000m3 propane storage tank and a 65,000m3 butane storage tank for eventual refrigerated export.

LPG consists of propane and butane gas and is commonly used for heating, cooking and automotive fuel. Some LPGs are used in the domestic gas supply and some are used on-site as a refrigerant gas in the liquefaction process.