Abstract

Carbon Capture and Storage (CCS) is the only option that allows the world’s existing investment in the fossil fuel infrastructure to be used whilst at the same time bringing about a major reduction in CO2 emissions.

Two CCS projects are planned in Western Australia. Both projects are supported by collaborative partnerships between the Australian and the Western Australian governments. One will store CO2 from a Liquefied Natural Gas (LNG) plant and the other CO2 from coal fired industry and power generation. They differ in their social and environment impact and reservoir geology. One is in an uninhabited location with high fauna conservation value; the other in a populated agricultural district. One has a conventional seal for storage while the other depends on several trapping mechanisms. Together these projects have the potential to store 11 percent of the Western Australia’s CO2 emissions.

The first and most advanced is a proposal to capture the CO2 which occurs naturally in the Greater Gorgon Area natural gas field 130 km off the north west coast of WA. This is known as the Gorgon Carbon Dioxide Injection Project and is an integral component of the much larger Gorgon Project to recover and export natural gas from the northwest shelf.

The joint venture operator Chevron is in the process of developing the Gorgon and Jansz fields to supply a 15.4 million tonne/ annum liquefied natural gas (LNG) plant on Barrow Island and a domestic supply pipeline with a capacity of 300 Terajoules/day to the mainland.

In most existing gas processing plants carbon dioxide extracted from the natural gas during the processing operations is vented to the atmosphere, but Chevron propose to inject this into strata over 2 km below the surface of Barrow Island. This is estimated to reduce CO2 emissions from the LNG plant by 40 percent.

The Collie-South West CO2 Geosequestration Hub project is a proposal by a consortium of electrical power generators and industrial users of coal to extract carbon dioxide from flue gasses and coal gasification processes in Collie and Kwinana. Participants include coal miners, electricity generators, alumina refiners and fertiliser manufacturers.

The captured CO2 will be transported by a common user pipeline to the proposed injection site in the Shire of Harvey where it will be injected into deep sandstone strata.

This paper explores the differences and similarities between these two leading projects.