Gorgon Carbon Dioxide Injection Project

The Gorgon Carbon Dioxide Injection Project is part of the Gorgon Project, one of the world's largest natural gas projects. The Gorgon Project, located on Barrow Island in Western Australia, includes a liquefied natural gas (LNG) plant, a domestic gas plant, and a Carbon Dioxide Injection Project.
Carbon dioxide injections commenced in 2019. Once operating at full capacity, the Gorgon Carbon Dioxide Injection Project will be the world's largest CO2 injection plant, with an ability to store up to 4 million tons of CO2 per year – approximately 120 million tons over the project’s lifetime, and 40 percent of total Gorgon Project emissions.
Technology.
Gas is supplied from two world-class gas fields namely, Gorgon field that contains on average 14% of naturally occurring reservoir CO2, and Jansz-lo field that contains less than 1% CO2. Reservoir CO2 is extracted from natural gas as a part of normal gas-processing operations. During the liquefaction process, natural gas is cooled to -162 °C. CO2 freezes above this temperature, so it needs to be separated from the natural gas stream prior to gas processing and liquefaction. Separation is performed using a basic absorber and stripper system and an amine-based solvent.
The Gorgon Carbon Dioxide Injection Project will compress and pipe separated CO2 to nine injection wells where it will be subsequently injected into the Dupuy Formation. Once the is injected, it will migrate through the Dupuy Formation until it remains trapped. The top of the Dupuy Formation reservoir is located approximately 2300 m below Barrow Island and is overlain by a thick shale cap-rock seal. The pressure in the reservoir will cause the injected CO2 to behave as a supercritical fluid with behavior of both a liquid and a gas. The reservoir CO2 will become trapped in the reservoir through a combination of residual saturation trapping and by dissolution into the waters in the formation.
Environmental impacts.
The carbon dioxide injection plant is located on Barrow Island, a Class A nature reserve. Therefore, the development of the processing plant had to undergo very strict environmental regulations. The Joint Venture established expert panels to protect the biodiversity of the island and surrounding marine environment. To ensure that the Dupuy Formation was suitable for underground injection of reservoir carbon dioxide, the Gorgon Joint Venture undertook additional drilling, well tests, and seismic surveys prior to making the final investment decision. An ongoing monitoring program, including observation wells and seismic surveys, will assist in managing the performance of the injected carbon dioxide in the Dupuy Formation.