Featured Story – Chevron’s Gorgon Project: CCS to mitigate CO2-footprint

^ Satellite image of the Gorgon Project

Article by Daniel Sweet
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Chevron’s Gorgon Project is one of the world’s largest natural gas ventures: an LNG operation in Australia, with the main production facility located on Barrow Island off the northwest coast.

The Barrow Island facility includes an LNG plant with three processing units designed to produce 15.6 million metric tons every year. In 2018, the total daily production rates averaged between 2.6 billion cubic feet of natural gas and 18,000 barrels of condensate.

The Gorgon Project has been under active development since 2010 and features several high-tech solutions, including a carbon capture and storage (CCS) injection site designed to reduce the project’s greenhouse gas emissions.

In traditional gas processing operations, the bulk of unwanted CO₂ is vented into the atmosphere after collection. As CO₂ represents the majority of the earth’s greenhouse gases, this practice has severe consequences for the environment.According to Reuters, Australia is the world’s largest carbon emitter per capita, emitting 538.2 million tons of CO₂ equivalent in 2018, up 0.7 per cent from the previous year, mainly due to increased LNG exports.

Before its implementation of CCS, Chevron’s Gorgon Project was the biggest emitter of carbon across all of Australia’s 10 LNG facilities.

But in August 2019, Chevron began depositing CO₂ deep underground—some 2.5km below Barrow Island. Their CCS injection facility should help reduce greenhouse gas emissions associated with the Gorgon Project by approximately 40 per cent, or more than 100 million tons over the life of the injection project.

According to Chevron, the gas in the Gorgon Field contains on average 14 per cent naturally occurring CO₂. This CO₂ is collected during the first stages of the production process but is quickly separated from the natural gas stream before liquefaction. If CO₂ remained in the stream during the liquefaction stage, when the natural gas is cooled to -162° C, it would freeze into a solid.While standard industry practice is to vent the separated CO₂ into the atmosphere, the Gorgon Project will inject the CO₂ into a massive turbidite sand deposit beneath Barrow Island. The CO₂ will be separated at the LNG plant site and transported by pipeline to one of three drill centres.

“To minimise the environmental footprint on the island, nine injection wells have been directionally drilled from the three drill centres. Once the CO₂ is injected, it will migrate through the formation until it becomes trapped. An on-going monitoring program, which includes observation wells and seismic surveys, will assist in managing the performance of the injected CO₂,” according to Chevron’s website.

Chevron anticipates that as a result of CCS technology, Gorgon will have the lowest greenhouse gas emissions intensity of any LNG project in Australia.

As explained by the Carbon Capture and Storage Association, CCS technology “can capture up to 90 per cent of the CO₂ emissions produced from industrial processes,” including natural gas processing. The technology has been in use since 1972, notably at the Terrell Natural Gas Processing Plant in Texas, the oldest operating industrial CCS project in the world.

The Journal of Petroleum Technology reports that “there are currently 23 large-scale CCS facilities in operation or under construction around the world, according to the Global Carbon Capture and Storage Institute (GCCSI), capturing almost 40 Mtpa of CO₂. An additional 28 pilot and demonstration-scale facilities in operation or under construction collectively capture another 3+ Mtpa.”

The increasing capacity for CCS is a source of optimism for those who realise its potential to curb the effects of climate change, as a significant reduction in carbon emissions is needed to achieve international climate goals.