PERTH (miningweekly.com) – US energy major Chevron is sharing lessons learned in its carbon capture and storage (CCS) operations at its Gorgon liquefied natural gas (LNG) project, in Western Australia, with fellow industry participants.
The company in 2021 conceded that it had failed to capture sufficient greenhouse-gas (GHG) emissions at its Gorgon oil and gas project and was working with the Western Australian regulator to make up the shortfall.
At the time, the major announced a A$40-million investment into other lower carbon projects in the region, to address the shortfall.
Under the terms of the project’s approval, the Gorgon LNG operation is meant to capture four-million tonnes a year of carbon dioxide (CO2), or 80% of the carbon extracted from its reservoir gas, and reduce GHG emissions by more than 100-million tonnes over the life of the injection project.
Since it was established in 2019, the project has captured 7.5-million tonnes of CO2.
“Despite the fact we are safely storing the CO2 on Barrow Island, the performance of the system is not where Chevron wants it to be. We're not actually achieving our design rates of CO2 capture today,” Chevron GM for energy transition David Fallon told delegates at the AOG Energy expo, in Perth.
“We've learned lots of lessons in our initial years of operation. We are acting on those and working out plans currently to implement some improvement optimization projects in the coming years to actually allow us to get close to those desired levels of CO2 performance.
“But as part of that we are actually actively going around industry and sharing our lessons learned with key stakeholders around the country,” Fallon said.
Fallon told delegates that the challenges faced by the Gorgon CCS projects were not related to the technology being used, but related rather to the pressure management system.
Chevron is currently injecting CO2 underneath Barrow Island into a saline aquifer, which is full of water. To manage the pressure within that reservoir, the company has to extract water which is injected into a different reservoir on Barrow Island.
“That is where we are seeing challenges. Those challenges around water injection are why we are currently limiting the rate of CO2 injection underneath Barrow Island,” Fallon said.
He noted that the company was also seeing unexpected contaminants in the water, combined with trace amounts of oil and gas, which further created challenges.
“So when we look to expand our water well capacity, we will also be putting in place treatment facilities to actually take out that trace amount of sand, oil and gas to ensure that we can continue to operate at the enhanced water rates in future,” he added.