US supermajor Chevron is facing issues at its carbon capture and storage (CCS) project associated with the Gorgon liquefied natural gas development in Western Australia, resulting in additional carbon dioxide being vented into the atmosphere.

Independent news outlet Boiling Cold this week published a document it obtained under freedom of information laws, which revealed the pressure management system at the world’s largest CCS project was currently off line.

In the annual report from Chevron, which was published on 30 September last year, the operator claimed the injection system was "operating reliably".

However, it revealed delays had been experienced with the commissioning of the pressure management system.

Injection issues

Delaying the commissioning of the system was the loss of injectivity at the project’s two water injection wells, with the loss believed to be related to plugging of the injection wells with “higher than expected solids production” from the four water production wells.

The produced water management is part of the pressure management system that creates more space for higher volumes of CO2 injection storage over time and involves pumping water out of the Dupuy formation beneath Barrow Island, to make room for the CO2, and pumping it back into the overlaying Barrow Group.

Chevron initially believed the plugging of the water injection wells was due to grease, perforation debris and some tubing corrosion material from the initial well completion activities.

However, it also observed “a significant volume of sand” being produced from the Dupuy formation by the water production wells, which was then making its way into the water injection wells, causing plugging of the water injection well perforations.

Due to the injectivity issues created by the sand production problem, the project’s pressure management system is currently offline.

Conditional consent

Western Australia’s Department of Mines, Industry Regulation & Safety (DMIRS) has granted a conditional “consent to operate” without the pressure management system online.

In May last year, it agreed to continue to give Chevron consent to operate as long as the pressure management system was operational by 31 December 2020.

DMIRS confirmed to Upstream on Thursday it had since approved a further six month extension, allowing Chevron to continue CO2 injection while the pressure management system is being brought back online, with the system required to be fully operational by 30 June.

"DMIRS conditional approval for Chevron to operate the CO2 injection system without the pressure management system being fully operational is subject to conditions, including reducing the limit for CO2 injection rates, and additional monitoring and reporting requirements," DMIRS Resource and Environmental Compliance Division executive Director, Karen Caple, said.

"DMIRS is closely monitoring Chevron’s progress on the CO2 injection system and will modify approval conditions if the risks change."

Additional CO2 venting

A Chevron spokesperson told Upstream that, while CO2 injection is continuing at the project, the operator has amended its daily injection rates, which they confirmed had resulted in additional CO2 venting “in the short-term”.

“In the Gorgon Emissions Reduction System, which continues to operate safely and inject CO2, Australia is demonstrating complex technology at a scale never undertaken by industry,” the spokesperson said.

“Like any pioneering endeavour, the carbon capture sequestration system has presented some challenges, and we continue to monitor and optimise system performance, with a focus on long-term, safe, efficient and reliable operation over its 40-plus year life.”

The spokesperson added that Chevron is continuing to work closely with DMIRS to optimise the pressure management system, which it anticipates will be operational in the first half of 2021.

“We are working with DMIRS and other stakeholders as we monitor the system’s performance and make adjustments as needed,” the spokesperson said.

“This includes the application of additional technology to continuously improve system performance, including, in co-ordination with the regulator, the installation of additional surface facilities during the first half of 2021 to remove solids from the produced water.”

The annual report also revealed the capital budget for the Gorgon CCS project had increased by $127.6 million, over the period from 1 July 2019 to 30 June 2020, to a total of $3.09 billion.


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Emission reduction target in doubt

Under the approvals for Gorgon, Chevron is required to sequester at least 80% of the CO2 emissions released from the reservoirs that feed the Gorgon LNG plant over a five-year period.

A review of the first five-year period is set to take place later this year and could see Chevron potentially required to pay offsets for failing to reach that target.

Chevron’s spokesperson told Upstream that more than 4 million tonnes of CO2 equivalent had been injected at the CCS project so far since its start up in 2019.

Chevron commenced operations from the Gorgon CO2 injection project in August last year, more than three years after the Gorgon project first started shipping gas.

The delay is reported to have resulted in an additional 7 million tonnes of CO2 being vented into the atmosphere.

Conservation group hits out

News of the latest increase in CO2 emissions from Gorgon was met with criticism this week from environmental group the Conservation Council of Western Australia (CCWA).

The CCWA had been appealing for tougher conditions on the operating licence for Chevron’s Gorgon project, however WA Environmental Minister Stephen Dawson has ruled out placing enforceable limits on the amount of carbon pollution that the company can release.

Dawson also rejected the CCWA’s request for Chevron to be required to make regular public disclosures of carbon injection volumes.

He did, however, uphold the conservation group’s bid to have Chevron’s licence conditions reviewed after 10 years instead of 20, something the US supermajor did not object to.

'International embarrassment'

CCWA director Piers Verstegen was not pleased with the government’s decision over its appeal, stating it was “an international embarrassment” to allow Chevron to continue to operate without any enforceable pollution limits.

“The shortening of the licence period to trigger a review of the licence after a decade is really the absolute minimum improvement that could possibly be made.

"Quite frankly it looks like a greenwash while the facility continues to operate with no pollution limits, no ongoing disclosure of its pollution, and no sanctions when it fails to meet its operating conditions,” he said.

“The real story here is that Chevron’s much-lauded carbon capture system is failing, and the state government and regulator is allowing itself to be complicit in the release of millions of tonnes of carbon pollution, while the public is kept in the dark about Chevron’s ongoing pollution breaches.”

Issues raise questions over CCS

Verstegen also claimed that the issues at Gorgon raised questions over CCS technology viability to reduce emissions for the oil and gas sector.

“The lack of disclosure and public reporting in this licence allows Chevron and others in the oil and gas industry to maintain the claim that carbon capture and storage will be a viable solution to their pollution problems,” Verstegen added.

“In reality, the world-first CCS facility on Barrow Islands has been plagued with technical problems, mismanagement, and regulatory failure from the very beginning.”

Chevron operates the Gorgon project with a 47.3% interest and is partnered by ExxonMobil and Shell, each on 25%, Osaka Gas on 1.25%, Tokyo Gas on 1% and Jera on 0.417%.