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Prof John Kaldi interviewed in PESA News

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Prof John Kaldi, CO2CRC distinguished scientist, was interviewed by PESA News as part of their report on the Gorgon Project. Read the article by Dale Granger below.


Gorgon CO2 injection system thrusts Australia to the forefront of CCS technology

The start‐up of Gorgon’s carbon dioxide injection system on Barrow Island – believed to be the biggest carbon capture and storage (CCS) operation of its kind in the world – has thrust Australia to the forefront of a potentially game‐changing global technology.

Once fully operational, the carbon dioxide injection facility will reduce Gorgon’s greenhouse gas emissions by about 40 percent, or more than 100 million tonnes over the life of the injection project.

The project, which will inject and store reservoir CO2 into the Kimmeridgian‐Tithonian Dupuy Formation more than two kilometres beneath Barrow Island, will mitigate both Gorgon field‐derived gas, which contains 14 per cent naturally occurring CO2, and Jansz‐lo gas, which contains less than one per cent.

Chevron said that prior to the liquefaction process, reservoir CO2 is separated from the natural gas stream and transported by pipeline to one of three drill centres – where nine injection wells have been directionally drilled – from where it will migrate through the Dupuy Formation until it becomes trapped.

During the liquefaction process, when the natural gas is cooled to ‐162°C, if CO2 remained in the natural gas stream it would freeze into a solid.

“An on‐going monitoring program, which includes observation wells and seismic surveys, will assist in managing the performance of the injected reservoir CO2 in the Dupuy Formation,” Chevron said.

In spite of the naysayers, sceptical of either the oil and gas industry or carbon capture’s credentials as a potential game‐changer – both in emissions reductions and meeting Paris Accord climate change obligations – the experts are optimistic about CCS as a significant panacea for combatting climate challenges.

Professor John Kaldi, Distinguished Scientist at CO2CRC and SA State Chair of Carbon Capture and Storage, said several dozen global CCS demonstration projects, albeit much smaller in scale to the Gorgon operation, have already proven the concept.

“There are several dozen demonstration CCS projects in the world, including one in Victoria’s Otway Basin, demonstrating that storage in a depleted gas field works perfectly well. Today there are approximately 20 commercial scale projects active in the world. The world’s first commercial scale project was Statoil’s (now Equinor’s) Sleipner project in the Norwegian North Sea, which put one million tonnes of CO2 per annum into the Utsira Formation and has been doing that since 1996.

“But that’s not all. The Boundary Dam coal‐fired power plant in Saskatchewan, Canada, is separating close to one million tonnes per annum, off the flue gas from the combusted coal.  Most of the CO2 is piped to the Weyburn project, also in Saskatchewan, an enhanced oil recovery project, while a portion is injected into the Cambrian age Deadwood Formation for permanent storage. Then we have the Archer Daniels Midland (ADM) project in Decatur, Illinois, which makes ethanol and would ordinarily emit close to one million tonnes per year of CO2 but today also puts that into a Cambrian Sandstone,” Kaldi said.

“So, there you have three CCS projects operating in three different emission source environments. It is not all altruism, however. For instance, in the case of The Sleipner project it is done because Norway has a carbon tax and Equinor has found an economic way of effectively reducing their tax burden, while still decreasing the greenhouse gas emissions to the atmosphere.”

Kaldi drew comparisons between Shell’s Quest CCS project in Alberta, which is reducing emissions from heavy oil processing, the Boundary Dam, and the ADM projects, all of which are injecting into porous and permeable Cambrian sandstone formations more than three kilometres below the ground.

“All of these projects have thoroughly characterised the subsurface formations and done their homework. It’s not like slap dash, let’s just put together a project. And Barrow Island is a first‐class nature reserve where you are not allowed to have any kind of pollution. Both the Federal and WA governments decreed that, in order to get the LNG‐permit, they had to do something with the emissions. Chevron (50%), Shell and ExxonMobil (25% each) decided they could do CCS and still be economical; and all the reasons that people have come up with for why you can’t do it have been negated just by doing it and demonstrating it to be valid.

“The biggest cost with CCS is in the capture side and the reason for that is because the technologies at present are using expensive amine solvents to separate the carbon dioxide from the methane. But the chemical engineering community is trying to come up with various other options, such as potassium carbonate absorbents or even membranes instead of solvent technologies,” said Kaldi.

With the ability to remove three to four million tonnes of CO2 per annum, Gorgon’s CCS project weighs in at about three to four times larger than comparative global operations.

“As we speak more and more of these are coming online. China has a couple on the go now and whether you are a sceptic or not about climate change being caused by CO2 we’ve all got to do our bit to reduce any kinds of these emissions. There is no silver bullet to solving climate change! If we are serious about reducing our greenhouse gas emissions, and meeting our Paris Accord commitments, however, we need a portfolio of mitigation measures, including renewables, increased efficiencies, switching to lower carbon fuels and CCS as a significant part of this paradigm,” he said.

While Kaldi estimates that Gorgon’s CCS project may have the potential to capture up to 90 per cent of its CO2 he believes the bigger picture could be potentially transformational on an industrial scale and Australia could play a lead role in this endeavour.

“We are not only talking about oil and gas, coal or the power sector; we are looking at industries like steel, aluminium, cement. All of these industries are stationary contributors to the big emissions base. Of interest is that the Gorgon Project, the world’s largest sequestration project, and the CO2CRC Otway Project, the premier demonstration site to test things like injectivity and monitoring, are both Australian! We are certainly in the game on the trial and demonstration side of things.

“One of the concerns people express is “how do we know what is happening to the CO2 once it is injected? Is it going to leak out, or what migration path will ensue once you put it in there?” These are the types of questions that projects like CO2CRC’s Otway Project strive to answer,” said Kaldi.

Kaldi further states “Of course, you have very vocal activist groups who assert that CCS is just a ploy of the fossil fuel industry to keep themselves in business. These folks tend to be against anything in industry that is not “green” and we will probably never convince them of the value of CCS. Then you have people who are well meaning, but poorly informed, and listen to those who are the loudest; these are the ones who, we as CCS proponents, need to bring on board.

“We saw an example of activists shutting down a project in the Netherlands where Shell had a gas field (Barendrecht) near Rotterdam, which they had used to store natural gas since World War 2.

“Shell wanted to turn it into a CO2 storage field and went to the government for permission to do a demo project. Protestors turned up and managed to shut down the project there, branding it as a big, dangerous “CO2 bomb”. Shell got their technical people out to try to explain what was going on and said they had safely stored methane there for a very long time.

“The demonstrators responded with, “Yeah, but we need methane for our heating and cooking” but insisted CO2 would “explode” and kill people, citing Lake Nyos in Cameroon – a volcano crater‐lake that unexpectedly released CO2 resulting in the tragic suffocation of people in a nearby village. This was a natural phenomenon, unlike any scenario that would be encountered by CCS, that is sometimes used to argue that CO2 is dangerous. However, such risks are reduced if we have it in a controlled environment and injected into the correct geological settings that are being properly monitored! By the way, subsequent to the Lake Nyos tragedy, they put a “mixer” in place to circulate the bottom waters of the lake to ensure it would never happen again.”

Ultimately, Kaldi believes that the same porous and permeable rocks in the subsurface, overlain by an impermeable seal rock that have held hydrocarbons for millions of years, are equally good “dungeons” to lock away unwanted emissions as one solution to safeguarding mother earth.

“Our understanding of geological systems, and our ability to visualise and model the subsurface, have improved by leaps and bounds over the last several decades. Thus, we can anticipate where problems might occur, such as minor earthquakes from movement along a fault or a fracture due to induced stresses from injection, which are the concerns sometimes raised.

“But if you know your stress field, and geomechanical understanding of the orientation of stress fields and where migration can go, you can anticipate through monitoring and reservoir characterisation future potential pitfalls; activities we do all the time in the oil and gas business,” said Kaldi.