By John Kemp
LONDON, Sept 11 Australia's prime minister-elect
Tony Abbott has pledged to repeal the country's carbon tax to
boost economic competitiveness, so it is ironic that Australia
is about to host the world's most ambitious project for
capturing carbon dioxide and storing it underground.
Starting in 2014/15, Chevron will begin injecting 120
million tonnes of pressurised supercritical carbon dioxide 2.5
kilometres underground as part of its giant Gorgon LNG project.
Raw gas from the Gorgon field contains about 14 percent
carbon dioxide (CO2), which must be separated out and safely
disposed of before the purified methane can be liquefied and
Under an ambitious programme agreed with the state and
federal governments back in 2009, Chevron will inject the CO2
into a saline aquifer beneath Barrow Island off the coast of
Chevron is spending $2 billion on the world's
largest CO2-injection facility, which will store over 3 million
tonnes per year, making it by far the world's largest CO2
storage project, and creating a unique opportunity to study how
injected CO2 behaves underground in saline aquifers.
Barrow Island is a Class A nature reserve and carbon dioxide
is fatal to humans in concentrations as low as 7-15 percent. So
Chevron has conducted extensive seismic surveys and drilling to
estimate the aquifer's storage capacity and ensure it will not
The company has also promised to monitor the underground
movement of the CO2 plume as it spreads away from the initial
injection wells using 4-dimensional seismic surveys.
Together with its joint venture partners, Chevron will be
responsible for any costs associated with leaks and other damage
duration the lifetime of the project and for 15 years after CO2
But the Commonwealth of Australia and the State of Western
Australia have agreed to accept responsibility for any long-term
liabilities. Commonwealth and state indemnities will protect the
joint venture partners from any common law liability arising
from third party claims for loss or damage, suffered after the
The indemnity will only occur after continuous monitoring
and modelling of the stored carbon dioxide for at least 15 years
after injection ceases, and when both state and commonwealth
governments are satisfied the CO2 has been stored safely. It is
not expected to become effective for at least 75 years,
according to an analysis prepared by law firm Baker & McKenzie.
CO2 storage is important because the International Energy
Agency (IEA) has identified carbon capture and storage (CCS)
programmes as an essential part of strategies to limit climate
"As long as fossil fuels and carbon-intensive industries
play dominant roles in our economies, carbon capture and storage
(CCS) will remain a critical greenhouse gas reduction solution.
With coal and other fossil fuels remaining dominant in the fuel
mix, there is no climate friendly scenario in the long run
without CCS," the IEA explained earlier this year.
But apart from a handful of small-scale CO2 injection
projects linked to enhanced oil recovery (EOR) schemes and
pressure maintenance in petroleum reservoirs, there are still no
large-scale examples of CO2 capture and storage underground.
"CCS has so far been developing at a slow pace despite some
technological progress, and urgent action is now needed to
accelerate its deployment," the IEA warned ("Technology roadmap:
carbon capture and storage" 2013).
Of the three elements involved in CCS projects -
separation/capture, transportation and injection/storage -
transportation is the most mature while separation/capture is
the most problematic. The key challenge is how to separate CO2
from other gases when it is present in low concentrations
without using too much energy in the process (minimising the
By contrast, storage is a moderately mature technology, not
as well understood as pipelines but much more advanced than
capture/separation. Oil and gas companies have been injecting
CO2 to enhance oil recovery or maintain pressure since the
1970s. Five projects currently inject at least 1 million tonnes
per year in locations ranging from Canada and Norway to Algeria.
But global emissions of carbon dioxide and other greenhouse
gases are currently running over 30 billion tonnes of
CO2-equivalent per year. The CO2 storage industry would need to
be scaled up 1,000-fold to make a meaningful contribution to
reducing greenhouse emissions.
Gorgon is significant because it is more than double the
scale of existing projects and has demonstrated how some of the
barriers to scaling up the industry might be overcome.
CO2 needs to be trapped safely underground for thousands of
years. But that is much longer than the expected lifetime of
Most concerns centre around the risks to human health and
the environment in the event that CO2 escapes from the
underground formations into which it is injected, and who would
be responsible for any associated costs.
Natural escapes from volcanic lakes in Cameroon have killed
thousands of people. Moreover, if companies receive credit for
underground CO2 storage under emissions trading schemes and
other regulations, it is not clear who would be responsible if
the CO2 started to leak out again.
"The major barrier for industry and its supporting financial
community to undertaking CCS projects is the undefined and
open-ended liability for any CCS project," according to the
authors of the 2012 "Global Energy Assessment."
"Liability and related long-term stewardship issues are
potentially the most significant impediments to creating a
global CCS industry," they concluded.
Member states of the European Union, Norway and some U.S.
oil and gas producing states such as Texas, Louisiana, Wyoming
and Montana have all introduced some sort of limitations on
long-term liability to stimulate their CCS and EOR industries.
Norway's government has taken long-term liability from
Statoil for CO2 injections linked to the Sleipner gas field. The
U.S. state of Illinois has accepted long-term liability for the
CO2 stored as part of the FutureGen clean coal demonstration
Unlike most other projects, Gorgon will inject CO2 into a
saline aquifer rather than a depleted oil and gas field,
providing an opportunity to test how CO2 injections into a
saline aquifer behave on a large scale.
The U.S. Department of Energy has identified saline aquifers
as a vital storage resource if CCS is to be captured on anything
like the scale that will make a difference to the climate.
In the United States alone, saline aquifers could store
between 1.6 and 20 trillion tonnes of CO2, compared with just
60-120 billion tonnes in unmineable coal seams and 120 billion
tonnes in depleted oil and gas fields.
Little is known about how stored CO2 behaves in saline
But with Gorgon, Australia's government will be sponsoring
the world's largest and most ambitious attempt to lock CO2 away
safely underground, even as it tries to water down other
elements of climate change policy.