out to have only a limited storage capacity, and pressure
continued to increase until injection was abandoned in
2011. Injection was then moved to the shallower Stø
Formation, below the gas reserves. As CO 2 migrates
updip and will mix with the natural gas, there is an
expectance that additional storage sites will be needed
in the future to continue the CO 2 storage operation.
24.7.3 In Salah CCS Project
The In Salah CCS project in central Algeria is an
example of an onshore CCS operation. During the
lifetime of the project, between 2004 and 2011, 3.8
Mt CO 2 was stored in a Carboniferous sandstone unit
1.9 km below the surface. The project demonstrated a
large number of monitoring technologies, such as the
use of Interferometric Synthetic Aperture Radar
(InSar) to monitor surface heave, 4D seismics to
track the underground CO 2 migration, geophones to
detect microseismicity, well-head sampling of geochemical tracers, etc. (Ringrose et al. 2013 and
references therein). The combination of all these
technologies enabled the tracking both of possible
hydrofractures and potential migration of the CO 2
outside the Krechba hydrocarbon lease, and remedial
action (operation and monitoring responses). The In
Salah CCS project has therefore provided highly valuable information on the whole chain, from planning to
operation and abandonment.
24.7.4 Weyburn-Midale CCS-EOR Project
The Weyburn-Midale project is at present the world’s
largest CCS operation, and is an example of a CCS
Enhanced Oil Recovery (EOR) project. The CCS
operation started in 2000, and currently nearly 3 Mt
CO 2 are annually injected in multiple wells and used
for enhanced oil recovery (Whittaker et al. 2011). At
the planned end of the operation, in 2035, the amount
of stored CO 2 is expected to be more than 40 Mt. The
injected CO 2 is a byproduct of coal gasification at the
Great Plains Synfuels Plant in North Dakota, USA.
The target reservoirs are of lower Carboniferous
age, at a present-day depth of 1,300–1,500 m. The
rocks were deposited in a peritidal sequence, with
carbonates deposited at highstands and evaporitic
dolomites formed at lowstands. The total storage
capacity of the Weyburn-Midale reservoirs, including
both the EOR phase and later CO 2 storage, is
estimated to be between 50 and 60 Mt. The
Weyburn-Midale CO 2 monitoring and storage project,
supported by the International Energy Agency Greenhouse Gas R&D program (IEA GHG), has invested in
an extensive geophysical and geochemical monitoring
programme, including passive seismic and soil gas and
fluid geochemistry monitoring (Whittaker et al. 2011).
24.8 What Is the Future of CCS?
The main obstacles to implementing CCS on a large
scale today are high costs and, for many regions, a lack
of a market for CO 2 . In North America, CO 2 has been
used for enhanced oil recovery for decades, and this
illustrates that the costs of capture and transport can be
more than compensated if a market exists to sell the
CO 2 . A second challenge is that the cost of releasing
CO 2 to the atmosphere is still too low to make it
financially viable for most emitters to store CO 2 .
Below is a short review of present-day activities to
utilise and store CO 2 in the USA, and a suggested
solution to lower the cost and allow large-scale storage
by gathering emissions from many point sources into
one shared pipeline network and storage site.
24.8.1 CCUS/EOR
CCUS (and CCUS/EOR), is short for Carbon Capture
Use (or Utilization) and Storage, and Enhanced Oil
Recovery (EOR). By using captured CO 2 in industrial
processes such as EOR, CCS may become profitable.
There are at present nine CCUS/EOR projects in the
operational phase and several in the planning and executive stage, most of them in the USA (Global CCS
Institute, Oct. 2013). Of these, the largest-scale is the
Weyburn-Midale CCS-EOR project described above.
Onshore CCUS/EOR has been a great success. The
same is not yet true for offshore CCUS/EOR. There are
several reasons for this: (1) seawater is readily available
offshore and can be used instead of the less available
CO 2 ; (2) the costs of installing CO 2 capture facilities
may be considerable; (3) injected CO 2 can lead to
corrosion of already existing infrastructure (wells etc.)
and investment in new infrastructure (in addition to the
capture facilities) may be required; (4) stored CO 2 may
600
H. Hellevang
continued to increase until injection was abandoned in
2011. Injection was then moved to the shallower Stø
Formation, below the gas reserves. As CO 2 migrates
updip and will mix with the natural gas, there is an
expectance that additional storage sites will be needed
in the future to continue the CO 2 storage operation.
24.7.3 In Salah CCS Project
The In Salah CCS project in central Algeria is an
example of an onshore CCS operation. During the
lifetime of the project, between 2004 and 2011, 3.8
Mt CO 2 was stored in a Carboniferous sandstone unit
1.9 km below the surface. The project demonstrated a
large number of monitoring technologies, such as the
use of Interferometric Synthetic Aperture Radar
(InSar) to monitor surface heave, 4D seismics to
track the underground CO 2 migration, geophones to
detect microseismicity, well-head sampling of geochemical tracers, etc. (Ringrose et al. 2013 and
references therein). The combination of all these
technologies enabled the tracking both of possible
hydrofractures and potential migration of the CO 2
outside the Krechba hydrocarbon lease, and remedial
action (operation and monitoring responses). The In
Salah CCS project has therefore provided highly valuable information on the whole chain, from planning to
operation and abandonment.
24.7.4 Weyburn-Midale CCS-EOR Project
The Weyburn-Midale project is at present the world’s
largest CCS operation, and is an example of a CCS
Enhanced Oil Recovery (EOR) project. The CCS
operation started in 2000, and currently nearly 3 Mt
CO 2 are annually injected in multiple wells and used
for enhanced oil recovery (Whittaker et al. 2011). At
the planned end of the operation, in 2035, the amount
of stored CO 2 is expected to be more than 40 Mt. The
injected CO 2 is a byproduct of coal gasification at the
Great Plains Synfuels Plant in North Dakota, USA.
The target reservoirs are of lower Carboniferous
age, at a present-day depth of 1,300–1,500 m. The
rocks were deposited in a peritidal sequence, with
carbonates deposited at highstands and evaporitic
dolomites formed at lowstands. The total storage
capacity of the Weyburn-Midale reservoirs, including
both the EOR phase and later CO 2 storage, is
estimated to be between 50 and 60 Mt. The
Weyburn-Midale CO 2 monitoring and storage project,
supported by the International Energy Agency Greenhouse Gas R&D program (IEA GHG), has invested in
an extensive geophysical and geochemical monitoring
programme, including passive seismic and soil gas and
fluid geochemistry monitoring (Whittaker et al. 2011).
24.8 What Is the Future of CCS?
The main obstacles to implementing CCS on a large
scale today are high costs and, for many regions, a lack
of a market for CO 2 . In North America, CO 2 has been
used for enhanced oil recovery for decades, and this
illustrates that the costs of capture and transport can be
more than compensated if a market exists to sell the
CO 2 . A second challenge is that the cost of releasing
CO 2 to the atmosphere is still too low to make it
financially viable for most emitters to store CO 2 .
Below is a short review of present-day activities to
utilise and store CO 2 in the USA, and a suggested
solution to lower the cost and allow large-scale storage
by gathering emissions from many point sources into
one shared pipeline network and storage site.
24.8.1 CCUS/EOR
CCUS (and CCUS/EOR), is short for Carbon Capture
Use (or Utilization) and Storage, and Enhanced Oil
Recovery (EOR). By using captured CO 2 in industrial
processes such as EOR, CCS may become profitable.
There are at present nine CCUS/EOR projects in the
operational phase and several in the planning and executive stage, most of them in the USA (Global CCS
Institute, Oct. 2013). Of these, the largest-scale is the
Weyburn-Midale CCS-EOR project described above.
Onshore CCUS/EOR has been a great success. The
same is not yet true for offshore CCUS/EOR. There are
several reasons for this: (1) seawater is readily available
offshore and can be used instead of the less available
CO 2 ; (2) the costs of installing CO 2 capture facilities
may be considerable; (3) injected CO 2 can lead to
corrosion of already existing infrastructure (wells etc.)
and investment in new infrastructure (in addition to the
capture facilities) may be required; (4) stored CO 2 may
600
H. Hellevang