be produced back along with the oil. Whether CCS/
EOR will be implemented offshore on a larger scale in
the future depends on the cost-benefit picture and the
availability of CO 2 . There are limits to the degree that
water can enhance oil recovery, and CO 2 is known to
further increase the amount of oil that can be extracted
and thus extend the lifetime of oil fields. Moreover, new
technologies using CO 2 for EOR are being developed.
One recent discovery is that CO 2 foams (rather than gas
or supercritical) can significantly improve the recovery
of medium to heavy oils and that foams are twice as
effective compared to water or gas/supercritical CO 2
(Rassenfoss 2012).
24.8.2 Large Scale Transport and Storage
Most of the discussion so far has been on capture and
storage from single point sources. This limits CCS
projects to a few Mt/a. The total emissions from point
sources in larger regions in Europe, Asia, and America
may however reach hundreds of Mt/a. By connecting
smaller (<20–40 Mt) CO 2 suppliers through hubs, and
transporting large amounts (hundreds of Mt/a) to
reservoirs such as the Utsira Sand with very large storage capacity, the cost of stored CO 2 per ton may be
reduced significantly. The cost of pipelines and infrastructure is shared among several stakeholders, and
larger dimensions of pipelines allow a greater volume
CO 2 to be transported per ton steel used (volume/crosssection ratio of pipelines increases). The amount of
pressure a pipeline can hold is a function of the diameter
of the pipeline, with smaller pipes withstanding higher
pressures. The upper limit of pipeline dimensions must
therefore be weighed against the pressures required to
transport the CO 2 as a dense phase.
To allow such large-scale CCS in Europe requires
regulations across national boundaries, and there are
several complicated issues that must be sorted out.
One is the ownership and risk responsibility of the
transport and storage of a mixture of CO 2 from several
sources. Who will be held responsible in case of a
pipeline rupture? Who owns the stored CO 2 and will
be responsible for a monitoring programme? It is
natural that in Europe the European Union and
associated nations such as Norway, should facilitate
such large scale CCS.
24.9 Summary
Carbon capture and storage is one out of several
strategies to mitigate rapidly increasing atmospheric
CO 2 levels. CCS involves capture of CO 2 from natural
gas or flue gas, and transport and storage in geological
formations. There are several technologies available for
capture, and the choice of technology depends on the
processing plant and the cost of operation. Because of
the relatively high costs of capture, there are large
research programmes underway to improve the
energy-efficincy of current methods and to come up
with new and more cost-effective capture technologies.
The captured CO 2 can be stored underground in geological formations, preferentially as a dense supercritical phase, but this also requires large amounts of
energy. The main requirements of a storage formation
are that it has sufficient injectivity and storage capacity
and a tight cap rock. Moreover, as water is mobilised by
the injected CO 2 and the pressure waves caused by the
injection, one has to ensure that freshwater resources
are not affected by the storage operation. In the future,
to meet the IPCC target of globally storing Gt of CO 2
per year rather than the few Mt/a stored today, storage
operations will have to be scaled up. One way to do this
is to collect CO 2 from several large point sources and
store it in sandstones, such as the Utsira Sand, that
possess a very high storage capacity (Fig. 24.1).
References
Alemu, B.L., Aagaard, P., Muntz, I.A. and Skurtveit, E. 2011.
Caprock interaction with CO 2 : A laboratory study of reactivity of shale with supercritical CO 2 and brine. Applied
Geochemistry 26(12), 1975–1989.
Bacci, G., Durucan, S. and Korre, A. 2013. Experimental and
numerical study of the effects of halite scaling on injectivity
and seal performance during CO 2 injection in saline aquifers.
Energy Procedia 37, 3275–3282.
Benson, S.M. and Cole, D.R. 2008. CO 2 sequestration in deep
sedimentary formations. Elements 4, 325–331.
Bjørlykke, K., Mo, A. and Palm, E. 1988. Modelling of thermal
convection in sedimentary basins and its relevance to diagenetic reactions. Marine and Petroleum Geology 5, 338–351.
Duan, Z. and Sun, R. 2006. A model to predict phase equilibrium of CH 4 and CO 2 clathrate hydrate in aqueous electrolyte solutions. American Mineralogist 91, 1346–1354.
24 Carbon Capture and Storage (CCS)
601
EOR will be implemented offshore on a larger scale in
the future depends on the cost-benefit picture and the
availability of CO 2 . There are limits to the degree that
water can enhance oil recovery, and CO 2 is known to
further increase the amount of oil that can be extracted
and thus extend the lifetime of oil fields. Moreover, new
technologies using CO 2 for EOR are being developed.
One recent discovery is that CO 2 foams (rather than gas
or supercritical) can significantly improve the recovery
of medium to heavy oils and that foams are twice as
effective compared to water or gas/supercritical CO 2
(Rassenfoss 2012).
24.8.2 Large Scale Transport and Storage
Most of the discussion so far has been on capture and
storage from single point sources. This limits CCS
projects to a few Mt/a. The total emissions from point
sources in larger regions in Europe, Asia, and America
may however reach hundreds of Mt/a. By connecting
smaller (<20–40 Mt) CO 2 suppliers through hubs, and
transporting large amounts (hundreds of Mt/a) to
reservoirs such as the Utsira Sand with very large storage capacity, the cost of stored CO 2 per ton may be
reduced significantly. The cost of pipelines and infrastructure is shared among several stakeholders, and
larger dimensions of pipelines allow a greater volume
CO 2 to be transported per ton steel used (volume/crosssection ratio of pipelines increases). The amount of
pressure a pipeline can hold is a function of the diameter
of the pipeline, with smaller pipes withstanding higher
pressures. The upper limit of pipeline dimensions must
therefore be weighed against the pressures required to
transport the CO 2 as a dense phase.
To allow such large-scale CCS in Europe requires
regulations across national boundaries, and there are
several complicated issues that must be sorted out.
One is the ownership and risk responsibility of the
transport and storage of a mixture of CO 2 from several
sources. Who will be held responsible in case of a
pipeline rupture? Who owns the stored CO 2 and will
be responsible for a monitoring programme? It is
natural that in Europe the European Union and
associated nations such as Norway, should facilitate
such large scale CCS.
24.9 Summary
Carbon capture and storage is one out of several
strategies to mitigate rapidly increasing atmospheric
CO 2 levels. CCS involves capture of CO 2 from natural
gas or flue gas, and transport and storage in geological
formations. There are several technologies available for
capture, and the choice of technology depends on the
processing plant and the cost of operation. Because of
the relatively high costs of capture, there are large
research programmes underway to improve the
energy-efficincy of current methods and to come up
with new and more cost-effective capture technologies.
The captured CO 2 can be stored underground in geological formations, preferentially as a dense supercritical phase, but this also requires large amounts of
energy. The main requirements of a storage formation
are that it has sufficient injectivity and storage capacity
and a tight cap rock. Moreover, as water is mobilised by
the injected CO 2 and the pressure waves caused by the
injection, one has to ensure that freshwater resources
are not affected by the storage operation. In the future,
to meet the IPCC target of globally storing Gt of CO 2
per year rather than the few Mt/a stored today, storage
operations will have to be scaled up. One way to do this
is to collect CO 2 from several large point sources and
store it in sandstones, such as the Utsira Sand, that
possess a very high storage capacity (Fig. 24.1).
References
Alemu, B.L., Aagaard, P., Muntz, I.A. and Skurtveit, E. 2011.
Caprock interaction with CO 2 : A laboratory study of reactivity of shale with supercritical CO 2 and brine. Applied
Geochemistry 26(12), 1975–1989.
Bacci, G., Durucan, S. and Korre, A. 2013. Experimental and
numerical study of the effects of halite scaling on injectivity
and seal performance during CO 2 injection in saline aquifers.
Energy Procedia 37, 3275–3282.
Benson, S.M. and Cole, D.R. 2008. CO 2 sequestration in deep
sedimentary formations. Elements 4, 325–331.
Bjørlykke, K., Mo, A. and Palm, E. 1988. Modelling of thermal
convection in sedimentary basins and its relevance to diagenetic reactions. Marine and Petroleum Geology 5, 338–351.
Duan, Z. and Sun, R. 2006. A model to predict phase equilibrium of CH 4 and CO 2 clathrate hydrate in aqueous electrolyte solutions. American Mineralogist 91, 1346–1354.
24 Carbon Capture and Storage (CCS)
601