Carbon dioxide injected into saline aquifers in a liquid or liquid-like supercritical(CO2Carbon dioxide) Conditions where carbon dioxide has some characteristics of a gas and some of a liquid dense phase does not mix with the host reservoirA subsurface body of rock with sufficient porosityMeasure for the amount of pore spaceSpace between rock or sediment grains that can contain fluids in a rock and permeabilityAbility to flow or transmit fluids through a porous solid such as rock to store and transmit fluids fluid and an immiscible flow occurs. The presence of two or more phases tends to decrease the effective phase permeabilityAbility to flow or transmit fluids through a porous solid such as rock and thus slow down the rate of migrationThe movement of fluids in reservoir rocks. On the other hand, if CO2Carbon dioxide is injected into a (depleted(hydrocarbon reservoir) one where production is significantly reduced) gas reservoirA subsurface body of rock with sufficient porosityMeasure for the amount of pore spaceSpace between rock or sediment grains that can contain fluids in a rock and permeabilityAbility to flow or transmit fluids through a porous solid such as rock to store and transmit fluids, a single miscible fluid phase consisting of natural gasGas stored underground; It consists largely of methane, but can also contain other hydrocarbons, water, hydrogen sulphide and carbon dioxide, these other substances are separated before the methane is put into a pipeline or tanker and CO2Carbon dioxide is formed locally. Van der Meer at al., 2009 states that although CH4 and CO2Carbon dioxide are fully miscible, instant mixing does not seem to occur in the reservoirA subsurface body of rock with sufficient porosityMeasure for the amount of pore spaceSpace between rock or sediment grains that can contain fluids in a rock and permeabilityAbility to flow or transmit fluids through a porous solid such as rock to store and transmit fluids and therefore gravity segregation is an important factor for CO2Carbon dioxide storage(CO2Carbon dioxide) A process for retaining captured CO2Carbon dioxide, so that it does not reach the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) in depleted(hydrocarbon reservoir) one where production is significantly reduced gas reservoirs. Carbon dioxide injected into an oil reservoirA subsurface body of rock with sufficient porosityMeasure for the amount of pore spaceSpace between rock or sediment grains that can contain fluids in a rock and permeabilityAbility to flow or transmit fluids through a porous solid such as rock to store and transmit fluids may be miscible or immiscible with oil, depending on the oil composition and the pressure and temperature of the system. Under miscible conditions, the oil swells and becomes less viscous. As a result, it flows more easily leading to increased oil production. When this oil is pumped to the surface, CO2Carbon dioxide coming out of the solution is captured by surface facilities for further injectionThe process of using pressure to force fluids down wells (Whittaker et al., 20112011 - S. Whittaker, B. Rostron, C. Hawkes, C. Gardner, D. White, J. Johnson, R. Chalaturnyk and D. SeeburgerA decade of CO2 injection into depleting oil fields: Monitoring and research activities of the IEA GHG Weyburn-Midale CO2 Monitoring and Storage Projectsee more). The flow of CO2Carbon dioxide in coalbeds is more complex because of shrinkage and swelling of the coal itself and the adsorptionThe adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface and desorption of the gases (Korre et al., 20072007 - A. Korre, J. Q. Shi, C. E. Imrie, C. Grattoni and S. DurucanCoalbed methane reservoir data and simulator parameter uncertainty modelling for CO2 storage performance assessmentsee more; Korre et al., 20092009 - A. Korre, J. Q. Shi, C. E. Imrie and S. DurucanModelling the uncertainty and risks associated with the design and life cycle of CO2 storage in coalbed reservoirssee more).