Simulation of CO2Carbon dioxide storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere in an underground formationA body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it requires a complex multi-disciplinary effort, with the analysis of a number of interacting processes, including multi-phase flow and transport, geochemistry and geomechanicsThe science of the movement of the Earth’s crust an rocks.
InjectionThe process of using pressure to force fluids down wells of a large volume of fluid in the subsurface over a period can have geomechanical as wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injection of fluids as hydrodynamic effects. During the injectionThe process of using pressure to force fluids down wells phase of a CO2Carbon dioxide storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere project, the (average) pore pressure in the storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere formationA body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it would increase with continuous CO2Carbon dioxide injectionThe process of using pressure to force fluids down wells. Spatially, the pressure increase would be highest at the injectionThe process of using pressure to force fluids down wells wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injection of fluids. Changes in the pore pressure will in turn alter the stress state. The associated changes in the effective stress (total stress minus the product of pore pressure and the Biot constant) cause rock to deform. If the injectionThe process of using pressure to force fluids down wells-induced pressure increase is too large, shear slip or tensile opening of pre-existing fault(geology) A surface at which strata are no longer continuous, but are found displaced(s) in the storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere reservoirA subsurface body of rock with sufficient porosity and permeability to store and transmit fluids/caprockRock of very low permeability that acts as an upper seal to prevent fluid flow out of a reservoir may occur, or new fractures may be created. This may cause a previously sealing fault(geology) A surface at which strata are no longer continuous, but are found displaced to become conductive, and thus potentially compromise the caprockRock of very low permeability that acts as an upper seal to prevent fluid flow out of a reservoir sealAn impermeable rock that forms a barrier above and around a reservoir such that fluids are held in the reservoir. Induced shear-stress changes may also induce micro-seismicityThe episodic occurrence of natural or man-induced earthquakes and even earthquakes of moderate local magnitudes (Bachu, 20082008 - S. BachuCO2 storage in geological media: Role, means, status and barriers to deploymentsee more). For example, in Germany earthquakes up to magnitudes of 2.6 to 2.8, triggered by 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 production, have been reported (Chadwick et al., 2008).
The injected fluids are accommodated in the subsurface through local displacement of resident fluids (water, oil or gas), compression of both the injected and in situ fluids, and expansion of the pore spaceSpace between rock or sediment grains that can contain fluids that sometimes may lead to ground heaving (Bachu, 20082008 - S. BachuCO2 storage in geological media: Role, means, status and barriers to deploymentsee more). Fractured and faulted reservoirs are generally highly compacted and, thus, severely affected by stress changes induced by reservoirA subsurface body of rock with sufficient porosity and permeability to store and transmit fluids thermal variations (e.g. cold CO2Carbon dioxide injectionThe process of using pressure to force fluids down wells).
Storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere reservoirA subsurface body of rock with sufficient porosity and permeability to store and transmit fluids pressure will start to subside when CO2Carbon dioxide injectionThe process of using pressure to force fluids down wells ceases. The riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event of leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column is expected to decrease as the pressure decays towards a stable condition. When the reservoirA subsurface body of rock with sufficient porosity and permeability to store and transmit fluids pressure reduces to this stable level, the reservoirA subsurface body of rock with sufficient porosity and permeability to store and transmit fluids is considered secure against geomechanical failure due to the internal forces (Chalaturnyk et al., 2005).
Geomechanical data, among other properties, are required under the EU CCS DirectiveDirective 2009/31/EC of the European Parliament and of the Council of 23 April 2009 on the geological storage of carbon dioxide (2009) during the storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere site characterisation stage in order to evaluate the geomechanical effects of CO2Carbon dioxide injectionThe process of using pressure to force fluids down wells. Knowledge of the elastic properties of the storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere formationA body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it/caprockRock of very low permeability that acts as an upper seal to prevent fluid flow out of a reservoir, pre-existing fault(geology) A surface at which strata are no longer continuous, but are found displaced strength properties, if any, in situ stress state, etc. allow the estimation of the fracturing pressure and, therefore, the determination of the upper limit of injectionThe process of using pressure to force fluids down wells pressure. They also help to assess and predict the reservoirA subsurface body of rock with sufficient porosity and permeability to store and transmit fluids behaviour with respect to its overall capacity and avoid critical pressure build-up.
CO2Carbon dioxide transport model simulations provide the information necessary to determine whether there is potential CO2Carbon dioxide leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column through the caprockRock of very low permeability that acts as an upper seal to prevent fluid flow out of a reservoir. Three key areas of simulation - focusing on faults andfFractures, subsurface behaviour and fate of CO2Carbon dioxide, and geomechanical/mechanical/flow models - show that numerical modelling is critical to CO2Carbon dioxide storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere evaluation and riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event. MonitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions programs or computer simulations can be used to determine whether hydraulic fracturing would pose a riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event to the confining layer, based on site-specific information.
Gaus, 20102010 - I. GausRole and impact of CO2-rock interactions during CO2 storage in sedimentary rockssee more stated that the coupling of geomechanical codes with coupled flow-transport codes remains a further challenge, although it is much-needed in order to assess the interplay between the two phenomena. This does not only require code development, but also the availability of the necessary datasets to feed into these codes and the correct treatment of uncertainties, since both geomechanical and geochemical processes are defined by highly uncertain parameters.