In the recentdecades, there has been a common concern about climate change and globalwarming, which have caused several natural disasters.
With respect to that,many experts have attributed it to the excessive CO2 emissions fromthe continuously growing industrial activities, including the burning of fossilfuels (Ampomah et al, 2016; Jamali et al, 2016; Asme, 2005; Li, 2005). Therefore,to mitigate the problems resulting from anthropogenic climate changes, the oiland gas industry combines the enhanced hydrocarbon recovery and carbon dioxide geologicalstorage (Ampomah et al. 2016). Zhang et al. (2014), affirms that in the newcentury, one of the major challenges it to develop sustainable and safetechnologies to mitigate greenhouse gas emissions to the atmosphere.Nonetheless, to achieve that purpose, Carbon Dioxide geological storage in deepformations is believed to be among the promising technology.
These deepgeological formations used for CO2 storage include depleted ornearly depleted Gas and Oil reservoirs, deep saline aquifers, and coal bedformations that are unmineable (Zhang et al., 2014; Ampomah et al., 2016). Theinjection of CO2 into depleted Oil or Gas reservoirs is seen in manystudies as the most beneficial among all currently known mechanisms because ofits economic and technical advantages (Jamali et al, 2016). Jamali et al,(2016) the sequestration of CO2 through CO2-EOR can helpto reduce the cost of storage when utilizing the already available facilitiesin the industry of oil and gas, benefiting from the oil production profitincrement which compensates the carbon dioxide capture costs. Apart from recovering huge amounts ofhydrocarbons which compensates the CO2 compression and injectioncosts, the utilisation of already existing production facilities for itsinjection, the sequestration of carbon dioxide for long terms, its flooding technologyalso has already been proven for more than five decades (Ampomah et al, 2016; Zhanget al., 2014; Jamali et al, 2016).
In another hand, due to its commonavailability around the world, saline geological aquifers are potentiallytargeted as adequate long term carbon dioxide underground storages, and thecorresponding technology has been studied for nearly two decades (Ampomah etal, 2016). Similarly, Graupner et al, (2011) has mentioned that the largecapacity and the common occurrence of deep saline aquifers have made it a majoroption for CO2 long term storage.Thewater-alternating-gas WAG has commonly been used in combination with CO2-EORto delay carbon dioxide breakthrough and increase the sweep efficiency (Ampomahet al, 2016). Several research works agree that there are basically fourprimary CO2 geological sequestration mechanisms, which includestructural stratigraphic trapping, solubility trapping, residual trapping, andmineral trapping (Ampomah et al, 2016).
Despite of CO2 injectiontechnique for oil and/or gas recovery being accepted worldwide for more thanfour decades, its expansion to include CO2 storage is still beingquestioned when it comes to the concerns related to its reliability and risksof potential leakage. Therefore, to avoid buoyancy effects which can make CO2migrate upwards leading to potential leakage, CO2 trapping is frequentlydone in the formations that have cape rock above it, such as mudstone and shaledue to its low permeability. Utilizing CO2 captured from thelignite-fuelled Great Plains Synfuels plant in the year of 2000, USA hasconducted the world’s first biggest CO2-EOR and storage project andits monitoring program to ensure the effectiveness and safe storage required toavoid underground CO2 leakage (Zhang et al, 2014). China hasdemonstrated its first big scale CO2-EOR and storage in Jilinoilfield to enhance CO2 oil recovery mechanism and to ensure a safeCO2 storage in the reservoir. Graupner et al,(2011) various computer codes including Eclipse (Schlumberger InformationSystem), are able to perform simulation of multiphase flow in porous media. Nevertheless,there are fewer computer codes like ToughReact which can simulate multiphaseflow with multi-component transport and reactions simultaneously.
As far as CO2storage is concerned, power companies frequently build specific models oftargeted CO2 storage sites, which usually rely on the Eclipsesimulator (Graupner et al, 2011).