An annotated bibliography on CO2 storage in saline aquifer Submitted by Ugbovoro Orevaoghene Kennedy Student number: V8044586 Module title: Research and Enterprise Module number: ENG4003-N-CFI 2018 Total word count: two thousand sixty-eight IntroductionCarbon dioxide is vital to life on earth and it is colourless and odourless gas. This material natural occurring chemical compound is composed of a carbon atom covalently bounded to two atoms. Carbon dioxide exist in the atmosphere as a trace gas with concentration of 0.04%. CO2 takes place naturally in rivers, lakes, ground water, in ice caps, glacier and also in sea water. It is also found in petroleum and natural gas deposit.
Carbon dioxide have various industrial uses such as inert gas, welding and fire extinguisher as well as oil recovery. In view of this, CO2 has drastically increase it atmospheric concentration, leading to global warming. In addition, CO2 properties, storage options, trapping mechanism, storage capacity, site selection, reservoir rock properties, injection strategies, economic and injections strategies, problem associated with injection, existing and planned CO2 project has to be properly considered before CO2 is stored in any saline aquifer Human and natural source are both source of carbon dioxide emission into the atmosphere. Decomposition, ocean release and respiration are natural sources. On the other hand, activities like cement production, deforestation as well as burning fossil fuel like coal and natural gas are source caused by human activities. Due to human activities, the atmospheric concentration of carbon dioxide has been increased extensively since industrial revolution and has now reached dangerous level not seen in the last 3 million years.
(A., k Jain). We know that the global climate is currently changing due to natural and human activities. Over the years, the last decade of the 20th century and the beginning of the 21st century have been the warmest period in the entire global instrumental temperature record, starting in the mid-19th century. Significant cause of recent climate change, often referred as global warming is identified as human activities.
Certain naturally occurring gases, such as CO2 and water vapor, trap heat in the atmosphere causing greenhouse effect. All these factors have directly and indirectly have effect on our climate. CitationsBachu, S. (20150).
“Review of CO2 storage efficiency in deep saline aquifers”, International Journal of Greenhouse Gas Control, vol. 40, pp. 188-202.This article identified that several categories and some factors can be grouped in different ways to determine the efficiency of CO2 storage. The author went further to explain conditions such as salinity, pressure, CO2 displacement, lithology, permeability, porosity, heterogeneity, thickness and boundaries, aquifer areal extend on how they characterised CO2 storage. In addition, he reviewed another characteristic which was the operation of CO2 storage which basically includes the rate of injection, injection time, orientation and spacing, injection well numbers, the strategy used production of water to the storage. This paper is useful because the experimental data reviewed shows that CO2 can be efficiently stored in saline aquifer.
Relating this storage measure to my topic, efficient storage of CO2 which depends mainly on pressure and then space, if properly assessed can results to avoiding some environmental pollutions caused by CO2 thereby making the environment safe for human inhabitation. Celia, M.A., Bachu, S., Nordbotten, J.M. & Bandilla, K.W. (2015), “Status of CO2 storage in deep saline aquifers with emphasis on modelling approaches and practical simulations”, Water Resources Research, vol. 51, no. 9, pp.
6846-6892.In this article, M.A Celia uses summary of modelling approach of different governing equation for CO2 migration and injection problems. They ranged from three- dimensional, multi-phase flow, geomechanic to model of intermediate complexity from vertical to simple algebraic.it was found out, that the solution to those governing equations, from the basis of any practical model of CO2 injection and migration. To relate this to my topic, storage formation and storage security of CO2 becomes necessary, storage unit should have sufficient capacity to store intended volume of CO2, storage unit should have the ability to accept injected CO2 at the rate at which it’s supplied from the source. The relevance of this to the general public, is to have knowledge of the need to know the status of CO2 storage and its environmental impact.
Eccles, J., Pratson, L., Newell, R. and Jackson, R. (2009). “Physical and Economic Potential of Geological CO2 Storage in Saline Aquifers”, ENVIRONMENTAL SCIENCE ; TECHNOLOGY, vol. 43, no. 6, pp.
1962-1969.The articles gave an exclusive description of the economic potential of CO2 storage in saline aquifer and how some measure are in place to control the emission of CO2 gases. To achieve this, some world market tends to impose some cost on companies emitting CO2. The author further explained that if the cost of capturing CO2 is less than the cost of emitting, and the technology is effective; then activities that could lead to climate change can be avoided. To this end the economics of CO2 depends on separate cost component, including capturing, transport, sequestration and monitoring. I find this article important to the public and specifically the companies involved in CO2 emission to always carry out market survey on the cost of capturing CO2 and make comparison to the cost of storing before deciding which is best and safer for them.
In all, CO2 storage safes the world from greenhouse gas and global warming. Ghanbari, S., Al-Zaabi, Y., Pickup, G.E., Mackay, E., Gozalpour, F. and Todd, A.C (2006)”Simulation of CO2 storage in saline aquifers”, Chemical Engineering Research and Design, vol. 84, no.
9 A, pp. 764-775.This article gave an exclusive description of the numerical modelling approach of CO2, other ways of trapping CO2, and to avoid the problem of two phase flow. Reactive transport reservoir stimulator was used to model CO2 in saline aquifer. The author discovered from the results that CO2 gas rich phase were always in equilibrium with the water phase due to immediate dissolution that occurs. He further explained that at high temperature and pressure CO2 injection can prevent difficulty with injection line and associated injection with two phase flow.
As a result a minimum aquifer depth of 800m is required to sustain supercritical pressure. Pruess et al (2003). This article also talked about several ways where CO2 as a separate phase, is trapped beneath impermeable cap rock. The author made vital point on how two phase flow can be controlled and trapped .To sum it up, if CO2 storage practice is carried out effectively, it would save the environment from greenhouse gases and reduce global warming.
Hajiw, M., Corvisier, J., Ahmar, E.E. and Coquelet, C. (2018), “Impact of impurities on CO2 storage in saline aquifers: Modelling of gases solubility in water”, International Journal of Greenhouse Gas Control, vol. 68, pp. 247-255.Greenhouse gases to the atmosphere could be caused by industrial process or fossil fuel combustion.
The author in this article explained that as fuel gas contains different impurities and the level of concentration depends on the industrial and capture process, hence the need to investigate solubility in water of CO2 became necessary. He went further to explain that if the impurities are not removed, their presence may interfere with thermophysical properties and have great impact on the condition of CO2 storage. The researcher major focus was the solubility of these impurity in water as their presence in fuel gas may change CO2 thermophysical properties (density, viscosity) and phase diagram behaviour. To this effects, for saline aquifer to be considered for CO2 storage, impurities that may impact the conditions of CO2 storage has to be properly studied with different experimental and modelling practice to avoid increasing the salinity of the aquifer thereby resulting to CO2 leakage. Le Guénan, T. and Rohmer, J.
(2011), “Corrective measures based on pressure control strategies for CO2 geological storage in deep aquifers”, International Journal of Greenhouse Gas Control, vol. 5, no. 3, pp. 571-578.In this review, the researcher investigated four different corrective measures which aimed at controlling the over pressure induced by the injection operation in the reservoir and intervention strategies using 2 D layer model. In addition, the author uses a process based on reservoir pressure control. Pressure was lowered at the region at risk when abnormal behaviour arises which shows that the measure present a good effectiveness in case of safety problem.
In view of this article, the undertaken comparison following a cost benefit approach provides basic understanding to support the development of robots best practice of large scale CO2 storage projects as required in recent regulation framework on carbon capture storage operations. My observation from this article is, if the aforementioned measures are fully practised, CO2 storage in saline aquifer would be safer and more economical than any other CO2 storage type. Michael, K., Golab, A., Shulakova, V., Ennis-King, J., Allinson, G., Sharma, S. and Aiken, T.
(2010). “Geological storage of CO2 in saline aquifers-A review of the experience from existing storage operations”, International Journal of Greenhouse Gas Control, vol. 4, no. 4, pp. 659-667.In this article, the author critically reviewed a detailed examination of data from existing saline aquifer storage site and pilot project; provision of database for available reservoir properties (e.g lithology, porosity, permeability, injectivity etc), to know if existing storage options have range of reservoir characteristics or if specific aquifer requires the future pilot project.
The author in addition compared and assessed monitoring technology of both methods. From the results obtained, the experience from CO2 injection at pilot project and existing commercial operations, shows that CO2 geological storage in saline aquifer is technological feasible. To sum it up, this article relates to CO2 storage in saline aquifer, as it’s geologically feasible to store CO2 and prevent or limit greenhouse gases emission. Morozova, D., Wandrey, M., Alawi, M., Zimmer, M., Vieth, A., Zettlitzer, M., Würdemann, (2010) “Monitoring of the microbial community composition in saline aquifers during CO2 storage by fluorescence in situ hybridisation”, International Journal of Greenhouse Gas Control, vol.
4, no. 6, pp. 981-989.This paper introduced monitoring of the microbial community composition in saline aquifer during CO2 storage, elaborate on monitoring during CO2 injection by using fluorescence in situ hybridisation. He also underlined bacteria populations and activity, can strongly be influenced by changes in pressure, temperature, PH value, salinity and other biotic factors which CO2 injection in saline aquifer can be influenced.
I find this article useful because, since microorganisms represent very effective geochemical catalyst, proper investigation of their distribution could be of great importance for the process of CO2 storage. To sum it up, the graphical interpretation of experiment carried out on number of active bacteria cell, probe specific count relative to number of active bacteria cells makes this paper very useful. Soroush, M. et al (2014). “Investigating residual trapping in CO2 storage in saline aquifers – application of a 2D glass model, and image analysis”, Energy Science & Engineering, vol. 2, no.
3, pp. 149-163In this article after CO2 is injected into aquifer formations, it is trapped into the reservoir through various mechanisms, where each trapping mechanism generally has a different timescale. At the start of the injection period, a structural or geological mechanism dominates, where CO2 is trapped below a sealing cap rock. CO2 is trapped in pore space during the movement of CO2 upward or along dipping barrier when brine imbibe the formation This phase of trapping happens very quickly as the porous rock act like a tigh sponge.
This article identified one of the trapping mechanisms for CO2 storage in saline aquifer. For CO2 to be stored into saline aquifers, the aquifer porosity and permeability must be considered in other to avoid CO2 leakage into water; which can result to water pollution thereby killing aquatic organisms Zeidouni, M. and Pooladi-Darvish, M. (2012).
“Leakage characterization through above-zone pressure monitoring: 2—Design considerations with application to CO2 storage in saline aquifers”, Journal of Petroleum Science and Engineering, vol. 98-99, pp. 69-82.This paper talks about possible CO2 leakage in saline aquifer and how it can be monitored to prevent CO2 water pollution. Since cap rocks overlying the aquifer may include leakage pathways that permit the injected fluids to leak to the subsurface formation, detection of such pathway from storage formation to overlying formation becomes necessary.
From the research carried out, the author uses analysis of the pressure data at a single monitoring well, in response to the injection at a constant rate through single injection well; which show that leakage characterized based on pressure measurement maybe difficult. The author used the strategies which include increasing pressure sampling frequency, use of pulsing, and increasing the number of monitoring to show that with proper CO2 trapping system and monitoring system, CO2 leakage can be totally prevented.
