Engineering Commons^™

Sandstone Wettability And Mixed Gas Composition: Unraveling The Impact Of Co2 In Hydrogen Geo-Storage, Zoha D. Isfehani, Amirmansour J. Jafari, Jalal Fahimpour, Mirhasan Hosseini, Stefan Iglauer, Alireza Keshavarz

Research outputs 2022 to 2026

Underground hydrogen storage (UHS) is gaining interest as a secure, long-term solution for storing hydrogen in porous geological formations. In UHS, a cushion gas like CO2 is crucial to maintain the reservoir pressure and optimize recovery. The concept of wettability plays a fundamental role in determining the system's multi-phase displacement characteristics in the porous media. However, there is a gap in the existing literature regarding the wettability of sandstone rocks under geo-storage conditions when H2 and CO2 are injected as the bulk and cushion gases, respectively. To address this gap, we conducted a study investigating the wettability hysteresis phenomenon by …

Enhancing Wettability Prediction In The Presence Of Organics For Hydrogen Geo-Storage Through Data-Driven Machine Learning Modeling Of Rock/H2/Brine Systems, Zeeshan Tariq, Muhammad Ali, Nurudeen Yekeen, Auby Baban, Bicheng Yan, Shuyu Sun, Hussein Hoteit

Research outputs 2022 to 2026

The success of geological H2 storage relies significantly on rock–H2–brine interactions and wettability. Experimentally assessing the H2 wettability of storage/caprocks as a function of thermos-physical conditions is arduous because of high H2 reactivity and embrittlement damages. Data-driven machine learning (ML) modeling predictions of rock–H2–brine wettability are less strenuous and more precise. They can be conducted at geo-storage conditions that are impossible or hazardous to attain in the laboratory. Thus, ML models were utilized in this research to accurately model the wettability behavior of a ternary system consisting of H2, rock minerals (quartz and mica), and brine at different operating geological …

Effect Of Methylene Blue On Wetting Characteristics Of Quartz/H2/Brine Systems: Implication For Hydrogen Geological Storage, Fatemah Alhamad, Mujahid Ali, Nurudeen P. Yekeen, Muhammad Ali, Hussein Hoteit, Stefan Iglauer, Alireza Keshavarz

Research outputs 2022 to 2026

Hydrogen (H2) is considered a promising replacement for fossil fuels due to its enormous potential as an environmentally friendly and sustainable option compared to carbon-based fossil fuels. However, storing the vast quantity of H2 required to satisfy the global energy demand on the earth's surface can be difficult due to its compressibility and volatility. The best option for large-scale storage is underground H2 storage (UHS), which can be retrieved when needed. Rock wettability is vital in UHS because it determines the H2 storage capacity, containment security, and potential withdrawal and injection rates. Organic acid inherent in storage formations could make …

Micro-Scale Wettability Of Carbonate Rocks Via High-Resolution Esem Imaging, Khaloud Al-Naimi, Muhammad Arif, Mahmoud Aboushanab, Dalaver Anjum, Mohammed Al Kobaisi, Md Motiur Rahman, Mohamed Mahmoud, Stefan Iglauer

Research outputs 2022 to 2026

The wettability of several materials has been traditionally quantified using macro-scale contact angles. However, precise identification of the three-phase contact (TPC) line is often difficult due to the resolution limit of macro-scale setups. Moreover, micro-level surface chemical heterogeneities can have a notable impact on the predicted wetting behavior which limits macro-scale contact angles. Thus, here, we investigate the micro-scale water wettability of condensed micro-droplets on carbonate rock surfaces via a high-resolution Environmental Scanning Electron Microscopy (ESEM). Macro- and micro-scale contact angles were evaluated under three conditions: 1) natural carbonate surfaces, 2) surfaces aged in crude oil, and 3) surfaces aged …

Influence Of Organics And Gas Mixing On Hydrogen/Brine And Methane/Brine Wettability Using Jordanian Oil Shale Rocks: Implications For Hydrogen Geological Storage, Amer Alanazi, Nurudeen Yekeen, Mujahid Ali, Muhammad Ali, Israa S. Abu-Mahfouz, Alireza Keshavarz, Stefan Iglauer, Hussein Hoteit

Research outputs 2022 to 2026

The substitution of fossil fuel with clean hydrogen (H₂) has been identified as a promising route to achieve net zero carbon emissions by this century. However, enough H₂ must be stored underground at an industrial scale to achieve this objective due to the low volumetric energy density of H₂. In underground H₂ storage, cushion gases, such as methane (CH₄), are required to maintain a safe operational formation pressure during the withdrawal or injection of H₂. The wetting characteristics of geological formations in the presence of H₂, cushion gas, …

A Review Of Hydrogen/Rock/Brine Interaction: Implications For Hydrogen Geo-Storage, Masoud Aslannezhad, Muhammad Ali, Azim Kalantariasl, Mohammad Sayyafzadeh, Zhenjiang You, Stefan Iglauer, Alireza Keshavarz

Research outputs 2022 to 2026

Hydrogen (H₂) is currently considered a clean fuel to decrease anthropogenic greenhouse gas emissions and will play a vital role in climate change mitigation. Nevertheless, one of the primary challenges of achieving a complete H₂ economy is the large-scale storage of H₂, which is unsafe on the surface because H₂ is highly compressible, volatile, and flammable. Hydrogen storage in geological formations could be a potential solution to this problem because of the abundance of such formations and their high storage capacities. Wettability plays a critical role in the displacement of formation water and determines …

Using Magnesium Oxide Nanoparticles In A Magnetic Field To Enhance Oil Production From Oil-Wet Carbonate Reservoirs, F. Amrouche, M. J. Blunt, Stefan Iglauer, M. Short, T. Crosbie, E. Cordero, D. Xu

Research outputs 2022 to 2026

Enhanced oil production can maximise yield from depleted reservoirs, and in the face of dwindling global oil reserves can reduce the need for exploratory drilling during the transition away from fossil fuels. A hybrid technique, merging a magnetic field (MF) and magnesium oxide (MgO) nanoparticles (NPs), was investigated as a potential method of enhancing oil production from oil-wet carbonate reservoirs. The impact of this hybrid technique on rock wettability, zeta potential, and interfacial tension was also investigated. Displacement experiments were carried out on oil-wet Austin chalk – a laboratory carbonate rock analogue – using MgO NPs in deionized water (DW) …

Live Imaging Of Micro And Macro Wettability Variations Of Carbonate Oil Reservoirs For Enhanced Oil Recovery And Co/ Trapping/Storage, Anastasia Ivanova, A. Orekhov, S. Markovic, Stefan Iglauer, P. Grishin, A. Cheremisin

Research outputs 2022 to 2026

Carbonate hydrocarbon reservoirs are considered as potential candidates for chemically enhanced oil recovery and for CO² geological storage. However, investigation of one main controlling parameter—wettability—is usually performed by conventional integral methods at the core-scale. Moreover, literature reports show that wettability distribution may vary at the micro-scale due to the chemical heterogeneity of the reservoir and residing fluids. These differences may profoundly affect the derivation of other reservoir parameters such as relative permeability and capillary pressure, thus rendering subsequent simulations inaccurate. Here we developed an innovative approach by comparing the wettability distribution on carbonates at micro and macro-scale by combining live-imaging …

Fluid–Rock Interactions And Its Implications On Eor: Critical Analysis, Experimental Techniques And Knowledge Gaps, Abubakar Isah, Muhammad Arif, Amjed Hassan, Mohamed Mahmoud, Stefan Iglauer

Research outputs 2022 to 2026

Characterization of fluid–rock interactions is essential for a broad range of subsurface applications such as understanding fluid flow in porous medium and enhanced oil recovery predictions. Enhanced oil recovery (EOR) is crucial in oil and gas production operations, it entails injecting fluids into the reservoir to enhance productivity. When fluids are injected, interactions occur between the injected fluids and the reservoir rock/fluids; and the outcomes of fluid–rock interactions critically impact the fluid flow in porous medium and the associated oil recovery. Furthermore, the associated changes in reservoir properties (porosity, permeability etc.) and flow behavior (i.e. wettability alteration and relative permeability …

Contact Angles Of A Brine On A Bituminous Coal In Compressed Hydrogen, Rossen Sedev, Hamed Akhondzadeh, Mujahid Ali, Alireza Keshavarz, Stefan Iglauer

Research outputs 2022 to 2026

Hydrogen storage is a main issue in the establishment of a hydrogen economy. Geo-storage could be a viable solution if hydrogen could be injected into and withdrawn from suitable geological formations, reversibly and reliably. Rock wettability is a major factor as it affects injectivities, withdrawal rates, storage capacities, and containment security. We report here the contact angles of a brine on the surface of a bituminous coal in a pressurized hydrogen atmosphere. Under realistic geo-storage conditions the coal surface was weakly water-wet. Hydrogen pressure increased brine contact angles at 25°C but did not have an impact at 50 or 70°C. …

Assessment Of Wettability And Rock-Fluid Interfacial Tension Of Caprock: Implications For Hydrogen And Carbon Dioxide Geo-Storage, Muhammad Ali, Bin Pan, Nurudeen Yekeen, Sarmad Al-Anssari, Amer Al-Anazi, Alireza Keshavarz, Stefan Iglauer, Hussein Hoteit

Research outputs 2022 to 2026

Underground hydrogen (H2) storage (UHS) and carbon dioxide (CO2) geo-storage (CGS) are prominent methods of meeting global energy needs and enabling a low-carbon global economy. The pore-scale distribution, reservoir-scale storage capacity, and containment security of H2 and CO2 are significantly influenced by interfacial properties, including the equilibrium contact angle (θE) and solid-liquid and solid-gas interfacial tensions (γSL and γSG). However, due to the technical constraints of experimentally determining these parameters, they are often calculated based on advancing and receding contact angle values. There is a scarcity of θE, γSL, and γSG data, particularly related to the hydrogen structural sealing potential …

Influence Of Organic Molecules On Wetting Characteristics Of Mica/H2/Brine Systems: Implications For Hydrogen Structural Trapping Capacities, Muhammad Ali, Nurudeen Yekeen, Nilanjan Pal, Alireza Keshavarz, Stefan Iglauer, Hussein Hoteit

Research outputs 2022 to 2026

Hypothesis:

Actualization of the hydrogen (H₂) economy and decarbonization goals can be achieved with feasible large-scale H₂ geo-storage. Geological formations are heterogeneous, and their wetting characteristics play a crucial role in the presence of H₂, which controls the pore-scale distribution of the fluids and sealing capacities of caprocks. Organic acids are readily available in geo-storage formations in minute quantities, but they highly tend to increase the hydrophobicity of storage formations. However, there is a paucity of data on the effects of organic acid concentrations and types on the H₂-wettability of caprock-representative minerals and …

Recent Advances In Carbon Dioxide Geological Storage, Experimental Procedures, Influencing Parameters, And Future Outlook, Muhammad Ali, Nilesh Kumar Jha, Nilanjan Pal, Alireza Keshavarz, Hussein Hoteit, Mohammad Sarmadivaleh

Research outputs 2022 to 2026

The oxidation of fossil fuels produces billions of tons of anthropogenic carbon dioxide (CO₂) emissions from stationary and nonstationary sources per annum, contributing to global warming. The natural carbon cycle consumes a portion of CO₂ emissions from the atmosphere. In contrast, substantial CO₂ emissions accumulate, making it the largest contributor to greenhouse gas emissions and causing a rise in the planet's temperature. The Earth's temperature was estimated to be 1 °C higher in 2017 compared to the mid-twentieth century. A solution to this problem is CO₂ storage in underground formations, abundant throughout the world. Millions …

Optimum Geological Storage Depths For Structural H2 Geo-Storage, Stefan Iglauer

Research outputs 2022 to 2026

H₂ geo-storage has been suggested as a key technology with which large quantities of H₂ can be stored and withdrawn again rapidly. One option which is currently explored is H₂ storage in sedimentary geologic formations which are geographically widespread and potentially provide large storage space. The mechanism which keeps the buoyant H₂ in the subsurface is structural trapping where a caprock prevents the H₂ from rising by capillary forces. It is therefore important to assess how much H₂ can be stored via structural trapping under given geo-thermal conditions. This structural trapping capacity is thus …

Influence Of Pressure, Temperature And Organic Surface Concentration On Hydrogen Wettability Of Caprock, Implications For Hydrogen Geo-Storage, Muhammad Ali, Nurudeen Yekeen, Nilanjan Pal, Alireza Keshavarz, Stefan Iglauer, Hussein Hoteit

Research outputs 2014 to 2021

Hydrogen (H₂) as a cleaner fuel has been suggested as a viable method of achieving the de-carbonization objectives and meeting increasing global energy demand. However, successful implementation of a full-scale hydrogen economy requires large-scale hydrogen storage (as hydrogen is highly compressible). A potential solution to this challenge is injecting hydrogen into geologic formations from where it can be withdrawn again at later stages for utilization purposes. The geo-storage capacity of a porous formation is a function of its wetting characteristics, which strongly influence residual saturations, fluid flow, rate of injection, rate of withdrawal, and containment security. However, literature …

Co2-Wettability Reversal Of Cap-Rock By Alumina Nanofluid: Implications For Co2 Geo-Storage, Muhammad Ali, Adnan Aftab, Faisal Ur Rahman Awan, Hamed Akhondzadeh, Alireza Keshavarz, Ali Saeedi, Stefan Iglauer, Mohammad Sarmadivaleh

Research outputs 2014 to 2021

© 2021 Elsevier B.V. The usage of nanofluids is vast in different applications of nano-energy. These minute nanoparticles can be used to alter the hydrophobicity into hydrophilicity for CO2-brine-mineral systems in the presence of organic acids. Nonetheless, the literature lacks the information for the behavior of nanoparticles and its associated concentrations in the presence of organic acids at the reservoir (high temperature and high pressure) conditions. In this study, we have investigated that how different alkyl chain organic acids impact the wettability of mica muscovite for different ageing times (7 days and one year) and how this impact can be …

Effect Of Humic Acid On Co2-Wettability In Sandstone Formation, Mujahid Ali, Faisal Ur Rahman Awan, Muhammad Ali, Ahmed Al-Yaseri, Muhammad Arif, Mónica Sánchez-Román, Alireza Keshavarz, Stefan Iglauer

Research outputs 2014 to 2021

© 2020 Elsevier Inc. Hypothesis: Millions of tons of CO2 are stored in CO2 geological storage (CGS) formations (depleted oil reservoirs and deep saline aquifers) every year. These CGS formations naturally contain small concentrations of water-soluble organic components in particular humic acid (HA), which may drastically affect the rock wettability - a significant factor determining storage capacities and containment security. Hence, it is essential to characterise the effect of humic acid concentration on CO2-wettability and its associated impact on storage capacity. Experimental: To achieve this, we measured advancing and receding contact angles at reservoir conditions using the pendant drop tilted …

Effect Of Co2 Flooding On The Wettability Evolution Of Sand-Stone, Cut Aja Fauziah, Ahmed Al-Yaseri, Emad Al-Khdheeawi, Nilesh Kumar Jha, Hussein R. Abid, Stefan Iglauer, Christopher Lagat, Ahmed Barifcani

Research outputs 2014 to 2021

Wettability is one of the main parameters controlling CO₂ injectivity and the movement of CO₂ plume during geological CO₂ sequestration. Despite significant research efforts, there is still a high uncertainty associated with the wettability of CO₂/brine/rock systems and how they evolve with CO₂ exposure. This study, therefore, aims to measure the contact angle of sandstone samples with varying clay content before and after laboratory core flooding at different reservoir pressures, of 10 MPa and 15 MPa, and a temperature of 323 K. The samples’ microstructural changes are also assessed to investigate any potential alteration …

Shale Adhesion Force Measurements Via Atomic Force Microscopy, Nikolai Mitiurev, Michael Verrall, Svetlana Shilobreeva, Alireza Keshavarz, Stefan Iglauer

Research outputs 2014 to 2021

Wettability of sedimentary rock surface is an essential parameter that defines oil recovery and production rates of a reservoir. The discovery of wettability alteration in reservoirs, as well as complications that occur in analysis of heterogeneous sample, such as shale, for instance, have prompted scientists to look for the methods of wettability assessment at nanoscale. At the same time, bulk techniques, which are commonly applied, such as USBM (United States Bureau of Mines) or Amott tests, are not sensitive enough in cases with mixed wettability of rocks as they provide average wettability values of a core plug. Atomic Force Microscopy …

Co2 – Brine – Sandstone Wettability Evaluation At Reservoir Conditions Via Nuclear Magnetic Resonance Measurements, Auby Baban, Ahmed Al-Yaseri, Alireza Keshavarz, R. Amin, Stefan Iglauer

Research outputs 2014 to 2021

CO₂-rock wettability is a key parameter which governs CO₂ trapping capacities and containment security in the context of CO₂ geo-sequestration schemes. However, significant uncertainties still exist in terms of predicting CO₂ rock wettability at true reservoir conditions. This study thus reports on wettability measurements via independent Nuclear Magnetic Resonance (NMR) experiments on sandstone (CO₂–brine systems) to quantify Wettability Indices (WI) using the United States Bureau of Mines (USBM) scale. The results show that CO₂ (either molecularly dissolved or as a separate supercritical phase) significantly reduced the hydrophilicity of the sandstone from strongly …

Improving Basalt Wettability To De-Risk Co2 Geo-Storage In Basaltic Formations, Stefan Iglauer, Ahmed Al-Yaseri

Research outputs 2014 to 2021

CO₂ geo-storage in basaltic formations has recently been identified as a viable option to rapidly dispose large quantities of CO₂, hence mitigating anthropogenic CO₂ emissions. However, it has been shown that basalt is weakly water-wet or intermediate-wet at typical storage conditions, which reduces capillary trapping capacities and increases lateral and vertical spreading of the CO₂ plume; and these effects increase project risk. We thus propose here to prime basalt surfaces with anionic surfactant (here we used sodium dodecyl benzene sulfonate), and demonstrate that such priming is highly efficient, and renders the basalt completely water-wet even …

Experimental Investigation Of The Effect Of Vitagnus Plant Extract On Enhanced Oil Recovery Process Using Interfacial Tension (Ift) Reduction And Wettability Alteration Mechanisms, Seyed Ramin Mousavi Dashtaki, Jagar A. Ali, Abbas Khaksar Manshad, Iman Nowrouzi, Amir H. Mohammadi, Alireza Keshavarz

Research outputs 2014 to 2021

© 2020, The Author(s). Surfactant flooding is a chemical enhanced oil recovery (cEOR) process wherein anionic, cationic, non-ionic, and amphoteric surfactants are injected into oil reservoirs to produce more hydrocarbon. These chemical and industrial agents might cause some economic and environmental challenges. Recently, injection of natural surfactants, as new environmentally friendly EOR agents, for improving oil recovery has been proposed by researchers. In this study, the extract of Vitagnus, a natural surfactant, was used to minimize the interfacial tension (IFT) and alter the rock wettability towards the strong water-wet system, thereby improving the oil recovery from the carbonate rock The …

In Situ Wettability Investigation Of Aging Of Sandstone Surface In Alkane Via X-Ray Microtomography, Nilesh Kumar Jha, Maxim Lebedev, Stefan Iglauer, Jitendra S. Sangwai, Mohammad Sarmadivaleh

Research outputs 2014 to 2021

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Wettability of surfaces remains of paramount importance for understanding various natural and artificial colloidal and interfacial phenomena at various length and time scales. One of the problems discussed in this work is the wettability alteration of a three-phase system comprising high salinity brine as the aqueous phase, Doddington sandstone as porous rock, and decane as the nonaqueous phase liquid. The study utilizes the technique of in situ contact angle measurements of the several 2D projections of the identified 3D oil phase droplets from the 3D images of the saturated sandstone miniature …

Basalt-Co2-Brine Wettability At Storage Conditions In Basaltic Formations, Stefan Iglauer, Ahmed Zarzor Al-Yaseri, Domenik Wolff-Boenisch

Research outputs 2014 to 2021

© 2020 Elsevier Ltd CO2 geo-storage in basaltic formations has recently been demonstrated as a viable solution to rapidly sequester and mineralize CO2. In case CO2 is injected into such basalt reservoirs in supercritical form, a two-phase system (reservoir brine and supercritical CO2) is created, and it is of key importance to specify the associated CO2-basalt wettability so that fluid distributions and CO2 flow through the reservoir can be predicted. However, there is a serious lack of data for basalt CO2-wettability. We therefore measured water contact angles on basalt substrates in CO2 atmosphere. The results indicate that at shallow depth …

Reversible And Irreversible Adsorption Of Bare And Hybrid Silica Nanoparticles Onto Carbonate Surface At Reservoir Condition, Zain-Ul-Abedin Arain, Sarmad Al-Anssari, Muhammad Ali, Shoaib Memon, Masood Ahmed Bhatti, Christopher Lagat, Mohammad Sarmadivaleh

Research outputs 2014 to 2021

© 2020 Southwest Petroleum University Realistic implementation of nanofluids in subsurface projects including carbon geosequestration and enhanced oil recovery requires full understanding of nanoparticles (NPs) adsorption behaviour in the porous media. The physicochemical interactions between NPs and between the NP and the porous media grain surface control the adsorption behavior of NPs. This study investigates the reversible and irreversible adsorption of silica NPs onto oil-wet and water-wet carbonate surfaces at reservoir conditions. Each carbonate sample was treated with different concentrations of silica nanofluid to investigate NP adsorption in terms of nanoparticles initial size and hydrophobicity at different temperatures, and pressures. …

Experimental Investigation Into L-Arg And L-Cys Eco-Friendly Surfactants In Enhanced Oil Recovery By Considering Ift Reduction And Wettability Alteration, Hamed Foroughi Asl, Ghasem Zargar, Abbas Khaksar Manshad, Mohammad Ali Takassi, Jagar A. Ali, Alireza Keshavarz

Research outputs 2014 to 2021

Surfactant flooding is an important technique used to improve oil recovery from mature oil reservoirs due to minimizing the interfacial tension (IFT) between oil and water and/or altering the rock wettability toward water-wet using various surfactant agents including cationic, anionic, non-ionic, and amphoteric varieties. In this study, two amino-acid based surfactants, named lauroyl arginine (l-Arg) and lauroyl cysteine (l-Cys), were synthesized and used to reduce the IFT of oil–water systems and alter the wettability of carbonate rocks, thus improving oil recovery from oil-wet carbonate reservoirs. The synthesized surfactants were characterized using Fourier transform infrared spectroscopy and nuclear magnetic resonance analyses, …

Effect Of Environment-Friendly Non-Ionic Surfactant On Interfacial Tension Reduction And Wettability Alteration; Implications For Enhanced Oil Recovery, Omid Mosalman Haghighi, Ghasem Zargar, Abbas Khaksar Manshad, Muhammad Ali, Mohammad Ali Takassi, Jagar A. Ali, Alireza Keshavarz

Research outputs 2014 to 2021

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Production from mature oil reservoirs can be optimized by using the surfactant flooding technique. This can be achieved by reducing oil and water interfacial tension (IFT) and modifying wettability to hydrophilic conditions. In this study, a novel green non-ionic surfactant (dodecanoyl-glucosamine surfactant) was synthesized and used to modify the wettability of carbonate reservoirs to hydrophilic conditions as well as to decrease the IFT of hydrophobic oil-water systems. The synthesized non-ionic surfactant was characterized by Fourier transform infrared spectroscopy (FTIR) and chemical shift nuclear magnetic resonance (HNMR) analyses. Further pH, turbidity, density, …

Local Instabilities During Capillary-Dominated Immiscible Displacement In Porous Media, Yang Liu, Stefan Iglauer, Jianchao Cai, Mohammad A. Amooie, Chaozhong Qin

Research outputs 2014 to 2021

Fully understanding the mechanism of pore-scale immiscible displacement dominated by capillary forces, especially local instabilities and their influence on flow patterns, is essential for various industrial and environmental applications such as enhanced oil recovery, CO₂ geo-sequestration and remediation of contaminated aquifers. It is well known that such immiscible displacement is extremely sensitive to the fluid properties and pore structure, especially the wetting properties of the porous medium which affect not only local interfacial instabilities at the micro-scale, but also displacement patterns at the macro-scale. In this review, local interfacial instabilities under three typical wetting conditions, namely Haines jump events …

Co 2 -Wettability Of Sandstones Exposed To Traces Of Organic Acids: Implications For Co 2 Geo-Storage, Muhammad Ali, Muhammad Arif, Muhammad Faraz Sahito, Sarmad Al-Anssari, Alireza Keshavarz, Ahmed Barifcani, Linda Stalker, Mohammad Sarmadivaleh, Stefan Iglauer

Research outputs 2014 to 2021

Wettability of CO 2 -brine-mineral systems plays a vital role during geological CO 2 -storage. Residual trapping is lower in deep saline aquifers where the CO 2 is migrating through quartz rich reservoirs but CO 2 accumulation within a three-way structural closure would have a high storage volume due to higher CO 2 saturation in hydrophobic quartz rich reservoir rock. However, such wettability is only poorly understood at realistic subsurface conditions, which are anoxic or reducing. As a consequence of the reducing environment, the geological formations (i.e. deep saline aquifers) contain appreciable concentrations of various organic acids. We thus demonstrate …