Impact of Wettability on CO2 Mineral Trapping in Carbonate Saline Aquifers: A Reactive Transport Simulation Study Reza Khoramian, Ibraheem Salaudeen, Peyman Pourafshary, Masoud Riazi, Riyaz Kharrat Greenhouse Gases Science and Technology, 2026 Long‐term containment of CO 2 in geological formations depends on both physical and chemical trapping mechanisms. Although capillary and solubility trapping have been widely studied, the role of reservoir wettability in governing geochemical interactions remains poorly understood, particularly in reactive carbonate systems. This study investigates how contrasting wetting states influence multiphase flow and mineralization in carbonate saline aquifers. Reactive transport simulations were conducted using a compositional simulator under water‐ and CO 2 ‐wet conditions over a 60‐year period. The model incorporates hysteresis in relative permeability, capillary pressure variation, and calcite reaction kinetics to evaluate the evolution of capillary, solubility, and mineral trapping mechanisms. Results show that wettability strongly affects both phase distribution and geochemical reactivity. Under CO 2 ‐wet conditions, mineral trapping more than doubled compared to the water‐wet case (6.5% vs. 2.8%) due to enhanced gas–rock contact and sustained local acidification. Solubility trapping also increased markedly (38.3% vs. 20.9%), facilitated by continuous CO 2 pathways that improved convective mass transfer. However, capillary trapping was significantly lower, resulting in reduced total retention (63.5%) compared to the water‐wet scenario (84.9%), where capillary forces immobilized more CO 2 but restricted mineralization. This analysis demonstrates that wettability directly influences geochemical reactions by controlling CO 2 access to mineral surfaces and shaping local pH conditions. The findings suggest that selectively adjusting wettability, depending on reservoir lithology and storage goals, may enhance long‐term CO 2 immobilization through mineral trapping without compromising containment.
Nanobiocatalytic upgrading of heavy oil using Geobacillus stearothermophilus and alumina nanoparticles Ali Maghzi, Arezou Jafari, Seyyed Mohammad Mousavi, Riyaz Kharrat Rsc Advances, 2026 We undertook the analyses to demonstrate the simultaneous application of Geobacillus stearothermophilus and nano alumina in heavy oil upgrading. It could be applied to environmental and technical industrial applications.
Polymer Flooding in Space-Constrained Reservoirs: Technical and Economic Assessment of Liquid vs. Powder Polymers Muhammad Tahir, Rafael E. Hincapie, Dominic Marx, Dominik Steineder, Amir Farzaneh, Torsten Clemens, Nikola Baric, Elham Ghodsi, Riyaz Kharrat Polymers, 2025 This study evaluates the technical and economic feasibility of liquid polymer emulsions as substitutes for powder polymers in polymer flooding applications, particularly in space-constrained, low-permeability reservoirs in Austria. Rheological tests determined that target viscosities of 20 mPa·s at 20 °C and a shear rate of 7.94 s−1 were achieved using concentrations of 1200 ppm for liquid polymer 1 (LP1), 2250 ppm for liquid polymer 2 (LP2), and 1200–1400 ppm for powder polymers. Injectivity tests revealed that liquid polymers encountered challenges in 60 mD and 300 mD core plugs, with pressure stabilization not achieved at injection rates of 1–2.5 ft/day. Powder polymers demonstrated stable injectivity, with powder polymer 1 (PP1) showing an optimal performance at 10 ft/day and a low residual resistance factor (RRF). Two-phase core floods using PP1 and powder polymer 2 (PP2) at 1 ft/day yielded incremental oil recovery factors of approximately 5%, with a maximum of 8% observed for higher viscosity slugs. Economic analysis indicated that over a 3-year horizon, liquid polymers are 30% cheaper than powder polymer Option 1 but 100% more expensive than Option 2. Over a 10-year horizon, liquid polymers are 50% more expensive than both powder polymer options. Although liquid polymers offer logistical advantages, they are unsuitable for low-permeability reservoirs. Powdered polymers, particularly PP1, are recommended for pilot implementation due to superior injectivity, mechanical stability, and recovery performance.
Atomistic Insights into Ion-Driven Interactions of Calcite/Carbonated Brine/Polar Model Oil: Implications for Carbonated Smart Waterflooding Ali Mirzaalian Dastjerdi, Riyaz Kharrat, Vahid Niasar, Holger Ott Langmuir, 2025 This study investigates the fundamental ion-specific (Na+, Cl-, Mg2+, and SO42-) interactions governing a polar model oil (decane + benzoic acid) at the calcite/carbonated brine interface by adopting a fully atomistic molecular dynamics (MD) simulation. By bridging molecular-scale interactions with macroscopic mechanisms, such as interfacial tension (IFT) reduction, oil viscosity, and wettability changes, this work provides the first direct mechanistic validation of phenomena that have previously been inferred only from experimental observations in carbonated smart water flooding systems. The results demonstrate that enhanced interactions between carboxylic acids and anions at the oil/brine interface significantly influence CO2 diffusion and distribution within the oleic phase, which affects the apparent oil viscosity. While variations in brine ionic composition cause only modest changes in IFT, a pronounced reduction is observed with increased concentrations of polar molecules in the oil phase. Structural analysis reveals that divalent ions (Mg2+, SO42-) are excluded from the hydration layers near the calcite surface but alter the arrangement of Na+ and Cl- ions in the hydration layer covering the calcite surface, thereby influencing wettability. Notably, SO42- neutralizes the calcite surface positive charge and facilitates Mg2+ access to the interface, promoting desorption of benzoic acid (BA) from the surface through the Mg-BA association. This highlights the cooperative role of SO42- and Mg2+ in releasing polar species from the calcite surface. The findings underscore the dominant influence of IFT over contact angle in capillary-driven recovery and show that apparent viscosity is more sensitive to CO2 content and overall salinity than specific ions. Therefore, from an industrial perspective, maintaining seawater-like salinity enriched with divalent ions offers a practical strategy to enhance the mobilization of polar acidic components during carbonated water flooding in carbonate reservoirs, supporting the design of more efficient Enhanced Oil Recovery (EOR) formulations.
Wettability-Driven Variations in CO2 Trapping: Coupled Impact of Capillary Forces and Reactive Transport in Saline Aquifers Reza Khoramian, Ibraheem Salaudeen, Peyman Pourafshary, Masoud Riazi, Riyaz Kharrat Society of Petroleum Engineers SPE Annual Caspian Technical Conference and Exhibition Ctc 2025, 2025 This study quantifies the impacts of wettability on CO2 trapping mechanisms in deep saline aquifers by comparing water-wet and weakly water-wet conditions. Wettability alteration, often triggered by prolonged CO2 exposure and organic acid generation, is widely observed in storage sites and can shift rock surfaces from strongly water-wet to intermediate states. Understanding how such transitions affect fluid behavior and geochemical trapping is essential for long-term storage security. A fine-scale heterogeneous model was developed using a Gaussian distribution and simulated over 200 years, including 5 years of CO2 injection followed by 195 years of post-injection monitoring. Grid sensitivity analysis was conducted to minimize numerical dispersion. Two wettability states were defined using distinct relative permeability and capillary pressure curves. Capillary effects were examined by calculating critical capillary numbers (NCap) that govern the shift between capillary and viscous regimes. Reactive transport modeling in a carbonate reservoir captured the evolution of solubility, residual, and mineral trapping. Results show that wettability exerts a first-order control on CO2 trapping. Incorporating capillary pressure notably enhanced residual trapping, with water-wet systems achieving up to ~80% immobilization, compared to ~55% in the absence of capillary forces. Capillary pressure restricted vertical migration and promoted lateral spreading, especially under water-wet conditions. In weakly water-wet systems, enhanced CO2 mobility facilitated greater dissolution and mineralization by increasing brine contact and lowering pH, thereby mobilizing ions such as Ca2+. Optimal trapping occurred below critical NCap thresholds (~6.31×10-7 for water-wet; ~3.05×10-6 for weakly water-wet), highlighting the importance of rate control. This study demonstrates how wettability shifts influence the balance among trapping mechanisms over time. Recognizing this shift in dominant trapping mechanisms enables better-informed decisions for reservoir management and long-term carbon storage planning. Future research could explore applying these findings to various reservoir types, broadening their impact.
Polymer Qualification for Low Permeability Reservoirs in Austria: Liquid vs. Powder Muhammad Tahir, Dominic Marx, Dominik Steineder, Rafael Hincapie, Torsten Clemens, Amir Farzaneh, Nikola Baric, Elham Ghodsi, Riyaz Kharrat Society of Petroleum Engineers SPE Europe Energy Conference and Exhibition Euro 2025, 2025 Liquid polymer emulsions, a promising alternative to powder polymers, can minimize facility footprint and initial CAPEX. This study evaluates their use in a low permeability, small-sized reservoir in Austria, typically used in high permeability reservoirs. It aims to assess the performance and economic feasibility of liquid versus powder polymers, identifying potential benefits and limitations of liquid polymer emulsions in pilot projects. Rheological measurements were conducted to estimate product consumption needed to achieve the target viscosity of chemical slugs under reservoir conditions. The primary focus for qualifying liquid and powder polymers was on rock-fluid interaction, with an emphasis on injectivity in low permeability core plugs (60 and 300 mD), considering reservoir heterogeneity. Single-phase core floods were performed at injector wellbore conditions. Additionally, two-phase core floods were conducted at deeper reservoir conditions for selected polymers to compare injectivity and assess additional oil recovery. Two liquid and four powder polymers from two vendors were tested. Fluid-fluid interactions were evaluated for emulsion polymers due to the small concentration of surfactants in liquid polymers. Interfacial tension measurements and phase behavior tests concluded that liquid polymers from both vendors are non-reactive with reservoir's crude oil. However, injectivity challenges were observed for liquid polymers from both vendors, indicating that liquid polymers are not suitable for low permeability reservoirs. A critical observation was the continuous increase in injection pressure after the brine flood. Tested powder polymers did not show injectivity issues, suggesting that the emulsion phase in liquid polymers potentially causes filtration or adsorption. Evaluations of powder polymers focused on the resistance factor, residual resistance factor, mechanical degradation, and conditions near the wellbore and deep in the reservoir. This screening process selected one product from each vendor. The powder polymer from vendorA showed higher injection pressure but required a lower concentration to achieve the target viscosity near wellbore conditions. Supplementary two-phase core floods performed at in-situ conditions concluded that both powder polymer products performed similarly in terms of injection pressure and additional oil recovery. Further cost analysis of all available options revealed similar economic results for liquid polymer emulsions and powder polymers. However, limitations for traditional powder polymers include higher intitial CAPEX, the availability of surface facilities and a comparatively larger physical footprint. Our comparative study provides valuable insight that the currently available commercial liquid polymers are not suitable for low permeability reservoirs, making powder polymers the only viable option. Furthermore, communication with vendors has highlighted the need to develop new liquid polymers specifically for small-scale, low permeability onshore reservoirs. Liquid polymers would have a beneficial impact on initial CAPEX investments for surface facilities, but the total costs are 50 % higher after 10-year project lifespan.
Experimental and numerical study of vapor extraction process (VAPEX) in heavy oil fractured reservoir Canadian International Petroleum Conference 2008, 2018
Experimental study of solvent flooding to heavy oil in fractured 5-spot micromodels: The role of fracture geometrical characteristics Canadian International Petroleum Conference 2008, 2018
An experimental and simulation study of asphaltene-lnduced permeability impairment under natural depletion condition SPE European Formation Damage Conference Proceedings Efdc, 2013
Investigation of effective mechanisms in permeability reduction due to asphaltene deposition through porous media SPE European Formation Damage Conference Proceedings Efdc, 2013
Simulation and analysis of production induced reservoir compaction using geomechanical formulation of fracturing technology (GFFT) for stress prediction Society of Petroleum Engineers International Petroleum Technology Conference 2012 Iptc 2012, 2012
The performance evaluation of viscous-modified surfactant waterflooding in heavy oil reservoirs at varying salinity of injected polymer-contained surfactant solution Iranian Journal of Chemistry and Chemical Engineering, 2012
A comprehensive eor study of a highly fractured matured field-Case study (SPE 153311) 74th European Association of Geoscientists and Engineers Conference and Exhibition 2012 Incorporating SPE Europec 2012 Responsibly Securing Natural Resources, 2012
Multi-scale analysis of gamma ray and resistivity logs as a new approach for early flow units identification Saint Petersburg 2012 Geosciences Making the Most of the Earth S Resources, 2012
Asphaltene deposition study and its effects on permeability reduction - A case study (SPE 153512) 74th European Association of Geoscientists and Engineers Conference and Exhibition 2012 Incorporating SPE Europec 2012 Responsibly Securing Natural Resources, 2012
On the effect of silica nanoparticles on wettability alteration during water flooding to heavy oils-A micromodel study 74th European Association of Geoscientists and Engineers Conference and Exhibition 2012 Incorporating SPE Europec 2012 Responsibly Securing Natural Resources, 2012
Investigation of top-down in-situ combustion process in complex fractured carbonate models: Effects of fractures' geometrical properties Society of Petroleum Engineers Canadian Unconventional Resources Conference 2011 Curc 2011, 2011
Experimental studies of cationic surfactant adsorption onto carbonate rocks Australian Journal of Basic and Applied Sciences, 2011
New method of generating approximation profile of highly noisy wireline logs through utilizing wavelet non-parametric regression Society of Petroleum Engineers Nigeria Annual International Conference and Exhibition 2011, 2011
Investigation of Steam Assisted Gravity Drainage (SAGD) and Expanding Solvent-SAGD (ES-SAGD) processes in complex fractured models: Effects of fractures' geometrical properties Society of Petroleum Engineers SPE International Heavy Oil Conference and Exhibition 2011, 2011
Identifying reservoir zones of Iranian formations through integrating wireline logs in time-scale space 73rd European Association of Geoscientists and Engineers Conference and Exhibition 2011 Unconventional Resources and the Role of Technology Incorporating SPE Europec 2011, 2011
Iterative coupled experimental-numerical evaluation of dispersivity in fractured porous media using micromodel system 73rd European Association of Geoscientists and Engineers Conference and Exhibition 2011 Unconventional Resources and the Role of Technology Incorporating SPE Europec 2011, 2011
Novel approach to mitigate gas production in a high GOR carbonate reservoir with drilled wells - Case study SPE Production and Operations Symposium Proceedings, 2010
A mechanistic analysis of viscous fingering in low-tension polymer flooding in heavy-oil reservoirs SPE Latin American and Caribbean Petroleum Engineering Conference Proceedings, 2010
Dynamic modeling and optimization of asphaltene deposition in reservoir rocks using genetic algorithm 72nd European Association of Geoscientists and Engineers Conference and Exhibition 2010 A New Spring for Geoscience Incorporating SPE Europec 2010, 2010
Quantitative analysis of ultrasonic wave radiation on reversibility and kinetics of asphaltene flocculation 4th International Conference and Exhibition New Discoveries Through Integration of Geosciences Saint Petersburg 2010, 2010
Integration of gustafson-kessel algorithm and ohonen's self-organizing maps for unsupervised clustering of seismic attributes Journal of Seismic Exploration, 2009
Integration of 3D seismic attributes and well logs for electrofacies mapping and prediction of reliable petrophysical properties Society of Petroleum Engineers Europec Eage Conference and Exhibition 2009, 2009
Experimental investigation of wettability effect on co-solvent flooding of heavy oil reservoirs Tunis 2009 4th North African Mediterranean Petroleum and Geosciences Conference and Exhibition, 2009
Simulation study of Conventional Fire Flooding (CFF) in fractured combustion cells: A promising tool along experiment 1st International Petroleum Conference and Exhibition, 2009
Prediction of asphaltene precipitation during gas injection in heavy crude using micellization model with a new approach 71st European Association of Geoscientists and Engineers Conference and Exhibition 2009 Balancing Global Resources Incorporating SPE Europec 2009, 2009
Investigating the effect of co-solvents on heavy oil recovery in different pore geometries using five-spot micromodels 15th European Symposium on Improved Oil Recovery 2009, 2009
Effect of pressure and CO2 composition changes on distribution of asphaltene molecular weight in heavy crude oil Canadian International Petroleum Conference 2009 Cipc 2009, 2009
Experimental investigation of effect of depletion rates on recovery of a heavy oil reservoir 15th European Symposium on Improved Oil Recovery 2009, 2009
The role of connate water saturation in VAPEX process Journal of Canadian Petroleum Technology, 2008
Effect of heterogeneity of layered reservoirs on polymer flooding: An experimental approach using five-spot glass micromodel 70th European Association of Geoscientists and Engineers Conference and Exhibition 2008 Leveraging Technology Incorporating SPE Europec 2008, 2008
Prediction of permeability reduction rate due to calcium sulfate scale formation in porous media SPE Middle East Oil and Gas Show and Conference Meos Proceedings, 2007
Feasibility study of in-situ combustion in a carbonate reservoir SPE Middle East Oil and Gas Show and Conference Meos Proceedings, 2007
Experimental and computer based simulation study of WAG process Chisa 2006 17th International Congress of Chemical and Process Engineering, 2006
Capillary pressure estimation of porous media using statistical pore size function Chisa 2006 17th International Congress of Chemical and Process Engineering, 2006
Relative permeability estimation of porous media: Comparison of implicit and explicit approaches Chisa 2006 17th International Congress of Chemical and Process Engineering, 2006
Feasibility study of autoignition process in heavy-oil reservoirs SPE PS CIM Choa International Thermal Operations and Heavy Oil Symposium Proceedings, 2005
