Mohammad Nooraiepour

• Hellevang, Helge; Nooraiepour, Mohammad; Sednev-Lugovets, Anton & Dziadkowiec, Joanna (2026). Crystal Growth in Porous Media. InterPore Journal. 3(3). doi: 10.69631/9kd53x06. Full text in Research Archive Show summary

  Crystalline silicate minerals and carbonates make up 90% to 95% of the Earth's lithosphere, the rigid outermost shell comprising the crust and uppermost solid mantle. Crystalline materials are continuously modified by fluid–rock interactions including crystal growth occurring along fractures and within pore spaces. Crystals form under conditions dictated by extrinsic factors, such as temperature, pressure, fluid composition, and pore confinement, as well as intrinsic factors such as crystal structure, chemical bonding, and anisotropy. While the thermodynamic stability and structure of crystals are well established, their rates of heterogeneous nucleation and growth remain poorly constrained. This is particularly true in porous media, where nucleation is frequently a distinct and rate-limiting step rather than a negligible precursor to growth, especially where non-classical pathways preclude a single, well-defined interfacial free energy. In this commentary, we outline how crystal nucleation and growth in porous media control pore-scale structure, flow, and transport, and we evaluate how these processes can be represented in numerical models across scales. We examine the distinct roles of nucleation pathways, growth kinetics, interfacial and confinement effects, and crystallization pressure in governing transient porosity, stress localization, and self-organized crystalline networks. Furthermore, we discuss how fluid flow and mixing modulate where and when these processes occur. These principles are illustrated through examples spanning well-controlled synthetic crystal growth in materials science to geo-energy and geoscience applications, such as basaltic CO2 mineralization, where probabilistic nucleation, reactive transport, and evolving pore architecture jointly control macroscopic behavior. Finally, we assess the potential of machine learning and surrogate modeling approaches to bridge the persistent gap between molecular-scale mechanisms and field-scale predictions. By emphasizing mechanistic understanding over system-specific details, our goal is to help porous media scientists judge when crystallization is likely to matter, and to guide the selection of modeling approaches that remain both physically grounded and computationally tractable. WHY THIS PAPER MATTERS Crystal nucleation and growth can progressively clog pore spaces, redirect fluid pathways, and transform the mechanical and transport behavior of porous rocks across scales. Is it possible to use information we have about nanoscale processes to predict reservoir-scale changes? This InterPore Commentary article synthesizes how confinement, interfacial free energies, and crystallization pressures control where crystals appear, how fast they grow, and when they damage or seal flow networks in natural and engineered systems. It then outlines how machine learning can be used to connect molecular, pore, and field scales for predictive modeling.

• Hellevang, Helge; Fischer, Cornelius; Nooraiepour, Mohammad; Molins, Sergi; Masoudi, Mohammad & Prasianakis, Nikolaos I. (2026). Bridging Nanoscopic Surface Heterogeneity and Macroscopic Nucleation Rates: A Perspective on Probabilistic Approaches. Crystal Growth & Design. ISSN 1528-7483. doi: 10.1021/acs.cgd.6c00312. Full text in Research Archive Show summary

  Abstract Predicting the number of newly formed crystals and their spatial distribution on surfaces or within pore spaces matters across many fields, from structural biology to coupled fluid flow and reactive transport in porous media to atmospheric physics. Nucleation occurs at molecular and nanoscopic scales, yet classical nucleation theory (CNT) provides an averaged, macroscopic description, and a growing body of experimental observations is inconsistent with CNT predictions. Probabilistic nucleation models have been developed to predict mineral formation in reactive porous geochemical systems and to generate uncertainty estimates, for example, of how mineral growth affects fluid flow. However, the probability density functions of nucleation rates or induction times that underlie these models remain poorly constrained and are not grounded in the intrinsic nanoscopic physicochemical mechanisms underlying the observed macroscopic behavior. This perspective reviews recent advances in mineral nucleation research, focusing on modeling in coupled reactive transport systems, and examines how the large uncertainties reported for macroscopic nucleation rates may be linked to the extent and spatial distribution of surface sites with contrasting reactivity, such as kinks, steps, and terraces. Building on this, we propose a framework that integrates site-specific nucleation probabilities and explicitly accounts for polymorph selection to enable deterministic prediction of macroscopic nucleation rates from intrinsic surface properties. While the resulting parameter space is extensive, recent advances in machine learning, combined with high-throughput experimentation and simulation, suggest that such predictive, multiscale models are now within reach.

• Nooraiepour, Mohammad (2026). Anisotropic permeability tensor prediction from porous media microstructure: A physics-informed MaxViT CNN-Transformer framework. Neural Networks. ISSN 0893-6080. 205. doi: 10.1016/j.neunet.2026.109421. Full text in Research Archive
• Da̧browski, Karol M.; Nooraiepour, Mohammad & Masoudi, Mohammad (2026). Transport-Controlled Halite Crystallization Kinetics during Geological CO2 Storage: Pore-Scale Quantification of Coupled Phase-State, Flow-Rate, and Temperature Effects on Near-Wellbore Precipitation. Energy & Fuels. ISSN 0887-0624. 40(24), p. 12945–12958. doi: 10.1021/acs.energyfuels.6c00898. Full text in Research Archive Show summary

  Salt precipitation near injection wells can reduce permeability, drive excess pressure buildup, and impair injectivity within days to weeks of CO2 injection; yet, the pore-scale mechanisms coupling multiphase flow, evaporation, and crystallization remain poorly quantified across different phase states and flow regimes. To address this gap, we present high-resolution microfluidic experiments that systematically quantify halite crystallization dynamics during CO2-driven brine evaporation in liquid, gaseous, and supercritical phases (50–80 bar, 20–60 °C, Pe = 50–1440). Crystallization kinetics are transport-controlled: the Avrami rate constant (K) increases by 2 orders of magnitude with the Péclet number and follows Arrhenius temperature dependence (Ea = 62.6 kJ/mol). Supercritical CO2 achieves superior displacement efficiency (residual saturation 0.22–0.36; fractal dimension D = 1.79–1.82) and the fastest evaporation rates (Sherwood numbers 2–3× higher than the liquid phase), compressing crystallite formation times from 57 min at 20 °C (liquid phase) to under 1 min at 40–60 °C (gas and supercritical phases). Final crystal area fractions increase 10-fold from liquid (∼0.008) to gas-phase conditions (0.08–0.12), confirming that convective transport and phase state dominate over diffusion-limited mechanisms under our experimental conditions. Despite inherently probabilistic nucleation, final crystal distributions within the microfluidic chip are spatially deterministic, with no systematic inlet-to-outlet bias observed across all tested conditions. Together, the quantitative relationships among dimensionless parameters (Pe, Sh), kinetic constants (K, Ea), and phase-dependent displacement patterns provide critical benchmarks for validating pore-scale models and predicting near-wellbore permeability impairment during geological CO2 storage in saline and hypersaline aquifers.

• Dąbrowski, Karol M.; Nooraiepour, Mohammad; Masoudi, Mohammad; Soomro, Ahsan N.; Smulski, Rafał & Barbacki, Jan [Show all 8 contributors for this article] (2026). Pore-scale salt precipitation during CO2 injection: How additives and interfacial tension govern crystallization? International Journal of Greenhouse Gas Control. ISSN 1750-5836. 154, p. 104695–104695. doi: 10.1016/j.ijggc.2026.104695. Full text in Research Archive
• Nooraiepour, Mohammad; Masoudi, Mohammad; Derluyn, Hannelore; Senechal, Pascale; Moonen, Peter & Hellevang, Helge (2026). Halite precipitates as porous crystalline networks, not dispersed crystals: Self-enhancing growth mechanisms during CO₂ storage in saline aquifers. Chemical Engineering Journal. ISSN 1385-8947. 543, p. 1–15. doi: 10.1016/j.cej.2026.178165. Full text in Research Archive Show summary

  Salt precipitation during CO₂ injection into saline aquifers obstructs flow-controlling pore throats and reduces injectivity, yet reactive transport models assume dispersed, non-porous crystals with negligible fluid flow impact. Here, we demonstrate that halite develops three-dimensional porous networks with 40 ± 15% internal porosity through self-enhancing growth mechanisms. Time-lapse X-ray micro-computed tomography and spectral imaging reveal preferential nucleation at gas-liquid interfaces, where porous hydrophilic aggregates generate capillary suction that draws brine films toward precipitation sites, thereby accelerating growth and expanding the reactive surface area in a positive feedback loop. Spectral tomography identifies two-stage precipitation: dense macrocrystalline cores formed under moderate supersaturation and evaporation, surrounded by microcrystalline overgrowths from rapid late-stage dynamics that produce umbrella-like crusts encapsulating residual brine. This porous architecture explains why modest bulk porosity reduction causes disproportionate permeability decline, as aggregates preferentially obstruct flow percolation pathways rather than uniformly cementing grains or filling pore space. Five interconnected mechanisms drive self-enhancing growth across nano- to centimeter scales: interface nucleation, secondary porous structure formation, steep concentration gradients, hydrophilic substrate film maintenance, and capillary-driven solute delivery. Pore network quantification delivers the first three-dimensional structural characterization of halite growth architecture under GCS-relevant conditions, resolving pore diameter distributions of 20–200 μm, mean coordination numbers of 5, and reactive surface areas averaging 0.04 mm2 per pore – parameters currently absent from reactive transport models yet essential for predicting injectivity impairment and containment integrity at operational storage scales.

• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2026). Carbon Mineralization in CO2–Seawater–Basalt Systems: Reactive Transport Dynamics and Vesicular Pore Architecture Controls. Langmuir. ISSN 0743-7463. 42(16), p. 11435–11456. doi: 10.1021/acs.langmuir.6c00958. Full text in Research Archive Show summary

  Carbon mineralization in basaltic rocks offers a promising pathway for rapid, permanent CO2 storage, yet fundamental controls on reactive transport, precipitation patterns, and permeability evolution under seawater conditions remain poorly constrained. This study integrates flow-through column experiments at 80 °C with CO2-acidified seawater, geochemical modeling, and multiscale pore imaging (SEM-EDS and micro-CT) to elucidate mineralization dynamics in basaltic glass. Results demonstrate that carbonate precipitation is nucleation-limited and kinetically controlled rather than thermodynamically driven or growth-dominated, forming discrete patchy accumulations despite sustained supersaturation. An order-of-magnitude reduction in flow rate (0.05 to 0.005 mL/min) was required to achieve visible precipitation, highlighting residence time as the primary control. Postexperiment characterization identified calcium carbonate and inferred smectite-like clays, with dissolution-induced surface roughening and localized precipitation evident across the column. Seawater chemistry further complicates mineralization kinetics and efficiency relative to freshwater systems. Micro-CT analysis of three vesicular basalt facies revealed low coordination numbers (modal = 2) and serial connectivity, contrasting sharply with higher-coordination sandstone networks. The connected porosity (1.3–32%) differs significantly from the total segmented porosity (18–42%), demonstrating that network topology, rather than total porosity, controls permeability. Pore-scale observations thus indicate that precipitation may render basalts inherently more vulnerable to permeability impairment from modest, distributed precipitation. We explore end-member precipitation-induced clogging scenarios in which small, distributed precipitates cause disproportionately severe permeability loss compared to large, isolated masses. These findings underscore the need for probabilistic reactive transport frameworks that incorporate realistic pore topologies and nucleation barriers, which are fundamentally different from conventional CCS in sedimentary reservoirs, to improve predictions of injectivity and long-term carbon mineralization performance in mafic formations.

• Dąbrowski, K.M.; Nooraiepour, Mohammad & Masoudi, Mohammad (2026). Microfluidic study of evaporation-driven crystallization of saline and ammonia brines under hydrogen flow. International Journal of Hydrogen Energy. ISSN 0360-3199. 219, p. 1–17. doi: 10.1016/j.ijhydene.2026.154090. Full text in Research Archive Show summary

  Underground hydrogen storage in geological formations is critical for renewable energy integration, but salt precipitation during gas injection can impair storage performance. While well studied for CO2 systems, precipitation mechanisms in hydrogen–brine and ammonia–brine systems remain poorly understood. This study presents a systematic microfluidic investigation of salt crystallization during hydrogen injection into saline and ammonia-containing brine aquifers under high pressure with varying compositions (1–5 mol/kg NaCl), chemical additives (surfactants, alcohols, ammonia), and hydrogen flow rates (200–1300 mL/min). Quantitative imaging shows hydrogen induces physical precipitation through evaporation and capillary trapping, resulting in discrete deposits, whereas CO2-ammonia systems produce interconnected ammonium bicarbonate networks. Interfacial tension controls brine distribution and crystal coverage: high-IFT fluids form large pools promoting crystallization, low-IFT fluids form isolated pools reducing coverage by 50%. Alcohols and surfactants suppress precipitation, while ammonia increases crystal fraction. Higher flow rates accelerate crystallization, highlighting gas-specific mitigation strategies for underground hydrogen storage.

• Masoudi, Mohammad; Meyra, Ariel G.; Nooraiepour, Mohammad; Nezhad, Mohaddeseh Mousavi; Hassanpouryouzband, Aliakbar & Hellevang, Helge (2026). Revisiting Hydrogen Sorption–Desorption in Natural Rocks. Industrial & Engineering Chemistry Research. ISSN 0888-5885. 65(6), p. 2984–3026. doi: 10.1021/acs.iecr.5c02081. Full text in Research Archive Show summary

  Hydrogen sorption and desorption in natural rocks are increasingly referenced across subsurface energy and environmental applications, including underground hydrogen storage, natural hydrogen exploration, geological hydrogen generation, and radioactive waste containment. However, the extent to which these physical interactions influence hydrogen behavior in geological materials remains poorly understood. This review examines current experimental and theoretical studies (atomistic simulation and isotherm modeling) of hydrogen sorption and desorption in natural rocks. We evaluated reported sorption capacities and their variability across different lithologies alongside the influencing parameters and the occurrence of hysteresis. Additionally, we modeled all available data using multiple isotherm models to identify the best-fitting formulations. By synthesizing results across diverse methods and geological settings, we identify where physical sorption–desorption is likely to matter, where it is negligible, and what this means for understanding hydrogen transport and retention in the subsurface. Additionally, we provided practical implications of adsorption–desorption, identified critical data gaps, and proposed future research directions to advance the understanding of hydrogen behavior in geological formations.

• Nooraiepour, Mohammad; Dąbrowski, Karol M.; Masoudi, Mohammad; Kuczyński, Szymon; Song, Zezhang & Lothe, Ane Elisabet [Show all 7 contributors for this article] (2025). Geological CO2 storage assessment in emerging CCS regions: Review of sequestration potential, policy development, and socio-economic factors in Poland. International Journal of Greenhouse Gas Control. ISSN 1750-5836. 148, p. 1–25. doi: 10.1016/j.ijggc.2025.104524. Full text in Research Archive Show summary

  Emerging carbon capture and storage (CCS) markets face critical challenges in developing systematic methodologies to assess geological CO2 storage potential under conditions of limited data availability, evolving regulatory frameworks, and nascent infrastructure development. This study establishes an integrated assessment framework for lower-maturity CCS regions that combines geological characterization, storage capacity assessment, regulatory analysis, and socio-economic evaluation through a structured approach adaptable to diverse global contexts. Poland serves as a representative case study, with its coal-reliant economy exemplifying the decarbonization challenges facing emerging regions while meeting European Union climate mandates, and its geological setting offering substantial sequestration opportunities across three major sedimentary regions. Through multidisciplinary analysis synthesizing scattered geological data, policy developments, CCUS value chain dynamics, and stakeholder perspectives, we systematically evaluate CO2 storage potential and demonstrate framework application. Analysis reveals that onshore saline aquifers and depleted hydrocarbon fields provide significant storage capacity, while offshore Baltic Basin sites face logistical and environmental regulatory constraints. Current assessments encounter limitations including sparse data, restricted research access, and inadequate industry-academia collaboration, preventing basin-scale analyses from advancing to higher storage readiness levels and undermining business decision-making reliability. This study contributes a replicable methodology extending beyond Poland to lower-maturity CCS regions worldwide, providing decision-makers with tools for storage assessment, policy development, and stakeholder engagement that support evidence-based deployment strategies. Success in emerging markets requires coordinated advancement across technical characterization, regulatory clarity, infrastructure development, and public engagement, with transparent governance and inclusive community participation as critical enablers for sustainable CCS implementation.

• Johnson, James Ronald; Kiss, Daniel; Shukla, Monika; Noort, Reinier Van; Nooraiepour, Mohammad & Yarushina, Viktoriya M. (2025). Multicycle Injection and Withdrawal in Sedimentary Basins, a Multi-Disciplinary Analysis of Pore-Scale Fluid Flow for Hydrogen Storage. First Break. ISSN 0263-5046. 43(6), p. 75–82. doi: 10.3997/1365-2397.fb2025046. Full text in Research Archive Show summary

  Hydrogen (H2) is viewed worldwide as one of the key pathways to reducing GHG emissions, especially in hard to abate sectors. However, the beneficial implementation of hydrogen as a fuel for transport, and in industries such as steel production requires a constant, reliable supply of hydrogen independent of the availability of energy. Therefore, hydrogen storage will be needed on a range of time scales, and over a range of volumes. Geological storage in porous reservoirs offer the largest storage ‘containers’, with volumes large enough to cover even seasonal cycles. However, this also means that H2 storage will be cyclic, and this cyclical nature in combination with the variable timeframes of that storage introduce complexity into the system at multiple scales. Effective and efficient operation of H2 storage sites thus requires understanding of how both injection rate itself, and how cyclical injection/ withdrawal cycles will impact fluid (e.g., H2-formation water, H2-buffer gas) interactions in the reservoir. To further develop this understanding, we utilise analogue and numerical modelling in addition to petrographical analysis to identify potential areas of further research within this underexplored topic.

• Dąbrowski, Karol; Nooraiepour, Mohammad; Masoudi, Mohammad; Smulski, Rafał; Hellevang, Helge & Nagy, Stanisław (2025). Understanding Salt Precipitation Dynamics during CO2 Injection into Saline Aquifers using Microfluidic Experiments. In EAGE (Eds.), 86th EAGE Annual Conference & Exhibition, June 2-5, 2025, Toulouse, France. European Association of Geoscientists and Engineers (EAGE). doi: https:/www.earthdoc.org/content/papers/10.3997/2214-4609.202510377. Full text in Research Archive Show summary

  This study investigates salt precipitation dynamics using microfluidic experiments, simulating CO2-brine flow in porous media. The results show that salt crystallization is influenced by factors such as capillary backflow, fluid flow, and the interaction between CO2 and brine. Salt precipitation occurs not only where brine was initially present but also in upstream areas due to capillary flow dynamics, highlighting the complexity of these processes. Variations in salinity and flow rates further affect the crystallization behavior, influencing the size, shape, and distribution of salt deposits. These findings emphasize the need for a comprehensive understanding of crystallization mechanisms to improve CO2 sequestration strategies and mitigate unwanted salt precipitation in saline aquifers. Incorporating spatial variability and flow dynamics into models will enhance predictive capabilities and guide operational strategies.

• Masoudi, Mohammad; Nooraiepour, Mohammad; Blom, Richard; Xi, Kelai; Cerasi, Pierre & Hellevang, Helge (2025). Evaluating Hydrogen Sorption in Shale: Effects of Mineral Composition and Sample Treatment. In EAGE (Eds.), 86th EAGE Annual Conference & Exhibition, June 2-5, 2025, Toulouse, France. European Association of Geoscientists and Engineers (EAGE). doi: https:/www.earthdoc.org/content/papers/10.3997/2214-4609.202510554. Full text in Research Archive Show summary

  Understanding hydrogen adsorption on clay minerals is vital for optimizing hydrogen energy applications, including storage, natural hydrogen exploration, and also waste containment. However, safety concerns such as high diffusivity and invisible flame risks limit data on hydrogen’s interaction with various natural settings. This study presents the hydrogen adsorption capacities of four clay-rich shale samples from the Norwegian Continental Shelf (NCS) and three pure clay fractions. Utilizing a high-pressure gas adsorption analyzer, we obtained hydrogen sorption isotherms and found that non-dried clay samples had lower hydrogen sorption due to competition with water molecules. The sorption data were analyzed using Freundlich, Langmuir, and Toth models, with the Freundlich model providing the best fit. These findings highlight the complexities involved in hydrogen interactions with natural materials and underscore the need for careful modeling and analysis.

• Nooraiepour, Mohammad; Polański, Krzysztof; Masoudi, Mohammad; Bohloli, Bahman & Hellevang, Helge (2025). CO2-Induced Salt Crystallization in Sandstone Reservoirs: Significance for Mechanical Properties and Containment in Saline Aquifers. In EAGE (Eds.), 86th EAGE Annual Conference & Exhibition, June 2-5, 2025, Toulouse, France. European Association of Geoscientists and Engineers (EAGE). doi: https:/www.earthdoc.org/content/papers/10.3997/2214-4609.202510772. Full text in Research Archive Show summary

  Effective predictive modeling of CO₂ storage sites requires a comprehensive understanding of the physico-chemical processes and the challenges of scaling up operations. In high-salinity aquifers, CO₂ injection can significantly reduce injectivity due to pore clogging from salt precipitation. This study investigates the effects of CO₂-induced salt crystallization on the geomechanical properties of sandstone reservoirs. We examine the geochemical and mechanical coupling effects through CO₂-brine-rock interactions, utilizing two experimental paths: treatment with (a) CO₂-acidified brine and (b) supercritical injection leading to salt crystallization. High-pressure, high-temperature (HPHT) triaxial tests were conducted on Boise Buff (BB) and Torrey Red (TR) sandstones, representative of North Sea CO₂ storage candidates. The results showed up to a 50% reduction in Young’s and shear moduli, with TR sandstones being more susceptible due to their lower porosity and higher stiffness. An increase in ductility suggests mechanical weakening and potential storage integrity risks. These findings highlight the containment and integrity challenges posed by salt crystallization in (hyper)saline aquifers beyond injectivity issues, emphasizing potential mechanical failure risks due to pressure buildup. The study underscores the importance of incorporating geochemical interactions into CO₂ storage assessments and reservoir management strategies to mitigate these risks.

• Nooraiepour, Mohammad; Gladysz, Pawel & Melaaen, Eirik (2025). Norwegian–Polish carbon capture and storage network: Bilateral collaboration for European climate action. Energy Research & Social Science. ISSN 2214-6296. 126. doi: 10.1016/j.erss.2025.104106. Full text in Research Archive Show summary

  Climate change demands urgent reductions in greenhouse gas emissions, especially from industries that are difficult to decarbonize. Carbon Capture and Storage (CCS) offers a critical solution by capturing CO at its source and storing it underground, supporting the European Union’s goal of climate neutrality by 2050. This study examines the emerging bilateral CCS network between Norway and Poland, designed to leverage complementary strengths and accelerate technology deployment through transnational collaboration. Norway brings decades of operational expertise demonstrated through landmark projects like Sleipner and Snøhvit, as well as forward-looking initiatives such as the open-access Northern Lights project. Its mature regulatory environment and robust infrastructure further enhance Norway’s position. Poland, with its coal-dependent economy and over 15.5 Gt of potential underground storage capacity, seeks to decarbonize major emitters while transitioning to a sustainable energy future. Our analysis identifies critical synergies arising from shared efforts in research and development, academic training, industrial implementation, regulatory harmonization, and public engagement. By highlighting the reciprocal benefits of such a partnership, the study emphasizes the indispensable role of bilateral cooperation in harnessing CCS’s capabilities to meet the EU’s ambitious climate objectives. This case study not only highlights mutual benefits but also proposes a scalable model for multilateral CCS networks, offering a blueprint for Europe and beyond to achieve ambitious climate targets and secure a low-carbon future.

• Masoudi, Mohammad; Nooraiepour, Mohammad; Blom, Richard; Xi, Kelai; Cerasi, Pierre & Hellevang, Helge (2025). Impact of hydration on hydrogen sorption in clay minerals and shale caprocks: Implications for hydrogen energy and waste storage. International Journal of Hydrogen Energy. ISSN 0360-3199. 99, p. 661–670. doi: 10.1016/j.ijhydene.2024.12.247. Full text in Research Archive Show summary

  Understanding hydrogen sorption on clay minerals is crucial for hydrogen energy applications such as surface and subsurface storage, natural hydrogen exploration, and waste storage. However, safety issues surrounding hydrogen gas handling limit the availability of comprehensive data. This study investigates hydrogen sorption in various geomaterials, including four shale caprocks from the Norwegian Continental Shelf and three reference pure clay fractions. We have conducted thorough sample characterization, low-temperature nitrogen sorption, and high-pressure high-temperature hydrogen sorption tests on both dried and non-dried samples. The results highlight the higher hydrogen uptake capacity of swelling clays, particularly montmorillonite. Non-dried clay samples demonstrated reduced hydrogen sorption, likely due to competition between hydrogen and water for sorption sites within the clay structure. Freundlich, Langmuir, and Toth models were employed to analyze the experimental hydrogen isotherms, with the Freundlich model providing the best fit due to the linear or convex-downward nature of the isotherms. Based on our results, we suggest that in a fully water-saturated medium, the sorption of hydrogen on clay minerals is very low, and it is unlikely to significantly affect hydrogen transport.

• Dąbrowski, Karol M.; Nooraiepour, Mohammad; Masoudi, Mohammad; Zając, Michał; Kuczyński, Szymon & Smulski, Rafał [Show all 9 contributors for this article] (2025). Surface wettability governs brine evaporation and salt precipitation during carbon sequestration in saline aquifers: Microfluidic insights. Science of the Total Environment. ISSN 0048-9697. 958, p. 1–13. doi: 10.1016/j.scitotenv.2024.178110. Full text in Research Archive Show summary

  Carbon sequestration in deep saline aquifers is a promising strategy for reducing atmospheric CO2 emissions. However, salt precipitation triggered by the evaporation of formation brine into injected supercritical CO2 can cause injectivity and containment issues in near-wellbore regions. Predicting the distribution of precipitated salts and their impact on near-wellbore properties remains challenging. This study investigates the influence of surface wettability on CO2-induced halite precipitation and growth within hydrophilic and hydrophobic microfluidic chips designed to mimic rock-structure porous geometries. A series of high-pressure brine-CO2 flow experiments, direct microscopic observations, and detailed image processing were conducted to explore how substrate wettability affects salt precipitation. The experiments show that wettability markedly controls residual brine relocation, film flow movement, solute consumption, and salt formation. Tracking halite precipitation dynamics revealed distinct crystal formation signatures: hydrophilic chips exhibited irregular, larger aggregation patches, while the hydrophobic network showed more numerous, smaller, and limited aggregations. Large individual crystals were observed in both chips, with a notable dominance in the hydrophobic one. Crystallization dynamics varied, with nucleation and growth occurring earlier, progressing faster, and forming bulkier aggregates in the hydrophilic chip. Despite these differences, the three identified temporal stages of brine evaporation and halite surface coverage were comparable. Spatial analysis along the chips indicated that crystal aggregation properties, such as size and distribution, were position-dependent, with hydrophilic chips exhibiting greater probabilistic variability. These observations underscore the impact of surface wettability on salt precipitation through brine accessibility and capillarity, with implications for mitigating and remediating salt issues in saline aquifers.

• Masoudi, Mohammad; Emmel, Benjamin; Betken, Benjamin; Cerasi, Pierre; Ahmed, Elyes & Stroisz, Anna Magdalena [Show all 9 contributors for this article] (2025). Feasibility of Hydrogen Storage in Depleted Hydrocarbon Reservoirs in Norway. In EAGE (Eds.), 86th EAGE Annual Conference & Exhibition (Workshop Programme), June 2-5, 2025, Toulouse, France. European Association of Geoscientists and Engineers (EAGE). doi: 10.3997/2214-4609.2025101675. Full text in Research Archive Show summary

  Underground hydrogen storage (UHS) in geological formations (aquifers, salt caverns, and depleted reservoirs) is a promising large-scale solution, with capacities reaching terawatt-hours. Depleted reservoirs are especially suitable due to well-characterized geological structures, existing wells and surface facilities, reduced cost of field exploration and decommissioning, lower investment cost, and proven sealing capabilities. To assess the feasibility of offshore UHS in Norway for powering platforms with renewables, interdisciplinary research has been conducted under the HyStorm project and the Hydrogeni FME Centre, combining experimental and modeling approaches to evaluate H2 storage potential in depleted offshore reservoirs. This paper summarizes completed and ongoing work within these projects, focusing on hydrogen storage in depleted oil and gas reservoirs. The studies include: 1. Evaluation of the hydrogen storage potential of shut-down fields on the Norwegian Continental Shelf. 2. Phase behaviour and black-oil simulations to model fluid dynamics in reservoir systems. 3. Hydrogen sorption/desorption experiments on clay minerals and shale caprocks. 4. Measurements of hydrogen and hydrogen-methane mixture viscosity for flow characterization. 5. Risk assessment of legacy wells and their potential impact on storage security. 6. Long-term reservoir sandstone and caprock shale exposure experiments, followed by post-exposure analysis using gas chromatography, XRD, and acoustic/rock mechanical tests.

• Nooraiepour, Mohammad; Polański, Krzysztof; Masoudi, Mohammad; Kuczyński, Szymon; Derluyn, Hannelore & Nogueira, Liebert Parreiras [Show all 9 contributors for this article] (2024). Potential for 50% Mechanical Strength Decline in Sandstone Reservoirs Due to Salt Precipitation and CO2–Brine Interactions During Carbon Sequestration. Rock Mechanics and Rock Engineering. ISSN 0723-2632. 58, p. 1239–1269. doi: 10.1007/s00603-024-04223-8. Full text in Research Archive Show summary

  Predictive modeling of CO2 storage sites requires a detailed understanding of physico-chemical processes and scale-up challenges. Dramatic injectivity decline may occur due to salt precipitation pore clogging in high-salinity aquifers during subsurface CO2 injection. This study aims to elucidate the impact of CO2-induced salt crystallization in the porous medium on the geomechanical properties of reservoir sandstones. As the impact of salt precipitation cannot be isolated from the precursor interactions with CO2 and acidified brine, we present a comprehensive review and discuss CO2 chemo-mechanical interactions with sandstones. Laboratory geochemical CO2–brine–rock interactions at elevated pressures and temperatures were conducted on two sandstone sets with contrasting petrophysical qualities. Interaction paths comprised treatment with (a) CO2-acidified brine and (b) supercritical injection until brine dry-out, salt crystallization, and growth. Afterward, the core samples were tested in a triaxial apparatus at varying stresses and temperatures. The elastic moduli of intact, CO2-acidified brine treated, and salt-affected sandstones were juxtaposed to elucidate the geochemical–geomechanical-coupled impacts and identify the extent of crystallization damages. The salt-affected sandstones showed a maximum of 50% reduction in Young’s and shear moduli and twice an increase in Poisson’s ratio compared to intact condition. The deterioration was notably higher for the tighter reservoir sandstones, with higher initial stiffness and lower porosity–permeability. We propose two pore- and grain-scale mechanisms to explain how salt crystallization contributes to stress localization and mechanical damage. The results highlight the potential integrity risk imposed by salt crystallization in (hyper)saline aquifers besides injectivity, signaling mechanical failure exacerbated by pressure buildup.

• Nooraiepour, Mohammad; Polanski, Krzysztof; Masoudi, Mohammad; Kuczyński, Szymon; Derluyn, Hannelore & Nogueira, Liebert Parreiras [Show all 9 contributors for this article] (2024). Assessing salt precipitation and weak acid interaction in subsurface CO2 injection: Potential 50% strength decline in near-wellbore reservoir sandstones. arXiv. doi: 10.48550/arXiv.2401.14852. Full text in Research Archive Show summary

  Predictive modeling of CO2 storage sites requires a detailed understanding of physico-chemical processes and potential challenges for scale-up. Dramatic injectivity decline may occur due to salt precipitation pore clogging in high-salinity reservoirs, even over a short time frame. This study aims to elucidate the adverse impact of CO2-induced salt crystallization in porous media on the geomechanical properties of near-wellbore reservoir sandstones. As the impact of salt precipitation cannot be isolated from the precursor effects of interaction with CO2 and carbonic acid, we initiated our study by a comprehensive review of CO2 chemo-mechanical interactions with sandstones. We conducted laboratory geochemical CO2-brine-rock interactions at elevated pressures and temperatures on two sets of porous sandstone with contrasting petrophysical qualities. Two paths were followed: treatment with (a) CO2-acidified brine at 10 MPa fluid pressure and 60C for 7 days, and a second subset continuation with (b) supercritical injection until complete dry-out and salt precipitation. Afterward, the core samples were tested in a triaxial apparatus at varying stresses and temperatures. The elastic moduli of intact, CO2-reacted, and salt-damaged sandstones were juxtaposed to elucidate the extent of crystallization damages. The salt-affected specimens showed a maximum of 50 percent reduction in Young's and shear moduli and twice an increase in Poisson's ratio compared to intact condition. The deterioration was notably higher for the tighter rocks with higher initial stiffness.

• Masoudi, Mohammad; Nooraiepour, Mohammad; Deng, Hang & Hellevang, Helge (2024). Mineral precipitation and geometry alteration in porous structures: How to upscale variations in permeability-porosity relationship? EarthArXiv preprint platform. doi: 10.31223/X56Q41. Full text in Research Archive Show summary

  Porous materials in natural and engineered environments are subject to morphological changes resulting from interacting chemical and physical processes. The complexity of coupled flow, transport, and chemical processes that occur on different temporal and spatial scales makes it difficult to predict the resulting porosity and permeability alterations. Delineating the controls of mineral precipitation reactions is particularly challenging because it requires the implementation of nucleation criteria and precipitation attributes. By conducting pore-scale simulations, we studied how the amount and stochastic distribution of crystallites, controlled by nucleation, affect the pore geometry and permeability in two-dimensional porous structures. The observed relationships between porosity and permeability show characteristics that differ from ones that are typically applicable in dissolving porous media because of the clogging effect. Additionally, we propose a stochastic framework that upscales the co-evolution of permeability and porosity across length scales. This framework enables precise communication of clogging behavior to continuum-scale simulations based on statistical probability distributions of permeability-porosity variations.

• Masoudi, Mohammad; Nooraiepour, Mohammad; Deng, Hang & Hellevang, Helge (2024). Mineral Precipitation and Geometry Alteration in Porous Structures: How to Upscale Variations in Permeability-Porosity Relationship? Energy & Fuels. ISSN 0887-0624. 38(11), p. 9988–1001. doi: 10.1021/acs.energyfuels.4c01432. Full text in Research Archive Show summary

  Porous materials in natural and engineered environments are subject to morphological changes resulting from interacting chemical and physical processes. The intricate nature of these coupled processes, occurring at various temporal and spatial scales, poses challenges in predicting alterations in porosity and permeability. Delineating the controls of mineral precipitation reactions is particularly challenging because it requires the implementation of nucleation criteria and growth mechanisms. By conducting pore-scale simulations, we investigated the impact of the amount and stochastic distribution of crystallites, controlled by nucleation, on pore geometry and permeability in two-dimensional porous structures. The observed relationships between porosity and permeability exhibit characteristics that differ from the ones that are typically applied in dissolving porous media because of the clogging effect. Additionally, we propose a stochastic framework that upscales the coevolution of permeability and porosity across length scales. This framework enables the upscaling of clogging behavior to continuum-scale simulations based on statistical probability distributions of permeability–porosity variations.

• Hellevang, Helge; Nooraiepour, Mohammad & Masoudi, Mohammad (2023). Mineral nucleation and growth in porous and fractured media. Goldschmidt Conference Abstracts. Full text in Research Archive Show summary

  Early simulation works on carbonization during CO2 storage overpredicted the amount and rate of mineral formation because of unrealistic growth models based on transition state theory (TST), where surface areas for growth were assumed to be present from day one. Inspired by [1], we made our first nucleation-growth model a decade ago [2], providing a zero-dimensional averaged kinetic nucleation-growth model for the continuum scale. This model provided some information on lag time for the onset of mineral growth, which is essential to understand why the lack of mineralization in short-term laboratory experiments cannot be extrapolated in time. The continuum-scale models, however, lack the potential to predict how the pore space geometries change and, thereby, how the permeability-porosity relationship changes in complex ways. Recent efforts have been to implement mineral nucleation and crystal growth in pore-scale models, using classical nucleation theory (CNT) and statistically derived expressions for the induction time of the formation of stable growing crystallites. In the new expressions, the probability of creating a crystallite at each surface site (solid surface area in the pore space) is estimated based on a normal distribution centered around the mean induction time value [τ] (symmetric between t= 0 and 2τ). This has been implemented and tested in 2D pore-scale models, showing strong mutual relations and impacts of transport and crystallization in porous media [3-4]. Another emerging field for nucleation-growth research is how the number of crystallites (or aggregates) and their spatial distribution control the evolution of porosity-permeability relations. 2D nucleation-growth Monte Carlo-type pore-scale RTMs show that the permeability-porosity relationship and the associated uncertainty depend on the number of crystallites (Figs. 1, 2). The relationship evolves predictably if the number of crystallites is small or large. If, on the other hand, the number of crystals is in an intermediate range, the permeability-porosity dynamics vary stochastically and are highly uncertain.

• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2023). Nucleation and Crystal Growth on the Secondary Substrate. In Médici, Ezequiel F. & Otero, Alejandro D. (Ed.), Album of Porous Media. Springer. ISSN 9783031238000. doi: 10.1007/978-3-031-23800-0_14. Full text in Research Archive
• Zając, Michał; Nagy, Stanisław; Kuczyński, Szymon; Dabrowski, Karol M.; Smulski, Rafal & Hellevang, Helge [Show all 8 contributors for this article] (2023). Multicomponent and multiphase CO2-brine system in microfluidic characterised in situ by Raman spectroscopy, 84th EAGE Conference & Exhibition 2023. European Association of Geoscientists and Engineers (EAGE). doi: 10.3997/2214-4609.2023101024. Full text in Research Archive Show summary

  Deep-saline aquifers could be instrumental in the geological storage of carbon dioxide due to their relatively good reservoir properties, high volume, and prevalence. However, there are a few difficulties which should be overcome to obtain effective stores in such reservoirs. Most problems are related to formation damage caused by salt precipitation. Due to the complexity of such systems, it is necessary to identify crucial processes, phenomena, factors, and products. In our work, we present a novel platform to trace precipitation ‘in situ’ using microfluidics and Raman spectroscopy. We have built a set in which we can investigate not only the salt deposition phenomenon in pores or microchannels by visual observation but also, because of Raman spectroscopy, determine the kinetics of reactions, carbon dioxide solubility, phase composition, and crystal composition. On the basis of our research, we have identified intensive clogging of pores and fast growth of crystals on the rock-like grain boundaries and bottlenecks. Furthermore, in a 20% weight NaCl solution we have found precipitated carbonates, for example, nitrate. Our results can broaden our understanding of CCS in high-saline aquifers and contribute to the development and common use of this process.

• Nooraiepour, Mohammad; Masoudi, Mohammad; Hellevang, Helge; Dąbrowski, Karol; Kuczyński, Szymon & Zając, Michał [Show all 8 contributors for this article] (2023). Why is it critical to revisit significance and consequences of salt precipitation during CO2 injection? 84th EAGE Conference & Exhibition 2023. European Association of Geoscientists and Engineers (EAGE). doi: 10.3997/2214-4609.2023101162. Full text in Research Archive Show summary

  Among the candidates for CO2 sequestration, deep saline aquifers are considered the best option because of their storage capacity and proximity to emission sources. Injection of large volumes (million tons scale) of supercritical CO2 into the geological formations causes evaporation of formation water near wellbores and precipitation of salt crystals inside the porous medium. CO2-induced salt precipitation can substantially threaten sequestration in saline aquifers. Most available experimental, numerical and theoretical works have focused on predicting the salt's location and amount. However, less attention is given to the precipitation physics, growth dynamics, and behavior of the fluid-solid interface near the evaporation/precipitation front. We report a series of experiments to provide new insights, beyond the current understanding, into the dynamics of brine evaporation and salt growth and to challenge the current understanding that might not be entirely representative of the field conditions. The research outcome highlights the interplay of complex processes (some of which are not yet fully characterized) crucial in investigating salt precipitation induced by million-tons-scale CO2 injection. The observed characteristics call for further in-depth investigation because, in the context of subsurface CO2 storage, we need to redefine how we see injectivity impairment due to salt precipitation.

• Masoudi, Mohammad; Nooraiepour, Mohammad & Hellevang, Helge (2023). Salt Precipitation during Geological CO2 Storage: Effect of Access to Continuous Brine Source. EarthArXiv preprint platform. doi: 10.31223/X5J68G. Full text in Research Archive Show summary

  During CO2 storage, the near-wellbore environment experiences significant chemical, physical, thermal, and mechanical perturbations. Therefore, it is crucial to characterize the coupled thermo-hydro-mechanical-chemical (THMC) processes in this region through representative experimental tests and numerical simulations to maximize the safety and cost-efficiency of CO2 storage. One common shortcoming of current experimental methods is failing to facilitate access and replicate the in-situ brine sources within geological repositories, particularly saline aquifers. This failure can significantly alter the dynamics and dimensionality of mineral/crystal growth in porous reservoir rocks due to the availability and continuity of solute. To address this issue, we designed surface mineral precipitation tests and large-scale sandbox experiments to investigate salt precipitation and growth under two different scales and regimes in porous geometries. The laboratory results indicated massive salt accumulation close to the injection port and underlined the effect of solute availability and continuity on intensifying severity of salt accumulation. The observed continued growth highlights the importance of designing representative laboratory experiments in exploring fluid-rock interactions during carbon sequestration in the subsurface geological media.

• Hellevang, Helge; Ippach, Mats Rouven; Westermann, Sebastian & Nooraiepour, Mohammad (2023). Formation of giant Siberian gas emission craters (GECs). EarthArXiv preprint platform. doi: 10.31223/X59Q3K. Full text in Research Archive Show summary

  The recent discovery of eight giant gas escape craters (GECs) in the Russian Yamal and Gydan peninsulas has challenged researchers for the past decade. Despite numerous proposed models, ranging from meteor impacts to gas explosions, none provide a comprehensive explanation for why the GECs are found only in this specific region. This study proposes a new general model for the formation of GECs in which local permafrost thinning is linked to the local geology, i.e., discrete conductive faults bring natural gas and heat to the base permafrost, deforming and melting the base leading to the development of domal gas and heat traps. Atmospheric warming results in further local thinning and eventually mechanical collapse. The morphology of the GECs initially reflects the concentric deformation above domal base-permafrost structures but are after a short time disguised by water and sediment infill, and over time peatification, and cannot be distinguished from e.g., thermokarst lakes. Thus, the true number of GECs may largely exceed those already discovered.

• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2023). Experimental and Numerical Description of Mineral Precipitation Dynamics on Heterogeneous Substrate Surfaces. EarthArXiv preprint platform. doi: 10.31223/X5SQ49. Full text in Research Archive Show summary

  Mineral precipitation reactions are critical in reactive transport studies of porous media due to their significant impacts on flow and transport properties. Understanding the nucleation process, a probabilistic phenomenon that determines the location and distribution of solid formation in space and time domains, is essential for accurately comprehending the effect of mineral precipitation on porous media surfaces. To this end, this paper presents microfluidic laboratory experiments and reactive transport modeling of mineral precipitation dynamics under different physicochemical conditions and substrate surface properties. Our results demonstrate the importance of the spatial and temporal location and distribution of nucleation and growth events when the interplay among several determining parameters is inevitable. We show mineral precipitation on primary and secondary substrate surfaces under different supersaturations and temperatures. Our high-resolution EDS-SEM surface maps identify the favorable sites and competing locations for attracting solute concentration and continued growth, providing valuable insights into the mineral precipitation mechanism.

• Sharifi, Javad; Nooraiepour, Mohammad; Mohammadkazem, Amiri & Mondol, Nazmul Haque (2022). Developing a relationship between static Young’s modulus and seismic parameters. Journal of Petroleum Exploration and Production Technology. ISSN 2190-0558. 13, p. 203–218. doi: 10.1007/s13202-022-01546-6. Full text in Research Archive Show summary

  Mechanical properties of petroleum reservoirs can be determined via static techniques based on laboratory triaxial tests under reservoir conditions. Dynamic approaches represent an alternative in cases where such static laboratory data are unavailable. Dynamic elastic properties are calculated using ultrasonic wave measurements in the laboratory or in situ well logging. Different relationships have been proposed to estimate static properties from dynamic ones based on the available data from a particular reservoir. However, these relationships are often reservoir-specific, making them inadequate for general seismic inversion purposes. This research proposes a method for developing relationships between seismic parameters and static Young’s modulus in carbonate reservoirs by integrating ultrasonic measurements, well logging data, and rock mechanic tests. A multistage triaxial test simulating the reservoir conditions was used to fully control the stress and strain during the geomechanical experiments. Static Young’s modulus was cross-correlated with a broad spectrum of seismic parameters that can be extracted from seismic inversion (e.g., acoustic impedance, shear impedance, Lambda–rho, and mu–rho). Separate analytic relationships were proposed to convert dynamic Young’s modulus and seismic parameters into static Young’s modulus. Analysis of variance was used to evaluate the results and study the applicability and reliability of the obtained relationships. Furthermore, the reliability of the obtained relationships was successfully confirmed by well logging data and blind well analysis. The proposed methodology can be used to predict rock behavior for geomechanical and structural modeling.

• Nooraiepour, Mohammad (2022). Clay Mineral Type and Content Control Properties of Fine-Grained CO<inf>2</inf> Caprocks—Laboratory Insights from Strongly Swelling and Non-Swelling Clay–Quartz Mixtures. Energies. 15(14). doi: 10.3390/en15145149. Full text in Research Archive Show summary

  Understanding and predicting sealing characteristics and containment efficiency as a function of burial depth across sedimentary basins is a prerequisite for safe and secure subsurface storage. Instead of estimators and empirical relationships, this study aimed to delineate data-driven variability domains for non-cemented fine-grained clastic caprocks. Constant rate-of-strain uniaxial compression experiments were performed to measure changes in properties of brine-saturated quartz–clay mixtures. The binary mixtures were prepared by mixing quartz with strongly swelling (smectite) and non-swelling (kaolinite) clays representing end-member clay mineral characteristics. The primary objective was to evaluate the evolution of mudstone properties in the first 2.5 km of burial depth before chemical compaction and cementation. By conducting systematic laboratory tests, variability domains, normal compaction trends, and the boundaries in which characteristics of fine-grained argillaceous caprocks may vary were identified, quantified, and mathematically described. The results showed distinct domains of properties, where kaolinite-rich samples showed higher compressibility, lower total porosity, higher vertical permeability, and higher Vp and Vs. Two discrepancies were discovered in the literature and resolved regarding the compaction of pure kaolinite and the ultimate lowest porosity for quartz–clay mixtures. The present experimental study can provide inputs for numerical simulation and geological modeling of candidate CO2 storage sites.

• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2022). Precipitation-Induced Geometry Evolution During Reactive Transport: Experimental and Numerical Insights into Stochastic Dynamics of Mineral Growth, 83rd EAGE Annual Conference & Exhibition 2022. European Association of Geoscientists and Engineers (EAGE). ISSN 9789073834125. doi: 10.3997/2214-4609.202210470. Full text in Research Archive Show summary

  Crystal nucleation, precipitation, and growth during a reactive fluid flow and solute transport are critical in many natural and industrial systems. Mineral growth is a prime example where (geo)chemical reactions give rise to geometry evolution in porous media. Motivated by the importance of incorporating stochastic dynamics of nucleation, crystallization, and growth kinetics in studying a variety of multiphase and multiscale processes occurring in geo-environmental and geo-energy systems, this work presents experimental and numerical results delineating geometry evolution induced by mineral precipitation. A total of 27 microfluidic experiments (3×3×3 sets of supersaturation-temperature-time) extend the understanding of factors controlling crystal nucleation and growth rates, the impact of ambient and aqueous phase properties, and the substrate characteristics. For numerical simulations, we used the Lattice Boltzmann Method (LBM) to solve the advection-diffusion-reaction equation for tracking the concentration of different species. We developed a reactive transport model based on our recently proposed probabilistic nucleation and crystal growth theory. The results indicated the probabilistic nature of the process, which is affected by the physiochemistry of the aqueous phase and governed by fluid-solid surface interactions. We underscore the importance of theoretical reactive transport models considering the probabilistic nature of nucleation events before crystal formation.

• Masoudi, Mohammad; Nooraiepour, Mohammad & Hellevang, Helge (2022). The Effect of Preferential Nucleation Sites on the Distribution of Secondary Mineral Precipitates, 83rd EAGE Annual Conference & Exhibition 2022. European Association of Geoscientists and Engineers (EAGE). ISSN 9789073834125. doi: 10.3997/2214-4609.202210445. Full text in Research Archive Show summary

  In the process of mineral nucleation and growth, substrate surface properties and substrate types introduce favorable areas where nucleation events are more likely to occur. The preferential sites for mineral nucleation exist because of the lower interfacial free energy between the precipitating phase and the substrate. In this work, we used a pore-scale Lattice Boltzmann (LB)-based reactive transport model incorporated with the developed probabilistic nucleation model in our previous works to investigate the role of the interfacial free energy between the nucleating phase and the substrate on the nucleation and growth of secondary minerals. We also used Shannon entropy to assess the spatial randomness and the evolution path of the systems as solid phases form. The results showed that the developed model can accurately capture the selective behavior of nucleation processes in the presence of preferential sites. The simulation results demonstrate the importance of using a probabilistic nucleation model to capture the correct physics of this phenomenon. It is also concluded that the probabilistic nucleation models are more relevant in environments with longer induction times.

• Nooraiepour, Mohammad; Masoudi, Mohammad; Shokri, Nima & Hellevang, Helge (2022). Precipitation-induced Geometry Evolution in Porous Media: Numerical and Experimental Insights based on New Model on Probabilistic Nucleation and Mineral Growth. 16th Greenhouse Gas Control Technologies Conference 2022 (GHGT-16). doi: 10.2139/ssrn.4272555. Full text in Research Archive Show summary

  Precipitation and growth of solid phases during a reactive fluid flow and solute transport are critical in many natural and industrial systems. Mineral nucleation and growth is a prime example where (geo)chemical reactions give rise to geometry evolution in porous media. The precipitation reactions can reduce the amount of void space, alter pore space connectivity and morphology, modify tortuosity, deteriorate permeability, and change the fluid flow and solute transport. Additionally, precipitation events reshape the available surface area for growth, leading to changes in reactivity, reaction progress, and reaction rates. The target is to ideally limit the mineral growth in many applications, such as avoiding damage to reservoir permeability due to solid precipitation near CO2 injection wells. In other cases, maximizing mineral growth in porous media can be highly favorable, such as sealing fractured caprocks or increasing mineral trapping in the sequestration sites. Understanding, controlling, and predicting this reactive transport phenomenon is challenging because it requires coupling flow, transport, and chemical processes often characterized by different temporal and spatial resolutions. Nucleation is the pre-growth process that controls the primary position of any mineral precipitation and subsequent growth dynamics. Mineral nucleation is a probabilistic process where crystals might nucleate anywhere given similar conditions, such as surface properties, supersaturation, and temperature. It is imperative to use a probabilistic approach or an upscaled physically sound representation to understand the effect of mineral precipitation on porous medium hydrodynamics. Motivated by the importance of incorporating stochastic dynamics of nucleation and growth kinetics in studying various multiphase and multiscale processes occurring in geo-environmental and geo-energy systems, this paper provides numerical and experimental insights into the recently proposed probabilistic nucleation model. We present laboratory experiments (microfluidic and flow-through column reactor) and pore-scale reactive Lattice Boltzmann Method (LBM) numerical simulations. As variations in the properties of the porous medium are intimately linked to the spatial distribution of the precipitation events, we quantify the evolution of experimental and numerical modeled systems at different physiochemical conditions by mapping the disorder of the system (Shannon's entropy) induced by the spatial mineral distributions across time. We use experimental and numerical results to show the importance of the spatial and temporal location and distribution of nucleation and growth events, particularly when the interplay among several determining parameters is inevitable. The results show that probabilistic nucleation contributes to broad stochastic distributions in both amounts and locations of crystals in temporal and spatial domains.

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• Nooraiepour, Mohammad; Masoudi, Mohammad; Derluyn, Hannelore; Senechal, Pascale; Moonen, Peter & Hellevang, Helge (2025). Role of Continuous Brine Access on Salt Precipitation Dynamics ─ Implications for Injectivity and Containment Integrity during Geological CO2 Storage. doi: https:/deca.upc.edu/ca/projectes/cryspom/abstracts-cryspom25.pdf/view. Full text in Research Archive Show summary

  Geological carbon storage emerges as a critical strategy for mitigating climate change via capturing and storing human-made CO₂ emissions. Salt precipitation during CO₂ injection in saline aquifers can cause pore clogging near the wellbore, reducing permeability and increasing pressure buildup, which may find significant consequences for injectivity, containment integrity, and the overall safety and efficiency of CO₂ storage operations. While increasingly more literature focuses on CO₂-induced salt precipitation, the underlying physics, growth dynamics, and fluid-solid interface behavior remain elusive. This study investigates the role of continuous brine access on pore-scale salt precipitation dynamics, significance for self-enhancing growth nature, and its broader implications for injectivity and containment criteria. Using laboratory techniques, including microfluidics, a Hele-Shaw cell, a flow-through system, a large-scale sandbox setup, and a triaxial geomechanical cell we explore the mechanisms governing brine evaporation and salt crystal growth, their pore occupancy and chemo-mechanical couplings. A key finding is the critical role of continuous brine sources, which significantly alter salt nucleation and growth dynamics by controlling solute availability and continuity through water film movement. Laboratory results reveal substantial salt accumulation near the injection port, emphasizing the importance of solute vailability in exacerbating salt accumulation severity. Two mechanisms accelerate growth dynamics. First, evaporation shifts the gas-liquid interface from larger to finer pores, expanding the surface area for brine evaporation and salt formation. Second, hydrophilic, hygroscopic halite crystals, nucleating on existing precipitates as secondary substrates via probabilistic nucleation, amplify reactive surface area and create a feedback loop. Salt crystallization can weaken reservoir rock, reducing mechanical strength and increasing susceptibility to shear failure. This weakening, evidenced by reduced Young’s and shear moduli, may lower the fracture gradient, posing a risk of unintentional fracturing during injection. By elucidating the role of continuous brine access on precipitation dynamics and the interplay of hydro-mechanical-chemical processes, the research offers insights for optimizing injection strategies and enhancing containment integrity. The findings underscore the need to incorporate these mechanistic aspects into reservoir-scale models to predict better and manage the impacts of salt precipitation on subsurface injection operations.

• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2025). Salt precipitation dynamics in saline aquifers during geological CO2 storage: Role of continuous brine access and its implications for injectivity and containment integrity. Water-rock interaction: the International Symposium on Water-Rock Interaction : Proceedings. Full text in Research Archive
• Masoudi, Mohammad; Nooraiepour, Mohammad & Hellevang, Helge (2025). Bridging numerical predictions and experimental realities: CO2 mineralization in basaltic rocks. Water-rock interaction: the International Symposium on Water-Rock Interaction : Proceedings. Full text in Research Archive
• Minakov, Alexander; Yarushina, Viktoriya M.; Bohaty, Steven M.; Childress, Laurel; Johansen, Ingar & Kihle, Jan [Show all 10 contributors for this article] (2025). Rapid Deformation-Induced Calcite Precipitation in Siltstone from IODP Hole U1581B, Transkei Basin. Full text in Research Archive
• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2023). How probabilistic nucleation controls spatiotemporal dynamics and dimensionality of mineral growth in porous media? Full text in Research Archive
• Masoudi, Mohammad; Nooraiepour, Mohammad & Hellevang, Helge (2023). How does probabilistic nucleation control the spatiotemporal distribution of minerals in porous media? Full text in Research Archive
• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2023). Predictive modeling of reactive transport processes during CO2 sequestration: Geometry alteration induced by mineral dissolution and precipitation. Full text in Research Archive
• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2023). Pore-scale investigation into dynamics of salt crystal nucleation, precipitation and growth in porous media during CO2 sequestration in saline aquifers Content. Full text in Research Archive
• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2023). Nucleation and mineral precipitation during reactive flow and transport: I nsights into porous media geometry alteration. Full text in Research Archive
• Masoudi, Mohammad; Nooraiepour, Mohammad & Hellevang, Helge (2023). Assessment of hydrogen uptake ability of clay-rich caprocks. Full text in Research Archive
• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2023). CO2-induced mineralization in porous reactive system: Implications for mineral precipitation and growth in basaltic layers. Full text in Research Archive
• Masoudi, Mohammad; Nooraiepour, Mohammad & Hellevang, Helge (2022). How the Probabilistic Nature of the Nucleation Process Affects and Controls the Distribution of Mineral Precipitates in Porous Media. Full text in Research Archive Show summary

  Nucleation and growth of secondary mineral phases is of great importance in a variety of processes in different fields. Mineral precipitation alters the morphology and hydrodynamics of the porous media by blocking the pore and throats and changing the tortuosity and permeability of flow paths. Even reaction rates are affected by the reshaping of available reactive surfaces. Any mineral precipitation process begins with the nucleation, which is a probabilistic phenomenon. It is often overlooked in studying the reactive transport phenomena. Nucleation controls the location and timing of crystal formation in a porous structure. The spatial distribution of stable secondary nuclei is crucial to precisely predict the hydrodynamics of the porous medium after mineral precipitation. Thus, a deeper understanding of the mineral nucleation and growth process is essential and it is necessary to develop a new probabilistic nucleation approach that could produce more reliable results. Accordingly, we have developed a new probabilistic nucleation model and incorporated it into a pore-scale Lattice Boltzmann reactive transport model to investigate the effect of various factors such as saturation ratio, flow rate, temperature, interfacial free energy, nucleation rate, and growth rates on the distribution of precipitated secondary minerals. In our model, the probabilistic induction time statistically spreads around the measured or reported induction time, either obtained from experiments or approximated by the exponential nucleation rate equation suggested by the classical nucleation theory (CNT). We provide a detailed explanation on how to implement the developed probabilistic nucleation approach into pore-scale reactive transport models. We also gave a thorough description of each parameter of the probabilistic nucleation model and how to measure or calculate them for different fluid and rock systems. Additionally, we used a new approach to measure the disorder of the spatial mineral distributions. The developed models provide new insights into the spatiotemporal evolution of porous media during mineral precipitation. Furthermore, the outcomes provide the basis for implementing mineral nucleation and growth for reactive transport modeling across timescales and length-scales.

• Nooraiepour, Mohammad; Masoudi, Mohammad; Shokri, Nima & Hellevang, Helge (2022). Heterogeneous nucleation and precipitation on solid surfaces: Experimental observation of calcium carbonate formation on primary and secondary substrates. Full text in Research Archive Show summary

  Mineral nucleation and growth are prime examples of (geo)chemical reactions giving rise to geometry evolution during reactive flow and transport in porous media. The precipitation reactions can reduce porosity, alter pore space connectivity and morphology, modify tortuosity, and deteriorate permeability. Therefore, change the fluid flow and solute transport. Additionally, precipitation reshapes the available surface area for growth, leading to changes in the system's reactivity, reaction progress, and reaction rates. As the probabilistic nucle-ation model highlights, it is necessary to delineate both amount and location of nucleation and precipitation events in the spatiotemporal domain for precise prediction of changes in transport properties. This work aims to improve the understanding of factors controlling crystal nucleation and growth rates, the impact of ambient and aqueous phase properties, and the substrate characteristics. To explore the effect of solute concentration, temperature, and experimental elapsed time on the surface coverage area and the number of precipitated crystals , we carried out a total of 27 mineral synthesis experiments on the surface of heterogeneous quartz-rich sandstone with a solution stoichiometry of close to 1 (Ca/CO3 ≈ 1). The tests were performed at three temperatures (T = 20, 40, and 60℃) and three supersaturations (Ω = 15, 50, and 130x). The principal objective was to evaluate solid formation at different controlling conditions when the solid-liquid interface plays a key role. Effects of primary and secondary substrates and control imposed by preferential precipitation locations are identified and discussed. The results indicate that supersaturation and temperature imposed control on the amount, distribution pattern, and growth rate of crystals while the phenomenon still being probabilistic. Substrate characteristics governed the nucleation and crystal growth location and stochastic dynamics across time and space evolution. Moreover, substrate surface properties introduced preferential sites that were occupied and covered with solids first. For reactive transport modeling, in addition to porous medium's geometry and aqueous phase properties, a stochastic nucleation and growth model is necessary to implement substrate surface properties and compute solute transport and fluid flow for different spatial and temporal locations distinctively.

• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2022). new probabilistic framework for nucleation and mineral growth in porous media helps bridge between different spatial and temporal scales— Theory, experiments and simulations. Full text in Research Archive
• Nooraiepour, Mohammad (2022). Career Development Event for the PhDs and Early Career Researchers. Full text in Research Archive
• Masoudi, Mohammad; Nooraiepour, Mohammad & Hellevang, Helge (2022). On the effect of probabilistic nucleation on the distribution of mineral precipitates in porous media. EGU General Assembly Conference Abstracts. doi: 10.5194/egusphere-egu22-8398. Full text in Research Archive

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