masoudi

• Masoudi, Mohammad; Bergmo, Per Eirik Strand & Grimstad, Alv-Arne (2026). Smart Inflow Control for Water Management: Case Studies From the Norne and Volve Oilfields. I 2026, OMAE (Red.), Proceedings of ASME 2026 45th International Conference on Ocean, Offshore and Arctic Engineering : Volume 9 : Petroleum Technology. The American Society of Mechanical Engineers (ASME). ISSN 9780791889589. doi: 10.1115/omae2026-177037. Fulltekst i vitenarkiv Vis sammendrag

  This paper investigates advanced inflow control for managing water production in mature fields, using two field-scale simulation case studies from the Norne and Volve oilfields on the Norwegian Continental Shelf. In both cases, density-activated recovery (DAR) autonomous inflow control devices were implemented in multi-segmented wells and tested under a range of water-cut (WCT) thresholds and nozzle configurations, with base cases representing conventional completions without inflow control. In the modified Norne model, moderate shutoff settings achieve 20–37% reductions in produced water and corresponding reductions in water injection, while limiting cumulative oil losses to 3–9%. More aggressive shutoff yields larger water savings but becomes increasingly penalizing for oil production and is unlikely to be optimal from an economic perspective. In the more heterogeneous and faulted Volve model, incorporating realistic valve hysteresis and moderate choking improves cumulative oil production relative to the base case, while reducing produced water by up to 85% and lowering the need for injection and water treatment. Together, the two case studies demonstrate that properly tuned autonomous inflow control can significantly reduce water handling and associated energy use, while maintaining or even enhancing oil recovery, provided that WCT limits and valve configurations are optimized to field-specific conditions.

• 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. Fulltekst i vitenarkiv Vis sammendrag

  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.

• Emmel, Benjamin; Stroisz, Anna Magdalena; Bjørkvik, Bård Johan Arnt; Jeante, Anthime; Cerasi, Pierre & Johnson, James Ronald [Vis alle 8 forfattere av denne artikkelen] (2026). Multianalytical Assessment of Shale Behavior after Medium-Pressure/Temperature Hydrogen Exposure. Energy & Fuels. ISSN 0887-0624. 40(34), s. 19134–19150. doi: 10.1021/acs.energyfuels.6c02121. Fulltekst i vitenarkiv Vis sammendrag

  Underground hydrogen (H2) storage (UHS) in siliciclastic porous reservoirs relies critically on the long-term integrity of shale caprocks. However, the influence of H2 on shale microstructure, elastic properties, and mechanical strength remains poorly constrained. This study investigates H2–rock interactions in shales from the Draupne Formation (i.e., Kimmeridge equivalent), a regionally important sealing unit on the Norwegian Continental Shelf. Samples from two wells representing contrasting shale facies were exposed for 7 days to 170 ± 1 bar and 60 ± 1 °C under either H2 or inert Ar atmospheres. Pre- and postexposure characterization employed X-ray micro-CT, scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), ultrasonic through-transmission acoustic wave velocity measurements, punch testing, and gas chromatography (GC). The two facies exhibit strong compositional and structural heterogeneity, with Draupne Shale 1 (DS1) dominated by carbonate-rich, relatively homogeneous layers, and DS2 characterized by organic-rich and laminated microstructures. SEM-EDS and GC analyses revealed no measurable evidence of mineralogical or chemical alteration, indicating that at these pressure and temperature (PT) conditions H2 does not react measurably with shale constituents. Acoustic velocities display small but inconsistent changes after gas exposure, which are best explained by sample heterogeneities and/or P-induced microcrack changes rather than H2-specific effects. In contrast, punch tests reveal distinct facies-dependent mechanical responses: DS2 shale shows reduced peak shear strength and more brittle postpeak behavior after H2 exposure, whereas Ar-treated samples remain more ductile. These results suggest that H2 may contribute to weakening along pre-existing heterogeneities in more compliant shale facies, even in the absence of detectable chemical reactions. The study demonstrates that microstructural variability governs shale behavior during H2 exposure and highlights the need for facies-specific assessment in UHS applications.

• 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), s. 12945–12958. doi: 10.1021/acs.energyfuels.6c00898. Fulltekst i vitenarkiv Vis sammendrag

  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 [Vis alle 8 forfattere av denne artikkelen] (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, s. 104695–104695. doi: 10.1016/j.ijggc.2026.104695. Fulltekst i vitenarkiv
• 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, s. 1–15. doi: 10.1016/j.cej.2026.178165. Fulltekst i vitenarkiv Vis sammendrag

  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), s. 11435–11456. doi: 10.1021/acs.langmuir.6c00958. Fulltekst i vitenarkiv Vis sammendrag

  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, s. 1–17. doi: 10.1016/j.ijhydene.2026.154090. Fulltekst i vitenarkiv Vis sammendrag

  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), s. 2984–3026. doi: 10.1021/acs.iecr.5c02081. Fulltekst i vitenarkiv Vis sammendrag

  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 [Vis alle 7 forfattere av denne artikkelen] (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, s. 1–25. doi: 10.1016/j.ijggc.2025.104524. Fulltekst i vitenarkiv Vis sammendrag

  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.

• Barrabino, Albert; Auflem, Helene Berntsen; Masoudi, Mohammad; Holt, Torleif; Bjørkvik, Bård Johan Arnt & Grimstad, Alv-Arne (2025). Effect of the concentration of commercial partially CO2-soluble surfactants on foam strength. Geoenergy Science and Engineering. ISSN 2949-8929. 257(Part A), s. 2–2. doi: 10.1016/j.geoen.2025.214223. Fulltekst i vitenarkiv Vis sammendrag

  Injection of CO2 foam is an emerging technology for CO2 mobility control. When searching for suitable surfactant system for maximum effect of the foam application it is necessary to consider deployment methods (dissolved in brine or in CO2) and ways to avoid loss of foam strength away from the injection well. Loss of strength is partially related to concentration depletion caused by surfactant adsorption and partitioning into formation brine. Here, two non-ionic surfactants with different CO2 solubilities were studied in steady-state core flooding experiments with co-injection of CO2 and surfactant solution with varying concentrations. For each surfactant concentration apparent viscosities were calculated from the measured differential pressures. The surfactant Brij L23 had a low partition coefficient at the experimental conditions used, meaning that little surfactant was found in the CO2. With this surfactant, foam was formed for low concentrations. The other surfactant, Tergitol TMN 10, was more CO2 soluble, and the partition coefficient increased when the pressure was increased. As a result of the pressure increase more surfactant partitioned into the CO2 and a higher concentration of surfactant was needed to form strong foam. The experimental observations are explained as a result of the surfactant partitioning and are related to the critical micelle concentration of surfactant in brine. Additional measurements were made to characterise the rheology of the CO2-brine interface for the different surfactant systems. It was shown that the interface was more flexible for the systems and conditions where strong foam was observed in the core flooding tests. The observation that surfactant systems with stronger partitioning into CO2 required higher concentrations to form strong foam, and also collapsed more rapidly for decreasing surfactant concentrations, seems to reject a proposition that high CO2 solubility is favourable for expanding the reservoir zone where foam is generated. This indicates that the search for methods for effective CO2 mobility control should concentrate on surfactants that are mainly water soluble. © 2025 The Authors

• 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. I EAGE (Red.), 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. Fulltekst i vitenarkiv Vis sammendrag

  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. I EAGE (Red.), 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. Fulltekst i vitenarkiv Vis sammendrag

  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. I EAGE (Red.), 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. Fulltekst i vitenarkiv Vis sammendrag

  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.

• 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, s. 661–670. doi: 10.1016/j.ijhydene.2024.12.247. Fulltekst i vitenarkiv Vis sammendrag

  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 [Vis alle 9 forfattere av denne artikkelen] (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, s. 1–13. doi: 10.1016/j.scitotenv.2024.178110. Fulltekst i vitenarkiv Vis sammendrag

  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 [Vis alle 9 forfattere av denne artikkelen] (2025). Feasibility of Hydrogen Storage in Depleted Hydrocarbon Reservoirs in Norway. I EAGE (Red.), 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. Fulltekst i vitenarkiv Vis sammendrag

  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.

• Zhang, Qianni; Wang, Jiguang; Zhang, Lunxiang; Masoudi, Mohammad; Hassanpouryouzband, Aliakbar & Song, Yongchen (2025). Hydrogen adsorption kinetics and diffusion of clays: Implications for hydrogen geo-storage and natural hydrogen exploration. Journal of Colloid and Interface Science. ISSN 0021-9797. 700, s. 1–17. doi: 10.1016/j.jcis.2025.138440. Fulltekst i vitenarkiv Vis sammendrag

  Hydrogen (H2) storage holds significant promise in facilitating the energy transition and mitigating the energy crisis and greenhouse effect. A thorough understanding of H2 storage and transport mechanisms is a prerequisite for advancing H2 energy applications such as underground H2 storage and natural H2 exploration. Clay minerals, abundant in reservoirs and caprocks, play a key role in gas adsorption and diffusion, influencing the behavior and fate of H2 in the subsurface. We conducted H2 isothermal adsorption and kinetic experiments on montmorillonite and sepiolite at 30 °C, 40 °C, and 50 °C over the pressure range of 0–9.8 MPa to investigate the modeling, kinetics, and diffusion of H2 adsorption behavior in clay minerals. The Langmuir, Freundlich, Sips, Temkin, Toth, Brunauer-emmett-teller (BET) and Dubinin-Astakhov (DA) models were used to fit the equilibrium data, while the pseudo-first-order, pseudo-second-order, and Bangham models analyzed adsorption kinetics. The stretched exponential model characterized diffusion properties. Results indicated that the BET model presents the best fitting results to the adsorption isotherms at different temperatures. The Bangham kinetic model can satisfactorily predict the experimental kinetics data at various pressure stages for the entire time range. Higher temperatures and pressures lead to a decrease in the Bangham adsorption rate constant. The Bangham adsorption rate constant and diffusion coefficient for sepiolite are significantly higher than those for montmorillonite. The H2 diffusion coefficient in clay minerals decreases with increasing pressure. These findings highlight sepiolite's high adsorption capacity and its potential impact on the fate of H2 in geological environment.

• Nooraiepour, Mohammad; Polański, Krzysztof; Masoudi, Mohammad; Kuczyński, Szymon; Derluyn, Hannelore & Nogueira, Liebert Parreiras [Vis alle 9 forfattere av denne artikkelen] (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, s. 1239–1269. doi: 10.1007/s00603-024-04223-8. Fulltekst i vitenarkiv Vis sammendrag

  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.

• Zhang, Qian; Masoudi, Mohammad; SUN, Lingjie; Zhang, Lunxiang; Yang, Lei & Song, Yongchen [Vis alle 7 forfattere av denne artikkelen] (2024). Hydrogen and Cushion Gas Adsorption–Desorption Dynamics on Clay Minerals. ACS Applied Materials & Interfaces. ISSN 1944-8244. 16(40), s. 53994–54006. doi: 10.1021/acsami.4c12931. Fulltekst i vitenarkiv Vis sammendrag

  Transitioning toward a hydrogen (H2)-centric energy paradigm necessitates understanding the adsorption properties of clay minerals, essential constituents of reservoirs and caprocks, for efficient geological H2 storage. This study examines the adsorption characteristics of H2 on various clay minerals (montmorillonite, illite, chlorite, kaolinite, and sepiolite) at different temperatures and the adsorption of cushion gases (N2, CH4, and CO2) under reservoir conditions (313.15 K, up to 10 MPa). The results indicate that sepiolite demonstrates superior adsorption capacity under all tested conditions, surpassing montmorillonite by over 12 times at 313.15 K for H2. Illite, chlorite, and kaolinite exhibit negligible H2 adsorption. Thermodynamic analysis reveals that H2 adsorption on clay minerals is a nonspontaneous and exothermic physisorption process. H2 loss due to adsorption hysteresis in montmorillonite and sepiolite is 42.19 and 3.56%, respectively. Sepiolite may exhibit more predictable and stable sorption properties under repeated pressure variations. The H2 adsorption capacity of montmorillonite and sepiolite is merely 0.4 and 4.5% of that of CO2, respectively. This study provides valuable insights for selecting clay minerals and cushion gases for efficient geological H2 storage and natural hydrogen exploration.

• Masoudi, Mohammad; Hassanpouryouzband, Aliakbar; Hellevang, Helge & Haszeldine, R. Stuart (2024). Lined rock caverns: A hydrogen storage solution. Journal of Energy Storage. ISSN 2352-152X. 84(Part B). doi: 10.1016/j.est.2024.110927. Fulltekst i vitenarkiv Vis sammendrag

  The inherent intermittency of renewable energy sources frequently leads to variable power outputs, challenging the reliability of our power supply. An evolving approach to mitigate these inconsistencies is the conversion of excess energy into hydrogen. Yet, the pursuit of safe and efficient hydrogen storage methods endures. In this perspective paper, we conduct a comprehensive evaluation of the potential of lined rock caverns (LRCs) for hydrogen storage. We provide a detailed exploration of all system components and their associated challenges. While LRCs have demonstrated effectiveness in storing various materials, their suitability for hydrogen storage remains a largely uncharted territory. Drawing from empirical data and practical applications, we delineate the unique challenges entailed in employing LRCs for hydrogen storage. Additionally, we identify promising avenues for advancement and underscore crucial research directions to unlock the full potential of LRCs in hydrogen storage applications. The foundational infrastructure and associated risks of large-scale hydrogen storage within LRCs necessitate thorough examination. This work not only highlights challenges but also prospects, with the aim of accelerating the realization of this innovative storage technology on a practical, field-scale level.

• Nooraiepour, Mohammad; Polanski, Krzysztof; Masoudi, Mohammad; Kuczyński, Szymon; Derluyn, Hannelore & Nogueira, Liebert Parreiras [Vis alle 9 forfattere av denne artikkelen] (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. Fulltekst i vitenarkiv Vis sammendrag

  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. Fulltekst i vitenarkiv Vis sammendrag

  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), s. 9988–1001. doi: 10.1021/acs.energyfuels.4c01432. Fulltekst i vitenarkiv Vis sammendrag

  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. Fulltekst i vitenarkiv Vis sammendrag

  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. I Médici, Ezequiel F. & Otero, Alejandro D. (Red.), Album of Porous Media. Springer. ISSN 9783031238000. doi: 10.1007/978-3-031-23800-0_14. Fulltekst i vitenarkiv
• Zając, Michał; Nagy, Stanisław; Kuczyński, Szymon; Dabrowski, Karol M.; Smulski, Rafal & Hellevang, Helge [Vis alle 8 forfattere av denne artikkelen] (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. Fulltekst i vitenarkiv Vis sammendrag

  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 [Vis alle 8 forfattere av denne artikkelen] (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. Fulltekst i vitenarkiv Vis sammendrag

  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. Fulltekst i vitenarkiv Vis sammendrag

  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.

• 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. Fulltekst i vitenarkiv Vis sammendrag

  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.

• 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. Fulltekst i vitenarkiv Vis sammendrag

  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. Fulltekst i vitenarkiv Vis sammendrag

  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. Fulltekst i vitenarkiv Vis sammendrag

  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.

• Nooraiepour, Mohammad; Fazeli, Hossein; Masoudi, Mohammad & Hellevang, Helge (2021). Effect of Mineral Heterogeneity on Fracture Dissolution in Carbonate-Rich Caprocks During Subsurface Co2 Injection. I SPE, , (Red.), SPE Europec featured at 82nd EAGE conference and exhibition, October 18-21, 2021, Amsterdam, The Netherlands. Society of Petroleum Engineers. ISSN 9781613997918. doi: 10.3997/2214-4609.202011174. Fulltekst i vitenarkiv Vis sammendrag

  Chemical interactions between CO2, brine and caprock-forming minerals might lead to the dissolution of the fractures present in the caprock of CO2 storage sites. One factor that can affect the chemically induced fracture alterations is mineral heterogeneity in the caprock. In this study, we investigate the effect of mineral heterogeneity on fracture dissolution of four carbonate-rich caprock samples, having different levels of heterogeneity, where CO¬2-rich brine flows through the fractured caprocks. A HPHT geomaterial microfluidic experimental setup is used to monitor the evolution of the fractures. Results indicate that the homogeneous caprock samples, i.e. the samples that are mainly composed of calcite, show a uniform fracture wall dissolution while fracture wall roughness increases for heterogeneous samples. The effluent chemistry analyses show that the sample-scale calcite dissolution rate decreases over time, which can be due to the mass transfer limitations in the boundary layer near the fracture wall (for the homogeneous sample) or in the altered layer formed around the fracture (for the heterogeneous samples). Microfluidic experiments were also done for one carbonate-rich fine-grained shale sample, which showed no detectable fracture alteration. However, the effluent analysis for the shale sample confirmed the calcite dissolution.

• Nooraiepour, Mohammad; Masoudi, Mohammad; Shokri, Nima & Hellevang, Helge (2021). Probabilistic Nucleation and Crystal Growth in Porous Medium: New Insights from Calcium Carbonate Precipitation on Primary and Secondary Substrates. ACS Omega. 6(42), s. 28072–28083. doi: 10.1021/acsomega.1c04147. Fulltekst i vitenarkiv Vis sammendrag

  Knowledge of crystal nucleation and growth is paramount in understanding the geometry evolution of porous medium during reactive transport processes in geo-environmental studies. To predict transport properties precisely, it is necessary to delineate both the amount and location of nucleation and precipitation events in the spatiotemporal domain. This study investigates the precipitation of calcium carbonate crystals on a heterogeneous sandstone substrate as a function of chemical supersaturation, temperature, and time. The main objective was to evaluate solid formation under different boundary conditions when the solid–liquid interface plays a key role. New observations were made on the effect of primary and secondary substrates and the role of preferential precipitation locations on the rock surfaces. The results indicate that supersaturation and temperature determine the amount, distribution pattern, and growth rate of crystals. Substrate characteristics governed the nucleation, growth location, and evolution probability across time and space. Moreover, substrate surface properties introduced preferential sites that were occupied and covered with solids first. Our results highlight the complex dynamics induced by substrate surface properties on the spatial and temporal solute distribution, transport, and deposition. We accentuate the great potentials of the probabilistic nucleation model to describe mineral formation in a porous medium during reactive transport.

• Fazeli, Hossein; Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2021). Effect of Mineral Heterogeneity on Fracture Dissolution in Carbonate-Rich Caprocks During Subsurface Co2 Injection. EAGE extended abstracts. doi: 10.3997/2214-4609.202011174. Fulltekst i vitenarkiv Vis sammendrag

  Chemical interactions between CO2, brine, and caprock-forming minerals might lead to dissolution of the fractures present in the caprock of CO2 storage sites. One factor that can affect the chemically induced fracture alterations is mineral heterogeneity in the caprock. In this study, we investigate the effect of mineral heterogeneity on fracture dissolution of four carbonate-rich caprock samples, having different levels of heterogeneity, where CO¬2-rich brine flows through the fractured caprocks. A HPHT geomaterial microfluidic experimental setup is used to monitor the evolution of the fractures. Results indicate that the homogeneous caprock samples, i.e. the samples that are mainly composed of calcite, show a uniform fracture wall dissolution while fracture wall roughness increases for heterogeneous samples. The effluent chemistry analyses show that the sample-scale calcite dissolution rate decreases over time, which can be due to the mass transfer limitations in the boundary layer near the fracture wall (for the homogeneous sample) or in the altered layer formed around the fracture (for the heterogeneous samples). Microfluidic experiments were also done for one carbonate rich finegrained shale sample, which showed no detectable fracture alteration. However, the effluent analysis for the shale sample confirmed the calcite dissolution.

• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2021). Probabilistic nucleation governs time, amount, and location of mineral precipitation and geometry evolution in the porous medium. Scientific Reports. 11. doi: 10.1038/s41598-021-95237-7. Fulltekst i vitenarkiv Vis sammendrag

  One important unresolved question in reactive transport is how pore-scale processes can be upscaled and how predictions can be made on the mutual effect of chemical processes and fluid flow in the porous medium. It is paramount to predict the location of mineral precipitation besides their amount for understanding the fate of transport properties. However, current models and simulation approaches fail to predict precisely where crystals will nucleate and grow in the spatiotemporal domain. We present a new mathematical model for probabilistic mineral nucleation and precipitation. A Lattice Boltzmann implementation of the two-dimensional mineral surface was developed to evaluate geometry evolution when probabilistic nucleation criterion is incorporated. To provide high-resolution surface information on mineral precipitation, growth, and distribution, we conducted a total of 27 calcium carbonate synthesis experiments in the laboratory. The results indicate that nucleation events as precursors determine the location and timing of crystal precipitation. It is shown that reaction rate has primary control over covering the substrate with nuclei and, subsequently, solid-phase accumulation. The work provides insight into the spatiotemporal evolution of porous media by suggesting probabilistic and deterministic domains for studying reactive transport processes. We indicate in which length- and time-scales it is essential to incorporate probabilistic nucleation for valid predictions.

• Masoudi, Mohammad; Fazeli, Hossein; Miri, Rohaldin & Hellevang, Helge (2021). Pore scale modeling and evaluation of clogging behavior of salt crystal aggregates in CO2-rich phase during carbon storage. International Journal of Greenhouse Gas Control. ISSN 1750-5836. 111. doi: 10.1016/j.ijggc.2021.103475. Fulltekst i vitenarkiv Vis sammendrag

  The optimal CO2 storage operation requires high permeability in the near-well region in order to keep it safe and cost-efficient. Nucleation and growth of salt crystals driven by the evaporation of formation water into under-saturated (dry) super-critical CO2 streams result in the changes in porosity and permeability of the near well-bore area. Permeability reduction is one of the main reasons for injectivity losses in the context of CO2 storage in saline aquifers. According to recent studies, during CO2 storage, salt crystals grow in two different forms: 1) single, large crystals in the aqueous phase, and 2) aggregates of micro-meter size salt crystals in the CO2-rich vapor phase. All previous numerical studies at pore-scale have addressed the formation of single, large crystals in the aqueous phase. In this work we have developed a 3D pore-scale reactive transport solver based on a D3Q19 advection-diffusion Lattice-Boltzmann model. The model takes for the first time salt nucleation into consideration via a new probabilistic approach to simulate the formation of micro-meter size salt crystal aggregates in the CO2-rich phase and their effect on changes in pore morphology and permeability. Comparing the results of porosity-permeability relations with some of the well-known clogging models, confirms the need for a new clogging model to capture the permeability reduction caused by salt aggregates.

• Masoudi, Mohammad; Sundal, Anja & Hellevang, Helge (2021). Estimation of Mutual Solubility of CO2-H2O in Saline Aquifer Systems Using ePC-SAFT Equation of State. I Røkke, Nils Anders & Knuutila, Hanna K (Red.), TCCS–11. CO2 Capture, Transport and Storage. Trondheim 22nd–23rd June 2021. Short Papers from the 11th International Trondheim CCS Conference. SINTEF akademisk forlag. ISSN 9788253617145. Fulltekst i vitenarkiv Vis sammendrag

  A primary assessment of mutual solubility of CO2 and water for estimated max and min temperatures and pressures of the prospective reservoir formations of Aurora; Cook (at >2650 m depth) and Johansen (at >2700 m depth) have been done using ePC-SAFT equation of estate. Mole fraction of CO2 in H2O ranges from 0.025 to 0.027, and H2O in CO2 form 0.016 to 0.023 over pressure-temperature ranges of 265 – 283 bar and 95 – 110 °C. The potential for drying out effects (H2O to CO2) is significant, and there would be risk of salt precipitation in the near well area.

• Fazeli, Hossein; Masoudi, Mohammad; Patel, Ravi A.; Aagaard, Per & Hellevang, Helge (2020). Pore-Scale Modeling of Nucleation and Growth in Porous Media. ACS Earth and Space Chemistry. 4(2), s. 249–260. doi: 10.1021/acsearthspacechem.9b00290. Fulltekst i vitenarkiv
• Parvin, Saeed; Masoudi, Mohammad; Sundal, Anja & Miri, Rohaldin (2020). Continuum scale modelling of salt precipitation in the context of CO2 storage in saline aquifers with MRST compositional. International Journal of Greenhouse Gas Control. ISSN 1750-5836. 99. doi: 10.1016/j.ijggc.2020.103075. Fulltekst i vitenarkiv Vis sammendrag

  Carbon capture and storage (CCS) would contribute considerably towards climate change mitigation, if it would be implemented on a very large scale; at many storage sites with substantial injection rates. Achieving high injection rates in deep saline aquifers requires a detailed assessment of injectivity performance and evaluation of the processes that alter the permeability of the near-well region. One of the most common forms of the injectivity loss in the context of CO2 storage in saline aquifers is salt precipitation driven by the evaporation of brine into the relatively dry injected CO2 stream. We present a novel compositional transport formulation based on overall-composition variables which models salt as a separate solid phase which could potentially form through two essentially different ways, i.e., kinetic or equilibrium. To model formation drying-out and subsequent halite-precipitation, an accurate and reliable fluid model ePC-SAFT, which can effectively account for ionic effects, is applied. In addition, a volume balance approach (i.e., depending on how far the salt saturation is from the solubility limit) is implemented to estimate solid saturation in a simulation cell. The resulting simulator is benchmarked against several well-known examples, with analytical solutions demonstrating the ability of the code to cover a variety of physical mechanisms. Finally, injection of dry CO2 into a brine-saturated core-scale domain is simulated and sensitivity analyses over various parameters are performed. We show that the new model is capable to quantitatively represent the physics of salt precipitation (for example salt self-enhancing) under different reservoir conditions.

• Daryasafar, Amin; Masoudi, Mohammad; Kord, S. & Madani, Mohammad (2020). Evaluation of different thermodynamic models in predicting asphaltene precipitation: A comparative study. Fluid Phase Equilibria. ISSN 0378-3812. 514. doi: 10.1016/j.fluid.2020.112557. Fulltekst i vitenarkiv Vis sammendrag

  One of the major issues in the oil industry is asphaltene precipitation. Modeling asphaltene precipitation is still considered as a complex problem due to various characteristics of different heavy components existing in the crude oil. Thermodynamic models have been found as accurate models for studying asphaltene precipitation in the past few years and a great deal of effort has been devoted to model this process by using different empirical models and equations of state. In this study, the obtained results of asphaltene precipitation from different models based on perturbed-chain statistical associating fluid theory (PC-SAFT), cubic-plus-association (CPA), solid model, Flory-Huggins (FH), and the modified Flory-Huggins (MFH) are compared and their accuracy and reliability are analyzed in detail. For this purpose, twelve crude oil types with different characteristics and asphaltene precipitation behavior are used. Additionally, the performance of the introduced models in predicting asphaltene precipitation during gas injection into the studied oil is investigated. Results demonstrated that PC-SAFT and CPA models have the highest accuracy for both precipitation estimation and behavior trend prediction. Afterward, sensitivity analysis is performed by using Monte-Carlo algorithm for better understanding of the effect of different adjusting parameters, which were used during the tuning process, on each model outputs. Results indicated that cross-association energy between asphaltene and heavy component (HC), self-association energy of asphaltene, and binary interaction coefficient between asphaltene and CO2 are the most sensitive tuning variables for PC-SAFT, CPA, and solid models, respectively. Finally, the CPU times of various models for simulating this process were compared. This comparison showed that the PC-SAFT model has more computational time due to the involved iterative processes for phase equilibrium calculations.

• Masoudi, Mohammad; Miri, Rohaldin; Hellevang, Helge & Kord, S. (2020). Modified PC-SAFT characterization technique for modeling asphaltenic crude oil phase behavior. Fluid Phase Equilibria. ISSN 0378-3812. 513. doi: 10.1016/j.fluid.2020.112545. Fulltekst i vitenarkiv Vis sammendrag

  The perturbed-chain version of Statistical Association Fluid Theory (PC-SAFT) emerged as a powerful tool to study the phase behavior of complex fluids such as polymers and asphaltene. In spite of this, it has not gained widespread acceptance in the industry because of its sophisticated oil characterization procedure. In fact, the predictive performance of the current characterization methods is limited and not all-inclusive as they use a large number of fitting parameters and/or a non-integrated procedure. In this study, a convenient and easy-to-use procedure for crude oil characterization is proposed, assuming asphaltene as a combination of poly-nuclear aromatics, benzene derivatives, and saturates. To achieve the best match between measured and model predictions, a simple and robust Trust-Region based optimization method is used. A set of weighting factors is also used based on uncertainties in experimental data. Additionally, it is showed that the poor agreement between the measured amounts of precipitated asphaltene (from filtration test) and thermodynamic model predictions —tuned toward experimental asphaltene onset pressure data— is because of the inherent difference between the accuracy of the experimental methods. The performance of the proposed method is evaluated against reliable literature data of three frequently used crude oils which have been previously characterized over wide range of temperature, pressure, and compositions, and a reservoir fluid sample taken from a southwestern Iranian reservoir. The results are encouraging if compared to the available characterization procedures in the literature.

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• Lothe, Ane Elisabet; Masoudi, Mohammad; Bergmo, Per Eirik Strand; Nybø, Roar & Torsvik, Annika (2026). OMAE 2026 in Japan: Presenting energy efficient drainage, digital solutions, and more – LowEmission. Fulltekst i vitenarkiv Vis sammendrag

  The OMAE 45th International Conference on Ocean, Offshore and Arctic Engineering is a premier conference for engineers, researchers, and technical specialists. This year, the conference took place in Tokyo with 1200 participants from more than 40 countries. And six of the participants were researchers from LowEmission.

• Nugrahaningtyas, Anisa; Masoudi, Mohammad; Bjørkvik, Bård Johan Arnt; Berg, Carl Fredrik & Net, Antje van der (2026). The Development of a Powder-Flotation Protocol for Rapid Screening of Aging- and Cleaning-Induced Wettability Alterations in Sandstone. doi: 10.5281/ZENODO.22123444. Fulltekst i vitenarkiv
• Masoudi, Mohammad (2026). Lined Rock Caverns: What? Why? and How? — Exploring the Future of Underground Energy Storage. Fulltekst i vitenarkiv
• Masoudi, Mohammad (2025). Hydrogen Adsorption-Desorption: Key Factors and Significance. Fulltekst i vitenarkiv
• 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. Fulltekst i vitenarkiv Vis sammendrag

  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. Fulltekst i vitenarkiv
• 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. Fulltekst i vitenarkiv
• Masoudi, Mohammad (2024). Hydrogen adsorption in clay minerals and shale. Fulltekst i vitenarkiv
• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2023). How probabilistic nucleation controls spatiotemporal dynamics and dimensionality of mineral growth in porous media? Fulltekst i vitenarkiv
• Masoudi, Mohammad; Nooraiepour, Mohammad & Hellevang, Helge (2023). How does probabilistic nucleation control the spatiotemporal distribution of minerals in porous media? Fulltekst i vitenarkiv
• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2023). Predictive modeling of reactive transport processes during CO2 sequestration: Geometry alteration induced by mineral dissolution and precipitation. Fulltekst i vitenarkiv
• 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. Fulltekst i vitenarkiv
• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2023). Nucleation and mineral precipitation during reactive flow and transport: I nsights into porous media geometry alteration. Fulltekst i vitenarkiv
• Masoudi, Mohammad; Nooraiepour, Mohammad & Hellevang, Helge (2023). Assessment of hydrogen uptake ability of clay-rich caprocks. Fulltekst i vitenarkiv
• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2023). CO2-induced mineralization in porous reactive system: Implications for mineral precipitation and growth in basaltic layers. Fulltekst i vitenarkiv
• Masoudi, Mohammad (2023). Estimating Hydrogen Sorption Capacity of clay-rich Caprocks. Fulltekst i vitenarkiv
• Masoudi, Mohammad & Hellevang, Helge (2023). Near injector salt scale buildup in CCS due to CO2 plume drying of aquifer. Fulltekst i vitenarkiv
• Masoudi, Mohammad; Ahmed, Elyes; Raynaud, Xavier Marcel & Hellevang, Helge (2023). Is salt precipitation an issue during geological storage of hydrogen in saline aquifers? from thermodynamic perspective using PC-SAFT EoS. Fulltekst i vitenarkiv
• 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. Fulltekst i vitenarkiv Vis sammendrag

  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. Fulltekst i vitenarkiv Vis sammendrag

  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. Fulltekst i vitenarkiv
• 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. Fulltekst i vitenarkiv
• Hellevang, Helge; Masoudi, Mohammad & Nooraiepour, Mohammad (2022). To what degree can the spatial distribution of secondary minerals in porous media be determined? Fulltekst i vitenarkiv
• Nooraiepour, Mohammad; Masoudi, Mohammad & Hellevang, Helge (2022). Reactive transport in porous media: How solid precipitation shapes geometry evolution? Fulltekst i vitenarkiv
• Masoudi, Mohammad; Nooraiepour, Mohammad; Berntsen, Andreas Nicolas & Hellevang, Helge (2021). A new probabilistic nucleation model to predict crystal growth in porous medium. Fulltekst i vitenarkiv Vis sammendrag

  A new probabilistic nucleation model to predict crystal growth in porous medium Tuesday, 1 June 2021 15:10 (15 minutes) Nucleation is the first step of any mineral precipitation and crystal growth process. 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 predict hydrodynam-ics of the porous medium after mineral precipitation precisely. To better understand the nucleation process, we developed a new probabilistic nucleation approach in which the induction time is considered a random variable. The random 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. In this work, we utilized inputs from the classical nucleation theory. In our model, both location and time of nucleation are probabilistic, affecting transport properties in different time-and length-scales. We developed a pore-scale Lattice Boltzmann reactive transport model and implemented the new probabilistic nucleation model to investigate the effect of nucleation rate and reaction rate on the extent, distribution, and precipitation pattern of the solid phases. The simulation domain is a 2D substrate with an infinite source of the supersaturated solution. We use Shannon entropy to measure the disorder of the spatial mineral distributions. The results of the simulations show that all the reactions follow similar random behavior with different Gauss-Laplace distributions. The simulation scenarios start from a fully ordered system with no solid precipitation on the substrate (entropy of 0). Entropy starts to increase as the secondary phase precipitates and grows on the surface until it reaches its maximum value (entropy of 1). Afterward, the overall disorder declines as more surface areas are getting covered, and eventually, entropy approaches a constant value. The research results indicate that the slower reactions have longer windows of the probabilistic regime before entering the deterministic regime. The outcomes provide the basis for implementing mineral nucleation and growth for reactive transport modeling across timescales and length-scales.

• Masoudi, Mohammad; Nooraiepour, Mohammad; Berntsen, Andreas Nicolas & Hellevang, Helge (2021). How to bridge between different time and length scales using a new probabilistic approach for mineral nucleation and growth. Fulltekst i vitenarkiv
• Nooraiepour, Mohammad; Masoudi, Mohammad; Fazeli, Hossein & Hellevang, Helge (2021). Geometry evolution and fracture alteration controlled by spatial mineral heterogeneity during CO2 sequestration -A reactive transport study. Fulltekst i vitenarkiv Vis sammendrag

  Geological CO2 storage and CCS have a crucial role in reducing CO2 emission and therefore mitigating climate change. One of the prerequisites for selecting CO2 storage sites is a low permeability caprock preventing potential CO2 leakage and migration from the storage reservoir. The presence of fractures in the caprock can adversely affect the sealing capacity of caprocks. Chemical interactions between CO2, brine, and caprock-forming minerals can cause fracture evolution, which results in changes in the transmissivity of fractures within the sealing layers. One factor that can affect the chemically induced fracture alterations is mineral het-erogeneity in the caprock. In the present work, we investigate the effect of mineral heterogeneity on fracture geometry evolution when CO2-rich brine flows through a single fracture scribed on different carbonate-rich caprock samples. The rock samples have different carbonate contents and different levels of mineral hetero-geneities. They can represent carbonate-rich caprocks such as some intervals of the Upper Jurassic (Kimmerid-gian) Draupne shales, the caprock for Smeaheia CO2 storage in Norway. An HPHT geomaterial microfluidic experimental setup is used to monitor the evolution of the fractures. Results indicate that the homogeneous caprock samples, i.e., the samples mainly composed of calcite, show a uniform fracture wall dissolution while fracture wall roughness increases for heterogeneous samples. The effluent chemistry analyses show that the sample-scale calcite dissolution rate decreases over time, which can be due to the mass transfer limitations in the boundary layer near the fracture wall (for the homogeneous sample) or the altered layer formed around the fracture (for the heterogeneous samples). Microfluidic experiments were also done for one carbonate-rich fine-grained shale sample, which showed dissolution of calcite with no macroscopic fracture alteration during the ten-day experiment. This indicates that in shale samples where the carbonate minerals, mainly calcite, are armored with other slow reacting minerals such as clays, the rate of fracture geometry evolution will be prolonged, which might be a positive point for the caprock integrity. However, the confirmed fluid-rock geochemical interactions within the shaly sample in a short time frame call for further investigations on the consequent impacts on caprock samples' geomechanical-hydrological properties for more extended periods relevant for subsurface CO2 storage. The microfluidic experiments are also used to validate a reactive transport model. The model will then be utilized to study changes in transport properties of different samples during experiments. The LBM-based model outputs, such as porosity-permeability relationships, can inform reactive models at larger scales to develop a better predictive numerical simulator for processes involved in CO2 storage projects.

• Masoudi, Mohammad; Parvin, Saeed; Miri, Rohaldin; Kord, Shahin & Hellevang, Helge (2021). Implementation of PC-SAFT Equation of State into MRST Compositional for Modelling of Asphaltene Precipitation. Fulltekst i vitenarkiv
• Masoudi, Mohammad; Fazeli, Hossein; Miri, Rohaldin & Hellevang, Helge (2021). Toward Probabilistic Modeling of Halite Nucleation and Growth during Carbon Storage Process: Pore Scale Modeling. Fulltekst i vitenarkiv
• Masoudi, Mohammad; Fazeli, Hossein; Miri, Rohaldin & Hellevang, Helge (2020). Probabilistic Modeling of Halite Nucleation and Growth in Porous Media: Pore Scale Modeling. Fulltekst i vitenarkiv
• Hellevang, Helge; Nooraiepour, Mohammad; Masoudi, Mohammad & Fazeli, Hossein (2020). Statistical Model for Mineral Nucleation and Growth. Fulltekst i vitenarkiv
• Masoudi, Mohammad; Parvin, Saeed; Miri, Rohaldin & Hellevang, Helge (2020). Implementation of ePc-SAFT Equation of State into MRST Compositional for Modelling of Salt Precipitation during CO2 Storage in Saline Aquifers. Fulltekst i vitenarkiv
• Masoudi, Mohammad (2020). Pore-Scale Modeling of Nucleation and Growth in Porous Media: A Probabilistic Approach. Fulltekst i vitenarkiv
• Hellevang, Helge; Miri, Rohaldin & Masoudi, Mohammad (2021). Near Wellbore Processes during Carbon Capture, Utilization, and Storage (CCUS): An Integrated Modeling Approach. Universitetet i Oslo. Fulltekst i vitenarkiv Vis sammendrag

  Carbon capture and storage (CCS) is a relatively new technology that captures CO2 before it reaches the atmosphere and safely stores it underground. CO2 storage will achieve significant climate change mitigation, only if it is implemented on a very large scale with considerable injection rates. To achieve a high injection rate, we need to ensure that the near wellbore area is clean because all the injected CO2 needs to pass through this zone before entering the reservoir. Clogging these paths reduces injectivity (ease of injection) and requires costly mitigation measures. In this PhD project, numerical models are developed at different scales to improve our understanding of near-well processes during CO2 storage and their effects on injectivity. It addresses the following research topics: 1. Thermodynamic modeling of complex systems: results showed that mutual solubilities of CO2 and H2O can provide a primary assessment of the possible risk of salt precipitation. 2. Continuum scale modeling of CO2 storage: results showed that the selected porosity-permeability relation is a significant source of uncertainty for simulation of injectivity impairment during CO2 injection. 3. Pore-scale modeling of mineral nucleation and growth: results showed that mineral nucleation should be modelled using a probabilistic approach to better predict the hydrodynamic properties of porous media. 4. Pore-scale modeling of salt aggregates formation during carbon storage: results showed that widely used porosity-permeability relations were unable to cover the clogging behavior of salt aggregates, indicating the need for developing a proper clogging model in this context.

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