Junpeng Zhang , Shaodong Jing , Zhenning Fan , Haining Liang , Junhui Zhang , Yan Zhang , Chunlong Sun , Jian Zhang
{"title":"Experimental and numerical investigation on near-field temperature and surface CO2 concentrations of buried dense phase CO2 pipeline leakage","authors":"Junpeng Zhang , Shaodong Jing , Zhenning Fan , Haining Liang , Junhui Zhang , Yan Zhang , Chunlong Sun , Jian Zhang","doi":"10.1016/j.ijggc.2025.104360","DOIUrl":"10.1016/j.ijggc.2025.104360","url":null,"abstract":"<div><div>Once the CO<sub>2</sub> fluid in the buried long-distance dense-phase pipeline leaks, it poses a significant threat to the surrounding environment and the safety of personnel. A large-scale field leakage diffusion test was conducted based on the CCUS million-ton buried dense phase long-distance CO<sub>2</sub> pipeline project in this study. The impact of the leakage's size (2 mm, 3 mm, 4 mm) and direction (horizontal, upward, and downward) on the soil morphology, temperature change, and surface CO<sub>2</sub> concentration around the leakage hole was studied. The velocity, CO<sub>2</sub> concentrations, and temperature field near the leakage port during the leakage process are simulated to supplement the experiments. The findings indicate that soil fissuring occurs when the leakage aperture exceeds 3 mm. The diameter of the frozen soil generated when the diameter of the vertical leakage is 4 mm is approximately twice that of the leakage diameter of 2 mm. Downward leakage has the most significant impact on low-temperature areas and the largest dry ice area under the condition of the same leakage port. The temperature drop rate increased directly to the size of the leakage hole, especially in the region 20–30 cm away from the leakage port. The surface CO<sub>2</sub> concentrations at the monitoring point at a height of 0.4 m above the leakage point for 2 mm leakage are predominantly influenced by wind. A height of 0.8–1.2 m can be selected as the appropriate monitoring height for leakage detection of the buried dense phase CO<sub>2</sub> pipeline. The surface CO<sub>2</sub> concentrations initially increase, subsequently decline and then experience a sudden surge due to the rupture and refreezing of the dry ice layer for leakage with an aperture larger than 3 mm. The horizontal and vertical diffusion distances of CO<sub>2</sub> concentrations up to 5 vol% were 1.5 m and 0.8 m for different direction tests after the rupture of soils. The research findings can provide valuable insights for improving leakage detection systems and performing risk assessments.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"143 ","pages":"Article 104360"},"PeriodicalIF":4.6,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143683603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ting Xiao , Jennifer Fitzgibbon , Michael Vanden Berg
{"title":"Early-stage risk assessment for the Uinta Basin CarbonSAFE Phase II project","authors":"Ting Xiao , Jennifer Fitzgibbon , Michael Vanden Berg","doi":"10.1016/j.ijggc.2025.104359","DOIUrl":"10.1016/j.ijggc.2025.104359","url":null,"abstract":"<div><div>Carbon dioxide (CO<sub>2</sub>) capture, utilization, and storage (CCUS) is considered a key solution to mitigate greenhouse gas emissions and limit climate change. Risk assessment and management are essential for CCUS projects. This article presents a case study of the Uinta Basin CarbonSAFE Phase II project to identify and assess potential risks associated with the development of commercial-scale CCUS in the Uinta Basin, eastern Utah, United States (U.S.), by an online questionnaire from six categories: economy, legal/policy, environment, social, management, and technicality. Specifically, 138 features, events, and processes (FEP) are identified and evaluated by feedback from project participants, experts, and residents.</div><div>Financial viability and CCUS legislation/policy are recognized as the highest-ranked risks. These are not unique to the Uinta Basin, but to the U.S. and the world. Updated legislation and policy incentives are expected to drive further development of CCUS, reduce the cost, and achieve climate expectations. Technical concerns include potential faults/fractures and their activation/growth, which require further quantitative assessment. In contrast, job loss is considered as a low risk, indicating potential economic growth with the deployment of CCUS. The results also suggest that preventive and mitigative activities should include technical assistance to operators and stakeholders regarding the most recent CCUS policies and requirements, and training programs for the next generation of the workforce.</div><div>This study provides an example of identifying potential risks at an early stage for CCUS deployment, and the responses of Uinta Basin residents can help establish effective communication channels between the project team and the local community.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"143 ","pages":"Article 104359"},"PeriodicalIF":4.6,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143683617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"High-spatial-resolution slip tendency modeling based on 3D seismic data to assess induced earthquake potential and identify suitable CO2 storage sites","authors":"Daulet Bakhtiyar , Takeshi Tsuji","doi":"10.1016/j.ijggc.2025.104355","DOIUrl":"10.1016/j.ijggc.2025.104355","url":null,"abstract":"<div><div>We propose a methodology for estimating slip tendency in a target geological setting with high spatial resolution using three-dimensional (3D) seismic reflection data. This framework assesses the potential for fluid-injection-induced earthquakes and identifies suitable well locations for CO<sub>2</sub> injection by integrating seismic interpretation, quantitative slip tendency analysis, and geostatistical modeling. A total of 242 normal and thrust faults extending to the seafloor were manually identified in the 3D seismic volume, with their dips and strikes determined. The stress tensor and slip tendencies for the faults were calculated mainly using fault geometry as input information for stress inversion, followed by geostatistical modeling. The validity of the slip tendency model was evaluated by comparing the modeled slip tendencies with past earthquake hypocenters. Areas of higher slip tendencies exhibited higher seismicity, indicating an increased likelihood of induced earthquakes in these regions. The mean slip tendency near hypocenters is much higher than the overall grid average. Although there are no CO<sub>2</sub> injection site in the study area, we present a case study for identifying suitable CO<sub>2</sub> storage sites within a 3D seismic data volume. The findings highlight the potential of this approach in advancing our understanding of fault behavior and seismicity within a given area, aiding in the assessment of geological hazards and the identification of slip-prone areas relevant to carbon capture and storage and other fluid management projects.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"143 ","pages":"Article 104355"},"PeriodicalIF":4.6,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143683615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amanda R. Stubbs , Faisal W.K. Khudhur , Ian M. Power , Linzi McDade , Mark Friel , Iain Neill , John MacDonald
{"title":"Optimizing the management of quarry fines for on-site carbon removal: Implications of grain size and mineralogy on CO2 mineralization","authors":"Amanda R. Stubbs , Faisal W.K. Khudhur , Ian M. Power , Linzi McDade , Mark Friel , Iain Neill , John MacDonald","doi":"10.1016/j.ijggc.2025.104344","DOIUrl":"10.1016/j.ijggc.2025.104344","url":null,"abstract":"<div><div>Weathering of basaltic quarry fines can enable quarries to remove CO<sub>2</sub> by optimizing the management of underutilized rock fines. In this study, basaltic fines from two quarries in Scotland are used as potential feedstocks for ERW. Using column experiments, fines from both sites were placed into columns as layers with varying thicknesses (1 cm and 5 cm) and grain sizes (bulk and <100 μm). Fines were saturated (≈60 % pore water) and exposed to ambient UK conditions (10 °C, 0.04 % CO<sub>2</sub>) and accelerated carbonation conditions (50 °C, 20 % CO<sub>2</sub>). Quarry site 1 experienced negligible increases in TIC within bulk fines under ambient conditions, yet fines <100 μm experienced carbonation equivalent to 440 g CO<sub>2</sub>/m<sup>2</sup>/yr. However, the total inorganic carbon content (TIC) nearly doubled in the bulk fines from quarry site 2 (5 cm) under ambient conditions, equivalent to 570 g CO<sub>2</sub>/m<sup>2</sup>/yr. In the sieved fines from the same site the TIC content nearly tripled, equivalent to 1330 g CO<sub>2</sub>/m<sup>2</sup>/yr. At site 2, if the bulk fines could be deposited over 0.8 km<sup>2</sup> of land in 5 cm thicknesses, approximately 460 t CO<sub>2</sub>/yr could be sequestered with minimal management practices in place. Using fresh fines that have not previously weathered in stockpiles is important for maximizing the carbon dioxide removal potential. Despite higher carbon offsets within the sieved material, the energy and cost required to crush rock from bulk to <100 μm is not economically feasible, as it exceeds the value of carbon which it could be sold for.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"143 ","pages":"Article 104344"},"PeriodicalIF":4.6,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143641923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Spatiotemporal shapley value-based pressure signal decomposition for enhanced geological carbon sequestration monitoring under uncertainty","authors":"Jose L. Hernandez-Mejia , Michael J. Pyrcz","doi":"10.1016/j.ijggc.2025.104356","DOIUrl":"10.1016/j.ijggc.2025.104356","url":null,"abstract":"<div><div>Geological Carbon Sequestration (GCS) involves capturing CO<sub>2</sub> from anthropogenic sources, such as power plants and industrial processes, and injecting it into geological formations for permanent storage. Monitoring subsurface CO<sub>2</sub> migration is essential to ensure that the injected CO<sub>2</sub> remains safely sequestered and does not leak into the atmosphere. Pressure sensing, in particular, is a cost-effective and efficient method for monitoring large pore networks and detecting changes in subsurface conditions. However, the presence of multiple CO<sub>2</sub> injector wells operating under distinct conditions, such as varying injection rates, well locations, and completion designs, complicates the pressure response observed in monitoring wells. This complexity makes it challenging to accurately track individual CO<sub>2</sub> plumes originating from specific injector wells. Understanding the pressure dynamics is crucial for ensuring the integrity of the storage site and optimizing injection strategies. To address this challenge, this study proposes a comprehensive workflow for bottomhole pressure (BHP) decomposition. We utilize Shapley values, combined with geostatistical modeling and numerical flow simulation, to determine the individual pressure contributions from each injector well to the monitoring wells. By discretizing Shapley values in both time and space for a given subsurface model, we calculate the marginal pressure contributions of injector wells while accounting for interaction effects, spatial context, and time-varying operational conditions. This approach enhances the accuracy and reliability of GCS monitoring. Additionally, partial dependency plots are created to evaluate the pressure dynamics between injectors and monitor BHP over time, providing valuable insights into the behavior of the storage reservoir.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"143 ","pages":"Article 104356"},"PeriodicalIF":4.6,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Decarbonising the energy sector with oxy-combustion CCS: A techno-economic analysis of the Graz Cycle power plant","authors":"Benjamin Mitterrutzner , Wolfgang Sanz","doi":"10.1016/j.ijggc.2025.104343","DOIUrl":"10.1016/j.ijggc.2025.104343","url":null,"abstract":"<div><div>The objective of this paper is to assess the economic costs of an oxy-combustion power plant with CO<sub>2</sub> capture, known as the Graz Cycle. For this purpose, we employ a methodology based on common practices in the field of point-source CO<sub>2</sub> capture and storage (CCS) utilising a process modelling tool to analyse the economic cost metrics under (a) full-load and (b) part-load condition. On this basis, we assess (i) the total annualised cost, (ii) the levelised cost of electricity, and (iii) the CO<sub>2</sub> avoidance cost of the Graz Cycle fired with natural gas. The result for a Graz Cycle pilot plant with approximately 62 MW net power output and a natural gas price of 30 €/MWh (base case) show a total annualised cost of 55.6 M€/a and a levelised cost of electricity of 113.3 €/MWh. An investment analysis shows that the Graz Cycle reaches economic break-even at a natural gas price of <span><math><mo>∼</mo></math></span>95 €/MWh. Moreover, the analysis reveals that the Graz Cycle has a cost advantage over natural gas combined cycles with post-combustion capture, particularly in scenarios with high CO<sub>2</sub> taxes and a large installed plant capacity. The main contribution of this paper is a unique techno-economic analysis of the Graz Cycle, demonstrating its efficiency and economic viability across varying operational scenarios and CO<sub>2</sub> tax regimes.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"143 ","pages":"Article 104343"},"PeriodicalIF":4.6,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Iain de Jonge-Anderson , Hariharan Ramachandran , Ana Widyanita , Andreas Busch , Florian Doster , Uisdean Nicholson
{"title":"Regional screening of saline aquifers in the Malay Basin for CO2 storage","authors":"Iain de Jonge-Anderson , Hariharan Ramachandran , Ana Widyanita , Andreas Busch , Florian Doster , Uisdean Nicholson","doi":"10.1016/j.ijggc.2025.104347","DOIUrl":"10.1016/j.ijggc.2025.104347","url":null,"abstract":"<div><div>The Malay Basin has received significant attention for geological carbon dioxide storage (GCS), but there are no published studies addressing the selection of appropriate deep saline aquifers. This study closes this gap. We process spatial data and use geological modelling and cluster analysis to identify optimal areas for GCS, considering various subsurface characteristics such as temperature, pressure, porosity and thermophysical CO<sub>2</sub> properties. It is found that the basin contains numerous Cenozoic aquifers suitable for GCS including locally thick, but low net-to-gross (NTG), stacked formations. Pliocene aquifers are too shallow to offer storage for CO<sub>2</sub> in large quantities, but upper Miocene aquifers located in the northwest of the basin contain promising intervals with significant porosities and conditions favouring denser CO<sub>2</sub>. Middle Miocene aquifers, while low NTG, are thick, and optimally located around the margins of the basin. They also have significant storage capacity and could be developed as a stacked GCS site. Lower Miocene aquifers are higher NTG, but deeply buried across many areas of the basin, yet the oldest aquifer evaluated still holds substantial storage capacity, where subject to minor burial at the margins of the basin. Overall, this study provides a novel first assessment of aquifer GCS potential in the Malay Basin, while also contributing to wider efforts to evolve screening workflows for other geological basins.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"143 ","pages":"Article 104347"},"PeriodicalIF":4.6,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143592647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Miguel Abreu, Athreya Suresh Babu, Gary T. Rochelle
{"title":"High CO2 removal with aqueous piperazine at the NCCC pilot plant under NGCC conditions","authors":"Miguel Abreu, Athreya Suresh Babu, Gary T. Rochelle","doi":"10.1016/j.ijggc.2025.104346","DOIUrl":"10.1016/j.ijggc.2025.104346","url":null,"abstract":"<div><div>A pilot plant campaign at the National Carbon Capture Center (NCCC) used the Piperazine with the Advanced Stripper (PZAS) treating gas with 4.3 mol % (dry) CO<sub>2</sub> and 8 mol % H<sub>2</sub>O at 110 °C. The absorber with pump-around intercooling (PA IC) maintained 95.5 % CO<sub>2</sub> removal for 4000 h. The lean loading was 0.2 mol/equiv N with an average rich loading of 0.4 mol/equiv N. The heat duty was minimized with sequential steps changes in bypass flowrates. The minimum net heat duty was 2.43 GJ/tonne, at 5 % cold and 64 % warm rich bypass. Parametric testing during the campaign included operation without a lean solvent cooler and at a low lean loading of 0.18 mol/equiv N.</div><div>Rigorous rate-based models predicted the performance of the stripper and absorber within ± 5 %. These models were used to study process design. In the absence of a lean solvent cooler, PA IC temperatures between 26.6 and 40 °C produced a CO<sub>2</sub> removal between 97 and 90 %, at a constant rich loading of 0.4 mol/equiv N. The feasibility of this design is contingent on the ability to maintain the PA IC temperature. The NCCC system could achieve 98.6 % CO<sub>2</sub> removal without causing water to condense in the absorber. Water condensation will limit all aqueous capture solvents with equilibrium constraints. Operating above this limit requires process modifications to enable water balance control and removal of volatile amine in the water wash or the addition of a direct contact cooler upstream of the absorber to avoid water condensation.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"143 ","pages":"Article 104346"},"PeriodicalIF":4.6,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143592076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Integration of KOH-based CO2 absorption and Ca(OH)2-triggered mineralization: Process tracking and kinetic analysis","authors":"Xing Fan , Yonne Syu , Firman Bagja Juangsa , Tomohiro Nozaki","doi":"10.1016/j.ijggc.2025.104339","DOIUrl":"10.1016/j.ijggc.2025.104339","url":null,"abstract":"<div><div>KOH-based CO<sub>2</sub> absorption was integrated with Ca(OH)<sub>2</sub>-triggered mineralization under ambient conditions. CO<sub>2</sub> is chemically absorbed into the aqueous KOH solution in two consecutive absorption stages, reacting rapidly with OH<sup>-</sup> to produce CO<sub>3</sub><sup>2-</sup> and slowly with CO<sub>3</sub><sup>2-</sup> to produce HCO<sub>3</sub><sup>-</sup> in the 1st and 2nd stage, respectively. The total CO<sub>2</sub> loading reaches 0.95 mol CO<sub>2</sub>/mol KOH. CO<sub>2</sub> absorption rate in the 1st stage is determined by the diffusion of CO<sub>2</sub> and is thus independent of the OH<sup>-</sup> concentration and enhanced by increasing inlet CO<sub>2</sub> concentration. In the 2nd stage, CO<sub>2</sub> absorption rate is determined by the absorption reaction and linearly decreased with decreasing CO<sub>3</sub><sup>2-</sup> concentration. The prepared K<sub>2</sub>CO<sub>3</sub> and KHCO<sub>3</sub> solutions exhibited similar performance toward mineralization by Ca(OH)<sub>2</sub>. After 20 min of reaction under a Ca/C molar ratio of 1.0, KOH regeneration efficiency reached 75.9 % from K<sub>2</sub>CO<sub>3</sub> and 76.1 % from KHCO<sub>3</sub>. Mineralization of the CO<sub>2</sub>-rich absorption solution occurred rapidly. Under a Ca/C molar ratio of 1.1, KOH regeneration efficiency reached 73.3 % after 5 min and 83.9 % at steady state after 20 min of reaction. Dissolution of Ca(OH)<sub>2</sub> is likely the rate-controlling step and XRD and SEM analysis confirmed the selective conversion of Ca(OH)<sub>2</sub> (portlandite) to CaCO<sub>3</sub> (calcite) during the mineralization process.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"143 ","pages":"Article 104339"},"PeriodicalIF":4.6,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143577949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andrea Callioli Santi , Philip Ringrose , Jo Eidsvik , Tor Andre Haugdahl
{"title":"Invasion percolation Markov Chains – A probabilistic framework for assessing vertical CO2 migration","authors":"Andrea Callioli Santi , Philip Ringrose , Jo Eidsvik , Tor Andre Haugdahl","doi":"10.1016/j.ijggc.2025.104338","DOIUrl":"10.1016/j.ijggc.2025.104338","url":null,"abstract":"<div><div>Potential CO<sub>2</sub> storage sites need to perform risk assessments on the likelihood of anomalous events such as leakage. The intrinsic heterogeneity of the rock system with uncertain values for the capillary threshold pressures of the various rock elements is the most likely reason for unexpected vertical migration of CO<sub>2</sub> within a storage complex. This study shows how the Invasion Percolation Markov Chain approach can be used to address this concern. We tested the approach using detailed 3D models of the multi-layer plume at Sleipner showing that even small variations in the threshold pressures of the shales can impact the flow of CO<sub>2</sub> into multiple accumulations. Models with and without shale breaks reveal the importance of vertical feeders and/or faults, and the geometry of the shale layers is also crucial as the CO<sub>2</sub> strongly conforms to topography. We demonstrate that the vertical migration of CO<sub>2</sub> at Sleipner follows a Markovian model in which the probability of later migration events is highly dependent of the probability of preceding events. This case study illustrates how the initial migration events, which have the highest probability of occurring, should be the focus of CO<sub>2</sub> storage risk assessments.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"142 ","pages":"Article 104338"},"PeriodicalIF":4.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}