Pub Date : 2025-04-23DOI: 10.1016/j.ijggc.2025.104377
Lei Qin , Siheng Lin , Haifei Lin , Shugang Li , Niandong Chen , Chengang Sun
The mineralization reaction characteristics of alkali-activated fly ash with CO2 directly influence its carbon sequestration capacity. Investigating the micro-scale carbon sequestration mechanisms in alkali-activated fly ash mineralization reactions is essential for improving the efficiency of mineralization and sequestration of fly ash. This study focuses on lignite fly ash from a coal-fired power plant in Shijiazhuang, China. A closed mineralization reactor experimental platform and a pressure drop method were utilized to characterize carbonation performance. The experimental results indicate that the alkali activation treatment effectively enhances the mineralization and carbon sequestration performance of fly ash. Alkali-activated lignite fly ash post-mineralization reaction surfaces showed significant carbonate material presence. After mineralization reaction, the distribution of particle sizes of alkali-activated lignite fly ash increased. The C-O bonds in mineralized fly ash increase with the degree of alkali activation, indicating that alkali activation treatment enhance the carbon sequestration capability of lignite fly ash.
{"title":"Characteristics of alkali-activated fly Ash-CO2 mineralization reaction and micro carbon sequestration mechanism","authors":"Lei Qin , Siheng Lin , Haifei Lin , Shugang Li , Niandong Chen , Chengang Sun","doi":"10.1016/j.ijggc.2025.104377","DOIUrl":"10.1016/j.ijggc.2025.104377","url":null,"abstract":"<div><div>The mineralization reaction characteristics of alkali-activated fly ash with CO<sub>2</sub> directly influence its carbon sequestration capacity. Investigating the micro-scale carbon sequestration mechanisms in alkali-activated fly ash mineralization reactions is essential for improving the efficiency of mineralization and sequestration of fly ash. This study focuses on lignite fly ash from a coal-fired power plant in Shijiazhuang, China. A closed mineralization reactor experimental platform and a pressure drop method were utilized to characterize carbonation performance. The experimental results indicate that the alkali activation treatment effectively enhances the mineralization and carbon sequestration performance of fly ash. Alkali-activated lignite fly ash post-mineralization reaction surfaces showed significant carbonate material presence. After mineralization reaction, the distribution of particle sizes of alkali-activated lignite fly ash increased. The C-O bonds in mineralized fly ash increase with the degree of alkali activation, indicating that alkali activation treatment enhance the carbon sequestration capability of lignite fly ash.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"144 ","pages":"Article 104377"},"PeriodicalIF":4.6,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143858989","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}
Pub Date : 2025-04-21DOI: 10.1016/j.ijggc.2025.104386
Abdulrauf R. Adebayo , Mohamed Gamal Rezk , Zuhair AlYousef , Rahul S. Babu , Almohannad Alhashboul
The trapping coefficient is a parameter that describes the relationship between the displacement efficiency and capillary trapping of a gas in a porous medium. Accurate prediction of gas residual trapping is essential in evaluating underground carbon storage projects. The determination of the gas trapping coefficient could be complicated when a high-pressure and high-temperature experiment is needed to mimic subsurface conditions and when a complex gas is involved. The objective of this study is to investigate the role of gas type and operating conditions on trapping coefficient using Indiana limestone core samples with different permeability ranges and different gases such as CO2, N2, H2, and air. A variety of displacement methods was employed such as a simple benchtop porous plate drainage chamber, an electrical resistivity-based saturation monitoring core flooding equipment, and a vapor desorption chamber to drain water-saturated rock samples to different levels of water saturation. The different methods displaced brine at different levels of capillary pressures. A benchtop spontaneous imbibition chamber was then used to spontaneously imbibe brine again under a capillary-dominated process until a residual gas saturation was attained in each case. A nuclear magnetic resonance (NMR) relaxation technique was used to monitor fluid distribution in the pores of the saturated samples, gas saturations after drainage, and the trapped gas saturations. An initial-residual saturation curve based on Land’s (1968) trapping model was then used to compare the trapping coefficient of the rock samples to the different gases. The trapping coefficients of the rock samples were similar for the tested gases, although hydrogen exhibited a relatively lower residual trapping efficiency. This observation further elucidates previous results and confirms that the trapping coefficient is mainly a function of pore structure. However, this observation is not conclusive until further tests are completed on rocks with a wider range of petrophysical properties and under the same flow conditions.
{"title":"Similarity of trapping efficiencies for N2, CO2, H2, and air in indiana limestone based on capillary gas displacement and spontaneous water imbibition experiments","authors":"Abdulrauf R. Adebayo , Mohamed Gamal Rezk , Zuhair AlYousef , Rahul S. Babu , Almohannad Alhashboul","doi":"10.1016/j.ijggc.2025.104386","DOIUrl":"10.1016/j.ijggc.2025.104386","url":null,"abstract":"<div><div>The trapping coefficient is a parameter that describes the relationship between the displacement efficiency and capillary trapping of a gas in a porous medium. Accurate prediction of gas residual trapping is essential in evaluating underground carbon storage projects. The determination of the gas trapping coefficient could be complicated when a high-pressure and high-temperature experiment is needed to mimic subsurface conditions and when a complex gas is involved. The objective of this study is to investigate the role of gas type and operating conditions on trapping coefficient using Indiana limestone core samples with different permeability ranges and different gases such as CO<sub>2</sub>, N<sub>2</sub>, H<sub>2</sub>, and air. A variety of displacement methods was employed such as a simple benchtop porous plate drainage chamber, an electrical resistivity-based saturation monitoring core flooding equipment, and a vapor desorption chamber to drain water-saturated rock samples to different levels of water saturation. The different methods displaced brine at different levels of capillary pressures. A benchtop spontaneous imbibition chamber was then used to spontaneously imbibe brine again under a capillary-dominated process until a residual gas saturation was attained in each case. A nuclear magnetic resonance (NMR) relaxation technique was used to monitor fluid distribution in the pores of the saturated samples, gas saturations after drainage, and the trapped gas saturations. An initial-residual saturation curve based on Land’s (1968) trapping model was then used to compare the trapping coefficient of the rock samples to the different gases. The trapping coefficients of the rock samples were similar for the tested gases, although hydrogen exhibited a relatively lower residual trapping efficiency. This observation further elucidates previous results and confirms that the trapping coefficient is mainly a function of pore structure. However, this observation is not conclusive until further tests are completed on rocks with a wider range of petrophysical properties and under the same flow conditions.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"144 ","pages":"Article 104386"},"PeriodicalIF":4.6,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855202","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}
Pub Date : 2025-04-21DOI: 10.1016/j.ijggc.2025.104381
Tae Wook Kim, Yunan Li, Arjun H. Kohli, Anthony R. Kovscek
A protocol is demonstrated for assessment of CO2 leakage through existing wellbores and faults at CO2 storage sites including pre-existing, plugged-and-abandoned wellbores and Quaternary faults. Total injection at the prospective saline aquifer site in the southern San Joaquin Basin, CA is planned as 12.3 Mt CO2 with variable annual rates over 18 years followed by 100 years of monitoring. Reservoir simulation optimized CO2 injection by minimizing the pressure build-up and the overall size of the CO2 plume. The plume pressure and saturation history are input to one of the reduced order models in NRAP-OPEN-IAM to obtain distributions of potential leakage rates. During leakage assessment, the permeability of the plugged wellbores is assumed to be large (1 mD to 10 mD) to obtain worst-case estimates. Faults are considered to stretch from the surface to the storage zone. Leakage rates to the USDW are found to be negligible and within background expectations. The ratio of cumulative CO2 mass leaked to injected using the optimized well scenarios is estimated to range from 0.0003% to 0.001% after 118 years. Additionally, leakage rates along Quaternary faults are predicted to be at least an order of magnitude less compared to leakage from the existing wellbores. The various injection well trajectory scenarios show different leakage rates due to the relative location of wellbores within the CO2 and pressure plumes. In all cases, the amount of CO2 that leaks relative to what is injected is much less than 1%.
{"title":"Assessment of CO2 leakage through existing wells and faults for a prospective storage site in the Southern San Joaquin Basin, California","authors":"Tae Wook Kim, Yunan Li, Arjun H. Kohli, Anthony R. Kovscek","doi":"10.1016/j.ijggc.2025.104381","DOIUrl":"10.1016/j.ijggc.2025.104381","url":null,"abstract":"<div><div>A protocol is demonstrated for assessment of CO<sub>2</sub> leakage through existing wellbores and faults at CO<sub>2</sub> storage sites including pre-existing, plugged-and-abandoned wellbores and Quaternary faults. Total injection at the prospective saline aquifer site in the southern San Joaquin Basin, CA is planned as 12.3 Mt CO<sub>2</sub> with variable annual rates over 18 years followed by 100 years of monitoring. Reservoir simulation optimized CO<sub>2</sub> injection by minimizing the pressure build-up and the overall size of the CO<sub>2</sub> plume. The plume pressure and saturation history are input to one of the reduced order models in NRAP-OPEN-IAM to obtain distributions of potential leakage rates. During leakage assessment, the permeability of the plugged wellbores is assumed to be large (1 mD to 10 mD) to obtain worst-case estimates. Faults are considered to stretch from the surface to the storage zone. Leakage rates to the USDW are found to be negligible and within background expectations. The ratio of cumulative CO<sub>2</sub> mass leaked to injected using the optimized well scenarios is estimated to range from 0.0003% to 0.001% after 118 years. Additionally, leakage rates along Quaternary faults are predicted to be at least an order of magnitude less compared to leakage from the existing wellbores. The various injection well trajectory scenarios show different leakage rates due to the relative location of wellbores within the CO<sub>2</sub> and pressure plumes. In all cases, the amount of CO<sub>2</sub> that leaks relative to what is injected is much less than 1%.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"144 ","pages":"Article 104381"},"PeriodicalIF":4.6,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851767","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}
Pub Date : 2025-04-18DOI: 10.1016/j.ijggc.2025.104376
Duncan T.E. McDonald , Ian M. Power , Carlos Paulo , Sasha Wilson
Kimberlite residues generated at diamond mines have the potential to substantially reduce net greenhouse gas emissions and contribute towards carbon-neutral mining. As part of the De Beers CarbonVault™, we conducted experiments using fine kimberlite residues from the Gahcho Kué Diamond Mine, Northwest Territories, Canada, to assess the mine's potential for CO2 sequestration. Batch CO2 leach tests indicate a CO2 sequestration potential of 12 kg CO2/t based on easily extractable cations from non-carbonate sources. However, an evaluation of the short-term reactivity of the residues post-deposition revealed the ability to sequester 0.86 kg CO2/t when residues were allowed to dry through optimal water saturation (30–40 %). Furthermore, year-long weathering columns determined a CO2 removal rate of 0.63 kg CO2/t/yr, primarily through mineral trapping. Extrapolating these rates to current annual residue production and emissions indicates that 7 % of the mine's estimated CO2e emissions could be sequestered over the life of mine. These rates are based on optimal storage conditions that keep residues exposed for long periods, which should be a consideration of residue management practices during the operating life of the mine and post closure. Further on-site investigations are necessary to refine rates and account for climatic conditions. Assessments conducted in this study affirm the suitability of Gahcho Kué residues for CO2 sequestration and present strategies for optimizing this process.
{"title":"CO2 mineralization of kimberlite residues from the Gahcho Kué Diamond Mine, Northwest Territories, Canada","authors":"Duncan T.E. McDonald , Ian M. Power , Carlos Paulo , Sasha Wilson","doi":"10.1016/j.ijggc.2025.104376","DOIUrl":"10.1016/j.ijggc.2025.104376","url":null,"abstract":"<div><div>Kimberlite residues generated at diamond mines have the potential to substantially reduce net greenhouse gas emissions and contribute towards carbon-neutral mining. As part of the De Beers CarbonVault™, we conducted experiments using fine kimberlite residues from the Gahcho Kué Diamond Mine, Northwest Territories, Canada, to assess the mine's potential for CO<sub>2</sub> sequestration. Batch CO<sub>2</sub> leach tests indicate a CO<sub>2</sub> sequestration potential of 12 kg CO<sub>2</sub>/t based on easily extractable cations from non-carbonate sources. However, an evaluation of the short-term reactivity of the residues post-deposition revealed the ability to sequester 0.86 kg CO<sub>2</sub>/t when residues were allowed to dry through optimal water saturation (30–40 %). Furthermore, year-long weathering columns determined a CO<sub>2</sub> removal rate of 0.63 kg CO<sub>2</sub>/t/yr, primarily through mineral trapping. Extrapolating these rates to current annual residue production and emissions indicates that 7 % of the mine's estimated CO<sub>2</sub>e emissions could be sequestered over the life of mine. These rates are based on optimal storage conditions that keep residues exposed for long periods, which should be a consideration of residue management practices during the operating life of the mine and post closure. Further on-site investigations are necessary to refine rates and account for climatic conditions. Assessments conducted in this study affirm the suitability of Gahcho Kué residues for CO<sub>2</sub> sequestration and present strategies for optimizing this process.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"144 ","pages":"Article 104376"},"PeriodicalIF":4.6,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844265","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}
Pub Date : 2025-04-18DOI: 10.1016/j.ijggc.2025.104378
Nadia Tarakki, David Risk
The radiocarbon isotope of CO2 (Δ14CO2) is a valuable tool for investigating soil-respired CO2 and identifying its sources. At Aquistore, a CCS project in Canada, Δ14CO2 is incorporated into surface soil-gas geochemical MMV studies to demonstrate the absence of surface impacts from CO2 injection. However, some monitoring locations consistently show negative Δ14CO2 values (usually indicative of fossil CO2) that predate CO2 injections, suggesting these anomalies are natural or linked to soil disturbances. This study investigates the origins of these anomalies. We first hypothesized that CO2 venting from coal seams underlying parts of the monitoring grid could explain the negative values. A spatial correlation between negative Δ14CO2 values, historic open-pit coal mines, and mine spoils supported this hypothesis. However, Δ14CO2 analysis from a nearby farm (control site) with intact coal seams but no mine spoils showed modern-age signatures (6.8 ± 16 %), ruling out the venting hypothesis. Next, we tested whether microbial decomposition of weathered coal fragments was responsible. A soil survey revealed a strong correlation between coal fragment concentrations (1.85–40.64 % w/w) and Δ14CO2 anomalies. Laboratory incubation experiments further supported this hypothesis, showing that dry soils with weathered coal fragments produced proportionately negative Δ14CO2 values, likely due to microbial activity. These findings underscore the need for a more nuanced and site-specific approach to CCS monitoring. In geochemically complex sites like Aquistore, relying solely on Δ14CO2 may be misleading, and alternative tracers should be considered to ensure accurate soil-gas anomaly interpretations.
{"title":"Investigating radiocarbon isotope anomalies in CO2 for CCS monitoring: Insights from the Aquistore project and the influence of coal mine spoils","authors":"Nadia Tarakki, David Risk","doi":"10.1016/j.ijggc.2025.104378","DOIUrl":"10.1016/j.ijggc.2025.104378","url":null,"abstract":"<div><div>The radiocarbon isotope of CO<sub>2</sub> (Δ<sup>14</sup>CO<sub>2</sub>) is a valuable tool for investigating soil-respired CO<sub>2</sub> and identifying its sources. At Aquistore, a CCS project in Canada, Δ<sup>14</sup>CO<sub>2</sub> is incorporated into surface soil-gas geochemical MMV studies to demonstrate the absence of surface impacts from CO<sub>2</sub> injection. However, some monitoring locations consistently show negative Δ<sup>14</sup>CO<sub>2</sub> values (usually indicative of fossil CO<sub>2</sub>) that predate CO<sub>2</sub> injections, suggesting these anomalies are natural or linked to soil disturbances. This study investigates the origins of these anomalies. We first hypothesized that CO<sub>2</sub> venting from coal seams underlying parts of the monitoring grid could explain the negative values. A spatial correlation between negative Δ<sup>14</sup>CO<sub>2</sub> values, historic open-pit coal mines, and mine spoils supported this hypothesis. However, Δ<sup>14</sup>CO<sub>2</sub> analysis from a nearby farm (control site) with intact coal seams but no mine spoils showed modern-age signatures (6.8 ± 16 %), ruling out the venting hypothesis. Next, we tested whether microbial decomposition of weathered coal fragments was responsible. A soil survey revealed a strong correlation between coal fragment concentrations (1.85–40.64 % w/w) and Δ<sup>14</sup>CO<sub>2</sub> anomalies. Laboratory incubation experiments further supported this hypothesis, showing that dry soils with weathered coal fragments produced proportionately negative Δ<sup>14</sup>CO<sub>2</sub> values, likely due to microbial activity. These findings underscore the need for a more nuanced and site-specific approach to CCS monitoring. In geochemically complex sites like Aquistore, relying solely on Δ<sup>14</sup>CO<sub>2</sub> may be misleading, and alternative tracers should be considered to ensure accurate soil-gas anomaly interpretations.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"144 ","pages":"Article 104378"},"PeriodicalIF":4.6,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847900","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}
Pub Date : 2025-04-17DOI: 10.1016/j.ijggc.2025.104371
L. Griffiths , N. Thompson , H. Smith , E. Skurtveit , L. Grande
This study presents and analyses the results of rock mechanical testing of sandstone and shale samples from the CO2 storage confirmation well 31/5–7 (Eos) in EL 001 in the North Sea. Although detailed experimental laboratory programs are performed for many hydrocarbon development projects in the North Sea, only a limited number of site-specific experimentally-derived mechanical data are available in the literature. The tested samples included sandstone from the Cook (2680.25–2680.5 m) and Johansen (2761.00–2761.25 m and 2725–2725.25 m) formations, and shale from the Intra-Drake Formation (2592.00–2595.18 m). For each of the sandstones, Brazilian tests, three drained isotropically-consolidated (CID) triaxial tests, one hydrostatic test, and one anisotropically-consolidated uniaxial strain test (CAUST) were performed. For the shale, the testing comprised four permeability tests conducted on both vertical and horizontal plugs, five undrained isotropically-consolidated triaxial tests (CIU; three on vertical plugs and two on horizontal plugs), seven Brazilian tests (on four horizontal and three vertical plugs), and a uniaxial strain test (CAUST). The tests were designed to characterize the mechanical behaviour of the reservoir and cap rocks within stress and strain regimes relevant to CO2 injection scenarios. Measurements of the elastic and poroelastic properties, strength, failure criteria, and permeability are provided, including an assessment of the mechanical and hydraulic anisotropy in the case of the shale samples. The data, accessible through CO2Datashare (Northern Lights JV, 2023), significantly enhance the understanding of North Sea lithologies and supply critical parameters for accurately modeling the geomechanical response of the reservoir and overburden in response to CO2 injection.
{"title":"Rock mechanical testing of core from the Eos Northern Lights CCS confirmation well and implications for the Geomechanics of North Sea CO2 storage","authors":"L. Griffiths , N. Thompson , H. Smith , E. Skurtveit , L. Grande","doi":"10.1016/j.ijggc.2025.104371","DOIUrl":"10.1016/j.ijggc.2025.104371","url":null,"abstract":"<div><div>This study presents and analyses the results of rock mechanical testing of sandstone and shale samples from the CO<sub>2</sub> storage confirmation well 31/5–7 (Eos) in EL 001 in the North Sea. Although detailed experimental laboratory programs are performed for many hydrocarbon development projects in the North Sea, only a limited number of site-specific experimentally-derived mechanical data are available in the literature. The tested samples included sandstone from the Cook (2680.25–2680.5 m) and Johansen (2761.00–2761.25 m and 2725–2725.25 m) formations, and shale from the Intra-Drake Formation (2592.00–2595.18 m). For each of the sandstones, Brazilian tests, three drained isotropically-consolidated (CID) triaxial tests, one hydrostatic test, and one anisotropically-consolidated uniaxial strain test (CAUST) were performed. For the shale, the testing comprised four permeability tests conducted on both vertical and horizontal plugs, five undrained isotropically-consolidated triaxial tests (CIU; three on vertical plugs and two on horizontal plugs), seven Brazilian tests (on four horizontal and three vertical plugs), and a uniaxial strain test (CAUST). The tests were designed to characterize the mechanical behaviour of the reservoir and cap rocks within stress and strain regimes relevant to CO<sub>2</sub> injection scenarios. Measurements of the elastic and poroelastic properties, strength, failure criteria, and permeability are provided, including an assessment of the mechanical and hydraulic anisotropy in the case of the shale samples. The data, accessible through CO2Datashare (Northern Lights JV, 2023), significantly enhance the understanding of North Sea lithologies and supply critical parameters for accurately modeling the geomechanical response of the reservoir and overburden in response to CO<sub>2</sub> injection.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"144 ","pages":"Article 104371"},"PeriodicalIF":4.6,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143839642","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}
Pub Date : 2025-04-17DOI: 10.1016/j.ijggc.2025.104380
Reinier van Noort , Gaute Svenningsen , Kai Li , Anne Pluymakers
Maintaining well integrity is a key challenge to the secure geological storage of CO2. Here, sealants based on Portland Cement form a key component, providing seals between the steel wellbore and surrounding caprock, as well as plugs for sealing wells that will no longer be used. However, exposure of sealants based on Portland Cement to CO2-bearing fluids may lead to carbonation, potentially followed by degradation of these materials during prolonged exposure or flow, which may thus negatively impact well integrity. Therefore, new sealant materials need to be developed to help ensure long-term well integrity.
This paper reports exposure of five different sealants to CO2-saturated water and wet supercritical CO2 at in-situ conditions (80 °C and 10 MPa). Three of the sealants investigated are based on Portland Cement, while the other two are based on Calcium Aluminate Cement, and a rock-based geopolymer specifically developed for Geological CO2 Storage (GCS). The five sealants were selected to represent different methods for improving wellbore seal integrity, such as restricting permeability (and porosity), or modifying how the material interacts with CO2-bearing fluids. Exposures were carried out in a purpose-built batch apparatus, enabling simultaneous exposure of up to 10 samples in total to CO2-saturated water and wet supercritical CO2.
After exposure, changes in the sealants’ microstructures and chemical and mineralogical compositions were assessed using scanning electron microscopy with energy-dispersive X-ray spectroscopy, computed tomography scanning, and fluid chemical analysis. The impact of exposure to CO2-bearing fluids was interpreted in terms of alteration and degradation of the materials, to compare how different sealant design modifications can be employed to enhance wellbore integrity.
{"title":"Exposure of five cementitious sealant materials to wet supercritical CO2 and CO2-saturated water under simulated downhole conditions","authors":"Reinier van Noort , Gaute Svenningsen , Kai Li , Anne Pluymakers","doi":"10.1016/j.ijggc.2025.104380","DOIUrl":"10.1016/j.ijggc.2025.104380","url":null,"abstract":"<div><div>Maintaining well integrity is a key challenge to the secure geological storage of CO<sub>2</sub>. Here, sealants based on Portland Cement form a key component, providing seals between the steel wellbore and surrounding caprock, as well as plugs for sealing wells that will no longer be used. However, exposure of sealants based on Portland Cement to CO<sub>2</sub>-bearing fluids may lead to carbonation, potentially followed by degradation of these materials during prolonged exposure or flow, which may thus negatively impact well integrity. Therefore, new sealant materials need to be developed to help ensure long-term well integrity.</div><div>This paper reports exposure of five different sealants to CO<sub>2</sub>-saturated water and wet supercritical CO<sub>2</sub> at in-situ conditions (80 °C and 10 MPa). Three of the sealants investigated are based on Portland Cement, while the other two are based on Calcium Aluminate Cement, and a rock-based geopolymer specifically developed for Geological CO<sub>2</sub> Storage (GCS). The five sealants were selected to represent different methods for improving wellbore seal integrity, such as restricting permeability (and porosity), or modifying how the material interacts with CO<sub>2</sub>-bearing fluids. Exposures were carried out in a purpose-built batch apparatus, enabling simultaneous exposure of up to 10 samples in total to CO<sub>2</sub>-saturated water and wet supercritical CO<sub>2</sub>.</div><div>After exposure, changes in the sealants’ microstructures and chemical and mineralogical compositions were assessed using scanning electron microscopy with energy-dispersive X-ray spectroscopy, computed tomography scanning, and fluid chemical analysis. The impact of exposure to CO<sub>2</sub>-bearing fluids was interpreted in terms of alteration and degradation of the materials, to compare how different sealant design modifications can be employed to enhance wellbore integrity.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"144 ","pages":"Article 104380"},"PeriodicalIF":4.6,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844268","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}
Pub Date : 2025-04-15DOI: 10.1016/j.ijggc.2025.104379
Mohammad Reza Nasiri , Behzad Rostami , Mohammad Keramati Nejad , Siavash Riahi , Alireza Fathollahi , Wael Fadi Al-Masri
Saline aquifers, the primary option for carbon dioxide (CO2) storage, face a significant challenge in the form of salt precipitation from water evaporation during geological CO2 sequestration. This salting-out phenomenon can alter reservoir porosity and permeability, impacting injectivity. While previous experimental studies have focused on how salt precipitation negatively affects CO2 injectivity, research on mitigation strategies is less prevalent. This study, however, places a strong emphasis on investigating the intermittent injection of brine and scCO2 as a potential mitigation strategy for salt precipitation in saline aquifers. The results of the experiments point to the significant potential of this method as a practical solution. Two high-pressure, high-temperature core flooding experiments were designed to look into how salt precipitation affects injectivity. The effect of formation water salinity was also studied, considering salinities of 2 g/L and 200 g/L. In the lower salinity experiment, no significant salt precipitation was observed at the end of the test. In contrast, the higher salinity experiment showed a 44 % decrease in CO2 relative permeability at residual water saturation, manifested as an increase in differential pressure. Following the dynamic experiments, Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) was performed on the effluent brine, revealing that geochemical interactions between the rock and fluids had a negligible impact on the outcomes. Additionally, the conditions of the plug samples before and after supercritical CO2 (scCO2) injection were analysed using Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS), revealing visible NaCl salt crystals and accumulation within the pore space of the rock. Subsequently, two additional core flooding experiments were conducted to investigate the effect of intermittent injection of brine and scCO2 on injectivity and mitigation salt precipitation. The injection procedure involves a continuous process of temporarily stopping scCO2 injection, followed by water injection, and then resuming scCO2 injection at the same rate. Two salinities, 200 g/L and 38 g/L, were evaluated for the intermediate injection. At a water salinity of 200 g/L, the CO2 relative permeability at the end of the test decreased by 26 % compared to the endpoint of the first CO2 injection period. In contrast, using a salinity of 38 g/L (seawater) resulted in a 22 % increase in CO2 relative permeability. The findings of this study strongly suggest that the intermittent injection method is a highly effective solution for enhancing injectivity and mitigating salt precipitation, underscoring its importance in the field of CO2 storage in saline aquifers.
{"title":"Experimental investigation of the intermittent injection of brine-scCO2 to mitigate salt precipitation during CO2 storage in saline aquifers","authors":"Mohammad Reza Nasiri , Behzad Rostami , Mohammad Keramati Nejad , Siavash Riahi , Alireza Fathollahi , Wael Fadi Al-Masri","doi":"10.1016/j.ijggc.2025.104379","DOIUrl":"10.1016/j.ijggc.2025.104379","url":null,"abstract":"<div><div>Saline aquifers, the primary option for carbon dioxide (CO<sub>2</sub>) storage, face a significant challenge in the form of salt precipitation from water evaporation during geological CO<sub>2</sub> sequestration. This salting-out phenomenon can alter reservoir porosity and permeability, impacting injectivity. While previous experimental studies have focused on how salt precipitation negatively affects CO<sub>2</sub> injectivity, research on mitigation strategies is less prevalent. This study, however, places a strong emphasis on investigating the intermittent injection of brine and scCO<sub>2</sub> as a potential mitigation strategy for salt precipitation in saline aquifers. The results of the experiments point to the significant potential of this method as a practical solution. Two high-pressure, high-temperature core flooding experiments were designed to look into how salt precipitation affects injectivity. The effect of formation water salinity was also studied, considering salinities of 2 g/L and 200 g/L. In the lower salinity experiment, no significant salt precipitation was observed at the end of the test. In contrast, the higher salinity experiment showed a 44 % decrease in CO<sub>2</sub> relative permeability at residual water saturation, manifested as an increase in differential pressure. Following the dynamic experiments, Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) was performed on the effluent brine, revealing that geochemical interactions between the rock and fluids had a negligible impact on the outcomes. Additionally, the conditions of the plug samples before and after supercritical CO<sub>2</sub> (scCO<sub>2</sub>) injection were analysed using Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS), revealing visible NaCl salt crystals and accumulation within the pore space of the rock. Subsequently, two additional core flooding experiments were conducted to investigate the effect of intermittent injection of brine and scCO<sub>2</sub> on injectivity and mitigation salt precipitation. The injection procedure involves a continuous process of temporarily stopping scCO<sub>2</sub> injection, followed by water injection, and then resuming scCO<sub>2</sub> injection at the same rate. Two salinities, 200 g/L and 38 g/L, were evaluated for the intermediate injection. At a water salinity of 200 g/L, the CO<sub>2</sub> relative permeability at the end of the test decreased by 26 % compared to the endpoint of the first CO<sub>2</sub> injection period. In contrast, using a salinity of 38 g/L (seawater) resulted in a 22 % increase in CO<sub>2</sub> relative permeability. The findings of this study strongly suggest that the intermittent injection method is a highly effective solution for enhancing injectivity and mitigating salt precipitation, underscoring its importance in the field of CO<sub>2</sub> storage in saline aquifers.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"144 ","pages":"Article 104379"},"PeriodicalIF":4.6,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143833902","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}
Pub Date : 2025-04-14DOI: 10.1016/j.ijggc.2025.104375
Huijie Sun , Shanshan Wang , Yingying Zhao , Hui Song , Yuhang Wu , Ruiqin Zhang
As the world's largest producer and consumer of aluminum, China's aluminum industry is facing enormous pressure to achieve the “Dual carbon” target. Exploring the carbon neutrality pathway for the aluminum sector at the provincial level is critical for achieving China's carbon neutrality target by 2060. This study established a GHG emissions inventory for Henan's aluminum industry (HAI) and analyzed the emission characteristics by LMDI method and Tapio model. Meanwhile, an integrated Energy-Environment-Economy analysis framework was constructed to explore the potential carbon neutrality pathway. The results showed that the total GHG emissions exhibited a trend of initially increasing and then falling over the past 17 years, driven primarily by product output effect and energy intensity effect, and the relationship between GHG emissions and the economy has not been completely decoupled in Henan. Scenario analysis indicated that comprehensive scenario with CCUS has the most significant emission reduction potential, achieving an 84 % reduction compared to business-as-usual scenario. However, GHG emissions are projected to remain at 5.47 Mt CO2-eq by 2060, indicating that the aluminum industry is a hard-to-decarbonize sector, so more positive development and practical application should be accelerated. In the short term, clean power improvement and energy efficiency improvement should be prioritized. In the long term, recycled aluminum utilization improvement shows greater mitigation potential, which also shows better economic benefits. Finally, recommendations were proposed for carbon neutrality pathway for HAI.
{"title":"Exploring the carbon neutrality pathway in the aluminum industry from the perspective of energy-environment-economy: A case study of Henan Province, China","authors":"Huijie Sun , Shanshan Wang , Yingying Zhao , Hui Song , Yuhang Wu , Ruiqin Zhang","doi":"10.1016/j.ijggc.2025.104375","DOIUrl":"10.1016/j.ijggc.2025.104375","url":null,"abstract":"<div><div>As the world's largest producer and consumer of aluminum, China's aluminum industry is facing enormous pressure to achieve the “Dual carbon” target. Exploring the carbon neutrality pathway for the aluminum sector at the provincial level is critical for achieving China's carbon neutrality target by 2060. This study established a GHG emissions inventory for Henan's aluminum industry (HAI) and analyzed the emission characteristics by LMDI method and Tapio model. Meanwhile, an integrated Energy-Environment-Economy analysis framework was constructed to explore the potential carbon neutrality pathway. The results showed that the total GHG emissions exhibited a trend of initially increasing and then falling over the past 17 years, driven primarily by product output effect and energy intensity effect, and the relationship between GHG emissions and the economy has not been completely decoupled in Henan. Scenario analysis indicated that comprehensive scenario with CCUS has the most significant emission reduction potential, achieving an 84 % reduction compared to business-as-usual scenario. However, GHG emissions are projected to remain at 5.47 Mt CO<sub>2</sub>-eq by 2060, indicating that the aluminum industry is a hard-to-decarbonize sector, so more positive development and practical application should be accelerated. In the short term, clean power improvement and energy efficiency improvement should be prioritized. In the long term, recycled aluminum utilization improvement shows greater mitigation potential, which also shows better economic benefits. Finally, recommendations were proposed for carbon neutrality pathway for HAI.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"144 ","pages":"Article 104375"},"PeriodicalIF":4.6,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143829635","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}
Pub Date : 2025-04-10DOI: 10.1016/j.ijggc.2025.104374
Ao Li, Hongquan Chen, Akhil Datta-Gupta
The performance of CO2 injection in geological carbon storage projects can be significantly influenced by the effects of gravity and subsurface heterogeneity, making effective monitoring and optimization essential. While streamlines are widely used to visualize fluid flow, they rely on instantaneous velocity fields and cannot account for dynamic conditions. To overcome this, we propose novel tools—pathlines, source clouds (streaklines), and time clouds (timelines)—to track CO2 movement across varying flow fields, particularly during the post-injection stage when gravity effects dominate. These tools serve as a foundation for optimizing injection strategies to enhance storage efficiency.
Pathlines trace the trajectories of CO2 particles over time, capturing dynamic flow field changes. Streaklines and timelines extend this by visualizing all particles emitted from a point or at a specific time, represented as source and time clouds in 3D. These tools enable precise visualization of CO2 movement in the reservoir, critical for optimizing storage efficiency. Our optimization framework identifies optimal injection rates by equalizing arrival times, maximizing storage efficiency under operational constraints. Using analytical sensitivities, a sequential quadratic programming (SQP) algorithm minimizes arrival time variance from the perforation zones, providing a comprehensive and effective strategy for CO2 injection optimization.
Applied to the Illinois Basin-Decatur Project (IBDP), our methods demonstrate improved plume visualization and optimization. Pathlines accurately represent plume distribution, while source and time clouds capture movement from perforations and front propagation. Optimizing injection rates across three perforation zones increased storage efficiency by 10.4 %, showcasing the effectiveness of this approach in advancing geological carbon storage projects.
{"title":"CO2 plume monitoring and injection optimization based on pathlines, source clouds and time clouds: Field application at the Illinois Basin-Decatur carbon sequestration project","authors":"Ao Li, Hongquan Chen, Akhil Datta-Gupta","doi":"10.1016/j.ijggc.2025.104374","DOIUrl":"10.1016/j.ijggc.2025.104374","url":null,"abstract":"<div><div>The performance of CO<sub>2</sub> injection in geological carbon storage projects can be significantly influenced by the effects of gravity and subsurface heterogeneity, making effective monitoring and optimization essential. While streamlines are widely used to visualize fluid flow, they rely on instantaneous velocity fields and cannot account for dynamic conditions. To overcome this, we propose novel tools—pathlines, source clouds (streaklines), and time clouds (timelines)—to track CO<sub>2</sub> movement across varying flow fields, particularly during the post-injection stage when gravity effects dominate. These tools serve as a foundation for optimizing injection strategies to enhance storage efficiency.</div><div>Pathlines trace the trajectories of CO<sub>2</sub> particles over time, capturing dynamic flow field changes. Streaklines and timelines extend this by visualizing all particles emitted from a point or at a specific time, represented as source and time clouds in 3D. These tools enable precise visualization of CO<sub>2</sub> movement in the reservoir, critical for optimizing storage efficiency. Our optimization framework identifies optimal injection rates by equalizing arrival times, maximizing storage efficiency under operational constraints. Using analytical sensitivities, a sequential quadratic programming (SQP) algorithm minimizes arrival time variance from the perforation zones, providing a comprehensive and effective strategy for CO<sub>2</sub> injection optimization.</div><div>Applied to the Illinois Basin-Decatur Project (IBDP), our methods demonstrate improved plume visualization and optimization. Pathlines accurately represent plume distribution, while source and time clouds capture movement from perforations and front propagation. Optimizing injection rates across three perforation zones increased storage efficiency by 10.4 %, showcasing the effectiveness of this approach in advancing geological carbon storage projects.</div></div>","PeriodicalId":334,"journal":{"name":"International Journal of Greenhouse Gas Control","volume":"144 ","pages":"Article 104374"},"PeriodicalIF":4.6,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143816737","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}
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