Chao Ding , Kaoping Song , Zhifeng Luo , Long Cheng
{"title":"Coupled thermo-hydro-mechanical simulation of fracture propagation in sandy conglomerate reservoirs","authors":"Chao Ding , Kaoping Song , Zhifeng Luo , Long Cheng","doi":"10.1016/j.geoen.2025.213907","DOIUrl":"10.1016/j.geoen.2025.213907","url":null,"abstract":"<div><div>In this paper, a thermo-hydro-mechanical coupling model is developed for simulating hydraulic fracture propagation in sandy conglomerate reservoirs. The rock deformation, fluid flow and heat transport are all considered in the model, then extended finite element method is adopted for achieving the numerical discretization. After validation, sensitive analysis is conducted. Numerical results show that gravel has great impact on hydraulic fracturing. Three interaction patterns between fracture and gravel are observed: the interaction, penetration and bypassing. And it is found that gravel size, axis ratio, approach angle, Young's modulus, fraction coefficient and cohesion will highly affect fracture propagation.</div></div>","PeriodicalId":100578,"journal":{"name":"Geoenergy Science and Engineering","volume":"252 ","pages":"Article 213907"},"PeriodicalIF":0.0,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Na Wei , Haoran Zheng , Boyun Guo , Haiyu Hu , Cong Li
{"title":"Acceleration mechanism of methane hydrate dissociation in inorganic salt solutions: Experimental and molecular dynamics study","authors":"Na Wei , Haoran Zheng , Boyun Guo , Haiyu Hu , Cong Li","doi":"10.1016/j.geoen.2025.213913","DOIUrl":"10.1016/j.geoen.2025.213913","url":null,"abstract":"<div><div>In the exploration and exploitation of methane hydrates, the influence of inorganic salt environments on hydrate behavior is particularly pronounced. This study employs experimental methodologies to evaluate the dissociation performance of hydrates in common inorganic salt solutions, coupled with molecular dynamics simulations to investigate the dissociation mechanisms under varying types of inorganic salts (MgCl<sub>2</sub>, CaCl<sub>2</sub>, KCl, and NaCl), mass concentrations, and multi-salt coexistence systems. The findings reveal that the efficacy of inorganic salt solutions in promoting hydrate dissociation follows the order: MgCl<sub>2</sub> > CaCl<sub>2</sub> > KCl > NaCl. The smaller ionic radius of Mg<sup>2+</sup> and its stronger adsorption capacity for water molecules facilitate ion intrusion and the disruption of the hydrate's cage-like structure. In systems where multiple inorganic salts coexist, the higher potential energy and adsorption capacity result in the dissociation-promoting ability being predominantly determined by higher-valent metal cations. This research provides valuable macro and micro perspectives on the dissociation mechanisms of methane hydrates in inorganic salt environments, holding significant implications for the development of high-performance hydrate drilling fluid systems.</div></div>","PeriodicalId":100578,"journal":{"name":"Geoenergy Science and Engineering","volume":"252 ","pages":"Article 213913"},"PeriodicalIF":0.0,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xinyu Guo , Ming Tang , Shiming He , Lu Zou , Guangfu Zhang , Long Zhang , Yu Zhang
{"title":"A new pore pressure model for pre-drilling prediction in carbonate rocks considering the abnormal pressure","authors":"Xinyu Guo , Ming Tang , Shiming He , Lu Zou , Guangfu Zhang , Long Zhang , Yu Zhang","doi":"10.1016/j.geoen.2025.213912","DOIUrl":"10.1016/j.geoen.2025.213912","url":null,"abstract":"<div><div>The pore pressure prediction methods for clastic rocks are well-established and highly accurate but are not directly applicable to carbonate formations. Existing carbonate pore pressure prediction models fail to fully account for the mechanisms of abnormal high pressure during diagenesis, leading to poor adaptability and significant errors. This results in flawed mud density designs and frequent drilling issues such as leakage and overflow. This study proposes a new one-dimensional pore pressure prediction method that incorporates both pressurization and depressurization mechanisms in carbonate diagenesis. Additionally, using well-seismic correlation, a three-dimensional pore pressure prediction model is developed based on sequential gaussian co-kriging interpolation. This model accounts for the influence of fracture-cavity systems, enabling more accurate pre-drilling pore pressure estimation. The results demonstrate that the new one-dimensional prediction method closely aligns with measured pore pressure values, with an error range of −7.35 %∼ 5.87 %. The sequential gaussian co-kriging interpolation overcomes the limitations of single interpolation methods by balancing the randomness of fractured fault zones with the continuity of non-fractured regions. The 3D pore pressure model's pre-drilling predictions show strong agreement with numerical results, with errors within ±10 %. By considering the formation mechanisms of abnormal pressure, this approach enhances the accuracy of carbonate pore pressure predictions, supporting effective risk assessment and the analysis of complex drilling conditions.</div></div>","PeriodicalId":100578,"journal":{"name":"Geoenergy Science and Engineering","volume":"252 ","pages":"Article 213912"},"PeriodicalIF":0.0,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Enbo Wang , Haiyan Zhu , Xiangyi Yi , Qin Li , Peng Zhao , Marembo Micheal , Huijing Tan , Zhaopeng Zhang
{"title":"Numerical simulation of fracture propagation in high-energy gas fracturing of shale reservoir","authors":"Enbo Wang , Haiyan Zhu , Xiangyi Yi , Qin Li , Peng Zhao , Marembo Micheal , Huijing Tan , Zhaopeng Zhang","doi":"10.1016/j.geoen.2025.213915","DOIUrl":"10.1016/j.geoen.2025.213915","url":null,"abstract":"<div><div>High-energy gas fracturing technology can create radial-shaped fractures through instantaneous high-pressure energy and represents a specialized production enhancement technique aimed at improving oil and gas well productivity. To analyze the fracture propagation mechanism using this technology, this study introduces a stress dependent numerical simulation strategy based on finite element method and discrete fracture network (FEM-DFN). A comparison of simulation results with physical experiments validated the accuracy of the model. The fracture propagation law of High-energy gas fracturing is studied from geological and engineering factors respectively. The results indicate that variations in natural fracture length and orientation significantly influence the propagation direction and morphology of high-energy gas fractures but have minimal impact on reservoir damage. When the angle between the natural fracture and the direction of the maximum principal stress increases, the inhibitory effect on fracture propagation and the activation of natural fractures become more pronounced. For in-situ stress differences ranging from 0 to 20 MPa, high-energy gas fracturing can overcome localized stress concentrations near the wellbore to generate multiple fractures. With the increase of in-situ stress difference, reservoir damage decreases, and the inhibitory effect of High-energy gas fracturing on fractures becomes more pronounced, promoting fracture propagation in the direction of maximum principal stress. For the horizontal section of the horizontal well, the smaller cluster spacing will lead to the intersection of fractures along the wellbore direction, and the number of fractures perpendicular to the horizontal direction will decrease. Smaller cluster spacing and longer explosion section lengths increase the likelihood of downhole accidents; therefore, field construction should design a reasonable explosion section length and cluster spacing to achieve optimal fracturing effects. This research provides theoretical guidance and a scientific foundation for designing schemes in High-energy gas fracturing technology for horizontal wells in shale gas reservoirs.</div></div>","PeriodicalId":100578,"journal":{"name":"Geoenergy Science and Engineering","volume":"252 ","pages":"Article 213915"},"PeriodicalIF":0.0,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143873484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wenxiang Lin , Huajie Liu , Chengyuan Ji , Yuhuan Bu , Hongxu Zhang , Hui Yin , Waheed Abdul
{"title":"Mechanistic analysis of the effect of polymers in cement slurry filtrates on the stability of natural gas hydrates","authors":"Wenxiang Lin , Huajie Liu , Chengyuan Ji , Yuhuan Bu , Hongxu Zhang , Hui Yin , Waheed Abdul","doi":"10.1016/j.geoen.2025.213910","DOIUrl":"10.1016/j.geoen.2025.213910","url":null,"abstract":"<div><div>In deep-water natural gas hydrate layer cementing, natural gas hydrate stability is crucial for production safety. During cement slurry coagulation, filtrate with organic matter and inorganic ions impacts the hydrate layer. Existing studies are unclear about the influence of polymers in cement slurry filtrate on natural gas hydrate stability. Therefore, it is necessary to clarify the influence of polymers in cement slurry filtrate on the stability of natural gas hydrate, so as to provide a basis for the development of cementing slurry system and theoretical support for safe cementing.</div><div>Based on previous research and actual production, representative cement slurry additive monomers such as AMPS, AA, AM, and AMPSNa were selected for well cementing. The effects of AM/AA, AA/AMPSNa, AM/AMPSNa, and AA/AMPSNa/AM on the stability of natural gas hydrates were studied using molecular dynamics simulation. Results showed that at the same solute concentration, the AM/AA - hydrate system had the fastest hydrate decomposition, with the water molecule diffusion coefficient increasing by 39.01 %–123.96 % compared to the pure water - hydrate system. Also, for the same molecule, lower solute concentration led to faster hydrate decomposition.</div></div>","PeriodicalId":100578,"journal":{"name":"Geoenergy Science and Engineering","volume":"252 ","pages":"Article 213910"},"PeriodicalIF":0.0,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bo Qi , Yang Cao , Guoqing Cui , Huanan Liu , Lianghao Zhai , Pinlu Cao , Jinghua Wu
{"title":"A comprehensive study on evaluating drainage capability of air reverse circulation down-the-hole hammer drill bits via numerical simulation and experimentation","authors":"Bo Qi , Yang Cao , Guoqing Cui , Huanan Liu , Lianghao Zhai , Pinlu Cao , Jinghua Wu","doi":"10.1016/j.geoen.2025.213918","DOIUrl":"10.1016/j.geoen.2025.213918","url":null,"abstract":"<div><div>The air down-the-hole (DTH) hammer reverse circulation drilling technique offers high drilling efficiency and preserves geothermal reservoirs, making it extensively used in geothermal well construction. However, because air is used as the circulation medium, this technique is highly sensitive to water production during formation. An excessive inflow rate of water can deteriorate the air circulation performance in a borehole, substantially limiting the applicability and progression of this technology. To assess the sensitivity of air DTH hammer reverse circulation drilling to the formation water inflow rate and to elucidate the mechanisms by which groundwater influences reverse circulation, we utilised computational fluid dynamics (CFD) multiphase modelling to conduct a series of simulations complemented by laboratory experiments. The results demonstrate that reverse circulation efficiency decreases significantly with increasing formation water inflow rate, with 0.2 kg/s identified as the critical threshold for effective drainage using 150-mm-diameter bits. However, elevating the air supply rate effectively improves drainage performance—increasing the air supply from 0.06 kg/s to 0.24 kg/s enhanced water outflow efficiency by about 82 % in this study. Furthermore, our research led to the optimization of conventional ejector-type reverse circulation drill bits, providing essential design principles for drill-bit structures. This study may provide valuable insights into the application of air down-the-hole hammer reverse circulation drilling technology in geothermal drilling and promote the research and development of high-performance drilling equipment.</div></div>","PeriodicalId":100578,"journal":{"name":"Geoenergy Science and Engineering","volume":"252 ","pages":"Article 213918"},"PeriodicalIF":0.0,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143892092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Seyed Hasan Hajiabadi , Mahmoud Khalifeh , Reinier van Noort
{"title":"Durability assessment of a granite-based one-part geopolymer system exposed to CO2-water conditions: Implications for CO2 geosequestration","authors":"Seyed Hasan Hajiabadi , Mahmoud Khalifeh , Reinier van Noort","doi":"10.1016/j.geoen.2025.213919","DOIUrl":"10.1016/j.geoen.2025.213919","url":null,"abstract":"<div><div>Geopolymers (GPs), derived from natural rock and other wastes, are viable alternatives to Ordinary Portland Cement (OPC) for various applications, including Carbon Capture and Storge (CCS), where high resistance to CO<sub>2</sub>-exposure is required. This study investigates the performance of a specialized one-part GP system tailored for CO<sub>2</sub> geosequestration under simulated downhole conditions. Cured GP specimens were subjected to an imposed flow of CO<sub>2</sub>-saturated water in coreflooding experiments, while reference samples were kept in water in an autoclave. These experiments were conducted at 30 MPa confining pressure and 80 °C for periods of three or six months. After exposure, the performance of the GP samples was assessed through uniaxial compressive strength (UCS) experiments, Brazilian tensile strength assessments, indentation tests, and density measurements. This was further supplemented with a range of analytical techniques to evaluate changes in the GPs' microstructure, chemical bonding, and mineralogical and chemical composition. The obtained results indicate that after three months of CO<sub>2</sub> exposure, there was a decline in mechanical performance, as evidenced by reductions in UCS and tensile strength. However, following an additional three-month exposure, while UCS remained constant, tensile strength exhibited an increase. Conversely, indentation tests demonstrated an enhancement in mechanical performance at both three and six months of CO<sub>2</sub> exposure, particularly notable near the inlet. Changes in Young's modulus after six months of exposure to CO<sub>2</sub>-saturated also revealed a return to ductility levels comparable to the reference sample, while a slight increase in Poisson's ratio may indicate a reduced risk of mechanical failure. Additionally, findings from Scanning Electron Microscopy (SEM) combined with Energy-Dispersive X-ray Spectroscopy (EDS), along with X-ray diffraction (XRD) analysis, demonstrated how increased crystallinity due to carbonate precipitation within the evolving carbonated zone contributed to improved system durability. Fourier-transform infrared (FTIR) analysis showed that carbonation also resulted in increased silica network connectivity. Chemical analysis of effluent samples provided further insight into how a complex interplay between silicate dissolution, alkali leaching, and carbonate mineral formation contributed to the significant resistance of the GP system to bi-carbonation and degradation. These results advance understanding of the GP system studied in CO<sub>2</sub>-rich environments and offer new insights into the impacts of carbonation on cementitious materials.</div></div>","PeriodicalId":100578,"journal":{"name":"Geoenergy Science and Engineering","volume":"252 ","pages":"Article 213919"},"PeriodicalIF":0.0,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Geo-storage of ammonia as an energy carrier: A review on the opportunities and challenges","authors":"Hadi Karimzadeh, Hassan Mahani, Shahab Ayatollahi","doi":"10.1016/j.geoen.2025.213906","DOIUrl":"10.1016/j.geoen.2025.213906","url":null,"abstract":"<div><div>Ammonia presents significant advantages over hydrogen as an emerging energy carrier for energy transition. However, the technical feasibility of underground ammonia storage (UAS) in porous media remains largely unexplored. This paper offers a critical and comprehensive review of the opportunities and challenges associated with UAS. A detailed comparison between ammonia and hydrogen is also included. Furthermore, given ammonia's miscibility with water and its reactive nature, this study investigates its geochemical reaction with rock minerals in detail. The results reveal that aqua ammonia does not significantly dissolve rock grains or alter the mineral compositions, particularly in quartz-rich rocks. Furthermore, it was found that reservoir temperature has a more pronounced effect on the ammonia-rock interactions than the reservoir pressure. The results showed that, in carbonate formations, the geochemical reactions are not severe at both low and high temperatures, while in sandstone formations, the reactions primarily occur at mid-range temperatures. According to the detailed review presented here, further development of the UASin porous media depends on multidimensional analysis that includes techno-socio-environmental aspects, economic viability, specific implementation strategies, and a thorough comparison with alternatives such as hydrogen. This review highlights the multifaceted challenges associated with the large-scale deployment of UAS and outlines key priorities for future research. One of the primary concerns and bottlenecks is the dissolution of ammonia in resident water and residual fluids, which must be addressed due to the potential of water contamination and safety hazards, as well as its negative impacts on ammonia purity and loss. Additionally, the lack of laboratory and field data should be addressed in future studies.</div></div>","PeriodicalId":100578,"journal":{"name":"Geoenergy Science and Engineering","volume":"252 ","pages":"Article 213906"},"PeriodicalIF":0.0,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Heng Yang , Yongcun Feng , Naikun Hu , Xiaorong Li , Guanyi Shang , Jingen Deng
{"title":"Data-driven surrogate model approach for recommending lost circulation treatments","authors":"Heng Yang , Yongcun Feng , Naikun Hu , Xiaorong Li , Guanyi Shang , Jingen Deng","doi":"10.1016/j.geoen.2025.213916","DOIUrl":"10.1016/j.geoen.2025.213916","url":null,"abstract":"<div><div>Lost circulation is a significant challenge in drilling operations, often resulting in increased non-productive time (NPT) and higher operational costs. Traditional methods for selecting lost circulation treatments rely heavily on trial-and-error, typically involving multiple field attempts before achieving success. This process is time-consuming, costly, inefficient, and has a low success rate. To overcome these limitations, we developed an innovative data-driven surrogate model that predicts the expected effects of lost circulation treatments. By integrating the surrogate model into a treatment decision-making framework, the model systematically evaluates various treatment options and predicts the probabilities of different effects, such as success, partial success, and failure. Based on comprehensive insights into the treatment outcomes, enabling more informed decisions and selecting the most optimal treatment option. The surrogate model was trained using a dataset of 813 lost circulation treatment cases, incorporating 15 key parameters such as well conditions, geological features, and operational drilling parameters. Built on the CatBoost algorithm, the model achieves an AUC consistently above 0.90, demonstrating high accuracy in predicting treatment effects. The model was integrated into the treatment decision-making framework and tested on three field cases. The results showed that the model's predictions aligned closely with actual field outcomes. Additionally, it provided comprehensive analyses of various treatment options, enabling engineers to enhance treatment success and improve decision reliability. In summary, the proposed intelligent decision-making framework offers a systematic, scientific approach to lost circulation management, reducing reliance on field experience, improving treatment success rates, enhancing drilling safety and efficiency, and lowering operational costs.</div></div>","PeriodicalId":100578,"journal":{"name":"Geoenergy Science and Engineering","volume":"252 ","pages":"Article 213916"},"PeriodicalIF":0.0,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yijie Zheng , Kaiyuan Mei , Tingcong Wei , Xin He , Chao Liu , Chunmei Zhang , Xiaowei Cheng
{"title":"Calcined Mg-rich olivine enhanced oil-well cement for anti-supercritical CO2 invasion under the high-temperature and high-pressure conditions","authors":"Yijie Zheng , Kaiyuan Mei , Tingcong Wei , Xin He , Chao Liu , Chunmei Zhang , Xiaowei Cheng","doi":"10.1016/j.geoen.2025.213914","DOIUrl":"10.1016/j.geoen.2025.213914","url":null,"abstract":"<div><div>In carbon capture, utilization, and storage (CCUS) wells, cementing cement paste based on Class G oil-well cement and compound with CO<sub>2</sub> corrosion-resistance materials are often used. This study aims to investigate the effect of calcined Mg-rich olivine (CMO) particles on mechanical properties and microstructure. During the sample preparation step, since ordinary Mg-rich olivine (MO) was found to provide limited improvement in the mechanical properties of cement paste, CMO was prepared through calcination to enhance the reactivity of MO. Experiments on cement paste corrosion under high-temperature and high-pressure (HTHP) conditions were then carried out using this activated CMO. The correlation between CMO and cement hydration products content was estimated by the thermodynamic model GEMS software. Furthermore, X-ray diffraction (XRD), thermogravimetry analysis (TGA), stereo microscope, vickers micro-hardness, permeability, and scanning electronic microscopy (SEM) testing methods were used to characterize the evolution of the physical properties, phase composition and pore structure of the cement paste sample under supercritical CO<sub>2</sub> (ScCO<sub>2</sub>) conditions. The cement paste with 2 % CMO had a highest compressive strength, 56.38 MPa, according to the results. However, after 28 days of ScCO<sub>2</sub> invasion, the compressive strength of both types of mixtures declined, although it was still 30.18 % higher than that of the CMO-0 sample. The CMO-2 cement paste showed a 5.34 % decrease in permeability, whereas the CMO-0 sample's permeability increased by 160.43 %, suggesting that the CMO-containing cement paste had a denser structure. The mechanism analysis showed that the addition of CMO as an additive can promote the prismatic Mg-Calcite formation and calcite crystallization, filling and blocking the micropores in comparison to CMO-0 samples. In CCUS wells, this dense structure improves the physical resistance and durability of Class G oil-well cement paste to ScCO<sub>2</sub> invasion.</div></div>","PeriodicalId":100578,"journal":{"name":"Geoenergy Science and Engineering","volume":"252 ","pages":"Article 213914"},"PeriodicalIF":0.0,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}