Geofluids最新文献

{"title":"Analysis of Gas Migration Characteristics and Controlling Factors in Nanopores of Deep Coal Seams","authors":"Ji Xiaofeng,&nbsp;Cao Jinyao,&nbsp;Song Dangyu,&nbsp;Jian Kuo,&nbsp;Li Quanzhong","doi":"10.1155/gfl/9280465","DOIUrl":"https://doi.org/10.1155/gfl/9280465","url":null,"abstract":"<p>Nanopores of various scales and morphologies in coal are important spaces for gas storage and migration. To deeply analyse the initial gas migration scale and characteristics in coal matrix micropores, this paper constructs an apparent permeability model describing the gas migration scale based on the gas transport mechanism, and analyses the controlling effects of pore structure, temperature, pressure and gas types on gas migration. The research results indicate that gas migration in coal matrix micropores is mainly through surface diffusion, contributing over 90%, while the contributions of Knudsen diffusion and slip flow are several orders of magnitude lower. As the tortuosity increases, the scale of gas migration in the micropores decreases in a negative exponential form. As the porosity increases, the scale of gas migration in micropores increases linearly. Compared with micropores, the forms, scales and levels of gas migration in mesopores and macropores have undergone significant changes. At pressures below 1 MPa, Knudsen diffusion predominates in mesopores and macropores, with the contribution of migration scales ranging from 97.33% to 99.90%. In the high-pressure stage, the contribution of slip flow in mesopores and macropores to the migration scale ranges from 64.55% to 99.86%; the contribution of surface diffusion to the migration scale ranges from 0.14% to 35.45%, without Knudsen diffusion. The research results can provide a theoretical basis for revealing the migration characteristics of deep coalbed methane at the microscopic nanoscale.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/9280465","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147668545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Combined Effect of Stress Mutation and Displacement Evolution on Overlying Rock Collapse From Physical Experiment and Numerical Simulation Study","authors":"Gang Wang,&nbsp;Daixin Deng,&nbsp;Jing Liu","doi":"10.1155/gfl/7729757","DOIUrl":"https://doi.org/10.1155/gfl/7729757","url":null,"abstract":"<p>This study investigates the complex failure mechanisms of overlying strata deformation induced by longwall mining, with a focus on the 21221 mining face in Qianqiu mine. Combining physical similarity simulation and numerical analysis, the research analyzes the abrupt changes in stress and displacement within the overlying rock mass during mining face advancement. The results show that roof failure occurs periodically, with collapse height and area progressively increasing as the intact bearing zone shifts upward, exerting continuous pressure on the stope. Mining disturbance significantly affects the roof ~40 cm ahead of the working face, where deformation and collapse are governed by gravitational forces and rock lithology. The maximum principal stress concentrates at the goaf edges, and vertical stress mutation accurately indicates impending roof fracture locations. Critically, the failure of hard conglomerate layers triggers a strong regional mutation in the mining-induced stress field. These results provide important insights into the dynamic evolution and instability precursors of overlying strata in deep mining conditions.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/7729757","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147668522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RETRACTION: Hydrate Dissociation Model with Time Fractional Derivative","authors":"Geofluids","doi":"10.1155/gfl/9815168","DOIUrl":"https://doi.org/10.1155/gfl/9815168","url":null,"abstract":"<p>RETRACTION: X. Fang, H. Lian, W. Luo, M. Liu, C. Chen, and Q. Wang, “Hydrate Dissociation Model with Time Fractional Derivative,” <i>Geofluids</i> 2022, no. 1 (2022): 5598287, https://doi.org/10.1155/2022/5598287.</p><p>The above article, published online on 12 April 2022 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the Journal Editor-in-Chief, Umberta Tinivella and John Wiley &amp; Sons Ltd. The retraction has been agreed due to unattributed overlap between this article and [<span>1</span>].</p><p>Several attempts by the journal to contact the authors have not resulted in a reply.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/9815168","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147668284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soil CO2 Degassing and Temperature at Poás Volcano: Evidence From the 2025 Eruptive Phase","authors":"Noé García-Martínez,&nbsp;Társilo Girona,&nbsp;Kyriaki Drymoni,&nbsp;Sara Emili,&nbsp;Martina Picciallo,&nbsp;Einat Lev,&nbsp;Conor A. Bacon,&nbsp;J. Maarten de Moor,&nbsp;Ángel Fernandez-Cortes,&nbsp;David Benavente","doi":"10.1155/gfl/9516969","DOIUrl":"https://doi.org/10.1155/gfl/9516969","url":null,"abstract":"<p>Soil carbon dioxide (CO₂) degassing provides valuable insights into volcano–hydrothermal systems, especially during their active phases. Soil CO₂ flux and temperature surveys are particularly useful where direct access to vents is limited, providing information on subsurface magmatic dynamics. This multidisciplinary study presents new heat and soil degassing data from Poás Volcano, which entered an active phase in early 2025 with frequent phreatic and phreatomagmatic eruptions. Between March 9 and 15, 2025, we conducted soil CO₂ flux and temperature surveys along the northeastern part of the crater rim and the crater upper terrace to investigate the spatial extent of soil degassing beyond the main fumarolic fields. Despite limited access, we obtained 251 flux and temperature measurements, using three portable accumulation chambers, complemented by seven samples for carbon isotopic analyses. Soil CO₂ fluxes were generally low in the study area, with a mean value of 1.89 ± 0.05 g m⁻² day⁻¹ at the crater rim, reaching a maximum of 624.31 ± 4.65 g m⁻² day⁻¹ near fumaroles on the upper terrace. Interestingly, we also detected a localized thermal anomaly of approximately 2–5°C above background levels in the crater rim, possibly associated with fumarolic activity on the upper terrace. The soil CO₂ flux along the crater rim exhibits minor contributions from biogenic and magmatic CO₂ (≤3%). At the Poás crater rim, low CO₂ fluxes, near-atmospheric CO₂ concentrations, and δ¹³C–CO₂ isotopic fractionation patterns indicate that gas transport is dominated by diffusion in the very shallow subsurface, as confirmed by Fick’s model, with negligible advection due to the absence of measurable pressure gradients.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/9516969","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147668559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Study on the Floor Heave Characteristics of a Gob-Side Entry in Deep-Thick Coal Seam During Longwall Mining","authors":"Yinghao Hao,&nbsp;Jinhai Liu,&nbsp;Xiaodong Miu,&nbsp;Guoli Ding,&nbsp;Pei Qi,&nbsp;Hao Wu,&nbsp;Linsheng Gao","doi":"10.1155/gfl/5536664","DOIUrl":"https://doi.org/10.1155/gfl/5536664","url":null,"abstract":"<p>Floor heave control becomes more and more prominent in engineering practice with the increased mining depth of the working face. The gob-side entry of the 21404 working face in Hulusu Coal Mine was taken to be the engineering background to study the gob-side entry’s floor heave in the working face with a deep, thick, and dense layer of coal. There was slight floor heave in the gob-side entry before mining the working face, and cracks appeared in the hardened bodies of the floor. The floor heave amount increased significantly before squaring. The roadway’s middle floor was heaved, and the highest floor heave was about 500 mm. The floor heave of the return-air entry increased significantly after squaring. It was squeezed from the two sides to the roadway’s middle part. Additionally, there was floor heave in the roadway’s middle part. The deformation of the roadway was accelerated when it was less than 90 m away from the working face, with a maximum floor-heave amount of 500 mm and a maximum two-side convergence of 300 mm. The amount of floor heave was greater than that of the two sides. There was an oblique triangular displacement area at the roadway side’s bottom in the gob-side entry. Coal on the solid sides moved to the roadway. The gob-side entry’s floor heave was serious, with coal pillars’ extensive deformation on the sides.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/5536664","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147668548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stability Analysis of Long-Span Temporary Support Roofs in Coal Mine Roadways Using Multistation Parallel Excavation Technology","authors":"Yunzhu Wang,&nbsp;Fenghui Li,&nbsp;Yunhai Cheng,&nbsp;Xin Yu,&nbsp;Hao Wu,&nbsp;Guandong Wang","doi":"10.1155/gfl/8899704","DOIUrl":"https://doi.org/10.1155/gfl/8899704","url":null,"abstract":"<p>The parallelisation of excavation and support operations remains a significant challenge for the rapid advancement of coal mine roadways. This study proposes an excavation technology incorporating multistation parallel operations. The roof stability of the large-span temporary support system, a core of the multistation parallel excavation system, was systematically investigated through theoretical analysis, numerical simulations and field experiments. The established mechanical model shows that the roof deformation of the unsupported area is serious and highly sensitive to the span. Subsequent numerical simulation using FLAC^3D shows that the large-span temporary support system significantly improves the roof stability. Key results show that the support improves the vertical stress <i>σ</i>_zz distribution, reducing the peak stress at the header′s leading edge by 1.32 MPa. Roof displacement distributions became more uniform, with a maximum displacement reduction of 79 mm. Furthermore, the system drastically reduced plastic damage, achieving a 97.93% decrease in surface tensile damage volume and a 21.50% reduction in total plastic damage. The preliminary testing of the ZLC-442 temporary support device verified the feasibility of its operating mode and its adaptability to underground working conditions. This research provides critical theoretical and technical insights for enabling safe and efficient parallel excavation-support operations in underground coal mines.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/8899704","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147668174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Zonal Evolution Mechanism and Coupled Superposed-Arch Bearing Effect in Loose-Fragmented Soft-Rock Roadways","authors":"Jin Chen,&nbsp;Hengkai Wang,&nbsp;Zhonghua Wei,&nbsp;Qingli Gao","doi":"10.1155/gfl/7819463","DOIUrl":"https://doi.org/10.1155/gfl/7819463","url":null,"abstract":"<p>To effectively address the challenge of stabilizing roadways in loose and fractured rock masses, the 12810 transportation roadway of the Yunjialing Mine was selected as the engineering case. The modified Hoek–Brown criterion was employed to derive analytical expressions for the stress distribution in different zones of the surrounding rock and for the radius of the plastic zone, thereby revealing the key factors controlling roadway stability. Based on the postexcavation degradation characteristics, the surrounding rock was divided from the excavation boundary inward into a fractured zone, a plastic softening zone, and an elastic zone, and the corresponding control principles and key techniques for extremely fractured soft-rock roadways were proposed. On this basis, three major control measures were identified: restraining the expansion of the fractured zone through high-prestress support components, mobilizing the bearing capacity of the surrounding rock through an effective support-bearing zone, and reinforcing weak sections to form a continuous bearing ring. Accordingly, a full-section combined control scheme of “high-strength prestressed long-short cables plus floor destressing anchorage” was developed. Considering the characteristics of this support scheme and based on the Hoek–Brown criterion suitable for loose and fractured rock masses, a “coupled superimposed bearing arch” capable of achieving both internal and external load bearing was proposed. This coupled bearing arch unifies the interaction between the support system and the surrounding rock with the radial confining force provided by the support, significantly amplifying the load-bearing capacity of rock bolts and cables. The results indicate that the extent of the fractured zone decreases with increasing uniaxial compressive strength and geological strength index (GSI) of the surrounding rock. Progressive expansion and transformation of the boundary between the fractured zone and the plastic softening zone is identified as the fundamental cause of large-scale rock mass fragmentation and bolt/cable anchorage failure. After applying the combined control scheme, deformation of the 12810 roadway was effectively controlled: The total convergence of the sidewalls was approximately 362 mm, roof subsidence about 142 mm, floor heave about 215 mm, and no large-scale cable ruptures occurred, ensuring roadway stability.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/7819463","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147668849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on the Optimized Layout of Boreholes in Low-Permeability Coal Seams to Eliminate Gas Drainage Blank Zones","authors":"Jingjing Huo,&nbsp;Hao Sun,&nbsp;Xiaofeng Jiang","doi":"10.1155/gfl/7298808","DOIUrl":"https://doi.org/10.1155/gfl/7298808","url":null,"abstract":"<p>With the increasing depth and complexity of coal mining in China, the gas control in coal seam has become increasingly important. Gas predrainage through boreholes is an effective means of gas control, and the effective drainage radius of boreholes is a significant index for gas drainage. Taking Sijiazhuang Coal Mine as the research object, the gas drainage radius of seam 15 at different drainage times have been measured. A gas–solid coupling model for coalbed gas drainage has been established by governing equations between porosity, permeability, stress, and seepage, which was applied to optimize the layout of coalbed gas drainage boreholes. The results show that the drainage radius of conventional boreholes in Sijiazhuang Coal Mine increases with time, namely, 3.0, 4.0, 4.4, and 5.0 m on 35, 70, 100, and 120 days, respectively. The model validation results are consistent with the field measured values, confirming the feasibility of the established model in simulating gas drainage effectiveness. When the borehole spacing is less than or equal to 3 m, the effective drainage rate reaches 100% with no blind zones; when the spacing is greater than or equal to 3.5 m, the effective drainage rate drops below 82.7% and blind zones appear. Therefore, the optimal spacing should be controlled within 3 m. The comparison of layout patterns shows that under the same number of boreholes, the double-row staggered (three-flower) layout has a larger negative pressure acting area and more uniform pressure reduction in the roof and floor compared with the single-row layout, with the time to meet standards shortened from 58 to 55 days, significantly improving the drainage efficiency.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/7298808","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147615361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on Failure Characteristics of Interlayer Water-Resisting Rock Strata and Water Inrush Evaluation in Roof Goafs Under Deep and Shallow Repeated Mining","authors":"Kai Ma,&nbsp;Yilong Liu,&nbsp;Xiaoxia Li","doi":"10.1155/gfl/9659638","DOIUrl":"https://doi.org/10.1155/gfl/9659638","url":null,"abstract":"<p>To address the risk of water inrush from old water-logged goafs during deep and shallow repeated mining, this study investigates the failure characteristics of interlayer water-resisting rock strata and establishes a corresponding water inrush evaluation method. Based on the roof and floor failure characteristic theories, the failure zoning of interlayer rock strata was distinguished for shallow and deep mining by analyzing their different stress environments and boundary conditions, and the applicable calculation formulas for each zoning index were proposed. For deep mining, the elliptical boundary of the depressurization zone and the tangential stress expression along the ellipse were defined, while the parabolic boundary of the stress concentration zone was determined using three characteristic stress points of the surrounding rock. A case study of a shallow repeated mining coal mine in Shanxi Province was conducted to calculate the failure zoning parameters of interlayer rock strata, identify the formation of water-conducting channels by the main key layer position, and derive the quantitative relationship between the initial fracture span of the main key layer and the goaf water accumulation height based on the elastic plate theory. The results clarify the differential failure mechanisms of interlayer water-resisting rock strata under shallow and deep repeated mining. The proposed evaluation method offers a theoretical basis and engineering reference for preventing and controlling roof goaf water inrush in coal mines.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/9659638","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147615444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydraulic-Mechanical Coupling-Driven In Situ Stress Field Evolution in Injection-Production Well Patterns With Artificial Fractures","authors":"Changkun Cheng,&nbsp;Shiduo Liu,&nbsp;Zhicheng Wang,&nbsp;Qian Xiao,&nbsp;Huan Liu,&nbsp;Ying Fu,&nbsp;Yuhang Zhang,&nbsp;Yan Deng","doi":"10.1155/gfl/5573945","DOIUrl":"https://doi.org/10.1155/gfl/5573945","url":null,"abstract":"<p>Based on the theory of porous media elasticity and the mechanisms of hydraulic-mechanical coupling, a fully coupled mathematical model for porous media deformation and fluid flow was established, incorporating a square inverted nine-spot well pattern with artificial fractures. The finite element method was employed for numerical solution, and the model′s accuracy was verified through comparison with the classical Terzaghi′s poroelastic problem. Numerical simulations were conducted to investigate the evolution of the in situ stress field during the development of injection-production well groups, exploring the optimal timing for refracturing and the influence of engineering-geological parameters on the stress field. Orthogonal experimental analysis was introduced to more precisely quantify the impact of various factors on the stress reorientation range in injection-production well groups. The results demonstrate that during production, reservoir stress reorientation is primarily governed by pore pressure and expands over time, with the optimal reorientation timing occurring when pore pressure stabilizes. Different fracturing conditions significantly alter the stress reorientation angle and range, thereby affecting the stress distribution among wells. The stress reorientation range exhibits a positive correlation with fracture penetration ratio but a negative correlation with initial stress ratio, Poisson′s ratio, porosity, and permeability. Among these factors, the initial horizontal principal stress ratio, fracture penetration ratio, and reservoir permeability exert the most pronounced influence, whereas the elastic modulus has minimal impact.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/5573945","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147615120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}