Gas Science and Engineering最新文献

{"title":"Synthesis of equilibrated geochemical systems using extended Debye-Huckel and Pitzer activity models for enhanced CO2 storage modelling","authors":"Shahryar Rashidi ,&nbsp;Seyed Shariatipour ,&nbsp;Masoud Ahmadinia","doi":"10.1016/j.jgsce.2025.205792","DOIUrl":"10.1016/j.jgsce.2025.205792","url":null,"abstract":"<div><div>Carbon capture and storage is a critical technology for reducing greenhouse gas emissions and mitigating climate change. Ensuring the safe, long-term CO₂ storage in geological formations requires accurate modelling of geochemical reactions between CO₂-saturated water and rock-forming minerals. Reactive-transport simulators represent these processes over extended timescales, but geochemical equilibrium must first be established, analogous to gravitational equilibrium in pressure initialization. This study presents a practical workflow for synthesizing equilibrated CO₂-rock-water systems, demonstrated for the Bunter Sandstone Formation. To ensure realistic initial pressure distributions that govern pressure-dependent trapping processes, gravitational equilibrium was first established. The mineralogy was then engineered to maintain a non-negative degree of freedom for chemically consistent equilibrium calculations. Long-term batch simulations using ideal, extended Debye-Huckel, and Pitzer activity models revealed significant discrepancies between activity-model-based equilibrium concentrations and short-term laboratory values, even though predictions of salinity and pH were consistent. These discrepancies highlight the importance of deriving equilibrium concentrations from long-term simulations for chemical initialization, as short-term laboratory measurements may not reflect true equilibrium conditions. The Pitzer model provided the most accurate predictions under high salinity but increased simulation time by over 100%, whereas the extended Debye-Huckel model required only 30% additional time but neglected short-range ionic interactions. The reduced-salinity scenario decreased equilibrium concentrations by approximately 20–100%, enhancing CO₂ dissolution and promoting mineral dissolution, thereby influencing structural, solubility, and mineral trapping mechanisms. These findings underscore the importance of careful activity model selection and accurate salinity characterization to balance computational efficiency with predictive accuracy and improve confidence in equilibrium predictions.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"145 ","pages":"Article 205792"},"PeriodicalIF":5.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222285","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":"Optimization of large-scale Ranque-Hilsch vortex tubes for enhanced CO2 separation in carbon capture and storage","authors":"Vahid Gholami,&nbsp;Seyyed Majid Malek Jafarian","doi":"10.1016/j.jgsce.2025.205788","DOIUrl":"10.1016/j.jgsce.2025.205788","url":null,"abstract":"<div><div>Due to the direct relationship between the global warming phenomenon and the atmospheric concentration of carbon dioxide, scientists are working on new gas purification methods for carbon capture and storage devices (CCS). Direct mass separation of this gas from the air is hard in the typical methods, due to the need to reduce the temperature of the <span><math><mrow><msub><mrow><mi>C</mi><mi>O</mi></mrow><mn>2</mn></msub></mrow></math></span> to the freezing point, and not suitable for large-scale use. <em>Ranque-Hilsch vortex tube (RHVT)</em> has the potential to reduce the air temperature near the freezing point of carbon dioxide. Most optimization is done on commercial ones that are smaller than the size needed to provide the air volume for large-scale direct mass separation of <span><math><mrow><msub><mrow><mi>C</mi><mi>O</mi></mrow><mn>2</mn></msub></mrow></math></span>. The optimized geometric and operating conditions of the device change with size, the present work aims to optimize the larger vortex tubes for this purpose. The genetic algorithm (GA) coupled with an artificial neural network (ANN) was used to perform the optimization from the numerical simulation data. After validating the result with experimental works, the effective parameters on the thermal separation of the vortex tubes, including inlet pressure, cold mass fraction, length to diameter, and cold outlet orifice diameter to the tube diameter, were optimized to achieve the temperature separation about <span><math><mrow><mn>60.5</mn><mo>°C</mo></mrow></math></span>. The findings contribute to a deeper understanding of mass separation phenomenon in vortex tubes and the feasibility, scalability of mass separation by RHVTs in CCS methods.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"145 ","pages":"Article 205788"},"PeriodicalIF":5.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222286","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":"Thermo-mechanical stress analysis of wellbore integrity in CO2 storage wells: A case study from the Tubåen Formation, Snøhvit Field Norway","authors":"Jawad Ali Khan ,&nbsp;Nejma Djabelkhir ,&nbsp;Mazda Irani ,&nbsp;Kegang Ling ,&nbsp;Saleem Ghori ,&nbsp;Sahar Ghannadi","doi":"10.1016/j.jgsce.2025.205758","DOIUrl":"10.1016/j.jgsce.2025.205758","url":null,"abstract":"<div><div>Ensuring long-term wellbore integrity is a critical challenge in carbon capture and storage (CCS) operations, where mechanical failure at the casing–cement and cement–formation interfaces can create potential leakage pathways. This study presents a fully coupled thermal mechanical Poroelastic finite element analysis (FEA) simulation to evaluate stress redistribution and failure risks in the Tubåen Formation, Snøhvit Field. Previous studies primarily focused on bulk stress distribution while this simulation captured dynamic stress evolution across initial and post-injection phases, providing insight into interface-specific failure mechanisms. Low-temperature CO₂ injections induced localized stresses amplification leading to radial cracking, debonding, and microannulus development. Long-term well integrity is seriously compromised by these mechanisms. The study also integrated the Drucker–Prager plasticity model to identify failures. High-resolution stress distribution maps identified critical failure zones, enabling more accurate predictions of failure initiation. This approach captured transient effects considering long term CO₂ injection projects, providing an understanding about well integrity challenges specifically at the cement interfaces. In addition to improving long-term storage performance and regulatory compliance, the findings support proactive risk mitigation strategies for CCS well designs.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"145 ","pages":"Article 205758"},"PeriodicalIF":5.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222287","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":"Dynamic mechanical property and flow performance of ball valve for hydrogen-blended natural gas pipeline","authors":"Yi Ma ,&nbsp;Qingyang Sun ,&nbsp;Ziang Li ,&nbsp;Xudong Peng ,&nbsp;Xiangkai Meng","doi":"10.1016/j.jgsce.2025.205785","DOIUrl":"10.1016/j.jgsce.2025.205785","url":null,"abstract":"<div><div>The blending of hydrogen into natural gas (NG) transmission networks holds significant importance for addressing the challenges of long-distance hydrogen transportation and large-scale renewable energy integration. This study focuses on the hydrogen-blended applicability of key ball valve components in existing long-distance NG pipelines. By comprehensively considering the physical characteristics of hydrogen-blended natural gas (HBNG) and material characteristics, a dynamic thermal-fluid-mechanical coupling numerical model of the ball valve was developed, integrating the multiphysics fields. The mechanical property, flow performance, and dynamic behavior of the ball valve under the NG and HBNG environments were intuitively compared. The influences of operating parameters and rotational modes on the ball valve's sealing specific pressure, thermal gradient, and flow coefficient in the HBNG environment were studied further. The findings indicate that HBNG induces greater flow instability within and downstream of the valve compared to NG. During valve closure, the dynamic sealing specific pressure and flow coefficient of the ball valve in the HBNG environment are generally smaller than those in the NG environment, while simultaneously increasing sealing surface failure risks. The slow-to-fast rotational motion of the valve ball is more conducive to maintaining the dynamic flow performance and seat sealing performance of the ball valve. This research provides fundamental insights for evaluating the feasibility of hydrogen blending in the ball valve of long-distance NG pipelines.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"145 ","pages":"Article 205785"},"PeriodicalIF":5.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222289","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":"Particle size tuning of Ni/CeO2 catalysts and their performance in methane dry reforming reaction","authors":"Yuxuan Niu,&nbsp;Xianrong Zheng,&nbsp;Baihe Guo,&nbsp;Haiyu Liu,&nbsp;Yan Jin,&nbsp;Juntian Niu","doi":"10.1016/j.jgsce.2025.205790","DOIUrl":"10.1016/j.jgsce.2025.205790","url":null,"abstract":"<div><div>Nickel-based catalysts are prone to sintering and carbon deposition during methane dry reforming (DRM), which limits their industrial application. This study addresses these challenges by designing Ni/CeO₂ catalysts with controlled Ni nanoparticle sizes. By varying calcination temperatures, selecting different calcination atmospheres, and comparing preparation methods (equal-volume impregnation vs. combustion method), a series of Ni-based catalysts with different particle sizes were synthesized. The physicochemical properties of the catalysts were elucidated through various characterization techniques. ICP-OES confirmed that the actual Ni loading closely matched the nominal value. XRD and TEM analyses verified that the combustion method yielded smaller NiO nanoparticles with higher dispersion compared to the impregnation method. This advantage stems from the rapid, self-sustaining redox reaction in the combustion process, which effectively inhibits NiO nuclei migration and agglomeration. Consequently, catalysts prepared by the combustion method exhibited superior catalytic activity and stability in DRM. The enhanced performance is directly linked to the smaller Ni particle size, which provides a greater number of active sites and promotes stronger metal-support interactions, thereby improving resistance to sintering and carbon deposition. Furthermore, kinetic studies showed that the smaller Ni nanoparticles were more active, possessing a lower apparent activation energy for methane reforming than the larger particles. These findings provide a clear strategy for the rational design of coke- and sintering-resistant Ni/CeO₂ catalysts for carbon-based energy conversion.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"145 ","pages":"Article 205790"},"PeriodicalIF":5.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269901","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":"Identification of acoustic spectral characteristics and propagation attenuation-based localization for gas pipeline leakage","authors":"Enbin Liu ,&nbsp;Shuang Li ,&nbsp;Diwen Zhao ,&nbsp;Shanbi Peng","doi":"10.1016/j.jgsce.2025.205801","DOIUrl":"10.1016/j.jgsce.2025.205801","url":null,"abstract":"<div><div>To address the challenge of traditional detection techniques failing due to the material characteristics of polyethylene (PE) gas pipelines, this paper proposes an acoustic-deep learning fusion leak diagnosis method. An experimental platform simulating medium and low-pressure gas pipelines with looped and branched configurations was established to systematically collect acoustic signals under diverse leakage conditions, including varying aperture sizes, pressures, and pipe network topologies. Analysis revealed that the main energy of the leakage signals is concentrated in the 0–20 Hz infrasound band, and the pipe network topology systematically modulates the signal's frequency domain characteristics, causing attenuation in the 0–10 Hz range and enhancement in the 70–90 Hz range. To enhance recognition accuracy in complex pipe networks, a leakage state recognition model based on a one-dimensional convolutional neural network (1D-CNN) was developed, and variational mode decomposition (VMD) was introduced for noise-signal separation. The results demonstrate that input signals optimized by VMD enable the model to achieve an average recognition accuracy of 88 % in looped and branched pipe networks, representing an 11.8 % improvement over raw signals. Furthermore, a single-sensor localization method based on waveform energy attenuation was proposed, achieving average localization errors of 0.72 % and 1.15 % in straight pipe sections and branch pipe scenarios, respectively, with an effective detection distance of up to 20 m. This work offers a solution for PE gas pipeline leak detection that integrates theoretical innovation with practical engineering value.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"145 ","pages":"Article 205801"},"PeriodicalIF":5.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474386","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":"Mechanisms of SO2 concentration-dependent pore evolution in anthracite during CO2 sequestration","authors":"Wenyu Fu ,&nbsp;Yiyu Lu ,&nbsp;Yunzhong Jia ,&nbsp;Zhaolong Ge ,&nbsp;Jiaqi Yi","doi":"10.1016/j.jgsce.2025.205804","DOIUrl":"10.1016/j.jgsce.2025.205804","url":null,"abstract":"<div><div>A critical pathway to cost reduction in CO₂-ECBM is the large-scale injection of high-concentration flue gas. However, the impact mechanisms of associated impurities on reservoir modification and storage security remain inadequately understood. This study addresses explicitly SO₂, a representative acidic impurity in flue gas, elucidating its regulatory mechanisms on pore networks in high-rank anthracite under supercritical CO₂ (ScCO₂) storage conditions and evaluating its potential for storage enhancement. We use multi-scale characterisation techniques, including NMR, XRD, and SEM, to quantify pore structure parameters, mineral migration patterns, and surface morphology evolution before and after exposure to SO₂-gradient concentrations (0–6000 ppm) in ScCO₂ environments. We do this by methodically analysing high-rank anthracite samples under simulated reservoir conditions (40 °C, 10 MPa). Experimental results reveal that low-concentration SO₂ (&lt;1000 ppm) synergises with ScCO₂ to enhance pore connectivity via dissolution-dominated actions, increasing porosity by up to 141.14 % and permeability increment by 3.04 times compared to pure CO₂ treatment. Conversely, high-concentration SO₂ (&gt;2000 ppm) triggers precipitation-dominated pore-blocking through sulfate mineralisation, reducing regulatory efficiency <em>η</em>_<em>S</em> to −63.15 %. Mineralogical analysis reveals that a dynamic equilibrium between mineral dissolution and secondary precipitation drives pore evolution. Crucially, SO₂ exhibits functional selectivity, as it preferentially remodels seepage pores (<em>φ</em>_se) over adsorption pores (<em>φ</em>_ad), with a 50.28-fold higher dynamic response intensity. We propose an alternating injection strategy to leverage these mechanisms: initial high-SO₂ (&gt;2000 ppm) injection mitigates adsorption-induced swelling, followed by optimised low-SO₂ (&lt;1000 ppm) stimulation for maximum reservoir modification. These findings provide fundamental insights for designing impurity-tolerant CCUS systems in anthracite seams.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"145 ","pages":"Article 205804"},"PeriodicalIF":5.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623525","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":"Pore-scale synchrotron imaging of scCO2-brine intermittent flow: Experimental insights into multiphase dynamics for geological carbon storage","authors":"Amin Taghavinejad ,&nbsp;Azibayam Josiah Amabogha ,&nbsp;Rukuan Chai ,&nbsp;Gioia Falcone ,&nbsp;Yihuai Zhang","doi":"10.1016/j.jgsce.2025.205806","DOIUrl":"10.1016/j.jgsce.2025.205806","url":null,"abstract":"<div><div>Underground carbon dioxide (CO₂) storage is a critical approach for mitigating climate change by sequestering CO₂ in deep geological formations. The interaction between injected super critical (sc) CO₂ and resident brine within pores results in complex two-phase flow dynamics that influence the efficiency and security of storage. While previous studies have mainly focused on capillary-dominated regimes, where fluid phases flow at low velocities, the transitional intermittent flow regime—characterised by higher flow rates and complex displacement dynamics—remains less understood. This study investigates the onset and development of intermittent flow pathways in CO₂-brine systems through high-resolution synchrotron X-ray micro-computed tomography imaging of a carbonate rock sample. The core-flooding experiments were conducted under 8 MPa and 50 °C to examine pore-scale fluid configuration changes as a function of capillary number (<em>Ca</em>). The results indicate that intermittent flow emerges at lower <em>Ca</em> values than previously observed in oil-brine systems, with a distinct transition from Darcy flow to intermittent flow. Moreover, the saturation of the intermittent phase stabilises beyond a threshold <em>Ca</em>, suggesting another phase transition within the intermittent flow regime. These findings provide new insights into the fundamental mechanisms of two-phase flow dynamics at the pore scale, revealing a stable intermittent flow regime at higher flow rates, with potential implications for improved injectivity under non-equilibrium conditions.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"145 ","pages":"Article 205806"},"PeriodicalIF":5.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623526","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":"Molecular simulation of CH4 replacement and coal structure by CO2 foam injection in slit pores","authors":"Hongyu Pan ,&nbsp;Bingnan Ji ,&nbsp;Yuxuan Zhou ,&nbsp;Tianjun Zhang ,&nbsp;Mingyue Pan ,&nbsp;Hongjiao Chen","doi":"10.1016/j.jgsce.2025.205783","DOIUrl":"10.1016/j.jgsce.2025.205783","url":null,"abstract":"<div><div>CO₂ foam fracturing technology in the coal seam offers the dual benefits of enhancing coalbed methane extraction and promoting carbon neutrality. However, the water lock effect and structural response mechanism following CO₂ foam injection into coal remain unclear. The occurrence and interaction mechanisms among CH₄, CO₂, and H₂O in coal slit pores were analyzed following CO₂ foam injection using molecular dynamics approach. The mechanism by which CO₂ foam injection influences CH₄ desorption, diffusion, and coal structure deformation was elucidated. The results indicate that with 25 % quality foam injection, water clusters nearly filled the coal slit pores, forming a water film that inhibited CH₄ desorption, and adsorbed CH₄ increased to 77 n/cell. At 85 % quality, the co-adsorption displacement effect of smaller clusters with CO₂ was significant, adsorbed CH₄ was sharply reduced to 26 n/cell, and CO₂ adsorption weakened the water film effect; The adsorption and occurrence of H₂O molecules induced shrinkage deformation of coal, whereas adsorption and diffusion collisions of CO₂ led to expansion deformation. High-quality CO₂ foam injection increased the coal matrix's pore volume and surface area but reduced the stability, facilitating CO₂ and H₂O adsorption and CH₄ displacement; The water clusters presence after CO₂ foam injection significantly altered the gas diffusion form, and the H₂O molecule diffusion coefficient was mainly correlated with volume and aggregation of clusters; As foam quality enhanced, the diffusion coefficients of adsorbed CO₂, free CH₄, and CO₂ rose gradually, while those for adsorbed CH₄ initially increased, then declined, and ultimately increased due to displacement effects.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"145 ","pages":"Article 205783"},"PeriodicalIF":5.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222290","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":"A new model for relative gas permeability considering the dynamics of pore-scale water distribution","authors":"Lin-Yong Cui ,&nbsp;Min Chen ,&nbsp;Shakil A. Masum ,&nbsp;Yuan-Hao Wei","doi":"10.1016/j.jgsce.2025.205800","DOIUrl":"10.1016/j.jgsce.2025.205800","url":null,"abstract":"<div><div>Investigating gas flow through unsaturated soils is crucial for various geoscientific and engineering applications. Traditional statistical permeability models, based on capillary-law theory, often overestimate gas permeability. While recent efforts have extended gas permeability functions into the adsorption region, they rarely consider the dynamics of water distribution at the pore scale. This study introduces a new approach to predicting gas permeability by considering the dynamics of flow regimes as water saturation increases. This approach employs a dual-regime framework that sequentially accounts for the funicular and separate channel flow regimes. At low saturation, water forms thin films on particle surfaces, and as saturation increases, these films thicken, creating a funicular flow regime. At higher saturation levels, capillary forces gradually dominate gas flow, and gas occupies larger pores while water fills smaller ones, enabling separate channel flow regime. To mathematically represent and integrate these two physical processes, a piecewise function is used, and a model parameter of critical saturation is defined to delineate the transition between these two regimes. For verification, a dataset comprising 31 different soils, including loam, sand, loess, and clay, was compiled from various literature sources. The prediction results by the proposed model show good agreement with experimental data, yielding low RMSE and MAE values of 0.050 and 0.028, respectively. To provide a rapid method for predicting relative gas permeability based on readily available parameters, this study established an empirical relationship between critical saturation and residual saturation, which also yields satisfactory results with RMSE and MAE values of 0.085 and 0.054, respectively. The findings of this study offer a new perspective on understanding gas transport within unsaturated soils.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"145 ","pages":"Article 205800"},"PeriodicalIF":5.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474388","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}