Geofluids最新文献

{"title":"Sonic Dispersions of P-Waves of Two Types: Fractured Safaniya Sandstone","authors":"Guangquan Li,&nbsp;Xiang Li,&nbsp;Zhongyuan Liu","doi":"10.1155/gfl/6165629","DOIUrl":"https://doi.org/10.1155/gfl/6165629","url":null,"abstract":"<p>As P-waves propagate in fractured porous rock, fluid pressure in fractures may be distinct from that in the contiguous matrix; the fluid pressure differential can drive a viscous squirt between them, which substantially attenuates the waves. A double porosity model of P-waves is constructed based on this mechanism and under the major assumption of isotropic fractures. As a second assumption, matrix permeability between two neighboring rock units is set to zero, whereas fracture permeability is not vanishing to allow the existence/propagation of slow P-wave. The resulting wavenumber equation has two eigenvalues representing two types of P-waves. The P-wave of the first type is the fast P-wave in acoustics, whereas the P-wave of the second type is the slow P-wave in hydrogeology. Safaniya sandstone of the Wasia Formation is used for illustration. The parameters of the sandstone are calibrated by the phase velocity and quality factor of the fast/acoustic P-wave, measured at 10 kHz from a sonic log in Saudi Arabia. Thus, the dispersions/attenuations of P-waves of the two types are determined. The results reveal that fast P-wave dispersion in the low-frequency (seismic) regime is small, whereas that in the high-frequency (sonic) regime is extraordinarily large. The small fracture Biot dispersion at low frequencies arises from interfracture viscous flow, whereas the large dispersion at high frequencies arises from fracture–matrix squirt. The clear separation of the two mechanisms in the frequency domain is the novelty of this study.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2026-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/6165629","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148994487","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":"Time-Dependent Mechanical Degradation and Constitutive Modeling of Longmaxi Shale Under Different pH Soaking Conditions","authors":"Yongzhou Wei,&nbsp;Guodong Feng","doi":"10.1155/gfl/5509112","DOIUrl":"https://doi.org/10.1155/gfl/5509112","url":null,"abstract":"<p>Fluid-rock interaction can weaken shale during drilling, stimulation, and prolonged wellbore exposure. Longmaxi Formation shale was soaked for 5–20 days in solutions with pH values of 2, 4, 7, 9, and 12, and was examined using physical-property measurements, P-wave testing, scanning electron microscopy, and uniaxial compression. After 20 days at pH = 2, the soaking-induced mass change reached −15.43 g, porosity increased by 1.06 percentage points, P-wave velocity decreased by 6.31%, peak strength decreased by 69.49%, and apparent elastic modulus decreased by 78.65%. Degradation was consistently strongest at pH = 2 and weakest near neutral conditions, whereas the relative severity of pH = 4 and pH = 12 depended on the selected indicator. Because the modulus-based index includes wetting, hydration, chemical reaction, and specimen variability, it is redefined as an equivalent soaking-induced stiffness damage index rather than a pure chemical-damage measure. An endpoint-constrained exponential function is used only to interpolate its evolution over the tested 0–20 day interval. To represent the initial nonlinear pore-compaction stage, axial strain is normalized and a threshold logistic mechanical-damage function is introduced. Unlike common damage formulations that permit damage growth from the onset of loading, the threshold function keeps mechanical damage close to zero during early crack closure and reproduces the compaction, hardening, peak, and postpeak portions of representative pH = 2 and pH = 12 curves. The model is a phenomenological curve representation for outcrop shale under ambient uniaxial conditions; replicated mechanical tests, quantitative chemical characterization, and triaxial validation are still required.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2026-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/5509112","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148994024","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":"Fluid-Driven Evolution of Deep In-Situ Stress Field in the Kuqa Depression: Insights From Seismic Monitoring and Stress Inversion","authors":"Hui Zhang,&nbsp;Zhimin Wang,&nbsp;Xin Wang,&nbsp;Bin Wang,&nbsp;Lei Liu,&nbsp;Haoyang Zan,&nbsp;Yu Zhang,&nbsp;Hongxiang Gao,&nbsp;Kezhen Zuo","doi":"10.1155/gfl/4488739","DOIUrl":"https://doi.org/10.1155/gfl/4488739","url":null,"abstract":"<p>The Kuqa Depression hosts deep, high-pressure, fractured tight sandstone gas reservoirs within a critically balanced compressional tectonic regime. Long-term gas extraction and subsequent water breakthrough cause widespread pore-pressure perturbations and gas–water fluid substitution, offering a natural laboratory for studying fluid-driven stress evolution in compressional foreland systems. This study integrates multitemporal seismic catalogs, focal mechanism solutions, seismic velocity tomography, and stress inversion to decipher the spatiotemporal evolution of deep in-situ stress throughout the full production cycle. Gas depletion systematically alters P-wave velocity (<i>V</i>_<i>p</i>), S-wave velocity (<i>V</i>_<i>s</i>), and the <i>V</i>_<i>p</i>/<i>V</i>_<i>s</i> ratio. Spatially, core-producing blocks show elevated <i>V</i>_<i>p</i> and <i>V</i>_<i>s</i> but reduced <i>V</i>_<i>p</i>/<i>V</i>_<i>s</i>, whereas peripheral zones exhibit increased <i>V</i>_<i>p</i>/<i>V</i>_<i>s</i>. These contrasting anomalies reflect coupled poroelastic compaction and fluid substitution under variable effective stress. Subsurface mechanical deformation migrates from east to west, with the 4–10 km interval confirmed as the primary stratigraphic layer modified by anthropogenic fluid activities. The in-situ stress field evolves through three stages. Pore-pressure drawdown and fluid displacement drive westward stress migration and pronounced stress localization in the KS8 block. We propose a cascaded geomechanical coupling pathway: gas extraction → fluid redistribution → rock compaction → stress re-equilibration. Our findings clarify sequential stress perturbations triggered by production and water influx in near-critical foreland thrust belts, providing practical insights into fluid-induced stress heterogenization and fault stability assessment for deep tight-gas reservoirs.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2026-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/4488739","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148943203","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":"Pore Development, Connectivity, and Their Controlling Factors in Shahejie Formation Shales, Bonan Sag, Jiyang Depression","authors":"Baojian Shen,&nbsp;Xiaoqi Xu,&nbsp;Peng Li,&nbsp;Huimin Liu,&nbsp;Suping Yao","doi":"10.1155/gfl/4012065","DOIUrl":"https://doi.org/10.1155/gfl/4012065","url":null,"abstract":"<p>Shale oil exploration in the Paleogene Shahejie Formation of eastern China has advanced substantially in recent years. Geological investigations and exploration practice have shown that pore structure and pore connectivity are fundamental controls on shale reservoir quality and shale oil productivity. This study is aimed at quantifying pore structure and pore connectivity across lithofacies in organic-rich shales from the lower submember of the third member of the Shahejie Formation (Es₃^L) in Well Luo-69, Bonan Subsag, Jiyang Depression. An integrated workflow combining Wood′s metal (WM) injection, scanning electron microscopy (SEM), small-angle and very-small-angle neutron scattering (SANS/VSANS), and x-ray computed tomography (X-ray CT) was applied. WM injection labels pores connected to the exterior of the sample, SEM identifies pore types and WM-filled pathways, SANS/VSANS constrains nanometer-scale porosity and connectivity, and X-ray CT reconstructs micrometer-scale three-dimensional pore and fracture networks. This integrated workflow provides complementary constraints on pore morphology, pore size distribution, connected pore volume, and pore architecture, with the combined investigated pore size range extending from 2 nm to 200 <i>μ</i>m. The results reveal pore systems controlled by lithofacies. The massive lithofacies is dominated by clay mineral-related nanopores and shows relatively weak connectivity because most nanopores are isolated or only weakly connected. The laminated lithofacies contains abundant carbonate laminae, dissolution pores, bedding fractures, and microfractures, forming a better connected pore and fracture network, especially at the micrometer scale. The bedded lithofacies displays transitional pore structure and connectivity characteristics. These differences are mainly controlled by depositional structure and mineral composition: Clay minerals promote nanoscale storage pores, whereas carbonate laminae and bedding structures favor dissolution pores and fracture connectivity. The results indicate that reservoir quality evaluation in the Shahejie Formation should integrate porosity, pore size distribution, pore morphology, and pore-fracture connectivity rather than relying on total porosity alone. Laminated intervals with high carbonate mineral content in the lower Es₃^L are interpreted as favorable targets for shale oil sweet spot evaluation and engineering stimulation.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/4012065","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148943290","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":"Study on the Feasibility and Safety Control of Main Roadway Excavation Through the Dashuigou Protective Coal Pillar Area","authors":"Yuanyue Pi,&nbsp;Xin Wang,&nbsp;Yawei Zhu,&nbsp;Chenglong Wei","doi":"10.1155/gfl/1496347","DOIUrl":"https://doi.org/10.1155/gfl/1496347","url":null,"abstract":"<p>To investigate the feasibility and safety control technologies for main roadway excavation through the Dashuigou protective coal pillar area, an elastoplastic mechanical model was used to characterize the roadway-induced expansion of the plastic zone and determine the width of the residual elastic core. A probability integral method was applied to predict overburden movement and surface deformation caused by roadway excavation. Three-dimensional FLAC3D simulations were subsequently conducted to examine stress redistribution, displacement development, and plastic-zone evolution around the roadways. Field monitoring was also performed to verify the analytical and numerical results. The results show that the maximum plastic-zone width on either side of the protective coal pillar is approximately 0.71 m, whereas the minimum elastic-core width remains 21.95 m. The estimated pillar load is approximately 3.27 MPa, which is substantially lower than the average failure strength of the coal pillar (10 MPa). The predicted maximum surface subsidence is approximately 28 mm, with a maximum tilt of 0.4 mm/m, a maximum curvature of 0.1 × 10⁻⁴ mm/m², and a maximum horizontal displacement of 12 mm. All these indices remain below the allowable limits specified in the relevant regulations. The numerical simulations indicate a peak stress of approximately 3.9 MPa at the roadway ribs, a maximum roof displacement of about 60 mm, and a plastic-zone depth of 1.2–2.5 m. Field measurements further show that the roof-to-floor convergence of the roadways in the 5-1 and 5-2 coal seams stabilizes at approximately 49.5 and 59 mm, respectively. Roof separation remains limited, and the surrounding-rock deformation gradually approaches a stable state during the later stage of roadway development. These observations agree well with the analytical predictions and numerical simulations. The results may provide a useful reference for roadway engineering in deferred-mining zones under surface-water bodies under comparable geological and hydrogeological conditions.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2026-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/1496347","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148848882","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":"Characterizing depth-dependent roof water abundance in underground coal mines using transient electromagnetic data","authors":"Sen Xue,&nbsp;Qichen Guo,&nbsp;Yun Wu,&nbsp;Zhen Song,&nbsp;Hu Zheng,&nbsp;Xiaowen Pan","doi":"10.1155/gfl/1161407","DOIUrl":"https://doi.org/10.1155/gfl/1161407","url":null,"abstract":"<p>Coal mining is a major industrial activity in North China, where water inrush hazards pose a persistent threat to safe and efficient mining operations. Accurate identification of water-abundant zones in coal seam floors and surrounding strata is therefore critical for mine water-hazard prevention. However, conventional geophysical investigations are often constrained by the half-space assumption and limited observation geometry, which restrict their applicability in underground mining environments. In this study, the transient electromagnetic (TEM) method was employed to investigate the spatial distribution of water abundance in an underground coal mine. A whole-space TEM configuration was adopted to account for the complex boundary conditions and confined observation space inherent to underground settings. By integrating time-domain electromagnetic responses with appropriate time–depth conversion, the electrical characteristics of water-bearing structures were systematically analyzed. The results indicate that the whole-space TEM investigation can effectively identify water-abundant zones and stereoscopically reflect their spatial distribution within the underground environment. Distinct low-resistivity anomalies were identified and shown to be consistent with known hydrogeological conditions, demonstrating the reliability of the proposed approach. This study highlights the advantages of whole-space TEM for underground water-hazard detection and provides a practical geophysical framework for improving water inrush risk assessment in coal mines of North China.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2026-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/1161407","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148848883","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 Fracture Propagation and Pressure Relief Mechanism in Layered Hard Roof Under Directional Slotting Conditions","authors":"Zhenguo Su,&nbsp;Shaogang Li,&nbsp;Shankun Zhao,&nbsp;Yue Shi,&nbsp;Weige Han,&nbsp;Junjun Jiang,&nbsp;Yunlong Mo,&nbsp;Guanghui Zhang","doi":"10.1155/gfl/5957723","DOIUrl":"https://doi.org/10.1155/gfl/5957723","url":null,"abstract":"<p>To reveal the role of directional slotting parameters in controlling fracture development in hard roof rocks, a multilayer hydraulic fracturing simulation model based on the extended finite element method (XFEM) was constructed. Parametric analyses were conducted to examine how slot inclination, differential horizontal stress, and slot dimensions affect crack extension patterns, breakdown pressure, and the redistribution of surrounding stresses. The results indicate that layered strata significantly constrain fracture propagation and induce strong stress redistribution within the fracturing layer, accompanied by asymmetric stress responses across bedding interfaces. During propagation, the principal stress direction rotates and a localized stress reconstruction zone forms around the fracture. The slotting angle plays a key role in controlling fracture behavior. When the angle is below 60°, fracture propagation is dominated by the in situ stress field. When it increases to 75° or higher, slot-guided effects become dominant, leading to a pronounced deviation in the fracture path. The breakdown pressure shows a nonmonotonic trend with the slotting angle, peaking near 60°, indicating a strong competition between slot guidance and stress control. At 75° slotting, increasing stress difference shifts fracture behavior from slot-controlled to stress-controlled, with increasing breakdown pressure. Slot geometry further affects initiation behavior: diamond-shaped slots generate the lowest breakdown pressure, followed by elliptical and circular slots. A larger slot size significantly reduces breakdown pressure. These findings demonstrate that fracture propagation in layered hard roofs is jointly governed by stratigraphic constraints, directional slot guidance, and in situ stress, providing guidance for parameter optimization in pressure relief design.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2026-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/5957723","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148783632","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":"Field and Laboratory Investigation of Pore Structure Evolution in CO2-Injected Sandstone Aquifers: Implications for Injectivity","authors":"Xihui Jia,&nbsp;Bo Xu,&nbsp;Zhiyuan Zhou,&nbsp;Liangzhu Yan","doi":"10.1155/gfl/3656777","DOIUrl":"https://doi.org/10.1155/gfl/3656777","url":null,"abstract":"<p>Geologic CO₂ storage in saline sandstone aquifers is controlled in part by injectivity, because the ability to sustain a target storage rate affects both pressure management and the number of injection wells required. Here we examine the Shenhua CCS Demonstration Project in the Ordos Basin, China, targeting the Triassic Liujiagou Formation at approximately 1.7–1.9 km depth, using an integrated workflow that combines field injection monitoring and pressure-transient analysis, laboratory characterization of preinjection and postinjection reservoir cores, and coupled flow and reactive-transport simulation. Pressure-rate monitoring and pressure-transient interpretation indicate that the injectivity index estimated from monitored pressure-rate data increased by about one order of magnitude during the test program, whereas falloff-derived apparent near-well permeability increased from ~0.06 to ~0.18 mD. Laboratory measurements of core samples show little change in bulk porosity (~10%), but a clear redistribution of pore-throat sizes, with more large throats and some additional fine pores after injection. XRD/XRF, thin-section, and SEM observations are consistent with partial dissolution of calcite and chlorite, limited secondary illite precipitation, and improved near-well pore connectivity. Reactive-transport model predictions indicate spatially differentiated reactions, with dissolution concentrated in the acidic near-well zone and model-predicted calcite/clay precipitation farther from the injector as a possible, unvalidated distal low-permeability halo. Improved injectivity could reduce the number of injectors needed to achieve a target storage rate and thus improve project economics. However, the core comparison is quasi-paired rather than strictly paired, and the far-field precipitation/fines-migration behavior remains incompletely validated because it is inferred mainly from a homogeneous radial model rather than direct far-field observations.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/3656777","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753811","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 Characteristics, Sources, and Geothermal Implications of Sulfur-Containing Nanoparticles in Deep High-Temperature Geothermal Fluids in the Jiyang Depression","authors":"Shanming Wei,&nbsp;Xubo Man,&nbsp;Xuefei Zheng,&nbsp;Tao Wang,&nbsp;Changsuo Li,&nbsp;Tongqian Jia,&nbsp;Xiaobo Tan,&nbsp;Chenkai Zhang,&nbsp;Rui Liu","doi":"10.1155/gfl/6661141","DOIUrl":"https://doi.org/10.1155/gfl/6661141","url":null,"abstract":"<p>Rising global demand for clean energy has elevated the status of geothermal resources as a sustainable renewable energy. Nevertheless, high costs and environmental risks of deep drilling restrict the development of geothermal research. Recent advances in transmission electron microscopy (TEM) have opened new avenues for studying geothermal systems. This study focuses on the southeastern Jiyang Depression. The region’s unique geological structure features a composite hydrothermal system and distinct geothermal anomalies, providing an ideal case study. Geothermal fluid samples were collected from Well Dongying-1 at a depth of 4283.6 m and analyzed using TEM, high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and energy-dispersive X-ray spectroscopy (EDS). These techniques enabled comprehensive characterization of micro-nanoparticles, including their morphology, size, crystallinity, aggregation state, chemical composition, and elemental distribution. The results reveal abundant sulfur-bearing micro-nanoparticles in the Dongying geothermal fluids, primarily exhibiting spherical and plate-like morphologies. The spherical nanoparticles (~500 nm in diameter) consist of smaller gypsum nanocrystals with numerous defects, consistent with crystallization under geothermal conditions via an oriented attachment mechanism. In contrast, the plate-like particles are larger, highly crystalline, and coated with NaCl nanoparticles, suggesting their origin from the Shahejie Formation gypsum layer through water−rock interactions. Elemental analysis confirmed that magma is the primary source of sulfur in the spherical gypsum nanoparticles with regular morphology. These nanoparticles, due to their unique mobility and physicochemical properties, serve as effective tracers of deep geothermal activity, offering insights into tectonic controls on heat distribution. Additionally, the study identifies a potential mechanism for scale formation, where nanoparticles aggregate under specific conditions to create nanoscale deposits. This finding provides a new perspective for developing anti-scaling technologies and advances the sustainable utilization of geothermal resources. The research also contributes to understanding material transport in geothermal systems, offering theoretical foundations for future studies.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2026-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/6661141","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752995","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":"Nonnegligible Groundwater Depletion From Aquitards in Multilayered Leaky Aquifer Systems","authors":"Xingyu Chen,&nbsp;Yan Zhang,&nbsp;Jun Yu,&nbsp;Xulong Gong,&nbsp;Shefeng Hao,&nbsp;Yun Yang,&nbsp;Chao Zhuang","doi":"10.1155/gfl/5383289","DOIUrl":"https://doi.org/10.1155/gfl/5383289","url":null,"abstract":"<p>Groundwater depletion constitutes a critical global challenge. Exploitation of deep aquifers leads to nonnegligible depletion of water stored in adjacent aquitards (termed aquitard depletion). Although aquitards generally exhibit lower permeability than aquifers, they possess significantly higher storativity. Accurately quantifying aquitard depletion remains a methodological challenge. This study develops a new methodology, based on the analytical well hydraulics model for a classical leaky aquifer system, to estimate aquitard depletion at a regional scale. Specifically, a formulation for the regional average completion degree of aquitard depletion is derived. Theoretically, when the pumping duration reaches the hydraulic response time of the aquitard, approximately 97% of its ultimate depletion is achieved. Furthermore, applying the frequently used step-drawdown model with half the actual pumping time yields a regionally representative estimate of aquitard depletion. Applications to the Su-Xi-Chang (China) and the Virginia Coastal Plain (United States) aquifer systems show that aquitards contribute dominantly to total depletion (~96% and ~94%, respectively), most of which is irreversible due to inelastic compaction. These findings underscore the predominant role of aquitards in groundwater storage loss and highlight the necessity of incorporating aquitard dynamics into assessments for sustainable groundwater management.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/5383289","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752870","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}