Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (4,901)

Search Parameters:
Keywords = pore development

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
18 pages, 3097 KB  
Article
Moso Bamboo Invasion Enhances Soil Infiltration and Water Flow Connectivity in Subtropical Forest Root Zones: Mechanisms and Implications
by Tianheng Zhao, Lin Zhang and Shi Qi
Forests 2025, 16(10), 1589; https://doi.org/10.3390/f16101589 - 16 Oct 2025
Abstract
Plant roots influence soil infiltration by altering its properties like porosity and bulk density, which are essential for ecohydrological cycles. Moso bamboo (Phyllostachys edulis), using its well-developed underground root system, invades neighbor forest communities, thereby influencing root characteristics and soil properties. [...] Read more.
Plant roots influence soil infiltration by altering its properties like porosity and bulk density, which are essential for ecohydrological cycles. Moso bamboo (Phyllostachys edulis), using its well-developed underground root system, invades neighbor forest communities, thereby influencing root characteristics and soil properties. Although Moso bamboo invasion may alter soil hydrology, its specific impact on soil infiltration capacity and water flow connectivity remains unclear. This work took a fir forest (Cunninghamia lanceolata), mixed fir and bamboo forest, and a bamboo forest which represent three different degrees of invasion: uninvaded, partially invaded, and completely invaded, respectively, as study objects, using double-ring dyeing infiltration method to measure soil infiltration capacity and calculating water flow connectivity index for the root zone. To assess the effects of soil properties and root characteristics on soil infiltration capacity and water flow connectivity, we employed random forest and structural equation modeling. The analysis revealed that Moso bamboo invasion significantly enhanced soil infiltration capacity. Specifically, in partially invaded forests, the initial infiltration rate, stable infiltration rate, and average infiltration rate increased by 31.5%, 26.1%, and 28.5%, respectively. In completely invaded forests, the corresponding increases were 6.6%, 35.6%, and 28.5%. Also, Moso bamboo invasion increased water flow connectivity of root zone, compared to the uninvaded forest, the water flow connectivity index increased by 29.4% in the completely invaded forest and by 15.6% in the partially invaded forest. The marked increase in fine root biomass density (RBD1), fine root length density (RLD1), soil organic carbon (SOC), and non-capillary pores (NCP) and the decrease in soil bulk density (SBD) followed by Moso bamboo invasion effectively improved water flow connectivity and soil infiltration capacity. The analysis identified that RBD1, RLD1, NCP, and SBD as the key drivers of soil infiltration capacity, whereas the water flow connectivity index was controlled mainly by SOC, NCP, RLD1, and RBD1. These findings help clarify the mechanistic pathways of Moso bamboo’s effects on soil infiltration. Full article
(This article belongs to the Section Forest Soil)
Show Figures

Figure 1

22 pages, 51773 KB  
Article
On a Software Framework for Automated Pore Identification and Quantification for SEM Images of Metals
by Michael Mulligan, Oliver Fowler, Joshua Voell, Mark Atwater and Howie Fang
Computers 2025, 14(10), 442; https://doi.org/10.3390/computers14100442 (registering DOI) - 16 Oct 2025
Abstract
The functional performance of porous metals and alloys is dictated by pore features such as size, connectivity, and morphology. While methods like mercury porosimetry or gas pycnometry provide cumulative information, direct observation via scanning electron microscopy (SEM) offers detailed insights unavailable through other [...] Read more.
The functional performance of porous metals and alloys is dictated by pore features such as size, connectivity, and morphology. While methods like mercury porosimetry or gas pycnometry provide cumulative information, direct observation via scanning electron microscopy (SEM) offers detailed insights unavailable through other means, especially for microscale or nanoscale pores. Each scanned image can contain hundreds or thousands of pores, making efficient identification, classification, and quantification challenging due to the processing time required for pixel-level edge recognition. Traditionally, pore outlines on scanned images were hand-traced and analyzed using image-processing software, a process that is time-consuming and often inconsistent for capturing both large and small pores while accurately removing noise. In this work, a software framework was developed that leverages modern computing tools and methodologies for automated image processing for pore identification, classification, and quantification. Vectorization was implemented as the final step to utilize the direction and magnitude of unconnected endpoints to reconstruct incomplete or broken edges. Combined with other existing pore analysis methods, this automated approach reduces manual effort dramatically, reducing analysis time from multiple hours per image to only minutes, while maintaining acceptable accuracy in quantified pore metrics. Full article
(This article belongs to the Section Human–Computer Interactions)
20 pages, 3504 KB  
Article
Modeling the Evolution of Mechanical Behavior in Rocks Under Various Water Environments
by Lixiang Liu, Sai Fu, Xianlin Jia, Xibin Li and Linfei Zhang
Water 2025, 17(20), 2983; https://doi.org/10.3390/w17202983 - 16 Oct 2025
Abstract
After reservoir impoundment, water infiltration weakens rock strength and accelerates creep deformation. Existing models seldom capture both strength degradation and creep behavior under prolonged saturation. This study develops a coupled hydro-mechanical creep model that integrates saturation-dependent elastic modulus reduction, cohesion decay with pore [...] Read more.
After reservoir impoundment, water infiltration weakens rock strength and accelerates creep deformation. Existing models seldom capture both strength degradation and creep behavior under prolonged saturation. This study develops a coupled hydro-mechanical creep model that integrates saturation-dependent elastic modulus reduction, cohesion decay with pore pressure, and a nonlinear creep law modified by a Heaviside function. Simulation of rock deformation during water infiltration reveals that water–creep coupling increases steady-state deformation by over 50% compared to strength degradation alone. A case study of a high arch dam reservoir slope demonstrates that models incorporating both water-weakening and creep effects predict significantly larger deformations than those ignoring these mechanisms. The model provides a practical tool for predicting long-term deformation in reservoir slopes under water–rock interaction. Full article
Show Figures

Figure 1

26 pages, 1281 KB  
Article
Mechanistic Investigation of CO2-Soluble Compound Foaming Systems for Flow Blocking and Enhanced Oil Recovery
by Junhong Jia, Wei Fan, Chengwei Yang, Danchen Li and Xiukun Wang
Processes 2025, 13(10), 3299; https://doi.org/10.3390/pr13103299 - 15 Oct 2025
Abstract
Carbon dioxide (CO2) has been widely applied in gas flooding for reservoir development due to its remarkable oil recovery potential. However, because its viscosity is lower than that of water and most crude oils, severe channeling often occurs during the flooding [...] Read more.
Carbon dioxide (CO2) has been widely applied in gas flooding for reservoir development due to its remarkable oil recovery potential. However, because its viscosity is lower than that of water and most crude oils, severe channeling often occurs during the flooding process, resulting in a significant reduction in the sweep efficiency. To address this issue, foam flooding has attracted considerable attention as an effective method for controlling CO2 mobility. In this study, a compound foam system was developed with alpha-olefin sulfonate (AOS) as the primary foaming agent, alcohol ethoxylate (AEO) and cetyltrimethylammonium bromide (CTAB) as co-surfactants, and partially hydrolyzed polyacrylamide (HPAM) as the stabilizer. The optimal system was screened through evaluations of comprehensive foam index, salt tolerance, oil resistance, and shear resistance. Results indicate that the AOS+AEO formulation exhibits superior foaming ability, salt tolerance, and foam stability compared with the AOS+CTAB system, with the best performance achieved at a mass ratio of 2:1 (AOS:AEO), balancing both adaptability and economic feasibility. A heterogeneous reservoir model was constructed using parallel core flooding to investigate the displacement performance and blocking capability of the system. Nuclear magnetic resonance (NMR) imaging was employed to monitor in situ oil phase migration and clarify the recovery mechanisms. Experimental results show that the compound foam system demonstrates excellent conformance control performance, achieving a blocking efficiency of 84.5% and improving the overall oil recovery by 4.6%. NMR imaging further reveals that the system effectively mobilizes low-permeability zones, with T2 spectrum analysis indicating a 4.5% incremental recovery in low-permeability layers. Moreover, in reservoirs with larger permeability ratio, the system exhibits enhanced blocking efficiency (up to 86.5%), though the incremental recovery is not strictly proportional to the blocking effect. Compared with previous AOS-based CO2 foam studies that primarily relied on pressure drop and effluent analyses, this work introduces NMR imaging and T2 spectrum diagnostics to directly visualize pore-scale fluid redistribution and quantify sweep efficiency within heterogeneous cores. The NMR data provide mechanistic evidence that the enhanced recovery originates from selective foam propagation and the mobilization of residual oil in low-permeability channels, rather than merely from increased flow resistance. This integration of advanced pore-scale imaging with macroscopic displacement analysis represents a mechanistic advancement over conventional CO2 foam evaluations, offering new insights into the conformance control behavior of AOS-based foam systems in heterogeneous reservoirs. Full article
(This article belongs to the Special Issue Flow Mechanisms and Enhanced Oil Recovery)
28 pages, 2435 KB  
Review
Traditional and Advanced Curing Strategies for Concrete Materials: A Systematic Review of Mechanical Performance, Sustainability, and Future Directions
by Robert Haigh and Omid Ameri Sianaki
Appl. Sci. 2025, 15(20), 11055; https://doi.org/10.3390/app152011055 - 15 Oct 2025
Abstract
Curing plays a fundamental role in determining the mechanical performance, durability, and sustainability of concrete structures. Traditional curing practices, such as water and air curing, are widely used but often limited by long durations, high water demand, and reduced effectiveness under extreme climatic [...] Read more.
Curing plays a fundamental role in determining the mechanical performance, durability, and sustainability of concrete structures. Traditional curing practices, such as water and air curing, are widely used but often limited by long durations, high water demand, and reduced effectiveness under extreme climatic conditions. In response, advanced curing methods such as steam, microwave, electric, autoclave, and accelerated carbonation have been developed to accelerate hydration, refine pore structures, and enhance durability. This review critically examines the performance of both conventional and advanced curing strategies across a range of concrete systems. Findings show that microwave curing achieves up to 85–95% of 28-day wet-cured strength within 24 h, whilst autoclave curing enhances early strength by 40–60%. Electric curing reduces energy demand by approximately 40% compared to steam curing, and carbonation curing lowers carbon dioxide emissions by 30–50% through carbon sequestration. While steam and autoclave curing provide rapid early strength, they may compromise long-term durability through microcracking and increased porosity. No single method was identified as universally optimal; the effectiveness depends on the mix design, application, and environmental conditions. The review highlights future opportunities in smart curing systems, integrating Internet of Things (IoT), sensor technologies, and AI-driven predictive control to enable real-time optimisation of curing conditions. Such innovations represent a critical pathway for improving concrete performance while addressing sustainability targets in the building and construction industry. Full article
(This article belongs to the Special Issue Sustainable Materials and Innovative Solutions for Green Construction)
Show Figures

Figure 1

12 pages, 2292 KB  
Article
PDMS Mixed Matrix Membrane with Confined Mass Transfer Structure: The Effect of COFs with Different Porous Structures and Chemical Properties in the Pervaperation Process
by Yuan Zhai, Zimeng Zheng, Xinhao Cui, Kun Jiang, Ao Sheng and Heyun Wang
Membranes 2025, 15(10), 316; https://doi.org/10.3390/membranes15100316 - 15 Oct 2025
Abstract
In this study, hydrophilic covalent organic framework (COF) nanosheets with triazine structures and hydrophobic COF nanosheets with fluorinated imine skeletons were designed to enhance the membrane separation process for ethanol pervaporation. The mass transfer of ethanol–water mixtures within the confined structures of COF [...] Read more.
In this study, hydrophilic covalent organic framework (COF) nanosheets with triazine structures and hydrophobic COF nanosheets with fluorinated imine skeletons were designed to enhance the membrane separation process for ethanol pervaporation. The mass transfer of ethanol–water mixtures within the confined structures of COF nanosheets was investigated through experimental characterization and computational simulations, establishing a quantitative relationship between mass transfer performance and the pore size/chemical properties of COF nanosheets. These COF nanosheets were employed to optimize the confined architecture of mixed matrix membranes (MMMs), effectively regulating the critical parameters of MMMs and improving their separation performance. Through systematic investigation of formation mechanisms and modulation principles, we revealed the correlation between confined structural parameters and membrane separation efficiency. This work develops methodologies and foundational theories to overcome the permeability-selectivity trade-off effect, providing theoretical guidance for designing novel membrane materials with ethanol-permelective COF-based MMMs. Full article
(This article belongs to the Section Membrane Fabrication and Characterization)
Show Figures

Figure 1

19 pages, 2287 KB  
Review
Hydrogen Adsorbents in the Vacuum Layer of Liquid Hydrogen Containers: Materials and Applications
by Meng Yu, Yang Wu, Jiake Wu, Yongxiang Zhu, Xiangjun Yu and Long Jiang
Hydrogen 2025, 6(4), 89; https://doi.org/10.3390/hydrogen6040089 (registering DOI) - 15 Oct 2025
Abstract
Hydrogen serves as a key clean-energy carrier, with the main hurdles lying in safe, efficient transport and storage (gas or liquid) and in end-use energy conversion. Liquid hydrogen (LH), as a high-density method of storage and transportation, presents cryogenic insulation as its key [...] Read more.
Hydrogen serves as a key clean-energy carrier, with the main hurdles lying in safe, efficient transport and storage (gas or liquid) and in end-use energy conversion. Liquid hydrogen (LH), as a high-density method of storage and transportation, presents cryogenic insulation as its key technical issues. In LH storage tanks, the performance of high vacuum multilayer insulation (HVMLI) will decline due to hydrogen release and leakage from the microscopic pores of steel, which significantly destroy the vacuum layer. The accumulation of residual gases will accelerate thermal failure, shorten the service life of storage tanks and increase safety risks. Adsorption is the most effective strategy for removing residual gases. This review aims to elucidate materials, methods, and design approaches related to hydrogen storage. First, it summarizes adsorbents used in liquid hydrogen storage tanks, including cryogenic adsorbents, metal oxides, zeolite molecular sieves, and non-volatile compounds. Second, it explores experimental testing methods and applications of hydrogen adsorbents in storage tanks, analyzing key challenges faced in practical applications and corresponding countermeasures. Finally, it proposes research prospects for exploring novel adsorbents and developing integrated systems. Full article
Show Figures

Figure 1

18 pages, 4921 KB  
Article
Nano-Encapsulated Spicule System Enhances Delivery of Wharton’s Jelly MSC Secretome and Promotes Skin Rejuvenation: Preclinical and Clinical Evaluation
by Na Eun Lee, Ji Eun Kim, Chi Young Bang and Oh Young Bang
Int. J. Mol. Sci. 2025, 26(20), 10024; https://doi.org/10.3390/ijms262010024 - 15 Oct 2025
Abstract
Wharton’s Jelly-derived mesenchymal stem cell (WJ-MSC) secretome contains diverse bioactive factors with potential for skin regeneration, but its clinical efficacy is limited by poor transdermal delivery. In this study, we developed a dual-delivery system by nanoencapsulating WJ-MSC secretome and coating it onto marine [...] Read more.
Wharton’s Jelly-derived mesenchymal stem cell (WJ-MSC) secretome contains diverse bioactive factors with potential for skin regeneration, but its clinical efficacy is limited by poor transdermal delivery. In this study, we developed a dual-delivery system by nanoencapsulating WJ-MSC secretome and coating it onto marine sponge-derived spicules. Physicochemical characterization, in vitro assays (fibroblast and keratinocyte proliferation, keratinocyte migration, type I procollagen secretion, and antioxidant activity), and in vivo penetration studies were conducted. A single-arm clinical trial evaluated dermal absorption, pore characteristics, skin texture, wrinkles, and pigmentation following topical application. Transdermal penetration efficiency was significantly higher in the nano-coated spicule group than in the uncoated secretome control. In vitro, secretome treatment promoted fibroblast and keratinocyte activity, accelerated wound closure, and increased collagen synthesis. Clinically, a single application enhanced dermal absorption and significantly reduced pore number, while two weeks of treatment decreased wrinkles and pigmentation. Spicule-based nanoencapsulation effectively overcomes the skin barrier, enhances the regenerative activity of WJ-MSC secretome, and induces measurable clinical improvements in skin rejuvenation. This platform represents a promising cosmetic and therapeutic strategy in dermatology. Full article
(This article belongs to the Special Issue Roles and Function of Extracellular Vesicles in Diseases: 3rd Edition)
Show Figures

Graphical abstract

23 pages, 2980 KB  
Article
Steam-Assisted Semi-Carbonization Pretreatment of Corn Stalks: Effects on Physicochemical Properties for Enhanced Biomass Utilization
by Shiyan Gu, Qi Li, Wei Kou, Zhaonan Sun, Xiaoxia Li, Yitong Wang, Haiqiao Zhao and Peng Gao
Sustainability 2025, 17(20), 9091; https://doi.org/10.3390/su17209091 (registering DOI) - 14 Oct 2025
Abstract
The inefficient disposal of corn stover (CS) and the accumulation of magnesite tailings (MMTs) pose dual environmental threats. Although biomass gasification can utilize CS, its inherent drawbacks result in syngas with low heating value and high tar content. Torrefaction pretreatment can effectively improve [...] Read more.
The inefficient disposal of corn stover (CS) and the accumulation of magnesite tailings (MMTs) pose dual environmental threats. Although biomass gasification can utilize CS, its inherent drawbacks result in syngas with low heating value and high tar content. Torrefaction pretreatment can effectively improve biomass properties, and the use of steam as a reaction medium can further optimize the product’s pore structure. This study proposes a steam-assisted torrefaction pretreatment to address the inefficient utilization of CS and the disposal challenges of MMTs. The experimental results demonstrated that torrefaction at 300 °C with 30% water content for 60 min significantly improved the raw material’s properties. The optimized CSBC exhibited a well-developed pore structure and achieved a phenol removal rate of 63.4%. The addition of MMTs further enhanced the pretreatment effect, increasing the removal rate to 75.5% and confirming the superiority of the CSBC–magnesite composite system. The steam atmosphere improved phenol adsorption by regulating pore structures and surface functional groups, offering a feasible approach for utilizing solid waste resources and developing a new in situ tar control strategy. Full article
Show Figures

Figure 1

18 pages, 7318 KB  
Article
Reconstruction of Pore Structures in Petroleum Coke Packed Beds Utilizing CT Scanning and CFD Simulation of Resistance Characteristics
by Jing Li, Jindi Huang and Songlin Zhou
Processes 2025, 13(10), 3272; https://doi.org/10.3390/pr13103272 - 14 Oct 2025
Viewed by 34
Abstract
During the calcination of petroleum coke in a vertical shaft calciner, the particle packing structure exerts a decisive influence on the bed resistance characteristics and further significantly affects the devolatilization efficiency. This study employs three-dimensional computed tomography (CT) scanning technology to digitally reconstruct [...] Read more.
During the calcination of petroleum coke in a vertical shaft calciner, the particle packing structure exerts a decisive influence on the bed resistance characteristics and further significantly affects the devolatilization efficiency. This study employs three-dimensional computed tomography (CT) scanning technology to digitally reconstruct the pore structure of a packed bed of petroleum coke particles. Moreover, a computational fluid dynamics (CFD) simulation model is developed to simulate gas flow at the pore scale within the packed bed. A systematic analysis is conducted on the influence mechanisms of various factors, including particle size, gas velocity, gas composition, temperature, and bed length, on the gas flow resistance characteristics within the bed. The research findings indicate that the porosity of the packed beds of petroleum coke particles with different sizes ranges from 38.7% to 52%. The pore size within the bed exhibits a positive correlation with particle size, and gas migration predominantly occurs through slit flow. Under identical inlet gas velocity conditions, smaller particle sizes result in higher maximum gas velocities and greater unit pressure drops within the bed. At low gas velocities (e.g., 0.01–0.06 m/s in this work), both the maximum gas velocity and maximum pore pressure demonstrate a significant linear increase. The various factors exhibit different degrees of influence on the unit pressure drop, with particle size having the most significant impact, followed by gas velocity, then temperature, and finally gas composition. Consequently, the relevant research findings provide crucial theoretical support for optimizing the calcination process in vertical shaft calciners, expanding the range of raw material adaptability, and reducing production energy consumption. Full article
(This article belongs to the Section Chemical Processes and Systems)
Show Figures

Figure 1

39 pages, 19794 KB  
Article
Cylindrical Coordinate Analytical Solution for Axisymmetric Consolidation of Unsaturated Soils: Dual Bessel–Trigonometric Orthogonal Expansion Approach to Radial–Vertical Composite Seepage Systems
by Yiru Hu and Lei Ouyang
Symmetry 2025, 17(10), 1714; https://doi.org/10.3390/sym17101714 - 13 Oct 2025
Viewed by 133
Abstract
This study develops a novel analytical solution for three-dimensional axisymmetric consolidation of unsaturated soils incorporating radial–vertical composite seepage mechanisms and anisotropic permeability characteristics. A groundbreaking dual orthogonal expansion framework is established, utilizing innovative Bessel–trigonometric function coupling to solve the inherently complex spatiotemporal coupled [...] Read more.
This study develops a novel analytical solution for three-dimensional axisymmetric consolidation of unsaturated soils incorporating radial–vertical composite seepage mechanisms and anisotropic permeability characteristics. A groundbreaking dual orthogonal expansion framework is established, utilizing innovative Bessel–trigonometric function coupling to solve the inherently complex spatiotemporal coupled partial differential equations in cylindrical coordinate systems. The mathematical approach synergistically combines modal expansion theory with Laplace transform methodology, achieving simultaneous spatial expansion of gas–liquid two-phase pressure fields through orthogonal function series, thereby transforming the three-dimensional problem into solvable ordinary differential equations. Rigorous validation demonstrates exceptional accuracy with coefficient of determination R2 exceeding 0.999 and relative errors below 2% compared to numerical simulations, confirming theoretical correctness and practical applicability. The analytical solutions reveal four critical findings with quantitative engineering implications: (1) dual-directional drainage achieves 28% higher pressure dissipation efficiency than unidirectional drainage, providing design optimization criteria for vertical drainage systems; (2) normalized matric suction variation exhibits characteristic three-stage evolution featuring rapid decline, plateau stabilization, and slow recovery phases, while water phase follows bidirectional inverted S-curve patterns, enabling accurate consolidation behavior prediction under varying saturation conditions; (3) gas-water permeability ratio ka/kw spanning 0.1 to 1000 produces two orders of magnitude time compression effect from 10−2 s to 10−4 s, offering parametric design methods for construction sequence control; (4) initial pressure gradient parameters λa and λw demonstrate opposite regulatory mechanisms, where increasing λa retards consolidation while λw promotes the process, providing differentiated treatment strategies for various geological conditions. The unified framework accommodates both uniform and gradient initial pore pressure distributions, delivering theoretical support for refined embankment engineering design and construction control. Full article
(This article belongs to the Section Engineering and Materials)
Show Figures

Figure 1

18 pages, 3724 KB  
Article
Reservoir Characteristics of Tight Sandstone in Different Sedimentary Microfacies: A Case Study of the Triassic Chang 8 Member in Longdong Area, Ordos Basin
by Jianchao Shi, Likun Cao, Baishun Shi, Shuting Shi, Xinjiu Rao, Xinju Liu, Wangyikun Fan, Sisi Chen and Hongyan Yu
Processes 2025, 13(10), 3246; https://doi.org/10.3390/pr13103246 - 12 Oct 2025
Viewed by 212
Abstract
The complexity of tight sandstone reservoirs challenges effective oil and gas exploration. The Chang 8 Member of the Yanchang Formation in the Longdong area of the Ordos Basin has significant exploration potential. However, its reservoir characteristics are controlled by two distinct provenance systems [...] Read more.
The complexity of tight sandstone reservoirs challenges effective oil and gas exploration. The Chang 8 Member of the Yanchang Formation in the Longdong area of the Ordos Basin has significant exploration potential. However, its reservoir characteristics are controlled by two distinct provenance systems and diverse sedimentary microfacies. The specific impacts of these factors on reservoir quality and their relative importance have remained unclear. This study employs an integrated analytical approach combining casting thin sections, conventional porosity-permeability measurements, and Nuclear Magnetic Resonance (NMR) to systematically investigate the petrological characteristics, pore structure, and physical properties of the Chang 8 reservoirs. Our findings reveal that the entire section of Chang 8 is a delta front subfacies, with sub sections of Chang 81 and 82 developing microfacies such as underwater distributary channels, underwater natural levees, sheet sand and mouth bars. The tight sandstone reservoir is mainly composed of lithic arkose and feldspathic litharenite, with its porosity dominated by dissolution and intergranular types. These secondary pores, particularly those resulting from feldspar dissolution, are of great importance. The underwater distributary channels have the best pores, followed by sheet sands, and underwater natural levees the worst. Compaction in Chang 82 is stronger than in Chang 81, leading to smaller pores. The northwest provenance is characterized by high clay content and small pores, while the southwest provenance has coarser grain size and better-preserved intergranular pores. Reservoir properties improve toward the lake but deteriorate at the lake-proximal end due to more small pores. This study reveals the control laws of sedimentary microfacies, provenance, and diagenesis on the pore development of tight sandstone in the Longdong area, providing theoretical guidance for the exploration and development of tight sandstone oil and gas in the region. Full article
(This article belongs to the Section Energy Systems)
Show Figures

Figure 1

19 pages, 19394 KB  
Article
Physio-Mechanical Properties and Meso-Scale Damage Mechanism of Granite Under Thermal Shock
by Kai Gao, Jiamin Wang, Chi Liu, Pengyu Mu and Yun Wu
Energies 2025, 18(20), 5366; https://doi.org/10.3390/en18205366 - 11 Oct 2025
Viewed by 156
Abstract
Clarifying the differential effects of temperature gradient and temperature change rate on the evolution of rock fractures and damage mechanism under thermal shock is of great significance for the development and utilization of deep geothermal resources. In this study, granite samples at different [...] Read more.
Clarifying the differential effects of temperature gradient and temperature change rate on the evolution of rock fractures and damage mechanism under thermal shock is of great significance for the development and utilization of deep geothermal resources. In this study, granite samples at different temperatures (20 °C, 150 °C, 300 °C, 450 °C, 600 °C, and 750 °C) were subjected to rapid cooling treatment with liquid nitrogen. After the thermal treatment, a series of tests were conducted on the granite, including wave velocity test, uniaxial compression experiment, computed tomography scanning, and scanning electron microscopy test, to explore the influence of thermal shock on the physical and mechanical parameters as well as the meso-structural damage of granite. The results show that with the increase in heat treatment temperature, the P-wave velocity, compressive strength, and elastic modulus of granite gradually decrease, while the peak strain gradually increases. Additionally, the failure mode of granite gradually transitions from brittle failure to ductile failure. Through CT scanning experiments, the spatial distribution characteristics of the pore–fracture structure of granite under the influence of different temperature gradients and temperature change rates were obtained, which can directly reflect the damage degree of the rock structure. When the heat treatment temperature is 450 °C or lower, the number of thermally induced cracks in the scanned sections of granite is relatively small, and the connectivity of the cracks is poor. When the temperature exceeds 450 °C, the micro-cracks inside the granite develop and expand rapidly, and there is a gradual tendency to form a fracture network, resulting in a more significant effect of fracture initiation and permeability enhancement of the rock. The research results are of great significance for the development and utilization of hot dry rock and the evaluation of thermal reservoir connectivity and can provide useful references for rock engineering involving high-temperature thermal fracturing. Full article
(This article belongs to the Section H2: Geothermal)
Show Figures

Figure 1

17 pages, 4602 KB  
Article
Experimental Investigation of Hydraulic Fracturing Damage Mechanisms in the Chang 7 Member Shale Reservoirs, Ordos Basin, China
by Weibo Wang, Lu Bai, Peiyao Xiao, Zhen Feng, Meng Wang, Bo Wang and Fanhua Zeng
Energies 2025, 18(20), 5355; https://doi.org/10.3390/en18205355 - 11 Oct 2025
Viewed by 198
Abstract
The Chang 7 member of the Ordos Basin hosts abundant shale oil and gas resources and plays a vital role in the development of unconventional energy. This study investigates differences in damage evolution and underlying mechanisms between representative shale oil and shale gas [...] Read more.
The Chang 7 member of the Ordos Basin hosts abundant shale oil and gas resources and plays a vital role in the development of unconventional energy. This study investigates differences in damage evolution and underlying mechanisms between representative shale oil and shale gas reservoir cores from the Chang 7 member under fracturing fluid hydration. A combination of high-temperature expansion tests, nuclear magnetic resonance (NMR), and micro-computed tomography (Micro-CT) was used to systematically characterize macroscopic expansion behavior and microscopic pore structure evolution. Results indicate that shale gas cores undergo faster expansion and higher imbibition rates during hydration (reaching stability in 10 h vs. 23 h for shale oil cores), making them more vulnerable to water-lock damage, while shale oil cores exhibit slower hydration but more pronounced pore structure reconstruction. After 72 h of immersion in fracturing fluid, both core types experienced reduced pore volumes and structural reorganization; however, shale oil cores demonstrated greater capacity for pore reconstruction, with a newly formed pore volume fraction of 34.5% compared to 24.6% for shale gas cores. NMR and Micro-CT analyses reveal that hydration is not merely a destructive process but a dynamic “damage–reconstruction” evolution. Furthermore, the addition of clay stabilizers effectively mitigates water sensitivity and preserves pore structure, with 0.7% identified as the optimal concentration. The research results not only reveal the differential response law of fracturing fluid damage in the Chang 7 shale reservoir but also provide a theoretical basis and technical support for optimizing fracturing fluid systems and achieving differential production increases. Full article
(This article belongs to the Section H: Geo-Energy)
Show Figures

Graphical abstract

14 pages, 2426 KB  
Article
Assessing Fault Slip Probability and Controlling Factors in Shale Gas Hydraulic Fracturing
by Kailong Wang, Wei Lian, Jun Li and Yanxian Wu
Eng 2025, 6(10), 272; https://doi.org/10.3390/eng6100272 - 11 Oct 2025
Viewed by 129
Abstract
Fault slips induced by hydraulic fracturing are the primary mechanism of casing de-formation during deep shale gas development in Sichuan’s Luzhou Block, where de-formation rates reach 51% and severely compromise productivity. To address a critical gap in existing research on quantitative risk assessment [...] Read more.
Fault slips induced by hydraulic fracturing are the primary mechanism of casing de-formation during deep shale gas development in Sichuan’s Luzhou Block, where de-formation rates reach 51% and severely compromise productivity. To address a critical gap in existing research on quantitative risk assessment systems, we developed a probabilistic model integrating pore pressure evolution dynamics with Monte Carlo simulations to quantify slip risks. The model incorporates key operational parameters (pumping pressure, rate, and duration) and geological factors (fault friction coefficient, strike/dip angles, and horizontal stress difference) validated through field data, showing >90% slip probability in 60% of deformed well intervals. The results demonstrate that prolonged high-intensity fracturing increases slip probability by 32% under 80–100 MPa pressure surges. Meanwhile, an increase in the friction coefficient from 0.40 to 0.80 reduces slip probability by 6.4% through elevated critical pore pressure. Fault geometry exhibits coupling effects: the risk of low-dip faults reaches its peak when strike parallels the maximum horizontal stress, whereas high-dip faults show a bimodal high-risk distribution at strike angles of 60–120°; here, the horizontal stress difference is directly proportional to the slip probability. We propose optimizing fracturing parameters, controlling operation duration, and avoiding high-risk fault geometries as mitigation strategies, providing a scientific foundation for enhancing the safety and efficiency of shale gas development. Full article
Show Figures

Figure 1

Back to TopTop