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

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (950)

Search Parameters:
Keywords = bedding formation

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
16 pages, 4123 KB  
Article
Dynamic Ultra-Fast Sorption/Desorption of Indigo Carmine onto/from Versatile Core-Shell Composite Microparticles
by Florin Bucatariu, Larisa-Maria Petrila, Timeea-Anastasia Ciobanu, Marius-Mihai Zaharia and Marcela Mihai
Appl. Sci. 2025, 15(19), 10725; https://doi.org/10.3390/app151910725 - 5 Oct 2025
Viewed by 143
Abstract
The direct deposition of highly concentrated polyelectrolyte complexes based on poly(ethyleneimine) (PEI) and poly(sodium methacrylate) (PMANa) onto inorganic sand microparticles (F100 and F200) resulted in the formation of versatile core-shell composites with fast removal properties in dynamic conditions toward anionic charged pollutants. Herein, [...] Read more.
The direct deposition of highly concentrated polyelectrolyte complexes based on poly(ethyleneimine) (PEI) and poly(sodium methacrylate) (PMANa) onto inorganic sand microparticles (F100 and F200) resulted in the formation of versatile core-shell composites with fast removal properties in dynamic conditions toward anionic charged pollutants. Herein, in situ-generated nonstoichiometric PEI/PMANa polyelectrolyte complexes were directly precipitated as a soft organic shell onto solid sand microparticles at a 5% mass ratio (organic/inorganic part = 5%, w/w%). The sorption of an anionic model pollutant (Indigo Carmine (IC)) onto the composite particles in dynamic conditions depended on the inorganic core size, the flow rate, the bed type (fixed or fluidized) and the initial dye concentration. The maximum sorption capacity, after 10 cycles of sorption/desorption of IC onto F100@P5% and F200@P5%, was between 16 and 18 mg IC/mL composite. The newly synthesized core-shell composites could immobilize IC at a high flow rate (8 mL/min), either from concentrated (CIC = 60 mg/L) or very diluted (CIC = 0.2 mg/L) IC aqueous solution, demonstrating that this type of material could be promising in water treatment or efficient in solid-phase extraction (concentration factor of 2000). Full article
(This article belongs to the Special Issue Water Pollution and Wastewater Treatment Chemistry)
Show Figures

Figure 1

17 pages, 5447 KB  
Article
Design and Evaluation of Drilling Fluid Systems for Wellbore Stabilization During Drilling in Deep Coalbed Gas Reservoirs in the Ordos Basin
by Gang Cao, Chaoqun Zhang, Zhenxing Li, Hongliang Ma, Dongsheng Cai, Xin Zhou, Xinchen Zhang, Lu Bai, Peng Zhang and Junjie Zhao
Processes 2025, 13(10), 3150; https://doi.org/10.3390/pr13103150 - 1 Oct 2025
Viewed by 358
Abstract
To overcome wellbore instability problems in deep coalbed gas reservoirs in the Ordos Basin, drilling fluid additives were evaluated and a drilling fluid system was designed. According to the SEM and CT analysis results, there were not only face and butt cleats in [...] Read more.
To overcome wellbore instability problems in deep coalbed gas reservoirs in the Ordos Basin, drilling fluid additives were evaluated and a drilling fluid system was designed. According to the SEM and CT analysis results, there were not only face and butt cleats in the coal rock but also bedding and layered fractures. Potassium chloride (KCl) and Potassium formate (HCOOK) drilling fluid systems were formulated. The recovery rate of shale and coal rock cuttings reached 99%, and the linear swelling rates for coal rock in both types of drilling fluid were less than 0.18%. Measured with a servo-controlled compression frame at a loading rate of 1 mm/min, the uniaxial compression strength of coal rock was 11.74 MPa, and it was 9.13 MPa and 10.35 MPa after immersion in KCl and HCOOK drilling fluid, respectively. This indicates that both systems have good inhibition properties. The invasion depth in packed sand was 15.5 mm for KCl drilling fluid and 8 mm for HCOOK drilling fluid, demonstrating good sealing performance by the systems. Compared to KCl drilling fluid, the HCOOK system exhibited better inhibition and sealing performance. After the removal of the 10 mm deep invasion section of drilling fluid, the permeability of the coal rock recovered by more than 90%, and the drilling fluid caused minimum damage to the reservoir. The optimized drilling fluid exhibits excellent sealing and inhibition capabilities, making it highly effective in addressing wellbore stability challenges in carbonaceous mudstone formations at 4000 m in depth in the deep coalbed methane reservoirs of the Ordos Basin. Full article
Show Figures

Figure 1

25 pages, 8488 KB  
Article
Limestone-Based Hybrid Passive Treatment for Copper-Rich Acid Mine Drainage: From Laboratory to Field
by Joshua Pascual Pocaan, Brian Gerald Bueno, Jaica Mae Pagaduan, Johara Capingian, Michelle Airah N. Pablo, Jacob Louies Rohi W. Paulo, Arnel B. Beltran, Aileen H. Orbecido, Renan Ma. Tanhueco, Carlito Baltazar Tabelin, Mylah Villacorte-Tabelin, Vannie Joy T. Resabal, Irish Mae Dalona, Dennis Alonzo, Pablo Brito-Parada, Yves Plancherel, Robin Armstrong, Anne D. Jungblut, Ana Santos, Paul F. Schofield, Richard Herrington and Michael Angelo B. Promentillaadd Show full author list remove Hide full author list
Minerals 2025, 15(10), 1043; https://doi.org/10.3390/min15101043 - 1 Oct 2025
Viewed by 300
Abstract
Acid mine drainage (AMD) is an environmental concern that needs to be addressed by some mining industries because of its high concentrations of metals and acidity that destroy affected ecosystems. Its formation typically persists beyond the operating life of a mine site. Its [...] Read more.
Acid mine drainage (AMD) is an environmental concern that needs to be addressed by some mining industries because of its high concentrations of metals and acidity that destroy affected ecosystems. Its formation typically persists beyond the operating life of a mine site. Its management is even more challenging for sites that are abandoned without rehabilitation. In this study, a legacy copper–gold mine located in Sto. Niño, Tublay, Benguet, Philippines, generating a copper- and manganese-rich AMD (Cu, maximum 17.2 mg/L; Mn, maximum 2.90 mg/L) at pH 4.59 (minimum) was investigated. With its remote location inhabited by the indigenous people local community (IPLC), a novel limestone-based hybrid passive treatment system that combines a limestone leach bed (LLB) and a controlled modular packed bed reactor (CMPB) has been developed from the laboratory and successfully deployed in the field while investigating the effective hydraulic retention time (HRT), particle size, and redox conditions (oxic and anoxic) in removing Cu and Mn and increasing pH. Laboratory-scale and pilot-scale systems using simulated and actual AMD, respectively, revealed that a 15 h HRT and both oxic and anoxic conditions were effective in treating the AMD. Considering these results and unsteady conditions of the stream in the legacy mine, a hybrid multi-stage limestone leach bed and packed bed were deployed having variable particle size (5 mm to 100 mm) and HRT. Regular monitoring of the system showed the effective removal of Cu (88.5%) and Mn (66.83%) as well as the increase of pH (6.26), addressing the threat of AMD in the area. Improvement of the lifespan of the system needs to be addressed, as issues of Cu-armoring were observed, resulting in reduced performance over time. Nonetheless, the study presents a novel technique in implementing passive treatment systems beyond the typical treatment trains reported in the literature. Full article
Show Figures

Graphical abstract

14 pages, 5130 KB  
Article
Study on the Drying Characteristics of Moist Fine Lignite in a Dense Gas–Solid Separation Fluidized Bed
by Huicheng Lei, Tengfeng Wan, Tingguan Chen, Bingbing Ma, Zongxu Yao, Bao Xu, Qingfei Wang and Xuan Xu
Minerals 2025, 15(10), 1039; https://doi.org/10.3390/min15101039 - 30 Sep 2025
Viewed by 143
Abstract
Coal serves as a cornerstone and stabilizer for China’s energy security; utilizing it in a clean and efficient manner aligns with the current national energy situation. The moisture content of coal is a crucial factor affecting its calorific value and separation efficiency. Therefore, [...] Read more.
Coal serves as a cornerstone and stabilizer for China’s energy security; utilizing it in a clean and efficient manner aligns with the current national energy situation. The moisture content of coal is a crucial factor affecting its calorific value and separation efficiency. Therefore, enhancing the drying rate while simultaneously reducing the moisture content in coal is essential to improve separation efficiency. This paper primarily investigates the drying and separation characteristics of wet fine coal particles within a gas–solid fluidized bed system. A hot gas–solid fluidized bed was employed to study the particle fluidization behavior, heat–mass transfer, and agglomeration drying properties under varying airflow temperatures. The results indicate that as the airflow temperature increases, the minimum fluidization velocity tends to decrease. Additionally, with an increase in bed height, the particle temperature correspondingly decreases, leading to weakened heat exchange capability in the upper layer of the bed. Faster heating rates facilitate rapid moisture removal while minimizing agglomeration formation. The lower the proportion of moisture and magnetite powder present, the less force is required to break apart particle agglomerates. The coal drying process exhibits distinct stages. Within a temperature range of 75 °C to 100 °C, there is a significant enhancement in drying rate, while issues such as particle fragmentation or pore structure collapse are avoided at elevated temperatures. This research aims to provide foundational insights into effective drying processes for wet coal particles in gas–solid fluidized beds. Full article
Show Figures

Graphical abstract

19 pages, 9703 KB  
Article
Study on the Corrosion Behavior of Additively Manufactured NiCoCrFeyMox High-Entropy Alloys in Chloride Environments
by Chaoqun Xie, Yaqing Hou, Youpeng Song, Zhishan Mi, Fafa Li, Wei Guo and Dupeng He
Materials 2025, 18(19), 4544; https://doi.org/10.3390/ma18194544 - 30 Sep 2025
Viewed by 348
Abstract
This study aims to determine the optimal Mo content for corrosion resistance in two alloys, FeCoCrNiMox and Fe0.5CoCrNiMox. The alloys were fabricated using laser powder bed fusion (LPBF) technology with varying Mo contents (x = 0, 0.05, 0.1, [...] Read more.
This study aims to determine the optimal Mo content for corrosion resistance in two alloys, FeCoCrNiMox and Fe0.5CoCrNiMox. The alloys were fabricated using laser powder bed fusion (LPBF) technology with varying Mo contents (x = 0, 0.05, 0.1, 0.15). The corrosion behavior of these alloys was investigated in 3.5 wt.% NaCl solution at room temperature and 60 °C using electrochemical testing and X-ray photoelectron spectroscopy (XPS). The results show that all alloys exhibit good corrosion resistance at room temperature. However, at 60 °C, both alloys without Mo addition exhibit severe corrosion, while the Fe0.5CoCrNiMo0.1 alloy demonstrates the best corrosion resistance while maintaining the highest strength. The enhanced corrosion resistance is attributed to the optimal molybdenum addition, which refines the passive film structure and promotes the formation of Cr2O3. Furthermore, molybdenum oxide exists as MoO42− ions on the surface of the passive film, significantly improving the alloy’s corrosion resistance in chloride-containing environments. Full article
(This article belongs to the Section Metals and Alloys)
Show Figures

Figure 1

13 pages, 2521 KB  
Article
Evaluation of the Relationship Between Straw Fouling Tendencies and Fuel Indices in CFB
by Rafał Rajczyk and Tomasz Idziak
Appl. Sci. 2025, 15(19), 10558; https://doi.org/10.3390/app151910558 - 29 Sep 2025
Viewed by 152
Abstract
Biomass combustion for the production of electricity and heat remains one of the most widespread renewable energy technologies. Biomass is commonly utilized in fluidized bed combustion systems. Over the years, numerous issues related to the preparation and combustion of biomass in fluidized beds [...] Read more.
Biomass combustion for the production of electricity and heat remains one of the most widespread renewable energy technologies. Biomass is commonly utilized in fluidized bed combustion systems. Over the years, numerous issues related to the preparation and combustion of biomass in fluidized beds have been identified, including fouling and slagging, which involve the formation of deposits. These phenomena can be mitigated through various methods, including design modifications to boilers, the application of additives, and the careful selection and classification of fuel. Several fuel indices have been proposed to predict the behavior of fuels in terms of their tendency to cause fouling and slagging. Most of these indices were developed for fossil fuels, and the discrepancies between them suggest that although these indices are widely applied, their applicability to agricultural residues, such as straw, remains uncertain. Researchers working in this field emphasize the need for further research, particularly focusing on the comparison of developed indices with the results of biomass combustion at both laboratory and industrial scales. In this study, ten assortments of straw sourced from Poland were selected, and chemical composition analyses were conducted to determine selected fuel indices. The analyzed straw samples were then combusted in a 100 kWₜₕ laboratory-scale circulating fluidized bed unit. Using a specialized austenitic steel probe, the growth rate of the deposit was measured. The collected deposit masses for each straw type were then compared with the calculated fuel indices. The best correlation between the interpretation of the index values and the deposit mass on the probe was observed for the Rs index. However, due to the low sulfur content of straw, Rs numerical interpretation was not adequate. Overall, the indices indicating both good correlation coefficients and an appropriate numerical interpretation for fouling tendency were B/A, Fu, and Cl. Full article
(This article belongs to the Special Issue Novel Advances of Combustion and Its Emissions)
Show Figures

Figure 1

22 pages, 5038 KB  
Article
Numerical Investigation of Flow Field Characteristics Around a Monopile Foundation with Collar Protection
by Lei Wu, Hao Meng, Haifei Sun, Lingfei Yu, Dake Chen, Xiyu Zhao and Dawei Guan
J. Mar. Sci. Eng. 2025, 13(10), 1841; https://doi.org/10.3390/jmse13101841 - 23 Sep 2025
Viewed by 228
Abstract
Collar structures are widely used to protect monopile foundations from scour, but their geometric obstruction hinders direct observation of the surrounding flow in physical experiments. To overcome this limitation, this study employs large-eddy simulation (LES) to investigate the flow characteristics around a monopile [...] Read more.
Collar structures are widely used to protect monopile foundations from scour, but their geometric obstruction hinders direct observation of the surrounding flow in physical experiments. To overcome this limitation, this study employs large-eddy simulation (LES) to investigate the flow characteristics around a monopile with collar protection. The LES model was validated against well-documented experimental data of pile-induced flow, confirming its reliability. Simulations under flat-bed and equilibrium scour conditions were conducted to evaluate the effects of the collar on time-averaged velocity, vortex dynamics, and turbulence intensity. The results show that the collar substantially weakens the upstream accelerated flow, suppresses horseshoe vortex formation, and reduces both the strength and extent of sidewall currents. Under flatbed conditions, the side-flow intensity decreases by 24.3% and the accelerated flow area is reduced by 93.3%. A counter-rotating vortex beneath the collar dissipates kinetic energy and simplifies the near-bed vortex system, thereby mitigating scour. However, the protective effect diminishes with increasing inflow velocity, with turbulence intensity rising by 159% for a 14% velocity increase. Overall, this study provides deeper insights into the protective mechanisms of collar structures, advancing the understanding of their effectiveness and limitations in monopile scour protection. Full article
(This article belongs to the Special Issue Advancements in Marine Hydrodynamics and Structural Optimization)
Show Figures

Figure 1

23 pages, 10074 KB  
Article
Research on Drillability Prediction of Shale Horizontal Wells Based on Nonlinear Regression and Intelligent Optimization Algorithm
by Yanbin Zang, Qiang Wang, Wei Wang, Hongning Zhang, Kanhua Su, Heng Wang, Mingzhong Li, Wenyu Song and Meng Li
Processes 2025, 13(9), 3021; https://doi.org/10.3390/pr13093021 - 22 Sep 2025
Viewed by 294
Abstract
Shale oil and gas reservoirs are characterized by low porosity and low permeability. The development of ultra-long horizontal wells can significantly increase reservoir contact area and enhance single-well production. Shale formations exhibit distinct bedding structures, high formation pressure, high rock hardness, and strong [...] Read more.
Shale oil and gas reservoirs are characterized by low porosity and low permeability. The development of ultra-long horizontal wells can significantly increase reservoir contact area and enhance single-well production. Shale formations exhibit distinct bedding structures, high formation pressure, high rock hardness, and strong anisotropy. These characteristics result in poor drillability, slow drilling rates, and high costs when drilling horizontally, severely restricting efficient development. Therefore, accurately predicting the drillability of shale gas wells has become a major challenge. Currently, most scholars rely on a single parameter to predict drillability, which overlooks the coupled effects of multiple factors and reduces prediction accuracy. To address this issue, this study employs drillability experiments, mineral composition analysis, positional analysis, and acoustic transit-time tests to evaluate the effects of mineral composition, acoustic transit time, bottom-hole confining pressure, and formation drilling angle on the drillability of horizontal well reservoirs, innovatively integrating multiple parameters to construct a nonlinear model and introducing three intelligent optimization algorithms (PSO, AOA-GA, and EBPSO) for the first time to improve prediction accuracy, thus breaking through the limitations of traditional single-parameter prediction. Based on these findings, a nonlinear regression prediction model integrating multiple parameters is developed and validated using field data. To further enhance prediction accuracy, the model is optimized using three intelligent optimization algorithms: PSO, AOA-GA, and EBPSO. The results indicate that the EBPSO algorithm performs the best, followed by AOA-GA, while the PSO algorithm shows the lowest performance. Furthermore, the model is applied to predict the drillability of Well D4, and the results exhibit a high degree of agreement with actual measurements, confirming the model’s effectiveness. The findings support optimization of drilling parameters and bit selection in shale oil and gas reservoirs, thereby improving drilling efficiency and mechanical penetration rates. Full article
(This article belongs to the Section Process Control and Monitoring)
Show Figures

Figure 1

19 pages, 1596 KB  
Article
Multistage Reaction Characteristics and Ash Mineral Evolution in Coal–Biomass Co-Combustion Process
by Yun Hu, Bo Peng, Songshan Cao, Zenghui Hou, Sheng Wang and Zefeng Ge
Energies 2025, 18(18), 5023; https://doi.org/10.3390/en18185023 - 22 Sep 2025
Viewed by 395
Abstract
This study investigates the combustion characteristics and ash behavior of coal–biomass co-combustion using Zhujixi coal and corn straw in a fixed-bed system. The research analyzes combustion stage division, gas release patterns, and mineral evolution of ash under varying blending ratios. Results indicate that [...] Read more.
This study investigates the combustion characteristics and ash behavior of coal–biomass co-combustion using Zhujixi coal and corn straw in a fixed-bed system. The research analyzes combustion stage division, gas release patterns, and mineral evolution of ash under varying blending ratios. Results indicate that biomass addition modifies the dynamic features of the combustion process by advancing the CO2 release peak; extending the release of CO, CH4, and H2; and enhancing the completeness of char oxidation. At moderate blending levels (20–60%), oxygen utilization is significantly improved and combustion stability is strengthened. Ash fusion temperatures exhibit a consistent decline with increasing biomass proportion due to the formation of low-melting eutectic phases such as KAlSiO4 and K, Ca-based phosphates. Mineralogical analysis further reveals that coal ash components promote the immobilization of alkali metals, thereby suppressing potassium volatilization. A blending ratio of 40% demonstrates the most favorable balance between burnout performance, oxygen efficiency, and alkali fixation, surpassing both pure coal and high-ratio biomass conditions. This optimized ratio not only improves energy conversion efficiency but also reduces slagging and corrosion risks, offering practical guidance for cleaner coal power transformation, stable boiler operation, and long-term reduction of carbon and pollutant emissions. Full article
(This article belongs to the Section I2: Energy and Combustion Science)
Show Figures

Figure 1

39 pages, 1469 KB  
Review
Catalytic Combustion of Fugitive Methane: Challenges and Current State of the Technology
by Robert E. Hayes, Joanna Profic-Paczkowska, Roman Jędrzejczyk and Joseph P. Mmbaga
Appl. Sci. 2025, 15(18), 10269; https://doi.org/10.3390/app151810269 - 21 Sep 2025
Viewed by 625
Abstract
This review covers the current state, challenges, and future directions of catalytic combustion technologies for mitigating fugitive methane emissions from the fossil fuel industry. Methane, a potent greenhouse gas, is released from diverse sources, including natural gas production, oil operations, coal mining, and [...] Read more.
This review covers the current state, challenges, and future directions of catalytic combustion technologies for mitigating fugitive methane emissions from the fossil fuel industry. Methane, a potent greenhouse gas, is released from diverse sources, including natural gas production, oil operations, coal mining, and natural gas engines. The paper details the primary emission sources, and addresses the technical difficulties associated with dilute and variable methane streams such as ventilation air methane (VAM) from underground coal mines and low-concentration leaks from oil and gas infrastructure. Catalytic combustion is a useful abatement solution due to its ability to destruct methane in lean and challenging conditions at lower temperatures than conventional combustion, thereby minimizing secondary pollutant formation such as NOX. The review surveys the key catalyst classes, including precious metals, transition metal oxides, hexa-aluminates, and perovskites, and underscores the crucial role of reactor internals, comparing packed beds, monoliths, and open-cell foams in terms of activity, mass transfer, and pressure drop. The paper discusses advanced reactor designs, including flow-reversal and other recuperative systems, modelling approaches, and the promise of advanced manufacturing for next-generation catalytic devices. The review highlights the research needs for catalyst durability, reactor integration, and real-world deployment to enable reliable methane abatement. Full article
(This article belongs to the Special Issue Applied Research in Combustion Technology and Heat Transfer)
Show Figures

Figure 1

20 pages, 5389 KB  
Article
Diffusion Behavior of Polyurethane Slurry for Simultaneous Enhancement of Reservoir Strength and Permeability Through Splitting Grouting Technology
by Xiangzeng Wang, Fengsan Zhang, Jinqiao Wu, Siqi Qiang, Bing Li and Guobiao Zhang
Polymers 2025, 17(18), 2513; https://doi.org/10.3390/polym17182513 - 17 Sep 2025
Viewed by 338
Abstract
A polyurethane slurry was developed to simultaneously enhance the strength and permeability of geological formations, differing from the conventional fracture grouting used for soft-soil reinforcement. Injected via splitting grouting, the slurry cures to form high-strength, highly permeable channels that increase reservoir permeability while [...] Read more.
A polyurethane slurry was developed to simultaneously enhance the strength and permeability of geological formations, differing from the conventional fracture grouting used for soft-soil reinforcement. Injected via splitting grouting, the slurry cures to form high-strength, highly permeable channels that increase reservoir permeability while improving mechanical stability (dual-enhanced stimulation). To quantify its diffusion behavior and guide field application, we built a splitting-grouting model using the finite–discrete element method (FDEM), parameterized with the reservoir properties of coalbed methane (CBM) formations in the Ordos Basin and the slurry’s measured rheology and filtration characteristics. Considering the stratified structures within coal rock formed by geological deposition, this study utilizes Python code interacting with Abaqus to divide the coal seam into coal rock and natural bedding. We analyzed the effects of engineering parameters, geological factors, and bedding characteristics on slurry–vein propagation patterns, the stimulation extent, and fracturing pressure. The findings reveal that increasing the grouting rate from 1.2 to 3.6 m3/min enlarges the stimulated volume and the maximum fracture width and raises the fracturing pressure from 26.28 to 31.44 MPa. A lower slurry viscosity of 100 mPa·s promotes the propagation of slurry veins, making it easier to develop multiple veins. The bedding-to-coal rock strength ratio controls crossing versus layer-parallel growth: at 0.3, veins more readily penetrate bedding planes, whereas at 0.1 they preferentially spread along them. Raising the lateral pressure coefficient from 0.6 to 0.8 increases the likelihood of the slurry expanding along the beddings. Natural bedding structures guide directional flow; a higher bedding density (225 lines per 10,000 m3) yields greater directional deflection and a more intricate fracture network. As the angle of bedding increases from 10° to 60°, the slurry veins are more susceptible to directional changes. Throughout the grouting process, the slurry veins can undergo varying degrees of directional alteration. Under the studied conditions, both fracturing and compaction grouting modes are present, with fracturing grouting dominating in the initial stages, while compaction grouting becomes more prominent later on. These results provide quantitative guidance for designing dual-enhanced stimulation to jointly improve permeability and mechanical stability. Full article
(This article belongs to the Special Issue Polymer Fluids in Geology and Geotechnical Engineering)
Show Figures

Graphical abstract

14 pages, 5731 KB  
Article
Challenges and Strategies in Modeling Thin-Bedded Carbonate Reservoirs Based on Horizontal Well Data: A Case Study of Oilfield A in the Middle East
by Dawang Liu, Xinmin Song, Wenqi Zhang, Jingyi Wang, Yuning Wang, Ya Deng and Min Gao
Processes 2025, 13(9), 2951; https://doi.org/10.3390/pr13092951 - 16 Sep 2025
Viewed by 319
Abstract
Thin-bedded carbonate reservoirs face significant challenges in characterization and development due to their thin formation thickness, strong interlayer heterogeneity, and rapid sedimentary transformation. In recent years, horizontal wells have played an increasingly important role in improving the productivity of thin-bedded carbonate reservoirs. However, [...] Read more.
Thin-bedded carbonate reservoirs face significant challenges in characterization and development due to their thin formation thickness, strong interlayer heterogeneity, and rapid sedimentary transformation. In recent years, horizontal wells have played an increasingly important role in improving the productivity of thin-bedded carbonate reservoirs. However, building accurate geological models from horizontal well data is a major challenge for geoscientists. Using Middle East Oilfield A as a case study, this paper analyzes the specific challenges of horizontal well geomodeling and proposes a dedicated strategy for integrating horizontal well-derived constraints into the geological modeling workflow. To address the challenges of structural modeling constrained by horizontal well data, this study proposes three methodologies: stratigraphic layer iteration, virtual control point generation, and localized grid refinement. These techniques collectively enable the construction of a higher-fidelity structural framework that rigorously honors hard well data constraints while incorporating geological plausibility. To address the challenges posed by the spatial configuration of vertical and horizontal wells and the dominant trajectory patterns of horizontal wells, this study introduces two complementary approaches: the exclusion of horizontal well section data (relying solely on vertical wells) and the selective extraction of representative horizontal well section data for variogram derivation. These methods collectively enable the construction of a geologically realistic reservoir model that accurately captures the spatial distribution of reservoir properties. These methodologies not only effectively leverage the rich geological information from horizontal wells but also mitigate spatial clustering effects inherent to such data. Validation through development well production data confirms robust performance, providing transferable insights for reservoir characterization in analogous fields worldwide. Full article
(This article belongs to the Section Energy Systems)
Show Figures

Figure 1

20 pages, 5098 KB  
Article
Underground Pumped Hydroelectric Energy Storage in Salt Caverns in Southern Ontario, Canada: Layout and Working Pressure Design
by Jingyu Huang, Yutong Chai, Jennifer Williams and Shunde Yin
Mining 2025, 5(3), 58; https://doi.org/10.3390/mining5030058 - 16 Sep 2025
Viewed by 492
Abstract
As the global shift toward renewable energy accelerates, large-scale energy storage is essential to balance intermittent supply and growing demand. While conventional Pumped Hydro Storage remains dominant, Underground Pumped Hydro Storage (UPHS) offers a promising alternative, particularly in flat regions with ample subsurface [...] Read more.
As the global shift toward renewable energy accelerates, large-scale energy storage is essential to balance intermittent supply and growing demand. While conventional Pumped Hydro Storage remains dominant, Underground Pumped Hydro Storage (UPHS) offers a promising alternative, particularly in flat regions with ample subsurface space. Southern Ontario, Canada, underlain by thick salt formations and a history of salt mining, presents favorable conditions for UPHS development, yet relative studies remain limited. This work presents the first UPHS-specific geomechanical feasibility assessment in the Canadian Salina Group, introducing a paired-cavern layout tied to Units B and A2 and explicitly capturing both elasto-plastic and creep behavior. Using COMSOL Multiphysics 6.3, a three-dimensional numerical model was developed featuring two vertically separated cylindrical caverns located in Unit B and the lower part of Unit A2. A 24 h operating cycle was simulated over a 10-year period, incorporating elasto-plastic deformation and salt creep. Minimum working pressures were varied to evaluate long-term cavern stability. The results show that a minimum pressure of 0.3 σv balances structural integrity and operational efficiency, with creep strain and volumetric convergence remaining within engineering limits. Beyond previous salt-cavern studies focused on hydrogen or CAES, this study provides the first coupled elasto-plastic and creep simulation tailored to UPHS operations in bedded salt, establishing a safe operating-pressure guideline and offering site-relevant design insights for modular underground energy storage systems in sedimentary basins. Full article
Show Figures

Figure 1

30 pages, 16948 KB  
Article
Dolomitization and Silicification in Syn-Rift Lacustrine Carbonates: Evidence from the Late Oligocene–Early Miocene Duwi Basin, Red Sea, Egypt
by Tawfiq Mahran, Reham Y. Abu Elwafa, Alaa Ahmed, Osman Abdelghany and Khaled M. Abdelfadil
Geosciences 2025, 15(9), 356; https://doi.org/10.3390/geosciences15090356 - 11 Sep 2025
Viewed by 589
Abstract
Studies of early syn-rift successions in the Duwi Basin have revealed repetitive lacustrine carbonate deposits exhibiting regressive sequences and early diagenetic processes. Two main informal stratigraphic units (Units 1 and 2), spanning the Late Oligocene to Early Miocene, have been identified in the [...] Read more.
Studies of early syn-rift successions in the Duwi Basin have revealed repetitive lacustrine carbonate deposits exhibiting regressive sequences and early diagenetic processes. Two main informal stratigraphic units (Units 1 and 2), spanning the Late Oligocene to Early Miocene, have been identified in the area. Unit 1 primarily consists of lacustrine limestone and calcrete deposits that formed in a palustrine environment, whereas Unit 2 is composed of dolomites and cherts, which developed during times of lake evaporation and desiccation under arid climatic conditions. A wide variety of pedogenic features, including brecciation, nodulization, rhizocretions, fissuring, microkarsts, and circumgranular cracks, dominate the carbonate sequence, indicating deposition in a marginal lacustrine setting. Integrated petrographic, mineralogical, geochemical, and isotopic studies of carbonate facies reveal two distinct evolutionary stages in the Duwi Basin, with dolomitization and silicification characterizing the late stage. Their isotopic compositions show a wide range of δ13C and δ18O values, ranging from −9.00‰ to −7.98‰ and from −10.03‰ to −0.68‰, respectively. Dolomite beds exhibit more negative δ13C and δ18O values, whereas palustrine limestones display higher (less negative) values. The upward trend of δ18O enrichment in carbonates suggests that the lake became hydrologically closed. Trace element concentrations serve as potential markers for distinguishing carbonate facies, aiding with paleoenvironmental and diagenetic interpretations. Our findings indicate that the studied dolomites and cherts formed under both biogenic and abiogenic conditions in an evaporative, alkaline-saline lake system. Biogenic dolomite and silica likely resulted from microbial activity, whereas abiogenic formation was driven by physicochemical conditions, including decreasing pH values and the presence of smectite clays. Tectonics, local climate, and provenance played crucial roles in controlling the overall diagenetic patterns and evolutionary history of the lake basin system during the Late Oligocene to Early Miocene. Full article
(This article belongs to the Section Sedimentology, Stratigraphy and Palaeontology)
Show Figures

Figure 1

14 pages, 4090 KB  
Article
Experimental Study on Water-Hammer-Effect Fracturing Based on High-Frequency Pressure Monitoring
by Yanchao Li, Hu Sun, Longqing Zou, Liang Yang, Hao Jiang, Zhiming Zhao, Ruchao Sun and Yushi Zou
Processes 2025, 13(9), 2900; https://doi.org/10.3390/pr13092900 - 11 Sep 2025
Viewed by 401
Abstract
Horizontal well multi-stage fracturing is the primary technology for deep shale gas development, but dense multi-cluster fractures are prone to non-uniform initiation and propagation, requiring real-time monitoring and interpretation techniques to adjust fracturing parameters. Although high-frequency water hammer pressure-monitoring technology shows diagnostic potential, [...] Read more.
Horizontal well multi-stage fracturing is the primary technology for deep shale gas development, but dense multi-cluster fractures are prone to non-uniform initiation and propagation, requiring real-time monitoring and interpretation techniques to adjust fracturing parameters. Although high-frequency water hammer pressure-monitoring technology shows diagnostic potential, the correlation mechanism between pressure response characteristics and multi-cluster fracture morphology remains unclear. This study utilized outcrop rock samples from the Longmaxi Formation shale to construct a long-injection-tube pipeline system and a 1 kHz high-frequency pressure acquisition system. Through a true triaxial fracturing simulation test system, it systematically investigated the effects of flow rate (50–180 mL/min) and fracturing fluid viscosity (3–15 mPa·s) on water hammer signal characteristics and fracture morphology. The results reveal that when the flow rate rose from 50 mL/min to 180 mL/min, the initiation efficiency of transverse fractures significantly improved, artificial fractures more easily broke through bedding plane limitations, and fracture height propagation became more complete. When the fracturing fluid viscosity increased from 3–5 mPa·s to 12–15 mPa·s, fracture height propagation and initiation efficiency significantly improved, but fewer bedding plane fractures were activated. The geometric complexity of fractures positively correlated with the water hammer decay rate. This research demonstrates a link between water hammer signal features and downhole fracture morphology, giving a theoretical basis for field fracturing diagnostics. Full article
(This article belongs to the Section Energy Systems)
Show Figures

Figure 1

Back to TopTop