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

Article Types

Countries / Regions

Search Results (301)

Search Parameters:
Keywords = reservoir margins

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
28 pages, 16740 KB  
Article
Quantifying Dynamic Evolution of Preferential Flow Paths in Displacement Units of Ultra-High Water-Cut Reservoirs
by Menghao Zhang, Daigang Wang, Kaoping Song and Zhenhai Jiang
Energies 2026, 19(13), 3056; https://doi.org/10.3390/en19133056 (registering DOI) - 28 Jun 2026
Abstract
Preferential flow paths and ineffective water circulation are difficult to quantify in ultra-high water-cut reservoirs because long-term waterflooding intensifies dynamic heterogeneity and oil–water flow interactions. This study develops a displacement unit (DU)-scale method that integrates dynamic liquid-volume splitting, saturation tracking, and techno-economic water-cut [...] Read more.
Preferential flow paths and ineffective water circulation are difficult to quantify in ultra-high water-cut reservoirs because long-term waterflooding intensifies dynamic heterogeneity and oil–water flow interactions. This study develops a displacement unit (DU)-scale method that integrates dynamic liquid-volume splitting, saturation tracking, and techno-economic water-cut evaluation while considering time-varying reservoir properties. The method was applied to a typical ultra-high water-cut block in the Daqing Oilfield to characterize the temporal evolution of preferential flow paths. A total of 902 DUs were delineated from streamline envelopes, and validation with production profile data from representative wells showed an accuracy exceeding 82%. Under an oil price of 60 USD/bbl, the proposed economic water-cut criterion identified 368 economically strong preferential-flow DUs, accounting for 40.79% of all DUs. Two indicators, the water-cut profit–loss margin (Δfw) and oil displacement efficiency (Ed), were then used to establish a Δfw-Ed classification matrix. The DUs were divided into four types: economically ineffective strong-channeling units, channeling units with remaining potential, mature stable production units, and homogeneous units. The results support differentiated control measures, such as channel plugging, profile control, cyclic waterflooding, and fluid-rate optimization, for improving waterflood management in mature reservoirs. Full article
Show Figures

Figure 1

22 pages, 17651 KB  
Article
Sensitivity Analysis of Geological–Engineering Parameters and Injection Optimization for CO2-ECBM in Coal Seams Based on Numerical Simulation
by He Wang, Longyong Shu, Yang Li, Zhonggang Huo, Shuxun Sang, Yongpeng Fan, Xin Song and Qixian Li
Processes 2026, 14(13), 2078; https://doi.org/10.3390/pr14132078 - 26 Jun 2026
Viewed by 152
Abstract
CO2-enhanced coalbed methane recovery and storage (CO2-ECBM) is a promising approach for improving methane recovery and increasing CO2 storage in low-permeability coal seams. However, limited injectivity and insufficient criteria for injection parameter optimization remain major constraints. Taking the [...] Read more.
CO2-enhanced coalbed methane recovery and storage (CO2-ECBM) is a promising approach for improving methane recovery and increasing CO2 storage in low-permeability coal seams. However, limited injectivity and insufficient criteria for injection parameter optimization remain major constraints. Taking the No. 11-2 coal seam of the Zhangji Coal Mine in the Huainan mining area as the study object, this study established a thermo–hydro–mechanical coupled model that considers CO2/CH4 competitive adsorption, matrix diffusion, fracture seepage, gas–water two-phase flow, coal deformation, and porosity–permeability evolution. A 10-year numerical simulation was conducted to evaluate the effects of initial porosity, initial permeability, elastic modulus, CO2 injection pressure, and injection scheme on CO2-ECBM performance. The comprehensive sensitivity results show that initial porosity, CO2 injection pressure, and initial permeability are the dominant controlling factors, whereas elastic modulus has a relatively weak influence. Initial porosity mainly determines reservoir storage space and CO2 sequestration potential; permeability controls pressure propagation and gas migration; and injection pressure directly affects CH4 displacement intensity, CO2 storage capacity, and reservoir safety margin. Multi-objective evaluation indicates that the injection pressure should be controlled within 8.0–9.0 MPa, with 8.0–8.5 MPa recommended for long-term stable operation. When the engineering objective prioritizes CO2 storage or CH4 recovery and sufficient safety margin is confirmed, the injection pressure may be increased to approximately 9.0 MPa. Continuous constant-pressure injection favors cumulative CH4 production and CO2 storage, whereas stepwise pressurization reduces early pressure disturbance and improves later-stage injectivity. Therefore, an injection strategy combining early-stage stepwise pressurization with middle- and late-stage constant-pressure injection is recommended. These results provide a reference for injection parameter optimization in similar low-permeability coal reservoirs. Full article
Show Figures

Figure 1

17 pages, 2678 KB  
Article
Adaptive Bi-Level Planning of Photovoltaic Hosting Capacity for Hydro-Dominant Distribution Grids Considering Hydraulic Safety Constraints
by Ruizhu Guo, Rongwei Peng, Zhenlong Zhu, Wenfeng Wang, Hongyin Liu, Chong Du, Xi Zhang, Yansong Cui, Jing Zi, Lv He, Shihao Deng, Yuan Cao and Zicong Chen
Symmetry 2026, 18(7), 1079; https://doi.org/10.3390/sym18071079 - 25 Jun 2026
Viewed by 173
Abstract
Hydro-dominant distribution grids with high penetrations of distributed photovoltaic (PV) generation exhibit a clear operational asymmetry. PV output changes rapidly at the minute scale, whereas hydropower regulation is constrained by reservoir water balance, turbine ramping capability, and hydraulic safety limits. During high-inflow periods, [...] Read more.
Hydro-dominant distribution grids with high penetrations of distributed photovoltaic (PV) generation exhibit a clear operational asymmetry. PV output changes rapidly at the minute scale, whereas hydropower regulation is constrained by reservoir water balance, turbine ramping capability, and hydraulic safety limits. During high-inflow periods, mandatory hydropower generation further reduces the downward regulation margin and restricts midday PV accommodation. To address this issue, this paper develops an asymmetry-aware adaptive bi-level planning framework for photovoltaic hosting capacity (PVHC) assessment. A db4 discrete wavelet transform is used to decompose PV output into low-frequency energy trends and high-frequency fluctuation components. The upper layer performs hourly economic dispatch while maintaining reservoir water balance, and the lower layer conducts minute-level constrained tracking under ramping and vibration-zone avoidance constraints. A bisection-type capacity-search procedure is then used to identify the PVHC boundary by jointly checking curtailment, ramping, frequency proxy, voltage, line-loading, point-of-common-coupling exchange, and vibration-zone residence constraints. Case studies based on a 15 min PV dataset from a 30 MW station, hydropower operation records, and a modified 15-node feeder in Southwest China show that hydrological asymmetry materially affects PV accommodation. The obtained PVHC ranges from 53.17 MW under the most restrictive high-proxy condition to 65.33 MW under low-proxy operation. Compared with the no-coordination case, representative-month PVHC increases from 49.80 MW to 65.33 MW, while the simulated residence time within the predefined vibration-prone zone decreases from 447 min to 0 min. These results indicate that PVHC evaluation in hydro-dominant feeders should jointly consider electrical constraints, hydrological asymmetry, and hydraulic safety limits. Full article
Show Figures

Figure 1

16 pages, 2029 KB  
Article
Optimal Capacity Allocation of Pumped Hydro Storage Towards Long-Term High-Penetration Renewable Energy Integration: A Case Study of a Coastal Power Grid
by Jiquan Chen, Jinxia Yu, Han Qin and Guobin Ye
Energies 2026, 19(13), 2982; https://doi.org/10.3390/en19132982 - 25 Jun 2026
Viewed by 151
Abstract
The integration of high-penetration renewable energy creates new requirements for cross-timescale peak shaving and for system robustness under extreme meteorological conditions. This study develops a dual-timescale capacity allocation method for pumped hydro storage (PHS), combining 8760 h chronological production simulation with monthly typical-day [...] Read more.
The integration of high-penetration renewable energy creates new requirements for cross-timescale peak shaving and for system robustness under extreme meteorological conditions. This study develops a dual-timescale capacity allocation method for pumped hydro storage (PHS), combining 8760 h chronological production simulation with monthly typical-day retrospective analysis. The model represents the operating limits of conventional units, nuclear power, hydropower, wind power, photovoltaic generation, tie-line exchange, and PHS energy shifting. On this basis, a stepwise capacity-sensitivity framework is established to minimize annualized comprehensive system cost while controlling renewable energy curtailment within a predefined planning threshold, rather than treating zero curtailment as an unconditional monthly hard constraint. Using long-term planning data from a coastal provincial power grid in southeastern China, the study compares the 2035 and 2040 planning scenarios. The results show that isolated typical-day models tend to overestimate PHS requirements because they disconnect chronological continuity and cross-day reservoir buffering. In 2035, the system presents a two-level seasonal capacity structure: 15,000 MW can support normalized operation in stable months, whereas the rigid boundary rises to 19,000 MW under extreme autumn high-wind conditions. In 2040, wind and photovoltaic capacity increase by approximately 20.01 GW compared with 2035, deepening low-net-load valleys and compressing seasonal regulation margins. Under the assumed planning boundary, the recommended PHS capacity converges to 23,000 MW. The proposed framework provides a practical reference for flexible resource planning in coastal power grids with deep renewable energy integration. Full article
Show Figures

Figure 1

16 pages, 323 KB  
Review
The Cariostatic Mechanisms of Fluoride—An Updated Review
by Ivana Šutej, Krešimir Bašić and Kristina Peroš
Dent. J. 2026, 14(7), 390; https://doi.org/10.3390/dj14070390 - 24 Jun 2026
Viewed by 205
Abstract
Fluoride remains the keystone of evidence-based caries prevention by stabilizing the mineral balance at the tooth–biofilm–saliva interface. Contemporary understanding emphasizes a predominantly post-eruptive, topical mode of action where fluoride inhibits demineralization and accelerates remineralization. This interfacial catalysis is reinforced by pH-responsive calcium-fluoride-like reservoirs [...] Read more.
Fluoride remains the keystone of evidence-based caries prevention by stabilizing the mineral balance at the tooth–biofilm–saliva interface. Contemporary understanding emphasizes a predominantly post-eruptive, topical mode of action where fluoride inhibits demineralization and accelerates remineralization. This interfacial catalysis is reinforced by pH-responsive calcium-fluoride-like reservoirs that release fluoride during acid challenges. While community water fluoridation confers population-level reductions, the most effective approach is sustaining low-level fluoride in the biofilm environment. Evidence confirms that toothpastes with 1000–1500 ppm fluoride provide a dose–response benefit in children, while 5000 ppm concentrations are indicated for high-risk scenarios such as root caries and xerostomia. Beyond physicochemical effects, fluoride modulates the oral microbiome by inhibiting bacterial enzymes and proton pumps, shifting community function toward a health-associated state without reducing overall diversity. In restorative dentistry, glass ionomer cements offer superior preventive effects against secondary caries compared to amalgam; however, marginal integrity, adhesive performance, and clinical technique, rather than fluoride release alone, remain the primary determinants of success. Despite well-known risks associated with high systemic intake, such as fluorosis, current evidence does not indicate genotoxic or adverse microbiome effects in humans from routine topical use of standard fluoride products at recommended preventive concentrations. Overall, fluoride’s cariostatic value rests on frequent, low-level exposures that maintain tissues in a repair-favoring state. Full article
(This article belongs to the Section Preventive Dentistry)
2 pages, 162 KB  
Abstract
Monitoring the Use of Pelagic Fish Aggregation Devices by Largemouth Bass Using Tridimensional Fine-Scale Acoustic Positional Telemetry
by Miguel Encarnado, Carlos M. Alexandre, Bernardo Quintella, Esmeralda Pereira, Ana F. Belo, Ana Filipa Silva, João P. Marques, António Faro and Pedro R. Almeida
Proceedings 2026, 146(1), 104; https://doi.org/10.3390/proceedings2026146104 - 23 Jun 2026
Viewed by 73
Abstract
Fish Aggregating Devices (FADs), traditionally used to attract and concentrate fish, can also serve as effective environmental enrichment tools in reservoirs, particularly in those with homogeneous characteristics and scarce refuge habitat, enhancing structural complexity and promoting recreational fishing opportunities. This study aimed to [...] Read more.
Fish Aggregating Devices (FADs), traditionally used to attract and concentrate fish, can also serve as effective environmental enrichment tools in reservoirs, particularly in those with homogeneous characteristics and scarce refuge habitat, enhancing structural complexity and promoting recreational fishing opportunities. This study aimed to evaluate patterns in the use of prototype fish aggregation devices (FADs) in small size reservoirs. It was conducted at the Nascentes Reservoir (Crato), a small Mediterranean reservoir (ca. 10 ha) located in southern Portugal. These FADs were installed to enhance refuge habitat for fish species of interest to recreational fisheries, particularly largemouth bass (Micropterus salmoides Lacepède, 1802), thereby promoting the occurrence of trophy specimens. Two types of FADs were deployed and tested: (1) bank FADs (TREES), used in shallow waters near the margins; and (2) pelagic FADs (DAPs), suspended in the water column in deeper areas at the center of the reservoir. To monitor movement patterns and habitat use, an acoustic telemetry receiver array was deployed with a design to secure a three-dimensional fine-scale positioning with high accuracy. A total of 20 largemouth bass were tagged with acoustic transmitters equipped with pressure (i.e., depth) sensors. A before–after approach was used with 10 fish tracked before FAD deployment and 10 after. Results of fish behavior analysis provide strong evidence of fish using DAPs, but not TREES. In the presence of FADs, fish reduced their home ranges and movement amplitudes, becoming closely associated with these artificial habitats. Several environmental predictors explained fish behavior in the presence of artificial refuges, namely, diel period, moonlight intensity, and fish depth. The findings of this study are expected to contribute to the development of guidelines for refuge habitat enhancement in small- to medium-sized Mediterranean reservoirs, thereby increasing their recreational fishing attractiveness. Full article
(This article belongs to the Proceedings of The XI Iberian Congress of Ichthyology)
28 pages, 4167 KB  
Article
Sedimentary Evolution and Reservoir Formation of the Late Triassic Bolila Formation in the Central Qiangtang Basin, Tibet
by Shangke Xie, Haisheng Yi, Wangzhong Zhan, Ruiyu Cheng, Wei Sun, Shengqiang Zeng, Qian Hou and Keyu Zhu
Minerals 2026, 16(6), 641; https://doi.org/10.3390/min16060641 - 18 Jun 2026
Viewed by 246
Abstract
The Late Triassic Bolila Formation in the central Qiangtang Basin is a typical carbonate buildup deposited during a regional transgression in the eastern Tethyan realm. Understanding its sedimentary evolution and reservoir-forming mechanisms is crucial for hydrocarbon exploration. This study integrates petrology, detrital zircon [...] Read more.
The Late Triassic Bolila Formation in the central Qiangtang Basin is a typical carbonate buildup deposited during a regional transgression in the eastern Tethyan realm. Understanding its sedimentary evolution and reservoir-forming mechanisms is crucial for hydrocarbon exploration. This study integrates petrology, detrital zircon U-Pb geochronology, carbon-oxygen isotopes, and reservoir property analysis of the Quemudongda section. The results show: (1) detrital zircon dating provides a maximum depositional age of 225.7–235.7 Ma (Carnian–Norian), correcting the previous Jurassic misassignment on the 1:250,000 geological map. Carbon-oxygen isotopes (average δ13C = +3.2‰, δ18O = −11.1‰) are consistent with the global Carnian–Norian positive δ13C excursion. (2) The section reveals a platform-margin reef (hexactinellid and calcareous sponges) and slump breccia (seven layers) association, representing a steep-rimmed carbonate platform margin. The sedimentary evolution comprises three stages: reef initiation, reef flourishing with frequent slumping, and reef decline with dolomitization. (3) Reservoirs are mainly breccia and reef dolostones, with intergranular, intercrystalline, and fracture-related pores. Porosity averages 2.8% (0.8%–7.2%), permeability averages 0.35 mD (0.001–8.5 mD), defining a low-porosity, ultra-low-permeability fracture-pore reservoir. Breccia dolostone has better properties (porosity 3.71%, permeability 2.412 mD). (4) Reservoir formation is controlled by sedimentation (platform-margin facies), diagenesis (dolomitization generates pores, but high-temperature recrystallization causes densification), and tectonics (microfractures enhance permeability). High-quality reservoirs occur where breccia dolostone and fractures overlap. (5) The Bolila reef-shoal complex and the overlying Bagong Formation source rocks form a “lower reservoir—upper source” assemblage, representing a new exploration target in the Tuonamu area. The breccia dolostone–fracture overlap zone is the core “sweet spot”. Full article
Show Figures

Figure 1

21 pages, 11667 KB  
Article
Land-Cover Responses to Reservoir Water-Level Regulation in the Danjiangkou Reservoir Shore Zone, China
by Zetao Chen, Baohua Zhang, Chengyu Zhang, Benning Liu and Debao Yuan
Land 2026, 15(6), 1042; https://doi.org/10.3390/land15061042 - 12 Jun 2026
Viewed by 273
Abstract
Land-use and land-cover changes around reservoirs mediate the interface between watershed land systems and managed surface-water resources. In regulated reservoirs, water-level regulation can rapidly expose or inundate shore-zone land, yet evidence remains limited on where these transitions occur, how landscape configuration changes, and [...] Read more.
Land-use and land-cover changes around reservoirs mediate the interface between watershed land systems and managed surface-water resources. In regulated reservoirs, water-level regulation can rapidly expose or inundate shore-zone land, yet evidence remains limited on where these transitions occur, how landscape configuration changes, and how such information can inform watershed and reservoir-margin management. Using 0.5 m Jilin-1 optical imagery from April and September of 2024 and 2025, this study mapped land-use/land-cover change (LUCC) in the Danjiangkou Reservoir shore zone and integrated transition matrices, class-level landscape metrics, shoreline-distance gradients, reach-level zoning, paired hydrological records, and multiscale geographically weighted regression (MGWR). The classification achieved an overall accuracy of 93.1% and a Kappa coefficient of 0.921. The strongest land-cover shift occurred between September 2024 and April 2025, when the water proportion declined from 78.74% to 60.10% and bare land expanded during the lowest observed reservoir stage (151.02 m). Subsequent refill was accompanied by partial re-inundation and increases in grassland, cropland, and forest. The 0–30 m shoreline belt was the principal response zone, indicating that hydrologically driven land-cover replacement was concentrated in the immediate reservoir margin. MGWR showed spatially varying positive associations between change-patch characteristics, distance to permanent water, and elevation, but the low explanatory power requires these results to be interpreted as spatial diagnostics rather than causal attribution. The study links land-cover monitoring with reservoir water-level regulation, identifies priority shoreline belts, and provides spatial information for field verification and reservoir-margin management. Full article
(This article belongs to the Special Issue Land-Use Impacts on Water Resources and Watershed Management)
Show Figures

Figure 1

42 pages, 12738 KB  
Article
Identifying Key Thresholds for Flood-Season Operating Water Levels in River-Type Reservoirs Based on the Beneficial Utilization of Small and Medium Floods: A Case Study of the Three Gorges Reservoir
by Yanwei Zhai, Dingguo Jiang, Hanqing Zhao and Guoliang Ji
Water 2026, 18(12), 1437; https://doi.org/10.3390/w18121437 - 11 Jun 2026
Viewed by 168
Abstract
The beneficial utilization of small and medium floods requires a clear flood-control safety boundary before floodwater can be moderately stored and regulated as a water resource. For the Three Gorges Reservoir, a large river-type reservoir with long-distance backwater effects and tributary blocking, this [...] Read more.
The beneficial utilization of small and medium floods requires a clear flood-control safety boundary before floodwater can be moderately stored and regulated as a water resource. For the Three Gorges Reservoir, a large river-type reservoir with long-distance backwater effects and tributary blocking, this boundary cannot be determined solely from the dam-front water level. This study developed a one-dimensional unsteady hydrodynamic model with dynamic roughness calibration to investigate the risk-constrained flood-season operating water level of the Three Gorges Reservoir. Typical flood events and the 20-year return period design flood were used to examine the responses of the maximum dam-front flood-regulation water level, excess flood volume, longitudinal water levels, and exceedance risk at key reservoir-area sections under different initial regulation water levels and release-discharge conditions. The results show that the Changshou reach is the main control section for high-water-level inundation risk under the study scenarios. When the initial regulation water level is at or below 155 m, the dam-front flood-regulation water level, the peak water level at Changshou, and the exceedance duration generally vary only slightly. When the initial regulation water level exceeds 155 m, these risk indicators increase markedly, indicating a reduced flood-control safety margin. Perturbation analysis further shows that the dam-front flood-regulation indicators are relatively insensitive to small roughness and dam-front boundary perturbations, whereas the Changshou water level and exceedance duration are more sensitive to roughness and flood-volume perturbations. Therefore, 155 m should be interpreted as a conservative operational reference boundary under the current design-flood framework, existing operation rules, and the assumption of no forecast-based pre-release, rather than as an absolute safety threshold. Increasing release discharge can reduce high-water-level risk in the reservoir area under preset release limits, but its practical application must remain conditional on downstream flood-control constraints and real-time flood-conveyance capacity. The results provide a hydrodynamic basis for risk-constrained flood-season operation of large river-type reservoirs. Full article
(This article belongs to the Special Issue Water-Related Disaster Assessments and Prevention)
Show Figures

Figure 1

36 pages, 4899 KB  
Article
Spatial Cascading of Extreme Water–Sediment Imbalance Risks in a Heavily Regulated River Reach: A Copula-CoVaR Framework
by Cheng Zhang, Zengchuan Dong and Wenzhuo Wang
Water 2026, 18(11), 1372; https://doi.org/10.3390/w18111372 - 4 Jun 2026
Viewed by 288
Abstract
The Inner Mongolia reach of the Yellow River faces compound “low flow, high sediment” extremes under reservoir regulation, threatening flood and ice-flood safety in ways that traditional mean-based or correlation-based methods fail to quantify. This study integrates POT-GPD extreme value theory with a [...] Read more.
The Inner Mongolia reach of the Yellow River faces compound “low flow, high sediment” extremes under reservoir regulation, threatening flood and ice-flood safety in ways that traditional mean-based or correlation-based methods fail to quantify. This study integrates POT-GPD extreme value theory with a vine copula-CoVaR framework using daily data (1951–2023) from four stations. The financial CoVaR concept was adapted to rivers through three hydrological modifications: a 5-day hydrodynamic lag, redefinition of the baseline to the downstream unconditional VaR, and semi-parametric tail modeling. Bootstrap confidence intervals (n = 1000) and a sensitivity analysis to the upstream–downstream lag (τ = 3–7 days) and the period cutoff (1984–1990) were used to assess robustness. Bayangol exhibits the highest Expected Shortfall (ES95 = 0.0329 kg·s·m−6). The Bayangol → Toudaoguai path is the only persistent positive risk transmission link, with ΔCoVaR showing a directionally consistent increase of 253% from the natural period (1951–1986) to the regulated period (1987–2023); by contrast, ΔCoVaR from Dengkou to Toudaoguai remains near zero or negative when assessed under the conventional bivariate framework. A three-dimensional vine copula analysis, conducted independently for the pre- and post-reservoir periods, reveals a qualitative reversal of compound extreme spillover that is masked when the two periods are pooled. While the bivariate analysis identifies Bayangol → Toudaoguai as the only persistent positive spillover route at the annual scale, the 3D vine analysis unpacks the compound extreme mechanism at the daily scale. Under the joint compound extreme condition (upstream Q and S each ≥ Q90), the conditional VaR95 of downstream sediment concentration shifts from systematically negative in P1 (ΔVaR95 = −4.75 kg·m−3 at the 90th-percentile threshold, indicating natural attenuation) to systematically positive in P2′ (ΔVaR95 = +4.70 kg·m−3, +86.9% relative increase, indicating amplification). The same reversal is observed for the tail mean (ΔES95), is preserved across four compound extreme thresholds (Q75–Q90), and is robust to the choice of period cutoff (28/28 cases reverse across seven candidate cutoffs). Bidirectional counterfactual simulations indicate that the copula shift from tail independence (Clayton) to tail dependence (Gaussian) alone elevates extreme concurrence probability by 58% (from 2.21% to 3.49%), while marginal distribution changes contribute negligibly (≤0.1 percentage points). Structural deterioration of water–sediment coordination therefore dominates risk amplification. The copula-CoVaR framework offers a candidate tool that requires further validation with large samples for tail risk assessment in heavily regulated fluvial systems. Full article
(This article belongs to the Section Water Erosion and Sediment Transport)
Show Figures

Figure 1

33 pages, 8195 KB  
Article
Sedimentary Characteristics of the Wufeng–Longmaxi Formation Shales and Their Controlling Mechanisms on Shale Gas Accumulation in the Mugan Syncline, Northeastern Yunnan, China
by Hao Ma, Junbin Chen, Nianfeng Li, Hua Chen, Bin Liu and Siqi Xiao
Processes 2026, 14(11), 1807; https://doi.org/10.3390/pr14111807 - 1 Jun 2026
Viewed by 272
Abstract
The Mugan Syncline in northeastern Yunnan represents a significant relay area for shale gas exploration in China. However, due to the combined effects of tectonic superimposition and sedimentary heterogeneity, systematic investigations into the intervals hosting high-quality shales and the coupling relationships among microfacies, [...] Read more.
The Mugan Syncline in northeastern Yunnan represents a significant relay area for shale gas exploration in China. However, due to the combined effects of tectonic superimposition and sedimentary heterogeneity, systematic investigations into the intervals hosting high-quality shales and the coupling relationships among microfacies, reservoir quality, and gas-bearing properties remain insufficient. The core objective of this study is to establish a high-resolution microfacies framework and to quantitatively elucidate the multi-parameter coupling mechanisms by which microfacies control organic matter enrichment, pore development, and gas storage capacity in this structurally complex, basin-margin setting. By integrating core observations, thin-section petrography, scanning electron microscopy (SEM), whole-rock X-ray diffraction (XRD), total organic carbon (TOC) analysis, trace-element geochemistry, and well-logging data, we establish a stratigraphic subdivision and cross-well correlation framework for the Wufeng (WF) Formation and the Long11 submember. Furthermore, a lithofacies (microfacies) identification scheme based on a “TOC + siliceous (quartz + feldspar)–carbonate–clay” ternary classification is applied. The results reveal the following: (1) Based on the locally developed erosional contact at the boundary between the Longmaxi (LMX) Formation and the underlying Guanyinqiao Formation, the WF Formation in the study area can be subdivided into two submembers, whereas the Long11 submember comprises four sublayers. The thicknesses of the Long11-1 through Long11-3 sublayers range from 21.42 to 25.47 m, exhibiting a subtle northward-thickening trend. In contrast, the Long11-4 sublayer displays a relatively uniform thickness and high stratigraphic continuity of shale deposition. (2) Based on TOC content and ternary mineral composition, the shales are classified into four lithofacies associations and sixteen lithofacies subtypes. The main favorable microfacies assemblages are identified as high-carbon siliceous/calcareous shale (C-1), high-carbon calcareous/siliceous mixed shale (M-1), carbon-rich argillaceous siliceous shale (S-3), and high-carbon siliceous/argillaceous mixed shale (M-2). (3) High-quality shales (TOC > 2%) are predominantly developed in the upper member of the WF Formation and in the Long11-1 through Long11-4 sublayers. Their lateral distribution is markedly controlled by variations in paleotopography and terrigenous sediment supply. (4) The microfacies exert a synergistic control on shale gas enrichment. Carbon-rich argillaceous siliceous and siliceous-rich microfacies generally correspond to higher TOC contents and better-developed organic-matter pores. Siliceous-rich and mixed microfacies exert a positive influence on pore preservation and rock brittleness. The gas-bearing properties are influenced not only by TOC content but also by pore structure, mineral composition, and tectonic preservation conditions. The findings of this study provide a scientific basis for the prediction of shale gas sweet spots and the optimization of target intervals in the Mugan Syncline and other structurally and sedimentologically complex regions of northeastern Yunnan. Full article
Show Figures

Figure 1

25 pages, 36295 KB  
Article
Differences in Reservoir Characteristics of Organic-Rich Deep-Water Shelf Shale with Variable Maturities
by Xianglong Fang, Yidong Cai, Longyong Shu, Zhonggang Huo, Ping Gao, Yujing Qian and Qixian Li
Processes 2026, 14(11), 1778; https://doi.org/10.3390/pr14111778 - 29 May 2026
Viewed by 299
Abstract
Organic-rich shales in China’s deep-water shelf environments possess significant shale gas resource potential. To investigate the reservoir development characteristics of deep-water shelf shale, 143 shale samples were collected from the low-maturity Xiamaling Formation in the Zhangjiakou area and the high to over-mature Wufeng–Longmaxi [...] Read more.
Organic-rich shales in China’s deep-water shelf environments possess significant shale gas resource potential. To investigate the reservoir development characteristics of deep-water shelf shale, 143 shale samples were collected from the low-maturity Xiamaling Formation in the Zhangjiakou area and the high to over-mature Wufeng–Longmaxi Formations in the southeastern margin of the Sichuan Basin. Basic analytical methods, including X-ray diffraction (XRD), total organic carbon (TOC) analysis, rock pyrolysis, and solid bitumen reflectance measurements, were employed alongside advanced reservoir characterization techniques such as field-emission scanning electron microscopy (FE-SEM), low-pressure CO2/N2 physisorption, mercury intrusion porosimetry (MIP), and focused ion beam scanning electron microscopy (FIB-SEM). This study focuses on the petrographical, geochemical, and microscopic pore structure characteristics of these marine shales. The results indicate that the mineral composition of deep-water shelf sedimentary shale is dominated by quartz, clay minerals, feldspar, calcite, dolomite, apatite, and pyrite, with quartz being the most abundant. The Xiamaling Formation shales, at low maturity, are relatively rich in siliceous components, while the high to over-mature Wufeng and Longmaxi Formation shales are richer in carbonate components. The kerogen type of organic matter in the Xiamaling Formation is primarily Types II1 and II2, whereas the Wufeng–Longmaxi shales are predominantly Types I and II1. TOC content is highest in the Wufeng Formation, followed by the Longmaxi Formation, with the Xiamaling Formation exhibiting the lowest TOC levels. Pore development in the Wufeng and Longmaxi shales is significantly superior to that in the Xiamaling shales. Overall, the Wufeng and Longmaxi Formations demonstrate more favorable pore characteristics and hydrocarbon generation potential compared to the Xiamaling Formation. The Wufeng and Longmaxi Formations’ shales will be the key targets for shale gas exploration in the future. The findings of this study contribute to the understanding and development of theories of marine shale gas accumulation in China and hold both theoretical and practical significance for the efficient and rational exploitation of shale oil and gas resources. Full article
(This article belongs to the Section Energy Systems)
Show Figures

Figure 1

25 pages, 13448 KB  
Article
Quantifying Dominant Remaining Oil Distribution in Displacement Units of High-Water-Cut Reservoirs
by Chao Chen, Zhou Li, Zhenping Liu, Menghao Zhang, Yaopan Yu, Junyao Xiang and Daigang Wang
Energies 2026, 19(11), 2519; https://doi.org/10.3390/en19112519 - 23 May 2026
Viewed by 506
Abstract
Remaining oil in high-water-cut reservoirs becomes increasingly dispersed during long-term waterflooding, while preferential flow paths cause severe ineffective water circulation and reduce the efficiency of further oil displacement. To improve the quantitative identification of remaining oil enrichment and water-flushed regions, this study proposes [...] Read more.
Remaining oil in high-water-cut reservoirs becomes increasingly dispersed during long-term waterflooding, while preferential flow paths cause severe ineffective water circulation and reduce the efficiency of further oil displacement. To improve the quantitative identification of remaining oil enrichment and water-flushed regions, this study proposes a displacement-unit-based classification and evaluation method for dominant remaining oil distribution. The method integrates dynamic allocation of injected water in multilayer reservoirs, time-varying characterization of reservoir physical properties, streamline-based delineation of displacement units, and saturation tracking using the φ-function. Two quantitative indicators, the remaining oil abundance index (Iso) and the water flushing intensity coefficient (Cf), were introduced to classify displacement units into strongly dominant, weakly dominant, and non-dominant types. The method was applied to a high-water-cut block of the W Oilfield, where 902 displacement units were identified from 65 oil and water wells and 36 sublayers. The results show that strongly dominant, weakly dominant, and non-dominant displacement units accounted for 37.9%, 33.7%, and 28.4% of the total, respectively. In 15 sublayers, the proportion of strongly dominant units exceeded 50%, indicating severe preferential water flow and limited remaining oil potential in these layers. Strongly dominant units were characterized by high water flushing intensity and low remaining oil abundance, whereas weakly dominant units showed remaining oil enrichment mainly at the margins of displacement units. The proposed method couples injection–production dynamics with seepage-field evolution and provides a quantitative basis for fine-scale adjustment of injection–production patterns in high-water-cut reservoirs. Full article
(This article belongs to the Section H1: Petroleum Engineering)
Show Figures

Figure 1

18 pages, 16934 KB  
Article
Geological Characteristics and Shale Gas Resource Potential of the Wufeng–Longmaxi Formations in the Complex Structural Zone, Eastern Sichuan Basin: A Western Hubei Case Study
by Yuke Wang, Xiaodong Wang, Xiuping Wang, Tianju Huang, Li Zhao, Bo Wang, Yun Guo and Junji Zhang
Energies 2026, 19(11), 2513; https://doi.org/10.3390/en19112513 - 23 May 2026
Viewed by 414
Abstract
This study is a systematical investigation of the fundamental geological conditions for shale gas in the Wufeng–Longmaxi formations in western Hubei, China, using drilling core data, with Well Xiandi-2 serving as the key well for core observation and experimental testing, integrated with outcrop [...] Read more.
This study is a systematical investigation of the fundamental geological conditions for shale gas in the Wufeng–Longmaxi formations in western Hubei, China, using drilling core data, with Well Xiandi-2 serving as the key well for core observation and experimental testing, integrated with outcrop profiles and regional provincial-level shale gas block data. The analysis encompasses petrology, organic geochemistry, mineral composition, physical properties, pore types, and gas content. Through a comprehensive comparison with established shale gas production fields in the Sichuan Basin, the shale gas resource potential of the study area is evaluated, and favorable zones for shale gas exploration are delineated. The results indicate that the study area contains a continuous organic-rich shale interval with a 18.84 m net thickness, 2.3% average total organic carbon, 65–89% brittle mineral content, 2.36% average porosity, and thermal maturity within the gas window. Systematic comparison with the Jiaoshiba and Changning fields confirms comparable geological attributes, including organic matter abundance, reservoir porosity, and brittle mineralogy. Given this comparability, areas with burial depths shallower than 1500 m on the northwestern margin of the Xuefeng Uplift are interpreted to retain moderate shale gas resource potential. Three favorable zones are delineated as priority targets: the synclines on both sides of the Longtan normal fault and the Lianghekou Syncline. These findings provide practical exploration value: the identified favorable zones offer immediate drilling targets, the analytical workflow is transferable to other structurally complex blocks on the basin margin, and the potential of shallow-buried sequences expands exploration beyond the core Sichuan Basin into previously overlooked transitional zones. Full article
Show Figures

Figure 1

29 pages, 8385 KB  
Article
Discovery of Potential Antihypertensive Agents from the Marine Microalga Phaeodactylum tricornutum Through Metabolite Profiling and In Silico Analysis
by Miguel Ernesto Guzmán-Rodríguez, Marco Antonio Valdez-Flores, Cinthia Ayón-Fernandez, José Juan Ordaz-Ortiz, Alma Marlene Guadrón-Llanos, Javier Magaña-Gómez, Alberto Kousuke de la Herrán-Arita, Josué Camberos-Barraza, Verónica Judith Picos-Cárdenas, Juan Fidel Osuna-Ramos, Claudia Desireé Norzagaray-Valenzuela and Loranda Calderón-Zamora
Sci. Pharm. 2026, 94(2), 43; https://doi.org/10.3390/scipharm94020043 - 21 May 2026
Viewed by 981
Abstract
Hypertension remains a leading cause of global morbidity and mortality, and angiotensin-converting enzyme (ACE) represents a central therapeutic target within the renin–angiotensin–aldosterone system. Marine microalgae, particularly Phaeodactylum tricornutum, provide an underexplored reservoir of structurally diverse metabolites with potential cardiovascular relevance. In this [...] Read more.
Hypertension remains a leading cause of global morbidity and mortality, and angiotensin-converting enzyme (ACE) represents a central therapeutic target within the renin–angiotensin–aldosterone system. Marine microalgae, particularly Phaeodactylum tricornutum, provide an underexplored reservoir of structurally diverse metabolites with potential cardiovascular relevance. In this in silico study, we characterized metabolites putatively annotated by UPLC-ESI-HRMS and evaluated their predicted ACE inhibitory potential. We performed molecular docking with AutoDock 4 and assessed pharmacokinetic and toxicological properties using the SwissADME, PASS, and ProTox platforms. Several metabolites showed favorable binding orientations within the ACE catalytic pocket, including interactions with key residues and proximity to the zinc-binding motif. Lehualide G, Val–Asn–Pro, tanariflavanone B, hydroxyterbinafine, and anhydro-vitamin A exhibited the most favorable docking profiles. PASS predictions indicated vascular-related bioactivity signals for selected compounds, whereas ADMET modeling revealed heterogeneous but classifiable pharmacokinetic and safety characteristics. The convergence of predicted binding compatibility, bioactivity signals, and stratified safety margins supports P. tricornutum as a promising source of candidate molecules for further experimental validation in antihypertensive research. Full article
Show Figures

Figure 1

Back to TopTop