Yandy Scientific Press
Not a member yet
641 research outputs found
Sort by
Caprock wettability: A cross-process perspective from CO₂ sequestration to underground hydrogen storage
Get PDFCaprock wettability is a fundamental control on the sealing capacity and integrity of subsurface energy storage systems. In CO₂ geological sequestration, a strongly water wet caprock ensures high capillary entry pressures, effectively preventing CO₂ migration. However, increased pressure and brine salinity can weaken hydrophilicity and compromise long-term sealing. In underground hydrogen storage, caprocks generally remain water wet, yet the high diffusivity of H₂ reduce capillary sealing efficiency and may induce wettability alteration due to microbial or redox processes. Repeated injection-withdrawal cycles further cause transient wetting-drying and hysteresis, altering interfacial structures and capillary behavior. Understanding these dynamic wettability responses under varying physicochemical conditions is crucial for assessing storage security. Future studies should integrate in-situ characterization and molecular modeling to reveal reactive and reversible wettability mechanisms, providing a unified framework for CO₂ and H₂ storage systems.Document Type: PerspectiveCited as: Tao, L., Liu, L., Zhu, S., Zhang, H. Caprock wettability: A cross-process perspective from CO₂ sequestration to underground hydrogen storage. Advances in Geo-Energy Research, 2025, 18(2): 199-201. https://doi.org/10.46690/ager.2025.11.0
In-situ hydrogen production from natural gas reservoirs and gas separation by graphite packing: Process simulation and experimental study
Get PDFThe generation of hydrogen in-situ from hydrocarbon reservoirs has emerged as a carbon neutral technology for fossil fuel-based hydrogen production. This technology has been extensively investigated for heavy oil reservoirs through in-situ combustion gasification. This study proposes in-situ hydrogen generation from depleted gas reservoirs and assess graphite gravel packing for selective hydrogen production with underground carbon storage. The viability of this hydrogen generation process was accessed through process simulation, followed by experimental investigation and molecular simulation of the selective production of hydrogen through graphite. Equilibrium and kinetic models reproduced measured effluent fractions, confirming their reliability. The simulation outcomes reveal that higher temperature and steam-to-carbon ratio increase hydrogen yield/purity, whereas high pressure favors methanation. This necessitates elevated temperatures beyond the usual reaction temperature under reservoir conditions. Longer residence time and judicious catalyst loading improve conversion while limiting diminishing returns. Adiabatic simulation yields lower hydrogen purity than isothermal but better reflects field behavior. Reservoir mineralogy governs outcomes as quartz-rich rocks inhibit hydrogen production by steam reforming, while clays/feldspars reported elsewhere can be catalytic. The experimental results showed that graphite can be used as gravel pack in the production well to produce hydrogen and retain carbon dioxide underground. Literature report indicates that high compaction can further enhance separation significantly reducing the carbon emission associated with hydrogen production from fossil fuels.Document Type: Original articleCited as: Tackie-Otoo, B. N., Mahmoud, M., Raza, A., Patil, S., Murtaza, M., Kamal, M. S., Zahid, U. In-situ hydrogen production from natural gas reservoirs and gas separation by graphite packing: Process simulation and experimental study. Advances in Geo-Energy Research, 2025, 18(2): 165-179. https://doi.org/10.46690/ager.2025.11.0
Efficient optimization of coupled geothermal reservoir modeling and power plant off-design based on deep learning
Get PDFThe accurate evaluation of the electricity output of geothermal power plants requires effective coupling between the geothermal reservoir and power plant. Existing coupling models integrate numerical simulation models of the reservoir and power plant; however, they are computationally expensive for electricity prediction (forward modeling) and integrated reservoir-power plant optimization. Therefore, this study aimed to enhance the efficiency of the coupled reservoir-power plant model for forward modeling and optimization by replacing simulation forward models with deep-learning-based surrogate models. Two independent surrogate models of the reservoir and power plant were trained and assembled into one coupled forward model. Moreover, a multiobjective optimizer was integrated with the coupled forward model to optimize reservoir operations and power plant designs to achieve the highest electricity output or the best economic outcome. Surrogate models for the reservoir and power plant accurately predicted the geothermal production temperature and electricity output while approximately achieving speedups of 1.23×105 and 1.77×105 times over those of the corresponding simulation models, respectively. Furthermore, optimization using our surrogate-based coupled model was 1.31 × 106 times faster than that using the simulation-based coupled models. Optimization results revealed that low injection temperature, large well distance, and stable reservoir injection and production rates contributed to better power plant performance. High design geothermal temperature, mass flow rate, and ambient temperature favored electricity generation, particularly in power plants located in hot regions. Our work remarkably accelerates the feasibility assessment and decision-making procedures for geothermal reservoirs and power plants.Document Type: Original articleCited as: Liu, Z., Gudala, M., Yan, B. Efficient optimization of coupled geothermal reservoir modeling and power plant off-design based on deep learning. Advances in Geo-Energy Research, 2025, 18(1): 84-98. https://doi.org/10.46690/ager.2025.10.0
Secondary cracking characteristics of asphaltenes and insights into the reservoir unblocking during oil shale in-situ exploitation
Get PDFIn-situ conversion is essential for the development of oil shale resources. Reservoir blockage has been confirmed to be a technological bottleneck via laboratory-scale experiments and field tests. This issue arises from the precipitated asphaltene and its thickening effect on the pyrolysis oil. Promoting in-situ secondary cracking of asphaltene has the potential to mitigate blockage. However, the secondary cracking characteristics of asphaltene have not yet been determined. In this study, asphaltenes were obtained under different pyrolysis temperatures, atmospheres and duration times, their secondary cracking mechanisms were investigated. These findings demonstrate considerable mass loss and discrepant reaction processes across different asphaltenes. Firstly, the mass loss of asphaltenes exceeds 80% at 500 ◦C for all the samples, and the released space can restore reservoir permeability. Second, based on the evolution of the activation energies and pyrolysis gas components, the asphaltenes obtained under severe conversion conditions undergo pyrolysis defined by synchronous two-stage reactions, whereas the asphaltenes obtained under mild conversion conditions undergo pyrolysis defined by sequential three-stage reactions. Finally, a method for eliminating reservoir blockage was proposed based on the above theories, involving inhibiting asphaltene migration and promoting its in-situ secondary cracking by controlling the parameters of the heat-carrying fluid, thereby achieving an unaffected reservoir or reservoir self-unblocking. The obtained results can provide valuable references for the in-situ exploitation of oil shale.Document Type: Original articleCited as: Guo, W., Fan, C., Deng, S., Shui, H., Liu, Z. Secondary cracking characteristics of asphaltenes and insights into the reservoir unblocking during oil shale in-situ exploitation. Advances in Geo-Energy Research, 2025, 15(1): 13-26. https://doi.org/10.46690/ager.2025.01.0
Three-terraced evaporated ramp model for differentiation of the massive dolomitization process: Insights from the Lower Cambrian Longwangmiao Formation in the Sichuan Basin
Get PDFWithin carbonate strata across the globe, dolostone reservoirs hold paramount importance in the realm of petroleum development. The genesis of dolostone has long perplexed geologists; however, despite the proliferation of various dolomitization models, the origin of dolostone and its capacity to elucidate the extensive dolomitization processes of the Lower Paleozoic on a platform scale remain subjects to debate. The present study endeavors scrutinizing the dolomitization process of the Lower Cambrian Longwangmiao Formation, with a particular emphasis on the impact of paleogeomorphology on platform- or basin scale dolomitization. Through meticulous field observations, petrological examinations and geochemical analyses, the correlation between the distribution of dolostones and paleogeomorphological features is elucidated, thereby establishing a dolomitization model that considers paleogeomorphological features. In contrast to prior investigations, this study discerns that the dolomitization process of the Longwangmiao Formation is not only governed by depositional facies environments and sea-level fluctuations but also markedly influenced by paleogeomorphological factors. Specifically, a distinct compositional and distributional gradient of dolomite is observed from the higher terrace to the lower terrace. These findings not only provide novel insights into the dolomitization process within the Sichuan Basin but also serve as a useful reference for analogous processes at the basin or craton scale in other sedimentary basins. The proposed three-terraced evaporated seepage reflux dolomitization model offers a fresh vantage point for describing the extensive dolomitization processes of the Lower Paleozoic on a global platform scale, and underscores the pivotal role of paleogeomorphology in the dolomitization process.Document Type: Original articleCited as: Jin, X., Song, J., Liu, S., Li, Z., Yang, D., Wang, H. Three-terraced evaporated ramp model for differentiation of the massive dolomitization process: Insights from the Lower Cambrian Longwangmiao Formation in the Sichuan Basin. Advances in Geo-Energy Research, 2025, 15(3): 216-229. https://doi.org/10.46690/ager.2025.03.05
Repurposing deep closed mines as seismic forecasting research platforms
Get PDFSeismic forecasting remains constrained by surface noise and low spatial resolution, limiting reproducible predictions. Although deep borehole stations and underground laboratories improve conditions, they face high costs, sparse coverage, and narrow disciplinary scope. In this work, the strategic reuse of deep closed mines as seismic forecasting laboratories was evaluated. Closed mines, abundant and deep with extensive tunnels and reusable infrastructure, provide ideal low-noise, near-source environments for scalable observation networks. They can lower construction costs, enable simultaneous monitoring of natural and induced earthquakes, and support comparative studies of source mechanisms and forecasting methods. Key challenges include processing massive data volumes, integrating multi-source information, and ensuring equipment reliability in harsh environments. Future directions emphasize building three-dimensional, multiphysics monitoring networks, advancing interdisciplinary and international collaboration, and developing an integrated “observation–warning–prevention” platform. Repurposing closed mines not only expands underground space utilization but also offers a potential paradigm shift in seismic monitoring, providing a novel pathway to overcome longstanding forecasting bottlenecks.Document Type: PerspectiveCited as: Li, P., Tang, C., Li, Y., Zhang, Y., Gorjian, M., Cai, M. Repurposing deep closed mines as seismic forecasting research platforms. Advances in Geo-Energy Research, 2025, 18(1): 1-6. https://doi.org/10.46690/ager.2025.10.0
Developing and characterizing magnetic nanocomposites for effective metal ion removal in wastewater treatment
Get PDFThis research explores the synthesis and application of magnetic nanocomposites as effective adsorbents for the removal of metal ions from wastewater. Using a chemical co-precipitation method, Fe3O4 nanoparticles were modified with branched polyethyleneimine and stover activated carbon,yiclding Fe3O4 /BranchedPolyethylencimine and Fe3O4 pherical-Activated-Carbon adsorbents. These materials were thoroughly characterized to confirm their functional groups and optimized surface structure for heavy metal uptake. Thanks to their paramagnetic properties, the adsorbents are easily recovered and readily recycled. Adsorption efficiency was systematically evaluated by varying contact time, Cu2+ concentration, and adsorbent dosage. Isotherm and kinetic models were applied to elucidate the adsorption mechanisms, with Fe3O4/BranchedPolyethyleneimine best described by the pseudo-second order kinetic model and the Sips isotherm. This study not only provides empirical evidence of the adsorbents’ efficacy but also lays a conceptual foundation for their practical implementation in industrial wastewater treatment applications, paving the way for future advancements in adsorbent technology.Document Type: Original articleCited as: Sun, Y., Wei, Z., Bian, D., Zhou, J. Developing and characterizing magnetic nanocomposites for effective metal ion removal in wastewater treatment. Capillarity, 2025, 16(2): 51-60. https://doi.org/10.46690/capi.2025.08.0
Enhancing fracture geometry monitoring in hydraulic fracturing using radial basis functions and distributed acoustic sensing
Get PDFAccurate identification of fracture geometry in hydraulic fracturing is essential for understanding fracture propagation, optimizing stimulation design, and predicting production performance. Distributed acoustic sensing, as a high-resolution near-wellbore monitoring technique, provides rich spatiotemporal data for real-time observation of fracture responses. However, reconstructing fracture geometry from distributed acoustic sensing measurements remains challenging due to high model dimensionality, ill-posed inversion processes and substantial computational costs. This study presents a fracture geometry inversion framework based on radial basis function, in which the fracture width distribution is represented using a small number of radial basis function modes. Owing to the intrinsic smoothness and symmetry of radial basis function, the method eliminates the need for explicit regularization terms, thereby simplifying the objective function and improving inversion stability. This approach significantly reduces the number of inversion parameters while enhancing both accuracy and physical consistency. Applications to a synthetic benchmark model and real field data from the hydraulic fracturing test site demonstrate that the radial basis function-based method consistently outperforms conventional fullparameter inversion approaches, in terms of fitting accuracy and computational efficiency. The proposed method provides a structurally informed and computationally efficient modeling framework for high-dimensional fracture inversion, offering a promising solution for real-time fracture monitoring and parameter estimation in hydraulic fracturing operations.Document Type: Original articleCited as: You, S., Liao, Q., Yue, Y., Tian, S., Li, G., Patil, S. Enhancing fracture geometry monitoring in hydraulic fracturing using radial basis functions and distributed acoustic sensing. Advances in Geo-Energy Research, 2025, 16(3): 260-275. https://doi.org/10.46690/ager.2025.06.0
Recent advances in phase change microcapsules for oilfield applications
Get PDFUnconventional oil and gas reservoirs have become a new focus of energy development due to their wide distribution and abundant reserves. However, the exploitation of these reservoirs is often accompanied by varying temperatures, which impose higher requirements for novel material, equipment, and technology. Recently, phase change microcapsules have been attracting increasing attention in oilfield applications, because they can absorb or release considerable latent heat during the phase change process, enabling stable temperature control. Herein, the current status and future development trend of phase change microcapsules in oilfield applications are reviewed. The classification of phase change materials, including solid-solid, solid-liquid, solid-gas, and liquid-gas phase change materials, is introduced, with an emphasis on their advantages and disadvantages. Then, the microencapsulation methods for phase change materials are presented. Next, the critical thermophysical properties of phase change microcapsules relevant to oilfield applications, including melting and freezing points, latent heat capacity, thermal conductivity, and cycling stability, are discussed. Subsequently, the specific applications of phase change microcapsules in oilfields, including temperature regulation of drilling fluid, thermal management of cement paste, thermal protection of drilling equipment, and thermal insulation of submarine oil and gas pipelines, are thoroughly overviewed. Finally, the critical challenges and future perspectives are outlined. This review highlights the critical role of phase change microcapsules in advancing thermal management solutions for the efficient development of oil and gas from high- and low-temperature reservoirs, guiding future research and development efforts.Document Type: Original articleCited as: Liu, F., Zhang, Z., Liao, B., Sun, J., Khan, M. A., Li, M. -C. Recent advances in phase change microcapsules for oilfield applications. Advances in Geo-Energy Research, 2025, 16(3): 211-228. https://doi.org/10.46690/ager.2025.06.0
Contribution of different shale storage spaces to recovery rate and mechanism of oil mobilization during imbibition
Get PDFThe influence of different reservoir spaces in shale reservoirs on imbibition recovery is a hot spot for improving shale oil recovery. However, the research on the influence of different chemical reagents on the recovery factor of different scale pores is limited, and the influence mechanism of shale imbibition recovery factor under the action of different media has not been systematically studied. Therefore, this study takes the Gulong shale oil reservoir as the research object, carries out imbibition experiments combined with nuclear magnetic resonance testing under different injection fluid conditions, quantifies the contribution of shale pores of different scales to imbibition recovery under different injection media conditions, and analyzes the influence of injection media types on imbibition recovery. The results show that the average contribution rate of different types of pores was in the order of interlayer clay (47.6%) > mesoscale pores (32.7%) > small pores (17.3%) > large pores (2.6%). The total imbibition recovery of shale with millimeter-scale sandy laminae was ranked as alkali solution (61.50%) > acid solution (60.92%) >GJ surfactant (39.79%)> distilled water (32.92%)>guanidine gum (30.38%) , and the total imbibition recovery of laminated shale was ranked as GJ surfactant (39.1%) > slick water (38.0%) > guanidine gum (34.7%) > distilled water (29.2%).Document Type: Original articleCited as: Wei, J., Wang, A., Wang, R., Yang, Y., Zhao, X., Zhou, X. Contribution of different shale storage spaces to recovery rate and mechanism of oil mobilization during imbibition. Capillarity, 2025, 15(1): 12-24. https://doi.org/10.46690/capi.2025.04.0