Energy Geoscience最新文献

{"title":"Sequence stratigraphic and sedimentary evolution of the Cambrian Xiannüdong Formation in the north central Sichuan Basin, SW China","authors":"Zhuangzhuang Bai,&nbsp;Shuyuan Shi,&nbsp;Wei Yang,&nbsp;Wuren Xie,&nbsp;Shiyu Ma,&nbsp;Saijun Wu,&nbsp;Wenzheng Li,&nbsp;Wenliang Shang","doi":"10.1016/j.engeos.2025.100442","DOIUrl":"10.1016/j.engeos.2025.100442","url":null,"abstract":"<div><div>The high-frequency cycles seen in the carbonates of the Cambrian Xiannüdong Formation in the Sichuan Basin commonly exhibit a certain coupling relationship with the development of grain shoals; this influences the accuracy of reservoir predictions and the selection of favorable zones for hydrocarbon. MATLAB-based wavelet transform technology is employed to analyze the characteristics of the high-frequency sequences in the Xiannüdong Formation, establish a sequence stratigraphic framework, and clarify their vertical and horizontal relationships with the development of grain shoals. The results indicate that using the Dmey wavelet for continuous wavelet transform of gamma ray (GR) curves effectively reflects regional sedimentary cycles. In the Xiannüdong Formation, we identified two third-order sequences, five fourth-order sequences, and ten fifth-order sequences, all of which exhibit a strong correlation with the one-dimensional wavelet curves derived from wavelet transformations. In the sequence stratigraphic framework, early deposition of the Xiannüdong Formation briefly inherited transgressive processes from the Qiongzhusi Formation, and subsequently underwent a long and frequently fluctuating regressive phase. This study elucidates the development characteristics of grain shoals during marine regressions, and identifies lithology primarily as oolitic limestone, oolitic dolostone, doloarenite, silty oolitic limestone, and silty oolitic dolostone. Longitudinally, grain shoals are primarily distributed in the SQ1², SQ2¹, and SQ2² intervals, and are characterized by the interbedded development of thin and thick layers. They form predominantly during the regressive phase of fourth-order sequences. Planarly, they exhibit a belt-like distribution in the southwest–northeast direction. These findings provide novel insights for conducting high-frequency sequence stratigraphy studies utilizing logging data. They also possess practical implications for constructing high-precision sequence stratigraphic frameworks as well as for predicting the distribution of grain shoals within the study area.</div></div>","PeriodicalId":100469,"journal":{"name":"Energy Geoscience","volume":"6 3","pages":"Article 100442"},"PeriodicalIF":0.0,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comprehensive review of CO2 subsurface storage: Integrity, safety, and economic viability","authors":"Ahmed Alsubaih,&nbsp;Kamy Sepehrnoori,&nbsp;Delshad Mojdeh,&nbsp;Manriquez Alberto Lopez","doi":"10.1016/j.engeos.2025.100441","DOIUrl":"10.1016/j.engeos.2025.100441","url":null,"abstract":"<div><div>Anthropogenic emissions reached 37.4 Gt/a in 2023, intensifying the need for effective carbon storage in subsurface formations to mitigate global warming. Carbon Capture and Storage (CCS) has emerged as a viable solution, with over 43 operational sites worldwide and projections for more than 840 projects by 2040, potentially storing 2225 Mt CO₂ annually. This review provides a comprehensive analysis of CCS technologies, focusing on the integrity, safety, and economic viability of storage sites, which are crucial for long-term success. It identifies knowledge gaps in existing research, revealing that most studies address specific aspects of CCS but lack integrated approaches combining data, technologies, risks, and economic assessments. Some studies emphasize numerical modeling and fault reactivation risks but overlook issues such as cement degradation and casing corrosion, which are critical to preventing wellbore leakage. Others explore CO₂-rock interactions without considering cement integrity or focus on cement degradation without accounting for other field-scale risks. This review bridges these gaps by examining failures across wellbores, reservoirs, and caprocks, including cement integrity, casing corrosion, uplifting, fault activation, and seismicity due to injection. It also covers numerical modeling, experimental work, and monitoring techniques to ensure CCS integrity. Additionally, this review assesses economic risks to build confidence in CCS deployment, offering a comprehensive framework to ensure secure and long-term CO₂ storage in subsurface formations.</div></div>","PeriodicalId":100469,"journal":{"name":"Energy Geoscience","volume":"6 3","pages":"Article 100441"},"PeriodicalIF":0.0,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144654198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental assessment of enhanced geothermal system potential of partially abandoned or dry oil wells in a sedimentary basin","authors":"Ajan Meenakshisundaram,&nbsp;Olusegun Stanley Tomomewo,&nbsp;Josh Crowell,&nbsp;Moones Alamooti,&nbsp;Shree om Bade","doi":"10.1016/j.engeos.2025.100436","DOIUrl":"10.1016/j.engeos.2025.100436","url":null,"abstract":"<div><div>An enhanced geothermal system (EGS) represents a promising approach to sustainable energy generation by harnessing subsurface heat from deep geological formations with low natural permeability. Sedimentary basins—such as the Williston Basin in North Dakota—are considered viable candidates for EGS development due to their broad geographic extent and moderate geothermal potential. Notably, depleted or non-productive oil wells within these basins offer a cost-effective opportunity for EGS implementation as they can be repurposed, thereby significantly reducing the need for new drilling. This study evaluates the feasibility of EGS deployment in McKenzie County, North Dakota. Core samples from five partially abandoned or dry oil wells associated with production from the Red River Formation were obtained from the Core Library of the North Dakota Geological Survey. These samples, spanning the entire thickness of the formation, were sectioned and polished at defined depth intervals for detailed analyses and precise measurements of key reservoir properties critical to geothermal assessment. Several parameters were analyzed to assess the geothermal viability of these wells, including formation temperature, temperature gradient, porosity, thermal conductivity, energy storage potential, and estimated power output via the Organic Rankine Cycle (ORC). The results demonstrate significant depth-dependent variations in thermal and petrophysical properties. Specifically, the depth range of 4000–4500 m is identified as a promising target for EGS stimulation since it is characterized by elevated temperatures, high thermal conductivity, favorable temperature gradients, and sufficient porosity—all essential properties for enhancing permeability through hydraulic fracturing. Furthermore, the calculated energy content and potential ORC power output at these depths indicate that effective geothermal energy extraction is technically feasible. This suggests a compelling opportunity to repurpose existing fossil energy infrastructure—such as abandoned oil wells—for renewable geothermal applications. Overall, the findings of this study underscore the potential of sedimentary formations for EGS development and contribute to advancing low-carbon, diversified energy solutions in alignment with national decarbonization goals.</div></div>","PeriodicalId":100469,"journal":{"name":"Energy Geoscience","volume":"6 3","pages":"Article 100436"},"PeriodicalIF":0.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144661962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cases of possible structural-stratigraphic accumulations in the Oriente Basin, analysis on their accumulation mechanisms and implication for future exploration","authors":"Feng Ding,&nbsp;Guangfu Wang,&nbsp;Mingxi Xue,&nbsp;Yu Sun,&nbsp;Yaping Liu,&nbsp;Jianfang Sun,&nbsp;Fayou Li","doi":"10.1016/j.engeos.2025.100435","DOIUrl":"10.1016/j.engeos.2025.100435","url":null,"abstract":"<div><div>Three cases of structural-stratigraphic accumulations in the foredeep zone of the Oriente Basin have been analyzed. The target reservoirs are U and M1 sections of Napo Fm. in the Basin. Seismic amplitude maps are used for sand distribution pattern, and wells interpretation and correlations are applied for fluid distribution and reservoir continuity. These cases show that their oil distribution areas are significantly larger than their structure closures and thus should be structural-stratigraphic traps. But only in one case, lateral stratigraphic/lithological seals can be clearly observed. In the other two, the lateral seals are apparently discontinuous and cannot provide a complete barrier at the up-dip of the structures. Possible factors for the formation of those untypical structural-stratigraphic accumulations are studied, such as formation water flow and water head variations, basin and field structure evolution patterns, oil generation and charging history etc. An integrated mechanism is proposed in this study, where three factors may have acted together. 1) Slow long distance oil migration in LU and M1 reservoirs, due to their lateral discontinuity in the foredeep of the basin. This is supported by the distal estuarine and prodelta depositional environment suggested by previous sedimentological studies. 2) Ongoing secondary oil migration from south to north, caused by southward plunging and destruction of proto accumulations in the southern and middle part of the basin. This structure deformation is in turn caused by differential subsidence between the southern and northern part of the basin. 3) Additional oil supplied from the southern kitchen. The southern source kitchen is still in the oil window and providing pulses of oil charge since the Oligocene. If this mechanism is valid, it would imply that in the southern and northern transition zone of the basin, similar untypical traps should also exist. The area of southern extension of the two untypical accumulation is over 50 km², while within the basin, the transition zone of differential basin subsidence with distal and thus discontinuous LU and M1 reservoirs covers an area over 2000 km². These findings suggest a new and potentially extensive play concept with significant exploration potential in the Oriente Basin.</div></div>","PeriodicalId":100469,"journal":{"name":"Energy Geoscience","volume":"6 3","pages":"Article 100435"},"PeriodicalIF":0.0,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144632825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-analytical assessment of shale gas potential in the West Bokaro Basin, India: A clean energy prospect","authors":"Manish Kumar Srivastava ,&nbsp;Kaushal Kishor ,&nbsp;Alok K. Singh ,&nbsp;Alok Kumar ,&nbsp;Khairul Azlan Mustapha ,&nbsp;Amit Saxena","doi":"10.1016/j.engeos.2025.100434","DOIUrl":"10.1016/j.engeos.2025.100434","url":null,"abstract":"<div><div>Shale gas, a type of unconventional natural gas found within shale formations, has emerged as a significant source of energy globally. The West Bokaro Basin, part of the Damodar Valley, is known for its rich coal deposits and complex geological history. The basin's stratigraphy includes significant coal-bearing formations interbedded with shales, which may be potential sources of shale gas. The key formations in the basin include the Barakar Formation, which is the primary coal-bearing unit, and the Raniganj Formation, which contains substantial shale intervals. These formations exhibit varying thicknesses, organic content, thermal maturity, and mechanical strength, all of which are critical factors influencing shale gas potential. The assessment of shale gas potential in the West Bokaro Basin involves evaluating the organic richness, thermal maturity, pore characteristics, geochemistry, and mineralogy of the shale formations. Apart from organic richness and thermal maturity, the shale formations must be friable, as they generally lack natural permeability. This study aims to present a comprehensive analysis of the prospects of shale gas in the West Bokaro Basin based on the organic petrography, geochemistry, mineralogical study, Fourier Transform Infrared Spectroscopy (FTIR) analysis, and low-pressure N₂ adsorption analysis. The dark color, greasy touch, and high total organic carbon (<em>TOC</em>) content (5.88 %–22.84 %) provided an initial clue for the shale's potential as a source rock. Results from organic petrographic analysis suggest that these shales contain kerogen type Ⅲ, which is a known indicator of gas-prone zones. The random vitrinite reflectance (<em>R</em>_o, 0.80 %–0.91 %) and the temperature of maximum pyrolysis yield (<em>T</em>_max, 434–448 °C) indicate that the organic matter has attained the sufficient thermal maturity required for the generation of hydrocarbons. FTIR and X-ray diffraction (XRD) analyses identified inorganic entities and high quartz content in the shale samples, confirming their friability. The brittleness index (<em>BI</em>) calculated using X-ray fluorescence (XRF) data showed <em>BI</em> values above 0.48, indicating that the shales are brittle, which is advantageous for hydraulic fracturing. The high quartz content in the shale might act as a natural proppant, enhancing gas extraction efficiency. These findings suggest that the West Bokaro shales hold promise for economically viable shale gas production.</div></div>","PeriodicalId":100469,"journal":{"name":"Energy Geoscience","volume":"6 3","pages":"Article 100434"},"PeriodicalIF":0.0,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144522965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geomechanical parameter-driven evaluation of ultra-deep reservoirs: An integrated methodology and its application to the Kuqa depression, Tarim Basin","authors":"Ke Xu ,&nbsp;Hui Zhang ,&nbsp;Weike Ning ,&nbsp;Jingrui Liang ,&nbsp;Jianli Qiang ,&nbsp;Xin Wang ,&nbsp;Penglin Zheng ,&nbsp;Ziwei Qian ,&nbsp;Yu Zhang ,&nbsp;Fang Yuan","doi":"10.1016/j.engeos.2025.100433","DOIUrl":"10.1016/j.engeos.2025.100433","url":null,"abstract":"<div><div>Reservoir evaluation is important in identifying oil and gas sweet spots in sedimentary basins. This also holds true in the Tarim Basin, where the ultra-deep oil and gas-bearing formations have high present-day <em>in situ</em> stress and geothermal temperature in addition to their considerable depth as a result of multiple stages of tectonic evolution. Traditional reservoir evaluation methods are based mainly on analyses of reservoir parameters like porosity, permeability, and pore throat structure; these parameters can sometimes vary dramatically in areas with complex Structures. Geomechanics-based reservoir evaluations are favored as they adequately capture the impact of tectonic processes on reservoirs, especially those in the Tarim Basin. This study evaluates the ultra-deep clastic reservoirs in the Kuqa Depression of the Tarim Basin by integrating the geomechanical parameters including elastic modulus, natural fracture density, and present-day <em>in situ</em> stress into a 3D geological modeling-based reservoir evaluation. The entropy weight method is introduced to establish a comprehensive index (Q) for reservoir evaluation. The results show that the positive correlation of the daily gas production rate of representative wells in the study area with this indicator is an effective way of reservoir evaluation in ultra-deep areas with complex structures.</div></div>","PeriodicalId":100469,"journal":{"name":"Energy Geoscience","volume":"6 3","pages":"Article 100433"},"PeriodicalIF":0.0,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144481452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating poro-elastic production drive mechanisms: Quantifying the potential contribution to well-rates and risk of core handling damage inflating pore-volume compressibility measurements","authors":"Ruud Weijermars","doi":"10.1016/j.engeos.2025.100432","DOIUrl":"10.1016/j.engeos.2025.100432","url":null,"abstract":"<div><div>By analyzing core data from an offshore Gulf of Mexico reservoir and developing analytical solutions, it can be demonstrated that laboratory measurements on pore-volume compressibility include artifacts, leading to a misinterpretation of porosity and permeability trends. A systematic evaluation of poro-elastic changes in pore volumes (and quantifying any consequent fluid expulsion during reservoir compaction) suggests that poro-elastic relaxation may enhance fluid production rates from deep reservoirs by up to 25 %. This value may be inadvertently inflated if the core samples used for pore-volume compressibility measurements suffered from handling damage. Nonetheless, poro-elastic fluid expulsion from the pores in producing reservoirs can provide additional lift and thus may enhance the recovery factor. Therefore, the possible contribution to well performance from poro-elastic production drive mechanisms ought to be carefully evaluated in reserves estimation. Reversely, injection wells may encounter poro-elastic suppression of injectivity due to elastic resistance, which would adversely affect the storage coefficient. By integrating geomechanical reservoir response with traditional fluid production models, reservoir model predictions of production under pressure depletion and injection conditions will be more accurate. The new insights reported here are essential for optimizing well performance, improving reservoir management, and extending the economic life of geological reservoirs. However, caution is warranted regarding pore-volume compressibility measurements. To what degree laboratory measurements of pore-volume compressibility measure true values or mainly record handling damage could not be conclusively settled in the present study.</div></div>","PeriodicalId":100469,"journal":{"name":"Energy Geoscience","volume":"6 3","pages":"Article 100432"},"PeriodicalIF":0.0,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144548787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatiotemporal distribution patterns and exploration implications of multi-type coal-measure gases in the Daniudi gas field, Ordos Basin, China","authors":"Zhenrui Bai ,&nbsp;Fengcun Xing ,&nbsp;Zengqin Liu","doi":"10.1016/j.engeos.2025.100431","DOIUrl":"10.1016/j.engeos.2025.100431","url":null,"abstract":"<div><div>Coal-measure gas is a primary target with significant potential for the exploration of unconventional hydrocarbon resources. However, the spatiotemporal distribution and combination patterns of multi-type coal-measure gases are yet to be clarified, directly impeding the sweet spot evaluation and exploration deployment of coal-measure gas. This study discussed the characteristics and distribution patterns of coal-measure gases in the Daniudi gas field in northeastern Ordos Basin, China, with abundant drilling data. The results indicate that the coal seams variably thin upward and are mainly seen in the first and second members of the Taiyuan Formation (also referred to as the Tai 1 and Tai 2 members, respectively) and the first member of the Shanxi Formation (Shan 1 Member). Nos. 8, 5 and 3 coal seams are laterally continuous, and significantly thicker in its southern part compared to the northern part. Moreover, carbonaceous mudstones and shales are better developed in the southern part, where limestones are only observed in the Tai 1 Member. Based on the main lithological types, we identified three lithologic roofs of coal seams, that is, limestone, mudstone, and sandstone, which determine the spatiotemporal distribution of coal-measure gases. Besides bauxite gas in the Benxi Formation, the coal-measure gases include tight-sand gas, coalbed methane (CBM), coal-measure shale gas, and tight-limestone gas, with CBM typically associated with coal-measure shale gas. The combinations of different types of coal-measure gas vary across different layers and regions. Tight-sand gas is well-developed in areas where tight sandstones are in contact with coal-measures. From the Taiyuan to the Shanxi formations, CBM gradually transitions into a combination of CBM and coal-measure shale gas, and coal-measure shale gas. Nos.8 and 5 coal seams in low-lying areas exhibit favorable gas-bearing properties due to their large thickness and favorable roof lithologies, serving as prospective play fairways. Mudstone and limestone roofs are more conducive to achieving good gas-bearing properties. The direct contact between sandstones and coal seams tends to result in the formation of tight-sand gas and a reduced gas content of CBM. While focusing on single types of gas reservoirs such as CBM and tight-sand gas, it is essential to consider the concurrent exploration of various coal-measure gas combinations to discover more additional gas resources and guide exploration deployment.</div></div>","PeriodicalId":100469,"journal":{"name":"Energy Geoscience","volume":"6 3","pages":"Article 100431"},"PeriodicalIF":0.0,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144338541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics of pore-throat structures in volatile oil reservoirs and strategies for optimal development","authors":"Ying Tang ,&nbsp;Zhao Li ,&nbsp;Shuai Yin ,&nbsp;Ruifei Wang ,&nbsp;Kai Feng ,&nbsp;Tao Jiang","doi":"10.1016/j.engeos.2025.100430","DOIUrl":"10.1016/j.engeos.2025.100430","url":null,"abstract":"<div><div>The third member of Shahejie Formation (also referred to as Sha 3 Member) in Dongpu Depression, China, a volatile, low-permeability oil reservoir with complex fluid compositions, is subjected to high temperature and high pressure (HPHT), which poses significant challenges to conventional water injection. To elucidate flow mechanisms and optimize development strategies, this study integrates constant-rate mercury injection (CRMI), nuclear magnetic resonance (NMR), and HPHT three-phase oil/gas/water relative permeability experiments to analyze pore-throat structures, movable fluid characteristics, and relative permeability. The CRMI results indicate that the reservoir exhibits low porosity and low permeability, with dominant throat radius ranging from 0.6 to 5.0 μm, and mean pore-throat radius ratio ranging from 40.303 to 278.320, demonstrating significant microscopic heterogeneity. The NMR results reveal that water-alternating-gas (WAG) injection enhances oil recovery by 16.28 % (Sample W1) and 13.52 % (Sample W2) compared to conventional water injection, primarily due to the gas phase's low viscosity and high mobility, enabling access to micropores unreachable by water phases. The HPHT three-phase relative permeability tests demonstrate positive correlations between saturation and relative permeability, with oil permeability significantly influenced by three-phase saturation and rock wettability. These findings establish a microscopic seepage model for optimizing enhanced oil recovery (EOR) strategies in volatile reservoirs.</div></div>","PeriodicalId":100469,"journal":{"name":"Energy Geoscience","volume":"6 3","pages":"Article 100430"},"PeriodicalIF":0.0,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144321637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative investigation of the heat extraction performance of an enhanced geothermal system using H2, CO2, and H2O as working fluids","authors":"Dandan Wang ,&nbsp;Xiong Wu ,&nbsp;Pu Zhao ,&nbsp;Huiming Fang ,&nbsp;Zhiwei Dang ,&nbsp;Zhewei Shi ,&nbsp;Chao Huo","doi":"10.1016/j.engeos.2025.100429","DOIUrl":"10.1016/j.engeos.2025.100429","url":null,"abstract":"<div><div>The optimization of working fluids in single-well coaxial geothermal systems presents a critical pathway for advancing the use of enhanced geothermal systems (EGS) in renewable energy applications. This study evaluates the thermo-hydraulic performance of three working fluids (H₂O, CO₂, and H₂) in a single-well coaxial geothermal system, focusing on the effects of their injection temperatures. Using a 3D finite element model in COMSOL Multiphysics, simulations were conducted at three injection temperatures (17 °C, 27 °C, 40 °C) under constant mass flow rates. The results reveal that hydrogen significantly outperforms water and carbon dioxide, achieving a 297.77 % and 5453.76 % higher thermal output, respectively. Notably, the heat transfer efficiency is significantly improved when the injected working fluids are at 40 °C, compared to 27 °C; this demonstrates a positive correlation between injection temperature and thermal recovery. Though water systems exhibit better geological compatibility, the superior thermal properties of hydrogen position it as a promising alternative—despite potential subsurface challenges. This study provides critical insights for advancing the application of high-efficiency geothermal systems as well as the development of non-aqueous working fluids, thus contributing to the sustainable utilization of geothermal energy.</div></div>","PeriodicalId":100469,"journal":{"name":"Energy Geoscience","volume":"6 3","pages":"Article 100429"},"PeriodicalIF":0.0,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144308026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}