Geothermal Energy最新文献

{"title":"Geothermal favourability in data-scarce regions: incorporating physical and socio-economic factors into a modified Play fairway approach, southwestern Yukon, Canada","authors":"F. M. Chapman,&nbsp;M. M. Miranda,&nbsp;S. Sternbergh,&nbsp;R. Soucy La Roche,&nbsp;J. Raymond","doi":"10.1186/s40517-025-00345-6","DOIUrl":"10.1186/s40517-025-00345-6","url":null,"abstract":"<div><p>Geothermal energy could be used to reduce or replace diesel for heating in remote northern communities. Geothermal development has primarily focused on shallow, high-temperature resources, but interest in low-temperature and deep geothermal resource exploration has increased as energy costs and climate change policy have evolved. Here, we evaluated the low-temperature geothermal favourability in southwestern Yukon by adapting Play fairway analysis to data-scarce regions. Play fairway analysis is a spatial statistical tool that uses a layered data approach to model favourability and risk assessments for resource exploration. Previous Play fairway analyses concentrate on the physical aspects of geothermal favourability: heat, permeability, and fluid availability. This study presents an overview of potential direct and indirect physical parameters that could be used in a geothermal Play fairway analysis in data-scarce regions and introduces the importance of considering socio-economic data in the exploration phase. The socio-economic controls are grouped into quantitative and qualitative parameters that describe population trends and community interests. The framework presented is then applied to a Play fairway analysis for southwestern Yukon. Based on the physical and socio-economic analysis, there is interest in exploring geothermal potential along the Denali fault near Duke River to support the community of Burwash Landing.</p></div>","PeriodicalId":48643,"journal":{"name":"Geothermal Energy","volume":"13 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://geothermal-energy-journal.springeropen.com/counter/pdf/10.1186/s40517-025-00345-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In-situ thermal properties of grouting materials in borehole heat exchangers","authors":"Anna Albers,&nbsp;Petra Huttenloch,&nbsp;Yannick Reduth,&nbsp;Roman Zorn,&nbsp;Hagen Steger,&nbsp;Philipp Blum","doi":"10.1186/s40517-025-00347-4","DOIUrl":"10.1186/s40517-025-00347-4","url":null,"abstract":"<div><p>The thermal properties of grouting materials characterise the heat transfer around borehole heat exchangers (BHE). However, these properties are typically determined in the laboratory. Thus, this study aims to assess the properties of grouting materials in the field. Two BHE grouted with two different grouting materials within unsaturated loess and limestone were excavated up to a depth of 15 m. Collected field samples show higher thermal conductivities by 13% (<i>W</i>/<i>S</i> = 0.3) and 35% (<i>W</i>/<i>S</i> = 0.8) than laboratory samples of the same material. These differences in thermal properties are mainly related to the filtration of the grouting suspension. In addition, with a short-time enhanced thermal response test (ETRT), 17% lower in-situ thermal conductivities are determined than in comparison with the field samples. The deviations are attributed to the geometry of the borehole, the trajectory of the BHE pipes and the heating cable. Thereby, this study shows the limitations when transferring laboratory-derived properties to a field site and emphasises the importance of considering site conditions, such as geology and hydrogeology.</p></div>","PeriodicalId":48643,"journal":{"name":"Geothermal Energy","volume":"13 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://geothermal-energy-journal.springeropen.com/counter/pdf/10.1186/s40517-025-00347-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Productivity zoning and petrophysical assessment in the Munich metropolitan area for hydro-geothermal utilization using multivariate methods","authors":"Felix Schölderle,&nbsp;Daniela Pfrang,&nbsp;Valerie Ernst,&nbsp;Theis Winter,&nbsp;Kai Zosseder","doi":"10.1186/s40517-025-00342-9","DOIUrl":"10.1186/s40517-025-00342-9","url":null,"abstract":"<div><p>The North Alpine Foreland Basin in Bavaria is one of Europe’s most important deep reservoirs for hydrogeothermal energy utilization for district heating. Most of the plants are located in the Munich metropolitan region, where there are both favorable geological conditions and a high demand for heat due to the urban character. However, the region's potential is far from fully utilized and extensive geothermal development is thus planned in the city of Munich and the surrounding municipalities. Reliable productivity prognoses help to ensure that this development is sustainable and efficient. We use the dense and comprehensive drilling data set in the region to derive a productivity zonation using multivariate methods. To do this, we derive geophysical and hydraulic parameters from the existing borehole measurements and combine them with hydrochemical, historical and technical data to derive a set of 24 individual parameters. For this parameter set, we carry out a principal component analysis (PCA) and single linkage hierarchical cluster analysis (HCA). The PCA reduces the data set to six main factors, which explain 80% of the data set variability. Of those, the most important factors fa1, fa2, and fa3, which explain 53% of the data set variability, contain mainly geological (fa1), hydrochemical (fa2), and technical parameters (fa3). The HCA reveals four main clusters, with clusters 3 and 2 in the north, 1 in the center of the study area, and 4 in the south. The spatial location of these clusters fits very well with the zoning assumed in the previous assessment analysis ‘Masterplan Geothermal Energy‘. Cluster 2 behaves very similar to cluster 3, but is separated from it by a different hydrochemistry (fa2). In addition, two outliers were identified at two doublets in the north of the study area, which are distinguished from the main clusters in one case by differing hydrochemistry and in the other case by differing hydraulic and thermal conditions. Furthermore, a sub-cluster of cluster 4 is the only one that scatters across the entire study area. However, this can be explained by factors that do not directly influence the productivity of the boreholes concerned. Our results indicate that we can divide the reservoir from north to south into three productivity types A to C, where we derive different outflow temperatures and porosities from regression equations of depth trends.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":48643,"journal":{"name":"Geothermal Energy","volume":"13 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://geothermal-energy-journal.springeropen.com/counter/pdf/10.1186/s40517-025-00342-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143908624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanisms of lithium and cesium enrichment in the Semi-Dazi geothermal field, Qinghai-Xizang Plateau: insights from H–O–Li–Sr isotopes","authors":"Sheng Pan,&nbsp;Ping Zhao,&nbsp;Hui Guan,&nbsp;Dawa Nan,&nbsp;Zhaoying Yang,&nbsp;Xiaoming Liu,&nbsp;Shaopeng Gao,&nbsp;Yahui Yue","doi":"10.1186/s40517-025-00348-3","DOIUrl":"10.1186/s40517-025-00348-3","url":null,"abstract":"<div><p>Hot springs in the southern Qinghai-Xizang Plateau show anomalous lithium (Li) and cesium (Cs) enrichment, but the mechanisms driving this enrichment remain poorly constrained. Using multi-isotope tracers (H, O, Li, Sr), we investigate the Semi-Dazi geothermal field, which hosts the Plateau’s highest recorded geothermal Cs concentrations. The system comprises two geographically separated geothermal areas: Semi and Dazi, spaced ~ 15 km apart, displaying distinct hydrogeochemical signatures. Semi hot springs show significantly higher Li (34.2 to 35.6 mg/L) and Cs (49.8 to 52.7 mg/L) concentrations than Dazi (Li: 11.4 to 21.1 mg/L; Cs: 21.5 to 37.7 mg/L). Isotopic contrasts further differentiate the areas: Semi exhibits elevated δ⁷Li (1.53 to 1.91 ‰) and lower ⁸⁷Sr/⁸⁶Sr (0.739 to 0.741), whereas Dazi shows δ⁷Li values of − 0.25 to 1.24 ‰ and ⁸⁷Sr/⁸⁶Sr ratios of 0.742 to 0.759. Two key processes govern enrichment: (1) atmospheric recharge infiltrates Li–Cs-rich strata, where high-temperature water–rock interactions (217 °C at Semi and 197 °C at Dazi reservoirs) mobilize these elements into geothermal waters; (2) phase separation during ascent causes differential steam loss (Semi: 24%, concentration factor 1.32; Dazi: 8 to 21%, 1.08 to 1.26). Secondary processes (cold water mixing, conductive cooling, mineral adsorption) further modify surface hot springs geochemistry. Semi-Dazi geothermal field illustrates how a shared geothermal system can yield chemically distinct fluids from separate reservoirs characterized by differing hydraulic connectivity and circulation pathways. Geyserite deposits and high reservoir temperatures suggest that a crustal partial melt layer adds extra heat, intensifying water–rock reactions. The occurrence of Li–Cs-rich springs on the Plateau is intrinsically linked to elevated concentrations of these elements in underlying crustal source rocks and spatially associated with deep, extensive fault systems, particularly at fault convergences. These findings underscore the necessity of multi-isotope models for interpreting geothermal Li–Cs anomalies in continental collision zones, with implications for strategic mineral exploration.</p></div>","PeriodicalId":48643,"journal":{"name":"Geothermal Energy","volume":"13 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://geothermal-energy-journal.springeropen.com/counter/pdf/10.1186/s40517-025-00348-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143908854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of stimulation techniques in a geothermal injection well in a sedimentary aquifer in Szentes, Hungary","authors":"Márton Pál Farkas,&nbsp;Gábor Magyar,&nbsp;Hannes Hofmann,&nbsp;Günter Zimmermann,&nbsp;Ferenc Fedor","doi":"10.1186/s40517-025-00344-7","DOIUrl":"10.1186/s40517-025-00344-7","url":null,"abstract":"<div><p>The Upper Pannonian (UP) sandstone formation in Hungary has been utilized for thermal water production without reinjection since the 1960s. However, there is an increasing need for setting up geothermal doublets or triplets, where used water is expected to be reinjected into the same formation. Sustainable injection into porous sandstone rock formation is not straightforward. Thus, the Hungarian research and development project “Development of a well completion technology for sustainable and cost-effective reinjection of thermal water” aims at designing a methodology for sustaining the injectivity of geothermal wells in UP sandstone reservoirs. In this case study, we present an intervention approach of an old geothermal production well for reinjection at the Szentes Geothermal Field. Based on the evaluation of well conditions, the injectivity decline may be associated with reservoir characteristics, i.e., low transmissibility, mineral precipitation or local particle migration. Thus, a stimulation program was designed, where various techniques such as hydraulic fracturing, acid treatment and skin frac experiment were conducted. The novelty of this study is that to the best of our knowledge, the skin frac technique has been applied for the first time in a geothermal injection well worldwide. Based on the comparison of the various stimulation experiments, the injectivity reduction is related to phenomena in the near-wellbore area, i.e., mechanical clogging due to fines migration in the reservoir. The largest injectivity enhancement was observed due to skin frac experiment and pump lift, which was not part of the original stimulation program. The skin frac method has the potential for providing injectivity enhancement of recompleted wells in poorly cemented sandstone formations, but further field demonstration with optimized design is required. The results of this well treatment, such as regular conduction of pump lift and recommendations for proper design of skin frac treatment can be used in designing long-term reinjection tests in loose sandstone formations in geothermal reservoirs. Furthermore, future study should focus on the investigation of the link between pressure depletion due to overexploitation, subsequent compaction and land subsidence as well as injectivity problems.</p></div>","PeriodicalId":48643,"journal":{"name":"Geothermal Energy","volume":"13 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://geothermal-energy-journal.springeropen.com/counter/pdf/10.1186/s40517-025-00344-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143892588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Support for regulation of enhanced geothermal systems research: examining the role of familiarity, credibility, and social endorsement","authors":"Meaghan McKasy,&nbsp;Sara K. Yeo,&nbsp;Jennifer Shiyue Zhang,&nbsp;Michael A. Cacciatore,&nbsp;Henry W. Allen,&nbsp;Leona Y.-F. Su","doi":"10.1186/s40517-025-00346-5","DOIUrl":"10.1186/s40517-025-00346-5","url":null,"abstract":"<div><p>Enhanced geothermal systems (EGS) are a new technology with the potential to expand renewable energy generation. Understanding how information about EGS affects people’s opinions and support for its development is critical for its implementation. The present study examines how social endorsement cues (SEC; e.g., number of likes and shares) and perceived familiarity with EGS might influence audience considerations. We found that SEC significantly influenced perceived credibility of a blog post. Perceived familiarity with EGS moderated the relationship between perceived credibility and support for regulation of academic and commercial EGS research. However, there were differences in the mediating effect of perceived credibility for support for regulation of commercial, compared to academic, research. If producers of commercial EGS want greater public support, engaging SEC on public platforms could be a promising path forward.</p></div>","PeriodicalId":48643,"journal":{"name":"Geothermal Energy","volume":"13 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://geothermal-energy-journal.springeropen.com/counter/pdf/10.1186/s40517-025-00346-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143888616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting terrestrial heat flow in Egypt using random forest regression: a machine learning approach","authors":"Ahmed Mohamed Bekhit,&nbsp;Mohamed Sobh,&nbsp;Mohamed Abdel Zaher,&nbsp;Tharwat Abdel Fattah,&nbsp;Ahmed I. Diab","doi":"10.1186/s40517-025-00341-w","DOIUrl":"10.1186/s40517-025-00341-w","url":null,"abstract":"<p>This work aims to create a machine-learning model that can contribute to a comprehensive understanding of Egypt's terrestrial heat flow distribution. The model is based on the random forest regression method, with a sparsely distributed dataset of heat flow measurements. The model is trained using 16 geophysical and geological databases, which are well-known for their efficacy in geothermal evaluation. These databases provide a robust foundation for the model, ensuring its accuracy in predicting the terrestrial heat flow in Egypt. The results confirm that the Red Sea rift region exhibits the highest terrestrial heat flow values, ranging from 100 to 185 mW/m². In contrast, the Mediterranean offshore zone shows values varying from 40 mW/m² in the eastern sector to 110 mW/m² in the west. The southern part of the Sinai Peninsula and the two Gulfs display heat flow values between 60 and 90 mW/m², while northern Sinai has lower values between 40 and 50 mW/m². The central region of the Eastern Desert presents heat flow values of 60 to 80 mW/m², with northern and southern areas showing 50 mW/m². The Nile Delta records a heat flow of 50 mW/m², peaking at 60 mW/m². The Western Desert reveals three distinct heat flow zones relevant to its geological structure: 60 mW/m² in the unstable shelf to the north, 50 to 80 mW/m² in the stable shelf at the center, and the Arabo-Nubian Massif in the south, which has the lowest terrestrial heat flow in Egypt, ranging from 30 to 60 mW/m². This study's findings underscore Egypt's complex geothermal nature, highlighting significant and intriguing variations in terrestrial heat flow influenced by tectonic activity and geological structures. The Red Sea rift region is a hotspot for geothermal potential, which could be harnessed for sustainable energy production.</p>","PeriodicalId":48643,"journal":{"name":"Geothermal Energy","volume":"13 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://geothermal-energy-journal.springeropen.com/counter/pdf/10.1186/s40517-025-00341-w","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analytically estimating the efficiency of high temperature aquifer thermal energy storage","authors":"David Geerts,&nbsp;Alexandros Daniilidis,&nbsp;Gert Jan Kramer,&nbsp;Martin Bloemendal,&nbsp;Wen Liu","doi":"10.1186/s40517-025-00343-8","DOIUrl":"10.1186/s40517-025-00343-8","url":null,"abstract":"<div><p>High-Temperature Aquifer Thermal Energy Storage (HT-ATES) can be used to reduce greenhouse gas emissions from heating. The thermal recovery efficiency is the main parameter indicating the performance of an HT-ATES system and it is influenced by multiple aquifer properties and storage characteristics. This study presents a method for estimating recovery efficiency through numerical modeling, data analysis, and curve fitting. This method shows the relation between the recovery efficiency and various storage conditions, such as aquifer properties and storage temperature. In addition, this research explores an analytical relationship between energetic efficiency and recovery efficiency and verifies that relationship with the generated data. The proposed method can be used for the purpose of initial screening to estimate the performance of an HT-ATES system and for efficiently using HT-ATES as a component in larger energy system models. This method uses the modified Rayleigh number in combination with aquifer thickness and injected volume and has a <span>(R^2)</span> of 85%. The analytical relation between energetic efficiency and recovery efficiency was shown to be accurate for all calculated energetic efficiency values above 60% and is less accurate with lower calculated energetic efficiency values.</p></div>","PeriodicalId":48643,"journal":{"name":"Geothermal Energy","volume":"13 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://geothermal-energy-journal.springeropen.com/counter/pdf/10.1186/s40517-025-00343-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143861221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanism of heat transfer and accumulation in sedimentary basin geothermal anomaly belts: a case study of Bohai Bay Basin, China","authors":"Xinwei Wang,&nbsp;Huiying Liu,&nbsp;Tinghao Wang,&nbsp;Nanan Gao,&nbsp;Zining Ma,&nbsp;Dan Li","doi":"10.1186/s40517-025-00337-6","DOIUrl":"10.1186/s40517-025-00337-6","url":null,"abstract":"<div><p>The mechanism of heat transfer and accumulation in sedimentary basin geothermal anomaly belts is very complicated, resulting in a lack of in-depth understanding. The Bohai Bay Basin is the largest Mesozoic–Cenozoic rifted basin in China and taken as the research object in the present work, the relationship between geothermal anomaly characteristics and influencing factors, including the structural geometry of the bedrock bulge, the bedrock thermal conductivity, and the caprock thickness was quantitatively discussed. Based on a typical measured geothermal geologic profile in the central Bohai Bay Basin, the formation mechanism, controlling factors, and the guiding significance for geothermal resources exploration of geothermal anomaly belts were analyzed. The formation of a geothermal anomaly in the sedimentary basin was driven by the rapid transfer of uniform deep heat flow in bedrock with the high thermal conductivity and accumulation of that in caprock with the low thermal conductivity of shallow bedrock bulge belts. As a result, heat flow depletion in the deep bedrock and heat flow enrichment in the shallow caprock were formed, with the characteristics of a nearly symmetrical coupling variation pattern. The bedrock bulge amplitude and the bedrock thermal conductivity were the main factors controlling geothermal anomaly characteristics, and the sufficient caprock thickness was vital to the formation of the geothermal anomaly. Simulation results of theoretical models showed that the top surface temperature of bedrock geothermal reservoirs with a depth of 2 km can increase by up to 31.3 ℃, and positive anomaly amplitudes were up to 41.8%. Based on the difference of tectonic deformation patterns in the rifted basin and their determining role in a geothermal gradient of caprock, geothermal fields developing bedrock geothermal reservoirs in the Bohai Bay Basin were divided into seven types, including the high bulge type, the bulge type, the low bulge type, the sag type, the gentle slope type, the basin margin fault-uplift type, and the shallow burial type, with a decrease in turn of the caprock geothermal gradient from &gt; 5.0 ℃/100 m to &lt; 2.0 ℃/100 m. The high bulge-type and the bulge-type geothermal fields were favorable targets for the shallow-burial bedrock geothermal reservoir exploration. The low bulge-type and the sag-type geothermal fields were the main targets for exploring deep-burial bedrock geothermal reservoirs with high temperatures above 150℃.</p></div>","PeriodicalId":48643,"journal":{"name":"Geothermal Energy","volume":"13 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://geothermal-energy-journal.springeropen.com/counter/pdf/10.1186/s40517-025-00337-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143840487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Viscosity of pure and mixed aqueous NaCl and CaCl2 solutions at 293 K to 353 K and 0.1 MPa: a simple empirical correlation parameterised with original analytical data","authors":"Ulrike Hoffert,&nbsp;Guido Blöcher,&nbsp;Stefan Kranz,&nbsp;Harald Milsch,&nbsp;Ingo Sass","doi":"10.1186/s40517-025-00339-4","DOIUrl":"10.1186/s40517-025-00339-4","url":null,"abstract":"<div><p>This paper reports more than 500 newly measured values of the dynamic viscosity of pure and mixed sodium chloride (NaCl) and calcium chloride (CaCl₂) aqueous solutions of which about half are unique. The data were acquired with a commercial rolling ball viscometer at ambient pressure, temperatures between 293 and 353 K, concentrations up to 6.0 mol/kg (NaCl) and 5.3 mol/kg (CaCl₂) as well as five different mixing ratios for the ternary system. Compared to existing values found in the literature, the present data match within mostly 5% uncertainty. Potential sources of errors are thoroughly discussed. An empirical correlation was derived from the measured data, accurately reproducing the measured data with good precision. This permits the functional dependence of dynamic viscosity on concentration and temperature of pure and mixed NaCl and CaCl₂ solutions to be easily and reliably implemented in coupled thermal–hydraulic–mechanical–chemical (THMC) numerical models aiming to predict the evolution of geothermal reservoir dynamics. Moreover, numerical sensitivity analyses were conducted exemplarily for one deep geothermal (DG) as well as one aquifer thermal energy storage (ATES) system to constrain the effect of viscosity variations and/or uncertainty on the prediction of key reservoir and operational parameters. It is demonstrated that viscosity variations systematically affect the productivity and injectivity indices (both systems) and the required pumping power (ATES), though no effect was observed for the timing of thermal breakthrough (DG) and the temperature evolution at the warm well (ATES). Not least, the stated precision of the analytical data obtained in this study proves well sufficient for the quality of numerical reservoir simulations aiming at predictions in a geothermal context.</p></div>","PeriodicalId":48643,"journal":{"name":"Geothermal Energy","volume":"13 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://geothermal-energy-journal.springeropen.com/counter/pdf/10.1186/s40517-025-00339-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}