Research

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19 pages, 4542 KiB

Open AccessArticle

Reservoirs and Hydrogeochemical Characterizations of the Yanggao Geothermal Field in Shanxi Province, China

by Xiaoxue Yan, Shuaichao Wei, Wei Zhang, Feng Liu and Yuzhong Liao

Water 2024, 16(5), 669; https://doi.org/10.3390/w16050669 - 24 Feb 2024

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Geothermal water is the product of deep circulation within the crust, and the understanding of its hydrogeochemical process can provide effective information for integrated research on its circulation pattern and formation mechanism. Based on the geothermal geological conditions of the Yanggao geothermal field, [...] Read more.

Geothermal water is the product of deep circulation within the crust, and the understanding of its hydrogeochemical process can provide effective information for integrated research on its circulation pattern and formation mechanism. Based on the geothermal geological conditions of the Yanggao geothermal field, this study analyzed water samples from thermal springs and geothermal wells in the geothermal field, ascertaining their hydrochemical components, along with their hydrogen and oxygen isotopes. Using methods like piper diagrams, ionic component ratio characterization, Na–K–Mg equilibrium diagrams, and reverse path simulations, this study elucidated the recharge source of geothermal water in the study area, revealed the water–rock interactions the geothermal water experienced, and evaluated the geothermal reservoir temperatures. The results show that the geothermal water has hydrochemical types of Na–Cl–HCO₃ and Na–HCO₃–Cl, and is primarily recharged by the atmospheric precipitation in the northern mountainous area. The geothermal water has experienced extended water runoff and deep thermal circulation, and its hydrochemical composition primarily results from the weathering and dissolution of silicate rocks and evaporites. The major hydrogeochemical processes of the geothermal water involve the dissolution of calcite, dolomite, gypsum, and kaolinite. In addition, the canon-exchange also changes the chemical component of the geothermal water. The SiO₂ Geothermometer, a multimineral equilibrium diagram, and the silica–enthalpy model reveal the presence of deep and shallow geothermal reservoirs in the study area, which exhibit temperatures of 73 °C and ranging from 125 to 150 °C, respectively. The open geothermal reservoir environment results in the mixing of geothermal water and cold water, with shallow and deep geothermal water mixing with cold water at ratios of 57% and 76%, respectively. Full article

(This article belongs to the Special Issue Development and Utilization of Regional Geothermal Water Resources under the Carbon Neutral Situation)

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22 pages, 13735 KiB

Open AccessArticle

Geochemical Characteristics and Controlling Factors of Groundwater Chemical Composition in the Zihe River Source Area, Shandong, China

by Jing You, Yueming Qi, Guangyu Shao and Chao Ma

Water 2024, 16(2), 298; https://doi.org/10.3390/w16020298 - 15 Jan 2024

Cited by 1 | Viewed by 860

Abstract

The geochemical characterization and evolution of shallow groundwater in the Zihe River source area is a key issue that needs to be addressed. In this study, a combination of traditional geochemical techniques and geochemical modeling was used to explain the geochemical processes and [...] Read more.

The geochemical characterization and evolution of shallow groundwater in the Zihe River source area is a key issue that needs to be addressed. In this study, a combination of traditional geochemical techniques and geochemical modeling was used to explain the geochemical processes and major ion sources in the chemical evolution of shallow groundwater in the Zihe River source area, Northeast China. Fifty-seven water samples were collected in June 2020 for chemical analysis, and the results showed that the main groundwater chemistry types in the three major aquifers are HCO₃·SO₄-Ca_·Mg-type pore water from loose quaternary rocks, HCO₃·SO₄-Ca_·Mg-type karstic fissure water from carbonate rocks, and HCO₃·SO₄-Ca-type weathered fissure water from massive rocks. Water–rock interactions in alkaline environments were the main causes of changes in groundwater chemistry. Rock weathering dominated the geochemical evolution of each aquifer. The analysis of ion concentration ratios and modeling revealed that the aquifer’s chemical components are mainly derived from the dissolution of dolomite and calcite and partly from the infiltration of pollutants containing

{C l}^{-}

and

{N O}_{3}^{-}

, as well as from the dissolution of quartz. Mg²⁺ is derived from the dissolution of dolomite.

{H C O}_{3}^{-}

is primarily derived from the co-dissolution of calcite and dolomite, and to a lesser extent, its content is also influenced by the recharge of rainfall.

{S O}_{4}^{2 -}

has two sources: it mainly originates from the dissolution of gypsum and the anhydrite layer, followed by atmospheric precipitation. The synthesis showed that the groundwater quality in the source area of Zihe River is good, all the indices reached the standard of class III groundwater quality, and the overall degree of human pollution is low. The results of this research will provide a scientific basis for the local authorities to delineate karst groundwater protection zones in the Zihe River source area and to formulate resource management strategies for the development, utilization, and protection of karst groundwater. Full article

(This article belongs to the Special Issue Development and Utilization of Regional Geothermal Water Resources under the Carbon Neutral Situation)

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18 pages, 8410 KiB

Open AccessArticle

Hydrogeochemical Characteristics of Geothermal Water in Ancient Deeply Buried Hills in the Northern Jizhong Depression, Bohai Bay Basin, China

by Mingxiao Yu, Xia Tian, Hanxiong Zhang, Jun Li, Laibin Wang, Zhigang Zhang, Hailiang Lin and Xinlong Yang

Water 2023, 15(22), 3881; https://doi.org/10.3390/w15223881 - 07 Nov 2023

Cited by 1 | Viewed by 1021

Abstract

The Jizhong Depression boasts rich geothermal resources with a lengthy history of geothermal exploitation. Buried hill geothermal reservoirs, which serve as primary thermal sources for hydrothermal resource exploitation, are prevalent in this region and have advantages such as extensive development potential, significant geothermal [...] Read more.

The Jizhong Depression boasts rich geothermal resources with a lengthy history of geothermal exploitation. Buried hill geothermal reservoirs, which serve as primary thermal sources for hydrothermal resource exploitation, are prevalent in this region and have advantages such as extensive development potential, significant geothermal reservoir capacity, superior water quality, and straightforward recharge. This study investigates the formation and evolution of deep geothermal water in the Jizhong Depression by analyzing the hydrochemical and isotopic data of geothermal water samples collected from buried hill geothermal reservoirs in the northern part of the depression. The findings reveal that the subsurface hot water samples from the carbonate geothermal reservoirs in this region were predominantly weakly alkaline water with a pH ranging between 6.61 and 8.87. The hot water samples collected at the wellhead exhibited temperatures varying from 33.9 °C to 123.4 °C and total dissolved solids (TDS) lying between 473.9 mg/L and 3452 mg/L. Based on the δ²H-δ¹⁸O stable isotope analysis, the geothermal fluids in the Jizhong Depression are predominantly sourced from atmospheric precipitation and exist in a somewhat isolated hydrogeological environment, exhibiting pronounced water–rock interactions and deep water circulation (with depths ranging from 1324 m to 3455 m). Through a comparison of various methods, it is deduced that the most appropriate geothermometer for deep karst geothermal reservoirs in the Jizhong Depression is a chalcedony geothermometer, and when using it, the deep reservoir temperature was estimated at 63–137.6 °C. The precipitation in the adjacent mountainous areas enables the groundwater to infiltrate and descend deep into the earth along piedmont faults. Subsequently, lateral runoff over extended periods replenishes the groundwater into the depression. This process allows for the groundwater to fully absorb heat from deep heat sources, resulting in the formation of the deep geothermal reservoirs in the northern Jizhong Depression. The insights obtained from this study offer a theoretical and scientific foundation for the exploitation and utilization of regional geothermal resources and the transformation of the energy structure in China. Full article

(This article belongs to the Special Issue Development and Utilization of Regional Geothermal Water Resources under the Carbon Neutral Situation)

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17 pages, 5943 KiB

Open AccessArticle

Characteristics and Research Significance of Micro-Nanoparticles in Geothermal Fluids in the Central Area of Shandong Province

by Lei Zuo, Peng Zhang, Yaqin Wang, Rui Liu and Guangxi Ma

Water 2023, 15(21), 3737; https://doi.org/10.3390/w15213737 - 26 Oct 2023

Viewed by 804

Abstract

The micro-nanoparticles found in geothermal fluids exhibit distinct characteristics that hold great potential for detecting deeply concealed geothermal resources. Utilizing a nanoparticle tracking analyzer (NTA), we conducted observations on karst geothermal fluids collected from the central region of Shandong Province, specifically Jinan and [...] Read more.

The micro-nanoparticles found in geothermal fluids exhibit distinct characteristics that hold great potential for detecting deeply concealed geothermal resources. Utilizing a nanoparticle tracking analyzer (NTA), we conducted observations on karst geothermal fluids collected from the central region of Shandong Province, specifically Jinan and Zibo. Our investigation revealed the presence of a significant quantity of naturally occurring micro-nanoparticles within these geothermal fluids, with particle sizes typically falling in the range of 100 nm to 5 μm. To gain a comprehensive understanding of these micro-nanoparticles, we subjected them to a detailed analysis, encompassing their type, shape, crystal structure, and chemical composition. This in-depth examination was carried out using transmission electron microscopy (TEM). Our findings, supported by TEM images and energy dispersive spectroscopy, indicated that these micro-nanoparticles in the geothermal fluid samples predominantly exhibit amorphous characteristics and possess irregular or nearly spherical shapes, often accompanied by rough edges. Furthermore, it was evident that the composition of these micro-nanoparticles primarily consists of carbonates, sulfates, and chlorides, which contain elements such as Fe, Ca, and Na. The distinctive features of these micro-nanoparticles provide valuable insights into the properties of the high-temperature reservoirs and aquifers from which they originate. As a result, we firmly assert that natural micro-nanoparticles can significantly contribute to the detection and comprehensive study of concealed geothermal resources within the Earth. This novel approach offers a promising method for exploring and gaining a deeper understanding of these hidden geothermal resources. Full article

(This article belongs to the Special Issue Development and Utilization of Regional Geothermal Water Resources under the Carbon Neutral Situation)

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13 pages, 2594 KiB

Open AccessArticle

Unraveling the Genesis of the Geothermal System at the Northeastern Edge of the Pamir Plateau

by Feng Chen, Shihua Qi, Shuai Wang, Genyi He and Boyuan Zhao

Water 2023, 15(20), 3583; https://doi.org/10.3390/w15203583 - 13 Oct 2023

Viewed by 837

Abstract

High-temperature geothermal systems hold promise for sustainable and environmentally friendly power generation. However, China’s geothermal power capacity significantly underutilizes its abundant resources. This study focuses on the geothermal potential of the Pamir Plateau, particularly its northeastern edge, where complex tectonic forces converge. We [...] Read more.

High-temperature geothermal systems hold promise for sustainable and environmentally friendly power generation. However, China’s geothermal power capacity significantly underutilizes its abundant resources. This study focuses on the geothermal potential of the Pamir Plateau, particularly its northeastern edge, where complex tectonic forces converge. We aim to unveil the mechanisms driving the emergence of high-temperature geothermal reservoirs in this unique geological setting. Hydrogeochemical analysis reveals diverse profiles in geothermal water, primarily derived from atmospheric precipitation. Estimation of reservoir temperatures and simulation of geotherms unveil distinct geothermal systems. Kongur exhibits a medium–low-temperature hydrothermal system and Tashkurgan demonstrates high-temperature hydrothermal system characteristics, while the Pamir’s northeastern edge hints at a potential high-temperature dry geothermal system where there might not be a fault. These findings have important implications for sustainable energy development and future geothermal exploration. Full article

(This article belongs to the Special Issue Development and Utilization of Regional Geothermal Water Resources under the Carbon Neutral Situation)

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24 pages, 11738 KiB

Open AccessArticle

Chemical Characterization and Genesis of Thermal Reservoir Water in the Southern Part of the Jizhong Depression

by Lijun Wang, Linxiao Xing, Wenjing Lin, Wei Zhang, Zirui Zhao, Jiayi Zhao and Tianlun Zhai

Water 2023, 15(20), 3532; https://doi.org/10.3390/w15203532 - 10 Oct 2023

Cited by 1 | Viewed by 731

Abstract

The Jizhong Depression is a typical Mesozoic and Cenozoic fault basin located in the northwestern part of the Bohai Bay Basin that has abundant hydrothermal and geothermal resources and enormous development potential. In this study, hydrochemical and isotopic analyses were conducted on water [...] Read more.

The Jizhong Depression is a typical Mesozoic and Cenozoic fault basin located in the northwestern part of the Bohai Bay Basin that has abundant hydrothermal and geothermal resources and enormous development potential. In this study, hydrochemical and isotopic analyses were conducted on water samples from the southern region of the Jizhong Depression. The formation and evolution processes of the deep geothermal water were analyzed, the circulation process of the deep geothermal water was determined, and the genetic mechanism of the geothermal systems was elucidated. The hydrochemical types of the geothermal fluids in the sandstone reservoirs in the research area are mainly Cl·HCO₃⁻Na type, while the geothermal fluids in the carbonate reservoirs are mainly Cl-Na type and Cl·HCO₃⁻Na type. The ion components in the geothermal water are mainly controlled by the dissolution of the carbonate rocks and the alternate adsorption of cations. The elevation of the geothermal water supply area is 763–1063 m, and the main source is precipitation from the mountainous areas in the western Taihang Mountains. The Na-K-Ca temperature scale and multi-mineral equilibrium method have relatively small errors and are suitable for the southern region of the Jizhong Depression, with average errors of 21.44 °C and 32.64 °C, respectively. The depth of the Jxw thermal storage cycle in the research area is 3033–5187 m, and the depth of the Ng thermal storage cycle is 1360–2862 m. The content of the main ions (Na⁺, K⁺, and Cl⁻) in the water samples of the study area is greater in the Jxw thermal storage than in the Ng thermal storage; the Jxw thermal storage water samples have lower γNa⁺/γCl⁻ values than the Ng thermal storage; and the γSO₄²⁻/γCl⁻ and γCl⁻/(γHCO₃⁻ + CO₃²⁻) values are greater than those of the Ng thermal storage, indicating that the Jxw thermal storage is located in a geological environment with better sealing, longer flow, slower water circulation, more complete leaching, and higher salinity than the Ng thermal storage. Part of the deep thermal storage is transmitted upwards through the rocks via thermal conduction, and part is transmitted upwards along fault channels via thermal convection, forming a convection–conduction-type geothermal system. Full article

(This article belongs to the Special Issue Development and Utilization of Regional Geothermal Water Resources under the Carbon Neutral Situation)

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14 pages, 5763 KiB

Open AccessArticle

Enrichment Mechanism of Lithium in Geothermal Waters from a Bedrock Reservoir in Xiong’an New Area, China

by Jun Li, Hanxiong Zhang, Yinmei Zhang, Laibin Wang and Zhigang Zhang

Water 2023, 15(19), 3518; https://doi.org/10.3390/w15193518 - 09 Oct 2023

Viewed by 824

Abstract

The lithium concentrations in the geothermal waters of the Wumishan Formation carbonate reservoir in China Xiong’an New Area are over 1 mg/L and are even higher than those in the geothermal waters of granite reservoirs in some areas of China. It is still [...] Read more.

The lithium concentrations in the geothermal waters of the Wumishan Formation carbonate reservoir in China Xiong’an New Area are over 1 mg/L and are even higher than those in the geothermal waters of granite reservoirs in some areas of China. It is still unknown which are the most important factors controlling the lithium concentrations in the geothermal waters in the study area. This article selected the analysis and test data of 32 geothermal water samples obtained in recent years from the study area and combined them with hydrochemical analysis and test data from granite reservoirs in other regions of China to study the enrichment mechanism of lithium in the geothermal waters in the study area. The results of the hydrochemical data analysis indicate that the lithology, pH, and water–rock interaction between geothermal water and carbonate rocks are not the main factors affecting the lithium concentrations in the study area. The mixing of paleo-seawater and the leaching of the evaporated rocks formed by it are the most important factors controlling the lithium concentrations in the study area, and temperature is also an important factor affecting the lithium concentrations. The research results are of great significance to the study of the enrichment mechanism of lithium in geothermal waters and the formation mechanism of geothermal waters in similar areas around the world. Full article

(This article belongs to the Special Issue Development and Utilization of Regional Geothermal Water Resources under the Carbon Neutral Situation)

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Review

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14 pages, 1411 KiB

Open AccessReview

Seepage and Heat Transfer of Dominant Flow in Fractured Geothermal Reservoirs: A Review and Outlook

by Zhiyan Liu, Yanguang Liu, Tingxin Li and Meihua Wei

Water 2023, 15(16), 2953; https://doi.org/10.3390/w15162953 - 16 Aug 2023

Viewed by 900

Abstract

Deep geothermal reservoirs have great potential for exploitation and are characterized by high temperatures, high stress, and strong heterogeneity. However, these reservoirs contain widely and continuously distributed dominant flow channels with high permeability, predisposing these reservoirs to the formation of dominant flow, which [...] Read more.

Deep geothermal reservoirs have great potential for exploitation and are characterized by high temperatures, high stress, and strong heterogeneity. However, these reservoirs contain widely and continuously distributed dominant flow channels with high permeability, predisposing these reservoirs to the formation of dominant flow, which notably decreases the efficiency of heat extraction. Focusing on the dominant flow in fractures, this study provides a definite concept, systematically reviews current studies, and puts forward suggestions for future research. It is expected that this study will serve as a reference for the sustainable, high-quality development of deep geothermal resources. Full article

(This article belongs to the Special Issue Development and Utilization of Regional Geothermal Water Resources under the Carbon Neutral Situation)

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