The Beijing-Tianjin-Hebei Plain is among the regions in China that feature the largest scale and the fastest growth in medium and deep geothermal heating.Based on tests of 82 geothermal fluid samples from 7 geothermal...The Beijing-Tianjin-Hebei Plain is among the regions in China that feature the largest scale and the fastest growth in medium and deep geothermal heating.Based on tests of 82 geothermal fluid samples from 7 geothermal fields in Hebei Province,2 geothermal fields in Henan Province,and 2 geothermal fields in Shandong Province,and combined with previous studies on the chemical characteristics of karst geothermal water in Beijing and Tianjin,this paper systematically analyzes the migration characteristics of geothermal fluids in karst geothermal reservoirs within the Beijing-Tianjin-Hebei Plain.The hydrochemical characteristics of karst geothermal water in the research areas exhibit certain differences.The geothermal water in Hebei is more mature than that in its neighboring provinces.The distribution of total dissolved solids(TDS)and strontium elements in the area is characterized by being low in the north and south and high in the middle,suggesting that the overall flow direction of geothermal fluid is from the north and south towards the middle.Combined with the groundwater flow field and the changing trend of the hydrochemical characteristics of geothermal wells along the geological section,a geothermal water migration model has been established.The geothermal fluids originating from Taihang Mountain,Yanshan Mountain,and Western Shandong Mountain enter the basin and continue to migrate towards the central part of the basin along water-conducting faults.However,the migration characteristics of geothermal fluids with the same supply direction are not identical.The geothermal fluids from Taihang Mountain are cut off by the Niudong Fault in the north and terminate in the central uplift belt of the Jizhong Depression,while in the south,they enter the east of the Jizhong Depression relatively quickly along the Hengshui Conversion Belt.The geothermal fluids from Yanshan Mountain migrate into the basin along the Cangdong Fault,yet this fault also disrupts the hydraulic connection between the tectonic units.Considering the effective dynamic conditions,it is recommended to further expand the scale of the scientific development and utilization of geothermal energy in the geothermal water catchment areas around Xiongxian County and southwest Cangzhou City.展开更多
The Enhanced Geothermal System(EGS) is a recognized geothermal exploitation system for hot dry rock(HDR), which is a rich resource in China. In this study, a numerical simulation method is used to study the effects of...The Enhanced Geothermal System(EGS) is a recognized geothermal exploitation system for hot dry rock(HDR), which is a rich resource in China. In this study, a numerical simulation method is used to study the effects of geothermal fluid dryness and non-condensable gas content on the specific enthalpy of geothermal fluid. Combined with the organic Rankine cycle(ORC), a numerical model is established to ascertain the difference in power generation caused by geothermal fluid dryness and non-condensable gas content. The results show that the specific enthalpy of geothermal fluid increases with the increase of geothermal fluid temperature and geothermal fluid dryness. If the dryness of geothermal fluid is ignored, the estimation error will be large for geothermal fluid enthalpy. Ignoring non condensable gas will increase the estimation of geothermal fluid enthalpy, so the existence of the non-condensable gas tends to reduce the installed capacity of a geothermal power plant. Additionally, both mass flow of the working medium and net power output of the ORC power generation system are increased with increasing dryness of geothermal fluid, however there is some impact of geothermal fluid dryness on thermal efficiency.展开更多
This paper elaborates the chemical constituent change principles of deep geothermal fluid during the process of upward movement. It summarizes research methods of hydrochemistry, isotope and numerical modelling techni...This paper elaborates the chemical constituent change principles of deep geothermal fluid during the process of upward movement. It summarizes research methods of hydrochemistry, isotope and numerical modelling technique for the physiochemical processes such as decreasing temperature, shallow groundwater infusion, and degassing. The multi-component chemical geothermometry methods including gas geochemical method are discussed. High-temperature geothermal fields in China are mostly located in the southwest with frequent new tectonic movements, especially in Tibet high-temperature geothermal areas. Therefore the paper also focuses the status of high-temperature geothermal fluid research. At last, it's pointed out in the paper that in the future we can start from typical high-temperature geothermal zones and geothermal fields to explore optimization of the multi-component geothermometry method and use it in the reconstruction and analogue of the formation mechanism and internal relevancy of regional geothermal systems.展开更多
Tho Gudui geothermal field records the highest temperature at equivalent borehole depths among the lainland hydrothermal systems in China's Mainland.Located about 150 km southeast of Lhasa City,the capital of Tibe...Tho Gudui geothermal field records the highest temperature at equivalent borehole depths among the lainland hydrothermal systems in China's Mainland.Located about 150 km southeast of Lhasa City,the capital of Tibet,the Gudui geothermal field belongs to the Sangri-Cuona rift belt,also known as the Sangri-Cuona geothermal belt,and is representative of the non-volcanic geothermal systems in the Himalayas.In this study,oxygen-18 and deuterium isotope compositions as well as 87Sr/86Sr ratios of water samples collected from the Gudui geothermal field were characterized to understand the origin and mixing processes of the geothermal fluids at Gudui.Hydrogen and oxygen isotope plots show both,deep and shallow reservoirs in the Gudui geothermal field.Deep geothermal fluids are the mixing product of magmatic and infiltrating snow-melt water.Calculations show that the magma fluid component of the deep geothermal fluids account for about 21.10%-24.04%;magma fluids lay also be a contributing source of lithium.The linear relationship of the 87Sr/86Sr isotopic ratio versus the 1/Sr plot indicates that shallow geothermal fluids form from the mixing of deep geothermal fluids with cold groundwater.Using a binary mixing model with deep geothermal fluid and cold groundwater as two end-members,the nixing ratios of the latter in most surface hot springs samples were calculated to be between 5% and 10%.Combined with basic geological characteristics,hydrogen and oxygen isotope characteristics,strontium concentration,87Sr/(86)Sr ratios,and the binary mixing model,we infer the 6 th-Class Reservoirs Evolution Conceptual Model(6-CRECM) for the Gudui geothermal system.This model represents an idealized summary of the characteristics of the Gudui geothermal field based on our comprehensive understanding of the origin and mixing processes of the geothermal fluid in Gudui.This study may aid in identifying the geothermal and geochemical origin of the Gudui high-temperature hydrothermal systems in remote Tibet of China,whose potential for geothermal development and utilization is enormous and untapped.展开更多
Based on introducing geological structure of Tanggu area, the authors analyzed the sedimentary environment of Paleogene Dongying Formation, and further analyzed its geothermal occurrence. The studied area spans two gr...Based on introducing geological structure of Tanggu area, the authors analyzed the sedimentary environment of Paleogene Dongying Formation, and further analyzed its geothermal occurrence. The studied area spans two grade IV tectonic units which are Beitang depression and Banqiao depression. The studied area is mainly located in the Tanggu nose-like structure which is the secondary structure of Beitang depression. Its existence affects the sedimentary distribution of the part strata of Paleogene. The depositions of Dongying Ⅲ （ SQEd3 ） and Dongying Ⅱ （ SQEd2 ） are mainly delta front facies and lake sand bars which are propitious to the geothermal fluid enrichment. The favorable enrichment region of geothermal fluid is located in south Hetou- Tanggu. Most of Dongying Ⅰ （ SQEd1 ） changes into swamp plain deposition, only the northeast part of this area is the distributary riverway facies with developed sand layers. There is the favorable enrichment region of geothermal fluid. The hydraulic connection is weak among the geothermal reservoirs of Dongying Formation and its overlying Guantao and Minghuazhen formations. The underlying Shahejie Formation geothermal reservoir pro- vides a steady stream of fluid supply and ground pressure protection for Dongying Formation geothermal reservoir.展开更多
Longling is characterized by a wide distribution of hydrothermal areas, among which the Banglazhang hydrothermal system is the most geothermally active. Banglazhang is marked by intensive hydrothermal activities inclu...Longling is characterized by a wide distribution of hydrothermal areas, among which the Banglazhang hydrothermal system is the most geothermally active. Banglazhang is marked by intensive hydrothermal activities including hot springs, geysers, fumaroles and hydrothermal explosions. The geothermal waters from the Longling region are mainly HCO3-Na type with low but comparable SO4 and Cl concentrations. Calculations based on a variety of chemical geothermometers and a K-Ca geobarometer indicate that the Banglazhang hydrothermal system has much higher subsurface temperature and CO2 pressure compared to the other systems such as Daheba, Dazhulin and Huangcaoba. However, geothermal water samples collected from all these alternative hydrothermal areas are either partially equilibrated with reservoir minerals or are immature. The silica-enthalpy relationships of Banglazhang geothermal waters indicate the presence of a deep geothermal fluid with an enthalpy value and silica concentration of 945 J/g（up to around 220 °C） and 339 mg/L. Our work indicates the Banglazhang area is a promising source in terms of long-term utilization of hydrothermal resources.展开更多
Geothermal fluids are extracted through deep wells drilled in a geological reservoir,which can be represented by highly heterogeneous volcanic complex,sedimentary basins or deep basement rocks.The main objective of th...Geothermal fluids are extracted through deep wells drilled in a geological reservoir,which can be represented by highly heterogeneous volcanic complex,sedimentary basins or deep basement rocks.The main objective of this project was to propose suitable methodologies and techniques for the characterization and modeling of fractured geothermal reservoirs,to ensure their sustainable exploitation and,therefore,ensure acceptation of this kind of energy by local communities.展开更多
The formation mechanism of high salinity geothermal water is significant for utilizing geothermal resources and mineral resources.The high salinity in geothermal water may be derived from the geothermal mother fluid o...The formation mechanism of high salinity geothermal water is significant for utilizing geothermal resources and mineral resources.The high salinity in geothermal water may be derived from the geothermal mother fluid or from the evaporite dissolution.It is difficult to distinguish between these two sources because they may have similar hydrochemistry.In this paper,water chemistry and stable isotopes were used to explore the high salinity geothermal water in Yanchanghe geothermal field,central China.It is a lowtemperature hydrothermal system in the inland karst area.The thermal water is Cl-Na type with high salinity(TDS>8,400 mg/L).The modified silicon thermometer is more suitable and the reasonable result is about 58.8℃.The maximum circulation depth is 1.9 km.Using the temperature of hot and cold water to estimate the mixing ratio is 58%-81%.Saturation index(SI),Na/1000-K/100-Mg1/2 and Gibbs diagram suggest that the main source of salt in geothermal water is derived from the evaporite dissolution,which provides Cl-of 11,264-31,279 mg/L and Na+of 9,272-21,236 mg/L.We found the combination of temperature and hydrogeochemistry can be used to investigate the formation mechanism and mixing process of high-salinity geothermal water formed in a karst low-temperature hydrothermal system.展开更多
基金support received from the National Major Special Project titled“Exploration and Evaluation of Deep Geothermal Energy in Key Regions”(Project No.2024ZD1003600)the Science and Technology Department of Sinopec(Project No.JP24071).
文摘The Beijing-Tianjin-Hebei Plain is among the regions in China that feature the largest scale and the fastest growth in medium and deep geothermal heating.Based on tests of 82 geothermal fluid samples from 7 geothermal fields in Hebei Province,2 geothermal fields in Henan Province,and 2 geothermal fields in Shandong Province,and combined with previous studies on the chemical characteristics of karst geothermal water in Beijing and Tianjin,this paper systematically analyzes the migration characteristics of geothermal fluids in karst geothermal reservoirs within the Beijing-Tianjin-Hebei Plain.The hydrochemical characteristics of karst geothermal water in the research areas exhibit certain differences.The geothermal water in Hebei is more mature than that in its neighboring provinces.The distribution of total dissolved solids(TDS)and strontium elements in the area is characterized by being low in the north and south and high in the middle,suggesting that the overall flow direction of geothermal fluid is from the north and south towards the middle.Combined with the groundwater flow field and the changing trend of the hydrochemical characteristics of geothermal wells along the geological section,a geothermal water migration model has been established.The geothermal fluids originating from Taihang Mountain,Yanshan Mountain,and Western Shandong Mountain enter the basin and continue to migrate towards the central part of the basin along water-conducting faults.However,the migration characteristics of geothermal fluids with the same supply direction are not identical.The geothermal fluids from Taihang Mountain are cut off by the Niudong Fault in the north and terminate in the central uplift belt of the Jizhong Depression,while in the south,they enter the east of the Jizhong Depression relatively quickly along the Hengshui Conversion Belt.The geothermal fluids from Yanshan Mountain migrate into the basin along the Cangdong Fault,yet this fault also disrupts the hydraulic connection between the tectonic units.Considering the effective dynamic conditions,it is recommended to further expand the scale of the scientific development and utilization of geothermal energy in the geothermal water catchment areas around Xiongxian County and southwest Cangzhou City.
基金support provided by the National Key Research and Development Program of China(Grant No.2018YFB1501805)the National Natural Science Foundation of China(Grant No.52176183)。
文摘The Enhanced Geothermal System(EGS) is a recognized geothermal exploitation system for hot dry rock(HDR), which is a rich resource in China. In this study, a numerical simulation method is used to study the effects of geothermal fluid dryness and non-condensable gas content on the specific enthalpy of geothermal fluid. Combined with the organic Rankine cycle(ORC), a numerical model is established to ascertain the difference in power generation caused by geothermal fluid dryness and non-condensable gas content. The results show that the specific enthalpy of geothermal fluid increases with the increase of geothermal fluid temperature and geothermal fluid dryness. If the dryness of geothermal fluid is ignored, the estimation error will be large for geothermal fluid enthalpy. Ignoring non condensable gas will increase the estimation of geothermal fluid enthalpy, so the existence of the non-condensable gas tends to reduce the installed capacity of a geothermal power plant. Additionally, both mass flow of the working medium and net power output of the ORC power generation system are increased with increasing dryness of geothermal fluid, however there is some impact of geothermal fluid dryness on thermal efficiency.
基金supported by the Chinese Academy of Geological Sciences Fund (No.YK201611)the Chinese Academy of Geological Sciences Hydrogeological Environment Geology Institute Fund (No. SK201408)
文摘This paper elaborates the chemical constituent change principles of deep geothermal fluid during the process of upward movement. It summarizes research methods of hydrochemistry, isotope and numerical modelling technique for the physiochemical processes such as decreasing temperature, shallow groundwater infusion, and degassing. The multi-component chemical geothermometry methods including gas geochemical method are discussed. High-temperature geothermal fields in China are mostly located in the southwest with frequent new tectonic movements, especially in Tibet high-temperature geothermal areas. Therefore the paper also focuses the status of high-temperature geothermal fluid research. At last, it's pointed out in the paper that in the future we can start from typical high-temperature geothermal zones and geothermal fields to explore optimization of the multi-component geothermometry method and use it in the reconstruction and analogue of the formation mechanism and internal relevancy of regional geothermal systems.
基金This work was financially supported by the China Geological Survey(Grant No.DD20160054)the National Natural Science Foundation of China(Grant No.U1407207)the National Key Research and Development Program of China(Grant No.2017YFC0602802).
文摘Tho Gudui geothermal field records the highest temperature at equivalent borehole depths among the lainland hydrothermal systems in China's Mainland.Located about 150 km southeast of Lhasa City,the capital of Tibet,the Gudui geothermal field belongs to the Sangri-Cuona rift belt,also known as the Sangri-Cuona geothermal belt,and is representative of the non-volcanic geothermal systems in the Himalayas.In this study,oxygen-18 and deuterium isotope compositions as well as 87Sr/86Sr ratios of water samples collected from the Gudui geothermal field were characterized to understand the origin and mixing processes of the geothermal fluids at Gudui.Hydrogen and oxygen isotope plots show both,deep and shallow reservoirs in the Gudui geothermal field.Deep geothermal fluids are the mixing product of magmatic and infiltrating snow-melt water.Calculations show that the magma fluid component of the deep geothermal fluids account for about 21.10%-24.04%;magma fluids lay also be a contributing source of lithium.The linear relationship of the 87Sr/86Sr isotopic ratio versus the 1/Sr plot indicates that shallow geothermal fluids form from the mixing of deep geothermal fluids with cold groundwater.Using a binary mixing model with deep geothermal fluid and cold groundwater as two end-members,the nixing ratios of the latter in most surface hot springs samples were calculated to be between 5% and 10%.Combined with basic geological characteristics,hydrogen and oxygen isotope characteristics,strontium concentration,87Sr/(86)Sr ratios,and the binary mixing model,we infer the 6 th-Class Reservoirs Evolution Conceptual Model(6-CRECM) for the Gudui geothermal system.This model represents an idealized summary of the characteristics of the Gudui geothermal field based on our comprehensive understanding of the origin and mixing processes of the geothermal fluid in Gudui.This study may aid in identifying the geothermal and geochemical origin of the Gudui high-temperature hydrothermal systems in remote Tibet of China,whose potential for geothermal development and utilization is enormous and untapped.
基金Supported by Project of Dongying Geothermal Resources Survey in Tanggu area of Tianjin(Tianjin Land and Housing Task[2008]No.003)
文摘Based on introducing geological structure of Tanggu area, the authors analyzed the sedimentary environment of Paleogene Dongying Formation, and further analyzed its geothermal occurrence. The studied area spans two grade IV tectonic units which are Beitang depression and Banqiao depression. The studied area is mainly located in the Tanggu nose-like structure which is the secondary structure of Beitang depression. Its existence affects the sedimentary distribution of the part strata of Paleogene. The depositions of Dongying Ⅲ （ SQEd3 ） and Dongying Ⅱ （ SQEd2 ） are mainly delta front facies and lake sand bars which are propitious to the geothermal fluid enrichment. The favorable enrichment region of geothermal fluid is located in south Hetou- Tanggu. Most of Dongying Ⅰ （ SQEd1 ） changes into swamp plain deposition, only the northeast part of this area is the distributary riverway facies with developed sand layers. There is the favorable enrichment region of geothermal fluid. The hydraulic connection is weak among the geothermal reservoirs of Dongying Formation and its overlying Guantao and Minghuazhen formations. The underlying Shahejie Formation geothermal reservoir pro- vides a steady stream of fluid supply and ground pressure protection for Dongying Formation geothermal reservoir.
基金financially supported by the National Natural Science Foundation of China (No. 41120124003, 41572335 and 41521001)the research program of China Power Investment Corporation (2015-138-HHS-KJ-X)the research program of State Key Laboratory of Biogeology and Environmental Geology of China
文摘Longling is characterized by a wide distribution of hydrothermal areas, among which the Banglazhang hydrothermal system is the most geothermally active. Banglazhang is marked by intensive hydrothermal activities including hot springs, geysers, fumaroles and hydrothermal explosions. The geothermal waters from the Longling region are mainly HCO3-Na type with low but comparable SO4 and Cl concentrations. Calculations based on a variety of chemical geothermometers and a K-Ca geobarometer indicate that the Banglazhang hydrothermal system has much higher subsurface temperature and CO2 pressure compared to the other systems such as Daheba, Dazhulin and Huangcaoba. However, geothermal water samples collected from all these alternative hydrothermal areas are either partially equilibrated with reservoir minerals or are immature. The silica-enthalpy relationships of Banglazhang geothermal waters indicate the presence of a deep geothermal fluid with an enthalpy value and silica concentration of 945 J/g（up to around 220 °C） and 339 mg/L. Our work indicates the Banglazhang area is a promising source in terms of long-term utilization of hydrothermal resources.
文摘Geothermal fluids are extracted through deep wells drilled in a geological reservoir,which can be represented by highly heterogeneous volcanic complex,sedimentary basins or deep basement rocks.The main objective of this project was to propose suitable methodologies and techniques for the characterization and modeling of fractured geothermal reservoirs,to ensure their sustainable exploitation and,therefore,ensure acceptation of this kind of energy by local communities.
基金supported by the National Natural Science Foundation of China(Grant number:41440027)。
文摘The formation mechanism of high salinity geothermal water is significant for utilizing geothermal resources and mineral resources.The high salinity in geothermal water may be derived from the geothermal mother fluid or from the evaporite dissolution.It is difficult to distinguish between these two sources because they may have similar hydrochemistry.In this paper,water chemistry and stable isotopes were used to explore the high salinity geothermal water in Yanchanghe geothermal field,central China.It is a lowtemperature hydrothermal system in the inland karst area.The thermal water is Cl-Na type with high salinity(TDS>8,400 mg/L).The modified silicon thermometer is more suitable and the reasonable result is about 58.8℃.The maximum circulation depth is 1.9 km.Using the temperature of hot and cold water to estimate the mixing ratio is 58%-81%.Saturation index(SI),Na/1000-K/100-Mg1/2 and Gibbs diagram suggest that the main source of salt in geothermal water is derived from the evaporite dissolution,which provides Cl-of 11,264-31,279 mg/L and Na+of 9,272-21,236 mg/L.We found the combination of temperature and hydrogeochemistry can be used to investigate the formation mechanism and mixing process of high-salinity geothermal water formed in a karst low-temperature hydrothermal system.
