Global energy structure is experiencing the third transition from fossil energy to non-fossil energy,to solve future energy problems,cope with climate change,and achieve net-zero emissions targets by 2050.Hydrogen is ...Global energy structure is experiencing the third transition from fossil energy to non-fossil energy,to solve future energy problems,cope with climate change,and achieve net-zero emissions targets by 2050.Hydrogen is considered to be the most potential clean energy in this century under the background of carbon neutrality.At present,the industrial methods for producing hydrogen are mainly by steam-hydrocarbon(such as coal and natural gas)reforming and by electrolysis of water,while the exploration and development of natural hydrogen had just started.According to this literature review:(1)Natural hydrogen can be divided into three categories,including free hydrogen,hydrogen in inclusions and dissolved hydrogen;(2)natural hydrogen could be mainly from abiotic origins such as by deep-seated hydrogen generation,water-rock reaction or water radiolysis;(3)natural hydrogen is widely distributed and presents great potential,and the potential natural hydrogen sources excluding deep source of hydrogen is about(254±91)×10^(9) m^(3)/a according to a latest estimate;(4)at present,natural hydrogen has been mined in Mali,and the exploration and development of natural hydrogen has also been carried out in Australia,Brazil,the United States and some European countries,to find many favorable areas and test some technical methods for natural hydrogen exploration.Natural hydrogen is expected to be an important part of hydrogen energy production in the future energy pattern.Based on a thorough literature review,this study introduced the origin,classification,and global discovery of natural hydrogen,as well as summarized the current global status and discussed the possibility of natural hydrogen exploration and development,aiming to provide reference for the future natural hydrogen exploration and development.展开更多
Hot dry rock(HDR)is a kind of clean energy with significant potential.Since the 1970s,the United States,Japan,France,Australia,and other countries have attempted to conduct several HDR development research projects to...Hot dry rock(HDR)is a kind of clean energy with significant potential.Since the 1970s,the United States,Japan,France,Australia,and other countries have attempted to conduct several HDR development research projects to extract thermal energy by breaking through key technologies.However,up to now,the development of HDR is still in the research,development,and demonstration stage.An HDR exploration borehole(with 236℃ at a depth of 3705 m)was drilled into Triassic granite in the Gonghe Basin in northwest China in 2017.Subsequently,China Geological Survey(CGS)launched the HDR resources exploration and production demonstration project in 2019.After three years of efforts,a sequence of significant technological breakthroughs have been made,including the genetic model of deep heat sources,directional drilling and well completion in high-temperature hard rock,large-scale reservoir stimulation,reservoir characterization,and productivity evaluation,reservoir connectivity and flow circulation,efficient thermoelectric conversion,monitoring,and geological risk assessment,etc.Then the whole-process technological system for HDR exploration and production has been preliminarily established accordingly.The first power generation test was completed in November 2021.The results of this project will provide scientific support for HDR development and utilization in the future.展开更多
Over the past decade,energy-related carbon dioxide(CO_(2))emissions have steadily increased worldwide,reaching 33.4 billion tons in 2019.Most climate scenarios suggest that carbon capture,utilization,and storage(CCUS)...Over the past decade,energy-related carbon dioxide(CO_(2))emissions have steadily increased worldwide,reaching 33.4 billion tons in 2019.Most climate scenarios suggest that carbon capture,utilization,and storage(CCUS)is critical for the reduction of direct CO_(2)emissions from industrial processes and the use of fossil fuels in power generation,industrial activities,and fuel conversion.Consequently.展开更多
The Hot Dry Rock(HDR)is considered as a clean and renewable energy,poised to significantly contribute to the global energy decarbonization agenda.Many HDR projects worldwide have accumulated valuable experience in eff...The Hot Dry Rock(HDR)is considered as a clean and renewable energy,poised to significantly contribute to the global energy decarbonization agenda.Many HDR projects worldwide have accumulated valuable experience in efficient drilling and completion,reservoir construction,and fracture simulation.In 2019,China Geological Survey(CGS)initiated a demonstration project of HDR exploration and production in the Gonghe Basin,aiming to overcome the setbacks faced by HDR projects.Over the ensuing four years,the Gonghe HDR project achieved the first power generation in 2021,followed by the second power generation test in 2022.After establishing the primary well group in the initial phase,two directional wells and one branch well were drilled.Noteworthy progress was made in successfully constructing the targeted reservoir,realizing inter-well connectivity,power generation and grid connection,implementing of the real-time micro-seismic monitoring.A closed-loop technical validation of the HDR exploration and production was completed.However,many technical challenges remain in the process of HDR industrialization,such as reservoir fracture network characterization,efficient drilling and completion,multiple fracturing treatment,continuous injection and production,as well as mitigation of induced seismicity and numerical simulation technology.展开更多
It is well known that during CO2 geological storage, density-driven convective activity can significantly accelerate the dissolution of injected CO2 into water. This action could limit the escape of supercritical CO2 ...It is well known that during CO2 geological storage, density-driven convective activity can significantly accelerate the dissolution of injected CO2 into water. This action could limit the escape of supercritical CO2 from the storage formation through vertical pathways such as fractures, faults and abandoned wells, consequently increasing permanence and security of storage. First, we investigated the effect of numerical perturbation caused by time and grid resolution and the convergence criteria on the dissolution-diffusion-convection （DDC） process. Then, using the model with appropriate spatial and temporal resolution, some uncertainty parameters investigated in our previous paper such as initial gas saturation and model boundaries, and other factors such as relative liquid permeability and porosity modification were used to examine their effects on the DDC process. Finally, we compared the effect of 2D and 3D models on the simulation of the DDC process. The above modeling results should contribute to clear understanding and accurate simulation of the DDC process, especially the onset of convective activity, and the CO2 dissolution rate during the convection-dominated stage.展开更多
Large-scale exploration and development of shale gas in Lower Cambrian Niutitang Formation of South China has been carried out in recent years,but the result is not good,only except some drilling wells in Jingyan-Qian...Large-scale exploration and development of shale gas in Lower Cambrian Niutitang Formation of South China has been carried out in recent years,but the result is not good,only except some drilling wells in Jingyan-Qianwei area of Sichuan Basin and Yichang of Hubei obtain some commercial gas flows.In order to clarify reasons for failure of shale gas exploration and development in Niutitang Formation around Sichuan Basin and to provide reservoir geological parameters for subsequent efficient exploration and development,taking a case of shale gas reservoirs in Lower Cambrian Niutitang Formation in northeast Chongqing around Sichuan Basin,some experimental methods,such as analysis of organic carbon pyrolysis,determination of equivalent vitrinite reflectance,focused ion beam scanning electron microscope(FIB-SEM)and other are adopted in this study.The results show that the average TOC of shale samples in Niutitang Formation in northeast Chongqing is 3.1%,the equivalent vitrinite reflectance ranges from 3.0%to 4.0%,and the degree of thermal evolution reaches the post-matureemetamorphic stage.Due to excessively high degree of the thermal evolution,organic pores in shale samples are not developed in Lower Cambrian Niutitang Formation in the study area,instead,micro-nano pores dominated by intergranular pores and intragranular pores are developed in the shale.The degree of the thermal evolution controls the sustaining gas generation of kerogen and retained liquid hydrocarbons in the shale,it also controls the development of organic pores of the shale.The evolution of organic pores and hydrocarbon generation in the shale of Niutitang Formation in northeast Chongqing around Sichuan Basin do not match best with each other,that is,during development period of a large number of organic pores,thermal evolution degree of reservoirs is further enhanced because the strata are not uplifted in time,therefore,the quantity of organic pores is decreased sharply,the shale gas would be escaped due to the absence of organic pores as effective storage space after the shale gas generation.Therefore,the efficient exploration and development of the shale gas in Lower Cambrian Niutitang Formation in South China should be focused on the shale development area where the shale is characterized by moderate thermal evolution degree(2.0%<R_(o)<3.0%)and shallow buried depth,that is,the shale distribution area with paleo-uplift or paleo-buried hill.展开更多
基金funded by the projects initiated by the China Geological Survey(DD20221794 and DD20190414).
文摘Global energy structure is experiencing the third transition from fossil energy to non-fossil energy,to solve future energy problems,cope with climate change,and achieve net-zero emissions targets by 2050.Hydrogen is considered to be the most potential clean energy in this century under the background of carbon neutrality.At present,the industrial methods for producing hydrogen are mainly by steam-hydrocarbon(such as coal and natural gas)reforming and by electrolysis of water,while the exploration and development of natural hydrogen had just started.According to this literature review:(1)Natural hydrogen can be divided into three categories,including free hydrogen,hydrogen in inclusions and dissolved hydrogen;(2)natural hydrogen could be mainly from abiotic origins such as by deep-seated hydrogen generation,water-rock reaction or water radiolysis;(3)natural hydrogen is widely distributed and presents great potential,and the potential natural hydrogen sources excluding deep source of hydrogen is about(254±91)×10^(9) m^(3)/a according to a latest estimate;(4)at present,natural hydrogen has been mined in Mali,and the exploration and development of natural hydrogen has also been carried out in Australia,Brazil,the United States and some European countries,to find many favorable areas and test some technical methods for natural hydrogen exploration.Natural hydrogen is expected to be an important part of hydrogen energy production in the future energy pattern.Based on a thorough literature review,this study introduced the origin,classification,and global discovery of natural hydrogen,as well as summarized the current global status and discussed the possibility of natural hydrogen exploration and development,aiming to provide reference for the future natural hydrogen exploration and development.
基金funded by the“Hot Dry Rock Resources Exploration and Production Demonstration Project”of the China Geological Survey(DD20190131,DD20190135,DD20211336).
文摘Hot dry rock(HDR)is a kind of clean energy with significant potential.Since the 1970s,the United States,Japan,France,Australia,and other countries have attempted to conduct several HDR development research projects to extract thermal energy by breaking through key technologies.However,up to now,the development of HDR is still in the research,development,and demonstration stage.An HDR exploration borehole(with 236℃ at a depth of 3705 m)was drilled into Triassic granite in the Gonghe Basin in northwest China in 2017.Subsequently,China Geological Survey(CGS)launched the HDR resources exploration and production demonstration project in 2019.After three years of efforts,a sequence of significant technological breakthroughs have been made,including the genetic model of deep heat sources,directional drilling and well completion in high-temperature hard rock,large-scale reservoir stimulation,reservoir characterization,and productivity evaluation,reservoir connectivity and flow circulation,efficient thermoelectric conversion,monitoring,and geological risk assessment,etc.Then the whole-process technological system for HDR exploration and production has been preliminarily established accordingly.The first power generation test was completed in November 2021.The results of this project will provide scientific support for HDR development and utilization in the future.
基金Supported by the projects of Geoscience Literature Knowledge Service and Decision Support(DD20230139)Natural Resource Information Tracking and Research(DD20221794).
文摘Over the past decade,energy-related carbon dioxide(CO_(2))emissions have steadily increased worldwide,reaching 33.4 billion tons in 2019.Most climate scenarios suggest that carbon capture,utilization,and storage(CCUS)is critical for the reduction of direct CO_(2)emissions from industrial processes and the use of fossil fuels in power generation,industrial activities,and fuel conversion.Consequently.
基金Funded by the“Investigation and Evaluation of the Hot Dry Rock Resources in the Guide-Dalianhai Area of the Gonghe Basin,Qinghai”(DD20211336,DD20211337,DD20211338)“Hot Dry Rock Resources Exploration and Production Demonstration Project”(DD20230018)of the China Geological Survey。
文摘The Hot Dry Rock(HDR)is considered as a clean and renewable energy,poised to significantly contribute to the global energy decarbonization agenda.Many HDR projects worldwide have accumulated valuable experience in efficient drilling and completion,reservoir construction,and fracture simulation.In 2019,China Geological Survey(CGS)initiated a demonstration project of HDR exploration and production in the Gonghe Basin,aiming to overcome the setbacks faced by HDR projects.Over the ensuing four years,the Gonghe HDR project achieved the first power generation in 2021,followed by the second power generation test in 2022.After establishing the primary well group in the initial phase,two directional wells and one branch well were drilled.Noteworthy progress was made in successfully constructing the targeted reservoir,realizing inter-well connectivity,power generation and grid connection,implementing of the real-time micro-seismic monitoring.A closed-loop technical validation of the HDR exploration and production was completed.However,many technical challenges remain in the process of HDR industrialization,such as reservoir fracture network characterization,efficient drilling and completion,multiple fracturing treatment,continuous injection and production,as well as mitigation of induced seismicity and numerical simulation technology.
基金This work was supported by the National Natural Science Foundation of China （Grant No. 40872158）, China Geological Survey Project （Grant Nos. 1212011220914 and 1212011220794）, and Librarian＇s Project of National Geological Library of China （Grant No. GZ201203）.
文摘It is well known that during CO2 geological storage, density-driven convective activity can significantly accelerate the dissolution of injected CO2 into water. This action could limit the escape of supercritical CO2 from the storage formation through vertical pathways such as fractures, faults and abandoned wells, consequently increasing permanence and security of storage. First, we investigated the effect of numerical perturbation caused by time and grid resolution and the convergence criteria on the dissolution-diffusion-convection （DDC） process. Then, using the model with appropriate spatial and temporal resolution, some uncertainty parameters investigated in our previous paper such as initial gas saturation and model boundaries, and other factors such as relative liquid permeability and porosity modification were used to examine their effects on the DDC process. Finally, we compared the effect of 2D and 3D models on the simulation of the DDC process. The above modeling results should contribute to clear understanding and accurate simulation of the DDC process, especially the onset of convective activity, and the CO2 dissolution rate during the convection-dominated stage.
基金The work was supported by the Geological Information Comprehensive Research Project of China Geological Survey(No.121201015000150002)Basic Geological Survey Project of Shale Gas in South China of China Geological Survey(No.12120114046701).
文摘Large-scale exploration and development of shale gas in Lower Cambrian Niutitang Formation of South China has been carried out in recent years,but the result is not good,only except some drilling wells in Jingyan-Qianwei area of Sichuan Basin and Yichang of Hubei obtain some commercial gas flows.In order to clarify reasons for failure of shale gas exploration and development in Niutitang Formation around Sichuan Basin and to provide reservoir geological parameters for subsequent efficient exploration and development,taking a case of shale gas reservoirs in Lower Cambrian Niutitang Formation in northeast Chongqing around Sichuan Basin,some experimental methods,such as analysis of organic carbon pyrolysis,determination of equivalent vitrinite reflectance,focused ion beam scanning electron microscope(FIB-SEM)and other are adopted in this study.The results show that the average TOC of shale samples in Niutitang Formation in northeast Chongqing is 3.1%,the equivalent vitrinite reflectance ranges from 3.0%to 4.0%,and the degree of thermal evolution reaches the post-matureemetamorphic stage.Due to excessively high degree of the thermal evolution,organic pores in shale samples are not developed in Lower Cambrian Niutitang Formation in the study area,instead,micro-nano pores dominated by intergranular pores and intragranular pores are developed in the shale.The degree of the thermal evolution controls the sustaining gas generation of kerogen and retained liquid hydrocarbons in the shale,it also controls the development of organic pores of the shale.The evolution of organic pores and hydrocarbon generation in the shale of Niutitang Formation in northeast Chongqing around Sichuan Basin do not match best with each other,that is,during development period of a large number of organic pores,thermal evolution degree of reservoirs is further enhanced because the strata are not uplifted in time,therefore,the quantity of organic pores is decreased sharply,the shale gas would be escaped due to the absence of organic pores as effective storage space after the shale gas generation.Therefore,the efficient exploration and development of the shale gas in Lower Cambrian Niutitang Formation in South China should be focused on the shale development area where the shale is characterized by moderate thermal evolution degree(2.0%<R_(o)<3.0%)and shallow buried depth,that is,the shale distribution area with paleo-uplift or paleo-buried hill.
