Earth Sciences Commons^™

Genetic Mechanisms Of Low-Temperature Geothermal Water And Its Associated Helium Gas In Meixian County In The Piedmont Of Qinling Mountains, Han Yuanhong, Lyu Jun, Zhang Yuping, Luo Naning, Li Bing, Shen Xiaolong

Coal Geology & Exploration

Meixian County in the piedmont of the Qinling Mountains boasts abundant geothermal water resources with high-abundance associated helium gas. However, the characteristics and origin of geothermal fluids in the study area are yet to be studied. By analyzing the chemical composition and isotopic geochemistry of geothermal fluids and combining the distributions of regional structures and faults, this study delved into the characteristics and genetic mechanisms of geothermal fluids in the study area. The results show that the geothermal water exhibits salinity ranging from 638.96 to 1026.83 mg/L and a hydrochemical type of HCO₃-Na. The low-degree metamorphism suggests that …

Sensitivity Analysis Of Development Parameters On The Production Temperature Of Karst Geothermal Reservoirs: A Case Study Of The Qingfeng Area In Henan, China, Han Yun, Li Kewen, He Jifu, Wang Xinwei, Gao Nan’An

Coal Geology & Exploration

The temperature of produced geothermal water serves as a pivotal indicator influencing the efficiency of geothermal energy utilization, with a higher temperature corresponding to more effective geothermal reservoir exploitation. For karst geothermal reservoirs, recognized as a significant type of geothermal reservoir, the temperature of produced geothermal water is influenced by reservoir parameters. Focusing on the Ordovician karst geothermal reservoirs in the Qingfeng area, Henan Province, this study established a geological model of the reservoirs, followed by numerical simulations based on thermal flow and well-reservoir coupling using the data of seven geothermal wells. The purpose is to explore the effects of …

A Joint Operation Mode Of Multi-Production Wells For Deep Geothermal Water Exploitation, Ping Yu, Li Fang, Ji Wenqing, Yuan Xiaoying, Qi Yufeng, Deng Xiaoying, Wang Xinyi

Coal Geology & Exploration

Deep geothermal water, a type of clean and low-carbon renewable energy, plays a significant role in achieving the goals of peak carbon dioxide emissions and carbon neutrality. However, its irrational exploitation will lead to many problems such as decreased water quantity, lowered water level, and low engineering benefits. Based on the available exploration data of geothermal wells in the urban area of Kaifeng City, Henan Province, this study constructed a hydrogeological model used to characterize the migration of geothermal water and a corresponding mathematical model, which was identified and verified using the Galerkin finite element method. Focusing on geothermal reservoirs …

Evaluating The Exploitation And Utilization Prospects Of Hot Dry Rock In Bohai Bay Basin: Understanding Based On Numerical Simulations For Exploitation Optimization, Jiang Xiaoxue, Zhu Chuanqing, Ding Rui, Xie Fang, Qiu Nansheng

Coal Geology & Exploration

The Bohai Bay Basin, characterized by high terrestrial heat flow, formation temperatures average of 175℃ at a depth of 5000 m, and reservoirs with lithologies dominated by low-porosity and low-permeability metamorphic and igneous rocks, meets the requirements for the formation of hot dry rock (HDR) resources. Based on geothermal parameters such as terrestrial heat flow, rock thermal conductivity, and heat production rate, this study established a three-dimensional HDR exploitation model with thermo-hydro coupling using the COMSOL software. Furthermore, this study analyzed the effects of spacing between production and reinjection wells, reinjection and production rates, and well arrangement mode on the …

Influencing Patterns Of Multiple Factors On The Heat Transfer Performance Of Moderately Deep Geothermal Wells, Han Yongliang, Wang Kaipeng, Wang Yijie, Gou Li, Yang Yanbin, Lei Yanzi, Wu Fangli, Shen Hao

Coal Geology & Exploration

Vigorously promoting the technology for heating using moderately deep geothermal energy serves as an important measure for China’s pursuit of carbon neutrality and peak carbon dioxide emissions. A coaxial double-pipe heat transfer system for moderately deep geothermal wells can avoid damage to groundwater resources and the environment. Furthermore, the influencing factors of the wells exhibit complicated and nonlinear interactions. Based on the theoretical analysis and mathematical description of a moderately deep well with a coaxial double-pipe heat exchanger, this study established a layered heat transfer model for the geothermal well and verified its reliability. This study investigated a moderately deep …

Effects Of Fracture Distribution On Heat Extraction Through Co2-Egs, Zhou Qing, Liao Jianxing, Xu Bin, Yao Liang, Zhou Haoyu, Zhao Quan

Coal Geology & Exploration

Geothermal energy, a promising source of renewable energy, has attracted considerable attention. In deep geothermal reservoirs, complex fracture networks formed by artificial stimulation provide predominant channels for heat extraction. Therefore, the spatial distribution of fractures directly affects the heat extraction efficiency. This study aims to explore the effects of different spatial distributions of fractures on the heat recovery performance. Based on the fracture network following a power-law distribution, this study systematically investigated the effects of the fracture network with different values of fracture length index (a) and density (β) on the heat recovery performance of a …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Major Challenges Of Deep Geothermal Systems And An Innovative Development Mode Of Regs Integrated With Energy Storage, Hou Zhengmeng, Wu Xuning, Luo Jiashun, Zhang Liehui, Li Zaoyuan, Cao Cheng, Wu Lin, Chen Qianjun

Coal Geology & Exploration

China has long been a global leader in the direct utilization of moderate- to low-temperature geothermal energy, in contrast to its sluggish progress in power generation using deep geothermal energy. Rocks in deep reservoirs exhibit decreased permeability under high-temperature and high-pressure conditions, necessitating the establishment of engineered geothermal system (EGS) for the exploitation of deep geothermal energy. In an EGS, hydraulic fracturing is employed for reservoir stimulation to create artificially enhanced geothermal reservoirs with higher permeability. The current techniques for deep geothermal reservoir stimulation are predominantly borrowed from hydraulic fracturing processes employed in the oil and gas sector, placing limitations …

Dating Methods For Travertine And Siliceous Sinter In Geothermal Systems: Progress And Applications, Li Bin, Li Yiman, Pang Zhonghe, Huang Tianming, Gao Binbin

Coal Geology & Exploration

Sinters of geothermal system are usually dominated by travertine and siliceous sinter. With rich information on multi-temporal and spatial scales, they can be used to restore paleohydrological and paleoclimatic histories, reconstruct the evolutionary process of regional hydrothermal activity, and constrain tectonic modes. Accurate dating of sinters is the basis of relevant researches. Common dating methods include radiocarbon dating (based on inorganic and organic carbon), uranium series disequilibrium dating, cosmogenic nuclide dating, optically stimulated luminescence (OSL) dating, and electron spin resonance dating. Radiocarbon dating has primarily used for the dating of hot-spring sinters in China, followed by electron spin resonance dating …

Thermal Conductivity Column Of Rocks And Distribution Characteristics Of Paleo-Geothermal Field In The Songliao Basin, Tang Boning, Qiu Nansheng, Zhu Chuanqing, Chang Jian, Li Xiao, Huang Yue, Yang Junsheng, Fu Xiuli

Coal Geology & Exploration

The paleo-geothermal field of a basin is closely related to the formation and evolution of geothermal, oil, and gas resources. To ascertain the characteristics of the paleo-geothermal field in the Songliao Basin during some critical periods, this study established the thermal conductivity column of rocks in the basin using measurements from 269 samples and compiled previous data. Then, it simulated the burial and thermal histories of multiple wells under the constraint of vitrinite reflectance (R_ran). The results indicate that the thermal conductivity of the Songliao Basin increases with the depth, with increasing rates higher in the upper …

Characteristics And Genetic Mechanism Of Geothermal Reservoirs In The Neogene Guantao Formation, Qikou Sag, Xia Guochao, Lou Da, Zhao Yanting, Wang Hui, Duan Zhongfeng, Sun Xiaolin, Zhang Feipeng, Luo Rong, Ge Jiacheng

Coal Geology & Exploration

The Qikou Sag in the Huanghua Depression, Bohai Bay Basin boasts extremely abundant geothermal resources. Among them, the geothermal reservoirs of the Neogene Guantao Formation have the greatest potential for exploitation. To ascertain the properties of geothermal resources in this formation and rationally exploit these resources, it is significant to investigate the geothermal field, porosity, permeability, geothermal water circulation patterns, and genetic mode of geothermal reservoirs in the formation. Based on data from drilling, geophysical exploration, thermometry, and production of the study area, this study determined that the geothermal reservoirs of the Guantao Formation in the Qikou Sag constitute a …

Hydrochemistry Characteristics And Genesis Mode Of Hot Springs In The Luolou River Basin, Yunnan, China, Luo Huan, Liu Zhennan, Ma Yiqi, Zhang Yunhui, Tao Lanchu, Chen Qingsong, Fu Dunkai, Wu Xiangchuan

Coal Geology & Exploration

The hydrochemistry and genesis mechanism of thermal springs hold great significance for the exploitation and utilization of low to intermediate temperature geothermal resources. Under the influence of a concealed fault zone, thermal springs in the Luolou River basin, Yunnan Province, are distributed along both sides of valleys and exposed in Quaternary loose deposits and Permian basalt strata. It belongs to low to intermediate temperature thermal spring water, with temperatures ranging between 34.5 and 50.0℃, pH is between 7.62-9.73, TDS is between 262-702 mg/L. Based on the hydrochemical and isotopic tests of thermal spring samples and nearby cold water samples from …

Long-Term Operation Performance Of Medium-Deep Borehole Heat Exchangers In The Guanzhong Area, Zhang Zhibin, Ma Zhendi, Hao Jianke, Jia Guosheng, Ke Tingting, Cheng Chonghua, Jin Liwen

Coal Geology & Exploration

Technologies for heating utilizing medium-deep geothermal energy exhibit promising application prospects in the Guanzhong area of China, which boasts abundant geothermal resources. Geological parameters serve as determining factors in the performance of medium-deep borehole heating systems. This study aims to explore the performance of medium-deep borehole heating systems in the Guanzhong area, Shaanxi Province. First, this study analyzed the geological parameters of five typical areas in Guanzhong: Xingping City under the jurisdiction of Xianyang City, Weicheng District of Xianyang, and Gaoling, Huyi, and Chang’an districts of Xi’an City. Then, by combining the typical structural parameters of buried pipes, this study …

Influencing Factor Analysis And Optimization Of Heat Extraction Performance Of Moderately Deep Coaxial Borehole Heat Exchangers In Northern Shaanxi, China, Zou Haijiang, Li Yongpeng, Zhang Lin, Hui Peng, Liu Houning, Shen Fang, Wang Fenghao

Coal Geology & Exploration

The geothermal heating technology utilizing moderately deep coaxial borehole heat exchangers (MDCBHEs) has emerged and found extensive applications in urban heating in northern China. Despite abundant geothermal resources, northern Shaanxi exhibits slightly low geothermal gradients and distinct thermophysical properties of rocks and soils. Therefore, geological parameters influence the heat transfer performance of MDCBHEs in this area. Using OpenGeoSys, an open-source numerical simulation platform, this study established a three-dimensional calculation model for heat transfer between a MDCBHE and surrounding strata. Based on typical geological parameters in northern Shaanxi, the study investigated the influence of various design parameters on the heat transfer …

Statistical Analysis Of The Spatial Distribution And Genesis Of Lithium In Geothermal Water In The Yangbajing-Gulu Rift, Xizang, Chen Yakui, Kong Yanlong, Duan Jiabin, Sun Wenjie, Cheng Yuanzhi

Coal Geology & Exploration

In the Yangbajing-Gulu rift, located in Xizang, the lithium concentration in geothermal water exceeds the average level of thermal springs in Xizang. However, the hydrochemical genesis of lithium in geothermal water in this rift remains controversial, and one primary reason for this is the unclear spatial distribution pattern of lithium. Common methods for analyzing spatial distribution patterns include Ordinary Kriging and CO-Kriging. Nevertheless, the former suffers low precision. For the latter, it is difficult to obtain suitable auxiliary variables. Given this, this study determined two auxiliary variables: (1) the Cl⁻ concentration, a physicochemical parameter exhibiting the strongest correlation with …

Fauna, Flora, And Land Cover Changes Over The Last Two Decades In The Mobile-Tensaw River Delta, Gabriel De Oliveria, Steven R. Schultze, Guilherme Mataveli

Technical Reports

A technical report documenting ecosystem changes to the Mobile-Tensaw River Delta region due to urban expansion over approximately two decades (2001-2019).

A Comparison Of Sediment Accumulation Effectiveness Behind Beaver Dam Analogues, One Rock Dams, And Post-Assisted Log Structures On East Foster Creek, Douglas County, Wa, Griffin Hansen

All Master's Theses

Waterways are valuable resources for communities and habitats, but are subject to degradation in the form of incision. This is a type of streambed erosion where streams narrow and deepen. Sediment control dams were placed on East Foster Creek in Douglas County, WA to control incision following the 2020 Pearl Hill fire. This study examined sediment capture in the ponds behind these dams, which included beaver dam analogues (BDAs), one rock dams (ORDs), and post-assisted log structures (PALS). Sediment capture may be influenced by several factors, including dam type, height, width, distance between dams, vegetation, land use, topography, soil type, …

Enhancing A Computer Model To Evaluate Rainwater Harvesting And Reuse Strategies For Landscape Irrigation Under Current And Future Climate Conditions, Siyu Li

Electronic Theses & Dissertations (2024 - present)

Urbanization and climate change have detrimental impacts on water quantity and quality. Rainwater harvesting/reuse for landscape irrigation with rain barrels/cisterns, which can assist urban hydrological/water quality restoration and provide a beneficial resource for irrigating landscape, holds significant potentials in urban areas under current and future climates. However, the impacts of rainwater harvesting/reuse strategies for landscape irrigation under a changing climate need to be comprehensively evaluated to assist decision-making. In addition, a comprehensive tool is needed to help stakeholders develop efficient strategies to harvest rainwater for landscape irrigation with rain barrels/cisterns.

To address the needs, the simulation of the sub-daily hydrological …

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Critical Links And Development Trends Of Research On Active Tectonics, Yuan Daoyang, Wang Youlin, Li Shuwu, Wang Wanhe, Li Linyuan, Zou Xiaobo, Wen Yameng

Coal Geology & Exploration

Following a brief introduction of the general characteristics of active tectonics in China, this study analyzed two new features of large earthquakes with M_s ≥ 7 that have struck continental China since the beginning of the 21st century: (1) Large earthquakes occur primarily in clusters along the boundary fault zone of the Bayanhar active tectonic block—part of the Qinghai-Tibet ateau active tectonic block. (2) Reverse fault-fold earthquakes have occurred multiple times within active basins or at basin-mountain boundaries. In response to the new seismic activity features and the new demand for disaster prevention and mitigation of engineering construction and …

Activity Variations Of The Shanzuokou-Sihong Fault Within The Jiangsu Segment Of The Tancheng-Lujiang Fault Zone And Their Origins, Zhang Hao, Li Wei, Li Limei, Yan Yunxiang, Jiang Xin, Wang Jinyan, Zhao Qiguang, Gu Qinping, Xu Hangang

Coal Geology & Exploration

The Shanzuokou-Sihong fault, having undergone the entire evolutionary process of the Tancheng-Lujiang fault zone, exhibits segmentation during the latest activity epoch. Determining the location and origin of its activity segmentation will provide a significant reference for exploring the activity variations of its branch faults and their origins. This study investigated the activity of the Shanzuokou-Sihong fault using a three-dimensional approach combining field geological surveys, shallow seismic exploration, and cross-well stratigraphic correlation. The results show that the Shanzuokou-Sihong fault is a Late Pleistocene active fault on the east side of the North Maling Mountain and a Middle Pleistocene fault in Xinyi …

Revealing Fine-Scale Crustal Structure And Tectonic Features In The Xiong’An New Area And Its Periphery Using Deep Seismic Reflection Profiling, Yue Hangyu, Wang Kai, Wang Xiaojiang, Zhang Baowei, Zhang Kai

Coal Geology & Exploration

As an effective method to accurately reveal the deep geological structures and tectonic features of the Earth, deep seismic reflection profiling has been increasingly applied to the exploration of the continental and oceanic crusts, as well as the upper mantle of the lithosphere, making it internationally recognized pioneer technique for deep Earth exploration. This study examined the deep seismic reflection profile spanning across the Xiong’an New Area in Hebei Province, aiming to reveal the crustal structure and tectonic features of the study area. Key findings are as follows: (1) The crust in the study area can be divided into the …

Application Of Integrated Geophysical Surveys In The Identification Of Hidden Fire Sources In Spontaneous Combustion Zones In Coal Seams, Ma Zijun, Yang Haiyan, Li Wenyu, Xu Yunlei, He Yunlan, Liu Zhuoming, Li Peng, Huang Jiu

Coal Geology & Exploration

Spontaneous combustion in coal seams, a factor influencing the development of many mining areas in China, can cause severe coal resource loss and environmental pollution. The positioning and distribution identification of hidden fire sources can provide an important basis for coal mine enterprises to prepare prevention and control measures. They are also a hot research topic and challenge in the field of coal fire disasters. Suitable channels for ventilation and oxygen supply are necessary for spontaneous combustion in coal seams. When the oxidative heat release rate of coals exceeds the heat dissipation rate, coal temperature will rise until the occurrence …

Chromium-Contaminated Sites: Migration Characteristics And Monitoring Using Dual-Frequency Ip Method, Wei Kaiyao, Liu Zhimin, Liang Chen, Zhang Jie, Ma Qiang

Coal Geology & Exploration

Given that the migration process of chromium-contaminated sites is subjected to various uncertainties, it is difficult to investigate the migration characteristics and explore the monitoring process using experiments. Based on the basic law of groundwater flow and the migration mechanisms of pollutants, this study conducted a simulation analysis of the migration characteristics of static chromium contamination sources and the law of changes in the migration characteristics using the COMSOL software. Then, this study verified the reliability and accuracy of numerical forward simulations through physical simulation experiments on a static soil bin. Specifically, using the model of chromium contamination source migration …

Dual-Frequency Transmission Radio Wave-Based Exploration Method And Its Application, Fu Xianjie, Hu Ze'an, Wu Rongxin, Li Peng

Coal Geology & Exploration

Coal seams can act as the guided wave layers of high-frequency electromagnetic waves, and radio wave perspective technology can be used to detect geological structures within coal seams of a working face. Presently, radio wave perspective methods usually use a single frequency, leading to some problems such as improper frequency selection and limited detection accuracy in the exploration of mining faces. In response, this study developed a dual-frequency transmission radio wave-based exploration method. Based on theoretical analysis, as well as the field strength of dual-frequency perspective and attenuation coefficient, this study derived the calculation formula for the absorption factor γ …

The Application Of The Opposing Coils Transient Electromagnetic Method And Microtremor Survey Method In Shallow Karst Detection, Zhang Xueliang, Xie Tao, Zhou Wei, Gao Hui, Deng Dong, Qu Jingyi

Coal Geology & Exploration

Concealed karsts frequently lead to disasters such as ground collapse, water reservoir seepage, and tunnel water inrush. Identifying the distribution and development of karsts in advance holds great significance for guiding engineering design and construction in karst areas. Geophysical methods rank among the most effective methods for karst detection. Given the problems of karst development, limited space, and serious electromagnetic interference in the tank farms of the Longkou Port, Shandong Province, this study explored shallow karsts in these farms through the joint application of the opposing coils transient electromagnetic (OCTEM) method and the microtremor survey method. Firstly, surface scanning was …

Advances In Research On Active Faults And Exploration Of Relevant Frontier Scientific Problems, Xu Xiwei, Li Feng, Cheng Jia, Liu Baojin, Chen Guihua, Li Kang, Ren Junjie, Jia Qichao

Coal Geology & Exploration

This study reviewed the approval and initiation processes and major research contents of China's active fault-related projects, such as the urban active fault survey projects, large-scale mapping programs of active faults, and the earthquake hazard assessment of active faults in key earthquake monitoring and prevention areas. By combining the scientific investigation results of the surface rupture zones induced by strong earthquakes over the past 20 years, this study elaborated on significant advances achieved in the following aspects: the survey and positioning techniques for concealed active faults under strong-noise and weak-signal conditions, the quantitative identification techniques for fault activity, theories and …

Optimization Of Data Acquisition Parameters For Deep Seismic Reflection Surveys In Complex Terrain, Yan Yunxiang, Li Pei, Zhi Min, Liu Jianda, Wang Zichen, Zhang Ying, Pei Gendi, Li Linyuan, Mou Qi, Jia Jin

Coal Geology & Exploration

Fujian, located in the orogen region of the coastal areas of southeast China, exhibits well-developed structures and complex surface conditions, which make deep seismic reflection surveys challenging. In response to the diversity and complexity of seismogeological conditions in Fujian, this study optimized the seismic excitation means based on previous deep seismic surveys. Specifically, the combination of large, medium, and small guns was transitioned into the layout of normal guns (spacing of shot points: 600 m) and large shots (spacing of shot points: 15 km), leading to enhanced folds of large shots. Through simulation analysis, this study calculated the spacing of …

Mechanical Behavior And Failure Response Characteristics Of Hard Sandstones Considering Bedding Dip Angles, Song Zhanping, Liu Hongke, Zheng Fang, Cheng Yun, Sun Yinhao, Song Wanxue

Coal Geology & Exploration

This study focuses on the mechanical behavior and failure responses of hard sandstones considering bedding dip angles. Through uniaxial compression tests of hard sandstones with different bedding dip angles, this study delved into the influence of bedding dip angles on the mechanical behavior of hard sandstones and the relationship between the bedding dip angles and fractal characteristics of hard sandstone fragments. The test results show that bedding dip angles produced negligible effects on the type of the stress-strain curves of hard sandstones. However, low dip angles (0°, 22.5°, and 45°) corresponded to unimodal curves, while high dip angles (67.5° and …