检索结果-南通市图书馆

Simulation of dilatancy-controlled Gas migration processes in saturated bentonite using a coupled multiphase flow and elastoplastic H2 M model

引用

Journal of Rock Mechanics and Geotechnical Engineering 2023年第4期15卷 803-813页

作者： Eike Radeisen Hua Shao Jürgen Hesser Olaf Kolditz Wenjie Xu Wenqing Wang Department of Rock Characterization for Storage and Final Disposal Federal Institute for Geosciences and Natural Resources(BGR)Hannover30655Germany Department of Environmental Informatics Helmholtz Center for Environmental Research(UFZ)Leipzig04341Germany Department of Applied Environmental Systems Analysis Technische Universität DresdenDresden01069Germany Department of Civil Engineering and Architecture Zhejiang UniversityHangzhou310058China

Dilatancy-controlled gas flow in preferential pathways plays a key role in the safety analysis of radioactive waste repositories.This is particularly the case for bentonite,an often-preferred barrier material.gas flow in preferential pathways is characterized by localization and spontaneous behavior,which is challenging to simulate in numerical models due to strong hydro-mechanical coupling.To analyze a laboratory experiment in the framework of the DECOVALEX-2023 project,this study introduced a new approach of combining continuous modelling methods with spatial material properties derived from material heterogeneities and experimental observations.The proposed model utilized hydro-mechanical spatial distributions,namely Young’s modulus and gas entry pressure,and elastoplasticity combined with a linear swelling model.A conceptual strain-dependent permeability approach simulated dilatancycontrolled gas flow based on hydro-mechanical coupling.To test the effectiveness of the presented approach,a gas injection test in a compacted,saturated bentonite sample was simulated using the opensource code OpenGeoSys 5.8 and compared with experimental observations.The presented methodology is capable of simulating localized gas flow in preferential pathways.The spatial distributions of Young’s modulus and gas entry pressure affect the swelling pressure,relative permeability and,in combination with the strain-dependent permeability model,also the intrinsic permeability.

关键词： H^(2)M coupling Gas migration Dilatancy-controlled flow Continuous approach Geomaterial heterogeneity OpenGeoSys

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Saturated hydraulic conductivity of compacted bentonite-sand mixtures before and after Gas migration in artificial seawater

引用

Journal of Rock Mechanics and Geotechnical Engineering 2023年第1期15卷 216-226页

作者： Yasutaka Watanabe Shingo Yokoyama Misato Shimbashi Yoichi Yamamoto Takahiro Goto Sustainable System Research Laboratory Central Research Institute of Electric Power IndustryChibaJapan Science and Technology Department Nuclear Waste Management Organization of JapanTokyoJapan

To understand the self-healing property of an engineered barrier for radioactive waste disposal,the hydraulic conductivity of compacted bentoniteesand mixtures saturated with artificial seawater(SW)before and after Gas migration was examined.Na-and Ca-bentonites were mixed with fine sand at a ratio of 70%bentonite in dry weight.Two aspects were considered during the experiment:the hydraulic conductivity of the specimen that was resaturated after Gas migration and the distribution of water content immediately after Gas migration to study Gas migration pathways.The gas migrated through the entire cross-section of the specimen,and gas breakthrough occurred in the equilibrium swelling pressure range approximately.Subsequently,the gas flow rate reached a sufficient large value when the gas pressure was approximately twice the equilibrium axial pressure(the sum of swelling and confining pressures),which excluded the back pressure.Although the Gas migration pathway was not visible when the specimen was observed immediately after Gas migration,the water content distribution showed that several parts of the specimen with lower water content were connected in the direction of Gas migration.After resaturation,the change in permeability was within a limited rangedtwo to three times larger than that before Gas migration for each type of bentonite in SW.This slight change suggests that Gas migration creates a pore structure that cannot be sealed via crystalline swelling of montmorillonite in SW,even if highly compacted bentonite is used under a constant-volume condition.

关键词： Bentonite Gas migration Hydraulic conductivity Seawater(SW) Self-healing

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Numerical simulation of Gas migration into mining-induced fracture network in the goaf

引用

International Journal of Mining Science and Technology 2017年第4期27卷 681-685页

作者： Cao Jie Li Wenpu State Key Laboratory of gas Disaster Detection Prevention and Emergency Control. Chongqing 400037. China Chongqing Research Institute Co. Ltd. of China Coal Technology and Engineering Group Chongqing 400037 China State Key Laboratory of Coal Mine Disaster Dynamics and Control. Chongqing University. Chongqing 400044 China

gas extraction practice has been proven for the clear majority of coal mines in China to be unfavorable using drill holes in the coal seam. Rather, mining-induced fractures in the goaf should be utilized for gas extraction. To study Gas migration in mining-induced fractures, one mining face of 10 th Mine in Pingdingshan Coalmine Group in Henan, China, has been selected as the case study for this work. By establishing the mathematical model of Gas migration under the influence of coal seam mining, discrete element software UDEC and Multiphysics software COMSOL are employed to model Gas migration in mining-induced fractures above the goaf. The results show that as the working face advances, the goaf overburden gradually forms a mining-induced fracture network in the shape of a trapezoid, the size of which increases with the distance of coal face advance. Compared with Gas migration in the overburden matrix, the gas flow in the fracture network due to mining is far greater. The largest mining-induced fracture is located at the upper end of the trapezoidal zone, which results in the largest gas flux in the network. When drilling for gas extraction in a mining-induced fracture field, the gas concentration is reduced in the whole region during the process of gas drainage, and the rate of gas concentration drops faster in the fractured zone. It is shown that with gas drainage, the gas flow velocity in the mininginduced fracture network is faster.

关键词： Gas migration Fractures Mining-induced Numerical simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Stress-unloading and Gas migration improvement mechanism in the soft and hard interbedded coal seam using directional hydraulic flushing technology

引用

International Journal of Mining Science and Technology 2023年第9期33卷 1165-1179页

作者： Hao Zhang Yuanping Cheng Cunbao Deng Jingyu Jiang Lei Zhang Xiaoyu Yan Junwei Guo Suifang Wang College of Safety&Emergency Management Engineering Taiyuan University of TechnologyTaiyuan 030024China Datong Coal Mine Group Co. LtdDatong 037037China Key Laboratory of Coal Methane and Fire Control Ministry of EducationChina University of Mining and TechnologyXuzhou 221116China National Engineering Research Center for Coal and gas Control China University of Mining and TechnologyXuzhou 221116China School of Safety Engineering China University of Mining and TechnologyXuzhou 221116China

To enhance gas drainage in the soft and hard interbedded(SHI)coal seam,it’s necessary to unload the insitu stress and improve its Gas migration performance.In this research,a directional hydraulic flushing(DHF)technology was carried out.The stress-unloading and Gas migration improvement mechanism was analyzed through numerical simulation,and systematic engineering tests were conducted to verify the gas drainage effect.The results show that the improvement of Gas migration performance in the SHI coal seam is caused by a combined effect of seepage-improving and diffusion-improving.After DHF,stress-unloading and plastic failure could be achieved both in the soft coal(SC)sublayer and in the hard coal(HC)sublayer.However,the gas diffusion capacity improves significantly in the SC sublayer,while the gas seepage capacity improves notably in the HC sublayer.Meanwhile,the stress-unloading and Gas migration improvement effect improves with the flushing radius and the thickness of the SC sublayer.Besides,after adopting the DHF technology,the gas drainage effect improved markedly.The borehole number dropped by 49%,the gas drainage ratio increased from 26.0%to 48.2%,and the average coal roadway excavation speed increased from 2.4 to 5.6 m/d.

关键词： Hydraulic flushing Stress-unloading Plastic failure Permeability-increasing Gas migration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The hydrogenmigration in cryogenic tubes of superconductive accelerator with gas source

引用

Radiation Detection Technology and Methods 2019年第2期3卷 8-14页

作者： Chuanfei Hu Feng Bai Wanhong Guo Yukui Yin Yugang Zhao Junhui Zhang University of Chinese Academy of Sciences BeijingChina Institute of Modern Physics Chinese Academy of SciencesLanzhouChina

Background In superconductive linear accelerator,the performance and stability can be impacted by gas adsorbed on cryogenic surfaces adversely.The cryogenic devices usually work at 4.2 K or 1.9 K and are refrigerated by normal or super fluid liquid helium,respectively.Purpose The purpose of this paper is to study the character of Gas migration in cryogenic tubes.Method Adsorption coefficient for hydrogen at 4.2 K is measured by experimental study.Then,a Gas migration model is established based on the experimental results to depict the hydrogen migration process in cryogenic tubes.Results The experimental results and model analysis indicated that at cryogenic temperature(4.2 K),adsorption coefficient for hydrogen is very close to 1,which is several orders higher than the adsorption coefficient at room temperature,resulting in a unique pressure distribution pattern in cryogenic tubes when compared with the pressure distribution in room temperature tubes.Conclusions At 4.2 K or 1.9 K,the Gas migration process is obviously different from the process at room temperature and is significantly affected by the gas adsorption on the cryogenic surfaces.The model established in this article can be applied not only to hydrogen migration in cryogenic tubes but also to other Gas migration in tubes with high adsorption coefficient.

关键词： Vacuum Cryogenic Gas migration Superconductive accelerator

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Complex genesis of multiperiod fractures in the Middle Triassic Leikoupo Formation in the Pengzhou gas field, western Sichuan Basin, China

引用

Petroleum Science 2023年第1期20卷 161-176页

作者： Xiao-Fei Hu Hu-Cheng Deng Jian-Hua He Zhong-Min Shen Xian-Feng Peng College of Energy Chengdu University of TechnologyChengduSichuan 610059China State Key Laboratory of Oil and gas Reservoir Geology and Exploitation(Chengdu University of Technology) ChengduSichuan 610059China

The cumulative expression of multistage deformation is complex multiperiod fractures,which are commonly seen in tectonic zones.The Middle Triassic Leikoupo Formation in the western Sichuan Basin Depression,China,is a typical marine carbonate reservoir with natural fractures caused mainly by tectonic movements.According to outcrops,drill cores,image logging,and fluid inclusions,the fracture characteristics,types of natural fractures,and interactions of fractures are determined.In total,419 natural fractures in 493.2 m of cores from 7 wells are investigated,which are mainly shear and tensile fractures with a small number of weathering generated fractures.Meanwhile,the results of the stable isotope analysis of δ13C and δ18O,as well as the flow fluid inclusion data,reveal four tectonic periods of fractures with different occurrences.Based on the history of regional tectonic evolution,indicating one period of weathering fractures ascribable to stratal uplift and three periods of structural fractures related to the sequential tectonic movements of the Longmenshan fault belt.By analyzing the interaction relationships of fractures,three types of fracture interaction relationships are observed:cutting,restraining,and overlapping.The four stages fractures are chronologically assigned to(1)the early Indosinian N-S trending compression,(2)the late Indosinian NW-SE compression,(3)the middle Yanshanian NE-SE compression,and(4)the early Himalayan E-W compression.The influence of natural fractures on Gas migration and well production in marine carbonates is discussed,and indicates that tectonic fractures could provide seepage channels for Gas migration and accumulation from near or distant hydrocarbon source rocks into the Middle Triassic Leikoupo Formation.This study utilizes a pragmatic approach for understanding the fracture genesis mechanism in oil and gas field with multiperiod fractures.

关键词： Multiperiod fractures Interaction relationships Genesis mechanism Gas migration Leikoupo formation Sichuan basin

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Experiment and analysis of the formation,expansion and dissipation of gasbag in fine sediments based on pore water pressure survey

引用

Acta Oceanologica Sinica 2022年第4期41卷 91-100页

作者： Shiyun Lei Xiujun Guo Haoru Tang College of Environmental Science and Engineering Ocean University of ChinaQingdao 266100China Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering Ocean University of ChinaQingdao 266100China Key Lab of Marine Environment and Ecology of Ministry of Education Ocean University of ChinaQingdao 266100China

Deep-seated gas in seabed sediments migrates upwards from effect of external factors,which easily accumulates to form gasbags at interface of shallow coarse-fine sediments.Real-time monitoring of this process is important to predict disaster.However,there is still a lack of effective monitoring methods,so we attempt to apply multi-points pore water pressure monitoring technology when simulating forming and dissipation of gasbags in sediments through laboratory experiment.This study focuses on discussion of sensitivity of pore water pressure monitoring data,as well as typical changing characteristics and mechanisms of excess pore water pressure corresponding to crack generation,gasbag formation and gas release.It was found that the value of excess pore water pressure in sediments is negatively correlated with vertical distance between sensors and gas source,and the evolution of gasbag forming and dissipation has a good corresponding relationship with the change of excess pore water pressure.gasbag formation process is divided into three stages:transverse crack development,longitudinal cavity expansion,and oblique crack development.Formation of gasbag begins with the transverse crack at the interface of coarse-fine sediments while excess pore water pressure attenuates rapidly and then drops,pressure remains almost unchanged when cavity expanses longitudinally,oblique crack appeared in final stage of gasbag evolution while excess pore water pressure accumulated and dissipated again.The variation curve of excess pore water pressure in gas release stage has saw-tooth fluctuation characteristics,and the value and time of pressure accumulation are also fluctuating,indicating the uncertainty and non-uniqueness of Gas migration channels in sediments.

关键词： pore water pressure monitoring technology excess pore water pressure gasbag cracks Gas migration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Thermo-hydro-mechanical behavior of clay rock for deep geological disposal of high-level radioactive waste

引用

Journal of Rock Mechanics and Geotechnical Engineering 2018年第5期10卷 992-1008页

作者： Chun-Liang Zhang Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) Repository Safety Research Division Theodor-Heuss-Str 4 Braunschweig 38122 Germany

In the context of deep geological disposal of radioactive waste in clay formations, the thermo-hydro- mechanical （THM） behavior of the indurated Callovo-Oxfordian and Opalinus clay rocks has been extensively investigated in our laboratory under repository relevant conditions：（1） rock stress covering the range from the lithostatic state to redistributed levels after excavation; （2） variation of the humidity in the openings due to ventilation as well as hydraulic drained and undrained boundary conditions; （3） gas generation from corrosion of metallic components within repositories; and （4） thermal loading from high-level radioactive waste up to the designed maximum temperature of 90 ~C and even beyond to 150 ~C, Various important aspects concerning the long-term barrier functions of the clay host rocks have been studied：（1） fundamental concept for effective stress in the porous clay-water system; （2） stress- driven deformation and damage as well as resulting permeability changes; （3） moisture influences on mechanical properties; （4） self-sealing of fractures under mechanical load and swelling]slaking of clay minerals upon water uptake; （5） Gas migration in fractured and resealed claystones; and （6） thermal impact on the hydro-mechanical behavior and properties, Major findings from the investigations are summarized in this paper,

关键词： Repository Clay rock Deformability Swelling Self-sealing Water permeability Gas migration Thermal impact

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Calculation analysis of sustained casing pressure in gas wells

引用

Petroleum Science 2012年第1期9卷 66-74页

作者： Zhu Hongjun Lin Yuanhua Zeng Dezhi Zhang Deping Wang Feng State Key Laboratory of Oil and gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengduSichuan 610500China Jilin Field Company PetroChinaSongyuanJilin 138000China

Sustained casing pressure （SCP） in gas wells brings a serious threat to worker safety and environmental protection. According to geological conditions, wellbore structure and cement data of gas wells in the Sichuan-Chongqing region, China, the position, time, environmental condition and the value of SCP have been analyzed. On this basis, the shape of the pressure bleed-down plot and pressure buildup plot were diagnosed and the mechanism of SCP has been clarified. Based on generalized annular Darcy percolation theory and gas-liquid two-phase fluid dynamics theory, a coupled mathematical model of Gas migration in a cemented annulus with a mud column above the cement has been developed. The volume of gas migrated in the annulus and the value of SCP changing with time in a gas well in Sichuan have been calculated by this model. Calculation results coincided well with the actual field data, which provide some reference for the following security evaluation and solution measures of SCP.

关键词： Sustained casing pressure Gas migration coupled mathematic model gas well

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：