Deep Underground Science and Engineering最新文献

筛选

英文中文

Gas migration at the granite–bentonite interface under semirigid boundary conditions in the context of high‐level radioactive waste disposal 高放射性废物处置背景下半刚性边界条件下花岗岩-膨润土界面的气体迁移

Deep Underground Science and Engineering Pub Date : 2024-07-23 DOI: 10.1002/dug2.12118

Jiangfeng Liu, Zhipeng Wang, Jingna Guo, A. Jivkov, Majid Sedighi, Jianfu Shao

{"title":"Gas migration at the granite–bentonite interface under semirigid boundary conditions in the context of high‐level radioactive waste disposal","authors":"Jiangfeng Liu, Zhipeng Wang, Jingna Guo, A. Jivkov, Majid Sedighi, Jianfu Shao","doi":"10.1002/dug2.12118","DOIUrl":"https://doi.org/10.1002/dug2.12118","url":null,"abstract":"The corrosion of waste canisters in the deep geological disposal facilities (GDFs) for high‐level radioactive waste (HLRW) can generate gas, which escapes from the engineered barrier system through the interfaces between the bentonite buffer blocks and the host rock and those between the bentonite blocks. In this study, a series of water infiltration and gas breakthrough experiments were conducted on granite and on granite–bentonite specimens with smooth and grooved interfaces. On this basis, this study presents new insights and a quantitative assessment of the impact of the interface between clay and host rock on gas transport. As the results show, the water permeability values from water infiltration tests on granite and granite–bentonite samples (10−19–10−20 m2) are found to be slightly higher than that of bentonite. The gas permeability of the mock‐up samples with smooth interfaces is one order of magnitude larger than that of the mock‐up with grooved interfaces. The gas results of breakthrough pressures for the granite and the granite–bentonite mock‐up samples are significantly lower than that of bentonite. The results highlight the potential existence of preferential gas migration channels between the rock and bentonite buffer that require further considerations in safety assessment.","PeriodicalId":505870,"journal":{"name":"Deep Underground Science and Engineering","volume":"32 23","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141814000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

In situ loading of a pore network model for quantitative characterization and visualization of gas seepage in coal rocks 原位加载孔隙网络模型，实现煤岩瓦斯渗流的定量表征和可视化

Deep Underground Science and Engineering Pub Date : 2024-07-18 DOI: 10.1002/dug2.12114

Hua-zhe Jiao, Xi Chen, Tiegang Zhang, Quilligan Michael, Yixuan Yang, Xiaolin Yang, Tongyi Yang

{"title":"In situ loading of a pore network model for quantitative characterization and visualization of gas seepage in coal rocks","authors":"Hua-zhe Jiao, Xi Chen, Tiegang Zhang, Quilligan Michael, Yixuan Yang, Xiaolin Yang, Tongyi Yang","doi":"10.1002/dug2.12114","DOIUrl":"https://doi.org/10.1002/dug2.12114","url":null,"abstract":"The flow characteristics of coalbed methane (CBM) are influenced by the coal rock fracture network, which serves as the primary gas transport channel. This has a significant effect on the permeability performance of coal reservoirs. In any case, the traditional techniques of coal rock fracture observation are unable to precisely define the flow of CBM. In this study, coal samples were subjected to an in situ loading scanning test in order to create a pore network model (PNM) and determine the pore and fracture dynamic evolution law of the samples in the loading path. On this basis, the structural characteristic parameters of the samples were extracted from the PNM and the impact on the permeability performance of CBM was assessed. The findings demonstrate that the coal samples' internal porosity increases by 2.039% under uniaxial loading, the average throat pore radius increases by 205.5 to 36.1 μm, and the loading has an impact on the distribution and morphology of the pores in the coal rock. The PNM was loaded into the finite element program COMSOL for seepage modeling, and the M3 stage showed isolated pore connectivity to produce microscopic fissures, which could serve as seepage channels. In order to confirm the viability of the PNM and COMSOL docking technology, the streamline distribution law of pressure and velocity fields during the coal sample loading process was examined. The absolute permeability of the coal samples was also obtained in order for comparison with the measured results. The macroscopic CBM flow mechanism in complex low‐permeability coal rocks can be revealed through three‐dimensional reconstruction of the microscopic fracture structure and seepage simulation. This study lays the groundwork for the fine description and evaluation of coal reservoirs as well as the precise prediction of gas production in CBM wells.","PeriodicalId":505870,"journal":{"name":"Deep Underground Science and Engineering","volume":" 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141826216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of elevated ground temperatures on properties of cement grouts for deep rock grouting 地温升高对用于深层岩石灌浆的水泥灌浆料性能的影响

Deep Underground Science and Engineering Pub Date : 2024-02-04 DOI: 10.1002/dug2.12073

Zhipeng Xu, Jianping Sun, Runguo Li, Lei He, Changwu Liu

{"title":"Effects of elevated ground temperatures on properties of cement grouts for deep rock grouting","authors":"Zhipeng Xu, Jianping Sun, Runguo Li, Lei He, Changwu Liu","doi":"10.1002/dug2.12073","DOIUrl":"https://doi.org/10.1002/dug2.12073","url":null,"abstract":"Appropriate determination of the mix ratios of cement grouts is of vital importance to the quality of rock grouting and the risk reduction of groundwater inflow. The behavior of grout, often highly temperature dependent, is likely to be affected by the elevated ground temperature in deep rock masses. This paper aims to experimentally gain insights into the effects of elevated ground temperatures on the properties of cement grout in fresh and hardened states in deep rock grouting. The results revealed that a temperature of 35°C is crucial for changes in the properties of thick cement grout with a water–cement ratio of less than 0.8. When the temperature is up to 35°C, there can be significant improvements in rheological parameters, acceleration of grout setting, and increase in the rheological time dependence of thick cement grout; however, there may also be a slight impact on the initial grout flowability and the nature of shear thinning. The high temperature may still improve the stability of fresh cement grout and also improve the porosity and creep deformation of hardened cement grout considerably. The proposed constitutive model that couples the Burgers model with a fractional derivative‐based Abel dashpot in the series can be used to characterize the creep behavior of hardened cement grout appropriately. The paper provides a valuable reference for optimization of mixture design of cement grouts, thus enhancing deep rock grouting quality and improving safety.","PeriodicalId":505870,"journal":{"name":"Deep Underground Science and Engineering","volume":"565 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139806786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0