Pub Date : 2024-03-16DOI: 10.1007/s40789-024-00666-0
Fatemeh Saberi, Mahboubeh Hosseini-Barzi
The Pabdeh Formation represents organic matter enrichment in some oil fields, which can be considered a source rock. This study is based on the Rock–Eval, Iatroscan, and electron microscopy imaging results before and after heating the samples. We discovered this immature shale that undergoes burial and diagenesis, in which organic matter is converted into hydrocarbons. Primary migration is the process that transports hydrocarbons in the source rock. We investigated this phenomenon by developing a model that simulates hydrocarbon generation and fluid pressure during kerogen-to-hydrocarbon conversion. Microfractures initially formed at the tip/edge of kerogen and were filled with hydrocarbons, but as catagenesis progressed, the pressure caused by the volume increase of kerogen decreased due to hydrocarbon release. The transformation of solid kerogen into low-density bitumen/oil increased the pressure, leading to the development of damage zones in the source rock. The Pabdeh Formation’s small porethroats hindered effective expulsion, causing an increase in pore fluid pressure inside the initial microfractures. The stress accumulated due to hydrocarbon production, reaching the rock’s fracture strength, further contributed to damage zone development. During the expansion process, microfractures preferentially grew in low-strength pathways such as lithology changes, laminae boundaries, and pre-existing microfractures. When the porous pressure created by each kerogen overlapped, individual microfractures interconnected, forming a network of microfractures within the source rock. This research sheds light on the complex interplay between temperature, hydrocarbon generation, and the development of expulsion fractures in the Pabdeh Formation, providing valuable insights for understanding and optimizing hydrocarbon extraction in similar geological settings.
{"title":"Effect of thermal maturation and organic matter content on oil shale fracturing","authors":"Fatemeh Saberi, Mahboubeh Hosseini-Barzi","doi":"10.1007/s40789-024-00666-0","DOIUrl":"https://doi.org/10.1007/s40789-024-00666-0","url":null,"abstract":"<p>The Pabdeh Formation represents organic matter enrichment in some oil fields, which can be considered a source rock. This study is based on the Rock–Eval, Iatroscan, and electron microscopy imaging results before and after heating the samples. We discovered this immature shale that undergoes burial and diagenesis, in which organic matter is converted into hydrocarbons. Primary migration is the process that transports hydrocarbons in the source rock. We investigated this phenomenon by developing a model that simulates hydrocarbon generation and fluid pressure during kerogen-to-hydrocarbon conversion. Microfractures initially formed at the tip/edge of kerogen and were filled with hydrocarbons, but as catagenesis progressed, the pressure caused by the volume increase of kerogen decreased due to hydrocarbon release. The transformation of solid kerogen into low-density bitumen/oil increased the pressure, leading to the development of damage zones in the source rock. The Pabdeh Formation’s small porethroats hindered effective expulsion, causing an increase in pore fluid pressure inside the initial microfractures. The stress accumulated due to hydrocarbon production, reaching the rock’s fracture strength, further contributed to damage zone development. During the expansion process, microfractures preferentially grew in low-strength pathways such as lithology changes, laminae boundaries, and pre-existing microfractures. When the porous pressure created by each kerogen overlapped, individual microfractures interconnected, forming a network of microfractures within the source rock. This research sheds light on the complex interplay between temperature, hydrocarbon generation, and the development of expulsion fractures in the Pabdeh Formation, providing valuable insights for understanding and optimizing hydrocarbon extraction in similar geological settings.</p>","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140146542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-15DOI: 10.1007/s40789-024-00663-3
Zhimei Shu, Tingting Xu, Jiayi Xiao, Qige Deng, Xuan Zhao, Tianjiao Li, Yaoyao Ying, Dong Liu
This study aimed to investigate the effects of ammonia addition on ethylene counter-flow diffusion flames with different diluents on the fuel or oxidizer side, using kinetic analyses. A special emphasis was put on assessing the coupled chemical effects of NH3 and CO2 on C2H4 combustion chemistry. The chemical effects could be evaluated by comparing fictitious inert NH3 or CO2 with normal active NH3 or CO2. The results revealed that the addition of NH3 decreased the mole fractions and production rates of key soot precursors, such as acetylene, propynyl, and benzene. When CO2 was used as the dilution gas, the coupled chemical effects of NH3 and CO2 were affected by the chemical effects of CO2 to varying degrees. With the oxidizer-side CO2 addition, the coupled chemical effects of NH3 and CO2 reduced the mole fractions of H, O, OH radicals, acetylene, propynyl, and benzene, while the effects differed from the fuel-side CO2 addition. The coupled chemical effects of NH3 and CO2 also promoted the formation of aldehyde contaminants, such as acetaldehyde, to some extent, particularly with CO2 addition on the oxidizer side.
本研究旨在通过动力学分析,研究在燃料或氧化剂侧添加不同稀释剂时,氨对乙烯逆流扩散火焰的影响。重点是评估 NH3 和 CO2 对 C2H4 燃烧化学的耦合化学效应。可通过比较虚构的惰性 NH3 或 CO2 与正常的活性 NH3 或 CO2 来评估化学效应。结果显示,NH3 的加入降低了乙炔、丙炔和苯等主要烟尘前体物的摩尔分数和生成率。当使用 CO2 作为稀释气体时,NH3 和 CO2 的耦合化学效应在不同程度上受到 CO2 化学效应的影响。在氧化剂侧加入 CO2 时,NH3 和 CO2 的耦合化学效应降低了 H、O、OH 自由基、乙炔、丙炔和苯的摩尔分数,而其效应与燃料侧加入 CO2 时不同。NH3 和 CO2 的耦合化学效应还在一定程度上促进了乙醛等醛类污染物的形成,尤其是在氧化剂侧添加 CO2 时。
{"title":"Comprehensive kinetic study on ammonia/ethylene counter-flow diffusion flames: influences of diluents","authors":"Zhimei Shu, Tingting Xu, Jiayi Xiao, Qige Deng, Xuan Zhao, Tianjiao Li, Yaoyao Ying, Dong Liu","doi":"10.1007/s40789-024-00663-3","DOIUrl":"https://doi.org/10.1007/s40789-024-00663-3","url":null,"abstract":"<p>This study aimed to investigate the effects of ammonia addition on ethylene counter-flow diffusion flames with different diluents on the fuel or oxidizer side, using kinetic analyses. A special emphasis was put on assessing the coupled chemical effects of NH<sub>3</sub> and CO<sub>2</sub> on C<sub>2</sub>H<sub>4</sub> combustion chemistry. The chemical effects could be evaluated by comparing fictitious inert NH<sub>3</sub> or CO<sub>2</sub> with normal active NH<sub>3</sub> or CO<sub>2</sub>. The results revealed that the addition of NH<sub>3</sub> decreased the mole fractions and production rates of key soot precursors, such as acetylene, propynyl, and benzene. When CO<sub>2</sub> was used as the dilution gas, the coupled chemical effects of NH<sub>3</sub> and CO<sub>2</sub> were affected by the chemical effects of CO<sub>2</sub> to varying degrees. With the oxidizer-side CO<sub>2</sub> addition, the coupled chemical effects of NH<sub>3</sub> and CO<sub>2</sub> reduced the mole fractions of H, O, OH radicals, acetylene, propynyl, and benzene, while the effects differed from the fuel-side CO<sub>2</sub> addition. The coupled chemical effects of NH<sub>3</sub> and CO<sub>2</sub> also promoted the formation of aldehyde contaminants, such as acetaldehyde, to some extent, particularly with CO<sub>2</sub> addition on the oxidizer side.</p>","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140146559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-14DOI: 10.1007/s40789-024-00662-4
Yinli Bi, Nan Guo, Yanxu Zhang, Xianglei Li, Ziheng Song
The objectives of this study were to explore the changes in soil stoichiometry and enzyme activities at different distances from an opencast coal mine in the Hulun Buir Grassland of China. Four transects were established on north and east sides of the opencast coal mining area, and samples were collected at 50 m, 550 m, and 1550 m from the pit on each transect. Control samples were collected from a grassland station 8 km from the opencast coal mining area that was not disturbed by mining. Four replicate soil samples were collected at each point on the four transects. Soil physicochemical properties and enzyme activities were determined, and correlations between soil properties and stoichiometric ratios and enzyme activities were explored using redundancy analysis. The increase in distance from mining did not significantly affect soil properties, although soil urease activity was significantly lower than that of the control area. Soil properties 1550 m from the mine pit were similar to those at the grassland control. In addition, soil total nitrogen had the greatest effect on soil stoichiometry, and soil total potassium had the greatest effect on soil enzyme activities. Coal dust from opencast mining might be the main factor affecting soil stoichiometry and enzyme activities. The results of this study provide direction for the next step in studying the influence of mining areas on soil properties and processes.
{"title":"Responses of soil stoichiometry and soil enzyme activities in the different distance around opencast coal mine of the Hulun Buir Grassland of China","authors":"Yinli Bi, Nan Guo, Yanxu Zhang, Xianglei Li, Ziheng Song","doi":"10.1007/s40789-024-00662-4","DOIUrl":"https://doi.org/10.1007/s40789-024-00662-4","url":null,"abstract":"<p>The objectives of this study were to explore the changes in soil stoichiometry and enzyme activities at different distances from an opencast coal mine in the Hulun Buir Grassland of China. Four transects were established on north and east sides of the opencast coal mining area, and samples were collected at 50 m, 550 m, and 1550 m from the pit on each transect. Control samples were collected from a grassland station 8 km from the opencast coal mining area that was not disturbed by mining. Four replicate soil samples were collected at each point on the four transects. Soil physicochemical properties and enzyme activities were determined, and correlations between soil properties and stoichiometric ratios and enzyme activities were explored using redundancy analysis. The increase in distance from mining did not significantly affect soil properties, although soil urease activity was significantly lower than that of the control area. Soil properties 1550 m from the mine pit were similar to those at the grassland control. In addition, soil total nitrogen had the greatest effect on soil stoichiometry, and soil total potassium had the greatest effect on soil enzyme activities. Coal dust from opencast mining might be the main factor affecting soil stoichiometry and enzyme activities. The results of this study provide direction for the next step in studying the influence of mining areas on soil properties and processes.</p>","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140146543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to study the problems of unreasonable airflow distribution and serious dust pollution in a heading surface, an experimental platform for forced ventilation and dust removal was built based on the similar principles. Through the similar experiment and numerical simulation, the distribution of airflow field in the roadway and the spatial and temporal evolution of dust pollution under the conditions of forced ventilation were determined. The airflow field in the roadway can be divided into three zones: jet zone, vortex zone and reflux zone. The dust concentration gradually decreases from the head to the rear of the roadway. Under the forced ventilation conditions, there is a unilateral accumulation of dust, with higher dust concentrations away from the ducts. The position of the equipment has an interception effect on the dust. The maximum error between the test value and the simulation result is 12.9%, which verifies the accuracy of the experimental results. The research results can provide theoretical guidance for the application of dust removal technology in coal mine.
{"title":"Experimental and numerical simulation study on forced ventilation and dust removal of coal mine heading surface","authors":"Haotian Zheng, Bingyou Jiang, Haoyu Wang, Yuannan Zheng","doi":"10.1007/s40789-024-00667-z","DOIUrl":"https://doi.org/10.1007/s40789-024-00667-z","url":null,"abstract":"<p>In order to study the problems of unreasonable airflow distribution and serious dust pollution in a heading surface, an experimental platform for forced ventilation and dust removal was built based on the similar principles. Through the similar experiment and numerical simulation, the distribution of airflow field in the roadway and the spatial and temporal evolution of dust pollution under the conditions of forced ventilation were determined. The airflow field in the roadway can be divided into three zones: jet zone, vortex zone and reflux zone. The dust concentration gradually decreases from the head to the rear of the roadway. Under the forced ventilation conditions, there is a unilateral accumulation of dust, with higher dust concentrations away from the ducts. The position of the equipment has an interception effect on the dust. The maximum error between the test value and the simulation result is 12.9%, which verifies the accuracy of the experimental results. The research results can provide theoretical guidance for the application of dust removal technology in coal mine.</p>","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140126536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-12DOI: 10.1007/s40789-024-00664-2
Tianhan Xu, Jian Wang, Yuhao Lu, Danling Wang, Li Yu, Ye Tian
Recent studies have indicated that the injection of carbon dioxide (CO2) can lead to increased oil recovery in fractured shale reservoirs following natural depletion. Despite advancements in understanding mass exchange processes in subsurface formations, there remains a knowledge gap concerning the disparities in these processes between the matrix and fractures at the pore scale in formations with varying permeability. This study aims to experimentally investigate the CO2 diffusion behaviors and in situ oil recovery through a CO2 huff ‘n’ puff process in the Jimsar shale oil reservoir. To achieve this, we designed three matrix-fracture models with different permeabilities (0.074 mD, 0.170 mD, and 0.466 mD) and experimented at 30 MPa and 91 °C. The oil concentration in both the matrix and fracture was monitored using a low-field nuclear magnetic resonance (LF-NMR) technique to quantify in situ oil recovery and elucidate mass-exchange behaviors. The results showed that after three cycles of CO2 huff ‘n’ puff, the total recovery degree increased from 30.28% to 34.95% as the matrix permeability of the core samples increased from 0.074 to 0.466 mD, indicating a positive correlation between CO2 extraction efficiency and matrix permeability. Under similar fracture conditions, the increase in matrix permeability further promoted CO2 extraction efficiency during CO2 huff ‘n’ puff. Specifically, the increase in matrix permeability of the core had the greatest effect on the extraction of the first-cycle injection in large pores, which increased from 16.42% to 36.64%. The findings from our research provide valuable insights into the CO2 huff ‘n’ puff effects in different pore sizes following fracturing under varying permeability conditions, shedding light on the mechanisms of CO2-enhanced oil recovery in fractured shale oil reservoirs.
{"title":"Exploring pore-scale production characteristics of oil shale after CO2 huff ‘n’ puff in fractured shale with varied permeability","authors":"Tianhan Xu, Jian Wang, Yuhao Lu, Danling Wang, Li Yu, Ye Tian","doi":"10.1007/s40789-024-00664-2","DOIUrl":"https://doi.org/10.1007/s40789-024-00664-2","url":null,"abstract":"<p>Recent studies have indicated that the injection of carbon dioxide (CO<sub>2</sub>) can lead to increased oil recovery in fractured shale reservoirs following natural depletion. Despite advancements in understanding mass exchange processes in subsurface formations, there remains a knowledge gap concerning the disparities in these processes between the matrix and fractures at the pore scale in formations with varying permeability. This study aims to experimentally investigate the CO<sub>2</sub> diffusion behaviors and in situ oil recovery through a CO<sub>2</sub> huff ‘n’ puff process in the Jimsar shale oil reservoir. To achieve this, we designed three matrix-fracture models with different permeabilities (0.074 mD, 0.170 mD, and 0.466 mD) and experimented at 30 MPa and 91 °C. The oil concentration in both the matrix and fracture was monitored using a low-field nuclear magnetic resonance (LF-NMR) technique to quantify in situ oil recovery and elucidate mass-exchange behaviors. The results showed that after three cycles of CO<sub>2</sub> huff ‘n’ puff, the total recovery degree increased from 30.28% to 34.95% as the matrix permeability of the core samples increased from 0.074 to 0.466 mD, indicating a positive correlation between CO<sub>2</sub> extraction efficiency and matrix permeability. Under similar fracture conditions, the increase in matrix permeability further promoted CO<sub>2</sub> extraction efficiency during CO<sub>2</sub> huff ‘n’ puff. Specifically, the increase in matrix permeability of the core had the greatest effect on the extraction of the first-cycle injection in large pores, which increased from 16.42% to 36.64%. The findings from our research provide valuable insights into the CO<sub>2</sub> huff ‘n’ puff effects in different pore sizes following fracturing under varying permeability conditions, shedding light on the mechanisms of CO<sub>2</sub>-enhanced oil recovery in fractured shale oil reservoirs.</p>","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140126349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-05DOI: 10.1007/s40789-023-00643-z
Yu Chen, Haodong Xiao
Rock bolts are extensively utilized in underground engineering as a means of offering support and stability to rock masses in tunnels, mines, and other underground structures. In environments of high ground stress, faults or weak zones can frequently arise in rock formations, presenting a significant challenge for engineering and potentially leading to underground engineering collapse. Rock bolts serve as a crucial structural element for the transmission of tensile stress and are capable of withstanding shear loads to prevent sliding of weak zones within rock mass. Therefore, a complete understanding of the behavior of rock bolts subjected to shear loads is essential. This paper presents a state-of-the-art review of the research progress of rock bolts subjected to shear load in three categories: experiment, numerical simulation, and analytical model. The review focuses on the research studies and developments in this area since the 1970s, providing a comprehensive overview of numerous factors that influence the anchorage performance of rock bolts. These factors include the diameter and angle of the rock bolt installation, rock strength, grouting material, bolt material, borehole diameter, rock bolt preload, normal stress, joint surface roughness and joint expansion angle. The paper reviews the improvement of mechanical parameter setting in numerical simulation of rock bolt shear. Furthermore, it delves into the optimization of the analytical model concerning rock bolt shear theory, approached from the perspectives of both Elastic foundation beam theory coupled with Elastoplasticity theory and Structural mechanic methods. The significance of this review lies in its ability to provide insights into the mechanical behavior of rock bolts. The paper also highlights the limitations of current research and guidelines for further research of rock bolts.
{"title":"State-of-the-art on the anchorage performance of rock bolts subjected to shear load","authors":"Yu Chen, Haodong Xiao","doi":"10.1007/s40789-023-00643-z","DOIUrl":"https://doi.org/10.1007/s40789-023-00643-z","url":null,"abstract":"<p>Rock bolts are extensively utilized in underground engineering as a means of offering support and stability to rock masses in tunnels, mines, and other underground structures. In environments of high ground stress, faults or weak zones can frequently arise in rock formations, presenting a significant challenge for engineering and potentially leading to underground engineering collapse. Rock bolts serve as a crucial structural element for the transmission of tensile stress and are capable of withstanding shear loads to prevent sliding of weak zones within rock mass. Therefore, a complete understanding of the behavior of rock bolts subjected to shear loads is essential. This paper presents a state-of-the-art review of the research progress of rock bolts subjected to shear load in three categories: experiment, numerical simulation, and analytical model. The review focuses on the research studies and developments in this area since the 1970s, providing a comprehensive overview of numerous factors that influence the anchorage performance of rock bolts. These factors include the diameter and angle of the rock bolt installation, rock strength, grouting material, bolt material, borehole diameter, rock bolt preload, normal stress, joint surface roughness and joint expansion angle. The paper reviews the improvement of mechanical parameter setting in numerical simulation of rock bolt shear. Furthermore, it delves into the optimization of the analytical model concerning rock bolt shear theory, approached from the perspectives of both Elastic foundation beam theory coupled with Elastoplasticity theory and Structural mechanic methods. The significance of this review lies in its ability to provide insights into the mechanical behavior of rock bolts. The paper also highlights the limitations of current research and guidelines for further research of rock bolts.</p>","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139754895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-05DOI: 10.1007/s40789-023-00637-x
Abstract
Deep shale reservoirs (3500–4500 m) exhibit significantly different stress states than moderately deep shale reservoirs (2000–3500 m). As a result, the brittleness response mechanisms of deep shales are also different. It is urgent to investigate methods to evaluate the brittleness of deep shales to meet the increasingly urgent needs of deep shale gas development. In this paper, the quotient of Young’s modulus divided by Poisson’s ratio based on triaxial compression tests under in situ stress conditions is taken as SSBV (Static Standard Brittleness Value). A new and pragmatic technique is developed to determine the static brittleness index that considers elastic parameters, the mineral content, and the in situ stress conditions (BIEMS). The coefficient of determination between BIEMS and SSBV reaches 0.555 for experimental data and 0.805 for field data. This coefficient is higher than that of other brittleness indices when compared to SSBV. BIEMS can offer detailed insights into shale brittleness under various conditions, including different mineral compositions, depths, and stress states. This technique can provide a solid data-based foundation for the selection of ‘sweet spots’ for single-well engineering and the comparison of the brittleness of shale gas production layers in different areas.
{"title":"Quantitative characterization of the brittleness of deep shales by integrating mineral content, elastic parameters, in situ stress conditions and logging analysis","authors":"","doi":"10.1007/s40789-023-00637-x","DOIUrl":"https://doi.org/10.1007/s40789-023-00637-x","url":null,"abstract":"<h3>Abstract</h3> <p>Deep shale reservoirs (3500–4500 m) exhibit significantly different stress states than moderately deep shale reservoirs (2000–3500 m). As a result, the brittleness response mechanisms of deep shales are also different. It is urgent to investigate methods to evaluate the brittleness of deep shales to meet the increasingly urgent needs of deep shale gas development. In this paper, the quotient of Young’s modulus divided by Poisson’s ratio based on triaxial compression tests under in situ stress conditions is taken as SSBV (Static Standard Brittleness Value). A new and pragmatic technique is developed to determine the static brittleness index that considers elastic parameters, the mineral content, and the in situ stress conditions (BIEMS). The coefficient of determination between BIEMS and SSBV reaches 0.555 for experimental data and 0.805 for field data. This coefficient is higher than that of other brittleness indices when compared to SSBV. BIEMS can offer detailed insights into shale brittleness under various conditions, including different mineral compositions, depths, and stress states. This technique can provide a solid data-based foundation for the selection of ‘sweet spots’ for single-well engineering and the comparison of the brittleness of shale gas production layers in different areas.</p>","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139755203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Excessive emissions of nitrogen oxides from flue gas have imposed various detrimental impacts on environment, and the development of deNOx catalysts with low-cost and high performance is an urgent requirement. Iron oxide-based material has been explored for promising deNOx catalysts. However, the unsatisfactory low-temperature activity limits their practical applications. In this study, a series of excellent low-temperature denitrification catalysts (Ha-FeOx/yZS) were prepared by acid treatment of zinc slag, and the mass ratios of Fe to impure ions was regulated by adjusting the acid concentrations. Ha-FeOx/yZS showed high denitrification performance (> 90%) in the range of 180–300 °C, and the optimal NO conversion and N2 selectivity were higher than 95% at 250 °C. Among them, the Ha-FeOx/2ZS synthesized with 2 mol/L HNO3 exhibited the widest temperature window (175–350 °C). The excellent denitrification performance of Ha-FeOx/yZS was mainly attributed to the strong interaction between Fe and impurity ions to inhibit the growth of crystals, making Ha-FeOx/yZS with amorphous structure, nice fine particles, large specific surface area, more surface acid sites and high chemisorbed oxygen. The in-situ DRIFT experiments confirmed that the SCR reaction on the Ha-FeOx/yZS followed both Langmuir-Hinshelwood (L-H) mechanism and Eley-Rideal (E-R) mechanism. The present work proposed a high value-added method for the preparation of cost-effective catalysts from zinc slag, which showed a promising application prospect in NOx removal by selective catalytic reduction with ammonia.
{"title":"Heteroatoms doped iron oxide-based catalyst prepared from zinc slag for efficient selective catalytic reduction of NOx with NH3","authors":"Jiale Liang, Yaojun Zhang, Hao Chen, Licai Liu, Panyang He, Lei Wu","doi":"10.1007/s40789-023-00634-0","DOIUrl":"https://doi.org/10.1007/s40789-023-00634-0","url":null,"abstract":"<p>Excessive emissions of nitrogen oxides from flue gas have imposed various detrimental impacts on environment, and the development of deNO<sub><i>x</i></sub> catalysts with low-cost and high performance is an urgent requirement. Iron oxide-based material has been explored for promising deNO<sub><i>x</i></sub> catalysts. However, the unsatisfactory low-temperature activity limits their practical applications. In this study, a series of excellent low-temperature denitrification catalysts (Ha-FeO<sub><i>x</i></sub>/yZS) were prepared by acid treatment of zinc slag, and the mass ratios of Fe to impure ions was regulated by adjusting the acid concentrations. Ha-FeO<sub><i>x</i></sub>/yZS showed high denitrification performance (> 90%) in the range of 180–300 °C, and the optimal NO conversion and N<sub>2</sub> selectivity were higher than 95% at 250 °C. Among them, the Ha-FeO<sub><i>x</i></sub>/2ZS synthesized with 2 mol/L HNO<sub>3</sub> exhibited the widest temperature window (175–350 °C). The excellent denitrification performance of Ha-FeO<sub><i>x</i></sub>/yZS was mainly attributed to the strong interaction between Fe and impurity ions to inhibit the growth of crystals, making Ha-FeO<sub><i>x</i></sub>/yZS with amorphous structure, nice fine particles, large specific surface area, more surface acid sites and high chemisorbed oxygen. The in-situ DRIFT experiments confirmed that the SCR reaction on the Ha-FeO<sub><i>x</i></sub>/yZS followed both Langmuir-Hinshelwood (L-H) mechanism and Eley-Rideal (E-R) mechanism. The present work proposed a high value-added method for the preparation of cost-effective catalysts from zinc slag, which showed a promising application prospect in NO<sub><i>x</i></sub> removal by selective catalytic reduction with ammonia.</p>","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139755076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-04DOI: 10.1007/s40789-023-00620-6
Yang Li, Renshu Yang, Yanbing Wang, Dairui Fu
This study investigates the impact of different water coupling coefficients on the blasting effect of red sandstone. The analysis is based on the theories of detonation wave and elastic wave, focusing on the variation in wall pressure of the blasting holes. Using DDNP explosive as the explosive load, blasting tests were conducted on red sandstone specimens with four different water coupling coefficients: 1.20, 1.33, 1.50, and 2.00. The study examines the morphologies of the rock specimens after blasting under these different water coupling coefficients. Additionally, the fractal dimensions of the surface cracks resulting from the blasting were calculated to provide a quantitative evaluation of the extent of rock damage. CT scanning and 3D reconstruction were performed on the post-blasting specimens to visually depict the extent of damage and fractures within the rock. Additionally, the volume fractal dimension and damage degree of the post-blasting specimens are calculated. The findings are then combined with numerical simulation to facilitate auxiliary analysis. The results demonstrate that an increase in the water coupling coefficient leads to a reduction in the peak pressure on the hole wall and the crushing zone, enabling more of the explosion energy to be utilized for crack propagation following the explosion. The specimens exhibited distinct failure patterns, resulting in corresponding changes in fractal dimensions. The simulated pore wall pressure–time curve validated the derived theoretical results, whereas the stress cloud map and explosion energy-time curve demonstrated the buffering effect of the water medium. As the water coupling coefficient increases, the buffering effect of the water medium becomes increasingly prominent.
{"title":"Influence of water coupling coefficient on the blasting effect of red sandstone specimens","authors":"Yang Li, Renshu Yang, Yanbing Wang, Dairui Fu","doi":"10.1007/s40789-023-00620-6","DOIUrl":"https://doi.org/10.1007/s40789-023-00620-6","url":null,"abstract":"<p>This study investigates the impact of different water coupling coefficients on the blasting effect of red sandstone. The analysis is based on the theories of detonation wave and elastic wave, focusing on the variation in wall pressure of the blasting holes. Using DDNP explosive as the explosive load, blasting tests were conducted on red sandstone specimens with four different water coupling coefficients: 1.20, 1.33, 1.50, and 2.00. The study examines the morphologies of the rock specimens after blasting under these different water coupling coefficients. Additionally, the fractal dimensions of the surface cracks resulting from the blasting were calculated to provide a quantitative evaluation of the extent of rock damage. CT scanning and 3D reconstruction were performed on the post-blasting specimens to visually depict the extent of damage and fractures within the rock. Additionally, the volume fractal dimension and damage degree of the post-blasting specimens are calculated. The findings are then combined with numerical simulation to facilitate auxiliary analysis. The results demonstrate that an increase in the water coupling coefficient leads to a reduction in the peak pressure on the hole wall and the crushing zone, enabling more of the explosion energy to be utilized for crack propagation following the explosion. The specimens exhibited distinct failure patterns, resulting in corresponding changes in fractal dimensions. The simulated pore wall pressure–time curve validated the derived theoretical results, whereas the stress cloud map and explosion energy-time curve demonstrated the buffering effect of the water medium. As the water coupling coefficient increases, the buffering effect of the water medium becomes increasingly prominent.</p>","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139677340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-03DOI: 10.1007/s40789-023-00660-y
Lirui Mao, Mingdong Zheng, Baoliang Xia, Facun Jiao, Tao Liu, Yuanchun Zhang, Shengtao Gao, Hanxu Li
Fine slag (FS) is an unavoidable by-product of coal gasification. FS, which is a simple heap of solid waste left in the open air, easily causes environmental pollution and has a low resource utilization rate, thereby restricting the development of energy-saving coal gasification technologies. The multiscale analysis of FS performed in this study indicates typical grain size distribution, composition, crystalline structure, and chemical bonding characteristics. The FS primarily contained inorganic and carbon components (dry bases) and exhibited a "three-peak distribution" of the grain size and regular spheroidal as well as irregular shapes. The irregular particles were mainly adsorbed onto the structure and had a dense distribution and multiple pores and folds. The carbon constituents were primarily amorphous in structure, with a certain degree of order and active sites. C 1s XPS spectrum indicated the presence of C–C and C–H bonds and numerous aromatic structures. The inorganic components, constituting 90% of the total sample, were primarily silicon, aluminum, iron, and calcium. The inorganic components contained Si–O-Si, Si–O–Al, Si–O, SO42−, and Fe–O bonds. Fe 2p XPS spectrum could be deconvoluted into Fe 2p1/2 and Fe 2p3/2 peaks and satellite peaks, while Fe existed mainly in the form of Fe(III). The findings of this study will be beneficial in resource utilization and formation mechanism of fine slag in future.
{"title":"Multiscale analysis of fine slag from pulverized coal gasification in entrained-flow bed","authors":"Lirui Mao, Mingdong Zheng, Baoliang Xia, Facun Jiao, Tao Liu, Yuanchun Zhang, Shengtao Gao, Hanxu Li","doi":"10.1007/s40789-023-00660-y","DOIUrl":"https://doi.org/10.1007/s40789-023-00660-y","url":null,"abstract":"<p>Fine slag (FS) is an unavoidable by-product of coal gasification. FS, which is a simple heap of solid waste left in the open air, easily causes environmental pollution and has a low resource utilization rate, thereby restricting the development of energy-saving coal gasification technologies. The multiscale analysis of FS performed in this study indicates typical grain size distribution, composition, crystalline structure, and chemical bonding characteristics. The FS primarily contained inorganic and carbon components (dry bases) and exhibited a \"three-peak distribution\" of the grain size and regular spheroidal as well as irregular shapes. The irregular particles were mainly adsorbed onto the structure and had a dense distribution and multiple pores and folds. The carbon constituents were primarily amorphous in structure, with a certain degree of order and active sites. C 1<i>s</i> XPS spectrum indicated the presence of C–C and C–H bonds and numerous aromatic structures. The inorganic components, constituting 90% of the total sample, were primarily silicon, aluminum, iron, and calcium. The inorganic components contained Si–O-Si, Si–O–Al, Si–O, SO<sub>4</sub><sup>2−</sup>, and Fe–O bonds. Fe 2<i>p</i> XPS spectrum could be deconvoluted into Fe 2<i>p</i><sub>1/2</sub> and Fe 2<i>p</i><sub>3/2</sub> peaks and satellite peaks, while Fe existed mainly in the form of Fe(III). The findings of this study will be beneficial in resource utilization and formation mechanism of fine slag in future.</p>","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139678242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}