Article
Geosciences, Multidisciplinary
Bo Wei, Fangkai Quan, Yu Song, Shuo Feng
Summary: This study used low-field nuclear magnetic resonance to examine the pore system of coal reservoirs and assess the impacts of reservoir parameters on coalbed methane (CBM) well performance. Results showed that the seepage pore had the most significant influence on CBM production. The dual porosity/single permeability model was inadequate for CBM well predictions and the triple porosity/dual permeability model was more suitable when the seepage pore was developed. The study highlights the importance of considering seepage pore in the development of middle-rank coal reservoirs for CBM production.
NATURAL RESOURCES RESEARCH
(2023)
Article
Energy & Fuels
Ju Liu, Zebin Wang, Xianqi Peng, Huaijun Ji
Summary: The diverse pore structures in coal significantly affect methane adsorption. Coal with multiple pore sizes has a higher methane adsorption capacity than coal with a single pore size. The combination of pore sizes in a specific ratio leads to the highest excess methane adsorption capacity in coal.
Article
Thermodynamics
Jun Li, Qiming Huang, Gang Wang, Enmao Wang, Shuang Ju, Cunli Qin
Summary: Slickwater fracturing has a significant impact on the pore structure of coal seams, resulting in a decrease in pore volume and specific surface area, as well as severe blockage of micropores by residual liquid. The development of a gel breaker suitable for slickwater can improve the flowback effect and reduce reservoir damage.
Article
Thermodynamics
H. W. Zhou, Z. L. Liu, J. C. Zhong, B. C. Chen, J. W. Zhao, D. J. Xue
Summary: A novel online observation approach that combines nuclear magnetic resonance imaging with triaxial loading techniques is employed to visualize and quantify the evolution of fracture and pore structure (FPS) in coal samples. The results indicate that increasing deviatoric stress leads to an increase in adsorption pore content and heterogeneity, as well as gas adsorption capacity of coal samples. However, the content and permeability of seepage pore and fracture initially decrease and then increase, while the heterogeneity of seepage space initially increases and then decreases.
Article
Energy & Fuels
Fangchao Lu, Jianliang Gao, Jiajia Liu, Xuebo Zhang, Chunxia Wang, Yapeng Liu
Summary: The development of the coal pore system plays a crucial role in gas disaster prevention and coalbed methane exploitation. This study investigated the relationship between total porosity, effective porosity, pore size distribution, and resistivity of coals with different degrees of metamorphic using resistance test and low field NMR techniques. A dimensionless parameter rho(P) was defined to characterize the coal pore system. The results showed that the variety of coal resistivity was mainly controlled by the pore system, which has implications for gas disaster prevention and coalbed methane exploitation.
ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS
(2022)
Article
Environmental Sciences
Lan Hoang, Ngoc Han Tran, Michael Urynowicz, Van Giap Dong, Kim Anh To, Zaixing Huang, Lan Huong Nguyen, Thi Mai Phuong Pham, Duc Dung Nguyen, Canh Duong Do, Quoc Hung Le
Summary: This study comprehensively analyzed the hydrogeological characteristics, coalbed water characteristics, and coal sample characteristics in the Red River Basin. High concentrations of chloride and sodium in the coalbed water were found to be associated with marine or marine-transitional beds. Additionally, a correlation between microbes and chemical components in the coalbed water was established.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Engineering, Environmental
Hao Wu, Yanbin Yao, Dameng Liu
Summary: This study investigated the water vapor sorption behavior in different maturity coal samples and identified two types of water adsorption mechanisms: attachment to oxygen functional groups and pore filling in hydrophilic and hydrophobic pores, respectively. The differences in water adsorption characteristics were found to be influenced by pore volume and the proportion of hydrophilic pores. The results also showed that water adsorption on methane adsorption in coal was attributed to the amount and proportion of hydrophilic pores.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Energy & Fuels
Lemei Zhang, Xiaoyang Guo, Yijia Liu, Cunbao Deng, Liuni Song, Quanjiang Zhou, Junjie Shi, Yonglu Zhou
Summary: This paper proposes a water-based ultrasonic cavitation-enhanced coalbed methane recovery (WUC-ECBM) technology, which can break through the water lock effect in coal pores and accelerate the pore water lock relief process through the generation of micro-jets, high temperature, and high pressure. The research results contribute to the green, efficient, and intelligent development of coalbed methane in harsh geological environments.
Article
Biochemistry & Molecular Biology
Qing Han, Cunbao Deng, Tao Gao, Zhixin Jin
Summary: This study investigates the adsorption characteristics of methane in different-sized pores and finds that the adsorption capacity is positively correlated with pore size for pure gas adsorption. In competitive adsorption of binary mixtures, the adsorption capacity increases with pressure and pore size. In ultramicropores, the concentration of CO2 has an impact on methane desorption, and relatively low pressure and CO2 concentration are favorable for effective desorption of methane.
Article
Geochemistry & Geophysics
Yingfeng Sun, Yixin Zhao, Yulin Li, Nima Noraei Danesh, Zetian Zhang
Summary: The liquid nitrogen freeze-thaw cycle has a positive impact on the multiscale structure evolution of coal samples, improving the connectivity between mesopores and macropores and promoting the formation and expansion of microscopic fractures. The initial NMR porosity of deep coal is lower than that of shallow coal, but both increase with the number of freeze-thaw cycles, with a lower growth rate for deep samples.
Article
Geosciences, Multidisciplinary
Di Gao, Huiling Guo, Bianqing Guo, Kaili Tan, Hengxing Ren
Summary: In this study, the pore structure characteristics of No. 3 coal seams in Qinshui Basin after microbial treatment were analyzed. It was found that microorganisms participated in the degradation of coal reservoirs and promoted the production of methane gas. The modification of meso-macropores was more significant, resulting in stabilized pore diameter, smoother pores, decreased specific surface area, and increased pore volume, which are beneficial for the adsorption and production of coalbed methane (CBM) after microbial treatment.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Wanchun Zhao, Xin Li, Tingting Wang, Xuehai Fu
Summary: This study conducted comprehensive analysis on the pore size distribution of high volatile bituminous coal from the southern Junggar Basin, revealing that the meso-pore volume was the greatest, followed by the transition pore volume or macro-pore volume, and the micro-pore volume was the lowest. The relationship between T-2 and the pore diameter varied for different samples, and the throat size distribution derived from nano-CT was close to that derived from rate-controlled mercury penetration while the macro-pore size distributions derived from those two methods were very different. These findings provide new insights for accurate pore size distribution characterization of high volatile bituminous coal.
FRONTIERS OF EARTH SCIENCE
(2021)
Article
Engineering, Environmental
Sijian Zheng, Yanbin Yao, Dameng Liu, Shuxun Sang, Shiqi Liu, Meng Wang, Xiaozhi Zhou, Ran Wang, Sijie Han, Tong Liu
Summary: This article proposed an innovative methodology to quantitatively characterize the multiphase water in coals, applicable to both water-saturated and sub-saturated coals, by combining theory and experiment.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Energy & Fuels
Yuejian Lu, Dameng Liu, Yidong Cai, Changjing Gao, Qifeng Jia, Yingfang Zhou
Summary: This study investigates the wettability of 17 different rank coals and finds a negative correlation between wettability and coal surface roughness and adhesive force. Line tension has the most significant impact on droplets smaller than 10 nanometers, while it can be neglected in the wetting process in micropores and mesopores.
Review
Energy & Fuels
He Li, Jiawei He, Jiexin Lu, Baiquan Lin, Yi Lu, Shiliang Shi, Qing Ye
Summary: Chemical stimulation is a potential technology for enhancing coal permeability. Current research focuses on developing efficient chemical stimulation techniques and understanding the mechanisms of permeability enhancement. Laboratory studies have shown that acidising, oxidizing, organic solvent extraction, and electrochemistry stimulation techniques can improve coal permeability. Factors such as coal composition, pore-fracture structure, chemical reagent type, precipitation formation, in-situ stress, and water blocking influence the efficiency of permeability enhancement. The field application of chemical stimulation techniques is still limited, and future research should investigate their feasibility and consider the synergistic effects of chemical and physical stimulation techniques.
Article
Energy & Fuels
Yanhai Chang, Yanbin Yao, Dameng Liu, Yong Liu, Chao Cui, Hao Wu
Summary: The migration and interaction of water and gas in coal are crucial for high-performance coalbed methane recovery, as water infiltration affects gas permeability. Water imbibition changes rock permeability, occupies gas flow paths, induces matrix swelling, and influences gas permeability.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Energy & Fuels
Xin Lei, Yanbin Yao, Wanjing Luo, Zhiang Wen
Summary: A new Cubic model was proposed to calculate the permeability increase induced by hydrate dissociation, and experimental results showed that a hybrid growth pattern of pore wall coating and pore center occupying hydrates better explained the data. This model can be applied to predict permeability changes during gas production and provide insights into microscopic hydrate growth mechanisms.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Geosciences, Multidisciplinary
Xin Lei, Yanbin Yao, Xuwen Qin, Cheng Lu, Wanjing Luo, Zhiang Wen, Xuehao Yuan
Summary: The study compared the pore characteristics and flow capability of hydrate-bearing layer and underlying layer in the South China Sea, finding that post-dissociation hydrate-bearing layer samples have larger pore sizes, better connectivity, and twice the producible porosity of underlying layer samples.
Article
Computer Science, Interdisciplinary Applications
Nan Li, Yang Zhang, Qiaohong Tang, Hongkun Wang, Da He, Yan Yao, Yubo Fan
Summary: In this study, two types of unit cells were designed using topology optimization method and introduced to the interbody fusion cage to improve its biomechanical performances. The results showed that the cage composed of D-unit cells had a more uniform stress distribution, smaller displacement on cage, a more reasonable internal stress transfer mode, and higher stress on the internal bone graft.
COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING
(2023)
Article
Computer Science, Interdisciplinary Applications
Kaixiang Jin, Yuanjun Zhu, Nan Li, Yinghui Li, Yan Yao, Zhongjun Mo, Yubo Fan
Summary: Laminectomy without posterior ligament repair can result in increased mobility in adjacent segments, potentially causing spinal instability. Repairing or preserving the posterior ligament is beneficial for spinal integrity and stability.
COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING
(2023)
Article
Engineering, Environmental
Qifeng Jia, Dameng Liu, Yidong Cai, Yanbin Yao, Yuejian Lu, Yingfang Zhou
Summary: The swelling strain caused by methane adsorption in coal affects reservoir permeability, and the interaction between different scales of coal pores and adsorption behavior was investigated. Larger coal particle size leads to smaller temperature variation during adsorption and more capillary condensation of methane. Higher temperature results in more concentrated distribution of adhesion in coal.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Hao Wu, Yanbin Yao, Dameng Liu
Summary: This study investigated the water vapor sorption behavior in different maturity coal samples and identified two types of water adsorption mechanisms: attachment to oxygen functional groups and pore filling in hydrophilic and hydrophobic pores, respectively. The differences in water adsorption characteristics were found to be influenced by pore volume and the proportion of hydrophilic pores. The results also showed that water adsorption on methane adsorption in coal was attributed to the amount and proportion of hydrophilic pores.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Sijian Zheng, Yanbin Yao, Dameng Liu, Shuxun Sang, Shiqi Liu, Meng Wang, Xiaozhi Zhou, Ran Wang, Sijie Han, Tong Liu
Summary: This article proposed an innovative methodology to quantitatively characterize the multiphase water in coals, applicable to both water-saturated and sub-saturated coals, by combining theory and experiment.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Energy & Fuels
Yong Liu, Yanbin Yao, Dameng Liu, Chi Zhang
Summary: Forced imbibition in shale reservoirs is crucial for efficient recovery of shale gas, but it can also lead to low flowback efficiency and reservoir damages. This study investigated imbibition behaviors in Longmaxi shales under four different boundary conditions using nuclear magnetic resonance technology. The results showed that the shale bedding structure is the key factor determining the imbibition dynamics and patterns under different boundary conditions.
Article
Geosciences, Multidisciplinary
Hao Wu, Yanbin Yao, Xuejia Du
Summary: There is water in coal pores in the form of adsorption, which can negatively affect coalbed methane production and carbon dioxide storage in coal. Particle size influences water adsorption in coal, with smaller particles having higher rates and amounts of water adsorption. However, the impact of particle size on water adsorption is weaker for high-rank coal compared to low-rank coal. The measurement of water adsorption properties by particles may not be applicable to real coal blocks. Nonetheless, the change in particle size does affect the flow rate of different samples. This study deepens the understanding of water adsorption mechanism in coal with typical particle sizes.
NATURAL RESOURCES RESEARCH
(2023)
Article
Engineering, Environmental
Hao Wu, Sean Aruch, Roni Grayevsky, Yanbin Yao, Simon Emmanuel
Summary: Coal combustion is a major source of CO2 emissions, but utilizing fly ash to store carbon through the reaction with oxalic acid can mitigate its environmental effects. Our study found that fly ash reacts with oxalic acid to form durable solid oxalate phases, such as whewellite and weddellite. The reaction is relatively rapid, reaching completion within 4 days, and the reacted material contains about 18% Ca oxalate. Based on our calculations, 1 tonne of reacted coal fly ash can store over 34 kg of carbon, with a potential global scale storage of over 35 Mt of carbon per year. Therefore, reacting fly ash with oxalic acid has the potential to reduce the environmental impact of coal burning and can be considered a critical green technology when applied to other alkaline solid wastes.
ACS ES&T ENGINEERING
(2023)
Article
Energy & Fuels
Hao Wu, Yanbin Yao, Simon Emmanuel
Summary: A novel workflow utilizing interactive machine learning software to improve pore segmentation accuracy in coal samples is presented. By manually labeling a portion of the images and training a classifier using features like intensity, edge, and texture, the machine learning method outperforms grayscale threshold segmentation in accurately segmenting the images and estimating porosity. This study highlights the potential of machine learning techniques in reliably characterizing the pore structure of coal and other geological materials.
Article
Geosciences, Multidisciplinary
Xiaona Zhang, Yanbin Yao, Guibin Zhang, Ruying Ma, Zefan Wang
Summary: This study used cores, thin sections, imaging logs, and laboratory measurements to investigate the factors influencing the formation and development of natural fractures in the Bozhong 19-6 gas field. Both tectonic fractures and dissolution fractures are well developed and interconnected. Lithology, stress, and weathering were found to affect fracture formation and development. A reservoir evolution pattern was proposed to target favorable reservoirs in the study area.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Energy & Fuels
Zishuo Li, Yanbin Yao, Chi Zhang, Yong Liu
Summary: This paper proposes a new spontaneous imbibition model based on modifications of the classical Handy model to better predict water imbibition in tight reservoirs. Two important parameters, the average capillary pressure, and the imbibition permeability are derived using a nuclear magnetic resonance spectroscopy method. The model enriches the classical imbibition theory and provides a new approach to analyzing the imbibition of fracturing fluids in complex tight reservoirs.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
Article
Mathematics, Interdisciplinary Applications
Zefan Wang, Yanbin Yao, Ruying Ma, Xiaona Zhang, Guibin Zhang
Summary: Based on multifractal theory, this study analyzed the NMR T-2 spectrum of saturated samples and found a strong correlation between the T-2C value and multifractal parameters D-q and singular intensity range Delta alpha. A method to predict the T-2C value was proposed and validated in field applications.
FRACTAL AND FRACTIONAL
(2023)
