Article
Biochemistry & Molecular Biology
Aiswarya Chalikunnath Venu, Rami Nasser Din, Thomas Rudszuck, Pierre Picchetti, Papri Chakraborty, Annie K. Powell, Steffen Kraemer, Gisela Guthausen, Masooma Ibrahim
Summary: The current trend in ultra-high-field magnetic resonance imaging (MRI) technologies is opening up new possibilities in clinical diagnostics and material imaging. Contrast agents (CAs) are being used to further enhance MRI selectivity and image contrast. New contrast agents, such as lanthanides, show promise in being effective at high magnetic fields.
Article
Chemistry, Physical
Ghazanfer Raza Abbasi, Ahmed Al-Yaseri, Abubakar Isah, Alireza Keshavarz, Stefan Iglauer
Summary: The research found that significantly higher hydrate saturation was observed in water-wet sandstone, and low-field NMR can quantify rock wettability and observe hydrate behavior in geological sediments.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Geosciences, Multidisciplinary
Qian Zhang, Xuwen Qin, Hong Zhang, Yanhui Dong, Cheng Lu, Shouding Li, Luokun Xiao, Chao Ma, Hang Bian
Summary: In this study, the process of hydrate formation and dissociation in sediments from the South China Sea was systematically studied to examine the evolution of hydrate saturation and permeability in sediments and their relationship. The results showed that the existing models considering a single pattern of hydrate growth cannot precisely describe the relationship between permeability and hydrate saturation.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Engineering, Multidisciplinary
Zekun Wu, Gang Liu, Zhanchao Liu, Xuelei Wang, Zhen Chai
Summary: We demonstrate an optimization method of the oscillating magnetic field to enhance the transverse nuclear magnetization in atomic co-magnetometers operated in the nuclear magnetic resonance (NMR) regime. The relationship between the transverse nuclear magnetization and the relaxation time is revealed. This optimization method allows for quick and accurate selection of the optimal operating point for each atomic co-magnetometer and effectively reduces the bias instability.
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
K. P. Lijith, Reddi Srinivasa Rao, Devendra Narain Singh
Summary: This study investigates the synthesis of CO2 hydrates in partially saturated finesands under triaxial conditions and analyzes their elastic properties and formation and dissociation processes. The results show that the induction time for CO2 hydrate formation increases and the water-to-hydrate conversion ratio decreases with an increase in the initial water content.
Article
Energy & Fuels
Zhiang Wen, Yanbin Yao, Wanjing Luo, Xin Lei
Summary: Monitoring the formation process of CO2 hydrate in sandstone cores revealed a memory effect, with secondary synthesis showing significantly higher rates and saturation levels compared to primary synthesis. This memory effect is attributed to changes in water molecular structure and the different pore occupation models during primary and secondary synthesis.
Article
Biochemistry & Molecular Biology
Songbai Zhang, Vega Lloveras, Silvia Lope-Piedrafita, Pilar Calero-Perez, Shuang Wu, Silvia Lope-Piedrafita, Ana Paula Candiota, Jose Vidal-Gancedo
Summary: MRI is a highly required imaging approach for the early diagnosis and follow-up of tumors, especially brain cancer. Organic radicals anchored on a dendrimer macromolecule surface show promising potential as alternatives to traditional Gd-based contrast agents, with similar contrast enhancement effects, lower toxicity, and longer biological stability.
Article
Computer Science, Interdisciplinary Applications
Yanlu Ding, Anna Qian, Hailong Lu, Yuan Li, Yi Zhang
Summary: Understanding the engineering properties of hydrate-bearing sands (HBS) is crucial for assessing the safety of natural gas hydrate exploitation. However, precise testing of HBS specimens with different hydrate morphologies has been difficult due to the challenges in controlling hydrate formation in the laboratory. In this study, the discrete element method (DEM) is employed to create HBS models with various hydrate morphologies, and biaxial compression tests are simulated to evaluate their mechanical properties. The numerical results demonstrate that the shear strength and secant modulus of HBS are affected by hydrate morphology and saturation, and relationships between micro mechanical analyses and macro mechanical properties are established. These findings provide valuable insights into the mechanical responses of HBS with complex hydrate morphologies.
COMPUTERS AND GEOTECHNICS
(2022)
Article
Energy & Fuels
Lihao Liu, Bohui Shi, Shangfei Song, Yuchuan Chen, Xinhao Luo, Shijia Zhang, Huirong Huang, Haiyuan Yao, Guangjin Chen, Jing Gong
Summary: The study focuses on the flow assurance of natural gas hydrates, paying attention to the co-deposition mechanism of Micron-sized Sand Particles and natural gas hydrate particles during pipeline transportation. Horizontal high-pressure flow loop experiments are conducted to understand the hydrates and MSPs slurry flow law and co-deposition mechanism. The findings reveal the stages of the hydrate-MSPs co-deposition process in the salt-sand coexistence system and provide insights into the solid deposition process. The influence of sand particle concentration and initial flow velocity on the co-deposition process is explored, and the interaction between particles in the deposition process is revealed by Particle Vision and Measurement.
Article
Energy & Fuels
Jie Chen, Gaowei Hu, Qingtao Bu, Changling Liu, Lin Dong, Yizhao Wan, Peixiao Mao, Yang Guo, Zihao Wang
Summary: In this study, the elastic wave velocities of hydrate-bearing sediments were investigated, revealing that the BGTL model is most accurate for hydrate saturation exceeding 45%, while the EMT-B model is more suitable for hydrate saturation ranging from 15% to 55%. The STPE model, without considering gas effects, overestimated the P-wave velocity. Additionally, a modified STPE model combining Wood and Domenico equations was proposed to improve the precision and applicability for predicting V-p in unconsolidated reservoirs.
JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING
(2021)
Article
Nanoscience & Nanotechnology
Yang Zhao, Mingzhao Yang, Man Li, Hongsheng Dong, Yang Ge, Qingping Li, Lunxiang Zhang, Yu Liu, Lei Yang, Yongchen Song, Jiafei Zhao
Summary: Efficient gas enrichment methods are crucial for the storage, transportation, and sequestration of clean energy and carbon dioxide. A novel recyclable hydrate promoter has been developed, which effectively reduces the induction time of methane hydrate formation, increases gas storage capacity, and inhibits foam during hydrate decomposition. Additionally, this promoter enhances CO2 storage capacity and shows potential for sequestering CO2 in the form of gas hydrate under the seafloor.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Sofia Marchesini, Keith R. Paton, Barry Brennan, Piers Turner, Andrew J. Pollard
Summary: Nanomaterials have a high surface-area-to-mass ratio, making surface properties crucial for product performance optimization. Characterizing nanoscale surfaces is challenging, especially in liquid dispersions, but nuclear magnetic resonance proton relaxation can quickly characterize the surface chemistry of graphitic materials.
Article
Thermodynamics
Juan He, Xiaosen Li, Zhaoyang Chen, Changyu You, Kefeng Yan, Zhiming Xia, Qingping Li
Summary: The distribution of hydrates in sediment affects the changing trends of effective thermal conductivity, especially influenced by gas saturation, water saturation or pressure. Different formation processes of hydrates exhibit various trends in thermal conductivity changes, with non-uniform distribution causing different behaviors.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Moises Martin-Garrido, Sagrario Martinez-Ramirez
Summary: Calcium silicate hydrate gel (C-S-H) was synthesized using the double decomposition method for its simplicity and quickness. Analysis using various spectroscopy methods showed changes in the gel structure over time, including polymerization and a decrease in the Ca/Si ratio. The DTA/TG/MS analysis revealed a mass loss due to CO2 adsorption on the gel at temperatures below 400 degrees C.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Thermodynamics
Xinxin Cao, Jiaxin Sun, Fanfan Qin, Fulong Ning, Peixiao Mao, Yuhang Gu, Yanlong Li, Heen Zhang, Yanjiang Yu, Nengyou Wu
Summary: Multilateral well technique is a promising approach to enhance gas recovery in heterogeneous hydrate reservoirs. A 3D numerical model is proposed to predict the production performance of hydrate reservoirs using multilateral wells. The optimal deployment location and branch length for dual-branch and quad-branch scenarios are determined. Dual-lateral wells have the most favorable yield-increasing effects compared to vertical wells. Well interference between branches may exist and worsens with an increase in branch number. This research provides insight into the industrialized co-production of hydrate and free gas.
Article
Energy & Fuels
Maryam Omidvar, Liwei Cheng, Abdolreza Farhadian, Avni Berisha, Alireza Rahimi, Fulong Ning, Harish Kumar, Kiana Peyvandi, Mohammad Reza Nabid
Summary: The modification of a gas hydrate inhibitor improves its performance in inhibiting corrosion and gas hydrate formation, thereby reducing operation costs in oil and gas pipelines.
Article
Green & Sustainable Science & Technology
Ruchun Wei, Lele Liu, Chao Jia, Hualin Zhao, Xiao Dong, Qingtao Bu, Changling Liu, Nengyou Wu
Summary: A series of undrained triaxial shear tests were conducted on shallow clayey-silty sediments in the Shenhu area of the South China Sea (SCS) to investigate their undrained shear properties under different overconsolidation ratio (OCR) conditions. The results showed that the undrained shear strength was proportional to the effective confining pressure for normally consolidated specimens, while it nonlinearly increased with increasing OCRs for OC specimens. A model was proposed to predict the pore pressure coefficient at failure, which successfully predicted the behavior of the sediments with different OCRs.
Article
Energy & Fuels
Man Huang, Zhirui Zhao, Dongchao Su, Lianghong Wu, Fanfan Qin, Meixia Zhang, Fulong Ning
Summary: To improve gas production in natural gas hydrate (NGH) reservoirs, a new method called radial water jet slotting and grouting (RWJSG) was proposed. A 3D gas production model based on the NGH reservoir in the South China Sea was constructed to evaluate the effectiveness of RWJSG. The results showed that RWJSG can effectively enhance gas recovery, with significant increases in hydrate dissociation efficiency, cumulative gas production, and gas to water production ratio.
Article
Energy & Fuels
Wei Li, Li Peng, Bin Fang, Wenjia Ou, Zhengtao Tao, Zhihui Liu, Jiangtao Pang, Fulong Ning
Summary: This study investigates the effects of two surfactants on the surface of a tetrahydrofuran (THF) hydrate using modified atomic force microscopy. It is found that the surfactants can change the grain size, decrease the grain boundary depth and surface roughness of the THF hydrate, as well as reduce the quasi-liquid layer thickness and adhesion forces. These findings provide important insights into the mechanism of how surfactants prevent hydrate aggregation.
Article
Geochemistry & Geophysics
Haitao Tian, Lele Liu, Linqi Zhu, Xinmin Ge, Pinbo Ding, Jianchao Cai
Summary: Permeability is a key factor in assessing fluid flow capacity and production performance of natural gas hydrate reservoirs. This study develops permeability and resistivity index models for grain-coating (GC) and pore-filling (PF) hydrates based on fractal geometry theory, establishing a new relationship between normalized permeability and resistivity index. Numerical simulations and analysis of pore microstructure images reveal that tortuosity fractal dimension is a critical parameter in this relationship. The proposed models are validated with laboratory and well log data, providing the possibility to predict normalized permeability of hydrate reservoirs based on electrical data alone.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Engineering, Marine
Zhichao Liu, Haoxian Shi, Zhiguo Zeng, Tao Zuo, Zhun Zhang, Li Peng, Dongdong Wang, Fulong Ning
Summary: An analysis of natural soil samples from the Shenhu area of the South China Sea revealed that the samples are clay-dominated soils with a low liquid limit. The presence of clay induces complex fluid-solid migration and water-induced bearing capacity decline. The samples exhibit strain-hardening and two-stage stiffness characteristics, with an absolute gas permeability varying from 0.05 to 1.5 mD and partial closed pores. The modulus-strength ratios of the natural soil samples in hydrate reservoirs of the South China Sea are independent of the confining stress, ranging from 24 to 107, and have recommended cohesion and friction angle values of 70 kPa and 28.2 degrees, respectively. These findings are important for parameter selection in numerical simulations and response evaluation of field hydrate productions.
Article
Computer Science, Interdisciplinary Applications
Xiaofeng Dou, Qi Wu, Zhichao Liu, Yingjie Zhao, Yanlong Li, Deli Gao, Fulong Ning
Summary: This study explores the influence of hydrate heterogeneity on the mechanical properties of hydrate-bearing sediments (HBSs) through discrete element modeling. The results show that HBSs with higher hydrate heterogeneity have lower peak strength, secant modulus, and maximum dilation angle. Additionally, weakly heterogeneous HBSs exhibit a more uniform contact force chain structure and more particle rearrangements. It is important to consider hydrate coalescence in laboratory experiments and field applications to accurately characterize the mechanical properties of HBSs with different hydrate heterogeneity degrees.
COMPUTERS AND GEOTECHNICS
(2023)
Review
Geosciences, Multidisciplinary
Zhun Zhang, Lele Liu, Wanjun Lu, Changling Liu, Fulong Ning, Sheng Dai
Summary: Commercial development of natural gas hydrate is important for energy structure, energy security, and global climate. Reservoir permeability is a critical parameter for hydrate exploitation and its dependence on various factors is comprehensively discussed. The study highlights the need for effective permeability models and challenges in accurately predicting gas production capacity. Collaborative research and development of agreeable measurement methods are proposed to address the challenges.
EARTH-SCIENCE REVIEWS
(2023)
Article
Thermodynamics
Bin Fang, Parsa Habibi, Othonas A. Moultos, Tao Lu, Fulong Ning, Thijs J. H. Vlugt
Summary: Continuous Fractional Component Monte Carlo (CFCMC) and molecular dynamics (MD) simulations were used to calculate the solubilities and self-diffusion coefficients of four light n-alkanes in aqueous NaCl solutions, as well as the thermodynamic properties of their corresponding hydrate crystals. Correction factors for alkane groups (CH3) and water were optimized by fitting excess chemical potentials to experimental data. Using these values, the solubilities of the four alkanes in NaCl solutions with different molalities and temperatures, and the diffusion coefficients in NaCl solutions were calculated. The lattice parameters and thermodynamic properties of the hydrates with different guest molecules were also computed. This research provides valuable thermodynamic data for understanding natural gas hydrate science.
JOURNAL OF CHEMICAL AND ENGINEERING DATA
(2023)
Article
Instruments & Instrumentation
Yapeng Zhao, Liang Kong, Gaowei Hu, Lele Liu, Jiaqi Liu, Yunkai Ji, Songkui Sang
Summary: Studying the mechanical behavior and permeability properties of hydrate-bearing sediments is important for the safe and efficient exploitation of hydrates. This paper proposes a new integrated experimental system (IES) that couples stress and seepage to study hydrate-bearing sediments. The results show that stress significantly affects permeability by compressing the seepage channels.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Engineering, Marine
Ruchun Wei, Lele Liu, Chao Jia, Xiao Dong, Qingtao Bu, Yongchao Zhang, Changling Liu, Nengyou Wu
Summary: This study proposes a prediction model of undrained shear strength of hydrate-bearing fine-grained sediments based on the critical state theory. Consolidated undrained triaxial shear tests are conducted on samples from the Shenhu area of the South China Sea to investigate the effects of consolidation stresses and hydrate saturations on the undrained shear strength. The results show that the undrained shear strength increases with increasing effective consolidation stress and hydrate saturation, and it is a two-parameter function of effective hydrate saturation and void ratio.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Energy & Fuels
Yizhao Wan, Yilong Yuan, Chao Zhou, Lele Liu
Summary: This paper provides an overview of the coupling processes in the exploitation and utilization of natural gas hydrates and geothermal energy, and presents future challenges and solutions. These studies are of great importance in advancing the development and utilization of geo-energy.
ADVANCES IN GEO-ENERGY RESEARCH
(2023)
Article
Energy & Fuels
Xiaodong Li, Gang Lei, Yizhao Wan, Wan Cheng, Jiaxin Sun, Fulong Ning
Summary: In this study, a novel model considering geomechanical behavior was proposed to simulate hydrate dissociation. The results showed that porosity strategies had little influence on the coupled system at small strains. Parametric analysis was conducted to study the effects of relative parameters on hydrate dissociation.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
Article
Energy & Fuels
Peixiao Mao, Nengyou Wu, Fulong Ning, Jiaxin Sun, Yizhao Wan, Xingxing Wang, Gaowei Hu
Summary: This study evaluated the effects of well number, deployment orientation, and production methods of spiral multilateral wells on gas production from muddy hydrate reservoirs. The results showed that increasing the number of wells improves gas recovery, while changing the deployment orientation has less impact on production. Additionally, synergistic depressurization of multiple wells enhances gas recovery, decreases water production, and eliminates gas production in blind zones.
GAS SCIENCE AND ENGINEERING
(2023)
