《佳文速递》2025年第10期

Freeze barrier enhanced depressurization of hydrate exploitation: An improved method for the permeability boundary of marine hydrates

冻土屏障增强的水合物开采减压技术：一种改进的海洋水合物渗透性边界方法

发表时间：2025年7月28日

发表期刊：《Energy》

Yuan Wang1,2, Chenli Dai1,2, Zhilin Chen1,2, Xiuping Zhong1,2, Wei Guo1,2,3

1 College of Construction Engineering, Jilin University, Changchun, 130021, China 

2 Key Lab of Ministry of Natural Resources for Drilling and Exploitation Technology in Complex Conditions, Jilin University, Changchun, 130021, China 

3 Key Laboratory of Groundwater Resources and Environment (Jilin University), Ministry of Education, Changchun, 130021, China

Abstract: The implementation of an artificial impermeable overlying boundary has been proven to enhance recovery efficiency and prevent methane leakage during marine natural gas hydrate extraction. However, traditional methods such as lurry, gel, or CO2 hydrate injection can cause irreversible damage to the marine ecosystem, and prevent effective recovery of the materials used. To overcome these drawbacks, this study proposes the construction of a frozen barrier in the overlying layer of marine gas hydrates, to suppress methane leakage, strengthen the overlying sediments, and prevent seawater intrusion. This approach avoids ecological damag, and ensures seabed strata resilience. Experimental results show that the critical temperature for frozen barrier formation is −3°C, this effectively prevents the infiltration of pore fluids under actual marine conditions. The effects of the barrier's freezing temperature and range on the gas production rate are numerically analysed, and simulation results show that the presence of the frozen barrier enhances the depressurization effect, thereby increasing the production rate by 18.67%. When the frozen barrier range is 60m, the hydrate dissociation rate increases by 24.67%, and cumulative gas production rises by 24.41%.

Keywords: Marine natural gas hydrate; Impermeable boundary; Numerical simulation; Permeability; Porosity

Fig. 5. Schematic diagram of the freezing mechanism of the pore medium.

阅读原文：https://doi.org/10.1016/j.energy.2025.137742.

A numerical study of hydrate-based CO2 storage using CO2-in-water emulsion: optimizing emulsion injectivity, and storage capacity

基于水合物二氧化碳储存的数值研究：采用二氧化碳-水乳液，优化乳液注入性能及储存容量

发表时间：2025年7月31日

发表期刊：《Fuel》

Aabes Bahmaee, Sumihiko Murata

Department of Civil and Earth Resources Engineering, Graduate School of Engineering, Kyoto University, Kyoto, Japan

Abstract: Carbon capture and storage (CCS) is critical for net-zero emissions, with hydrate-based CO2 storage (HBCS) offering enhanced capacity but facing injectivity challenges from rapid near-wellbore hydrate formation. This study employs our improved 3D numerical model, implemented in the MATLAB Reservoir Simulation Toolbox (MRST), to investigate the feasibility of injecting CO2-in-water (C/W) emulsions into hydrate stability zones (HSZs), focusing on optimizing injectivity, storage capacity, and long-term CO2 fate. Qualitatively validated against 3D reactor experiments, the model confirmed that the hydrate film volume fraction (α) profoundly influenced injectivity: higher α values enabled sustained injection for higher CO2 emulsions, while lower α led to immediate wellbore blockage. Water-Alternating-Emulsion (WAE) injections effectively mitigated near-wellbore hydrate blockage. Salinity’s impact was nuanced, facilitating injection for high CO2 fractions by inhibiting hydrate formation, but alleviating blockage for low CO2emulsions through enhanced solubility. Our model demonstrated the emergence of a self-trapping cap-and-channel flow regime. This regime optimized C/W emulsion sweep efficiency and pore‑space utilization, boosting HBCS capacity and achieving local hydrate particle saturations exceeding 40%. Our schemes successfully injected up to 0.128 Mt of CO2 into HSZs through a single well. Long-term simulations then confirmed secure CO2 trapping: all liquid CO2 droplets eventually underwent phase change, with the total CO2 mass securely partitioned (nearly 60% as hydrate particles and the remaining ∼40% dissolved via density-driven downward migration), resulting in minimal leakage. This confirmed high conversion efficiency and secure trapping. This work underscores the importance of optimizing injection parameters and WAE efficacy, providing a robust foundation for scalable carbon storage and enhanced methane recovery from hydrate reservoirs.

Keywords: Geological carbon storage; Hydrate-based CO2 storage; Numerical simulation; CO2-in-water emulsion; Water-alternating-emulsion; Methane hydrate enhanced recovery

Fig. 11. Spatial distribution of temperature in the aquifer for the CE15 (α = 0.25) case at various time points.

阅读原文：https://doi.org/10.1016/j.fuel.2025.136399

Unveiling hydrate nucleation mechanisms: gas concentration thresholds and memory effect origins

揭示水合物成核机制：气体浓度阈值与记忆效应起源

发表时间：2025年7月25日

发表期刊：《Journal of Molecular Liquids》

Zixuan Dong, Jinxiang Liu, Jiawei Cao, Enze Wu, Fengfeng Chi, Shengli Liu

School of Science, Nanjing University of Posts and Telecommunications, Nanjing 210023, China

Abstract: Abstract: Understanding hydrate nucleation mechanisms is critical for both fundamental research and technological applications. This study employs molecular dynamics simulations to investigate hydrate formation kinetics and elucidate the microscopic origin of the memory effect. Our results demonstrate that high gas concentrations amplify the thermodynamic driving force for nucleation, significantly accelerating the nucleation process. Below a critical gas concentration threshold, nucleation is suppressed as thermal fluctuations are insufficient to induce phase transition. Furthermore, pre-existing hydrate-like structures are shown to facilitate nucleation by serving as templates, reducing induction times through preferential nucleation site modification. The promotion efficiency scales with the size of pre-existing structures and is most pronounced at moderate gas concentrations. Notably, the memory effect exhibits strong temperature dependence (270–290K) but weak pressure dependence (20–35MPa).

Keywords: Natural gas hydrate; Nucleation; Memory effect; Residual structure

Fig. 6. The time evolution of the number of water molecules in the hydrate phase for systems with/without a pre-existing 5-Å-radius hydrate nucleus under different  methane concentrations at 270K and 35MPa.

阅读原文：https://doi.org/10.1016/j.molliq.2025.128213.

Comparative studies of methane hydrate formation from water adsorbed by montmorillonite, kaolinite and bentonite

蒙脱石、高岭石和膨润土吸附水形成的甲烷水合物形成机制的比较研究

发表时间：2025年7月25日

发表期刊：《Journal of Molecular Liquids》

Andrey Y. Manakov1, Sergey S. Skiba1, Tatyana P. Adamova1, Andrey S. Stoporev2

1 Nikolaev Institute of Inorganic Chemistry SB RAS, Lavrentieva ave. 3, Novosibirsk 630090, Russian Federation 

2 Moscow Institute of Physics and Technology, National Research University, Institutskiy per. 9, Dolgoprudny 141700, Russian Federation

Abstract: Clays are one of the most common components of hydrate-containing sedimentary rocks. This is the reason for the interest in studying hydrate formation in them. This work is devoted to studying the equilibrium conditions of methane hydrate formed from water adsorbed by three types of clays: kaolinite, montmorillonite, and bentonite in the temperature range -20 – +20 °C and pressures of 60–110bar. The pore size distribution and cation composition were also determined for each clay sample. It was found that gradual decomposition of the methane hydrate in the montmorillonite sample occurs in the temperature range from -20°C (the lowest temperature used in the experiment) to a temperature slightly below the equilibrium point for the bulk hydrate. For kaolinite and bentonite, the temperature range of hydrate decomposition was substantially narrower, spanning from ∼-1 °C to temperature ∼1 °C below the bulk hydrate equilibrium point. The degree of water to hydrate conversion varies from 0.7 to 1, 0.45 to 0.76, and 0.13 to 0.20 for kaolinite, montmorillonite, and bentonite, respectively. The discovered features of hydrate formation are explained in terms of the structure and composition of the clays used. It was shown that the peculiarities of hydrate formation in clays depend significantly on the magnitude of the layer charge and the composition of interlayer cations.

Keywords: Gas hydrate; Methane; Water adsorption; Montmorillonite; Kaolinite; Bentonite

Fig. 4. Cumulative pore volume and differential distribution of pore volumes depending on pore diameter for (a) kaolinite, (b) montmorillonite, (c) bentonite. The 

curves are plotted based on the adsorption branch of the nitrogen sorption isotherm using the BJH method.

阅读原文：https://doi.org/10.1016/j.molliq.2025.128209

Dynamic Electrical Properties of Hydrate during Dissociation: New Insights from Multiphysics Coupling Simulation

水合物在解离过程中的动态电学性质：多物理场耦合模拟的新见解

发表时间：2025年7月29日

发表期刊：《Energy & Fuels》

Yilun Zhang1,2,3 and Xixi Lan4

1 Yunnan Key Laboratory of Unmanned Autonomous Systems, Kunming 650504, China; 

2 School of Electrical and Information Engineering, Yunnan Minzu University, Kunming 650504, China; 

3 School of Earth and Space Sciences, Peking University, Beijing 100871, China

4 Faculty of Electric Power Engineering, Kunming University of Science and Technology, Kunming 650500,

China

Abstract: Since natural gas hydrate is stable only under low-temperature and high-pressure conditions, it will dissociate and transform from a solid to gas state once conditions vary in the course of exploitation, and the massive release of methane gas will lead to the greenhouse effect. Characterizing the dynamic electrical properties during hydrate dissociation presents fundamental challenges, particularly with regard to time-dependent mechanisms. This study investigates marine hydrate-bearing sediments through pore-scale finite element modeling, coupling thermal and electrical fields to dynamically simulate phase transition processes. The constructed three-dimensional framework accounts for diverse hydrate distribution patterns and saturation levels during dissociation. The results show that resistivity decreases gradually with temperature changes and hydrate phase transition. According to the temperature change caused by heat conduction, the hydrate dissociation process can be divided into three stages. Moreover, the variation in saturation during the hydrate phase transition affects the speed of resistivity variation but does not change the trend of that. It is also found that the trend of hydrate dissociation with time is similar for different distribution morphologies. This study enhances the understanding of coupled thermoelectrical responses in hydrate-bearing sediments under dynamic dissociation conditions and provides insight into the electrical properties of hydrate-bearing sediments with phase transition and shows potential application value in the exploitation of natural gas hydrate.

Fig.7 (a−h) Schematic diagrams of the hydrate phase transition at different times in the PF mode.

阅读原文：https://doi.org/10.1021/acs.energyfuels.5c02407