《佳文速递》2025年第9期

Mechanisms and Effectiveness of Microbial-Induced Carbonate Precipitation Reinforcement for Sand Control in Hydrate Reservoir

微生物诱导碳酸盐沉淀强化在水合物储层防砂中的机制与效果

发表时间：2025年7月14日

发表期刊：《Energy & Fuels》

Tianle Liu1, Shunbo Qin1, Jiaxin Sun1,2, Chengxiang Tang1, Enhao Luo1, Haitao Wang1, Yingtao Feng3, and Ce Cui3

1 National Center for International Research on Deep Earth Drilling and Resource Development, Faculty of Engineering, China University of Geosciences, Wuhan, Hubei 430074, China

2 Key Laboratory of Gas Hydrate, Ministry of Natural Resources, Qingdao Institute of Marine Geology, Qingdao, Shandong 266237, China

3 Institute of Oilffeld Chemistry, CNOOC OIL SERVICE CO. LTD., Beijing 065201, China

Abstract: Sand production restricts the safe extraction of hydrates, making efficient sand control technology essential for the industrialization of hydrate development. Microbial-induced carbonate precipitation (MICP) has emerged as a promising technique for reservoir reinforcement, offering both formation stabilization and effective sand control. In this study, the sand control efficiency and underlying mechanisms of MICP-reinforced hydrate deposits are explored. Meanwhile, the sensitivity analysis of factors that influence the sand control effect and the impact of reinforcement on permeability are examined. The experimental results demonstrate that the amount of sand production in the MICP-reinforced deposits can be reduced by more than 96%, as the calcium carbonate bridge effectively enhances the resistance of the sand particles against fluid erosion. Moreover, the reinforcement allows sand particles to aggregate, enhancing the stability of both the sand bridge and the clogging structure. The critical operational factors affecting sand control efficiency include treatment duration, reinforcement range, and grouting flow rate, which should be greater than 3 days, at least 3 times the thickness of the gravel layer, and less than 4 mL/min under investigation, respectively. Although there is a certain reduction in porosity and permeability, any loss in production potential during depressurization can be compensated for by optimizing the reinforcement range and increasing the production pressure differential.

Fig.11. EDS plane test results with different processing times (200× magniffcation). (a) and (d): MICP-treated sample after 1 day; (b) and (e): MICP-treated sample after 2 days; (c) and (f): MICP-treated sample after 3 days.

阅读原文：https://doi.org/10.1021/acs.energyfuels.5c01839

Mesoscale Mechanisms of Drilling Fluid Invasion on Hydrate Reservoir Stability: Effects of Drilling Fluid and Reservoir Properties

钻井液侵入对水合物储层稳定性的中尺度机制：钻井液与储层性质的影响

发表时间：2025年7月15日

发表期刊：《Energy & Fuels》

Faling Yin1, Yonghai Gao1,2, Yaqiang Qi3, Xinxin Zhao1,2, and Baojiang Sun1,2

1 School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, China

2 School of Petroleum Engineering and State Key Laboratory of Deep Oil and Gas,  Qingdao 266580, China

3 Tarim Oilffeld Company, China National Petroleum Corporation (CNPC), Korla 841000, China

Abstract: The disturbance around the well caused by drilling fluid invasion is the main reason for wellbore instability during drilling in hydrate reservoirs. Current research mainly focuses on the macro scale. This study explores the mechanism between invading drilling fluid and hydrate reservoir from a mesoscopic scale. The morphological characteristics of hydrate reservoirs in the invasion zone were observed by using a mesoscale experimental system. The influence mechanisms of different disturbance factors and reservoir properties on drilling fluid invasion and reservoir strength were analyzed through changes in pressure, temperature, and invasion front velocity during the invasion process. The results indicate that the local high pore pressure generated by hydrate decomposition has a dual mechanism for reservoir stability: weakening reservoir mechanical strength and hindering drilling fluid deep invasion. When drilling fluid invasion does not cause hydrate decomposition, the reservoir does not show significant strength-weakening characteristics, and the increase in pore pressure is relatively small. When the hydrate decomposes, the peak pore pressure increases by 0.13 MPa under an invasion pressure difference of 0.3 MPa, and the loose and weak cementation characteristics of the reservoir in the decomposition zone are observed. However, the high pore pressure reduced the drilling fluid invasion depth by 8.14 mm. During the invasion process of drilling fluid, local high pressure is manifested as a package-like protrusion, and the dissipation rate of the package-like protrusion depends on the decomposition rate of the upper hydrate and the permeability of the reservoir, which is more likely to occur in low-permeability reservoirs. Because of the slow heat and mass transfer rates in low-permeability reservoirs, the decomposition rates of upper hydrates and the release rates of decomposed gases are both relatively low. This study provides valuable insights for the control of wellbore stability during drilling in hydrate reservoirs.

Fig.4. Schematic diagram of the hydrate formation process in the microreactor.

阅读原文：https://doi.org/10.1021/acs.energyfuels.5c01947

The T+CO2H Code for the Analysis of Coupled Processes, Including CO2 Hydrate Formation and Behavior, during Sequestration in Saline Geological Formations

T+CO2H 代码用于分析在咸水地质构造中封存过程中耦合过程，包括二氧化碳水合物形成与行为。

发表时间：2025年7月15日

发表期刊：《Energy & Fuels》

George J. Moridis*

Department of Petroleum Engineering, Texas A&M University, College Station, Texas 77843, United States

Abstract: This paper discusses the development of T+CO2H, a numerical simulator that describes all the coupled processes involved in CO2 sequestration in saline aquifers. An impetus for this study was the investigation of the benefits of hydrate-assisted sequestration (HAS): (i) large CO2 amounts can be trapped as immobile solid hydrates, which (ii) deteriorate very slowly and (iii) reduce the permeability of the media they impregnate, thus (iv) restricting─and possibly completely eliminating by creating a hydrate caprock─the escape of the underlying CO2. The mathematical and numerical basis for the Jacobian-based, fully implicit, multiphase, multicomponent simulator was developed first. All available laboratory data were then used to develop new constitutive equations describing the entire CO2–H2O phase diagram and the effect of salt on CO2 hydration. It accounts for heat and up to four mass components (water, CO2, hydrate, and water-soluble inhibitors such as salts or alcohols) that are partitioned among six possible phases: gas, aqueous, liquid CO2, ice, CO2 hydrate, and halite. The phase diagrams identified 40 possible states and the criteria for state changes. The code can handle any combination of the possible hydrate formation and dissociation mechanisms under either equilibrium or kinetic conditions. The code was tested in validation problems that included (a) comparison against the results of an earlier study involving CO2 sequestration in a saline aquifer and (b) a series of relatively small problems that involved system changes covering most regions of the CO2–H2O phase diagram. Application tests included large-scale, long-term studies ranging from gaseous CO2 injection into an onshore saline aquifer to liquid CO2 injection into an oceanic aquifer. The study also analyzed the feasibility of HAS in onshore and offshore aquifers, and defined the envelope of the rather narrow, geology-imposed depth and temperature range that is conducive for oceanic hydrate formation.

Fig.19. Schematic of (a) pore channels, showing convergent-divergent geometry with a succession of pore throats and pore bodies and (b) a tubesin-series model of pore channels. Reproduced with permission from ref 38. Copyright 2014, Lawrence Berkeley National Laboratory.

阅读原文：https://doi.org/10.1021/acs.energyfuels.5c01808

Gas Hydrate Fire Extinguishers: A Novel Approach for Class B Fire Suppression

气体水合物灭火器：一种新型B类火灾扑灭方法

发表时间：2025年7月17日

发表期刊：《Energy & Fuels》

Sai Kiran Burla1, Jihoon Han1, Seong Deok Seo1, Sang-Gyu Cho1, Sohee Hong1, Jinwoo Lee2,3, Changsu Jeon1, Subhash Kumar Sharma1, and Ju Dong Lee1

1 Offshore Plant Resources R&D Center, Korea Institute of Industrial Technology, Busan 46744, Republic of Korea

2 School of Chemical Engineering, Pusan National University, Busan 46241, Republic of Korea;

3 R&D Center, CATOZ Co., Ltd., Busan 46744, Republic of Korea

Abstract: This study investigates the potential of hydrate-based fire extinguishers for Class B fire suppression, presenting the first comparative analysis of different hydrate extinguishers. The gas uptake kinetics and suppression efficiency of fire extinguisher hydrates were examined, revealing a strong dependence on the guest gas type and its selective occupancy within the hydrate cavities. A novel hydrate pelletization technique was developed, enabling the continuous production of hydrate-based fire suppression materials. Fire suppression trials using hydrates of HFC-125a, HFC-23, and CO2 in both cube (1–10 mm) and powder (0.5 mm) forms demonstrated that hydrate powders exhibited superior suppression performance due to their larger surface area and faster dissociation. The study also highlights the critical role of dispersion within the fire zone, which significantly influences the suppression efficiency. Comparative evaluations showed that hydrate powders outperformed conventional agents such as ammonium dihydrogen phosphate and ice powders, particularly in preventing flame reignition. Among the tested hydrates, HFC-125a and HFC-23 effectively inhibited reignition, whereas CO2 hydrates demonstrated lower efficiency. Additionally, results emphasized the necessity of maintaining a minimum extinguishing concentration for optimal fire suppression with the hydrate yield playing a key role in determining total gas release. HFC-23 required the highest heat of dissociation of HFC-125a and CO2. The suppression efficiency followed the order: HFC-125a > HFC-23 > CO2. These findings establish gas hydrates as promising fire suppression agents, offering both enhanced suppression performance and improved resistance to flame reignition. This study provides valuable insights for further optimization and large-scale application of hydrate-based fire extinguishing technologies.

Fig.6. Photographic images of ffre extinguisher experiments using 10 g of hydrate-based ffre extinguishers in cube and powder forms. Panels A1, B1, and C1 represent the cube forms of HFC-125a, HFC-23, and CO2 hydrates, respectively, while panels A2, B2, and C2 correspond to their powder forms. The 0 s time marks the moment of ffre suppressant application onto the pool fire.

阅读原文：https://doi.org/10.1021/acs.energyfuels.5c02431

Predicting the Thermo-Kinetics of sII Structure with Parameter-Free Hydrate Phase Description: Validation and Derivative-Free Optimization

利用无参数水合物相描述预测sII结构的热动力学：验证与无导数优化

发表时间：2025年7月21日

发表期刊：《Energy & Fuels》

Modhu Sailan Bagani, Shubhangi Sharma, and Amiya K. Jana

Energy and Process Engineering Laboratory, Department of Chemical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, India

Abstract: This work aims at developing the theoretical framework of sII hydrate structure, taking its kinetic and thermodynamic aspects relevant to formation dynamics. To make it rigorous and versatile for various applications in the hydrate domain, fundamental issues are addressed with practical relevance, including a wide range of guest gas species and their compositions, presence of salt ions in water, porous particles with variable size and shape, and porosity and permeability associated with an underground reservoir, among others. Along with fractional order kinetics and changeable reaction surface, the phase equilibrium among coexisting hydrate–vapor–liquid makes the hydrate dynamics complex and highly parametric with infinite solution sets. Estimating the thermodynamic equilibrium for vapor and liquid phases is at the matured state. For the rest of the hydrate phase, a recently proposed parameter-free model is adopted for the first time for the dedicated sII structure. Converging to an optimal parameter set specific to hydrate kinetics is one of the major concerns, for which a robust derivative-free global optimization method, namely, simplicial homology global optimization, is strategized. Finally, this proposed thermo-kinetic model framework is tested with a large variety of experimental data sets under reservoir mimicking conditions, including single to multicomponent guests, pure and saline water, and porous media.

Fig.1. Illustration of sII hydrate formation with mixed gases caged inside water molecules.

阅读原文：https://doi.org/10.1021/acs.energyfuels.5c01763