Understanding the dynamic evolution of gas hydrates within hydrophobic fine-grained sediments remains a significant challenge for predicting natural hydrate heterogeneity and for improving production strategies. However, the mechanism controlling the hydrate spatial heterogeneity and temporal evolution during phase changes are poorly understood. To address this, we investigated the formation and dissociation dynamics of gas hydrates in hydrophobic porous media using in situ X-ray computed tomography (X-CT). We observed a distinct boundary-driven growth mode, termed "wall-climbing", in which hydrates preferentially accumulated as massive aggregates with isolated pores at the upper region of the sediment, rather than forming uniform pore-filling hydrates within the internal matrix. During depressurization-induced dissociation, the decomposition of boundary-localized hydrate triggers fluid redistribution and substantial secondary hydrate formation in the lower sediment pores, highlighting a non-equilibrium self-organization pathway during decomposition. We elucidate the dynamic mechanism of gas hydrates in hydrophobic sediments by linking the wall-climbing effect and secondary formation to coupled effects of wettability-controlled capillary redistribution, preferential migration pathways, gravity, and boundary-localized heat transfer. We further propose a field-relevant conceptual analogy in which similar interface-driven accumulation and redistribution may occur at natural high-contrast boundaries, such as fractures, seep conduits, sediment-carbonate interfaces. These findings provide mechanistic insights into hydrate heterogeneity and dynamic redistribution, with implications for gas recovery, flow assurance, and interpretation of cold seep hydrate architectures.

The extraction of natural gas hydrates faces challenges due to unresolved in situ decomposition and permeability mechanisms, with reservoir permeability being a pivotal parameter for extraction safety, efficiency, and economics. This study addresses this by developing a novel competition model and models reconstructed via a multi-point statistical method based on real CT images. Using the lattice Boltzmann method, we examine the influence of key factors, such as porosity and saturation, on permeability. Since single-hydrate-morphology models often fail to match practical observations, we propose a competition model that describes the dynamic transition from grain-coating to pore-filling habits. Simulations show that predictions from the competition model converge more closely with experimental data than single-state models. Furthermore, the MPS-based reconstructions provide a realistic benchmark, validating the representativeness of the modeling approaches. The framework demonstrates promising potential for capturing diverse sedimentary scenarios, indicating wide applicability and avenues for future research.

Natural Gas Hydrate (NGH), as a significant and promising energy resource for advancing low-carbon development, has long been the focus of global energy resource research. The research on the extraction methods of submarine natural gas hydrate has attracted much attention. Recently, the most promising production method is depressurization, but the regular depressurization method is difficult to meet the efficiency requirement for commercial production. Therefore, it is necessary to innovate the depressurization method in order to develop a more effective approach for NGH production. The Pilot-scale Hydrate Simulator (PHS), with a volume of 117.8L, was employed in this study to conduct four NGH decomposition experiments with horizontal well under different methods including the Regular Depressurization (RD), the Cyclic Depressurization Above the Quadruple point (CD-AQ), the Cyclic Depressurization at the Quadruple point (CD-Q), and the Cyclic Depressurization Below the Quadruple point (CD-BQ). The experimental results show that the horizontal well exhibits higher production efficiency than the vertical well with the CD-AQ mode. When horizontal well is adopted, compared with the RD, the CD-AQ, the CD-Q, and the CD-BQ all enhance gas production efficiency and hydrate decomposition rate. Among three cyclic methods, lower starting pressure results in greater gas output. In the CD-BQ mode, with an initial pressure of 2.2 MPa, ice formation occurs during the process, which not only hinders gas production but also introduces potential safety risks. Therefore, CD-BQ requires specific geological conditions to be viable. In contrast, CD-Q significantly improves hydrate decomposition efficiency while maintaining process stability during both the depressurization and cyclic depressurization stages. This method optimizes both the well type and the cyclic pressure range, providing a new strategy for the NGH commercial development. Further studies on better optimization methods can be conducted based on this.

International field trials have demonstrated that sand production and control are crucial issues that need to be addressed and resolved to achieve the commercial exploitation of natural gas hydrate (NGH). The objective of this study is to investigate sand migration and control in sediments with different particle size distributions during depressurization-induced hydrate exploitation. A 50PPI (pores per linear inch) polyurethane foam was chosen as the sand control material to further explore its performance under conditions closer to actual field reservoirs, which is the continuation and extension of previous investigations. Experimental results confirm that the 50 PPI polyurethane foam demonstrates good sand control effectiveness for reservoirs with a median particle size (D 50) of quartz sands ranging from 10 to 100 mu m, even under material extrusion deformation. Under comparable reservoir conditions, finer and more heterogeneous sediments increase sand control requirements. Meanwhile, no definitive correlation between internal sand migration and actual sand production was observed. In reservoirs with fine quartz sand, sand production manifests as consolidated sediment migration after hydrate exploitation, while heterogeneous quartz sand reservoirs undergo significant internal changes before and after the NGH exploitation, accompanied by a evident decrease in gas production rate. Based on the experimental study, a theoretical framework for sand migration and production mechanisms during NGH exploitation is proposed, defining three distinct states. The state of sand migration shifts when local blockages reach a threshold, transitioning from particle migration to block displacement.

Clathrate hydrate-based hydrogen storage is an emerging technology that allows safe storage and the controllable release of hydrogen, making it a promising approach for secure hydrogen storage. In this study, hydrogen hydrate formation kinetics were first investigated in sodium dodecyl sulfate (SDS)/cyclopentane (CP)/H2 systems, using aluminum foam (AF) with pore densities of 20, 90, and 120 pores per inch (PPI). The results indicate that the AF framework provides abundant nucleation sites for hydrate formation, leading to a significant reduction in the induction time to within 20 min. Compared to AF with other pore densities, the 90 PPI AF demonstrates the most pronounced enhancement effect on hydrate formation, achieving a hydrogen gas uptake of up to 24.8 mmol H2/mol H2O at 12 MPa. In addition, a higher filling ratio of AF effectively promotes axial heat transfer during hydrate formation, leading to an increased hydrogen storage capacity. However, for systems with a high AF filling ratio, increasing the pressure shows no significant improvement in gas uptake.

Abstract As CO2 emissions from anthropogenic activities continue to increase, hydrate-based CO2 sequestration has attracted considerable attention. This study systematically investigated the formation behavior and the coupled heat and mass processes of CO2 hydrates under different injection well configurations. Experiments were conducted under single-well, dual-well, and triple-well gas injection conditions in a high-pressure crystallizer. The results indicate that the effect of well number on CO2 hydrate formation is nonmonotonic, while injection configuration plays a decisive role in governing hydrate formation behavior. The linear triple-well gas injection configuration reduced the induction time by 31.7% relative to the other triple-well configurations and achieved the highest final hydrate saturation of 23.45% among the configurations tested in this study. In addition, multiwell injection promoted a more uniform temperature distribution within the crystallizer. These results show that well-configuration optimization enhances hydrate formation efficiency and provides guidance for the design of multiwell CO2 injection strategies in heterogeneous porous media.

The CO2 replacement method, which enables simultaneous CH4 recovery and CO2 sequestration, is a highly promising green technology for natural gas hydrate (NGH) extraction. However, the replacement efficiency remains relatively low under conventional conditions. To overcome this limitation, the promoting effect of depressurization stimulation on the replacement process was systematically investigated using a laboratory-scale hydrate extraction apparatus. The results indicate that depressurization stimulation can effectively enhance CH4 recovery, primarily by disrupting the mixed hydrate layer on sediment particle surfaces and driving the replacement front deeper into the reservoir. While early depressurization favors CH4 recovery, later depressurization benefits CO2 sequestration. Increasing depressurization magnitude enhances CH4 recovery but contributes minimally to CO2 sequestration and is detrimental to geomechanical stability. Under five-stage depressurization, the CH4 recovery increased from 35.7% in the control experiment to 66.1%. Moreover, a threshold effect was observed for multistage depressurization, beyond which CH4 production primarily stems from hydrate dissociation, and replacement efficiency plateaus. These findings provide important experimental evidence and engineering guidance for the synergistic extraction of marine NGH coupled with geological CO2 sequestration.

Natural gas hydrates (NGHs) are recognized as a promising strategic green energy source due to their vast reserves and high energy density. Understanding their growth kinetics is of great significance for the comprehensive utilization of hydrates. However, the time-dependent hydrate growth kinetics remain unknown due to the difficulty of directly revealing the local growth behavior of hydrate crystals and the underlying controlling mechanisms. To address this unsolved problem, a newly developed 3D high spatiotemporal resolution in-situ visualization platform was employed to characterize the hydrate phase transition habits, aiming to explore influencing factors of morphological evolution and growth kinetics of gas hydrates from a microscopic perspective. Our results show that higher subcooling degree increases the morphological irregularity of hydrate crystals. More importantly, we found that the apparent kinetic parameter (Kapp) is not a constant; instead, the increase in crystal size leads to a significant reduction in Kapp. The change in kinetic parameter is attributed to the rise in crystal surface temperature caused by the exothermic heat released during hydrate growth. Meanwhile, once the crystal size reaches a certain threshold, the geometric effect becomes the dominant factor limiting the hydrate growth kinetics. Based on these in-situ time dependent hydrate growth observations, this study reveals the dynamic “morphology-volume” coupling mechanism of gas hydrate growth. Our findings provide mechanistic insights and theoretical support for the prediction and regulation of hydrate growth rates in the comprehensive utilization of gas hydrates.

The homogeneity of methane hydrates in marine sediments plays a significant role in determining the efficiency of gas production during exploitation processes. Revealing their distribution mechanisms is crucial for optimizing the development of gas hydrates. This work systematically investigates the evolution patterns of effective thermal conductivity (ETC) during the formation and dissociation of methane hydrate in marine sediments, focusing on their major mineral components, such as quartz sand, illite, and montmorillonite. The results reveal the influence of thermal conductivity (TC) characteristics in porous media on hydrate phase transition behavior and spatial distribution. Key findings demonstrate that the TC characteristics of porous media are one of the dominant factors controlling hydrate formation rates. High-conductivity porous media significantly accelerate hydrate formation through efficient heat transfer. The swelling characteristics of montmorillonite and its coupling effects with salt ions impair heat transfer pathways, thereby inhibiting hydrate formation. Further analysis reveals that the spatial heterogeneity in reservoir TC is the primary intrinsic mechanism responsible for the macroscopic heterogeneous distribution of hydrates. Additionally, the hydrate dissociation process disrupts solid-state thermal bridging and generates gaseous thermal barriers, causing irreversible attenuation of reservoir TC. This phenomenon exacerbates the non-uniformity of the front during dissociation and increases the risk of secondary formation during exploitation. From a novel perspective of reservoir TC heterogeneity, this study establishes mechanistic links between the thermophysical properties of porous media and the spatial distribution patterns of hydrates. This provides significant theoretical guidance for resource exploration and the safe, efficient exploitation of marine gas hydrate reservoirs.

The dynamic behavior of gas-water two-phase flow in hydrate-bearing sediments is critical for developing effective gas recovery strategies. To simulate the gas-water two-phase flow during gas production, water was injected from one end to displace methane from the initially methane-saturated pore space. The gas-water flow in hydrate-bearing sediments was investigated by integrated digital core analysis with computational fluid dynamics (CFD). A pore-scale model was constructed based on CT scan images through digital processing and segmentation, allowing CFD simulations of the displacement process. The results systematically reveal the effects of the displacement pressure, wall wettability, and hydrate saturation on flow behavior and displacement efficiency. Residual methane saturation decreases with increasing displacement pressure, but the marginal improvement diminishes beyond 400 Pa. Higher pressure also promotes the formation of connected flow channels. Wettability plays a critical role in displacement dynamics: hydrophilic surfaces improve efficiency by reducing residual gas, shortening breakthrough time, and facilitating flow channel development, whereas hydrophobic surfaces hinder the process. Furthermore, an increased hydrate saturation reduces pore connectivity. This results in higher displacement pressure and elevated pressure gradients along the flow path. Ultimately, more tortuous pathways and stronger capillary forces lead to greater residual methane saturation. The findings indicate that gas recovery from hydrate-bearing sediments can be improved by optimizing the displacement pressure and controlling the reservoir wettability.

Natural gas hydrates play a critical role in energy resource development and geological stability. Their phase transition is accompanied by significant volume expansion and thermal effects. To enable in situ, high-precision monitoring of this process, this study develops a multiparameter sensing system based on fiber Bragg grating (FBG) sensors. Water-ice freezing-thawing experiments were first conducted as a reference system to characterize baseline liquid-solid phase transition-induced strain behavior in sediments. Subsequently, temperature-controlled formation and dissociation experiments of tetrahydrofuran (THF) hydrate were performed to systematically investigate hydrate-induced strain responses. The effects of sediment grain size, hydrate saturation, and the spatial positioning of FBG sensors on phase change responses were analyzed, and the evolution of strain rate and spectral response during phase transitions was thoroughly investigated. Results demonstrate that FBG sensors can sensitively capture strain fluctuations induced by phase transitions, with strain amplitude positively correlated with hydrate saturation. Fast Fourier Transform (FFT) analysis of strain-rate signals successfully identified characteristic frequency bands and energy distribution patterns associated with phase transitions in sediments of different grain sizes. Furthermore, finer-grained sediments and higher hydrate saturation levels are associated with markedly larger strain amplitudes and more pronounced strain-rate responses during phase transition processes. Finally, a quantitative inversion model linking FBG parameters to hydrate saturation was developed, and the predicted values showed excellent agreement with experimental data. This study demonstrates the reliability of FBG-based monitoring for tracking hydrate evolution and provides essential experimental support for geological risk assessment during hydrate extraction.

The influence of salt on gas hydrates formation in pores is important for the efficient exploitation of gas hydrates in actual sediments. In this study, the experiments of methane hydrate formation in pores with different concentrations (0.00 wt%, 0.40 wt%, 1.00 wt%, 2.00 wt%, and 3.50 wt%) of sodium chloride (NaCl) brine were carried out in a glass micromodel. The effects of salinity on the micro growth morphology and growth rate of methane hydrate formed by free gas and dissolved gas in pores were studied. The results showed that, for the hydrate formed by free gas in pores, the hydrate was preferentially formed at the gas-liquid interface and then grew toward the gas body center. The hydrate growth rate along the gas-liquid interface (vinterface) was 100 to 150 times higher than that toward the gas bubble center (vcenter). Meanwhile, with the increase of salt concentration, the vinterface decreased. However, for the vcenter, it increased first and then decreased with the increase of the salt concentration, and the maximum average vcenter was obtained in the pores containing 0.40 wt% NaCl brine. The possible promotion mechanism of NaCl on the vcenter was analyzed in detail. For the hydrate formed by dissolved gas, the hydrate growth rate decreased with the increase of the distance between the hydrate growth front and the surrounding free gas bubble, and it also decreased with the increase of the salt concentration in pore water. This work is helpful in understanding the influences of salt on the microscopic growth characteristics of hydrate formed by free gas and dissolved gas in pores, so as to provide guidance for the efficient exploitation of gas hydrates.

Carbon capture and storage (CCS) in subocean environments is a promising solution due to its vast storage potential and accessibility. Herein, the particle fluidization approach is proposed for in situ CO2 hydrate formation in marine environments. We systematically assess the feasibility of clathrate (sI and sII) hydrates for CO2 sequestration in marine environments. Results show that CO2 can compete with promoters to occupy the 5(12)6(4) cages of sII hydrate, leading to enhanced storage capacity. With sII hydrate synthesized using 1,3-dioxane (5.56 mol %) at 8.5 degrees C and 3.6 MPa (real marine conditions), a CO2 uptake of 62.18 (+/- 2.23) VgVw-1 (volume of gas at STP/volume of seawater) was achieved, accompanied by an induction time of 7.33 (+/- 0.58) s and a formation rate of 6.562 (+/- 0.491) mmol/(mol & centerdot; min) (millimoles of gas/mol of seawater per minute). By comparison, sI hydrate exhibits a longer induction time of 2.44 (+/- 0.20) min, a lower formation rate of 0.538 (+/- 0.070) mmol/(mol & centerdot;min), and a reduced uptake of 47.36 (+/- 1.24) VgVw-1. The milder P-T conditions of sII hydrates make them ideal for various reservoirs, with the northern area of the South China Sea (SCS) potentially storing 19.76-26.05 Gt of CO2. The particle fluidization approach, combined with natural gas hydrate production, offers a transformative and sustainable model for hydrate-based CCS technology.

The process of exploiting natural gas hydrates involves complex phase changes, multiphase seepage, and intricate heat transfer processes. A comprehensive understanding of the heat transfer characteristics in natural gas hydrate reservoirs is crucial for enhancing their exploitation efficiency. However, at present, there is a limited amount of research on the effective thermal conductivity (ETC) of complex component systems in marine natural gas hydrate reservoirs, which directly restricts the optimization of natural gas hydrate exploitation technologies in marine sediments. This study proposes a method to predict the ETC of marine natural gas hydrate reservoirs based on machine learning (ML). This method constructed an ETC dataset under the conditions including reservoir environmental characteristics (temperature, pressure, salt concentration), reservoir physical property characteristics (quartz sand content, montmorillonite content, illite content), and reservoir structural characteristics (initial water saturation, hydrate saturation, component phase). In this work, a dataset containing 200 data points from various literature was compiled. Six ML models were employed to predict the ETC of the reservoirs based on this dataset with a high-precision ETC prediction model being derived through ML training. The SHapley Additive exPlanations (SHAP) method was subsequently applied to conduct interpretability analysis on the model prediction results. This has not only confirmed the model’s reliability but also quantitatively highlighted the sensitivity of key reservoir characteristics to ETC. The research results show that the Gradient Boosting Decision Tree (GBDT) model is particularly effective for predicting the ETC of marine natural gas hydrate reservoirs, as evidenced by its coefficient of determination (R2) exceeding 0.95. Sensitivity analysis reveals that the reservoir’s salt concentration and illite content are the primary determinants of its overall ETC. The prediction method established in this study can provide effective technical support for the real-time evaluation of reservoir ETC during the on-site exploitation of marine natural gas hydrate reservoirs.

Natural gas hydrates, with their vast reserves and high gas storage density, have emerged as a highly promising alternative energy source and technology for gas storage and transportation. Wettability, as a core surface property of porous media, directly influences hydrate nucleation, growth, occurrence morphology, and flow behavior. In this study, quartz sand with varying surface properties was prepared with the octyltrimethoxysilane (OTMS) silane coupling agent via surface chemical reactions. The methane hydrate (MH) equilibrium conditions as well as the formation kinetics in silica sand were measured, and the mechanism and potential of the surface modification for enhancing methane hydrate storage capacity were analyzed. The experimental results indicate that surface modification of quartz sand has no significant effect on the MH equilibrium condition. Hydrophobic modification of quartz sand provides more gas–liquid interfaces, increases the contact area, and thereby significantly enhances mass transfer under high-water-saturation conditions and accelerates the MH formation rate. However, excessively high surface hydrophobicity may reduce the effective gas–liquid interfacial area and limit the overall hydrate formation rate. Due to the influences of the hydrate distribution and aggregation, as well as gas diffusion on hydrate formation, the effect of the initial formation pressure on MH formation is only observed during the early stages of MH formation, while the temperature effect is less pronounced than that of formation pressure. It is suggested to further consider combining stirring with continuous gas injection to enhance gas–liquid flow and improve gas–liquid contact, thereby increasing the formation rate of hydrates.

As a promising clean energy resource, the industrial development of deep-water natural gas hydrate still encounters numerous challenges, particularly regarding the impact of hydrate heterogeneity on production performances and geological responses. The heterogeneous characteristics of hydrate-bearing sediments fundamentally affect the reliability and adaptability of production predictions and development strategies. This study innovatively constructs the hydrate-related geological models of homogeneous, locally heterogeneous, and layered heterogeneous reservoirs according to the first hydrate production test (2017) in the Shenhu Area, South China Sea and numerically analyzes the effects of hydrate heterogeneity on long-term depressurization-induced production performances and geological responses. Modeling and simulation results indicate that the layered heterogeneous reservoirs exhibit superior production performances with higher gas production and lower water production compared with the homogeneous and locally heterogeneous reservoirs. During the depressurization-induced production, the propagations of pressure and temperature reductions display symmetrical funnel-shaped distributions in homogeneous reservoirs, while these manifest as irregular, finger-like variations in the locally and layered heterogeneous reservoirs. Notably, the underlying free gas layer acts as a crucial pathway that effectively facilitates hydrate dissociation from the gas-hydrate interlayer to the overlying hydrate sediments. The heterogeneous hydrates promote the development of gas-dominant pathways, which can significantly improve the gas production efficiency and simultaneously suppress the water output in the reservoirs. Furthermore, sensitivity analysis results indicate that high long-term stable gas production is typically favored in highly permeable layered heterogeneous reservoirs and free gas layers with high gas saturation. These findings can provide theoretical guidance for optimizing the heterogeneous reservoir target and production development of the hydrate resources.

Natural gas hydrate is an alternative energy source with both reserve advantages and environmental friendliness. Thermal stimulation is a common method for extracting natural gas hydrate, and how to improve the extraction efficiency of natural gas hydrate by optimizing the layout of thermal injection well pattern is a subject worthy of in-depth exploration. This study conducted three sets of hydrate decomposition experiments in a pilot-scale hydrate simulator (PHS) with an effective volume of 117.8 L under different thermal injection well pattern conditions, including single-point heating, two-point heating, and four-point heating. The gas-water production characteristics and heat transfer processes of the three experimental groups were analyzed, and the real-time decomposition rate and energy efficiency ratio of hydrate decomposition under different extraction methods were quantitatively investigated. Experimental results show that under conditions of consistent total heating rate and hydrate saturation, the cumulative gas production of the experiments remained essentially the same, but increasing the density of heat source arrangements shortened the hydrate extraction time. Compared with twopoint and single-point heating, four-point heating intensified heat diffusion, but the reservoir temperature gradient in the four-point heating system decreased compared to single-point and two-point modes. Increasing the density of heating points improved heat exchange efficiency, but the dispersed arrangement of heat sources also increased heat losses. The two-point configuration exhibited the highest gas production rate and energy efficiency ratio, followed by four-point, while single-point showed the lowest values. These results may hold implications for optimizing thermal injection well patterns in trial production projects and future commercial exploitation of natural gas hydrates.

Gas hydrate is viewed as a potential energy, and the multihorizontal depressurization wells are expected to achieve its commercial production. However, how to optimize the multihorizontal wells layout in hydrate reservoirs is controversial. In this research, the numerical study on the hydrate exploitation from the Shenhu Area of the South China Sea by the dual-horizontal depressurization wells (DHDW) was conducted, and the optimal spatial position of DHDW was first studied. It is realized that the optimal spatial position of DHDW for gas hydrate production should be in the center of the hydrate layer. Based on this conclusion, the influences of the well spacing between DHDW (ranging from 22 to 582 m) on hydrate exploitation were then investigated. It is found that there was a strong interference between DHDW when the well spacing was smaller, leading to the lower total produced gas volume. When the well spacing increased to a certain value, the interference disappeared, and the total produced gas volume reached the maximum. On this basis, a new method to calculate the optimal well spacing (d o) between DHDW was proposed. According to the calculation, when the exploitation period was 10 years, the d o between the DHDW values was 73.06 m. Finally, the influences of the permeability (k) in the hydrate layer (2.9-145 mD) and the exploitation period (t) of gas hydrate (5-30 years) on the d o were further studied. The function relations of d o and k, and d o and t were obtained, respectively. Furthermore, the implications for the optimal layout of multihorizontal depressurization wells in hydrate reservoirs were discussed. This study could provide guidance for the efficient exploitation of gas hydrate.

The gas-liquid production behaviors of hydrate-bearing layers involve the coupling of thermal-hydraulicchemical (THC) multi-physical fields. The behaviors of methane hydrate dissociation in porous sands by pure depressurization and thermal-assisted depressurization methods via a single vertical well are investigated in a cuboid high-pressure reactor (CPR). Numerical models are developed to quantify the physical and chemical processes of fluid flow in porous media. The simulation results suggest that key indicators, including the gas and water production profiles, the spatial distributions of pressure, temperature, and phase saturations, and component mass, all agree well with the experimental data. It also clarifies the evolution of the dissociation front of methane hydrate in porous sands under the synergy effect of depressurization and electrical heating, and visualizes the complex hydrate dissociation mechanisms that are technically difficult to be measured in the experiment. In the earlier (0-160 min in Reference Case) and later (160-280 min) stages of hydrate dissociation, the kinetics and heat transfer are the dominant factors, respectively. The key finding is that the laboratory trials of pressure-induced and thermal-assisted methane hydrate reactions can be reproduced faithfully by numerical models with a group of unaltered parameters. By minimizing the deviations between numerical simulations and experimental data (less than 10 %), this study gives some deep insight into the determination of key parameters in the coupled THC system affecting hydrate dissociation, including the thermal conductivity of quartz sands lambda s = 2.4 W/m/K, the absolute permeability k0 = 21.1 D, and the adjustment factor FA = 0.03 in the kinetic model of methane hydrate dissociation. It is noteworthy that the mathematical models and the above parameters apply to both of the two simulated cases of methane hydrate dissociation under depressurization and thermal stimulation.