Methane Gas Extraction Research Articles

Optimizing unconventional gas extraction: The role of fracture roughness

In unconventional reservoir engineering, such as coalbed methane and shale gas extraction, fracture behavior is pivotal in gas accumulation, migration, and extraction, acting as a primary channel for gas flow. Current research inadequately addresses the quantitative impact of fracture roughness on gas extraction. In this study, we introduce a novel interdisciplinary model that quantitatively characterizes shale fracture roughness and correlates it with shale permeability. This model comprehensively considers factors affecting shale extraction, including fracture roughness, in situ stress, reservoir deformation, and adsorption-desorption dynamics. It provides a thorough analysis of how fracture roughness influences gas seepage, extraction efficiency, and reservoir stability under various physical conditions. Our validated findings reveal that fracture roughness significantly affects shale permeability, stress responses, and displacement. As the fracture roughness coefficient χ increases from 0.2 to 1.0, the maximum reduction in gas pressure within the hydraulically fractured region is 4.7%, while the maximum increase in reservoir stress is 2.8%. In shale reservoirs near extraction well, particularly in hydraulically fractured zones, the maximum decrease in shale gas pressure is 11.1%, and the maximum increase in stress is 3.2%, which offer a groundbreaking approach for optimizing extraction rates and ensuring project safety in the industry.

Characterization of methane hydrate extraction influenced by hydraulic fractures using a coupled thermo-hydro-mechanical-chemical model

The low permeability of the methane hydrate-bearing sediment limits the methane gas extraction. To enhance methane hydrate extraction, hydraulic fracturing can be a promising approach to improve the hydrate reservoir permeability by creating a fracture network in the reservoir. In this study, a coupled thermo-hydro-mechanical-chemical mathematical model and its numerical implementation based on finite element technology are introduced to analyze the methane hydrate extraction through fractured methane hydrate-bearing sediment considering methane hydrates dissociation, gas-water two-phase flow, heat transfer, dynamic changes of the sediment permeability, and deformation of both sediment matrix and fractures as well as capturing the interplay between them. The coupled thermo-hydro-mechanical-chemical numerical model is verified by reproducing a methane hydrates dissociation laboratory test. Finally, we conduct a series of simulations for the methane gas depressurization extraction through the sediments with the DFNs assigned as diverse geometrical characteristics. The influence of hydraulic fracture network geometrical and hydraulic characteristics on methane hydrate extraction are discussed. The results can offer a reference for enhancing the methane hydrate extraction efficiency.

Expulsion of small molecule hydrocarbons and expansion of nanopores effect in tectonically deformed coal evolution

This work aimed to investigate the impact of the evolution of small molecular structures during the deformation of coal on the constraints imposed on nanoscale pores and adsorption behaviors. Both undeformed and tectonically deformed coal (TDC) from the Huaibei mining area in China were collected for analysis. The pyridine was employed for the extraction of small molecules from coal, which was further complemented by Fourier-transform infrared spectroscopy (FTIR) and low-pressure CO2 and N2 adsorption experiments (LP-CO2/N2AD). The study yielded the following results: (1) Intense tectonic stresses facilitate the removal and recombination of small molecular side chains within the basic structural units (BSU) of coal. As deformation occurs, hydroxyl groups, aliphatic hydrocarbons, C=O, C=C, aromatic hydrocarbons, and 'C' structures tend to accumulate, resulting in an enhanced extraction rate. (2) The deformation process of the coal demonstrates a significant pore-expansion effect, with the most substantial increase observed in micropores (surface area increased by over 70 %), followed by mesopores and macropores. This enlargement facilitates the aggregation of small molecules and gas storage. (3) Intense deformation stages involving shear slip, ductile deformation, and maceral fragmentation result in small molecular fractures and an increased number of micropores. The removal and recombination of I, DOC, and CH2/CH3 within BSUs lead to the formation of larger interconnected pores accompanied by the aggregation of hydroxyl groups (OH–), C=O, C=C, aliphatic hydrocarbons, and 'C' structures. (4) The adsorption capacity of residual coal is lower than that of the raw coal before extraction, indicating that small molecular structures contribute to increased adsorption. This likely plays a significant role in the higher gas content observed in structurally deformed coal. The removal of small molecular structures effectively diminishes the adsorption capacity, providing novel perspectives for coalbed methane development and gas extraction in TDC areas.

Assessment of the Suitability of Coke Material for Proppants in the Hydraulic Fracturing of Coals.

To enhance the extraction of methane gas from coal beds, hydraulic fracturing technology is used. However, stimulation operations in soft rocks, such as coal beds, are associated with technical problems related mainly to the embedment phenomenon. Therefore, the concept of a novel coke-based proppant was introduced. The purpose of the study was to identify the source coke material for further processing to obtain a proppant. Twenty coke materials differing in type, grain size, and production method from five coking plants were tested. The values of the following parameters were determined for the initial coke: micum index 40; micum index 10; coke reactivity index; coke strength after reaction; and ash content. The coke was modified by crushing and mechanical classification, and the 3-1 mm class was obtained. This was enriched in heavy liquid with a density of 1.35 g/cm3. The crush resistance index and Roga index, which were selected as key strength parameters, and the ash content were determined for the lighter fraction. The most promising modified coke materials with the best strength properties were obtained from the coarse-grained (fraction 25-80 mm and greater) blast furnace and foundry coke. They had crush resistance index and Roga index values of at least 44% and at least 96%, respectively, and contained less than 9% ash. After assessing the suitability of coke material for proppants in the hydraulic fracturing of coal, further research will be needed to develop a technology to produce proppants with parameters compliant with the PN-EN ISO 13503-2:2010 standard.

Numerical simulation and investigation of methane gas distribution and extraction in goaf with U-type ventilation of working face

The accumulated methane in goaf during coal mining may leak into the working face under the airflow influence, which is possibly causing disasters such as methane gas excessive at the working face and seriously threatening the mine safety. This paper first established a three-dimensional numerical model of the mining area under U-shaped ventilation, introducing the gas state equation, continuity equation, momentum equation, porosity evolution equation, and permeability evolution equation to simulate the airflow field and gas concentration field in the mining area under the natural state. The reliability of the numerical simulations is then verified by the measured air volumes at the working face. The areas in the mining area where gas is likely to accumulate are also delineated. Subsequently, the gas concentration field in goaf under the gas extraction state was theoretically simulated for different locations of large-diameter borehole. The maximum gas concentration in goaf and the gas concentration trend in the upper corner were analyzed in detail, and the critical borehole location (17.8m from the working face) was determined as the optimum location for gas extraction from the upper corner. Finally, a gas extraction test was carried out on-site to evaluate the application effect. The results show that the measured airflow rate has a small error with the simulated results. The gas concentration in the area without gas extraction is high, with the gas concentration in the upper corner being over 1.2%, which is greater than the critical value of 0.5%. The maximum reduction in gas concentration was 43.9%, effectively reducing the gas concentration in the extraction area after employing a large borehole to extract methane gas. The gas concentration in the upper corner and the distance of the borehole from the working face are expressed as a positive exponential function. The field engineering results show that the implementation of the large borehole at a distance of less than 17.8m from the working face can control the gas in the upper corner to less than 0.5%, effectively reducing the risk of gas in the upper corner. The numerical simulation work in this paper can provide some basic support for the design of an on-site borehole to extract gas from the mining void and reduce the gas hazard in coal mines.

Multiscale Piezoelasticity of Methane Gas Hydrates: From Bonds to Cages to Lattices

For the past several decades, natural gas, also called methane gas, has been recognized as a green energy resource. It can generate energy by burning and produces fewer pollutants and carbon dioxide than coal and petroleum. For these reasons, it is also being viewed as a bridge fuel to renewable energy. Conservative estimates suggest that 80% of the naturally occurring hydrates on the planet contains natural gas. This vast amount translates to approximately twice the amount of energy stored in fossil fuels and oils. In addition, the special guest–host structure of gas hydrates provides a significant storage capacity, which makes the hydrate become a competitive candidate for carbon dioxide sequestration. However, the instability of hydrates during exploration becomes the biggest barrier for methane gas extraction and carbon dioxide sequestration. Thus, to overcome this barrier, this paper aims to investigate the stability limits and study the piezo effect of structure I (sI) methane gas hydrates at 0 K. This work investigates the structure, thermodynamics, and elasticity of sI methane hydrates subjected to pressure loads, at three scales, atoms, cages, and lattice, using the density functional theory in conjunction with homogenization methods and the theory of mixtures. The distribution functions of bond parameters are characterized in the hydrate system, which provides a novel understanding on the spread of values at the smallest scale. The roles of different types of cages at the mesoscale have been identified, such as continuous phase and disperse inclusion. At the continuum scale, the different deformation mechanisms are observed (affine and non-affine), which correspond to different fracture mechanisms (brittle and ductile) under tensile and compressive pressures, respectively. Taken together, the systematic atomic–cage–lattice multiscale characterization proves fruitful in linking processes that connect mechanical properties, cage geometry, and hydrogen bonding. The multiscale methodology can be generalized to other gas hydrates to improve the fundamental understanding and obtain engineering correlations.

Investigations on the influence of wellbore configuration and permeability anisotropy on the gas production from a turbidite hydrate reservoir of KG Basin

Extraction of methane gas from the gas hydrate bearing sediments (GHBS) would primarily depend upon its overall characteristics such as type of the sediments and their stratification, hydrate saturation and morphology, thermo-hydro-mechanical properties (viz., thermal properties, permeability, compressibility), in-situ pressure and temperature conditions prevailing in the reservoir, wellbore configuration (vertical and horizontal), and the process of dissociation (viz., depressurization and thermal stimulation). However, out of these parameters which one(s) would control enhanced gas production from a turbidite hydrate reservoir is a question that needs to be addressed. With this in view, numerical simulations were conducted by employing TOUGH + HYDRATE and considering a clay-dominant turbidite hydrate reservoir, which is a typical of KG Basin, India, and its properties ascertained during the NGHP-02 expedition. This exercise reveals that the vertical wellbore, which is easier to execute as compared to the horizontal wellbore, and depressurization in tandem with wellbore heating would enhance the gas production from the GHBS. In addition, the presence of clay layers has been noticed to impede the dissociation front migration and gas production. It has also been observed that the short-term gas and water production increases and the time required for production of significant gas decreases with an increase in the permeability anisotropy. However, the mass of methane produced has been found to be practically uninfluenced by permeability anisotropy.

Numerical modeling of gas extraction from coal seam combined with a dual-porosity model: Finite difference solution and multi-factor analysis

Gas extraction from coal seams is an extremely significant technical measure for preventing gas hazards and predicting coalbed methane (CBM) reservoir. Gas diffusion and seepage properties during the extraction process jointly dominate the CBM migration and production. How to integrate diffusion and seepage theories to construct numerical models of coalbed methane flow and evaluate extraction performance has become one of the hot spots of competitive research. In this work, we developed an integrated mathematical model of seepage and diffusion during borehole gas extraction combined with a dual-porosity model. Emphatically, the gas diffusion driver in coal matrix is no longer the concentration gradient (CG) associated with Fick's Law, but the innovative free gas density gradient (FGDG). The driving force for gas seepage in fractures remains the pressure gradient (PG) with respect to Darcy's law. Here, seepage and diffusion were coupled by a gas source term equation. Subsequently, a numerical simulator based on finite difference method (FDM) was programmed to compute the mathematical equations of gas extraction. Finally, the simulation results were validated by field gas extraction data and the contribution of some key parameters to the gas flow rate was discussed. The findings indicate that: (i) the simulation results are generally consistent with field data, and the developed model as well as simulator both have the capability to predict methane gas extraction. (ii) The gas diffusion process in coal matrix can be considered to be dominated by the FGDG. (iii) The gas permeability coefficient in fractures mainly controls the gas flow rate in the early extraction stages, while the coal matrix radius and microchannel diffusion coefficient contribute more in the later periods of gas extraction. (iv) Fracture porosity is positively correlated with gas flow rate and negatively correlated with the magnitude of flow rate decay. (v) The higher the original gas pressure or the lower the extraction pressure, the greater the pressure gradient between the borehole and the coal seam, contributing to an increase in gas flow. This work is expected to provide some support in modelling the gas flow in coal seam and assessing the dynamic CBM production.

Mapping methane point emissions with the PRISMA spaceborne imaging spectrometer

The detection and repairment of methane leaks from fossil fuel production activities have been identified as a key climate change mitigation strategy. Several types of optical satellite sensors have recently shown potential to support this task. Spaceborne imaging spectrometers measuring in the 400–2500 nm spectral range belong to this group. These instruments measure the solar radiation reflected by the Earth in hundreds of spectral channels with a typical spectral resolution of 10 nm and a spatial resolution of 30 m. The PRISMA mission from the Italian Space Agency is the first system of this type providing data openly to the international scientific community. In this work, we evaluate the potential of PRISMA to map methane point emissions, which are typical for fossil fuel production activities. Our retrieval of methane concentration enhancements is based on a matched-filter based algorithm applied to PRISMA spectra in the 2300 nm shortwave infrared spectral region. We perform a simulation-based sensitivity analysis to assess the retrieval performance for different sites. We find that surface brightness and homogeneity are major drivers for the detection and quantification of methane plumes with PRISMA, with retrieval precision errors ranging from 61 to 197 parts-per-billion in the evaluated images. The potential of PRISMA for methane mapping is further illustrated by real plume detections at different methane hotspot regions, including oil and gas extraction fields in Algeria, Turkmenistan, and the USA (Permian Basin), and coal mines in the Shanxi region in China. Our study reports several important findings regarding the potential and limitations of PRISMA for methane mapping, most of which can be extrapolated to upcoming satellite imaging spectroscopy missions.

Small Angle X-ray Scattering Test of Hami Coal Sample Nanostructure Parameters with Gas Adsorbed Under Different Pressures.

The complexity and multiscale structure of coal pores significantly influence the gas diffusion and seepage characteristics of coal. To apply small angle X-ray scattering (SAXS) to study the coal pore structure parameters within the scale of 1-100 nm in the methane adsorption process, the X-ray window was optimized and a gas adsorption chamber was designed to interface with the small angle X-ray scattering platform. The fractal dimension and porosity of Hami coal samples under different methane pressures were studied using the small angle X-ray scattering platform and adsorption chamber. The surface and nanopore fractal information of the nanopores in coal were distinguished. The variation trends of the pores and surface fractal dimension with time under the same methane pressure were compared. The results indicate that the surface dimension changes from 2.56 to 2.75, and the extremum point may indicate that the primary nanopore structure is crushed by the adsorbed gas after approximately 15 minutes. This work clarifies that the fractal dimension can characterize the changes in nanopores in the process of gas adsorption by using SAXS. According to the fractal characteristics, the adsorption of gas in coal nanopores is summarized as four steps: expansion from adsorbance, deformation, crushing and recombination. The minimum porosity is 0.95% and the extreme value point is 1.47%. This work also shows that decrease in surface energy affect the porosity changes in nano-size pores. This work is of some significance to coalbed methane permeability improvement and gas extraction.

Modeling of Gas Transport Driven by Density Gradients of Free Gas within a Coal Matrix: Perspective of Isothermal Adsorption

Gas transport in a coal matrix is critical for the evaluation of coalbed methane storage and gas extraction. This transport behavior is generally considered to be in accordance with Fick’s law but ...

Carbon emission assessment and control measures for coal mining in China

Coal is the most important primary energy in China. Although the proportion of coal in China's total energy consumption continues to decline it will still be the main energy in China for a long time in the future. As the largest contributor to China's greenhouse gas emissions, the energy conservation and emission reduction of coal industry will be the most critical step for China to cope with global climate change and solve environmental problems at present and in the future for a long time. The object of this study was coal mining in China. Life cycle assessment (LCA) was used to quantify carbon emissions in whole process of coal mining, including mining, ventilation, drainage, power consumption, transportation, and post-mining activities. The analysis result shows that the carbon emissions of producing tons of coal are 164.403 kg of carbon dioxide equivalent per ton. The analysis further emphasizes that the methane contributes the most, accounting for 62.21% of the total emissions, and plays an important role in the full life cycle of coal mining. Therefore, it presents a potential to mitigate the environmental impact of coal mining, and its main task is to recover and recycle methane. Based on the technical level, this study puts forward the low-carbon development countermeasures for coal enterprises. Then the technical system of methane emission control and utilization is constructed from three aspects: coal-bed methane development, gas extraction, and utilization and gas utilization. Finally, a trinity resource utilization system of coal mine gas is constructed. This study hopes to help practitioners to realize the importance of coal mine methane to the coal mining process. If the efficient resource utilization of methane be realized, it could not only save energy and reduce emissions in coal enterprises, but also promote the safety production of coal mines and improve the economic benefits of coal mines. It is also of great significance for optimizing China's energy structure, realizing low-carbon transformation, and safeguarding China's strategic energy security.

Hydrate occurrence in Europe: Risks, rewards, and legal frameworks

In January of this year (2020), a major scientific study (‘the Minshull report’) announced that gas hydrate reservoirs were found in many offshore areas across Europe. The European Commission is now considering a policy view to commercialize the development and extraction of methane gas from European offshore areas. Affirmation from the European Commission that offshore methane hydrates are too useful and too valuable to forego development could initiate a global response to adopt offshore methane hydrates as a new source of natural gas for heating, for electrical power supplies, and for potential new revenues.The upside? The potential rewards from offshore methane hydrates are multi-fold. Coastal states are surrounded in methane hydrate resources that if responsibly developed could enable vast amounts of methane (natural gas) to be produced for decades or centuries beyond the timelines of conventional natural gas assets. There are also massive volumes of fresh water trapped in hydrates that could aid in fighting droughts and desertification.The downside? There are novel foreseeable risks that might result from those commercial methane hydrate activities. The climate change risks and geo-physical hazards from offshore methane hydrates are quite distinct from both conventional and unconventional hydrocarbons. There are new challenges to achieving safety and sustainability.In review, this paper both welcomes the discovery and confirmation of offshore methane hydrates in European waters and also raises concerns that more research is required on the optimal policy strategies for the known and foreseeable risks to best enable safe and sustainable policy choices.

Hydrate Occurrence in Europe: Risks, Rewards, and Legal Frameworks

In January of this year (2020), a major scientific study (‘the Minshull report’) announced that gas hydrate reservoirs were found in many offshore areas across Europe. The European Commission is now considering a policy view to commercialize the development and extraction of methane gas from European offshore areas. Affirmation from the European Commission that offshore methane hydrates are too useful and too valuable to forego development could initiate a global response to adopt offshore methane hydrates as a new source of natural gas for heating, for electrical power supplies, and for potential new revenues. The upside? The potential rewards from offshore methane hydrates are multi-fold. Coastal states are surrounded in methane hydrate resources that if responsibly developed could enable vast amounts of methane (natural gas) to be produced for decades or centuries beyond the timelines of conventional natural gas assets. There are also massive volumes of fresh water trapped in hydrates that could aid in fighting droughts and desertification. The downside? There are novel foreseeable risks that might result from those commercial methane hydrate activities. The climate change risks and geo-physical hazards from offshore methane hydrates are quite distinct from both conventional and unconventional hydrocarbons. There are new challenges to achieving safety and sustainability. In review, this paper both welcomes the discovery and confirmation of offshore methane hydrates in European waters and also raises concerns that more research is required on the optimal policy strategies for the known and foreseeable risks to best enable safe and sustainable policy choices.

Microbial-induced carbonate precipitation applicability with the methane hydrate-bearing layer microbe

Production of methane gas from the methane-hydrate-bearing layer below the deep-ocean floor is expected to be crucial in the future of energy resources worldwide. During the methane gas-production phase from the methane hydrate with the depressurisation method, the depressurising zone around the production well will lose strength, causing a potential geohazard. In this study, a bio-mediated treatment to reinforce the methane hydrate layers is proposed. A urease-producing bacterium, Sporosarcina newyorkensis, was isolated for the first time from a pressure core sampled from the Nankai Trough seabed methane-hydrate-bearing layer in Japan. This newly isolated species can survive deep-seabed environments and also enhance the population under nutrient-rich conditions. In addition, it is uniquely characterised with higher urease activities under low-temperature conditions in comparison to the well-known bacterium S. pasteurii. The results of triaxial tests suggest that this bacterium can catalyse the precipitation of calcium carbonate through urea hydrolysis, which enhances the soil strength below the ocean floor and hence reinforces the production well. This will not only make methane gas extraction safer but may also reduce sand production in the well, making extraction operations more efficient and cost effective.

A formalism to compute permeability changes in anisotropic fractured rocks due to arbitrary deformations

The Liu-Elsworth (1997) formalism that predicts permeability in deformed fractured rock has been highly useful and successful in numerous engineering situations involving mining, coal-bed methane and shale gas extraction. The formalism assumes the rock's fractures are aligned with three orthogonal axes and that the rock is subjected to strains along these three directions only.Here we relax these assumptions: our proposed formula yields the permeability tensor for an anisotropic arbitrarily-fractured rock subjected to arbitrary deformations. Unlike the original Liu-Elsworth approach, our formula may therefore be used confidently in situations involving any stress and strain states, including those that are non-diagonal, and with rocks with any distribution of fracture orientations, including those that are non-orthogonal. This is advantageous in numerical simulation and in mining situations that frequently involve such situations. Our formula adds no discernible computational load to numerical simulations. Our proposal agrees with lab and in-situ direct and indirect tests of permeability.

Sistema de extraccion y tratamiento de metano

Currently sanitary landfills are considered sources of atmospheric pollutants. Biogas, a product of the biological decomposition of organic waste, incorporates mostly methane (CH4) and carbon dioxide (CO2), which are greenhouse gases. A large number of municipal sanitary landfills do not have control over methane gas emissions to the surface. This project is based on the construction of a portable prototype system for the extraction and treatment of methane gas from landfills. The objective was to manufacture and build a portable prototype system for the extraction and treatment of methane gas from municipal sanitary landfills. That it implements the necessary sections and devices to treat the gas and in this way facilitate its later use as fuel in heating systems, domestic use and / or internal and external combustion thermal machines. Using for this purpose a system of gas extraction, separation of solids, de-humidification and desulphurisation process. In the system variables such as the percentage of methane, temperature and humidity are monitored, in order to give a stability to the gas treatment process.

Optimization of the evaluation indexes of coalbed methane gas extraction

The extraction procedure of coalbed methane is usually different from conventional type of gas extraction. Generally, the CBM extraction procedure is completed within two approaches. First one is drilling on the surface for heading downward through the ground & second one is extracting through the existed underground coal mines. For making the CBM extraction an economic viable, well optimization development should be implemented with carefully. So, an evaluative technique called ‘Unit Technical Cost’ briefly known as UTC can be one of the better way to evaluate the well optimization development. This optimization technique is evaluated practically based on the two major coal basins of china, known as ‘Qinshui basin & Ordos Eastern Margin basin’. The well completion & simulation process can be examined by the parameters that are used in this technique. This paper is tried to give a new research on CBM well development based on using the UTC method for making decision criteria to calculate the optimization level. The calculation is done using the detailed properties of UTC in the well development by establishing the process theory. In this research, the production profiles are evaluated for building up the engineering & geologic parameters where the product price, operating cost & project investment is evaluated for finding the economic parameters. This is found from the optimized results that a horizontal well should be optimized for its economic feasibility in the Qinshui Basin where directional well optimization is better for Ordos Eastern Margin Basin.Keywords: Well optimization, well completion, unit technical cost, technical evaluation, evaluation index

Comparison of Simplistic and Geologically Descriptive Production Modeling for Natural-Gas Hydrate by Depressurization

Summary Marine-gas-hydrate-drilling exploration at the Eastern Nankai Trough of Japan revealed the variable distribution of hydrate accumulations, which are composed of alternating beds of sand, silt, and clay in sediments, with vertically varying porosity, permeability, and hydrate saturation. The main purposes of this work are to evaluate gas productivity and identify the multiphase-flow behavior from the sedimentary-complex hydrate reservoir by depressurization through a conventional vertical well. We first established a history-matching model by incorporating the available geological data at the offshore-production test site in the Eastern Nankai Trough. The reservoir model was validated by matching the fluid-flow rates at a production well and temperature changes at a monitoring well during a field test. The modeling results indicate that the hydrate-dissociation zone is strongly affected by the reservoir heterogeneity and shows a unique dissociation front. The gas-production rate is expected to increase with time and reach the considerable value of 3.6 × 104 std m3/d as a result of the significant expansion of the dissociation zone. The numerical model, using a simplified description of porosity, permeability, and hydrate saturation, leads to significant underestimation of gas productivity from the sedimentary-complex hydrate reservoir. The results also suggest that the interbedded-hydrate-occurrence systems might be a better candidate for methane (CH4) gas extraction than the massive hydrate reservoirs.

A coupled thermal–hydraulic–mechanical–chemical (THMC) model for methane hydrate bearing sediments using COMSOL Multiphysics

Methane gas extraction by a deep well installed in methane hydrate bearing sediments (MHBS) found in deep subsea and permafrost regions is a coupled thermal–hydraulic–mechanical–chemical (THMC) process. The key processes include heat convection between layers, local deformation due to compaction, and stress relaxation caused by damage of the bonded structure. As improper production may induce formation compaction, sand production, and wellbore failures, a numerical code is needed to simulate the THMC processes during methane gas production so that geomechanics and production risks can be quantified. In this study, a nonlinear THMC model was implemented in the partial differential equations (PDE) and structural mechanics module of the COMSOL Multiphysics® finite element code. This paper describes the non-linear coupled governing equations of the mechanical behavior during hydrate dissociation. In particular, it introduces a new thermodynamics-based constitutive model to simulate the mechanical behavior of hydrate bearing sediments. The performance of the newly developed code was examined by comparing the computed results with test data and other simulation results. The differences between fully coupled and semi-coupled models were analyzed. For example, heterogeneous turbidite layers observed in the Nankai Trough were modeled, and behaviors such as heat convection between different layers, shear stress and strain concentration were examined.