Pore‐Scale Investigation of Methane Hydrate Dissociation Using the Lattice Boltzmann Method

Abstract

Fundamental understanding of pore‐scale methane hydrate dissociation in porous media is important to evaluate submarine slope stability and potential utilization of methane resources. In this paper, a general pore‐scale framework based on the lattice Boltzmann (LB) method is established for reactive transport coupled with nonisothermal multiple physicochemical processes in porous media. The framework combines the gas hydrate dissociation kinetic model, the single‐phase flow LB model, the mass transport LB model, and the conjugate heat transfer LB model. The pore‐scale framework is validated by several benchmark problems and then employed to investigate the endothermic dissociation process of methane hydrate with pore‐filling and grain‐coating habits in porous media. The methane hydrate endothermic dissociation behavior coupled with nonlinear nonisothermal multiple physicochemical processes involving intrinsic dissociation dynamics, gas flow, mass transport, phase change heat transfer, and conjugate heat transfer is well captured by the framework. The phase change of methane hydrate dissociation and pore structure evolution for different pore habits of hydrate are well depicted, and some insights about the dissociation front advancement and temperature distributions are also obtained. In addition, the effects of temperature field, inlet temperature, and inlet pressure on methane hydrate dissociation are investigated. The pore‐scale methane hydrate dissociation helps to advance our understanding of permeability‐saturation variation relation for continuum models.

Numerical Simulation on the Dissociation, Formation, and Recovery of Gas Hydrates on Microscale Approach

“…Gas hydrate (i.e., methane) is a complex multi-component and multi-phase fluid flow process accompanied by mass transport and heat transfer in porous media [ 81 ]. One method that can be implemented to analyze that process is LBM [ 31 , 61 ]. Due to its attractive advantages, such as simplicity in coding, dealing with complex solid boundaries, and parallelization, LBM has become a very popular CFD method in many fields, such as multi-phase and multi-component flow, reactive flow, microscale, and nanoscale flow [ 66 , 84 ].…”

“…Hence, the mean size and the deviation as distribution factors are crucial parameters for the blockage. Zhang, Zhang [ 31 ] used LBM by combining the gas hydrate dissociation kinetic model, the single-phase flow LB model, the mass transport LB model, and the conjugate heat transfer LB model. The results showed that the simulation using LBM could easily evaluate the reactive transport framework effect to the coupled physicochemical thermal process and provide an understanding of the methane dissociation process at the pore scale.…”

“…One numerical simulation that has potential (when investigating the conditions of the gas hydrate complexes) is the Lattice Boltzmann Method (LBM). LBM can solve the coupled multiple process problems due to its capacity in computing the complex geometrical boundaries [ 31 ]. Considering gas hydrate conditions for dissociation and formation are multi-phase and multi-component complexes, particular attention should be paid to the microscale effects of the gas hydrate processes in the microporous media channels [ 7 ].…”

Heat Transfer in Unfrozen and Frozen Porous Media: Experimental Measurement and Pore‐Scale Modeling

“…LBM is a computational fluid dynamics solver based on mesoscopic kinetic equations, which could be utilized to study fluid flow problems (Krüger et al, 2017). LBM has proven to be a powerful tool for solving problems at different length and time scales owing to its advantages in numerical simulation of single‐phase and multiphase fluid flows in pore scale (Bakhshian et al, 2019; Chen et al, 2019; Norouzi et al 2019; Zhang et al, 2019), particularly in complex geometries such as porous media (Bakhshian & Sahimi, 2016; Vasheghani Farahani et al, 2019; Vora & Dugan, 2019). Free‐energy LBM as an option for simulating multiphase and multicomponent fluid flow is able to appropriately account for fluid‐fluid interfacial tensions and solid surface contact angles.…”

Lattice Boltzmann Simulation of Multicomponent Porous Media Flows With Chemical Reaction

“…This is attributed to its attractive advantages, like its general kinetic foundation, high parallelism, and ability to handle multiphysics and complex boundaries [33,34]. Recently, LB models have been proposed to simulate flows of reactive fluids in porous media, like methane hydrate dissolution [35], solid coke combustion [32], and reactive mixing with viscous fingering [36]. Although these works showed the superior ability of the LB method in modeling porous media flows, some limitations should be noted.…”