Pore-scale study of multicomponent multiphase heat and mass transfer mechanism during methane hydrate dissociation process

Pore-scale study of the multiphase methane hydrate dissociation dynamics and mechanisms in the sediment

“…As mentioned in the previous work [24], the lattice Boltzmann method (LBM) has the solid capacity for pore-scale multi-physics problems, which benefits from its high computational efficiency [37] and abundant numerical models for multiphase flow with heat and mass transport [38,39]. In the present study, a pore-scale numerical model based on LBM was developed to simulate the hydrate dissociation with low-methaneconcentration gas injection in the hydrate sediment, considering the multiphase flow, heat and mass transfer, heterogeneous reaction, and hydrate structure evolution.…”

“…The multiple physicochemical processes during methane hydrate dissociation can be schematically described in Figure 1 [24]. Initially, the methane hydrate exists stably with water and gas in the phase equilibrium state.…”

“…The permeability and specific surface area development were analyzed to derive the REV-scale models of the transport and geometrical properties for the variable dissociation patterns. Since the numerical model was improved compared with the previous pore-scale studies for the single-phase system [35] or closed system [24], the present work can provide a more comprehensive understanding of the methane hydrate dissociation in the sediment.…”

“…Therefore, these numerical simulations need the assistance of the history matching tool to reproduce the experimental results from the perspective of mathematical optimization [23] although these lab-scale investigations escape the uncertainty of the geoelectrical structure and the complexity of the wells configuration in field-scale. Moreover, the effect of complicated pore structure evolution, phase behavior, and reaction nonlinearity of the methane hydrate dissociation process is always filtered in the REV models, which may introduce significant inaccuracy [24]. Therefore, pore-scale studies are necessary to understand the controlling mechanisms of the methane hydrate dissociation process in the sediment and provide more accurate kinetic and transport parameters for the REV models in field or lab scales.…”

“…Still, the interfacial transport phenomena and hydrate structure evolution could not be visually represented with the phase distribution computed by the saturation. For improvement, our previous work [24] established the pore-scale numerical model to simulate methane hydrate dissociation in the multiphase system. The numerical study achieved a satisfactory agreement on the residual hydrate profile by comparing numerical simulations and experiments, emphasized the role of mass-transfer limitation on the hydrate dissociation, and eventually obtained a corrected model of the kinetic parameters for the REV-scale model.…”