Thermo-Hydro-Mechanical Coupled Modeling of Methane Hydrate-Bearing Sediments: Formulation and Application

Abstract

We present a fully coupled thermo-hydro-mechanical formulation for the simulation of sediment deformation, fluid and heat transport and fluid/solid phase transformations occurring in methane hydrate geological systems. We reformulate the governing equations of energy and mass balance of the Code_Bright simulator to incorporate hydrate as a new pore phase. The formulation also integrates the constitutive model Hydrate-CASM to capture the effect of hydrate saturation in the mechanical response of the sediment. The thermo-hydraulic capabilities of the formulation are validated against the results from a series of state-of-the-art simulators involved in the first international gas hydrate code comparison study developed by the NETL-USGS. The coupling with the mechanical formulation is investigated by modeling synthetic dissociation tests and validated by reproducing published experimental data from triaxial tests performed in hydrate-bearing sands dissociated via depressurization. Our results show that the formulation captures the dominant mass and heat transfer phenomena occurring during hydrate dissociation and reproduces the stress release and volumetric deformation associated with this process. They also show that the hydrate production method has a strong influence on sediment deformation.

State‐of‐the‐art brief review on sanding problem of offshore natural gas hydrates sediments

“…It is quite vital to study the coupling of multiple physical fields when using numerical simulation to investigate sand production in NGH development. Ning et al 99 and Fuente et al 110 presented how the multiple physical fields affect the sand production in the NGH development process as shown in Figure 2. This section has explained how the multiple physical fields work in the sand production investigation with a detailed review.…”

Modelling Methane Hydrate Saturation in Pores: Capillary Inhibition Effects

“…For the simulations we use the version of Code_Bright extended to methane hydrate systems [35]. These simulations consider an axisymmetric computational domain of 10 cm × 2.5 cm.…”

“…Then, this equation is combined with the van Genuchten's capillary pressure to relate the thermodynamic properties of the system to the host sediment pore size distribution and hydrate saturation. Finally, the formulation is implemented on the finite element simulator Code_Bright extended to methane hydrate systems [35]. In this paper, the Clausius-Clapeyron equation for the methane hydrate system is validated against experimental data at predicting the P-T conditions required to form and dissociate methane hydrates in narrow pores.…”

Dilation Behavior of Gas-Saturated Methane-Hydrate Bearing Sand

“…Methane-hydrates have attracted increased interest in recent years as a potential energy source due to the existence of extensive methane-hydrate-bearing sediments (MHBS) around the world [1][2][3][4][5][6]. Taken together, these reserves are estimated to contain double the productive energy potential of all known fossil fuel resources [7][8][9].…”