Introduction

This page contains three supplementary videos with the evolution of gas generated from hydrate dissociation, as supplemental material of the paper:

Thermodynamic and hydrodynamic constraints on overpressure caused by hydrate dissociation: a pore-scale model.
R. Holtzman and R. Juanes, Geophysical Research Letters, 38, L14308 (2011).

Animation S1

The evolution of pore pressure during hydrate dissociation. Grayscale intensity represents the pressure (scaled to increase contrast): white corresponds to the ambient pressure, black to high pressures in gas-filled pores. During an invasion event, a pressure halo develops ahead of the invaded sites as a result of rapid water flow, causing local meniscus readjustments.

Animation S2

Expansion and coalescence of gas clusters. Highlights the expansion and coalescence of gas clusters by showing only the pore occupancy: white and black pixels represent water- and gas-filled pores. To better visualize the dynamics, the time increment between frames in the videos is nonuniform. Nonuniform increments are required because of the sharp contrast between the characteristic timescales for pressure buildup by dissociation and its dissipation by drainage. Animations S1 and S2 correspond to the simulation in Figure 1 in the paper.

Animation S3

The creation and propagation of a fracture as a result of hydrate dissociation in low-permeability medium (Figure 4, left). White and black pixels represent water- and gas-filled pores. Fracturing by grain rearrangements causing pore-opening is the preferred mode of gas invasion in soft, fine-grained sediments.