Effects of sediment characteristics on gas hydrate accumulation; continental margins and permafrost; model results from 2018

• Main Author: Rempel, Alan
• Format: Dataset
• Language: English
• Published: NSF Arctic Data Center 2021
• Subjects: gas hydrate; pore-scale equilibrium controls; Walker Ridge; Methane hydrate; permafrost
• Online Access: https://dx.doi.org/10.18739/a2nv99c17; https://arcticdata.io/catalog/view/doi:10.18739/A2NV99C17

The occurrence of methane hydrate in marine reservoirs often correlates with the physical properties of the host sediments. High hydrate saturations (greater than 60% of the pore volume) found in association with coarser-grained strata have been attributed to both enhanced advective transport through more permeable sediment layers and to perturbations in phase equilibrium related to pore-space geometry that results in increased diffusive transport. To assess the relative importance of these mechanism in controlling hydrate occurrence, we developed a 1D (1-dimensional) model for hydrate growth along dipping, coarse-grained layers embedded in a fine-grained sediment package. We explicitly account for pore-size effects on methane solubility and permeability-driven variations in fluid flux. We show how the vertical distribution of hydrate varies in response to changes in grain size and rates of fluid advection, sedimentation, and in situ methane production. As an example, we use our model to simulate centimeter-scale variations in hydrate saturation observed at Walker Ridge Block 313, Hole H in the Gulf of Mexico. The model m-files and parameter text files are contained in this dataset. The results from this study are published by Brandon P. van der Beek and Alan W. Rempel as “On the importance of advective versus diffusive transport in controlling the distribution of methane hydrate in heterogeneous marine sediments”, doi: 10.1029/2017jb015298, Journal of Geophysical Research, 2018.