|THCM Coupled Model for Hydrate-bearing Sediments: Data Analysis and Design of New Field Experiments (Marine and Permafrost Settings)
||Last Reviewed 1/7/2015
The primary goals of this research effort are to develop a truly coupled numerical model that addresses the complex thermo-hydro-chemo-mechanical (THCM) phenomena in hydrate-bearing sediments through incorporation of proven constitutive relationships that also satisfy fundamental conservation principles (conservation of mass, energy, and momentum) and apply that model to analyze available data and further enhance understanding of the behavior of hydrate-bearing sediments in the context of field production experiments and the development of hydrate production approaches and technology.
Texas A&M University, College Station, TX
Georgia Tech Research Corporation, Atlanta GA
The experimental study of hydrate-bearing sediments has been hindered by the very low solubility of methane in water (lab testing); the complexity of synthesizing hydrate-bearing sediments in the lab that are representative of those found in nature; and inherent sampling difficulties associated with depressurization and thermal changes to hydrate-containing samples during core extraction. This situation has prompted the need for more decisive developments in numerical modeling in order to help advance our understanding of hydrate-bearing sediments and investigate/optimize production strategies and their implications.
Project personnel will undertake an in-depth review of the properties of hydrate-bearing sediments and use the results to update a numerical model capable of simulating the complex thermo-hydro-chemo-mechanical behaviors of hydrate-bearing sediments. This updated model will be corroborated through the use of close-form analytical solutions and then used to analyze data available from past production related hydrate field experiments and develop optimized approaches for potential future field production studies in marine and permafrost environments.
Results will provide critical insights into the behavior of gas hydrate-bearing sediments caused by THCM perturbations such as those that can be triggered by environmental changes or activities aimed at the production of gas from hydrates. The results of the effort will assist in the development of optimal, technically viable strategies for methane production in both marine and permafrost settings and improve our understanding of the potential reaction of hydrate systems to natural or induced changes in their environment.
Accomplishments (most recent listed first)
- Completed initial validation of functions implemented in the code, including constitutive equations and phase relationships.
- Conducted numerical tests of the updated system to validate the numerical approach that was implemented, including one case involving the depressurization of hydrate-bearing sediment.
- Completed review of literature associated with published constitutive models for hydrate-bearing sediments and analytical and numerical modeling of and laboratory and field investigations related to hydrate-bearing sediments.
- Completed an update of the constitutive model for hydrate-bearing sediments to include dynamic effects of capillary pressure-saturation relationships.
- Updated the THCM-Hydrate code including validation of the incorporation functions capturing the effect of cryogenic suction on the mechanical behavior of frozen sediments.
- Began testing the THCM-Hydrate code against the DOE Hydrate numerical simulator Code Comparison problem set.
Current Status (January 2015)
The upcoming project quarter will focus on advancing the analytical and numerical simulation fronts to enhance the code to solve coupled THCM problems with emphasis on capturing natural processes under in-situ conditions as well as behavior during gas production from hydrate-bearing sediments.
Project Start: October 1, 2013
Project End: September 30, 2015
Project Cost Information:
Planned Total Funding (through all project phases): $485,700
DOE Contribution: $388,560
Cost Share Contribution: $97,140
NETL Project Manager – Richard Baker (Richard.Baker@netl.doe.gov)
Texas A&M University – Marcelo Sanchez (email@example.com)
Research Performance Progress Report [PDF-1.47] July - September, 2014
Research Performance Progress Report [PDF-1.35] April - June, 2014
Research Performance Progress Report [PDF-1.39] January - March, 2014
Research Performance Progress Report [PDF-1.58] October - December, 2013