|Hydrate-Bearing Clayey Sediments: Morphology, Physical Properties, Production and Engineering/Geological Implications
||Last Reviewed November 2016
The primary goal of this research effort is to contribute to an in-depth understanding of hydrate bearing, fine-grained sediments with a focus on investigation of their potential for hydrate-based gas production.
Georgia Tech Research Corporation, Atlanta GA
Fine-grained sediments host more than 90 percent of global gas hydrate accumulation. Yet hydrate formation in clay-dominated sediments is less understood and characterized than other types of hydrate occurrence. There is an inadequate understanding of hydrate formation mechanisms, segregation structures, hydrate-lense topology, system connectivity, and physical macro-scale properties of clay-dominated hydrate-bearing sediments. This situation hinders further analyses of the global carbon budget as well as engineering challenges/solutions related to hydrate instability and production.
Research on hydrate-bearing clay-dominated sediments is needed to enhance fundamental understanding of hydrate formation and resulting morphology, develop laboratory techniques to emulate “natural” hydrate formations in this type of material, develop and assess analytical tools to predict physical properties, evaluate engineering and geological implications, and advance understanding of the potential for gas production from these sediments.
The project will add significant data and knowledge to the body of hydrates science. An enhanced understanding of the occurrence and behavior of hydrates in clay-dominated sediments will inform discussions of both the role of hydrates in the global carbon cycle and the potential feasibility of production from a portion of the hydrate resource base not currently considered producible.
Accomplishments (most recent listed first)
- Completed theoretical study of capillary effect on gas production in fine-grained sediments, resulting in conclusion that the effect inhibits hydrate dissociation.
- Conducted experimental study of gas migration in soft sediments focusing on shallow marine gas hydrate accumulations including investigation of the memory effect and the effect of the over consolidation ratio on gas flow in fine grained sediments.
- Developed data on critical pore size for nucleation and potential impact on hydrate formation in fine grained sediments.
- Conducted stress field analyses leading to different crystal morphologies.
- Investigated potential new analogs for hydrate in fine grained sediment (high solubility gas study, study of stability boundaries for Xenon and CO2 hydrate with hydrate promoters)
- Tested methods of tetrahydrofuran (THF) hydrate formation in fine grained media (bentonite, kaolinite, diatomaceous earth, silica flour)
- Continued monitoring of hydrate formation processes through X-ray imaging
- Developed additional new methods for formation of carbon dioxide (CO2) hydrate in fine grained sediments including injection of gas bubbles into a kaolinite slurry and the transformation of ice to hydrate in hydrophobi silica
- Demonstrated capability to form carbon CO2 hydrate in fine grained sediments with segregated topology analogous to natural sediments using both the injection of liquid CO2 and ice-to-hydrate formation techniques
- Completed development of numerical solutions for large-strain stiffness of the hydrate-bearing sediments with varying hydrate lens angles
- Implemented a novel approach to beam hardening correction for additional computed tomography (CT) image processing
- Completed thermal analysis of aluminum X-ray CT pressure vessel in an effort to optimize the insulation system used for system experiments
- Completed initial analysis of effective medium properties of hydrate-bearing sediments to attempt to capture the difference in these properties between hydrate formation in coarse vs. fine grained sediments
- Demonstrated capability for CO2 hydrate formation in clay and tetrahydrofuran hydrate formation in clay paste with concurrent X-ray CT scanning
- Completed installation and initial testing of new X-ray CT system to be used in lab visualization experiments
- Completed literature review of hydrate topology differences among Indian, Korean, and U.S. sites and analyses focused on hydrate morphology in fine-grained sediment and phase boundary conditions for stable/efficient hydrate exchange
- Initiated study on gas replacement as a potential production mechanism to reduce reservoir deformation and closure in fine-grained systems
Current Status (November 2016)
Going forward, researchers will concentrate on advancing understanding of crystal-sediment interaction in hydrate bearing sediments and conduct of numerical experiments to predict hydrate bearing (fine-grained) sediment properties. The team also plans to continue theoretical and analytical studies of factors potentially affecting gas production from fine grained sediments and to conduct stiffness characterizations of hydrate bearing clays.
Project Start: October 1, 2012
Project End: September 30, 2016
Project Cost Information:
Planned Total Funding: $810,167
DOE Contribution: $627,393
Cost Share Contribution: $182,774
NETL – Richard Baker (Richard.Baker@netl.doe.gov or 304-285-4714)
Georgia Tech – Carlos Santamarina (Carlos.Santamarina@ce.gatech.edu)
Research Performance Progress Report [PDF-280KB] July - September, 2016
Research Performance Progress Report [PDF-866KB] April - June, 2016
Research Performance Progress Report [PDF-3.17MB] January - March, 2016
Research Performance Progress Report [PDF-1.72MB] October - December, 2015
Research Performance Progress Report [PDF-1.65MB] July - September, 2015
Research Performance Progress Report [PDF-5.22MB] April - June, 2015
Research Performance Progress Report [PDF-4.97MB] January - March, 2015
Research Performance Progress Report [PDF-414KB] October - December, 2014
Research Performance Progress Report [PDF-9.71MB] July - September, 2014
Research Performance Progress Report [PDF-5.00MB] April - June, 2014
Research Performance Progress Report [PDF-2.51MB] January - March, 2014
Research Performance Progress Report [PDF-2.24MB] October - December, 2013
Research Performance Progress Report [PDF-1.08MB] July - September, 2013
Research Performance Progress Report [PDF-899KB] April - June, 2013
Research Performance Progress Report [PDF-1.13MB] January - March, 2013
Research Performance Progress Report [PDF-1.13MB] October - December, 2012