Methane hydrate distribution from prolonged and repeated formation in natural and compacted sand samples: X-ray CT observations

• Main Authors: Rees, E.V.L., Kneafsey, T.J., Seol, Y.
• Other Authors: Lawrence Berkeley National Laboratory. Earth Sciences Division.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Lawrence Berkeley National Laboratory 2010
• Subjects: Computerized Tomography; Methane; Physical Properties; Sediments; Exploratory Wells; Water Saturation; Hydrates; 58 Geosciences; Cat Scanning; Sand; Gas Hydrates; 54 Environmental Sciences; Morphology; Water; 03 Natural Gas; Distribution; Availability; Methane hydrate
• Online Access: https://digital.library.unt.edu/ark:/67531/metadc834847/

To study physical properties of methane gas hydrate-bearing sediments, it is necessary to synthesize laboratory samples due to the limited availability of cores from natural deposits. X-ray computed tomography (CT) and other observations have shown gas hydrate to occur in a number of morphologies over a variety of sediment types. To aid in understanding formation and growth patterns of hydrate in sediments, methane hydrate was repeatedly formed in laboratory-packed sand samples and in a natural sediment core from the Mount Elbert Stratigraphic Test Well. CT scanning was performed during hydrate formation and decomposition steps, and periodically while the hydrate samples remained under stable conditions for up to 60 days. The investigation revealed the impact of water saturation on location and morphology of hydrate in both laboratory and natural sediments during repeated hydrate formations. Significant redistribution of hydrate and water in the samples was observed over both the short and long term.