Methane Hydrate Formation and Dissociation in a PartiallySaturated Core-Scale Sand Sample

• Main Authors: Kneafsey, Timothy J., Tomutsa, Liviu, Moridis, George J., Seol,Yongkoo, Freifeld, Barry M., Taylor, Charles E., Gupta, Arvind
• Language: unknown
• Published: 2018
• Subjects: 54 ENVIRONMENTAL SCIENCES; ALUMINIUM; COMPUTERIZED TOMOGRAPHY; DEPRESSURIZATION; DISSOCIATION; GAS HYDRATES; HYDRATES; KINETICS; PRESSURE VESSELS; SAND; STABILITY; STIMULATION; THERMODYNAMIC PROPERTIES; WATER SATURATION; Methane hydrate
• Online Access: http://www.osti.gov/servlets/purl/919929; https://www.osti.gov/biblio/919929

We performed a sequence of tests on a partiallywater-saturated sand sample contained in an x-ray transparent aluminumpressure vessel that is conducive to x-ray computed tomography (CT)observation. These tests were performed to gather data for estimation ofthermal properties of the sand/water/gas system and thesand/hydrate/water/gas systems, as well as data to evaluate the kineticnature of hydrate dissociation. The tests included mild thermalperturbations for the estimation of the thermal properties of thesand/water/gas system, hydrate formation, thermal perturbations withhydrate in the stability zone, hydrate dissociation through thermalstimulation, additional hydrate formation, and hydrate dissociationthrough depressurization with thermal stimulation. Density changesthroughout the sample were observed as a result of hydrate formation anddissociation, and these processes induced capillary pressure changes thataltered local water saturation.