HR: 0800h
AN: NS51B-02    [Abstracts]
TI: Relative Permeability of Gas Hydrate Bearing Sediments
AU: * Kneafsey, T J
EM: TJKneafsey@lbl.gov
AF: Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, United States
AU: Seol, Y
EM: yseol@lbl.gov
AF: Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, United States
AU: Gupta, A
EM: argupta@mines.edu
AF: Colorado School of Mines, PO Box 4028, Golden, CO 80401-1887, United States
AU: Tomutsa, L
EM: ltomutsa@lbl.gov
AF: Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, United States
AU: Moridis, G J
EM: gjmoridis@lbl.gov
AF: Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, United States
AB: Permeability controls the rate of fluid flow through porous media and relative permeability describes the phase interference when more than one phase is present in the pore space. The presence of gas hydrate in sediments reduces the effective permeability (product of intrinsic and relative permeability) of water and gas released from hydrate dissociation. Knowledge of the relative permeabilities of gas and water or brine as a function of gas hydrate, gas, and water saturation is essential in the prediction production of natural gas from hydrate-bearing reservoirs. We have measured the effective permeability of confined dry sand samples (with mineral grain-to-grain contact) and of the same samples containing water, ice, and hydrate under a variety of conditions to determine the impact of hydrate in the pore space and estimate relative permeabilities. In our tests, the presence of hydrate strongly affects the gas relative permeability, which decreases as the hydrate saturation increases. Hydrate saturations near 50 percent resulted in a very low effective permeability. We conducted experiments using two different sands, with differences in the hydrate formation procedure resulting in changes in hydrate saturation morphology. In addition, we performed water floods of our hydrate-bearing samples, and used x-ray CT scanning to monitor water saturation changes at several locations. These data were used to estimate properties of the hydrate- bearing porous medium by means of inverse modeling.
DE: 1859 Rocks: physical properties
DE: 1866 Soil moisture
DE: 3004 Gas and hydrate systems
SC: Near-Surface Geophysics [NS]
MN: 2007 Joint Assembly