HR: 1330h
AN: GC32A-0204    [PDF]
TI: The Streaming Potential Coupling Coefficient of Liquid Carbon Dioxide Injected Into Water Saturated Berea Sandstone
AU: * Moore, J R
EM: moore@decf.berkeley.edu
AF: University of California, Berkeley, 440 Davis Hall, Berkeley, CA 94720 United States
AU: Glaser, S D
EM: glaser@ce.berkeley.edu
AF: University of California, Berkeley, 440 Davis Hall, Berkeley, CA 94720 United States
AU: Morrison, H F
EM: hfmengeo@socrates.berkeley.edu
AF: University of California, Berkeley, 440 Davis Hall, Berkeley, CA 94720 United States
AB: The streaming potential coupling coefficient was determined for a liquid carbon dioxide flood of a water-saturated sample of Berea sandstone. The coupling coefficient for the rock/water case was determined both before and after each CO2 flood of three samples using a low-pressure static head method. Next, liquid CO2 was allowed to flow through each sample. As the CO2 displaced the water the coupling coefficient decreased. At longer times, when all mobile pore water was displaced, the coupling coefficient maintained a steady state, and was lower than that for water by about 10 times. The results of this testing reveal a coupling coefficient of 30 mV/0.1MPa, for 125 Ohm-m water flow through the sample, and 3.0 mV / 0.1 MPa for liquid CO2 flow. Calculated zeta potentials are -3.4 mV using water as the pore fluid and -1.7 x 10-6 mV for liquid CO2. We propose that the lower coupling coefficient for CO2 flow is primarily a result of changes in zeta potential, since changes in pore fluid resistivity and viscosity would act to increase the coupling coefficient. Zeta potential for the liquid CO2 / mineral interface is a function of the low polarity and lack of mobile ions associated with liquid CO2. We find no anomalous 2-phase liquid/gas effects, which may have augmented single-phase streaming potentials by many times. We propose that although CO2 gas may have been present for some of the higher pressure drop events, the low gas fraction (or quality) of the two-phase mixture did not lead to any significant anomalous or augmented observations. Implications of this work include spatial and temporal monitoring of CO2 injectate in subsurface reservoirs and the identification of flow paths, with the recommendation being to attempt to image the advancing CO2/water front, where the coupling coefficient is higher.
DE: 1640 Remote sensing
DE: 1694 Instruments and techniques
DE: 1699 General or miscellaneous
SC: Global Climate Change [GC]
MN: 2003 Fall Meeting