Effect of Temperature on Three-phase Water-oil-gas Relative Permeabilities of Unconsolidated Sand

Abstract

Abstract The objective of this paper is to evaluate experimentally the effect of temperature on the three-phase brine-oil-gas relative permeabilities of an unconsolidated sand system. Two and threephase relative penneabilities have been measured at 75 °C and 125 °C. The experiments were performed under steady-state conditions. These measurements were conducted in Ottawa sand using a clean mineral oil 1% brine and nitrogen gas. The measured relative permeabilities showed no significant temperature effect. The three-phase brine relative permeability was found to be a function of brine saturation alone. The threephas gas relative permeability was always lower than the threephase values. This is consistent with some of the previously published results. The oil relative permeability was found to vary with the saturations or the other fluids. Oil isoperms were concave towards the oil apex. Finally, oil relative permeabilities were compared with predictions obtained using modifications of Stone's Methods I and II. The prediction of Stone I was good for both temperatures. But Stone II predictions were consistently lower than the experimental values. Introduction Three-phase relative permeability plays an important role in the numerical stimulation of oil recovery processes. Thermal methods for heavy oil recovery, such as steam drive and in situ combustion involve the simultaneous flow of three immiscible fluids through the porous rock formation at elevated temperatures. Over the past 25 years, a number of studies have evaluated the temperature effects on two -phase relative permabilities in porous media. Edmondson (1) found that the oil /water relative permeability of Berca sandstone was temperature dependent. In his experiment involving water flooding at elevated temperatures ranging from 24 ° to 260 °C (75 ° to 500 °F, be slowed a charge in relative permeability ratio accompanied by a decrease in residual of saturation with temperature increase. Davidson(2) investigated the temperature dependence of the permeability ration by conducting isothermal displacements of No. 15 white oil from an unconsolidated sandpack by either nitrogen, steam, or distilled water; and displacement of water by nitrogen. Values of the water oil permeability ratio were obtained over the temperature rang e of 24 ° to 282 °C (75 ° to 540 ° F) . At low water when hard, the gas-oil permeability ratio calculated from a nitrogen while oil displacement indicated a define dependence on temperature over the range 24 ° to 260 ° C (75 ° to 500 °F) and over the entire gas saturation range. He also found a decrease in residual oil saturation range. He also found a decrease in residual oil saturation with temperature increase. Poston et al. presented waterflood data for unconsolidated sandpacks containing 80.99 and 600 up viscosity oil a temperatures from 21 ° to 149 °C (70 ° to 300 °F), and observed an increase in the individual relative permeability curves as appeared temperature was increased. Although the water-oil permeability ratio appeared temperature sensitive no definite trend was found for the change of relative permeability ratio with temperature. They also found an increase in irreducible water saturation and a decrease in residual oil saturation as temperature increased. They concluded that unconsolidated sands became more water-wet with an increase in temperature.