RELATIVE PERMEABILITY MEASUREMENTS IN OIL SANDS

Petroleum reservoir engineers use relative permeability to describe the simultaneous flow of oil, water and gas in the reservoir during oil recovery operations. For thermal recovery processes in oil sand systems, there are very few published experimental data on residual fluid saturations or relative permeability curves. The effect of temperature on these parameters has not been established. This study was initiated to address these deficiencies and is the first extensive report of bitumen-water relative permeability functions measured for temperatures up to 250{dollar}spcirc{dollar}C.; An apparatus was developed for the determination of two phase oil-water relative permeabilities. A packing technique was developed for preparing laboratory cores containing clean unconsolidated Ottawa sand, homogenized heavy oils and deionized water. Experiments were conducted over a large temperature range (20{dollar}spcirc{dollar}C to 250{dollar}spcirc{dollar}C) with both clean sands and reservoir sands for evaluating differences between ideal and real systems, using proven and reliable experimental procedures. The experimental work comprised the measurement of bitumen-water end point relative permeabilities and residual saturations as functions of temperature, followed by the determination of bitumen-water and Kaydol-water relative permeability curves by the steady and unsteady state methods.; No significant temperature effects were found for the Athabasca bitumen-water system in clean or reservoir sands, nor for the Kaydol-water system in clean sands. More reactive fluid-fluid-solid combinations may show temperature effects on relative permeability. End point experiments with clean sand gave reproducible results, whereas the reservoir sand results showed the variation that can be encountered in heterogeneous systems such as those containing clays. The convex shape of the oil curves reflected the recovery mechanism of heavy oil by hot water under adverse mobility ratio conditions.; A comparison of normalized relative permeability curves for heavy oils of Alberta showed that wide variations existed among the reported data. Therefore, a range of relative permeability curves may be necessary to describe the various recovery mechanisms of heavy oils by hot water from heterogeneous unconsolidated sands.