Experimental validation of the theory of extending two‐phase saturation‐pressure relations to three‐fluid phase systems for monotonic drainage paths

Abstract

An experimental apparatus was developed to directly measure functional relationships between fluid saturations S and pressures P of three‐phase (air‐oil‐water) or two‐phase fluid systems in unconsolidated porous media. Porous ceramic rings were chemically treated to enable simultaneous measurement or regulation of water and oil fluid pressures. Direct measurements of water and total liquid saturations in three fluid phase systems as functions of oil‐water and air‐oil capillary heads, respectively, were compared to S‐P measurements in two‐phase air‐oil and oil‐water systems for monotonic drainage saturation paths to test commonly employed assumptions of extending these two‐phase S‐P measurements to air‐oil‐water fluid systems. Excellent agreement was observed between total liquid saturations in an air‐oil‐water system and oil saturations in a two‐phase air‐oil system as functions of air‐oil capillary head. Excellent agreement was also found between water saturations in air‐oil‐water and oil‐water fluid systems versus oil‐water capillary head. The accordance between two‐ and three‐phase results indicates that two‐phase air‐oil S‐P relations can be used to predict total liquid content in air‐oil‐water systems and that two‐phase oil‐water S‐P relations can be used to predict water saturation in three‐phase systems for rigid water wet porous media subject to monotonic drainage saturation paths. The S‐P scaling format proposed by Parker et al. (1987a) to generate a single multiphase retention function capable of describing S‐P relations of either two‐ or three‐phase fluid systems was further evaluated using the measured two‐ and three‐phase S‐P relations. Comparison of scaled two‐ and three‐phase S‐P drainage data indicated that a single scaled multiphase retention function may be employed to describe S‐P relations in either two‐ or three‐fluid phase systems.

Multiphase flow modeling of a crude‐oil spill site with a bimodal permeability distribution

“…Once the air-water primary drainage curve parameters were obtained, the oil-water and air-oil retention curves were scaled from the air-water curves using surface tensions [Lenhard and Parker, 1988 To adequately represent the small-scale north pool aquifer heterogeneity, the discretization of the multiphase model was finer in the north pool study than in the south pool study. We assumed an average size for our samples and resulting permeability estimates, and this thickness was represented as the vertical discretization (0.1 m) in our numerical model.…”

Experimental Study on the Measurement of S-p Relations of LNAPL in a Porous Medium

“…Therefore, researchers have suggested the use of S-p relations in two-phase system to predict those in three-phase system (Parker et al, 1987). Lenhard and Parker (1988) developed an experimental apparatus to measure directly the relationships between saturation and capillary pressure in a three-phase system with unconsolidated porous media. Their results indicated a close agreement between water saturation in a three-phase system and that in a two-phase system as a function of water-LNAPL capillary pressure.…”

On the movement of an LNAPL lens on the water table

“…Following Lenhard and Parker (1988), henceforth LP, the scaling rules, implied by the above considerations, will be used…”