Saturation Function Card (EOR)

STOMP-EOR is designed to solve problems involving the transport of energy, water, CO₂, CH₄, salt, and a user-defined number of petroleum components with passive solutes or reactive species through variably saturated geologic media under non-isothermal conditions. The saturation function describe the relationship between interphase capillary pressure and phase saturation.  STOMP-EOR is currently being developed as a three phase simulator: 1) gas, 2) aqueous, and 3) nonaqueous-liquid.  The liquid phases (i.e., aqueous and nonaqueous liquid) are assumed to wet the solid surfaces of the geologic media.  The gas phase is assumed to be the nonwetting phase.  The degree to which the solid surface is wet is controlled by the contact angle; where, the contact angle varies from 0˚ to 180˚.  A contact angle of 0˚ indicates the system is aqueous wet (i.e., water wet) and a contact angle of 180˚ indicates a nonaqueous-liquid wet (i.e., oil wet) system.  Mixed-wettability between the aqueous and nonaqueous phase occur at contact angles between 0˚ and 180˚.  The sP function in STOMP-EOR is used to calculate the phase capillary pressures from phase saturations, or in an inverse manner the phase saturations from phase capillary pressures.  The primary variable set in STOMP-EOR uses phase saturations as unknowns, so the forward calculation will be from phase capillary saturations to phase capillary pressures. The saturation function and its parameters are considered to be intrinsic properties of the rock/soil and are associated with grid cells via the rock/soil zonation.  The Saturation Function Card is used to specify relative permeability models for each of the three mobile phases, and to specify properties for the model parameters.