EXPERIMENTAL-VERIFICATION OF A MODIFIED SCALING GROUP FOR SPONTANEOUSIMBIBITION

Spontaneous imbibition is of critical importance to oil recovery from fractured reservoirs. A widely used approach to predict oil recovery i nvolves scab-up of laboratory results to reservoir conditions. Scaling Involves the effects of sample size, shape, boundary conditions, visc osity and viscosity ratios, interfacial tension (IFT), pore structure, wettability, capillary pressure, and relative permeability, This work addresses the application of a characteristic length to scaling the c ombined effects of sample shape and boundary conditions with only mino r variations in other parameters except for liquid/liquid (L/L) viscos ity ratios. Imbibition measurements are presented for cylindrical Bere a sandstone cores of different lengths. For some experiments, core sur faces were partially sealed with epoxy to give different boundary cond itions, Cores were initially saturated with refined mineral oils of di fferent viscosities. A synthetic reservoir brine was used as the wetti ng phase. The characteristic length is defined as a function of bulk v olume, areas of surfaces open to imbibition, and the distances from th ese surfaces to their respective no-flow boundaries. The characteristi c length, in combination with a term that compensates for the effect o f L/L viscosity ratio, gave close correlation of all data.