APPLICATION OF FRACTIONAL FLOW THEORY TO ENHANCED OIL RECOVERY--THE HIGH PH FLOODING PROCESS (POROUS MEDIA, RELATIVE PERMEABILITY, ALKALINE)

The principal objective of this thesis is to develop a model for predicting the performance of a high pH flooding process. The model development can be classified into three parts. The first part deals with both, fluids distribution and flow in porous media. Here, the phenomena of two phase distribution i.e., saturation alteration due to capillary pressure changes is examined using percolation theory. Initial drainage, initial and primary inhibition processes are considered. Subsequently, the reduction in the residual nonwetting phase saturation as predicted by the above model is evaluated as a function of the viscous to capillary force ratio (capillary number). The resulting normalized residual nonwetting phase saturation is found to be an approximately universal function of the capillary number for porous media within a wide range of permeability. This information is finally used to develop relative permeabilities for both drainage and imbibition. The relative permeability model is based on the cut and rejoin approach and includes situations where viscous and capillary forces are comparable. Available experimental data are shown to concur with model predictions.;The concluding section deals with the alkaline injection process in terms of multicomponent, two phase flow in porous media. Using the relative permeability, interfacial activity and the reaction equilibria models, a system of quasilinear partial differential equations is formulated. The system is solved using the generalized Reimann invariants technique. Profiles, exit history and cumulative oil production are predicted including the case when mineral/alkali interaction occurs. A major conclusion of the model is that interfacial tension between a solution of injection composition and the crude oil does not necessarily correlate with oil recovery. In addition, it is found that the dominant performance determining parameter is the viscosity ratio.;The high pH injection process uses the fact that some crude oils contain acids that can react with alkali to form surfactants. In the second section, the reaction equilibria for acidic crude oil/caustic systems are developed. Along with this, the adsorption isotherm and two equivalent methods for predicting interfacial tension in acidic/crude oil caustic systems are obtained.