A Comparison of Laboratory Linear and Pattern Flow Chemical Floods Using a Volumetric Linear Scaling Concept for Oil Saturation Distributions

Abstract

A laboratory quarter five-spot pattern chemical flood was conducted in a consolidated, homogeneous porous matrix for comparison with standard linear core floods. In addition to the routine material balance information, quantitative areal oil saturation isometric and contour plots were obtained from microwave attenuation measurements made during the flood. The microwave instrument provides the actual observation of oil banking and movement in a laboratory pattern chemi ca 1 flood.Pattern fl ood oil banki ng characteri st i cs are compared wi th those observed in linear floods.A volumetric linear scaling approach was used to predi ct the behavi or of the pattern chem; ca 1 flood from linear flood data. First, a stream tube model was assumed for the quarter five-spot flow pattern. The oil saturation distribution in each tube was computed from scaled linear core flood oil saturation distributions obtained by microwave attenuation. Details of this procedure are given. The comparison between predicted and observed pattern flood behavi or is most encouragi ng. The average tertiary residual oil saturation and the tertiary oi 1 breakthrough time were very accurately predicted. The observed tertiary S contours in the or pattern flood did show slightly more cusping toward the producer than predicted by the simple model. An i nterpretat i on of the pattern fl ood response is proposed in terms of the scaling theory, its assumptions and its limitations.