Improved representation of sub-wireline scale lithological heterogeneity in geological models

Abstract

Siliciclastic reservoirs often comprise lithological heterogeneity at mm-to cm-scales in the form of fine laminations of intraformational baffles. Such heterogeneities enhance capillarity and are often enriched in clay minerals such as chlorites. These properties could significantly influence subsurface fluid flow and fluid rock reactions. However, these heterogeneities are difficult to represent in geological models primarily because they exist at a scale which is below the resolution of conventional wireline logs. This paper presents an approach for deducing such heterogeneities using a combination of core plug and wireline log data to derive rock types capturing variations in intraformati..