A Fractal Index of Reservoir Heterogeneity

STOLUM, HANS-HENRIK, Stavanger, Norway

Heterolithic reservoirs representing fan, tidal, or fluvial deposition commonly have a fractal distribution of sand and shale. Based on 1-D core data, self-similar heterogeneity is well described by three parameters: the fractal dimension, the shale factor (which is a measure of amplitude, or shale density), and core length. These parameters are combined to form a heterogeneity index.

The index is a simple, quantitative expression of the heterogeneity seen in cores. It efficiently summarizes the very complex information of heterolithic sequences, and is directly related to reservoir quality and flow properties. Lateral variation in reservoir characteristics may be assessed if the index is calculated well by well. It may also be used as an indicator of depositional environment, and for transferring data to reservoir simulators.

AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)