3-D Upscaling of Fault Damage Zones for Reservoir Modeling

Simon D. Harris, Atilla Vaszi, and Rob J. Knipe
Rock Deformation Research Limited, Leeds, United Kingdom

The characterisation of the architecture of fault zones, where a damage zone surrounds the major slip surface, is only usually achievable via 2D maps, or 1D line samples or well logs. In this paper we address issues related to generating a 3D stochastic fault damage zone (FDZ) model that creates realistic fault systems resembling those encountered in nature, as well as developing a 3D fault flow model that can capture critical 3D upscaled properties of the damage zone. The properties of interest to predict from the upscaling process include the bulk permeability of selected domains, the fault rock thickness on streamlines, the tortuosity and length of flow pathways, and the efficiency of the fault network in behaving as a barrier to the flow. Examining the fault rock thickness encountered on flow pathways across a major fault allows us to investigate the ‘effective' fault rock thickness within the damage zone, thus allowing the contribution of the whole FDZ to be incorporated into a large-scale flow simulation.

Based upon a vast sequence of simulations through fault damage zones with varying fault length–frequency, fault density, fault orientation distributions and spatial clustering relations, a summary of flow behaviours has been created, which forms the basis for a predictive/uncertainty tool for the flow characteristics of cells used in production simulation models.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005