These effective properties include directional permeability, matrix block sizes and shapes, and appropriate continuum cell size. Matrix block sizes are required to represent mobilisation of oil in the matrix via the fracture system. The continuum cell size used for a fractured reservoir should reflect the length scales of fracture connectivity and heterogeneities in the effective flow properties.

Subvertical fracturing is a common feature of carbonate reservoirs. Fracturing occurs on the local scale due to variable stress, differential compaction and chemical weakening of the rock. Larger-scale features occur due to deformation associated with folds or faults. Such fractures can act as major flow conduits and hence impact significantly on the fluid flow characteristics of a reservoir. The design and operation of wells and enhanced oil recovery systems require an accurate assessment of fractures and other flowing features.
To understand and simulate fractured reservoirs the geometry, connectivity and permeability of the fracture system must be represented realistically. A stochastic discrete fracture network (DFN) approach can be used to provide effective properties for the fracture system as input for conventional dual-permeability dual-porosity simulators.
 



Run
Reservoir
Case Study
Presentation
A VRML plug in is required to view parts of this presentation. You can download the Parallel Graphics Cortona VRML Client from http://www.parallelgraphics.com/products/cortona/download. You may also need a Cortona VRML 1.0 Converter, which can be downloaded from http://www.parallelgraphics.com/products/cortona/converter

 
  The scene shows the block-scale principal permeability component for a geostatistical simulation of a fracture network for a 50m by 50m by 10m block size. Colouring is according to the logarithm of the major principal permeability component K1 from red (high) to blue (low). The red lines show the boundary modelled region.