Immature Reservoirs — Using Borehole Images to Improve Permeability Estimates
Gabrielle Rumbach2 and Nicholas M. Harvey1
1Weatherford, Perth, WA, Australia
2Maurel et Prom, Paris, France
A problem that is often presented by combining borehole image data with open hole log data and core data is the often empirical approach of correlating facies derived from the images through image character with the openhole log data. We intend to demonstrate a use of textural grain size analysis from images (Newberry et al, 2004) to refine computation of permeability in proximal immature reservoirs that have variable grain size, thus directly relating a flow unit property to the images.
We describe the methodology which involves the use of the grainsize distribution in a self organising neural network to define flow units that have independent permeability relationships whereby the different relationships incorporate both grain size distribution as well as porosity.
The methodology is demonstrated through a West African example that shows that by incorporating grainsize as inferred, the permeability estimate is improved. This provides a means of better representing individual flow unit permeability within the reservoir.
AAPG International Conference and Exhibition, Cape Town, South Africa 2008 © AAPG Search and Discovery