Publication Name: The Cooper & Eromanga Basins Australia
Authors: B. B. Farrow
Date Published: June 1989
Number of Pages: 19
Reference Type: Book Section
Abstract:
A method is presented by which the permeability of Jurassic-Early Cretaceous rocks in the Eromanga Basin maybe estimated from four non-electric geophysical logs, viz. gamma ray, bulk density, neutron porosity and sonic. The method is based on a detailed statistical analysis of core and log data. The data used in this study were made available by the South Australian Department of Mines and Energy and comprised 534 samples from 16 wells spread throughout the Basin and representing depths between 4000 and 9000 ft (1200 and 2700 m).
At the depth of interest the probability that a particular value of a log correlates with a particular permeability is
derived for each log. These values are then combined to determine the most probable permeability represented by the set of log values. A good correlation between estimated and measured permeabilities is achieved (Pearson's R = 0.85) with 68 per cent lying within a factor of 6 and about 85 per cent lying within a factor of 20.