Relationships Between V-Shale, Petrographic Character and Petrophysical Data from the Jurassic Reservoir Sandstones in the Southern Vulcan Sub-Basin

Topham, Brett D. (Halliburton Energy Services) | Liu, Keyu (CSIRO Petroleum) | Eadington, Peter J. (CSIRO Petroleum)


An integrated study of well log data, petrographic characterization and laboratory petrophysical measurement of core plug samples was carried out on the upper Early to Late Jurassic reservoir sandstones from the Vulcan Subbasin on the North West Shelf of Australia using 86 samples from seven wells. The data collected show relationships between the gamma ray log derived V-shale parameter, petrographically determined porosity, grain size, and sorting, and laboratory measured porosity and permeability. For reservoir sandstones that display minimal post-depositional diagenesis, V-shale correlates well with lithological descriptors and the petrographic parameters derived from microscopic analysis. In the wells investigated V-shale correlates with the laboratory measured porosity and permeability, with correlation coefficients of ?0.72 and ?0.73 respectively. Visual porosity, grain sorting and matrix percentage correlated best with the laboratory measured porosity and permeability data. Dominant grain size is least correlated to laboratory measured porosity and permeability with a correlation coefficient of less than 0.5. In reservoir rocks comparable with those investigated the log derived V-shale parameter may be used to extend permeability prediction into non-cored depth intervals, similar to the use of petrographical parameters in some empirical equations.