Using electrofacies cluster analysis to evaluate shale-gas potential: Carynginia Formation, Perth Basin, Western Australia

Abstract

Unconventional hydrocarbon resources are becoming increasingly important to keep pace with the global rising energy demands. Identification of reservoir electrofacies plays an important role in petro physical evaluation of hydrocarbon bearing intervals. In order to provide criteria to highlight the sweet spots for shale-gas in the Perth Basin, electrofacies analysis was done for Carynginia Formation, using cluster analysis techniques. This analysis was carried out by identifying electrofacies from wireline well log responses and from the available core data, focused in six selected wells. Three types of situations have been defined, regarding shale-gas potential and characteristic electrofacies identification – Type I, Gas-window wells with shale-gas; Type II, oil-window wells with shale-gas; Type III, non-mature wells with no shale-gas. From the 30 identified electrofacies, three appear as more promising in terms of shale-gas bearing layers of the Carynginia formation. This method may be used to help detecting shale-gas targets based on electrofacies analysis.