Coupling Petrography And Seismic Attributes For Locating Permeable Zones In The Cooper Basin/South Australia, A Possible Workflow For Geothermal Projects.

Abstract

Hutton sandstone in Celsius-1 and Burley1, 2, 3 were studied both under thin sections and using seismic attributes for reservoir characterization. Hutton sandstone in Celsius-1 showed extensive quartz cementation in the form of overgrowth composing a percentage of around 50% of the overall rock volume. This quartz cement caused strong reduction in porosity and permeability. Several diagenetic processes such as authigenic muscovite formation in the pore spaces and pressure solutions indicated that the rock was subjected to temperatures up to 295 C. Wells close to Celsius-1 (e.g. Burley-1, 2, 3 located 4 km from Celsius-1) show no quartz cementation or high temperature diagenetic processes. Thus, vertical or horizontal migration of hot fluids can explain high temperature diagenesis variation between Celsius-1 and the adjacent wells. I calculated 2D seismic attribute (e.g. reflection intensity, relative acoustic impedance, envelope, and sweetness) for the seismic sections passing through Celsius-1 and compared it to the same attributes in adjacent wells. Some attributes showed different rock elastic properties of the Hutton sandstone in Celsius-1 compared with the near wells. This indicated the ability of using commercial seismic attributes for locating porous and permeable zones.