Rock properties and in-situ stress state of the Egilabria Prospect, Lawn Hill Platform, Queensland

Abstract

The Energy component of Geoscience Australia’s Exploring for the Future (EFTF) program is aimed at improving our understanding of the petroleum resource potential of northern Australia, in partnership with the state and territory geological surveys. The sediments of the Mesoproterozoic South Nicholson Basin and the underlying Paleoproterozoic Isa Superbasin in the Northern Territory and Queensland are amongst the primary targets of the EFTF Energy program, as they are known to contain organic-rich sedimentary units with the potential to host unconventional gas plays, although their subsurface extent under the cover of the Georgina Basin is presently unknown. In order to economically produce from unconventional reservoirs, the petrophysical rock properties and in-situ stresses must be conducive to the creation of secondary permeability networks that connect a wellbore to as large a reservoir volume as possible. This study utilises data from the recently drilled Armour Energy wells Egilabria 2, Egilabria 2-DW1, and Egilabria 4 to constrain rock properties and in-situ stresses for the Isa Superbasin sequence where intersected on the Lawn Hill Platform of north-west Queensland. These results have implications for petroleum prospectivity in an area with proven gas potential, which are discussed here in the context of the rock properties and in-situ stresses desired for a viable shale gas play. In addition, these results are relevant to potential future exploration across the broader Isa Superbasin sequence.