Gibson-Poole, Catherine M.¹, Simon C. Lang¹, Jürgen E. Streit¹, Allison L. Hennig², Claus J. Otto²
(1) University of Adelaide, South Australia, Australia
(2) CSIRO Petroleum, Kensington, Australia

ABSTRACT: Geological Storage of Carbon Dioxide: Assessing the Suitability of the Early Cretaceous in the Barrow Sub-basin, NW Australia

Potential sites for geological storage of CO₂ require detailed geological, geophysical and hydrodynamic assessment, as conducted in the GEODISC program. The Flag Sandstone of the Barrow Sub-basin, NW Australia, sealed by the Muderong Shale, is a possible candidate. The Flag Sandstone is a series of stacked, amalgamated, basin floor fan lobes with good lateral interconnectivity. The main reservoir sandstones have high reservoir quality with average porosities of 21% and average permeability of 1273mD. The Muderong Shale has excellent seal capacity, with the potential to withhold an average CO₂ column height of 750m. Geomechanical analyses indicate an average orientation of 095°N for the maximum horizontal stress. At the likely injection depth (below 1800m), the stress regime is strike-slip. Most of the major faults in the study area have E to NE trends and failure plots indicate that some of these faults may be reactivated if injection pressures are not monitored closely. Where average fault dips are known, maximum sustainable formation pressures were estimated to be less than 27MPa at 2km depth. Hydrodynamic modelling indicates that the pre-production regional flow direction was from the sub-basin margins towards the centre, with an exit point to the southwest. However, flow direction and rate have been altered by a hydraulic low in the eastern part of the sub-basin due to hydrocarbon production. The potential storage capacity is estimated in the order of tens to hundreds of TCF of CO₂. Such capacity for geological storage could provide a technical solution for reducing greenhouse gas emissions.

AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.