Reservoir-Seal Characterisation for Potential Geological CO2 Sequestration near Munmorah, Sydney Basin, Australia.
Stephen Uche Ibe
Master of Science 2010
University of Adelaide
Human and industrial development over the past hundred years has led to a large increase in fossil fuel consumption and CO2 emissions, causing a dramatic increase in atmospheric CO2 concentration. Scientific solutions towards reducing anthropogenic carbon dioxide (CO2) emissions are been developed around the world. One of the methods is the geological sequestration of carbon dioxide. One area that is being considered for possible storage is the Sydney Basin NSW. Two wells within the Sydney Basin have been studied to provide insight into the geologic sequestration potentials. Petrography of sandstone intervals suggests an average porosity of 10.8 % and permeability of 0.938mD. Seal studies using Mercury injection capillary pressure (MICP) data indicate that the Wallis Creek Formation can support a carbon dioxide column of approximately 265m at maximum wettability, whereas the Mulbring Siltstone can contain a 245m CO2 column at maximum wettability before breaching the seal. Scanning electron microscopy data indicate that the reservoir lithologies have only minor variations in sand composition across the study area. No secondary porosity or intra-granular porosity was visible. X-ray Diffraction analysis indicates that the dominant minerals are quartz, detrital kaolin, illite and siderite cement. Core examination resulted in the interpretation of facies associations and depositional environments. The integration of petrographic analysis results and core facies correlations will enable a seal- reservoir characterisation of the study area in relation to its geosequestration potentials.