A Geological Model for CO2 Storage within the Otway Basin

Kaia Little
Australian School of Petroleum, The University of Adelaide
Australia
klittle@asp.adelaide.edu.au

The Otway Basin in southern Australia is a significant source of natural gas, with locally high carbon dioxide (CO2) compositions; never the less it is still economically attractive due to its proximity to domestic markets. Natural gas production however, will increase CO2 emissions, so a satisfactory method of CO2 storage must be found. Subsurface geological storage of CO2 is the preferred emissions mitigation option due to its large potential storage capacities, long residence times, relatively low cost and the large impact on reducing emissions.

This project will specifically focus on geological modelling of suitable CO2 storage sites within the Otway Basin. This basin contains a number of natural CO2 fields, which demonstrate the basin’s suitability as a CO2 storage site. A geological model of the selected area will be built by combining data from seismic lines, well log correlations, core logging, drill cuttings analysis, field samples and thin sections. MICP analysis will determine seal and reservoir capacities. The geological model built will highlight a series of sites that could potentially be used as pilot injection sites to study CO2 storage in Australia.