First order sealing and hydrocarbon migration processes, Gippsland Basin, Australia: implications for CO2 geosequestration
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Product description:Abstract The petroleum systems of the Gippsland Basin have been evaluated to provide insights into how hydrocarbons have migrated and accumulated and how injected CO2 could migrate and be either retained or lost from the system. This study has provided both new insights into the petroleum systems in this mature basin and a regional framework for assessing the viability of the Gippsland Basin for large-scale Carbon Capture and Storage (CCS) in relation to containment and migration. New data on the palaeo-charge history suggest that the initial hydrocarbon charge into many of the existing giant gas and oil accumulations was actually oil and that signifi cant oil columns were present in the Neogene. Subsequently, increased maturation and gas expulsion from a gas-prone, upper coastal plain source kitchen located south of Barracouta caused the partial to complete displacement of the oil columns in what are now giant gas fields. Thickness, distribution and MICP capacity data for the Lakes Entrance Formation suggest that the base top-seal within the Central Deep has excellent containment characteristics, with the capacity to withhold hundreds of metres of gas or CO2. The Central Deep represents an ideal setting for large-scale CO2 injection. CO2 injected either east or west of Halibut should, because of the connectedness of the traps, eventually migrate into Halibut and then progressively fill and spill through Kingfish, Bream and Barracouta. Further north, there is an analogous fill-spill chain associated with Marlin, Snapper and Barracouta. The very high integrity of the Lakes Entrance Formation seal and the porous nature of the Latrobe Group sandstones suggest that the storage capacity of the Central Deep is very large. The flanking Northern and Southern terraces appear to have lesser, but still adequate containment, with the potential to withhold 50-100 m gas being proven on parts of the Northern Terrace. In contrast, the Northern and Southern platforms have very poor sealing characteristics; sealing capacity decreases to only 5 m of gas and 13 m of CO2 at Groper-2. Onshore, the top-seal is relatively thick and offers good containment within the Lake Wellington and Seaspray depressions. However, outside these areas, the Lakes Entrance Formation onshore has generally poor MICP characteristics and it is likely that containment is inadequate. Download The downloadable version of this paper is supplied in PDF format. Bibliographic reference O'Brien, G.W., Tingate, P.R., Goldie Divko, L.M., Harrison, M.L., Boreham, C.J., Liu, K., Arian, N. & Skladzien, P., 2008. First order sealing and hydrocarbon migration processes, Gippsland Basin, Australia: implications for CO2 geosequestration. Eastern Australasian Basins Symposium III, Petroleum Exploration Society of Australia, Special Publication, 1-28. Related products:
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