VIMP Report 15 - The Stratigraphy and Structure of the Tyrendarra Embayment, Otway Basin, Victoria
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Product description:Download The downloadable version of this report is supplied in PDF format. Executive Summary The geology and prospectivity of the Tyrendarra Embayment has been summarized for explorers in the Otway Basin. The study has focussed on the stratigraphy and structure of Cretaceous units within the Tyrendarra Embayment. In the two main producing areas of the Otway Basin, hydrocarbons are hosted by the Early Cretaceous Katnook Sandstone in the Katnook field of South Australia, and the Late Cretaceous Waarre Sandstone in the Port Campbell area of Victoria. The hydrocarbon prospectivity of the Tyrendarra Embayment, in particular oil generation and entrapment, has been directly influenced by structural events within and around the embayment. The nature and timing of these events has been interpreted using detailed seismic, gravity and magnetic images. The Tyrendarra Embayment has a similar history of development to the gas prone Port Campbell Embayment. Complex structuring, not only within the Tyrendarra Embayment, but also in the accommodation, or transfer zones separating it from other regional depocentres, provides ample opportunity for hydrocarbon entrapment. The nature and distribution of Cretaceous units within the Tyrendarra Embayment have been mapped in detail through correlation of wireline logs, examination of core and cuttings, and utilising biostratigraphic and seismic data. This work indicates that the key rock units for hydrocarbon exploration, as observed elsewhere in the Otway Basin, are present in the Tyrendarra Embayment. These include the Casterton and Eumeralla formations as potential source rocks, proven reservoir sands in the Eumeralla Formation, and the Eumeralla Formation mudstones and the Belfast Mudstone as seals. Other potential reservoirs mapped in detail were the Paaratte Formation sands, particularly the Timboon Sand Member. The Tyrendarra Embayment, like most of the Otway Basin, is relatively underexplored for hydrocarbons, and although hydrocarbon shows are scarce, there is plenty of scope for future discoveries. This study has added considerable knowledge to the stratigraphic and structural history of the Tyrendarra Embayment, indicating that the key factors important to hydrocarbon exploration do exist in the embayment. Further exploration, particularly drilling, holds the promise of substantial hydrocarbon finds in the future. Bibliographic reference Ryan, S.M., Knight, L.A. & Parker, G.J., 1995. The stratigraphy and structure of the Tyrendarra Embayment, Otway Basin, Victoria. Victorian Initiative for Minerals and Petroleum Report 15. Department of Agriculture, Energy and Minerals. | ||||||
