Sedimentary And Facies Analysis Of The Youngest Reservoir Sequence, Bream Field, Gippsland Basin, Victoria.
Mennie, James R.
Honours Degree, 1995
University of Adelaide
The Late Cretaceous to Early Tertiary Latrobe Group acts as the main reservoir unit in producing fields throughout the Gippsland Basin, including the Bream Field. A range of depositional settings occur within the group causing confusion in determination of the exact stratigraphic framework. This thesis utilises a variety of tools such as petrographic analysis, XRD and SEM analysis, well log correlation and petrophysical evaluation, seismic interpretation and production statistics. These methods enable subdivision of the reservoir sequence in the Bream Field into discrete subfacies recognised as A) bayhead delta, B) lagoonal, C) barrier bar and D) stacked channel facies. Facies analysis may then be utilised to probabilistically define parameters such as the permeability distribution through the reservoir sequence.
The most influential facies delineated in the Bream Field is a barrier bar sand unit. This is characterised by high production rates and sand highs on isopach maps of the total reservoir sands in the interval. There is evidence of poor communication between the sand units in the field, as shown by pulsed neutron logs designed to monitor the movement of fluid contacts with production. This also can be justified by facies variations through the field. By incorporating all of these features of the Upper Latrobe Group, an estuarine sedimentary model is proposed.