Jurassic To Recent Sequence Stratigraphy Of The Money Shoal Basin, Arafura Sea, Northern Australia.
Pollock, Rosalie Miranda
Honours Degree, 1998
University of Adelaide
The Money Shoal Basin is situated in the Arafura Sea, on the northern margin of Australia. Sediments are Middle Jurassic to Recent in age and were relatively widespread with the best development above the WNW trending Goulburn Graben. Sediments of the Money Shoal Basin have undergone very little tectonic deformation since their deposition.
Depositional environments range from non-marine through to deep marine when a radiolarian-rich claystone was deposited at the peak of the Aptian transgression. During the earliest Tertiary, climatic changes resulted in an increase in carbonate deposition, which continued to recent times.
Comparisons were made to adjacent and nearby basins, as previous work on the sequence stratigraphy of the Money Shoal Basin was limited. A sequence stratigraphic study was conducted with the objective of deriving depositional models that would allow prediction of hydrocarbon plays in the basin. The study focused on the use of well logs with correlations between wells based on biostratigraphic data and supported by seismic sections through the wells. Chronostratigraphic charts were constructed to give an idea of the extent of erosion and condensation that occurred within the Basin. Time and data restrictions prevented extensive and detailed mapping of facies across the basin.
It was found there was a distinct lack of quality reservoirs due to the formation of cements and clay matrix. The dominantly silty and sandy nature of the sediments above potential reservoirs poses a significant seal risk. Forced regressive systems tracts and basin floor fans with overlying shaley transgressive systems tracts were identified as having the best hydrocarbon potential within the study area. Evidence suggests these potential plays may be best developed in the western part of the basin. The lack of structure within the Money Shoal Basin sediments indicates the main trap type will be stratigraphic, rather than structural.