>Magister Scientiae - MSc / The North West Shelf of Australia is a prolific gas province. The Thebe Gas Field is situated
within the northern central Exmouth Plateau in the Northern Carnarvon Basin. The Exmouth
Plateau is a submerged continental block whose culmination lies at about 800m below sea
level. The seismic data used for this study is the HEX07B survey which was conducted in
2007.
The objective of this study was to interpret all available seismic data, of which six horizons
were picked, generating two-way-time structure maps and an average velocity map,
performing depth conversion and generating various depth maps. The horizons picked were
the economic basement, Triassic Mungaroo, Murat Siltstone, Muderong Shale, Gearle
Siltstone and the Sea Bed. The horizon of interest was the Triassic Mungaroo Formation and
therefore it was the only horizon with an average velocity map. The seismic sections were
used in conjunction with the structure maps generated to identify possible locations for
appraisal wells to be drilled. Prospect X was identified on the basis of amplitude and structure
present within the Triassic Mungaroo Formation. The final task was to calculate the volumes
present and a Monte-Carlo Simulation was used for this.
The results obtained showed that Prospect X has a good petroleum system in place. The
Mungaroo Formation is identified as being the possible source and reservoir rock, the
Muderong Shale is the seal, structural traps are provided by large fault block and faults
provided the migration pathways from the source in to the reservoir.
The volumes were calculated using three areas identified on the structure maps by three
closing contours. These areas are the P90, P50, P10 and the volumes for the gas in place were
as follows, P90 = 893 Bcf (0.9Tcf), P50 = 1128 Bcf (1.1 Tcf), P10 = 1367 Bcf (1.4Tcf).
Using the various parameters the probability of success for Prospect X was calculated to be
20%.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uwc/oai:etd.uwc.ac.za:11394/4028 |
| Date | January 2013 |
| Creators | Bailey, Brett B. |
| Contributors | Opuwari, Mimonitu |
| Publisher | University of the Western Cape |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Rights | University of the Western Cape |
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