Areas W07-16 and W07-17
Exmouth Plateau, Carnarvon Basin
Exploration History
The Exmouth Plateau, Rankin Platform and Dampier Sub-basin are all proven hydrocarbon provinces with many oil and gas accumulations (Figure 1); however, while the release areas are close to significant hydrocarbon accumulations, they have to be considered as frontier areas for exploration.
Two wells, Lacerta 1 and Tigger 1, have been drilled in Area W07-17 while none have been drilled in Area W07-16.
The first well to be drilled in this part of the Exmouth Plateau was Brigadier 1, drilled by Woodside Petroleum Development Pty Ltd in 1978. It was drilled to a total depth (TD) of 4292 m in 313 m of water. The objectives were the Late Triassic to earliest Jurassic and the Early to Middle Jurassic on a prominent horst trend. No significant hydrocarbon shows were encountered.
Gandara 1 (1979) was drilled by Hudbay Oil (Australia) Limited to a TD of 4361 m in 305 m of water. This well was also drilled on the Brigadier Trend. Some high gas readings were encountered in coal seams near to TD, but no significant hydrocarbon shows were observed.
Drilling in this area remained dormant for 19 years until Andromeda 1 was drilled by Mobil Exploration and Producing Australia Pty Ltd in 1997 to a TD of 4208 m in 343 m of water. This well also targeted the Brigadier Trend. The well had two objectives; a four-way drape closure in the Middle Jurassic Legendre Formation beneath the Base Cretaceous Unconformity, and a deeper fault-dependent closure in the Early Jurassic to Late Triassic North Rankin and Brigadier formations. All objectives proved to have good quality reservoirs, but all were water wet. Possible oil staining observed in sidewall cores within the Athol Formation hints at a Triassic or older carbonate source, but the interpretation is clouded by the presence of contaminants.
Banambu 1 (1998) was drilled by Woodside Offshore Petroleum Pty Ltd to a TD of 4001 m in 295 m of water. The primary objective was Early Jurassic to Triassic reservoirs in a large upthrown fault block on the Brigadier Trend. Good quality reservoirs were intersected in the North Rankin, Brigadier and Mungaroo formations, but no hydrocarbon shows were encountered. GOI™ studies gave results ≤ 0.1 %.
Lacerta 1 (1998) was drilled by Mobil Exploration and Producing Australia Pty Ltd and targeted the mid-Jurassic Legendre Formation on the northeastern end of the Rankin Platform. This was a combination structural/stratigraphic trap with good quality reservoirs encountered, but only minor to weak hydrocarbon shows were observed. The well reached at TD of 3393 m in 134 m of water.
Glatton 1 (1999) was drilled by Woodside Energy Ltd. The well reached a TD of 2985 m in 360 m of water and targeted sub-cropping Legendre Formation below the Main Unconformity. Good quality reservoir was encountered, but only trace fluorescence was observed.
Tigger 1 (2003) was drilled by Woodside Energy Ltd and targeted the Tithonian Angel Formation on the northwestern edge of the Dampier Sub-basin. This formation is oil-bearing in the nearby Mutineer/Norfolk, Exeter, Egret, Lambert and Hermes accumulations. The well was drilled to a TD of 3650 m in a water depth of 140 m, but no hydrocarbon shows were encountered.
The latest well drilled in the immediate vicinity of the release areas
was Plymouth 1 (2005), which was drilled by Santos Limited
to a TD of 3457 m in 168 m of water. Data for this well are still confidential.
Relevant Wells Listing
| Well | Operator | Year | Total Depth (m) | Hydrocarbons |
|---|---|---|---|---|
| Andromeda 1 | Mobil Exploration and Producing Australia Pty Ltd | 1997 | 4208 | Oil Indication |
| Banambu 1 | Woodside Offshore Petroleum Pty Ltd | 1998 | 4001 | No shows |
| Brigadier 1 | Woodside Offshore Petroleum Pty Ltd | 1978 | 4292 | Oil & gas indications |
| Carteret 1 | Woodside Energy Ltd | 2003 | 3515 | Proven oil zone, gas indication |
| Gandara 1 | Hudbay Oil (Australia) Limited | 1979 | 4361 | Oil & gas indications |
| Glatton 1 | Woodside Energy Ltd | 1999 | 2985 | No shows |
| Lacerta 1 | Mobil Exploration & Producing Australia Pty Ltd | 1998 | 3393 | No shows |
| Plymouth 1 | Santos Limited | 2005 | 3547 | No shows |
| Tigger 1 | Woodside Energy Ltd | 2003 | 3650 | No shows |