A joint venture of Santos Ltd. and Carnarvon Petroleum Ltd. is moving swiftly in preparation for its appraisal of last year’s large Dorado oil and gas discovery in permit WA-437-P in the Bedout subbasin offshore Western Australia (OGJ Online, July 24, 2018).
Carnarvon said in its quarterly report that the Noble Tom Prosser jack up drilling rig has been contracted to drill the Dorado-2 and Dorado-3 appraisal wells, the first of which is to be spudded in April.
The group is hoping the two-well program will put it in a strong position to consider a final investment decision for Dorado development in 2020.
Dorado-1 indicated a 2C resource of 171 million bbl of oil, 16 million bbl of condensate, and 525 bcf of gas.
Dorado-2 will target the hydrocarbon columns in a down-dip location to the discovery to confirm the extent of the accumulations and further calibrate the reservoir and fluid properties.
Dorado-3 is being planned to include drill stem tests and also will be critical to an understanding of reservoir performance as well as obtaining fluid samples required for design of the proposed production facilities.
Meanwhile, the group is continuing work to define the follow-up potential of the region. Specifically, the Roc South prospect about 13 km from the crest of the Dorado structure is seen as having a high probablility of success and capable of holding as much as 74 million boe.
Roc South has a similar trap to Dorado and is updip of the previous Roc discoveries.
Another two prospects, Pavo and Apus, also have been derisked following the Dorado discovery and could hold a respective 82 million bbl and 612 million bbl of recoverable oil.
Santos is the new operator of the joint venture, having completed its acquisition of Quadrant Energy Ltd. late last year. Santos has 80% of Dorado and Carnarvon the remainder.