Perth-based duo Quadrant Energy Ltd. and Carnarvon Petroleum Ltd.’s multizone Dorado oil discovery in the Bedout subbasin has been assessed as the largest field found on the North West Shelf off Western Australia in the last 30 years.
Carnarvon has completed its assessment of the hydrocarbon volumes in the Dorado structure in permit WA-437-P and reported a 2C contingent resource figure for oil of 171 million bbl plus 16 million bbl of condensate. Contingent 2C gas resources have been assessed as 552 bcf.
Adrian Cook, Carnarvon’s managing director and chief executive officer, said the 171 million bbl of oil discovered with the Dorado-1 wildcat is one of the largest oil resources ever found in the region.
“Oil fields of this significant scale are not often found, with the last large field discovery on the North West Shelf being around 30 years ago,” he said.
“It is common for additional resources to be discovered in the surrounding area after a large discovery. In this regard we expect to provide the market with further details on prospects identified by the play concept now proven at Dorado, that we believe have the potential to also contain oil resources,” Cook added.
Combining the contingent resources at Dorado into barrels of oil equivalent, Carnarvon has assessed the 1C resources at 128 million boe, 2C resources at 283 million boe, and 3C resources at 566 million boe.
Cook also said the gas and condensate discovered at the Phoenix project to the north in neighboring permit WA-435-P is also a valuable resource that is in addition to the discovered oil. When combined with nearby Roc field, which lies 20 km north and down-dip from Dorado, the aggregate resources are 884 bcf of gas and 36 million bbl of associated condensate on a 2C basis.
The group has confirmed that the Dorado structure contains multiple oil columns in the Caley, Crespin, and Milne Members and a gas-condensate column in the Baxter Member aggregating to a total net hydrocarbon pay of 132 m.
No water was found in the Caley, Baxter, or Milne sands, but the lower section of the Crespin does contain an interpreted water contact.
Quadrant is operator with 80% interest; Carnarvon holds the remaining interest.
