Santos has confirmed a ‘larger than anticipated’ oil and gas resource at the Dorado-2 appraisal well in the Bedout Basin, offshore Western Australia, following the latest appraisal drilling.

In the latest campaign the Dorado-2 appraisal well, around 2km from the Dorado-1 discovery, encountered 85m of net reservoir in the primary Caley Formation. It intersected an oil-water contact at 4,003m with 40m of net oil pay. The appraisal well also encountered 11m of pay in the Upper Caley sands, indicating that this upper zone is oil-bearing.

An additional 32m of net pay was encountered in the underlying Baxter and Milne sandstones. Preliminary reports suggest both these sands as gas bearing, significantly increasing the gas resources in the site compared to earlier estimates.

The Dorado-2 well was drilled by Noble Tom Prosser jack-up mobile offshore drilling unit at a water depth of 91m to a total depth of 4,573m.

Dorado-2 is located in petroleum permit WA-437-P. Santos is the operator of the permit with 80% stake, while the remaining 20% is owned by Carnarvon Petroleum. Once wireline logging operations are completed at Dorado-2, the well will be plugged and abandoned. The rig will then move to drill the Roc South-1 exploration well and return to spud Dorado-3.

Santos managing director and CEO Kevin Gallagher said: “This is a great result which indicates the Dorado discovery is larger than anticipated and which significantly de-risks a future development.

“The value of the discovery is greatly enhanced by the high quality reservoirs and fluids and the shallow-water setting, which should facilitate a cost-competitive development.

“Dorado opens a new basin with high prospectivity in permits where Santos has a high equity position and rich exploration inventory with potential to substantially grow the resource base.”