A joint venture of Santos Ltd. and Carnarvon Petroleum Ltd. reported it has started drilling the second appraisal well in Dorado oil and gas field in the Bedout subbasin off Western Australia.
Noble Corp.’s Noble Tom Prosser jack up drilling rig has moved to the location in 95 m of water.
Dorado-3 is to be sited 900 m northwest of the Dorado-1 discovery well, drilled last year. The well will conduct 2-3 flow tests targeting the Caley, Baxter, and Milne reservoirs as well as acquire about 380 m of full-bore core through all three reservoirs plus the Crespin sand.
Carnarvon says this program will result in an abundant amount of new data to characterize the field. It is expected that the Caley, Baxter, and Milne reservoirs will be intersected above the hydrocarbon-water contacts.
Well testing will enable collection of fluid samples to help fine-tune processing requirements for the production equipment and provide information about flow potential of the different reservoirs for later use in determining the size of development facilities. The Dorado-3 well test program is expected to take 30-40 days to complete.
The core program will help understand the reservoir architecture as well as calibrate the petrophysical models to provide a better definition of the reservoir porosity, permeability, and hydrocarbon saturation. It also will provide rock samples for detailed engineering analysis in preparation for development.
Carnarvon added that the location for Dorado-3 was chosen to ensure the main Caley interval will be fully oil saturated and provide data of the field structure west of the discovery well. Based on seismic interpretation, the location should also encounter the Milne reservoir where it seems to be thicker and better developed.
Dorado-3 is slightly downdip from Dorado-1, but substantially updip from Dorado-2 drilled earlier this year 2.2 km east of Dorado-1.
The successful Dorado-2 proved connectivity with the same intervals in Dorado-1 and confirmed the oil-water contact in the Caley reservoir as well as extending the proven extent of the other hydrocarbon columns.
Dorado and nearby Roc oil and gas fields are in WA-437-P about 160 km north northwest of Port Hedland on the Western Australian coast.
Santos is operator with 80% interest. Carnarvon has the remaining 20%.
