The completed Baxter formation flow test was the first of two planned for the Dorado field in the Bedout Basin, offshore Western Australia, from the Dorado-3 appraisal well.
Caley reservoir testing next
Testing of the primary Caley oil reservoir will be undertaken in coming weeks.
Multi-rate flow testing has confirmed excellent productivity and fluid quality from the Baxter reservoir.
Santos managing director and CEO Kevin Gallagher has described Dorado as “one of the most exciting growth projects across the Santos portfolio”.
Dorado-3 is in petroleum permit WA-437-P, in which Santos is operator and has an 80% interest, with Carnarvon holding the balance.
It is in Commonwealth waters about 160 kilometres north of Port Hedland and 1-kilometre northwest of the Dorado-1 discovery, made in July last year.
Capacity to flow at higher rates
The initial clean-up test over the Baxter reservoir was conducted over a 12-hour period and achieved a maximum rate of approximately 48 million standard cubic feet per day of gas and 4,500 barrels per day of associated condensate through a 60/64” choke.
This well test was conducted over a 7.4-metre net interval between 4,136 and 4,156 metres Measured Depth and achieved with only 150 psi of drawdown.
Production was limited by surface equipment constraints indicating the reservoir has the capacity to flow at significantly higher rates.
Gallagher said: “The flow rate in the Baxter confirms our interpretation of a high-quality reservoir with excellent productivity and condensate-rich gas with low levels of impurities.
“This result further increases our confidence in our ability to commercialise the significant condensate resources in the Dorado field.”
Dorado-3 was drilled using the jack-up mobile offshore drilling unit, Noble Tom Prosser, in a water depth of 95 metres and reached a total measured depth of 4,643 metres.
Better than expected
Preliminary interpretation of the well test points to reservoir quality and condensate gas ratio better than initially expected, which will result in higher well deliverability when the field is developed.
A separate test will be undertaken over the Caley oil reservoir to provide key information on deliverability and fluid compositions.
Gallagher added, “We look forward to the results from the planned test of the Caley oil reservoir, which should close out the Dorado appraisal program and allow us to work towards a Final Investment Decision on the project.”
Once operations are completed, the well will be plugged and abandoned as planned, thereby concluding Santos’ 2019 offshore drilling program.