Santos achieves strong oil flow from Dorado appraisal well

The initial flow test of the Caley reservoir from the Santos-operated Dorado-3 appraisal well off Australia has confirmed the main oil pool in the field is capable of producing flow rates at the higher end of pre-drill expectations.

The Noble Tom Prosser jack-up rig
The Noble Tom Prosser jack-up rig; Source: Carnarvon

The Dorado-3 appraisal well is located in WA-437-P where Santos is the operator an 80% interest, and Carnarvon is its partner. It is in Commonwealth waters approximately 160 kilometres north of Port Hedland and one kilometre north-west of the Dorado-1 discovery, made in July last year.

The well was spudded in late July using the Noble Tom Prosser jack-up rig in a water depth of 95 metres and reached a total measured depth of 4,643 metres. It was designed to appraise the original Dorado oil discovery.

Preparations for flow testing of the well started in mid-September with the first test undertaken on the Baxter reservoir and Caley test came next. The Baxter test late last month confirmed excellent productivity and fluid quality.

In an update on Tuesday, Santos said that the initial clean-up flow test of the Caley reservoir, in the Dorado field located in the Bedout Basin, was conducted over a 12-hour period and achieved a maximum measured rate of approximately 11,100 barrels of oil per day and 21 million standard cubic feet of associated gas per day through a 68/64” choke.

According to Santos, the oil rate is one of the highest ever from a North West Shelf appraisal well test.

The test was conducted over an 11 metre net interval between 3,999 and 4,015 metres Measured Depth and achieved with only 220 psi of drawdown. As with the recent Baxter test, the Caley production was constrained by surface equipment, indicating the reservoir has the capacity to flow at significantly higher rates.

Santos Managing Director and Chief Executive Officer Kevin Gallagher said the test result was extremely positive.

“The test was conducted over only an 11 metre net section of the Caley from a total net reservoir interval of 53 metres, which demonstrates the high quality of the Caley reservoir.

“The results are very encouraging for development of the shallow-water Dorado field, with the test indicating very high potential flow rates of around 30,000 barrels per day from each single production well in the Caley reservoir. This positive result represents a significant step in progressing Dorado as one of Santos’ most exciting new development projects.”

Together, the results from the two tests indicate potential for field production flow rates at the higher end of expectations and strongly support progress towards FEED entry in early 2020.

Once operations are completed, the well will be plugged and abandoned as planned, thereby concluding Santos’ 2019 offshore drilling program.

Carnarvon Managing Director, Adrian Cook, said: “These results are the highlight of an incredibly successful 2019 appraisal program in which we have now confirmed a very large resource of oil and gas at Dorado and prolific production flow rates.

“Dorado is an exceptional project given these appraisal outcomes and is complemented by its local jurisdiction, it’s location in shallow water and its services advantages given its proximity to shore and supporting infrastructure which will aid development and operational costs.


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