The well has encountered a 39-m thick hydrocarbon-bearing zone with what it calls significant gas influx and elevated reservoir pore pressure at or near the Caley formation primary target.
The group added that it was unable to assess up to 185-m thickness of additional potential hydrocarbon-bearing Caley reservoir below 5,215-m depth because of the higher-than-anticipated pressures.
Putting a positive spin on this, Carnarvon said that higher formation pressures typically support larger volumes and higher gas and condensate flow rates over a given reservoir.
The company said that because a different wellbore design is required to meet these circumstances than that used in Phoenix South-2, no further drilling and formation evaluation can occur in the current well.
Quadrant, the operator, and Carnarvon now plan to assess the results to determine an appropriate forward strategy to assess the Caley reservoir.
The companies are confident there is significant potential upside still to be assessed in the reservoir underneath total depth of Phoenix South-2.
Quadrant has 80% of the permit with Carnarvon holding the remaining 20%.