The semisubmersibleIsland Innovator drilled well 7120/1-4S in 331.5 m (1,087 ft) of water in license PL492, 5.3 km (3.3 mi) northwest of the discovery well.
The main aims were to confirm the extent and reservoir properties of the Permian carbonates and to establish oil/water and gas/oil contacts in this area of the structure.
The well encountered 10 m (33 ft) of Upper Permian limestone conglomerate containing gas condensate, while the fractured limestone underneath had traces of oil but appears to be tight. The depth interval of oil traces in the appraisal well corresponded with the oil column in the discovery well.
Pressure and fluid properties indicated communication between the reservoirs in the two wells.
During a drillstem test the oil zone produced 6.4 MMcf/d (181,228 cm/d) of gas, however pressure build-up data revealed drainage from a porous reservoir caused by insufficient isolation between the oil and gas zones on the outside of the production liner. Results were therefore inconclusive.
Another test of the 10-m thick gas condensate zone flowed 26.4 MMcf/d (747,564 cm/d) of gas and 880 b/d of condensate with good production characteristics close to the limestone conglomerate.