US independent Apache has firmed up a gas discovery in the Carnarvon basin, off the coast of Western Australia.

Joint venture partner Tap Oil said wireline logs from the Bianchi-1 appraisal well confirmed a gas discovery, with gas gradients established and gas samples recovered in the upper sands of the potential gas bearing interval.

As previously reported, initial logging while drilling results from the well indicated 128 metres of potential net gas pay across several sandstone intervals.

Tap noted on Tuesday that the logging programme had been interrupted so the joint venture could carry out rig repairs, which have since been completed, adding that further analysis was needed on the lower section of the potential gas bearing interval.

It also revealed that the joint venture had agreed to drill an additional 100 metres of section beneath the current total depth to 5480 metres, after which it will resume the wireline logging programme to finalise the evaluation of the well.

Bianchi-1 is being drilled in the WA-49-R retention lease, targeting a Triassic age Mungaroo formation within a separate fault block down dip of the Zola-1/ST1 gas discovery.

Apache operates WA-49-R on 30.25%, and is partnered by Santos on 24.75%, OMV on 20%, JX Nippon Oil & Gas on 15% and Tap on 10%.