The Perth-based company today said as of this morning, the Century 18 drilling rig drilled a 12¼-inch hole to 425m.

Located about 12km southeast of the Western Australian town of Dongara, the primary target is the Late Permian Dongara Sandstone, the main oil-producing reservoir in the Jingemia, Hovea and Eremia oil fields.

Arc said the well is designed to intersect the Dongara Sandstone as close as possible to the structural crest of the Eremia oil field and updip of existing Eremia wells.

Eremia-5 is being drilled directionally and is expected to intersect the top of the Dongara Sandstone at about 2142m measured depth, which is about 306m northeast of the surface location.

The well has a planned total depth of about 2331m and is expected to take 18 days to drill and finish.

Participants in L1 are operator Arc Energy and Origin Energy Developments, both with a 50% stake.