First production started from the near vertical CH-6 well at an initial controlled clean-up rate of about 1000 barrels of oil per day.

Field production rates are expected to increase to more than 10,000bpd as the five other designated oil producers, including four horizontal wells, are brought on-stream over the next few weeks.

The oil will be transported via a 14km pipeline to the onshore Arrowsmith Stabilisation Plant, from where it will be trucked to the new BP Crude Oil Unloading Facility at Kwinana, which was purpose-built to handle oil deliveries from Cliff Head.

While Roc Oil chief executive John Doran recognised first oil from the development as an “obvious landmark” for all involved, he said the company had now turned its attention to bringing the remaining wells into production.

“Roc’s current focus is not on statistical niceties as much as completing the other wells and bringing them on-stream,” he said.

“In this sense, first oil from Cliff Head is more like another day at the office rather than an end in itself.”

Meanwhile, joint venture partner Australian Worldwide Exploration said Cliff Head marked the second of its cornerstone projects to enter production over the past few months.

“Following the recently commissioned Casino gas field in the offshore Otway Basin, the Cliff Head project will provide a sharp lift in revenues for AWE,” managing director Bruce Phillips said.

“Importantly in the current oil price environment, AWE’s share of the Cliff Head oil production and reserves are unhedged.”

The Cliff Head development comprises an offshore, unmanned wellhead platform located about 10km offshore in 18m of water. The development includes six production wells and two water injectors.

Proved and probable (2P) oil reserves in the field are estimated at 14.8 million bbls.

In its first year, Cliff Head oil production is expected to account for 10% of WA’s oil consumption, according to AWE and Roc.

The Cliff Head joint venture comprises Roc, which holds a 37.5% stake, AWE Oil (27.5%), Wandoo Petroleum (24%), Arc Energy (6%) and CIECO Exploration and Production (5%).