The Ironbark joint venture has finally submitted its environment plan to the national regulator for the Ironbark-1 exploration well in exploration permit WA-359-P off the northern coast of Western Australia.

In February this year BP (42.5%) contracted the Ocean Apex semisubmersible rig from Diamond Drilling to drill the well.

Other joint venture partners include Cue Energy (21.5%), Beach Energy (21%) and New Zealand Oil and Gas (15%).

The National Offshore Petroleum Safety and Environmental Management Authority said operator BP had submitted the EP on Tuesday.

According to BP the well will spud in the third quarter of 2020, however it may be drilled earlier or later pending operational delays.

Ironbark-1 will be the venture's first exploration well targeting the Ironbark Mungaroo Formation which has a best estimate of trillion cubic feet of gas reserves.

The formation contains multiple objectives which have been "intensely explored at comparably shallower depths," BP said in its EP.

The same formation has resulted in the Gorgon, Julimar-Brunello, Iago, Goodwyn, Perseus and North Rankin gas discoveries. All six fields produce gas condensate.

Ironbark-1 is expected to take around 100 days to drill to a total depth of 5500 metres. It will be drilled in water depths of approximately 300m, 170km offshore from Karratha.

The Ironbark prospect lies some 50km from the North Rankin platform which ties into the North West Shelf LNG plant and is close to both Pluto and Wheatstone LNG.

The EP was made available for public comment yesterday and will close on January 11, 2020.

Ironbark-1 will be the first well BP has drilled as operator in Western Australia in over 10 years.

However the high-risk well was a major issue for shareholders at yesterday's NZOG annual general meeting.

Shareholders demanded to see "all relevant reports and analysis" including technical and financial chance of success projections for the Ironbark prospect.

NZOG, which has a 50% interest in Cue Energy effectively, has a 25.75% stake in the well.

The company's CEO Andrew Jefferies attempted to quell the motion and reassure spooked shareholders the costly well could be a success despite it being the deepest target drilled to date offshore Australia.

"As has been pointed out elsewhere - the result at Ironbark is likely to be binary. Either it will be full of hydrocarbons and very valuable, or it will be dry and the cost of drilling it will be lost.

"If it comes in, it will be world scale. But the size of the target doesn't affect the chance of success - just as when the Lotto jackpot goes up, your ticket doesn't have a better chance of winning," Jefferies said.