Three protesters have been charged over a demonstration in Western Australia's north that blocked access to the country's biggest LNG hub for more than 12 hours.

The protesters locked themselves inside concrete barrels in a car and caravan to obstruct the road to the Burrup Peninsula, near Karratha, at 4am on Wednesday.

They were demonstrating against this week's announcement from Woodside to press ahead with its $16.5 billion Scarborough gas project.

Specialist police were flown in from Perth to help remove the protesters.

Companies with operations on the peninsula, including Woodside, had to find alternative ways to get workers in an out while the blockade was in place.

Police said a man and two women were charged overnight with failing to obey a move-on notice, unreasonably obstructing a carriageway and obstructing a public officer.

'Significant drain'

Pilbara District Superintendent Kim Massam said he was angry at the way the protesters carried out the demonstration.

"There is a right way of doing this and a wrong way, and yesterday was a wrong way," he said.

"It put people's lives at risk and I'm quite angry.

"That was a significant police effort, a significant drain on our resources, a significant drain on emergency services."

Superintendent Massam described the group as "professional protesters".

"We're very disappointed to see the appearance of Perth-based protesters," he said.

"It wasn't just Woodside that these protesters affected — it was a broader community, it was small businesspeople trying to do their job, going around the Pilbara.

Two of the protesters are expected to appear in court today.