Around 6.50am on Wednesday (October 6), Extinction Rebellion Scotland members began their protest at the facility at the Invergordon Service Base of the Cromarty Firth Port Authority.
They placed a 13ft 8in (4.2m) oil rig made from scrap materials with a banner saying “Decommission Me Now” on the road, and four people locked themselves on to prop oil barrels to block traffic.
Activists also unfurled banners stating “Climate Emergency” and “No Future in Fossil Fuels”.
The group are calling for an end to fossil fuel extraction and want to see support for a transition of skilled oil and gas workers into decommissioning and renewable industries, not new oil fields.
John Lardner, 69, Extinction Rebellion (XR) Scotland activist, said “The Chatham House report says even if the Paris Agreement carbon emissions were achieved, we have almost no chance of staying below pre-industrial levels of warming. We have to act now.”