An investigation is under way into a gas leak at the St Fergus terminal near Peterhead.
The operators, Total confirmed that a hydro-carbon leak occurred just after 1300 BST.
Grampian Fire and Rescue Service and Grampian Police were called to the plant but were stood down shortly after.
The company said the section of the terminal affected was immediately shut down and depressurised.
Workers were called to muster and all non-essential personnel sent home.
A spokesman for Total said a full investigation into the cause of the leak would now be undertaken.