Abstract: A vessel for producing hydrocarbons, the vessel being adapted to be connected to at least one riser for transport of the hydrocarbons from a well on the seabed towards the vessel, wherein the vessel includes a separation station for separation of the hydrocarbons into gaseous hydrocarbons and non-gaseous hydrocarbons, storing elements for storing the hydrocarbons and processing elements for processing at least part of the hydrocarbons. The vessel further includes a positioning system for controlling the position and orientation of the vessel with respect to the seabed, wherein the positioning system includes a Dynamic Positioning (DP) system allowing the control of the position and the orientation of the vessel with respect to the seabed without the use of mooring lines, wherein the DP system is adapted to be driven by at least a portion of the gaseous part of the hydrocarbons separated in the separation station.