A radio frequency applicator and method for heating a hydrocarbon formation is disclosed. An aspect of at least one embodiment disclosed is a linear radio frequency applicator. It includes a transmission line and a current return path that is insulated from the transmission line. At least one conductive sleeve is positioned around the transmission line and the current return path. The transmission line and the current return path are electrically connected to the conductive sleeve. A radio frequency source is configured to apply a signal to the transmission line. When the linear applicator is operated, a circular magnetic field forms, which creates eddy current in the formation causing heavy hydrocarbons to flow. The heat is reliable as liquid water contact is not required. The applicator may operate in permafrost regions and without caprock.