A dipole antenna system emplaced in a subsurface formation is configured to produce radio frequency (RF) fields for recovery of thermally responsive constituents in a subsurface formation. Coaxially disposed inner and outer conductors connected at an earth surface to an RF power source form a transmission line carrying power from the earth surface to a dipole antenna proximate said formation. The inner conductor protrudes from the outer conductor at a junction forming one pole of the antenna. The system also includes at least one choke structure attached to the outer conductor at a distance at least ¼ wavelength above said junction, confining the RF fields such that the exposed portion of the outer conductor between the junction and the choke forms a second pole of the antenna. The dipole system is configured to confine a majority of said RF fields in a volume of said formation situated adjacent to the antenna. The antenna deposits heat into the formation around an oil well independent of the flow of oil carrying heat back into the well. Such heating provides several mechanisms to enhance the flow of oil into a well.