Tubular Protection for Radiofrequency System to Improve the Recovery of Heavy Oils

A system for heating high viscosity hydrocarbons in a reservoir comprising at least one drain, the system comprising:

• an antenna connected to a radio frequency generator capable of generating an electromagnetic signal, the antenna comprising:
• a coaxial transmission line connected to the generator and capable of transmitting the signal along the drain;
• at least one mode converter positioned along the coaxial transmission line inside the drain, in which the at least one mode converter interrupts the coaxial transmission line;
• the at least one mode converter being able, when an RF signal is present along the coaxial transmission line, to produce a disturbance in the differential mode disturbance of propagation of the signal along the coaxial transmission line and to induce an electromagnetic field in the surrounding space which causes the hydrocarbons within the reservoir to be heated;
• a tubular jacket of material transparent to electromagnetic waves, the tubular jacket containing the antenna and being filled with a dielectric fluid.