Method of heating a hydrocarbon resource including lowering a settable frequency based upon impedance

摘要

A method for heating a hydrocarbon resource in a subterranean formation having a laterally extending wellbore therein may include supplying radio frequency (RF) power at a settable frequency from an RF radiator positioned within the laterally extending wellbore to heat the hydrocarbon resource and start formation of a steam bubble adjacent the laterally extending wellbore while sensing an impedance matching value of the RF radiator. The method may also include lowering the settable frequency at least one time based upon the sensed impedance matching value as the steam bubble grows. The frequency may rise after the steam bubble is formed and induction heating operation occurs.