Patent ID: 7312428
Filing Date: 2007-12-25
Classification: E21B,H05B

Abstract:
1. A method for heating a medium, said medium comprising fossil fuel related hydrocarbonaceous material selected from the group consisting of oil shale, tar sand, oil sand, coal, bitumen, heavy oil, crude petroleum, petroleum distillates, and/or kerogen, comprising: maintaining said medium in an alternating electrical field provided by a radio frequency signal not greater than 300 MHz at a resonance frequency of said medium; sensing the temperature of said medium to produce a sensor output signal; and determining the resonance frequency which corresponds to the most recently sensed temperature by applying the sensor output signal to a computer which supplies resonance frequency vs. temperature information for said medium to produce a control signal output of the computer corresponding to the resonance frequency; as said medium increases in temperature, adjusting the frequency of said radio frequency signal by the control signal output of the computer to match the resonance frequency for the most recently sensed temperature.