Method for in situ heat processing of hydrocarbonaceous formations

A method for in situ extraction of valuable constituents from an oil shale bed, comprising the steps of:

• drilling a plurality of boreholes which bound a particular volume of said shale;
• inserting electrical conductors into said boreholes;
• introducing electrical excitation to said shale bed to establish alternating electric fields in said volume, the frequency of said excitation being selected as a function of the volume dimensions so as to establish substantially non-radiating electric fields which are substantially confined in said volume so that volumetric dielectric heating of said shale bed will occur to effect approximately uniform heating of said volume;
• continuing said electrical excitation to effect heating of said volume to a temperature of about 425.degree. C.;
• and
• recovering volatilized products from said volume.

A method for in situ extraction of valuable constituents from an oil shale bed, comprising the steps of:

• drilling a plurality of boreholes which bound a particular volume of said shale;
• inserted electrical conductors into said boreholes;
• introducing electrical excitation to said shale bed to establish alternating electric fields in said volume, the frequency of said excitation being selected as a function of the volume dimensions so as to establish substantially non-radiating electric fields which are substantially confined in said volume so that volumetric dielectric heating of said shale bed will occur to effect approximately uniform heating of said volume;
• continuing said electrical excitation to effect heating of said volume to a temperature sufficient to cause the volatilization of moisture therein and resulting porosity and permeability in said volume;
• and
• withdrawing valuable constituents from said volume.

A method for in situ extraction of useful constituents from a tar sand deposit, comprising the steps of:

• inserting a plurality of conductors into said deposit which bound a particular volume of said deposit;
• introducing electrical excitation to said tar sand deposit to establish alternating electric fields in said volume;
• the frequency of said excitation being selected as a function of the volume dimensions so as to establish substantially non-radiating electric fields which are substantially confined in said volume so that volumetric dielectric heating of said tar sand deposit will occur to effect approximately uniform heating of said volume;
• and
• recovering valuable hydrocarbonous fluids from said volume.