US4144935A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for in situ heat processing of hydrocarbonaceous formations
Assignee: IIT Research Institute
•
Filing: 1977-08-29
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Granted: 1979-03-20
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Expires: 1997-08-29
Abstract
Abstract The disclosure describes a technique for uniform heating of relatively large blocks of hydrocarbonaceous formations in situ using radio frequency (RF) electrical energy that is substantially confined to the volume to be heated and effects of dielectric heating of the formations. An important aspect of the disclosure relates to the fact that certain hydrocarbonaceous earth formations, for example raw unheated oil shale, exhibit dielectric absorption characteristics in the radio frequency range. In accordance with the system of the invention, a plurality of conductors are inserted in the formations and bound a particular volume of the formations. The phrase "bounding a particular volume" is intended to mean that the volume is enclosed on at least two sides thereof. Electrical excitation is provided for establishing alternating electric fields in the volume. The frequency of the excitation is selected as a function of the dimensions of the volume so as to establish a substantially non-radiating electric field which is substantially confined in the volume. In this manner, volumetric dielectric heating of the formations will occur to effect approximately uniform controlled heating of the volume. BACKGROUND OF THE INVENTION
Inventors
- 👤 Jack Bridges
- 👤 Allen Taflove
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 01:16
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/24; E21B43/2401; E21B36/00; E21B36/04; E21B43/30; E21B43/305
Claims Analysis
Total Claims: 74
Claim 1
Independent Claim
87 words
A system for in situ heat processing of hydrocarbonaceous earth formations, comprising: a plurality of conductive means inserted in said formations and bounding a particular volume of said formations; electrical excitation means for establishing alternating electric fields in said volume; the frequency of said excitation means 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; whereby volumetric dielectric heating of the formations will occur to effect approximately uniform heating of said volume.
Claim 2
Independent Claim
87 words
A system for in situ heat processing of hydrocarbonaceous earth formations, comprising: a plurality of conductive means inserted in said formations and bounding a particular volume of said formations; electrical excitation means for establishing alternating electric fields in said volume; the frequency of said excitation means 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; whereby volumetric dielectric heating of the formations will occur to effect approximately uniform heating of said volume.
Claim 3
Dependent Claim
19 words
A system as defined by claim 1 wherein the frequency of said excitation is in the radio frequency range.
Claim 4
Dependent Claim
27 words
A system as defined by claim 2 wherein said conductive means comprise opposing spaced rows of conductors disposed in opposing spaced rows of boreholes in said formations.
Claim 5
Dependent Claim
17 words
A system as defined by claim 3 wherein the conductors of each row comprise spaced elongated conductors.
Claim 6
Dependent Claim
30 words
A system as defined by claim 4 wherein said excitation is applied as a voltage as between the conductors of the outer rows and the conductors of the central row.
Claim 7
Dependent Claim
26 words
A system as defined by claim 4 wherein said electrical excitation is a source of current applied to at least one current loop in said volume.
Claim 8
Dependent Claim
22 words
A system as defined by claim 4 wherein said electrical excitation is applied across at least one electrical dipole in said volume.
Claim 9
Dependent Claim
37 words
A system as defined by claim 4 wherein the conductors of the central row are of substantially shorter length than the conductors of the outer rows so as to reduce radiation at the ends of said conductors.
Claim 10
Dependent Claim
50 words
A system as defined by claim 8 wherein the frequency of said excitation is selected such that a half wavelength of electromagnetic energy in the region beyond the center conductor is substantially greater than the spacing between the outer rows to give rise to a cutoff condition in said region.
Claim 11
Dependent Claim
61 words
A system as defined by claim 9 wherein the frequency of said excitation is selected as a function of the electrical lossiness of the formations in said volume to be sufficiently low such that the 1/e attenuation distance of the electric field in any direction in said volume is more than twice the physical dimension of said volume in that direction.
Claim 12
Dependent Claim
36 words
A system as defined by claim 9 further comprising means for modifying the electric field pattern so as to average the electric field intensity in said volume to enhance the uniformity of heating of said volume.
Claim 13
Dependent Claim
61 words
A system as defined by claim 8 wherein the frequency of said excitation is selected as a function of the electrical lossiness of the formations in said volume to be sufficiently low such that the 1/e attenuation distance of the electric field in any direction in said volume is more than twice the physical dimension of said volume in that direction.
Claim 14
Dependent Claim
36 words
A system as defined by claim 8 further comprising means for modifying the electric field pattern so as to average the electric field intensity in said volume to enhance the uniformity of heating of said volume.
Claim 15
Dependent Claim
24 words
A system as defined by claim 2 wherein said excitation in applied as to a voltage as between different groups of said conductive means.
Claim 16
Dependent Claim
26 words
A system as defined by claim 2 wherein said electrical excitation is a source of current applied to at least one current loop in said volume.
Claim 17
Dependent Claim
22 words
A system as defined by claim 2 wherein said electrical excitation is applied across at least one electrical dipole in said volume.
Claim 18
Dependent Claim
61 words
A system as defined by claim 2 wherein the frequency of said excitation is selected as a function of the electrical lossiness of the formations in said volume to be sufficiently low such that the 1/e attenuation distance of the electric field in any direction in said volume is more than twice the physical dimension of said volume in that direction.
Claim 19
Dependent Claim
36 words
A system as defined by claim 2 further comprising means for modifying the electric field pattern so as to average the electric field intensity in said volume to enhance the uniformity of heating of said volume.
Claim 20
Dependent Claim
27 words
A system as defined by claim 1 wherein said conductive means comprise opposing spaced rows of conductors disposed in opposing spaced rows of boreholes in said formations.
Claim 21
Dependent Claim
18 words
A system as defined by claim 19 wherein said rows of conductors comprise three spaced rows of conductors.
Claim 22
Dependent Claim
17 words
A system as defined by claim 20 wherein the conductors of each row comprise spaced elongated conductors.
Claim 23
Dependent Claim
30 words
A system as defined by claim 21 wherein said excitation is applied as a voltage as between the conductors of the outer rows and the conductors of the central row.
Claim 24
Dependent Claim
37 words
A system as defined by claim 22 wherein the conductors of the central row are of substantially shorter length than the conductors of the outer rows so as to reduce radiation at the ends of said conductors.
Claim 25
Dependent Claim
50 words
A system as defined by claim 23 wherein the frequency of said excitation is selected such that a half wavelength of electromagnetic energy in the region beyond the center conductor is substantially greater than the spacing between the outer rows to give rise to a cutoff condition in said region.
Claim 26
Dependent Claim
26 words
A system as defined by claim 21 wherein said electrical excitation is a source of current applied to at least one current loop in said volume.
Claim 27
Dependent Claim
37 words
A system as defined by claim 25 wherein the conductors of the central row are of substantially shorter length than the conductors of the outer rows so as to reduce radiation at the ends of said conductors.
Claim 28
Dependent Claim
50 words
A system as defined by claim 26 wherein the frequency of said excitation is selected such that a half wavelength of electromagnetic energy in the region beyond the center conductor is substantially greater than the spacing between the outer rows to give rise to a cutoff condition in said region.
Claim 29
Dependent Claim
22 words
A system as defined by claim 21 wherein said electrical excitation is applied across at least one electrical dipole in said volume.
Claim 30
Dependent Claim
61 words
A system as defined by claim 20 wherein the frequency of said excitation is selected as a function of the electrical lossiness of the formations in said volume to be sufficiently low such that the 1/e attenuation distance of the electric field in any direction in said volume is more than twice the physical dimension of said volume in that direction.
Claim 31
Dependent Claim
42 words
A system as defined by claim 29 wherein said rows of conductors are inserted in said formations at angles such that said rows are closer together at far ends thereof to compensate for attenuation of the electrical field at said far end.
Claim 32
Dependent Claim
36 words
A system as defined by claim 20 further comprising means for modifying the electric field pattern so as to average the electric field intensity in said volume to enhance the uniformity of heating of said volume.
Claim 33
Dependent Claim
30 words
A system as defined by claim 31 wherein said means for modifying the electric field pattern comprises means for modifying the effective length of the conductors of the central row.
Claim 34
Dependent Claim
32 words
A system as defined by claim 32 wherein said means for modifying the effective length of the conductors of the central row comprises means for physically shortening the length of said conductors.
Claim 35
Dependent Claim
27 words
A system as defined by claim 32 wherein said means for modifying the effective length of said conductors comprises means for electrically modifying the effective length thereof.
Claim 36
Dependent Claim
42 words
A system as defined by claim 20 wherein said rows of conductors are inserted in said formations at angles such that said rows are closer together at far ends thereof to compensate for attenuation of the electrical field at said far end.
Claim 37
Dependent Claim
61 words
A system as defined by claim 19 wherein the frequency of said excitation is selected as a function of the electrical lossiness of the formations in said volume to be sufficiently low such that the 1/e attenuation distance of the electric field in any direction in said volume is more than twice the physical dimension of said volume in that direction.
Claim 38
Dependent Claim
36 words
A system as defined by claim 19 further comprising means for modifying the electric field pattern so as to average the electric field intensity in said volume to enhance the uniformity of heating of said volume.
Claim 39
Dependent Claim
42 words
A system as defined by claim 19 wherein said rows of conductors are inserted in said formations at angles such that said rows are closer together at far ends thereof to compensate for attenuation of the electrical field at said far end.
Claim 40
Dependent Claim
23 words
A system as defined by claim 1 wherein said excitation is applied as a voltage as between different groups of said conductive means.
Claim 41
Dependent Claim
37 words
A system as defined by claim 39 wherein the conductors of the central row are of substantially shorter length than the conductors of the outer rows so as to reduce radiation at the ends of said conductors.
Claim 42
Dependent Claim
26 words
A system as defined by claim 1 wherein said electrical excitation is a source of current applied to at least one current loop in said volume.
Claim 43
Dependent Claim
22 words
A system as defined by claim 1 wherein said electrical excitation is applied across at least one electrical dipole in said volume.
Claim 44
Dependent Claim
61 words
A system as defined by claim 1 wherein the frequency of said excitation is selected as a function of the electrical lossiness of the formations in said volume to be sufficiently low such that the 1/e attenuation distance of the electric field in any direction in said volume is more than twice the physical dimension of said volume in that direction.
Claim 45
Dependent Claim
36 words
A system as defined by claim 43 further comprising means for modifying the electric field pattern so as to average the electric field intensity in said volume to enhance the uniformity of heating of said volume.
Claim 46
Dependent Claim
36 words
A system as defined by claim 1 further comprising means for modifying the electric field pattern so as to average the electric field intensity in said volume to enhance the uniformity of heating of said volume.
Claim 47
Independent Claim
95 words
A method for in situ heating of hydrocarbonaceous earth formations, comprising the steps of: forming a plurality of boreholes which bound a particular volume of said formations; inserting elongated electrical conductors in said boreholes; and introducing electrical excitation to said formations 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; whereby volumetric dielectric heating of the formations will occur to effect approximately uniform heating of said volume.
Claim 48
Independent Claim
95 words
A method for in situ heating of hydrocarbonaceous earth formations, comprising the steps of: forming a plurality of boreholes which bound a particular volume of said formations; inserting elongated electrical conductors in said boreholes; and introducing electrical excitation to said formations 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; whereby volumetric dielectric heating of the formations will occur to effect approximately uniform heating of said volume.
Claim 49
Dependent Claim
19 words
A method as defined by claim 46 wherein the frequency of said excitation is in the radio frequency range.
Claim 50
Dependent Claim
25 words
A method as defined by claim 47 wherein the step of introducing electrical excitation comprises applying a voltage as between different groups of said conductors.
Claim 51
Dependent Claim
27 words
A method as defined by claim 47 wherein the step of introducing electrical excitation comprises applying electrical current to at least one current loop in said volume.
Claim 52
Dependent Claim
61 words
A method as defined by claim 47 wherein the frequency of said excitation is selected as a function of the electrical lossiness of the formations in said volume to be sufficiently low such that the 1/e attenuation distance of the electric field in any direction in said volume is more than twice the physical dimension of said volume in that direction.
Claim 53
Dependent Claim
37 words
A method as defined by claim 47 further comprising the step of modifying the electric field pattern so as to average the electric field intensity in said volume to enhance the uniformity of heating of said volume.
Claim 54
Dependent Claim
29 words
A method as defined by claim 51 wherein the step of modifying the electric field pattern comprises the step of modifying the effective length of some of said conductors.
Claim 55
Dependent Claim
23 words
A method as defined by claim 47 further comprising the step of withdrawing through said boreholes the valuable constituents resulting from said heating.
Claim 56
Dependent Claim
56 words
A method as defined by claim 47 wherein said dielectric heating is continued to heat said volume to a temperature below the temperature required for extraction of valuable constituents from said volume, and further comprising the steps of applying further nonelectrical heating means to said volume and withdrawing through said boreholes valuable constituents from said volume.
Claim 57
Dependent Claim
19 words
A method as defined by claim 46 wherein said boreholes are formed in opposing spaced rows in said formations.
Claim 58
Dependent Claim
14 words
A method as defined by claim 55 wherein said rows comprise three spaced rows.
Claim 59
Independent Claim
83 words
A system for in situ heat processing of an oil shale bed, comprising: a plurality of conductive means bounding a particular volume of said bed; electrical excitation means for establishing alternating electric fields in said volume; the frequency of said excitation means 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; whereby volumetric dielectric heating of the bed will occur to effect approximately uniform heating of said volume.
Claim 60
Independent Claim
83 words
A system for in situ heat processing of an oil shale bed, comprising: a plurality of conductive means bounding a particular volume of said bed; electrical excitation means for establishing alternating electric fields in said volume; the frequency of said excitation means 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; whereby volumetric dielectric heating of the bed will occur to effect approximately uniform heating of said volume.
Claim 61
Dependent Claim
19 words
A system as defined by claim 57 wherein the frequency of said excitation is in the radio frequency range.
Claim 62
Dependent Claim
24 words
A system as defined by claim 57 wherein the frequency of said excitation is in the range between about 1 MHz and 40 MHz.
Claim 63
Dependent Claim
27 words
A system as defined by claim 59 wherein said conductive means comprise opposing spaced rows of conductors disposed in opposing spaced rows of boreholes in said bed.
Claim 64
Dependent Claim
18 words
A system as defined by claim 60 wherein said rows of conductors comprise three spaced rows of conductors.
Claim 65
Dependent Claim
37 words
A system as defined by claim 61 wherein the conductors of the central row are of substantially shorter length than the conductors of the outer rows so as to reduce radiation at the ends of said conductors.
Claim 66
Dependent Claim
50 words
A system as defined by claim 62 wherein the frequency of said excitation is selected such that a half wavelength of electromagnetic energy in the region beyond the center conductor is substantially greater than the spacing between the outer rows to give rise to a cutoff condition in said region.
Claim 67
Dependent Claim
61 words
A system as defined by claim 59 wherein the frequency of said excitation is selected as a function of the electrical lossiness of the formations in said volume to be sufficiently low such that the 1/e attenuation distance of the electric field in any direction in said volume is more than twice the physical dimension of said volume in that direction.
Claim 68
Dependent Claim
27 words
A system as defined by claim 57 wherein said conductive means comprise opposing spaced rows of conductors disposed in opposing spaced rows of boreholes in said bed.
Claim 69
Dependent Claim
61 words
A system as defined by claim 57 wherein the frequency of said excitation is selected as a function of the electrical lossiness of the formations in said volume to be sufficiently low such that the 1/e attenuation distance of the electric field in any direction in said volume is more than twice the physical dimension of said volume in that direction.
Claim 70
Independent Claim
88 words
A system for in situ heat processing of a tar sand deposit, comprising: a plurality of conductive means inserted in said deposit and bounding a particular volume of said deposit; electrical excitation means for establishing alternating electric fields in said volume; the frequency of said excitation means 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; whereby volumetric dielectric heating of the deposit will occur to effect approximately uniform heating of said volume.
Claim 71
Independent Claim
88 words
A system for in situ heat processing of a tar sand deposit, comprising: a plurality of conductive means inserted in said deposit and bounding a particular volume of said deposit; electrical excitation means for establishing alternating electric fields in said volume; the frequency of said excitation means 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; whereby volumetric dielectric heating of the deposit will occur to effect approximately uniform heating of said volume.
Claim 72
Dependent Claim
19 words
A system as defined by claim 67 wherein the frequency of said excitation is in the radio frequency range.
Claim 73
Dependent Claim
60 words
A system as defined by claim 68 wherein the frequency of said excitation is selected as a function of the electrical lossiness of the formations in said volume to be sufficiently low such that the skin depth of the electric field in any direction in said volume is more than twice the physical dimension of said volume in that direction.
Claim 74
Dependent Claim
60 words
A system as defined by claim 67 wherein the frequency of said excitation is selected as a function of the electrical lossiness of the formations in said volume to be sufficiently low such that the skin depth of the electric field in any direction in said volume is more than twice the physical dimension of said volume in that direction.
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USPTO Annuity & Maintenance Windows
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|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-19 | 1982-09-18 | 1983-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-19 | 1986-09-18 | 1987-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-19 | 1990-09-18 | 1991-03-20 | $7700.00 | Window Closed / Lapsed |