US4147389A
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Method for establishing a combustion zone in an in situ oil shale retort
Assignee: Occidental Oil Shale Inc
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Filing: 1977-06-27
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Granted: 1979-04-03
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Expires: 1997-06-27
Abstract
Abstract A method for retorting oil shale in an in situ oil shale retort includes the steps of excavating a void in a subterranean formation containing oil shale and placing combustible material in the void adjacent an ignition situs. Formation is then explosively expanded toward the void to form a retort containing a fragmented permeable mass of formation particles containing oil shale, the top layer of the fragmented mass adjacent an ignition situs containing such combustible material. The combustible material is then ignited for establishing a combustion zone in the retort.
Inventors
- 👤 William J. Bartel
- 👤 Chang Y. Cha
- 👤 Robert S. Burton, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:43
CPC Classifications
E; E21; E21C; E21C41/00; E21C41/16; E21C41/24; E21B; E21B43/00; E21B43/16; E21B43/24; E21B43/243; E21B43/247
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
147 words
A method for retorting oil shale in an in situ oil shale retort in a subterranean formation containing oil shale, such a retort containing a fragmented permeable mass of formation particles containing oil shale, comprising the steps of: excavating a void in the subterranean formation within the boundaries of an in situ oil shale retort to be formed in the subterranean formation; placing combustible material in the void in the subterranean formation, the combustible material being placed adjacent an ignition situs; explosively expanding formation toward the void to form an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale, at least a portion of the fragmented mass adjacent an ignition situs containing such combustible material; and igniting such combustible material for establishing a combustion zone adjacent the ignition situs and retorting oil shale in the in situ oil shale retort.
Claim 2
Independent Claim
147 words
A method for retorting oil shale in an in situ oil shale retort in a subterranean formation containing oil shale, such a retort containing a fragmented permeable mass of formation particles containing oil shale, comprising the steps of: excavating a void in the subterranean formation within the boundaries of an in situ oil shale retort to be formed in the subterranean formation; placing combustible material in the void in the subterranean formation, the combustible material being placed adjacent an ignition situs; explosively expanding formation toward the void to form an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale, at least a portion of the fragmented mass adjacent an ignition situs containing such combustible material; and igniting such combustible material for establishing a combustion zone adjacent the ignition situs and retorting oil shale in the in situ oil shale retort.
Claim 3
Dependent Claim
29 words
The method of claim 1 in which the combustible material has a higher heat of combustion than the heat of combustion of the oil shale in the subterranean formation.
Claim 4
Dependent Claim
33 words
The method of claim 1 in which the combustible material has a lower ash content per unit volume than the ash content per unit volume of the oil shale in the subterranean formation.
Claim 5
Dependent Claim
29 words
The method of claim 1 in which the combustible material has a lower spontaneous ignition temperature than the spontaneous ignition temperature of the oil shale in the subterranean formation.
Claim 6
Dependent Claim
37 words
The method of claim 1 in which the combustible material comprises oil shale having a higher kerogen content per unit volume than the average kerogen content per unit volume of the oil shale in the subterranean formation.
Claim 7
Dependent Claim
12 words
The method of claim 1 in which the combustible material comprises coal.
Claim 8
Dependent Claim
29 words
The method of claim 1 in which the combustible material has a higher heat of combustion than the average heat of combustion of oil shale in the subterranean formation.
Claim 9
Dependent Claim
33 words
The method of claim 1 in which the combustible material has a lower ash content per unit volume than the average ash content per unit volume of oil shale in the subterranean formation.
Claim 10
Dependent Claim
124 words
A subterranean formation containing oil shale in an intermediate stage of preparation for in situ recovery of liquid and gaseous hydrocarbons from the oil shale comprising: a chamber in the subterranean formation located at the top boundary of an in situ oil shale retort to be formed in the subterranean formation; a zone of unfragmented formation containing oil shale below the chamber; fragmented material comprising combustible material in the chamber adjacent an ignition situs; and means for explosively expanding unfragmented formation adjacent the chamber toward the chamber to form an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale wherein at least a portion of the fragmented mass adjacent such an ignition situs contains such combustible material.
Claim 11
Dependent Claim
124 words
A subterranean formation containing oil shale in an intermediate stage of preparation for in situ recovery of liquid and gaseous hydrocarbons from the oil shale comprising: a chamber in the subterranean formation located at the top boundary of an in situ oil shale retort to be formed in the subterranean formation; a zone of unfragmented formation containing oil shale below the chamber; fragmented material comprising combustible material in the chamber adjacent an ignition situs; and means for explosively expanding unfragmented formation adjacent the chamber toward the chamber to form an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale wherein at least a portion of the fragmented mass adjacent such an ignition situs contains such combustible material.
Claim 12
Independent Claim
150 words
A method for retorting oil shale in an in situ oil shale retort in a subterranean formation containing oil shale, such a retort having top, bottom, and side boundaries and containing a fragmented permeable mass of formation particles containing oil shale, comprising the steps of: excavating a void in the subterranean formation at the top boundary of an in situ oil shale retort to be formed in the subterranean formation; placing combustible material in the void adjacent an ignition situs; explosively expanding formation toward the void to form an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale, the top layer of the fragmented mass adjacent an ignition situs containing such combustible material; and igniting such combustible material for establishing a combustion zone in the top layer adjacent the ignition situs and for retorting oil shale in the in situ oil shale retort.
Claim 13
Independent Claim
150 words
A method for retorting oil shale in an in situ oil shale retort in a subterranean formation containing oil shale, such a retort having top, bottom, and side boundaries and containing a fragmented permeable mass of formation particles containing oil shale, comprising the steps of: excavating a void in the subterranean formation at the top boundary of an in situ oil shale retort to be formed in the subterranean formation; placing combustible material in the void adjacent an ignition situs; explosively expanding formation toward the void to form an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale, the top layer of the fragmented mass adjacent an ignition situs containing such combustible material; and igniting such combustible material for establishing a combustion zone in the top layer adjacent the ignition situs and for retorting oil shale in the in situ oil shale retort.
Claim 14
Dependent Claim
29 words
The method of claim 10 in which the combustible material has a higher heat of combustion than the heat of combustion of the oil shale in the subterranean formation.
Claim 15
Dependent Claim
33 words
The method of claim 10 in which the combustible material has a lower ash content per unit volume than the ash content per unit volume of the oil shale in the subterranean formation.
Claim 16
Dependent Claim
29 words
The method of claim 10 in which the combustible material has a lower spontaneous ignition temperature than the spontaneous ignition temperature of the oil shale in the subterranean formation.
Claim 17
Dependent Claim
31 words
The method of claim 10 in which the combustible material comprises oil shale having a higher kerogen content than the average kerogen content of the oil shale in the subterranean formation.
Claim 18
Dependent Claim
12 words
The method of claim 10 in which the combustible material comprises coal.
Claim 19
Dependent Claim
29 words
The method of claim 10 in which the combustible material has a higher heat of combustion than the average heat of combustion of oil shale in the subterranean formation.
Claim 20
Dependent Claim
33 words
The method of claim 10 in which the combustible material has a lower ash content per unit volume than the average ash content per unit volume of oil shale in the subterranean formation.
Claim 21
Independent Claim
187 words
A method for establishing a combustion zone in an in situ oil shale retort in a subterranean formation containing oil shale, such a retort comprising a cavity having top, bottom, and side boundaries and substantially completely filled with a fragmented permeable mass of formation particles containing oil shale, comprising the steps of: excavating a void in a subterranean formation containing oil shale substantially completely across the top boundary of an in situ oil shale retort to be formed in the subterranean formation; placing a layer of combustible material in the void adjacent an ignition situs, the combustible material having a higher heat of combustion than the heat of combustion of oil shale in the subterranean formation; explosively expanding formation toward the void to form an in situ oil shale retort comprising a cavity having top, bottom, and side boundaries and substantially completely filled with a fragmented permeable mass of formation particles containing oil shale, the top layer of the fragmented mass adjacent an ignition situs containing such combustible material; and igniting such combustible material for establishing a combustion zone in the top layer adjacent the ignition situs.
Claim 22
Independent Claim
187 words
A method for establishing a combustion zone in an in situ oil shale retort in a subterranean formation containing oil shale, such a retort comprising a cavity having top, bottom, and side boundaries and substantially completely filled with a fragmented permeable mass of formation particles containing oil shale, comprising the steps of: excavating a void in a subterranean formation containing oil shale substantially completely across the top boundary of an in situ oil shale retort to be formed in the subterranean formation; placing a layer of combustible material in the void adjacent an ignition situs, the combustible material having a higher heat of combustion than the heat of combustion of oil shale in the subterranean formation; explosively expanding formation toward the void to form an in situ oil shale retort comprising a cavity having top, bottom, and side boundaries and substantially completely filled with a fragmented permeable mass of formation particles containing oil shale, the top layer of the fragmented mass adjacent an ignition situs containing such combustible material; and igniting such combustible material for establishing a combustion zone in the top layer adjacent the ignition situs.
Claim 23
Dependent Claim
19 words
The method of claim 18 in which the entire top layer of the fragmented mass contains such combustible material.
Claim 24
Dependent Claim
29 words
The method of claim 18 in which the top layer of the fragmented permeable mass adjacent the side boundaries of the cavity of the retort comprises such combustible material.
Claim 25
Independent Claim
309 words
A method for retorting oil shale in an in situ oil shale retort in a subterranean formation containing oil shale, such a retort comprising a cavity having top, bottom, and side boundaries and containing a fragmented permeable mass of formation particles containing oil shale, comprising the steps of: forming a first void in a subterranean formation containing oil shale at the bottom boundary of an in situ oil shale retort to be formed in the subterranean formation; forming a second void in the subterranean formation above the first void at the top boundary of the in situ oil shale retort to be formed in the subterranean formation; placing a layer of combustible material in the upper void, the combustible material having a higher heat of combustion than the heat of combustion of oil shale in the subterranean formation; explosively expanding formation remaining in the subterranean formation between the two voids to form an in situ oil shale retort comprising a cavity containing a fragmented permeable mass of formation particles containing oil shale and having top, bottom, and side boundaries, the fragmented mass filling the lower void and extending up into the upper void, a top layer of the fragmented mass containing such combustible material; introducing air downwardly into the top of the in situ oil shale retort; igniting combustible material in the top layer of the fragmented permeable mass with a flame to establish a combustion zone in the fragmented permeable mass; turning off the flame and interrupting the downward introduction of air into the top of the retort after ignition of combustible material in the top of the fragmented permeable mass; and restarting the introduction of air into the top of the in situ oil shale retort after the combustion zone has spread across the top of the fragmented permeable mass to the side boundaries of the cavity.
Claim 26
Independent Claim
309 words
A method for retorting oil shale in an in situ oil shale retort in a subterranean formation containing oil shale, such a retort comprising a cavity having top, bottom, and side boundaries and containing a fragmented permeable mass of formation particles containing oil shale, comprising the steps of: forming a first void in a subterranean formation containing oil shale at the bottom boundary of an in situ oil shale retort to be formed in the subterranean formation; forming a second void in the subterranean formation above the first void at the top boundary of the in situ oil shale retort to be formed in the subterranean formation; placing a layer of combustible material in the upper void, the combustible material having a higher heat of combustion than the heat of combustion of oil shale in the subterranean formation; explosively expanding formation remaining in the subterranean formation between the two voids to form an in situ oil shale retort comprising a cavity containing a fragmented permeable mass of formation particles containing oil shale and having top, bottom, and side boundaries, the fragmented mass filling the lower void and extending up into the upper void, a top layer of the fragmented mass containing such combustible material; introducing air downwardly into the top of the in situ oil shale retort; igniting combustible material in the top layer of the fragmented permeable mass with a flame to establish a combustion zone in the fragmented permeable mass; turning off the flame and interrupting the downward introduction of air into the top of the retort after ignition of combustible material in the top of the fragmented permeable mass; and restarting the introduction of air into the top of the in situ oil shale retort after the combustion zone has spread across the top of the fragmented permeable mass to the side boundaries of the cavity.
Claim 27
Dependent Claim
12 words
The method of claim 21 in which the combustible material comprises coal.
Claim 28
Independent Claim
183 words
A method for retorting oil shale in an in situ oil shale retort in a subterranean formation containing oil shale, such a retort containing a fragmented permeable mass of formation particles containing oil shale and having top, bottom, and side boundaries, comprising the steps of: forming a vertically extending void in a subterranean formation containing oil shale within the boundaries of an in situ oil shale retort to be formed in the subterranean formation; explosively expanding formation remaining in the subterranean formation toward the void to form an in situ oil shale retort containing a fragmented permeable mass of formation particle containing oil shale; forming a layer of combustible particles derived from coal adjacent the top of the fragmented permeable mass; introducing air onto the top of the fragmented permeable mass; igniting combustible particles adjacent the top of the fragmented permeable mass for heating and igniting adjacent oil shale particles; and after ignition temporarily interrupting introduction of air onto the top of the fragmented mass until the combustible particles adjacent the top of the fragmented permeable mass are heated to their ignition temperature.
Claim 29
Independent Claim
183 words
A method for retorting oil shale in an in situ oil shale retort in a subterranean formation containing oil shale, such a retort containing a fragmented permeable mass of formation particles containing oil shale and having top, bottom, and side boundaries, comprising the steps of: forming a vertically extending void in a subterranean formation containing oil shale within the boundaries of an in situ oil shale retort to be formed in the subterranean formation; explosively expanding formation remaining in the subterranean formation toward the void to form an in situ oil shale retort containing a fragmented permeable mass of formation particle containing oil shale; forming a layer of combustible particles derived from coal adjacent the top of the fragmented permeable mass; introducing air onto the top of the fragmented permeable mass; igniting combustible particles adjacent the top of the fragmented permeable mass for heating and igniting adjacent oil shale particles; and after ignition temporarily interrupting introduction of air onto the top of the fragmented mass until the combustible particles adjacent the top of the fragmented permeable mass are heated to their ignition temperature.
Claim 30
Independent Claim
217 words
A method for retorting oil shale in an in situ oil shale retort in a subterranean formation containing oil shale, such a retort containing a fragmented permeable mass of formation particles containing oil shale, comprising the steps of: forming a first void in a subterranean formation containing oil shale at the bottom boundary of an in situ oil shale retort to be formed in the subterranean formation; forming a second void in the subterranean formation above the first void at the top boundary of the in situ oil shale retort to be formed in the subterranean formation; placing a layer of combustible material in the upper void, the combustible material having a higher heat of combustion than the heat of combustion of oil shale in the subterranean formation; explosively expanding formation remaining in the subterranean formation between the two voids to form an in situ oil shale retort comprising a cavity containing a fragmented permeable mass of formation particles containing oil shale, the fragmented mass filling the lower void and extending up into the upper void, a top portion of the fragmented permeable mass containing said placed combustible material; and igniting combustible material in the top portion of the fragmented permeable mass containing said placed combustible material to form a combustion zone in the fragmented permeable mass.
Claim 31
Independent Claim
217 words
A method for retorting oil shale in an in situ oil shale retort in a subterranean formation containing oil shale, such a retort containing a fragmented permeable mass of formation particles containing oil shale, comprising the steps of: forming a first void in a subterranean formation containing oil shale at the bottom boundary of an in situ oil shale retort to be formed in the subterranean formation; forming a second void in the subterranean formation above the first void at the top boundary of the in situ oil shale retort to be formed in the subterranean formation; placing a layer of combustible material in the upper void, the combustible material having a higher heat of combustion than the heat of combustion of oil shale in the subterranean formation; explosively expanding formation remaining in the subterranean formation between the two voids to form an in situ oil shale retort comprising a cavity containing a fragmented permeable mass of formation particles containing oil shale, the fragmented mass filling the lower void and extending up into the upper void, a top portion of the fragmented permeable mass containing said placed combustible material; and igniting combustible material in the top portion of the fragmented permeable mass containing said placed combustible material to form a combustion zone in the fragmented permeable mass.
Claim 32
Dependent Claim
12 words
The method of claim 24 in which the combustible material comprises coal.
Claim 33
Independent Claim
165 words
A method for retorting oil shale in an in situ oil shale retort in a subterranean formation containing oil shale, such a retort containing a fragmented permeable mass of formation particles containing oil shale, comprising the steps of: forming a vertically extending void in a subterranean formation containing oil shale within the boundaries of an in situ oil shale retort to be formed in the subterranean formation; forming a layer of combustible particles derived from coal adjacent the top of the fragmented permeable mass, including the step of mixing the combustible particles with the top layer of the fragmented mass by placing the combustible particles on top of oil shale formation and explosively expanding such formation to fragment such formation into a fragmented permeable mass of formation particles containing oil shale; and igniting the combustible particles mixed with the top layer of the fragmented permeable mass for heating and igniting formation particles in the fragmented mass adjacent to the combustible particles and containing oil shale.
Claim 34
Independent Claim
165 words
A method for retorting oil shale in an in situ oil shale retort in a subterranean formation containing oil shale, such a retort containing a fragmented permeable mass of formation particles containing oil shale, comprising the steps of: forming a vertically extending void in a subterranean formation containing oil shale within the boundaries of an in situ oil shale retort to be formed in the subterranean formation; forming a layer of combustible particles derived from coal adjacent the top of the fragmented permeable mass, including the step of mixing the combustible particles with the top layer of the fragmented mass by placing the combustible particles on top of oil shale formation and explosively expanding such formation to fragment such formation into a fragmented permeable mass of formation particles containing oil shale; and igniting the combustible particles mixed with the top layer of the fragmented permeable mass for heating and igniting formation particles in the fragmented mass adjacent to the combustible particles and containing oil shale.
Claim 35
Dependent Claim
12 words
The method of claim 26 in which the combustible particles comprise coal.
Claim 36
Dependent Claim
29 words
The formation of claim 9 in which the combustible material has a higher heat of combustion than the heat of combustion of the oil shale in the subterranean formation.
Claim 37
Dependent Claim
33 words
The formation of claim 9 in which the combustible material has a lower ash content per unit volume than the ash content per unit volume of the oil shale in the subterranean formation.
Claim 38
Dependent Claim
29 words
The formation of claim 9 in which the combustible material has a lower spontaneous ignition temperature than the spontaneous ignition temperature of the oil shale in the subterranean formation.
Claim 39
Dependent Claim
37 words
The formation of claim 9 in which the combustible material comprises oil shale having a higher kerogen content per unit volume than the average kerogen content per unit volume of the oil shale in the subterranean formation.
Claim 40
Dependent Claim
12 words
The formation of claim 9 in which the combustible material comprises coal.
Claim 41
Dependent Claim
29 words
The formation of claim 9 in which the combustible material has a higher heat of combustion than the average heat of combustion of oil shale in the subterranean formation.
Claim 42
Dependent Claim
33 words
The formation of claim 9 in which the combustible material has a lower ash content per unit volume than the average ash content per unit volume of oil shale in the subterranean formation.
Claim 43
Dependent Claim
132 words
A subterranean formation containing oil shale in an intermediate stage of preparation for in situ recovery of liquid and gaseous hydrocarbons from the oil shale comprising: a chamber in the subterranean formation located at the top boundary of an in situ oil shale retort to be formed in the subterranean formation; a zone of unfragmented formation containing oil shale below the chamber; a top layer of fragmented material comprising combustible material in the chamber adjacent an ignition situs; and means for explosively expanding unfragmented formation adjacent the chamber toward the chamber to form an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale wherein at least a portion of the top layer of the fragmented mass adjacent such an ignition situs contains such combustible material.
Claim 44
Dependent Claim
132 words
A subterranean formation containing oil shale in an intermediate stage of preparation for in situ recovery of liquid and gaseous hydrocarbons from the oil shale comprising: a chamber in the subterranean formation located at the top boundary of an in situ oil shale retort to be formed in the subterranean formation; a zone of unfragmented formation containing oil shale below the chamber; a top layer of fragmented material comprising combustible material in the chamber adjacent an ignition situs; and means for explosively expanding unfragmented formation adjacent the chamber toward the chamber to form an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale wherein at least a portion of the top layer of the fragmented mass adjacent such an ignition situs contains such combustible material.
Claim 45
Dependent Claim
29 words
The formation of claim 35 in which the combustible material has a higher heat of combustion than the heat of combustion of the oil shale in the subterranean formation.
Claim 46
Dependent Claim
33 words
The formation of claim 35 in which the combustible material has a lower ash content per unit volume than the ash content per unit volume of the oil shale in the subterranean formation.
Claim 47
Dependent Claim
29 words
The formation of claim 35 in which the combustible material has a lower spontaneous ignition temperature than the spontaneous ignition temperature of the oil shale in the subterranean formation.
Claim 48
Dependent Claim
12 words
The formation of claim 35 in which the combustible material comprises coal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-04-02 | 1982-10-02 | 1983-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-02 | 1986-10-02 | 1987-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-02 | 1990-10-02 | 1991-04-03 | $7700.00 | Window Closed / Lapsed |