US4326751A — Blasting to a horizontal free face with mixing of…

Claim 1

Independent Claim 238 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: excavating formation to form at least one void in the subterranean formation leaving zones of unfragmented formation above and below such a void, such a zone of unfragmented formation having a substantially horizontal free face adjoining the void; forming substantially vertical blastholes in at least one of such zones of unfragmented formation for forming at least one array of spaced apart blastholes; placing explosive into such blastholes for forming a substantially horizontal array of main explosive charges and at least one substantially horizontal array of satellite explosive charges, wherein each of the satellite explosive charges has a scaled point charge depth of burial substantially equal to the scaled point charge depth of burial of each of the main explosive charges and the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating explosive in the blastholes in a single round of explosions for explosively expanding at least one of the zones of unfragmented formation toward such a void to form a fragmented permeable mass of formation particles containing oil shale in the in situ oil shale retort.

Claim 2

Independent Claim 238 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: excavating formation to form at least one void in the subterranean formation leaving zones of unfragmented formation above and below such a void, such a zone of unfragmented formation having a substantially horizontal free face adjoining the void; forming substantially vertical blastholes in at least one of such zones of unfragmented formation for forming at least one array of spaced apart blastholes; placing explosive into such blastholes for forming a substantially horizontal array of main explosive charges and at least one substantially horizontal array of satellite explosive charges, wherein each of the satellite explosive charges has a scaled point charge depth of burial substantially equal to the scaled point charge depth of burial of each of the main explosive charges and the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating explosive in the blastholes in a single round of explosions for explosively expanding at least one of the zones of unfragmented formation toward such a void to form a fragmented permeable mass of formation particles containing oil shale in the in situ oil shale retort.

Claim 3

Dependent Claim 70 words

The method according to claim 1 wherein the length of each of the main explosive charges is about one-half the thickness of such a zone of unfragmented formation which is to be expanded towards such a free face and wherein such a main explosive charge is located in the portion of the unfragmented formation most remote from the free face toward which such unfragmented formation is to be explosively expanded.

Claim 4

Dependent Claim 62 words

The method according to claim 1 comprising forming the array of main explosive charges and the array of satellite explosive charges by: placing a first explosive charge into each blasthole for forming the substantially horizontal array of main explosive charges; and placing a second explosive charge into at least a portion of such blastholes for forming the array of satellite explosive charges.

Claim 5

Dependent Claim 24 words

The method according to claim 3 comprising detonating such a main explosive charge and satellite explosive charge located in the same blasthole substantially simultaneously.

Claim 6

Dependent Claim 51 words

The method according to claim 3 wherein the first explosive charge has a first energy per unit volume of explosive charge and the second explosive charge has a second energy per unit volume of explosive charge, such second energy per unit volume being less than the first energy per unit volume.

Claim 7

Dependent Claim 46 words

The method according to claim 1 wherein the blastholes are formed in a substantially rectangular array wherein the length of a side of each rectangle defined by each four adjacent blastholes is not less than about 75% of the length of another side of such rectangle.

Claim 8

Dependent Claim 16 words

The method according to claim 6 wherein the blastholes are formed in a substantially square array.

Claim 9

Dependent Claim 108 words

The method according to claim 1 wherein the steps of forming blastholes and placing explosive comprise: forming a first set of blastholes, each of such first blastholes having a substantially equal hole diameter; forming a second set of blastholes, each of such second blastholes having a substantially equal hole diameter, the hole diameter of each of the second blastholes being less than the hole diameter of each of the first blastholes; placing explosive into the first set of blastholes for providing the substantially horizontal array of main explosive charges; and placing explosive into the second set of blastholes for providing the substantially horizontal array of satellite explosive charges.

Claim 10

Dependent Claim 46 words

The method according to claim 8 comprising forming each satellite explosive charge having an actual depth of burial less than the actual depth of burial of each main explosive charge by forming each satellite explosive charge having a longer charge length than each main explosive charge.

Claim 11

Dependent Claim 44 words

The method according to claim 8 comprising forming each satellite explosive charge having an actual depth of burial less than the actual depth of burial of each main explosive charge by forming such first set of blastholes longer than such second set of blastholes.

Claim 12

Dependent Claim 108 words

The method according to claim 1 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes; forming a second substantially rectangular array of spaced apart blastholes, such a second array having substantially the same spacing distance as the first array and such a second array being diagonally offset from such first array by less than about the spacing distance; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the second substantially rectangular array for forming such an array of satellite charges.

Claim 13

Dependent Claim 40 words

The method according to claim 11 wherein the length of a side of each rectangle defined by each four adjacent blastholes of the first array is not less than about 75% of the length of another side of such rectangle.

Claim 14

Dependent Claim 45 words

The method according to claim 1 comprising providing at least one group of main explosive charges and at least one group of satellite explosive charges wherein a first group of main explosive charges is detonated substantially simultaneously with a first group of satellite explosive charges.

Claim 15

Dependent Claim 87 words

The method according to claim 1 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes and forming a second substantially rectangular array of spaced apart blastholes; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the first substantially rectangular array and in each blasthole of the second substantially rectangular array for forming such an array of satellite explosive charges.

Claim 16

Dependent Claim 40 words

A method according to claim 1 wherein the ratio of actual depth of burial to spacing distance of the satellite explosive charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges.

Claim 17

Independent Claim 195 words

A method for explosively expanding formation toward a limited void in a subterranean formation which comprises the steps of: excavating formation to form at least one limited void in the subterranean formation leaving zones of unfragmented formation adjacent such a void, such a zone of unfragmented formation having a free face adjoining the void; forming blastholes in at least one of such zones of unfragmented formation for forming an array of spaced apart blastholes; placing explosive into such blastholes for forming an array of main explosive charges and an array of satellite explosive charges, wherein each of the satellite explosive charges has a scaled point charge depth of burial substantially equal to the scaled point charge depth of burial of each of the main explosive charges and the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating explosive in the blastholes in a single round of explosions for explosively expanding at least one of the zones of unfragmented formation toward such a void to form a fragmented permeable mass of formation particles in the subterranean formation.

Claim 18

Independent Claim 195 words

A method for explosively expanding formation toward a limited void in a subterranean formation which comprises the steps of: excavating formation to form at least one limited void in the subterranean formation leaving zones of unfragmented formation adjacent such a void, such a zone of unfragmented formation having a free face adjoining the void; forming blastholes in at least one of such zones of unfragmented formation for forming an array of spaced apart blastholes; placing explosive into such blastholes for forming an array of main explosive charges and an array of satellite explosive charges, wherein each of the satellite explosive charges has a scaled point charge depth of burial substantially equal to the scaled point charge depth of burial of each of the main explosive charges and the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating explosive in the blastholes in a single round of explosions for explosively expanding at least one of the zones of unfragmented formation toward such a void to form a fragmented permeable mass of formation particles in the subterranean formation.

Claim 19

Dependent Claim 70 words

The method according to claim 16 wherein the length of each of the main explosive charges is about one-half the thickness of such a zone of unfragmented formation which is to be expanded towards such a free face and wherein such a main explosive charge is located in the portion of the unfragmented formation most remote from the free face toward which such unfragmented formation is to be explosively expanded.

Claim 20

Dependent Claim 61 words

The method according to claim 16 comprising forming the array of main explosive charges and the array of satellite explosive charges by: placing a first explosive charge into each blasthole for forming the array of main explosive charges; and placing a second explosive charge into at least a portion of such blastholes for forming such an array of satellite explosive charges.

Claim 21

Dependent Claim 24 words

The method according to claim 17 comprising detonating such a main explosive charge and satellite explosive charge located in the same blasthole substantially simultaneously.

Claim 22

Dependent Claim 51 words

The method according to claim 16 wherein the first explosive charge has a first energy per unit volume of explosive charge and the second explosive charge has a second energy per unit volume of explosive charge, such second energy per unit volume being less than the first energy per unit volume.

Claim 23

Dependent Claim 46 words

The method according to claim 16 wherein the blastholes are formed in a substantially rectangular array wherein the length of a side of each rectangle defined by each four adjacent blastholes is not less than about 75% of the length of another side of such rectangle.

Claim 24

Dependent Claim 16 words

The method according to claim 21 wherein the blastholes are formed in a substantially square array.

Claim 25

Dependent Claim 105 words

The method according to claim 21 wherein the steps of forming blastholes and placing explosive comprise: forming a first set of blastholes, each of such first blastholes having a substantially equal hole diameter; forming a second set of blastholes, each of such second blastholes having a substantially equal hole diameter, the hole diameter of each of the second blastholes being less than the hole diameter of each of the first blastholes; placing explosive into the first set of blastholes for providing the array of main explosive charges; and placing explosive into the second set of blastholes for providing such an array of satellite explosive charges.

Claim 26

Dependent Claim 46 words

The method according to claim 23 comprising forming each satellite explosive charge having an actual depth of burial less than the actual depth of burial of each main explosive charge by forming each satellite explosive charge having a longer charge length than each main explosive charge.

Claim 27

Dependent Claim 44 words

The method according to claim 23 comprising forming each satellite explosive charge having an actual depth of burial less than the actual depth of burial of each main explosive charge by forming such first set of blastholes longer than such second set of blastholes.

Claim 28

Dependent Claim 101 words

The method according to claim 16 comprising: forming a first substantially rectangular array of spaced apart blastholes; forming a second substantially rectangular array of spaced apart blastholes, such a second array having substantially the same spacing distance as the first array and such a second array being diagonally offset from such first array by less than about the spacing distance; placing explosive in each blasthole of the first substantially rectangular array for forming such an array of main explosive charges; and placing explosive in each blasthole of the second substantially rectangular array for forming such an array of satellite explosive charges.

Claim 29

Dependent Claim 40 words

The method according to claim 26 wherein the length of a side of each rectangle defined by each four adjacent blastholes of the first array is not less than about 75% of the length of another side of such rectangle.

Claim 30

Dependent Claim 45 words

The method according to claim 16 comprising providing at least one group of main explosive charges and at least one group of satellite explosive charges wherein a first group of main explosive charges is detonated substantially simultaneously with a first group of satellite explosive charges.

Claim 31

Dependent Claim 87 words

The method according to claim 16 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes and forming a second substantially rectangular array of spaced apart blastholes; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the first substantially rectangular array and in each blasthole of the second substantially rectangular array for forming such an array of satellite explosive charges.

Claim 32

Dependent Claim 40 words

A method according to claim 16 wherein the ratio of actual depth of burial to spacing distance of the satellite explosive charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges.

Claim 33

Independent Claim 211 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: excavating formation to form at least one limited void in the subterranean formation leaving zones of unfragmented formation above and below such a void, such a zone of unfragmented formation having a substantially horizontal free face adjoining the void; forming a substantially horizontal array of main explosive charges and at least one substantially horizontal array of satellite explosive charges in the formation wherein each of the satellite explosive charges has a scaled point charge depth of burial substantially equal to the scaled point charge depth of burial of each of the main explosive charges and the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating the explosive charges in a single round of explosions for explosively expanding at least one of the zones of unfragmented formation toward such a void to form a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort.

Claim 34

Independent Claim 211 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: excavating formation to form at least one limited void in the subterranean formation leaving zones of unfragmented formation above and below such a void, such a zone of unfragmented formation having a substantially horizontal free face adjoining the void; forming a substantially horizontal array of main explosive charges and at least one substantially horizontal array of satellite explosive charges in the formation wherein each of the satellite explosive charges has a scaled point charge depth of burial substantially equal to the scaled point charge depth of burial of each of the main explosive charges and the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating the explosive charges in a single round of explosions for explosively expanding at least one of the zones of unfragmented formation toward such a void to form a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort.

Claim 35

Dependent Claim 70 words

The method according to claim 31 wherein the length of each of the main explosive charges is about one-half the thickness of such a zone of unfragmented formation which is to be expanded towards such a free face and wherein such a main explosive charge is located in the portion of the unfragmented formation most remote from the free face toward which such unfragmented formation is to be explosively expanded.

Claim 36

Dependent Claim 46 words

The method according to claim 32 comprising forming each satellite explosive charge having an actual depth of burial less than the actual depth of burial of each main explosive charge by forming each satellite explosive charge having a longer charge length than each main explosive charge.

Claim 37

Dependent Claim 40 words

A method according to claim 31 wherein the ratio of actual depth of burial to spacing distance of the satellite explosive charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges.

Claim 38

Dependent Claim 31 words

A method according to claim 31 comprising detonating at least a portion of such satellite explosive charges substantially simultaneously with detonation of at least a portion of such main explosive charges.

Claim 39

Independent Claim 286 words

A method of recovering shale oil from an in situ oil shale retort within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: excavating formation to form at least one limited void in the subterranean formation leaving zones of unfragmented formation above and below such a void, such a zone of unfragmented formation having a substantially horizontal free face adjoining the void; forming substantially vertical blastholes in at least one of such zones of unfragmented formation for forming at least one array of spaced apart blastholes; placing explosive into such blastholes for forming a substantially horizontal array of main explosive charges and at least one substantially horizontal array of satellite explosive charges, wherein each satellite charge has a scaled point charge depth of burial substantially equal to the scaled point charge depth of burial of each of the main explosive charges, and the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; detonating explosive in the blastholes in a single round of explosions for explosively expanding at least one of such zones of unfragmented formation toward such a void to form a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort; and introducing an oxygen-supplying gas into such an oil shale retort for establishing a retorting zone in the fragmented permeable mass wherein oil shale is retorted to produce gaseous and liquid products, and for advancing the retorting zone through the fragmented permeable mass, and withdrawing gaseous and liquid products from the retort.

Claim 40

Independent Claim 286 words

A method of recovering shale oil from an in situ oil shale retort within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: excavating formation to form at least one limited void in the subterranean formation leaving zones of unfragmented formation above and below such a void, such a zone of unfragmented formation having a substantially horizontal free face adjoining the void; forming substantially vertical blastholes in at least one of such zones of unfragmented formation for forming at least one array of spaced apart blastholes; placing explosive into such blastholes for forming a substantially horizontal array of main explosive charges and at least one substantially horizontal array of satellite explosive charges, wherein each satellite charge has a scaled point charge depth of burial substantially equal to the scaled point charge depth of burial of each of the main explosive charges, and the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; detonating explosive in the blastholes in a single round of explosions for explosively expanding at least one of such zones of unfragmented formation toward such a void to form a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort; and introducing an oxygen-supplying gas into such an oil shale retort for establishing a retorting zone in the fragmented permeable mass wherein oil shale is retorted to produce gaseous and liquid products, and for advancing the retorting zone through the fragmented permeable mass, and withdrawing gaseous and liquid products from the retort.

Claim 41

Dependent Claim 70 words

The method according to claim 36 wherein the length of each of the main explosive charges is about one-half the thickness of such a zone of unfragmented formation which is to be expanded towards such a free face and wherein such a main explosive charge is located in the portion of the unfragmented formation most remote from the free face toward which such unfragmented formation is to be explosively expanded.

Claim 42

Dependent Claim 60 words

The method according to claim 36 comprising forming the array of main explosive charges and the array of satellite explosive charges by: placing a first explosive charge in each blasthole for forming the substantially horizontal array of main explosive charges; and placing a second explosive charge in a plurality of such blastholes for forming the array of satellite explosive charges.

Claim 43

Dependent Claim 24 words

The method according to claim 38 comprising detonating such a main explosive charge and satellite explosive charge located in the same blasthole substantially simultaneously.

Claim 44

Dependent Claim 51 words

The method according to claim 38 wherein the first explosive charge has a first energy per unit volume of explosive charge and the second explosive charge has a second energy per unit volume of explosive charge, such second energy per unit volume being less than the first energy per unit volume.

Claim 45

Dependent Claim 46 words

The method according to claim 33 wherein the blastholes are formed in a substantially rectangular array wherein the length of a side of each rectangle defined by each four adjacent blastholes is no less than about 75% of the length of another side of such rectangle.

Claim 46

Dependent Claim 16 words

The method according to claim 31 wherein the blastholes are formed in a substantially square array.

Claim 47

Dependent Claim 108 words

The method according to claim 31 wherein the steps of forming blastholes and placing explosive comprise: forming a first set of blastholes, each of such first blastholes having a substantially equal hole diameter; forming a second set of blastholes, each of such second blastholes having a substantially equal hole diameter, the hole diameter of each of the second blastholes being less than the hole diameter of each of the first blastholes; placing explosive into the first set of blastholes for providing the substantially horizontal array of main explosive charges; and placing explosive into the second set of blastholes for providing the substantially horizontal array of satellite explosive charges.

Claim 48

Dependent Claim 46 words

The method according to claim 43 comprising forming each satellite explosive charge having an actual depth of burial less than the actual depth of burial of each main explosive charge by forming each satellite explosive charge having a longer charge length than each main explosive charge.

Claim 49

Dependent Claim 109 words

The method according to claim 36 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes; forming a second substantially rectangular array of spaced apart blastholes, such a second array having substantially the same spacing distance as the first array and such a second array being diagonally offset from such first array by less than about the spacing distance; placing explosive into each blasthole of the first substantially rectangular array for forming such an array of main explosive charges; and placing explosive into each blasthole of the second substantially rectangular array for forming such an array of satellite charges.

Claim 50

Dependent Claim 40 words

The method according to claim 45 wherein the length of a side of each rectangle defined by each four adjacent blastholes of the first array is not less than about 75% of the length of another side of such rectangle.

Claim 51

Dependent Claim 45 words

The method according to claim 45 comprising providing at least one group of main explosive charges and at least one group of satellite explosive charges wherein a first group of main explosive charges is detonated substantially simultaneously with a first group of satellite explosive charges.

Claim 52

Dependent Claim 87 words

The method according to claim 36 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes and forming a second substantially rectangular array of spaced apart blastholes; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the first substantially rectangular array and in each blasthole of the second substantially rectangular array for forming such an array of satellite explosive charges.

Claim 53

Dependent Claim 40 words

A method according to claim 36 wherein the ratio of actual depth of burial to spacing distance of the satellite explosive charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges.

Claim 54

Independent Claim 236 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such as in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation leaving zones of unfragmented formation above and below such a void, such a zone of unfragmented formation having a substantially horizontal free face adjoining the void; forming a plurality of substantially vertical blastholes in at least one of such zones of unfragmented formation for forming at least one array of spaced apart blastholes; placing explosive into such blastholes for forming an array of main explosive charges and at least one array of satellite explosive charges, wherein each of the satellite explosive charges has a scaled point charge depth of burial substantially equal to the scaled point charge depth of burial of each of the main explosive charges and the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating the explosive charges in the blastholes, in a single round of explosions, for explosively expanding at least one of the zones of unfragmented formation toward such a void for forming a fragmented permeable mass of formation particles containing oil shale in the in situ oil shale retort.

Claim 55

Independent Claim 236 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such as in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation leaving zones of unfragmented formation above and below such a void, such a zone of unfragmented formation having a substantially horizontal free face adjoining the void; forming a plurality of substantially vertical blastholes in at least one of such zones of unfragmented formation for forming at least one array of spaced apart blastholes; placing explosive into such blastholes for forming an array of main explosive charges and at least one array of satellite explosive charges, wherein each of the satellite explosive charges has a scaled point charge depth of burial substantially equal to the scaled point charge depth of burial of each of the main explosive charges and the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating the explosive charges in the blastholes, in a single round of explosions, for explosively expanding at least one of the zones of unfragmented formation toward such a void for forming a fragmented permeable mass of formation particles containing oil shale in the in situ oil shale retort.

Claim 56

Dependent Claim 70 words

The method according to claim 50 wherein the length of each of the main explosive charges is about one-half the thickness of such a zone of unfragmented formation which is to be expanded towards such a free face and wherein such a main explosive charge is located in the portion of the unfragmented formation most remote from the free face toward which such unfragmented formation is to be explosively expanded.

Claim 57

Dependent Claim 60 words

The method according to claim 50 comprising forming the array of main explosive charges and the array of satellite explosive charges by: placing a first explosive charge into each blasthole for forming the array of main explosive charges; and placing a second explosive charge into at least a portion of such blastholes for forming the array of satellite explosive charges.

Claim 58

Dependent Claim 24 words

The method according to claim 52 comprising detonating such a main explosive charge and satellite explosive charge located in the same blasthole substantially simultaneously.

Claim 59

Dependent Claim 104 words

The method according to claim 50 wherein the steps of forming blastholes and placing explosive comprise: forming a first set of blastholes, each of such first blastholes having a substantially equal hole diameter; forming a second set of blastholes, each of such second blastholes having a substantially equal hole diameter, the hole diameter of each of the second blastholes being less than the hole diameter of each of the first blastholes; placing explosive into the first set of blastholes for providing the array of main explosive charges; and placing explosive into the second set of blastholes for providing the array of satellite explosive charges.

Claim 60

Dependent Claim 46 words

The method according to claim 54 comprising forming each satellite explosive charge having an actual depth of burial less than the actual depth of burial of each main explosive charge by forming each satellite explosive charge having a longer charge length than each main explosive charge.

Claim 61

Dependent Claim 44 words

The method according to claim 54 comprising forming each satellite explosive charge having an actual depth of burial less than the actual depth of burial of each main explosive charge by forming such first set of blastholes longer than such second set of blastholes.

Claim 62

Dependent Claim 108 words

The method according to claim 50 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes; forming a second substantially rectangular array of spaced apart blastholes, such a second array having substantially the same spacing distance as the first array and such a second array being diagonally offset from such first array by less than about the spacing distance; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the second substantially rectangular array for forming such an array of satellite charges.

Claim 63

Dependent Claim 45 words

The method according to claim 50 comprising providing at least one group of main explosive charges and at least one group of satellite explosive charges wherein a first group of main explosive charges is detonated substantially simultaneously with a first group of satellite explosive charges.

Claim 64

Dependent Claim 87 words

The method according to claim 50 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes and forming a second substantially rectangular array of spaced apart blastholes; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the first substantially rectangular array and in each blasthole of the second substantially rectangular array for forming such an array of satellite explosive charges.

Claim 65

Dependent Claim 40 words

A method according to claim 50 wherein the ratio of actual depth of burial to spacing distance of the satellite explosive charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges.

Claim 66

Independent Claim 194 words

A method for explosively expanding formation toward a limited void in a subterranean formation which comprises the steps of: forming at least one limited void in the subterranean formation leaving a zone of unfragmented formation adjacent such a void, the zone of unfragmented formation having a free face adjoining the void; forming blastholes in the zone of unfragmented formation for forming an array of spaced apart blastholes; placing explosive into such blastholes for forming an array of main explosive charges and an array of satellite explosive charges, wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges and the ratio of actual depth of burial to spacing distance of the satellite explosive charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges; and detonating such main explosive charges and satellite explosive charges in a single round of explosions for explosively expanding at least one of the zones of unfragmented formation toward such a void for forming a fragmented permeable mass of formation particles in the subterranean formation.

Claim 67

Independent Claim 194 words

A method for explosively expanding formation toward a limited void in a subterranean formation which comprises the steps of: forming at least one limited void in the subterranean formation leaving a zone of unfragmented formation adjacent such a void, the zone of unfragmented formation having a free face adjoining the void; forming blastholes in the zone of unfragmented formation for forming an array of spaced apart blastholes; placing explosive into such blastholes for forming an array of main explosive charges and an array of satellite explosive charges, wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges and the ratio of actual depth of burial to spacing distance of the satellite explosive charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges; and detonating such main explosive charges and satellite explosive charges in a single round of explosions for explosively expanding at least one of the zones of unfragmented formation toward such a void for forming a fragmented permeable mass of formation particles in the subterranean formation.

Claim 68

Dependent Claim 45 words

The method according to claim 61 comprising providing at least one group of main explosive charges and at least one group of satellite explosive charges wherein a first group of main explosive charges is detonated substantially simultaneously with a first group of satellite explosive charges.

Claim 69

Dependent Claim 87 words

The method according to claim 61 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes and forming a second substantially rectangular array of spaced apart blastholes; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the first substantially rectangular array and in each blasthole of the second substantially rectangular array for forming such an array of satellite explosive charges.

Claim 70

Dependent Claim 70 words

The method according to claim 61 wherein the length of each of the main explosive charges is about one-half the thickness of such a zone of unfragmented formation which is to be expanded towards such a free face and wherein such a main explosive charge is located in the portion of the unfragmented formation most remote from the free face toward which such unfragmented formation is to be explosively expanded.

Claim 71

Dependent Claim 61 words

The method according to claim 61 comprising forming the array of main explosive charges and the array of satellite explosive charges by: placing a first explosive charge into each blasthole for forming the array of main explosive charges; and placing a second explosive charge into at least a portion of such blastholes for forming such an array of satellite explosive charges.

Claim 72

Dependent Claim 37 words

The method according to claim 61 wherein such a main explosive charge and such a satellite explosive charge are located in the same blasthole and comprising detonating such main explosive charge and satellite explosive charge substantially simultaneously.

Claim 73

Dependent Claim 40 words

A method according to claim 61 wherein the ratio of actual depth of burial to spacing distance of the satellite explosive charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges.

Claim 74

Independent Claim 237 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation, leaving a zone of unfragmented formation above such a void having a substantially horizontal free face adjoining the void; forming at least one array of spaced apart substantially vertical blastholes in the zone of unfragmented formation above the void; placing explosive in such blastholes for forming an array of main explosive charges in the zone of unfragmented formation and at least one array of satellite explosive charges in the zone of unfragmented formation between the array of main explosive charges and the free face wherein each of the satellite explosive charges has a scaled point charge depth of burial substantially equal to the scaled point charge depth of burial of each of the main explosive charges and the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating the explosive charges in a single round of explosions for explosively expanding the zone of unfragmented formation toward the void for forming a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort.

Claim 75

Independent Claim 237 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation, leaving a zone of unfragmented formation above such a void having a substantially horizontal free face adjoining the void; forming at least one array of spaced apart substantially vertical blastholes in the zone of unfragmented formation above the void; placing explosive in such blastholes for forming an array of main explosive charges in the zone of unfragmented formation and at least one array of satellite explosive charges in the zone of unfragmented formation between the array of main explosive charges and the free face wherein each of the satellite explosive charges has a scaled point charge depth of burial substantially equal to the scaled point charge depth of burial of each of the main explosive charges and the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating the explosive charges in a single round of explosions for explosively expanding the zone of unfragmented formation toward the void for forming a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort.

Claim 76

Dependent Claim 51 words

The method according to claim 68 wherein the length of each of the main explosive charges is about one-half the thickness of the zone of unfragmented formation and wherein such a main explosive charge is located in the portion of the zone of unfragmented formation most remote from the free face.

Claim 77

Dependent Claim 62 words

The method according to claim 68 comprising forming the array of main explosive charges and the array of satellite explosive charges by: placing a first explosive charge into each blasthole for forming the substantially horizontal array of main explosive charges; and placing a second explosive charge into at least a portion of such blastholes for forming the array of satellite explosive charges.

Claim 78

Dependent Claim 108 words

The method according to claim 68 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes; forming a second substantially rectangular array of spaced apart blastholes, such a second array having substantially the same spacing distance as the first array and such a second array being diagonally offset from such first array by less than about the spacing distance; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the second substantially rectangular array for forming such an array of satellite charges.

Claim 79

Dependent Claim 87 words

The method according to claim 68 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes and forming a second substantially rectangular array of spaced apart blastholes; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the first substantially rectangular array and in each blasthole of the second substantially rectangular array for forming such an array of satellite explosive charges.

Claim 80

Dependent Claim 31 words

A method according to claim 68 comprising detonating at least a portion of such satellite explosive charges substantially simultaneously with detonation of at least a portion of such main explosive charges.

Claim 81

Dependent Claim 40 words

A method according to claim 68 wherein the ratio of actual depth of burial to spacing distance of the satellite explosive charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges.

Claim 82

Independent Claim 297 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation, leaving a zone of unfragmented formation above such a void having a substantially horizontal free face adjoining the void; forming at least one array of spaced apart substantially vertical blastholes in the zone of unfragmented formation above the void by: forming a first set of blastholes, each of such first blastholes having a substantially equal hole diameter; and forming a second set of blastholes, each of such second blastholes having a substantially equal hole diameter, the hole diameter of each of the second blastholes being less than the hole diameter of each of the first blastholes; placing explosive into the first set of blastholes for providing a substantially horizontal array of main explosive charges in the zone of unfragmented formation; placing explosive into the second set of blastholes for providing a substantially horizontal array of satellite explosive charges in the zone of unfragmented formation, wherein each of the satellite explosive charges has a scaled point charge depth of burial substantially equal to the scaled point charge depth of burial of each of the main explosive charges and the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating the explosive charges in a single round of explosions for explosively expanding the zone of unfragmented formation toward the void for forming a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort.

Claim 83

Independent Claim 297 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation, leaving a zone of unfragmented formation above such a void having a substantially horizontal free face adjoining the void; forming at least one array of spaced apart substantially vertical blastholes in the zone of unfragmented formation above the void by: forming a first set of blastholes, each of such first blastholes having a substantially equal hole diameter; and forming a second set of blastholes, each of such second blastholes having a substantially equal hole diameter, the hole diameter of each of the second blastholes being less than the hole diameter of each of the first blastholes; placing explosive into the first set of blastholes for providing a substantially horizontal array of main explosive charges in the zone of unfragmented formation; placing explosive into the second set of blastholes for providing a substantially horizontal array of satellite explosive charges in the zone of unfragmented formation, wherein each of the satellite explosive charges has a scaled point charge depth of burial substantially equal to the scaled point charge depth of burial of each of the main explosive charges and the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating the explosive charges in a single round of explosions for explosively expanding the zone of unfragmented formation toward the void for forming a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort.

Claim 84

Independent Claim 265 words

A method of recovering shale oil from an in situ oil shale retort within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation leaving a zone of unfragmented formation above such a void having a substantially horizontal free face adjoining the void; forming a plurality of spaced apart substantially vertical blastholes in an array extending across the zone of unfragmented formation; placing explosive into such blastholes for forming an array of main explosive charges and at least one array of satellite explosive charges, wherein each satellite charge has a scaled point charge depth of burial substantially equal to the scaled point charge depth of burial of each of the main explosive charges and the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; detonating the explosive charges in the blastholes in a single round of explosions for explosively expanding the zone of unfragmented formation toward the void for forming a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort; and introducing an oxygen-supplying gas into the oil shale retort for establishing a retorting zone in the fragmented permeable mass wherein oil shale is retorted to produce gaseous and liquid products and for advancing the retorting zone through the fragmented permeable mass; and withdrawing gaseous and liquid products including shale oil from the retort.

Claim 85

Independent Claim 265 words

A method of recovering shale oil from an in situ oil shale retort within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation leaving a zone of unfragmented formation above such a void having a substantially horizontal free face adjoining the void; forming a plurality of spaced apart substantially vertical blastholes in an array extending across the zone of unfragmented formation; placing explosive into such blastholes for forming an array of main explosive charges and at least one array of satellite explosive charges, wherein each satellite charge has a scaled point charge depth of burial substantially equal to the scaled point charge depth of burial of each of the main explosive charges and the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; detonating the explosive charges in the blastholes in a single round of explosions for explosively expanding the zone of unfragmented formation toward the void for forming a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort; and introducing an oxygen-supplying gas into the oil shale retort for establishing a retorting zone in the fragmented permeable mass wherein oil shale is retorted to produce gaseous and liquid products and for advancing the retorting zone through the fragmented permeable mass; and withdrawing gaseous and liquid products including shale oil from the retort.

Claim 86

Dependent Claim 51 words

The method according to claim 76 wherein the length of each of the main explosive charges is about one-half the thickness of the zone of unfragmented formation and wherein such a main explosive charge is located in the portion of the zone of unfragmented formation most remote from the free face.

Claim 87

Dependent Claim 58 words

The method according to claim 76 comprising forming the array of main explosive charges and the array of satellite explosive charges by: placing a first explosive charge in each blasthole for forming the array of main explosive charges; and placing a second explosive charge in a plurality of such blastholes for forming the array of satellite explosive charges.

Claim 88

Dependent Claim 24 words

The method according to claim 78 comprising detonating such a main explosive charge and satellite explosive charge located in the same blasthole substantially simultaneously.

Claim 89

Dependent Claim 51 words

The method according to claim 78 wherein the first explosive charge has a first energy per unit volume of explosive charge and the second explosive charge has a second energy per unit volume of explosive charge, such second energy per unit volume being less than the first energy per unit volume.

Claim 90

Dependent Claim 104 words

The method according to claim 76 wherein the steps of forming blastholes and placing explosive comprise: forming a first set of blastholes, each of such first blastholes having a substantially equal hole diameter; forming a second set of blastholes, each of such second blastholes having a substantially equal hole diameter, the hole diameter of each of the second blastholes being less than the hole diameter of each of the first blastholes; placing explosive into the first set of blastholes for providing the array of main explosive charges; and placing explosive into the second set of blastholes for providing the array of satellite explosive charges.

Claim 91

Dependent Claim 46 words

The method according to claim 81 comprising forming each satellite explosive charge having an actual depth of burial less than the actual depth of burial of each main explosive charge by forming each satellite explosive charge having a longer charge length than each main explosive charge.

Claim 92

Dependent Claim 109 words

The method according to claim 76 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes; forming a second substantially rectangular array of spaced apart blastholes, such a second array having substantially the same spacing distance as the first array and such a second array being diagonally offset from such first array by less than about the spacing distance; placing explosive into each blasthole of the first substantially rectangular array for forming such an array of main explosive charges; and placing explosive into each blasthole of the second substantially rectangular array for forming such an array of satellite charges.

Claim 93

Dependent Claim 45 words

The method according to claim 76 comprising providing at least one group of main explosive charges and at least one group of satellite explosive charges wherein a first group of main explosive charges is detonated substantially simultaneously with a first group of satellite explosive charges.

Claim 94

Dependent Claim 87 words

The method according to claim 76 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes and forming a second substantially rectangular array of spaced apart blastholes; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the first substantially rectangular array and in each blasthole of the second substantially rectangular array for forming such an array of satellite explosive charges.

Claim 95

Independent Claim 223 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation leaving zones of unfragmented formation above and below such a void, such a zone of unfragmented formation having a substantially horizontal free face adjoining the void; forming substantially vertical blastholes in at least one of such zones of unfragmented formation for forming at least one array of spaced apart blastholes; placing explosive into such blastholes for forming an array of main explosive charges and at least one array of satellite explosive charges, wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating such explosive charges in a single round of explosions for explosively expanding at least one of the zones of unfragmented formation toward such a void for forming a fragmented permeable mass of formation particles containing oil shale in the in situ oil shale retort wherein at least a portion of such satellite charges are detonated substantially simultaneously with detonation of at least a portion of such main explosive charges.

Claim 96

Independent Claim 223 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation leaving zones of unfragmented formation above and below such a void, such a zone of unfragmented formation having a substantially horizontal free face adjoining the void; forming substantially vertical blastholes in at least one of such zones of unfragmented formation for forming at least one array of spaced apart blastholes; placing explosive into such blastholes for forming an array of main explosive charges and at least one array of satellite explosive charges, wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating such explosive charges in a single round of explosions for explosively expanding at least one of the zones of unfragmented formation toward such a void for forming a fragmented permeable mass of formation particles containing oil shale in the in situ oil shale retort wherein at least a portion of such satellite charges are detonated substantially simultaneously with detonation of at least a portion of such main explosive charges.

Claim 97

Dependent Claim 60 words

The method according to claim 86 comprising forming the array of main explosive charges and the array of satellite explosive charges by: placing a first explosive charge into each blasthole for forming the array of main explosive charges; and placing a second explosive charge into at least a portion of such blastholes for forming the array of satellite explosive charges.

Claim 98

Dependent Claim 24 words

The method according to claim 87 comprising detonating such a main explosive charge and satellite explosive charge located in the same blasthole substantially simultaneously.

Claim 99

Dependent Claim 104 words

The method according to claim 86 wherein the steps of forming blastholes and placing explosive comprise: forming a first set of blastholes, each of such first blastholes having a substantially equal hole diameter; forming a second set of blastholes, each of such second blastholes having a substantially equal hole diameter, the hole diameter of each of the second blastholes being less than the hole diameter of each of the first blastholes; placing explosive into the first set of blastholes for providing the array of main explosive charges; and placing explosive into the second set of blastholes for providing the array of satellite explosive charges.

Claim 100

Dependent Claim 108 words

The method according to claim 86 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes; forming a second substantially rectangular array of spaced apart blastholes, such a second array having substantially the same spacing distance as the first array and such a second array being diagonally offset from such first array by less than about the spacing distance; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the second substantially rectangular array for forming such an array of satellite charges.

Claim 101

Dependent Claim 87 words

The method according to claim 86 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes and forming a second substantially rectangular array of spaced apart blastholes; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the first substantially rectangular array and in each blasthole of the second substantially rectangular array for forming such an array of satellite explosive charges.

Claim 102

Independent Claim 189 words

A method for explosively expanding formation toward a limited void in a subterranean formation which comprises the steps of: forming at least one limited void in the subterranean formation leaving zones of unfragmented formation adjacent such a void, such a zone of unfragmented formation having a free face adjoining the void; forming blastholes in at least one of such zones of unfragmented formation for forming an array of spaced apart blastholes extending across such zone; placing explosive into such blastholes for forming an array of main explosive charges and an array of satellite explosive charges, wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating such explosive charges in a single round of explosions for explosively expanding at least one of the zones of unfragmented formation toward such a void for forming a fragmented permeable mass of formation particles in the subterranean formation wherein at least a portion of such satellite explosive charges are detonated substantially simultaneously with detonation of at least a portion of such main explosive charges.

Claim 103

Independent Claim 189 words

A method for explosively expanding formation toward a limited void in a subterranean formation which comprises the steps of: forming at least one limited void in the subterranean formation leaving zones of unfragmented formation adjacent such a void, such a zone of unfragmented formation having a free face adjoining the void; forming blastholes in at least one of such zones of unfragmented formation for forming an array of spaced apart blastholes extending across such zone; placing explosive into such blastholes for forming an array of main explosive charges and an array of satellite explosive charges, wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating such explosive charges in a single round of explosions for explosively expanding at least one of the zones of unfragmented formation toward such a void for forming a fragmented permeable mass of formation particles in the subterranean formation wherein at least a portion of such satellite explosive charges are detonated substantially simultaneously with detonation of at least a portion of such main explosive charges.

Claim 104

Dependent Claim 61 words

The method according to claim 92 comprising forming the array of main explosive charges and the array of satellite explosive charges by: placing a first explosive charge into each blasthole for forming the array of main explosive charges; and placing a second explosive charge into at least a portion of such blastholes for forming such an array of satellite explosive charges.

Claim 105

Dependent Claim 24 words

The method according to claim 92 comprising detonating such a main explosive charge and satellite explosive charge located in the same blasthole substantially simultaneously.

Claim 106

Dependent Claim 97 words

The method according to claim 92 comprising: forming a first substantially rectangular array of spaced apart blastholes; forming a second substantially rectangular array of spaced apart blastholes, the second array having substantially the same spacing distance as the first array and the second array being diagonally offset from the first array by less than about the spacing distance; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the second substantially rectangular array for forming the array of satellite explosive charges.

Claim 107

Dependent Claim 87 words

The method according to claim 92 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes and forming a second substantially rectangular array of spaced apart blastholes; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the first substantially rectangular array and in each blasthole of the second substantially rectangular array for forming such an array of satellite explosive charges.

Claim 108

Independent Claim 229 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation, leaving a zone of unfragmented formation above such a void having a substantially horizontal free face adjoining the void; forming at least one array of spaced apart substantially vertical blastholes in the zone of unfragmented formation above the void; placing explosive in such blastholes for forming an array of main explosive charges in the zone of unfragmented formation and at least one array of satellite explosive charges in the zone of unfragmented formation between the array of main explosive charges and the free face wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating the explosive charges in a single round of explosions for explosively expanding the zone of unfragmented formation toward the void for forming a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort, wherein at least a portion of the satellite explosive charges are detonated substantially simultaneously with at least a portion of the main explosive charges.

Claim 109

Independent Claim 229 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation, leaving a zone of unfragmented formation above such a void having a substantially horizontal free face adjoining the void; forming at least one array of spaced apart substantially vertical blastholes in the zone of unfragmented formation above the void; placing explosive in such blastholes for forming an array of main explosive charges in the zone of unfragmented formation and at least one array of satellite explosive charges in the zone of unfragmented formation between the array of main explosive charges and the free face wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating the explosive charges in a single round of explosions for explosively expanding the zone of unfragmented formation toward the void for forming a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort, wherein at least a portion of the satellite explosive charges are detonated substantially simultaneously with at least a portion of the main explosive charges.

Claim 110

Dependent Claim 51 words

The method according to claim 97 wherein the length of each of the main explosive charges is about one-half the thickness of the zone of unfragmented formation and wherein such a main explosive charge is located in the portion of the zone of unfragmented formation most remote from the free face.

Claim 111

Independent Claim 205 words

A method for forming an in situ oil shale retort within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation leaving a zone of unfragmented formation above such a void having a substantially horizontal free face adjoining the void; forming a plurality of spaced apart substantially vertical blastholes in an array extending across the zone of unfragmented formation; placing explosive into such blastholes for forming a substantially horizontal array of main explosive charges and at least one array of satellite explosive charges, wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating the explosive charges in a single round of explosions for explosively expanding the zone of unfragmented formation toward the void for forming a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort, wherein at least a portion of the satellite explosive charges are detonated substantially simultaneously with detonation of at least a portion of the main explosive charges.

Claim 112

Independent Claim 205 words

A method for forming an in situ oil shale retort within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation leaving a zone of unfragmented formation above such a void having a substantially horizontal free face adjoining the void; forming a plurality of spaced apart substantially vertical blastholes in an array extending across the zone of unfragmented formation; placing explosive into such blastholes for forming a substantially horizontal array of main explosive charges and at least one array of satellite explosive charges, wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges; and detonating the explosive charges in a single round of explosions for explosively expanding the zone of unfragmented formation toward the void for forming a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort, wherein at least a portion of the satellite explosive charges are detonated substantially simultaneously with detonation of at least a portion of the main explosive charges.

Claim 113

Dependent Claim 60 words

The method according to claim 99 comprising forming the array of main explosive charges and the array of satellite explosive charges by: placing a first explosive charge in each blasthole for forming the substantially horizontal array of main explosive charges; and placing a second explosive charge in a plurality of such blastholes for forming the array of satellite explosive charges.

Claim 114

Dependent Claim 24 words

The method according to claim 100 comprising detonating such a main explosive charge and satellite explosive charge located in the same blasthole substantially simultaneously.

Claim 115

Dependent Claim 109 words

The method according to claim 99 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes; forming a second substantially rectangular array of spaced apart blastholes, such a second array having substantially the same spacing distance as the first array and such a second array being diagonally offset from such first array by less than about the spacing distance; placing explosive into each blasthole of the first substantially rectangular array for forming such an array of main explosive charges; and placing explosive into each blasthole of the second substantially rectangular array for forming such an array of satellite charges.

Claim 116

Dependent Claim 87 words

The method according to claim 99 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes and forming a second substantially rectangular array of spaced apart blastholes; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the first substantially rectangular array and in each blasthole of the second substantially rectangular array for forming such an array of satellite explosive charges.

Claim 117

Independent Claim 231 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation leaving zones of unfragmented formation above and below such a void, such a zone of unfragmented formation having a substantially horizontal free face adjoining the void; forming substantially vertical blastholes in at least one of such zones of unfragmented formation for forming at least one array of spaced apart blastholes; placing explosive into such blastholes for forming an array of main explosive charges and at least one array of satellite explosive charges, wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges and the ratio of actual depth of burial to spacing distance of the satellite charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges; and detonating such explosive charges in a single round of explosions for explosively expanding at least one of the zones of unfragmented formation toward such a void for forming a fragmented permeable mass of formation particles containing oil shale in the in situ oil shale retort.

Claim 118

Independent Claim 231 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation leaving zones of unfragmented formation above and below such a void, such a zone of unfragmented formation having a substantially horizontal free face adjoining the void; forming substantially vertical blastholes in at least one of such zones of unfragmented formation for forming at least one array of spaced apart blastholes; placing explosive into such blastholes for forming an array of main explosive charges and at least one array of satellite explosive charges, wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges and the ratio of actual depth of burial to spacing distance of the satellite charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges; and detonating such explosive charges in a single round of explosions for explosively expanding at least one of the zones of unfragmented formation toward such a void for forming a fragmented permeable mass of formation particles containing oil shale in the in situ oil shale retort.

Claim 119

Dependent Claim 70 words

The method according to claim 104 wherein the length of each of the main explosive charges is about one-half the thickness of such a zone of unfragmented formation which is to be expanded towards such a free face and wherein such a main explosive charge is located in the portion of the unfragmented formation most remote from the free face toward which such unfragmented formation is to be explosively expanded.

Claim 120

Dependent Claim 108 words

The method according to claim 104 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes; forming a second substantially rectangular array of spaced apart blastholes, such a second array having substantially the same spacing distance as the first array and such a second array being diagonally offset from such first array by less than about the spacing distance; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the second substantially rectangular array for forming such an array of satellite charges.

Claim 121

Dependent Claim 45 words

The method according to claim 104 comprising providing at least one group of main explosive charges and at least one group of satellite explosive charges wherein a first group of main explosive charges is detonated substantially simultaneously with a first group of satellite explosive charges.

Claim 122

Dependent Claim 87 words

The method according to claim 104 wherein the steps of forming blastholes and placing explosive comprises: forming a first substantially rectangular array of spaced apart blastholes and forming a second substantially rectangular array of spaced apart blastholes; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the first substantially rectangular array and in each blasthole of the second substantially rectangular array for forming such an array of satellite explosive charges.

Claim 123

Independent Claim 195 words

A method for explosively expanding formation toward a limited void in a subterranean formation which comprises the steps of: excavating formation to form at least one limited void in the subterranean formation leaving zones of unfragmented formation adjacent such a void, such a zone of unfragmented formation having a free face adjoining the void; forming blastholes in at least one of such zones of unfragmented formation for forming an array of spaced apart blastholes; placing explosive into such blastholes for forming an array of main explosive charges and an array of satellite explosive charges, wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges and the ratio of actual depth of burial to spacing distance of the satellite charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges; and detonating the explosive charges in a single round of explosions for explosively expanding at least one of the zones of unfragmented formation toward such a void for forming a fragmented permeable mass of formation particles in the subterranean formation.

Claim 124

Independent Claim 195 words

A method for explosively expanding formation toward a limited void in a subterranean formation which comprises the steps of: excavating formation to form at least one limited void in the subterranean formation leaving zones of unfragmented formation adjacent such a void, such a zone of unfragmented formation having a free face adjoining the void; forming blastholes in at least one of such zones of unfragmented formation for forming an array of spaced apart blastholes; placing explosive into such blastholes for forming an array of main explosive charges and an array of satellite explosive charges, wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges and the ratio of actual depth of burial to spacing distance of the satellite charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges; and detonating the explosive charges in a single round of explosions for explosively expanding at least one of the zones of unfragmented formation toward such a void for forming a fragmented permeable mass of formation particles in the subterranean formation.

Claim 125

Dependent Claim 70 words

The method according to claim 109 wherein the length of each of the main explosive charges is about one-half the thickness of such a zone of unfragmented formation which is to be expanded towards such a free face and wherein such a main explosive charge is located in the portion of the unfragmented formation most remote from the free face toward which such unfragmented formation is to be explosively expanded.

Claim 126

Dependent Claim 31 words

A method according to claim 109 comprising detonating at least a portion of such satellite explosive charges substantially simultaneously with detonation of at least a portion of such main explosive charges.

Claim 127

Independent Claim 239 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation, leaving a zone of unfragmented formation above such a void having a substantially horizontal free face adjoining the void; forming at least one array of spaced apart substantially vertical blastholes in the zone of unfragmented formation above the void; placing explosive in such blastholes for forming an array of main explosive charges in the zone of unfragmented formation and at least one array of satellite explosive charges in the zone of unfragmented formation between the array of main explosive charges and the free face wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges and the ratio of actual depth of burial to spacing distance of the satellite explosive charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges; and detonating the explosive charges in a single round of explosions for explosively expanding the zone of unfragmented formation toward the void for forming a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort.

Claim 128

Independent Claim 239 words

A method for forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation, leaving a zone of unfragmented formation above such a void having a substantially horizontal free face adjoining the void; forming at least one array of spaced apart substantially vertical blastholes in the zone of unfragmented formation above the void; placing explosive in such blastholes for forming an array of main explosive charges in the zone of unfragmented formation and at least one array of satellite explosive charges in the zone of unfragmented formation between the array of main explosive charges and the free face wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges and the ratio of actual depth of burial to spacing distance of the satellite explosive charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges; and detonating the explosive charges in a single round of explosions for explosively expanding the zone of unfragmented formation toward the void for forming a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort.

Claim 129

Dependent Claim 51 words

The method according to claim 112 wherein the length of each of the main explosive charges is about one-half the thickness of the zone of unfragmented formation and wherein such a main explosive charge is located in the portion of the zone of unfragmented formation most remote from the free face.

Claim 130

Dependent Claim 61 words

The method according to claim 112 comprising forming the array of main explosive charges and the array of satellite explosive charges by: placing a first explosive charge into each blasthole for forming the array of main explosive charges; and placing a second explosive charge into at least a portion of such blastholes for forming such an array of satellite explosive charges.

Claim 131

Dependent Claim 24 words

The method according to claim 112 comprising detonating such a main explosive charge and satellite explosive charge located in the same blasthole substantially simultaneously.

Claim 132

Dependent Claim 101 words

The method according to claim 112 comprising: forming a first substantially rectangular array of spaced apart blastholes; forming a second substantially rectangular array of spaced apart blastholes, such a second array having substantially the same spacing distance as the first array and such a second array being diagonally offset from such first array by less than about the spacing distance; placing explosive in each blasthole of the first substantially rectangular array for forming such an array of main explosive charges; and placing explosive in each blasthole of the second substantially rectangular array for forming such an array of satellite explosive charges.

Claim 133

Dependent Claim 45 words

The method according to claim 112 comprising providing at least one group of main explosive charges and at least one group of satellite explosive charges wherein a first group of main explosive charges is detonated substantially simultaneously with a first group of satellite explosive charges.

Claim 134

Dependent Claim 87 words

The method according to claim 112 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes and forming a second substantially rectangular array of spaced apart blastholes; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the first substantially rectangular array and in each blasthole of the second substantially rectangular array for forming such an array of satellite explosive charges.

Claim 135

Independent Claim 214 words

A method for forming an in situ oil shale retort within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation leaving a zone of unfragmented formation above such a void having a substantially horizontal free face adjoining the void; forming a plurality of spaced apart substantially vertical blastholes in an array extending across the zone of unfragmented formation; placing explosive into such blastholes for forming an array of main explosive charges and at least one array of satellite explosive charges, wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges and the ratio of actual depth of burial to spacing distance of the satellite explosive charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges; and detonating the explosive charges in the blastholes in a single round of explosions for explosively expanding the zone of unfragmented formation toward the void for forming a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort.

Claim 136

Independent Claim 214 words

A method for forming an in situ oil shale retort within a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale comprising the steps of: forming at least one void in the subterranean formation leaving a zone of unfragmented formation above such a void having a substantially horizontal free face adjoining the void; forming a plurality of spaced apart substantially vertical blastholes in an array extending across the zone of unfragmented formation; placing explosive into such blastholes for forming an array of main explosive charges and at least one array of satellite explosive charges, wherein the actual depth of burial of each of the satellite explosive charges is less than the actual depth of burial of each of the main explosive charges and the ratio of actual depth of burial to spacing distance of the satellite explosive charges is less than the ratio of actual depth of burial to spacing distance of the main explosive charges; and detonating the explosive charges in the blastholes in a single round of explosions for explosively expanding the zone of unfragmented formation toward the void for forming a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort.

Claim 137

Dependent Claim 51 words

The method according to claim 119 wherein the length of each of the main explosive charges is about one-half the thickness of the zone of unfragmented formation and wherein such a main explosive charge is located in the portion of the zone of unfragmented formation most remote from the free face.

Claim 138

Dependent Claim 109 words

The method according to claim 119 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes; forming a second substantially rectangular array of spaced apart blastholes, such a second array having substantially the same spacing distance as the first array and such a second array being diagonally offset from such first array by less than about the spacing distance; placing explosive into each blasthole of the first substantially rectangular array for forming such an array of main explosive charges; and placing explosive into each blasthole of the second substantially rectangular array for forming such an array of satellite charges.

Claim 139

Dependent Claim 45 words

The method according to claim 119 comprising providing at least one group of main explosive charges and at least one group of satellite explosive charges wherein a first group of main explosive charges is detonated substantially simultaneously with a first group of satellite explosive charges.

Claim 140

Dependent Claim 87 words

The method according to claim 119 wherein the steps of forming blastholes and placing explosive comprise: forming a first substantially rectangular array of spaced apart blastholes and forming a second substantially rectangular array of spaced apart blastholes; placing explosive in each blasthole of the first substantially rectangular array for forming the array of main explosive charges; and placing explosive in each blasthole of the first substantially rectangular array and in each blasthole of the second substantially rectangular array for forming such an array of satellite explosive charges.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1985-04-26	1985-10-26	1986-04-27	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1989-04-26	1989-10-26	1990-04-27	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1993-04-26	1993-10-26	1994-04-27	$7700.00	Window Closed / Lapsed

Blasting to a horizontal free face with mixing of fragments

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