US3917347A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of developing a permeable underground zone
Assignee: Atlantic Richfield Co
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Filing: 1974-08-22
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Granted: 1975-11-04
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Expires: 1994-08-22
Abstract
Abstract A subterranean ore deposit, such as oil shale, is undercut to form a cavity of predetermined void volume. A specific block of the deposit overlaying this cavity is designated together with an intermediate level thereof. From a suitable working space, explosively charged primary blasting holes are drilled substantially horizontally into the block so as to provide a uniform explosive charge distribution therein below the intermediate level. At least one secondary blasting hole is driven downwardly into the block from the surface of the earth or from an upper mining level and explosively charged above the intermediate level. The primary and secondary explosives are detonated in upwardly progressing timed sequence. This results in expansion of the overlaying block into the cavity and fragmentation thereof in a cone-shaped configuration above the intermediate level.
Inventors
- 👤 Albert T Janssen
- 👤 Richfield Company Atlantic
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:03
CPC Classifications
E; E21; E21C; E21C41/00; E21C41/16; E21C41/24
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
103 words
A method of developing and shaping a permeable zone within a subterranean ore deposit so that it will have a lower portion of substantially constant horizontal cross-section below a predetermined level from which it tapers upwardly to an apex to form a cone-shaped upper portion comprising the steps of: a. placing an explosive charge into the deposit adjacent said apex; b. expanding a volume of said deposit underlying said predetermined level to form said lower portion; and c. thereafter detonating said explosive charge to produce cratering of said deposit between said apex and said predetermined level so as to form said upper portion.
Claim 2
Independent Claim
103 words
A method of developing and shaping a permeable zone within a subterranean ore deposit so that it will have a lower portion of substantially constant horizontal cross-section below a predetermined level from which it tapers upwardly to an apex to form a cone-shaped upper portion comprising the steps of: a. placing an explosive charge into the deposit adjacent said apex; b. expanding a volume of said deposit underlying said predetermined level to form said lower portion; and c. thereafter detonating said explosive charge to produce cratering of said deposit between said apex and said predetermined level so as to form said upper portion.
Claim 3
Dependent Claim
24 words
A method as in claim 1 comprising placing said explosive charge within a blasting hole drilled into said deposit in a substantially vertical direction.
Claim 4
Dependent Claim
18 words
A method as in claim 2 wherein said blasting hole extends downwardly from the surface of the earth.
Claim 5
Dependent Claim
17 words
A method as in claim 2 wherein said blasting hole extends downwardly from an upper mining level.
Claim 6
Dependent Claim
19 words
A method as in claim 2 wherein said blasting hole extends upwardly from the bottom of said lower portion.
Claim 7
Dependent Claim
14 words
A method as in claim 1 wherein said ore deposit is a carbonaceous material.
Claim 8
Dependent Claim
13 words
A method as in claim 1 wherein said ore deposit is oil shale.
Claim 9
Independent Claim
146 words
A method of forming an upright retort in a subterranean ore deposit wherein the base of the deposit is partially undercut to form a cavity therebeneath connecting with the surface, a designated block of the overlaying deposit being thereafter expanded to fill said cavity, the improvement comprising the steps of: a. providing a substantially vertically directed blasting hole extending into said block so that said blasting hole lies at least partially above a predetermined level of said block; b. charging said blasting hole with a length of explosive above said intermediate level; c. explosively fragmenting the portion of said designated block below said intermediate level to effect expansion thereof into said cavity; and d. thereafter detonating the explosive in said blasting hole to produce a downwardly widening crater of fragmented material of said designated block extending from the top of said explosive to said intermediate level.
Claim 10
Independent Claim
146 words
A method of forming an upright retort in a subterranean ore deposit wherein the base of the deposit is partially undercut to form a cavity therebeneath connecting with the surface, a designated block of the overlaying deposit being thereafter expanded to fill said cavity, the improvement comprising the steps of: a. providing a substantially vertically directed blasting hole extending into said block so that said blasting hole lies at least partially above a predetermined level of said block; b. charging said blasting hole with a length of explosive above said intermediate level; c. explosively fragmenting the portion of said designated block below said intermediate level to effect expansion thereof into said cavity; and d. thereafter detonating the explosive in said blasting hole to produce a downwardly widening crater of fragmented material of said designated block extending from the top of said explosive to said intermediate level.
Claim 11
Dependent Claim
21 words
A method as in claim 8 wherein said blasting hole is approximately centered within the cross-sectional dimensions of said designated block.
Claim 12
Dependent Claim
28 words
A method as in claim 8 wherein said at least one blasting hole is connected to a source of air and fuel adapted to ignite said fragmented ore.
Claim 13
Dependent Claim
47 words
A method as in claim 8 wherein said ore deposit comprises an upper low quality layer lying above and contiguous with A lower high quality layer and wherein said intermediate level of said detonated block is situated at the interface between said low and high quality layers.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |