Patent US4248303A successfully refreshed from Google Patents.
US4248303A
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Explosive well-fracturing system
Assignee: XPLO CORP
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Filing: 1978-12-01
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Granted: 1981-02-03
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Expires: 1998-12-01
Abstract
Abstract Method of and apparatus for fracturing and creating multiple fissures in hydrocarbon impregnated rock. The invention uses a sequence of explosive charges involving a main, centrally located high velocity, shape charge shot directed out horizontally into the stratum to be fractured, and two supplemental charges of bulk explosives of a lower detonation velocity positioned above and below the main shot and simultaneously detonated following the main charge, the purpose of the sequence and the physical arrangements being to effect greater penetration of the stratum. In the preferred embodiment a metal shaped charge containing a liquid explosive is used for the centrally located main shot comprising a number of longitudinally extended tined spokes directed radially outward from a common center (note FIG. 3). The diameter of the shaped charge can be varied to fit and preferably generally fills up the diameter of the well bore.
Inventors
- 👤 John J. Charpentier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:30
CPC Classifications
F; F42; F42D; F42D1/00; E; E21; E21B; E21B43/00; E21B43/25; E21B43/26; E21B43/263
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
106 words
The method of fracturing wells comprising the following steps: (a) positioning in the well holes a first, relatively low velocity, supplemental explosive charge at a position below the area to be fractured; (b) positioning in the well hole a relatively high velocity, central explosive charge at a position next to the area to be fractured and adjacent said first charge; (c) positioning in the well hole a second, relatively low velocity supplemental explosive charge at a position above the area to be fractured and adjacent the top of said central charge, (d) detonating said central charge; and (e) thereafter detonating said first and second supplemental charges.
Claim 2
Independent Claim
106 words
The method of fracturing wells comprising the following steps: (a) positioning in the well holes a first, relatively low velocity, supplemental explosive charge at a position below the area to be fractured; (b) positioning in the well hole a relatively high velocity, central explosive charge at a position next to the area to be fractured and adjacent said first charge; (c) positioning in the well hole a second, relatively low velocity supplemental explosive charge at a position above the area to be fractured and adjacent the top of said central charge, (d) detonating said central charge; and (e) thereafter detonating said first and second supplemental charges.
Claim 3
Dependent Claim
15 words
The method of claim 1 wherein in step "e" the supplemental charges are detonated simultaneously.
Claim 4
Dependent Claim
23 words
The method of claim 2 wherein in step "e" the supplemental charges are detonated within a few microseconds of detonating the central charge.
Claim 5
Dependent Claim
29 words
The method of claim 1 wherein in steps "a" and "c" said first and second supplemental charges are positioned by placing in the hole explosives in loose bulk form.
Claim 6
Dependent Claim
48 words
The method of claim 4 wherein in step "b" said central charge is provided in the form of an elongated body with the explosive located in the central area thereof behind longitudinally extending "V" shaped air stand-off areas and is lowered down in the hole in unitary form.
Claim 7
Dependent Claim
136 words
An explosive system for fracturing a well comprising: a first, lower, relatively low velocity, supplemental explosive charge in bulk form; a relatively high velocity, central explosive shaped charge comprising a cylindrical metal member containing a liquid explosive in its cental area extending axially at least substantially the full axial length of said cylindrical member and surrounded by longitudinally extending air stand-off areas in said cylindrical member having at least a general "V" shape to each of them with their apexes located to the inside of said cylindrical members; and a second, upper, relatively low velocity, supplemental explosive charge in bulk form; said three charges being associated for positioning in the hole with said central charge located adjacent the area to be fractured with said first and second supplemental charges being located below and above it respectively.
Claim 8
Dependent Claim
136 words
An explosive system for fracturing a well comprising: a first, lower, relatively low velocity, supplemental explosive charge in bulk form; a relatively high velocity, central explosive shaped charge comprising a cylindrical metal member containing a liquid explosive in its cental area extending axially at least substantially the full axial length of said cylindrical member and surrounded by longitudinally extending air stand-off areas in said cylindrical member having at least a general "V" shape to each of them with their apexes located to the inside of said cylindrical members; and a second, upper, relatively low velocity, supplemental explosive charge in bulk form; said three charges being associated for positioning in the hole with said central charge located adjacent the area to be fractured with said first and second supplemental charges being located below and above it respectively.
Claim 9
Dependent Claim
42 words
The system of claim 6 wherein the diameter of said cylindrical member is comparable to the diameter of the hole to thereby fill up the hole with the exterior surface of said cylindrical member being in near face-to-face engagement with the hole.
Claim 10
Dependent Claim
33 words
The system of claim 6 wherein there is further included detonation means associated with said three charges for initially detonating said central charge and thereafter detonating said supplemental charges simultaneously with each other.
References Cited (Backward Citations)
US2251712A
Cited
US2789504A
Cited
US2921519A
Cited
US2775940A
Cited
US2831429A
Cited
US2837027A
Cited
US4018293A
Cited
US4081031A
Cited
US4091870A
Cited
US4160412A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-03 | 1984-08-04 | 1985-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-03 | 1988-08-04 | 1989-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-03 | 1992-08-04 | 1993-02-03 | $7700.00 | Window Closed / Lapsed |