US3848674A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for fracturing oil and gas strata
Assignee: Individual
•
Filing: 1973-10-18
•
Granted: 1974-11-19
•
Expires: 1993-10-18
Abstract
Abstract A high pressure pipe has its lower end sealed in a well bore, and dispersed outlets are formed explosively through the pipe and seal at a fuel producing stratum of the well. A mechanically driven hydraulic pump connected to the top of the pipe fills the pipe and exposed surfaces of the stratum to be fractured with fracturing liquid at an intermediate pressure. A first valve in the pipe between the pump and the downwardly extending pipe is then closed. A second valve connecting the upper end of the pipe with an explosion chamber is closed while an explosive charge in the nature of a blank artillery shell is locked in the explosion chamber. The second valve is opened and the charge is exploded to create a very high over-pressure in the pipe. The over-pressure transmitted through the liquid creates multiple radiating fractures in the stratum. The valves are then reversed and the pump is again operated to force more fluid plus a quantity of a granular proppant such as fine sand into the newly created fractures. The explosive step may be repeated with the same or progressively stronger explosive charges.
Inventors
- 👤 A Mccoll
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:31
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/25; E21B43/26; E21B43/263
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
112 words
Apparatus for developing sub-stratum fracturing pressure from an adjacent portion of a well bore having a high pressure pipe extending to the top of the bore and having its lower end sealed to the bore along said stratum with pressure openings in the pipe and the seal comprising, means for introducing fracturing liquid into the top of said pipe, a means defining charge receiving and explosion chamber adapted to be connected to the top of said pipe in pressure transmitting relation to the interior of the pipe, and means for exploding an explosive charge in said chamber, said pipe and said chamber being capable of withstanding pressures of at least 2,000 p.s.i.
Claim 2
Dependent Claim
112 words
Apparatus for developing sub-stratum fracturing pressure from an adjacent portion of a well bore having a high pressure pipe extending to the top of the bore and having its lower end sealed to the bore along said stratum with pressure openings in the pipe and the seal comprising, means for introducing fracturing liquid into the top of said pipe, a means defining charge receiving and explosion chamber adapted to be connected to the top of said pipe in pressure transmitting relation to the interior of the pipe, and means for exploding an explosive charge in said chamber, said pipe and said chamber being capable of withstanding pressures of at least 2,000 p.s.i.
Claim 3
Dependent Claim
42 words
Apparatus as defined in claim 1 in which said means for introducing the liquid is a pump connected to said pipe, and a valve adapted to be closed between said pump and said chamber when a charge is exploded in the chamber.
Claim 4
Dependent Claim
26 words
Apparatus as defined in claim 2 which further includes: means for selectively introducing a quantity of granular proppant material into the liquid delivered by said pump.
Claim 5
Dependent Claim
37 words
Apparatus as defined in claim 3 in which there is a second valve connected between said chamber and said pipe and adapted to be closed to isolate said chamber from said pump while said pump is operating.
Claim 6
Dependent Claim
30 words
Apparatus as defined in claim 4 in which said chamber has a breech closed opening at the rear and is permanently connected at its front end to said second valve.
Claim 7
Dependent Claim
22 words
Apparatus as defined in claim 3 in which there is a pressure gauge means connected to said pipe to indicate pressure therein.
Claim 8
Dependent Claim
36 words
Apparatus as defined in claim 1 in which there are plural explosion chambers associated with said pipe, and means for successively bringing each chamber into communication with said pipe to the exclusion of the other chambers.
Claim 9
Dependent Claim
54 words
Apparatus as defined in claim 7 in which said means for bringing said chambers into communication with said pipe includes a body rotatable on said pipe and having said chambers mounted thereon and opening therethrough, said port means in said pipe adapted to register with different chambers in different rotated positions of said body.
Claim 10
Independent Claim
96 words
The method of stimulating the flow of fluid from wells by fracturing the fluid bearing stratum of the well which comprises the steps of: lowering a high pressure pipe into said well and forming a seal between said pipe and said stratum, forming flow openings through said pipe and said seal, filling said pipe with a substantially imcompressible fracturing liquid, connecting a charge receiving explosion chamber to the top of said pipe, and exploding a charge of explosive in said chamber to produce a pressure in excess of 2,000 p.s.i. in said pipe and said liquid.
Claim 11
Independent Claim
96 words
The method of stimulating the flow of fluid from wells by fracturing the fluid bearing stratum of the well which comprises the steps of: lowering a high pressure pipe into said well and forming a seal between said pipe and said stratum, forming flow openings through said pipe and said seal, filling said pipe with a substantially imcompressible fracturing liquid, connecting a charge receiving explosion chamber to the top of said pipe, and exploding a charge of explosive in said chamber to produce a pressure in excess of 2,000 p.s.i. in said pipe and said liquid.
Claim 12
Dependent Claim
29 words
The method as defined in claim 9 which comprises the further step of: introducing additional liquid with proppant granules therein into said stratum after said charge has been exploded.
Claim 13
Dependent Claim
21 words
The method as defined in claim 10 in which the step of introducing additional liquid is performed by a hydraulic pump.
Claim 14
Dependent Claim
38 words
The method as defined in claim 9 in which the step of filling said pipe is accomplished at an intermediate pressure not materially exceeding 1,200 p.s.i. but in excess of two atmospheres at the top of the pipe.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |