Patent US3201421A successfully refreshed from Google Patents.
US3878884A
Expired / Lapsed
US
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Formation fracturing method
Assignee: Individual
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Filing: 1973-04-02
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Granted: 1975-04-22
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Expires: 1993-04-02
Abstract
Abstract A method for producing multiple fractures in earth formations in which the lines of least principal stress deviate substantially from vertical is described. A generally vertical borehole is drilled into the formation, the formation is hydraulically fractured from the vertical borehole, the plane in which the fracture lies is determined, a slanted borehole is drilled out from the vertical borehole in a direction such that the azimuth of slanted borehole is generally perpendicular to the plane of the fracture and then the formation adjacent the slanted borehole is hydraulically fractured at a plurality of positions along the length of the slanted borehole. When the direction of lines of least principal stress is known for the formation, the steps of hydraulically fracturing from the vertical borehole and determining the plane in which the fracture lies may be omitted and the slanted borehole is drilled in the azimuth parallel to the known lines of least principal stress.
Inventors
- 👤 Cecil B Raleigh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:39
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/25; E21B43/26; E21B43/16; E21B43/17; F; F24; F24T; F24T10/00; F24T10/30; Y; Y02; Y02E; Y02E10/00; Y02E10/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
105 words
A method of opening an earth formation in which the lines of least principal stress deviate substantially from the vertical to facilitate recovery of a resource held in the formation which comprises the steps of: a. drilling an approximately vertical borehole into the formation; b. drilling a slanted borehole extending from the vertical borehole into the formation in a direction such that the angle between the slanted borehole and the lines of least principal stress in the formation is not more than 60*; and c. hydraulically fracturing the formation adjacent the slanted borehole at a plurality of positions along the length of the slanted borehole.
Claim 2
Independent Claim
105 words
A method of opening an earth formation in which the lines of least principal stress deviate substantially from the vertical to facilitate recovery of a resource held in the formation which comprises the steps of: a. drilling an approximately vertical borehole into the formation; b. drilling a slanted borehole extending from the vertical borehole into the formation in a direction such that the angle between the slanted borehole and the lines of least principal stress in the formation is not more than 60*; and c. hydraulically fracturing the formation adjacent the slanted borehole at a plurality of positions along the length of the slanted borehole.
Claim 3
Independent Claim
134 words
The method of opening an earth formation in which the lines of least principal stress deviate substantially from the vertical to permit recovery of a resource held in the formation which comprises the steps of: a. drilling an approximately vertical borehole in the earth formation; b. hydrofracturing the formation adjacent the lower portion of the borehole; c. determining the plane in which the fracture lies; d. drilling a slanted borehole extending from the vertical borehole into the formation in a direction such that the angle between the slanted borehole and the perpendicular to any plane parallel to the plane determined in step (c) which is intersected by the borehole is less than 60*; and e. hydrofracturing the formation adjacent the slanted borehole at a plurality of positions along the length of the slanted borehole.
Claim 4
Independent Claim
134 words
The method of opening an earth formation in which the lines of least principal stress deviate substantially from the vertical to permit recovery of a resource held in the formation which comprises the steps of: a. drilling an approximately vertical borehole in the earth formation; b. hydrofracturing the formation adjacent the lower portion of the borehole; c. determining the plane in which the fracture lies; d. drilling a slanted borehole extending from the vertical borehole into the formation in a direction such that the angle between the slanted borehole and the perpendicular to any plane parallel to the plane determined in step (c) which is intersected by the borehole is less than 60*; and e. hydrofracturing the formation adjacent the slanted borehole at a plurality of positions along the length of the slanted borehole.
Claim 5
Dependent Claim
22 words
The method defined in claim 2 wherein the angle between the borehole and the perpendicular to the plane is less than 30*.
Claim 6
Dependent Claim
75 words
The method defined in claim 1 characterized by a further step of drilling a second vertical borehole adjacent the first borehole and a second slanted borehole extending from the second vertical borehole into the formation generally parallel to the first sLanted borehole and spaced from the first slanted borehole by a distance such that the second slanted borehole intersects at least a major proportion of the formation fractures produced in step (c) of claim 1.
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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) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |