Patent US3602311A successfully refreshed from Google Patents.
US3602311A
Expired / Lapsed
US
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Pressure pulse hydraulic fracturing for subsurface formations
Assignee: Western Company of North America
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Filing: 1970-01-23
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Granted: 1971-08-31
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Expires: 1990-01-23
Abstract
Abstract Subsurface formations are fractured by a process wherein a first path of flow of a fracturing fluid is established from a pump through a flow control-hammer valve, and a second path of flow is established to the formation to be fractured from a point between the pump and the valve, the pressure of the fluid against the formation from the second path of flow being controlled at a predetermined level, preferably slightly less than the formation fracture pressure, by controlling the fluid flow through the valve in the first path of flow. Next, the flow through the valve is instantaneously terminated to cause a pressure pulse to be transmitted through the second path of flow and against the formation and to cause fracturing thereof. In one embodiment, a rarefaction pulse is transmitted down the second path of flow a spaced distance behind the pressure pulse to cause a decay of the pressure pulse after it has reflected from the formation and before it radiates up the well casing and damages the system.
Inventors
- 👤 Norman F Whitsitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:32
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/25; E21B43/26; E21B43/2607
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
156 words
A method of fracturing a subterranean formation penetrated by a well bore comprising: a. establishing a first path of flow of a fracturing fluid from a pumping zone through a flow control zone; b. establishing a second path of flow of said fracturing fluid from a point between said pumping zone and said flow control zone to said formation to be fractured; c. controlling the flow of said fracturing fluid through said flow control zone to thereby establish a predetermined prefracturing pressure against said formation to be fractured; d. instantaneously terminating said first path of flow through said flow control zone while maintaining said flow through said pumping zone to yield a fracturing pulse which is transmitted down said second path of flow and against said formation to cause the fracturing thereof; and e. transmitting a rarefaction pulse down said second path of flow to thereby decay said fracturing pulse within said formation after said fracturing.
Claim 2
Independent Claim
156 words
A method of fracturing a subterranean formation penetrated by a well bore comprising: a. establishing a first path of flow of a fracturing fluid from a pumping zone through a flow control zone; b. establishing a second path of flow of said fracturing fluid from a point between said pumping zone and said flow control zone to said formation to be fractured; c. controlling the flow of said fracturing fluid through said flow control zone to thereby establish a predetermined prefracturing pressure against said formation to be fractured; d. instantaneously terminating said first path of flow through said flow control zone while maintaining said flow through said pumping zone to yield a fracturing pulse which is transmitted down said second path of flow and against said formation to cause the fracturing thereof; and e. transmitting a rarefaction pulse down said second path of flow to thereby decay said fracturing pulse within said formation after said fracturing.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein said predetermined pressure is slightly below the fracture pressure of said formation.
Claim 4
Dependent Claim
22 words
The method of claim 2 wherein said predetermined pressure is at least about 40 percent of the fracture pressure of said formation.
Claim 5
Dependent Claim
22 words
The method of claim 1 wherein said pumping zone and said flow control zone are located above the surface of the earth.
Claim 6
Independent Claim
192 words
A method of fracturing a subterranean formation penetrated by a well bore comprising: a. establishing a first path of flow of a fracturing fluid from a pumping zone through flow control zone; b. establishing a second path of flow of flow said fracturing fluid from a point between said pumping zone and said flow control zone to said formation to be fractured; c. controlling the flow of said fracturing fluid through said flow control zone to thereby establish a predetermined prefracturing pressure against said formation to be fractured; d. instantaneously terminating said first path of flow through said flow control zone while maintaining said flow through said pumping zone to yield a fracturing pulse which is transmitted down said second path of flow and against said formation to cause the fracturing thereof; and e. imparting a rarefaction pulse to the fluid in said second path of flow which is sufficient to cause decay of said fracturing pulse in a manner so that said rarefaction pulse follows said fracturing pulse a spaced linear distance that is at least the length of said formation to be fractured which is traversed by said well bore.
Claim 7
Independent Claim
192 words
A method of fracturing a subterranean formation penetrated by a well bore comprising: a. establishing a first path of flow of a fracturing fluid from a pumping zone through flow control zone; b. establishing a second path of flow of flow said fracturing fluid from a point between said pumping zone and said flow control zone to said formation to be fractured; c. controlling the flow of said fracturing fluid through said flow control zone to thereby establish a predetermined prefracturing pressure against said formation to be fractured; d. instantaneously terminating said first path of flow through said flow control zone while maintaining said flow through said pumping zone to yield a fracturing pulse which is transmitted down said second path of flow and against said formation to cause the fracturing thereof; and e. imparting a rarefaction pulse to the fluid in said second path of flow which is sufficient to cause decay of said fracturing pulse in a manner so that said rarefaction pulse follows said fracturing pulse a spaced linear distance that is at least the length of said formation to be fractured which is traversed by said well bore.
Claim 8
Dependent Claim
28 words
The method of claim 5 wherein said spaced linear distance is about twice the length of said formation to be fractured which is traversed by said well bore.
Claim 9
Dependent Claim
43 words
The method of claim 5 wherein said rarefaction pulse is formed by decaying the pressure pulse emitted toward said pump by said instantaneous terminating at a distance from said point to said pump which corresponds to at least one-half of said linear distance.
Claim 10
Dependent Claim
41 words
The method of claim 5 wherein said decay occurs in said first stream at a distance from said point to said pump which corresponds to about the length of said formation to be fractured which is traversed by said well bore.
Claim 11
Independent Claim
147 words
An apparatus positioned upon the surface of the earth for fracturing a subsurface formation penetrated by a well bore comprising: a. a pumping means for imparting a constant motion to a fracturing fluid; b. a valve means for controlling flow of said fracturing fluid, and adapted to instantaneously terminate flow of said fracturing fluid therethrough to thereby impart a fracturing pulse in said fracturing fluid; c. first conduit means communicating between the outlet of said pumping means and the inlet of said valve means; d. second conduit means communicating between said first conduit means and said well bore at a point between said pumping means and said valve means; and e. pressure decay means positioned in said first conduit means at a point between said second conduit means and said pumping means to impart a rarefaction pulse in said fracturing fluid sufficient to decay said fracturing pulse.
Claim 12
Independent Claim
147 words
An apparatus positioned upon the surface of the earth for fracturing a subsurface formation penetrated by a well bore comprising: a. a pumping means for imparting a constant motion to a fracturing fluid; b. a valve means for controlling flow of said fracturing fluid, and adapted to instantaneously terminate flow of said fracturing fluid therethrough to thereby impart a fracturing pulse in said fracturing fluid; c. first conduit means communicating between the outlet of said pumping means and the inlet of said valve means; d. second conduit means communicating between said first conduit means and said well bore at a point between said pumping means and said valve means; and e. pressure decay means positioned in said first conduit means at a point between said second conduit means and said pumping means to impart a rarefaction pulse in said fracturing fluid sufficient to decay said fracturing pulse.
Claim 13
Dependent Claim
52 words
The apparatus of claim 9 further comprising: a. a reservoir means for holding a supply of the fracturing fluid; b. third conduit means communicating between said reservoir means and the inlet of said pumping means; and c. fourth conduit means communicating between the outlet of said valve means and said reservoir means.
Claim 14
Dependent Claim
60 words
The apparatus of claim 10 further comprising a fifth conduit means communicating between said reservoir and a point in said first conduit means between said pumping means and said second conduit means, and having a check valve means operatively positioned therein to allow fluid flow therethrough only from the first conduit to said reservoir in response to said fracturing pulse.
Claim 15
Dependent Claim
55 words
The apparatus of claim 11 wherein the length of said first conduit means from the intersection of said second conduit means with said first conduit means to said pressure decay means is at least about one-half the length to about the length of said formation to be fractured which is traversed by said well bore.
Claim 16
Independent Claim
168 words
An apparatus for fracturing a subsurface formation penetrated by a well bore comprising: a. a pumping means for imparting a constant motion to a fracturing fluid; b. a valve means for controlling fluid of said fracturing fluid, and adapted to instantaneously terminate flow of said fracturing fluid therethrough; c. a first conduit means communicating between the outlet of said pumping means and the inlet of said valve means; d. second conduit means communicating between said first conduit means and said well bore at a point between said pumping means and said valve means, and e. a pressure decay means positioned in said first conduit means at a point between said second conduit means and said pumping means, and wherein the length of said first conduit means from the intersection of said second conduit means with said first conduit means to said pressure decay means is at least about one-half the length to about the length of said formation to be fractured, which is traversed by said well bore.
Claim 17
Independent Claim
168 words
An apparatus for fracturing a subsurface formation penetrated by a well bore comprising: a. a pumping means for imparting a constant motion to a fracturing fluid; b. a valve means for controlling fluid of said fracturing fluid, and adapted to instantaneously terminate flow of said fracturing fluid therethrough; c. a first conduit means communicating between the outlet of said pumping means and the inlet of said valve means; d. second conduit means communicating between said first conduit means and said well bore at a point between said pumping means and said valve means, and e. a pressure decay means positioned in said first conduit means at a point between said second conduit means and said pumping means, and wherein the length of said first conduit means from the intersection of said second conduit means with said first conduit means to said pressure decay means is at least about one-half the length to about the length of said formation to be fractured, which is traversed by said well bore.
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) | 1974-08-30 | 1975-03-01 | 1975-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-30 | 1979-03-01 | 1979-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-30 | 1983-03-01 | 1983-08-31 | $7700.00 | Window Closed / Lapsed |