US3743017A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Use of fluidic pressure fluctuation generator to stimulate underground formations
Assignee: BP America Production Co
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Filing: 1972-04-21
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Granted: 1973-07-03
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Expires: 1992-04-21
Abstract
Abstract This invention concerns the use of a fluidic pressure fluctuation generator in a well bore to stimulate a subsurface formation. The generator is connected to the lower end of a string of tubing or drill pipe and is suspended in a well bore adjacent the formation interval to be stimulated or fractured. A fluid is pumped down the tubing string and through the fluidic generator and returned to the surface through the annulus between the tubing string and the wall of the well bore. A backpressure is held at the surface on the returning fluid such that the hydrostatic pressure Ph of the fluid in the well bore at any level is less than the hydraulic fracturing pressure but sufficiently great so that Ph plus the maximum pressure increase Pm caused by said fluidic pressure fluctuation generator is sufficient to fracture the formation. Other formation stimulation methods are also described.
Inventors
- 👤 R Veatch
- 👤 C Fast
- 👤 L Wilder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:10
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/003; E21B43/25; E21B43/26
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
144 words
A method of fracturing a selected formation penetrated by a well bore which comprises the steps of: pumping a fracturing fluid down said well bore through a tubing string; converting a portion of the energy of said fracturing fluid into acoustical vibrations at a level adjacent said formation to be fractured to cause positive pressure variations of Pm; transmitting said acoustic vibrations to the fluid in the well bore adjacent the formation to be fractured; returning said fracturing fluid to the surface through the annular space external of said tubing string; holding a backpressure at the surface on the returning fluid in the annulus such that the hydrostatic pressure Ph of the fluid in the well bore at the level of said formation is less tHan the hydraulic fracturing pressure but sufficiently great so that Pm plus Ph is sufficient to fracture said formation.
Claim 2
Independent Claim
144 words
A method of fracturing a selected formation penetrated by a well bore which comprises the steps of: pumping a fracturing fluid down said well bore through a tubing string; converting a portion of the energy of said fracturing fluid into acoustical vibrations at a level adjacent said formation to be fractured to cause positive pressure variations of Pm; transmitting said acoustic vibrations to the fluid in the well bore adjacent the formation to be fractured; returning said fracturing fluid to the surface through the annular space external of said tubing string; holding a backpressure at the surface on the returning fluid in the annulus such that the hydrostatic pressure Ph of the fluid in the well bore at the level of said formation is less tHan the hydraulic fracturing pressure but sufficiently great so that Pm plus Ph is sufficient to fracture said formation.
Claim 3
Dependent Claim
46 words
A method as defined in claim 1 including the step of pumping a slug of formation treating fluid down said tubing string so that at least a portion of said treating fluid is injected into said formation by the combination of pressures of Pm and Ph.
Claim 4
Dependent Claim
75 words
A method as defined in claim 1 including the steps of: reducing the rate of pumping of fracturing fluid through said tubing string so that Pm plus Ph is now less than the pressure required to fracture the formation; stopping the return of fracturing fluid to the surface through the annular space and thereafter injecting a fracturing fluid down the annulus at a pressure below the fracture initiation pressure but above the fracture opening pressure.
Claim 5
Dependent Claim
23 words
A method as defined in claim 3 which includes the step of adding propping agents to the fracturing fluid injected down the annulus.
Claim 6
Independent Claim
194 words
A method of fracturing a selected formation penetrated by a well bore which comprises the steps of: pumping a fluid down a tubing string suspended in said well bore; converting a portion of the energy of said circulating fluid into acoustical vibrations by means of a fluidic pressure fluctuation generator suspended in the well bore adjacent said selected formation; transmitting said acoustic vibrations from the fluidic pressure fluctuation generator to the fluid in the well bore at the level of the selected formation so that said fluid at said level has a positive pressure variation peak of Pm; acoustically isolating the acoustic vibrations to the region in the well bore adjacent said selected formation; returning said circulating fluid to the surface through an annular space exterior of the tubing string; maintaining a backpressure on the returning circulating fluid, said backpressure being limited such that the hydrostatic pressure in the well bore at any level is less than the formation breakdown pressure to which the fluid is exposed but in which Pm plus the hydrostatic pressure in the well bore adjacent the selected formation exceeds its fracturing pressure so that said selected formation is fractured.
Claim 7
Independent Claim
194 words
A method of fracturing a selected formation penetrated by a well bore which comprises the steps of: pumping a fluid down a tubing string suspended in said well bore; converting a portion of the energy of said circulating fluid into acoustical vibrations by means of a fluidic pressure fluctuation generator suspended in the well bore adjacent said selected formation; transmitting said acoustic vibrations from the fluidic pressure fluctuation generator to the fluid in the well bore at the level of the selected formation so that said fluid at said level has a positive pressure variation peak of Pm; acoustically isolating the acoustic vibrations to the region in the well bore adjacent said selected formation; returning said circulating fluid to the surface through an annular space exterior of the tubing string; maintaining a backpressure on the returning circulating fluid, said backpressure being limited such that the hydrostatic pressure in the well bore at any level is less than the formation breakdown pressure to which the fluid is exposed but in which Pm plus the hydrostatic pressure in the well bore adjacent the selected formation exceeds its fracturing pressure so that said selected formation is fractured.
Claim 8
Dependent Claim
64 words
A method as defined in claim 5 which includes pumping the fluid down the tubing string at a constant rate, holding a constant backpressure on the returning circulating fluid, measuring the flow of fluid from the annular space and pumping not over about 20 barrels of circulating fluid down said tubing string after a sharp drop in flow rate from the annular space occurs.
Claim 9
Dependent Claim
35 words
A method as defined in claim 6 including the step of moving said fluidic vibration generator to the level of a second formation to be fractured and thereafter repeating the method defined in claim 5.
Claim 10
Dependent Claim
35 words
A method as defined in claim 5 in which the amount of fluid injected after the sharp drop in rate of fluid flow from the said annular space is in the range of 5-20 barrels.
Claim 11
Independent Claim
167 words
A method of stimulating a selected formation penetrated by a well bore which comprises the steps of: positioning a fluidic pressure fluctuation generator at the lower end of a tubing string in the well bore adjacent the formation to be treated; pumping a fluid down said tubing string to convert a portion of the energy of said fluid into pressure vibrations by means of said generator having a positive pressure variation peak of Pm; acoustically isolating the pressure vibrations to the region in the well bore adjacent said selected formation; returning said fluid to the surface through the annular space external of said tubing string; holding a backpressure at the surface on said returning fluid, said backpressure being such that the hydrostatic pressure Ph at any level is less than the fracturing pressure; injecting a slug of formation treating fluid down said tubing string through said generatoR so that the pressure Pm generated by the said generator drives a portion of said treating fluid into said formation.
Claim 12
Independent Claim
167 words
A method of stimulating a selected formation penetrated by a well bore which comprises the steps of: positioning a fluidic pressure fluctuation generator at the lower end of a tubing string in the well bore adjacent the formation to be treated; pumping a fluid down said tubing string to convert a portion of the energy of said fluid into pressure vibrations by means of said generator having a positive pressure variation peak of Pm; acoustically isolating the pressure vibrations to the region in the well bore adjacent said selected formation; returning said fluid to the surface through the annular space external of said tubing string; holding a backpressure at the surface on said returning fluid, said backpressure being such that the hydrostatic pressure Ph at any level is less than the fracturing pressure; injecting a slug of formation treating fluid down said tubing string through said generatoR so that the pressure Pm generated by the said generator drives a portion of said treating fluid into said formation.
Claim 13
Dependent Claim
25 words
A method as defined in claim 9 in which the sum of the pressures Pm and Ph is below the fracturing pressure of the formation.
Claim 14
Dependent Claim
50 words
A method as defined in claim 9 in which sufficient formation treating fluid is injected to fill the tubing string from the surface to the said generator and then suddenly increasing the injection rate of fluid into said tubing string so that there is a sudden buildup of pressure Ph.
Claim 15
Dependent Claim
36 words
A method as defined in claim 9 in which a constant backpressure is held throughout the treatment and then injecting the treating fluid at an increased rate over the prior injection rate of the prior fluid.
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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) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |