US3700034A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for well cleanout
Assignee: Chevron USA Inc
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Filing: 1971-03-11
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Granted: 1972-10-24
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Expires: 1991-03-11
Abstract
Abstract A method of well cleanout by circulating preformed foam in a well through a segmented tubing string and the annulus between the tubing string and the well wall to remove sand and fluids from the well. Check valve means are placed in the segmented tubing string at preselected positions to maintain control over the foam in the well while foam injection is temporarily halted to permit addition of another tubular section to the tubing string. The check valve means insures that the foam in the well remains in a dynamic condition during such temporary halts so as to prevent sticking of the tubing string in the well.
Inventors
- 👤 Stanley O Hutchison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:03
CPC Classifications
E; E21; E21B; E21B37/00; E21B21/00; E21B21/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
145 words
A method for cleaning undesirable material from a well utilizing an aqueous-gas foam circulating medium comprising inserting an elongated tubing string into a well, said tubing string being formed by successively connecting together a plurality of pipe sections, lowering the so-formed tubing string into the well until the lower end of the tubing string reaches the undesirable material which is to be removed from the well, then connecting a downwardly opening check valve into the tubing string near the upper end thereof, said check valve permitting flow of foam down the tubing string but preventing flow of foam up the tubing string and injecting foam down the tubing string through said check valve at a velocity less than the critical velocity required to break the foam into separate liquid and gas phases and into said well to assist in removing undesirable material from the well.
Claim 2
Independent Claim
145 words
A method for cleaning undesirable material from a well utilizing an aqueous-gas foam circulating medium comprising inserting an elongated tubing string into a well, said tubing string being formed by successively connecting together a plurality of pipe sections, lowering the so-formed tubing string into the well until the lower end of the tubing string reaches the undesirable material which is to be removed from the well, then connecting a downwardly opening check valve into the tubing string near the upper end thereof, said check valve permitting flow of foam down the tubing string but preventing flow of foam up the tubing string and injecting foam down the tubing string through said check valve at a velocity less than the critical velocity required to break the foam into separate liquid and gas phases and into said well to assist in removing undesirable material from the well.
Claim 3
Dependent Claim
51 words
The method of claim 1 further characterized by connecting a second downwardly opening check valve into the tubing string near the bottom end thereof and passing foam through said second check valve at a velocity less than the critical velocity required to break the foam into separate liquid and gas phases.
Claim 4
Independent Claim
145 words
A method for cleaning undesirable material from a well utilizing an aqueous-gas foam circulating medium comprising inserting an elongated tubing string into a well, said tubing string being formed by successively connecting together a plurality of pipe sections, lowering the so-formed tubing string into the well until the lower end of the tubing string reaches the undesirable material which is to be removed from the well, then connecting a downwardly opening flapper valve into the tubing string near the upper end thereof, said flapper valve permitting flow of foam down the tubing string but preventing flow of foam up the tubing string and injecting foam down the tubing string through said flapper valve at a velocity less than the critical velocity required to break the foam into separate liquid and gas phases and into said well to assist in removing undesirable material from the well.
Claim 5
Independent Claim
145 words
A method for cleaning undesirable material from a well utilizing an aqueous-gas foam circulating medium comprising inserting an elongated tubing string into a well, said tubing string being formed by successively connecting together a plurality of pipe sections, lowering the so-formed tubing string into the well until the lower end of the tubing string reaches the undesirable material which is to be removed from the well, then connecting a downwardly opening flapper valve into the tubing string near the upper end thereof, said flapper valve permitting flow of foam down the tubing string but preventing flow of foam up the tubing string and injecting foam down the tubing string through said flapper valve at a velocity less than the critical velocity required to break the foam into separate liquid and gas phases and into said well to assist in removing undesirable material from the well.
Claim 6
Dependent Claim
23 words
The method of claim 3 further characterized by connecting a downwardly opening flapper valve into the tubing string near the bottom end thereof.
Claim 7
Independent Claim
152 words
A method of circulating foam into a well comprising inserting an elongated tubiNg string into a well, said tubing string being formed by successively connecting together a plurality of pipe sections, lowering the so-formed tubing string into the well, connecting a downwardly opening flapper valve into the tubing string near the upper end thereof, said flapper valve permitting flow of foam down the tubing string but preventing flow of foam up the tubing string, preforming on the surface a gas-liquid foam, said foam formed from an aqueous surfactant solution and a gas and having a gas to liquid volume ratio in the range of 3-50: 1, flowing said foam to the upper end of said tubing string and injecting said foam down said tubing string through said flapper valve at a velocity less than the critical velocity required to break the foam into separate liquid and gas phases and into said well.
Claim 8
Independent Claim
152 words
A method of circulating foam into a well comprising inserting an elongated tubiNg string into a well, said tubing string being formed by successively connecting together a plurality of pipe sections, lowering the so-formed tubing string into the well, connecting a downwardly opening flapper valve into the tubing string near the upper end thereof, said flapper valve permitting flow of foam down the tubing string but preventing flow of foam up the tubing string, preforming on the surface a gas-liquid foam, said foam formed from an aqueous surfactant solution and a gas and having a gas to liquid volume ratio in the range of 3-50: 1, flowing said foam to the upper end of said tubing string and injecting said foam down said tubing string through said flapper valve at a velocity less than the critical velocity required to break the foam into separate liquid and gas phases and into said well.
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) | 1975-10-24 | 1976-04-24 | 1976-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-24 | 1980-04-24 | 1980-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-24 | 1984-04-24 | 1984-10-24 | $7700.00 | Window Closed / Lapsed |