US3782469A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Formation and wellbore scale prevention
Assignee: Cities Service Oil Co
•
Filing: 1972-05-25
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Granted: 1974-01-01
•
Expires: 1992-05-25
Abstract
Abstract Disclosed herein is a method for the reduction of the scale deposition in the formation and fractures about a producing wellbore. In particular, gypsum scale deposition is avoided by the addition of scale preventative to an absorbent which may be used as a propping agent and positioned in hydraulically created fractures within the formation. Subsequent production from the formation, through the fractures, slowly bleeds the gypsum scale preventative into the produced water and thereby prevents gypsum scale deposition in the wellbore.
Inventors
- 👤 R Fulford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:43
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/25; E21B43/26; E21B43/267; C; C09; C09K; C09K8/00; C09K8/52; C09K8/528
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
30 words
The process of claim 1 further comprising repeating steps (a), (b) and (c) when the scale preventative concentration in the produced waters become less than about 10 parts per million.
Claim 2
Dependent Claim
29 words
The process of claim 1 in which the propping agent is positioned in the fracture by simultaneously introducing it into the calcium carbonate formation with a hydraulic fracturing fluid.
Claim 3
Dependent Claim
11 words
The process of claim 1 in which scale is calcium sulfate.
Claim 4
Dependent Claim
75 words
A process for inhibiting scale deposition in a producing oil well which comprises: a. fracturing a carbonate formation in the vicinity of a wellbore; b. positioning a propping agent in the fissures of the fractured formation, said propping agent being selected from the group consisting of sand, silica gel, and alumina and having a polyacrylamide scale inhibitor adsorbed directly on the surface thereof, c. producing the oil well through the propped fissures of the formation.
Claim 5
Dependent Claim
30 words
The process of claim 5 further comprising repeating steps (a), (b) and (c) when the scale preventative concentration in the produced waters become less than about 10 parts per million.
Claim 6
Dependent Claim
29 words
The process of claim 5 in which the propping agent is positioned in the fracture by simultaneously introducing it into the calcium carbonate formation with a hydraulic fracturing fluid.
Claim 7
Dependent Claim
12 words
The process of claim 5 in which the scale is calcium sulfate.
References Cited (Backward Citations)
US3179170A
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US3258071A
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US3283817A
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US3502587A
Cited
US3481400A
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US3467192A
Cited
US3483925A
Cited
US3528502A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-31 | 1977-07-02 | 1978-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-31 | 1981-07-02 | 1982-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-31 | 1985-07-02 | 1986-01-01 | $7700.00 | Window Closed / Lapsed |