US3766984A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for temporarily sealing a permeable formation
Assignee: Schlumberger Technology Corp
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Filing: 1972-01-31
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Granted: 1973-10-23
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Expires: 1992-01-31
Abstract
Abstract A composition is provided a degradation may be employed for the selective sealing of permeable formations. The composition contains at least one particulate galactomannan gum which is treated with a hydrophobing agent to render the gum hydrophobic in aqueous solutions having a pH of at least about 7.5, a pH control agent and a water-soluble organic polymeric suspending agent. Optionally, a degradation agent, a cross-linking agent and/or a hydration agent can be included.
Inventors
- 👤 K Nimerick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:51
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/84; C09K8/86; C09K8/88; C09K8/887; C08; C08L; C08L5/00; C09K8/90; E; E21; E21B; E21B33/00; E21B33/10; E21B33/13; E21B33/138
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
37 words
The method as defined in claim 1 wherein the slurry includes in addition a degradation agent for a hydrated cross-linked galactomannan gum said degradation agent characterized as having a characteristic time delay effectiveness in degradating said gum.
Claim 2
Independent Claim
251 words
A method for temporarily plugging a permeable formation located adjacent to a well bore located in a subterranean formation which comprises injecting into said formation prior to any substantial hydration of the treated galactomannan gum a slurry composition which comprises: a. from about 300 to about 750 pounds of a galactomannan gum which is pretreated with an effective amount of a material which releases borate ions when dispersed in an aqueous solution to render the gum less hydrophilic than normal when dispersed in an aqueous solution having about a neutral to alkaline pH value and normal hydrophilic characteristics in aqueous solution having an acidic pH value; b. a water-soluble organic polymeric suspending agent of at least one of a water-soluble homopolymer or copolymer of acrylamide or methacrylamide from about 6 to about 30 pounds; c. a buffering agent in an amount ranging from about 24 to about 60 pounds wherein said buffering agent is at least one of NaH2PO4-Na2HPO4, boric acid-borax, sodium carbonate-sodium bicarbonate, sodium bicarbonate, citric acid-sodium hydroxide, or boric acid-sodium hydroxide; d. at least one of an acidic material which releases an ion in aqueous solution which cross-links a hydrated galactomannan gum upon hydrolysis decreases the pH of an aqueous solution said acid material further characterized as having a characteristic time delayed hydrolysis rate, in an amount sufficient to overcome the effect of said buffering agent after a period of time; e. a sufficient quantity of an aqueous solution to make about 1, 000 gallons of said slurry composition.
Claim 3
Dependent Claim
43 words
The method as defined in claim 3 wherein the slurry composition comprises in addition a degradation agent which is characterized as breaking down the Cross-linked hydrated galactomannan gum after a period of time to render it flowable and removable from the treated formation.
References Cited (Backward Citations)
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US3084056A
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US3227212A
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US3500929A
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US3611733A
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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) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |