US4464268A
Expired / Lapsed
US
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Method for restoring permeability of injection wells
Assignee: Texaco Inc
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Filing: 1982-01-11
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Granted: 1984-08-07
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Expires: 2002-01-11
Abstract
Abstract A method is disclosed for restoring permeability of injection wells which have become plugged with polymer residue, protein debris, biological matter and the like. The method includes treating the well for a period of time with an aqueous solution containing hydrogen peroxide and optionally a surfactant.
Inventors
- 👤 Vernon H. Schievelbein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:58
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/72; C09K8/74; C09K8/78; C09K8/52; C09K8/524; Y; Y10; Y10S; Y10S507/00; Y10S507/921; Y10S507/927; Y10S507/929
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
132 words
A method of restoring the permeability of a porous subterranean petroleum containing formation adjacent a well bore wherein organic or synthetic polymeric material and biological matter are lodged in the pores thus restricting the flow of aqueous fluids, the method comprising injecting into the formation through the well bore an aqueous solution consisting of water or brine wherein is dissolved from about 1% to about 30% by weight of hydrogen peroxide and from about 1% to about 30% by weight of an acid selected from the group consisting of hydrochloric, hydroflouric and acetic; and then allowing the well to remain quiescent for from 2 to 96 hours and then backflowing or displacing with an aqueous solution containing water or brine and from about 0.5% to about 3.0% by weight of sodium bisulfite.
Claim 2
Independent Claim
132 words
A method of restoring the permeability of a porous subterranean petroleum containing formation adjacent a well bore wherein organic or synthetic polymeric material and biological matter are lodged in the pores thus restricting the flow of aqueous fluids, the method comprising injecting into the formation through the well bore an aqueous solution consisting of water or brine wherein is dissolved from about 1% to about 30% by weight of hydrogen peroxide and from about 1% to about 30% by weight of an acid selected from the group consisting of hydrochloric, hydroflouric and acetic; and then allowing the well to remain quiescent for from 2 to 96 hours and then backflowing or displacing with an aqueous solution containing water or brine and from about 0.5% to about 3.0% by weight of sodium bisulfite.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein the aqueous solution contains dissolved therein from about 2 to about 10% be weight of hydrogen peroxide.
Claim 4
Dependent Claim
24 words
The method of claim 1 wherein the aqueous solution contains dissolved therein from about 200 ppm to about 2% by weight of a surfactant.
Claim 5
Dependent Claim
47 words
The method of claim 1 wherein the aqueous solution contains dissolved therein from about 0.1% to about 1% by weight of a surfactant selected from the group consisting of ethoxylated alcohols, ethoxylated alkyl phenols, alkylaryl sulfonates, alkyl polyethoxylated sulfates and sulfonates and alkylaryl polyethoxylated sulfates and sulfonates.
Claim 6
Dependent Claim
32 words
An aqueous solution for use in restoring the permeability of a porous subterranean petroleum containing formation comprising water or brine and from about 1% to about 30% by weight of hydrogen peroxide.
Claim 7
Dependent Claim
32 words
An aqueous solution for use in restoring the permeability of a porous subterranean petroleum containing formation comprising water or brine and from about 1% to about 30% by weight of hydrogen peroxide.
Claim 8
Dependent Claim
33 words
The aqueous solution of claim 5 wherein is dissolved from about 200 ppm to about 2% by weight of a surfactant and from about 1% to about 30% by weight of an acid.
Claim 9
Independent Claim
132 words
A method of restoring the permeability of a porous subterranean petroleum containing formation adjacent a well bore wherein organic or synthetic polymeric material and biological matter are lodged in the pores, thus restricting the flow of aqueous fluids, the method comprising circulating an aqueous solution consisting of water or brine, from about 1% to about 30% by weight of hydrogen peroxide and from about 1% to about 30% by weight of an acid selected from the group consisting of hydrochloric, hydroflouric and acetic, down the tubing of a well bore and out the annulus for a period of time of about 12 hours to about 36 hours and then backflowing or displacing with an aqueous solution containing water or brine and from about 0.5% to about 3.0% by weight of sodium bisulfite.
Claim 10
Independent Claim
132 words
A method of restoring the permeability of a porous subterranean petroleum containing formation adjacent a well bore wherein organic or synthetic polymeric material and biological matter are lodged in the pores, thus restricting the flow of aqueous fluids, the method comprising circulating an aqueous solution consisting of water or brine, from about 1% to about 30% by weight of hydrogen peroxide and from about 1% to about 30% by weight of an acid selected from the group consisting of hydrochloric, hydroflouric and acetic, down the tubing of a well bore and out the annulus for a period of time of about 12 hours to about 36 hours and then backflowing or displacing with an aqueous solution containing water or brine and from about 0.5% to about 3.0% by weight of sodium bisulfite.
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) | 1987-08-07 | 1988-02-06 | 1988-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-07 | 1992-02-06 | 1992-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-07 | 1996-02-06 | 1996-08-07 | $7700.00 | Window Closed / Lapsed |