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Well treatment with emulsion dispersions

Assignee: ExxonMobil Upstream Research Co
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Filing: 1979-10-09
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Granted: 1982-11-16
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Expires: 1999-10-09
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Abstract

Abstract In a method of treating a subterranean formation, a well treatment composition comprising a dispersion of a water-in-oil emulsion in an aqueous medium is injected into the formation. The water-in-oil emulsion has an internal aqueous phase and an external phase containing a liquid hydrocarbon and a surfactant soluble in the hydrocarbon. The compositions can be designed to perform various well treatment applications including hydraulic fracturing and acidizing and can also be used to encapsulate or to transport well treatment materials and chemicals into the wellbore or formation. Treatment methods may also employ dispersions of a reactive simple or multiple emulsion. The distinct phases of the compositions may be selected to form treatment solutions upon mixing. Thus, improved acidizing may be achieved through an in situ reaction format.

Inventors

  • 👤 William M. Salathiel
  • 👤 Thomas W. Muecke
  • 👤 Claude E. Cooke, Jr.
  • 👤 Norman N. Li

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 14:26
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/92; C09K8/02; C09K8/32; C09K8/36; C09K8/50; C09K8/502; C09K8/62; C09K8/72; Y; Y10; Y10S; Y10S507/00; Y10S507/933

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 98 words
A method for acidizing a subterranean formation surrounding a well which comprises: (a) contacting the formation with a dispersion of a reactive multiple emulsion which comprises a dispersing solution, a liquid hydrocarbon external phase, comprising a blend of a liquid hydrocarbon and an oil soluble surfactant, and more than one solution internal phase wherein at least two solutions comprising the dispersing solution and the solution internal phases are capable of forming an acidizing solution upon mixing with one another; and (b) causing the solutions to mix in situ to form the acidizing solution and to treat the formation.
Claim 2
Independent Claim 98 words
A method for acidizing a subterranean formation surrounding a well which comprises: (a) contacting the formation with a dispersion of a reactive multiple emulsion which comprises a dispersing solution, a liquid hydrocarbon external phase, comprising a blend of a liquid hydrocarbon and an oil soluble surfactant, and more than one solution internal phase wherein at least two solutions comprising the dispersing solution and the solution internal phases are capable of forming an acidizing solution upon mixing with one another; and (b) causing the solutions to mix in situ to form the acidizing solution and to treat the formation.
Claim 3
Dependent Claim 24 words
The method of claim 1 wherein the solutions capable of forming the acidizing solution upon mixing are solution internal phases of the multiple emulsion.
Claim 4
Dependent Claim 37 words
The method of claim 2 wherein the solutions capable of forming the acidizing solution upon mixing are aqueous solutions of hydrochloric acid and ammonium bifluoride, and wherein the dispersing solution is an aqueous solution of ammonium chloride.
Claim 5
Independent Claim 86 words
A method for acidizing a subterranean formation surrounding a well which comprises: (a) forming a simple emulsion of a liquid hydrocarbon external phase, comprising a blend of a liquid hydrocarbon and an oil soluble surfactant, and a solution internal phase; (b) dispersing the emulsion in a dispersing solution which is capable of forming an acidizing solution upon mixing with the solution internal phase of the emulsion; and (c) contacting the formation with the dispersion to mix the two solutions in situ and to treat the formation.
Claim 6
Independent Claim 86 words
A method for acidizing a subterranean formation surrounding a well which comprises: (a) forming a simple emulsion of a liquid hydrocarbon external phase, comprising a blend of a liquid hydrocarbon and an oil soluble surfactant, and a solution internal phase; (b) dispersing the emulsion in a dispersing solution which is capable of forming an acidizing solution upon mixing with the solution internal phase of the emulsion; and (c) contacting the formation with the dispersion to mix the two solutions in situ and to treat the formation.
Claim 7
Dependent Claim 20 words
The method of claim 4 which further comprises preflushing the formation by employing an acidic solution as the dispersing solution.
Claim 8
Dependent Claim 25 words
The method of claim 4 which further comprises reducing drill string corrosion by employing an aqueous solution of a fluoride salt as the dispersing solution.
Claim 9
Dependent Claim 18 words
The method of claim 4 wherein the solution internal phase is an aqueous solution of a fluoride salt.
Claim 10
Dependent Claim 35 words
The method of claim 4 wherein the solution internal phase is an aqueous solution of a fluoride salt selected from the group consisting of ammonium fluoride, ammonium bifluoride, sodium fluoride, calcium fluoride, and potassium fluoride.
Claim 11
Dependent Claim 29 words
The method of claim 4 wherein the solution internal phase is an aqueous solution of a fluoride salt selected from the group consisting of ammonium fluoride and ammonium bifluoride.
Claim 12
Dependent Claim 21 words
The method of claim 6 wherein the fluoride salt is selected from the group consisting of ammonium fluoride and ammonium bifluoride.
Claim 13
Independent Claim 73 words
A method of acidizing a subterranean formation surrounding a well which comprises: (a) forming a simple emulsion of a liquid hydrocarbon external phase, comprising a blend of a liquid hydrocarbon and an oil soluble surfactant, and a solution internal phase of hydrochloric acid; (b) dispersing the emulsion in a solution of ammonium bifluoride; and (c) contacting a formation so that the hydrochloric acid and ammonium bifluoride mix in situ to treat the formation.
Claim 14
Independent Claim 73 words
A method of acidizing a subterranean formation surrounding a well which comprises: (a) forming a simple emulsion of a liquid hydrocarbon external phase, comprising a blend of a liquid hydrocarbon and an oil soluble surfactant, and a solution internal phase of hydrochloric acid; (b) dispersing the emulsion in a solution of ammonium bifluoride; and (c) contacting a formation so that the hydrochloric acid and ammonium bifluoride mix in situ to treat the formation.
Claim 15
Independent Claim 85 words
A method for acidizing a subterranean formation surrounding a well which comprises: (a) forming a simple emulsion of a liquid hydrocarbon external phase, comprising a blend of a liquid hydrocarbon and an oil soluble surfactant, and a solution internal phase of ammonium bifluoride; (b) dispersing the emulsion in a solution of hydrochloric acid; (c) preflushing the formation by injecting the dispersion into the formation; and (d) contacting the ammonium bifluoride with the hydrochloric acid in situ to form an acidizing solution that treats the formation.
Claim 16
Independent Claim 85 words
A method for acidizing a subterranean formation surrounding a well which comprises: (a) forming a simple emulsion of a liquid hydrocarbon external phase, comprising a blend of a liquid hydrocarbon and an oil soluble surfactant, and a solution internal phase of ammonium bifluoride; (b) dispersing the emulsion in a solution of hydrochloric acid; (c) preflushing the formation by injecting the dispersion into the formation; and (d) contacting the ammonium bifluoride with the hydrochloric acid in situ to form an acidizing solution that treats the formation.
Claim 17
Dependent Claim 16 words
The method of either claim 11 or 12 which employs ammonium fluoride instead of ammonium bifluoride.

References Cited (Backward Citations)

US3710865A Cited
US4098736A Cited
US3799266A Cited
US3977472A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1985-11-15 1986-05-17 1986-11-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1989-11-15 1990-05-17 1990-11-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1993-11-15 1994-05-17 1994-11-16 $7700.00 Window Closed / Lapsed

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