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US4223731A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for enhanced recovery of petroleum

Assignee: Texaco Inc
•
Filing: 1978-11-24
•
Granted: 1980-09-23
•
Expires: 1998-11-24
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Abstract

Abstract An enhanced oil recovery method comprising injecting an aqueous solution of ammonium salts selected from the group consisting of ammonium sulfite, ammonium bisulfite, and mixtures thereof into a petroleum-bearing earth formation, heating said injected aqueous solution to a temperature in the range of about 120°-300° F., or higher in the presence of said petroleum-bearing earth formation, flowing said heated aqueous solution through said petroleum bearing earth formation to drive petroleum to a recovery well, and producing increased amounts of petroleum from said earth formation through said recovery well.

Inventors

  • 👤 John H. Estes
  • 👤 Ernest P. Buinicky

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 06:12
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/58; C09K8/592; E; E21; E21B; E21B43/00; E21B43/16; E21B43/24

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 117 words
In a process for the recovery of petroleum oil from an earth formation penetrated by at least one injection well and by at least one recovery well spaced therefrom, the method which comprises: (a) injecting, via said injection well, an aqueous solution of an ammonium salt selected from the group consisting of ammonium bisulfite, ammonium sulfite, and mixtures thereof at a temperature less than about 120° F. into said earth formation; (b) heating said injected aqueous solution to a temperature above about 120° F.; (c) driving said heated aqueous solution from said injection well toward said production well for displacing petroleum oil from said earth formation; and (d) producing said displaced petroleum oil from said recovery well.
Claim 2
Dependent Claim 117 words
In a process for the recovery of petroleum oil from an earth formation penetrated by at least one injection well and by at least one recovery well spaced therefrom, the method which comprises: (a) injecting, via said injection well, an aqueous solution of an ammonium salt selected from the group consisting of ammonium bisulfite, ammonium sulfite, and mixtures thereof at a temperature less than about 120° F. into said earth formation; (b) heating said injected aqueous solution to a temperature above about 120° F.; (c) driving said heated aqueous solution from said injection well toward said production well for displacing petroleum oil from said earth formation; and (d) producing said displaced petroleum oil from said recovery well.
Claim 3
Dependent Claim 24 words
The method of claim 1 wherein said aqueous solution comprises from about 0.01 to about 1.0 moles of ammonium salt per liter of solution.
Claim 4
Dependent Claim 19 words
The method of claim 2 wherein said aqueous solution solvent selected from the group consisting of water and brine.
Claim 5
Dependent Claim 27 words
The method of claim 3 wherein said injected aqueous solution is heated by injection of a hot drive fluid into said earth formation via said injection well.
Claim 6
Dependent Claim 29 words
The method of claim 4 wherein said ammonium concentration in said aqueous solution is about 0.1 moles/liter and wherein said injected aqueous solution is heated to about 200°-300° F.
Claim 7
Dependent Claim 20 words
The method of claim 3 wherein said injected aqueous solution is heated by direct heat exchange with said earth formation.
Claim 8
Dependent Claim 20 words
The method of claim 3 wherein said injected aqueous solution is heated by direct heat exchange with said earth formation.
Claim 9
Dependent Claim 26 words
The method of claim 7 wherein said injected aqueous solution is driven through said earth formation by injection of a drive fluid via said injection well.
Claim 10
Dependent Claim 18 words
The method of claim 8 wherein said ammonium salt concentration in said aqueous solution is about 0.1 moles/liter.
Claim 11
Dependent Claim 12 words
The method of claim 8 wherein said ammonium salt is ammonium sulfite.
Claim 12
Dependent Claim 142 words
In the recovery of petroleum oil from an earth formation penetrated by at least one injection well, the method which comprises: (a) injecting, via said injection well, an aqueous solution of an ammonium salt selected from the group consisting of ammonium bisulfite, ammonium sulfite, and mixtures thereof at a temperature less than about 120° F. into said earth formation; (b) heating said injected aqueous sulfite solution to a temperature about 120° F.; (c) injecting a drive fluid, at an elevated pressure, into said injection well for driving said aqueous solution into said earth formation and displacing oil from the pores and interstitial spaces of said earth formation; (d) relieving pressure on said injection well such that displaced oil, said aqueous solution and other injected fluids flow from said earth formation to said injection well; and (e) producing petroleum from said injection well.
Claim 13
Dependent Claim 142 words
In the recovery of petroleum oil from an earth formation penetrated by at least one injection well, the method which comprises: (a) injecting, via said injection well, an aqueous solution of an ammonium salt selected from the group consisting of ammonium bisulfite, ammonium sulfite, and mixtures thereof at a temperature less than about 120° F. into said earth formation; (b) heating said injected aqueous sulfite solution to a temperature about 120° F.; (c) injecting a drive fluid, at an elevated pressure, into said injection well for driving said aqueous solution into said earth formation and displacing oil from the pores and interstitial spaces of said earth formation; (d) relieving pressure on said injection well such that displaced oil, said aqueous solution and other injected fluids flow from said earth formation to said injection well; and (e) producing petroleum from said injection well.
Claim 14
Dependent Claim 57 words
The method of claim 11 wherein said aqueous ammonium salt solution comprises from about 0.01 to about 1.0 moles ammonium salt per liter of a solvent selected from the group consisting of water and brine, and wherein said injected aqueous solution is heated to a temperature in the range of about 200°-300° F. within said earth formation.
Claim 15
Dependent Claim 12 words
The method of claim 12 wherein said ammonium salts is ammonium sulfite.

References Cited (Backward Citations)

US3042114A Cited
US3258072A Cited
US3357487A Cited
US3343601A Cited
US3360043A Cited
US3385359A Cited
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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) 1983-09-23 1984-03-24 1984-09-23 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1987-09-23 1988-03-24 1988-09-23 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1991-09-23 1992-03-24 1992-09-23 $7700.00 Window Closed / Lapsed

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