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US3882938A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for recovering oil from heterogeneous reservoirs

Assignee: Union Oil Company of California
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Filing: 1972-07-17
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Granted: 1975-05-13
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Expires: 1992-07-17
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Abstract

Abstract A process for recovering oil from heterogeneous subterranean reservoirs having strata of widely varying permeabilities in which a soluble oil miscible with the connate reservoir oil and with water is injected into the reservoir through an injection well and wherein one or more aqueous solutions of reagents that react in the reservoir to form a plugging material are injected into the reservoir through the injection well prior to completing the injection of the soluble oil, and thereafter an aqueous flooding medium is injected to drive the soluble oil towards a spaced production well from which fluids are recovered.

Inventors

  • 👤 George G Bernard

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 16:08
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/84; C09K8/845; C09K8/50; C09K8/62; C09K8/72; C09K8/74; E; E21; E21B; E21B43/00; E21B43/16

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 139 words
IN THE METHOD OF RECOVERING PETROLEUM FROM HETEROGENEOUS SUBTERRANEAN RESERVOIRS HAVING STRATA OF WIDELY VARYING PERMEABILITIES WHEREIN A SUBSTANTIAL PROPORTION OF THE OIL IS THE MORE PERMEABLE STRATA AND IN WHICH A SOLUBLE OIL MISCIBLE WITH BOTH THE CONNATE RESERVOIR OIL AND WITH WATER IS FIRST INJECTED INTO THE RESERVOIR THROUGH AN INJECTION WELL, AND THEREAFTER AN AQUEOUS FLOODING MEDIUM IS INJECTED TO DRIVE THE SOLUBLE OIL TOWARDS SPACED PRODUCTION WELL FROM WHICH FLUIDS ARE RECOVERED, THE IMPROVEMENT WHICH COMPRISES INJECTING THROUGH SAID INJECTION WELL AND INTO SAID RECERVOIR A FIRST PORTION OF SAID SOLUBLE OIL, NEXT INJECTING ONE OR MORE AQUEOUS SOLUTIONS OF REAGENTS THAT REACT TOGETHER IN THE RESERVOIR TO FORM A PLUGGING MATERIAL THAT SUBSTANTIALLY REDUCES THE PERMEABILITY OF THE MORE PERMEABLE STRATA OF THE FORMATION, AND THEREAFTER INJECTING A SECOND PORTION OD SAID SOLUBLE OIL.
Claim 2
Dependent Claim 139 words
IN THE METHOD OF RECOVERING PETROLEUM FROM HETEROGENEOUS SUBTERRANEAN RESERVOIRS HAVING STRATA OF WIDELY VARYING PERMEABILITIES WHEREIN A SUBSTANTIAL PROPORTION OF THE OIL IS THE MORE PERMEABLE STRATA AND IN WHICH A SOLUBLE OIL MISCIBLE WITH BOTH THE CONNATE RESERVOIR OIL AND WITH WATER IS FIRST INJECTED INTO THE RESERVOIR THROUGH AN INJECTION WELL, AND THEREAFTER AN AQUEOUS FLOODING MEDIUM IS INJECTED TO DRIVE THE SOLUBLE OIL TOWARDS SPACED PRODUCTION WELL FROM WHICH FLUIDS ARE RECOVERED, THE IMPROVEMENT WHICH COMPRISES INJECTING THROUGH SAID INJECTION WELL AND INTO SAID RECERVOIR A FIRST PORTION OF SAID SOLUBLE OIL, NEXT INJECTING ONE OR MORE AQUEOUS SOLUTIONS OF REAGENTS THAT REACT TOGETHER IN THE RESERVOIR TO FORM A PLUGGING MATERIAL THAT SUBSTANTIALLY REDUCES THE PERMEABILITY OF THE MORE PERMEABLE STRATA OF THE FORMATION, AND THEREAFTER INJECTING A SECOND PORTION OD SAID SOLUBLE OIL.
Claim 3
Dependent Claim 27 words
The method defined in claim 1 wherein a plurality of successive slugs of said soluble oil and said aqueous reagent solutions are alternately injected into the reservoir.
Claim 4
Dependent Claim 33 words
The method defined in claim 1 wherein one of said aqueous reagent solutions is an aquEous solution of a sodium silicate having a weight ratio of SiO2/Na2O from about 1.5/1 to about 4/1.
Claim 5
Dependent Claim 37 words
The method defined in claim 3 wherein said aqueous sodium silicate solution contains a gelling agent selected from the group consiting of acid and acid-forming compounds, water-soluble ammonium salts, lower aldehydes, aluminum salts, and alkali metal aluminates.
Claim 6
Dependent Claim 36 words
The method defined in claim 3 wherein there is also separately injected into the reservoir immediately preceding or following said aqueous solution of sodium silicate an aqueous solution containing a water-soluble salt of a polyvalent metal.
Claim 7
Independent Claim 135 words
A method for flooding a heterogeneous reservoir having oil-containing strata of widely varying permeabilities, which comprises: injecting through an injection well and into said reservoir a first portion of a soluble oil miscible with the connate reservoir oil and with water; thereafter injecting through said injection well one or more solutions of reagents that react together in the reservoir to form a plugging material that substantially reduces the permeability of the more permeable strata of the formation; next injecting a second portion of said soluble oil; next injecting about 0.1 to 1 pore volume of flood water thickened by the addition of a viscosity increasing agent; thereafter injecting flood water to drive said previously injected fluids through said reservoir; and recovering oil from a production well spaced apart in the reservoir from said injection well.
Claim 8
Independent Claim 135 words
A method for flooding a heterogeneous reservoir having oil-containing strata of widely varying permeabilities, which comprises: injecting through an injection well and into said reservoir a first portion of a soluble oil miscible with the connate reservoir oil and with water; thereafter injecting through said injection well one or more solutions of reagents that react together in the reservoir to form a plugging material that substantially reduces the permeability of the more permeable strata of the formation; next injecting a second portion of said soluble oil; next injecting about 0.1 to 1 pore volume of flood water thickened by the addition of a viscosity increasing agent; thereafter injecting flood water to drive said previously injected fluids through said reservoir; and recovering oil from a production well spaced apart in the reservoir from said injection well.
Claim 9
Dependent Claim 28 words
The method defined in claim 6 wherein each portion of said soluble oil is injected into said reservoir in an amount equivalent to 0.01 to 0.08 pore volume.
Claim 10
Dependent Claim 56 words
The method defined in claim 6 wherein said aqueous reagent solution is an aqueous solution of sodium silicate having a weight ratio of SiO2/Na2O from about 1.5/1 to about 4/1 and containing a gelling agent selected from the group consisting of acid and acid-forming compounds, water-soluble ammonium salts, lower aldehydes, aluminum salts, and alkali metal aluminates.
Claim 11
Dependent Claim 62 words
The method defined in claim 6 wherein one of said aqueous reagent solutions is an aqueous solution of sodium silicate having a weight ratio of SiO2/Na2O from about 1.5/1 to about 4/1 and wherein there is also separately injected into the reservoir immediately preceding or following said aqueous sodium silicate solution an aqueous solution containing a water-soluble salt of a polyvalent metal.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-05-12 1978-11-11 1979-05-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-05-12 1982-11-11 1983-05-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-05-12 1986-11-11 1987-05-13 $7700.00 Window Closed / Lapsed

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