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US3648774A Expired / Lapsed US ⏱️ 0.0 years remaining

Increasing the injectivity index and productivity index of wells

Assignee: Marathon Oil Co
•
Filing: 1970-03-19
•
Granted: 1972-03-14
•
Expires: 1990-03-19
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Abstract

Abstract The injectivity index of injection wells and the productivity index of producing wells in fluid communication with a hydrocarbon-bearing formation is improved by injecting about 1500 gallons of a micellar dispersion per vertical foot of hydrocarbon-bearing formation, thereafter injecting about 1-500 gallons of a mobility buffer per vertical foot of hydrocarbonbearing formation, and injecting sufficient displacing fluid to displace the micellar dispersion to a radius of at least about 7.5 feet from the well bore, and thereafter injecting about 1-500 gallons of a solution capable of counteracting the decrease in permeability caused by the mobility reducing agent in the mobility buffer. For example, the micellar dispersion can be followed by a mobility buffer containing water and a partially hydrolyzed, high molecular weight polyacrylamide and this followed by 0.1-50 volumes of water per volume of mobility buffer and this, in turn, followed by about 1-500 gallons of a sodium hypochlorite solution per vertical foot of hydrocarbon-bearing formation. The displacing fluid and the mobility buffer can be substantially hydrocarbon in an ''''oil-wet'''' reservoir.

Inventors

  • 👤 Walter B Kirk

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 22:27
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/58

Claims Analysis

Total Claims: 20
Claim 1
Independent Claim 17 words
injecting into the formation about 1-500 gallons of a mobility buffer per vertical foot of the formation,
Claim 2
Dependent Claim 17 words
The process of claim 1 wherein the micellar dispersion is comprised of hydrocarbon, surfactant, and aqueous medium.
Claim 3
Dependent Claim 7 words
injecting a mobility buffer slug, and then,
Claim 4
Dependent Claim 27 words
injecting sufficient displacing fluid to substantially displace the mobility buffer to a distance of at least about 7.5 feet in radius from the well bore, and then,
Claim 5
Dependent Claim 14 words
The process of claim 2 wherein the micellar dispersion optionally contains cosurfactant and/or electrolyte.
Claim 6
Dependent Claim 25 words
injecting sufficient water into the formation to substantially displace the micellar dispersion to a radius of at least about 7.5 feet from the well bOre,
Claim 7
Dependent Claim 15 words
injecting about 1 to about 500 gallons of an aqueous solution containing sodium hypochlorite, and,
Claim 8
Dependent Claim 22 words
The process of claim 1 wherein the mobility buffer is an aqueous solution comprised of a partially hydrolyzed, high molecular weight polyacrylamide.
Claim 9
Dependent Claim 50 words
injecting sufficient amounts of a fluid different from the displacing fluid of step 3 and which will act on the formation to substantially increase the relative permeability to the flow of fluids through the reservoir wherein a decreased permeability was caused by a mobility reducing agent within the mobility buffer.
Claim 10
Dependent Claim 28 words
The process of claim 1 wherein from about 1 to about 500 gallons of a mobility buffer per vertical foot of hydrocarbon-bearing formation is injected into the formation.
Claim 11
Dependent Claim 10 words
thereafter continuing the injection of water into the injection well.
Claim 12
Dependent Claim 26 words
The process of claim 1 wherein from about 0.1 to about 50 volumes of water per volume of the mobility buffer is injected into the reservoir.
Claim 13
Dependent Claim 29 words
The process of claim 1 wherein said fluid of step 4 comprises about 5 to about 250 gallons of a sodium hypochlorite solution per vertical foot of hydrocarbon-bearing reservoir.
Claim 14
Dependent Claim 21 words
A process of increasing the injectivity index of an injection well in fluid communication with a hydrocarbon-bearing formation, the process comprising:
Claim 15
Dependent Claim 25 words
The process of claim 8 wherein from about 5 to about 250 gallons of the mobility buffer per vertical foot of the formation is injected.
Claim 16
Dependent Claim 23 words
The process of claim 8 wherein the mobility buffer contains a mobility reducing agent which is a partially hydrolyzed, high molecular weight polyacrylamide.
Claim 17
Dependent Claim 31 words
The process of claim 8 wherein sufficient water is injected to substantially displace the mobility buffer to a distance of at least about 7.5 feet in radius from the well bore.
Claim 18
Dependent Claim 25 words
The process of claim 8 wherein from about 0.5 to about 30 volumes of water per volume of mobility buffer is injected into the reservoir.
Claim 19
Dependent Claim 29 words
The process of claim 8 wherein from about 10 to about 200 gallons of the sodium hypochlorite solution per vertical foot of hydrocarbon-bearing formation is injected into the formation.
Claim 20
Dependent Claim 21 words
The process of claim 8 wherein the sodium hypochlorite solution contains from about 0.1 to about 30 percent of sodium hypochlorite.

References Cited (Backward Citations)

US3482635A Cited
US3460622A 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) 1975-03-14 1975-09-13 1976-03-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-03-14 1979-09-13 1980-03-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-03-14 1983-09-13 1984-03-14 $7700.00 Window Closed / Lapsed

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