US3713489A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plugging of fractures in underground formations
Assignee: BP America Production Co
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Filing: 1970-09-08
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Granted: 1973-01-30
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Expires: 1990-09-08
Abstract
Abstract This information concerns a method of selectively plugging fractures in an underground formation by injecting a slurry of finely divided non-settling solids into the fracture. The finely divided solids disclosed are fly ash, amorphous silica, and finely divided limestone. These solids have a particle size smaller than 50 mesh U.S. Standard Sieve Series. Suitable water loss additives and viscosity reducers are disclosed.
Inventors
- 👤 C Fast
- 👤 M Mallinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:12
CPC Classifications
E; E21; E21B; E21B33/00; E21B33/10; E21B33/13; E21B33/138
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
80 words
A method of plugging a fracture in an inter-well area of an underground formation penetrated by a well bore which comprises the step of injecting a liquid slurry containing fly ash into said formation through said well at a pressure in the range from the fracture opening pressure to below the pressure required to create a fracture therein, said liquid slurry includes water as the carrier fluid containing about 18 to 26 pounds of fly ash per gallon of water.
Claim 2
Independent Claim
80 words
A method of plugging a fracture in an inter-well area of an underground formation penetrated by a well bore which comprises the step of injecting a liquid slurry containing fly ash into said formation through said well at a pressure in the range from the fracture opening pressure to below the pressure required to create a fracture therein, said liquid slurry includes water as the carrier fluid containing about 18 to 26 pounds of fly ash per gallon of water.
Claim 3
Dependent Claim
31 words
A method as defined in claim 1 in which the solids of the slurry contain a mixture of 1 part cement to between about 10 to about 40 parts fly ash.
Claim 4
Dependent Claim
18 words
A method as defined in claim 1 in which the slurry is displaced away from the well bore.
Claim 5
Dependent Claim
17 words
A method as defined in claim 1 in which the liquid slurry contains a water loss additive.
Claim 6
Independent Claim
75 words
A method of plugging a fracture in an inter-well area of an underground formation penetrated by a well bore which comprises the step of injecting a liquid slurry containing fly ash into said formation through said well at a pressure in the range from the fracture opening pressure to below the pressure required to create a fracture therein and injecting a slug of cement into said fracture after the injection of said fly ash slurry.
Claim 7
Independent Claim
75 words
A method of plugging a fracture in an inter-well area of an underground formation penetrated by a well bore which comprises the step of injecting a liquid slurry containing fly ash into said formation through said well at a pressure in the range from the fracture opening pressure to below the pressure required to create a fracture therein and injecting a slug of cement into said fracture after the injection of said fly ash slurry.
Claim 8
Dependent Claim
27 words
A method as defined in claim 5 including the step thereafter injecting a second slurry of fly ash and thereafter injecting a driving fluid through said well.
Claim 9
Dependent Claim
22 words
A method as defined in claim 6 in which said liquid slurry contains a fluid loss additive and a viscosity reducing agent.
Claim 10
Dependent Claim
37 words
A method as defined in claim 7 in which said fluid loss additive is a cellulose derivative and is used in a concentration in the range from about 0.5 to 1.3 percent by weight of fly ash.
Claim 11
Independent Claim
76 words
A method of plugging a fracture in an inter-well area of an underground formation penetrated by a well bore which comprises the step of injecting a liquid slurry containing fly ash into said formation through said well at a pressure in the range from the fracture opening pressure to below the pressure required to create a fracture therein and in which the liquid slurry includes water as the carrier fluid and contains a viscosity reducing agent.
Claim 12
Independent Claim
76 words
A method of plugging a fracture in an inter-well area of an underground formation penetrated by a well bore which comprises the step of injecting a liquid slurry containing fly ash into said formation through said well at a pressure in the range from the fracture opening pressure to below the pressure required to create a fracture therein and in which the liquid slurry includes water as the carrier fluid and contains a viscosity reducing agent.
Claim 13
Dependent Claim
40 words
A method as defined in claim 9 in which the viscosity reducing agent is a sodium salt of alkyl aryl sulfonate used in a concentration in the range from about 0.02 to 0.05 gallons per 74 pounds of fly ash.
Claim 14
Independent Claim
123 words
A method of plugging an inter-wall area of an underground formation having fracturEs therein and penetrated by a well bore which comprises the step of injecting a liquid slurry having a water base containing finely divided non-settling solids into said formation through said well at a pressure in the range from the fracture opening pressure to below the fracture creating pressure, said solids selected from a group consisting of fly ash, amorphous silica, and powdered limestone, which solids pass a 50 mesh sieve, U.S. Standard Sieve Series, the ''''filtrate'''' of said liquid of the slurry being of a type to readily penetrate the walls of said fracture, the slurry having at least about 10 pounds of such selected solids per gallon of water.
Claim 15
Independent Claim
123 words
A method of plugging an inter-wall area of an underground formation having fracturEs therein and penetrated by a well bore which comprises the step of injecting a liquid slurry having a water base containing finely divided non-settling solids into said formation through said well at a pressure in the range from the fracture opening pressure to below the fracture creating pressure, said solids selected from a group consisting of fly ash, amorphous silica, and powdered limestone, which solids pass a 50 mesh sieve, U.S. Standard Sieve Series, the ''''filtrate'''' of said liquid of the slurry being of a type to readily penetrate the walls of said fracture, the slurry having at least about 10 pounds of such selected solids per gallon of water.
Claim 16
Dependent Claim
24 words
A method as defined in claim 11 in which the slurry is displaced away from the well bore by injection of a displacing fluid.
Claim 17
Dependent Claim
33 words
A method as defined in claim 11 including the step of adding to said liquid slurry, a water loss additive in the amount of 0.5 to 1.3 percent by weight of the solids.
Claim 18
Dependent Claim
33 words
A method as defined in claim 13 including the step of adding to said slurry a viscosity reducer in the concentration of about 0.02 to 0.05 gallon per 74 pound sack of solids.
Claim 19
Independent Claim
85 words
A method of plugging a fracture in an inter-well area of an underground formation penetrated by a well bore which comprises the step of injecting a liquid slurry containing powdered limestone which passes a 50 mesh sieve, U. S. Standard Sieve Series, into said formation through said well at a pressure in the range from the fracture opening pressure to below the pressure required to create a fracture therein and injecting a slug of cement into said fracture after the injection of said limestone slurry.
Claim 20
Independent Claim
85 words
A method of plugging a fracture in an inter-well area of an underground formation penetrated by a well bore which comprises the step of injecting a liquid slurry containing powdered limestone which passes a 50 mesh sieve, U. S. Standard Sieve Series, into said formation through said well at a pressure in the range from the fracture opening pressure to below the pressure required to create a fracture therein and injecting a slug of cement into said fracture after the injection of said limestone slurry.
Claim 21
Dependent Claim
27 words
A method as defined in claim 15 including the step of thereafter injecting a second slurry of limestone and thereafter injecting a driving fluid through said well.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |