Patent US3566967A successfully refreshed from Google Patents.
US3566967A
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Thermal plugging with silicate solutions
Assignee: Pan American Petroleum Corp
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Filing: 1969-06-19
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Granted: 1971-03-02
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Expires: 1989-06-19
Abstract
Abstract In an underground forward combustion process for recovering petroleum from earth formations, more uniform progress of the combustion front through a formation over a wide area is obtained by injecting a water solution of a water-soluble silicate after the combustion operation has been started. As the solution approaches the combustion front, evaporation of water results in formation of a cohesive, solid mass in the pores of the formation. Flow channels are plugged in this way, providing a more uniform progress of the combustion front. Preferably, the silicate solution is preceded and followed by water. If the formation contains exposed silica, sodium silicate can be formed in the formation by injecting sodium hydroxide.
Inventors
- 👤 Jack L Shelton
- 👤 Syed H Raza
- 👤 H R Froning
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:06
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/24; E21B43/243; E21B33/00; E21B33/10; E21B33/13; E21B33/138
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
53 words
The method of claim 1 in which the silicate is sodium silicate having a silica-to-sodium oxide mole ratio between about 1.5 to 1 and about 4 to 1, and the concentration of said silicate in said solution is sufficient to provide a silica concentration between about 3 and about 10 percent by weight.
Claim 2
Dependent Claim
26 words
The method of claim 1 in which the silicate solution is followed by water which displaces the silicate solution through the formation toward the combustion zone.
Claim 3
Dependent Claim
19 words
The method of claim 3 in which said water is injected in small batches alternated with said oxygen-containing gas.
Claim 4
Dependent Claim
160 words
In a forward combustion process in which air is injected through an injection well into an oil-bearing formation to support a combustion zone which moves through the formation displacing oil ahead of the combustion zone to a producing well from which oil is produced to the surface, the improvement comprising injecting through said producing well into said formation an aqueous sodium hydroxide solution to absorb carbon dioxide, then injecting an aqueous solution of a sodium silicate having a silica-to-sodium oxide mole ratio from about 3.0 to 1 to about 3.5 to 1, said sodium silicate being present in a concentration sufficient to provide a silica concentration from about 3 to about 10 percent by weight, and the pH of said sodium silicate solution being at least about 11.5, and then injecting sufficient water to displace said sodium silicate solution to a point sufficiently close to said combustion zone to form a plug in the principal flow channels of the formation.
Claim 5
Dependent Claim
138 words
In a forward combustion process in which air is injected through an injection well into an oil-bearing formation to support a combustion zone which moves through the formation displacing oil ahead of the combustion zone to a producing well from which oil is produced to the surface, the improvement comprising injecting through said producing well into said formation an aqueous sodium hydroxide solution to absorb carbon dioxide, then injecting an aqueous solution of a water-soluble silicate selected from the group consisting of sodium silicates, potassium silicates, and mixtures of sodium silicates and potassium silicates, the pH of said sodium silicate solution being at least about 11.0, and then injecting sufficient water to displace said sodium silicate solution to a point sufficiently close to said combustion zone to form a plug in the principal flow channels of the formation.
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) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |