Claims
- 1. A method for closing pores in a more permeable zone of a formation where a cross-linked gel is obtained by activating components at a temperature greater than about 300.degree. F. comprising:
- a) making an aqueous mixture comprising:
- i) a water dispersible polymer selected from a member of the group consisting of polyvinyl alcohol, polyvinyl alcohol copolymer, and sulfonated polyvinyl alcohol which member has at least one functional group selected from a member of the group consisting of an amine, an amide, a hydroxyl, or a thiol group;
- ii) a phenolic compound, and
- iii) an aldehyde producing compound which when heated to a temperature above about 300.degree. F. in a formation decomposes to yield an aldehyde and forms a phenolic resin which combines with the polymer and makes a solid gel sufficient to close one or more permeable zones in said formation;
- b) injecting said aqueous mixture into said more permeable zone; and
- c) allowing said mixture to remain in said zone for a time sufficient to reach a temperature above about 300.degree. F. and form a solid gel sufficient to close pores in said zone.
- 2. The method as recited in claim 1 where prior to injecting said mixture into said zone the zone is heated to a temperature greater than about 300.degree. F.
- 3. The method as recited in claim 1 where the aldehyde producing compound comprises trioxane, tetraoxane and polyoxymethylene.
- 4. The method as recited in claim 1 where said gel contains the polymer in about 0.5 about 5.0 wt. percent, the phenolic compound in about 0.5 wt. percent or higher, and the aldehyde producing compound in about 0.5 to about 5.0 wt. percent.
- 5. The method as recited in claim 1 where a rigid gels forms at a temperature of from about 300.degree. F. to about 450.degree. F. in about 1 day to 15 days.
- 6. A method for closing pores in a more permeable zone of a formation where a cross-linked gel is obtained by activating components at a temperature greater than about 300.degree. F. comprising:
- a) making an aqueous mixture comprising:
- i) about 0.5 to about 5.0 wt. percent of a cross-linkable polyvinyl alcohol polymer;
- ii) about 0.5 wt. percent or higher of phenol;
- iii) sodium hydroxide in an amount of about 0.5 to about 0.5 wt. percent;
- iv) about 0.5 to about 5.0 wt. percent of trioxane which, when heated to a temperature of from about 300.degree. F. to about 450.degree. F. in said formation, decomposes to yield an aldehyde and forms a phenolic resin which combines with the polymer and makes a solid gel;
- b) injecting said aqueous mixture into said more permeable zone;
- c) allowing said mixture to remain in said zone for a time sufficient to reach a temperature above about 300.degree. F. and form a solid gel sufficient to close pores in said zone.
- 7. The method as recited in claim 6 where a rigid gel is formed in from about 1 day to about 15 days.
- 8. The method as recited in claim 6 where the polyvinyl alcohol to phenol weight ratio is from about 0.2 to about 2.0 and the phenol to trioxane weight ratio is about 0.5 to about 5.0.
- 9. The method as recited in claim 1 where the gel contains sodium hydroxide in about 0.05 to about 0.5 wt. percent.
Parent Case Info
This application is a divisional application of Ser. No. 292,799, filed on Jan. 3, 1989, now U.S. Pat. No. 4,950,698.
US Referenced Citations (11)
Divisions (1)
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Number |
Date |
Country |
Parent |
292799 |
Jan 1989 |
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