Claims
- 1. A method of plugging the perforations in a casing which has been set in a wellbore which penetrates a subterranean formation comprising:
- (a) flowing down said casing a wellbore fluid having dispersed therein a plurality of ball sealers, said ball sealers being sized to seal said perforations and being comprised of a polyester polymer which is substantially insoluble in said wellbore fluid and degradable in the presence of water at the formation temperature to oligomers which are at least partially soluble in a formation fluid, and
- (b) continuing the flow of said wellbore fluid until at least a portion of said perforations are sealed by said ball sealers.
- 2. A method of plugging the perforations in a casing which has been set in a wellbore which penetrates a subterranean formation comprising:
- (a) flowing down said casing a wellbore fluid having dispersed therein a plurality of ball sealers, said ball sealers being sized to seal said perforations and being comprised of a polymer having the repeating unit: ##STR3## wherein R is H, C.sub.1 to C.sub.4 alkyl and n is sufficiently large to form a solid polymer, said polymer being substantially insoluble in said wellbore fluid and degradable in the presence of water at an elevated temperature to oligomers which are at least partially soluble in oil or water; and
- (b) continuing the flow of said wellbore fluid until at least a portion of said perforations are sealed by said ball sealers.
- 3. The method of claim 2 wherein said polymer is selected from the group consisting of poly (D,L-lactide) crosslinked poly (D,L-lactide) and copolymers of glycolide and D, L-lactide.
- 4. The method of claim 2 wherein said ball sealers are substantially spherical with a diameter greater than one-quarter inch.
- 5. The method of claim 4 wherein the diameter is in the range one-half inch to one inch.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a file wrapper continuation of patent application Ser. No. 712,045, filed on Mar. 15, 1985, now abandoned, which was a division of patent application Ser. No. 464,084, filed on Feb. 4, 1983 which issued as U.S. Pat. No. 4,526,695 on July 2, 1985 and which, in turn, was a division of patent application Ser. No. 291,200 filed on Aug. 10, 1981 which issued as U.S. Pat. No. 4,387,769 on June 14, 1983.
US Referenced Citations (9)
Divisions (2)
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Date |
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464084 |
Feb 1983 |
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Parent |
291200 |
Aug 1981 |
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Continuations (1)
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712045 |
Mar 1985 |
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