摘要 |
A polyvinyl alcohol-aldehyde gel having a high water content and low degree of crosslinking is provided which has improved stability. The gel can be used to retard the flow of water in subterranean formations encountered in hydrocarbon production. One embodiment of the invention provides a method of forming the gel in-situ in the pores of subterranean zones thereby retarding or blocking the flow of water therein. This application is a continuation application of copending Ser. No. 027,723, filed Mar. 19, 1987, now abandoned which was a divisional application of Ser. No. 693,680, filed Jan. 22, 1985, now U.S. Pat. No. 4,664,194 which was a continuation-in-part application of Serial No. 514,557, filed Jul. 18, 1982, now U.S. Pat. No. 4,498,540 which issued Feb. 12, 1985.
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