Treating subterranean formations with cellulose and guar derivatives

摘要

Subterranean formations are treated by contacting them with a composition comprising a mixture of (i) an aqueous liquid containing at least a trace amount of at least one divalent cation, (ii) a polymer derivative made by reacting one or more of the polymers guar, hydroxypropylguar, hydroxyethyl cellulose and hydroxypropyl cellulose, with a vinyl phosphonic acid in the presence of a redox system, and (iii) a crosslinking activator comprising a Lewis base or a Bronsted-Lowry base which is substantially free of polyvalent metal ions.