Cellulose ether-based gel-forming composition and methods of use and preparation thereof

Abstract

The application discloses a gel-forming composition based on (a) water, (b) a water-soluble cellulose mixed ether having at least one nonionic substituent from the group comprising hydroxyalkyl and alkyl and at least one anionic phosphorus-containing substituent, and (c) a salt containing a cation which is at least divalent. The phosphorus-containing substituent is a phosphonoalkyl group or a p-alkylphosphinoalkyl group. The application also relates to a process for the preparation of a gel from this composition, to the reversible reversing of the gel by the addition of an agent which complexes the cation, e.g. in the case of Al.sup.3+ ions, Fe.sup.3+ ions, Zr.sup.4+ ions or ZrO.sup.2+ ions, by means of an amount of fluoride ions, and to the use of this gel-forming compostion in the secondary production of petroleum.

Dependencies are inferred from the claim text.