PROCESS FOR PRODUCING AND USING A GEL SYSTEM FOR OILFIELD AND GASFIELD APPLICATIONS, SUCH AS FRACKING AND WELL CLEANING, AND GEL SYSTEM PRODUCED BY THIS PROCESS

摘要

A process for producing a reversible, nonmetal-bonded gel system for fracking and well cleaning purposes, consisting of a hydrogel based on (water-soluble) carbohydrate polymers from the group of guar and guar derivatives, which contain substituents which enable a Diels-Alder or free-radical reaction with a linker containing at least two complementary groups (bifunctional linkers) (= linking group), and the viscosity and hydrophilicity of which are reduced by addition of a reagent (= antidote) which contains diene, dienophile, Diels-Alder adduct, nitroxide or nitroxide-alkyl groups or other stable free radicals, and subsequent reduction at elevated temperature and elevated pressure. The invention further relates to the gel system and to the use of the gel system for oilfield and gasfield applications.