Viscous wellbore fluids

Abstract

A wellbore fluid contains a viscosifying polymer in which portions of the polymer are connected through formation of an inclusion complex involving cucurbituril 8 (i.e. CB[8]) as host molecule. The fluid contains guest molecules with first and second guest groups covalently attached wherein at least one of the guest molecules comprises a polymer chain. The CB[8] host and the guest molecules attach together through reception of first and second guest groups within CB[8] host cavities, thereby connecting polymer chains together as a larger, supramolecular polymer and enhancing viscosity of the fluid. Polymer molecules may be synthetic polymers and guest groups may be attached to monomers before polymerization. Alternatively guest groups may be attached to existing polymers which may be polysaccharide.

Dependencies are inferred from the claim text.