Fracturing fluids comprising fibers treated with crosslinkable, hydratable polymers and related methods

A method comprising:

• providing a low-polymer-load fracturing fluid consisting of an aqueous carrier fluid, proppant, and polymer-treated degradable fibers that have been treated with a crosslinkable, hydratable polymer on the fiber surface, the low-polymer-load fracturing fluid having an initial viscosity;
• placing the low-polymer-load fracturing fluid into a portion of a subterranean formation at a rate to generate pressure above fracture gradient to form or enhance at least one fracture in the portion of the subterranean formation;
• placing the low-polymer-load fracturing fluid into the fracture and after placing the low-polymer-load fracturing fluid into the fracture, crosslinking the polymer to form crosslinks between the polymer-treated degradable fibers so as to increase the viscosity of the low-polymer-load fracturing fluid to a gelled viscosity, the gelled viscosity being higher than the initial viscosity;
• and
• allowing the polymer-treated degradable fibers to degrade so that the viscosity of the low-polymer-load fracturing fluid is reduced to a broken viscosity, the broken viscosity being lower than the gelled viscosity of the low-polymer-load fracturing fluid,
• wherein the polymer-treated degradable fibers have an average or effective diameter of about 2 microns to about 200 microns, and a length of at least about 1 millimeter.