It has been discovered that fracturing fluid breaker mechanisms are
improved by the inclusion of a polyol alone that directly degrades the
polysaccharide backbone, and optionally additionally by removing the
crosslinking ion, if present. That is, viscosity reduction (breaking)
occurs by breaking down the chemical bonds within the backbone directly,
rather than by merely removing the crosslinking ion, if present. The gel
does not have to be crosslinked for the method of the invention to be
successful, although it may be crosslinked. In one non-limiting
embodiment, the polyol has at least two hydroxyl groups on adjacent
carbon atoms. In another embodiment, the polyols are monosaccharides such
as glycerols and sugar alcohols, and may include mannitol, sorbitol,
glucose, fructose, galactose, mannose, lactose, maltose, allose, etc. and
mixtures thereof.