US Patent 9663707 Stimulation method using biodegradable zirconium crosslinker

A fracturing fluid containing a hydratable viscosifying polymer and a zirconium acetylacetonate crosslinker provides a green alternative to conventional systems. The zirconium aceylacetonate is dissolved in benzyl alcohol or in a mixture of benzyl alcohol and 2,2-dimethyl-1,3-dioxolan-4(yl)-methanol. The pH of the fracturing fluid may be between from about 3.5 to about 11.5. The fracturing fluid may contain an acidic buffering agent or a basic buffering agent. The fracturing fluid may be pumped into a well in order to initiate or enlarge a fracture within a subterranean formation penetrated by the well.