| abstract |
A transition metal complex useful as a crosslinking agent for high temperature, high pH, water-based fracturing fluids incorporating polysaccharide polymers is provided. The crosslinker comprises a zirconium/triethanolamine complex having a Zr/TEA molar ratio of between about 1/6.0 and 1/10.0, with 1/6.5 to 1/9.5 being preferred. Methods for preparing the zirconium/triethanolamine crosslinker are also provided. The methods comprise mixing effective amounts of either n-butyl zirconate or n-propyl zirconate with triethanolamine until a uniform blend is obtained. Further, an improved hydraulic fracturing fluid incorporating a polysaccharide polymer, buffer, crosslinker, pH adjusting agent and antioxidant is provided wherein the improvement is utilizing a zirconium/triethanolamine crosslinker. Improved methods for crosslinking fracturing fluids and for hydraulically fracturing well formations are also provided. |