Rheological behaviors of a novel ultra-high temperature fracturing fluid

By introducing the complex of hydrolyzed polyacrylamide and hydroxypropyl guar as the thickener and organic zirconium as the delayed crosslinker, a novel ultra-high temperature fracturing fluid was developed and its rheological behaviors were investigated. The results show that the crosslinked network structure of this new type fracturing fluid is optimized by introducing the complex thickener and delayed crosslinker of organic zirconium. In particular, by introducing organic zirconium as the delayed crosslinker, the fracturing fluid is crosslinked once again during the process of shearing at high temperature. As a result, the high temperature resistance of the fracturing fluid is improved significantly. The shear viscosity of this novel fracturing fluid is larger than 80 mPa · s even if this fracturing fluid is sheared more than two hours under the shear rate of 170 s -1 and at the temperature of 200°C. This suggests that this novel fracturing fluid can be applied to stimulate the tight and high temperature natural gas reservoirs with the depth of 4.7-5.0 km in Daqing Oilfield.