An increase in the number of explorations of deeper and hotter formations has prompted the need for an ultrahigh- temperature fracturing fluid. Conventional fracturing fluids are typically based on polysaccharides or their derivatives, which can provide enough viscosity to carry proppant deep into the formation at temperatures only up to 177 °C (350 °F). Beyond this temperature, these biopolymers hydrolyze too rapidly to be an effective and cost-efficient carry fluid; therefore, a new fluid was needed. We developed a new fluid system that can deliver the required rheological properties for successful fracturing operations up to bottom hole static temperature of 232 °C (450 °F) without the need for cool-down. This fluid is composed of a fast-hydrating synthetic copolymer and a metal crosslinker. This system has been engineered to provide a controllable crosslink mechanism and viscosity reduction profile to accommodate varying well conditions and job designs. Numerous proppant-pack conductivity tests have shown that this resilient fluid system can be broken and easily cleaned up at temperatures above 149 °C (300 °F). The rheological performance of the fluid, along with its high proppant pack regained permeability, makes the new fluid ideal in ultrahigh-temperature explorations. The fluid has already been successfully applied in the field. Preliminary lab and field implementation results are discussed.