Synthetic Polymer Fracturing Fluid for High-Temperature Applications

Abstract

Abstract High-temperature fracturing fluids based on guar degrade rapidly at temperatures above 300°F, complicating stimulation of high-temperature wells. A synthetic polymer was developed that overcomes the hydrolytic stability limitations of polysaccharides while maintaining the ability to crosslink and break the fluid. This paper presents the initial laboratory development of a fracturing fluid using the synthetic polymer. Hydration is rapid compared to guar, eliminating the need for special hydration tanks or equipment when mixed on-the-fly. Crosslinking is achieved with conventional zirconium crosslinkers to yield a highly viscoelastic gel. Static and dynamic fluid-loss test data are presented and compared to guar-based fluids. Dynamic effects on fluid-loss rates were negligible compared to a borate-crosslinked guar fluid over a wide range of matrix permeabilities. Rheological characterization up to 400°F was performed with a Fann Model 50 viscometer and clearly demonstrated the synthetic frac fluid's high stability relative to guar. Additionally, effects of various breaker types are presented.