A New Noncrosslinked Foam-Based Fluid for High-Temperature Fracturing Applications

Abstract This study presents the development of an innovative fluid for high-temperature carbon dioxide (CO2) foam fracturing applications. Using an advanced closed-loop foam rheometer as well as a coaxial cylinder rotational rheometer, detailed measurements of CO2 foam and base fluid rheology under realistic conditions were obtained. The findings demonstrated that a proprietary acrylamide-based polymer exhibited superior stability compared with diutan gum and scleroglucan at 300°F. An amphoteric surfactant was shown to deliver excellent foamability and foam stability. Additionally, the introduction of CO2 significantly enhanced the viscosity of fluid containing 35 lbm per 1,000 gal of an acrylamide-based polymer and amphoteric surfactant. The viscosity of foam containing specified base fluid increased alongside foam quality (the volumetric percentage of the gas phase). The study also examined the impact of the polymer concentration on the base fluid’s viscosity and evaluated its compatibility with hydrochloric acid and spent acid, highlighting its potential for acid fracturing applications.