Foamed nitrogen in liquid CO2 for fracturing

摘要

A method for fracturing subterranean formations surrounding oil and gas wells using a fracturing fluid consisting of a foam constituted by a liquid phase and a gaseous phase. The liquid phase has a foam forming substance dissolved therein. The foam forming substance is preferably a surfactant such as a non-ionic hydrofluoroether surfactant. The liquid phase is preferably CO2 and the gaseous phase N2.