While several three-dimensional (3D) fracturing models exist for incompressible water-based fluids, none are able to capture the thermal and compositional effects that are important when using energized fluids. This paper introduces a new 3D, compositional, non-isothermal, fracturing model designed for compressible fracturing fluids. The new model predicts changes in temperature and fluid density. These changes are treated on a firm theoretical basis by using an energy balance equation and an equation of state, both in the fracture and in the wellbore. The model is capable of handling any multi-component mixture of fluids and chemicals. Changes in phase behavior with temperature, pressure and composition can be modeled.

A new simulator has been developed based on the compositional model presented in this paper. The simulator is validated for traditional fluid formulations against known anlytical solutions and against a well-established commercial fracutring simulator. Results from teh new simulator are then presented for energized fluids such as CO₂ and LPG. This tool is specifically suited for fracture design in formations in which energized fluids constitude a viable alternative to traditional fracturing fluids. This is notably the case in reservoirs that are depleted, under-saturated, or water-sensitive.