LPG Saturation Curve
LPG Saturation Curve (Pumping) - The following graph shows the temperature/pressure combinations at which LPG exists as a liquid or a vapour. Liquid LPG exists when the corresponding Pressure and Temperature is above the blue line (Liquid Vapour Curve). LPG remains as Liquid over a wide range of Pressures and Temperatures that are encountered during typical fracture stimulation.
PG Saturation Curve (Flow- back) - The following graph shows temperature/pressure combinations at which an LPG/Methane mixture exists as a liquid or a vapour. Methane is used in this example as it constitutes a major component of Natural Gas. Liquids and vapour exists when the corresponding pressure and temperature is above the Liquid Vapour Curve. Pure vapour and gas exists at a point below and to the right of the Liquid Vapour Curve. This graph shows that when mixed in formation and flowed back, LPG carrier fluid, which is highly soluble in reservoir gas (Methane), pushes the Liquid Vapour Curve up and to the left. The LPG/Ethane mixture will then form a multi-phase or a single phase that further reduces the specific gravity of the LPG and enhances the rapid recovery the fracturing fluid.