Abstract: A well service fluid comprising one or more anionic viscoelastic surfactants and one or more polymers is described. The fluids can contain an aqueous or non-aqueous fluid and/or a buffer for adjusting the pH of the fracturing fluid. The well service fluid can be used as a fracturing fluid in order to control water production from a well, while simultaneously increasing the oil production from the well.

Abstract: A well fracturing fluid comprising one or more anionic viscoelastic surfactants and one or more polymers is described. The fluids can contain an aqueous or non-aqueous fluid and/or buffer for adjusting the pH of the fracturing fluid. The well service fluid can used as a fracturing fluid in order to control water production from a well, while simultaneously increasing the oil production from the well.

Abstract: A viscous fluid is shown which is useful in treating subterranean formations. The fluid is formulated from an aqueous base, an alkyl sarcosinate surfactant and a buffer suitable for adjusting the pH of the blended fluid to a range in which the fluid is suitably viscosified. The fluid can also include an additional source of anions, such as chloride or fluoride ions, in order to increase the temperature stability of the fluid. The fluids have application for conventional well fracturing, coiled tubing fracturing, gravel packing and frac packing, as well as for use as selective water control additives and other applications.

Abstract: A well fracturing fluid comprising one or more anionic viscoelastic surfactants and one or more polymers is described. The fluids can contain an aqueous or non-aqueous fluid and/or a buffer for adjusting the pH of the fracturing fluid. The well service fluid can be used as a fracturing fluid in order to control water production from a well, while simultaneously increasing the oil production from the well.

Abstract: A viscous fluid is shown which is useful in treating subterranean formations. The fluid is formulated from an aqueous base, an alkyl sarcosinate surfactant and a buffer suitable for adjusting the pH of the blended fluid to a range in which the fluid is suitably viscosified. The fluid can also include an additional source of anions, such as chloride or fluoride ions, in order to increase the temperature stability of the fluid. The fluids have application for conventional well fracturing, coiled tubing fracturing, gravel packing and frac packing, as well as for use as selective water control additives and other applications.