Abstract: An aqueous viscoelastic fluid for enhancing the productivity of a subterranean formation contains, in addition to an anionic surfactant and a cationic surfactant, hydroxyethyl cellulose (HEC). The fluid may be pumped neat into the formation, foamed with nitrogen to qualities exceeding 90% or emulsified with liquid carbon dioxide to emulsion quality approaching 90%.

Abstract: Disclosed is a method for fracture stimulating well bores using gaseous nitrogen and/or liquid carbon dioxide combined with a partially dehydrated proppant. The method includes mixing proppant with a fracturing fluid to create a proppant-laden slurry, removing the majority of the fluid from the proppant using centrifugal forces, blending the proppant with gaseous nitrogen and/or liquid carbon dioxide, and thereafter utilizing that combination to fracture-stimulate well bores. The method also includes the use of monitoring and flow control equipment to regulate and/or automate the method.

Abstract: Disclosed is a method for fracture stimulating well bores using gaseous nitrogen and/or liquid carbon dioxide combined with a partially dehydrated proppant. The method includes mixing proppant with a fracturing fluid to create a proppant-laden slurry, removing the majority of the fluid from the proppant using centrifugal forces, blending the proppant with gaseous nitrogen and/or liquid carbon dioxide, and thereafter utilizing that combination to fracture-stimulate well bores. The method also includes the use of monitoring and flow control equipment to regulate and/or automate the method.