Baker Hughes Corporation

James H Treadway

James B Crews

Tianping Huang

John Robert Willingham

Allen Dale Gabrysch

Patrick Arthur Kelly

William Russell Wood

An aqueous, viscoelastic fluid gelled with a viscoelastic surfactant (VES) is stabilized and improved with an effective amount of an alkaline earth metal oxide, alkaline earth metal hydroxide, alkali metal oxides, alkali metal hydroxides, transition metal oxides, transition metal hydroxides, post-transition metal oxides, and post-transition metal hydroxides. These fluids are more stable and have a reduced or no tendency to precipitate, particularly at elevated temperatures. The additives may reduce the amount of VES required to maintain a given viscosity. These stabilized, enhanced, aqueous viscoelastic fluids may be used as treatment fluids for subterranean hydrocarbon formations, such as in hydraulic fracturing. The particle size of the magnesium oxide or other agent may be nanometer scale, which scale may provide unique particle charges that use chemisorption, crosslinking and/or other chemistries to associate and stabilize the VES fluids.

Nano-sized particles for stabilizing viscoelastic surfactant fluids

Viscoelastic surfactant (VES) gelled aqueous fluids containing water, a VES, an internal breaker, a VES stabilizer, a fluid loss control agent and a viscosity enhancer are useful as treating fluids and particularly as fracturing fluids for subterranean formations. These VES-based fluids have faster and more complete clean-up than polymer-based fracturing fluids. The use of an internal breaker permits ready removal of the unique VES micelle based pseudo-filter cake with several advantages including reducing the typical VES loading and total fluid volume since more VES fluid stays within the fracture, generating a more optimum fracture geometry for enhanced reservoir productivity, and treating reservoirs with permeability above the present VES limit of approximately 400 md to at least 2000 md.

Methods and compositions for fracturing subterranean formations

Alkaline earth metal compounds may be fluid loss control agents for viscoelastic surfactant (VES) fluids used for well completion or stimulation in hydrocarbon recovery operations. The VES fluid may further include proppant or gravel, if it is intended for use as a fracturing fluid or a gravel packing fluid, although such uses do not require that the fluid contain proppant or gravel. The fluid loss control agents may include, but not be limited to, oxides and hydroxides of alkaline earth metal, and in one case magnesium oxide where the particle size of the magnesium oxide is between 1 nanometer to 0.4 millimeter. The fluid loss agent appears to associate with the VES micelles and together form a novel pseudo-filter cake crosslinked-like viscous fluid layer that limits further VES fluid flow into the porous media. The fluid loss control agent solid particles may be added along with VES fluids.

Fluid loss control agents for viscoelastic surfactant fluids

An aqueous, viscoelastic fluid gelled with a viscoelastic surfactant (VES) is stabilized and improved with an effective amount of an alkali earth metal oxide and/or alkali earth metal hydroxide. These fluids are more stable and have reduced or no tendency to precipitate, particularly at elevated temperatures. The additives may also increase viscosity to the point where less VES is required to maintain a given viscosity. These stabilized, enhanced, aqueous viscoelastic fluids may be used as treatment fluids for subterranean hydrocarbon formations, such as in hydraulic fracturing.

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Magnolia, TX, United States of America

James H Treadway