Acidic viscosity enhancer for viscoelastic surfactant fluids
The invention discloses method of treating a subterranean formation of a well bore, the method comprising: providing a treatment fluid comprising: an aqueous base fluid; a viscosity enhancer; and a viscoelastic surfactant, wherein the enhancer is acid in the aqueous base fluid and co-operates with the viscoelastic surfactant to enhance viscosity compared to viscoelastic surfactant alone in the aqueous base fluid; and introducing the treatment fluid into the well bore.
1. A method of treating a subterranean formation of a well bore, the method comprising:
providing a treatment fluid comprising: an aqueous base fluid; a viscosity enhancer; and a cationic viscoelastic surfactant, wherein the enhancer is selected from the group consisting of salicylate, HCl, HNO 3 , and salts of HCl or HNO 3 in the aqueous base fluid, is in a concentration by weight in the range of from 0.001% to 0.5% and co-operates with the viscoelastic surfactant to enhance viscosity compared to viscoelastic surfactant alone in the aqueous base fluid; and
introducing the treatment fluid into the well bore.
2. The method of claim 1 , wherein the enhancer co-operates with the viscoelastic surfactant to increase viscosity compared to viscoelastic surfactant alone in the aqueous base fluid.
3. The method of claim 1 , wherein the viscoelastic surfactant is erucyl bis-(2-hydroxyethyl)methyl ammonium chloride.
4. The method of claim 1 , wherein the treatment fluid is foamed or energized.
5. A method of fracturing a subterranean formation of a well bore, the method comprising: providing a treatment fluid comprising: an aqueous base fluid; from 0.001% to 0.5% a viscosity enhancer; and a viscoelastic surfactant, wherein the enhancer is acid in the aqueous base fluid and co-operates with the viscoelastic surfactant to enhance viscosity compared to viscoelastic surfactant alone in the aqueous base fluid; and introducing the treatment fluid into the well bore at or above a pressure sufficient to create or enhance one or more fractures in a portion of the subterranean formation; wherein the viscosity enhancer is selected from the group consisting of salicylate, HCl, HNO 3 , and salts of HCl or HNO 3 .
6. The method of claim 5 , wherein the enhancer co-operates with the viscoelastic surfactant to increase viscosity compared to viscoelastic surfactant alone in the aqueous base fluid.
7. The method of claim 5 , wherein the viscoelastic surfactant is erucyl bis-(2-hydroxyethyl)methyl ammonium chloride.
8. The method of claim 5 , further comprising introducing proppant into the well bore.
9. The method of claim 5 , further comprising creating or enhancing wormholes in one or more fractures.
10. A method of gravel packing a subterranean formation of a well bore, the method comprising: providing a fluid comprising: an aqueous base fluid; from 0.001% to 0.5% a viscosity enhancer; and a viscoelastic surfactant, wherein the enhancer is acid in the aqueous base fluid and co-operates with the viscoelastic surfactant to enhance viscosity compared to viscoelastic surfactant alone in the aqueous base fluid; and introducing the fluid into the well bore; wherein the viscosity enhancer is selected from the group consisting of salicylate, HCl, HNO 3 , and salts of HCl or HNO 3 .
11. The method of claim 10 , wherein the enhancer co-operates with the viscoelastic surfactant to increase viscosity compared to viscoelastic surfactant alone in the aqueous base fluid.
12. The method of claim 10 , wherein the viscoelastic sufactant is crucyl bis-(2-hydroxyethyl)methyl ammonium chloride.
13. The method of claim 10 , wherein the treatment fluid is foamed or energized.
14. The method of claim 10 , further comprising introducing proppant into the well bore.