Nano-dispersion well servicing fluid containing a pH adjuster

• US 9,518,213 B2
• Filed: 07/09/2015
• Issued: 12/13/2016
• Est. Priority Date: 05/28/2010
• Status: Active Grant

• Current Assignee: Baker Hughes Holdings LLC (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Gupta, D. V. Satyanarayana, Cawiezel, Kay Elaine
• Primary Examiner(s): Hutton, Jr., Doug
• Assistant Examiner(s): RUNYAN, SILVANA C
• Application Number:
  US14/795,504
• Publication Number:
  US 20150307771A1
• Time in Patent Office: 523 Days
• Field of Search: 166/305.1, 166/268, 166/280.1, 166/300
• US Class Current: 1/1
• CPC Class Codes: C09K 2208/10 Nanoparticle-containing well treatment fluids
• CPC Class Codes: C09K 8/665 containing inorganic compounds proppants C09K8/80
• CPC Class Codes: C09K 8/68 containing organic compounds
• CPC Class Codes: C09K 8/685 containing cross-linking agents
• CPC Class Codes: C09K 8/80 Compositions for reinforcing fractures, e.g. compositions of proppants used to keep the fractures open
• CPC Class Codes: C09K 8/845 containing inorganic compounds

Abstract

A nano-dispersion well servicing fluid is disclosed. The well servicing fluid is formulated with components comprising: nanoparticles comprising at least one material chosen from aluminum oxides, aluminum hydroxides, aluminum hydroxyoxides, zirconium oxides, zirconium hydroxides, zirconium hydroxyoxides, wherein the concentration of nanoparticles is greater than 0.5% by weight based on the total weight of the nano-dispersion well servicing fluid. The well servicing fluid also comprises an aqueous base continuous phase. Methods of employing the nano-dispersion to service a wellbore are also disclosed.

Claims

1. A nano-dispersion well servicing fluid in a wellbore, the fluid being formulated with components comprising:

nanoparticles comprising at least one material chosen from aluminum oxides, aluminum hydroxides, aluminum hydroxyoxides, zirconium oxides, zirconium hydroxides, zirconium hydroxyoxides, the concentration of nanoparticles being greater than 0.5% by weight based on the total weight of the nano-dispersion well servicing fluid;

an aqueous base continuous phase, the nanoparticles forming a dispersion in the aqueous base continuous phase, the nanoparticles having a crystallized size of 100 nm or less in diameter prior to being dispersed, and the nanoparticles carrying a charge resulting in a Zeta potential in the nano-dispersion well servicing fluid; and

a pH adjuster configured to decrease the Zeta potential of the nano-dispersion well servicing fluid in the wellbore closer to zero and thereby to increase viscosity, the nano-dispersion well servicing fluid exhibiting a viscosity greater than would be exhibited without the pH adjuster.

2. The fluid of claim 1, wherein the concentration of nanoparticles ranges from about 2% to about 20% by weight based on the total weight of the nano-dispersion well servicing fluid.

3. The fluid of claim 1, wherein the fluid does not comprise a viscoelastic surfactant gelling agent in an amount effective to significantly increase the viscosity of the fluid.

4. The fluid of claim 1, wherein the nanoparticles comprise more than 50 wt. % boehmite.

5. The fluid of claim 1, wherein the pH adjuster decreases Zeta potential by increasing pH.

6. The fluid of claim 1, having a Zeta potential ranging from about 0 to about 50.

7. The fluid of claim 1, having a pH ranging from about 2 to about 14.

8. The fluid of claim 1, further comprising at least one delayed compound chosen from pH adjusters, surfactants, and esters configured to increase Zeta potential after a delay and thereby to decrease viscosity.

9. The fluid of claim 1, wherein the pH adjuster is chosen from NaOH, KOH, Ca(OH)₂, sodium bicarbonate, potassium carbonate, and sodium carbonate.

10. The fluid of claim 8, wherein the at least one delayed compound is an ester of polycarboxylic acid.

11. The fluid of claim 1, further comprising proppant or gravel.

12. The fluid of claim 1, wherein the continuous phase is a liquid chosen from fresh water, brine, and produced water.

13. The fluid of claim 12, wherein the concentration of salt in the brine is 0.5% by weight or more, based on the total weight of the brine.

14. The fluid of claim 1, wherein the fluid is formulated with at least one breaker.

15. The fluid of claim 1, wherein the fluid is formulated with at least one additional compound chosen from water wetting surfactants, non-emulsifiers, additional viscosifying agents, surfactants, clay stabilization additives, scale dissolvers, biopolymer degradation additives, fluid loss control additives and high temperature stabilizers.

16. A nano-dispersion well servicing fluid in a wellbore, the fluid being formulated with components comprising:

nanoparticles comprising at least one material chosen from aluminum oxides, aluminum hydroxides, aluminum hydroxyoxides, zirconium oxides, zirconium hydroxides, zirconium hydroxyoxides, the concentration of nanoparticles being greater than 0.5% by weight based on the total weight of the nano-dispersion well servicing fluid;

an aqueous base continuous phase, the nanoparticles forming a dispersion in the aqueous base continuous phase, the nanoparticles having a crystallized size of 100 nm or less in diameter prior to being dispersed, and the nanoparticles carrying a charge resulting in a Zeta potential ranging from about 0 to about 50 in the nano-dispersion well servicing fluid; and

a pH adjuster configured to decrease the Zeta potential of the nano-dispersion well servicing fluid in the wellbore closer to zero by increasing pH and thereby to increase viscosity, the nano-dispersion well servicing fluid exhibiting a viscosity greater than would be exhibited without the pH adjuster; and

an ester configured to increase Zeta potential after a delay and thereby to decrease viscosity.

17. The fluid of claim 16, wherein the pH adjuster is chosen from NaOH, KOH, Ca(OH)₂, sodium bicarbonate, potassium carbonate, and sodium carbonate and the at least one delayed compound is an ester of polycarboxylic acid.

18. The fluid of claim 17, further comprising proppant or gravel.