Method for drilling and completing boreholes with electro-rheological fluids

• US 20040094331A1
• Filed: 11/10/2003
• Published: 05/20/2004
• Est. Priority Date: 01/23/2002
• Status: Active Grant

• Current Assignee: Ali Mese, Mohamed Soliman
• Original Assignee: Ali Mese, Mohamed Soliman
• Inventors: Soliman, Mohamed, Mese, Ali
• Granted Patent: US 6,959,773 B2
• Time in Patent Office: Days
• US Class Current: 175/65
• CPC Class Codes: C09K 8/32 Non-aqueous well-drilling compositions, e.g. oil-based
• CPC Class Codes: C10M 171/001 Electrorheological fluids; smart fluids
• CPC Class Codes: E21B 21/003 Means for stopping loss of drilling fluid plastering the borehole wall E21B33/138
• CPC Class Codes: Y10S 507/904 Process of making fluids or additives therefor

Abstract

A method is provided for drilling, completing and fracturing a subterranean formation. In the method, an electrical potential is applied to oil or synthetic based drilling fluid to increase the viscosity of the fluid and enable the fluid to entrain drill cuttings and proppant. The same base fluid may be used for drilling, completion and fracturing by adjusting the electrical potential and consequently the viscosity of the fluid for the particular application. In fracturing, little or no potential is applied until the fluid enters the zone of the formation to be fractured. High potential is then applied at the fracture point of the formation to effect fracturing and to enable the fluid to transport proppant into the fracture.

Claims

1. A method for controlling or modifying the viscosity of a synthetic wellbore fluid in a wellbore penetrating a subterranean formation, said method comprising:

determining the amount of viscosity desired for said fluid;

determining the electrical potential that, when applied to or contacted with said fluid, will cause said fluid to have said viscosity desired;

providing said electrical potential to said fluid or contacting said fluid with said electrical potential, at the point in the wellbore at which the wellbore fluid is desired to have said viscosity;

continuing said application or contact of said electrical potential to said fluid for as long as said viscosity is desired.

2. The method of claim 1 wherein said fluid is used for drilling said wellbore.

3. The method of claim 1 wherein said fluid is used for completing said wellbore.

4. The method of claim 1 wherein said fluid is used for both drilling and completing said wellbore.

5. The method of claim 1 wherein said fluid is used for fracturing the subterranean formation.

6. The method of claim 1 wherein said fluid is used for a well treatment operation.

7. The method of claim 1 wherein said fluid is a Newtonian fluid.

8. The method of claim 1 further comprising considering the depth of the wellbore and wellbore conditions at such depth in determining the desired viscosity of the wellbore fluid and the electrical field and the electrical potential needed to effect such viscosity.

9. The method of claim 8 wherein said wellbore is fitted with at least one electrical source or transmitter to effect application of said potential to said wellbore fluid.

10. The method of claim 8 further comprising repeating the steps of said method for different wellbore depths.

11. The method of claim 10 wherein different electrical potentials are applied to the fluid at different depths of the wellbore.

12. The method of claim 11 wherein said different potentials at different depths are applied simultaneously.

13. A method for drilling or completing a borehole penetrating a subterranean formation, said method comprising employing an electro-rheological synthetic fluid whose viscosity varies with application and level of an electrical potential on the fluid, such that the viscosity of said fluid is adjusted by adjusting said electrical potential.

14. The method of claim 13 wherein said potential is applied to increase the viscosity of said fluid at the same time as or after said fluid is introduced into the borehole.

15. The method of claim 13 wherein said potential is decreased or eliminated to reduce the viscosity of said fluid for ease of pumping or to avoid fracturing said formation.

16. The method of claim 13 wherein said potential is applied to increase the viscosity of said fluid for removal of cuttings from the wellbore.

17. The method of claim 13 wherein said potential is applied to increase the viscosity of said fluid for well-cleanup.

18. The method of claim 18 wherein less potential is applied to decrease the viscosity of said fluid for ease of removal of said fluid after well-cleanup.

19. A method for drilling a borehole penetrating a subterranean formation, said method comprising:

introducing an electro-rheological synthetic fluid into said borehole during said drilling;

applying an electrical potential to said fluid to increase the viscosity of said fluid;

circulating said fluid in the formation;

entraining drill cuttings in said fluid;

decreasing said potential to decrease the viscosity of said fluid; and

removing said fluid from said borehole.

20. The method of claim 19 further comprising employing said fluid in completing said borehole, applying an electrical potential to said fluid to increase the viscosity of said fluid, and removing or reducing said electrical potential to said fluid to decrease the viscosity of said fluid as desired to effect such completion.

21. A method for drilling or completing a borehole penetrating a subterranean formation, or for fracturing said formation, said method comprising:

(a) fitting said borehole with electrical sources or transmitters;

using a synthetic electro-rheological fluid as a drilling or completing fluid in said borehole;

(b) using said electrical sources or transmitters to selectively apply an electrical potential to said fluid to selectively increase the viscosity of said fluid to entrain drill cuttings, or to effect borehole completion, or to facilitate fracturing of the formation; and

(c) reducing said electrical potential to facilitate pumping of said fluid or removal of said fluid from the formation or the borehole.

22. The method of claim 21 wherein said fluid is used for both drilling and completion of said borehole.

23. The method of claim 21 wherein said fluid is used only for fracturing said formation.

24. The method of claim 23 wherein said fluid comprises proppant.

25. The method of claim 21 wherein said fluid is a drilling fluid used in drilling said borehole.

26. The method of claim 21 wherein no potential or low potential is applied to said fluid while the fluid is introduced into the wellbore so that the fluid has low viscosity, a low friction pressure drop occurs, and the fluid enters the formation.