Methods for Controlling Lost Circulation in A Subterranean Well and Materials There for

• US 20120322695A1
• Filed: 12/03/2010
• Published: 12/20/2012
• Est. Priority Date: 12/24/2009
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Kefi, Slaheddine, Lee, Jesse C., Shindgikar, Nikhil, Brunet-Cambus, Chrystel
• Granted Patent: US 9,896,612 B2
• Time in Patent Office: Days
• US Class Current: 507/118
• CPC Class Codes: C09K 2208/08 Fiber-containing well treatment fluids
• CPC Class Codes: C09K 8/32 Non-aqueous well-drilling compositions, e.g. oil-based
• CPC Class Codes: C09K 8/502 Oil-based compositions
• CPC Class Codes: C09K 8/516 characterised by their form or by the form of their components, e.g. encapsulated material
• CPC Class Codes: E21B 21/003 Means for stopping loss of drilling fluid plastering the borehole wall E21B33/138

Abstract

Method for controlling lost circulation in a subterranean well using oil-dispersible lost-circulation materials which comprise fibers that are coated (or sized) with a lipophilic coupling agent, a lipophilic film-forming polymer or both. The fibers are preferably between about 6 mm and about 25 mm long, and between about 10 μm and about 200 μm in diameter. The fibers may be added to carrier fluids comprising oil-base fluids, synthetic-base fluids, invert-emulsion-base fluids and combinations thereof. The preferred fiber concentration in the carrier fluid is between about 0.55 g/L and about 28.5 g/L. The carrier fluid may be a drilling fluid, a spacer fluid or a lost-circulation pill.

Claims

1. A method for controlling lost circulation in a subterranean well, comprising:

(i) selecting one or more fibers that are sized with a nonpolymeric lipophilic coupling agent;

(ii) mixing the selected fibers with a carrier fluid comprising one or more members of the list comprising;

an oil-base fluid, a synthetic-base fluid and an invert-emulsion-base fluid; and

(iii) pumping the carrier fluid into the lost-circulation zone.

2. The method of claim 1, wherein the fibers are chosen from polyamide fibers, polypropylene fibers, alkali-resistant glass fibers, or combinations thereof.

3. The method of claim 1, wherein the fiber length is between about 6 mm and about 25 mm.

4. The method of claim 1, wherein the fiber diameter is between about 10 μ

m and about 200 μ

m.

5. The method of claim 1, wherein the fibers are added to the carrier fluid at a concentration between about 0.55 g/L and about 28.5 g/L of fluid.

6. The method of claim 1, wherein the lipophilic coupling agent comprises one or more members of the list comprising:

alkyl groups, aromatic groups, acetic anhydride, n-alkyl isocyanate, titanates, trichloro-s-triazine, and organosilanes of the structure R—

S—

X₃, wherein R is an organic group and X comprises Cl, OMe or OEt.

7. The method of claim 1, further comprising the addition of one or more water-dispersible fibers that are sized with a hydrophilic coupling agent, a hydrophilic film-forming polymer or both.

8. The method of claim 1, wherein granular or flaked particles are added to the fibers.

9. A lost-circulation material comprising fibers that are sized with a nonpolymeric lipophilic coupling agent.

10. The material of claim 9, wherein the fibers are chosen from polyamide fibers, polypropylene fibers, alkali-resistant glass fibers, or combinations thereof.

11. The material of claim 9, wherein the fiber length is between about 6 mm and about 25 mm, and the fiber diameter is between about 10 μ

m and about 200 μ

m.

12. The material of claim 9, wherein the lipophilic coupling agent comprises one or more members of the list comprising:

alkyl groups, aromatic groups, acetic anhydride, n-alkyl isocyanate, titanates, trichloro-s-triazine, and organosilanes of the structure R—

S—

X₃, wherein R is an organic group and X comprises Cl, OMe or OEt.

13. The material of claim 9, further comprising one or more water-dispersible fibers that are sized with a hydrophilic coupling agent, a hydrophilic film-forming polymer or both.

14. A lost-circulation-treatment fluid comprising:

(i) fibers sized with a nonpolymeric lipophilic coupling agent; and

(ii) a carrier fluid comprising an oil-base fluid, synthetic-base fluid, or an invert-emulsion-base fluid, and mixtures thereof.

15. The fluid of claim 14, wherein the fibers are chosen from polyamide fibers, polypropylene fibers, alkali-resistant glass fibers, or combinations thereof.

16. The fluid of claim 14, wherein the fiber length is between about 6 mm and about 25 mm.

17. The fluid of claim 14, wherein the fiber diameter is between about 10 μ

m and about 200 μ

m.

18. The fluid of claim 14, wherein the fibers are added to the carrier fluid at a concentration between about 0.55 g/L and about 28.5 g/L of fluid.

19. The fluid of claim 14, wherein the lipophilic coupling agent comprises one or more members of the list comprising:

alkyl groups, aromatic groups, acetic anhydride, n-alkyl isocyanate, titanates, trichloro-s-triazine, and organosilanes of the structure R—

S—

X₃, wherein R is an organic group and X comprises Cl, OMe or OEt.

20. The fluid of claim 14, further comprising one or more fibers that are sized with a hydrophilic coupling agent, a hydrophilic film-forming polymer or both.