Degradable Material Assisted Diversion or Isolation

• US 20080200352A1
• Filed: 02/29/2008
• Published: 08/21/2008
• Est. Priority Date: 09/01/2004
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Fredd, Christopher N., Willberg, Dean M., Sullivan, Philip F., Bulova, Marina, Boney, Curtis L., Lassek, John, Hoefer, Ann M.W., Vostrukhov, Alexey
• Granted Patent: US 7,775,278 B2
• Time in Patent Office: Days
• US Class Current: 507/219
• CPC Class Codes: C09K 8/508 macromolecular compounds C09K8/512 takes precedence
• CPC Class Codes: C09K 8/516 characterised by their form or by the form of their components, e.g. encapsulated material
• CPC Class Codes: C09K 8/70 characterised by their form or by the form of their components, e.g. foams
• CPC Class Codes: C09K 8/74 combined with additives added for specific purposes
• CPC Class Codes: E21B 33/138 Plastering the borehole wall; Injecting into the formation
• CPC Class Codes: E21B 43/267 reinforcing fractures by propping

Abstract

A method for well treatment by forming a temporary plug in a fracture, a perforation, a wellbore, or more than one of these locations, in a well penetrating a subterranean formation is provided, in which the method of well treatment includes: injecting a slurry comprising a degradable material, allowing the degradable material to form a plug in a perforation, a fracture, or a wellbore in a well penetrating a formation; performing a downhole operation; and allowing the degradable material to degrade after a selected time such that the plug disappears.

Claims

1. A method of well treatment, comprising:

a) injecting a slurry comprising a degradable material, provided the degradable material is present in the slurry as a dispersed material;

b) allowing the degradable material to form a plug in one or more than one of a perforation, a fracture, and a wellbore in a well penetrating a formation;

c) performing a downhole operation; and

d) allowing the degradable material to at least partially degrade after a selected duration such that the plug disappears.

2. The method of claim 1, wherein the polymer is selected from a polymer of lactide, glycolide, polylactic acid, polyglycolic acid, amide, and mixtures thereof.

3. The method of claim 1, wherein the degradable material is present at a concentration of no less than 40 lbm/1,000 gal (4.8 g/L).

4. The method of claim 1, further comprising injecting a second material to induce a screenout.

5. The method of claim 1, wherein the degradable material is a fiber.

6. The method of claim 1, wherein the slurry further comprises a particulate material.

7. The method of claim 6, wherein the particulate material is degradable

8. The method of claim 7, wherein the particulate material is a proppant.

9. The method of claim 8, wherein the proppant comprises particles having a distribution of sizes.

10. The method of claim 1, wherein the slurry further comprises an additive for delaying degradation of the degradable material.

11. The method of claim 1, wherein the slurry further comprises an additive for accelerating degradation of the degradable material.

12. The method of claim 1, further comprising modeling to optimize parameters for the well treatment, wherein the step of injecting the slurry is based on the optimized parameters.

13. The method of claim 12, wherein the optimized parameters comprise the selected duration before the degradable material degrades.

14. The method of claim 1, wherein the well treatment comprises hydraulic fracturing.

15. The method of claim 14, wherein the hydraulic fracturing comprises injecting a pad, said pad comprising a fiber comprising a degradable material.

16. The method of claim 14, wherein hydraulic fracturing is applied to more than one layer of a multilayer formation.

17. The method of claim 15, wherein the step of injecting the slurry is performed at the tail end of fracturing a layer.

18. The method of claim 16, wherein no bridge plug or sand plug is placed in the wellbore before fracturing a subsequent layer.

19. The method of claim 16, wherein the degradable material forms the plug in the fracture by bridging with proppants in the fracture.

20. The method of claim 1, wherein the well treatment comprises acid fracturing or waterfrac.

21. The method of claim 1, wherein the selected duration is between 0.5 and 6 hours.

22. The method of claim 1, wherein the step of injecting the slurry is via coiled tubing installed in the well.

23. The method of claim 1 wherein the degradable material comprises a polyvinyl ester.

24. The method of claim 1, wherein the treatment is used to isolate a region selected from a fracture, a production zone, and a part of the wellbore, wherein the part of the wellbore is above the formation pressure.

25. The method of claim 1, wherein the degradable material is selected from limestone fibers and glass fibers.

26. The method of claim 1, wherein the well treatment comprises workover, cleanout, gravel packing, acid diversion, fluid loss control, diversion, cementing, acidizing, matrix acidizing, scale control, completion, water control, or sand control, or any combination thereof.

27. The method of claim 1, wherein the degradable material has a shape selected from the group consisting of powder, particulates, chips, fiber, bead, ribbon, platelet, film, rod, strip, spheroid, toroid, pellet, tablet, capsule, shaving, any round cross-sectional shape, any oval cross-sectional shape, trilobal shape, star shape, flat shape, rectangular shape, cubic, bar shaped, flake, cylindrical shape, filament, thread, or any mixtures thereof.

28. A method of well treatment, comprising:

a) injecting a slurry comprising a degradable material, provided the degradable material is present in the slurry as a finely divided material;

b) allowing the degradable material to form a plug in one or more than one of a perforation, a fracture, and a wellbore in a well penetrating a formation;

c) performing a downhole operation; and

d) allowing the degradable material to at least partially degrade after a selected duration such that the plug disappears.

29. A method of well treatment, comprising:

a) injecting a slurry comprising a degradable material, provided the degradable material is not in a bulk form;

b) allowing the degradable material to form a plug in one or more than one of a perforation, a fracture, and a wellbore in a well penetrating a formation;

c) performing a downhole operation; and

d) allowing the degradable material to at least partially degrade after a selected duration such that the plug disappears.