Drilling Fluid Additive for Reducing Lost Circulation in a Drilling Operation

• US 20100193244A1
• Filed: 07/04/2008
• Published: 08/05/2010
• Est. Priority Date: 07/06/2007
• Status: Active Grant

• Current Assignee: Canadian Energy Services L.P. (Ces Energy Solutions Corp.)
• Original Assignee: Canadian Energy Services L.P. (Ces Energy Solutions Corp.)
• Inventors: Hoskins, Terry W.
• Granted Patent: US 8,607,895 B2
• Time in Patent Office: Days
• US Class Current: 175/5
• CPC Class Codes: C09K 2208/08 Fiber-containing well treatment fluids
• CPC Class Codes: C09K 8/035 Organic additives
• CPC Class Codes: C09K 8/36 Water-in-oil emulsions
• 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

Generally, the present invention provides drilling fluid additives for reducing or controlling lost circulation in a drilling operation. The additives comprises particles. The particles comprise one or more solids in association a wax or waxy substance. A drilling fluid comprising a drilling fluid additive of the invention is also provided, as well as a method and use of the drilling fluid additive in a drilling operation to reduce or control lost circulation. Methods for manufacturing the drilling fluid additives are also described.

Claims

1. A drilling fluid additive for reducing or controlling lost circulation in a drilling operation, the additive having particles comprising:

one or more solids in association with a wax or waxy substance.

2. The drilling fluid additive of claim 1, wherein particles remain substantially solid at ambient temperature.

3. The drilling fluid additive of claim 1, wherein the one or more solids is blended, mixed, coated or layered with wax, or a combination thereof.

4. The drilling fluid additive of claim 1, wherein the one or more solids are coated with wax.

5. The drilling fluid additive of claim 1, wherein the one or more solids are blended with wax.

6. The drilling fluid additive of claim 1, wherein the one or more solids is a lost circulation material.

7. The drilling fluid additive of claim 6, wherein the lost circulation material is selected from sawdust, refined wood fibers, ground or refined cellulosic materials, ground or refined rubber or plastic, plastic or cellophane flakes, gilsonite, asphalt, asphaltenes, waxes, thickening agents, gelling agents, coffee grinds, paper, grass, glass or plastic beads, weighting agents, nut hulls or shells, bagasse fibers, minerals, course or fine mica, dried drill cuttings, sand or dirt;

or a combination of any of the above.

8. The drilling fluid additive of claim 7, wherein the lost circulation material is sawdust.

9. The drilling fluid additive of claim 7, wherein the lost circulation material is a ground or refined cellulosic material.

10. The drilling fluid additive of claim 7, wherein the lost circulation material is gilsonite.

11. The drilling fluid additive of claim 7, wherein the lost circulation material is nut hull.

12. The drilling fluid additive of claim 7, wherein the lost circulation material is a weighting agent selected from barite or calcium carbonate.

13. The drilling fluid additive of claim 1, wherein the particles comprise microparticles, macroparticles or a mixture thereof.

14. The drilling fluid additive of claim 13, wherein the microparticles are less than about 50 microns in size.

15. The drilling fluid additive of claim 13, wherein the microparticles are from about 0.01 to about 50 microns.

16. The drilling fluid additive of claim 13, wherein the macroparticles are greater than about 50 microns.

17. The drilling fluid additive of claim 13, wherein the macroparticles are from about 50 microns to about 40,000 microns.

18. The drilling fluid additive of claim 1, wherein the wax or waxy substance is a natural wax or a synthetic wax or a combination thereof.

19. The drilling fluid additive of claim 18, wherein the natural wax is beeswax, lanolin wax, lanocerin wax, shellac wax, soy wax, carnauba wax, candellila wax, jojoba wax, flax wax, sugarcane wax, ouricouri wax, petroleum wax, earth wax, fossil wax, paraffin wax, petrolatum wax, microcrystalline wax, semi-microcrystalline wax, intermediate wax, ozocerite wax, ceresine wax or montan wax.

20. The drilling fluid additive of claim 18, wherein the synthetic wax is polypropylene, polyethylene, high density polyethylene, polytetrafluoroethylene, Fischer-Tropsch, fatty acid amine, fatty amide, polyolefin, alpha olefin, polyamide wax, chlorinated wax, or other chemically modified wax.

21. The drilling fluid additive of claim 20, wherein the synthetic wax is polyethylene wax.

22. The drilling fluid additive of claim 1, wherein the particles comprise refined paraffin wax, microcrystalline wax, polyethylene wax or a mixture thereof.

23. The drilling fluid additive of claim 1, wherein the wax or waxy substance is selected such that all or a portion of the particles are substantially insoluble in a selected base fluid, carrier fluid or drilling fluid at temperatures below the melt point of the particles.

25. The drilling fluid additive of claim 1, wherein the wax or waxy substance is selected such that all or a portion of the particles will melt at a geothermal temperature in an underground formation or at a production zone in an underground formation for geothermal removal.

26. The drilling fluid additive of claim 1, wherein the wax or waxy substance is substantially insoluble in hydrocarbons below the melt point of the particles.

27. The drilling fluid additive of claim 1, wherein the wax or waxy substance or mixture thereof has a melt point between about 40°

C. and about 160°

C.

28. The drilling fluid additive of claim 1, which is non-toxic and biodegradable.

30. The drilling fluid additive according to claim 1, further comprising, in combination, a drilling fluid of in which the drilling fluid additive is provided.

31. The drilling fluid additive of claim 30, wherein the drilling fluid is hydrocarbon based, aqueous based, synthetic based or an emulsion.

32. The drilling fluid additive of claim 31, wherein the drilling fluid is aqueous based.

33. The drilling fluid additive of claim 32, wherein the drilling fluid is fully disposable.

34. The drilling fluid additive of claim 31, wherein the drilling fluid is a hydrocarbon or an invert emulsion.

29. Use of a drilling fluid additive having particles comprising one or more solids in association with a wax or waxy substance for reducing or controlling lost circulation during a drilling operation.

24. The use of claim 29, wherein the wax or waxy substance remains substantially solid during the drilling operation.

35. A method of reducing or controlling lost circulation in a drilling operation, comprising:

providing a drilling fluid, the drilling fluid comprising a drilling fluid additive having particles comprising one or more solids in association with a wax or waxy substance; and

pumping the drilling fluid downhole during the drilling operation.

36. The method of claim 35, wherein the drilling fluid is viscosified.

37. The method of claim 35, wherein the drilling operation is an oil and gas drilling operation or a mining operation.

38. The method of claim 37, wherein the drilling operation is an oil and gas drilling operation.

39. The method of claim 38, wherein the oil and gas drilling operation is an offshore drilling operation.