AMENDED CLAIMS [Received by the International Bureau on 03 August 2004 (03.08.2004); original claims 1-60 replaced by amended claims 1-62
1. A system fluid having effective rheology comprising an amount of one or more aerogels comprismg particles comprising a bubble matrix comprising retained gas, said aerogels being effective to reduce density of said system fluid compared to the same system fluid absent said amount of said one or more aerogels.
2. The system fluid of claim 1 selected from the group consisting of drilling fluids, drill-in fluids, completion fluids, workover fluids, spotting fluids, and cementing fluids.
3. The system fluid of claim 1 comprising a drilling system fluid selected from the group consisting of drilling fluids, drill-in fluids, completion fluids, workover fluids, and spotting fluids.
4. The system fluid of claims 1-2 and 3 wherein said one or more aerogels comprise one or more inorganic aerogels.
5. The system fluid of claims 1-2 and 3 wherein said one or more aerogels comprise one or more organic aerogels,
6. The system fluid of claims 1-4 and 5 wherein said one or more aerogels are hydrophilic,
7. The system fluid of claim 1-5 and 6 wherein said one or more aerogels comprise an element selected from the group consisting of silicon, aluminum, titanium, zirconium, tin, lithium, cerium, vanadium, and mixtures thereof.
8. The system fluid of claims 1-6 and 7 wherein said one or more aerogels comprise silicon.
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9. The system fluid of claims 1-7 and 8 wherein said one or more aerogels comprise silicon oj de.
10. The system fluid of claims 1-S and 9 wherein said one or more aerogels comprise particles having an average diameter of about 200 μm or less.
11. The system fluid of claims 1-9 and 10 wherein said one or more aerogels comprising particles having an average diameter of about 1 μm or more.
12. The system fluid of claims 1-8 and 9 wherein said one or more aerogels comprises particles having an average diameter of from about 1 μm to about 44 μm.
13. The system fluid of claims 1-11 and 12 wherein said one or more aerogels comprise particles having a particle size distribution effective to bridge pores in a subterranean formation.
14. The system fluid of claims 1-12 and 13 wherein said one or more aerogels comprise particles having a particle size distribution which produces an effective filter cake during drilling operations.
15. The system fluid of claims 1-13 and 14 wherein said one or more aerogels comprise particles having a density of about 0.2 g/cm3 or less.
16. The system fluid of claims 1-14 and 15 wherein said one or more aerogels comprise particles having a density of about 0.35 g/cm3 or less.
17. The system fluid of claims 1-13 and 14 wherein said one or more aerogels comprise particles having a density of from about 0.1 to about 0.35 g/cm .
IS. The system fluid of claims 1-16 and 17 wherein said one or more aerogels ι comprise particles comprising about 90% gas or more.
1 . The system fluid of claims 1-16 and 17 wherein said one or more aerogels comprises particles comprising about 95% gas or more.
20. The system, fluid of claims 1-18 and 19 wherein said one or more aerogels comprise particles having a total surface area of about 200 m2/g or more.
21. The system fluid of claims 1-1S and 19 wherein said one or more aerogels comprise particles having a total surface area of about 600 m2/g or more.
22. The system fluid of claims 1-18 and 19 wherein said one or more aerogels comprise particles having a total surface area of about 700 m2/g or more.
23. The system fluid of claims 1-21 and 22 wherein said retained gas is selected from the group consisting of air, oxygen, helium, nitrogen, carbon dioxide, and inert or low activity gases.
24. The system fluid of claims 1-21 and 22 wherein said retained gas comprises air.
25. The system fluid of claims 1-21 and 22 wherein said retained gas comprises helium.
26. The system fluid of claims 1 -24 and 25 wherein said one or more aerogels are stable at temperatures of about 150 °C or more.
27. The system fluid of claims 1-24 and 25 wherein said one or more aerogels are stable at temperatures of about 250 °C or more.
28. The system fluid of claims 1 -24 and 25 wherein said one or more aerogels are stable at temperatures of about 350 °C or more.
29. The system fluid of claims 1-24 and 25 wherein said one or more aerogels are stable al temperatures of about 450 °C. or more.
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30. The system fluid of claims 1-24 and 25 wherein said one or more aerogels are stable at temperatures ©f about 600 °C or more.
31. The system fluid of claims 1-29 and 30 wherein said one or more aerogels comprise NANOGEL®.
32. Th© system fluid of claims 1-30 and 31 wherein said amount of said one or more aerogels produces a system fluid density of from about 1 lb/gal to about 8 lb/gal.
33. The system fluid of claims 1-30 and 31 wherein said amount of said one or more aerogels produces a system fluid density of from about 3 lb/gal to about 6 lb/gal.
34. The system fluid of claims 1-32 and 33 wherein said system fluid is hydrophilic and said one or more aerogels are hydrophilic.
35. The system fluid of claims 1-32 and 33 wherein said system fluid is hydrophobic and said one or more aerogels are hydrophobic.
36. The system fluid of claims 1-34 and 35 wherein a filter cake comprising said one or more aerogels is converted to a gel upon exposure to one or more component selected from the group consisting of heat, a pH of from about 8 to about 13, and contact with water.
37. The system fluid of claims 1-35 and 36 wherein a borehole comprismg a filter cake comprising said one or more aerogels is cleaned in the absence of acid.
38. The system fluid of claims 1-36 and 37 wherein said system fluid is selected from the group consisting of water-based and oil-based fluid.
39. The system fluid of claims 1-37 and 38 wherein said system fluid comprises an oil selected from the group consisting of olefins, paraffins, water insoluble polyglycols,
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water insoluble esters, diesel, water insoluble Fischer-Tropsch reaction products, other organic materials tlrøt are aon-toide at the concentrations used9 and combinations thereof.
40. The system fluid of claims 1-37 and 38 wherein said system fluid comprises one or more non-tosde synthetic olefins.
41. The system fluid of claims 1-37 and 38 wherein said system fluid comprises one or more non-toxic olefins selected from the group consisting of polyalphaolefms, linear alpha olefins, and internal olefins.
42. The system fluid of claims 1-37 and 38 wherein said system fluid is selected from the group consisting of PERFFLOW® and SCIFLOW™.
43. The system fluid of claims 1-41 and 42 wherein the amount of said one or more aerogels produces a system fluid density of from about 1 lb/gal to about 8 lb/gal.
44. The system fluid of claims 1-41 and 42 wherein the amount of said one or more aerogels produces a system fluid density of from about 3 lb/gal to about 6 lb/gal.
45. The system fluid of claims 1-43 and 44 wherein said amount of said one or more aerogels is from about 55 to about 62% of said system fluid.
46. A method comprising using the system fluid of any of claims 1-44 and 45 during drilling operations.
47. The method of claim 46 further comprising effectively bridging pores in a formation during said drilling operations with a bridging agent comprising said one or more aerogels.
48. The method of claims 46 and 47 further comprising producing an effective filter cake comprising said one or more aerogels during said drilling operations.
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49. The method of claim 48 further comprising converting said filter cake to a gel upon exposure to one or more component selected from the group consisting of heat, a pH of from about § to about 13S and contact with water.
50. The method of claim 4 further comprising effectively cleaning a borehole comprising said filter cake in the absence of acid.
51. A method for reducing density of fluids useful during drilling operations comprising providing a quantity of a system fluid comprising an amount of one or more aerogels comprising particles comprising a bubble matrix comprising retained gas, the system fluid having effective rheology and lubricity properties and having a reduced density compared to the same system fluid absent said amount of said one or more aerogels.
52. The method of claim 51 wherein said system fluid is selected from the group consisting of drilling fluids, drill-in fluids, completion fluids, workover fluids, spotting fluids, and cementing fluids.
53. The method of claim 51 wherein said system fluid is a drilling system fluid selected from the group consisting of drilling fluids, drill-in fluids, completion fluids, workover fluids, and spotting fluids.
54. The method of claims 51 -52 and 53 further comprising effectively bridging pores in a formation during said drilling operations using a bridging agent comprising said one or more aerogels.
55. The method of claims 51 -53 and 54 further comprising producing an effective filter cake comprising said one or more aerogels during said drilling operations.
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56. The method of claims 51-54 and 55 wherein said amount of said one or more aerogels is effective to produce a system fluid density of from about 1 lb/gal to shout 8 lb/gal.
57. The method of claims 51 -54 and 55 wherein said amount of said one or more aerogels is effective to produce a system fluid density of from about 3 lb/gal to about 6 lb/gal.
58. The method of claims 55-56 and 57 further comprising converting said filter cake to a gel upon exposure to one or more component selected from the group consisting of heat, a pH of from about 8 to about 13, and contact with water.
59. The method of claims 55-56 and 57 further comprising cleaning a borehole comprising said filter cake in the absence of acid.
60. The system fluid of claims 51-58 and 59 wherein said amount of said one or more aerogels is from about 55 to about 62% of said system fluid.
61. The system fluid of claims 51-59 and 60 wherein said amount of said one or more aerogels comprise particles having a density of about 0.35 g/cm3 or less.
62. The system fluid of claims 51 -60 and 1 wherein said amount of said one or more aerogels comprise particles comprising about 90% gas or more.
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