초록 ▼

The present invention relates to proppants which can be used to prop open subterranean formation fractions. Proppant formulations are further disclosed which use one or more proppants of the present invention. Methods to prop open subterranean formation fractions are further disclosed. In addition,

The present invention relates to proppants which can be used to prop open subterranean formation fractions. Proppant formulations are further disclosed which use one or more proppants of the present invention. Methods to prop open subterranean formation fractions are further disclosed. In addition, other uses for the proppants of the present invention are further disclosed, as well as methods of making the proppants.

대표청구항 ▼

What is claimed is: 1. A proppant comprising a template sphere having at least one void within the interior of the template sphere and said template sphere having a Krumbein sphericity of at least about 0.3 and a roundness of at least about 0.1, said proppant having a Krumbein sphericity of at leas

What is claimed is: 1. A proppant comprising a template sphere having at least one void within the interior of the template sphere and said template sphere having a Krumbein sphericity of at least about 0.3 and a roundness of at least about 0.1, said proppant having a Krumbein sphericity of at least about 0.5 and a roundness of at least about 0.4, and a continuous sintered shell around the entire outer surface of said template sphere, and wherein said shell comprises a ceramic material or oxide thereof and said template sphere comprises a material that withstands sintering at a temperature of 700�� C. for 30 minutes, in air or an oxidizing atmosphere. 2. The proppant of claim 1, wherein said continuous shell has a thickness of from about 5 microns to 150 microns, and said template sphere has a specific gravity of 0.01 g/cc to about 1.5 g/cc, and said proppant has a crush strength of about 1,500 psi or greater, and said template sphere has a void volume % of at least 30%. 3. The proppant of claim 1, wherein said template sphere having a sphericity of at least about 0.6, a continuous sintered shell around the entire outer surface of said template sphere, wherein said continuous shell has a substantially uniform thickness, and wherein said template sphere has a specific gravity of 0.01 g/cc to about 1.5 g/cc, and said proppant has a crush strength of about 1,500 psi or greater, and said template sphere has a void volume % of at least 30%. 4. The proppant of claim 2, wherein said crush strength is at least 2,500 psi. 5. The proppant of claim 2, wherein said crush strength is 2,500 psi to 15,000 psi. 6. The proppant of claim 3, wherein said crush strength is at least 2,500 psi. 7. The proppant of claim 3, wherein said crush strength is 2,500 psi to 15,000 psi. 8. The proppant of claim 2, wherein said void volume % is from 30 % to 95 %. 9. The proppant of claim 2, wherein said void volume % is from 50 % to 95 %. 10. The proppant of claim 2, wherein said void volume % is from 60 % to 90%. 11. The proppant of claim 2, wherein said template sphere has one central void. 12. The proppant of claim 2, wherein said template sphere has one central void and multiple voids throughout said template sphere. 13. The proppant of claim 1, wherein said template sphere comprises a mixture of aluminum oxide and silicon oxide. 14. The proppant of claim 1, wherein said shell comprises aluminum oxide, silicon oxide, zirconium oxide, magnesium oxide, or any combination thereof. 15. The proppant of claim 1, wherein said template sphere comprises aerogel, xerogel, pumice, envirospheres, perlite, vermiculite, or fired template spheres. 16. The proppant of claim 1, wherein said shell comprises two or more layers, wherein one of the layers comprises said ceramic material or oxide thereof. 17. The proppant of claim 16, wherein at least one layer of said shell comprises a resin layer or polymer layer. 18. The proppant of claim 17, wherein said resin layer or polymer layer is the outermost layer comprising said shell. 19. The proppant of claim 1, wherein said template sphere has a crush strength of 100 psi to 1,000 psi and said proppant has a crush strength of at least 2,500 psi. 20. The proppant of claim 1, wherein said shell comprises a reinforcement material. 21. The proppant of claim 20, wherein said reinforcement material is a fiber, whisker, filler, or any combination thereof. 22. The proppant of claim 20, wherein said reinforcement material is carbon black, fiberglass, carbon fibers, ceramic whiskers, ceramic particulates, metallic particles, or any combination thereof. 23. The proppant of claim 1, wherein said shell comprises a metal carbide, metal nitride, or any combination thereof. 24. The proppant of claim 1, wherein said shell comprises a zirconium oxide, a zirconium carbide, a zirconium nitride, or any combination thereof. 25. The proppant of claim 24, wherein said shell further comprises magnesium oxide, calcium oxide, cerium oxide, yttrium oxide, scandium oxide, or any combination thereof. 26. The proppant of claim 1, wherein said shell comprises a metal oxide, a metal carbide, a metal nitride, or any combination thereof, along with silicon, titantium, tungsten, aluminum, boron, or any combination thereof. 27. The proppant of claim 1, wherein said shell is surface modified with the addition of silicon oxide, sodium oxide, potassium oxide, calcium oxide, zirconium oxide, aluminum oxide, lithium oxide, iron oxide, or any combination thereof. 28. The proppant of claim 1, wherein said shell is surface modified by applying at least one organic material to said shell. 29. The proppant of claim 1, wherein said shell comprises multiple layers, wherein one of the layers comprises a metal nitride or metal carbide or both. 30. The proppant of claim 1, wherein a glazing layer is present on said template sphere and in immediate contact with said template sphere. 31. The proppant of claim 30, wherein said glazing layer comprises silica, mullite, cordierite, spodumene, or any combination thereof. 32. The proppant of claim 30, wherein at least a portion of said glazing layer penetrates or infiltrates below the surface of said template sphere. 33. A method of forming the proppant of claim 1, comprising blowing into template spheres with a coaxial blowing nozzle, a suspension or dispersion comprising inorganic or organic solid particles having particle diameters in the range of from 0.001 to 10 microns and heating said template spheres to evaporate any liquid from said suspension or dispersion, and then optionally hardening the template spheres, and further providing a shell around the entire outer surface of said template spheres and then sintering said shell to form a continuous sintered shell. 34. The method of claim 33, further comprising subjecting the template spheres to elevated temperatures to sinter and/or fuse said particles that form the template spheres. 35. The method of claim 33, wherein said suspension or dispersion further comprises a binder material, a film stabilizing agent, a dispersing agent, and a continuous aqueous or non-aqueousl liquid phase. 36. The method of claim 33, wherein providing said shell comprises introducing said template spheres into a fluidized bed and coating said template spheres with a suspension or dispersion comprising a ceramic material or oxide thereof. 37. A method of forming the proppant of claim 1, comprising: a) forming template spheres by tumbling together and mixing (1) solidifiable liquid material comprising a thermally fugitive organic binder material and a source of void-forming agent adapted to evolve as a gas and convert the liquid material to a template sphere and (2) a mass of minute discrete free-flowing inorganic heat-sinterable parting agent particles selected from metals, metalloids, metal oxides and metal salts that are welled by, and at least partially absorbed into, the liquid material during the tumbling action to form liquid spheres; sufficient parting agent particles being present so that any portion of liquid material uncovered by parting agent particles tumble against discrete unabsorbed parting agent particles; b) providing conditions during the tumbling action, and tumbling for a sufficient time for the void-forming agent to evolve as a gas and form a central interior space within the liquid spheres and for the thus-hollowed liquid spheres to solidify; c) collecting the spheres after they have solidified to a shape-retaining condition; d) optionally firing the hollow spheres to first burn out the organic binder, and to then sinter the parting agent particles to form template spheres; and e) providing a shell around the entire outer surface of said template spheres and then sintering said shell to form a continuous sintered shell. 38. The method of claim 37, where in step (d) occurs. 39. The method of claim 37, wherein providing said shell comprises introducing said template spheres into a fluidized bed and coating said template spheres with a suspension or dispersion comprising a ceramic material or oxide thereof. 40. A method of forming the proppant of claim 1, comprising providing a precursor by forming a mixture of inorganic material and a blowing agent in the shapes of template spheres, optionally drying the mixture and firing the precursor to activate the blowing agent, wherein activation of the blowing agent is controlled such that the blowing agent is activated within a predetermined temperature range, and further providing a shell around the entire outer surface of said template spheres and then sintering said shell to form a continuous sintered shell. 41. The method of claim 40, further comprising firing the precursor to activate the blowing agent. 42. The method of claim 40, wherein providing said shell comprises introducing said template spheres into a fluidized bed and coating said template spheres with a suspension or dispersion comprising a ceramic material or oxide thereof. 43. A method of forming the proppant of claim 1, comprising: a) delivering particles comprising inorganic material to an inlet of a furnace; b) passing the particles through the furnace; c) heating the particles as the particles traverse through a heating portion of the furnace to melt at least an outer surface of the particles such that a majority of the particles become substantially spheroidal; d) cooling the particles as the particles traverse through a cooling portion of the furnace to deter agglomeration and form template spheres; and e) providing a shell around the entire outer surface of said template sphere and then sintering said shell to form a continuous sintered shell. 44. The method of claim 43, wherein providing said shell comprises introducing said template spheres into a fluidized bed and coating said template spheres with a suspension or dispersion comprising a ceramic material or oxide thereof. 45. The method of claim 43, wherein said furnace is a drop tower furnace, a drop tube furnace, a rotary kiln, a fluidized bed furnace, or a gravity fed furnace. 46. The method of claim 43, wherein said passing the particles in step b) is achieved by gravity. 47. The method of claim 43, wherein the step of cooling comprises cooling the particles as the particles traverse through a cooling portion of the furnace, wherein, after cooling, the particles have a substantially higher bulk density at room temperature than prior to delivering the particles to the inlet of the furnace. 48. A method of forming the proppant of claim 1, comprising: a) coating dissolvable beads with a solution comprising an inorganic material; b) drying the beads so as to form an inorganic coating on the beads; c) heating the beads to a first temperature, wherein the first temperature is sufficient to form a continuous inorganic coating and is not sufficient to decompose the beads; d) dissolving all or some portion of the beads; e) optionally removing the dissolved beads from within the continuous inorganic coating; and f) optionally heating the continuous inorganic coating to a second temperature that is sufficient to form said template spheres, and g) providing a shell around the entire outer surface of said template sphere and then sintering said shell to form a continuous sintered shell. 49. The method of claim 48, wherein step e) and step f) occur. 50. The method of claim 48, wherein said dissolvable beads are polymeric beads. 51. The method of claim 48, wherein said dissolvable beads are inorganic beads. 52. The method of claim 48, wherein said dissolvable beads are geopolymers, ceramic beads, metallic beads, glass beads, ground shells, rust, diatomaceous earth, diatomite, kesselgur, fly ash, gypsum, spent catalyst, clinker, blast furnace slag, or any combination thereof. 53. The method of claim 52, wherein at least 20 volume percent of the dissolvable beads are removed in each template sphere. 54. The method of claim 48, wherein said dissolvable beads are plant seeds; plant husks; soil; crushed nuts; ground hulls of nuts; whole nuts; plant pips; cells; coffee grinds; food products; algae; plankton; animal eggs; wax; surfactant-derived liquid beads; powdered, ground, or crushed agglomerates of wood products; powdered, ground, or crushed whey; cellulose; soap; bacteria; rubber; powdered milk; animal waste; unprocessed polymeric resin; or animal hair. 55. The method of claim 48, wherein said dissolvable bead is spheronized prior to said coating of step a). 56. The method of claim 48, wherein providing said shell comprises introducing said template spheres into a fluidized bed and coating said template spheres with a suspension or dispersion comprising a ceramic material or oxide thereof. 57. A method of forming the proppant of claim 1, comprising: a) coating burnable beads with a solution comprising an inorganic material; b) drying the burnable beads so as to form an inorganic coating on the beads; c) heating the coated burnable beads in controlled fashion such that the burnable bead undergoes controlled thermolysis leaving an intact substantially hollow template sphere; d) providing a shell around the entire outer surface of said template sphere and then sintering said shell to form a continuous sintered shell. 58. The method of claim 57, wherein said beads are polymeric beads. 59. The method of claim 57, wherein said beads are plant seeds; plant husks; soils; crushed nuts; ground hulls of nuts; whole nuts; plant pips; cells; coffee grinds; food products; algae; plankton; animal eggs; wax; surfactant-derived liquid beads; powdered, ground, or crushed agglomerates of wood products; powdered, ground, or crushed whey; cellulose; soap; bacteria; rubber; powdered milk; animal waste; unprocessed polymeric resin; or animal hair. 60. The method of claim 57, wherein said burnable bead is spheronized prior to said coating of step a) by spray drying, rolling, tumbling, or other processes. 61. The method of claim 57, wherein providing said shell comprises introducing said template spheres into a fluidized bed and coating said template spheres with a suspension or dispersion comprising a ceramic material or oxide thereof. 62. A method of forming the proppant of claim 1, comprising forming a template sphere and providing a shell around the entire outer surface of said template sphere, and then sintering said shell to form a continuous sintered shell. 63. The method of claim 62, wherein said sintering comprises liquid phase sintering, reactive phase sintering, solid state sintering, or pressure-assisted sintering. 64. The method of claim 63, wherein said pressure-assisted sintering comprises the application of external gas pressure during heat treatment, with pressures ranging from ambient to 1500 PSIG. 65. The method of claim 62, wherein said sintering comprises indirect radiant heating, direct infrared radiation, direct conduction of heat flux from an environment to said proppant, excitation of molecules of said shell, and consequent heating of said shell by electromagnetic radiation, or inductive coupling of the shell to an external excitation field of alternating current. 66. The method of claim 62, wherein said forming of said template sphere is by a spray drying process, a dehydrating gel process, a sol-gel process, a sol-gel-vibrational dropping process, a drop tower process, a fluidized bed process, a coaxial nozzle gas-bubble process, a thermolysis process, a chemical etching process, or a blowing process. 67. The method of claim 62, wherein said template sphere has a template surface with cracks or flaws, and said method further comprises surface repairing said cracks or flaws with a composition comprising at least one inorganic or ceramic-containing material. 68. The method of claim 67, wherein surface repairing comprises infiltrating said cracks or flaws with a suspension comprising alumoxane, mullite, or a combination thereof. 69. The method of claim 62, wherein said proppant has a proppant surface with cracks or flaws, and said method further comprises surface repairing said cracks or flaws with a composition comprising at least one inorganic or ceramic-containing material. 70. The method of claim 69, wherein surface repairing comprises infiltrating said cracks or flaws with a suspension comprising alumoxane, mullite, or a combination thereof. 71. The proppant of claim 1, wherein said proppant has each of the following characteristics: (a) an overall diameter of from about 90 microns to about 1,600 microns; (b) spherical; (c) said shell is substantially non-porous; (d) said proppant has a crush strength of about 3,000 psi or greater; (e) said coating has a wall thickness of from about 15 to about 120 microns; and (f) said proppant has a specific gravity of from about 0.9 to about 1.5 g/cc. 72. A proppant formulation comprising the proppant of claim 1 and a carrier. 73. A method to prop open subterranean formation fractions comprising introducing the proppant formulation of claim 72 into said subterranean formation. 74. A method of treating a subterranean producing zone penetrated by a well bore comprising the steps of: (a) preparing or providing a treating fluid that comprises a hydrocarbon or water carrier fluid having the proppant of claim 1 suspended therein, and (b) pumping said treating fluid into said subterranean producing zone whereby said particles are deposited therein. 75. The method of claim 74, wherein said treating fluid is a fracturing fluid and said particles are deposited in fractures formed in said subterranean producing zone. 76. The method of claim 74, wherein said treating fluid is a gravel packing fluid and said particles are deposited in said well bore adjacent to said subterranean producing zone.