Patent EA-002634-B1 (EA)
Title: Composite particles, method for producing thereof, method of treating a hydraulically induced fracture, method for water filtration
Inventor: MCDANIEL ROBERT R
IPC: B01J2/20
Filed: 1999-07-22
Abstract: 1. A composite particle having a sphericity of at least about 0.7 comprising: a substantially homogeneous formed particle comprising: a first portion of a binder and filler particles dispersed throughout said first portion of binder, wherein said first portion is at least partly cured; particle size of said filler particles ranges from about 0.5 to about 60 μm; and an optional second portion of a binder coating the formed particle; the composite particle being 60-85 volume percent said filler particles. 2. The composite particle of Claim 1, wherein the sphericity is at least about 0.85. 3. The composite particle of Claim 1, wherein the sphericity is at least about 0.9. 4. The composite particle of Claim 1, further comprising a member selected from the group consisting of milled glass fibers, milled ceramic fibers, milled carbon fibers, natural fibers and synthetic fibers having a softening point of at least about 93 degree C. 5. The composite particle of Claim 1, wherein the composite particle bulk density ranges from about 1.12 to 1.52 G/cm<3> (70 to about 95 lbs/ft<3>). 6. The composite particle of Claim 1, wherein the binder consists essentially of at least one member of the group consisting of inorganic binder, epoxy resin, novolac resin and resol resin and further consists essentially of optional cross-linking agents and conventional additives. 7. The composite particle of Claim 1, wherein the binder comprises a high ortho resin, hexamethylenetetramine, a silane adhesion promoter, a silicone lubricant, a wetting agent and a surfactant. 8. The composite particle according to Claim 1, wherein the composite particles have diameters between 20 and 40 mesh and comprise a coating of a layer of synthetic resin. 9. The composite particle according to Claim 1, wherein the composite particles have diameters between 30 and 40 mesh and comprise a coating of a layer of synthetic resin. 10. The composite particle according to Claim 1, wherein the composite particles have diameters between 8 and 20 mesh and comprise a coating of a layer of synthetic resin. 11. The composite particle of Claim 1, wherein the filler particles are a finely divided mineral. 12. The composite particle of Claim 1, wherein the filler particles are present in a proportion from about 60 to about 75% by volume of composite particle. 13. The composite particle of Claim 1, wherein the proportion of filler particles substance is from about 65 to about 75% by volume of composite particle. 14. The composite particle of Claim 1, wherein the binder comprises a member of the group consisting of a phenolic/furan resin, a furan resin, and mixtures thereof. 15. The composite particle of Claim 1, wherein the binder comprises a bisphenolicaldehyde novolac polymer. 16. The composite particle according to Claim 1, wherein the first portion of binder comprises resol resin. 17. The composite particle according to Claim 1, wherein the first portion of binder comprises resol resin modified with gamma-aminopropyltriethoxy-silane acting as a coupling agent between the filler and the synthetic resin. 18. The composite particle according to Claim 1, wherein the first portion of binder comprises resol resin with a phenol: formaldehyde ratio of 1:1.1 to 1:1.95. 19. The composite particle according to Claim 1, wherein the first portion of binder comprises resol resin with a phenol: formaldehyde ratio of 1:1.2 to 1:1.6. 20. The composite particle of Claim 1, wherein the first portion of binder comprises cured binder. 21. The composite particle of Claim 1, wherein the first portion of binder comprises a cured binder, and the second portion of binder comprises a curable binder. 22. The composite particle of Claim 1, wherein the filler particles at least one mineral selected from the group consisting of silica (quartz sand), alumina, mica, meta-silicate, calcium silicate, calcine, keoline, talc, zirconia, boron and glass. 23. The composite particle of Claim 1, wherein the filler particles are at least one mineral selected from the group consisting of quartz sand and aluminum oxide. 24. The composite particle of Claim 1, wherein the filler particles comprise fly ash. 25. The composite particle of Claim 1, wherein the filler particles are a mineral having a grain size, dso, of 4 to 6 μm. 26. The composite particle of Claim 1, wherein the filler particles are a mineral having a grain size, d50, of 4 to 10 μm. 27. The composite particle of Claim 1, wherein the filler particles are of mineral substance and the proportion of mineral substance is about 70 to 90% by weight of composite particle. 28. A method for producing a composite particle according to Claim 1, comprising mixing the filler particles, the first portion of binder, at least one member of the group consisting of water and an organic solvent, and optional additives to form a mixture and to adjust agglomeration behavior of the filler particles ; subjecting the mixture to agglomerative granulation ; and curing the first portion of binder. 29. The method according to Claim 28, wherein the agglomerative granulation of the mixture is performed by contacting the mixture with a rotating disc. 30. The method according to Claim 28, wherein the agglomerative granulation of the mixture is performed by spraying the mixture. 31. The method according to Claim 28, wherein the filler particles, the first portion of binder, at least one member of the group consisting of water, and an organic solvent, and optional additives are mixed to form the mixture and to adjust the plasticity of the mixture; the mixture is granulated in the plastic state to form the formed particles; and the first portion of binder in the formed particles is cured. 32. The method according to Claim 28, wherein the agglomerative granulating is done by extrusion as strands, cutting the strands into fragments, and shaping the fragments under the influence of centrifugal force into spherical granules. 33. The method according to Claim 28, wherein the first portion of binder consists essentially of a resole resin. 34. The method according to Claim 31, wherein the formed particles are smoothed and compressed by rolling before crosslinking of the binder. 35. The method according to Claim 31, wherein after the first portion of binder has cured, the formed particles are coated with the second portion of binder and cured again. 36. The method according to Claim 31, wherein after granulation the solvent is dried, after the drying but before curing the first portion of binder, the formed particles are coated with resin. 37. A method of treating a hydraulically induced fracture in a subterranean formation surrounding a wellbore comprising introducing composite particles of Claim 1 into the fracture. 38. The method according to Claim 36, wherein a multi-layer pack comprising the composite particles is formed in the formation. 39. The method of Claim 37, wherein the proppant further comprises introducing particles selected from at least one member of the group consisting of sand, sintered ceramic particles and glass beads. 40. The method of Claim 39, wherein the sand particles comprise resin-coated sand particles. 41. The method of Claim 37, wherein the sphericity of the composite particles is at least about 0. 85. 42. The method of Claim 37, wherein the composite particles have diameters between 20 and 40 mesh and comprise a coating of a layer of synthetic resin. 43. The method of Claim 37, wherein the composite particles have diameters between 8 and 20 mesh and comprise a coating of a layer of synthetic resin. 44. The method of Claim 37, wherein the filler particles are a finely divided mineral. 45. The method of Claim 37, wherein the proportion of filler particles substance is from about 65 to about 75% by volume of composite particle. 46. The method of Claim 37, wherein the filler particles comprise fly ash. 47. The method of Claim 37, wherein the filler particles are a mineral having a grain size, d50, of 4 to 10 μm. 48. A method for water filtration comprising passing water through a filtration pack comprising the composite particles of Claim 1.