权利要求：
1. A 3D printed proppant comprising:
a core;
support bars extending from the core to a shell; and
the shell encapsulating the core and the support bars, wherein:
the support bars have a length of from 85 micrometers to 200 micrometers,
the core comprises metal, polymer, ceramic, composite, or combinations thereof,
the support bars comprise metal, polymer, ceramic, composite, or combinations thereof,
the shell comprises metal, polymer, ceramic, composite, or combinations thereof, and
the 3D printed proppant has a particle size from 8 mesh to 140 mesh.
2. The 3D printed proppant of claim 1, wherein the core, the support bars, the shell, or combinations thereof comprises metal comprising titanium alloy, nickel alloy, aluminum alloy, titanium-aluminum alloy, chromium alloy, cobalt alloy, copper alloy, gallium alloy, iron alloy, or combinations thereof.
3. The 3D printed proppant of claim 1, wherein the core, the support bars, the shell, or combinations thereof comprises ceramic comprising crystalline inorganic metal oxides, bauxite, kaolin, magnesium oxide, alumina, nitride, carbide, carbon, silicon, ground ceramic, ceramic matrix composites, composites, or combinations thereof.
4. The 3D printed proppant of claim 3, wherein the core, the support bars, the shell, or combinations thereof comprises ground ceramic comprising calcined clay, un-calcined clay, bauxite, silica, alumina, geopolymer, or combinations thereof and having an average particle size from 1 to 12 micron.
5. The 3D printed proppant of claim 4, wherein:
the ground ceramic comprises reinforcing agents;
the reinforcing agents comprise alumina, carbon, silicon carbide, alumina, mullite, or combinations thereof; and
the reinforcing agents comprise particles having a particle size from 1 to 50 microns, fibers having an aspect ratio of greater than 1:2, or both.
6. The 3D printed proppant of claim 4, wherein:
the ground ceramic comprises from 0.1 to 1.5 wt. % binder material by weight of ground ceramic; and
the binder material comprises metal, ceramic, heavy fuel oil, boron nitride, oxynitride glass, aluminum carbide, silicon carbide, aluminum nitride, bismuth tertroxide, boron oxide, zirconia, silica, rare earth oxides, poly(2-ethyl-2-oxazoline) solution, polyvinyl alcohol solution, waxes, starch, or combinations thereof.
7. The 3D printed proppant of claim 1, wherein the core, the support bars, the shell, or combinations thereof comprises polymer comprising thermoset resins, polyester, urea aldehyde, polyurethane, vinyl esters, furfural alcohol, or combinations thereof.
8. The 3D printed proppant of claim 7, wherein the core, the support bars, the shell, or combinations thereof comprises resin comprising phenolic resin, epoxy resin, furan resin, polyurethane resin, polyurea resin, polyamide-imide resin, polyamide resin polyurea/polyurethane resin, urea-formaldehyde resin, melamin resin, silicone resin, vinyl ester resin, or combinations thereof.
9. A method of producing a 3D printed proppant comprises:
providing a 3D printing apparatus that produces the 3D printed proppant;
distributing a layer of build material within a build chamber of the 3D printing apparatus, wherein the build material comprises metal, polymer, ceramic, composite, or combinations thereof;
depositing a layer of binder material on the layer of build material;
curing the binder material within the 3D printing apparatus; and
repeating as necessary to produce the 3D printed proppant, wherein:
the 3D printed proppant comprises a core, support bars extending from the core to a shell, and the shell encapsulating the core and the support bars,
the support bars have a length of from 85 micrometers to 200 micrometers,
the core comprises metal, polymer, ceramic, composite, or combinations thereof,
the support bars comprise metal, polymer, ceramic, composite, or combinations thereof,
the shell comprises metal, polymer, ceramic, composite, or combinations thereof, and
the 3D printed proppant has a particle size from 8 mesh to 140 mesh.
10. The method of claim 9, wherein, the support bars, the core, the shell, or combinations thereof comprises metal comprising titanium alloy, nickel alloy, aluminum alloy, titanium-aluminum alloy, chromium alloy, cobalt alloy, copper alloy, gallium alloy, iron alloy, or combinations thereof.
11. The method of claim 9, wherein the core, the support bars, the shell, or combinations thereof comprises ceramic comprising crystalline oxide, bauxite, kaolin, magnesium oxide, alumina, nitride, carbide, carbon, silicon, ground ceramic, composite, or combinations thereof.
12. The method of claim 9, wherein the core, the support bars, the shell, or combinations thereof comprises polymer comprising resin, polyester, urea aldehyde, polyurethane, vinyl esters, furfural alcohol, or combinations thereof.
13. The 3D printed proppant of claim 1, wherein the 3D printed proppant has a density of less than 2.5 grams per cubic centimeter (g/cc) and a tensile strength of from 40 to 1500 Mega Pascals (MPa).
14. The method of claim 9, wherein the 3D printed proppant has a density of less than 2.5 grams per cubic centimeter (g/cc) and a tensile strength of from 40 to 1500 Mega Pascals (MPa).
15. The 3D printed proppant of claim 1, wherein the 3D printed proppant consists of:
the core;
the support bars; and
the shell.
16. The method of claim 11, wherein the core, the support bars, the shell, or combinations thereof comprises ground ceramic comprising calcined clay, un-calcined clay, bauxite, silica, alumina, geopolymer, or combinations thereof and having an average particle size from 1 to 12 micron.
17. The method of claim 16, wherein:
the ground ceramic comprises reinforcing agents;
the reinforcing agents comprise alumina, carbon, silicon carbide, alumina, mullite, or combinations thereof; and
the reinforcing agents comprise particles having a particle size from 1 to 50 microns, fibers having an aspect ratio of greater than 1:2, or both.
18. The method of claim 16, wherein:
the ground ceramic comprises from 0.1 to 1.5 wt. % binder material by weight of ground ceramic; and
the binder material comprises metal, ceramic, heavy fuel oil, boron nitride, oxynitride glass, aluminum carbide, silicon carbide, aluminum nitride, bismuth tertroxide, boron oxide, zirconia, silica, rare earth oxides, poly(2-ethyl-2-oxazoline) solution, polyvinyl alcohol solution, waxes, starch, or combinations thereof.
19. The method of claim 12, wherein the core, the support bars, the shell, or combinations thereof comprises resin comprising phenolic resin, epoxy resin, furan resin, polyurethane resin, polyurea resin, polyamide-imide resin, polyamide resin polyurea/polyurethane resin, urea-formaldehyde resin, melamin resin, silicone resin, vinyl ester resin, or combinations thereof.
20. The method of claim 9, wherein the 3D printed proppant consists of:
the core;
the support bars; and
the shell.
具体实施方式：
[0015]As used throughout this disclosure, the term “hydraulic fracturing” refers to a stimulation treatment routinely performed on hydrocarbon wells in reservoirs with a permeability of less than 200 milliDarcys. Hydraulic fracturing fluids are pumped into a subsurface formation, causing a fracture to form or open. The wings of the fracture extend away from the wellbore according to the natural stresses within the subsurface formation. Proppants are mixed with the treatment fluid and deposited in the created fracture to keep the fracture open when the treatment is complete. Hydraulic fracturing increases surface area to increase fluid production and fluid communication with a subsurface formation and bypasses damage, such as a plugged near wellbore due to drilling fluid or condensate banking that may exist in the near-wellbore area.
[0016]As used throughout this disclosure, the term “subsurface formation” refers to a body of rock that is sufficiently distinctive and continuous from the surrounding rock bodies that the body of rock can be mapped as a distinct entity.
[0017]As used throughout this disclosure, the term “lithostatic pressure” refers to the pressure of the weight of overburden, or overlying rock, on a subsurface formation.
[0018]As used throughout this disclosure, the term “producing subsurface formation” refers to the subsurface formation from which hydrocarbons are produced.
[0019]As used throughout this disclosure, the term “proppants” refers to particles of sand, ceramic or other materials that can be mixed with hydraulic fracturing fluid to hold fractures open after a hydraulic fracturing treatment. Proppant materials are carefully sorted for mesh size, roundness and sphericity to provide an efficient conduit for fluid production from the reservoir to the wellbore.
[0020]As used throughout this disclosure, the term “reservoir” refers to a subsurface formation having sufficient porosity and permeability to store and transmit fluids.
[0021]As used throughout this disclosure, the term “wellbore” refers to the drilled hole or borehole, including the openhole or uncased portion of the well. Borehole may refer to the inside diameter of the wellbore wall, the rock face that bounds the drilled hole.
[0022]The present disclosure is directed to compositions and methods for producing 3D printed proppants, to hydraulic fracturing fluids including 3D printed proppants, and to methods for increasing a rate of hydrocarbon production from a subsurface formation through the use of 3D printed proppants including a core and a shell, where the 3D printed proppants have a particle size ranging from 8 mesh to 140 mesh. Mesh is a measurement of particle size often used in determining the particle-size distribution of a granular material. As used throughout this disclosure, “mesh” sizes are designated by the number of openings per linear inch in the sieve. For example, if the proppant particle size is from 8 to 140 mesh, then the proppants will pass through an 8-mesh sieve (particles smaller than 2380 μm) and be retained by a 140-mesh sieve (particles larger than 105 μm). For ease of conversion to particle size, the conversions from mesh to particle size are as follows: 8 mesh (diam. 2380 μm); 16 mesh (diam. 1190 μm); 20 mesh (diam. 841 μm); 30 mesh (diam. 595 μm); 40 mesh (diam. 420 μm); 70 mesh (diam. 210 μm); and 140 mesh (diam. 105 μm).
[0023]The 3D printed proppant may include various sizes or shapes. In some embodiments, the one or more 3D printed proppants may have sizes from 8 mesh to 140 mesh, from 8 mesh to 70 mesh, from 8 mesh to 40 mesh, from 8 mesh to 30 mesh, from 8 mesh to 20 mesh, from 8 mesh to 16 mesh, from 16 mesh to 140 mesh, from 16 mesh to 70 mesh, from 16 mesh to 40 mesh, from 16 mesh to 30 mesh, from 16 mesh to 20 mesh, from 20 mesh to 140 mesh, from 20 mesh to 70 mesh, from 20 mesh to 40 mesh, from 20 mesh to 30 mesh, from 30 mesh to 140 mesh, from 30 mesh to 70 mesh, from 30 mesh to 40 mesh, from 40 mesh to 140 mesh, from 40 mesh to 70 mesh, or from 70 mesh to 140 mesh. The 3D printed proppant may be any shape, including spherical, elliptical, cylindrical, or ovoid, as non-limiting examples. The 3D printed proppants may be formed into asymmetrical shapes that are formed to lock in with each other, thereby limiting flowback during production. The 3D printed proppant may have a length from 1 to 5 millimeter (mm), from 1 to 4 mm, from 1 to 3 mm, from 1 to 2 mm, from 2 to 5 mm, from 2 to 4 mm, from 2 to 3 mm, from 3 to 5 mm, from 3 to 4 mm, or from 4 to 5 mm. The 3D printed proppant may have an outer diameter of from 100 to 2000 microns, from 100 to 1500 microns, from 100 to 1000 microns, from 100 to 500 microns, from 500 to 2000 microns, from 500 to 1500 microns, from 500 to 1000 microns, from 1000 to 2000 microns, from 1000 to 1500 microns, or from 1500 to 2000 microns.
[0024]As shown in FIG. 1A, in embodiments, the 3D printed proppant 100 may include a core 120 having support bars 112 extending from the core 120 to the shell 110, where the shell 110 encapsulates the core 120 and the support bars 112. The core 120 may include metal, polymer, ceramic, composite, or combinations thereof; the support bars 112 may include metal, polymer, ceramic, composite, or combinations thereof; and the shell 110 may include metal, polymer, ceramic, composite, or combinations thereof. The core 120 may have a diameter ranging from 50 μm to 1000 μm, from 50 μm to 500 μm, from 50 μm to 300 μm, from 50 μm to 200 μm, from 50 μm to 150 μm, from 50 μm to 100 μm, from 100 μm to 1000 μm, from 100 μm to 500 μm, from 100 μm to 300 μm, from 100 μm to 200 μm, from 100 μm to 150 μm, from 150 μm to 1000 μm, from 150 μm to 500 μm, from 150 μm to 300 μm, from 150 μm to 200 μm, from 200 μm to 1000 μm, from 200 μm to 500 μm, from 200 μm to 300 μm, from 300 μm to 1000 μm, from 300 μm to 500 μm, or from 500 μm to 1000 μm.
[0025]As shown in FIG. 1B, in embodiments, the 3D printed proppant 100 may include a hollow core 122 having support bars 112 extending from the hollow core 122 to the shell 110, where the shell 110 encapsulates the hollow core 122 and the support bars 112. The hollow core 122 may include metal, polymer, ceramic, composite, or combinations thereof; the support bars 112 may include metal, polymer, ceramic, composite, or combinations thereof; and the shell 110 may include metal, polymer, ceramic, composite, or combinations thereof. The hollow core 122 may have an inner diameter ranging from 50 μm to 1000 μm, from 50 μm to 500 μm, from 50 μm to 300 μm, from 50 μm to 200 μm, from 50 μm to 150 μm, from 50 μm to 100 μm, from 100 μm to 1000 μm, from 100 μm to 500 μm, from 100 μm to 300 μm, from 100 μm to 200 μm, from 100 μm to 150 μm, from 150 μm to 500 μm, from 150 μm to 300 μm, from 150 μm to 200 μm, from 200 μm to 1000 μm, from 200 μm to 500 μm, from 200 μm to 300 μm, from 300 μm to 1000 μm, from 300 μm to 1000 μm, or from 300 μm to 500 μm. The hollow core 122 may have an outer diameter ranging from 200 μm to 1000 μm, from 200 μm to 800 μm, from 200 μm to 700 μm, from 200 μm to 600 μm, from 200 μm to 500 μm, from 200 μm to 400 μm, from 400 μm to 1000 μm, from 400 μm to 800 μm, from 400 μm to 700 μm, from 400 μm to 600 μm, from 400 μm to 500 μm, from 500 μm to 1000 μm, from 500 μm to 800 μm, from 500 μm to 700 μm, from 500 μm to 600 μm, from 600 μm to 1000 μm, from 600 μm to 800 μm, from 600 μm to 700 μm, from 700 μm to 1000 μm, from 700 μm to 800 μm, or from 800 μm to 1000 μm.
[0026]As shown in FIG. 1C, in embodiments, the 3D printed proppant 110 may include a porous core 124 and a shell 110, where the shell 110 encapsulates the porous core 124. The porous core 124 may have a porosity from 10% to 75% and may have empty pores 126 as shown in FIG. 1C. The porous core 124 may have a porosity from 10% to 75%, 25% to 75%, from 25% to 70%, from 25% to 60%, from 25% to 55%, from 25% to 50%, from 25% to 45%, from 25% to 40%, from 25% to 30%, from 30% to 75%, from 30% to 70%, from 30% to 60%, from 30% to 55%, from 30% to 50%, from 30% to 45%, from 30% to 40%, from 40% to 75%, from 40% to 70%, from 40% to 60%, from 40% to 55%, from 40% to 50%, from 40% to 45%, from 45% to 75%, from 45% to 70%, from 45% to 60%, from 45% to 55%, from 45% to 50%, from 50% to 75%, from 50% to 70%, from 50% to 60%, from 50% to 55%, from 55% to 75%, from 55% to 70%, from 55% to 60%, from 60% to 75%, from 60% to 70%, or from 70% to 75%. The porous core 124 may include metal, polymer, ceramic, composite, or combinations thereof; and the shell 110 may include metal, polymer, ceramic, composite, or combinations thereof.
[0027]The proppants may be 3D printed using any 3D printing technology known in the art. The method may include providing any 3D printing apparatus known in the art that is capable of producing the 3D printed proppant described in this disclosure. Referring to FIG. 2, method of making the 3D printed proppants (200) may include where the 3D printing apparatus distributes a layer of build material (210) within a build chamber of the 3D printing apparatus. The method (200) may further include depositing a layer of binder material (220) on the layer of build material. The method (200) further includes curing the binder material (230) within the 3D printing apparatus and repeating as necessary to produce the 3D printed proppant.
[0028]The 3D printed proppant may need post printing processing to realize the ultimate strength in some cases. For example the ceramic proppants may need to be sintered for realizing the ultimate strength to weight ratio. Polymer based proppants may need to be cured later at higher temperature to cure, crosslink to get the strength. To enhance the properties additives and fillers may need to be added to the printed proppant to enhance mechanical strength such as creep resistance, crush strength improvement, modulus increase, chemical resistance, or to control density.
[0029]The build material may include any material suitable for use in hydraulic fracturing applications. The build material of the 3D printed proppant may be chosen based on the particular application and characteristics desired, such as the depth of the subsurface formation in which the proppant particles will be used, as proppant particles with greater mechanical strength are needed at greater lithostatic pressures. For instance, ceramic proppant materials exhibit greater strength, thermal resistance, and conductivity than conventional proppant particles made out of sand. In embodiments, the build material may include metal, polymer, ceramic, composite, or combinations thereof, to form the 3D printed proppant.
[0030]The metal may include titanium alloy, nickel alloy, aluminum alloy, titanium-aluminum alloy, chromium alloy, cobalt alloy, copper alloy, gallium alloy, iron alloy, iron, nickel, chromium, silicon, aluminum, copper, cobalt, beryllium, tungsten, molybdenum, titanium, magnesium, silver, as well as alloys of metals, and the like, or any combination of these. The metal may also include the family of intermetallic materials, such as iron aluminides, nickel aluminides, and titanium aluminides, or combinations thereof. The 3D printed proppant may include from 0 to 100 wt. % metal, by weight of the 3D printed proppant. In embodiments, the 3D printed proppant may include from 0 to 100 wt. %, from 0 to 90 wt. %, from 0 to 80 wt. %, from 0 to 70 wt. %, from 0 to 60 wt. %, from 0 to 50 wt. %, from 0 to 40 wt. %, from 0 to 30 wt. %, from 0 to 20 wt. %, from 0 to 10 wt. %, from 0 to 1 wt. %, from 1 to 100 wt. %, from 1 to 90 wt. %, from 1 to 80 wt. %, from 1 to 70 wt. %, from 1 to 60 wt. %, from 1 to 50 wt. %, from 1 to 40 wt. %, from 1 to 30 wt. %, from 1 to 20 wt. %, from 1 to 10 wt. %, from 10 to 100 wt. %, from 10 to 90 wt. %, from 10 to 80 wt. %, from 10 to 70 wt. %, from 10 to 60 wt. %, from 10 to 50 wt. %, from 10 to 40 wt. %, from 10 to 30 wt. %, from 10 to 20 wt. %, from 20 to 100 wt. %, from 20 to 90 wt. %, from 20 to 80 wt. %, from 20 to 70 wt. %, from 20 to 60 wt. %, from 20 to 50 wt. %, from 20 to 40 wt. %, from 20 to 30 wt. %, from 30 to 100 wt. %, from 30 to 90 wt. %, from 30 to 80 wt. %, from 30 to 70 wt. %, from 30 to 60 wt. %, from 30 to 50 wt. %, from 30 to 40 wt. %, from 40 to 100 wt. %, from 40 to 90 wt. %, from 40 to 80 wt. %, from 40 to 70 wt. %, from 40 to 60 wt. %, from 40 to 50 wt. %, from 50 to 100 wt. %, from 50 to 90 wt. %, from 50 to 80 wt. %, from 50 to 70 wt. %, from 50 to 60 wt. %, from 60 to 100 wt. %, from 60 to 90 wt. %, from 60 to 80 wt. %, from 60 to 70 wt. %, from 70 to 100 wt. %, from 70 to 90 wt. %, from 70 to 80 wt. %, from 80 to 100 wt. %, from 80 to 90 wt. %, or from 90 to 100 wt. % metal by weight of the 3D printed proppant.
[0031]In embodiments, the metal may include a titanium alloy including titanium, molybdenum, vanadium, iron, aluminum, nickel, or combinations thereof. In embodiments, the titanium alloy may include titanium, molybdenum, vanadium, iron, and aluminum. In embodiments, the titanium alloy may include titanium, molybdenum, and nickel. The titanium alloy may include from 70 to 99.9 weight percent (wt. %), from 70 to 99.5 wt. %, from 70 to 99.3 wt. %, from 70 to 99.0 wt. %, from 70 to 98 wt. %, from 70 to 95 wt. %, from 70 to 90 wt. %, from 70 to 85 wt. %, from 70 to 82 wt. %, from 70 to 80 wt. %, from 75 to 99.9 wt. %, from 75 to 99.5 wt. %, from 75 to 99.3 wt. %, from 75 to 99.0 wt. %, from 75 to 98 wt. %, from 75 to 95 wt. %, from 75 to 90 wt. %, from 75 to 85 wt. %, from 75 to 82 wt. %, from 75 to 80 wt. %, from 77 to 99.9 wt. %, from 77 to 99.5 wt. %, from 77 to 99.3 wt. %, from 77 to 99.0 wt. %, from 77 to 98 wt. %, from 77 to 95 wt. %, from 77 to 90 wt. %, from 77 to 85 wt. %, from 77 to 82 wt. %, from 77 to 80 wt. %, from 90 to 99.9 wt. %, from 90 to 99.5 wt. %, from 90 to 99.3 wt. %, from 90 to 99.0 wt. %, from 90 to 98 wt. %, from 90 to 95 wt. %, from 95 to 99.9 wt. %, from 95 to 99.5 wt. %, from 95 to 99.3 wt. %, from 95 to 99.0 wt. %, from 95 to 98 wt. %, from 98 to 99.9 wt. %, from 98 to 99.5 wt. %, from 98 to 99.3 wt. %, from 98 to 99.0 wt. %, from 99.0 to 99.9 wt. %, from 99.0 to 99.5 wt. %, from 99.0 to 99.3 wt. %, approximately 79 wt. %, or approximately 99.1 wt. % titanium by weight of the titanium alloy.
[0032]The titanium alloy may include from 0.1 to 20 wt. %, from 0.1 to 15 wt. %, from 0.1 to 10 wt. %, from 0.1 to 9 wt. %, from 0.1 to 8 wt. %, from 0.1 to 7 wt. %, from 0.1 to 5 wt. %, from 0.1 to 2 wt. %, from 0.1 to 1 wt. %, from 0.1 to 0.5 wt. %, from 0.1 to 0.4 wt. %, from 0.2 to 20 wt. %, from 0.2 to 15 wt. %, from 0.2 to 10 wt. %, from 0.2 to 9 wt. %, from 0.2 to 8 wt. %, from 0.2 to 7 wt. %, from 0.2 to 5 wt. %, from 0.2 to 2 wt. %, from 0.2 to 1 wt. %, from 0.2 to 0.5 wt. %, from 0.2 to 0.4 wt. %, from 2 to 20 wt. %, from 2 to 15 wt. %, from 2 to 10 wt. %, from 2 to 9 wt. %, from 2 to 8 wt. %, from 2 to 7 wt. %, from 2 to 5 wt. %, from 5 to 20 wt. %, from 5 to 15 wt. %, from 5 to 10 wt. %, from 5 to 9 wt. %, from 5 to 8 wt. %, from 5 to 7 wt. %, from 7 to 20 wt. %, from 7 to 15 wt. %, from 7 to 10 wt. %, from 7 to 9 wt. %, from 7 to 8 wt. %, from 8 to 20 wt. %, from 8 to 15 wt. %, from 8 to 10 wt. %, from 8 to 9 wt. %, approximately 0.3 wt. %, or approximately 8 wt. % molybdenum by weight of the titanium alloy.
[0033]The titanium alloy may include from 5 to 20 wt. %, from 5 to 15 wt. %, from 5 to 10 wt. %, from 5 to 9 wt. %, from 5 to 8 wt. %, from 5 to 7 wt. %, from 7 to 20 wt. %, from 7 to 15 wt. %, from 7 to 10 wt. %, from 7 to 9 wt. %, from 7 to 8 wt. %, from 8 to 20 wt. %, from 8 to 15 wt. %, from 8 to 10 wt. %, from 8 to 9 wt. %, or approximately 8 wt. % vanadium by weight of the titanium alloy.
[0034]The titanium alloy may include from 0.1 to 10 wt. %, from 0.1 to 5 wt. %, from 0.1 to 3 wt. %, from 0.1 to 2 wt. %, from 0.1 to 1 wt. %, from 0.5 to 10 wt. %, from 0.5 to 5 wt. %, from 0.5 to 3 wt. %, from 0.5 to 2 wt. %, from 0.5 to 1 wt. %, from 1 to 10 wt. %, from 1 to 5 wt. %, from 1 to 3 wt. %, from 1 to 2 wt. %, from 2 to 10 wt. %, from 2 to 5 wt. %, from 2 to 3 wt. %, from 3 to 10 wt. %, from 3 to 5 wt. %, from 5 to 10 wt. %, or approximately 2 wt. % iron by weight of the titanium alloy.
[0035]The titanium alloy may include from 0.5 to 10 wt. %, from 0.5 to 5 wt. %, from 0.5 to 4 wt. %, from 0.5 to 3 wt. %, from 0.5 to 2 wt. %, from 1 to 10 wt. %, from 1 to 5 wt. %, from 1 to 4 wt. %, from 1 to 3 wt. %, from 1 to 2 wt. %, from 2 to 10 wt. %, from 2 to 5 wt. %, from 2 to 4 wt. %, from 2 to 3 wt. %, from 3 to 10 wt. %, from 3 to 5 wt. %, from 3 to 4 wt. %, from 4 to 10 wt. %, from 4 to 5 wt. %, from 5 to 10 wt. %, or approximately 3 wt. % aluminum by weight of the titanium alloy.
[0036]The titanium alloy may include from 0.1 to 5 wt. %, from 0.1 to 2 wt. %, from 0.1 to 1.5 wt. %, from 0.1 to 1.0 wt. %, from 0.1 to 0.7 wt. %, from 0.1 to 0.5 wt. %, from 0.5 to 5 wt. %, from 0.5 to 2 wt. %, from 0.5 to 1.5 wt. %, from 0.5 to 1.0 wt. %, from 0.5 to 0.7 wt. %, from 0.7 to 5 wt. %, from 0.7 to 2 wt. %, from 0.7 to 1.5 wt. %, from 0.7 to 1.0 wt. %, from 1.0 to 5 wt. %, from 1.0 to 2 wt. %, from 1.0 to 1.5 wt. %, from 1.5 to 5 wt. %, from 1.5 to 2 wt. %, from 2 to 5 wt. %, or approximately 0.8 wt. % nickel by weight of the titanium alloy.
[0037]The ceramic may include crystalline inorganic metal oxides, bauxite, kaolin, magnesium oxide, alumina, nitride, carbide, carbon, silicon, ground ceramic, zirconia, stabilized zirconia, mullite, zirconia toughened alumina, spinel, aluminosilicates (such as mullite or cordierite), silicon carbide, silicon nitride, titanium carbide, titanium nitride, aluminum oxide, silicon oxide, zirconium oxide, stabilized zirconium oxide, aluminum carbide, aluminum nitride, zirconium carbide, zirconium nitride, aluminum oxynitride, silicon aluminum oxynitride, silicon dioxide, aluminum titanate, tungsten carbide, tungsten nitride, steatite, or combinations thereof. The 3D printed proppant may include from 0 to 100 wt. % ceramic, by weight of the 3D printed proppant. In embodiments, the 3D printed proppant may include from 0 to 100 wt. %, from 0 to 90 wt. %, from 0 to 80 wt. %, from 0 to 70 wt. %, from 0 to 60 wt. %, from 0 to 50 wt. %, from 0 to 40 wt. %, from 0 to 30 wt. %, from 0 to 20 wt. %, from 0 to 10 wt. %, from 0 to 1 wt. %, from 1 to 100 wt. %, from 1 to 90 wt. %, from 1 to 80 wt. %, from 1 to 70 wt. %, from 1 to 60 wt. %, from 1 to 50 wt. %, from 1 to 40 wt. %, from 1 to 30 wt. %, from 1 to 20 wt. %, from 1 to 10 wt. %, from 10 to 100 wt. %, from 10 to 90 wt. %, from 10 to 80 wt. %, from 10 to 70 wt. %, from 10 to 60 wt. %, from 10 to 50 wt. %, from 10 to 40 wt. %, from 10 to 30 wt. %, from 10 to 20 wt. %, from 20 to 100 wt. %, from 20 to 90 wt. %, from 20 to 80 wt. %, from 20 to 70 wt. %, from 20 to 60 wt. %, from 20 to 50 wt. %, from 20 to 40 wt. %, from 20 to 30 wt. %, from 30 to 100 wt. %, from 30 to 90 wt. %, from 30 to 80 wt. %, from 30 to 70 wt. %, from 30 to 60 wt. %, from 30 to 50 wt. %, from 30 to 40 wt. %, from 40 to 100 wt. %, from 40 to 90 wt. %, from 40 to 80 wt. %, from 40 to 70 wt. %, from 40 to 60 wt. %, from 40 to 50 wt. %, from 50 to 100 wt. %, from 50 to 90 wt. %, from 50 to 80 wt. %, from 50 to 70 wt. %, from 50 to 60 wt. %, from 60 to 100 wt. %, from 60 to 90 wt. %, from 60 to 80 wt. %, from 60 to 70 wt. %, from 70 to 100 wt. %, from 70 to 90 wt. %, from 70 to 80 wt. %, from 80 to 100 wt. %, from 80 to 90 wt. %, or from 90 to 100 wt. % ceramic by weight of the 3D printed proppant. In embodiments where the 3D printed proppant includes ceramic, the 3D printed proppant may include from 0.5 to 10 wt. % ceramic fiber material. In such embodiments, the 3D printed proppant may include ceramic matrix composite including the ceramic fiber material. In embodiments, carbon nanotubes, graphite, or both may be included in the 3D printed proppant.
[0038]The ground ceramic may include calcined clay, un-calcined clay, bauxite, silica, alumina, geopolymer, or combinations thereof. The geopolymer may include an aluminosilicate including calcined clays, kaolinitic clays, lateritic clays, volcanic rocks, mine tailings, Hast furnace slag, coal fly ash, and combinations thereof. The geopolymer may be formed from a geopolymer precursor fluid including aluminosilicate and an alkaline reagent. The alkaline reagent may include sodium silicate solution and potassium silicate solution. The concentration of potassium hydroxide may be selected so that the ratio of SiO2 to potassium oxide (K2O) in the potassium silicate solution is in the range of about 0.5:1 to about 2:1, alternately in the range from about 0.5:1 to about 1:1, alternately in the range from 1:1 to about 2:1, and alternately in the range from about 1.5:1 to about 2:1, where the formula for potassium silicate is K2O(SiO2). The Si to Al ratio may be in the range between 0.5:1 and 2:1. The geopolymer may have a silicon (Si) to aluminum (Al) ratio (Si/Al ratio) in the range between and 2:1, alternately between 1:1 and 2:1, alternately between 1:1 and 1.5:1, and alternately between 0.5:1 and 1:1. The aluminosilicate and the alkaline reagent, where sodium hydroxide is the alkaline reagent, may be mixed in stoichiometric amounts so that the ratio of Al2O3 to MIAS) is 1. In embodiments, the amount of aluminosilicate and the amount of the alkaline reagent, where potassium hydroxide is the alkaline reagent, are mixed in stoichiometric amounts so that the ratio of Al2O3 to K2O is 1. In embodiments, the ground ceramic may have an average particle size from 1 to 12 microns, from 1 to 10 microns, from 1 to 7 microns, from 1 to 5 microns, from 1 to 3 microns, from 3 to 12 microns, from 3 to 10 microns, from 3 to 7 microns, from 3 to 5 microns, from 5 to 12 microns, from 5 to 10 microns, from 5 to 7 microns, from 7 to 12 microns, from 7 to 10 microns, or from 10 to 12 microns. In embodiments, the ground ceramic may have a total alumina content from 30 to 90 wt. %, from 30 to 80 wt. %, from 30 to 70 wt. %, from 30 to 60 wt. %, from 30 to 50 wt. %, from 30 to 40 wt. %, from 40 to 90 wt. %, from 40 to 80 wt. %, from 40 to 70 wt. %, from 40 to 60 wt. %, from 40 to 50 wt. %, from 50 to 90 wt. %, from 50 to 80 wt. %, from 50 to 70 wt. %, from 50 to 60 wt. %, from 60 to 90 wt. %, from 60 to 80 wt. %, from 60 to 70 wt. %, from 70 to 90 wt. %, from 70 to 80 wt. %, or from 80 to 90 wt. %.
[0039]In certain implementations, the ground ceramic has total alumina content greater than 40 weight percent (wt. %). As for the ground ceramic mixture, the ground ceramic material may be mixed with a binder such as a poly(2-ethyl-2-oxazoline) solution, polyvinyl alcohol solution, waxes, or starch. The ground ceramic mixture may include the binder, for example at 0.1 wt. % to 1.5 wt. % of the amount of ceramic in the mixture.
[0040]A slurry having the ground ceramic mixture and water can be used. The ground-ceramic solid mixture combined with a liquid (for example, water) to form the slurry may have particle sizes in the range of 1 micron to 12 microns. The ground ceramic mixture may be mixed with water (for example, deionized water) to give the slurry, for instance, with 10% to 50% by weight of solids content. As mentioned, the ground ceramic may include reinforcing particles or fibers. The ground ceramic of the slurry may include a reinforcing agent (for example, reinforcing particles or fibers).
[0041]An example of a slurry that can be used is powder Alumina (25-30 vol %), Solvent such as ethyl alcohol (50-60 vol %), binder such as polyvinyl butyrol (1-5 vol %) and a plasticizer such as polyethylene glycol (5-10 vol %). In a different example water can replace the solvent to avoid the environmental issues. In aqueous based slurries, solid can be in the range from 25-75 vol % while water phase and the other additives are the remaining volume of the slurry.
[0042]After printing of these ceramic particles, they may be post cured to get strength. In ceramic proppants they may be sintered in an oven at temperature of 800-1400 C for 30 minutes to 2 hours to get the strength. At sintering temperature binder gets burned and smaller ceramic grain fuse with surrounding grains. The time required for sintering is such that the porosity created by 3D printing is not lost. It can be tailored by tailoring the time for sintering. The polymer may include resin, polyester, urea aldehyde, polyurethane, vinyl esters, furfural alcohol, or combinations thereof. The resin may include phenolic resin, epoxy resin, furan resin, polyurethane resin, polyurea resin, polyamide-imide resin, polyamide resin polyurea/polyurethane resin, urea-formaldehyde resin, melamin resin, silicone resin, vinyl ester resin, or combinations thereof. The 3D printed proppant may include from 0 to 100 wt. % polymer, by weight of the 3D printed proppant. In embodiments, the 3D printed proppant may include from 0 to 100 wt. %, from 0 to 90 wt. %, from 0 to 80 wt. %, from 0 to 70 wt. %, from 0 to 60 wt. %, from 0 to 50 wt. %, from 0 to 40 wt. %, from 0 to 30 wt. %, from 0 to 20 wt. %, from 0 to 10 wt. %, from 0 to 1 wt. %, from 1 to 100 wt. %, from 1 to 90 wt. %, from 1 to 80 wt. %, from 1 to 70 wt. %, from 1 to 60 wt. %, from 1 to 50 wt. %, from 1 to 40 wt. %, from 1 to 30 wt. %, from 1 to 20 wt. %, from 1 to 10 wt. %, from 10 to 100 wt. %, from 10 to 90 wt. %, from 10 to 80 wt. %, from 10 to 70 wt. %, from 10 to 60 wt. %, from 10 to 50 wt. %, from 10 to 40 wt. %, from 10 to 30 wt. %, from 10 to 20 wt. %, from 20 to 100 wt. %, from 20 to 90 wt. %, from 20 to 80 wt. %, from 20 to 70 wt. %, from 20 to 60 wt. %, from 20 to 50 wt. %, from 20 to 40 wt. %, from 20 to 30 wt. %, from 30 to 100 wt. %, from 30 to 90 wt. %, from 30 to 80 wt. %, from 30 to 70 wt. %, from 30 to 60 wt. %, from 30 to 50 wt. %, from 30 to 40 wt. %, from 40 to 100 wt. %, from 40 to 90 wt. %, from 40 to 80 wt. %, from 40 to 70 wt. %, from 40 to 60 wt. %, from 40 to 50 wt. %, from 50 to 100 wt. %, from 50 to 90 wt. %, from 50 to 80 wt. %, from 50 to 70 wt. %, from 50 to 60 wt. %, from 60 to 100 wt. %, from 60 to 90 wt. %, from 60 to 80 wt. %, from 60 to 70 wt. %, from 70 to 100 wt. %, from 70 to 90 wt. %, from 70 to 80 wt. %, from 80 to 100 wt. %, from 80 to 90 wt. %, or from 90 to 100 wt. % polymer by weight of the 3D printed proppant. In embodiments, ceramic or inorganic particles may be added to the polymer or resin to increase the toughness of the material. The 3D printed proppant may include from 0.1 to 20 wt. % inorganic or ceramic material by weight of the 3D printed proppant. It also help in reducing creep in the polymeric or resin based proppants. In embodiments, the ceramic or inorganic particles may include fibers. Resin is a substance of plant or synthetic origin that is typically convertible into polymers, and may be a mixture of organic compounds such as terpenes, an organic compound produced by plants. The viscosity of resin may be greater than 20 centiPoise (cP), measured at a temperature of 120° C. The resin may comprise phenolic resin, epoxy resin, furan resin, polyurethane resin, polyurea resin, polyester, polyamide-imide resin, polyamide resin polyurea/polyurethane resin, urea-formaldehyde resin, melamine resin, silicone resin, vinyl ester resin, or combinations of these. Novolacs are phenol-formaldehyde resins with a formaldehyde to phenol molar ratio of less than 1, where the phenol units are mainly linked by methylene or ether groups, or both. The novolac polymer may have a molecular weight of from 1,000 to 100,000 grams per mole (g/mol). The novolac polymer comprises a glass transition temperature greater than 250° F., 300° F., 350° F., 390° F., 400° F., 450° F., or 500° F. Novolacs are stable, meaning that novolacs do not react and do retain their polymer properties at temperatures of up to 300° F., 400° F., 425° F., 450° F., 475° F., 500° F., 550° F., or 600° F. Resoles are phenol-formaldehyde resins with a formaldehyde to phenol molar ratio of more than 1, where the phenol units are mainly linked by methylene or ether groups, or both. This can harden without the addition of a crosslinking agent due to abundance of methylene to bridge the phenol groups. The resole may have a molecular weight of from 1,000 to 100,000 grams per mole (g/mol). Resin or polymer inks may also be used. Resin or polymer inks are a photocurable polymer material, i.e., a “photopolymer” which may be cured on receiving light. Within technologies such as SLA, DLP, or even PolyJet, photosensitive liquid resins are used for manufacturing. These can be divided into two categories, thermoplastics and thermo-solids. These resins allow for objects to be printed with either matte or glossy finishes. The polymeric proppants are cured with hardened or crosslinked to get the thermoset material either at room temperature or by post curing at higher temperature in the oven. For example novolac resin is crosslinked with from 13 to 16 wt. % hexamine at from 200° F. to 400° F. to give fully cured thermoset proppant. In the present disclosure, the 3D printed proppant that includes polymer may have a glass transition temperature Tg, of greater than 150° F., greater than 200° F., greater than 250° F., greater than 300° F., greater than 350° F., or greater than 400° F., and less than 1000° F. Sometime Tg is also lowered due to temperature and the absorption of moisture and other fluids in the proppant. This has to be taken into account and testing need to be done prior to deployment in the field.
[0043]The 3D printed proppant may include reinforcing agents. In embodiments, the build material may include reinforcing agents. In embodiments, the ground ceramic may include reinforcing agents. The reinforcing agents may include comprise alumina, carbon, silicon carbide, alumina, mullite, organic materials, inorganic materials, ceramic materials, metallic materials, nanomaterials or combinations thereof. The organic materials may include carbon-based structures such as carbon nanotubes, single walled carbon nanotubes (SWNT), double walled nanotubes (DWNT), multi-walled carbon nanotubes (MWNT), armchair nanotubes, zig-zag nanotubes, helical nanotubes, bundles of single wall nanotubes, bundles of multi-wall nanotubes, nanofibers, nanorods, nanowires, nanospheres, microspheres, whiskers of oxide, fullerenes, graphene, carbon fibers, graphite fibers, nomex fibers, or combinations thereof. The inorganic materials may include vanadium pentoxide nanotubes, boron-nitride nanotube, tungsten, disulfidezinc oxide, diamond, clay, boron, boron nitride, silver, titanium dioxide, carbon, molybdenum disulfide, γ-aluminium oxide, titanium, palladium, tungsten disulfide, silicon dioxide, graphite, zirconium(IV) oxide-yttria stabilized, carbon, gd-doped-cerium(IV) oxide, nickel cobalt oxide, nickel(II) oxide, rhodium, sm-doped-cerium(IV) oxide, barium strontium titanate and silver. The nanomaterials may include nano-silica, nano-alumina, nano-zinc oxide, carbon nanotubes, nano-calcium carbonate, mica, vanadium pentoxide, boron nitride nanotubes, nano-zirconium oxide, or any of the reinforcing agents previously discussed at a nanoscale. The ceramic materials may include alumina, zirconia, stabilized zirconia, mullite, zirconia toughened alumina, spinel, aluminosilicates (such as mullite or cordierite), silicon carbide, silicon nitride, titanium carbide, titanium nitride, aluminum oxide, silicon oxide, zirconium oxide, stabilized zirconium oxide, aluminum carbide, aluminum nitride, zirconium carbide, zirconium nitride, aluminum oxynitride, silicon aluminum oxynitride, silicon dioxide, aluminum titanate, tungsten carbide, tungsten nitride, steatite, or any combination of these. The metallic materials may include iron, nickel, chromium, silicon, aluminum, copper, cobalt, beryllium, tungsten, molybdenum, titanium, magnesium, silver, as well as alloys of metals, and the like, or any combination of these. Metallic materials may also include the family of intermetallic materials, such as iron aluminides, nickel aluminides, and titanium aluminides. The reinforcing agents may include coated carbon nanotubes, such as zinc sulfide (ZnS) coated carbon nanotubes. The reinforcing agents may include particles, fibers, or both. The particles may have a particles size from 1 to 50 microns, from 1 to 40 microns, from 1 to 30 microns, from 1 to 20 microns, from 1 to 10 microns, from 10 to 50 microns, from 10 to 40 microns, from 10 to 30 microns, from 10 to 20 microns, from 20 to 50 micron