Mold Assemblies Used for Fabricating Downhole Tools

Abstract

An example mold assembly for fabricating an infiltrated downhole tool includes a mold forming a bottom of the mold assembly, and a funnel operatively coupled to the mold and having an inner wall, an outer wall, and a cavity defined between the inner and outer walls. An infiltration chamber is defined at least partially by the mold and the funnel. The inner wall faces the infiltration chamber and the outer wall forms at least a portion of an outer periphery of the mold assembly.

What is claimed is: 
     
         1 . A mold assembly for fabricating an infiltrated downhole tool, comprising:
 a mold forming a bottom of the mold assembly;   a funnel operatively coupled to the mold and having an inner wall, an outer wall, and a cavity defined between the inner and outer walls; and   an infiltration chamber defined at least partially by the mold and the funnel, wherein the inner wall faces the infiltration chamber and the outer wall forms at least a portion of an outer periphery of the mold assembly.   
     
     
         2 . The mold assembly of  claim 1 , wherein the infiltrated downhole tool is selected from the group consisting of a drill bit, a cutting tool, a non-retrievable drilling component, a drill bit body associated with casing drilling of wellbores, a drill-string stabilizer, a cone for a roller-cone drill bit, a model for forging dies used to fabricate support arms for roller-cone drill bits, an arm for a fixed reamer, an arm for an expandable reamer, an internal component associated with expandable reamers, a rotary steering tool, a logging-while-drilling tool, a measurement-while-drilling tool, a side-wall coring tool, a fishing spear, a washover tool, a rotor, a stator, a blade for a downhole turbine, and a housing for a downhole turbine. 
     
     
         3 . The mold assembly of  claim 1 , wherein the cavity is filled at least partially with a thermal material selected from the group consisting of a ceramic, a ceramic-fiber blanket, a polymer, a metal, an insulating metal composite, a carbon, a nanocomposite, a glass, a foam, a gas, any composite thereof, and any combination thereof. 
     
     
         4 . The mold assembly of  claim 3 , wherein the thermal material is in the form of at least one of beads, cubes, pellets, particulates, a powder, flakes, fibers, wools, a woven fabric, a bulked fabric, sheets, bricks, stones, blocks, cast shapes, molded shapes, sprayed insulation, a vacuum, any hybrid thereof, and any combination thereof. 
     
     
         5 . The mold assembly of  claim 3 , wherein the cavity is sealed and the gas is selected from the group consisting of air, argon, neon, helium, krypton, xenon, oxygen, carbon dioxide, methane, nitric oxide, nitrogen, nitrous oxide, and any combination thereof. 
     
     
         6 . The mold assembly of  claim 3 , wherein the thermal material is segmented into multiple rings disposed within the cavity. 
     
     
         7 . The mold assembly of  claim 1 , wherein the funnel has a top and a bottom and a height that extends between the top and the bottom, and wherein at least one of a thickness and a geometry of one or both of the inner and outer walls varies along the height to vary a thermal property of the funnel along the height. 
     
     
         8 . The mold assembly of  claim 1 , further comprising a reflective coating disposed within the cavity and applied to or adjacent a surface of one or both of the inner and outer walls. 
     
     
         9 . The mold assembly of  claim 1 , further comprising a thermal barrier disposed within the cavity and applied to or adjacent a surface of one or both of the inner and outer walls. 
     
     
         10 . The mold assembly of  claim 1 , wherein the inner and outer walls are concentric cylinders and a footing extends horizontally from the inner wall to support the outer wall. 
     
     
         11 . The mold assembly of  claim 10 , wherein the inner and outer walls are made of different materials selected from the group consisting of graphite, alumina, a ceramic, a metal, an insulating metal composite, a nanocomposite, a foam, and a ceramic-fiber blanket. 
     
     
         12 . The mold assembly of  claim 1 , wherein the cavity is filled at least partially with a thermal material selected from the group consisting of a metal, a salt, and a ceramic in the form of at least one of beads, cubes, pellets, particulates, a powder, and flakes, fibers, wools, a woven fabric, a bulked fabric, sheets, bricks, stones, blocks, cast shapes, molded shapes, sprayed insulation, any hybrid thereof, and any combination thereof. 
     
     
         13 . The mold assembly of  claim 12 , wherein the thermal material is disposed within a vessel that is removably positionable within the cavity. 
     
     
         14 . The mold assembly of  claim 1 , wherein the cavity has a bottom surface that defines alternating high points and low points about a circumference of the funnel within the cavity. 
     
     
         15 . The mold assembly of  claim 1 , wherein the inner and outer walls are segmented axially into a plurality of rings. 
     
     
         16 . The mold assembly of  claim 15 , wherein the plurality of rings are made of at least two dissimilar materials that exhibit different thermal properties. 
     
     
         17 . The mold assembly of  claim 1 , further comprising at least one of:
 a gauge ring interposing the mold and the funnel, wherein the funnel is operatively coupled to the mold via the gauge ring;   a binder bowl positioned above the funnel; and a cap positionable on the binder bowl.   
     
     
         18 . The mold assembly of  claim 17 , wherein one or more of the mold, the funnel, the gauge ring, the binder bowl, and the cap are made of a material that includes embedded refractory particles. 
     
     
         19 . The mold assembly of  claim 17 , wherein one or more of the mold, the funnel, the gauge ring, the binder bowl, and the cap are made of a material that defines a plurality of small, air filled cavities. 
     
     
         20 . The mold assembly of  claim 17 , wherein the cavity is a first cavity and at least one of the mold, the gauge ring, the binder bowl, and the cap defines a second cavity, and wherein the second cavity is filled at least partially with a thermal material selected from the group consisting of a ceramic, a polymer, a metal, an insulating metal composite, a carbon, a nanocomposite, a glass, a foam, a gas any composite thereof, and any combination thereof.