US20100101747A1 - Mold used in manufacture of drill bits and method of forming same - Google Patents
Mold used in manufacture of drill bits and method of forming same Download PDFInfo
- Publication number
- US20100101747A1 US20100101747A1 US12/590,561 US59056109A US2010101747A1 US 20100101747 A1 US20100101747 A1 US 20100101747A1 US 59056109 A US59056109 A US 59056109A US 2010101747 A1 US2010101747 A1 US 2010101747A1
- Authority
- US
- United States
- Prior art keywords
- mold
- drill bit
- bit body
- shell
- combinations
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims abstract description 41
- 238000004519 manufacturing process Methods 0.000 title claims description 13
- 239000000463 material Substances 0.000 claims abstract description 80
- 239000007787 solid Substances 0.000 claims abstract description 20
- 239000004576 sand Substances 0.000 claims abstract description 19
- 238000010438 heat treatment Methods 0.000 claims abstract description 10
- 238000003754 machining Methods 0.000 claims abstract description 5
- 238000001816 cooling Methods 0.000 claims abstract description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 30
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 28
- 229910002804 graphite Inorganic materials 0.000 claims description 27
- 239000010439 graphite Substances 0.000 claims description 27
- 239000011159 matrix material Substances 0.000 claims description 9
- 239000011347 resin Substances 0.000 claims description 9
- 229920005989 resin Polymers 0.000 claims description 9
- 230000015572 biosynthetic process Effects 0.000 claims description 8
- 239000000203 mixture Substances 0.000 claims description 8
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 claims description 8
- 239000004014 plasticizer Substances 0.000 claims description 6
- 239000012255 powdered metal Substances 0.000 claims description 6
- 239000011230 binding agent Substances 0.000 claims description 5
- 238000003801 milling Methods 0.000 claims description 5
- 229920000642 polymer Polymers 0.000 claims description 5
- 239000000377 silicon dioxide Substances 0.000 claims description 5
- 229910000831 Steel Inorganic materials 0.000 claims description 4
- 239000004927 clay Substances 0.000 claims description 4
- 229910001092 metal group alloy Inorganic materials 0.000 claims description 4
- 239000010959 steel Substances 0.000 claims description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims 4
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims 4
- 229910000792 Monel Inorganic materials 0.000 claims 2
- 229910017052 cobalt Inorganic materials 0.000 claims 2
- 239000010941 cobalt Substances 0.000 claims 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims 2
- 229910052742 iron Inorganic materials 0.000 claims 2
- 238000002844 melting Methods 0.000 claims 2
- 230000008018 melting Effects 0.000 claims 2
- 229910052759 nickel Inorganic materials 0.000 claims 2
- 229910052723 transition metal Inorganic materials 0.000 claims 2
- 150000003624 transition metals Chemical class 0.000 claims 2
- 239000012530 fluid Substances 0.000 claims 1
- 239000000155 melt Substances 0.000 claims 1
- 230000008569 process Effects 0.000 description 14
- 238000000465 moulding Methods 0.000 description 13
- 238000005520 cutting process Methods 0.000 description 5
- 238000005553 drilling Methods 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- 230000006378 damage Effects 0.000 description 2
- 229910003460 diamond Inorganic materials 0.000 description 2
- 239000010432 diamond Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 238000005219 brazing Methods 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 230000000284 resting effect Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D19/00—Casting in, on, or around objects which form part of the product
- B22D19/06—Casting in, on, or around objects which form part of the product for manufacturing or repairing tools
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/02—Sand moulds or like moulds for shaped castings
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/10—Cores; Manufacture or installation of cores
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/22—Moulds for peculiarly-shaped castings
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D19/00—Casting in, on, or around objects which form part of the product
- B22D19/04—Casting in, on, or around objects which form part of the product for joining parts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D23/00—Casting processes not provided for in groups B22D1/00 - B22D21/00
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/42—Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits
Definitions
- the present invention relates, generally, to the manufacture of drill bits usable to drill oil and gas wells.
- Bits typically used for drilling boreholes in the oil and gas industry include roller cone bits and fixed cutter bits.
- Cutting structures on bits vary depending on the type of bit and the type of formation being cut.
- Roller cone cutting structures typically include milled steel teeth, tungsten carbide inserts, or diamond enhanced inserts.
- Cutting structures for fixed cutter bits typically include polycrystalline diamond compacts, commonly referred to as “PDC” cutters.
- PDC polycrystalline diamond compacts
- Fixed cutter drill bits also referred to as fixed head bits or drag bits, are generally more expensive than mill tooth roller cone drill bits and are considered to offer less aggressive cutting structures than roller cone drill bits. However, in several applications, fixed cutter bits can be used to drill longer well segments in a single run and can be rebuilt and reused multiple times to provide an overall economic benefit that outweighs the higher cost. Fixed cutter bits which include PDC cutters are typically referred to as PDC bits.
- a conventional graphite mold is first machined to provide desired features to the mold for forming a drill bit body having selected characteristics.
- desired features For example, features usable to provide a drill bit body with nozzles, a bore, blades and/or lugs, junk slots, pockets for containing PDC cutters, and other drill bit elements known in the art can be provided to a mold for formation of a drill bit body having such elements.
- the drill bit body is then formed through a powdered metal infiltration casting method, which includes packing the mold with a powdered metal matrix material, such as tungsten carbide, then providing pieces of a metal or alloy to be used as a binding material above the packed mold, often in a separate chamber provided with a bore, funnel, or similar member used to allow molten metal to flow into the packed mold.
- the mold is then heated in a furnace to a temperature sufficient to melt the binding material, typically at or in excess of 2000 degrees Fahrenheit, such that the molten binding material is drawn into the spaces between particles of the packed powdered metal matrix material through capillary action. Once cooled through a controlled process, the binding material hardens between matrix particles to form the drill bit body.
- the mold must then be physically broken, such as by striking the mold with a hammer or similar implement.
- FIG. 1 of the drawings illustrates a conventional, prior art, single piece graphite mold usable to manufacture a body for a drill bit.
- FIG. 1 is a pictorial, isometric view of a conventional, prior art, single piece graphite mold used for manufacturing a drill bit body;
- FIGS. 2A , 2 B and 2 C respectively illustrate an exploded view of a mold usable in accordance with an embodiment of the present invention
- FIG. 3A illustrates an assembled view of the elements illustrated in FIGS. 2A , 2 B and 2 C;
- FIG. 3B is a schematic view, partially in cross section, illustrating the assembled mold
- FIG. 4A is an elevated, schematic view, in cross section, illustrating an embodiment of the assembled mold
- FIG. 4B is a top plan, schematic view of the embodiment illustrated in FIG. 4A with the top portion of FIG. 4A removed;
- FIG. 5 is a side view, in cross section of the mold shell illustrated in FIG. 2A ;
- FIG. 6 is a side view, in cross section, illustrating the mold core illustrated in FIG. 2B ;
- FIG. 7 is a pictorial, isometric view of an embodiment of the assembled mold.
- FIG. 8 illustrates the equipment used in milling the drill bit within the mold while resting on a fixture to support the mold core.
- the present invention relates, generally, to methods for forming a mold usable to create a drill bit body, and subsequent use of the mold to manufacture the drill bit body. While conventional methods for forming a drill bit body include use of graphite molds, embodiments of the present invention incorporate use of an inexpensive, fusible material, such as foundry sand or a similar mixture of silica, binders, resins, plasticizers, and/or polymers, which can be mixed, heated, or otherwise fused to form a solid insert within a generally rigid shell.
- an inexpensive, fusible material such as foundry sand or a similar mixture of silica, binders, resins, plasticizers, and/or polymers, which can be mixed, heated, or otherwise fused to form a solid insert within a generally rigid shell.
- Typical varieties of resin-bonded foundry sand usable within the scope of the present invention include fine sand particles, each coated with a thin layer of resin, which can be heated to approximately 250 to 450 degrees Fahrenheit to cause the resin to at least partially melt, thereby causing the particles of sand to adhere together to form a solid insert within the shell.
- a solid insert formed in such a manner from fused foundry sand or a similar fusible material is more easily machined or otherwise modified than conventional graphite molds, enabling a mold for forming a drill bit body having desired characteristics to be created more efficiently than conventional methods, using less costly materials. Machining of the solid insert can be performed within the shell, without requiring removal of the fused material, however in an embodiment of the invention, the solid insert can be removed from the shell to facilitate precise modifications and/or use of specific equipment to form the mold.
- materials such as foundry sand are very friable, enabling the mold to be easily removed from the shell, such that the shell can be reused.
- the heat applied through the drill bit molding process which can exceed 2000 degrees Fahrenheit, can destroy the remaining resin or other binding component of the fusible material, such that after the drill bit body has been molded, the fusible material will simply fall away from the drill bit body when the drill bit body is removed from the mold, reducing the time and labor normally required to destroy a conventional graphite mold.
- This feature substantially reduces manufacturing and material costs when compared with conventional methods, as a graphite mold can require a significant expense, while foundry sand or a similar material can cost as little as $0.50 per pound, or less.
- the relatively inexpensive nature of the fusible mold material of the present invention and the comparative ease with which it can be machined or milled to form molds reduces the loss incurred when a mold is destroyed after use, or otherwise discarded.
- molds formed from fusible material can be recovered intact and reused.
- the present invention thereby provides a hybrid molding method for forming a drill bit body that incorporates use of a reusable shell formed from a generally rigid material, such as graphite, having an interior that can be provided with an inexpensive, easily-machined, fusible material, such as foundry sand, which is usable to form a mold.
- a reusable shell formed from a generally rigid material such as graphite
- fusible material such as foundry sand
- Embodiments of the invention contemplate that use of a mold formed from foundry sand or a similar fusible material can provide drill bit bodies with generally rough finishes, which can be machined after molding.
- the interior of the mold can be provided with a mixture of clay and graphite powder, such as that used to repair cracks in conventional graphite molds, or a similar material that will melt under the high heat of the molding process.
- the presence of the liquid clay mixture within the mold results in the formation of drill bit bodies having an exceptionally smooth finish, superior to that obtained through use of conventional graphite molds.
- selective regions of the mold can be provided with a mixture of clay and graphite powder or a similar material, such that desired regions of the formed drill bit body are provided with a smooth finish, while other regions, such as pockets for containing PDC cutters, are provided with a rough finish, which would enable a more secure bond to be formed between the drill bit body and one or more cutter elements through a brazing process.
- FIG. 1 a pictorial, isometric view of a single piece, prior art graphite mold, known in the art, is shown.
- the depicted mold ( 10 ) is generally usable to form PDC drill bits.
- the mold ( 10 ) is shown having a lower portion ( 12 ) and an upper ring ( 14 ), the upper ring ( 14 ) containing a cavity used as the mold for manufacturing a PDC drill bit body.
- the depicted mold ( 10 ) is partially filled with a tungsten carbide powder to which a metal alloy is applied. Upon heating, the alloy mixes with the molten tungsten carbide to form a matrix, which assumes the shape of the mold ( 10 ) to form a drill bit body ( 18 ).
- FIG. 8 depicts an embodiment of this process, in which a milling device ( 16 ) is usable to mill portions of the drill bit body.
- the mold ( 10 ) is generally removed from the drill bit body ( 18 ) by physically breaking the mold ( 10 ), such as through use of a hammer or similar implement.
- the conventional molding process incurs a substantial quantity of waste, as the broken mold cannot be reused. Additionally, imprecise breaking of the mold ( 10 ) can potentially cause damage to the drill bit body ( 18 ).
- FIGS. 2A , 2 B, and 2 C there is illustrated a mold shell ( 30 ) having a cavity ( 34 ) therein.
- the mold shell ( 30 ) can be formed from any generally rigid material able to withstand the molding process, such as graphite.
- FIG. 5 depicts a cross-sectional view of the mold shell ( 30 ) and cavity ( 34 ).
- FIG. 2B depicts a mold core ( 32 ), sized to closely fit within the cavity ( 34 ), enabling the mold core ( 32 ) to be easily removed from the mold shell ( 30 ) after the molding process has been completed. As a result, the mold shell ( 30 ) is not broken to free the drill bit body and can be reused.
- the mold core ( 32 ) can be formed by providing, into the cavity ( 34 ), a fusible material, such as foundry sand or a similar mixture of silica or another structural component with one or more binders, resins, plasticizers, and/or polymer components.
- the fusible material can then be fused, such as by applying heat using a heating device, or simply through use of a mixing or machining device, to cause fusing of the resins, plasticizers, or other components of the fusible material.
- a generally solid insert is formed within the cavity ( 34 ), which can be machined, milled, or otherwise modified to form the mold core ( 32 ).
- FIG. 6 depicts a cross-sectional view of the mold core ( 32 ), which has been provided with regions for molding nozzles ( 44 ) and cutter pockets ( 46 ) in a drill bit body.
- FIG. 2C depicts a gauge ring ( 36 ), sized to sit on top of the mold shell ( 30 ) and surround the cavity, the gauge ring ( 36 ) being usable to define the outer diameter of the resulting drill bit body.
- the gauge ring ( 36 ) and other components disposed above the mold shell ( 30 ) can be formed from similar, generally rigid materials, such as graphite. In an embodiment of the invention, the gauge ring ( 36 ) and similar components can be recovered for reuse.
- FIG. 3A depicts an assembled view of the mold shell, mold core, and gauge ring of FIGS. 2A , 2 B, and 2 C.
- FIG. 3B depicts a schematic view, partially in cross section, illustrating the assembled mold of FIG. 3A , showing the mold shell ( 30 ) disposed about the mold core ( 32 ), with the gauge ring ( 36 ) positioned above the mold shell ( 30 ).
- FIG. 4A depicts a cross-sectional, assembled view of the mold shell ( 30 ), mold core ( 32 ), and gauge ring ( 36 ).
- FIG. 4A also depicts a funnel member ( 38 ) disposed above the gauge ring ( 36 ), the funnel member ( 38 ) being usable to provide drill bit materials, such as tungsten carbide powder, nickel alloys, and other metals and alloys therethrough. Materials provided through the funnel member ( 38 ) enter the mold core ( 32 ). Heating and subsequent cooling of the drill bit materials thereby forms a drill bit body having a shape defined by the mold core ( 32 ) and any other components of the mold, such as the gauge ring ( 36 ).
- fusible materials used to form the mold core ( 32 ) can also be provided through the funnel member ( 38 ) into the mold shell ( 30 ) without requiring disassembly of the mold.
- FIG. 4A also depicts an end cap ( 42 ), which can be attached to the top of the funnel member ( 38 ), such as through use of a threaded connection.
- FIG. 4A further depicts, schematically, parts of a drill bit that can be formed through the molding process, described above. Specifically, nozzles ( 44 ) and cutter pockets ( 46 ) of the resulting drill bit body are shown, which can be milled or otherwise modified, and/or fitted with additional parts or components following the molding process.
- FIG. 4B illustrates a top plan view of the mold shell, mold core and gauge ring of FIG. 4A , with the end cap removed, such that the funnel member ( 38 ) is visible.
- FIG. 7 is a pictorial, isometric view of an embodiment of the present mold, depicting a mold core ( 32 ) disposed within a mold shell ( 30 ).
- FIG. 7 depicts the mold core ( 32 ) having a machined surface used to form various components of a drill bit body.
- the mold core ( 32 ) is easily removable from the mold shell ( 30 ), without damaging the mold shell ( 30 ).
- the drill bit body can then be removed from the mold core ( 32 ), which in certain embodiments of the invention, can involve breaking of the mold core ( 32 ) and/or heating the mold core ( 32 ) to cause the fusible material to fall away from the drill bit body during removal. Due to the less costly nature of foundry sand and similar fusible materials, when compared to graphite and other conventional materials, little loss is incurred when a mold core ( 32 ) formed from fusible materials must be destroyed.
- the present invention thereby provides molds and methods of manufacture that incorporate use of inexpensive fusible materials, avoiding the need for use and destruction of costly graphite molds.
- the fusible materials of the present invention are more easily machined than conventional mold materials, providing for a more efficient process.
Abstract
Description
- The present application is a continuation-in-part application which claims priority to the copending U.S. patent application having Ser. No. 12/288,889, filed Oct. 24, 2008, the entirety of which is incorporated herein by reference.
- The present invention relates, generally, to the manufacture of drill bits usable to drill oil and gas wells.
- Various types of drill bits have been developed and found useful in different drilling environments. Bits typically used for drilling boreholes in the oil and gas industry include roller cone bits and fixed cutter bits. Cutting structures on bits vary depending on the type of bit and the type of formation being cut. Roller cone cutting structures typically include milled steel teeth, tungsten carbide inserts, or diamond enhanced inserts. Cutting structures for fixed cutter bits typically include polycrystalline diamond compacts, commonly referred to as “PDC” cutters. The selection of a bit type and cutting structure for a given drilling application depends on many factors including the formation type to be drilled, rig equipment capabilities, and the time and cost associated with drilling.
- Fixed cutter drill bits, also referred to as fixed head bits or drag bits, are generally more expensive than mill tooth roller cone drill bits and are considered to offer less aggressive cutting structures than roller cone drill bits. However, in several applications, fixed cutter bits can be used to drill longer well segments in a single run and can be rebuilt and reused multiple times to provide an overall economic benefit that outweighs the higher cost. Fixed cutter bits which include PDC cutters are typically referred to as PDC bits.
- It is common in the art of manufacturing PDC, fixed cutter drill bits, to manufacture the body of the drill bit using a graphite mold. Conventional molds are typically manufactured as a single piece of machined graphite. Graphite is used primarily due to the ability to readily machine the material to provide mold features, and due to the low coefficient of expansion, and uniformity of expansion, of the material when exposed to high heat during the drill bit molding process.
- In use, a conventional graphite mold is first machined to provide desired features to the mold for forming a drill bit body having selected characteristics. For example, features usable to provide a drill bit body with nozzles, a bore, blades and/or lugs, junk slots, pockets for containing PDC cutters, and other drill bit elements known in the art can be provided to a mold for formation of a drill bit body having such elements. The drill bit body is then formed through a powdered metal infiltration casting method, which includes packing the mold with a powdered metal matrix material, such as tungsten carbide, then providing pieces of a metal or alloy to be used as a binding material above the packed mold, often in a separate chamber provided with a bore, funnel, or similar member used to allow molten metal to flow into the packed mold. The mold is then heated in a furnace to a temperature sufficient to melt the binding material, typically at or in excess of 2000 degrees Fahrenheit, such that the molten binding material is drawn into the spaces between particles of the packed powdered metal matrix material through capillary action. Once cooled through a controlled process, the binding material hardens between matrix particles to form the drill bit body. To remove the drill bit body from the mold, the mold must then be physically broken, such as by striking the mold with a hammer or similar implement.
-
FIG. 1 of the drawings illustrates a conventional, prior art, single piece graphite mold usable to manufacture a body for a drill bit. - Due to the expense of large, single piece graphite molds, it has become desirable to minimize the quantity of graphite required to produce a drill bit body. Copending U.S. patent application Ser. No. 12/288,889 describes use of a two-piece mold that includes a reusable graphite shell sized to contain interchangeable graphite molds. The use of the two-piece mold also enables the manufacture of several sizes of drill bit bodies using a single reusable mold shell, thus reducing the quantity of graphite used to produce each drill bit body. However, the materials, time, equipment, and labor necessary to produce graphite molds carry a significant cost, ranging from $500 to $5000 per mold, or more.
- As such, a need exists for apparatuses and methods usable to form drill bit bodies that incorporate use of less expensive materials that are more easily machined or otherwise manipulated when compared to graphite.
-
FIG. 1 is a pictorial, isometric view of a conventional, prior art, single piece graphite mold used for manufacturing a drill bit body; -
FIGS. 2A , 2B and 2C respectively illustrate an exploded view of a mold usable in accordance with an embodiment of the present invention; -
FIG. 3A illustrates an assembled view of the elements illustrated inFIGS. 2A , 2B and 2C; -
FIG. 3B is a schematic view, partially in cross section, illustrating the assembled mold; -
FIG. 4A is an elevated, schematic view, in cross section, illustrating an embodiment of the assembled mold; -
FIG. 4B is a top plan, schematic view of the embodiment illustrated inFIG. 4A with the top portion ofFIG. 4A removed; -
FIG. 5 is a side view, in cross section of the mold shell illustrated inFIG. 2A ; -
FIG. 6 is a side view, in cross section, illustrating the mold core illustrated inFIG. 2B ; -
FIG. 7 is a pictorial, isometric view of an embodiment of the assembled mold; and -
FIG. 8 illustrates the equipment used in milling the drill bit within the mold while resting on a fixture to support the mold core. - The present invention relates, generally, to methods for forming a mold usable to create a drill bit body, and subsequent use of the mold to manufacture the drill bit body. While conventional methods for forming a drill bit body include use of graphite molds, embodiments of the present invention incorporate use of an inexpensive, fusible material, such as foundry sand or a similar mixture of silica, binders, resins, plasticizers, and/or polymers, which can be mixed, heated, or otherwise fused to form a solid insert within a generally rigid shell. Typical varieties of resin-bonded foundry sand usable within the scope of the present invention include fine sand particles, each coated with a thin layer of resin, which can be heated to approximately 250 to 450 degrees Fahrenheit to cause the resin to at least partially melt, thereby causing the particles of sand to adhere together to form a solid insert within the shell.
- A solid insert formed in such a manner from fused foundry sand or a similar fusible material is more easily machined or otherwise modified than conventional graphite molds, enabling a mold for forming a drill bit body having desired characteristics to be created more efficiently than conventional methods, using less costly materials. Machining of the solid insert can be performed within the shell, without requiring removal of the fused material, however in an embodiment of the invention, the solid insert can be removed from the shell to facilitate precise modifications and/or use of specific equipment to form the mold.
- Additionally, materials such as foundry sand are very friable, enabling the mold to be easily removed from the shell, such that the shell can be reused. The heat applied through the drill bit molding process, which can exceed 2000 degrees Fahrenheit, can destroy the remaining resin or other binding component of the fusible material, such that after the drill bit body has been molded, the fusible material will simply fall away from the drill bit body when the drill bit body is removed from the mold, reducing the time and labor normally required to destroy a conventional graphite mold.
- This feature substantially reduces manufacturing and material costs when compared with conventional methods, as a graphite mold can require a significant expense, while foundry sand or a similar material can cost as little as $0.50 per pound, or less. The relatively inexpensive nature of the fusible mold material of the present invention and the comparative ease with which it can be machined or milled to form molds reduces the loss incurred when a mold is destroyed after use, or otherwise discarded. However, it should also be noted that when desired, molds formed from fusible material can be recovered intact and reused.
- The present invention thereby provides a hybrid molding method for forming a drill bit body that incorporates use of a reusable shell formed from a generally rigid material, such as graphite, having an interior that can be provided with an inexpensive, easily-machined, fusible material, such as foundry sand, which is usable to form a mold. Conventional sand-molding processes, such as those used in foundries, are unsuitable for use with most matrix materials desirable for formation of drill bit bodies due to the weight of such materials. For example, a quantity tungsten carbide has a weight of approximately 2.5 times that of an equal quantity of steel. Use of a hybrid mold containing fusible material within a generally rigid shell provides sufficient strength for containing powdered matrix materials and binding metals, while minimizing the time and expense required to utilize conventional graphite molds.
- Embodiments of the invention contemplate that use of a mold formed from foundry sand or a similar fusible material can provide drill bit bodies with generally rough finishes, which can be machined after molding. However, the interior of the mold can be provided with a mixture of clay and graphite powder, such as that used to repair cracks in conventional graphite molds, or a similar material that will melt under the high heat of the molding process. The presence of the liquid clay mixture within the mold results in the formation of drill bit bodies having an exceptionally smooth finish, superior to that obtained through use of conventional graphite molds. In further embodiments of the invention, selective regions of the mold can be provided with a mixture of clay and graphite powder or a similar material, such that desired regions of the formed drill bit body are provided with a smooth finish, while other regions, such as pockets for containing PDC cutters, are provided with a rough finish, which would enable a more secure bond to be formed between the drill bit body and one or more cutter elements through a brazing process.
- Referring now to
FIG. 1 , a pictorial, isometric view of a single piece, prior art graphite mold, known in the art, is shown. The depicted mold (10) is generally usable to form PDC drill bits. The mold (10) is shown having a lower portion (12) and an upper ring (14), the upper ring (14) containing a cavity used as the mold for manufacturing a PDC drill bit body. In use, the depicted mold (10) is partially filled with a tungsten carbide powder to which a metal alloy is applied. Upon heating, the alloy mixes with the molten tungsten carbide to form a matrix, which assumes the shape of the mold (10) to form a drill bit body (18). - After formation of the drill bit body (18), a milling process can be performed to mill various components of the drill bit body to form the finished product.
FIG. 8 depicts an embodiment of this process, in which a milling device (16) is usable to mill portions of the drill bit body. - Following formation of a drill bit body using the single piece mold (10) of
FIG. 1 , the mold (10) is generally removed from the drill bit body (18) by physically breaking the mold (10), such as through use of a hammer or similar implement. As a result, the conventional molding process incurs a substantial quantity of waste, as the broken mold cannot be reused. Additionally, imprecise breaking of the mold (10) can potentially cause damage to the drill bit body (18). - Referring now to
FIGS. 2A , 2B, and 2C, there is illustrated a mold shell (30) having a cavity (34) therein. The mold shell (30) can be formed from any generally rigid material able to withstand the molding process, such as graphite.FIG. 5 depicts a cross-sectional view of the mold shell (30) and cavity (34).FIG. 2B depicts a mold core (32), sized to closely fit within the cavity (34), enabling the mold core (32) to be easily removed from the mold shell (30) after the molding process has been completed. As a result, the mold shell (30) is not broken to free the drill bit body and can be reused. - The mold core (32) can be formed by providing, into the cavity (34), a fusible material, such as foundry sand or a similar mixture of silica or another structural component with one or more binders, resins, plasticizers, and/or polymer components. The fusible material can then be fused, such as by applying heat using a heating device, or simply through use of a mixing or machining device, to cause fusing of the resins, plasticizers, or other components of the fusible material. After fusing the fusible material, a generally solid insert is formed within the cavity (34), which can be machined, milled, or otherwise modified to form the mold core (32).
FIG. 6 depicts a cross-sectional view of the mold core (32), which has been provided with regions for molding nozzles (44) and cutter pockets (46) in a drill bit body. - While the mold core (32) is usable to form a first portion of a drill bit body, other components can be provided above the mold core (32) to form other portions of the drill bit body. For example,
FIG. 2C depicts a gauge ring (36), sized to sit on top of the mold shell (30) and surround the cavity, the gauge ring (36) being usable to define the outer diameter of the resulting drill bit body. The gauge ring (36) and other components disposed above the mold shell (30) can be formed from similar, generally rigid materials, such as graphite. In an embodiment of the invention, the gauge ring (36) and similar components can be recovered for reuse. -
FIG. 3A depicts an assembled view of the mold shell, mold core, and gauge ring ofFIGS. 2A , 2B, and 2C.FIG. 3B depicts a schematic view, partially in cross section, illustrating the assembled mold ofFIG. 3A , showing the mold shell (30) disposed about the mold core (32), with the gauge ring (36) positioned above the mold shell (30). -
FIG. 4A depicts a cross-sectional, assembled view of the mold shell (30), mold core (32), and gauge ring (36).FIG. 4A also depicts a funnel member (38) disposed above the gauge ring (36), the funnel member (38) being usable to provide drill bit materials, such as tungsten carbide powder, nickel alloys, and other metals and alloys therethrough. Materials provided through the funnel member (38) enter the mold core (32). Heating and subsequent cooling of the drill bit materials thereby forms a drill bit body having a shape defined by the mold core (32) and any other components of the mold, such as the gauge ring (36). Due to the pourable nature of foundry sand and other usable fusible materials, fusible materials used to form the mold core (32) can also be provided through the funnel member (38) into the mold shell (30) without requiring disassembly of the mold. -
FIG. 4A also depicts an end cap (42), which can be attached to the top of the funnel member (38), such as through use of a threaded connection.FIG. 4A further depicts, schematically, parts of a drill bit that can be formed through the molding process, described above. Specifically, nozzles (44) and cutter pockets (46) of the resulting drill bit body are shown, which can be milled or otherwise modified, and/or fitted with additional parts or components following the molding process.FIG. 4B illustrates a top plan view of the mold shell, mold core and gauge ring ofFIG. 4A , with the end cap removed, such that the funnel member (38) is visible. -
FIG. 7 is a pictorial, isometric view of an embodiment of the present mold, depicting a mold core (32) disposed within a mold shell (30).FIG. 7 depicts the mold core (32) having a machined surface used to form various components of a drill bit body. After the molding process, the mold core (32) is easily removable from the mold shell (30), without damaging the mold shell (30). The drill bit body can then be removed from the mold core (32), which in certain embodiments of the invention, can involve breaking of the mold core (32) and/or heating the mold core (32) to cause the fusible material to fall away from the drill bit body during removal. Due to the less costly nature of foundry sand and similar fusible materials, when compared to graphite and other conventional materials, little loss is incurred when a mold core (32) formed from fusible materials must be destroyed. - The present invention thereby provides molds and methods of manufacture that incorporate use of inexpensive fusible materials, avoiding the need for use and destruction of costly graphite molds. The fusible materials of the present invention are more easily machined than conventional mold materials, providing for a more efficient process.
- While various embodiments of the present invention have been described with emphasis, it should be understood that within the scope of the appended claims, the present invention might be practiced other than as specifically described herein.
Claims (24)
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/590,561 US20100101747A1 (en) | 2008-10-24 | 2009-11-10 | Mold used in manufacture of drill bits and method of forming same |
US12/806,704 US20110056751A1 (en) | 2008-10-24 | 2010-08-19 | Ultra-hard matrix reamer elements and methods |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/288,889 US20100101750A1 (en) | 2008-10-24 | 2008-10-24 | Two piece mold used in manufacture of PDC drill bits and method of using same |
US12/590,561 US20100101747A1 (en) | 2008-10-24 | 2009-11-10 | Mold used in manufacture of drill bits and method of forming same |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/288,889 Continuation-In-Part US20100101750A1 (en) | 2008-10-24 | 2008-10-24 | Two piece mold used in manufacture of PDC drill bits and method of using same |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/288,889 Continuation-In-Part US20100101750A1 (en) | 2008-10-24 | 2008-10-24 | Two piece mold used in manufacture of PDC drill bits and method of using same |
Publications (1)
Publication Number | Publication Date |
---|---|
US20100101747A1 true US20100101747A1 (en) | 2010-04-29 |
Family
ID=42116352
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/590,561 Abandoned US20100101747A1 (en) | 2008-10-24 | 2009-11-10 | Mold used in manufacture of drill bits and method of forming same |
Country Status (1)
Country | Link |
---|---|
US (1) | US20100101747A1 (en) |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110056751A1 (en) * | 2008-10-24 | 2011-03-10 | James Shamburger | Ultra-hard matrix reamer elements and methods |
US20110115118A1 (en) * | 2009-11-16 | 2011-05-19 | Varel Europe S.A.S. | Compensation grooves to absorb dilatation during infiltration of a matrix drill bit |
WO2012073102A2 (en) * | 2010-11-29 | 2012-06-07 | Halliburton Energy Services, Inc. | Mold assemblies including a mold insertable in a container |
WO2015088488A1 (en) * | 2013-12-10 | 2015-06-18 | Halliburton Energy Services, Inc. | Vented blank for producing a matrix bit body |
WO2016089365A1 (en) * | 2014-12-02 | 2016-06-09 | Halliburton Energy Services, Inc. | Mold assemblies used for fabricating downhole tools |
WO2016089374A1 (en) * | 2014-12-02 | 2016-06-09 | Halliburton Energy Services, Inc. | Mold assemblies with integrated thermal mass for fabricating infiltrated downhole tools |
WO2016089370A1 (en) * | 2014-12-02 | 2016-06-09 | Halliburton Energy Services, Inc. | Mold assembly caps used in fabricating infiltrated downhole tools |
WO2016089376A1 (en) * | 2014-12-02 | 2016-06-09 | Halliburton Energy Services, Inc. | Mold assemblies that actively heat infiltrated downhole tools |
US9790744B2 (en) | 2010-11-29 | 2017-10-17 | Halliburton Energy Services, Inc. | Forming objects by infiltrating a printed matrix |
US10399258B2 (en) | 2010-11-29 | 2019-09-03 | Halliburton Energy Services, Inc. | Heat flow control for molding downhole equipment |
CN112876250A (en) * | 2021-03-26 | 2021-06-01 | 中国石油化工股份有限公司 | PDC drill bit die and preparation method thereof |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3770465A (en) * | 1971-07-19 | 1973-11-06 | Exoment Inc | Mold wash composition |
US4194915A (en) * | 1978-01-03 | 1980-03-25 | N L Industries, Inc. | Foundry mold and core wash additives |
US6209420B1 (en) * | 1994-03-16 | 2001-04-03 | Baker Hughes Incorporated | Method of manufacturing bits, bit components and other articles of manufacture |
US6353771B1 (en) * | 1996-07-22 | 2002-03-05 | Smith International, Inc. | Rapid manufacturing of molds for forming drill bits |
US6655481B2 (en) * | 1999-01-25 | 2003-12-02 | Baker Hughes Incorporated | Methods for fabricating drill bits, including assembling a bit crown and a bit body material and integrally securing the bit crown and bit body material to one another |
US20080028891A1 (en) * | 2006-04-28 | 2008-02-07 | Calnan Barry D | Molds and methods of forming molds associated with manufacture of rotary drill bits and other downhole tools |
-
2009
- 2009-11-10 US US12/590,561 patent/US20100101747A1/en not_active Abandoned
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3770465A (en) * | 1971-07-19 | 1973-11-06 | Exoment Inc | Mold wash composition |
US4194915A (en) * | 1978-01-03 | 1980-03-25 | N L Industries, Inc. | Foundry mold and core wash additives |
US6209420B1 (en) * | 1994-03-16 | 2001-04-03 | Baker Hughes Incorporated | Method of manufacturing bits, bit components and other articles of manufacture |
US6353771B1 (en) * | 1996-07-22 | 2002-03-05 | Smith International, Inc. | Rapid manufacturing of molds for forming drill bits |
US6655481B2 (en) * | 1999-01-25 | 2003-12-02 | Baker Hughes Incorporated | Methods for fabricating drill bits, including assembling a bit crown and a bit body material and integrally securing the bit crown and bit body material to one another |
US20080028891A1 (en) * | 2006-04-28 | 2008-02-07 | Calnan Barry D | Molds and methods of forming molds associated with manufacture of rotary drill bits and other downhole tools |
Cited By (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110056751A1 (en) * | 2008-10-24 | 2011-03-10 | James Shamburger | Ultra-hard matrix reamer elements and methods |
US20110115118A1 (en) * | 2009-11-16 | 2011-05-19 | Varel Europe S.A.S. | Compensation grooves to absorb dilatation during infiltration of a matrix drill bit |
US8251122B2 (en) * | 2009-11-16 | 2012-08-28 | Varel Europe S.A.S. | Compensation grooves to absorb dilatation during infiltration of a matrix drill bit |
WO2012023985A1 (en) * | 2010-08-19 | 2012-02-23 | Tercel Ip Ltd. | Ultra-hard matrix reamers and methods |
US9790744B2 (en) | 2010-11-29 | 2017-10-17 | Halliburton Energy Services, Inc. | Forming objects by infiltrating a printed matrix |
WO2012073102A2 (en) * | 2010-11-29 | 2012-06-07 | Halliburton Energy Services, Inc. | Mold assemblies including a mold insertable in a container |
WO2012073102A3 (en) * | 2010-11-29 | 2012-11-15 | Halliburton Energy Services, Inc. | Mold assemblies including a mold insertable in a container |
US10399258B2 (en) | 2010-11-29 | 2019-09-03 | Halliburton Energy Services, Inc. | Heat flow control for molding downhole equipment |
GB2549756A (en) * | 2013-12-10 | 2017-11-01 | Halliburton Energy Services Inc | Vented blank for producing a matrix bit body |
US10029300B2 (en) | 2013-12-10 | 2018-07-24 | Halliburton Energy Services, Inc. | Vented blank for producing a matrix bit body |
WO2015088488A1 (en) * | 2013-12-10 | 2015-06-18 | Halliburton Energy Services, Inc. | Vented blank for producing a matrix bit body |
CN105849354A (en) * | 2013-12-10 | 2016-08-10 | 哈里伯顿能源服务公司 | Vented blank for producing a matrix bit body |
WO2016089365A1 (en) * | 2014-12-02 | 2016-06-09 | Halliburton Energy Services, Inc. | Mold assemblies used for fabricating downhole tools |
US9718126B2 (en) * | 2014-12-02 | 2017-08-01 | Halliburton Energy Services, Inc. | Mold assembly caps used in fabricating infiltrated downhole tools |
WO2016089374A1 (en) * | 2014-12-02 | 2016-06-09 | Halliburton Energy Services, Inc. | Mold assemblies with integrated thermal mass for fabricating infiltrated downhole tools |
WO2016089370A1 (en) * | 2014-12-02 | 2016-06-09 | Halliburton Energy Services, Inc. | Mold assembly caps used in fabricating infiltrated downhole tools |
US20160346833A1 (en) * | 2014-12-02 | 2016-12-01 | Halliburton Energy Services, Inc. | Mold assembly caps used in fabricating infiltrated downhole tools |
US10118220B2 (en) | 2014-12-02 | 2018-11-06 | Halliburton Energy Services, Inc. | Mold assemblies used for fabricating downhole tools |
US10350672B2 (en) | 2014-12-02 | 2019-07-16 | Halliburton Energy Services, Inc. | Mold assemblies that actively heat infiltrated downhole tools |
WO2016089376A1 (en) * | 2014-12-02 | 2016-06-09 | Halliburton Energy Services, Inc. | Mold assemblies that actively heat infiltrated downhole tools |
US10807152B2 (en) | 2014-12-02 | 2020-10-20 | Halliburton Energy Services, Inc. | Mold assemblies that actively heat infiltrated downhole tools |
CN112876250A (en) * | 2021-03-26 | 2021-06-01 | 中国石油化工股份有限公司 | PDC drill bit die and preparation method thereof |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20100101747A1 (en) | Mold used in manufacture of drill bits and method of forming same | |
US4499795A (en) | Method of drill bit manufacture | |
US4884477A (en) | Rotary drill bit with abrasion and erosion resistant facing | |
US4919013A (en) | Preformed elements for a rotary drill bit | |
US5373907A (en) | Method and apparatus for manufacturing and inspecting the quality of a matrix body drill bit | |
US5090491A (en) | Earth boring drill bit with matrix displacing material | |
EP2156003B1 (en) | Method of repairing diamond rock bit | |
US6220117B1 (en) | Methods of high temperature infiltration of drill bits and infiltrating binder | |
US8061405B2 (en) | Casting method for matrix drill bits and reamers | |
EP0995876B1 (en) | Methods of manufacturing rotary drill bits | |
US8925422B2 (en) | Method of manufacturing a drill bit | |
US8814968B2 (en) | Thermally conductive sand mould shell for manufacturing a matrix bit | |
ITMI20060745A1 (en) | TIPS FOR COMPOSITE DRILLING AUGUST AND RELATED PRODUCTION METHOD | |
EP2913474A2 (en) | Manufacture of low cost bits by infiltration of metal powders | |
US8561725B2 (en) | Ultra-hard drill collar | |
CA1311234C (en) | Earth boring drill bit with matrix displacing material | |
GB2364529A (en) | Methods of high temperature infiltration of drill bits and infiltrating binder | |
EP0197741A2 (en) | Improvements in or relating to rotary drill bits and methods of manufacture thereof | |
US20110056751A1 (en) | Ultra-hard matrix reamer elements and methods | |
US20210238928A1 (en) | Displacement members comprising machinable material portions, bit bodies comprising machinable material portions from such displacement members, earth-boring rotary drill bits comprising such bit bodies, and related methods | |
US20220001444A1 (en) | Mold for downhole tool or component thereof | |
US20100101750A1 (en) | Two piece mold used in manufacture of PDC drill bits and method of using same | |
JP2002120042A (en) | Method for manufacturing casting mold and casting mold | |
GB2384262A (en) | A method of fabricating an earth-boring drill bit | |
JPS60199189A (en) | Production fo rotary drill bit |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: ENCORE BITS, LLC,TEXAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:TOMCZAK, MICHAEL M.;SALVO, VINCENTE S.;RIOS, JUAN;AND OTHERS;SIGNING DATES FROM 20091022 TO 20091023;REEL/FRAME:023727/0664 |
|
AS | Assignment |
Owner name: OMNI LP LTD.,TEXAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ENCORE BITS, LLC;REEL/FRAME:024052/0770 Effective date: 20100304 |
|
AS | Assignment |
Owner name: OMNI IP LTD., VIRGIN ISLANDS, BRITISH Free format text: ADDRESS CHANGE AND CORRECTION FOR ASSIGNMENT RECORDED AT REEL 024052 FRAME 0770. THE NEW ADDRESSIS LISTED ABOVE AND THE CORRECT SPELLING OF THE ASSIGNEE NAME IS OMNI IP LTD;ASSIGNOR:OMNI IP LTD.;REEL/FRAME:024634/0080 Effective date: 20100304 |
|
AS | Assignment |
Owner name: TERCEL IP LTD., VIRGIN ISLANDS, BRITISH Free format text: CHANGE OF NAME;ASSIGNOR:OMNI IP LTD.;REEL/FRAME:033577/0571 Effective date: 20110627 |
|
AS | Assignment |
Owner name: SILICON VALLEY BANK, CALIFORNIA Free format text: SECURITY INTEREST;ASSIGNOR:TERCEL IP LTD.;REEL/FRAME:036216/0095 Effective date: 20150728 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |
|
AS | Assignment |
Owner name: TERCEL IP LTD., TEXAS Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:SILICON VALLEY BANK;REEL/FRAME:047900/0534 Effective date: 20181217 |