BIT

BACKGROUND OF THE DISCLOSURE

Field of the Disclosure

[0001] The present disclosure generally relates to a high angle claw shaped gouging cutter for a fixed cutter drill bit.

Description of the Related Art

[0002] US 8,794,356 discloses an earth-boring tool including a body, one or more blades projecting outwardly from the body, and cutting elements carried by the blade. The cutting elements include at least one shearing cutting element and at least one gouging cutting element. Methods of forming an earth-boring tool include mounting a shearing cutting element including an at least substantially planar cutting face to a body of an earth-boring tool, and mounting a gouging cutting element including a non-planar cutting face to the body of the earth-boring tool. The gouging cutting element may be positioned on the body of the earth-boring tool such that the gouging cutting element will gouge formation material within a kerf cut in the formation material by the shearing cutting element, or between kerfs cut in the formation material by a plurality of shearing cutting elements.

[0003] US 8,960,337 discloses a high impact resistant tool including a sintered polycrystalline diamond body bonded to a cemented metal carbide substrate at an interface, the body comprising a substantially pointed geometry with an apex, the apex comprising a curved surface that joins a leading side and a trailing side of the body at a first and second transitions respectively, an apex width between the first and second transitions is less than a third of a width of the substrate, and the body also includes a body thickness from the apex to the interface greater than a third of the width of the substrate.

[0004] US 9,316,058 discloses cutting elements for an earth-boring tool including a substrate base and a cutting tip. The cutting tip may include a first generally conical surface, a second, opposite generally conical surface, a first flank surface extending between the first and second generally conical surfaces, and a second, opposite flank surface. The cutting tip may include a central axis that is not co-linear with a longitudinal axis of the substrate base. The cutting tip may include a surface defining a longitudinal end thereof that is relatively more narrow in a central region thereof than in a radially outer region thereof. Earth-boring tools include a body and a plurality of such cutting elements attached thereto, at least one cutting element oriented to initially engage a formation with the first or second generally conical surface thereof. Methods of drilling a formation use such cutting elements and earth boring tools.

SUMMARY OF THE DISCLOSURE

[0005] The present disclosure generally relates a high angle claw shaped gouging cutter for fixed cutter drill bit. In one embodiment, a cutter for use with a drill bit includes: a substrate for mounting in a pocket of the drill bit and made from a cermet material; and a head made from a superhard material, mounted to the substrate, and having a chisel inclined relative to a longitudinal axis of the cutter by an attack angle greater than sixty degrees.

[0006] In another embodiment, a cutter for use with a drill bit includes: a substrate for mounting in a pocket of the drill bit and made from a cermet material; and a head made from the cermet material, mounted to the substrate, and having a chisel inclined relative to a longitudinal axis of the cutter by an attack angle greater than sixty degrees.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

[0008] Figures 1A-1D illustrate a claw shaped gouging cutter, according to one embodiment of the present disclosure. [0009] Figures 2 and 3 illustrate a fixed cutter drill bit equipped with a plurality of the claw shaped gouging cutters.

[0010] Figures 4A-4D illustrate a second claw shaped gouging cutter, according to another embodiment of the present disclosure.

[0011] Figures 5A-5D illustrate a third claw shaped gouging cutter, according to another embodiment of the present disclosure.

[0012] Figures 6A-6D illustrate a fourth claw shaped gouging cutter, according to another embodiment of the present disclosure.

[0013] Figures 7A, 7B, 8A, and 8B illustrate a fifth claw shaped gouging cutter, according to another embodiment of the present disclosure.

DETAILED DESCRIPTION

[0014] Figures 1A-1D illustrate a claw shaped gouging cutter 1, according to one embodiment of the present disclosure. The gouging cutter 1 may include a substrate 2 and a head 3 mounted to the substrate. The head 3 may be made from a polycrystalline superhard material, such as polycrystalline diamond (PCD), and the substrate 2 may be made from a hard material, such as a cermet. The cermet may be a cemented carbide, such as a group VI 11 B metal-tungsten carbide. The group VI I IB metal may be cobalt. The gouging cutter 1 may be manufactured by a high pressure, high temperature (HPHT) sintering operation using either a belt press or a cubic press.

[0015] Alternatively, the head 3 may be made from a composite material, such as a cermet impregnated with superhard material, such as monocrystalline or thermally stable polycrystalline diamond. The cermet may be a cemented carbide and the diamond may be dispersed therein at a content ranging between twenty-five percent and sixty percent by volume. The gouging cutter 1 may then be manufactured by a hot isostatic pressing operation. Alternatively, the head 3 may be made from the same cermet material as the substrate 2.

[0016] The head 3 may have an interface 4 with the substrate 2, a chisel 5 at an end thereof opposite to the interface, a pedestal 3p extending from the interface and connecting a side 5s of the chisel to the interface, and a dome segment 3d connecting a base 5b of the chisel to the pedestal. The substrate 2 may have the interface 4 with the head 3 and a mounting end opposite to the interface for being received in a pocket of a drill bit 7. The mounting end of the substrate 2 may have a chamfer 2c formed in a periphery thereof. The interface 4 may be planar or non- planar.

[0017] The pedestal 3p may have a frusto-conical portion extending from the interface 4 and an irregular portion extending from the frusto-conical portion to the dome segment 3d and to a side 5s of the chisel 5. The chisel 5 may resemble a frusto-cone with the side 5s having a truncated portion adjacent to the pedestal 3p, the base 5b having a truncated portion adjacent to the dome segment 3d, and an edge 5e formed by a pair of flats 5f formed into opposite non-truncated portions of the side. The edge 5e may be planar. The planar edge 5e may have a slight curvature. The edge 5e may have a length 6e ranging between one percent and thirty percent of a diameter of the substrate 2, ranging between five percent and thirty percent thereof, or ranging between ten percent and thirty percent thereof. The edge 5e may have a width 6w ranging between one percent and sixty percent of the length 6e thereof or ranging between ten percent and sixty percent thereof.

[0018] The chisel 5 may have an axis 6c perpendicular to the edge 5e and the base 5b and inclined relative to a longitudinal axis 6g of the gouging cutter 1 by an attack angle 6a ranging between fifteen and sixty degrees. The flats 5f may be formed in the chisel 5, such as by laser cutting or electrical discharge machining, after the gouging cutter 1 has been sintered. The head 3 may have a height 6h greater than or equal to a thickness 6t of the substrate 2 and less than or equal to the diameter of the substrate. The gouging cutter 1 may be symmetrical about a longitudinal plane extending through the edge 5e.

[0019] Alternatively, the flats 5f may be roughly formed during sintering and finished by laser cutting or electrical discharge machining.

[0020] Figures 2 and 3 illustrate a fixed cutter drill bit 7 equipped with a plurality of the claw shaped gouging cutters 1, 1a, 1b. The drill bit 7 may include a cutting face 9, a bit body 8, a shank (not shown), and a gage section 10. A lower portion of the bit body 8 may be made from a composite material, such as a ceramic and/or cermet matrix powder infiltrated by a metallic binder, and an upper portion of the bit body may be made from a softer material than the composite material of the upper portion, such as a metal or alloy shoulder powder infiltrated by the metallic binder. The bit body 8 may be mounted to the shank during molding thereof. The shank may be tubular and made from a metal or alloy, such as steel, and have a coupling, such as a threaded pin, formed at an upper end thereof for connection of the drill bit 7 to a drill collar (not shown). The shank may have a flow bore formed therethrough and the flow bore may extend into the bit body 8 to a plenum (not shown) thereof. The cutting face 9 may form a lower end of the drill bit 7 and the gage section 10 may form at an outer portion thereof.

[0021] Alternatively, the bit body 8 may be metallic, such as being made from steel, and may be hardfaced. The metallic bit body may be connected to a modified shank by threaded couplings and then secured by a weld or the metallic bit body may be monoblock having an integral body and shank.

[0022] The cutting face 9 may include one or more (three shown) primary blades 11 p, one or more (three shown) secondary blades 11s, fluid courses formed between the blades, and the gouging cutters 1, 1a, 1b. The cutting face 9 may have one or more sections, such as an inner cone 12c, an outer shoulder 12s, and an intermediate nose 12n between the cone and the shoulder sections. The blades 11 may be disposed around the cutting face 9 and each blade may be formed during molding of the bit body 8 and may protrude from a bottom of the bit body. The primary blades 11 p and the secondary blades 11s may be arranged around the cutting face 9 in an alternating fashion. The primary blades 11 p may each extend from a center of the cutting face, across a portion of the cone section 12c, across the nose 12n and shoulder 12s sections, and to the gage section 10. The secondary blades 11s may each extend from a periphery of the cone section 12c, across the nose 12n and shoulder 12s sections, and to the gage section 10. Each blade 11 may extend generally radially across the portion of the cone section 12c (primary only) and nose section 12n with a slight spiral curvature and across the shoulder section 12s radially and longitudinally with a slight helical curvature. Each primary blade 11 p may be inclined in the cone section 12c by a cone angle. The cone angle may range between five and forty-five degrees.

[0023] Each blade 11 may have a bearing face 11f extending between a leading edge and a trailing edge thereof. Each blade 11 may be made from the same material as the lower portion of the bit body 8. The leading gouging cutters 1a may be mounted, such as by brazing or interference fit, in respective leading pockets formed in the in the bearing faces 11f of the primary blades 11 p adjacent to the leading edges thereof. The leading gouging cutters 1a may be mounted into the leading pockets after infiltration of the bit body 8. The gouging cutters 1 may be mounted, such as by brazing or interference fit, in respective pockets formed in the in the bearing faces 11f of the secondary blades 11s midway between leading edges and trailing edges thereof. The gouging cutters 1 may be mounted into the pockets after infiltration of the bit body 8.

[0024] Starting in the nose section 12n, each primary blade 11 p may have a row of backup pockets formed in the bearing face 11f thereof adjacent to the trailing edge thereof and extending therealong through most of the shoulder section 12s. Each backup pocket may be located to straddle a gap formed between adjacent leading pockets. The backup gouging cutters 1b may be mounted into the backup pockets after infiltration of the bit body 8 and may be mounted by brazing or interference fit. The longitudinal axis 6g of each gouging cutter 1, 1a, 1b may be transverse to a projection of the respective bearing face 11f through the respective pocket, such as perpendicular or substantially perpendicular (plus or minus ten degrees forward rake angle). An effective forward rake angle of each gouging cutter 1, 1a, 1b may be determined by the sum of the forward rake angle and the attack angle 6a thereof. As used herein, forward rake angle is relative to an axis perpendicular to the bearing face 11 f of the respective blade 11 at a location adjacent to the gouging cutter 1, 1a, 1b.

[0025] Each blade 11 may have an orientation guide (not shown), such as a hole, formed in the bearing face 11 f thereof adjacent to each pocket. During mounting, a technician or robot may align a back of the edge 5e of each gouging cutter 1, 1a, 1b with the respective orientation guide, thereby ensuring the proper orientation of the gouging cutter. The proper orientation may be where a projection from the edge 5e intersects the bearing face 11f at a point closest to the respective leading edge. Positions of the gouging cutters 1, 1a, 1b may be staggered across the blades 11 to obtain complete and overlapping coverage.

[0026] One or more ports (not shown), such as a port for each blade 11, may be formed in the bit body 8 and each port may extend from the plenum and through the bottom of the bit body to discharge drilling fluid (not shown) along the fluid courses. A nozzle (not shown) may be disposed in each port and fastened to the bit body 8. Each nozzle may be fastened to the bit body 8 by having a threaded coupling formed in an outer surface thereof and each port may be a threaded socket for engagement with the respective threaded coupling. The ports may include an inner set of one or more ports disposed in the cone section 12c and an outer set of one or more ports disposed in the nose section 12n and/or shoulder section 12s. Each inner port may be disposed between an inner end of a respective secondary blade 11s and the center of the cutting face 9.

[0027] The gage section 10 may define a gage diameter of the drill bit 7. The gage section 10 may include a plurality of gage pads, such as one gage pad for each blade 11, and junk slots formed between the gage pads. The junk slots may be in fluid communication with the fluid courses formed between the blades 11. The gage pads may be disposed around the gage section 10 and each pad may be formed during molding of the bit body 8 and may protrude from the outer portion of the bit body. Each gage pad may be made from the same material as the bit body 8 and each gage pad may be formed integrally with a respective blade 11. Each gage pad may extend upward from an end of the respective blade 11 in the shoulder section 12s to an exposed outer surface of the shank. Each gage pad may include a transition portion located adjacent to the shoulder section 12s, a full diameter portion extending from the transition portion, and a tapered portion extending from the full diameter portion to the shank.

[0028] Alternatively, the gage pads may have gage protectors embedded therein. Each gage protector may be a thermally stable polycrystalline diamond.

[0029] In use (not shown), the drill bit 7 may be assembled with one or more drill collars, such as by threaded couplings, thereby forming a bottomhole assembly (BHA) (not shown). The BHA may be connected to a bottom of a pipe string, such as drill pipe or coiled tubing, thereby forming a drill string. The BHA may further include a steering tool, such as a bent sub or rotary steering tool, for drilling a deviated portion of the wellbore. The pipe string may be used to deploy the BHA into the wellbore. The drill bit 7 may be rotated, such as by rotation of the drill string from a rig (not shown) and/or by a drilling motor (not shown) of the BHA, while drilling fluid, such as mud, may be pumped down the drill string. A portion of the weight of the drill string may be set on the drill bit 7. The drilling fluid may be discharged by the nozzles and carry cuttings up an annulus formed between the drill string and the wellbore and/or between the drill string and a casing string and/or liner string.

[0030] As the drill bit 7 engages a rock formation (not shown) adjacent to the wellbore, each gouging cutter 1, 1a, 1b may gouge and/or crush the formation. As compared to conventional shear cutters, the gouging cutters 1, 1a, 1b may be mounted in pockets transverse to the bearing face 11f instead of parallel thereto, thereby allowing more cutters to be mounted onto a given blade 11. The transverse mounting of the gouging cutters 1, 1a, 1b are much easier to braze into the respective pockets than conventional shear cutters and result in a better bond therein. Further, the gouging cutters 1, 1a, 1b have a much greater height than the thickness of conventional shear cutters, thereby providing greater protection to the bearing faces 11f once the cutters become worn.

[0031] Alternatively, the secondary blades 11s may have backup cutters similar to the primary blades 11 p. Alternatively, the blades 11 may have shear cutters as the leading cutters instead of the gouging cutters 1, 1a. Alternatively, the blades 11 may have shear cutters as the backup cutters instead of the gouging cutters 1, 1b. Alternatively, the blades 11 may have both shear cutters and gouging cutters 1 as either the leading cutters or backup cutters or as both leading cutters and backup cutters. In this alternative, the arrangement of both shear cutters and gouging cutters 1 may be alternating or there may be groups of shear cutters and groups of gouging cutters arranged based on the section of the cutting face (i.e., a group of gouging cutters 1 in the cone section 12c and a group of shear cutters in the shoulder section 12s or vice versa). [0032] Alternatively, the substrate 2 may have a knob (not shown) mounted to a back face thereof for orienting the gouging cutters 1, 1a, 1b. The knob may be formed separately from the rest of the gouging cutter 1, 1a, 1b and then mounted to the substrate thereof, such as by brazing. The knob may be angularly offset from the edge 5e, such as being located opposite therefrom (one-hundred eighty degrees therefrom). The knob may be hemi-spherical and have a diameter ranging between twenty-five and forty-five percent of a diameter of the back face. Instead of an orientation guide adjacent to each pocket, the drill bit 7 may have a dimple (not shown) formed in the pocket thereof for mating with the knob, thereby ensuring that the gouging cutter 1, 1a, 1b has been properly oriented. The knob may be made from the same material as the substrate or a different material than the substrate, such as a metal or alloy, such as steel.

[0033] Alternatively, the substrate 2 may have a keyway (not shown) formed therein for orienting the gouging cutters 1, 1a, 1b. The keyway may be located at an edge of the substrate 2 and may extend from the back face thereof along a portion of a side thereof. The keyway may be a slot inclined relative to a longitudinal axis 6g by an angle ranging between ten and seventy degrees. Instead of an orientation guide adjacent to each pocket, the drill bit 7 may have a mating key (not shown) formed in the pocket and the slot may have a width corresponding to a diameter of the mating key. The keyway may be angularly offset from the edge 5e, such as being located opposite therefrom.

[0034] Figures 4A-4D illustrate a second claw shaped gouging cutter 13, according to another embodiment of the present disclosure. The second claw shaped gouging cutter 13 may be similar to the gouging cutter 1 except for having a modified chisel 14 with a wedge-shaped edge 14e instead of the planar edge 5e. The rest of the modified chisel 14 may be similar to the chisel 5. The wedge-shaped edge 14e may have a length (see 6e in Figure 1A) and width (see 6w in Figure 1B) within the ranges discussed above for the planar edge 5e. The second claw shaped gouging cutter 13 may be used with the drill bit 7 instead of the gouging cutters 1, 1a, 1b.

[0035] Figures 5A-5D illustrate a third claw shaped gouging cutter 15, according to another embodiment of the present disclosure. The third gouging cutter 15 may include a substrate 16 and a head 17 mounted to the substrate. The head 17 may be made from any of the materials discussed above for the head 3 and the third gouging cutter 15 may be made from any of the processes discussed above for the gouging cutter 1. The substrate 16 may be made from any of the materials discussed above for the substrate 2.

[0036] The head 17 may have the interface 4 with the substrate 16, a chisel 18 at an end thereof opposite to the interface, a pedestal 17p extending from the interface and connecting a side 18s of the chisel to the interface, and a dome segment 17d connecting a base 18b of the chisel to the pedestal. The substrate 16 may have the interface 4 with the head 17 and a mounting end opposite to the interface for being received in a pocket of the drill bit 7 instead of the gouging cutters 1, 1a, 1b. The mounting end of the substrate 16 may have the chamfer 2c formed in a periphery thereof.

[0037] The pedestal 17p may have a frusto-conical portion extending from the interface 4 and an irregular portion extending from the frusto-conical portion to the dome segment 17d and to a side 18s of the chisel 18. The chisel 18 may resemble a frusto-cone with the side 18s having a truncated portion adjacent to the pedestal 17p, the base 17b having a truncated portion adjacent to the dome segment 17d, and an edge 18e formed by a pair of flats 18f formed into opposite non-truncated portions of the side. The edge 18e may be sharp. The edge 18e may have a length (see 6e in Figure 1A) within the ranges discussed above for the planar edge 5e. The edge 18e may have an infinitesimal width (see 6w in Figure 1B).

[0038] The chisel 18 may have an attack angle (see 6a in Figure 1A) within the range discussed above for the chisel 5. The flats 18f may be formed using the same process, discussed above for the flats 5f. The flats 18f may be primarily formed in the chisel 18 but may also extend slightly into the pedestal 17p. The head 17 may have a height 6h less than or equal to a thickness (see 6t between Figures 1A and 1B) of the substrate 16 and less than or equal to the diameter of the substrate. The third gouging cutter 15 may be symmetrical about a longitudinal plane extending through the edge 18e. [0039] The attack angle 6a of the gouging cutter 1 may be thirty-five degrees as shown while the attack angle of the third gouging cutter 15 may be twenty-five degrees as shown. The dome 17d and pedestal 17p differ accordingly with respect to the dome 3d and pedestal 3p.

[0040] Alternatively, the third gouging cutter 15 may have either the planar edge 5e or the wedge-shaped edge 14e instead of the sharp edge 18e. Alternatively, the gouging cutter 1 may have the sharp edge 18e instead of the planar edge 5e. The sharp edge 18e may perform better during drilling of softer formations, the planar edge 5e may perform better during drilling of harder formations, and the wedge- shaped edge 14e may perform better during drilling of intermediate hardness formations. The planar edge 5e may have better impact resistance than the wedge- shaped edge 14e and the wedge-shaped edge may have better impact resistance than the sharp edge 18e.

[0041] Figures 6A-6D illustrate a fourth claw shaped gouging cutter 19, according to another embodiment of the present disclosure. The fourth claw shaped gouging cutter 19 may be similar to the gouging cutter 1 except for having a frusto-cone 20 instead of a chisel 5. A tip 20t of the frusto-cone 20 may have a diameter corresponding to the length 6e of the edge 5e. The fourth claw shaped gouging cutter 19 may be used with the drill bit 7 instead of the gouging cutters 1, 1a, 1b.

[0042] Figures 7A, 7B, 8A, and 8B illustrate a fifth claw shaped gouging cutter 21, according to another embodiment of the present disclosure. The fifth claw shaped gouging cutter 21 may be used with the drill bit 7 instead of the gouging cutters 1, 1a, 1b. The fifth gouging cutter 21 may include a substrate 22 and a head 23 mounted to the substrate. The head 23 may be made from any of the materials discussed above for the head 3 and the fifth gouging cutter 21 may be made from any of the processes discussed above for the gouging cutter 1. The substrate 22 may be made from any of the materials discussed above for the substrate 2.

[0043] The head 23 may have the interface 4 with the substrate 22, a chisel 24 at an end thereof opposite to the interface, a pedestal 23p extending from the interface and connecting a side 24s of the chisel to the interface, and a dome segment 23d connecting a base 24b of the chisel to the pedestal. The substrate 22 may have the interface 4 with the head 23 and a mounting end opposite to the interface for being received in a pocket of the drill bit 7 instead of the gouging cutters 1, 1a, 1b. The mounting end of the substrate 22 may have the chamfer 2c formed in a periphery thereof.

[0044] The pedestal 23p may have a frusto-conical portion extending from the interface 4 and a smooth transition 23t portion extending from the frusto-conical portion to the dome segment 23d and to the chisel 24. The chisel 24 may have the frusto-conical side 24s with a truncated portion adjacent to the pedestal 23p, the base 24b adjacent to the pedestal and to the dome 23d, and a boss 24o formed at a front of the chisel distal from the base. The chisel 24 may further have a prismatic cutting face formed at the front thereof adjacent to the boss 24o and the side 24s thereof. The cutting face may have a pair of ears 24a adjacent to the side 24s of the chisel 24 and the boss 24o thereof, a wedge 24w adjacent to the side and the boss and having an edge 24e, and a pair of ramps 24r adjacent to the side and the boss and extending between respective ears and the wedge.

[0045] The edge 24e may have a length 6e ranging between ten percent and fifty percent of a diameter of the substrate 22 or ranging between fifteen percent and forty percent thereof. The wedge 24w may have a width 6w ranging between five percent and fifty percent of the length 6e of the edge 24e or ranging between five percent and thirty percent thereof.

[0046] The chisel 24 may have an axis 6c perpendicular to the edge 24e and inclined relative to a longitudinal axis 6g of the fifth gouging cutter 21 by an attack angle 6a greater than sixty degrees or greater than forty-five degrees. The cutting face of the chisel 24 may be formed using the same process, discussed above for the flats 5f. The head 23 may have a height 6h less than or equal to a thickness 6t of the substrate 22 and less than or equal to the diameter of the substrate. The height 6h of the head 23 may be greater than forty percent of the thickness 6t of the substrate 22 and greater than thirty percent of the diameter of the substrate. The fifth gouging cutter 21 may be symmetrical about a longitudinal plane extending through the edge 24e. [0047] Alternatively, the fifth gouging cutter 21 may have the planar edge 5e, the sharp edge 18e, or a round edge instead of the wedge-shaped edge 24e, 24w. Alternatively, the pedestal 23 may be made from a superhard material which may be monocrystalline or partially polycrystalline, the chisel 24 may be made from a polycrystalline superhard material, and the dome 23d may be made from a polycrystalline superhard material. Alternatively, the fourth claw shaped gouging cutter 19 may have an attack angle greater than sixty degrees or greater than forty- five degrees.

[0048] Alternatively, the drill bit 7 may have a first set of one of the gouging cutters 1, 13, 15, 19, 21 in the cone section 12c, a second set of a different one of the gouging cutters in the nose section 12n, and a third set of another different one of the gouging cutters in the shoulder section 12s.

[0049] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope of the invention is determined by the claims that follow.