MXPA01005058A - Rotary cone drill bit having a bit body with integral stabilizers - Google Patents

Abstract

A rotary cone drill bit for forming a borehole having a bit body with a plurality of stabilizer pads formed as integral components thereof. The bit body includes an upper portion adapted for connection to a drill string. A number of support arms preferably extend from a lower portion of the bit body. A number of cutter cone assemblies equal to the number of support arms are rotatably mounted on respective support arms and project generally downwardly and inwardly from each support arm. The stabilizer pads project radially outward from the bit body and are disposed intermediate adjacent support arms. Both the stabilizer pads and the support arms preferably have surfaces that form a fluid flow channel therebetween to direct drilling fluids and cuttings to flow upward in the borehole. Layer of hardfacing may be disposed on selected portions of each stabilizer pad. One or more inserts may be installed in selected portions of each stabilizer pad.

Description

ROTATING CONE DRILL WITH A BARRENA BODY WITH INTEGRAL STABILIZERS Technical Field of the Invention This invention relates generally to the field d rotary cone drills used in the drilling d holes deep in the ground and in particular to a drill bit that has a bit body with integral stabilizers formed on the outside thereof.

Background of the Invention Several types of drill bits and drill bits can be used to form a deep hole in the ground.

Examples of such drill bits include rotary drill bits or rotary cone drill bits used in the drilling of oil and gas wells. A typical rotating cone bit includes a bit body with a top end adapted for connection to a drill string. A plurality of support arms, typically two or three, depends on a lower part of the auger body. Each support arm generally has a spindle or stump attached thereto projecting radially inwardly and downwardly relative to a rotational axis projected from the bit body.

Conventional rotary cone bits are often constructed in three segments. The segments are generally placed together longitudinally with a groove weld between each segment. The segments can then be welded together using conventional techniques to form the auger body. Each segment also includes an associated support arm as an integral component extending from a lower part of the auger body. An enlarged cavity or fluid conduit is generally formed in the auger body to receive the drilling fluids from a drilled drill string. U.S. Patent No. 4,054,772 entitled "Rock Auger Welding Placement System" shows a method of an apparatus for constructing a rotating cone drill for three individual segments.

Rotating cone bits are sometimes manufactured with only two support arms and cutter cone assemblies. See, for example, U.S. Patent No. 4,067,406 entitled "Soft-forming Drill" and U.S. Patent No. 1,143,273 entitled "Rotary Drilling." The rotating cone bits can also be manufactured from a single auger body with the respective support arm and cutter cone assemblies attached thereto. See for example the Patent of United States of America No. 5,641,029 entitled, modular bra of rotating drill.

A cutter cone assembly is generally mounted on each spindle and is rotatably supported on bearings placed between the outside of each spindle and the interi of a cavity formed in the respective cut cone assembly. One or more nozzles may be formed in the auger body on one side of the support arms. The nozzles typically positioned to direct the drilling fluid passes downwardly from an associated drilling string through the cavity or fluid conduit in the drier body to the bottom of the deep bore.

The drilling fluid is generally provided by the drill string to carry out various functions including washing the cuts and other material from the bottom of the deep hole, cleaning the cutter cone assemblies, and carrying the cutters and other material radially. outwards and then upwards in a ring defined partly by the outside of the drilling string and the side wall of the deep hole. L United States of America Patent No. 4,056.15 entitled Rotating Rock Auger with Multiple Hiler Coverage for Very Hard Formations and United States of America Patent No. 4,280,571 entitled Auger for Roc shows examples of conventional rotary drills with cutter cone assemblies mounted on an axis projecting from a support arm.

The rotation and vibration of a drilling string, particularly in deep and / or highly deviated drilling holes, frequently requires stabilization of the drill string and the drill bit held within the deep bore. Several types of stabilizers and / or centralizers have previously been used as part of a deep-hole drilling assembly.

For some applications, a stabilizer can be a separate component attached to the drill string above the drill bit. Alternatively, the stabilizer pads or appendages can be welded to the outside of a drill bit after the original manufacture of the drill. Typically, such stabilizing pads have been attached to the support arms. For example, the Security DB company, a division of Dresser Industries, has developed stabilizing pad or appendages to provide additional bit stabilization and short skirt protection during severe deep hole drilling applications. Tale stabilizing pads can be particularly effective during drilling horizontal directional well holes which result in a lateral load of the associated bit and premature bit failure due to increased abrasion, erosion and / or wear of the associated skirt portions. Such stabilizing pads or appendages are generally fabricated as separate components and are welded to the outside of the support arms of a selected drill. The even-surface tungsten carbide inserts can be included as part of the stabilizing pads or appendages to further increase resistance to abrasion, erosion and / or wear.

U.S. Patent No. 5,755,297 entitled "Rotating Cone Drill with Integral Stabilizers" describes a rotary cone drill in which a stabilizing pad is formed as an integral part of the outer surface of each support arm clamped to and extending from the associated auger body. The stabilizing pads project radially outward from the respective support arms by a distance approximately equal to a desired radius for the drill hole being formed by the drill. Any heat generated by the contact between such stabilizing pads and the inner diameter of the piercing hole may on occasion be transferred to various components such as the elastomeric seals and / or a reservoir. lubricant carried within the cutter cone assembly / associated support arm.

The hard coating of the meta surfaces and substrates is a well-known technique to minimize the avoidance of abrasion, erosion and wear of metal surfaces or substrates. The hard coating can generally be defined as applying a layer of an abrasion resistant and hard material to a less resistant surface to a less resistant substrate by means of welding, spraying or other known meta depositing techniques. Hard coating is often used to extend the service life of drill bits and other tools used in the orifice in the oil and gas industry. E tungsten carbide and various other alloys are some of the most widely used hard coating materials to protect bits and other tools associated with drilling and production of oil and gas wells.

Synthesis of the Invention In accordance with the teachings of the present invention, the disadvantages and problems associated with the previous rotary cone bits have been substantially reduced or eliminated. An embodiment of the present invention includes a rotating cone bit having a body auger with stabilizing pads or appendages formed as integral components thereof and extending generally radially therefrom. Each stabilizing pad of an appendage is preferably placed on the outside of the auger body between the respective supporting arms. For some applications. , the stabilizer pads and the support arms will be placed in a generally symmetrical pattern on the outside of the associated drill body. For other applications the stabilizer pads and the support arms may be placed in a generally non-symmetrical configuration on the associated auger body exterior. Non-symmetric configurations can be particularly beneficial for some directional drilling requirements. Also, n symmetric configurations can increase the flow of drilling fluids with cuts and other debris from the bottom of a deep hole inside the associated ring for the return of the well surface.

For an application, a drill is provided with two support arms and the respective cutter cone assemblies rotatably mounted thereon. The respective arms and the cutter cone assemblies are preferably fastened to and spaced about 180 ° from each other on the outside of an associated auger body. At least two pads or appendages Stabilizers are preferably formed as integral components of the auger body. The stabilizing pads or appendage preferably extend radially from opposite sides of the auger body in the middle of the support arms. The stabilizing pads or appendages can have several configurations to optimize the drilling in the deep hole and the return of the drilling fluids with the integrated cuts to the surface of the well.

For another application, a drill bit is provided with an auger body having three support arms and the respective cutter cone assemblies rotatably mounted thereon. The respective support arms and cutter cone assemblies are preferably spaced about one hundred twenty degrees (120 °) from each other on the outside of an associated auger body. At least three stabilizing pads or appendages are preferably formed as integral components of the auger body. The stabilizing pads or appendages are preferably placed at approximately one hundred and twenty degrees (120 °) from one another on the outside of the auger body and extend radially therefrom. Each stabilizing pad or appendix is preferably positioned between two of the support arms.

The technical advantages of the present invention include providing a drill having an auger body with a plurality of stabilizing pads or appendages formed as an integral component thereof. Integral stabilizing pads or appendages will often eliminate any requirement to include a stabilizer as a separate component in an associated drill string above the drill bit and associated extra threaded connections. Stabilizing pads or appendages formed as an integral component of an auger body in accordance with the teachings of the present invention are essentially less subject to cracking and / or corrosion than composite pads or appendages added to previously manufactured drills using appropriate welding. Sometimes the stabilizing pads or appendages may be attached to the outside of an auger body in field locations that have less than the desired welding capabilities and / or quality control procedures. The teachings of the present invention allow an essentially improved quality control and an essentially reduced variation in dimensional tolerances.

The formation of the stabilizing pads or appendages as integral components of an auger body will often allow any heat generated by contact between the pads or appendages stabilizers and the inner diameter or side wall of a deep hole is dissipated more quickly through the auger body and the drilling fluids flow through it.

The present invention allows the manufacture of a plurality of stabilizing pads or appendages with integral components of an auger body prior to the attachment of the support arms and the cutter assemblies to the auger body. As a result of the present invention, the compacts and / or the inserts can be installed within the integral stabilizing pads or appendages and / or the hard coating material applied to the outer portions of the stabilizing pads or appendages to minimize abrasion, erosion and / or wear before assembly of the bit. As a result of this, the components of the lubricant reservoir and the elastomeric sealing systems which are typically installed within a cutter cone / support arm assembly are not exposed to the high temperatures associated with the insert installation and compact and / or hard coating application. Alternatively, the stabilizing pads or appendages may be manufactured with one or more bags to accommodate the inserts and / or installation compacts after the associated broach has been assembled. For some environments of deep orifices it may not be necessary to include the inserts, compact or hard coating as part of the stabilizing pads.

One aspect of the present invention includes the manufacture of a plurality of stabilizing pads or appendages as integral components of an auger body at intermediate locations for securing the support arms and the cutter cone assemblies. The stabilizing pads or appendages will thus provide additional contact points between the outside of the associated bit and the inner diameter or the side wall of the deep hole which are off-centered both radially and longitudinally of the contact point of each cutter cone assembly / Support arm and inner diameter or side wall of the deep hole. The formation of the stabilizing pads or appendages as integral components of a bit body will often substantially increase downward stability in the hole of the associated bit.

Additional technical benefits of the present invention include optimizing the location and configuration of each integral stabilizer pad on the inside of an auger body to optimize fluid flow and downward stability of the resulting drill. For example, various configurations such as swirl or straight can be selected to optimize the operation of the associated drill The stabilizing pads are preferably offset from each other and from the respective support arms attached to the auger body to optimize the flow of fluids, cuts and other debris from the bottom of a deep hole to a ring formed between the wall lateral of the deep hole and outside of the associated drill string. The welding techniques associated with securing the stabilizer pads and the exterior of previously fabricated bits often limit the proper locations for attachment to the outside of the bit. Therefore, the manufacture of the stabilizing pads or appendages as an integral component of the auger body and the application of a hard coating prior to the assembly of the resulting drill can be optimized without concern for potential heat damage to other components such as elastomeric seals. and / or the lubricant deposits.

The still further technical advantages of the present invention include providing a plurality of integral stabilizing pads on the outside of the drill body to divide the turbulent fluid flow around the associated rotary cutter cone assemblies from the fluid flow in the ring above. of the bit so that cuts and other debris that enter the ring will not generally be pulled back down towards the sets of the cutter cone. The flow of fluid down the integral stabilizing pads is generally turbulent and multidirectional due to the fluid exiting the associated nozzles and the spinning effect of the cutter cone assemblies. The stabilizer pads cooperate with other components of the auger body to separate the flow of fluid in the drill in two essentially independent regions. The fluid flow above the stabilizing pads is generally less turbulent and more unidirectionally upward.

Another aspect of the present invention includes providing a drill bit having an auger body with a plurality of stabilizing pads formed as integral components thereof with a plurality of inserts and / or compacts placed on the outer portions of each stabilizer pad. For some applications, the inserts and / or the compacts may be essentially the same as the conventional inserts and compacts associated with the reduction of erosion from abrasion and / or wear of conventional bits. For other applications, one or more crystalline polydimmer inserts (PDC) may be installed at selected locations within each stabilizing pad or appendage. The crystalline inserts of polydymanter can be designed to help the cutting structure of the bit associated with maintaining the desired caliber diameter of an orifice of drilling. The number, location and types of the inserts and / or compacts installed within each stabilizer pad can be selected according to the teachings of the present invention to optimize the operation of the perforation and the service life in the orifice of the associated broc.

The combined surface area of the integral stabilizing pads or aprons is preferably relatively large compared to the total surface area of the contact between the associated cutting structure and the inner diameter of the deep orifice. Therefore, as the gaging surface or the gauge diameter of the associated cutting structure begins to wear out and / or erode, the stabilizing pads will contact the adjacent portions of the deep hole. The increased surface area of the stabilizing pads or appendages will result in an increased torsional force loading of the drill bit and the associated drill string. This increased torsional force load can be monitored at the well surface to indicate the extent of any wear and / or erosion of the drill bit surfaces. Therefore, the formation of the stabilizing pads or appendages as integral components of a bit body according to the teachings of the present invention will provide an early warning of the drill wear before a catastrophic failure of the associated cutting structure.

The formation of the stabilizing pads or appendages as an integral component of the drill body according to the teachings of the present invention will often allow the installation of fluid nozzles at a distance greater than the longitudinal axis of an associated auger body and / or the installation of an increased number of fluid nozzles within the lower part of the auger body. As a result, the formation of an auger body with integral stabilizing appendages or pads allows more opportunity to optimize the number, location and size of the nozzles used to direct the drilling fluid from the associated drillstring towards the bottom of a deep piercing.

By forming stabilizing pads or appendages as integral components of an auger body, the corresponding dimensions (thickness, length, width and outer radius) of the stabilizing pads can be optimized to increase the operation of the deep hole drilling of the resulting bit. . The vibration and lateral movement of the associated bit at the bottom of the deep hole drilling during the Drilling operations can be reduced or eliminated essentially.

The marking of the side wall is a significant concern in the applications of horizontal drilling extended reach and / or directional. For some deep hole applications, the length of the auger body can be increased to provide larger stabilizing pads or appendages for even greater deep hole drilling stability.

Drills incorporating the teachings of the present invention can demonstrate a longer drilling hole life, a higher penetration rate (ROP) and lower total drilling costs. The technical advantages of such drill bits can include improved deep-hole cleaning, superior fluid flow rate capabilities, reduced barrow-down problems, a more consistent uniform orifice drilling performance and reduced direct drilling problems by eliminating or essentially reduce the marked "plow" of the side wall of a deep hole while the associated bit is tripped.

Brief Description of the Drawings For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings to which the reference numbers indicate the same characteristics and where: Figure 1 is a schematic elevational drawing with parts cut away showing a rotating cone bit incorporating the teachings of the present invention having an auger body with integral stabilizer pads three support arm / cutter cone assemblies; Fig. 2 is a schematic drawing showing an end view of an auger body, satisfactory for use with the drill of Fig. 1, having stabilizing pads formed as integral components thereof according to the teachings of the present invention; Figure 3 is a schematic sectional drawing of the auger body of Figure 2; Figure 4 is a schematic elevation drawing with cut-away portions showing a rotating cone drill incorporating the teachings of the present invention having a auger body with integral stabilizing pads two support arm / cutter cone assemblies; Y Figure 5 is a schematic drawing showing an end view of the drill of Figure 4.

Detailed description of the invention The present invention and its advantages are better understood with reference to Figures 1 to 5 of the drawings, like numbers being used for like and corresponding parts of the drawings.

Figure 1 is a schematic drawing showing an isometric view of a rotating cone drill generally indicated with the number 20, incorporating various teachings of the present invention. The bit 20 can sometimes be referred to as a rotating cone bit or a rotating rock bit.

The drill 20 can be attached to a drill string 22 (shown in dotted lines) and placed within a deep hole (not expressly shown). A ring (not expressly shown) is formed between the outside of the drill string 22 and the inner diameter or side wall of the deep hole. In addition to turning the bit 20, the string of perforation 22 is used as a conduit for communicating drilling fluids and other fluids from the well surface (not expressly shown) to drill 20 at the deep-hole bottom. Such drilling fluids may be directed to flow from the drill string 22 through the auger body 30 to several nozzles (not expressly shown) placed within the respective openings 3 provided in the drill 20. The cuts formed by the drill 20 and other debris at the bottom of the drilling hole will be mixed with the drilling fluid that leaves one or more nozzles and returns to the surface of the well through the ring.

For the embodiment shown in Figure 1, the drill 20 preferably includes a piece or body of unitary auger 30. The auger body 30 includes the upper part 34 having the threaded connection or bolt 36 adapted to secure the drill 20 with the bottom end of the drill string 22. Three support arms 70 are preferably clamped to and extend longitudinally from the opposite auger body 30 from the threaded connection 36. Only the two support arms 70 and the clamped cutter cone assemblies 90 are shown in figure 1.

Each support arm 70 preferably includes a spindle (not expressly shown) connected to and extending from the inner surface 72 of the respective support arm. 70. The cutter cone assemblies 90 are rotatably mounted on the respective spindles which extend generally downwardly and inwardly from each of the support arms 70. Each cutter cone assembly 90 includes a plurality of inserts 92 which scrape and gouge the gouge in FIG. against the sides and the bottom of the deep hole in response to weight and rotation applied to the drill 20 by the drill string 22. A plurality of compact d surfaces 94 are placed on the surface of face 98 of cad cutter cone assembly 90. The inserts 92 and the surface compacts 94 can be formed from various types of hard materials associated with the manufacture of drill bits.

An important feature of the present invention includes the ability to manufacture stabilizing pads 50 as integral components of auger body 30 prior to clamping support arms 70 to cutter cone assemblies 90 thereto. However, a auger body having stabilizing pads formed as integral components thereof according to the teachings of the present invention can be used with a wide variety of cutting structures. Other types of cutter cone assemblies and cutter structures can be successfully used with the present invention including, but not limited to, cutter cone assemblies having serrated teeth instead of inserts 92. invention is not limited to use with only support arms and cutter cones 90.

As shown in Figures 2 and 3, the amplified cavity 31 can be formed within the upper part 3 of the barrier body 30. An opening (not expressly shown) is provided in the upper part 34 to communicate the fluids between the string 22 and l cavity 31. The cavity 31 preferably has a generally uniform inner diameter extending from the upper part 34 to a position in the middle of the middle portion 42 of auger body 30. For some applications, the cavity can be formed concentric with the longitudinal axis 46 of auger body 30. The cavity 31 provides a relatively large fluid chamber having little if any resistance to fluid flow from the drilling string 22 to the drill 20.

One or more fluid conduits 42 may be formed in the auger body 30 extending between the cavity 31 and the convex surface 40 on the lower portion 3 of the auger body 30. The openings 2 may be provided in each fluid conduit. 42 on one side of the convex surface 40. A plurality of recesses are preferably provided within each opening 32 to allow installation of various types of nozzles or insert nozzles within each fluid conduit 42. Additional components (not expressly shown), such as an automatic seal ring and / or a 0-ring seal can be provided to place each nozzle opening 32 within its respective recesses. The cavity 31 and the conduits 4 cooperate with each other to provide the improved fluid flow and increased cleaning efficiency in the cutter cone assemblies 90.

Various techniques are commercially available to satisfactorily install each of the nozzle inserts and / or the nozzles within the openings 32. For some applications, such nozzles may be formed from tungsten carbide or other suitable materials to resist the erosion of fluids. flowing therethrough. Also, one or more access ports (not shown) may be provided in the auger body 30 on one side of the nozzle openings 32 to allow the bolts or locking screw and / or the plug welds (not shown) and securing the nozzle openings 32 within the respective recesses.

The nozzle openings 32 can be positioned in each fluid flow conduit 42 to regulate fluid flow from the cavity 31 through the respective fluid conduit 42 and the associated nozzle openings 3. to the outside of the bore body 30. The length and diameter of each fluid conduit 42 may be selected for some applications to provide a laminar flow between the cavity 31 and the respective nozzle openings 32. The present invention allows the formation of the fluid conduit 42 with a larger diameter than previously possible with conventional rotating cone drills.

An important feature of the present invention includes the ability to vary the position of the fluid conduits 42 and the associated nozzle openings 32 inside the auger body 30 without affecting the location of the bags 48 and associated support arms 70. For some applications, the nozzle openings 32 will preferably be positioned to direct the flow of drilling fluid between the cutter cone assemblies adjacent 90. As a result of improved cutting removal and better cleaning at the bottom of a deep hole, the efficiency and penetration rate (ROP) of drill 20 will be substantially improved.

The stabilizing pads 50 are formed on the outside of the drill body 30 as integral components thereof to stabilize the drill 20 within the associated deep hole and to provide an early indication of erosion, abrasion and / or wear. The stabilizing pads 50 preferably extends radially from the auger body 30 at a distance 4b which is slightly less than that of the desired radius or gauge diameter of the associated deep bore. For the incorporation of the present invention as shown in Figures 1, 2 and 3, the auger body 30 includes three stabilizing pads 50.

For some applications, the stabilizer pads 50 can be formed as integral components of the auger body 30 by machining an appropriately sized piece of raw material. The stabilizer pads 50 can also be formed as an integral part of the auger body 30 during forging or setting thereof. After the auger body 30 has been formed by the forge or cast, the stabilizer pads 50 can be further machined to provide the desired dimensions and configurations thereof.

U.S. Patent No. 5,439,067 entitled "Rock Drill with Increased Fluid Return Area" and U.S. Patent No. 5,439,068 entitled "Modular Rotary Drill" provide additional information regarding fabrication and assembly of unit augers and assemblies of associated support arm / cone cutter satisfactory for use with the present invention.

The auger body 30 includes the lower part 38 which has a generally convex outer surface 4 formed thereon. The lower part 38 can sometimes be referred to as a dome. The dimensions of the convex surface 40 and the location of the cutter cone assemblies 90 relative to the bottom portion 38 can be varied by adjusting the length of the support arms 70 and the radial spacing between each support arm 70 on the outside of the auger body 30. However, an auger body having stabilizing pads formed as integral components thereof according to the teachings of the present invention may have a wide variety of configurations other than the convex surface 40.

The debris carried by the drainage fluid will generally flow radially outwardly between the convex surface 40 and the bottom of the associated deep hole and will then generally flow upward towards the surface of the well through the associated ring. For incorporation of the present invention as shown in Figures 1, 2 and 3, a drill body 30 includes three nozzle openings 32 and the respective fluid flow passages 42.

The formation of the nozzle openings 32 and d their associated fluid flow conduits 42 within the unitary auger body 30 eliminates the requirement for nozzle protuberances associated with conventional drill bit on the outside of the auger body 30. Stabilizing pads 50 as an integral component of the auger body 30 allows selecting the desired number and / or location of the nozzle openings 3 to optimize the flow of drilling fluid from the drilling pan 22 through the auger body 30 toward bottom of the associated deep hole according to the teachings of the present invention.

As shown in Figure 2, the location of each nozzle opening 32 which generally corresponds to the respective stabilizing pad 50. As a result of this, the stabilizer pads 50 allow locating each nozzle opening 32 at a greater distance radially from the longitudinal axis 46 in comparison to a similar size and type of auger body which does not include the stabilizing pads or appendages as an integral component thereof.

The auger body 30 includes the middle part 44 positioned between the upper part 34 and the lower part 38. The longitudinal axis or the central axis 46 extends through the auger body 30 and generally correspond to the projected rotation for the drill 20. The middle part preferably has a generally cylindrical configuration with the bags 48 formed on the outside thereof spaced radially from one another. The number of bags 48 e selected to correspond to the number of supporting arms 70 which will be attached thereto. The spacing between the bags 48 on the outside of the middle part 44 e selected to correspond to the desired spacing between the support arms 70 and their associated cut cone assemblies 90. The location of the bags 48 can also be varied to provide any offset desired for the cutter cone assemblies 90 with respect to the longitudinal ej 46 and the projected axis of rotation for the drill 20 Figure 2 shows the lower body portion 38 of auger 30 having three bags 48 and three openings d nozzle 32. The fluid conduits 42 are shown in dotted line extending from the enlarged cavity 31 to the respective nozzle openings 32. The fluid conduits 4 are spaced radially with respect to each other and extend from the longitudinal axis 46. For the example shown in Fig. 2, the fluid conduits 42 and the associated nozzle openings 32 are radially spaced by approximately 120 °. One of another. In a similar way each bag 48 is spaced radially by approximately 120 ° from an adjacent bag 48.

Each support arm 70 has a longitudinal axis extending therethrough. The support arms are preferably mounted in their respective pockets 48 c their respective longitudinal axis aligned parallel with each other with the longitudinal axis 46 of the associated drill body 30. L parts of each support arm 70 are preferably welded within the respective bag 48 by a series of welds (expressly shown) formed between the outside or the perimeter of each bag 48 and the adjacent portions of the respective supporting arm 70. The perimeter of each bag 48 on an outer side d of the auger body 30 may be modified to provide the welded surfaces and / or the weld grooves to assist with the securing of the support arms 7 within the respective pockets 46.

Each bag 48 is preferably positioned between the adjacent stabilizing pads 50. As a result of this, the stabilizer pads 52 and the support arms 70 installed within the bags 48 will be spaced radially from one another around the outside of the auger body 30.

The bit 20 can be used to form a deep hole having a nominal or bore diameter which generally corresponds to the combined diameter of the 98-gauge face surfaces of the sets of cutters 90 in the area of contact with the inner diameter of the cutter. deep hole. The approximate area of contact between the 98 gauge face surfaces and the deep bore is generally designated 100 in FIG. 1. L gauge face surfaces 98 of the cutter assembly 90 generally represent one of the components the bit 20 subjected to substantial abrasion, erosion and / or wear.

The number, configuration, dimensions and location of the stabilizer pads 50 on the barrel body exterior 30 are preferably selected in accordance with the teachings of the present invention to maximize the stability of the drill bit 20 within a deep orifice, so as to optimizing the flow of fluid within the deep orifice to one side of the bit 20 and the ring extending therefrom and / or to provide an early indication of wear of the cutting structure. The number, configuration, dimensions and location of the stabilizer pads 50 on the outside of the auger body 30 are preferably selected in accordance with the teachings of the present invention to minimize marking and / or plowing. side wall while the drill string 2 and the bit 20 are stuck in and out of the deep hole The stability of the bit, of fluid flow to the side of the bit and through the ring extending from it Marking or plowing of the sidewall are of particular concern while deep horizontal and / or highly deviated holes are drilled.

For some applications during normal downhole hole drilling conditions, the outer surfaces 52 of the stabilizer pads 50 may be spaced apart from the side wall of a deep bore by a nominal distance in the range of about 0.0 inches to about 0.9 inches. . The contact between the outer surfaces 52 of the stabilizer pads 5 and the adjacent parts of the side wall will generally only occur during specific downhole drilling conditions, such as excessive wear of the cutting structure associated with the drill 20. surfaces of the stabilizer pads 50 can be protected by the inserts, the compacts and / or a hard coating which can be described later in greater detail.

For incorporation of the present invention as shown in Figures 1, 2 and 3, the bags 48 and their respective support arms 70 are preferably spaced radially by approximately 120 ° from each other on the outside of the auger body 30. The stabilizing appendages 50 are also preferably radially spaced by approximately 120 ° from each other. Each stabilizing pad 50 projects radially outwardly from the drill body 30 in the middle of the respective support arms 70. The combined outer diameter of the support arm 70 is generally smaller than the combined outer diameter of the stabilizing pads 50.

For some applications, the combined outside diameter of the support arms 70 may be about 1/8 of an inch (.125 inches) less than the bore diameter of the drill 20. As a result, any contact between the outside of the auger body 40 and the wall of an associated deep hole will generally occur on the outer surfaces of the stabilizer pads 50 and not along the outer surfaces of the associated support arms 70. Thus, the support arms 70 and the components placed there such as the lubricant reservoir will be protected from contact with the side wall of an associated deep hole.

A plurality of fluid flow channels 54 are formed on the outside of the auger body 30 between each stabilizer pad 50 and the support arms adjacent 70. The fluid flow channels 54 extend generally longitudinally from the lower portion 38 to the upper portion 34 of the auger body 30. The fluid flow channels 54 cooperate with each other to direct turbulent fluid flow and the cuts from the bottom of the deep hole up to the ring 26. One of the benefits of placing the stabilizer pads 50 in the middle of the support arms 70 is the increased separation of the turbulent fluid in the vicinity of the cutter cone assemblies. 90 at the bottom of the deep hole from the fluid flow generally upwards in the ring above the drill 20. As shown in Figure 1, the stabilizing pads 50 can be protected by a plurality of inserts or compact 56 and 58 placed on the outer surface 52 and the hard coating layers 60. The inserts 56 are preferably placed in each stabilizer pad 50 on one side of the top surface 62. For some applications the inserts 56 may have a cutter element typically associated with the fixed cutter bits.

The dimensions and configurations of the inserts 56 may be selected such that the combined outer diameter of the inserts 56 on the respective stabilizing pads 50 approximately corresponds to the bore diameter of the drill 20. As a result of this, the inserts 56 can be used to maintain the desired nominal diameter of the associated deep hole.

The drill string 22 preferably rotates the bit 20 to the right to form a hole while the drilling fluid is expelled from the nozzle openings 32 towards the bottom of the hole. The arrow 72 in Figures 2 and 3 shows the normal direction of rotation for the auger body 30. As shown in Figures 2 and 3, each stabilizing pad 50 includes the front surface 64 and the tail surface 66 positioned on the opposite sides of the outer surface 52. Therefore, each stabilizer pad 50 on the front surface 64 will contact the cuts and fluids from the bottom of the deep hole. The fluid and cuts move upward to the surface 64 within the fluid flow channel 54 and flow up to the associated ring towards the well surface. The fluid flow channels 54 are defined in part by the respective front surfaces 64 of the stabilizer pads 50 and the respective outer surfaces 102 of the adjacent support arms 70.

The upper surface 62 and the lower surface 68 of each stabilizer pad 50 may be inclined generally outwardly from the auger body 30 to the outer surface 52 of the stabilizer pads 50.

The upper surface 62 and the lower surface 68 may comprise a flat surface, a concave surface, or any other appropriate configuration to assist in removing cuts and other debris from a deep hole and to minimize marking or plowing of the adjacent side wall. while the drill string is tripped 22.

The configuration and the dimension of the stabilizing pads 50 can be varied without departing from the teachings of the present invention. For example, the stabilizer pads 50 may have linear inclinations along the front surface 64 and the tail surface 68. alternatively, the stabilizer pads 50 may not have variable uniform and / or wide inclinations across the outer surface 52, of the upper surface 62, the front surface 64, the tail surface 66 and the bottom surface 68.

For some applications, it may be desirable to install one or more inserts on the front surface 64 on one side of the fluid flow channel 54. Also, the inserts may be installed within the upper surface 62 and the lower surface 68. Various types of inserts or compacts can be used successfully, including, but not limited to, tungsten carbide inserts, polycrystalline diamond inserts, boron nitride inserts cubic and other types of inserts formed from hard materials compatible with the associated orifici downward drilling environment.

For some applications, inserts and compacts that have high abrasion, erosion and / or wear resistance will preferably be installed within the selected portions of the stabilizer pads 50. For other applications, the inserts having various types of cutter elements or Cutting structures can be installed on selected portions of the stabilizer pads 50. The type of the inserts and / or the compacts selected for use with the stabilizer pads 50 will depend on the anticipated deep hole drilling conditions and the cutting structure. of the associated drill.

Figure 4 is a schematic drawing showing an isometric view of a rotating cone drill generally indicated at point 120, incorporating various teachings of the present invention. Drill bit 120, sometimes referred to as a rotating cone bit or rotating rock auger, can be attached to drill string 22 (shown in dotted lines) and placed inside a deep hole (not expressly shown). A ring (not expressly shown) is formed between the outside of the string of perforation 22 and the inner diameter or the side wall of deep hole.

For the embodiment shown in Figures 4 5, the drill 120 preferably includes a piece or body d auger 130. The upper part 34 of the barrel body 120 includes the bolt or threaded connection 36 adapted to secure the auger body 130 with the drill string 22. Two support arms 170 are preferably fastened to and extend from the opposite bit body 130 from the threaded connection 36. The support arms 170 and clamped cutter cone assemblies 190 can essentially have the same design and configuration as previously described of the support arms 70 and the cutter cone assemblies 90.

Since the drill 120 includes only two support arms and cutter cone assemblies, the support arms 170 and the cutter cone assemblies 190 can be substantially larger than the support arms 70 and the cutter cone assemblies 90 for the Drill bit that has the same nominal or gauge diameter. The stabilizer pads 150 on the drill 120 can also be substantially larger than the stabilizer pads 50 on the outside of the drill 20 even though both the drill 20 and 120 can have essentially the same bore diameter.

Some of the advantages of a two-cone drill such as a drill 120 include a larger cutter structure and a larger bearing system for each cutter cone assembly compared to a three-cone drill having the same nominal diameter or diameter of caliber. The disadvantages of a two-cone bit include the relative instability compared to a three-cone bit that has the same nominal diameter or gauge diameter. Two-cone bits can sometimes have a tendency to become unstable at the bottom of a deep hole. Thus, the stabilizer pads 150 are especially beneficial for use with the bits 120 having only two support arms 170 and the attached cutter cone assemblies 190.

The auger body 130 includes the lower part 138 having a generally convex outer surface 140 formed thereon. For incorporation of the present invention as shown in Figures 4 and 5, the auger body 130 preferably includes four openings 132 and the respective fluid conduits (not expressly shown). As discussed previously with respect to the drill 20, various types of nozzles can be installed within the openings 132. The auger body 130 also includes a middle part 144 positioned between the upper part 34 and the lower part 138.

The longitudinal axis or central axis 146 extends through the auger body 130 and generally corresponds to a projected axis of rotation for the drill 120. The middle part 144 preferably has a generally cylindrical configuration with a pair of bags (not expressly shown). ) formed on the outside thereof and spaced radially from one another.

Each cutter cone assembly 190 preferably includes a plurality of inserts 92 which scrape and float against the sides and bottom of a deep hole in response to the weight and rotation applied to drill 120 by drilling string 22. Other Types of cutter cone assembly and cutter structures can be used successfully with the present invention including, but not limited to, cutter cone assemblies having spline teeth instead of inserts 92. A plurality of surface compacts (not expressly shown) ) are preferably placed on a 198 gauge face surface of each cutter cone assembly 190.

The bit 120 can be used to form a deep hole having a nominal diameter or a bore diameter which generally corresponds to the combined diameter of the 198 gauge face surfaces of the cutter cone assemblies 190 in the contact area he inner diameter of the deep hole. The dotted line 200 as shown in FIG. 5 corresponds to the bore diameter of the bit 120.

A pair of stabilizing pads 150 are formed on the outside of the auger body 130 as integral components thereof according to the teachings of the present invention. The stabilizer pads 150 preferably extend radially from the auger body 130 at a distance which is slightly less than the desired radius or the associated deep bore gauge diameter. The dotted line 202 represents the combined outside diameter corresponding to the outer surfaces 152 of the stabilizer pads 150.

The number, configuration, dimensions and locations of the stabilizer pads 150 on the outside of the auger body 130 are preferably selected in accordance with the teachings of the present invention to maximize the stability of the drill 120 within the bore, to optimize the flow of fluid into the deep hole at one side of the drill 120 and the ring extending therefrom and / or provide an early indication of wear on the cutting structure. The number, configuration, dimensions and location of the stabilizer pads 150 on the outside of the auger body 130 they are also preferably selected in accordance with the teachings of the present invention to minimize marking and / or plowing of the side wall while tripping the drill string 22 and the drill 120 in and out of a deep hole. The stabilizing pads 150 can be formed as integral components of an auger body 130 using the same techniques and procedures as previously described with respect to the stabilizer pads 50 and the auger body 30.

For some applications, the outer surfaces 152 of the stabilizer pads 150 will normally be spaced from the side wall of a deep hole by a nominal distance in the range of approximately 0.03 inches to 0.09 inches. The distance between dotted lines 202 and 200 shown in Figure 5 is enlarged for purposes of illustrating various features of the present invention.

For incorporation of the present invention as shown in Figures 4 and 5, the support arms 170 are preferably spaced approximately 180 ° apart from each other on the outside of the auger body 130. The stabilizer pads 150 are preferably radially spaced apart from each other. about 180 ° from each other in the middle of the respective support arms 170. The radial spacing increased between the support arms 170 provides more area for the installation of the stabilizer pads 150.

A plurality of fluid flow channels 15 are formed on the outside of the auger body 130 between each stabilizer pad 150 and the adjacent support arms 170. The fluid flow channels 154 extend from the bottom 138 to the top 34 of the body d auger 130.

For the embodiment shown in Figures 4 5, each stabilizer pad 150 includes the front surface 164, the tail surface 166 positioned on opposite sides of the outer surface 152. The front surfaces 164, the tail surfaces 168 and the outer surfaces 152 are preferably positioned at an angle in relation to the longitudinal axis 146. As a result the stabilizing pads 150 have a shape of generally spiral shape relative to the outside of the auger body 130.

The outer surfaces 152 of the stabilizer pads 150 have a generally rectangular configuration. However, by forming the stabilizing pads 150 with a generally spiral shaped configuration as shown in Figures 4 and 5, the effective width of the portion of each stabilizer pad 150 which will contact the adjacent side wall is substantially increased compared to the width of the respective outer surface 152. For some applications, a spiral-shaped stabilizing pad may have an effective width between one and a half and twice the width of the associated outer surface.

The formation of stabilizing pads with a generally spiral shaped configuration optimizes the fluid flow path to move the drilling fluid with the cutouts within from under the drill associated with a ring that extends around and significantly increases the surface area total of the associated stabilizing pad that can be engaged with the inner diameter or side wall of an associated hole. Increasing the effective surface area of those parts of a stabilizing pad which can make contact with the side wall of a deep hole provides greater downward stability and a higher torsional force of feedback at the well surface to indicate erosion and / or wear of the associated cutting structure.

When the drill string 22 rotates the drill 120, the front surface 164 will operate in a manner similar to a ramp to lift the drilling fluids and the cuttings from the bottom of a deep hole and direct the movement of the drilling fluids and the cuttings longitudinally upwards to the ring. The fluid flow channels 154 are defined in part by the respective front surfaces 164 of the stabilizer pads 150 and the respective outer surfaces 172 of the support arms 170.

As previously noted, the stabilizer pads 50 and 150 are preferably manufactured as integral components of the respective auger bodies 30 and 130. For some applications, the stabilizer pads 50 and 150 can be manufactured with only bags or openings to receive the corresponding inserts. and compact which are not installed during the initial manufacture and assembly of the associated drill. By not installing the inserts and compacts during the initial manufacture of the drill bits and 120, it is possible to grind or alter the configuration of the stabilizer pads 50 and 150 at a field location before using the associated bit. Also, inserts and compacts made of various types of material, suitable for a specific downhole drilling environment, can be installed in a field location.

During normal downhole drilling conditions, the drill 20 will generally make contact with the side wall of a deep hole in three separate locations corresponding approximately to the area 100 on the respective gauge face surfaces 98. The dimensions and configuration of the stabilizer pads 50 are preferably selected so that additional contact between the drill bit 20 and the side wall of the deep hole on the respective outer surfaces 52. As previously noted, the stabilizer pads 50 are preferably radially offset from one another and radially offset from the respective support arms 70. Also, the stabilizer pads 50 are longitudinally spaced from the respective gauge face surfaces 98. Thus, incorporation of the stabilizer pads 50 as an integral component of a bit body 30 provides three additional possible contact areas between the outside of the bit 20 and the parts adjacent to a deep hole. Since these additional contact areas are both radially and longitudinally spaced from the face surfaces 98, the stability of the downward hole of the drill 20 is essentially improved.

The stabilizer pads 150 also improve downhole stability of the drill 120 for essentially the same reasons. The stabilizer pads 150 increase the number of contact areas between the bit 120 and the side wall of a deep hole from 2 to 4.

The total area of the outer surfaces 52 of the stabilizing pads 50 and of the outer surfaces 152 of the stabilizing pads 150 is essentially larger than the area of contact between the respective caliper face surfaces 98 and 198 with the side wall of a deep hole during normal down hole drilling conditions. By eroding and / or abrading the parts of the cutting structure associated with the cutter cone assemblies 90 and 98, the inner diameter of the associated deep hole will decrease until the stabilizing pads 50 or 150 contact the respective side wall.

Since the area of the outer surfaces 52 and 152 is essentially larger than the contact area associated with the face faces of gauge 98 and 198 and the respective side wall during normal drilling operations, the torsional force load on the drilled drill string 22 will increase significantly. By carefully monitoring the torsional force load on the drill string 22 on the well surface, the stabilizer pads 50 and 150 will provide an early indication of erosion and / or wear of the cutting structure associated with the respective drills 20 and 120.

The 98 and 198 gauge face surfaces will often be the respective parts of the drills 20 and 120 which will experience erosion and wear early. When the torsional load on the drill string 22 exceeds a selected value depending on the size and type of the drill bit and the associated downhole drilling conditions, the drill 20 and 120 will preferably be removed from the associated deep hole before a more catastrophic failure of the respective drill bit or cutter structure occurs.

For the embodiments of the present invention as shown in Figures 1-5, the stabilizer pads 150 and 152 are arranged in a generally symmetrical configuration with respect to each other and the respective support arms 70 and 170 and the cutter cone assemblies. 90 and 190. For some applications, it may be desirable to provide only two stabilizing pads 50 on the outside of the auger body 30 or only one stabilizing pad 150 on the outside of the auger body 130.

The formation of non-symmetrical stabilizing pads on the outside of an auger body In accordance with the teachings of the present invention, it will be beneficial for use in the directional drilling of highly deviated and / or horizontal deep holes. Also, a non-symmetrical configuration of the stabilizing pads formed on the outside of a drill body according to the teachings of the present invention can be used to increase fluid flow and the return of cuts or other waste from the bottom of a deep hole along one side of the associated bit. Therefore, the stabilizer pads can be formed as an integral component of an auger body to aid in the directional drilling control and / or improved hydraulic performance of the associated drill.

The formation of stabilizing pads as an integral component of an auger body with a non-symmetric configuration can be particularly beneficial when the associated drill bit is used in relatively smooth formations which require the removal of a high volume of drilling and cut-off fluid. others from the bottom of a deep hole. Alternatively, the size of the stabilizer pads can be reduced to provide enlarged flow channels between each stabilizer pad and an adjacent support arm. For example, decreasing the width of the stabilizer pads 50 will enlarge the flow area of the fluid flow channels 54.

For the embodiments of the present invention as shown in Figures 1-5, the outer surfaces 5 and 152 of the respective stabilizing pads 150 have a relatively uniform outer diameter relative to the respective longitudinal ej 46 and 146. For some applications, the Stabilizing pads 50 and / or 150 can be formed with the outer surfaces 52 and 152 having a radius of curvature relative to the respective longitudinal axis 46 and 146. The formation of the stabilizing pads with a radius of curvature can improve fluid flow and the return of the cuttings during normal downhole drilling operations while providing a sufficient contact area to stabilize the associated drill bit and / or to provide an early indication of the erosion and / or wear of the associated cutter structure .

For some applications, the stabilizer pads 50 and / or 150 can be formed with exterior surfaces 52 and 152 having a generally tapered configuration. For applications such as highly deviated and deep well bores and / or well bores having relatively long horizontal portions extending therefrom, the outer diameter of the outer surface 52 adjacent the lower surface 68 may be more larger than the outer diameter of the outer surface 52 on one side of the upper surface 62. As a result of the difference in the outer diameters, the outer surface 52 will have a generally tapered configuration to help pull the drill 20 from the bottom of a deep hole.

Conventional rotary cone bits (not expressly shown) are constructed in two or three segments. The segments can be placed together longitudinally with a weld slot placed between each segment. The segments can then be welded to one another using conventional welding techniques to form the associated auger body. Each segment also includes an associated support arm extending from the auger body. An amplified cavity is typically formed in the auger body to receive the drilling fluids from the drill string. U.S. Patent No. 4,054,772 entitled "Welding System for Rock Auger" shows a method and an apparatus for constructing a rotary rock drill of three cones of three individual segments and shows an example of a cone drill. conventional rotating The segments of a conventional drill are generally manufactured using the prior techniques used in the manufacture of oil and gas production and drilling equipment. One or more of the forged drill segments will typically include a nozzle protrusion (not shown) expressly). In accordance with the teachings of the present invention, a stabilizer pad or appendage may also be included as an integral component of individual forged segments. By providing stabilizing pads as integral components of the forged segments, the number, size, location, and orientation of the resulting stabilizing pads and nozzles can be optimized for the resulting drill essentially the same as previously described for the drill bits 20 and 120.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (24)

R E I V I ND I C A C I O N S

1. A drill to form a deep hole comprising: A bit body having a top adapted for connection to a drill string for rotation of the bit; A number of support arms extending from the auger body; A number of cutter cone assemblies equal to the number of support arms; Each cutter cone assembly is rotatably mounted on one of the support arms; At least two stabilizing pads formed as integral components of the auger body and projecting radially outwardly from the auger body. The stabilizing pads are radially spaced from one another with one of the support arms placed between them.

2. The bit, as claimed in clause 1, further characterized in that it comprises each of the stabilized pads having a front surface, a tail surface and an outer surface placed therein.

3. The drill bit, and as claimed in clause 1, characterized in that each stabilizer pad comprises a layer of hard coating material.

4. The bit, as claimed in clause 1, characterized in that each stabilizing pad comprises a plurality of inserts placed there.

5. The bit, as claimed in clause 1, characterized in that it also includes: Cutter cone assemblies that cooperate with one another to define in part a bore diameter for the drill; The stabilizer pads project from the auger body by a radial distance less than the bore diameter of the bit so that when the other components of the drill wear out, the stabilizer pads will contact the adjacent parts of a deep hole associated and will increase torsional force loads on the drill string.

6. The drill bit, as claimed in clause 1, characterized in that it further comprises a fluid flow channel formed on the outside of the auger body between each stabilizer pad and an adjacent support arm.

7. The bit, as claimed in clause 1, characterized in that it also comprises a one-piece unitary auger body.

8. The bit, as claimed in clause 1, characterized in that it also comprises a bit body formed of two or more segments with each segment having a stabilizing pad and a support arm formed as integral components thereof.

9. The bit, as claimed in clause 1, characterized in that it also includes: At least three stabilizing pads formed as integral components of the auger body; The stabilizer pads are radially spaced from one another and from the adjacent support arms to define the respective fluid flow channels between the stabilizer pads and the support arms.

10. The bit, as claimed in clause 1, characterized in that it also includes: Each stabilizing pad has an outer surface with a generally rectangular configuration; The outer surface of each stabilizer pad is generally positioned parallel with a longitudinal axis extending through the auger body.

11. The bit, as claimed in clause 1, characterized in that it also includes: A longitudinal axis extending through the auger body which generally corresponds to a projected axis of rotation for the drill; Each stabilizing pad has an outer surface positioned at an angle relative to the longitudinal axis of the auger body.

12. The bit, as claimed in clause 1, also characterized because it comprises: Two stabilizing pads formed with integral components of the auger body; The stabilizing pads are positioned between the adjacent support arms to define the respective fluid flow channels between the stabilizing pads and the support arms.

13. The drill bit, as claimed in clause 12, characterized in that it also comprises a longitudinal axis extending through the auger body which generally corresponds to the projected axis of the rotation for the drill; Each stabilizing pad has a configuration of generally spiral shape in relation to the longitudinal axis of the auger body.

14. The drill bit, as claimed in clause 1, characterized in that it also comprises at least one PDC insert placed inside each stabilizer pad; Each PDC insert has a shear structure to make contact with the adjacent parts of a side wall of the deep hole.

15. A bit body for a bit that comprises: At least two stabilizing pads formed as integral components of the sweeping body during the initial fabrication thereof; Each stabilizing pad has a front surface, a tail surface and an outer surface formed therebetween; Each stabilizer pad projects radially from the auger body.

16. The auger body, as claimed in clause 15, further characterized in that it comprises each stabilizing pad having a lower surface inclined at an angle extending from the drill body to the outer surface of the stabilizing pad.

17. The auger body, as claimed in clause 15, characterized in that in addition it comprises that each stabilizing pad has a top surface inclined at an angle extending from the auger body to the outer surface of the stabilizing pad.

18. The auger body, as claimed in clause 15, characterized in that each stabilizing pad further comprises a hard coating layer placed thereon.

19. The auger body, as claimed in clause 15, characterized in that it comprises a plurality of inserts placed in each stabilizer pad.

20. A rotating cone drill to form a deep hole comprising: A auger body having a top adapted for connection to a drill string for rotation of the auger body; Three support arms extending from the auger body; Three cutter cone assemblies respectively mounted on one of the support arms; Three stabilizing pads formed as integral components of the auger body; Each stabilizer pad projects radially outwardly from the auger body; The auger body has a longitudinal axis that generally corresponds to the projected axis of the rotation for the bit; Each stabilizer pad is spaced radially from one another on the outside of the auger body; Each support arm is spaced radially from one another and placed between the respective stabilizing pads.

21. The bit, as claimed in clause 20, also characterized because it comprises: Each stabilizer pad has a front surface; A plurality of inserts installed within the front surface of each stabilizer pad.

22. The drill bit, as claimed in clause 20, further characterized in that each stabilizing pad has an outer surface; Y A plurality of inserts installed within the outer surface of each stabilizer pad.

23. The bit, as claimed in clause 20, also characterized because it comprises: Each stabilizing pad has a front surface, an outer surface, a tail surface, an upper surface and a lower surface; A hard coating layer placed on selected portions of the front surface, the outer surface, the glue surface, an upper surface and the lower surface.

24. The drill bit, and as claimed in clause 20, characterized in that it also comprises each stabilizing pad having a front surface, a outer surface, a tail surface, an upper surface and a lower surface; Y A plurality of inserts installed within selected portions of the front surface, the outer surface, the glue surface, the top surface and the bottom surface. SUMMARY A rotary cone bit for forming a deep hole having a bit body with a plurality of stabilizing pads formed as integral components thereof. The auger body includes a top adapted for connection to a drill string. A number of support arms preferably extend from a lower part of the auger body. A total number of cutter cone assemblies equal to the number of support arms are rotatably mounted on the respective support arms and project generally downward and inward from each support arm. The stabilizing pads project radially outwardly from the auger body and are positioned in the middle of the adjacent support arms. Both the stabilizer pads and the support arms have surfaces that form a fluid flow channel therebetween to direct the drilling fluids and the cutouts to flow up into the deep bore. The hard coating layer can be placed on selected portions of each stabilizer pad. One or more inserts can be installed on the selected parts of each stabilizer pad.