EP0326176A2 - Trépan rotatif renforcé - Google Patents

Trépan rotatif renforcé Download PDF

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Publication number
EP0326176A2
EP0326176A2 EP89101527A EP89101527A EP0326176A2 EP 0326176 A2 EP0326176 A2 EP 0326176A2 EP 89101527 A EP89101527 A EP 89101527A EP 89101527 A EP89101527 A EP 89101527A EP 0326176 A2 EP0326176 A2 EP 0326176A2
Authority
EP
European Patent Office
Prior art keywords
drill bit
rotary drill
bit
main body
body portion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP89101527A
Other languages
German (de)
English (en)
Other versions
EP0326176A3 (fr
Inventor
Royce A. Anthon
Dewayne C. Fox
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Norton Christensen Inc
Original Assignee
Christensen Inc
Norton Christensen Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Christensen Inc, Norton Christensen Inc filed Critical Christensen Inc
Publication of EP0326176A2 publication Critical patent/EP0326176A2/fr
Publication of EP0326176A3 publication Critical patent/EP0326176A3/fr
Withdrawn legal-status Critical Current

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00—Drill bits
    • E21B10/46—Drill bits characterised by wear resisting parts, e.g. diamond inserts
    • E21B10/56—Button-type inserts
    • E21B10/567—Button-type inserts with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts

Definitions

  • This invention relates to drill bits, and more particularly to rotary drill bits with diamond cutting elements used in the drilling of bore holes in earth formations.
  • Earth boring diamond drill bits may typically include an integral bit body which may be of steel faced with an abrasion-resistant material such as tungsten carbide or may itself be fabricated of a hard metal matrix material such as tungsten carbide.
  • a plurality of diamond cutting elements are mounted along the exterior face of the bit body.
  • Each diamond cutter typically may be mounted on a stud the other end of which is mounted in a recess in the exterior face of the bit body, or the cutter mount may be integrally cast with the matrix of the bit body.
  • the cutting elements are positioned along the leading edges of the bit body so that as the bit body is rotated in its intended direction of use, the cutting elements engage and drill the earth formation. In use, tremendous forces are exerted on the cutting elements, particularly against the face thereof in the forward to rear direction as the bit is rotated. Additionally, the bit and cutting elements are subjected to substantial abrasive forces. In some instances, impact, lateral, and/or abrasive forces have caused drill bit failure and cutter loss.
  • bits have been designed with relatively large cutters with strong hydraulics in the proximity of the cutters to remove the cuttings from the cutter faces with a high volume, high velocity, hydraulic fluid flow.
  • While tungsten carbide or other hard metal matrix bits are highly erosion resistant, such materials are relatively brittle and can crack upon being subjected to the impact forces encountered during drilling. Typically, such cracks have occurred proximate where the cutting element support structures join the matrix body.
  • the shoulders or protrusions on the exterior of the drill bits to accommodate large diameter cutting exposes these areas of the bit to high impact and shear forces.
  • Bits having large cutter elements thereon extending outwardly from the body of the bit are particularly susceptible to cracking and failure due to these high impact and shear forces. If the cutting elements are sheared from the drill bit body, the expensive diamonds on the cutter elements are lost, and the bit may cease to drill.
  • a rotary drill bit in which the areas supporting the cutter elements are reinforced to provide those areas with increased impact strength.
  • a rotary drill bit which includes a main body portion of a hard metal matrix material and at least one shoulder or protrusion formed of the same hard metal matrix material.
  • the protrusion is integral with the main body portion of the bit and extends outwardly from the exterior surface of the bit.
  • protrusion encompasses protrusions, shoulders, blades, ridges, or other structures extending outwardly from the main profile of the bit body.
  • a cutting element is mounted on the protrusion and is angled as known in the art to accomplish drilling of an earth formation. There may be one or a plurality of individual cutter elements mounted on each protrusion. Means for reinforcing the protrusions are provided and extend between the main body portion of the bit and individual protrusions.
  • the reinforcing structure comprises a solid preformed arrangement positioned rearwardly of the cutting elements and extending at an acute angle with respect to the main body portion of the bit.
  • the reinforcing structure may be in the form of one or more rods, bars, disks, or wires which are preferably of metal. While steel is the preferred composition for the reinforcing structure, other metals and metal alloys such as stainless steel, nickel alloys or molybdenum may be utilized.
  • the present invention also encompasses drill bits having a plurality of such protrusions and cutting elements and is particularly suited for use with rotary bits having relatively large diameter cutting elements.
  • the portions of the matrix on which the elements are mounted are reinforced to provide the bit with greater impact strength and greater resistance to cracking and failure of the bit matrix. Accordingly, it is an object of the present invention to provide a rotary drill bit matrix having improved impact strength and resistance to cracking over prior bits.
  • the bit may be designed for either a flat, parabolic, or extended blade crown profile.
  • the invention may also be useful in any hard metal matrix bit configuration which has one or more shoulders, ridges, blades, or other protrusions extending outwardly from the main body of the bit.
  • rotary drill bit 10 of the type disclosed in the above referenced copending application includes an exterior generally cylindrical surface or gage 12 having a bit face 14 on its lowermost portion. Both gage 12 and bit face 14 are formed of the hard metal matrix material of the bit body, such as tungsten carbide. Defined within gage 12 are a plurality of junk slots 16 and 18. The junk slots are designed to facilitate the upward flow of the drilling fluid and cuttings away from the bit face 14. A number of fluid nozzles 20 are also located on bit face 14. Each of fluid nozzles 20 is designed to provide directed fluid flow to a specific cutting element 22. Each cutting element 22 comprises a tungsten carbide backing 25 having deposited thereon a thin synthetic diamond cutting face 23 which performs the cutting operation.
  • Cutting elements 22 are mounted on shoulders or protrusions 24 which extend outwardly from the bit face 14.
  • the cutting elements are secured in place by brazing or otherwise fixing them to the bit face in a conventional manner.
  • cutting elements 22 may be secured to the matrix and to tungsten carbide slug 26 cast into the trailing portion ot sockets 28 (best shown in Fig. 2) on bit face 14 by brazing or other suitable means.
  • the cutting faces 23 of cutting elements 22 are one inch in diameter or larger.
  • each cutter element 22 has an associated fluid nozzle 20 which provides a directed hydraulic flow of fluid to the face of the cutting element. This fluid flow applies a force to chips cut from the earth formation, loosening and removing the chips from the faces of the cutting elements.
  • bit 10 includes a plurality of gage cutting elements 30 which comprise smaller diameter diamonds which are mounted on the gage 12 of bit face 14. The gage cutters insure that the drill cuts a path of the desired diameter through the earth formation.
  • each cutting element 22 positioned rearwardly of each cutting element 22 is reinforcing means 32 extending between the main body portion of drill bit 10 and protrusion or shoulder 24.
  • cutting element 22 includes a hard metal matrix backing 25 of tungsten carbide or the like, and is preferably substantially laterally symmetrical.
  • the backing 25, having cutting face 23 thereon, is brazed into socket 28 in the bit matrix.
  • Backing 25 provides shock protection and load resistance to the cutting face 23.
  • the bit 10 rotates in the direction of the arrow and encounters impact forces on cutting face 23 as indicated by the arrow shown in phantom lines.
  • the cutting element 22 will have a predetermined rake angle to the formation encountered depending upon placement of cutting element 22 and the bit profile and the desired operation of the bit, which depends upon the formations to be drilled.
  • Reinforcing means 32 may comprise a longitudinally extending element which takes the form of a rod, bar, disk, or wire. It may also comprise a plurality of such structures.
  • reinforcing means 32 comprises a threaded rod of cylindrical steel stock, such as 1018 or 1020 steel.
  • the steel stock has no coatings on it and the stock is cleaned of any oxides prior to being used.
  • reinforcing means 32 is positioned rearwardly of cutting element 22 and extends between the main body of the bit and substantially the outermost extent of protrusion 24. Reinforcing means 32 is positioned at an acute angle with respect to the main body ot the bit. At such an angle, the reinforcing means is pointed slightly toward cutting element 22. Reinforcing means 32 also extends at least partially behind cutting element 22 and is also preferably centered with respect to cutting element 22 so that impact forces will be focused thereon.
  • a somewhat differently configured bit has a shoulder or protrusion 24, which may be a blade-shaped protrusion emanating from the center of a "fishtail" bit toward the gage of the bit.
  • Cutting element 22 is mounted into socket 28 in the bit matrix.
  • reinforcing rod 32 is positioned rearwardly of cutting element 22 and extends between the bit matrix and substantially the outermost extent of shoulder or protrusion 34.
  • Reinforcing rod 32 is preferably angled so that it is roughly parallel or at a slight angle (as shown) to the surface of cutting element 22 (as shown).
  • Reinforcing rod 32 is disposed in a substantially perpendicular orientation to the profile of the main body portion of the bit.
  • Rotary drill bits employing the present invention are generally made by powder metallurgical techniques which are known in the art.
  • the bit is formed in a carbon mold having an internal configuration corresponding generally to the required surface shape of the bit body, including protrusions for mounting cutting elements.
  • the areas where the junk slots are found on the finished bit body contain carbon or clay displacement material in the mold.
  • the areas in the mold which correspond to where the cutting elements are to be mounted after furnacing of the bit body are filled with a displacement material such as carbon discs of like size to the cutting elements having clay adjacent thereto so that the furnaced bit body has mounting sockets 28 formed therein.
  • Reinforcing means 32 are positioned in the mold by embedding them in the clay displacement material placed at the outermost extent of the protrusion cavitities from the body mold cavity.
  • Reinforcing means 32 are positioned rearwardly of where the cutting elements 22 are to be mounted.
  • the reinforcing means 32 is a threaded steel rod which is desirably positioned to be perpendicular to the mold profile from which it protrudes.
  • reinforcing means 32 extends from the main profile or surface of the bit in a perpendicular manner to the point on the profile from which it extends.
  • elements which will form the internal fluid passages and nozzles in the finished bit are also positioned in the mold at this time.
  • a steel blank is also positioned in the mold at this time.
  • a hard metal matrix material such as tungsten carbide is then added to the mold.
  • a binder material preferably a copper-based alloy, in the form of pellets or other small particles, is then poured over the matrix material.
  • the filled mold is then placed in a furnace and heated to above the melting point of the binder, typically above about 1100 degrees C. The molten binder passes through and infiltrates the matrix material.
  • the matrix and binder are consolidated into a solid body which is bonded to the steel blank.
  • the bit body is removed from the mold.
  • the steel blank is then welded or otherwise secured to an upper body or shank. Clay and other displacement material is removed at this time. Because reinforcing means 32 was embedded in the clay, the portion of the reinforcing means which extends from the bit body is machined off flush to the trailing edge of the protrusion.
  • Cutting elements 22 are then mounted to the bit body. As is conventional, cutting element 22 is mounted into socket 28 and backing 25 secured therein by brazing with a suitable metal brazing material. The gage cutting elements may also be mounted to the exterior of the bit body at this time.
  • the test measured the resistance to fracture by impact forces of a matrix material reinforced by a steel rod such as the preferred reinforcing rods of the present invention.
  • Samples of matrix material were fabricated in a conventional manner by filling a cylindrical mold with tungsten carbide matrix material and a copper-based alloy binder. The mold was sized to produce a sample specimen six inches in length with a 1/2 inch diameter. The matrices were furnaced at 2150 degrees F for 60 minutes. Previous testing established that such a sample, when subjected to an impact force with a Charpy Impact Tester, would fracture at an impact force of about 3.5 ftlb.
  • Sample specimen 1 included a 3/16 inch diameter mild 1018 steel rod positioned centrally within the specimen.
  • Sample specimen 2 included a 3/16 inch diameter threaded mild 1018 steel rod positioned centrally within the specimen.
  • Sample specimen 3 included a 1/8 inch diameter tool steel rod positioned centrally within the specimen. All steel rods were grit blasted prior to placement in the respective mold to remove any oxides.
  • multiple cutting elements may be mounted on each protrusion; half-circular or other shape cutting elements may be used; several reinforcing elements may be employed for a single protrusion; U or V-shaped reinforcing elements may be used either right side up or upside down; reinforcing elements of a variety of cross-sections, including but not limited to square, rectangular, triangular, elliptical, half-circular, etc., may be employed.

Landscapes

  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mining & Mineral Resources (AREA)
  • Geology (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Earth Drilling (AREA)
  • Excavating Of Shafts Or Tunnels (AREA)
EP89101527A 1988-01-28 1989-01-30 Trépan rotatif renforcé Withdrawn EP0326176A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US14937488A 1988-01-28 1988-01-28
US149374 1988-01-28

Publications (2)

Publication Number Publication Date
EP0326176A2 true EP0326176A2 (fr) 1989-08-02
EP0326176A3 EP0326176A3 (fr) 1990-03-21

Family

ID=22529996

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89101527A Withdrawn EP0326176A3 (fr) 1988-01-28 1989-01-30 Trépan rotatif renforcé

Country Status (3)

Country Link
EP (1) EP0326176A3 (fr)
AU (1) AU612224B2 (fr)
CA (1) CA1314866C (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5007493A (en) * 1990-02-23 1991-04-16 Dresser Industries, Inc. Drill bit having improved cutting element retention system
AU612224B2 (en) * 1988-01-28 1991-07-04 Norton Christensen Inc. Reinforced rotary drill bit
EP0534370A1 (fr) * 1991-09-23 1993-03-31 Smith International, Inc. Trépan racleur diamanté

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0032428A1 (fr) * 1980-01-10 1981-07-22 Stonehouse U.K. Limited Trépan pour forage rotary
EP0145421A2 (fr) * 1983-12-03 1985-06-19 Reed Tool Company Limited Fabrication de trépans de forage rotatifs

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4397361A (en) * 1981-06-01 1983-08-09 Dresser Industries, Inc. Abradable cutter protection
DE3751672T2 (de) * 1986-10-06 1996-05-30 De Beers Ind Diamond Schneidelement
AU612224B2 (en) * 1988-01-28 1991-07-04 Norton Christensen Inc. Reinforced rotary drill bit

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0032428A1 (fr) * 1980-01-10 1981-07-22 Stonehouse U.K. Limited Trépan pour forage rotary
EP0145421A2 (fr) * 1983-12-03 1985-06-19 Reed Tool Company Limited Fabrication de trépans de forage rotatifs

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU612224B2 (en) * 1988-01-28 1991-07-04 Norton Christensen Inc. Reinforced rotary drill bit
US5007493A (en) * 1990-02-23 1991-04-16 Dresser Industries, Inc. Drill bit having improved cutting element retention system
EP0534370A1 (fr) * 1991-09-23 1993-03-31 Smith International, Inc. Trépan racleur diamanté

Also Published As

Publication number Publication date
AU612224B2 (en) 1991-07-04
AU2887589A (en) 1989-08-03
CA1314866C (fr) 1993-03-23
EP0326176A3 (fr) 1990-03-21

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