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
  • E21B10/42—Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits
  • E21B10/43—Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits characterised by the arrangement of teeth or other cutting elements
• • 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
  • E21B10/54—Drill bits characterised by wear resisting parts, e.g. diamond inserts the bit being of the rotary drag type, e.g. fork-type bits
  • E21B10/55—Drill bits characterised by wear resisting parts, e.g. diamond inserts the bit being of the rotary drag type, e.g. fork-type bits with preformed cutting elements

Definitions

• the invention relates to rotary bits, especially to bits for drilling wells in oil or gas deposits or coring in such deposits.
• the invention more particularly relates to a rotary bit of the type comprising a tool body with an axial core and radial fins pierced with cells containing impregnated diamond abrasive elements.
• Rotary drill bits of the type defined above are commonly used for drilling wells in oil or gas deposits.
• a trephine of the type defined above in which the body and the fins form a unitary set of impregnated diamonds, the fins being pierced with cylindrical cells containing impregnated diamond abrasive elements.
• the manufacture of such drill bits has the disadvantage of subjecting the tool body to very high temperatures (a temperature of 1.204 ° C.) for a relatively long time, which has the disadvantageous result of generating mechanical stresses therein. likely to weaken it.
• the insertion and fixing of the abrasive elements in the cylindrical cells is made complicated by the cylindrical profile of the cells.
• the invention aims to overcome the aforementioned disadvantages of known drills described above.
• the invention aims more particularly to provide a rotary bit of a new design, the manufacture of which does not require the implementation of high temperatures for excessively long time.
• Another object of the invention is to provide a rotary bit which is not the seat of internal mechanical stresses capable of weakening it and which therefore has improved mechanical strength.
• a further object of the invention is to provide a drill bit for more economical use of the abrasive elements and which, therefore, has a higher efficiency and a longer service life.
• the invention also aims to provide drill bits, adapted to undergo repairs and rehabilitation after use.
• the invention also aims to provide a new process for the manufacture of such a bit, which does not require a heat treatment at high temperature and which, consequently, avoids the risk of cracking of the tool, inherent to the known method described upper.
• the invention relates to a rotary bit comprising a tool body which is of revolution about an axis of rotation, said tool body comprising an axial core and radial vanes pierced with cells containing abrasive elements. impregnated diamonds, the bit being characterized in that the fins are made of steel, in that the cells are grooves cut in the edge of the fins, in the direction of rotation of the tool body and in that the abrasive elements are cylinders which are arranged in the grooves, in the direction of rotation of the tool body.
• the body of the bit according to the invention is of revolution and is intended to be equipped with abrasive elements designed to drill wells, for example in deposits. oil or gas.
• the rear part of the axial core is normally arranged to be attached to a drill string coupled to a motor.
• the fins are normally uniformly distributed around the periphery of the core and are pierced with cells containing abrasive elements.
• the profile of the fins is not critical for the definition of the invention. They can be flat or spiral faces.
• the fins are made of steel.
• the choice of the grade of steel is not critical for the definition of the invention.
• the steel grade that is suitable can be readily determined by those skilled in the art. In practice, and as examples, the following grades are suitable: 4145H, 4140, ST52, CK45.
• the core is preferably also of steel.
• the fins may be separate elements welded to the core. However, according to the invention, it is preferred that the core and the fins form a monolithic block.
• the tool body of the bit carries impregnated diamond abrasive elements.
• Impregnated diamond abrasives are well known in the mining sector, particularly in the oil and gas fields. They are the active tools of the bit, digging and debiting the rock by abrasion.
• the abrasive elements are obtained by mixing a diamond powder (optionally added with a metal carbide powder, for example tungsten carbide) with a powder of a fusible binder (eg Cu-Mn solder) and then subjecting the resulting mixture to compaction followed by sintering. Information on this technique is available in US 2002 / 0125048A1.
• the impregnated diamond abrasive elements are cylinders.
• Another feature of the invention lies in the shape and arrangement of the cells containing the cylindrical abrasive elements.
• said cells are grooves, which are hollowed out in the edge or edge of the fins and which are oriented transversely relative thereto, so as to be substantially directed tangentially with respect to the direction of rotation of the body. 'tool.
• the grooves are advantageously semi-cylindrical, their cross section preferably being circular or oval or oblong.
• the invention however also covers polygonal cross sections, for example square, rectangular, hexagonal or octagonal or trapezoidal.
• the abrasive elements of the bit according to the invention are cylinders.
• the cross section of the cylinders is not critical for the definition of the invention. It is preferably circular, oval or oblong.
• the invention however also covers polygonal cross-sections, for example square, rectangular, hexagonal, octagonal or trapezoidal.
• the rear face of the rolls is preferably curved and their anterior face is usually flat.
• the term "Curved” means not only a substantially curved surface (for example a spherical surface or an ovoid surface), but also a surface comprising one or more flat faces extended by one or more curved faces.
• the terms "posterior” and “anterior” are defined below.
• the cylindrical abrasive elements are each housed in one of the aforementioned grooves of the fins. It is normally preferable that the cross section of the cylinder of the abrasive elements is compatible with that of the grooves, so that the cylinder is substantially in contact with the entire wall of the groove.
• Each groove may comprise a single abrasive element.
• grooves may include an alignment of a plurality of adjacent cylindrical abrasive elements.
• the contiguous faces of the abrasive elements are normally complementary. They are preferably flat. This variant of the invention allows the use of abrasive elements of standard length, which facilitates the manufacture of the bit and reduces its cost.
• the fixing of the abrasive elements in their respective grooves can be carried out by any appropriate means. They are advantageously brazed in their groove.
• the cylinder of the abrasive elements forms a projecting protuberance in front of the edge of the fins.
• This face constitutes the front face of the abrasive element with respect to the direction of progression bit during a drilling operation. In this memo, it is called "front face”.
• the grooves open through a radial face of their fin and the cylinder of the abrasive elements has an end projecting from said radial face of the fin.
• This radial face of the fin is normally that which is located in front of its edge, relative to the normal direction of rotation of the body of the bit around the axis of the core. In the rest of this specification, this face of the fin will be referred to as the "anterior face" of the fin.
• the depth of the grooves is as large as possible. By definition, the depth of a groove is the dimension thereof, transversely to the edge of the fin.
• the depth of the grooves is such that the distance between the bottom thereof and the core is less than 7 cm, preferably 5 cm.
• it is advantageous to maintain a sufficient gap between the bottom of the groove and the core generally at least equal to 0.10 cm. . Deviations between 0.10 and 2.50 cm are preferred, those between 0.25 and 1.50 cm being especially recommended.
• This embodiment allows optimum use of the abrasive elements, the blades being caused to be eroded and worn progressively as the wear of the abrasive elements wears on.
• the face of the abrasive elements which is normally applied against the bottom of the grooves, is made of a material with a high resistance to wear, designed not to exert abrasion on the rock.
• this face of the abrasive elements is referred to as the "back face", as opposed to the front face, which has been defined above.
• the aforementioned material with high wear resistance may for example comprise a matrix of impregnated material which, in contact with the rock, wears progressively to form a polished surface.
• This variant of the invention aims to prevent destruction of the core in case the abrasive elements and fins would be consumed completely.
• the width of the grooves is usually less than their depth and the cross section of the abrasive elements is oblong.
• the width of a groove is, by definition, the dimension thereof, transversely to its depth and to the direction of rotation of the tool body. In the case of flat fins, the width of the grooves is measured in the axial plane of the fin.
• the grooves have two substantially flat faces and transverse to the edge of the fins, against which two flat longitudinal faces of the abrasive elements are applied.
• the flat faces of the abrasive elements are connected by two opposite convex convex faces.
• One of said convex curved faces forms the rear face of the abrasive element and is applied against a corresponding concave curved surface forming the bottom of the groove, while the other convex face of the abrasive element is its front face projecting forward. of the slice of the fin.
• the two planar faces of at least some of the grooves are substantially parallel, as are the two flat faces of the abrasive elements they contain.
• the two planar faces of at least one groove and the abrasive element which it contains diverge from the bottom of the groove to the edge of the fin .
• This variant of the invention makes it possible to optimize the effective surface of the abrasive elements on the edge of the fins, taking into account the curvature of the fins.
• the effective area of the abrasive elements on the edge of the fins is optimized by judiciously combining a distribution of grooves (and abrasive elements) with parallel plane faces and grooves (and abrasive elements) to divergent flat faces. This optimization must be determined in each particular case by the man of the profession, depending on the profile of the fins and their edge.
• the rear face of the cylinder of the abrasive elements is applied against the rear face of its groove.
• the rear faces of the cylinder and the groove are defined relative to the normal direction of rotation of the bit.
• the rear face of the cylinder is preferably in contact with the entire rear face of the groove.
• the aforementioned posterior faces of the cylinder and its groove are substantially planar.
• the aforementioned posterior faces of the cylinder and its groove are curved, the posterior face of the cylinder being convex and that of the groove being concave.
• the rotary bit according to the invention has applications for drilling all types of wells for various applications. It is especially suitable for drilling deep wells in oil or gas deposits or for coring in such deposits.
• the invention also relates to an original process for the manufacture of a rotary bit according to the invention. Accordingly, the invention also relates to a method for manufacturing a rotary bit comprising a tool body which comprises an axial core of revolution, radial fins fixed to the core and cylindrical impregnated diamond abrasive elements housed in formed in the fins, the method being characterized in that the core and the steel fins are manufactured, in that the cells are grooves which are cleaned through the peripheral edge of the fins, in the direction of rotation of the tool body, and in that the abrasive elements are cylinders that are inserted into the grooves.
• the characteristics of the core, fins, grooves and abrasive elements are identical to those defined above, in relation to the bit according to the invention.
• the tool body can be manufactured in a monolithic block incorporating the core and the fins.
• the core is made separately, on the one hand, and the fins, on the other hand, and the fins are subsequently assembled to the core, for example by a welding operation.
• any suitable means may be used to shape the grooves in the fins. Nevertheless, it is preferred to use a mechanical machining, it is then normally performed by milling on a machine bench.
• the machining of the ribs is performed on the fins dissociated from the core, the fins being subsequently attached to the periphery of the core.
• Another embodiment which is preferred, applies to monolithic tool bodies, the machining of the grooves being performed on the fins integral with the core.
• This embodiment is especially adapted to the manufacture of drill bits in which the grooves have their rounded posterior face. It is particularly applicable to the embodiment described above, in which the grooves open through the anterior radial face of their fin and in which the cylinder of the abrasive elements has its anterior end projecting from said anterior radial face of the blade. 'fin.
• the manufacture of impregnated diamond abrasive elements comprises compacting a powder in a cylindrical mold by means of a piston or a pair of pistons, compacting followed by sintering.
• the piston of the compacting press has a concave curved profile, the peripheral edge of which is subjected to intense wear.
• Figure 1 shows in perspective a drill bit according to the invention
• Fig. 2 is a perspective view of an abrasive element of the bit of Fig. 1;
• Figures 3 to 6 show four particular embodiments of a detail of the abrasive element of Figure 2, in cross section along the Y-Y plane of Figure 2;
• Figure 7 shows on a large scale, a cell of a fin bit of Figure 1, in section along an axial plane of the bit;
• Figure 8 is a section along the plane VIII-VIII of Figure 7.
• the drill bit shown in FIG. 1 comprises a tool body incorporating an axial core 1 and radial fins 2 fixed to the periphery of the core 1.
• the core 1 is extended by a threaded end 3 intended to attach it to a drill string (not shown) of a drilling or coring installation.
• the radial fins 2 are uniformly distributed at the periphery of the core 1. They each have, in a conventional manner, two plane radial faces 4 and 17, and a wafer 5 connecting the two radial faces.
• the radial face 4 of the fin 2 is in front of its portion 5 relative to the normal direction of rotation X of the bit. It is, by definition, the anterior face 4 of fin 2.
• the radial face 17, which is behind the edge 5 of the fin relative to the normal direction of rotation X of the bit is, by definition, its posterior radial face 17 .
• the core 1, the threaded end 3 and the fins 2 form a monolithic assembly or block made of steel.
• the fins are pierced with cells 6.
• the cells 6 are grooves which are hollowed out in the edge 5 of the fins, transversely to the radial faces 4 and 17.
• the grooves 6 pass through the anterior radial face 4 and their posterior end 7, located near of the radial face 17, is curved concave ( Figure 8).
• Figures 7 and 8 show a groove 6 on a large scale.
• the groove 6 comprises two parallel flat faces 18 and 19 and a concave curved bottom 20.
• the concave bottom 20 is located a short distance from the core 1.
• the gap between the core 1 and the bottom 20 of the groove is for example between 0.5 and 0.75 cm.
• the depth of the groove 6 is the distance between its bottom 20 and the slice
• the width of the groove 6 is the distance separating its two flat faces 18 and 19.
• the grooves 6 each contain an abrasive element 8 (not shown in Figures 7 and 8).
• the abrasive elements 8 are of the impregnated diamond type, defined above. They were obtained by a process comprising compacting a diamond powder containing tungsten carbide (optionally added with cobalt carbide) and a powder of a Cu-Mn solder, the compacted powder obtained then being subjected to sintering under inert atmosphere (eg under argon) or reducing. It is advantageous to use the hot isostatic pressing technique, generally called “HIP technique (" Hot isostatic pressing "in English language).
• HIP technique Hot isostatic pressing
• An abrasive element 8 is shown on a large scale in FIG. 2. It has an oblong profile, with a substantially planar front face 9, a convex curved rear face 10 and two flat and parallel lateral faces 13.
• the convex convex face 10 corresponds to the concave convex posterior face 7 of the grooves 6.
• the Adjectives "anterior” and “posterior” are defined with respect to the X-axis of rotation of the bit, as stated above.
• abrasive elements 8 When the abrasive elements 8 are inserted in their respective grooves 6, their lateral faces 13 are applied against the lateral faces 18 and 19 of the groove, their convex rear face 10 is applied against the corresponding convex posterior face 7 of the groove and their face bottom or rear 21 is applied against the bottom 20 of the groove. It is desirable that the convex convex faces 10 and 21 of the abrasive element 8 are in contact with the concave curved faces 7 and 20 of the groove 6, over their entire surface.
• the anterior face 9 of the abrasive elements 8 is projecting in front of the anterior face 4 of the groove and its face 11 forms a protruding protrusion in front of the edge 5 of the fin 2 and constitutes the front face of the abrasive element 8.
• abrasive elements 8 rest on the bottom 20 of the grooves 6, to which they are secured by means of a solder.
• Their convex convex posterior face 10 can optionally be brazed to the corresponding conca
• the rear face 21 of the abrasive element 8 is intended to be applied against the bottom 20 of the groove. It is made of a material with high resistance to wear but not having an abrasive action on the rock. This material is generally a matrix of impregnated material which, in contact with the rock, gradually wears out to form a polished surface. She can be a plate attached to the abrasive element. It is alternatively preferred that the matrix of impregnated material be an integral part of the abrasive element 8, of which it constitutes the whole of the convex rear part 21.
• FIGS. 3 to 6 show four particular profiles of the curved posterior face 10 of the abrasive elements 8.
• the rear face 10 of the abrasive element of FIG. 3 has a circular cylindrical portion 12 which is connected to the flat lateral faces 13 two projections 14. These two projections 14 are the result of the tooling used for compacting the diamond powder during the manufacture of the abrasive element. More particularly, the compacting has been carried out in a tubular press by means of a piston whose concave curved profile comprises a flat annular edge at its periphery.
• the rear face 10 of the abrasive element 8 has a flat face 15, which is connected to the two flat faces 13 by two curved faces 16 and the two steps 14 described above.
• FIGS. 5 and 6 show variants of the embodiment of FIG. 4.
• the curved faces 16 have larger radii of curvature than in FIG. 4, which reduces the importance of the face place 15.
• the posterior face 7 of the grooves 6 must have a profile complementary to that of the posterior face 10 of the abrasive element 8.
• the posterior face 7 of the grooves 6 is generally obtained by machining by means of a milling cutter which is correctly positioned and moved in groove 6.

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• Engineering & Computer Science (AREA)
• Geology (AREA)
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• Mining & Mineral Resources (AREA)
• Physics & Mathematics (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Polishing Bodies And Polishing Tools (AREA)
• Processing Of Stones Or Stones Resemblance Materials (AREA)
• Drilling Tools (AREA)
• Earth Drilling (AREA)

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• 2010
  • 2010-01-05 BE BE2010/0006A patent/BE1019132A3/fr not_active IP Right Cessation
  • 2010-12-31 US US13/520,718 patent/US9194188B2/en not_active Expired - Fee Related
  • 2010-12-31 BR BR112012016529A patent/BR112012016529A2/pt not_active IP Right Cessation
  • 2010-12-31 WO PCT/EP2010/007999 patent/WO2011082821A1/fr active Application Filing
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