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
  • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
  • E21B17/10—Wear protectors; Centralising devices, e.g. stabilisers
  • E21B17/1042—Elastomer protector or centering means
• • 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
  • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
  • E21B17/18—Pipes provided with plural fluid passages
• • 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
  • E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
  • E21B21/12—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor using drilling pipes with plural fluid passages, e.g. closed circulation systems

Definitions

• Drill sting component, wear protection component and cutter head for use in a rock drilling process.
• the invention relates to a drill string component for i- se in a drilling process as defined in the preamble of claim 1.
• the invention further relates to a wear protection component for use with a drill string component as defined in the preamble of claim 7.
• the invention also relates to a cutter head for use with a drill string component as defined in the preamble of claim 14.
• Drilling apparatuses may be used in a number of applications.
• rock drilling apparatuses may be used in tunnelling, underground mining, rock reinforcement, raise boring, and for drilling of blast holes, grout holes and holes for installing rock bolts.
• the drill cuttings have to be moved from the cutting face during the drilling process. Depending on drilling method, this may be accomplished in a number of ways. For example, one common method is to flush the drill cuttings away from the hole with a suitable med-Lum.
• the drill cuttings may for example be flushed out of the htole by a flushing medium that is fed through a tube in, preferably the center of, a drill string connecting a drill tool to a drill rig, and discharged near the drill tool in order to also cool the drill tool.
• the flushing medium then flushes the drill cuttings through and out of the hole.
• Another method for removing drill cuttings is to evacuate the drill cuttings through the drill string, for example by supplying the cooling and/or flushing medium to the cutting area in the space between the drill string and rock wall so that the drill cuttings then are flushed through a channel in the drill string.
• This flushing medium is usually air in surface drilling apparatuses and water in underground working apparatuses .
• watermist with or without a chemical additive or foam may be used in both types of apparatuses .
• a problem that is encountered during rock drilling is that the drill string, and in particular expensive drill string components, have to be replaced.
• the drill string component according to the present invention comprises an outer casing and a channel for evacuating drill cuttings from a rock cutting surface.
• the channel is constituted by a first tubular member, and at least one portion of the first tubular member, which in operation is subjected to wear from drill cuttings, is, or is provided with, a replaceable wear protection component.
• the first tubular member may be a replaceable tubular wear protection component. This has the advantage that the channel for evacuating drill cuttings may be replaced in a simple manner when the existing channel has been subject to extensive wear.
• the first tubular member may be arranged to receive a second tubular member constituting the replaceable wear component. This has the advantage that an even cheaper component may be used since it does not have to be able to withstand transversal forces due to the support by the outer casing.
• the drill string component may be provided with an annular projection arranged to abut a wear protection component. This has the advantage that the wear protection component may be kept in position in a simple manner.
• the drill string component may be arranged such that a wear protection component can be attached to it by a screw joint reinforcement. This has the advantage that it provides an alternative way to keep the wear protection component in position in a simple manner.
• a wear protection component includes a first surface, which is an area of wear, and means for engagement with corresponding means of the drill string component, such that when it is engaged, the first surface forms at least part of said channel.
• the first and/or second tubular member may be made from a material from the group: plastic such as PVC, metal or a ceramic material.
• Fig. 1 is a section through a drift extending through a rock and a rock drilling apparatus therein for drilling a series of intersecting holes .
• Fig. 2 shows a front view of the rock drilling of fig. 1.
• Fig. 3 shows in a longitudinal section a cutter head and a drill string component according to the present invention.
• Fig. 4 shows in a longitudinal section a drill string component according to the present invention.
• Fig. 5a-5e show alternative embodiments of a drill string component and wear protection component according to the present invention.
• a rock drilling apparatus 1 suitable for use with the present invention.
• the rock drilling apparatus 1 is shown having at its left end a compartment for storing drill string components 2' to be assembled into a drill string.
• a derrick 8 includes assembling means for assembling the drill string components into a drill string getting longer and longer as the drilling process goes on.
• the assembling means may be constituted by a holding wrench.
• FIG. 2 In fig. 2 is shown a front view of the rock drilling apparatus in an ongoing drilling process. As is shown, the apparatus 1 is used to excavate an inclined cylindrical portion of a rock formation .
• the drilling is performed by a reamer 3 with a relatively larger diameter.
• the reamer 3 is mounted together with a pilot bit 4 of a smaller diameter.
• the pilot bit is used to ascertain that the drilling is performed in a desired direction throughout the drilling of the particular hole.
• the reamer 3 is carried by a drill string 2, at present constituted by drill string components 2a, 2b, 2c, where additional drill string components 2d, 2e, etc. (not shown) may be added to the drill string by the assembling device as the drilling process progresses until a hole of desired length has been acquired.
• Each drill string component 2 ' may for example be of 1000 mm length.
• drill cuttings are evacuated through a channel in the drill string.
• the drill cuttings may be evacuated through the channel by the attraction of gravity.
• the evacuation may, however, advantageously be assisted by for example either: i) providing a flushing medium to the drilling area which then flushes the drill cuttings through the channel in the drill string and out of the hole, the flushing medium for example being supplied to the drilling area through a second channel in the drill string or in the space between drill string and rock wall, or ii) connecting the drill string to a suction device 5 via a hose 6 (shown in fig.
• a drill string component 30 according to the present invention, at one end connected to a reamer 31, and at its other end being intended to be connected to another drill string component or, if the drillin ⁇ g process is in its beginning, the rock drill device.
• the actiial rock breaking action is performed by continuously applying pressure onto the drill string so that the pilot bit cutte s 32, and the reamer cutters 33, 34 are continuously pressed against the rock, while simultaneously the drill string is rotated.
• the pilot bit cutters are consti tuted by three conically shaped roller bits with tungste n carbide inserts and each with an axis inclined at an angle re lative to the normal to the axis of the drill string in such a manner that the pilot bit cutters are normal to the drill string when facing the rock.
• the diameter of the roller bits may for example be 9-14 inches.
• the cutters 33, 34 cause annular kerfs, and when the kerfs are deep enough the rock between the kerfs falls off.
• the cutters 45 are provided to make sure that the reamer may be pulled out of the hole backwards towards the machine without getting stuck when the drilling of the hole is finished and the machine is to be moved to another hole.
• the reamer diameter may for example be 500-2000 mm.
• the distance between the pilot bit cutters 32 and the reamer cutters may for example be 500-1000 mm.
• drill cuttings of the pilot bit along with the drill cuttings produced by the reamer are led to a center channel 37 in the drill string via inlets 35 between the reamer cutters along the dashed arrowed line 36.
• the inlets 35 may preferably be covered by wire netting or grating to prevent large pieces from getting stuck in the inlets .
• the drill string component 30 is shown in more detail in fig. 4.
• the center channel 37 is constituted by a tubular member 38, which is a replaceable wear protection component.
• the wear protection component 38 In this way, only the wear protection component 38 is exposed to passing drill cuttings and thus the replaceable wear protection component, and not the actual drill string component, will be subjected to wear from passing drill cuttings.
• the wear protection component In position, the wear protection component will protect the drill string, and in particular the individual drill string component from wear, and after a suitable time, when the wear protection component is worn out, it is replaced by a similar wear protection component. In this way, the lifetime of the drill string component will be extended substantially and a repair of a drill string component by replacement of a wear protection component may be carried out at a considerably lower cost than would be the cost of replacing the entire drill string component .
• the wear protection component 38 is in this embodiment inserted into the drill string component 30 from the leftmost end thereof and is kept in position by a sleeve portion 40 as follows.
• the drill string component 30 and the sleeve portion 40 each comprise a chamfered end, which together with a groove in the wear protection component forms an annular channel 46.
• a steel wire with a diameter substantially corresponding to the diameter of the annular channel 46 is positioned inside the annular channel 46, whereupon the wear protection component 38 is locked in position by securing the sleeve portion 40 to the drill string component by e . g . a number of fasteners such as screws, indicated at 41.
• the wear protection component 38 and sleeve portion 40 may be constituted by for example a metal tube, a PVC tube, a tube made of other plastic or a tube made of a ceramic material.
• the wear protection component 38 and sleeve portion 40 may constitute an integral part or two separate parts. Apart from the above described example, the separate parts may for example be welded together, threaded together, soldered together, glued together or joined with a combination thereof.
• the drill string component includes portions for connecting drill string components to each other, a cutter head or rock drill device. These portions are however not described in detail since this assembly is not part of the present invention.
• the wear protection component 38 is arranged such that there is a free space 42 between the wear protection component and the outer casing 43.
• the free space 42 may for example be used as a second channel to supply the drilling area with a cooling and/or flushing medium as indicated by solid arrows 29 in fig. 3, in which the cooling and/or flushing medium is let out in the pilot bit.
• a sealing 44 is used to prevent leakage of the cooling and/or flushing medium into the channel for evacuating drill cuttings .
• the flushing and cooling medium may for example be constituted by air, water or watermist with or without a chemical additive or foam depending of what is suitable for the particular application.
• the whole tubular member 38 is replaceable. It is, however, also possible to have a tubular member 38 constituting an integral part of the drill string component and a thinner wear protection component that is inserted into the integrated tubular member. In this way, an even cheaper replacement component may be used.
• the wear protection component may for example be attached to the drill string component as above or as will be described below in connection with fig. 5.
• wear protection components of adjacent drill string components will substantially abut against each other so as to provide a continuous protection against wear for the drill string components throughout the drill string.
• the channel is defined by the outer casing of the drill string component.
• the wear protection component 51 is in fig. 5a inserted into the drill string 50 from one end thereof and may be kept in place through friction and wear protection components of adjacent drill strings (indicated by broken lines) .
• the drill string component 60 is provided with an annular projection 61 at one end thereof so as to prevent movement of the wear protection component 62 relative to the drill string component 60.
• the wear protection component 62 may in one end be provided with a shoulder 63 as shown.
• the wear protection component may be provided with a socket 64 as shown in fig. 5c to protect the annular projection 61.
• the socket 64 partly covers the wear protection component of the drill string component next to the left so that there is a continuous protection throughout the drill string.
• the drill string component 70 is provided with an annular projection 71 more towards the drill tool end of the drill string component, and the wear protection component is provided with a socket 72 and a projecting portion 73 arranged to fit into a connecting drill string component. In this way, removal of the wear protection component when it is to be replaced is facilitated.
• the socket partly covers the wear protection component of the drill string component next to the left.
• a wear protection component that covers substantially all of the drill string component it is possible to use a wear protection component that only protect one or more portions of it. These portions may be particularly exposed portions. This is illustrated in fig. 5e where only end portions of the drill string component are covered by a wear protection component. This may be advantageous in order to for example protect those portions of the drill string component that is used to connect to other drill string components.
• the wear protection component is held in position by respective annular projections 82 on the two drill string components it is arranged to protect. It is, of course, possible to have a wear protection component in each end of the drill string component, or one or more wear protection components in between as an alternative to, or in addition to the above described.
• the wear protection component does not have to be able to withstand transversal forces since it is supported by the outer casing and thus can be produced by a less expensive material .
• the cutter head may comprise one or more channels to lead the drill cuttings to a channel in the drill string. These channels in the cutter head may be covered by suitably shaped wear protection components which are inserted into the channels and fixed to the cutter head. Accordingly, wear on the cutter head caused by drill cuttings may be limited and by replacing wear protection components of the cutter head the lifetime thereof may be substantially prolonged.
• the present invention has been described in connection with a particular rock drilling apparatus, it is to be understood that the present invention is suitable for use in connection with any rock drilling apparatus where the drill string is used for evacuation of drill cuttings, in particular rock drill apparatuses used for box hole/blind hole drilling in for example a tunnel, or rock drill apparatuses used for drilling in hazardous or unhealthy minerals.
• the drill cuttings have been evacuated via a channel centrally located in the drill string components. It is to be understood however, that also other configurations may be used.
• the drill cuttings may be evacuated via a non-centrally located channel or two or more channels. Each of these channels may of course be protected by a wear protection component.
• channel and wear protection component have been described as having a circular cross section.
• the cross section may however be square, elliptical or of any other suitable geometrical shape.
• Drill string component for use in a rock drilling process, wherein the drilling is performed by a drill tool connected to a drill string including plural drill string components, the drill string component comprising an outer casing and a channel for evacuating drill cuttings from a rock cutting surface, characterised in that the channel is constituted by a first tubular member and that at least one portion of the first tubular member, which in operation is subjected to wear from drill cuttings is, or is provided with, a replaceable wear protection component.
• Drill string component according to claim 1 characterised in that that the first tubular member is a replaceable tubular wear protection component.
• Drill string component according to claim 1 characterised in that that the first tubular member is arranged to receive a second tubular member constituting the replaceable wear component.

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• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Geology (AREA)
• Mining & Mineral Resources (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Earth Drilling (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (6)

Citations (5)

• 2004
  • 2004-02-20 SE SE0400402A patent/SE528766C2/sv not_active IP Right Cessation
• 2005
  • 2005-01-31 WO PCT/SE2005/000111 patent/WO2005080743A1/en not_active Application Discontinuation
  • 2005-01-31 AU AU2005215570A patent/AU2005215570A1/en not_active Abandoned
  • 2005-01-31 EP EP05711018A patent/EP1716312A1/en not_active Withdrawn
  • 2005-01-31 ZA ZA200606228A patent/ZA200606228B/xx unknown
  • 2005-01-31 CA CA002553606A patent/CA2553606A1/en not_active Abandoned

Patent Citations (5)

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