EP2029851B1 - Mud shaft for the drill string of a rotary percussive drilling rig, impact stack for a mud shaft and rotary percussive drilling rig - Google Patents

Mud shaft for the drill string of a rotary percussive drilling rig, impact stack for a mud shaft and rotary percussive drilling rig Download PDF

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Publication number
EP2029851B1
EP2029851B1 EP07720159.8A EP07720159A EP2029851B1 EP 2029851 B1 EP2029851 B1 EP 2029851B1 EP 07720159 A EP07720159 A EP 07720159A EP 2029851 B1 EP2029851 B1 EP 2029851B1
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EP
European Patent Office
Prior art keywords
hammer
percussive
drill pipe
disks
hole
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EP07720159.8A
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German (de)
French (fr)
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EP2029851A1 (en
Inventor
Marcel Dell'anna
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BTD BOHRTECHNIK AG
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Btd Bohrtechnik AG
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    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B6/00—Drives for drilling with combined rotary and percussive action
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B4/00—Drives for drilling, used in the borehole
    • E21B4/20—Drives for drilling, used in the borehole combined with surface drive

Definitions

  • the invention relates to a flushing shaft for the drill string of a rotary impact drilling according to the preamble of claim 1.
  • the invention also relates to a baffle package for a flushing shaft and equipped with a flushing shaft rotary impact drilling.
  • the two drill heads are acted upon by a hydraulic hammer arranged outside the borehole.
  • the axial strokes of the hydraulic external hammer are transmitted via a coaxial drill string arrangement on the two rotary driven drill heads.
  • the drilling capacity of such rotary impact drills are limited. In particular, with deep holes of 200 m and more, the drilling capacity of these rigs is not particularly high, because of the outside of the borehole hydraulically applied impact energy only a part arrives at the two drill heads and is also divided into the central drill bit and the surrounding drill bit.
  • rotary impact drills provides that the central chisel in addition to the rotary drive acted upon by a pneumatically operated down-the-hole hammer while the outer cylindrical drill bit is rotated.
  • the advantage of the Imlochhammers is that the impact introduction is always carried out at the same axial distance from the central drill bit and dependent on the hole depth transmission paths omitted.
  • Rotary impact drills with downhole hammers are mainly used in medium-hard to very hard rock and already have acceptable drilling speeds.
  • an overburden drilling apparatus which has a downhole hammer and an outer hammer which impacts the outer linkage with impacts.
  • the internal linkage with the in-hole hammer is decoupled from the blows of the external hammer by a damping element, in order to avoid damaging the through-hole hammer by these blows.
  • a damping element is an elastic disc or a pneumatic damping member, which may be designed as a shock absorber proposed.
  • the pneumatic damping member is relatively expensive, requires a complicated construction and is therefore not practical.
  • An elastic disk as a damping member also proves to be impractical, since it can heat up by the impact effect that it liquefies. As a result, the damping effect is lost in a relatively short time. Without damping, however, it can relatively soon damage the Imlochhammers or the drill pipe.
  • a flushing shaft for the drill string of a rotary impact drilling machine which has the features mentioned in the characterizing portion of claim 1.
  • the tasks are further solved by a baffle package for a flushing shaft for the drill pipe of a rotary hammer drill with the cited in the characterizing part of the corresponding claim Features. Further developments and / or advantageous embodiments of the invention are the subject of the respective dependent claims.
  • the inventive flushing shaft is designed for installation in an outer drill pipe of a rotary impact drilling with a superimposed impact.
  • the rotary impact drill has a arranged on an inner drill string central drill bit, which is rotationally driven and is acted upon by a punch hammer with axial blows, and a rotationally driven and acted upon by an external hammer with axial strokes drill bit, the so on the inner drill string receiving outer drill string is arranged to lag behind the central drill bit.
  • the flushing shaft has a cylindrical body, at the axial end of standardized connection threads for connection to the outer drill string or with the outer hammer are provided, and at its in the assembled state the downhole hammer facing end portion has a blind hole-like recording with a supply hole for the Imlochhammer communicates.
  • a baffle package is arranged, which comprises a number of annular steel discs and, preferably vulcanized, elastomer discs. In this case, an elastomer disc is always arranged between two steel discs.
  • the flushing shaft according to the invention serves to decouple the blows generated by the impact systems (in-hole hammer or external hammer).
  • the flushing shaft with the baffle package is arranged behind the perforated hammer with respect to a drilling direction and is connected to the outer drill string.
  • the flushing shaft according to the invention is a modular component which can be installed in the rotary impact drilling rig if required and desired. This preserves flexibility for the user. If he wants to operate the rotary hammer drill as a conventional, known from the prior art system, for example, has only one, acting jointly on the central drill bit and drill bit outer hammer or equipped only with a hole hammer, instead of the inventive flushing wave with baffle a conventional flushing shaft are installed in the drill pipe.
  • the inventive flushing wave with baffle is based on the drilling direction behind the Imlochhammer inserted into the outer drill pipe simply.
  • the baffle package is a composite of steel discs and elastomer discs clamped in the receptacle of the flushing shaft.
  • the elastomeric disks are always arranged between two steel discs.
  • the steel disks serve to stiffen the impact package mechanically and ensure a good distribution of the impact energy over the entire surface of an elastomer disk.
  • they serve to dissipate the heat occurring in the damping of shocks.
  • the flushing shaft is cylindrical and has at its two end portions connecting thread for the coupling to the outer drill pipe.
  • the connecting threads can be standardized internal and / or external threads, so that the intermediate piece can be built into the drill string in a modular manner.
  • the axially elastically deformable baffle package is housed in a receptacle.
  • the elastically deformable impact package is used to decouple introduced by the two impact systems in the inner and the outer drill pipe axial shocks.
  • the receptacle for the baffle package is disposed on the end of the purging shaft facing the Imlochhammer and communicates with a supply hole for the Imlochhammer in connection.
  • a flushing ring arranged in the region of the supply bore serves to introduce the flushing medium, for example a mixture of compressed air and water, and to supply the in-hole hammer with compressed air.
  • the supply bore discharges into the receptacle for the baffle package in such a way that, during operation, an air cushion can form on the side remote from the downhole hammer, which provides for an additional decoupling of the axial beats of the two beater systems.
  • the elastomeric disks of the impact package arranged in the receptacle of the flushing shaft have a slightly smaller outside diameter than the steel disks. This ensures that the elastomer discs can expand elastically radially unimpeded in an axial compression.
  • the baffle package advantageously has a central passage opening for the unhindered passage of the flushing medium.
  • the steel discs are used for mechanical stiffening of the baffle package. The actual damping and decoupling function, however, is perceived by the elastomeric discs.
  • the axial height of the elastomer discs is about the simple to about two and a half times the axial height of the steel discs.
  • the baffle package advantageously has an overall axial height of about 35 mm to about 105 mm.
  • the baffle has advantageously the central passage of the annular steel and elastomer discs passing through, provided with a central bore sleeve whose foot is supported at the bottom of the recording in the flushing.
  • the bushing closes off the baffle package radially inwards and ensures a further improved removal of the heat which occurs during the compression of the elastomeric disks.
  • the bush limits the expansion of the elastomeric disks under load.
  • the sleeve of the baffle preferably also made of steel.
  • a rotary impact drilling system with a central drill bit arranged on an inner drill string which is rotationally driven and acted upon by a downhole hammer, and a drill bit which is rotationally driven and subjected to axial impacts by its own outer hammer and is thus arranged on an outer drill string receiving the inner drill string, that it lags against the central drill bit, is for decoupling of the Imlochhammer and the axial hammer generated by the outer hammer with a clamped baffle package, which consists of a composite of steel discs and elastomer discs equipped.
  • the baffle package is arranged in an inventive trained Spülwelle.
  • the rotary impact drilling rig is equipped with two impact systems.
  • a down hole hammer acts on the central drill bit.
  • the leading central drill bit has to do most of the mining work.
  • the Imlochhammer offers optimum support for the removal work.
  • the impact energy transferred from the downhole hammer to the central drill bit is not dependent on the drill hole depth or the length of the inner drill string. Rather, the axial impacts of the Imlochhammers are always introduced at the same distance from the drill hole on the inner drill string in the central drill bit.
  • the drill bit following the central drill bit is subjected to axial impacts by the outer hammer via the outer drill string.
  • the axial impacts of the additional impact system are solely to aid in the mining work of the drill bit connected to the outer drill string.
  • the impact energy of the additional impact system does not have to be distributed to the drill bit and the central drill bit as in the case of the rotary impact drills known from the prior art. Rather, the baffle serves to decouple the axial shocks generated by the outer hammer of the forces acting on the central Bohrmeissel axial blows of the Imlochhammers.
  • the impact energies of the two impact systems are independent of each other on the particular application and surface tunable. As a result, a very high drilling performance can be achieved.
  • the decoupling of the impact systems according to the invention significantly improves the service life of the rotary impact drilling rig. Fractures of the drill string within the wellbore, for example, in threaded areas of the modular drill pipe can thereby be largely prevented.
  • the arrangement of the baffle in a flushing wave increases the modularity of the system, which can be operated without this flushing wave if necessary. This preserves flexibility for the user. If he the rotary hammer drill as a conventional, known from the prior art Plant want to operate, for example, only one, acting jointly on the central drill bit and drill bit outer hammer or is equipped only with a downhole hammer, instead of the inventive flushing wave with baffle a conventional flushing wave can be installed in the drill pipe. If the rotary hammer drill, however, again work with two independently acting impact systems, simply the invention according to the flushing wave with the baffle package based on the drilling direction behind the Imlochhammer inserted into the outer drill pipe.
  • the outer hammer is preferably operated hydraulically.
  • the hydraulic drive has been tested and can be derived, for example, from the hydraulic rotary drive of the drill string.
  • the downhole hammer is pneumatically operated with advantage.
  • the supply of the pneumatic Imlochhammers with compressed air is generally easier to accomplish even with large drilling depths or drill lengths as a hydraulic supply. Leaks in the pneumatic supply lines are far less problematic than those in hydraulic systems.
  • a clamped impact package which is composed of a clamped composite of annular steel discs and elastomer discs, wherein in each case an elastomer disc between two steel discs is arranged.
  • the blows generated by the downhole hammer and delivered to the central drill bit and the hammer generated by the external hammer and transferred to the drill bit are decoupled from each other by the baffle package.
  • the baffle serves on the one hand for damping the Axialdite and on the other hand to dissipate the heat occurring in the damping.
  • the axial blows transmitted to the drill bit are preferably generated by a hydraulically operated external hammer and introduced into the outer drill pipe. This allows a simple adjustment of the single impact energy.
  • the axial impacts transmitted to the central drill bit are advantageously generated by a pneumatically driven downhole hammer.
  • the pneumatic operation The in-hole hammer is easier to accomplish than, for example, a hydraulic operation. Leakage of the pneumatic within the wellbore is less critical than in hydraulic operation.
  • the schematic representation in Fig. 1 shows an embodiment of the present invention trained rotary impact drilling, which is provided overall with the reference numeral 1.
  • the rotary impact drilling rig 1 has an inner drill pipe 2 and an outer drill pipe 5 receiving the inner drill pipe 2.
  • the front end of the inner drill pipe 2 bears with respect to a drilling direction D a central drill bit 3, for example a pin drill bit with diamond and / or hard metal pins.
  • a central drill bit 3 for example a pin drill bit with diamond and / or hard metal pins.
  • an annular drill bit 6 is mounted with hard metal bodies or the like.
  • the inner and the outer drill pipe 2, 5 are rotationally driven via a preferably hydraulic drive 15.
  • the central drill bit 3 connected to the inner drill string 2 precedes the drill bit 6 mounted on the outer drill rod 5 and, during operation, performs the greatest work of dismantling.
  • the inner drill pipe 2 has immediately behind the central drill bit 3 a so-called in-hole hammer 4, the pneumatic operated is.
  • the Imlochhammer 4 is supplied via a central bore 10 with the required compressed air and applied in operation the central drill bit 3 with axial blows.
  • the compressed air also forms the flushing medium which is required for the removal of the drill bit which has been comminuted by the drill heads at the drillhole.
  • the flushing medium is a mixture of compressed air and water.
  • the drill pipe 2, 5 is connected via an ejection bell 13 and a flushing shaft 8 with the hydraulic rotary drive 15.
  • the shredded cuttings transported by the flushing medium from the wellbore depth are ejected.
  • the flushing shaft 8 is supplied via a flushing ring 11 mounted around it with a connection 12 with the flushing medium.
  • the ejection bell 13 and all subsequent components are outside the borehole.
  • the adjoining the ejection bell 13 in the direction of drilling D sections of the drill string 2, 5 are located within the borehole.
  • the drill string 2, 5 is modular and extendable arbitrarily what is in Fig. 1 is indicated by interrupt lines.
  • the rotary impact drilling system according to the invention is equipped with an additional impact system 7, which exerts axial impacts on the drill pipe during operation.
  • Decoupling means ensure that the axial impacts of the additional impact system 7 are transmitted only to the outer drill pipe 5.
  • the decoupling means consist of a specially designed flushing shaft 8 with an axially elastically deformable impact package 9.
  • the axial impacts of the additional impact system 7 are preferably generated hydraulically. For example, it is a well-known from the prior art external hammer whose hydraulic operation is derived from the hydraulic drive 15 for the rotational movement of the drill string 2, 5.
  • the axial impacts of the additional impact system 7 serve exclusively to support the dismantling work of the drill bit 6 mounted on the outer drill pipe 5.
  • the impact energy of the additional impact system 7, which is preferably hydraulically operated, does not have to be on the drill bit 6, as is the case with the rotary impact drilling systems known from the prior art and the central drill bit 3 are distributed. Rather, the provided decoupling means 8, 9 ensure that the force exerted by the additional impact system 7 Axial impacts are decoupled from acting on the central drill bit 3 axial blows of the Imlochhammers 4.
  • the impact energy transferred from the downhole hammer 4 to the central drill bit 3 is not dependent on the drill hole depth or the length of the inner drill pipe 2. Rather, the axial impacts of the in-hole hammer 4 are always introduced at the same distance from the drill hole into the central drill bit 3.
  • the impact energies of the two impact systems 4, 7 are independent of each other on the particular application and background tunable. As a result, a very high drilling performance can be achieved. Due to the decoupling of the impact systems 4, 7, the service life of the rotary impact drilling rig is significantly improved. Fractions of the drill string 2, 5 within the wellbore, for example in threaded areas of the modular drill pipe 2, 7, can be largely prevented.
  • FIG. 2 and 3 Details of a rotary hammer drill according to the invention are shown.
  • the illustrated components bear for better understanding the same reference numerals as the corresponding components in the overview in Fig. 1 Even if they may be formed differently in individual, not essential to the invention features, such as outer diameter.
  • Fig. 2 and 3 are an inventive flushing shaft 8 with a baffle package 9 and an ejection bell 13 with a balance bar 14 in an extended state ( Fig.2 ) and in the assembled state ( Fig. 3 ).
  • the flushing shaft 8 has an overall cylindrical body, at the two axial end portions standardized connection threads 81, 82 are provided for connection to the outer drill pipe 5 and with the additional impact system 7.
  • the additional impact system facing the end portion has to a blind hole with an internal thread.
  • the pointing in the drilling direction end portion is provided with an external thread 82.
  • the end region of the flushing shaft 8 facing the through-hole hammer in the assembled state has a blind-hole-like receptacle 83.
  • the receptacle 83 is in communication with a supply bore 84 extending from the bottom 85 of the Recording to the periphery of the flushing shaft 8 extends.
  • the in Fig. 1 illustrated flushing ring surrounds the flushing shaft in the region of the mouth and ensures the supply of the flushing medium, for example a mixture of compressed air and water, through the supply hole 84 in the central channel of the inner drill string.
  • the aggregate provided with the reference numeral 9 baffle package is inserted into the receptacle 83. It consists of a sequence of annular steel and preferably vulcanized elastomeric disks 91 and 92, respectively. Each elastomeric disk 92 is disposed between two steel disks 91. The two outermost discs of the baffle 9 are steel discs 91.
  • the baffle has a central passage 93 which receives a sleeve 94.
  • the sleeve 94 protrudes from a foot part 95, which is supported in the assembled state at the bottom 85 of the receptacle 83.
  • the sleeve 94 is provided with a central bore 96.
  • the flushing shaft 8 can be screwed with its end region provided with the external thread 82 with an end region of the ejection bell 13 that is correspondingly provided with an internal thread 131.
  • the second end region of the ejection bell 13 has a connection region, for example, provided with an external thread 132 for connection to the outer drill pipe.
  • a balance bar 14 is mounted, which is equipped with a connection portion 141 to the inner drill string.
  • the opposite head-like extended end portion 142 of the balance bar 14 projects in the assembled state into the receptacle 83 of the flushing shaft 8.
  • the balancing bar 14 has following the head-like end portion 142 has a portion 143 with a polygonal cross section.
  • the balance bar 14 is formed octagonal in this section 143.
  • the ejection bell 13 has inside a corresponding region 133, which is also polygonal, for example, octagonal, is formed.
  • the cooperating surfaces on the polygonal section 143 of the balance bar 14 and on the polygonal section 133 of the ejector bell 13 serve to transmit torque from the outer drill pipe to the inner drill pipe.
  • Fig. 3 shows the assembled with the ejection bell 13 Spülwelle 8.
  • the baffle package 9 is housed in the receptacle 83 and held between the base 85 of the receptacle 83 and the head-like end portion 142 of the balance bar 14.
  • the thus clamped impact package 9 prevents axial shocks of the outer hammer 7, which are introduced via the flushing shaft 8, are transmitted to the balance bar 14 and the inner drill pipe.
  • the axial impacts generated by the outer hammer are thus transmitted only via the outer drill pipe.
  • the baffle package also prevents blows from the pneumatically operated punching unit from being transmitted to the outer drill pipe via the inner drill string.
  • the baffle package thus ensures a largely complete decoupling of the two striking mechanisms.
  • the decoupling is further supported by the fact that the supply bore 84 at the bottom of the receptacle 83 opens into the flushing shaft 8. Because of the high pressure with which the flushing medium is fed, an air cushion forms during operation between the base 85 of the receptacle 83 and the baffle package, which ensures an additional decoupling of the beating systems.
  • Fig. 4 schematically shows the baffle package 9. It consists of a sequence of annular steel discs 91 and elastomeric discs 92.
  • the outer discs of the baffle package 9 are steel discs.
  • the elastomeric disks 92 have a thickness r, which is about the simple to about two and a half times the thickness t of the steel disks 91.
  • the overall axial height h of the baffle package is about 35 mm to about 105 mm.
  • the elastomeric disks 92 have an outer diameter which is smaller than that of the steel disks 91. As a result, they can freely expand radially during the axial compression.
  • the elastomeric discs Due to the fully clamped arrangement of the elastomer discs in the recording of the Rinsing wave used impact package, the elastomeric discs can only deform controlled in the impact damping. The heat dissipation through the steel discs ensures that the elastomer discs are not transferred in a flowable state.
  • the invention proposes a rotary impact drilling machine with two independent, decoupled striking mechanisms and components essential to the invention.
  • the operation of such a rotary impact drilling machine allows higher drilling speeds with longer service lives of the components. Because of the modular structure of the system and the components and existing rotary percussion drilling without major difficulties according to the invention are convertible.

Description

Die Erfindung betrifft eine Spülwelle für das Bohrgestänge einer Drehschlagbohranlage gemäss dem Oberbegriff des Patentanspruchs 1. Die Erfindung betrifft auch ein Prallpaket für eine Spülwelle und eine mit einer Spülwelle ausgestattete Drehschlagbohranlage.The invention relates to a flushing shaft for the drill string of a rotary impact drilling according to the preamble of claim 1. The invention also relates to a baffle package for a flushing shaft and equipped with a flushing shaft rotary impact drilling.

Im Tiefbau und im Tunnelbau werden Bohranlagen eingesetzt, die eine möglichst hohe Bohrleistung erzielen. Dabei kommen Drehbohranlagen mit Bohrschnecken, oder Drehschlagbohranlagen mit Aussenhammer oder mit Innenhammer oder auch Doppelkopfbohranlagen zum Einsatz. Die meisten dieser Tiefbohranlagen weisen einen zentralen Bohrmeissel auf, der gegenüber einer den Bohrmeissel umgebenden zylindrischen Bohrkrone vorauseilt. Der zentrale Bohrmeissel und die Bohrkrone sind drehangetrieben. Die Drehrichtung kann gleich oder gegenläufig (Doppelkopfbohranlagen) sein. Das von den beiden Bohrköpfen zerkleinerte Bohrgut wird durch ein im Gestänge in die Tiefe gepumptes Spülmedium, beispielsweise Luft, Wasser, Suspensionen, etc., aufgenommen und zur Oberfläche gebracht. Eine Variante der aus dem Stand der Technik bekannten Bohranlagen sieht vor, dass zur Verbesserung der Abbauleistung . die beiden Bohrköpfe von einem ausserhalb des Bohrlochs angeordneten Hydaulikhammer beaufschlagt sind. Die axialen Schläge des hydraulischen Aussenhammers werden über eine koaxiale Bohrgestängeanordnung auf die beiden drehangetriebenen Bohrköpfe übertragen. Die Bohrleistung derartiger Drehschlagbohranlagen sind beschränkt. Insbesondere bei tiefen Bohrungen von 200 m und mehr ist die Bohrleistung dieser Bohranlagen nicht besonders hoch, da von der ausserhalb des Bohrlochs hydraulisch aufgebrachten Schlagenergie nur ein Teil an den beiden Bohrköpfen ankommt und überdies auf den zentralen Bohrmeissel und die umgebende Bohrkrone aufgeteilt wird.In civil engineering and tunneling drilling rigs are used, which achieve the highest possible drilling performance. It uses rotary drilling rigs with augers, or rotary impact drills with external hammer or with internal hammer or double-head drilling rigs. Most of these deep drilling rigs have a central drill bit that precedes a cylindrical drill bit surrounding the drill bit. The central drill bit and the drill bit are rotationally driven. The direction of rotation can be the same or opposite (double-head drilling machines). The cuttings shredded by the two drill heads are picked up and brought to the surface by a flushing medium, for example air, water, suspensions, etc., pumped into the drill string in the depth. A variant of the known from the prior art rigs provides that to improve the degradation performance. the two drill heads are acted upon by a hydraulic hammer arranged outside the borehole. The axial strokes of the hydraulic external hammer are transmitted via a coaxial drill string arrangement on the two rotary driven drill heads. The drilling capacity of such rotary impact drills are limited. In particular, with deep holes of 200 m and more, the drilling capacity of these rigs is not particularly high, because of the outside of the borehole hydraulically applied impact energy only a part arrives at the two drill heads and is also divided into the central drill bit and the surrounding drill bit.

Eine andere Variante von Drehschlagbohranlagen sieht vor, dass der zentrale Meissel zusätzlich zum Drehantrieb von einem pneumatisch betriebenen Imlochhammer beaufschlagt wird, während die äussere zylindrische Bohrkrone drehangetrieben ist. Der Vorteil des Imlochhammers besteht darin, dass die Schlageinleitung immer im selben axialen Abstand vom zentralen Bohrmeissel erfolgt und von der Bohrlochtiefe abhängige Übertragungswege entfallen. Drehschlagbohranlagen mit Imlochhammer kommen vor allem in mittelhartem bis sehr hartem Gestein zur Anwendung und weisen bereits akzeptable Bohrgeschwindigkeiten auf.Another variant of rotary impact drills provides that the central chisel in addition to the rotary drive acted upon by a pneumatically operated down-the-hole hammer while the outer cylindrical drill bit is rotated. The advantage of the Imlochhammers is that the impact introduction is always carried out at the same axial distance from the central drill bit and dependent on the hole depth transmission paths omitted. Rotary impact drills with downhole hammers are mainly used in medium-hard to very hard rock and already have acceptable drilling speeds.

Aus der WO 93/09328 ist beispielsweise eine Überlagerungsbohrvorrichtung bekannt, die einen Imlochhammer und einen Aussenhammer aufweist, der das Aussengestänge mit Schlägen beaufschlagt. Das Innengestänge mit dem Imlochhammer ist durch ein Dämpfungselement von den Schlägen des Aussenhammers entkoppelt, um ein Beschädigung des Imlochhammers durch diese Schläge zu vermeiden. Als Dämpfungselement ist eine elastische Scheibe oder ein pneumatisches Dämpfungsorgan, welches wie ein Stossdämpfer ausgebildet sein kann, vorgeschlagen. Das pneumatische Dämpfungsorgan ist relativ aufwendig, bedingt eine komplizierte Konstruktion und ist daher wenig praxistauglich. Eine elastische Scheibe als Dämpfungsorgan erweist sich ebenfalls als nicht praktikabel, da diese sich durch die Schlageinwirkung soweit erwärmen kann, dass sie verflüssigt. Dadurch geht die Dämpfwirkung in relativ kurzer Zeit verloren. Ohne Dämpfung kann es aber relativ bald zu Beschädigungen des Imlochhammers oder des Bohrgestänges kommen.From the WO 93/09328 For example, an overburden drilling apparatus is known which has a downhole hammer and an outer hammer which impacts the outer linkage with impacts. The internal linkage with the in-hole hammer is decoupled from the blows of the external hammer by a damping element, in order to avoid damaging the through-hole hammer by these blows. As a damping element is an elastic disc or a pneumatic damping member, which may be designed as a shock absorber proposed. The pneumatic damping member is relatively expensive, requires a complicated construction and is therefore not practical. An elastic disk as a damping member also proves to be impractical, since it can heat up by the impact effect that it liquefies. As a result, the damping effect is lost in a relatively short time. Without damping, however, it can relatively soon damage the Imlochhammers or the drill pipe.

Das Dokument US 4,257,245 offenbart in Figur 6 ein Prallpaket für ein Bohrgestänge mit Elastomerscheiben 64 und Metallscheiben 67. Aufgabe der vorliegenden Erfindung ist es daher, Drehschlagbohranlagen mit Überlagerungsbohrvorrichtungen dahingehend zu verbessern, dass sie höhere Standzeiten aufweisen und die Bohrleistungen verbessert sind. Insbesondere sollen Brüche des innerhalb des Bohrlochs angeordneten Bohrgestänges oder Beschädigungen des Imlochhammers vermieden werden können.The document US 4,257,245 discloses in Figure 6 a baffle package for a drill string with elastomeric disks 64 and metal disks 67. It is therefore an object of the present invention to improve rotary impact drilling rigs with overburden drilling apparatuses in that they have longer tool life and improved drilling performance. In particular, fractures of the drill pipe arranged inside the borehole or damage to the downhole hammer should be avoided.

Zur Lösung dieser Aufgaben ist eine Spülwelle für das Bohrgestänge einer Drehschlagbohranlage vorgeschlagen, welche die im kennzeichnenden Abschnitt des Patentanspruchs 1 angeführten Merkmale aufweist. Die Aufgaben werden weiters gelöst durch ein Prallpaket für eine Spülwelle für das Bohrgestänge einer Drehschlagbohranlage mit den im Kennzeichen des entsprechenden Anspruchs angeführten Merkmalen. Weiterbildungen und/oder vorteilhafte Ausführungsvarianten der Erfindung sind Gegenstand der jeweiligen abhängigen Patentansprüche.To solve these problems, a flushing shaft for the drill string of a rotary impact drilling machine is proposed which has the features mentioned in the characterizing portion of claim 1. The tasks are further solved by a baffle package for a flushing shaft for the drill pipe of a rotary hammer drill with the cited in the characterizing part of the corresponding claim Features. Further developments and / or advantageous embodiments of the invention are the subject of the respective dependent claims.

Die erfindungsgemässe Spülwelle ist für den Einbau in ein äusseres Bohrgestänge einer Drehschlagbohranlage mit einem Überlagerungsschlagwerk ausgebildet. Dabei weist die Drehschlagbohranlage einen an einem inneren Bohrgestänge angeordneten zentralen Bohrmeissel auf, der drehangetrieben ist und von einem Imlochhammer mit axialen Schlägen beaufschlagt wird, sowie eine drehangetriebene und von einem Aussenhammer mit axialen Schlägen beaufschlagte Bohrkrone, die derart an dem das innere Bohrgestänge aufnehmenden äusseren Bohrgestänge angeordnet ist, dass sie gegenüber dem zentralen Bohrmeissel nacheilt. Die Spülwelle weist einen zylindrischen Körper auf, an dessen axialen Endbereichen genormte Anschlussgewinde für die Verbindung mit dem äusseren Bohrgestänge bzw. mit dem Aussenhammer vorgesehen sind, und der an seinem im montierten Zustand dem Imlochhammer zugewandten Endbereich eine sacklochartige Aufnahme aufweist, die mit einer Versorgungsbohrung für den Imlochhammer in Verbindung steht. In der Aufnahme ist ein Prallpaket angeordnet, das eine Anzahl kreisringförmiger Stahlscheiben und, vorzugsweise vulkanisierter, Elastomerscheiben umfasst. Dabei ist immer jeweils eine Elastomerscheibe zwischen zwei Stahlscheiben angeordnet.The inventive flushing shaft is designed for installation in an outer drill pipe of a rotary impact drilling with a superimposed impact. In this case, the rotary impact drill has a arranged on an inner drill string central drill bit, which is rotationally driven and is acted upon by a punch hammer with axial blows, and a rotationally driven and acted upon by an external hammer with axial strokes drill bit, the so on the inner drill string receiving outer drill string is arranged to lag behind the central drill bit. The flushing shaft has a cylindrical body, at the axial end of standardized connection threads for connection to the outer drill string or with the outer hammer are provided, and at its in the assembled state the downhole hammer facing end portion has a blind hole-like recording with a supply hole for the Imlochhammer communicates. In the receptacle, a baffle package is arranged, which comprises a number of annular steel discs and, preferably vulcanized, elastomer discs. In this case, an elastomer disc is always arranged between two steel discs.

Die erfindungsgemässe Spülwelle dient zur Entkopplung der von den Schlagsystemen (Imlochhammer bzw. Aussenhammer) erzeugten Schläge. Die Spülwelle mit dem Prallpaket ist bezogen auf eine Bohrrichtung hinter dem Imlochhammer angeordnet und mit dem äusseren Bohrgestänge verbunden ist. Die erfindungsgemässe Spülwelle ist ein modulares Bauteil, das bei Bedarf und Wunsch in die Drehschlagbohranlage einbaubar ist. Dadurch bleibt für den Anwender die Flexibilität erhalten. Falls er die Drehschlagbohranlage als eine konventionelle, aus dem Stand der Technik bekannte Anlage betreiben will, die beispielsweise nur einen, gemeinsam auf den zentralen Bohrmeissel und die Bohrkrone wirkenden Aussenhammer aufweist oder nur mit einem Imlochhammer ausgestattet ist, kann an Stelle der erfindungsgemässen Spülwelle mit Prallpaket eine konventionelle Spülwelle in das Bohrgestänge eingebaut werden. Soll die Drehschlagbohranlage mit zwei unabhängig voneinander wirkenden Schlagsystemen arbeiten, wird einfach die erfindungsgemässe Spülwelle mit Prallpaket bezogen auf die Bohrrichtung hinter dem Imlochhammer in das äussere Bohrgestänge eingefügt. Bei dem Prallpaket handelt es sich um einen in der Aufnahme der Spülwelle eingespannten Verbund aus Stahlscheiben und Elastomerscheiben. Die Elastomerscheiben sind dabei immer jeweils zwischen zwei Stahlscheiben angeordnet. Die Stahlscheiben dienen einerseits zur mechanischen Versteifung des Prallpakets und gewährleisten eine gute Verteilung der Schlagenergie über die gesamte Fläche einer Elastomerscheibe. Andererseits dienen sie zur Ableitung der bei der Dämpfung der Schläge auftretenden Wärme. Dadurch wird eine übermässige Erhitzung der Elastomerscheiben, die sogar zu einem Fliessen des Materials und zur Zerstörung des Prallpakets führen könnte, zuverlässig verhindert. Durch die eingespannte Anordnung des Prallpakets in der Aufnahme der Spülwelle ist bei der Schlagdämpfung eine kontrollierte Deformation gewährleistet.The flushing shaft according to the invention serves to decouple the blows generated by the impact systems (in-hole hammer or external hammer). The flushing shaft with the baffle package is arranged behind the perforated hammer with respect to a drilling direction and is connected to the outer drill string. The flushing shaft according to the invention is a modular component which can be installed in the rotary impact drilling rig if required and desired. This preserves flexibility for the user. If he wants to operate the rotary hammer drill as a conventional, known from the prior art system, for example, has only one, acting jointly on the central drill bit and drill bit outer hammer or equipped only with a hole hammer, instead of the inventive flushing wave with baffle a conventional flushing shaft are installed in the drill pipe. Should the rotary impact drilling system with two independently acting impact systems work, the inventive flushing wave with baffle is based on the drilling direction behind the Imlochhammer inserted into the outer drill pipe simply. The baffle package is a composite of steel discs and elastomer discs clamped in the receptacle of the flushing shaft. The elastomeric disks are always arranged between two steel discs. On the one hand, the steel disks serve to stiffen the impact package mechanically and ensure a good distribution of the impact energy over the entire surface of an elastomer disk. On the other hand, they serve to dissipate the heat occurring in the damping of shocks. As a result, excessive heating of the elastomeric disks, which could even lead to a flow of the material and to the destruction of the baffle package, reliably prevented. Due to the clamped arrangement of the baffle package in the recording of the flushing wave a controlled deformation is ensured in the impact damping.

Die Spülwelle ist zylindrisch ausgebildet und weist an seinen beiden Endbereichen Anschlussgewinde für die Kopplung an das äussere Bohrgestänge auf. Die Anschlussgewinde können genormte Innen- und/oder Aussengewinde sein, damit das Zwischenstück modulartig in das Bohrgestänge einbaubar ist. Im Inneren der Spülwelle ist in einer Aufnahme das axial elastisch deformierbare Prallpaket untergebracht. Das elastisch deformierbare Prallpaket dient zur Entkopplung der von den beiden Schlagsystemen in das innere bzw. das äussere Bohrgestänge eingeleiteten axialen Schläge. Die Aufnahme für das Prallpaket ist an dem dem Imlochhammer zugewandten Endbereich der Spülwelle angeordnet und steht mit einer Versorgungsbohrung für den Imlochhammer in Verbindung. Ein im Bereich der Versorgungsbohrung angeordneter Spülring dient zur Einleitung des Spülmedium, beispielsweise eines Gemischs aus Druckluft und Wasser, und zur Versorgung des Imlochhammers mit Druckluft. Die Versorgungsbohrung mündet dabei derart in die Aufnahme für das Prallpaket, dass sich im Betrieb an der vom Imlochhammer abgewandten Seite ein Luftpolster ausbilden kann, welches für eine zusätzliche Entkopplung der axialen Schläge der beiden Schlagsysteme sorgt.The flushing shaft is cylindrical and has at its two end portions connecting thread for the coupling to the outer drill pipe. The connecting threads can be standardized internal and / or external threads, so that the intermediate piece can be built into the drill string in a modular manner. Inside the flushing shaft, the axially elastically deformable baffle package is housed in a receptacle. The elastically deformable impact package is used to decouple introduced by the two impact systems in the inner and the outer drill pipe axial shocks. The receptacle for the baffle package is disposed on the end of the purging shaft facing the Imlochhammer and communicates with a supply hole for the Imlochhammer in connection. A flushing ring arranged in the region of the supply bore serves to introduce the flushing medium, for example a mixture of compressed air and water, and to supply the in-hole hammer with compressed air. The supply bore discharges into the receptacle for the baffle package in such a way that, during operation, an air cushion can form on the side remote from the downhole hammer, which provides for an additional decoupling of the axial beats of the two beater systems.

Die Elastomerscheiben des in der Aufnahme der Spülwelle angeordneten Prallpakets haben einen etwas kleineren Aussendurchmesser als die Stahlscheiben. Dadurch ist sichergestellt, dass sich die Elastomerscheiben bei einer axialen Stauchung radial ungehindert elastisch ausdehnen können. Das Prallpaket weist mit Vorteil eine zentrale Durchgangsöffnung für den ungehinderten Durchtritt des Spülmediums auf.
Die Stahlscheiben dienen zur mechanischen Versteifung des Prallpakets. Die eigentliche Dämpf- und Entkopplungsfunktion wird hingegen von den Elastomerscheiben wahrgenommen. Die axiale Höhe der Elastomerscheiben beträgt etwa das Einfache bis etwa das Zweieinhalbfache der axialen Höhe der Stahlscheiben. Das Prallpaket weist mit Vorteil eine axiale Gesamthöhe von etwa 35 mm bis etwa 105 mm auf. Diese Dimensionierung des Prallpakets in Verbindung mit einem im Betrieb in der Aufnahme ausgebildeten Luftpolster sorgt im Betrieb dafür, dass bei den üblichen Einzelschlagenergien der beiden Schlagsysteme eine zuverlässige Entkopplung der axialen Schläge gewährleistet ist.
Das Prallpaket weist mit Vorteil eine den zentralen Durchgang der kreisringförmigen Stahl- und Elastomerscheiben durchsetzende, mit einer zentralen Bohrung versehene Büchse auf, deren Fussteil sich am Boden der Aufnahme in der Spülwelle abstützt. Die Büchse schliesst das Prallpaket radial nach innen ab und sorgt für einen noch weiter verbesserten Abtransport der bei der Kompression der Elastomerscheiben auftretenden Wärme. Zusätzlich begrenzt die Büchse die Ausdehnung der Elastomerscheiben bei Belastung.
Aus Festigkeitsgründen besteht die Büchse des Prallpakets vorzugsweise ebenfalls aus Stahl.
Eine erfindungsgemässe Drehschlagbohranlage mit einem an einem inneren Bohrgestänge angeordneten zentralen Bohrmeissel, der drehangetrieben und von einem Imlochhammer beaufschlagt ist, und einer Bohrkrone, die drehangetrieben und von einem eigenen Aussenhammer mit Axialschlägen beaufschlagt ist und derart an einem das innere Bohrgestänge aufnehmenden äusseren Bohrgestänge angeordnet ist, dass sie gegenüber dem zentralen Bohrmeissel nacheilt, ist zur Entkopplung der vom Imlochhammer und der vom Aussenhammer erzeugten Axialschläge mit einem eingespannten Prallpaket, das aus einem Verbund aus Stahlscheiben und Elastomerscheiben besteht, ausgestattet. Das Prallpaket ist dabei in einer erfindungsgemäss ausgebildeten Spülwelle angeordnet.The elastomeric disks of the impact package arranged in the receptacle of the flushing shaft have a slightly smaller outside diameter than the steel disks. This ensures that the elastomer discs can expand elastically radially unimpeded in an axial compression. The baffle package advantageously has a central passage opening for the unhindered passage of the flushing medium.
The steel discs are used for mechanical stiffening of the baffle package. The actual damping and decoupling function, however, is perceived by the elastomeric discs. The axial height of the elastomer discs is about the simple to about two and a half times the axial height of the steel discs. The baffle package advantageously has an overall axial height of about 35 mm to about 105 mm. This dimensioning of the baffle in conjunction with a trained in operation in the recording air cushion ensures during operation that a reliable decoupling of the axial shocks is ensured in the usual single beat energies of the two impact systems.
The baffle has advantageously the central passage of the annular steel and elastomer discs passing through, provided with a central bore sleeve whose foot is supported at the bottom of the recording in the flushing. The bushing closes off the baffle package radially inwards and ensures a further improved removal of the heat which occurs during the compression of the elastomeric disks. In addition, the bush limits the expansion of the elastomeric disks under load.
For strength reasons, the sleeve of the baffle preferably also made of steel.
A rotary impact drilling system according to the invention with a central drill bit arranged on an inner drill string which is rotationally driven and acted upon by a downhole hammer, and a drill bit which is rotationally driven and subjected to axial impacts by its own outer hammer and is thus arranged on an outer drill string receiving the inner drill string, that it lags against the central drill bit, is for decoupling of the Imlochhammer and the axial hammer generated by the outer hammer with a clamped baffle package, which consists of a composite of steel discs and elastomer discs equipped. The baffle package is arranged in an inventive trained Spülwelle.

Die erfindungsgemässe Drehschlagbohranlage ist mit zwei Schlagsystemen ausgestattet. Ein Imlochhammer beaufschlagt den zentralen Bohrmeissel. Der vorauseilende zentrale Bohrmeissel muss einen Grossteil der Abbauarbeit leisten. Der Imlochhammer bietet dabei eine optimale Unterstützung der Abtragarbeit. Die vom Imlochhammer auf den zentralen Bohrmeissel übertragene Schlagenergie ist nicht abhängig von der Bohrlochtiefe bzw. der Länge des inneren Bohrgestänges. Vielmehr werden die axialen Schläge des Imlochhammers immer im gleichen Abstand von der Bohrsohle über das innere Bohrgestänge in den zentralen Bohrmeissel eingeleitet. Die gegenüber dem zentralen Bohrmeissel nacheilende Bohrkrone wird durch den Aussenhammer über das äussere Bohrgestänge mit axialen Schlägen beaufschlagt. Die axialen Schläge des zusätzlichen Schlagsystems dienen ausschliesslich zur Unterstützung der Abbauarbeit der mit dem äusseren Bohrgestänge verbundenen Bohrkrone. Die Schlagenergie des zusätzlichen Schlagsystems muss nicht wie bei den aus dem Stand der Technik bekannten Drehschlagbohranlagen auf die Bohrkrone und den zentralen Bohrmeissel verteilt werden. Vielmehr dient das Prallpaket dazu, die vom Aussenhammer erzeugten Axialschläge von den auf den zentralen Bohrmeissel einwirkenden axialen Schläge des Imlochhammers entkoppeln. Die Schlagenergien der beiden Schlagsysteme sind unabhängig voneinander auf den jeweiligen Anwendungszweck und Untergrund abstimmbar. Dadurch ist eine sehr hohe Bohrleistung erzielbar. Durch die erfindungsgemässe Entkopplung der Schlagsysteme ist die Standzeit der Drehschlagbohranlage deutlich verbessert. Brüche des Bohrgestänges innerhalb des Bohrloches, beispielsweise in Gewindebereichen des modular aufgebauten Bohrgestänges können dadurch weitgehend verhindert werden. Die Anordnung des Prallpakets in einer Spülwelle erhöht die Modularität der Anlage, die bei Bedarf auch ohne diese Spülwelle betrieben werden kann. Dadurch bleibt für den Anwender die Flexibilität erhalten. Fall er die Drehschlagbohranlage als eine konventionelle, aus dem Stand der Technik bekannte Anlage betreiben will, die beispielsweise nur einen, gemeinsam auf den zentralen Bohrmeissel und die Bohrkrone wirkenden Aussenhammer aufweist oder nur mit einem Imlochhammer ausgestattet ist, kann an Stelle der erfindungsgemässen Spülwelle mit Prallpaket eine konventionelle Spülwelle in das Bohrgestänge eingebaut werden. Soll die Drehschlagbohranlage hingegen wieder mit zwei unabhängig voneinander wirkenden Schlagsystemen arbeiten, wird einfach die erfindungsgemässe Spülwelle mit dem Prallpaket bezogen auf die Bohrrichtung hinter dem Imlochhammer in das äussere Bohrgestänge eingefügt.The rotary impact drilling rig according to the invention is equipped with two impact systems. A down hole hammer acts on the central drill bit. The leading central drill bit has to do most of the mining work. The Imlochhammer offers optimum support for the removal work. The impact energy transferred from the downhole hammer to the central drill bit is not dependent on the drill hole depth or the length of the inner drill string. Rather, the axial impacts of the Imlochhammers are always introduced at the same distance from the drill hole on the inner drill string in the central drill bit. The drill bit following the central drill bit is subjected to axial impacts by the outer hammer via the outer drill string. The axial impacts of the additional impact system are solely to aid in the mining work of the drill bit connected to the outer drill string. The impact energy of the additional impact system does not have to be distributed to the drill bit and the central drill bit as in the case of the rotary impact drills known from the prior art. Rather, the baffle serves to decouple the axial shocks generated by the outer hammer of the forces acting on the central Bohrmeissel axial blows of the Imlochhammers. The impact energies of the two impact systems are independent of each other on the particular application and surface tunable. As a result, a very high drilling performance can be achieved. The decoupling of the impact systems according to the invention significantly improves the service life of the rotary impact drilling rig. Fractures of the drill string within the wellbore, for example, in threaded areas of the modular drill pipe can thereby be largely prevented. The arrangement of the baffle in a flushing wave increases the modularity of the system, which can be operated without this flushing wave if necessary. This preserves flexibility for the user. If he the rotary hammer drill as a conventional, known from the prior art Plant want to operate, for example, only one, acting jointly on the central drill bit and drill bit outer hammer or is equipped only with a downhole hammer, instead of the inventive flushing wave with baffle a conventional flushing wave can be installed in the drill pipe. If the rotary hammer drill, however, again work with two independently acting impact systems, simply the invention according to the flushing wave with the baffle package based on the drilling direction behind the Imlochhammer inserted into the outer drill pipe.

Der Aussenhammer ist vorzugsweise hydraulisch betrieben. Der hydraulische Antrieb ist erprobt und kann beispielsweise vom hydraulischen Drehantrieb der Bohrgestänge abgeleitet werden.The outer hammer is preferably operated hydraulically. The hydraulic drive has been tested and can be derived, for example, from the hydraulic rotary drive of the drill string.

Der Imlochhammer ist mit Vorteil pneumatisch betrieben. Die Versorgung des pneumatischen Imlochhammers mit Druckluft ist auch bei grossen Bohrtiefen bzw. Bohrlängen im allgemeinen einfacher zu bewerkstelligen als eine Hydraulikversorgung. Undichtigkeiten der pneumatischen Versorgungsleitungen sind weit weniger problematisch als solche bei hydraulischen Systemen.The downhole hammer is pneumatically operated with advantage. The supply of the pneumatic Imlochhammers with compressed air is generally easier to accomplish even with large drilling depths or drill lengths as a hydraulic supply. Leaks in the pneumatic supply lines are far less problematic than those in hydraulic systems.

Bei dem erfindungsgemässen Verfahren zum Betrieb einer Drehschlagbohranlage mit einem an einem inneren Bohrgestänge angeordneten zentralen Bohrmeissel, der drehangetrieben wird und von einem Imlochhammer mit axialen Schlägen beaufschlagt wird, und mit einer drehangetriebenen und von einem Aussenhammer mit axialen Schlägen beaufschlagten Bohrkrone, die derart an einem das innere Bohrgestänge aufnehmenden äusseren Bohrgestänge angeordnet ist, dass sie gegenüber dem zentralen Bohrmeissel nacheilt, werden die axialen Schläge des Imlochhammers und des Aussenhammers weitgehend voneinander entkoppelt. Zur Entkopplung der axialen Schläge des Imlochhammers und des Aussenhammers wird ein eingespanntes Prallpaket verwendet, das aus einem eingespannten Verbund aus kreisringförmigen Stahlscheiben und Elastomerscheiben zusammengesetzt wird, wobei jeweils eine Elastomerscheibe zwischen zwei Stahlscheiben angeordnet wird.In the inventive method for operating a rotary hammer drill with a central drill bit arranged on an inner drill string, which is rotationally driven and is impacted by an in-hole hammer with axial blows, and with a rotationally driven and acted upon by an external hammer with axial blow drill bit, the at such a Inner drill string receiving outer drill string is arranged that it lags relative to the central drill bit, the axial impacts of the in-hole hammer and the outer hammer are largely decoupled from each other. To decouple the axial impacts of the idler hammer and the external hammer a clamped impact package is used, which is composed of a clamped composite of annular steel discs and elastomer discs, wherein in each case an elastomer disc between two steel discs is arranged.

Die mit dem Imlochhammer erzeugten und an den zentralen Bohrmeissel abgegebenen und die vom Aussenhammer erzeugten und auf die Bohrkrone übertragenen Schläge werden durch das Prallpaket voneinander entkoppelt. Das Prallpaket dient dabei einerseits zur Dämpfung der Axialschläge und andererseits zur Ableitung der bei der Dämpfung auftretenden Wärme. Das Betreiben der Drehschlagbohranlage mit zwei voneinander unabhängigen Schlagsystemen erlaubt eine auf die jeweiligen Anforderungen und den Untergrund angepasste Einzelschlagenergie der jeweiligen axialen Schläge. Dadurch ist eine sehr hohe Bohrleistung erzielbar. Durch die Entkopplung der Schlagsysteme voneinander ist eine höhere Standzeit der Drehschlagbohranlage erreichbar und können Brüche des Bohrgestänges innerhalb des Bohrloches weitgehend vermieden werden.The blows generated by the downhole hammer and delivered to the central drill bit and the hammer generated by the external hammer and transferred to the drill bit are decoupled from each other by the baffle package. The baffle serves on the one hand for damping the Axialschläge and on the other hand to dissipate the heat occurring in the damping. The operation of the rotary impact drilling rig with two independent impact systems allows a single impact energy of the respective axial impacts adapted to the respective requirements and the ground. As a result, a very high drilling performance can be achieved. By decoupling the impact systems from one another a longer service life of the rotary impact drilling is reached and fractures of the drill string within the well can be largely avoided.

Die an die Bohrkrone übertragenen axialen Schläge werden bevorzugt mit einem hydraulisch betriebenen Aussenhammer erzeugt und in das äussere Bohrgestänge eingeleitet. Dies erlaubt eine einfache Verstellung der Einzelschlagenergie.The axial blows transmitted to the drill bit are preferably generated by a hydraulically operated external hammer and introduced into the outer drill pipe. This allows a simple adjustment of the single impact energy.

Die auf den zentralen Bohrmeissel übertragenen axialen Schläge werden mit Vorteil mit einer pneumatisch angetriebenen Imlochhammer erzeugt. Der pneumatische Betrieb des Imlochhammers ist einfacher zu bewerkstelligen als beispielsweise ein hydraulischer Betrieb. Undichtigkeiten der Pneumatik innerhalb des Bohrlochs sind weniger kritisch als bei hydraulischem Betrieb.The axial impacts transmitted to the central drill bit are advantageously generated by a pneumatically driven downhole hammer. The pneumatic operation The in-hole hammer is easier to accomplish than, for example, a hydraulic operation. Leakage of the pneumatic within the wellbore is less critical than in hydraulic operation.

Weitere Vorteile und Merkmale ergeben sich aus der nachfolgenden Beschreibung eines Ausführungsbeispiels der Erfindung unter Bezugnahme auf die schematischen Zeichnungen. Es zeigen in nicht massstabsgetreuer Darstellung:

Fig. 1
eine Darstellung einer Drehschlagbohranlage gemäss der Erfindung;
Fig. 2
eine auseinandergezogene Darstellung einer erfindungsgemässen Spülwelle mit Prallpaket, die mit einer mit einer Ausgleichsstange versehenen Auswurfglocke verbindbar ist;
Fig. 3
die Spülwelle und die Auswurfglocke gemäss Fig. 2 im zusammenmontierten Zustand; und
Fig. 4
ein Prallpaket mit Büchse.
Further advantages and features will become apparent from the following description of an embodiment of the invention with reference to the schematic drawings. It shows in not to scale representation:
Fig. 1
an illustration of a rotary impact drilling system according to the invention;
Fig. 2
an exploded view of an inventive flushing with baffle package, which is connectable to a provided with a balance bar ejector bell;
Fig. 3
the flushing shaft and the ejection bell according to Fig. 2 in the assembled state; and
Fig. 4
a baffle package with rifle.

Die schematische Darstellung in Fig. 1 zeigt ein Ausführungsbeispiel der erfindungsgemäss ausgebildete Drehschlagbohranlage, die gesamthaft mit dem Bezugszeichen 1 versehen ist. Die Drehschlagbohranlage 1 besitzt ein inneres Bohrgestänge 2 und ein das innere Bohrgestänge 2 aufnehmendes äusseres Bohrgestänge 5. Das bezogen auf eine Bohrrichtung D vordere Ende des inneren Bohrgestänges 2 trägt einen zentralen Bohrmeissel 3, beispielsweise eine Stiftbohrkrone mit Diamant und/oder Hartmetallstiften. Am vorderen Ende des äusseren Bohrgestänges 5 ist eine ringförmige Bohrkrone 6 mit Hartmetallkörpern oder dergleichen montiert. Das innere und das äussere Bohrgestänge 2, 5 sind über einen vorzugsweise hydraulischen Antrieb 15 drehangetrieben. Der mit dem inneren Bohrgestänge 2 verbundene zentrale Bohrmeissel 3 eilt der am äusseren Bohrgestänge 5 montierten Bohrkrone 6 voraus und leistet im Betrieb die grösste Abbauarbeit. Das innere Bohrgestänge 2 weist unmittelbar hinter dem zentralen Bohrmeissel 3 einen sogenannten Imlochhammer 4 auf, der pneumatische betreibbar ist. Der Imlochhammer 4 wird über eine zentrale Bohrung 10 mit der erforderlichen Druckluft versorgt und beaufschlagt im Betrieb den zentralen Bohrmeissel 3 mit axialen Schlägen. Die Druckluft bildet zugleich auch das Spülmedium, das für den Abtransport des an der Bohrsohle von den Bohrköpfen zerkleinerten Bohrguts erforderlich ist. Gegebenenfalls ist das Spülmedium ein Gemisch aus Druckluft und Wasser. Am rückwärtigen Ende ist das Bohrgestänge 2, 5 über eine Auswurfglocke 13 und eine Spülwelle 8 mit dem hydraulischen Drehantrieb 15 verbunden. An der Auswurfglocke 13 wird das vom Spülmedium aus der Bohrlochtiefe transportierte zerkleinerte Bohrgut ausgeworfen. Die Spülwelle 8 wird über einen darum montierten Spülring 11 mit einem Anschluss 12 mit dem Spülmedium versorgt. Im Betrieb befinden sich die Auswurfglocke 13 und alle dahinter anschliessenden Bauteile ausserhalb des Bohrlochs. Die an die Auswurfglocke 13 in Bohrrichtung D anschliessenden Abschnitte des Bohrgestänges 2, 5 befinden sich innerhalb des Bohrlochs. Das Bohrgestänge 2, 5 ist modular aufgebaut und beliebig verlängerbar, was in Fig. 1 durch Unterbrechungslinien angedeutet ist.The schematic representation in Fig. 1 shows an embodiment of the present invention trained rotary impact drilling, which is provided overall with the reference numeral 1. The rotary impact drilling rig 1 has an inner drill pipe 2 and an outer drill pipe 5 receiving the inner drill pipe 2. The front end of the inner drill pipe 2 bears with respect to a drilling direction D a central drill bit 3, for example a pin drill bit with diamond and / or hard metal pins. At the front end of the outer drill pipe 5, an annular drill bit 6 is mounted with hard metal bodies or the like. The inner and the outer drill pipe 2, 5 are rotationally driven via a preferably hydraulic drive 15. The central drill bit 3 connected to the inner drill string 2 precedes the drill bit 6 mounted on the outer drill rod 5 and, during operation, performs the greatest work of dismantling. The inner drill pipe 2 has immediately behind the central drill bit 3 a so-called in-hole hammer 4, the pneumatic operated is. The Imlochhammer 4 is supplied via a central bore 10 with the required compressed air and applied in operation the central drill bit 3 with axial blows. At the same time, the compressed air also forms the flushing medium which is required for the removal of the drill bit which has been comminuted by the drill heads at the drillhole. Optionally, the flushing medium is a mixture of compressed air and water. At the rear end of the drill pipe 2, 5 is connected via an ejection bell 13 and a flushing shaft 8 with the hydraulic rotary drive 15. At the ejection bell 13, the shredded cuttings transported by the flushing medium from the wellbore depth are ejected. The flushing shaft 8 is supplied via a flushing ring 11 mounted around it with a connection 12 with the flushing medium. In operation, the ejection bell 13 and all subsequent components are outside the borehole. The adjoining the ejection bell 13 in the direction of drilling D sections of the drill string 2, 5 are located within the borehole. The drill string 2, 5 is modular and extendable arbitrarily what is in Fig. 1 is indicated by interrupt lines.

Zum Unterschied vom Stand der Technik ist die erfindungsgemässe Drehschlagbohranlage mit einem zusätzlichen Schlagsystem 7 ausgestattet, welches im Betrieb axiale Schläge auf das Bohrgestänge ausübt. Entkopplungsmittel sorgen dafür, dass die axialen Schläge des zusätzlichen Schlagsystems 7 nur auf das äussere Bohrgestänge 5 übertragen werden. Die Entkopplungsmittel bestehen aus einer speziell ausgebildeten Spülwelle 8 mit einem axial elastisch deformierbaren Prallpaket 9. Die axialen Schläge des zusätzlichen Schlagsystems 7 werden vorzugsweise hydraulisch erzeugt. Beispielsweise handelt es sich um einen aus dem Stand der Technik hinlänglich bekannten Aussenhammer dessen hydraulischer Betrieb aus dem hydraulischen Antrieb 15 für die Drehbewegung des Bohrgestänges 2, 5 abgeleitet ist. Die Axialschläge des zusätzlichen Schlagsystems 7 dienen ausschliesslich zur Unterstützung der Abbauarbeit der am äusseren Bohrgestänge 5 montierten Bohrkrone 6. Die Schlagenergie des zusätzlichen Schlagsystems 7, das vorzugsweise hydraulisch betrieben ist, muss nicht wie bei den aus dem Stand der Technik bekannten Drehschlagbohranlagen auf die Bohrkrone 6 und den zentralen Bohrmeissel 3 verteilt werden. Vielmehr sorgen die vorgesehenen Entkopplungsmittel 8, 9 dafür, dass die vom zusätzlichen Schlagsystem 7 ausgeübten Axialschläge von den auf den zentralen Bohrmeissel 3 einwirkenden axialen Schlägen des Imlochhammers 4 entkoppelt sind. Der zentrale Bohrmeissel 3, der gegenüber der am äusseren Bohrgestänge 5 montierten Bohrkrone 6 vorauseilt und einen Grossteil der Abbauarbeit leistet, wird nur vom Imlochhammer 4 beaufschlagt und bietet dabei eine optimale Unterstützung der Abtragarbeit. Die vom Imlochhammer 4 auf den zentralen Bohrmeissel 3 übertragene Schlagenergie ist nicht abhängig von der Bohrlochtiefe bzw. der Länge des inneren Bohrgestänges 2. Vielmehr werden die axialen Schläge des Imlochhammers 4 immer im gleichen Abstand von der Bohrsohle in den zentralen Bohrmeissel 3 eingeleitet. Die Schlagenergien der beiden Schlagsysteme 4, 7 sind unabhängig voneinander auf den jeweiligen Anwendungszweck und Untergrund abstimmbar. Dadurch ist eine sehr hohe Bohrleistung erzielbar. Durch die Entkopplung der Schlagsysteme 4, 7 ist auch die Standzeit der Drehschlagbohranlage deutlich verbessert. Brüche des Bohrgestänges 2, 5 innerhalb des Bohrloches, beispielsweise in Gewindebereichen des modular aufgebauten Bohrgestänges 2, 7, können dadurch weitgehend verhindert werden.In contrast to the prior art, the rotary impact drilling system according to the invention is equipped with an additional impact system 7, which exerts axial impacts on the drill pipe during operation. Decoupling means ensure that the axial impacts of the additional impact system 7 are transmitted only to the outer drill pipe 5. The decoupling means consist of a specially designed flushing shaft 8 with an axially elastically deformable impact package 9. The axial impacts of the additional impact system 7 are preferably generated hydraulically. For example, it is a well-known from the prior art external hammer whose hydraulic operation is derived from the hydraulic drive 15 for the rotational movement of the drill string 2, 5. The axial impacts of the additional impact system 7 serve exclusively to support the dismantling work of the drill bit 6 mounted on the outer drill pipe 5. The impact energy of the additional impact system 7, which is preferably hydraulically operated, does not have to be on the drill bit 6, as is the case with the rotary impact drilling systems known from the prior art and the central drill bit 3 are distributed. Rather, the provided decoupling means 8, 9 ensure that the force exerted by the additional impact system 7 Axial impacts are decoupled from acting on the central drill bit 3 axial blows of the Imlochhammers 4. The central drill bit 3, which leads ahead of the drill bit 6 mounted on the outer drill pipe 5 and performs a large part of the work of dismantling, is acted upon only by the in-hole hammer 4 and thereby offers optimal support for the removal work. The impact energy transferred from the downhole hammer 4 to the central drill bit 3 is not dependent on the drill hole depth or the length of the inner drill pipe 2. Rather, the axial impacts of the in-hole hammer 4 are always introduced at the same distance from the drill hole into the central drill bit 3. The impact energies of the two impact systems 4, 7 are independent of each other on the particular application and background tunable. As a result, a very high drilling performance can be achieved. Due to the decoupling of the impact systems 4, 7, the service life of the rotary impact drilling rig is significantly improved. Fractions of the drill string 2, 5 within the wellbore, for example in threaded areas of the modular drill pipe 2, 7, can be largely prevented.

In den Fig. 2 - 4 sind Details einer erfindungsgemässen Drehschlagbohranlage dargestellt. Die dargestellten Komponenten tragen dabei zum besseren Verständnis die gleichen Bezugszeichen wie die entsprechenden Komponenten in der Übersichtsdarstellung in Fig. 1, auch wenn sie in einzelnen, für die Erfindung nicht wesentlichen Merkmalen, beispielsweise Aussendurchmesser, unterschiedlich ausgebildet sein können. In Fig. 2 und 3 sind eine erfindungsgemässe Spülwelle 8 mit einem Prallpaket 9 und eine Auswurfglocke 13 mit einer Ausgleichsstange 14 in auseinandergezogenem Zustand (Fig.2) und im zusammengebauten Zustand (Fig. 3) dargestellt. Die Spülwelle 8 weist einen insgesamt zylindrischen Körper auf, an dessen beiden axialen Endbereichen genormte Anschlussgewinde 81, 82 für die Verbindung mit dem äusseren Bohrgestänge 5 bzw. mit dem zusätzlichen Schlagsystem 7 vorgesehen sind. Der dem zusätzlichen Schlagsystem zugewandte Endabschnitt weist dazu eine Sacklochbohrung mit einem Innengewinde auf. Der in Bohrrichtung weisende Endabschnitt ist mit einem Aussengewinde 82 versehen. Der im montierten Zustand dem Imlochhammer zugewandte Endbereich der Spülwelle 8 weist eine sacklochartige Aufnahme 83 auf. Die Aufnahme 83 steht mit einer Versorgungsbohrung 84 in Verbindung, die sich vom Grund 85 der Aufnahme zum Umfang der Spülwelle 8 erstreckt. Der in Fig. 1 dargestellte Spülring umgibt die Spülwelle im Bereich der Mündung und sorgt für die Zufuhr des Spülmediums, beispielsweise ein Gemisch aus Druckluft und Wasser, über die Versorgungsbohrung 84 in den zentralen Kanal des inneren Bohrgestänges.In the Fig. 2-4 Details of a rotary hammer drill according to the invention are shown. The illustrated components bear for better understanding the same reference numerals as the corresponding components in the overview in Fig. 1 Even if they may be formed differently in individual, not essential to the invention features, such as outer diameter. In Fig. 2 and 3 are an inventive flushing shaft 8 with a baffle package 9 and an ejection bell 13 with a balance bar 14 in an extended state ( Fig.2 ) and in the assembled state ( Fig. 3 ). The flushing shaft 8 has an overall cylindrical body, at the two axial end portions standardized connection threads 81, 82 are provided for connection to the outer drill pipe 5 and with the additional impact system 7. The additional impact system facing the end portion has to a blind hole with an internal thread. The pointing in the drilling direction end portion is provided with an external thread 82. The end region of the flushing shaft 8 facing the through-hole hammer in the assembled state has a blind-hole-like receptacle 83. The receptacle 83 is in communication with a supply bore 84 extending from the bottom 85 of the Recording to the periphery of the flushing shaft 8 extends. The in Fig. 1 illustrated flushing ring surrounds the flushing shaft in the region of the mouth and ensures the supply of the flushing medium, for example a mixture of compressed air and water, through the supply hole 84 in the central channel of the inner drill string.

Das gesamthaft mit dem Bezugszeichen 9 versehene Prallpaket ist in die Aufnahme 83 einsetzbar. Es besteht aus einer Abfolge von kreisringförmigen Stahl- und vorzugsweise vulkanisierten Elastomerscheiben 91 bzw. 92. Jede Elastomerscheibe 92 ist zwischen zwei Stahlscheiben 91 angeordnet. Die beiden äussersten Scheiben des Prallpakets 9 sind Stahlscheiben 91. Das Prallpaket weist einen zentralen Durchgang 93 auf, der eine Büchse 94 aufnimmt. Die Büchse 94 ragt von einem Fussteil 95 ab, das sich im montierten Zustand am Grund 85 der Aufnahme 83 abstützt. Die Büchse 94 ist mit einer zentralen Bohrung 96 versehen.The aggregate provided with the reference numeral 9 baffle package is inserted into the receptacle 83. It consists of a sequence of annular steel and preferably vulcanized elastomeric disks 91 and 92, respectively. Each elastomeric disk 92 is disposed between two steel disks 91. The two outermost discs of the baffle 9 are steel discs 91. The baffle has a central passage 93 which receives a sleeve 94. The sleeve 94 protrudes from a foot part 95, which is supported in the assembled state at the bottom 85 of the receptacle 83. The sleeve 94 is provided with a central bore 96.

Die Spülwelle 8 ist mit Ihrem mit dem Aussengewinde 82 versehenen Endbereich mit einem korrespondierend mit einem Innengewinde 131 versehenen Endbereich der Auswurfglocke 13 einschraubbar. Der zweite Endbereich der Auswurfglocke 13 weist einen beispielsweise mit einem Aussengewinde 132 versehenen Anschlussbereich für die Verbindung mit dem äusseren Bohrgestänge auf. In der Auswurfglocke 13 ist eine Ausgleichsstange 14 gelagert, die mit einem Anschlussbereich 141 zu dem inneren Bohrgestänge ausgestattet ist. Der gegenüberliegende kopfartige erweiterte Endabschnitt 142 der Ausgleichsstange 14 ragt im zusammengebauten Zustand in die Aufnahme 83 der Spülwelle 8. Die Ausgleichsstange 14 weist im Anschluss an den kopfartigen Endabschnitt 142 einen Abschnitt 143 mit einem polygonalen Querschnitt auf. Beispielsweise ist die Ausgleichsstange 14 in diesem Abschnitt 143 achteckig ausgebildet. Die Auswurfglocke 13 weist im Inneren einen korrespondierenden Bereich 133 auf, der ebenfalls polygonal, beispielsweise achteckig, ausgebildet ist. Die zusammenwirkenden Flächen am polygonalen Abschnitt 143 der Ausgleichsstange 14 und am polygonalen Bereich 133 der Auswurfglocke 13 dienen zur Drehmomentübertragung vom äusseren Bohrgestänge an das innere Bohrgestänge.The flushing shaft 8 can be screwed with its end region provided with the external thread 82 with an end region of the ejection bell 13 that is correspondingly provided with an internal thread 131. The second end region of the ejection bell 13 has a connection region, for example, provided with an external thread 132 for connection to the outer drill pipe. In the ejection bell 13, a balance bar 14 is mounted, which is equipped with a connection portion 141 to the inner drill string. The opposite head-like extended end portion 142 of the balance bar 14 projects in the assembled state into the receptacle 83 of the flushing shaft 8. The balancing bar 14 has following the head-like end portion 142 has a portion 143 with a polygonal cross section. For example, the balance bar 14 is formed octagonal in this section 143. The ejection bell 13 has inside a corresponding region 133, which is also polygonal, for example, octagonal, is formed. The cooperating surfaces on the polygonal section 143 of the balance bar 14 and on the polygonal section 133 of the ejector bell 13 serve to transmit torque from the outer drill pipe to the inner drill pipe.

Fig. 3 zeigt die mit der Auswurfglocke 13 zusammenmontierte Spülwelle 8. Das Prallpaket 9 ist in der Aufnahme 83 untergebracht und zwischen dem Grund 85 der Aufnahme 83 und dem kopfartigen Endabschnitt 142 der Ausgleichsstange 14 gehalten. Das derart eingespannte Prallpaket 9 verhindert, dass axiale Schläge des Aussenhammers 7, die über die Spülwelle 8 eingeleitet werden, auf die Ausgleichsstange 14 und das innere Bohrgestänge übertragen werden. Die vom Aussenhammer erzeugten Axialschläge werden somit nur über das äussere Bohrgestänge übertragen. Gleichzeitig verhindert das Prallpaket auch, dass Schläge des pneumatisch betriebenen Imlochschlagwerks über das innere Bohrgestänge auf das äussere Bohrgestänge übertragen werden. Das Prallpaket gewährleistet somit eine weitgehend vollständige Entkopplung der beiden Schlagwerke. Die Entkopplung wird noch dadurch unterstützt, dass die Versorgungsbohrung 84 am Grund der Aufnahme 83 in die Spülwelle 8 mündet. Wegen des hohen Druckes, mit dem das Spülmedium eingespeist wird, bildet sich im Betrieb zwischen dem Grund 85 der Aufnahme 83 und dem Prallpaket ein Luftpolster, welches für eine zusätzliche Entkopplung der Schlagsysteme sorgt. Fig. 3 shows the assembled with the ejection bell 13 Spülwelle 8. The baffle package 9 is housed in the receptacle 83 and held between the base 85 of the receptacle 83 and the head-like end portion 142 of the balance bar 14. The thus clamped impact package 9 prevents axial shocks of the outer hammer 7, which are introduced via the flushing shaft 8, are transmitted to the balance bar 14 and the inner drill pipe. The axial impacts generated by the outer hammer are thus transmitted only via the outer drill pipe. At the same time, the baffle package also prevents blows from the pneumatically operated punching unit from being transmitted to the outer drill pipe via the inner drill string. The baffle package thus ensures a largely complete decoupling of the two striking mechanisms. The decoupling is further supported by the fact that the supply bore 84 at the bottom of the receptacle 83 opens into the flushing shaft 8. Because of the high pressure with which the flushing medium is fed, an air cushion forms during operation between the base 85 of the receptacle 83 and the baffle package, which ensures an additional decoupling of the beating systems.

Fig. 4 zeigt schematisch das Prallpaket 9. Es besteht aus einer Abfolge von kreisringförmigen Stahlscheiben 91 und Elastomerscheiben 92. Die äusseren Scheiben des Prallpakets 9 sind Stahlscheiben. Die Elastomerscheiben 92 weisen eine Dicke r auf, die etwa das Einfache bis etwa das Zweieinhalbfache der Dicke t der Stahlscheiben 91 beträgt. Die axiale Gesamthöhe h des Prallpakets beträgt etwa 35 mm bis etwa 105 mm. Die Elastomerscheiben 92 weisen einen Aussendurchmesser auf, der kleiner ist als derjenige der Stahlscheiben 91. Dadurch können sie sich bei der axialen Komprimierung ungehindert radial ausdehnen. Durch die kreisringförmige Ausbildung der Stahl- und Elastomerscheiben 91, 92 bleibt im Prallpaket ein zentraler Durchgang 93 frei. Dieser dient zur Aufnahme der Büchse 94, die sich vom Fussteil 95 axial erstreckt. Im montierten Zustand liegt das Fussteil 95 am Grund der Aufnahme in der Spülwelle an. Die Büchse 94 samt Fussteil besteht vorzugsweise aus Stahl. Eine axiale Bohrung 96 in der Büchse 94 gewährleistet den Durchtritt des Spülmediums durch das Prallpaket 9. Die Stahlscheiben und die Büchse dienen zur mechanischen Versteifung des Prallpakets und zur Ableitung der bei der Schlagdämpfung auftretenden Wärme. Durch die vollständig eingespannte Anordnung der Elastomerscheiben des in die Aufnahme der Spülwelle eingesetzten Prallpakets können sich die Elastomerscheiben bei der Schlagdämpfung nur kontrolliert deformieren. Die Wärmeableitung über die Stahlscheiben gewährleistet, dass die Elastomerscheiben nicht in einem fliessfähigen Zustand übergeführt werden. Fig. 4 schematically shows the baffle package 9. It consists of a sequence of annular steel discs 91 and elastomeric discs 92. The outer discs of the baffle package 9 are steel discs. The elastomeric disks 92 have a thickness r, which is about the simple to about two and a half times the thickness t of the steel disks 91. The overall axial height h of the baffle package is about 35 mm to about 105 mm. The elastomeric disks 92 have an outer diameter which is smaller than that of the steel disks 91. As a result, they can freely expand radially during the axial compression. Due to the annular formation of the steel and elastomeric disks 91, 92 remains in the baffle a central passage 93 free. This serves to accommodate the sleeve 94 which extends axially from the foot 95. In the assembled state, the foot part 95 rests against the bottom of the receptacle in the flushing shaft. The bush 94 together with foot part is preferably made of steel. An axial bore 96 in the sleeve 94 ensures the passage of the flushing medium through the baffle package 9. The steel discs and the sleeve are used for mechanical stiffening of the baffle and for dissipating the heat occurring in the impact damping. Due to the fully clamped arrangement of the elastomer discs in the recording of the Rinsing wave used impact package, the elastomeric discs can only deform controlled in the impact damping. The heat dissipation through the steel discs ensures that the elastomer discs are not transferred in a flowable state.

Durch die Erfindung werden eine Drehschlagbohranlage mit zwei voneinander unabhängigen, entkoppelten Schlagwerken und erfindungswesentliche Komponenten vorgeschlagen. Der Betrieb einer derartigen Drehschlagbohranlage erlaubt höhere Bohrgeschwindigkeiten bei grösseren Standzeiten der Komponenten. Wegen des modularen Aufbaus der Anlage und der Komponenten sind auch bereits bestehende Drehschlagbohranlagen ohne grössere Schwierigkeiten gemäss der Erfindung umrüstbar.The invention proposes a rotary impact drilling machine with two independent, decoupled striking mechanisms and components essential to the invention. The operation of such a rotary impact drilling machine allows higher drilling speeds with longer service lives of the components. Because of the modular structure of the system and the components and existing rotary percussion drilling without major difficulties according to the invention are convertible.

Claims (16)

  1. Flushing shaft to be mounted into an outer drill pipe (5) of a rotary percussive installation (1) that has a central drill bit (3), placed on an inner drill pipe (2), that is rotationally driven and that is loaded by a down-the-hole hammer (4) with axial impacts and that has a rotationally driven core bit (6) loaded by an outer hammer (7) with axial impacts, core bit that is placed on the outer drill pipe (5) that receives the inner drill pipe (2) in such a manner that it lags the central drill bit (3), which flushing shaft (8) has a cylindrical body at the axial end portions of which standardized connecting threads (81, 82) are provided for connecting with the outer drill pipe (5) or with the outer hammer (7) and that has a percussive assembly for decoupling the down-the-hole hammer (4) from the outer hammer (7), characterized in that the cylindrical body has a recess in the manner of a blind hole (83) in its end portion turned in mounted condition to the down-the-hole hammer (7), recess that communicates with a supply drilled hole (84) for the supply of a flushing medium for the down-the-hole hammer (4) and in which the percussive assembly (9) is placed and that the percussive assembly (9) comprises a group of circular ring-shaped steel disks (91) and elastomer disks, wherein an elastomer disk (92) is placed respectively between two steel disks (91).
  2. Flushing shaft according to claim 1, characterized in that the end portion of the body that is provided with the recess (83) has a cylindrical extension provided with a standardized outer thread (82), the extension being configured for connecting with an ejection bell (13) of the outer drill pipe (13) and that a drilled hole in the manner of a blind hole with a standardized inner thread (81) is provided in the opposed end portion of the body.
  3. Flushing shaft according to one of the preceding claims, characterized in that the percussive assembly (9) has a central passage (93).
  4. Flushing shaft according to one of the preceding claims, characterized in that the percussive assembly (9) has a bush (94) provided with a central drilled hole (96) that traverses the central passage (93) of the circular ring-shaped steel disks and elastomer disks (91, 92), bush the bottom part (95) of which bears on the bottom (85) of the recess (83) in the flushing shaft (91).
  5. Flushing shaft according to one of the preceding claims, characterized in that the elastomer disks (92) have a smaller outer diameter than the steel disks (91).
  6. Percussive assembly for inserting into a recess in a flushing shaft of a drill pipe of a rotary percussive installation with an outer hammer and a down-the-hole hammer, which recess communicates with a supply drilled Bore for the supply of a flushing medium for the down-the-hole hammer (4), comprising a succession of a number of circular ring-shaped steel disks (91) and preferably vulcanized elastomer disks (92), wherein an elastomer disk (92) is placed respectively between two steel disks (91).
  7. Percussive assembly according to claim 6, characterized in that the elastomer disks (92) have a smaller outer diameter than the steel disks (91).
  8. Percussive assembly according to claim 6 or 7, characterized in that the axial height (r) of the elastomer disks (92) is approximately one time to approximately two-and-a-half times the axial height of the steel disks (91).
  9. Percussive assembly according to claim 8, characterized in that the percussive assembly (9) has an axial overall height (h) of approximately 35 mm to approximately 105 mm.
  10. Percussive assembly according to one of the claims 6 to 9, characterized in that the percussive assembly (9) has a central passage (93).
  11. Percussive assembly according to claim 10, characterized in that the percussive assembly (9) has a metallic bush (94) provided with a central drilled hole (96) that traverses the central passage (93) of the circular ring-shaped steel disks and elastomer disks (91, 92), bush the bottom part (95) of which forms an outer steel disk.
  12. Rotary percussive installation with a central drill bit (3), placed on an inner drill pipe (2), that is rotationally driven and that is loaded by a down-the-hole hammer (4) with axial impacts and with a rotationally driven core bit (6) loaded by an outer hammer (7) with axial impacts, core bit that is placed on an outer drill pipe (5) that receives the inner drill pipe (2) in such a manner that it lags the central drill bit (3), wherein means (8, 9) for decoupling the axial impacts produced by the down-the-hole hammer (4) and the outer hammer (7), characterized in that the means for decoupling the axial impacts are formed by a percussive assembly according to one of the claims 6 to 11.
  13. Rotary percussive installation according to claim 12, characterized in that the percussive assembly is placed in a flushing shaft according to one of the claims 1 to 4.
  14. Rotary percussive installation according to claim 12 or 13, characterized in that the outer hammer (7) is operated hydraulically.
  15. Rotary percussive installation according to one of the claims 12 to 14, characterized in that the down-the-hole hammer (4) is operated pneumatically.
  16. Method for operating a rotary percussive installation (1) with a central drill bit (3), placed on an inner drill pipe (2), that is rotationally driven and that is loaded by a down-the-hole hammer (4) with axial impacts and with a rotationally driven core bit (6) loaded by an outer hammer (7) with axial impacts, core bit that is placed on an outer drill pipe (5) that receives the inner drill pipe (2) in such a manner that it lags the central drill bit (3), wherein the axial impacts of the down-the-hole hammer (4) and the outer hammer (7) are widely decoupled from each other, characterized in that a clamped percussive assembly (9) is used for decoupling the axial impacts of the down-the-hole hammer (4) and of the outer hammer (7), percussive assembly that consists of a group of circular ring-shaped steel disks (91) and elastomer disks (92), wherein an elastomer disk (92) is placed respectively between two steel disks (91) and wherein the percussive assembly (9) is placed in a recess in the manner of a blind hole (83) in a flushing shaft (8) in the outer drill pipe (5), which recess (83) supply drilled hole (84) for the supply of a flushing medium for the down-the-hole hammer (4).
EP07720159.8A 2006-05-24 2007-05-23 Mud shaft for the drill string of a rotary percussive drilling rig, impact stack for a mud shaft and rotary percussive drilling rig Active EP2029851B1 (en)

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CH8412006 2006-05-24
PCT/CH2007/000262 WO2007134478A1 (en) 2006-05-24 2007-05-23 Mud shaft for the drill string of a rotary percussive drilling rig, impact stack for a mud shaft and rotary percussive drilling rig

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EP2029851A1 EP2029851A1 (en) 2009-03-04
EP2029851B1 true EP2029851B1 (en) 2018-08-29

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