WO2002097232A1 - Procede et dispositif de forage de roches, outil et trepan utilise pour le forage de roches - Google Patents

Procede et dispositif de forage de roches, outil et trepan utilise pour le forage de roches Download PDF

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Publication number
WO2002097232A1
WO2002097232A1 PCT/FI2001/000524 FI0100524W WO02097232A1 WO 2002097232 A1 WO2002097232 A1 WO 2002097232A1 FI 0100524 W FI0100524 W FI 0100524W WO 02097232 A1 WO02097232 A1 WO 02097232A1
Authority
WO
WIPO (PCT)
Prior art keywords
tool
rock
bit
stress wave
compressive stress
Prior art date
Application number
PCT/FI2001/000524
Other languages
English (en)
Inventor
Markku Keskiniva
Pekka Salminen
Jorma MÄKI
Pasi Latva-Pukkila
Original Assignee
Sandvik Tamrock Oy
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sandvik Tamrock Oy filed Critical Sandvik Tamrock Oy
Priority to PCT/FI2001/000524 priority Critical patent/WO2002097232A1/fr
Publication of WO2002097232A1 publication Critical patent/WO2002097232A1/fr

Links

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
    • E21B17/02—Couplings; joints
    • E21B17/04—Couplings; joints between rod or the like and bit or between rod and rod or the like
    • 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
    • E21B6/00—Drives for drilling with combined rotary and percussive action

Definitions

  • the invention relates to a method of rock drilling, in which method rock is broken by creating a compressive stress wave by means of a hammering apparatus belonging to a rock drill to a tool arranged in the drill, whereby a bit at the outermost end of the tool is hit against the rock and causes compression stress in the rock.
  • the invention further relates to an arrangement for rock drilling, which arrangement comprises a rock drill having a hammering apparatus and a tool connectable to the rock drill, whereby the hammering apparatus is arranged to create a compression stress wave in the tool whose outermost end has a bit for breaking rock.
  • the invention also relates to a tool used in rock drilling, whose first end has fastening means for fastening to a rock drill and whose other end has a bit or fastening means for fastening such a bit used in breaking rock, whereby an impact impulse caused to the tool by the hammering apparatus of the rock drill is arranged to be transmitted in the tool as a compressive stress wave to the bit and to make the bit hit the rock being drilled.
  • the invention also relates to a rock drill comprising a hammering apparatus for creating a compressive stress wave to a tool fastened to the rock drill.
  • rock drilling and mining include cutting, crushing and hammering methods.
  • Soft rock is usually drilled by pressing a tool at a certain feed force against the rock while rotating a bit, whereby the bit removes rock by cutting.
  • the method is, however, only suited for soft rock, because hard rock would require an unreasonably great propulsive force and torque. Further, with hard rock the wear of the bit would be so intense that the method would no longer be economical.
  • the crushing method is applied to all types of rock.
  • the tool comprises one or more rotating bits having bit studs. The tool is pushed against the rock and simultaneously rotated, whereby the bits crush the rock. In this method, a great feed force is required, since the rock is crushed by pressure.
  • the breaking speed of rock is lower than with hammering methods.
  • Hammering methods are most commonly used with hard rock.
  • the tool In a hammering method, the tool is rotated and hammered.
  • the rock breaks mainly due to the impact.
  • the rotation mainly ensures that the bit studs or other working parts of the bit always hit a new section.
  • a rock drill usually comprises a hydraulic hammering apparatus, whose percussion piston creates the necessary compressive stress waves, and a rotating motor separate from the hammering apparatus.
  • efficient rock breaking requires that the bit is heavily pressed against the surface of the rock.
  • drilling equipment must be designed to endure heavy loads.
  • the service life of tools is often very short.
  • Another drawback with normal hammering drilling is that the breaking speed of the rock is not sufficient and that the breaking process requires a lot of energy.
  • the method of the invention is characterized in that when the working parts of the bit are inside the rock due to the compressive stress wave, a percussive torsional load is caused to the bit after a predefined time delay from the longitudinal impact of the bit, and that the bit rotating in a percussive manner removes rock by cutting.
  • the arrangement of the invention is characterized in that the arrangement comprises means for directing a percussive torsional stress wave to the bit after a predefined delay from the compressive stress wave, while the working parts of the bit are inside the rock due to the compressive stress wave.
  • the tool of the invention is characterized in that the tool comprises an anisotropic section where a primary compressive stress wave caused in the tool is divided into two components, a secondary compressive stress wave and a torsional stress wave, and that said anisotropic section is at a predefined distance from the tip of the bit, whereby the torsional stress wave reaches the tip of the bit later by a time delay proportional to said distance than the secondary compressive stress wave.
  • the rock drill of the invention is characterized in that the rock drill or the tool being connected to it comprises means for creating a torsional stress wave to the tool and that the rock drill comprises a latch mechanism or the like allowing the tool to turn to a desired direction only, whereby the torsional stress caused in the tool is arranged to make the bit at the outermost end of the tool change position between impacts.
  • the essential idea of the invention is that in addition to the longitudinal compressive stress wave caused by the hammering apparatus, a pulse-like torsional stress wave is caused in the rock through the bit.
  • the compressive stress wave causes the working parts of the bit to penetrate the rock being drilled and possibly to cause cracks, and the torsional stress wave rotates in an percussive manner the working part of the bit which has penetrated the rock, thus making the rock cut.
  • the two force components affecting the rock through the bit are timed in such a manner that the longitudinal impact of the tool takes place first and then, after the predefined delay, the rock is cut by means of the torsional component.
  • the essential idea of a preferred embodiment of the invention is that the force caused by the impact of the hammering apparatus is divided into two components, the longitudinal force component of the tool and the torsional component rotating the bit, in such a manner that the energy content of said components is in desired proportion with respect to each other.
  • Dividing the primary compressive stress wave into components is done at a predefined distance LQ E N from the tip of the bit, whereby the force components progressing in a wave motion reach the tip of the bit at different times. Because the compressive stress wave progresses faster in the tool than the torsional stress wave, it reaches the bit first. The torsional stress wave makes the bit rotate only after a delay when the working parts of the bit have already hit the rock at full force. The length of the delay can be changed by changing the distance L GE - Further, the essential idea of a second preferred embodiment of the invention is that the division of the primary compressive stress wave into two wave components is done by means of an anisotropic section formed in the tool on a section of a certain length.
  • the tool comprises drill rods connectable to each other, and at least one, preferably the outermost, drill rod has a spirally grooved section at a distance LQ EN from the tip of the bit, the grooved section forming a geometric anisotropic section in the tool.
  • the primary compressive stress wave encounters such an anisotropic section when progressing in the tool, a part of the energy of the primary compressive stress wave is converted to a torsional stress wave and a part of it continues as a compressive stress wave on towards the bit.
  • the invention provides the advantage that drilling becomes more efficient that before.
  • the ratio between the compressive and torsional stress can be affected just by changing the tool. This way, the drill and other drilling equipment can remain the same.
  • extension rod drilling it is enough that the drill rod comprising the anisotropic section is changed.
  • Drill rods arranged between the hammering apparatus and the drill rod with the anisotropic section, and the joints between them do not affect the division into components or the timing of the compressive and torsional stress, since the division into components is only done in the drill rod after them.
  • Geometric anisotropicity is quite easily achieved by arranging the anisotropic section by shaping the geometry of the tool arm or the drill rod.
  • the anisotropic section can conveniently be made by making grooves, for instance, on the outer surface of a drill rod having otherwise constant dimensions.
  • Figures 1 and 2 show schematically the principle of some rock drills of the invention
  • Figure 3 shows schematically a detail of a tool of the invention
  • FIG. 4a and 4b show schematically the principle of drilling according to the invention
  • Figure 5 shows schematically a drill rod of the invention
  • Figures 6a to 6d show schematically the division of a primary compressive stress wave into components when using the drill rod described in Figure 5
  • Figure 7 shows schematically a second way of arranging an anisotropic section based on geometric form into the tool
  • Figures 8 and 9 show schematically some arrangements according to the inventive idea.
  • Figure 1 shows in a simplified manner drilling equipment of the invention.
  • a rock drill 1 comprises a hammering apparatus 2 and rotating apparatus 3.
  • the rotating apparatus transmits a continuous rotating force to a tool 4, by means of which a bit 5 connected to the tool changes its position after an impact and hits a new place in the rock with the next impact.
  • the hammering apparatus usually has a percussion piston reciprocating by means of a pressure medium, the piston hitting the top of the tool 4 or an intermediate piece arranged between the tool and the hammering apparatus.
  • the structure of the hammering apparatus can naturally be of another kind.
  • the impact impulse can, for instance, be provided by means based on electromagnetism and with properties of a magnetostrictive material, for instance. Apparatuses based on such properties are also considered hammering apparatuses herein.
  • the inner end of the tool can be connected to a rock drill and the outer end of the tool has a fixed or detachable bit 5 for breaking the rock. During drilling, the bit is pushed by means of a feeding apparatus against the rock.
  • the bit is typically a drill bit having bit studs 5a, but other kinds of bit structures are also possible. Drilling deep holes, i.e. in extension rod drilling, a number of drill rods 6a to 6c forming a tool are added between the bit and the drill depending on the depth of the hole.
  • Impact energy provided by the hammering apparatus 2 is transmitted along the drill rods 6a to 6c as a compressive stress wave towards the bit 5 at the end of the outermost drill rod.
  • the stress wave hits the bit
  • the bit and the bit studs 5a hit the material being drilled causing a strong compressive stress.
  • the rock being drilled cracks due to the strong compressive stress.
  • the primary compressive stress wave caused by the hammering apparatus is divided into two components, a torsional stress wave and a longitudinal secondary compressive stress wave of the tool.
  • the figure shows in the outermost drill rod 6c an anisotropic section 7 where the division into components takes place.
  • the anisotropic section is arranged at a predefined distance L GE N from the tip of the bit.
  • the distance LQEN is defined by calculation, simulation or by experimental tests in such a manner that the secondary compressive stress wave obtained by division meets the tip of the bit first, and only after a desired time delay from the longitudinal impact of the tool caused by the compressive stress wave, does the torsional stress wave reach the bit and make it rotate.
  • the propagation speeds of the compressive and torsional stress waves are different.
  • the propagation speeds of the waves depend on the material of the tool. In a normal drill rod, the speed of compressive stress is approximately 5, 180 m/s and the speed of the torsional wave is approximately 3,220 m/s. Since there is a delay between the compressive stress and the torsional stress, the compressive stress has had time to use its full force before the bit is rotated. Thus, the compressive force has had time to abate slightly before the torsion, making the frictional forces smaller and the force required for rotation reasonable.
  • Figure 2 shows a solution in which a tool connected to a rock drill comprises a uniform arm with a bit at its free end. Such an arrangement can be used in drilling shallow holes, for instance. In this case, too, an anisotropic section has been formed in the tool at a predefined distance L G E N from the tip of the bit.
  • Figure 3 shows a detail of the tool of the invention.
  • Metals are typically isotropic, which means that their properties in all directions are the same. Materials whose properties are different in different directions are called anisotropic.
  • anisotropic When the main rigidity axes E-, and E 2 form a 0° to 90° angle ⁇ with the longitudinal axis of the tool, a force transmitted to such a section is divided in proportion to the size of the angle ⁇ . If the angle ⁇ is 0° or 90°, division into components does not occur in the anisotropic section.
  • Anisotropicity can be achieved by influencing the geometry of a structure or by means of the internal structure of a material.
  • An example of the latter is rolling of metals, with which the internal structure of a material can be oriented in a certain manner.
  • reinforced fibres, for instance, of plastic and composite structures can be oriented, whereby the material acts in an anisotropic manner.
  • this is simplest arranged by making spiral grooves 8 on the outer surface of the drill rod on a section of predefined length and with a certain gradient (corresponding to the angle ⁇ ), as shown in the figure.
  • the dimensioning of the geometrically adjusted section for instance the profile, depth and gradient of the grooves, decide the ratio of the division of the compressive stress wave F P into the secondary compressive stress wave F s and torsional stress wave F ⁇ in the anisotropic section.
  • the compressive stress is designed to be greater than the torsional stress, because the compressive strength of rocks is higher than the shear strength. Compression must be made with a great force so as to make the bit penetrate the rock and create cracks. After this, only a smaller force is required to cut the rock off.
  • Figures 4a and 4b show the principle of the drilling of the invention.
  • a secondary compressive stress wave F s causes strong compressive stress in the rock, whereby the rock is typically crushed under high pressure into powder in the contact area 9 between the bit and the rock, and cracks 10 extending into the rock are created.
  • Figure 4b shows the second stage of drilling. Because the bit studs 5a are due to the impact caused by the secondary compressive stress still inside the rock, the percussive torsional movement causes the bit studs to cut the rock material when the bit rotates. The area being cut is marked with reference number 11 in the figure. The cutting is aided by the fact that cracks have been formed in the rock due to compressive stress.
  • the chippings created during drilling are more rough in composition than the powder-like chippings created during conventional hammering drilling, which fact also shows that in this kind of drilling, the use of energy is more economical than before.
  • FIG. 5 shows a drill rod with which experimental tests were made. The measurement results of the drilling are presented later in Figures 6a to 6d.
  • a 500 mm anisotropic section L A was formed at about the centre point of the drill rod whose total length is 3,660 mm.
  • the measures L-i and L 2 marked in the figure are 1,580 mm in size.
  • the distance LQ E N between the tip of the bit and the anisotropic section becomes approximately 1 ,700 mm when using conventional bits.
  • a grooving of 500 mm having 8 pieces of 10 mm deep and about 5 mm wide spiral grooves at a 40° angle to the longitudinal axis of the drill rod was made in the anisotropic section. The angle ⁇ affecting the division of the primary compressive stress wave is thus in this case said 40°.
  • Figure 6a shows the primary compressive stress wave measured before the anisotropic section from the drill rod shown in the previous figure.
  • Figure 6b shows the secondary compressive stress wave F s created by division and measured from the bit.
  • Figure 6c shows the torsional stress wave F ⁇ created by division and moving towards the rock.
  • Figure 6d shows the torsional wave reflected back towards the hammering apparatus from the grooved section.
  • the secondary compressive stress wave is in its energy content considerably larger than the torsional stress wave.
  • the figures further show the phase difference caused by the difference in speed in the compressive and torsional stress waves. Because the momentum of the system must be maintained, balancing torsional wave components are created in the drill rod.
  • the rock-cutting torsional wave component F ⁇ is balanced by both the opposing torsional wave component F T1 ( Figure 6c) coming after the component F ⁇ and the torsional wave components F T2 ( Figure 6d) reflecting back from the grooved section.
  • the interrelation of the balancing components can be adjusted by the geometry of the grooved section.
  • Figure 7 shows the principle of a second anisotropicity achieved by geometric form.
  • the tool may have counter surfaces slanted with respect to its longitudinal axis, whereby the compressive stress wave progressing in the tool is divided into components in proportion to the size of the slanted angle ⁇ .
  • such a section can be formed on the outermost drill rod only.
  • a percussive torsional stress wave can alternatively be formed by means of a torsion apparatus 12 arranged to the drill, as shown in Figure 8.
  • the torsion apparatus may be mechanical, electromagnetic or use a pressure medium.
  • the torsion apparatus may be an apparatus which converts a part of the impact of the hammering apparatus into a torsional impact. At its simplest it resembles an impact screwdriver-type solution.
  • the torsion apparatus may be independent of the hammering apparatus, in which case it produces the necessary force for the torsional impact itself.
  • a sufficiently long time delay between the compressive stress wave and the torsional stress wave is not created automatically with especially short tools in which the distance LQEN between the drill and the tip of the bit is short.
  • One possibility is to arrange the bit to rotate by means of the torsional stress wave created in the tool. Then, the torsional stress wave alone causes the bit to rotate and the bit studs to change place for a new impact.
  • a conventional rotating motor is thus not necessarily needed any more in a drill.
  • the drill then becomes simpler in structure and its manufacturing and operating costs lower than before. In addition, its structure is smaller and lighter.
  • the equipment must comprise means, such as a one-way clutch, a latch mechanism or the like, which allow the rotation of the tool into a desired direction only.
  • a latch mechanism 13a can be arranged between the bit and the outermost drill rod ( Figure 9).
  • the bit rotates in the rock a step forward with each torsional stress wave.
  • the latch mechanism stops the bit from rotating back.
  • Another alternative is to arrange a latch mechanism 13b or the like to the drill between the tool and the drill. A reflecting torsional stress wave is then utilised in rotating the tool.
  • the solution of the invention can also be applied to rock drilling in which the bit is not rotated by means of a rotating motor. This includes some of the mining methods. Further, the invention can be applied to rock breaking apparatuses, such as impact hammers/demolition apparatuses arranged in excavators. It should be noted that a drill rod or drill rods comprising an anisotropic section need not be arranged as the outermost in an extension rod combination, but a normal drill rod can be placed outermost. The essential thing is that the distance LQ E N is made suitable.

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

Abstract

La présente invention concerne un procédé de forage de roches, procédé selon lequel une contrainte de compression est appliquée sur la roche par un appareil de martelage (2) d'un trépan. Après un retard prédéfini à partir de l'onde de contrainte de compression, un composant de torsion par percussion est également appliqué sur un trépan, éliminant la roche par havage. L'invention concerne également un dispositif de forage de roches, ledit dispositif comprenant un trépan (1) présentant un appareil de martelage (2) permettant de créer une onde de contrainte de compression dans un outil (4) relié au trépan. Le dispositif comprend également des moyens permettant de créer une onde de contrainte de torsion par percussion dans le trépan de manière à couper la roche. L'invention concerne également un outil utilisé pour le forage de roches, lequel comprend une partie anisotrope (7) où l'onde de contrainte de compression principale (FP) dirigée vers l'outil est divisée en une onde de contrainte de compression secondaire (FS) et en une onde de contrainte de torsion (FT).
PCT/FI2001/000524 2001-06-01 2001-06-01 Procede et dispositif de forage de roches, outil et trepan utilise pour le forage de roches WO2002097232A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/FI2001/000524 WO2002097232A1 (fr) 2001-06-01 2001-06-01 Procede et dispositif de forage de roches, outil et trepan utilise pour le forage de roches

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/FI2001/000524 WO2002097232A1 (fr) 2001-06-01 2001-06-01 Procede et dispositif de forage de roches, outil et trepan utilise pour le forage de roches

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008060233A1 (fr) * 2006-11-16 2008-05-22 Atlas Copco Rock Drills Ab Machine à impulsions, procédé de génération d'impulsions mécaniques et perforatrice et installation de forage comprenant une telle machine à impulsions
CN107060738A (zh) * 2017-05-25 2017-08-18 中国石油天然气股份有限公司 一种抽油机井井下数据传输装置及方法
CN112198051A (zh) * 2020-09-29 2021-01-08 河北工业大学 侧压作用下基于能量演化的岩石拉伸破裂识别方法及应用

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE121304C1 (fr) *
US4497866A (en) * 1981-08-31 1985-02-05 Albany International Corp. Sucker rod
US5348096A (en) * 1993-04-29 1994-09-20 Conoco Inc. Anisotropic composite tubular emplacement
US6012744A (en) * 1998-05-01 2000-01-11 Grant Prideco, Inc. Heavy weight drill pipe

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE121304C1 (fr) *
US4497866A (en) * 1981-08-31 1985-02-05 Albany International Corp. Sucker rod
US5348096A (en) * 1993-04-29 1994-09-20 Conoco Inc. Anisotropic composite tubular emplacement
US6012744A (en) * 1998-05-01 2000-01-11 Grant Prideco, Inc. Heavy weight drill pipe

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008060233A1 (fr) * 2006-11-16 2008-05-22 Atlas Copco Rock Drills Ab Machine à impulsions, procédé de génération d'impulsions mécaniques et perforatrice et installation de forage comprenant une telle machine à impulsions
JP2010510413A (ja) * 2006-11-16 2010-04-02 アトラス コプコ ロツク ドリルス アクチボラグ パルス発生装置、機械的パルスの発生方法、並びにこのようなパルス発生装置を備えた削岩機及び削岩リグ
CN107060738A (zh) * 2017-05-25 2017-08-18 中国石油天然气股份有限公司 一种抽油机井井下数据传输装置及方法
CN112198051A (zh) * 2020-09-29 2021-01-08 河北工业大学 侧压作用下基于能量演化的岩石拉伸破裂识别方法及应用
CN112198051B (zh) * 2020-09-29 2022-10-04 河北工业大学 侧压作用下基于能量演化的岩石拉伸破裂识别方法及应用

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