EP0657620B1 - Verfahren und System zur Kontrolle des "Stick-Slip" eines Bohrwerkzeugs - Google Patents

Verfahren und System zur Kontrolle des "Stick-Slip" eines Bohrwerkzeugs Download PDF

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Publication number
EP0657620B1
EP0657620B1 EP94402698A EP94402698A EP0657620B1 EP 0657620 B1 EP0657620 B1 EP 0657620B1 EP 94402698 A EP94402698 A EP 94402698A EP 94402698 A EP94402698 A EP 94402698A EP 0657620 B1 EP0657620 B1 EP 0657620B1
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EP
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Prior art keywords
bit
tool
rotation
torque
speed
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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EP94402698A
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English (en)
French (fr)
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EP0657620A1 (de
Inventor
Didier Pavone
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IFP Energies Nouvelles IFPEN
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IFP Energies Nouvelles IFPEN
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    • 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
    • E21B44/00—Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions
    • E21B44/02—Automatic control of the tool feed
    • E21B44/04—Automatic control of the tool feed in response to the torque of the drive ; Measuring drilling torque
    • 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
    • E21B44/00—Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions
    • E21B44/005—Below-ground automatic control systems

Definitions

  • the present invention relates to a method and a system suitable for controlling a dysfunction in the behavior of a drilling tool driven in rotation by means of a drilling string. This dysfunction is commonly called "stick-slip”.
  • the present invention is applicable to the oscillatory behavior of the speed of rotation of a drilling tool around an average speed imposed on the surface.
  • the so-called "stick-slip” behavior is well known to drillers and is characterized by very appreciable variations in the speed of rotation of the drilling tool while it is being driven by means of a drill string put rotating from the surface at a substantially constant speed.
  • the speed of the tool can vary between a practically zero speed and a value of the speed of rotation of the tool much greater than the speed applied on the surface to the lining. This can in particular have the consequences of harmful effects on the life of the drilling tools, on the increase of the mechanical fatigue of the drill string and the frequency of the ruptures of the connections.
  • the present invention relates to a method of controlling the stability of the speed of rotation of a drilling tool driven in rotation by means of a tubular lining rotated from mechanical surface means, said tool being subjected to a reactive torque due to the drilling action of a well.
  • an additional resistive torque is created in the vicinity of the tool, a function of the speed of rotation of the tool and of a determined value so that the overall reactive torque of the drilling tool resulting from the addition of the torque to the tool and of said additional torque is an increasing function of the speed of rotation of the tool.
  • Said additional resistant torque can be created by friction means integral with the lining in the vicinity of the tool.
  • Said additional resistant torque can be created by varying the weight on the tool.
  • Said variation in weight on the tool can be provided by specific means located in the vicinity of the tool and controlled by the speed of rotation of the drilling tool.
  • the invention also relates to a system for controlling the stability of the speed of rotation of a drilling tool driven in rotation by means of a tubular lining rotated by mechanical surface means, said tool being subjected to a reactive torque due to the drilling action of a well.
  • the system comprises regulation means integral with the lining in the vicinity of the tool, said means being adapted to create an additional resistant torque to the tool, the value of said torque being a function of the speed of rotation of the tool.
  • Said regulating means may include friction means on the walls of the well.
  • Said regulation means may include means for varying the force of application of the tool on the bottom of the well.
  • Said regulating means may include means for measuring the speed of rotation of the drilling tool and means for adjusting the value of the additional resistive torque as a function of the speed of rotation of the tool.
  • FIG. 1 is a recording of the angular position of a drilling tool connected integrally to drill collars in which the measuring instruments are placed. These records have been obtained, for example using the means described according to patent FR-92/02273. Such a recording curve is described in the article "Wired Pipes for a High-Data-Rate MWD System” by JB Fa ⁇ , H. Fa ⁇ and A. Couturier (SPE 24971, European Petroleum Conference, 1991, 16- 18 November 1992).
  • the measurements of the speed of rotation of the tool can preferably be obtained by deriving the curve 1 representing the recording of the angular position of the drilling tool by sets of magnetic sensors.
  • Measuring the speed of rotation of the tool can be compared to the speed of rotation of the drill collars, since all the drill collars are very rigid in torsional deformation. There is therefore practically no difference in speed between the measuring means, preferably located for practical reasons in the drill collars, and the drilling tool.
  • curve 1 in FIG. 1 presents zones 2 in which the displacement of the tool is practically zero for durations substantially equal to one second.
  • the rotation speed can reach the frequency of 3.2 Hz, while the nominal speed of the lining, here 90 revolutions / minute, corresponds to a 1.5 Hz frequency.
  • Figure 2 shows schematically the mathematical model used to highlight and analyze the unstable behavior of the speed of rotation of the drilling tool.
  • a drilling tool 5 rests on the cutting face 8.
  • the drill string is constituted by drill collars 3 and rods 4 with determined mechanical and dimensional characteristics.
  • a rotation device 9 imposes a speed of rotation on the whole of the lining. Friction is imposed between the rods and the drill collars against the walls of the well.
  • the friction equations may be chosen as a function of the weight of the entire packing, the speed of rotation at table 9, the drilling fluid, the geometry of the rods and drill-rods respectively in zones 6 and 7, or the shape of the well trajectory.
  • the resistance to rotation of the tool 5 on the face of size 8 is also defined according to a relationship of the torque as a function of the speed of rotation for a weight on the determined tool ( Figure 4).
  • Figure 4 shows the curves representing the function between the friction torque (C) of a drilling tool and its speed of rotation.
  • C friction torque
  • This example was published in the article SPE 21943 cited above. The measurements were carried out with a used PDC tool (one-piece tool comprising cutting pads made of polychrystalline material), at constant weight and for several weight values on the tool.
  • the abscissa is graduated in revolutions / minute and the ordinate in ft ⁇ lbf, unit of torque which is converted to m ⁇ daN by multiplying by 0.1356.
  • Curve 10 was obtained for a weight on the tool of 4 tonnes, curve 11 for a weight on the tool of 2.7 tonnes and curve 12 for a weight on the tool of 1.33 tonnes. Note that the tool torque decreases when the rotation speed increases. In addition, when the weight on the tool decreases, the decreasing curve becomes flat.
  • FIG. 3 shows the response of the mathematical model according to FIG. 2 to a stress created by a variation in the speed of rotation applied to the drill string by the means 9 (FIG. 2).
  • the conditions of friction between the tool 5 and the cutting face 8 are imposed according to a law arising from the curves of FIG. 4.
  • the speed is 110 revolutions per minute.
  • the speed of rotation applied to the drill string increases until it reaches 120 revolutions per minute.
  • Curve 16 represents the speed of rotation of the drilling tool as a function of time.
  • the behavior of the drilling tool in rotation speed is unstable and oscillates around the set value of 120 revolutions per minute.
  • the speed of rotation of the tool varies according to oscillations which amplify, then reach a maximum of amplitude according to a stabilized behavior (15) representing the dysfunction "stick-slip" in which the speed of rotation is canceled before reaching a maximum much higher than the set speed.
  • the model confirms and highlights that the instability of the speed of rotation of a drilling tool driven in rotation by a drill string, is the result of the fact that the torque to the tool decreases as a function of an increase of the speed of rotation.
  • the present invention proposes to prevent the occurrence of the so-called "stick-slip” dysfunction by making the behavior of the drilling tool stable in rotation speed by acting on the cause of the instability.
  • FIGS. 5 and 6 Two methods are preferably used and illustrated by FIGS. 5 and 6.
  • curve 17 represents the torque resistant to the drilling tool in the range of rotational speeds N1 and N2.
  • Curve 18 represents a friction torque supplied by appropriate means integral with the drilling tool or drill collars.
  • the overall torque at the drilling tool will be the sum of the torque at the tool and the additional torque.
  • the overall torque is represented here by the curve 19 resulting from the addition of the curve 17 with the curve 18.
  • the friction means are determined to generate a friction curve 18 increasing with the speed of rotation.
  • the overall resistance to rotation, at the level of the drilling tool is represented by an increasing curve 19 as a function of the speed.
  • the friction means may require a measurement of the speed of rotation of the drilling tool to control, for example by electronic controls, the value of the additional torque as a function of the speed. Purely mechanical means can also be used as friction adjustment means.
  • FIG. 7A illustrates friction means designed from a stabilizer with variable geometry 22.
  • the means 22 are fixed on a tool 20 in the drilling operation of a well 21.
  • Skids 23, 25, 26 have surfaces of friction with the walls of the well 21 so as to create a friction torque.
  • the number of pads in contact with the walls is a function of the speed measured by the measuring and control apparatus 24 which controls the output of the number of pads necessary for the additional resistive torque to follow a growth law similar to the curve. 18.
  • Variable geometry stabilizers whose blades are radially movable are known and will not be described here.
  • a rotation speed sensor integrated into the device 24 controls a motorization means which radially moves the support blades against the wall of the well.
  • the energy to activate the motor can come from an electric accumulator, an electricity generating turbine or the pressure of the drilling fluid circulating in the lining.
  • the friction pads can be replaced by rollers 27 with an axis parallel to the axis of rotation of the tool 20.
  • the number of rollers distributed over the circumference will be determined for proper centering of the tool in the well.
  • Pushing means hydraulic or mechanical, apply the rollers against the walls of the well.
  • the rotation of the drilling tool rotates the rollers 27 in contact with the walls of the well, for example as a roller reamer commonly used by the profession, would.
  • a measuring and control apparatus 24 adjusts the rolling resistance as a function of the speed of rotation, for example by regulating the braking of the rollers and / or the force of application of the rollers to the walls of the well.
  • FIG. 6 which reproduces, for the example only, in part FIG. 4, illustrates another means of making the behavior of a drilling tool stable in speed.
  • Point A represents the operating point at the weight on the tool of 2.7 tonnes, at the speed of rotation N A and at the torque C A.
  • N A to N B When the speed increases from N A to N B while providing an increase in weight on the tool corresponding to point B at substantially 3 tonnes, the operating point follows the path shown by the arrows 30.
  • the torque at tool becomes C B greater than C A.
  • an increase in the speed of rotation caused an increase in the reactive torque to the tool.
  • the behavior of the drilling tool is stable in speed as described above.
  • the solution here is to create a determined increase in weight on the tool as a function of an increase in the speed of rotation.
  • FIG. 7C shows the principle of an embodiment of means for applying a weight to the additional tool when the speed of rotation increases.
  • the tool 20 is screwed onto a mandrel 31 contained in a body 32.
  • the body 32 is integral with the drill collars.
  • the mandrel 31 can slide longitudinally over a determined length while being fixed in rotation, for example by a key system 38 in a groove.
  • the shape of the mandrel 31 is such that it provides two annular chambers 33 and 34 between the exterior of the mandrel and the interior of the body 32. Sealing elements, not shown here, isolate the chambers from each other and with the outside. These chambers are filled with a substantially incompressible fluid.
  • Means 35 for adjusting the hydraulic pressure in the chambers 33 and 34 communicate with these chambers by conduits 36 and 37.
  • An apparatus 24 for measurement and control controls the adjustment means 35 as a function of measuring the speed of rotation.
  • the operation of such means can be as follows: The driller places, for example, 2.7 tonnes on a tool driven in rotation by the drilling string in rotation at the speed N A. The driller must ensure that there is an excess of weight of drill collars in the packing so as to be able to apply an increase in weight, for example of 0.3 tonnes. This safety on the weight of drill collars is generally common in the profession.
  • the apparatus 24 detects this increase and sends the order to the adjusting means 35 to increase the hydraulic pressure in the chamber 33 to a value such that this increase in pressure corresponds to about 0.3 tonnes.
  • the operating point has gone from curve 11 to 2.7 tonnes, to a point B belonging to a curve at 3 tonnes, not shown in the example.
  • the behavior of the drilling tool is thus that of a tool whose resistive torque increases with speed.

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  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (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)
  • Earth Drilling (AREA)
  • Automatic Control Of Machine Tools (AREA)
  • Drilling And Boring (AREA)

Claims (8)

  1. Verfahren zur Steuerung der Stabilität der Drehgeschwindigkeit eines Bohrwerkzeuges, das mittels einer rohrförmigen Ausrüstung in Drehung versetzt ist, die auf der Grundlage von mechanischen Oberflächeneinrichtungen in Drehung versetzt ist, wobei das Werkzeug einem Reaktionsmoment entsprechend der Bohrtätigkeit eines Bohrloches unterworfen ist, in welchem man in der Nachbarschaft des Werkzeuges ein zusätzliches Gegenmoment erzeugt, abhängig von der Drehgeschwindigkeit des Werkzeuges und eines bestimmten Wertes, damit das gesamte Reaktionsmoment auf das Bohrwerkzeug, das aus der Addition des Momentes auf das Werkzeug und des zusätzlichen Momentes resultiert, eine zunehmende Funktion der Drehgeschwindigkeit des Werkzeuges ist.
  2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß man das zusätzliche Gegenmoment durch Reibungseinrichtungen erzeugt, die aus einem Stück mit der Ausrüstung in der Nachbarschaft des Werkzeuges sind.
  3. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß man das zusätzliche Gegenmoment durch eine Gewichtserhöhung auf das Werkzeug erzeugt.
  4. Verfahren nach Anspruch 3, dadurch gekennzeichnet, daß die Gewichtserhöhung auf das Werkzeug durch spezifische Einrichtungen vorgenommen wird, die in der Nachbarschaft des Werkzeuges angeordnet und durch die Drehgeschwindigkeit des Bohrwerkzeuges aktiviert werden.
  5. System zur Steuerung der Stabilität der Drehgeschwindigkeit eines Bohrwerkzeuges, das mittels einer rohrförmigen Ausrüstung in Drehung versetzt ist, die auf der Grundlage von mechanischen Oberflächeneinrichtungen in Drehung versetzt ist, wobei das Werkzeug einem Reaktionsmoment entsprechend der Bohrtätigkeit eines Bohrloches unterworfen ist, wobei das System Einrichtungen zur Steuerung umfaßt, die aus einem Stück mit der Ausrüstung in der Nachbarschaft des Werkzeuges sind, wobei die Einrichtungen geeignet sind, ein zusätzliches Gegenmoment auf das Werkzeug auszuüben, wobei der Wert des Momentes eine Funktion der Drehgeschwindigkeit des Werkzeuges ist.
  6. System nach Anspruch 5, dadurch gekennzeichnet, daß die Einrichtungen zur Steuerung Reibungseinrichtungen an den Wänden des Bohrloches umfassen.
  7. System nach Anspruch 5, dadurch gekennzeichnet, daß die Einrichtungen zur Steuerung Einrichtungen zur Veränderung der Anwendungskraft des Werkzeuges auf dem Boden des Bohrloches umfassen.
  8. System nach Anspruch 5, dadurch gekennzeichnet, daß die Einrichtungen zur Steuerung Einrichtungen zur Messung der Drehgeschwindigkeit des Bohrwerkzeuges und Einrichtungen zur Steuerung des Wertes des zusätzlichen Gegenmomentes in Abhängigkeit der Drehgeschwindigkeit des Werkzeuges umfassen.
EP94402698A 1993-12-08 1994-11-25 Verfahren und System zur Kontrolle des "Stick-Slip" eines Bohrwerkzeugs Expired - Lifetime EP0657620B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9314837 1993-12-08
FR9314837A FR2713700B1 (fr) 1993-12-08 1993-12-08 Méthode et système de contrôle de la stabilité de la vitesse de rotation d'un outil de forage.

Publications (2)

Publication Number Publication Date
EP0657620A1 EP0657620A1 (de) 1995-06-14
EP0657620B1 true EP0657620B1 (de) 1997-06-18

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EP94402698A Expired - Lifetime EP0657620B1 (de) 1993-12-08 1994-11-25 Verfahren und System zur Kontrolle des "Stick-Slip" eines Bohrwerkzeugs

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US (1) US5507353A (de)
EP (1) EP0657620B1 (de)
FR (1) FR2713700B1 (de)
NO (1) NO306521B1 (de)

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2720440B1 (fr) * 1994-05-24 1996-07-05 Inst Francais Du Petrole Méthode et système de transmission d'un signal de forage.
EP0870899A1 (de) * 1997-04-11 1998-10-14 Shell Internationale Researchmaatschappij B.V. Bohreinrichtung mit reduzierter Stick-Slipneigung
US6173793B1 (en) 1998-12-18 2001-01-16 Baker Hughes Incorporated Measurement-while-drilling devices with pad mounted sensors
US6179066B1 (en) 1997-12-18 2001-01-30 Baker Hughes Incorporated Stabilization system for measurement-while-drilling sensors
NO322069B1 (no) * 1998-01-15 2006-08-07 Baker Hughes Inc Fremgangsmate og anordning for stabilisering av en borestreng ved formasjonsevalueringsmaling
EP1163419B1 (de) 1999-11-10 2004-06-16 Schlumberger Holdings Limited Steuerungsverfahren für steuerbares bohrsystem
US6962214B2 (en) 2001-04-02 2005-11-08 Schlumberger Wcp Ltd. Rotary seal for directional drilling tools
US6467341B1 (en) 2001-04-24 2002-10-22 Schlumberger Technology Corporation Accelerometer caliper while drilling
US7188685B2 (en) * 2001-12-19 2007-03-13 Schlumberge Technology Corporation Hybrid rotary steerable system
SE529230C2 (sv) * 2004-12-10 2007-06-05 Atlas Copco Rock Drills Ab Anordning och metod vid borrning i berg
US7540337B2 (en) * 2006-07-03 2009-06-02 Mcloughlin Stephen John Adaptive apparatus, system and method for communicating with a downhole device
CN101408100B (zh) * 2008-11-25 2012-09-05 天水电气传动研究所有限责任公司 电动钻机转盘柔性扭矩控制方法及其系统
CA2745198C (en) 2008-12-02 2014-10-14 National Oilwell Varco, L.P. Method and apparatus for reducing stick-slip
EP2843186B1 (de) * 2008-12-02 2019-09-04 National Oilwell Varco, L.P. Verfahren und Vorrichtung zur Reduzierung von Haftgleiten
CA2814862C (en) 2010-11-10 2017-06-20 Baker Hughes Incorporated Drilling control system and method
EP3014045B1 (de) * 2013-06-27 2018-03-07 Schlumberger Technology Corporation Änderung der sollwerte in einem resonanzsystem
US10689967B2 (en) 2017-05-05 2020-06-23 Schlumberger Technology Corporation Rotational oscillation control using weight

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1703234A (en) * 1920-11-04 1929-02-26 Erle P Halliburton Method and apparatus for drilling wells, such as oil wells
US1786173A (en) * 1926-04-17 1930-12-23 Standard Oil Co California Drilling apparatus
US1935105A (en) * 1931-07-18 1933-11-14 Standard Oil Co Torque control drill feed
US3550697A (en) * 1966-04-27 1970-12-29 Henry Hobhouse Drilling condition responsive drive control
US3593807A (en) * 1969-12-11 1971-07-20 Frank J Klima Drilling apparatus
US3675727A (en) * 1970-10-23 1972-07-11 Wallace Clark Apparatus and method for governing the operation of down- hole earth boring motors
US4660656A (en) * 1985-11-22 1987-04-28 Amoco Corporation Method and apparatus for controlling the rotational torque of a drill bit
FR2666374B1 (fr) * 1990-09-04 1996-01-26 Elf Aquitaine Procede de determination de la vitesse de rotation d'un outil de forage.
US5226332A (en) * 1991-05-20 1993-07-13 Baker Hughes Incorporated Vibration monitoring system for drillstring

Also Published As

Publication number Publication date
US5507353A (en) 1996-04-16
NO944726D0 (no) 1994-12-07
EP0657620A1 (de) 1995-06-14
FR2713700B1 (fr) 1996-03-15
NO944726L (no) 1995-06-09
NO306521B1 (no) 1999-11-15
FR2713700A1 (fr) 1995-06-16

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