EP0947664A2 - Method for monitoring a telescopic drill string and a protection device for a telescopic drill string - Google Patents

Abstract

The method involves measuring the required holding force for the rotary drive holder (8). This is compared with the theoretical pulling force based on the weight of the tubes (2,6,7). This force starts with the total weight of the tubes and is successively reduced to the weight of at least a further tube in dependence on the stroke distance covered. A signal is generated when the measured holding force falls to a predetermined value below the force corresponding to the respective stroke distance. Independent claims also cover a protective device for a telescopic tube.

Description

The invention relates to a method for monitoring the intended Behavior of individual tubes of a telescopic Boring bar (Kelly bar) when pulling apart the pulled apart Pipes, with the outer, upper pipe initially attached to a rotary actuator holder is supported and pulling up with the inner, lower tube begins, which every other tube according to a defined travel distance.

The invention further relates to a protective device for a telescopic boring bar that carries an inner tube a drilling tool, an outer tube in which the inner tube axially movably guided between two stops and in one Locking position can be fixed in a rotationally fixed manner, a rotary drive for the boring bar that engages the outer tube and by means of a rotary drive holding device can be raised and lowered, and a boring bar support connected to the inner tube for raising and lowering the boring bar.

Such telescopic boring bars, called Kelly bars are known, for example, in the Bauer company brochure: Large rotary drilling rig Kelly rods (release note: 905.518.2 11/94). You will be using rotary drilling Rotary drilling rigs for Drilling holes used in the ground. Such Boring bar contains at least two nested and telescopic tubes for torque transmission from the rotary drive mounted on the rotary drilling rig onto the drilling tool are rotatably connected to each other, and the Pull apart telescopically as the drilling depth increases can. This is sufficient from the prior art known, so that the subsequent Designs only in a short form on structure and Go into operation of the boring bar, as far as this Understanding of the invention is required.

The inner tube of the boring bar is attached to a rope Main or Kelly winch of the drill attached. To extend of the drill pipe during drilling falls due to the Weight of the Kelly tubes the next Kelly tube down to a stop. At the subsequent Twist this outer Kelly tube with the help of the rotary drive it is due to the engagement of locking elements in am Locking pockets on the outer circumference of the inner tube locked with this and axially attached to it so that over the on a mast of the drill using a cable winch vertically displaceable rotary drive an axial Compressive force on the drill pipe and thus on the drilling tool can be applied.

For emptying the drilling tool and lifting it from the Borehole must be the telescoped, interlocked Kelly tubes are retracted. To do this, first of all outer Kelly tube slightly into the opposite direction of drilling so that the two or several interlocking Kelly tubes from her Move the locking position. With the main rope that always attached to the top of the inner or innermost Kelly tube the Kelly tubes can be pulled up. With this Pulling up the Kelly tubes can happen that the next outer Kelly tube with the inner Kelly tube, the is being lifted, jammed and therefore already is pulled up, although the inner Kelly tube is not yet on axial end stop abuts the surrounding Kelly tube. This is due to a game between the Kelly tubes and themselves randomly changing friction in the different Kelly tubes possible.

If the next outer Kelly tube with the inner Kelly pipe taken away due to such a jam there is a danger to the Kelly bar and the Rotary drive, because the pulled up due to frictional forces Kelly tubes suddenly overcome the friction and up to each stop can fall down. This failing can damage the actuator because of a Kelly tube several meters in free fall to the lowest Stop fails and this weight-related impulse over the Kelly rod is transferred directly to the rotary drive.

If the entire Kelly rod is in contact with the individual during drilling The operator has kelly tubes in the borehole no visibility to ensure the correct entry to monitor the interlocking Kelly tubes. This causes the Kelly tubes to get caught or jammed only noticeable when a Kelly tube fails and the Impulse via the rotary drive on the drill pipe and the Mast of the drill is transferred.

To prevent damage from this diarrhea Kellyrohres it is known in the art that the Rotary drives or the Kelly pots, which the top edition form the Kelly rod on the rotary drive, a protective device have either spring packs or a combination of spring assemblies with damper elements can. Shocks that occur can be dampened, however cannot be prevented.

The invention is therefore based on the object of specifying a method for monitoring a telescopic boring bar so that undesired falling through of individual tubes when the boring bar is being raised can be avoided.

It is a further object of the present invention to provide a protective device for a telescopic boring bar, with which the operator can recognize whether a kelly tube has become jammed when the kelly bar is pulled up and thus the risk of a kelly tube falling through when the jam is released unexpectedly consists.

According to the invention, the first-mentioned object is achieved that according to the invention in a method mentioned in the introduction one required for the rotary drive holding device Holding force is measured and with the theoretical tensile force is compared based on the weight of the pipes, whereby the tensile force is initially determined by the total weight of the pipes and successively depending on the travel distance reduced by the weight of at least one other tube and that a signal is generated when the measured Holding force a certain value below that of the respective Stroke corresponding pulling force falls.

The first-mentioned object is also achieved in that a method mentioned above, a lifting force for lifting of the tubes measured depending on the detected stroke and with a theoretical pull due to weight of the pipes is compared, with the tensile force initially determined by the weight of the lower tube and depending from the travel distance covered successively by adding the Weight of at least one other tube is increased, and that a signal is generated when the measured lifting force the respective traction corresponding to a certain traction Value exceeds. In this way, one can simple force measurement and by comparison with one stored or immediately to be calculated weight force at least of a pipe a statement about the condition of the pipes the boring bar is hit when it is pulled up.

This is an alternative solution that is comparable delivers good result.

These solutions are based on the basic idea of an assignment between a travel distance covered and an expected one Weight change, and when pulling up a cable travel measurement and a weight measurement and a match or deviation with the specified values ascertain.

The signal is preferably converted into a warning message for a Operator implemented. Then the operator can also without Visual contact to the boring bar necessary actions in time to protect the boring bar from damage protect.

In an expedient embodiment of the method the starting positions of the rotary drive holding device and the boring bar is determined and for a zero setting of the Stroke measurement used before pulling up the boring bar. The method can thus be used universally and always allows accurate monitoring of the forces that occur.

The second-mentioned object is achieved in that a protective device for a telescopic boring bar mentioned above has a measuring device for detecting the lifting or pulling force F ₁ between the boring bar support device and the boring bar and / or a measuring device for detecting the holding force F ₂ between the rotary drive -Holding device and the rotary drive, wherein a comparator is provided which compares the force F ₁ and / or the force F ₂ with a theoretical weight due to the number of tubes to be carried depending on the stroke and when generating the boring bar and generates a signal , if the force F ₁ and / or the force F ₂ deviates by a certain value from the theoretical weight to be borne in each case.

Advantageous embodiments of the invention are in the subclaims specified.

A simple, yet reliable design exists in that the boring bar support and Rotary drive holding device one winch with one Has suspension rope. On the winch or the pull rope can on easily detected a rope movement or change in stroke become. However, the rotary drive holding device can also in particular from a hydraulically operated piston-cylinder unit are driven.

The measuring devices expediently measure the tensile forces in the suspension cables. Various measuring sensors can be used for this be used.

When the signal is used as a warning signal on a display for an operator is transferred, if necessary, one can be transferred immediately Actuation of the control for raising and lowering the Boring bar, for example actuation of the cable winch, be carried out to avoid possible damage.

Instead of manual operation, the signal or warning signal can be used also a control for pulling up the boring bar fed to automatically perform an action be, in particular a safety operation such as for example, lowering the boring bar again Release of a jam can be made.

The display option for the driver or the operator can also be based on the fact that the tensile force F ₂ applied to the rotary drive is measured and the position of the rotary drive along the drilling mast is determined by means of a rope length measurement. The force F ₂ is compared with the force F ₁ , which may reach certain values depending on the length of the Kelly rope F ₁ . If the rope length measurement on the support or Kelly rope shows that only the innermost tube is carried by the Kelly rope, then the force F ₁ can be calculated, since the weight of each individual tube is known. This arithmetically determined force is compared with the force F ₁ measured via the cable tension measuring device and compared as a function of the force F ₂ and the cable length measurement on the cable F ₂ . If the difference between the measured force F ₁ and the calculated force F ₁ exceeds a defined value, a warning message appears in the driver's cab of the drilling device, whereupon the operator can prevent the Kelly tubes from falling through, for example by allowing the Kelly rod to extend again (i.e. lowering via the Kelly rope), so that the undesired jamming can be released again before the telescopic Kelly tubes are pushed together again (ie lifting over the Kelly rope).

Fig. 1

in einer Seitenansicht eine teleskopierbare Bohrstange mit einem Drehantrieb;

Fig. 2

in einer Seitenansicht in vergrößerter Darstellung den Drehantrieb mit einer partiell und geschnitten dargestellten Bohrstange;

Fig. 3

in einer Seitenansicht ein Drebbohrgerät in Gesamtdarstellung; und

Fig. 4

in einer Seitenansicht ein Drehbohrgerät mit teleskopierter Bohrstange.

The invention is explained in more detail below using an exemplary embodiment of a protective device according to the invention with reference to drawings. It shows:

Fig. 1

in a side view a telescopic boring bar with a rotary drive;

Fig. 2

in a side view in an enlarged view, the rotary drive with a boring bar shown partially and in section;

Fig. 3

in a side view a rotary drilling machine in an overall view; and

Fig. 4

in a side view a rotary drilling rig with telescopic boring bar.

A telescopic drill or Kelly rod 1 with itself known structure contains an inner tube 2, for example, which can also be a rod (see Fig. 2), on the Upper end of a Kelly eye 3 for attaching a suspension cable 4 and a drilling tool 5 is attached to the lower end thereof. The inner tube 2 is in a middle tube 6 through (not shown) Carrier strips guided axially and at the same time rotatably mounted and thus in a known Way telescopic. The middle tube 6 is in turn an outer tube 7 added in the same way. The outer Tube 7 is in one pass of a power head 8 of a rotary drive 9 axially displaceably received and over a driver ring 10 of the rotary head 8 and associated Driver strips on the circumference of the outer tube 7 in rotation drivable. The power turret 8 is by means of a gear slide 11 on a mast 12 (see Fig. 3) of a rotary drilling machine 13 slidably mounted and by means of a rope 14 and a winch 15 over the length of the mast 12 can be moved up and down. The 12 is on a movable Equipment carrier 16 stored a cabin 17 for an operator having.

The individual tubes 2, 6, 7 have upper and lower end stops on who move or telescopic limit their relative axial movements. By mutual Twisting two pipes each via the rotary drive Locks can be snapped into place so that the Tubes axially fixed to each other and to the rotary head 8 are and an axial drilling force on the drill pipe (the Kelly rod 1) can be applied. By opposite The latches can rotate in a known manner be solved again.

With the support rope 4 and an associated winch 18 can the boring or Kelly bar 1 are raised and lowered. With the feed rope 14 (alternatively with a hydraulic Feed cylinder), the power turret 8 can be raised and with the feed movement when drilling together with the boring bar 1 can be lowered.

This structure and the mode of operation described so far are known from the prior art.

For measuring the tensile or lifting force F ₁ in the support cable 4 and the tensile or lifting force F ₂ in the feed cable 14, which carries the power turret 8, or alternatively in a corresponding hydraulic cylinder device, respective force measuring devices or sensors (not shown) are provided which deliver a respective tensile force signal to a comparison device.

4 is a rotary drilling machine with a hydraulic cylinder as a holding or feed device for the rotary head 8 shown. The following considerations of forces apply for both cylinders and winches as feed devices.

In the following step-by-step analysis, the Simplification only the weight of pipes 2, 6 and 7 (i.e. H. without the weight of the drilling tool, the power turret or the like) is taken into account.

Before pulling out or lifting the boring bar 1 supports the outer tube 7 with its pot-like shoulder 20 (See Fig. 2) on the power turret 8, so that the power turret 8 carries the weight of the entire boring bar 1. Fig. 2 also shows damping device mounted on the power turret 8 with springs 21. On the springs 21 can measuring devices be attached for force detection. Especially simply by measuring the distance in proportion to the force or by Piezo force transducers or the like performed the measurement become.

Compared to the measurement of the pulling or lifting force F ₂ pre-lifting rope 14, the weight of the rotary power head 8 is not measured here.

The following equation of forces results: F 1 = 0; F 2nd = F R1 + F R2 + F R3 ;

F _R1 , F _R2 and F _R3 denote the weight of the inner, middle and outer tubes 2, 6 and 7, respectively (see FIG. 4).

When the boring bar 1 is initially raised, the inner tube 2 is first lifted over the supporting cable 4: F 1 = F R1 ; F 2nd = 0 + F R2 + F R3 ;

When lifting further, the inner tube 2 comes to a longitudinal stop on the middle tube 6 and also lifts it: F 1 = F R1 + F R2 ; F 2nd = 0 + 0 + F R3 ;

When lifting further, the inner tube 2 with the middle tube 6 finally reaches the longitudinal stop of the outer tube 7 and lifts it relative to the rotary power head 8: F 1 = F R1 + F R2 + F R3 ; F 2nd = 0 + 0 + 0;

In the comparison device, the tensile force F ₁ is compared with the stored weight forces F _R1 , F _R2 and F _R3 , taking into account the stroke path of the suspension cable 4, with normal operation during a first stroke path which is proportional to the length of the inner tube 2, and the above-mentioned force relationships will occur during the further stroke distances. If the measured force values F _{1 deviate} from the permissible, calculated force values by more than a certain force value, as can occur when two pipes are jammed, the comparison device generates a signal. This signal is shown, for example, in the cabin 17 of the equipment carrier 16 as a warning signal, for example as a visual display or as an acoustic warning signal, so that the operator can initiate an action in good time. For example, it can stop lifting and lower the jammed pipes by lowering it. However, the signal can also be operated by a control which stops the lifting of the boring bar by itself.

The position of the power turret can be determined by measuring the distance on the cable 14 8 on the mast 12 and thus the starting position of the Boring bar 1 can be determined when pulling up and a zero setting for the suspension cable 4 at the start of lifting be made. It can therefore be used at any height position of the rotary drive 9 on the mast 12 made this method that the position deviation of the rotary drive from the zero position when measuring the rope travel on rope 4 is taken into account, i.e. added or subtracted depending on the direction becomes.

The above equations of forces show that the aim according to the invention can be achieved with different measuring possibilities and measuring arrangements. For example, either only the force F ₁ in the suspension cable 4 or only the holding force F ₂ required for the power turret 8 can be measured, which are then compared with the theoretically existing tensile forces, each of which is a function of the distance traveled and the associated theoretical change in weight force change the number of pipes to be held. However, the forces F ₁ and F ₂ can also be compared in order to obtain a signal which provides information about the safe operation when pulling up a telescopic boring bar.

Claims (12)

Method for monitoring the intended behavior of individual pipes of a telescopic boring bar (Kelly bar) when pulling up the pulled-apart pipes, the outer, upper pipe being initially supported on a rotary drive holding device and the pulling-up starting with the inner, lower pipe, which follows each further pipe takes along a defined travel distance,
characterized by that a holding force (F ₂ ) required for the rotary drive holding device (8) is measured and compared with the theoretical tensile force based on the weight of the tubes (2, 6, 7), the tensile force initially being determined by the total weight of the tubes (2, 6, 7) is determined and, depending on the travel distance covered, is successively reduced by the weight of at least one further tube (6, 2), and that a signal is generated when the measured holding force (F ₂ ) falls by a certain value below the pulling force corresponding to the respective stroke (F _R1 , F _R2 and F _R3 ; F _R1 and F _R2 ; F _R1 ). Method for monitoring the intended behavior of individual pipes of a telescopic boring bar (Kelly bar) when pulling up the pulled-apart pipes, the outer, upper pipe being initially supported on a rotary drive holding device and the pulling-up starting with the inner, lower pipe, which follows each further pipe takes along a defined travel distance,
characterized by that a lifting force (F ₁ ) for pulling up the pipes (2, 6, 7) is measured as a function of the detected stroke and is compared with a theoretical pulling force based on the weight of the pipes (2, 6, 7), the pulling force being dependent on the Weight of the lower tube (2) is determined and, depending on the travel distance covered, is successively increased by adding the weight of at least one further tube (6, 7), and that a signal is generated when the measured lifting force (F ₁ ) exceeds the pulling force corresponding to the respective lifting path (F _R1 ; F _R1 and F _R2 ; F _R1 , F _R2 and F _R3 ) by a certain value. The method of claim 1 or 2,
characterized by that the signal is converted into a warning message for an operator. Method according to one of claims 1 to 3,
characterized by that the starting positions of the rotary drive holding device (8) and the boring bar (1) are determined and used for a zero setting of the stroke distance measurement before the boring bar (1) is pulled up. Protection device for a telescopic boring bar, which has an inner tube for carrying a drilling tool, an outer tube in which the inner tube is axially movable between two stops and can be fixed in a locked position in a locking position, a rotary drive for the boring bar, which engages the outer tube and can be raised and lowered by means of a rotary drive holding device, and has a boring bar support device connected to the inner tube for raising and lowering the boring bar,
characterized by that they have a measuring device for detecting the lifting or pulling force (F ₁ ) between the boring bar support device (4) and the boring bar (1) and / or a measuring device for detecting the holding force (F ₂ ) between the rotary drive holding device (14) and the rotary drive (9), that a comparator is provided, which compares the force (F ₁ ) and / or the force (F ₂ ) with a theoretical weight due to the number of tubes to be carried depending on the stroke and generates a signal when the boring bar (1) is pulled up , if the force (F ₁ ) and / or the force (F ₂ ) deviates by a certain value from the theoretical weight to be borne in each case. Protection device according to claim 5,
characterized by that the boring bar support device (4) and the rotary drive support device (14) each have a winch (18 or 15) with a support cable (4, 14). Protection device according to claim 5 or 6,
characterized by that the measuring devices measure the tensile forces (F ₁ , F ₂ ) in the supporting cables (4, 14). Protection device according to one of claims 5 to 7,
characterized by that the signal is transmitted as a warning signal to a display for an operator. Protection device according to one of claims 5 to 7,
characterized by that the signal or the warning signal of a control for pulling up the boring bar (1) is supplied. Protection device according to claim 9,
characterized by that the signal or the warning signal in the control for pulling up the boring bar (1) performs a safety actuation. Protection device according to one of claims 5 to 10,
characterized by that the weight of the boring bar (1) on the rotary head (8) is determined by a measuring device. Protection device according to claim 11,
characterized by that the boring bar (1) is supported by a spring device (21) on the rotary power head (8), and that the bearing force of the boring bar (1) is determined by measuring the spring travel.

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