Patent Application
20160145955
The present invention relates to a clamping device for a drive shaft of a delivery pump and a method for fixing a drive shaft of a delivery pump in a stationary manner according to the features of the invention.
Shut-off valves are known at drilling sites, said shut-off valves serving to safeguard against the borehole pressure and being capable of preventing a blowout of oil and/or gas in the event of an impending excess pressure, in that they are rapidly shut off. So-called blowout preventers are an example of this. A blowout preventer BOP in short—is a device which is installed on the wellhead and which, during drilling, production start-up, testing or maintenance work, serves as a safeguard against the borehole pressure in the annular space between the casing and the tubing or in an uncased borehole.
Thus, a BOP is a special closure device or a special shut-off valve of a delivery pump at a drilling site, which prevents an oil or gas blowout in the event of sudden excess pressure. The conventionally known abbreviation BOP is used below for such a closure device. The BOP serves in particular as a central safety element in a deep borehole. A single shut-off valve can be arranged at a drilling site. Particularly preferably, however, a plurality of shut-off valves is combined to form a BOP stack. The BOPs are actuated for example by powerful hydraulics. The use of a plurality of BOPs also signifies a redundant design with regard to high functional safety. The BOP is provided directly above the borehole. In the case of undersea boreholes, it is thus located directly on the seabed.
Known BOPs, such as described for example in U.S. Pat. No. 5,875,841 B, comprise a central housing with a passage for the delivered medium and a passage for a drive rod or polished rod. The passage for the drive rod represents an opening for the entry of the drive rod into the borehole. The BOP also comprises a clamping bolt pair—so-called RAMs—which can be disposed in a variable manner and thus form a seal around the drive rod or polished rod, in order to prevent an unintentional escape of medium.
U.S. Pat. No. 5,765,813 B describes a BOP, wherein the sealing rubber layer of the RAM bolt is reinforced in the region of the sealing surfaces. The reinforcement consists in the fact that the RAM bolt core comprises ribs pointing outwards. The ribs serve to resist the extrusion of the rubber layer when the BOP is subjected to high pressure.
The problem of the invention is to make available a clamping device which is suitable, apart from the known sealing function, for securely fixing the drive shaft of a delivery pump when required, for example during maintenance work, when the drive head has to be replaced and so forth. The problem consists in particular in making available a clamping device for securely holding drive shafts with a large mass.
The above problem is solved by a clamping device for the drive shaft of a delivery pump and a method for spatially fixing a drive shaft of a delivery pump in a stationary manner, which comprise the features claimed in the invention. Further advantageous embodiments are described in the sub-claims.
The invention relates to a clamping device for fixing a drive shaft of a delivery pump in a rising pipe of a borehole, in particular the clamping device is used for the secure clamping of the drive shaft. The clamping device comprises a securing mechanism for the drive shaft, which mechanically fixes the position of the drive shaft spatially, especially during the disconnection of the rod assembly of a drilling rig and/or during the performance of maintenance work.
The clamping device according to the invention in particular does not represent a conventionally known blowout preventer or BOP, since there is no provision to completely shut off the pipeline by the clamping device in order thus to prevent a blowout of delivery fluid.
The rising pipe of the borehole serves to deliver a delivery fluid by means of a delivery pump with a drive shaft. The drive shaft is for example a component of an eccentric pump or a so-called beam pump or a horse head pump with a rod assembly. The clamping device comprises a housing with a first passage bore, through which the drive shaft of the delivery pump passes.
Furthermore, the housing of the clamping device comprises a second lateral passage bore which meets the first passage bore orthogonally. A mechanically acting clamping means is accommodated and/or guided in the second passage bore. The drive shaft of the delivery pump can be clamped or fixed axially and/or radially with the clamping means in the housing of the clamping device.
In particular, the drive shaft is fixed in a stationary manner by means of the at least one clamping means of the clamping device, in such a way that the weight of the drive shaft and any further components of the delivery pump disposed on the drive shaft is held inside the rising pipe by the clamping device. This means, however, that such high clamping forces have to be applied by the clamping device to the drive shaft, which can have a weight of up to several tonnes, since the drive shaft can have a length extension of several hundred up to 1600 m or more than 1600 m depending on the depth of the borehole.
According to a preferred embodiment of invention, the clamping means comprises a first and a second clamping mechanism. The two clamping mechanisms are disposed in the second passage bore each lying opposite one another, on both sides of the first passage bore. In particular, the first passage bore separates the second passage bore into a first and a second lateral opening. The first clamping mechanism is disposed for example in the first lateral bore and the second clamping mechanism is disposed in the second lateral bore. Furthermore, the two clamping mechanisms are each displaceable orthogonal to the longitudinal axis of the drive shaft. A stop is preferably assigned to the first clamping mechanism, said stop limiting the displacement path in the direction of the drive shaft. The stop is necessary for correct centring during the spatial fixing of the drive shaft inside the rising pipe. The fixing takes place in particular by clamping the drive shaft between the two clamping mechanisms. The necessary compressive and/or clamping force is applied to the drive shaft by means of the second clamping mechanism. The centring of the drive shaft by means of the stop is important especially when the two clamping mechanisms are not advanced towards the drive shaft in a simultaneous and synchronous manner. As a result of the limitation of the movement of the centring first clamping mechanism, the drive shaft is centred inside the rising pipe, before or while the second clamping mechanism is advanced towards the drive shaft.
According to an embodiment of the invention, provision is made such that the first clamping mechanism can be positioned or traversed into at least a first working position and a second working position. In the first working position, no operative connection is created between the first clamping mechanism and the drive shaft. The delivery fluid can thus be conducted through the clamping device. In the second working position of the first clamping mechanism, the latter is displaced so far inside the second passage bore in the direction of the first passage bore that the first clamping mechanism lies adjacent to the stop and the drive shaft and centres the arrangement of the drive shaft inside the rising pipe in the clamping device.
According to a further embodiment of the invention, provision is made such that the second clamping mechanism can also be brought into at least a first working position or into at least a second working position. In the first working position, no operative connection is created between the second clamping mechanisms and the drive shaft. The delivery fluid can thus be conducted through the clamping device. In the second working position of the second clamping mechanism, the latter is displaced so far inside the second passage bore in the direction of the first passage bore that the second mechanism lies adjacent to the drive shaft and pressed against the drive shaft. The necessary clamping force is thus applied to the drive shaft in order to fix the drive shaft.
The clamping device comprises at least one sealing means, in order to seal the drive shaft inside the clamping device against the rising pipe or in order to connect the drive shaft with the rising pipe in a sealing manner and thus to prevent delivery fluid from continuing to rise when the drive shaft is static and is clamped in the clamping device. A suitable sealing means preferably comprises a first and a second sealing block, which are guided towards one another orthogonal to the drive shaft and surround the drive shaft in a sealing manner, so that no delivery fluid can rise upwards.
According to an embodiment of the invention, the clamping means also forms the sealing means. In particular, the clamping means comprises sealing elements which can seal the drive shaft against the rising pipe. In this case, it is proposed that the first and the second clamping mechanism, in their second working position, engage together completely around the drive shaft. If, on the other hand, the sealing means are constituted as additional components of the clamping device, the first and second clamping mechanisms can be constituted such that, in their respective second working position, they do not engage completely around the drive shaft. In this case, clamping may be sufficient that extends only around partial circumferential regions of the drive shaft.
In a first operating position of the clamping device, both the first and the second clamping mechanism of the clamping means preferably lie in their respective first working position. This means that the clamping device in the first operating position is open for the delivery fluid, so that the latter can be conducted through the clamping device by means of the delivery pump. In a second operating position of the clamping device, both the first and the second clamping mechanism have preferably assumed their respective second working position. In this case, the drive shaft is mechanically fixed with respect to the rising pipe. In particular, the drive shaft in the second operating position inside the clamping device is secured against twisting by the clamping mechanism of the clamping means and/or the drive shaft in the second operating position inside the clamping device is secured against an axial displacement by the clamping mechanism of the clamping means. In a further possible operating position of the clamping device, in which for example the first clamping mechanism is in the second operating position, but the second clamping mechanism has not yet been advanced towards the drive shaft and therefore is in its first working position or an intermediate position between the first and second working position, delivery fluid can also be conducted through the clamping device. According to the embodiment described above, wherein the clamping means is simultaneously constituted as a sealing means, the drive shaft is not only mechanically fixed, but also sealed with respect to the rising pipe. In particular, the passage of fluid through the clamping means constituted as a sealing means is prevented.
The securing of the drive shaft against twisting and/or slipping in the region of the clamping device, in particular in combination with simultaneous sealing of the rising pipe upwards, is necessary in order to carry out service work on the borehole, the rising pipe, the delivery pump and suchlike.
In particular, provision is made such that a force is applied to the drive shaft with the second clamping mechanism. This can take place manually, for example by using a manual spindle for the longitudinal displacement of the second clamping mechanism inside the second passage bore. Furthermore, a motor-driven drive is conceivable. According to a further embodiment of the invention, a hydraulic force-increasing device is assigned to the second clamping mechanism to generate the necessary working pressure at the free end of the second clamping mechanism facing the first passage bore. The second clamping mechanism can thus press more forcefully against the drive shaft with a lower expenditure of force. In order to apply the necessary clamping force, approx. 2000 Nm tightening moment has to be generated with a conventional spindle as the second clamping mechanism. If, on the other hand, a force-increasing device is used, it is sufficient to apply a clamping force of approx. 60 Nm. In particular, this means that sufficiently high clamping forces can also be produced manually with the use of a hydraulic force-increasing device.
The clamping mechanisms comprise actuating elements, by means of which the clamping mechanisms can be moved with the aid of tools inside the second passage bore orthogonal to the longitudinal axis of the drive shaft. For example, the clamping mechanisms each comprise locating means for wrenches or suchlike at their free end orientated opposite the first passage bore, or the free ends are constituted as a hexagon etc. By means of the actuating elements, a displacement in the longitudinal direction of the respective first and second clamping mechanisms inside the second passage bore of the clamping device is brought about with suitable tools. Since no working pressure has to be applied by means of the first clamping mechanism, the force that is required for the displacement is small compared to the force that is required for the displacement and adjustment of the second clamping mechanism. In order to apply the necessary clamping force at the second clamping mechanism, the wrench to be used would have to be equipped with a correspondingly large lever, i.e. the tool has to be dimensioned sufficiently large. When use is made of a hydraulic force-increasing device assigned to the second clamping mechanism, the required tool can be dimensioned smaller. In particular, the same tool can then be used for the displacement of the first and the second clamping mechanism.
The clamping device preferably has a modular design, i.e. there is at least one housing module with the described first and second passage bores, a first clamping mechanism module and a second clamping mechanism module. Depending on the diameter of the drive shaft, the free end regions of the clamping mechanisms of the clamping means pointing in the direction of the first passage bore have to be designed correspondingly dimensioned, in order each to be able to surround and clamp the drive shaft laterally. In particular, the second clamping mechanism of the clamping means must be dimensioned correctly depending on the weight of the drive shaft to be borne and any further components disposed thereon, in order that the clamping means can also securely take the weight of the so-called drill string.
According to a further embodiment of the invention, the clamping device comprises two further lateral passage bores, which each meet the first passage bore at least for the most part orthogonally. The total of three lateral passage bores are preferably each disposed in different positions along the longitudinal axis of the first passage bores. After assembly of the clamping device on the rising pipe, the first passage bore is orientated vertically or orientated parallel to the longitudinal extension of the rising pipe. Accordingly, the total of three lateral passage bores are disposed such as to be horizontally orientated. The three lateral passage bores are a preferably provided at different heights of the housing of the clamping device.
According to a preferred embodiment of the invention, a further clamping means and a sealing means are disposed in the two further lateral passage bores. The further clamping means comprises—like the clamping means already described above—two clamping mechanisms disposed lying opposite one another, in particular a first clamping mechanism with a stop for the spatial centring of the drive shaft and a second clamping mechanism for applying the clamping force or a clamping pressure on the drive shaft. The sealing means comprises two sealing elements disposed lying opposite one another for the purpose of sealing the drive shaft with respect to the rising pipe.
A force can preferably be applied to the drive shaft in a defined direction by means of each of the clamping means each comprising a first and second clamping mechanism. According to an embodiment, the directions with which the forces are applied are each directed differently. In particular, the first clamping means is provided for the radial securing and comprises clamping mechanisms which are constituted especially for the radial clamping of the drive shaft and securing the drive shaft against twisting. The second clamping means is provided for the axial securing and comprises clamping mechanisms for the axial clamping of the drive shaft in order to secure the drive shaft against an axial displacement. The sealing elements serve only to seal the rising pipe with respect to the drive shaft, in order to prevent an undesired upwardly directed exit of the delivery fluid.
According to an embodiment of the invention, at least one clamping mechanism of the first clamping means of a clamping device comprises a first internal space with at least one inclined side wall. The at least one inclined side wall runs inside the clamping device from top to bottom in the direction of the first vertical passage bore, which runs parallel to the drive shaft of the delivery pump. At least two first ball-shaped or ball-like clamping elements are disposed at least for the most part one upon the other in the first internal space. The drive shaft can be clamped with the aid of the at least two first clamping elements, which prevents a downwardly directed axial movement of the drive shaft. In particular, the side of the first internal space facing away from the drive shaft comprises an inclined wall and the cross-sectional area of the first internal space diminishes from top to bottom. The diameter of the clamping elements also diminishes from top to bottom, i.e. the uppermost clamping element is larger than the lowest clamping element. If the drive shaft slips downwards, the first clamping elements rub along the inclined side wall and move downwards in the first internal space. As a result of the fact that the cross-section of the first internal space tapers downwards on account of the inclined side wall, the first clamping elements become wedged inside the first internal space and thus firmly clamp the drive shaft. A further downwardly directed axial movement of the drive shaft is thus effectively prevented.
According to an embodiment of the invention, at least one clamping mechanism of the second clamping means of the clamping device comprises a second internal space, which is disposed at least partially around the first passage bore. The bottom face is preferably orientated largely orthogonal to the longitudinal axis of the drive shaft or to the longitudinal axis of the rising pipe. In the second internal space, at least two second ball-shaped or ball-like clamping elements are disposed beside one another in a plane for the most part orthogonal to the longitudinal axis of the first passage bore or orthogonal to the longitudinal axis of the drive shaft. By means of the second clamping elements, the drive shaft can be clamped radially and a further rotational movement of the drive shaft can thus be prevented. In particular, the drive shaft is clamped and therefore locked when it rotates against the intended direction of rotation for the pump drive. Such a rotary motion can arise for example when the drive head fails. Since the drive linkages of delivery pumps for boreholes are up to 1.600 m long, torsion of the drive linkage arises in the region between the drive and the pump. If the drive shaft is uncoupled from the motor, a rapid backspin takes place. Even if, for example, the belt of the drive is torn, the drive wheel at the upper end of the drive shaft may accelerate so fast that it can break.
According to an embodiment, the cross-section of the second internal space diminishes in the anticlockwise direction and the diameter of the clamping elements disposed in the second internal space also diminishes in the anticlockwise direction. If both clamping mechanisms are disposed in their respective second working position, so that the drive shaft is clamped between the two clamping mechanisms, and the drive shaft moves in the anticlockwise direction, the at least two clamping elements inside the second internal space are then also moved in the anticlockwise direction and thus jam the drive shaft more forcefully, as a result of which a further rotation of the drive shaft in the anticlockwise direction is effectively prevented.
According to another embodiment, the cross-section of the second internal space diminishes, in each case proceeding from the centre, in the clockwise and anticlockwise direction. Correspondingly, the clamping elements disposed in the central region have a larger diameter than that the clamping elements disposed in the respectively outer end regions of the second internal space. If both clamping mechanisms are disposed in their respective second working position, so that the drive shaft is clamped between the two clamping mechanisms, and if the drive shaft seeks to move in the clockwise or anticlockwise direction, the clamping elements inside the second internal space are also moved in the clockwise and anticlockwise direction and at least some of the clamping elements jam, so that a further rotation of the drive shaft in the clockwise or anticlockwise direction is effectively prevented.
The clamping device according to the invention can thus perform the following functions:
The clamping device can apply a first compressive and/or clamping force, which prevents the drive shaft from twisting radially. A first function thus consists in securing the drive shaft against twisting.
And/or
The clamping device can apply a second compressive and/or clamping force, with which the drive shaft is clamped axially, in order to take up the axial load—more precisely the downwardly acting mass or gravitational force of the drill string. A second function accordingly consists in securing the drive shaft against an axial displacement.
And/or
Like conventionally know shut-off valves, a rising pipe can be sealed upwards with respect to the drive shaft by means of the clamping device, so that no delivery fluid can escape upwards. A third function thus consists in sealing the drive shaft with respect to the rising pipe for the delivery fluid.
A further secondary function of the clamping device consists in the active conducting of the delivery fluid through the rising pipe when the drive shaft is rotating, i.e. in the normal operating mode.
According to an embodiment of the invention, provision is made such that the clamping device comprises a first clamping means with a first internal space with an inclined side wall and clamping elements for the axial clamping of the drive shaft; furthermore, a second clamping means with a second internal space and clamping elements for the radial clamping of the drive shaft, as well as a sealing means for sealing the drive shaft with respect to the rising pipe.
According to an alternative embodiment, the clamping device comprises a clamping and sealing means, wherein the first clamping mechanism comprises a first internal space with an inclined side wall and clamping elements for the axial clamping of the drive shaft and wherein the second clamping mechanism comprises a second internal space and clamping elements for the radial clamping of the drive shaft and wherein the free ends of the first and second clamping mechanism orientated towards the first passage bore completely seal the outer lateral surface of the drive shaft inside the clamping device with respect to the rising pipe.
According to a further alternative embodiment, the clamping device comprises a so-called sealing and clamping means, wherein the first clamping mechanism of the clamping and sealing means comprises a first internal space with an inclined side wall and clamping elements for the axial clamping of the drive shaft and wherein the first clamping mechanism comprises a second internal space and clamping elements for the radial clamping of the drive shaft and wherein the free ends of the first and second clamping mechanism orientated towards the first passage bore completely seal the outer lateral surface of the drive shaft inside the clamping device with respect to the rising pipe.
The clamping device according to the invention is provided for installation between a borehole and the rising pipe for delivering a delivery fluid. The clamping device comprises an upper fixing region for the fixing to a drive head connected to the rising pipe and a lower fixing region for the fixing to the borehole. Provision is preferably made such that the lower and/or the upper fixing region comprises an interchangeable flange with a modular design. In particular, the lower flange can comprise means for angular adjustment, so that the arrangement or positioning of the clamping device on the borehole can preferably be adjusted in a stepless manner, in particular so that a stepless angular adjustment of the clamping device on the borehole is possible.
According to an embodiment of the invention, the lower flange device is provided as a module, which is selected using an appropriate size and is fixed to the housing of the clamping device. The lower flange device is constituted such that it enables a variable orientation of the housing of the clamping device between the borehole and the drive head. The flange device comprises a first fixing plate, with which the flange device is screwed to the housing of the clamping device. Furthermore, the flange device comprises a second fixing plate with fixing bores, which are disposed corresponding to corresponding standardised fixing devices on the borehole. Since there are various standard specifications worldwide, the clamping device can easily be adapted to the borehole by selecting the suitable flange device with a corresponding lower fixing plate which has suitably dimensioned fixing bores for the given borehole.
The first fixing plate comprises elongated bores for screwing the flange device to the housing of the clamping device. Said elongated bores can in particular be constituted as a part radius. The flange device is first arranged on the borehole and fixed to the latter. The clamping device is then placed on the flange device and orientated in such a way that the clamping device can be advantageously connected to existing pipes, for example to discharge pipes via which the delivery fluid is fed for further processing. The clamping device preferably comprises, above the lateral passage bore for the clamping mechanisms of the clamping means or above the lateral passage bore for the sealing mechanisms of the sealing means, at least one further discharge bore orientated orthogonal to the first passage bore and meeting the first passage bore, through which discharge bore the delivery fluid can be carried away. The clamping device thus also performs the function of a so-called FlowT device. Especially in the case of discharge pipes already laid in an oilfield, a subsequently installed clamping device should therefore be able to be adapted flexibly to the arrangement of the discharge pipes, without the course thereof also having to be changed. The first fixing plate comprises elongated bores, which enable an angular fine adjustment and optimum orientation of the housing of the clamping device on the flange device. The housing is placed in the optimum orientation on the flange device and screwed to the latter via the elongated bores. Conventionally, fixed fixing bores have enabled the orientation only at defined angular distances, the elongated bores now enabling a stepless orientation.
The invention also relates to a method for the spatial fixing of a drive shaft in a rising pipe assigned to a borehole. At least one clamping device, in particular the clamping device such as has been described above, is disposed between the borehole and a drive head assigned to the drive shaft. In a first operating position of the clamping device, delivery fluid is conducted through the clamping device. According to the invention, the clamping device can assume at least a second operating position. In the second operating position, a first compressive or clamping force is applied to the drive shaft by the clamping device, said compressive or clamping force preventing the drive shaft from twisting radially. Additionally or alternatively, a second compressive or clamping force is applied to the drive shaft, which clamps the drive shaft inside the clamping device in such a way that an axial movement of the drive shaft inside the rising pipe is prevented. In particular, the second compressive or clamping force prevents the drive shaft from moving axially inside the rising pipe. Furthermore, the drive shaft can be sealed with respect to the rising pipe in the second operating position, in such a way that no delivery medium can rise upwards.
According to an embodiment of the invention, the application of the respective compressive or clamping force for the radial and/or axial clamping of the drive shaft takes place by means of at least one clamping means in each case and the sealing of the drive shaft with respect to the rising pipe takes place by means of at least one sealing means of the clamping device. According to an alternative embodiment of the invention, the sealing of the drive shaft with respect to the rising pipe and the application of the respective compressive or clamping force for the radial and/or axial clamping of the drive shaft takes place by means of a single sealing and clamping means, which comprises a first and a second sealing and clamping mechanism.
The sealing and clamping of the drive shaft preferably takes place by means of a clamping device described above. In particular, the first clamping mechanism can be displaced rapidly inside the second passage bore in the direction of the first passage bore. The displacement path is limited by a stop inside the clamping device. The compressive or clamping force is then applied in a controlled manner on the drive shaft by the second clamping mechanism.
The present invention describes the clamping device for a delivery pump, in particular for a borehole eccentric pump, with which the drive shaft of the delivery pump can be sealed especially for maintenance and/or repair work and fixed axially and/or radially in a clamping manner.
The three functions of sealing, radial securing and axial securing can be implemented either by a single sealing and clamping means comprising a first and second sealing and clamping mechanism. According to preferred embodiment, the three functions are each implemented individually, preferably by two clamping means and one sealing means. The clamping means each comprise a first and second clamping mechanism and the sealing means comprises a first and second sealing mechanism. The first and second clamping mechanisms and the first and second sealing means are each disposed in pairs lying opposite one another in horizontally orientated, lateral passage bores. When use is made of two clamping means and one sealing means, a clamping means comprising a first and a second clamping mechanism is provided in each case for a force which is applied in a defined direction in each case. Each clamping means comprises a first clamping mechanism with which the drive shaft is spatially centred and second clamping means which is preferably provided with a hydraulic force-increasing device and generates the actual working pressure, i.e. the clamping or compressive force.
In particular, the clamping device according to the invention is a manually operated safety valve for ensuring the safety during control and maintenance work on the drive unit or the borehole, in particular when the delivery pump is at a standstill. In particular, the clamping device is used for the well control. The clamping device is disposed between the drive head of the delivery pump and the wellhead. The rising pipe can be sealed with respect to the drive shaft or the rod assembly and the drive shaft can be additionally fixed in a stationary manner and, in particular, can be secured against radial twisting and/or axial displacement.
The position of the drive shaft in an axial direction and/or in a radial direction can be fixed and secured with the clamping device according to the invention. The fixing in the axial direction is necessary particularly for securing the drive shaft during the disconnection of the rod assembly, for example during the replacement of the delivery pump. The securing in the radial direction is necessary especially as part of maintenance work on the delivery pump and/or on the rising pipe. In particular, the radial fixing is intended to prevent the backspin of the drive shaft when the delivery pump is stopped.
High clamping forces can be applied manually with the clamping device according to the invention, in particular clamping forces that are sufficient to fix the drive shaft securely in a stationary manner inside the rising pipe when, for example, the drive head is to be replaced or further maintenance work is to be carried out. Expensive, large additional equipment can thus be dispensed with which it is conventionally used to hold the drive shaft, which can have a weight of several tonnes.
The clamping device described here is provided in particular for borehole pumps for drilling on land, i.e. onshore, in order for example to enable a replacement of the drive of the delivery pump used, without providing expensive securing devices that reliably take the weight of the drive shaft disposed in the rising pipe and any further components. A use for deep-sea drilling should not however be excluded.
The clamping device comprises in particular a quick-acting closure function. On the account of the stop for limiting the displacement path of the first clamping device, the latter can be advanced rapidly towards the drive shaft. The stop prevents the first clamping mechanism from being pushed too far into the first passage bore of the clamping device and centres the drive shaft inside the rising pipe in the region of the clamping device. The required working pressure is then applied by the second clamping mechanism, wherein devices are provided which mark the operating position up to which the clamping mechanism can be rapidly pushed. The remaining clamping or compressive force is then applied in a controlled manner, in particular by a slow further insertion of the second clamping device, in order to prevent excessively forceful clamping and thus possible damage to the drive shaft.
Examples of embodiment of the invention and its advantages are explained in greater detail below with the aid of the appended figures. The size ratios of the individual elements with respect to one another in the figures do not always correspond to the actual size ratios, since some forms are represented simplified and other forms are represented enlarged in relation to the other elements for the sake of better illustration.
Identical reference numbers are used for identical or identically acting elements of the invention. Furthermore, for the sake of a clearer view, only reference numbers are represented in the individual figures that are required from the description of the respective figure. The represented embodiments merely represent examples as to how the device according to the invention or the method according to the invention can be constituted and do not represent a definitive limitation.
Furthermore, first and second clamping mechanism 10, 11 form clamping means, by means of which the drive shaft of the delivery pump can be clamped axially and/or radially inside clamping device 1. In particular, such high clamping forces can be applied by clamping mechanisms 10, 11 of the clamping means that the total weight of the drive shaft can be held by clamping device 1 when, for example, the drive head has to be the maintained, repaired or replaced.
Clamping mechanisms 10, 11 are disposed in a first working position in their respective lateral bores 6a, 6b in such a way that clamping mechanisms 10, 11 do not clamp the drive shaft, but rather that delivery fluid can flow through clamping device 1.
Housing 2 comprises, above second passage bore 6, at least one discharge bore 19, preferably a passage discharge bore 19*, which also meets first passage bore 5 orthogonally. In the represented embodiment, discharge bore 19, 19* is disposed at least for the most part at a 90° angle to second passage bore 6. Passage discharge bore 19* represents the function of a FlowT inside clamping device 1. This means that a direct connection between the rising pipe, in which the delivery fluid is pumped upwards, and discharge pipes, via which the upwardly pumped delivery fluid is fed for its further processing, can be produced by passage discharge bore 19*.
Furthermore, a stop 9 is assigned to first clamping mechanism 10, said stop limiting the displacement path inside lateral bore 6a in the direction of the drive shaft or in the direction of first passage bore 5. Stop 9 is required for correct centring during the spatial fixing of the drive shaft, which is explained in greater detail in connection with
First fixing plate 13 comprises elongated bores 17* for the purpose of fixing flange device 4 to housing 2 by means of screws 15, said elongated bores extending radially in segments via first fixing plate 13. Clamping device 1 is orientated on the borehole in such a way that it can be connected advantageously to existing pipes, in particular to pipes with which the delivery fluid is carried away. The connection to existing pipes preferably takes place without their positioning or course having to be changed. Flange device 4 is preferably first fixed to the borehole when clamping device 1 is being fixed to the borehole. Housing 2 of clamping device 1 with the further components such as for example clamping mechanisms 10, 11 etc. is then placed on first fixing plate 13 of flange device 4 and fixed in the desired orientation. An angular fine adjustment and optimum orientation of housing 2 of clamping device 1 on first fixing plate 13 of flange device 4 is made possible by elongated bores 17*.
Since the clamping force for holding the weight of the drive shaft and any further components of the drilling string has to be applied by means of second clamping mechanism 11, a tool with a correspondingly long lever or suchlike is required for the manual adjustment.
In the case of hydraulic force-increasing device 40 according to
In this embodiment of a first clamping mechanism 10b, free end 20 comprises a receiving arrangement 55 for a module insert 60. Module insert 60 is arbitrarily interchangeable and is selected, before the assembly of clamping mechanism 10b, according to the intended use, in particular according to the weight of the drive shaft and other requirements made on the clamping device, and is assembled in receiving arrangement 55 of free end region 20.
On account of the at least one inclined side wall 66, the cross-sectional area of first internal space 65 inside the clamping device tapers from top to bottom. The diameter of clamping or rolling elements 67 also diminishes from top to bottom, i.e. uppermost rolling element 67o is larger than lowest rolling element 67u. It drive shaft 70 clamped between clamping mechanisms 10b, 11 slips downwards, this leads to a downwardly directed movement of rolling elements 67 in first internal space 65. Rolling elements 67 become wedged in downwardly tapering, first internal space 65, as a result of which the clamping of drive shaft 70 becomes even firmer. A further downwardly directed axial movement of drive shaft 70 is thus effectively prevented.
In second internal space 70, rolling elements 71 are disposed beside one another in a plane, which runs at least for the most part orthogonal to longitudinal axis L of drive shaft 70. According to the represented embodiment, the cross-section of second internal space 70 diminishes in anticlockwise direction GUZ and the diameter of rolling elements 71 disposed in the second internal space also diminishes in anticlockwise GUZ. By means of rolling elements 71, drive shaft 70 can be clamped radially and a further rotational motion of drive shaft 70 is thus prevented. In particular, drive shaft 70 is clamped when it turns in a rotary manner against the intended direction of rotation for the pump drive. In the example of embodiment, provision is made such that drive shaft 70 is additionally clamped radially when the two clamping mechanisms 10c, 11 are each located in their second working position against drive shaft 70 and the drive shaft rotates in anticlockwise direction GUZ. Rolling elements 71 are moved in anticlockwise direction GUZ inside second internal space 70 and thus jam drive shaft 70 more forcefully, as a result of which a further rotation of drive shaft 70 in anticlockwise direction GUZ is effectively prevented.
First clamping mechanism K1-1 and K2-1 and second clamping mechanism K1-2 and K2-2 and first and second sealing means D1, D2 are each disposed in pairs lying opposite one another in horizontally orientated, lateral passage bores 6. In particular, 6K1 denotes the passage bore for first clamping means K1, 6K2 the passage bore for second clamping means K2 and 6o the passage bore for sealing means D. For example, first clamping means K1 is provided for the radial clamping and second clamping means K2 is provided for the axial clamping of the drive shaft (not represented) disposed in first passage bore 5. Each clamping means K1, K2 comprises a first clamping mechanism K1-1, K2-1 with a stop, with which the drive shaft is spatially centred, and a second clamping mechanism K1-2, K2-2, which is preferably provided with a hydraulic force-increasing device and generates the actual working pressure, i.e. the clamping or compressive force.
The at least one lateral discharge bore 19 (see
The invention has been described by reference to a preferred embodiment. The person skilled in the art can however envisage that modifications or changes can be made to the invention without thereby departing from the scope of protection of the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102013108322.6 | Aug 2013 | DE | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/DE2014/000396 | Jul 2014 | US |
| Child | 15012298 | US |
