EP2789859A1 - Pump system for deep drilling - Google Patents

Abstract

The invention relates to a system (20) for conveying water from wells and deep wells for water supply and geothermal use of hot water or other liquids and comprises a conveying device (8) for conveying a conveying medium, a drive device (1) which controls the conveying device (8 ) drives a drive shaft (6) interconnecting the drive device (1) and the conveyor (8) to drive the conveyor (8), a riser (2) in which at least the drive shaft (6) and the conveyor (8 ), and a fastening device (10), which defines the conveying device (8) in the end position at least in the circumferential direction, wherein the drive shaft (6) and the conveying device (8) in the riser (2) are mounted such that these at least when removing the conveyor device (8) in the axial direction relative to the riser (2) are freely movable.

Description

Field of the invention

The invention relates to a system for the promotion of water from wells and deep wells for water supply and geothermal use of hot water or other liquids.

State of the art

In FIG. 2 is a conveyor system 100 to see from the prior art. For such a conventional plant, a wellbore is inserted into the soil at a desired depth, and the wellbore is stabilized by wellbore casing with a support tube. The conveyor system 100 itself has a drive motor 101, a riser 102 formed from tube segments, a pump device 108 and a multiply mounted and coupled drive shaft 106, which connects the drive motor 101 to the pump device 108. In FIG. 2 the pump device 108 is integrated in a pump tube, which is flanged at the lower end by means of a transition tube 103 to the riser 102. As it were, the pump 108 is arranged in one end of the riser 102, wherein this end is then in the installed state of the conveyor 100 at the lower end in the borehole. The drive shaft 106 for transmitting the torque from the drive motor 101 to the pump device 108 is mounted at regular intervals in the riser 102 with plain bearings 107 to avoid damage from the vibrations of the drive shaft. The drive motor 101 is located at the upper end of the riser 102.

Usually, when using pumps for hot water production from deep geothermal wells Underwater centrifugal pumps used. These centrifugal pumps operate on the principle of action of the swirl due to the transfer of energy to a liquid through a rotating impeller in a fixed nozzle. The design of the centrifugal pumps differs according to the requirements of the design and the number of stages. As an alternative to the centrifugal pump, however, displacement pumps, for example progressing cavity pumps according to the Moineau pump principle, can also be used at lower temperatures.

The riser 102 consists of individual segments which are modularly flanged together with pre-assembled and integrated pump device 108 and drive shaft 106 to each other and then inserted into the support tube. Finally, the riser is then flanged to the support tube for attachment to the head. The shaft segments of these standardized riser modules may further each be surrounded by a further cladding tube (not shown) to allow the lubrication of the individual bearing segments independently of the axially upward flow rate. The lubricant partially penetrates into the pumped medium, thus causing contamination of the pumped medium. The overall length of the riser segments is shorter than 6 m. The number of stacked riser segments is limited, so that only a total length of about 400 m can be achieved.

Especially with very deep holes, the cost of building and using such conveyors is therefore very large. This is particularly problematic when a part of the conveyor system has to be replaced, for example because it is worn or damaged. Because in order to remove the pump or parts of the bearing, it is always necessary to remove the riser segments together with the integrated shaft. In this case, the hole must be interrupted for a long period of time, since the riser and the in Riser mounted components (drive shaft, bearing, pump) must be removed together from the support tube. Since these components are very often massive and extremely heavy, often special vehicles are needed for the assembly and disassembly.

In order to avoid at least the storage of the drive shaft in the riser alternative underwater motor pumps are used. In such centrifugal pumps, one or more axially underlying electric motors are present as a drive, which are filled with water or oil. However, such underwater pumps and in particular their motors are much more susceptible to wear in heat, high voltage and corrosion, which in turn often occurs in deep wells. In addition, for the removal of these pumps, the riser pipes must also always be removed, as the pump is integrated in the riser.

Presentation of the invention

Object of the present invention is therefore to provide a conveyor system that can not only be used optimally for deep wells, but also allows a reliable and relatively uncomplicated replacement of relevant components and parts.

In order to achieve this object, a system for conveying water from wells and deep wells for water supply and geothermal use of hot water or other liquids comprises the features of claim 1.

Such a conveyor includes a conveying device for conveying water, a driving device that drives the conveying device, a drive shaft that drives the driving device, and the conveying device for driving the conveyor device connects to each other, and a riser, and in which at least the drive shaft and the conveying device are arranged, wherein the drive shaft and the conveyor are mounted movably in the riser and relative to the riser in the axial direction. This makes it possible to remove the drive shaft and the conveyor independent of the riser from the pump system. This means that the riser pipe can remain in the borehole after a single installation and the delivery pump is installed and removed by removing the drive shaft (with delivery device) without the simultaneous removal of the riser pipe being required. This allows the replacement of parts of the system (eg. The conveyor) can be significantly accelerated and the standstill of the system can be reduced accordingly. Further, since the drive shaft is installed without intermediate connection to flanged riser segments, but as a screwed drive shaft whose lateral deflection during rotation by variable bias in the longitudinal direction and conditional centering is prevented can be dispensed with lubricants that can otherwise escape into the fluid. The running safety is achieved by an axial tensile force (the weight of conveyed in the riser medium) through which the drive shaft is stretched and elongated and thus stretched.

Preferably, the conveyor system further comprises a bearing device, which supports the conveyor device in the riser. Such a bearing device enables a precise positioning of the conveying device in the end position in a simple manner. In particular, the bearing device may comprise a first bearing element, which is attached to the conveying device, and a second bearing element, which is fixedly mounted on the riser, wherein the first and second bearing element are axially movable relative to each other. Such a two-part storage device is a little expensive construction to design the storage device safely.

In the conveyor system, the conveying device is preferably mounted rotationally fixed to the riser in the circumferential direction. By a rotationally fixed mounting to the riser, the function of the conveyor system is ensured and an optimal position of the conveyor system allows, so that the pump in the axial direction of the riser, the pumped medium (eg water) can promote. The rotationally fixed mounting of the bearing device in the riser can be provided such that the bearing elements have complementary projections and recesses, for example. Guide ribs and grooves, so that the bearing elements are fixed to each other in the direction of rotation. Since the storage devices are respectively fixed to the riser and to the conveyor, a relative movement in the circumferential direction between the conveyor and the riser can be prevented.

The pump system may further comprise a guide portion which guides the conveyor to its working position. In particular, the guide section may be provided in the storage device. The guide portion facilitates the positioning of the conveyor and also makes it possible to fix the position concretely. In particular, when the guide portion is integrated in the two-part bearing device, such a predetermined positioning in the end position (which is also the storage position) is very simple and effective to perform.

The guide portion is preferably provided by the complementary projections and recesses. Thereby, a simple construction of the bearing device with a multi-layered functional bundling is provided.

In the conveyor system can be provided between the drive device and drive shaft and / or between the drive shaft and conveyor each have a transmission device. As a result, any desired drive device can be combined with any conveying device and at the same time the rotational speed of the drive shaft can also be controlled so that fewer vibrations occur there. Of course, such a reduction gear can also be removed independently of the riser together with the drive shaft and the feed pump.

To avoid vibrations of the drive shaft, the drive shaft can also be stored in the riser. In particular, bearing cages are suitable as storage in the radial direction. As a result, vibrations of the drive shaft can be better damped and the life of the system can be increased.

Preferably, in the conveyor system, the bearing element is sealed against the riser, in particular with a plastic seal. This reliably prevents leakage on the bearing element and maintains the efficiency of the conveyor system.

The drive shaft of the conveyor system can be mechanically prestressed. As a result, a higher running safety is achieved when starting the system, since at this time, the pumped medium is first pumped into the riser.

The system also preferably has a locking device by means of which the conveyor system can be locked in the riser in the axial direction. These Locking is releasable, so that the maintenance or dismantling of the system can still be easily performed. By the locking device, the shaft can be effectively biased, which has a very beneficial effect on the running properties. In particular, a locking device that acts like a bayonet lock is a simple but effective and inexpensive way to implement such a locking mechanism.

Brief description of the figures

FIG. 1

shows a preferred embodiment of a conveyor system according to the invention;

FIG. 2

shows an enlargement of the bearing device of an embodiment of the present invention;

FIG. 3

shows a conveyor system of the prior art in a partial section with a rigidly connected to the riser drive shaft and with an integrated conveyor system.

Description of the Preferred Embodiments

In the following description, various terms are used to define directions and locations. "Top" is used to denote a direction in FIG. 1 in the installed state of the conveyor 8 in the direction of the drive device 1 shows and "down" in the direction of the bottom of the hole. "Axial" refers to a direction that runs along the axis of the drive shaft 6, that is usually from top to bottom or vice versa. "Radial" means a direction perpendicular to the axial direction, ie, with respect to the drive shaft from the central axis of the drive shaft in the direction of the lateral surface. And the term "circumferential direction" means along the lateral surface of the drive shaft or the riser (for example, the rotational direction of the drive shaft). The term "medium" means in the The present application any conceivable liquid, such as water, but also oil or even gas are conceivable with the present invention. Preferably, however, the invention is used in a geothermal plant, which can generate heat by means of hot water.

The term "riser" is thus used in principle for each tube in which the fluid can rise to the top, that is promoted to the surface. This can thus also be the well casing (the support tube) 14 itself. Preferably, however, the term refers to a additionally provided in the well casing 14 pipe 2, in which the medium is conveyed upwards.

The conveyor system according to the invention consists of a drive device 1, a drive shaft 6 and a conveyor 8. As mentioned above, usually also a riser 2 is provided, which is provided separately from the support tube 14 of the borehole. In principle, however, the present invention can also be realized with only one tube, for example if a support tube is not necessary, as may be possible with holes having a shallow depth of, for example, 30 m. In the following, however, it is assumed that an installation in which the borehole itself is stabilized by an additional pipe and in which the riser pipe 2 is then used.

The riser 2 is depending on the depth of the hole from different modules that are flanged to each other or attached to each other in other ways. In the present invention, it is conceivable that the individual modules are welded together when inserted into the borehole, so that a single, very long pipe is formed. This is possible because the riser 2 after installation in the well or can remain in the support tube 14 and no longer needs to be taken out for maintenance of the system 1. The riser 2 is then flanged to the support tube 14, making it immobile to the environment. However, the riser 2 can also be fixed differently, for example, via its own storage or anchoring in the ground, so that it is fixed to the environment. At the upper end of the riser, in particular in an area which is located outside the borehole, an outlet pipe 3 may be provided, in which the conveying medium is led out of a side arm 3 of the riser. The lower end of the riser 2 is either made open or the riser 2 has openings in the side, so that the medium to flow freely into the riser and can be supported from there. The same applies to the support tube 14th

The drive device may be any drive device, preferably an (electric) motor, which is tuned to the respective load. The drive device 1 can also have a variable speed for adaptation of delivery rate and pressure, for example by being operated by use of a frequency converter. The drive device 1 is preferably attached via a torque receiving 7 on the riser, so that the torque of the motor 1 can also be transmitted to the drive shaft 6. Here, the torque holder 7 on an intermediate tube 17 on the motor side and also attached to the riser (eg, verscheißt, screwed, etc.). The drive device can also be attached differently to the environment so that it does not rotate around itself when driving the drive shaft. Further preferably, the intermediate tube is at least axially movable to the riser 2. Here, the intermediate tube 17 via two seals 11 a, 11 b to the drive shaft 6 (eg with roof boots) and the riser. 2 sealed (eg with one or more sealing rings). The conveyor 20 may also include a lifting device 15, which is preferably used as a biasing means for the drive shaft 6 and with which the drive shaft 6 can be raised in the axial direction. In particular, in conjunction with a fastening device described later, the drive shaft 6 can be mechanically biased and thus made less sensitive to vibration build-up. In particular, when starting the system, this is advantageous. Preferably, the torque receiver 7 is also provided in the lifting device 15 in order to save space and costs.

The drive shaft 6 is preferably also divided into segments and modular. The individual segments of the drive shaft 6 can, with a thread which is introduced directly into the shaft, screwed together and thus connected, but can also be connected to each other via connecting flanges or be coupled via universal joints. The drive shaft 6 is preferably formed as a hollow shaft (represented by the dashed line in, so that on the one hand can be saved weight and on the other an easy way to lay lines for conveying devices., For example, with such lines hydraulic, electro-hydraulic, electronic or electromagnetic Functions on the conveyor device 8 are actuated.

The conveying device 8 can be any pump, for example a centrifugal pump or a rotary displacement pump, such as an eccentric screw pump according to the principle of the Moineau pump. The conveyor 8 is fastened with a fastening device 10 in the riser 2, that it is fixed in the circumferential direction, but can move in the axial direction or at least can be brought into a position in which it can be taken out of the riser 6 in the axial direction without having to remove this too. This can be done, for example, by a fixing unit provided on the pump, which can press, for example by a signal of a control unit electrically, electromagnetically, electrohydraulically or hydraulically brake shoes (not shown) against the riser, so that the conveyor device 8 is fixed in position. In addition, at a predetermined position, the riser may have a conical shape expanding from top to bottom so that the jaws have a self-reinforcing clamping function when the drive shaft 6 is pulled up together with the conveyor 8. Another possibility are bolts that can be extended in the radial direction and the conveyor 8 also set in the circumferential and axial directions.

Preferably, however, a bearing device 10 is provided at a predetermined position in a riser segment, which cooperates with the conveying device 8 and supports the conveying device 8 in the riser pipe 2. Such a bearing element should set the conveyor 8 in the circumferential direction. In the concrete in Fig. 1 In the embodiment shown, the bearing device 10 consists of two separate elements 10a and 10b, wherein a bearing element 10a is fixed to the riser 2, for example by welding or screwing, or is integrally implemented in the corresponding riser segment, for example, by being cast or forged during manufacture, or is milled into the riser 2. A second bearing element 10b is provided on the conveying device 8 itself and cooperates with the first bearing element 10a. The two bearing elements 10a, 10b can be used as radially protruding projections on the Conveying device 8 and complementary recesses or grooves may be formed in the riser 2, which are formed in particular at a portion with a radially inwardly reinforced wall (a thickening) of the riser 2. The projections and the recesses may, for example, each be designed as intermeshing ribs. By the projections and the recesses can be reliably prevented movement in the circumferential direction of the conveyor 8 in the riser 2, so that the conveyor 8 is fixed in the circumferential direction and the rotation of the drive shaft 6 or the self-rotation of a pump in the conveyor 8, the conveyor 8 in Rising tube 2 can not move in the circumferential direction in motion, so that the torque of the drive device 1 is reliably transmitted to the conveyor device 8. The projections and the recesses have a guide device with which the conveyor device 8 is automatically guided into the first bearing element 10 a of the riser 2 when a predetermined position is reached. Preferably, the protrusions on the conveyor 8 on the underside and the walls of the grooves on the upper side are tapered or rounded, so that when these peaks / roundings meet, a guide results and the respective bearing elements 10a, 10b automatically slide into one another.

The projections or the walls of the grooves can also have ends 16 which are inclined in the radial direction on the upper side (rising tube) or underside (conveying device 8). These can serve for Radialzentrierung the conveyor system, for example, by deflecting an annular portion 9 at the lower end of the conveyor towards the center.

It is also possible to provide a locking mechanism for the conveyor 8, which also prevents upward movement in the axial direction. This can be realized simply by the principle of a bayonet closure, i. the recess or groove 13 in the first bearing element 10a is U-shaped and the projection 12 is guided along this U-groove. In this case, the projection 12 of the conveyor 8 is guided to a lower stop of the groove, then the projection 12 along the Nutgrundes guided by rotating the conveyor 9 and finally lifted back up against a stop. Such a mechanism is, for example, also referred to as a bayonet closure, in which the recess 13 is then, so to speak, a movement space for locking and unlocking. But can also be provided on the two bearing elements 10a, 10b each hook-shaped ribs that can be hooked into each other. To assist in lifting the conveyor, a hydraulic or electromagnetic lifting mechanism (not shown) provided in the riser 2 below the storage device 10 and below the conveyor 8 may serve. In the present embodiment, however, a lifting device 15 is provided at the upper end of the drive shaft 6, which can then also be used as a biasing means.

It is of course possible to provide the recesses on the conveyor 8 and the projections on the riser 2 and to modify the corresponding structure described above for Axialverriegelung accordingly.

Preferably located below the bearing device 10, a ring section 9. This ring section can directly adjacent to the bearing device 10, as in the FIGS. 1 and 2 is shown and so as an axial stop for the conveyor 8 or also used as a lower groove base for a bayonet closure or the like, as described above. In particular, the projections 12 or ribs 12 of the second bearing device 10b may abut against the ring portion 9 and thus prevent the conveyor 8 from being further lowered. This can thus also assume a display function with which it is pointed out during installation that the conveying device 8 has reached the predetermined position. This adjacent ring section 9 is used in particular as a sealing section, by means of which the conveying device 8 is sealed against the riser pipe on the outside. This can be done by a fit between conveyor and ring section 9, but preferably instead or additionally a sealing ring 5 made of plastic or metal is used, which is shown in the present embodiment. In particular, the seal should be provided on a sealing portion 9, which includes two opposite smooth surfaces to improve the sealing effect. This prevents leakage of the pumped medium.

The drive shaft can be additionally stored in the riser, even if this is not absolutely necessary. Such storage can be carried out by means of bearing cages, which store the drive shaft in the radial direction relative to the riser and can mitigate or prevent vibrations. However, the bearing cages are not fixed axially in the riser so that the bearing drive shaft 6 can be out of the riser together with the conveyor 8. The drive shaft 6 is preferably also mounted directly behind the drive device 1 with corresponding bearings.

The conveyor may have on the conveyor 8, a transmission 19, with which the speed and the torque of Drive shaft 6 are set to the conveyor device 8, that is, the torque and the rotational speed are adapted to the conveyor device 8. Thus, for example, the drive shaft 6 run at a very low speed, which in turn has a positive effect on resulting vibrations. An additional transmission device (not shown) between the drive device 1 and the drive shaft 6 may be provided. So any drive device can be used, because the respective power can be converted by the gearbox suitable.

The construction of a plant is as follows: First, a hole in the desired depth is introduced into the ground and secured the hole with a support tube. This support tube preferably has holes in the lower region, so that the medium to be pumped can flow from the ground into the support tube. Then the riser is inserted segment by segment in the support tube and flanged with the support tube (or attached to the environment accordingly). Then the conveyor 8 is used with the drive shaft in the riser and brought to the final position. In this case, the conveyor system is preferably used in the bearing element and set in the circumferential direction. Eventually there is also a locking in the axial direction, as described above. Then, preferably, the riser section is attached to the side arm, the pretensioner, if any, is mounted, and finally the drive device is mounted.

Now, either the drive shaft is mechanically preloaded first, or else the delivery medium is conveyed, so that a pressure on the delivery device 8 is built up by the weight of the delivery medium above the delivery device 8. This pressure gives the drive shaft a tension that makes her run smoothly. Thus, vibrations during operation are mitigated solely by the conveyor medium located above the conveying medium, or even prevented. Of course, this can also be supported by the biasing device 15.

LIST OF REFERENCE NUMBERS

1 Driving device / motor 2 riser 3 outlet pipe 4 Rotation / clamping cylinder 5 Seal / Seal 6 drive shaft 7 torque absorption 8th conveyor 9 ring section 10 Fastening device / storage device 10a Attaching / bearing element 10b Attaching / bearing element 11a Gasket (eg gaskets, sliding ring) 11b Seal (eg O-ring) 12 head Start 13 recess 14 Well casing / support tube 15 Lifting / tensioning device 16 radially inclined end 17 Intermediate tube, drive carrier 19 transmission 20 conveyor system

Claims (13)

Plant (20) for pumping water from wells and deep wells for water supply and geothermal use of hot water or other liquids, comprising: A conveying device (8) for conveying a conveying medium; a drive device (1) which drives the conveyor device (8); a drive shaft (6) interconnecting said drive device (1) and said conveyor (8) for driving said conveyor (8); a riser (2) in which at least the drive shaft (6) and the conveying device (8) are arranged; and a fastening device (10) which fixes the conveying device in the end position at least in the circumferential direction; characterized in that the drive shaft (6) and the conveying device (8) are mounted in the riser pipe (2) so that they are freely movable in the axial direction relative to the riser pipe (2) at least when the conveying device (8) is removed. Installation (1) according to claim 1, wherein the fastening device comprises at least one bearing device (10a, 10b) in the riser, which supports the conveying device (8) in the riser pipe (2). Installation (1) according to claim 2, wherein the bearing device (10a, 10b) comprises a first bearing element (10a) which is fixed to the conveying device (8), and a second bearing element (10b), that motion-resistant on Rising pipe (2) is mounted, wherein the first (10 a) and second (10 b) bearing element are axially movable to each other. Installation (1) according to one of the preceding claims, in which the conveying device (8) is mounted in a rotationally fixed manner to the riser pipe (2). Installation (1) according to claim 3 and 4, in which the rotationally fixed mounting is provided by in the bearing device (10a, 10b) such that the bearing elements (10a, 10b) have complementary projections and recesses, which the bearing elements (10a, 10b) fix each other in the direction of rotation. Installation (1) according to one of the preceding claims, further comprising a guide section, which guides the conveying device (8) into its working position. Plant (1) according to claim 3 and 6, wherein the guide section is provided in the bearing device (10a, 10b). Plant (1) according to one of the preceding claims, in which the installation further comprises a lifting device (15) which can move the drive shaft (6) in the axial direction. Plant (1) according to one of the preceding claims, in which a transmission device is provided between the drive device (2) and the drive shaft (6) and / or between the drive shaft (6) and the conveying device (8). Plant (1) according to one of the preceding claims, in which the drive shaft (4) is mounted in the riser pipe (8) by means of bearing cages axially movable in the riser pipe (2). Plant (1) according to one of the preceding claims in conjunction with claim 2, wherein the bearing element is sealed against the riser, in particular with a plastic seal. Installation (1) according to one of the preceding claims, wherein a locking device is further provided by means of which the conveyor system (8) in the riser pipe (2) can be locked in the axial direction. Plant (1) according to claim 12, in which the locking device comprises a bayonet closure.

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