NO341890B1 - Position control tool for production pipe trailers and a method - Google Patents

Abstract

A production control hanger position control tool (10) has a wellhead landing section (19, 21) and a wellhead lock (23) arranged to lock the tool (10) to a wellhead (1). The tool (10) comprises an alignment member (30) which is rotationally and axially movable relative to the wellhead landing section (19, 21). The alignment member (30) comprises a alignment clamp (41) adapted to fit into a production pipe hanger alignment groove (27). The alignment portion (30) comprises a position fixing device (11).

Description

Position control tool for production pipe hanger and associated method

The present invention relates to the field of seabed wells and more particularly a tool for checking the correct position of a production pipe hanger that is installed in a seabed wellhead. The tool according to the invention is a low-weight, ROV-operable tool which enables the operator to carry out the position check in a fast and cost-saving way.

Background

In a subsea well with a vertical valve tree, a production tubing hanger (TH) is installed in the wellhead before the vertical valve tree (VXT) is installed above the production tubing hanger. To ensure proper engagement between TH and VXT, both TH and VXT are installed relative to an orientation reference. In addition, the VXT must be correctly installed in relation to a production guide base (PGB) that surrounds the wellhead. This is, among other things, necessary to ensure that the interface to the VXT for peripheral infrastructure, such as fluid lines and control lines, is correctly positioned. Consequently, TH must also have a correct position in relation to PGB.

Even if the production pipe hanger has been correctly installed, you want to check the position of the production pipe hanger before installing the VXT over it. If the VXT is installed on top of an incorrectly positioned TH, both the TH and the VXT can be destroyed, resulting in large costs and loss of time. For various reasons, the TH may move after installation, even if it is installed correctly. The PGB can also in some cases move. This can result in a misalignment between TH and PGB, and later also between VXT and PGB, if VXT is installed correctly, per se, on a TH (which is misaligned in relation to PGB).

To check the position of the TH, it is known to lower a copy of the VXT down to the wellhead to see if it fits the TH when the copy is in the correct position. As the replica is a large and heavy piece of equipment, it is lowered onto cables or a riser, which is a time-consuming process. Furthermore, due to its size and considerable weight, it can damage the TH and parts of the wellhead, such as the sealing surfaces.

British patent application publication GB2099881 describes a tool which is adapted to detect and give an indication of whether a subsea well component, such as a pipe hanger, is correctly positioned. This tool has a spring-loaded feeler that is designed to engage the component. When the component is correctly installed, the sensor will operate an indicator valve assembly. A television camera is also described which enables visual inspection.

European patent application publication EP1319800 further describes a system designed to detect the position of equipment down a wellbore.

It is an aim of the present invention to provide a new tool and an associated method for checking the correct position of a TH installed in a wellhead in a faster, more cost-effective and less prone to damage way than with known techniques.

Another object of the present invention is to provide a new assembly and a method for predicting a correct production pipe hanger position for a production pipe hanger in a wellhead.

The invention

In accordance with a first aspect of the present invention, there is provided a production tubing hanger position control tool comprising a wellhead landing section and a wellhead lock adapted to lock the tool to a wellhead. In accordance with the first aspect of the present invention, the tool comprises an alignment part (in the description of the embodiment below referred to as the central part) which is rotationally and axially movable in relation to the wellhead landing section. Furthermore, the alignment part comprises an alignment clip which is adapted to fit into a production pipe hanger alignment slot. The alignment part also includes a position determination device.

The wellhead landing section is a part of the tool that is designed to land on a wellhead. In a typical embodiment, it may involve a mounting ring that surrounds the wellhead and a plate that lands on top of the wellhead.

In some embodiments, the position fixing device may be placed on the tool after the alignment member has been aligned with the production pipe hanger.

The alignment part may further comprise a guide rib and the wellhead landing section may comprise a guide rib entry groove with which the guide rib is rotationally aligned when the alignment part is axially movable.

In some embodiments, the tool exhibits a storage position in which the guide rib is misaligned with the guide rib entry slot and in which a spring biased clip engages a clip slot. In such embodiments, the tool also exhibits an alignment position in which the guide rib is aligned with the guide rib engagement groove and in which the spring-loaded clip is out of engagement with the clip groove. In a preferred embodiment, the clamping groove coincides with, or is the same groove as, the guide rib entry groove.

In some embodiments, the wellhead landing section may include a fitting ring adapted to surround an upper portion of a wellhead, and a main plate attached to the fitting ring and adapted to land on top of the wellhead.

In such embodiments, the aligning part may be arranged in an opening in the main plate and may comprise a lower ring, on which the wellhead landing part is arranged to rest when the tool is in a suspended position. In such a hanging position, the spring biased clamp will typically engage with the clamp groove to prevent mutual rotation between the alignment part and the wellhead landing part.

An ROV handle may be provided to the alignment section. The alignment part can then be rotated using an ROV.

The position control tool for the production pipe hanger may comprise a production pipe hanger height control pin that abuts a part of the production pipe hanger upon landing of the tool on the wellhead, so that it is displaced upwards in relation to the tool.

The tool can advantageously be carried by a remote-controlled vessel. The design of the tool in accordance with the invention is such that its weight can be limited compared to known solutions. For example, the weight can typically be 50 kg, but also more, especially if it is equipped with buoyancy devices.

The position control tool for the production pipe hanger may comprise a landing device for the position determination unit and the position determination device may be a position determination unit landed on said landing device for the position determination unit.

The position determination unit can comprise measuring devices which are placed at different positions on the position determination unit.

The position determination device may also be a production pipe hanger position prediction unit landed on a production pipe hanger position prediction unit landing device of the tool, whereby the production pipe hanger position prediction unit comprises a production pipe hanger position prediction alignment arm adapted to engage a receiving slot in the production guide base. As will be apparent from the description of the embodiment below, the production pipe hanger prediction alignment arm of the production pipe hanger position prediction unit may advantageously be an arm extending radially from the production pipe hanger position prediction unit. However, it can also have other configurations that are different from an "arm-shape".

In accordance with a second aspect of the present invention, there is provided a method for controlling the position of a production pipe hanger installed in a subsea wellhead. This procedure includes the following steps

a) landing a production tubing hanger position control tool on a wellhead in which the production tubing hanger is installed;

e) aligning an alignment portion of the tool with the production pipe hanger; f) with a position determination device arranged on the alignment part, to determine the position of the production pipe hanger.

In an embodiment of the second aspect of the present invention, step e) further comprises rotating the alignment member relative to the production pipe hanger until an alignment clip attached to the alignment member enters a production pipe hanger alignment groove.

The method can advantageously include the following steps after step a) and before step e):

b) locking a landing section of the tool to the wellhead;

c) rotating the alignment member relative to the landing section so as to enable it to be lowered relative to the landing section;

d) lowering the alignment section relative to the landing section, down to abutment with a landing shoulder in the production pipe hanger.

In some embodiments, step f) may include the following steps:

i) landing a position determination unit on the production pipe hanger position control tool in a predetermined mutual position;

ii) by means of measuring devices arranged at different positions on the position determination unit, to determine the position of the production pipe hanger.

Also disclosed is a production pipe hanger position determination assembly. The assembly includes a wellhead landing section configured to be landed on and rotated relative to the upper portion of a subsea wellhead. It also includes a production tubing hanger position prediction unit that engages the wellhead landing section. The production hanger position prediction unit further has a production pipe hanger prediction alignment arm and measuring devices. The measuring devices may advantageously be carried by legs extending from the main body of the unit, to provide a suitable mutual distance between them.

With the measuring devices, the operator is able to determine the position of the production tubing hanger position determination assembly, and consequently to determine a correct position of a production tubing hanger which may already be installed or which may not yet be installed in the wellhead. By knowing the correct position of a present or future production tubing hanger, the operator will also know the position of a wiring interface to the valve tree to be installed above the production tubing hanger. Consequently, he can start designing and manufacturing lines in accordance with this known position, before the valve tree or even the production pipe hanger has been installed.

Furthermore, a method is described for predicting a correct production pipe hanger position for a production pipe hanger in connection with a seabed wellhead. The procedure includes the following steps:

a) landing a wellhead landing section on a wellhead;

b) landing a production tubing hanger position prediction unit on the wellhead landing section;

c) moving a production pipe hanger alignment arm of the production pipe hanger position prediction unit into engagement with a receiving slot in the production guide base, so as to align the production pipe hanger position prediction unit with the production guide base; and

d) with measuring devices provided on the production pipe hanger position prediction unit, to determine the correct production pipe hanger position.

The wellhead landing section may be part of the production tubing hanger position control tool described above, or may be other components not equipped to control the position of an installed production tubing hanger.

Step a) and step b) above can be done simultaneously in an embodiment where the wellhead landing section is attached to the production tubing hanger position prediction unit during landing on the wellhead.

Example of embodiment

As the general features of the present invention have been described above, a more detailed and non-limiting example of embodiment will be described in the following with reference to the drawings, in which

Fig. 1 is a schematic side view of a subsea wellhead and a tool that is installed on the wellhead;

Fig. 2 is a schematic perspective view of the wellhead and the tool, whereby the tool has landed on the wellhead;

Fig. 3a and Fig. 3b are a side view and a perspective view of the tool that is installed on the wellhead;

Fig. 4a and Fig. 4b are a side cross-sectional view and a perspective cross-sectional view of the tool that has landed on the wellhead;

Fig. 5 is an enlarged cross-sectional perspective view of the tool landed on the wellhead;

Fig. 6 is an enlarged perspective view of the tool in accordance with the invention; Fig. 7a and Fig. 7b are cross-sectional views of perspective views of the tool on the wellhead, after rotation of the central part of the tool;

Fig. 8a and Fig. 8b are cross-sectional side views and perspective views of the tool and the wellhead, whereby the central part has been lowered somewhat;

Fig. 9a and Fig. 9b are cross-sectional side views and perspective views of the tool and the wellhead, whereby the central part of the tool is arranged with a production pipe hanger in the wellhead;

Fig. 10 is an enlarged cross-sectional view of the tool landed on the wellhead;

Fig. 11 is an enlarged side view of the tool in accordance with the invention;

Fig. 12 is an enlarged side view of the tool, shown in another situation;

Fig. 13 is another enlarged side view of the tool, shown in yet another situation;

Fig. 14a and Fig. 14b are side cross-sectional views of the tool and wellhead, as well as an enlarged perspective view of parts of the tool;

Fig. 15 is a perspective view of an alternative embodiment of the tool in accordance with the invention;

Fig. 16 is a perspective view corresponding to Fig. 15, shown in another position; Fig. 17 is another view corresponding to Fig. 15, showing a position determination unit;

Fig. 18 is an enlarged perspective view of the alternative embodiment of the tool, shown with the position determination unit landed on the tool; Fig. 19 is yet another embodiment shown with a perspective view;

Fig. 20 is a perspective view of the embodiment of Fig. 19, landed on a wellhead; and

Fig. 21 is another perspective view illustrating the embodiment shown in Fig. 19 and Fig. 20.

Fig. 1 is a principle side view of a seabed wellhead 1 to a seabed well 3 that extends into the seabed 5. The wellhead 1 is surrounded by a production guide base 7 (PGB – production guide base).

Above the wellhead 1 is shown a production tubing hanger position check tool 10 (THPCT – tubing hanger position check tool) in accordance with the invention (hereinafter referred to as the tool). In this embodiment, the tool 10 is carried by a remotely operated vessel 9 (ROV), whose arm is shown in Fig.1.

Fig. 2 is a perspective principle price showing mainly the same components as in Fig.1. However, the tool 10 is landed on the wellhead 1. As will be described in more detail later, the tool 10 is equipped with a TH installed in the wellhead 1. A laser device 11 beams a laser beam on a target plate 13 which is fixed to the PGB 7. The position until the laser beam on target plate 13 is then read to determine the orientation of TH. This can be done, for example, with a camera on an ROV, or through a reading device that can be arranged, for example, on the tool 10 or on the PGB 7.

Fig. 1 and Fig.2 illustrate the overall concept for determining or controlling the angular position of the TH inside the wellhead. In the following, the functions of the tool 10 will be discussed in detail.

Fig. 3a and Fig. 3b illustrate the same situation as in Fig. 1 in more detail. The ROV 9 is in the process of landing the tool 10 on the wellhead 1, inside which a TH (not shown) is installed. The tool 10 is preferably lowered to the seabed 5 in a basket. The weight of the tool 10 is advantageously sufficiently low to be carried and manipulated by the ROV 9, for example 50 kg.

In this embodiment, the tool 10 has a first and a second ROV lever, here in the form of an upper ROV lever 15 and a lower ROV lever 17. During landing of the tool 10 on the wellhead, the ROV 9 carries the entire tool 10 in the upper ROV lever 15.

In Fig.4a and Fig.4b, the tool 10 has been landed on top of the wellhead 1. The tool 10 comprises a fitting ring 19 which extends around the outer and upper circumference until the wellhead 1 reaches the landed position. The fitting ring 19 is attached to a main plate 21. As can be seen from Fig.3b and Fig.4b, the main plate 21 covers only part of the area inside the fitting ring 19, as it presents a majority of parts which are open. This design reduces the weight of the tool 10 itself, and also reduces added mass when lowering or lifting the tool 10 through the seawater.

When landed on the wellhead 1, the ROV 9 releases its grip on the upper ROV lever 15, allowing the tool 10 to rest on the wellhead 1. The lower lever 17 is functionally connected to a pass ring lock 23. Upon rotation of the lower lever 17, the ROV 9 locks the fitting ring to the wellhead 1. The function of the fitting ring lock 23 is not described herein, as a specialist in the field can use any suitable solution. For example, a concentric element may be connected to the lower lever 17 through a bolt which is attached eccentrically to the concentric element. By rotation of the lower lever 17 and the bolt, the concentric element can be pressed into engagement with the outer surface of the wellhead 1, thus fixing the fitting ring 19 to the wellhead 1.

In Fig.4a and Fig.4b, the production pipe hanger (TH) 25 can be seen installed inside the inner bore of the wellhead. In the perspective drawing in Fig.4b, one can see different parts of TH 25, such as the production bore, the annulus access bore, and various connectors. Also visible in Fig.4b is a production pipe hanger alignment groove 27. TH 25 will typically have two such alignment grooves 27.

Advantageously, they are arranged in the inner, upper TH bore 29 to TH 25, and positioned 170 degrees apart, in relation to the inner circumference of the TH bore 29.

Fig. 5 is an enlarged part of Fig. 4b, and illustrates parts of the tool 10 and TH 25 in more detail. Several parts will now be identified with reference to Fig.5.

Centrally arranged in the main plate 21 is an alignment part, here in the form of a central part 30, on top of which the upper ROV lever 15 is arranged. The central part 30 is rotatably supported on the main plate 21 by a circular sliding bearing 31 which is attached to the main plate 21. Consequently, the ROV 9 is able to rotate the central part 30 relative to the main plate 21, when the main plate 21 is locked to the wellhead 1 using the fitting ring lock 23.

Furthermore, the central part 30 is arranged to move up and down, that is to say axially, in relation to the main plate 21. In the position shown in Fig.5, however, this is not yet possible. Attached to the central part 30 are two guide ribs 33 which, in the position shown, rest on the slide bearing 31. The slide bearing 31, as well as the main plate 21, has two guide rib entry grooves 35 through which the two guide ribs 33 can be lowered when aligned with the guide rib entry grooves 35. Accordingly, to move the central part 30 axially downward relative to the main plate 21 and the wellhead 1, the central part is rotated with the ROV 9 until the guide ribs 33 are aligned with the guide rib entry grooves 35. This position is shown in Fig. 7a and Fig. 7b. When in this position, the central part is lowered to land on a landing shoulder 26 inside the TH bore 29.

The central part 30 further comprises a lower ring 37, which in the position shown in Fig.5 is arranged directly under the main plate 21. Down from the lower ring 37 extend two alignment clamp flanges 39. On each alignment clamp flange 39 a radially projecting alignment clamp is arranged 41. The two alignment clips 41 are adapted to enter into the two TH alignment grooves 27 discussed above.

Fig. 6 is a perspective view of the tool 10, and clearly shows a guide rib engagement groove 35 and a guide rib 33 that has not yet been aligned with the guide rib engagement groove 35. Up from the lower ring 37, a spring-loaded clip 43 extends into the guide rib engagement groove 35. The spring-biased clip 43 exhibits inclined side surfaces and will be pressed down upon rotation of the body of the sliding bearing 31. Consequently, spring-biased clip 43 ensures that the central part 30 and the main plate 21 remain in a constant position relative to each other until the above-discussed intentional rotation takes place .

Reference is again made to Fig.7a and Fig.7b. The fitting ring 19 is locked to the wellhead 1 by means of the fitting ring lock 23. The ROV 9 grasps the upper ROV lever 15 and has rotated the central part 30 in relation to the fitting ring 19 and the main plate 21, until the two guide ribs 33 have been aligned with the guide rib entry ring grooves 35. The spring-loaded clamp 43 was pressed down into the lower ring 37 during this rotational movement. In Fig.7a, a spring 45 is visible under the spring-loaded clamp 43.

Fig. 8a and Fig. 8b show a situation where the central part 30 has been lowered in relation to the remaining main plate 21. The alignment clamps 41 have landed on the landing shoulder 26 (cf. Fig. 5) in the TH 25. In some cases the alignment clamps can 41 will already be aligned with the production pipe hanger alignment grooves 27. In such a case, the central part 30, together with the alignment clips 41, will continue the downward movement without landing on the landing shoulder 26.

Usually, however, the alignment clips 41 will land on the landing shoulder 26. To move further down into the production tubing hanger alignment slots 27, the tool 10 must be rotated relative to the wellhead 1 and TH 25. Accordingly, the snap ring lock 23 is unlocked so that the entire tool 10 can rotate. The ROV 9 rotates the tool 10, together with the central part 30 and the alignment clamps 41, until the latter is aligned with the production tubing hanger alignment slots 27. The central part 30 then moves into the bottom position, in which it is rotationally aligned and engaged with the TH 25. This position is shown in Fig.9a and Fig.9b.

As shown in Fig.9a and Fig.9b, two stop flanges 36 abut against the main plate 21 when in this position, thus stopping the downward movement of the central part 30.

Fig. 10 is a perspective view of the tool 10 in the situation in Fig. 5, although shown from a different angle.

Fig. 11 is a side view of the tool 10 before lowering the central part 30.

Fig. 12 is another side view which corresponds to Fig. 11, but which shows the situation in Fig. 8a and Fig. 8b.

Fig. 13 is another side view showing the tool in the final lowered and aligned position, corresponding to the situation in Fig. 9a and Fig. 9b.

Reference is again made to the principle sketch in Fig.2. When the tool 10 is in the lowered and aligned position, the laser device 11 is brought into use to control the orientation of the tool 10, and consequently the TH 25, in relation to the laser target plate 13.

As will be understood by one skilled in the art, another position fixing device can be used instead of the laser 11, for example transmitters/transponders/gyroscopes.

One can even use mechanical measurement, such as an extendable rod which, with the help of the ROV, can be extended against a painted target scale and inspected by camera. Such rods can also be retrofitted to the tool after installation and alignment.

Another alternative is to have a camera on the tool 10 which takes a picture of the TH position inside the wellhead. Such an image can then be compared with the optimal TH position and the actual orientation is thus verified.

Fig. 14a and Fig. 14b illustrate a possible embodiment of the present invention. In this embodiment, the tool 10 is provided with a production pipe hanger height control pin 51. When the tool 10 has been lowered onto the wellhead 1, a lower part of the production pipe hanger height control pin 51 will abut an upper surface of the wellhead 1, and thus be moved upwards in relation to the tool 10. An (not shown) indicator ring on the control pin 51 will appear above the upper edge of a support sleeve 53, by means of which the control pin 51 is supported. That is, the control pin 51 extends through the support sleeve 53 in a sliding manner.

Fig. 15 and Fig. 16 illustrate an alternative embodiment of the present invention. In this embodiment, the tool 10 is provided with a landing plate 55. The landing plate 55 is attached to the central part 30 of the tool 10, above the guide ribs 33. Projecting upwards from the landing plate 55 are a first guide pin 57 and a second guide pin 59, which are of different shapes .

In the situation shown in Fig.16, the tool has been aligned with TH 25 inside the wellhead 1 in the manner discussed above. As can be understood from Fig.15 and Fig.16, in this embodiment the tool 10 is without the laser device 11. Instead, a position determination unit 100 is arranged to land on the landing plate 55 of the tool 10. Fig.17 shows a situation where the position determination unit 100 is in about to land. The position determination unit 100 is typically operated with an ROV. The operator will ensure that the first and second guide pins 57, 59 of the tool 10 enter receiving recesses (not shown) in the positioning unit 100. Since the first and second guide pins 57, 59 are of different shapes, there will be only one possible mutual engagement position between the tool 10 and the position determination unit 100 when the guide pins are engaged with the recesses. Consequently, as the tool 10 is correctly aligned in relation to the TH 25 inside the wellhead 1, the position of the position determination unit 100 is also known.

In Fig.18, the positioning unit 100 is shown in a landed position on the tool 10. The positioning unit 100 presents a central opening through which the upper ROV lever 15 extends, together with the upper part of the central part 30.

The position determination unit 100 exhibits a plurality of radially extending legs 101, four legs in this embodiment. The legs 101 extend mainly radially from a common main body 103. At an outer end part of the legs 101, they each have a receiving receptacle 105. The receiving receptacles are arranged to receive measuring devices 107 which are used to determine the position/orientation of the position determination unit 100 In this embodiment, the measuring devices are transponders 107. The operator may preferably use an ROV to place the transponders 107 into the receiving receptacles after the positioning device 100 has landed on the tool 10.

This embodiment, which includes the position determination unit 100, enables the operator to know the position of the entire system, i.e. PGB 7, TH 25 and the manifold (not discussed herein). As a result, he can start fabrication of interconnecting pipes before the installation of VXT. This car helps to save considerable time for the operator. Furthermore, the operator is able to determine the future routing of interconnection pipes and the position of interconnection connectors before the VXT is installed on top of the TH 25.

Fig. 19 shows yet another embodiment. This embodiment comprises a TH prediction unit 200. The TH prediction unit 200 is used to determine or to predict a correct present or future position / orientation of the production pipe hanger (TH) 25. That is, it can be used in a situation where the TH 25 is installed in wellhead 1, as well as in a situation where TH has not yet been installed.

Around the wellhead 1 is arranged an orientation trough 8 which is part of the PGB 7. In the orientation trough 8 there are four Y-tracks 6. The TH prediction unit 200 is generally shaped in accordance with the position determination unit 100, and similar components will not be described again. However, the TH prediction unit 200 additionally has a production pipe hanger prediction alignment arm 209. In the illustrated embodiment, the production pipe hanger prediction alignment arm 209 is attached to two legs 201 of the TH prediction unit 200. In some embodiments, the production pipe hanger prediction alignment arm 209 can be supported in a pivoting manner so that it can rotate about its attachment points against the legs 201. As will be understood by those skilled in the art, the production pipe hanger prediction alignment arm 209 may have any suitable shape that will meet its technical purpose. Consequently, it does not need to be shaped like an arm.

Fig. 20 shows the TH prediction unit 200 landed on a tool 10 already landed on the wellhead 1. As with the position determination unit 100 discussed above, the TH prediction unit 200 also exhibits the first and second guide pins 57, 59. After landing the TH position prediction unit 200 on the tool 10, they are both rotated until the production pipe hanger prediction alignment arm 209 is aligned with and engages a Y slot 6 in the orientation cup 8 of the PGB 7. To make such rotation possible, the snap ring lock 23 of the tool 10 is not actuated. Alternatively, the pass ring lock 23 is not present at all. Accordingly, the tool 10 rotates freely on the wellhead 1. Furthermore, the first and second guide pins 57, 59 on the landing plate 55 cause the TH prediction unit 200 to rotate upon rotation of the tool 10. To rotate the tool 10, an ROV 9 can be used, in engagement with the upper ROV lever 15.

In this embodiment, the tool 10 is used only as a landing device for the TH prediction unit 200, and as a rotational interface with the wellhead 1. Accordingly, the tool 10 may have been landed on the wellhead 1 without any TH present in the wellhead 1. In such a case, the tool may be a stripped down version of the tool 10 discussed above, as it would not need to engage a TH and therefore would not need to exhibit an axially/vertically movable central portion 30. For example, the TH prediction unit 200 may land on and/or or be engaged with a simple wellhead landing section which only provides for landing on the wellhead and the possibility of rotation in relation to the wellhead.

At an end part of the production pipe hanger prediction alignment arm 209, a track engagement unit 211 is provided that fits tightly in the lower part of the Y groove 6. Accordingly, when the track engagement unit 211 is in the engagement position, the TH prediction unit 200 is oriented with respect to the PGB 7 with high accuracy . Using the measuring devices 207, similar to those discussed above, the operator is now able to accurately determine the correct position of a TH 25, which may or may not be installed in the wellhead 1.

The production pipe hanger prediction alignment arm 209 and/or the engagement unit 211 can advantageously be easily exchanged to adapt to different shapes of the PGB 7, especially different shapes of the orientation can 8 and its Y-groove 6.

As will be understood by one skilled in the art, this embodiment, comprising the TH prediction unit 200, does not use the production pipe hanger alignment track 27 to determine the correct position of a TH. When the TH 25 is installed, it will typically be aligned in relation to the Y-slot 6.

Fig. 21 is an overview side view showing the PGB 7, the wellhead 1, the tool 10 and the PGB positioning unit 200.

With the embodiment comprising the TH prediction unit 200, the operator is able to determine the future position of connecting lines that will connect to the valve tree. Consequently, he can start producing the wires even before the TH 25 is installed in the wellhead.

Claims (15)

Patent requirements 1. A position control tool (10) for production pipe hanger, comprising a wellhead landing section (19, 21) and a wellhead lock (23) adapted to lock the tool (10) to a wellhead (1), characterized by - the tool (10) comprises an alignment part (30) which is rotatable and axially movable in relation to the wellhead landing section (19, 21); - the alignment part (30) comprises an alignment clip (41) which is adapted to fit in a production pipe alignment groove (27); and that - the alignment part (30) comprises a position fixing device (11). 2. A position control tool (10) for production pipe hangers in accordance with patent claim 1, characterized in that the alignment part (30) further comprises a guide rib (33) and that the wellhead landing section (19, 21) comprises a guide rib entry groove (35) with which the guide rib (33) is rotationally aligned until the alignment part (30) is axially movable. 3. A position control tool (10) for production pipe hangers in accordance with patent claim 2, characterized in that it displays - a storage position in which the guide rib (33) is misaligned with the guide rib entry groove (35) and in which a spring-loaded clamp (43) is engaged with a clamp groove (35); and - an alignment position in which the guide rib (33) is aligned with the guide rib entry groove (35) and in which the spring-loaded clamp (43) is not engaged with the clamp groove (35). 4. A position control tool (10) for production pipe hangers in accordance with one of the preceding patent claims, characterized in that the wellhead landing section (19, 21) comprises a fitting ring (19) which is arranged to surround an upper part of a wellhead (1), and a main plate (21) which is connected to the fitting ring (19) and aligned to land on top of the wellhead (1). 5. A position control tool (10) for a production pipe hanger in accordance with patent claim 4, characterized in that the alignment part (30) is arranged in an opening in the main plate (21) and includes a lower ring (37) on which the wellhead landing section (19, 21) is aligned to rest, the tool (10) reaches you in a hanging position. 6. A position control tool (10) for production pipe hangers in accordance with one of the preceding patent claims, characterized in that an ROV handle (15) is provided to the alignment part (30). 7. A position control tool (10) for a production pipe hanger in accordance with one of the preceding patent claims, characterized in that it comprises a production pipe hanger height control pin (51) which is arranged to abut a part of the production pipe hanger (25) upon landing of the tool on the wellhead (1), so as to be pushed upwards in relation to the tool (10) . 8. A position control tool (10) for a production pipe hanger in accordance with one of the preceding patent claims, characterized in that it is carried by a remotely controlled vessel. 9. A position control tool (10) for production pipe hangers in accordance with one of the preceding patent claims, characterized in that it comprises a position determination unit landing device (55, 57, 59) and that the position determination device (11) is a position determination unit (100) landed on said position determination unit landing device (55 , 57, 59). 10. A position control tool (10) for a production pipe hanger in accordance with patent claim 9, characterized in that the position determination device (100) comprises measuring devices (107) arranged at different positions on the position determination unit (100). 11. A position control tool (10) for a production pipe hanger in accordance with one of claims 1 to 9, characterized in that the position determination device is a production pipe hanger position prediction unit (200) landed on a production pipe hanger position prediction unit landing device (55, 57, 59) to the tool, whereby the production pipe hanger position prediction unit (200) includes a production pipe hanger prediction alignment arm (209) adapted to engage a receiving slot (6) in the production guide base (7). 12. Procedure for checking the position of a production pipe hanger (25) installed in a subsea wellhead (1), comprising the following steps: a) landing a production pipe position control tool (10) on a wellhead (1) in which the production pipe hanger (25) is installed; characterized in that the method further comprises the following steps: e) aligning an alignment part (30) to the tool (10) with the production pipe hanger (25); f) with a position fixing device (11) arranged on the alignment part (30), to fix the position of the production pipe hanger (25). 13. Method in accordance with patent claim 12, characterized in that step e) further comprises: to rotate the alignment part (30) relative to the production pipe hanger (25), until an alignment clip (41) attached to the alignment part (30) enters a production pipe hanger alignment groove (27). 14. Method in accordance with patent claim 13, characterized in that it comprises the following steps after step a) and before step e): b) to lock a landing section (19, 21) to the tool (10) to the wellhead (1); c) to rotate the alignment part (30) relative to the landing section (19, 21), thus enabling it to be lowered relative to the landing section (19, 21); d) to lower the alignment part (30) in relation to the landing section (19, 21), down to abutment with a landing shoulder (26) in the production pipe hanger (25). 15. Method in accordance with one of patent claims 12 to 14, characterized in that step f) comprises: i) landing a position determination unit (100) on the production pipe hanger control tool (10) in a predetermined mutual position; ii) by means of measuring devices (107) arranged at different positions on the position determination unit (100), to determine the position of the production pipe hanger (25).