NO20211178A1

NO20211178A1 - Wireline tool exchange assembly

Info

Publication number: NO20211178A1
Application number: NO20211178A
Authority: NO
Inventors: Steingrim Thommesen; Andreas Hallingstad; Alf Kristensen
Original assignee: Akofs Offshore Operations As
Priority date: 2021-10-01
Filing date: 2021-10-01
Publication date: 2023-04-03
Also published as: WO2023055240A1; NO347144B1

Description

WIRELINE TOOL EXCHANGE ASSEMBLY

Technical Field

The present invention relates to wireline tools used for subsea wells. In particular, the invention relates to equipment and a method for efficient exchange of wireline tools.

Background Art

Various types of wellbore tools exist, which are used for work inside a subsea well. Wireline tools are typically run on a heave-compensated wireline from the surface. A pressure control head is landed above the well, with the wireline extending through it, down to the wireline tool inside the well.

When exchanging one wireline tool with another, the tool is retrieved to the surface, along with the pressure control head. Once the tool is retrieved, it is released from the wireline, and the succeeding tool is attached to the wireline.

This operation, at the surface, takes considerable time. Moreover, manual work is often performed at the center of the moonpool, something which may represent a safety risk. Since such work is directly affecting costly rig time, the work may also be stressful.

An object of the present invention may be to provide equipment and a method that reduces the time needed for exchanging the tool.

Another object may be to reduce safety risk.

Summary of invention

According to a first aspect of the present invention, there is provided a wireline tool exchange assembly comprising a support base, a cradle arrangement supported by the support base, and comprising two tool cradles and two pressure control head cradles. The assembly further has a cradle actuator and a hinge arrangement. The tool cradles and the pressure control head cradles are movable, for instance pivotable, about the hinge arrangement, between a horizontal orientation and a vertical orientation. Moreover, the cradle actuator is configured to actuate movement between said horizontal and vertical orientations.

With the term hinge arrangement, is herein meant an arrangement, for instance in the form of a hinge, configured to guide the tool cradles and the PCH cradles between the horizontal and vertical orientations. Hence, it will be understood that the term hinge arrangement is meant to include any type of such guide means and not merely the strict meaning of a hinge as such.

In some embodiments, the tool cradles can be movable or pivotable independently of the pressure control head cradles.

The assembly may in some embodiments further comprise a cradle displacement arrangement which is configured to displace the mutual position between the support base and the cradle arrangement.

Advantageously, the direction of displacement is transversal to the longitudinal extension of the tool cradles, such that said displacement can be used to position the wireline tool at the well center.

Thus, while the entire wireline tool exchange assembly can be movable, such as on a deck, the said mutual movement of the cradle arrangement with respect to the support base enables a better accuracy of the movement and movement of less weight and equipment.

The assembly may advantageously comprise a well center arrestor arrangement, configured to arrest a wireline tool in a well center of a surface structure.

In particular, the well center arrestor arrangement can be configured to hang off the wireline tool in the well center. In this way, tension in the wireline, with which the wireline tool has been suspended, can be released.

In some embodiments, the tool cradles can comprise a tool securing means and the pressure control head cradles can comprise pressure control head securing means. The tool securing means and the pressure control head securing means are changeable between a tool-arresting position and a non-arresting position, and between a pressure control head-arresting position and a non-arresting position, respectively. With such securing means, the operator is enabled to maintain the well tools and the PCHs in a secure position when the cradles are in the vertical orientation.

In some embodiments, one or more of the tool cradles and the pressure control head cradles can comprise a retractable support, wherein the retractable support can be configured to support a wireline tool or a pressure control head when in said vertical orientation.

Advantageously, the retractable support can be in form of a retractable plate member that can move between a supporting and a non-supporting state.

Moreover, the retractable support can advantageously comprise a wirelinereceiving recess, such that the wireline can extend through the recess when the plate supports a pressure control head.

One or more of the retractable supports of the pressure control head cradles can comprise a wireline reception which is configured to receive a wireline.

According to a second aspect of the present invention, there is provided a method of replacing a first wireline tool inside a subsea well with a second wireline tool. The first wireline tool connects to a surface structure through a first wireline, and the first wireline extends through a first well control head. The method comprising the following steps

a) on a wireline tool exchange assembly, preparing a second wireline tool and a second well control head while in a horizontal orientation, comprising extending a second wireline through the second well control head and connecting the second wireline to the second wireline tool;

b) retrieving the first wireline tool and the first well control head to the surface structure;

c) arranging the first well control head to the wireline tool exchange assembly;

d) arranging the first wireline tool to the wireline tool exchange assembly;

e) moving the first control head and the first wireline tool from a vertical orientation into a horizontal orientation, with the wireline tool exchange assembly;

f) moving the second control head and the second wireline tool from the horizontal orientation to the vertical orientation, with the wireline exchange assembly;

g) with the second wireline, lowering the second wireline tool into the subsea well.

As will be readily understood, the method according to the second aspect of the invention can advantageously be performed using the assembly according to the first aspect of the invention.

Detailed description of the invention

While various features of the invention have been presented above, a more detailed and non-limiting example of embodiment will be given in the following with reference to the drawings, in which

Fig. 1 is a schematic diagram showing a floating structure operating a wireline tool arranged inside a subsea well;

Fig. 2 is a schematic diagram corresponding to Fig.1, wherein the wireline tool is about to be retrieved to the surface;

Fig. 3 is a perspective view of a wireline tool exchange assembly, located at a tool reservoir on the floating structure;

Fig. 3a is a principle view of one tool cradle and one pressure control head cradle, wherein a wireline extends through the pressure control head and is attached to the wireline tool;

Fig. 4 is a perspective overview of the deck of a surface structure, wherein a wireline tool exchange assembly is located in a first position, close to the tool reservoir;

Fig. 5 is a perspective overview corresponding to Fig.4, however with the wireline tool exchange assembly has been moved closer to the well center;

Fig. 6 is a perspective view showing the wireline tool exchange assembly arranged at the well center, and wherein a pressure control head (PCH) is about to be retrieved;

Fig. 7 is a perspective view similar to Fig.6, however wherein a PCH cradle has been pivoted into a vertical orientation and wherein the PCH is received in the PCH cradle;

Fig. 7a is an enlarged, more realistic, perspective view of a tool cradle and pressure control head (PCH) cradle, supporting a wireline tool and a PCH, respectively;

Fig. 8 corresponds to Fig.7, showing however that the tool cradle has been lowered back to the horizontal orientation, and that the cradle arrangement is moved with respect to the support base;

Fig. 9 shows the wireline tool being retrieved into the vertically oriented tool cradle, wherein a second wireline tool has been prepared and is waiting in the adjacent tool cradle;

Fig. 10 shows a situation wherein the second wireline tool has been lowered and the associated wireline is clamped in a fixed position such that the tool cradle can be pivoted back into the horizontal orientation;

Fig. 11 shows the second PCH being lowered down from the PCH cradle, depending, with the wireline extending through it.

Fig. 1 shows, with a simplified and schematic view, a surface structure 1 at the sea surface 3. The surface structure can be a ship or another type of floating structure, or a structure resting on the seabed 7. A subsea well 5 extends into the seabed 7. Inside the subsea well 5 there is arranged a first wireline tool 9. The first wireline tool 9 is suspended on a first wireline 11 that is operated from the surface structure 1. On the surface structure 1 there is a wireline winch 13 operating the first wireline 11, and a tower 15.

At the seabed 7, the first wireline 11 extends through a pressure control head (PCH) 17 and a lubricator package 19. Further, the first wireline 11 extends through a well control package (WCP) 21 and a valve tree 23, often referred to as a Xmas tree.

Fig. 2 depicts a situation where the first wireline tool 9 has been pulled out from the subsea well 5 and back to the surface structure 1. Along with the first wireline tool 9, the PCH 17 is also pulled up to the surface structure 1. Since the first wireline 11 extends freely through the PCH 17, the PCH 17 is lifted with a separate cable (not shown).

In the present example embodiment, which will be elaborated below, the first wireline tool 9 shall be replaced with a second wireline tool (not shown in Fig.1 and Fig.2).

Fig. 3 depicts a wireline tool exchange assembly 100, arranged on a deck 1a of the surface structure 1. The tool exchange assembly 100 has a personnel platform 101, on which personnel 25 can stand. The tool exchange assembly 100 further has a cradle arrangement 103. The cradle arrangement 103 has, in the shown embodiment, two tool cradles 105a, and two pressure control head cradles (PCH cradles) 105b.

In one of the PCH cradles 105b, there is arranged a second PCH 18. In one of the tool cradles 105a, there is arranged a second wireline tool 27. In this example embodiment, the first wireline tool 9, which was shown being retrieved in Fig.2, shall be replaced by the second wireline tool 27. While the first wireline tool 9 is in use in the subsea well 5, and/or while it is being retrieved to the surface, personnel 25 can assemble the second wireline tool 27 in the tool cradle 105a. As indicated in Fig.4 and Fig.5, the wireline tool exchange assembly 100 can be located away from the well center 33. The assembly of the second wireline tool 27 will thus not affect the ongoing operations with the first wireline tool 9.

Still referring to Fig.3, a tool supply arrangement 29, typically a crane arrangement, is provided for transferring the required wireline tools from a tool reservoir 31 to the tool cradle 105a.

Fig. 3a is a schematic diagram showing one tool cradle 105a and one PCH cradle 105b, such as the ones shown in Fig.3. Also shown in Fig.3a is a second wireline 35. The second wireline 35 corresponds to the first wireline 11 shown in Fig.1. However, the second wireline 35 will be used when employing the second wireline tool 27.

As can be seen in Fig.3a, the second wireline 35 is extended through the second PCH 18 and connects to the second wireline tool 27. The second wireline tool 27 and the second PCH 18 is now ready to be used.

Referring again to Fig.4 and Fig.5, when the second wireline tool 27 has been assembled in the tool cradle 105a and the second PCH 18 has been assembled in the PCH cradle 105b, the entire wireline tool exchange assembly 100, is moved towards the well center 33 below the tower 15. A rail system, which as such is known to the skilled person, can be used to enable this movement, and will not be discussed herein.

In the situation shown in Fig.6, the wireline tool exchange assembly 100 has been moved to the well center 33. Furthermore, the first PCH 17 has been lifted up and can now be seen at the well center 33.

The wireline tool exchange assembly 100 has a support base 107. As will be shown further below, the cradle arrangement 103 is configured to move with respect to the support base 107, in a direction crosswise to the longitudinal extensions of the tool cradles 105a and the PCH cradles 105b.

Reference is now made to Fig.7. One of the two PCH cradles 105b, namely the one not supporting the second PCH 18, has now been pivoted into a substantially vertical orientation. The PCH cradle 105b is connected to the rest of the cradle arrangement 103 with a hinge arrangement 106.

While in this vertical orientation, the first PCH 17 has been lifted further upwards and into the PCH cradle 105b. Moreover, the PCH 17 has been fixated in this position by means of a pressure control head (PCH) securing means 109b, which in the shown embodiment has the form of a bow that engages with the PCH 17 in the PCH cradle 105b. Furthermore, a retractable PCH support 111b protrudes out from the PCH cradle 105b and constitutes a support carrying the weight of the PCH 17.

The retractable PCH support 111b is in the present embodiment in the form of a plate that has a wireline reception 114, typically in the form of a slit, which can receive the first wireline 11. The PCH support 111b is shown in better detail in Fig. 7a, which also depicts the wireline reception 114 of the PCH support 111b. In the situation shown in Fig.7a, the second PCH 18 is supported in a horizontal orientation.

The wireline tool exchange assembly 100 comprises a well center arrestor arrangement 113. The PCH 17 was arrested in the PCH cradle 105b.

Furthermore, the well center arrestor arrangement 113 arrested the first wireline tool 9. Also, the first wireline 11 run back down some distance, such that the first wireline 11 formed a loop 11a, which can be seen in Fig.7.

In the situation shown in Fig.7, there is thus some slack, or excessive length of the first wireline 11 between the first PCH 17 and the first wireline tool 9. The PCH cradle 105b is then pivoted back down to the horizontal orientation, without causing tension in the first wireline 11 above the position of the well center arrestor arrangement 113.

This is shown in Fig.8, wherein the first PCH 17 now is supported in the PCH cradle 105b, both having a horizontal orientation. The well center arrestor arrangement 113 still holds the first wireline tool 9 at the well center 33.

Also shown in Fig.8, the cradle arrangement 103 has been moved a distance, in a direction normal to the longitudinal extension of the cradles 105a, 105b, as indicated with the dotted arrow. This is to prepare the empty tool cradle 105a, i.e. the one not supporting the second wireline tool 27, to receive the first wireline tool 9. This displacement is brought about by means of a cradle displacement arrangement 108. The cradle displacement arrangement 108 can advantageously be in the form of a set of hydraulic cylinders arranged between the cradle arrangement 103 and the support base 107.

Fig. 9 shows that both tool cradles 105a have been erected into a substantially vertical orientation. The tool cradles 105a have been pivoted about a hinge arrangement 106. The empty tool cradle 105a was thus positioned directly above the well center 33 and the first wireline tool 9 was pulled up and into the tool cradle 105a.

Corresponding to the PCH securing means 109b of the PCH cradle 105b, the tool cradle 105a has a tool securing means 109a.

Moreover, corresponding to the retractable PCH support 111b of the PCH cradle 105b, the tool cradle 105a has a tool support 111a.

In the situation shown in Fig.9, the first PCH 17 and the first wireline tool 9 have been retrieved and secured. The operator is immediately ready to run the second wireline tool 27 and the second PCH 18, as the second wireline tool 27 already has been prepared on the cradle arrangement 103.

Fig. 9 further depicts a cradle actuator 112, configured to move the tool cradle 105a between the horizontal and vertical orientations. In the shown embodiment, the cradle actuator 112 is in the form of a hydraulic piston. The PCH cradles 105b can be provided with corresponding cradle actuators 112, for their corresponding movement.

In the situation shown in Fig.10, the cradle arrangement 103 has moved even further, thus positioning the tool cradle 105a supporting the second wireline tool 27 above the well center 33. Moreover, the second wireline tool 27 has been lowered down and is arrested by the well center arrestor arrangement 113. Then, the second PCH 18 is raised into the vertical orientation and positioned directly over the well center 33, as illustrated in Fig.11. The operator can now lower the second wireline tool 27 on the second wireline 35 down to the subsea well 5, along with the second PCH 18.

As will be appreciated, since the second PCH 18 and the second wireline tool 27 is already assembled when the first wireline tool 9 has been retrieved, the operator needs little time before the running of the second wireline tool 27 can commence. The amount of work taking place at the well center 33 is limited and can be done swiftly. Moreover, the present solution reduces the manual work taking place close to the well center 33.

Claims

1. A wireline tool exchange assembly (100) comprising

- a support base (107);

- a cradle arrangement (103) supported by the support base (107) and comprising two tool cradles (105a) and two pressure control head cradles (105b);

- a cradle actuator (112);

- a hinge arrangement (106);

wherein the tool cradles (105a) and the pressure control head cradles (105b) are movable about the hinge arrangement (106), between a horizontal orientation and a vertical orientation, and wherein the cradle actuator (112) is configured to actuate movement between said horizontal and vertical orientations.

2. A wireline tool exchange assembly (100) according to claim 1, characterized in that the tool cradles (105a) are pivotable independently of the pressure control head cradles (105b).

3. A wireline tool exchange assembly (100) according to claim 1 or claim 2, characterized in that it further comprises a cradle displacement arrangement (108), configured to displace the mutual position between the support base (107) and the cradle arrangement (103).

4. A wireline tool exchange assembly (100) according to any one of the preceding claims, characterized in that it comprises a well center arrestor arrangement (113), configured to arrest a wireline tool (9, 27) in a well center (33) of a surface structure (1).

5. A wireline tool exchange assembly (100) according to any one of the preceding claims, characterized in that the tool cradles (105a) comprise a tool securing means (109a) and that the pressure control head cradles (105b) comprise pressure control head securing means (109b), wherein the tool securing means (109a) and the pressure control head securing means (109b) are changeable between a tool-arresting position and a non-arresting position, and between a pressure control head-arresting position and a non-arresting position, respectively.

6. A wireline tool exchange assembly (100) according to any one of the preceding claims, characterized in that one or more of the tool cradles (105a) and the pressure control head cradles (105b) comprises a retractable support (111a, 111b), wherein the retractable support (111a, 111b) is configured to support a wireline tool (9, 27) or a pressure control head (17, 18) when in said vertical orientation.

7. A wireline tool exchange assembly (100) according to claim 6, characterized in that one or more of the retractable supports (111b) of the pressure control head cradles (105b) comprises a wireline reception (114), configured to receive a wireline (11, 35).

8. Method of replacing a first wireline tool (9) inside a subsea well (5) with a second wireline tool (27), wherein the first wireline tool (9) connects to a surface structure (1) through a first wireline (11), and wherein the first wireline (11) extends through a first well control head (17), the method comprising the following steps

a) on a wireline tool exchange assembly (100), preparing a second wireline tool (27) and a second well control head (18) while in a horizontal orientation, comprising extending a second wireline (35) through the second well control head (18) and connecting the second wireline (35) to the second wireline tool (27);

b) retrieving the first wireline tool (9) and the first well control head (17) to the surface structure;

c) arranging the first well control head (17) to the wireline tool exchange assembly (100);

d) arranging the first wireline tool (9) to the wireline tool exchange assembly (100);

e) moving the first control head (17) and the first wireline tool (9) from a vertical orientation into a horizontal orientation, with the wireline tool exchange assembly (100);

f) moving the second control head (18) and the second wireline tool (27) from the horizontal orientation to the vertical orientation, with the wireline exchange assembly (100);

g) with the second wireline (35), lowering the second wireline tool (27) into the subsea well (5).