SETTING AND RETRIEVAL DEVICE

Abstract

A setting and retrieval device includes a first connection device connected to a first connection interface of a plugging device and a second connection device connected to a second connection interface of the plugging device. The device includes a charging device having first and second fluid chambers, a displaceable charging piston, a power supplying device included a fluid pump device for pumping fluid between the first and second fluid chambers via first and second fluid channels, and a volume adjusting device including a volume adjusting piston displaceable into the first fluid chamber. The energy storing device is charged with potential energy by the charging piston moving in a first direction by pumping fluid from the first to the second fluid chamber and the energy stored in the energy storing device is discharged by movement in a second, axial, direction between the first and second connection devices.

Description

FIELD OF THE INVENTION

The present invention relates to a setting and retrieval device for setting and/or retrieval of a plugging device in a well.

BACKGROUND OF THE INVENTION

There are known several setting tools for setting a plugging device into a well, such as an oil and/or gas well. Typically, such plugging devices are bridge plugs, straddle packers, gauge hangers etc, which is set or fixed to the inside surface of the well during a period in which a well operation is performed. In this period, the setting tool must be removed from the well. Many such plugging devices are retrievable, i.e. they must be retrieved from the well after the well operation. A retrieval tool is used for such types of retrieval operations.

Plugging devices have a run or retracted state, in which the outer diameter is smaller than the inner diameter of the well in order to transport the plugging device into and out from the well. First, the setting tool is connected to the plugging device and the plugging device is guided in its run state to the desired location. Here, the setting tool is bringing the plugging device into its set state, before the setting tool is disconnected from the plugging device and removed out from the well. When the plugging device is to be retrieved, the retrieval tool is guided into the well, connected to the plugging device, and the retrieval tool is bringing the plugging device to its run state and then the retrieval tool together with the plugging device is transported out from the well. One example of a plugging device is known from U.S. Pat. No. 7,178,602 (in the name of Bronnteknologiutvikling AS)

To bring the plugging device from the run state to its set state, and then from its set state and back to its run state, the plugging device comprises an actuation interface. Often, this actuation interface is actuated by moving a first or radially inner part in an axial direction in relation to a second or radially outer part. Shear pins are often used in the plugging device to ensure that the plugging device is in its correct state—i.e. a predetermined force must break one or several sets of shear pins in order to actuate the plugging device. This is a common way to avoid that the plugging device is accidentally brought to its set state during the transport to and from the desired setting location in the well. Such shear pins may require a weight of up to ca 2.5 tons to break.

The object of the invention is to provide a setting and retrieval device which gives an accurate and reliable actuation of the plugging device between its run and set positions.

Moreover, a safety requirement for some oil and/or gas companies is that it no pressurized devices are allowed on deck of platforms and vessels due to the risk of personal injuries. Hence, one object of the present invention is to provide a setting and retrieval device which has no internal pressure before the setting operation, and which has no internal pressure after the retrieval operation.

SUMMARY OF THE INVENTION

The present invention relates to a setting and retrieval device for setting and/or retrieval of a plugging device in a well, comprising:

• • a first connection device adapted to be connected to a first connection interface of the plugging device;
  • a second connection device adapted to be connected to a second connection interface of the plugging device;
  • a charging device comprising a first fluid chamber, a second fluid chamber and a displaceable charging piston comprising a first end facing towards the second fluid chamber and a second end facing towards an energy storing device, where the first and second fluid chambers are provided radially between the first and second connection devices and where the energy storing device is charged with potential energy as the charging piston moves in a first direction by pumping fluid from the first chamber to the second fluid chamber and where energy stored in the energy storing device is discharged by providing a relative movement in a second, axial, direction between the first connection device and the second connection device;
  • a power supplying device comprising a fluid pump device for pumping fluid between the first and second fluid chambers via a first fluid channel and a second fluid channel;
  • a volume adjusting device comprising a first volume adjusting piston displaceable into the first fluid chamber.

In one aspect, the charging piston is movable in the second direction during discharge of the energy storing device.

In one aspect, the energy storing device is a spring device.

In one aspect, the energy storing device is configured to be compressed by the charging piston.

In one aspect, the first fluid channel is provided between the fluid pump device and the first fluid chamber and the second fluid channel is provided between the fluid pump device and the second fluid chamber.

In one aspect, the first connection device is provided radially outside the second connection device.

In one aspect, the second connection device comprises a substantially cylindrical body.

In one aspect, the first connection device comprises a substantially sleeve-shaped body.

In one aspect, the first and second fluid chambers are separated by a first separation wall protruding radially inwards from the substantially cylindrical body.

In one aspect, the first volume adjusting piston is axially displaceable, where the axial displacement of the volume adjusting piston in a first direction decreases the volume of the first chamber and axial displacement of the volume adjusting piston in a second direction increases the volume of the first chamber.

In one aspect, the volume adjusting piston is provided radially between the first and second connection devices.

In one aspect, the volume adjusting device comprises a second axially displaceable volume adjusting piston comprising a first end sealing the opening between the first and second connection devices, where a spring device is provided axially between a second end of the second volume adjusting piston and the first volume adjusting piston.

In one aspect, the volume adjusting device comprises a movement restraining device fixed to the first volume adjusting piston for restraining the movement of the second volume adjusting piston in relation to the first volume adjusting piston.

In one aspect, the device comprises a triggering device adapted for triggering the discharge of the potential energy stored in the energy storing device.

DETAILED DESCRIPTION

Embodiments of the invention will now be described with reference to the enclosed drawings, where:

FIG. 1 illustrates a cross sectional view of a first embodiment in a first state;

FIG. 2 illustrates a cross sectional view of a second embodiment in a first state;

FIG. 3 illustrates a cross sectional view of a second embodiment in a second state;

FIG. 4 illustrates a cross sectional view of a second embodiment in a third state;

FIG. 5 illustrates a cross sectional view of a second embodiment in a fourth state; and

FIG. 6 illustrates a cross sectional view of a third embodiment.

In the following, the term “plugging device” is used to describe any type of device which has a run state, in which the device can be transported through a well, and a set state, in which the device can be expanded and fixed to the inner surface of the well.

The term “well” is used to describe oil and/or gas wells, oil and/or gas pipes, water wells and/or water pipes, or other types of wells and pipes in which a plugging device can be set.

It is now referred to FIG. 1, where a first embodiment of a setting and retrieval device 1 is illustrated. The setting and retrieval device 1 can be used for setting and/or for retrieval of a plugging device in a well. In FIG. 1, the plugging device is only indicated by its connection interfaces shown to the right in FIG. 1. It should be noted that for most plugging devices, the present invention can be used for both setting operations and retrieval operations. However, a plugging device might be designed so that different tools are needed for their setting operation and their retrieval operation, and hence, the present invention may only be used for one of those operations.

The device 1 comprises a first connection device 2 comprising a first connection interface 2a adapted to be connected to a first plug connection interface 2b of the plugging device. Hence, the first connection device 2 itself comprises a second connection interface 2a for connection to the first plug connection interface 2b of the plugging device.

The device 1 also comprises a second connection device 3 comprising a second connection interface 3a adapted to be connected to a second plug connection interface 3b of the plugging device. Hence, the second connection device 3 itself comprises a second connection interface 3a for connection to the second plug connection interface 3b of the plugging device.

It should be noted that the design of the first and second connection devices 2, 3 will of course depend on the design of the first and second connection interface of the plugging device. Many different designs for the first and second connection devices 2, 3 are possible with the present invention as long as the first and second connection devices 2, 3 provide that a relative movement between the first connection device 2 and the second connection device 3 causes a relative movement between the first connection interface and the second connection interface of the plugging device.

In the present embodiment, the first connection device 2 comprises a substantially sleeve-shaped body 21 and the second connection device 3 comprises a substantially cylindrical body 31. The connection interfaces of the first and second connection devices 2, 3 are located in the lower end of the device 1, that is, the right end of the bodies 21, 31 in FIG. 1.

The first connection device 2 is provided radially outside the second connection device 3, i.e. the cylindrical body 31 is located radially inside the sleeve-shaped body 21. In the initial position, as will be described below, the outer surface of the first connection device provides the outer surface of the lowermost part of the device 1.

A longitudinal or axial direction of the device 1 is defined by the central axis I-I.

The device 1 further comprises a charging device 4 and a main body 5. The main body 5 comprises a power supplying device adapted to supply energy to the charging device 4. It should be noted that the main body 5 is only partially shown in the drawings.

The charging device 4 comprises a first fluid chamber 41 and a second fluid chamber 42. The first and second fluid chambers 41, 42 are separated by a separation wall 43. In the present embodiment, the separation wall 43 is protruding radially inwards from the substantially cylindrical body 21, and is fixed to the body 21. Alternatively, the wall 43 could be a part of the body 21 itself.

In the present invention, the first and second fluid chambers 41, 42 are provided radially between the first and second connection devices 2, 3, i.e. radially inside the first connection device 2 and radially outside the second connection device 3.

The charging device 4 further comprises a displaceable charging piston 44 comprising a first end 44a facing towards the second fluid chamber 42 and a second end 44b facing towards an energy storing device 45. The second end 44b comprises a radially protruding stop flange to prevent the energy storing device 45 from being damaged. Hence, the first end 44a of the charging piston 44 is protruding into the second fluid chamber 42, and by movement of the charging piston 44, the volume of the second fluid chamber 42 can be increased or decreased.

The energy storing device 45 may be a spring device configured to be compressed by the charging piston 44. The spring device may be a gas spring, a cup or spiral spring etc. In FIG. 1, the energy storing device 45 is a cup spring, which is supported by an area 5a of the main body 5. The energy storing device 45 is in a radial direction located between the second connection device 3 and an axially protruding element 53 of the main body 5.

The energy storing device 45 is charged with potential energy as the charging piston 44 moves in a first direction by pumping fluid from the first chamber 41 to the second fluid chamber 42. The energy stored in the energy storing device 45 is discharged by providing a relative movement between the first connection device 2 and the second connection device 3 in a second, axial, direction. The axial direction is parallel to the longitudinal direction or central axis I-I of the device 1.

In FIG. 1, the first direction is indicated by arrow A and the second direction is indicated by arrow B. In FIG. 1, the arrow A is opposite of the arrow B, i.e. the charging movement of the charging piston 44 is parallel to the second, axial direction. However, it may also be possible that the movement of the charging piston 44 in the first direction A is non-parallel to the second, axial direction B, since it is the fluid flow between the first and second chambers which provides the relative movement between the first connection device 2 and the second connection device 3.

In the present embodiment, the charging piston 44 is also moved in the second direction B during discharge of the energy storing device 45.

It should also be noted that the discharge of the energy storing device 45 may provide that the first connection device 2 is moved axially while the second connection device 3 is stationary, or that the first connection device 2 is held stationary while the second connection device 3 is moved axially, or that both move relative to each other in an axial direction. In the present embodiment, the first connection device 2 is moved axially while the second connection device 3 is stationary during the discharge of the energy storing device. The second connection device 3 is fixed to the structure of the main body 5.

The main body 5 comprises a fluid pump device 51 for pumping fluid between the first and second fluid chambers 41, 42 via a first fluid channel 11 and a second fluid channel 12. In FIG. 1 it is shown that the first fluid channel 11 is provided inside the cylindrical body 31 from the fluid pump device 51 to the first fluid chamber 41, while the second fluid channel 12 is provided inside the cylindrical body 31 from the fluid pump device 51 to the second fluid chamber 42.

The main body 5 further comprises batteries or another type of power source to supplying power to the fluid pump device 51.

The device 1 further comprises a volume adjusting device 7 for adjusting the volume of the first fluid chamber 41. The volume adjusting device 7 comprises a first volume adjusting piston 71 displaceable into the first fluid chamber 41. The piston 71 is provided radially between the first and second connection devices 2, 3.

According to the above, the first fluid chamber 41 is limited by the volume adjusting piston 71, the wall 43, the outer surface of the body 31 and the inner surface of the body 21. By pumping fluid into or out from the first fluid chamber 41, the piston 71 would move axially to the right or left of FIG. 1 respectively, assuming that the first and second connection devices 2, 3 are held stationary with respect to each other. Hence, the axial displacement of the volume adjusting piston 71 in the first direction decreases the volume of the first chamber 41 and axial displacement of the volume adjusting piston 71 in the second direction increases the volume of the first chamber 41.

According to the above, the second fluid chamber 42 is limited by the axially protruding element 53 of the main body 5, the piston 44, the wall 43, the outer surface of the body 31 and the inner surface of the body 21. By pumping fluid into or out from the second fluid chamber 41, the piston 44 will move axially to the left or right of FIG. 1 respectively, assuming that the first and second connection devices 2, 3 are held stationary with respect to each other.

The device 1 may also comprise a triggering device 6 adapted for triggering the discharge of the potential energy stored in the energy storing device 45. The triggering device 6 could for example be a shear pin which shears off at a predetermined load. In the present embodiment, the triggering device 6 fixes the first connection device 2 to an axial protruding element 53 of the main body 5 and thereby prevents any axial displacement of the first connection device 2 in relation to the second connection device 3. Alternatively, the triggering device 6 in the form of a shear pin may be located on the plugging device instead of the setting and retrieval device 6.

The operation of the device of FIG. 1 will now be described.

Initially, the first fluid chamber 41 is filled with hydraulic fluid and the second fluid chamber 42 is empty or nearly empty. The pressure of the hydraulic fluid in the first fluid chamber 41 may be equal to the pressure at the surface (platform/vessel etc). A plugging device which is to be set in the well is connected to the first and second connection devices 2, 3, as is known for a skilled person. The plugging device and the setting and retrieval tool are then lowered to the desired position in the well and the setting operation can start. During the lowering process into the well, the volume adjusting piston 71 may move axially due to the pressure variations.

First, hydraulic fluid is pumped from the first chamber 41 to the second chamber 42 by means of the fluid pump device 51 via the first fluid channel 11 and the second fluid channel 12. The fluid pump device 51 is supplied with power from the power supply device.

Hence, as the fluid is pumped out from the first chamber 41, the volume of the first chamber 41 decreases as the volume adjusting piston 71 is moving towards the separation wall 43.

As the fluid is pumped in to the first chamber 42, the volume of the second chamber 42 increases as the charging piston 44 is moving towards the energy storing device 45 and stores potential energy in the energy storing device 45. In the present embodiment, the potential energy is stored by compressing a cup spring.

When the potential energy has reached a certain level, the triggering device 6, either of the plugging device or of the setting and retrieval device 1, is triggered, and an axial movement of the first connection device 2 in relation to the second connection device 3 is no longer prevented. Hence, the first connection device 2 is pressed towards the right of FIG. 1 due to the energy stored in the energy storing device 45.

The result is that a controlled axial movement of the first connection device 2 is achieved in the form of a stroke. The axial movement is transferred to the plugging device and causes a setting action of the plugging device, for example by radial expansion of a packer, an anchor etc.

The process can then be repeated by pumping more fluid from the first chamber 41 to the second chamber 42 for charging the energy storing device 45 again. A second triggering device may then be provided for triggering the second axial displacement of the first connection device 2. The second triggering device may be configured to withstand a higher load before breaking off than the first triggering device. The process can be repeated as many times as required, provided that the volume of the first fluid chamber 41 is sufficiently large. If the first axial movement did not move the first connection device far enough, the fluid pump is used to move the first connection device axially until the second triggering device prevents further axial movement. When the plugging device is set, the first and second connection devices 2, 3 are disconnected from the plugging device and the device 1 is retrieved to the surface. The pressure of the first and second fluid chamber 41, 42 can be aligned when there is no well pressure at the right side of the volume adjusting piston 71 in FIG. 1 to avoid any pressure inside the device 1 when retrieved to the deck of the platform.

Second Embodiment

The second embodiment will now be described with reference to FIG. 2-5.

The second embodiment has the same features and functions as the device of the first embodiment, and the same reference numbers are used for the same features. These features will therefore not be described here in detail.

The volume adjusting device 7 of the second embodiment comprises a second axially displaceable pre-charge piston 72 comprising a first end 72a sealing the opening between the first and second connection devices 2, 3, where a spring device 73 is provided axially between a second end 72b of the second pre-charge piston 72 and the first volume adjusting piston 71. In the present embodiment, the spring device 72 is a cup spring. The pre-charge piston 72 is used to pre-charge the charging device 4.

The volume adjusting device 7 may also comprise a movement restraining device 74 fixed to the first volume adjusting piston 71 for restraining the movement of the second pre-charge piston 72 pre-charge piston 72 in relation to the first volume adjusting piston 71.

The operation of the device of FIGS. 2-5 will now be described.

As described, the first and second fluid chamber 41, 42 are initially filled with hydraulic fluid. The volume of the second chamber is small, nearly all the hydraulic fluid of the setting tool is provided in the first fluid chamber 41. The pressure of the hydraulic fluid in the first and second fluid chambers 41, 42 may be equal to the pressure at the surface (platform/vessel etc). Moreover, the positions of the different parts of the volume adjusting device 7 are as shown in FIG. 2.

The plugging device and the setting and retrieval tool are connected to each other and are lowered to the desired position in the well, thereafter the setting operation can start. Since the well pressure is larger than the surface pressure, the well pressure will press the second pre-charge piston 72 towards the first volume adjusting piston 71 during the lowering into the well, and hence, the spring device 73 will be compressed, as shown in FIG. 3.

In FIG. 4 it is shown that the pumping device has pumped fluid from the first chamber 41 to the second chamber 42: The volume adjusting piston 71 has moved towards the separation wall 43 and the charging piston 44 has moved towards the main body 5 and has started the charging of the energy storing device 45. It should be noted that the second piston 72 of the volume adjusting device 7 is limited due to the movement of the movement restraining device 74 fixed to the first volume adjusting piston 71. However, the volume adjusting piston 71 moves in the same direction as the charging piston 44. When the load threshold for the triggering device 6 is reached, the potential energy stored in the energy storing device is released through an axial displacement of the first connection device 2. This operation can be repeated one or several times depending of the design of the device 1, as mentioned above for the first embodiment.

In FIG. 5 it is shown that the first connection device 2 has been displaced to the right in relation to the second connection device 3, and has contributed to a corresponding relative axial displacement between connection interfaces of the plugging device. In FIG. 5, the end position for the axial movement is achieved, by the separation wall 43 abutting against a radially protruding stop 32 of the body 31 of the second connection device 2.

When the device 1 is to be retrieved, the fluid pressure of the first and second chamber 41, 42 can be aligned by using the pumping device actively or by opening a third fluid channel between the chambers 41, 42. The second piston 72 of the volume adjusting device 7 will also move and align the pressure inside the device 1 with the surrounding pressure.

Hence it is achieved that when the device 1 is retrieved from the well and to the deck of the platform, there is no internal pressure in the device 1.

Third Embodiment

A third embodiment is shown in FIG. 6. The third embodiment has the same features and functions as the device of the second embodiment, and the same reference numbers are used for the same features. These features will therefore not be described here in detail.

In the third embodiment, the substantially cylindrical body 31 of the connection device 3 comprises a third fluid channel or bleed off channel 33 between an inner section 34 and an outer section 35. The inner section 34 is closer to the main body 5 than the outer section 35. The bleed off channel 33 provides that fluid may flow between the first and second chambers 41, 42 in order to bleed off the pressure difference between the first and second fluid chambers. The bleed off channel 33 may comprise a separate channel provided in the body 31, as indicated by the dashed line in FIG. 6, or it may comprise one or several longitudinal grooves in the body 31.

Alternatively, it may comprise a tapered area of the body 31, where the inner section 34 has a larger diameter than the outer section 35. The bleed off channel is closed in the initial state, but will open when the separation wall 43 is abutting against the radially protruding stop 32 as shown in FIG. 6, here it is shown that the separation wall 43 is passing the left opening of the channel 33, thereby allowing fluid to flow between the first and second chamber 41, 42.

Hence, in the state shown in FIG. 6, the fluid pressure is aligned between the first chamber and the second chamber 41, 42. Hence it is achieved that when the device 1 is retrieved from the well and to the deck of the platform, there is no internal pressure in the device 1.

It should be noted that the first, second and third embodiments described above may be used to set and retrieve other types of well plugging devices or well tools in addition to those mentioned above. It should also be mentioned that the present invention may also be used to set and retrieve plugging devices and tools in other types of wells, such as water wells.

Moreover, it should be noted that the present invention can be used for both setting operations and retrieval operations. However, there might be plugging devices which may need a different tool for either the setting operation or the retrieval operation. In this situation, the device according to the invention will be a setting tool only or a retrieval tool only.

It should also be noted that in addition to the elements and parts of the device 1 described above, the device 1 also comprises seals, O-rings etc for providing that the first and second chambers 41, 42 is tight with respect to fluid. Moreover, the body 31 and body 21 may comprise several subparts to ease the assembly of the device 1.

Claims

1. A setting and retrieval device for setting and/or retrieval of a plugging device in a well, the device comprising: a first connection device comprising a first connection interface adapted to be connected to a first plug connection interface of the plugging device, wherein the first connection device comprises a substantially sleeve-shaped body;a second connection device comprising a second connection interface adapted to be connected to a second plug connection interface of the plugging device, wherein the second connection device comprises a substantially cylindrical body, wherein the substantially cylindrical body is located radially inside the substantially sleeve-shaped body and wherein the first and second plug connection interfaces are located in a lower end of the device;a charging device comprising a first fluid chamber, a second fluid chamber and a displaceable charging piston, wherein the first and second fluid chambers are separated by a first separation wall protruding radially inwards from the substantially cylindrical body;a triggering device adapted for triggering discharge of potential energy stored in an energy storing device;a power supplying device comprising a fluid pump device for pumping fluid between the first and second fluid chambers via a first fluid channel and a second fluid channel, respectively; anda volume adjusting device comprising a first volume adjusting piston displaceable into the first fluid chamber,wherein the displaceable charging piston comprises a first end facing towards the second fluid chamber and protruding radially inwards from the substantially cylindrical body and a second end facing towards the energy storing device, wherein a volume of the second fluid chamber can be increased or decreased by movement of the displaceable charging piston,wherein the first and second fluid chambers are provided radially between an outer surface of the substantially cylindrical body and an inner surface of the substantially sleeve-shaped body,wherein the energy storing device is charged with potential energy by the displaceable charging piston moving in a first direction (A) caused by pumping fluid from the first fluid chamber to the second fluid chamber by the pumping device, andwherein a relative movement in a second, axial, direction (B) between the first connection device and the second connection device is caused by discharging the potential energy stored in the energy storing device.

2. The device according to claim 1, wherein the displaceable charging piston is movable in the second direction (B) during discharge of the energy storing device.

3. The device according to claim 1, wherein the energy storing device is a spring device.

4. The device according to claim 1, wherein the energy storing device is configured to be compressed by the displaceable charging piston.

5. The device according to claim 1, wherein the first fluid channel is provided between the fluid pump device and the first fluid chamber and wherein the second fluid channel is provided between the fluid pump device and the second fluid chamber.

6. The device according to claim 1, wherein the first connection device is provided radially outside the second connection device.

7.-9. (canceled)

10. The device according to claim 1, wherein the first volume adjusting piston is axially displaceable, wherein the axial displacement of the first volume adjusting piston in a first direction decreases the volume of the first chamber and axial displacement of the first volume adjusting piston in a second direction increases the volume of the first chamber.

11. The device according to claim 10, wherein the first volume adjusting piston is provided radially between the first and second connection devices.

12. The device according to claim 10, wherein the volume adjusting device comprises a second volume adjusting piston comprising a first end sealing an opening between the first and second connection devices, wherein a spring device is provided axially between a second end of the second volume adjusting piston and the first volume adjusting piston.

13. The device according to claim 12, wherein the volume adjusting device comprises a movement restraining device fixed to the first volume adjusting piston for restraining the movement of the second volume adjusting piston in relation to the first volume adjusting piston.

14. (canceled)

15. The device according to claim 2, wherein the energy storing device is a spring device.

16. The device according to claim 2, wherein the energy storing device is configured to be compressed by the displaceable charging piston.

17. The device according to claim 3, wherein the energy storing device is configured to be compressed by the displaceable charging piston.

18. The device according to claim 2, wherein the first fluid channel is provided between the fluid pump device and the first fluid chamber and wherein the second fluid channel is provided between the fluid pump device and the second fluid chamber.

19. The device according to claim 3, wherein the first fluid channel is provided between the fluid pump device and the first fluid chamber and wherein the second fluid channel is provided between the fluid pump device and the second fluid chamber.

20. The device according to claim 4, wherein the first fluid channel is provided between the fluid pump device and the first fluid chamber and wherein the second fluid channel is provided between the fluid pump device and the second fluid chamber.