NL2033608B1

NL2033608B1 - Arrangements and methods for well abandonment

Info

Publication number: NL2033608B1
Application number: NL2033608A
Authority: NL
Inventors: Veenstra Feitze
Original assignee: Callidus Capital B V
Priority date: 2022-11-24
Filing date: 2022-11-24
Publication date: 2024-05-30
Also published as: WO2024112200A1; AU2023384853A1; EP4623182A1

Abstract

Method of removing a length of conduit (104), such as a tubing or casing from an underground passage, such as a well, the method comprising steps of: - inserting an inner gripper (230) into the conduit; - increasing an outer dimension of the inner gripper such that the inner gripper engages an inner wall (141) of the conduit; - moving at least part of the conduit out of the underground passage by moving the inner gripper; - gripping the conduit with an outer gripper (2 10); and - decreasing the outer dimension of the inner gripper such that the inner gripper disengages the inner wall of the conduit, wherein the method further comprises severing the conduit at a severing location with a severing module (220), which severing location is positioned above the outer gripper, thereby forming a severed conduit section severed from the conduit.

Description

P134103NL00

Title: Arrangements and methods for well abandonment

TECHNICAL FIELD

The aspects and embodiments thereof relate to the field of well abandonment, or more in general to removal of conduits from underground passages.

BACKGROUND

When a well for production of hydrocarbons, such as oil or gas, is no longer used, the well has to be abandoned in an environmentally safe manner. In the well abandonment process, it is typically desired to remove a length of the tubing in the well, for example about 50 metres. The remaining tubing may be left in place. The tubing is thus severed at a particular depth, for example at about 50 metres, and the severed tubing is pulled out of the well. For pulling the tubing out of the well, a rig is positioned over the well and using the rig, tubing can be lifted up and out of well. After the tubing has been removed, a cement plug can be placed in the casing which previously surrounded the tubing.

Alternatively, a through-tubing abandonment process may be performed. In such a process, the production tubing is cut or punched and cemented inside the production casing. This may save time because the tubing can remain inside the well.

SUMMARY

It is an object to improve the process of well abandonment. More in general, it is an object to improve the process of removing conduits from underground passages. Improvements may relate to a time reduction of the abandonment process, increased safety, decreased costs, increased efficiency, increased quality of the abandonment process, or any combination thereof.

A first aspect provides a method of removing a length of conduit from an underground passage. Generally, the conduit may be a pipe, tubing, casing or any other type of conduit. A conduit is generally an elongated cylinder, for example for transporting one or more fluids or cables through. It will be understood that whenever in the present disclosure a specific type of conduit is mentioned, this specific type of conduit — such as a tubing — may be replaced by any other type of conduit — such as a casing or pipe. Generally, the conduit may be oriented at least partially vertically, at least partially horizontally, or any combination thereof.

The conduit is at least partially positioned in an underground passage. The underground passage may for example be a drilled borehole.

Alternatively, the conduit may have been buried underground, or for example the conduit may have been driven into the ground. The conduit may be a subsea conduit, for example positioned below the seabed. The conduit may be at least partially submerged in a body of water, and any method disclosed herein may be performed on an off-shore platform or floating vessel. Thus, any arrangement disclosed herein may be positioned on such an off-shore platform or floating vessel.

According to the first aspect, the method comprises steps of: inserting an inner gripper into the conduit, alternately engaging the conduit with the inner gripper and an outer gripper, moving at least part of the conduit out of the underground passage by moving the inner gripper and/or the outer gripper.

The method further comprises a step of severing the conduit at a severing location, preferably with a severing module, which severing module is positioned above the outer gripper, thereby forming a severed conduit section severed from the conduit. Throughout the present disclosure, it will be understood that severing means that a part of the conduit — the severed conduit section — becomes separated from the remaining part of the conduit.

Typically, part of the remaining part of the conduit remains underground.

Severing may be a destructive process, for example by cutting or sawing.

Alternatively, severing may be non-destructive, for example by releasing a coupling between different sections of the conduit, for example by unscrewing the coupling.

When the inner gripper is inserted into the conduit, the inner gripper may be pass through the severing module. This allows for the stroke of the inner gripper to be less or not restricted by the shape and position of the severing module. An inner gripper allows for a conduit to be pulled on without requiring access to the outer wall of the conduit.

The inner gripper generally comprises an inner gripper mechanism arranged to engage an inner wall of any conduit. The inner gripper mechanism may for example be inflated, expanded, or otherwise have an outer dimension increased to engage the inner wall of the conduit.

The outer gripper generally comprises an outer gripper mechanism arranged to engage an outer wall of any conduit. The outer gripper mechanism may for example be any clamping mechanism. A clamping mechanism may generally comprise multiple clamp members which can be moved relative to each other towards one another. Clamp members moving relative to each other implies that any one or both clamp members move.

When part of the conduit is positioned between the clamp members and the clamp member are moved relative to each other towards one another, the conduit can be clamped between the clamp members. As a particular option, the outer gripper mechanism may be a ram of a blowout preventer, for example a pipe ram or a shear ram.

Whenever the conduit is a pipeline which is buried underground, and 1s thus approximately horizontal, the outer gripper may be omitted. In particular, the outer gripper may be omitted because the conduit from which section are severed is held in place by the ground surrounding the conduit. A method for removing a removing a length of horizontally oriented conduit, such as pipeline, from an underground passage is thus envisioned, the method comprising steps of inserting an inner gripper into the conduit, pulling the conduit further out of the underground passage by moving the inner gripper away from the underground passage, and severing the conduit at a severing location with a severing module. The method for removing a removing a length of horizontally oriented conduit may be performed using any arrangement disclosed herein.

As a particular option, for example when it is desired to displace the severed conduit section, embodiments of the method may comprise a step of moving the severed conduit section relative to a centreline of the conduit and decreasing an outer dimension of the inner gripper such that the inner gripper disengages the inner wall of the conduit. The resulting movement of the severed conduit section may be over one or more translation axes, one or more rotation axes, in any combination thereof. An inner gripper actuator may be used for moving the inner gripper, and thus for displacing the severed conduit section.

The severing location is preferably but not necessarily positioned between an inner gripper mechanism of the inner gripper and the longitudinal cutter.

In general, in any embodiment of the method, at least part of the inner gripper may pass through the outer gripper when the inner gripper is inserted into the conduit. This may allow for the stroke of the inner gripper being less or not limited by the outer gripper, and thus for an increased stroke for the inner gripper.

For example to facilitate the removal of the severed conduit section, any method disclosed herein may further comprise a step of cutting through the conduit in a direction parallel to an elongation direction of the conduit. In particular when the entire severed conduit section is also cut through over the longitudinal direction, the severed conduit section may be split open as the previously closed circumference of the severed conduit section is opened by virtue of the cut over the elongation direction of the severed conduit section.

Cutting through the conduit in the longitudinal direction may in general be performed by a cutting action, sawing action, milling action, or any 5 other cutting action, for example using scissors, a rotating saw blade, a cutting wheel, or any other cutting tool, in any combination thereof.

The step of cutting through the conduit in a longitudinal direction parallel to an elongation direction of the conduit may result in a single cut, or in multiple separate cuts, for example two cuts or more or even four cuts or more.

As a non-limitative example, when any method comprises the step of cutting through the conduit in the longitudinal direction, a longitudinal cutter may be connected to the inner gripper for cutting through the conduit in a direction parallel to an elongation direction of the conduit, and the cutting through the conduit is performed while inserting the inner gripper into the conduit.

In any method disclosed herein, the outer gripper may be moveable relative to the conduit. For example, the outer gripper may be moveable in an upward direction relative to the conduit. When both the inner gripper and the outer gripper are moveable relative to the conduit, the inner gripper may move simultaneously with the outer gripper, in particular in opposite directions, during at least part of the method. This in turn allows the conduit to be moved out of the underground passage with a generally constant speed, at least during times when the conduit is not being severed.

When the conduit is a tubing or casing of a well, the inner gripper may be lowered into a well cellar before inserting the inner gripper into the tubing or casing. In the well cellar, an opening into the tubing or casing may be present, for example when at least part of a well head has been previously removed to expose the opening into the tubing or casing.

It has been observed that a control line may be connected to a conduit, in particular a tubing of a well. The control line has been used for example to provide hydraulic pressure to a particular depth in the well.

Typically, the control line is connected to the conduit by one or more clamps.

Whenever a control line is connected to the conduit by one or more clamps, embodiments of the method may comprise a step of removing at least one of the clamps and winding the control line onto a spool. Removing the at least one of the clamps may for example comprise a destructive action of cutting through the at least one of the clamps. By winding the control line onto a spool, the control line may be conveniently stored for example for transportation. A destructive action may be advantageous in that it may require less time than a non-destructive action.

In any embodiment of the method, a fluid-tight seal may be formed between the inner gripper and an inner wall of the conduit. A fluid is generally understood to comprise one or more liquids and/or one or more gasses. A fluid-tight seal may allow for the inner gripper to be used as a piston for forcing a fluid further down into the underground passage. In particular, when the conduit is a tubing or casing of a well, the fluid-tight seal may allow for the inner gripper to be used as a piston for forcing a fluid through said tubing or casing.

A fluid may be fed into the conduit via a passage through the inner gripper. For example, the fluid may be a plug-forming fluid such as cement or a fluid for forcing a wiper plug further down in the conduit. In another example, the method further comprises prior to inserting the inner gripper into the conduit, filling at least part of the conduit with a plug-forming fluid, and after inserting the inner gripper into the conduit, feeding the fluid into the tubing to force the plug-forming fluid further down into the well.

Additionally or alternatively to feeding a fluid into the conduit, a suspension member such as a wire, slickline, conduit, or E-line may be fed into the conduit via the passage through the inner gripper. In such cases, a flud-tight seal may be formed between the passage and the suspension member, for example using a snubbing box.

A second aspect provides an arrangement for removing a length of conduit, such as a tubing or casing from an underground passage, such as a well. The arrangement comprises an inner gripper arranged to be at least partially inserted into the conduit, the inner gripper comprising an inner gripper mechanism for selectively engaging and disengaging an inner wall of the conduit, an outer gripper with a passage through which the conduit can extend, wherein the outer gripper comprises an outer gripper mechanism arranged for selectively engaging and disengaging an outer wall of the conduit, and a severing module for severing the conduit. The arrangement further comprises an actuator for moving one of the inner gripper or the outer gripper relative to the other of the inner gripper and the outer gripper.

The second aspect also provides an alternative embodiment of the arrangement for removing a length of conduit, such as a tubing or casing from an underground passage, such as a well, the arrangement comprising at least one of an inner gripper arranged to be at least partially inserted into the conduit, the inner gripper comprising an inner gripper mechanism for selectively engaging and disengaging an inner wall of the conduit and an outer gripper with a passage through with the conduit can extend, wherein the outer gripper comprises an outer gripper mechanism arranged for selectively engaging and disengaging an outer wall of the conduit, an actuator for moving the conduit by moving the inner gripper and/or the outer gripper, a severing module for severing the conduit, and a longitudinal cutter for forming a longitudinal cut in the conduit in a longitudinal direction parallel to an elongation direction of the conduit.

Any embodiment of the arrangement may comprise an axial connector cutter for removing an axial connector connecting two sections of conduit, wherein the axial connector cutter is positioned above the outer gripper.

Additionally or alternatively, any embodiment of the arrangement comprise a clamp cutter for destructively removing a clamp connecting a control line to the conduit, wherein the clamp cutter is positioned below the outer gripper. In particular when an arrangement comprises the clamp cutter, a spool may be provided for winding a length of control line onto.

Any time the inner gripper of the arrangement comprises a passage there through, the arrangement may further comprise a fluid container in fluid communication with a passage through the inner gripper. The fluid container may be filled with any fluid, for example but not limited to plug- forming fluid. An optional fluid pump may be positioned between the fluid container and the inner gripper for forcing fluid from the fluid container to the inner gripper.

Different embodiments of the arrangement are thus envisioned for performing one, more, or all steps of the methods disclosed herein. As such, any optional features disclosed in conjunction with any method may be readily applied to any arrangement, and vice versa.

Generally, for any method and arrangement disclosed herein, the inner gripper may be arranged to be rotated around a rotation axis which in use is parallel or even aligned with a centreline of the conduit, for example using an inner gripper actuator. Additionally or alternatively, the outer gripper may be arranged to may be arranged to be rotated around a rotation axis which in use is parallel or even aligned with a centreline of the conduit, for example using an outer gripper actuator.

Embodiments of the arrangement are envisioned comprising multiple outer grippers. This for example allows the outer grippers to be used to move the conduit. A first outer gripper can move the conduit away from the underground passage. Subsequently, the conduit can be engaged by a second outer gripper to prevent the conduit from falling back into the underground passage as the first outer gripper moves back towards the underground passage while being disengaged from the conduit. When an arrangement comprises multiple outer grippers, the inner gripper may be omitted.

A third aspect provides an inner gripper for engaging a conduit.

Engaging throughout the disclosure implies that in an engaged state, forces and/or torques can be transferred between the two elements which are engaged. Preferably, when two elements are engaged, such as a gripper engaging a conduit, the two elements move together.

The inner gripper according to the third aspect comprises an inner gripper mechanism for selectively engaging and disengaging an inner wall of the conduit and a longitudinal cutter for cutting through the conduit in a longitudinal direction parallel to an elongation direction of the conduit. As such, the inner gripper may be used for selectively engaging and disengaging the conduit using the inner gripper mechanism, and also while the inner gripper is inserted further into the conduit, the longitudinal cutter can cut through the conduit in the longitudinal direction.

When the inner gripper further comprises a seal, a fluid-tight seal may be formed with the conduit. Such as a fluid-tight seal may for example form a safety barrier to prevent leakage of fluid between the inner gripper and the inner wall of the conduit.

When the inner gripper further comprises the seal, the inner gripper mechanism may be positioned in-between the seal and the longitudinal cutter or the seal may be positioned in-between the inner gripper mechanism and the longitudinal cutter. In use, the inner gripper may be inserted into the conduit with the seal first of the seal, the longitudinal cutter, and the inner gripper mechanism. More in general, the seal is inserted into the conduit prior to the longitudinal cutter.

A passage may be provided through any inner gripper disclosed herein. The passage may be used to pass one or more fluids through, and/or to pass a rope, wire, slickline, conduit, or any other suspension member through.

Any inner gripper disclosed herein may be comprised by any arrangement disclosed herein, and may be used in any method as disclosed herein.

A fourth aspect of the present disclosure provides a method of severing a conduit in an underground passage, such as severing a tubing in a well. The method comprises inserting at least part of using any inner gripper disclosed herein into the conduit, using the inner gripper to engage an inner wall of the conduit, and pulling on the conduit by pulling on the inner gripper.

The method further comprises severing the conduit at a severing depth in the underground passage while pulling on the conduit. The pulling force of the conduit may aid the severing step. Severing may be performed by any one or combination of milling, sawing, punching, demolition, incineration, or any other method for severing a conduit.

In a fifth aspect, the present disclosure contemplates a method of removing a control line from a conduit, such as a tubing. The method comprises steps of transporting the conduit relative to a clamp cutter for destructively removing a clamp connecting a control line to the conduit. The conduit can generally be transported relative to the clamp cutter for example by using an inner gripper or outer gripper as disclosed herein, but also other transportation methods are envisioned.

The clamp cutter preferably comprises one or more cutting wheels, which one or more cutting wheel may cut into the clamp connecting the control line to the conduit. Alternatively, any other cutting member may be comprised by the clamp cutter, such as a knife, laser cutter, scissors, saw or any other member for destructively removing the clamp.

As the control line is released from the conduit by removing the clamps, the control line can be wound on a spool or cut into smaller sections.

BRIEF DESCRIPTION OF THE FIGURES

In the figures,

Fig. 1 schematically shows a section view of a well;

Fig. 2 shows the well of Fig. 1 after a step of severing the tubing at a severing depth;

Fig. 3A shows the well of Fig. 2, with an arrangement for removing a length of conduit;

Fig. 3B shows a schematic top view of the situation of Fig. 3A;

Fig. 4A shows the well and the arrangement, after a step of lowering the inner gripper into the tubing;

Fig. 4B and Fig. 4C show a detailed view of the tubing, with a particular embodiment of an inner gripper positioned in the tubing;

Fig. 5A shows the step of inserting the inner gripper into the tubing, but with another embodiment of the inner gripper;

Figs. 5B and 5C show the inner gripper of Fig. 5A in more detail;

Fig. 6 shows the well after a step of pulling the severed part of the tubing upward;

Fig. 7A shows the well after a step of severing the tubing using the severing module;

Figs. 7B and 7C show a particular embodiment of the outer gripper in more detail;

Fig. 8 shows another situation of the well;

Fig. 9 shows yet another situation of the well;

Fig. 10 shows another example of the well with a particular arrangement;

Fig. 11 shows another example of the well with a particular arrangement,

Fig. 12 again shows an example of the well;

Fig. 13A shows another example of a well;

Fig. 13B and Fig. 13C show the inner gripper of Fig. 13A in more detail;

Fig. 14 schematically depicts a well with a particular inner gripper;

Fig. 15 shows the well of Fig. 14 after the flow of fluid has forced the wiper plug further down into the upper tubing section;

Fig. 16 shows an example of a well wherein a flow of plug-forming fluid is supplied into the upper tubing section;

Fig. 17 shows the well of Fig. 16 after part of the upper tubing section has been lifted out of the well;

Fig. 18 shows a first embodiment of an arrangement for removing a length of conduit, such as a tubing or casing from an underground passage, such as a well;

Fig. 19 shows a second embodiment of an arrangement for removing a length of conduit, such as a tubing or casing from an underground passage, such as a well;

Figs. 20A and 20B show a third embodiment of an arrangement for removing a length of conduit;

Figs. 21A and 21B depict a longitudinal cutter;

Figs. 22A and 22B depict a particular embodiment of the inner gripper; and

Figs. 23A and 23B schematically depict a horizontal pipeline.

DETAILED DESCRIPTION OF THE FIGURES

Fig. 1 schematically shows a section view of a well 100, which is as an option depicted in a well cellar 102. The well 100 comprises a tubing 104 extending into the ground, and a casing 106 surrounding at least part of the tubing 104. The well 100 is depicted without the wellhead, because the wellhead has at least been partially removed previously, and the upper end 105 of the tubing 104 is thus accessible. Preferably, at least a tubing hanger has been removed. When the tubing hanger and/or casing hanger has not been removed, it will be appreciated that the arrangements disclosed herein may be adapted to accommodate the tubing hanger and/or casing hanger. For example, the outer gripper and/or severing module may be dimensioned to allow the tubing hanger and/or casing hanger to pass there through.

A longitudinal direction L of the tubing 104 as an example of a conduit is indicated in Fig. 1. The longitudinal direction L 1s parallel to an elongation direction of the tubing 104. Although in the figures the longitudinal direction L corresponds to a vertical direction, it will be understood that the technology disclosed herein may be readily applied to conduits of which the longitudinal direction is generally horizontal. The longitudinal direction may for example be horizontal in case the conduit is a pipeline.

Typically, a production packer 108 is positioned in an annulus 110 between the tubing 104 and the casing 106. A plug 112 may have been positioned in the tubing 104 to close off the tubing 104 from a reservoir 111 from which for example oil or gas has been produced. The casing 106 may for example be a 7 5/8” casing. It will be appreciated that the figures are not drawn to scale. Although not depicted, a blowout preventer may be comprised by the well. Additionally, or alternatively, a wellhead may still be present, for example comprising a X-mas tree. Such a wellhead then has a passage sufficiently dimensioned to allow passage of the conduit, optionally with any axial coupling and/or control line connected to the conduit.

Fig. 2 shows the well 100 of Fig. 1 after a step of severing the tubing at a severing depth 114. By virtue of the severing, an upper tubing section 104 and a lower tubing section 104” are obtained. Typically, the lower tubing section 104” will remain in place, also after abandonment of the well. Many methods and tools are known in the art for severing the tubing 104, for example but not limited to milling, cutting, sawing, incineration, using explosives, or any other means for severing the tubing 104. After the tubing

104 has been severed, the upper tubing section 104’ can at least be partially lifted out of the casing 106.

Fig. 3A shows the well 100 of Fig. 2, with an arrangement 200 for removing a length of conduit from an underground passage positioned over the well cellar 102. In case the well 100 1s not positioned in a well cellar, the arrangement 200 may be positioned on the ground surrounding the well. Fig. 3A shows a schematic section view, and Fig. 3B shows a schematic top view of the situation of Fig. 3A.

The arrangement 200 comprises an arrangement frame 202, providing a working surface 201. Generally, the working surface 201 is arranged for supporting one or more pieces of equipment. In the embodiment of Figs. 3A and 3B, as an option applicable to any arrangement disclosed herein, an opening 204 is provided through the arrangement frame 202, in particular through the working surface 201. In use, the opening 204 may be positioned over the tubing 104 and the casing 106, to allow access to at least the tubing 104 through the opening in a vertical direction — as shown in Fig. 3B. Instead of or additionally to the opening 204, a notch may be provided into the working surface.

As can be seen in the schematic top view of Fig. 3B, at least part of the arrangement frame 202 can be positioned over opposing edges of the well cellar 102. As an option also shown in Fig. 3B, but applicable to any embodiment of the arrangement disclosed herein, the arrangement frame 202 may cover all edges of the well cellar 102. As such, for example, a risk of personnel or equipment falling into the well cellar 102 may be reduced.

Any embodiment of the arrangement frame 202 may be positioned over the well cellar 102 by first placing one side of the arrangement frame 202 on the ground level, and subsequently placing the opposite side of the arrangement frame 202 on the ground level. The arrangement frame 202 may for example be carried on a vehicle, and placed from the vehicle using a hook lift or hook arm system. As an alternative option for any embodiment of the arrangement 200, the arrangement frame 202 may be connected to or comprised by a vehicle, such as a truck or trailer.

The arrangement 200 as shown in Fig. 3A comprises an outer gripper 210, severing module 220, and an inner gripper 230. In Fig. 3B, for clarity of the figure, only the arrangement frame 202 with the opening 204 is depicted.

The arrangement 200 shown in Fig. 3A comprising a support 206 to which in general one or more or all of the outer gripper 210, severing module 220, and inner gripper 230 are connected. In general, also further components of the arrangement 200 may be connected to the support 206.

Preferably, but not necessarily, the support 206 is moveably connected to the arrangement frame 202, for example via a support actuator 208 arranged to move the support 206 relative to the arrangement frame 202.

In Fig. 3A, the support 206 1s depicted in an upward position. For example during transport of the arrangement 200, it may be preferred to have the support 206 positioned in a folded-down position. To place the support 206 in the folded-down position, for example using the support actuator 208, the support 206 may be pivoted down towards the working surface 201 in a movement generally depicted with arrow A. For example after the arrangement frame 202 has been positioned over the well cellar 102, the support 206 can be pivoted upward into the upright position as shown in Fig. 3A.

Although the outer gripper 210, severing module 220, and inner gripper 230 are in Fig. 3A depicted as being positioned above the working surface 201 and/or the well cellar 102, in any embodiment disclosed herein, one, more, or all of the outer gripper 210, severing module 220, and inner gripper 230 may be at least partially or entirely positioned below the working surface 201 and/or in the well cellar 102, in any combination thereof.

For moving the inner gripper 230 relative to the arrangement frame 202, the arrangement 200 comprises an inner gripper actuator 231.

The inner gripper 230 may for example be suspended from a cable or rope, and the inner gripper actuator 231 may be a winch on which the cable or rope can be wound. Alternatively, the inner gripper actuator 231 is a hydraulic actuator for moving the inner gripper 230. The inner gripper 230 may is such case be suspended from or connected to a piston rod 235 of the hydraulic actuator.

The severing module 220 is preferably rigidly connected to the arrangement frame 202, but may in examples be moveably connected to the arrangement frame 202 using a severing module actuator 222. For example, the severing module 220 may be rotatable around the centreline of the conduit. Additionally or alternatively, the severing module 220 may be moved parallel to the centreline of the conduit using the severing module actuator 222. When it is preferred that the severing module 220 moves together with the inner gripper or outer gripper, the severing module actuator 222 may be the same actuator as the inner gripper actuator or the outer gripper actuator.

In any embodiment of the arrangement 200 disclosed herein, the outer gripper 210 may either be rigidly connected to the arrangement frame 202, or moveably connected to the arrangement frame 202 via an outer gripper actuator 222. The outer gripper actuator 222 may for example be a hydraulic actuator.

More imm general, any actuator disclosed herein may be electric, hydraulic, pneumatic, or any other type or combination of actuators for moving an element, such as the inner gripper, outer gripper, severing module, or any other element of the arrangement.

Fig. 4A shows the well 100 and the arrangement 200, after a step of lowering the inner gripper 230 into the tubing 104’. For lowering the inner gripper 230, the inner gripper 230 may have passed through the opening 204 in the arrangement frame 202. Furthermore, the inner gripper 230 may have passed through the severing module 220 and the outer gripper 210. For example when the inner gripper actuator 231 is a hydraulic actuator, a cylinder of the hydraulic actuator may be filled to drive a piston rod to which the inner gripper is connected towards the tubing 104.

Fig. 4B and Fig. 4C show a detailed view of the tubing 104, with a particular embodiment of an inner gripper 230 positioned in the tubing 104.

Fig. 4B and Fig. 4C respectively show the inner gripper 230 in a state with an outer dimension smaller than an inner diameter of the tubing 104 and in a state with an outer dimension increased to engage the inner wall 141 of the tubing 104.

For adjusting the outer dimension of the inner gripper 230, as an option applicable to any embodiment of the arrangement and method disclosed herein, a wedge mechanism may be comprised by the inner gripper 230. The wedge mechanism is an example of an inner gripper mechanism 233.

The wedge mechanism comprises one or more inner wedge members 232 and one or more outer wedge members 234. The inner wedge members 232 and the one or more outer wedge members 234 comprise slanted wedge surfaces.

The wedge surfaces are oriented such that the outer wedge members 234 are pushed radially outwards when the inner wedge members 232 are pulled upwards.

The outer wedge member 234 may be embodied as a crown of fingers surrounding the inner wedge member 232. Although the wedge mechanism 233 is in Figs. 4B and 4C shows as comprising a single inner wedge member 232, other embodiments are envisioned wherein the wedge mechanism 233 comprises multiple inner wedge members and one or more outer wedge members per inner wedge member.

When the wedge mechanism 233 is moved into the tubing 104, the outer wedge members 234 may slip relative to the inner wall 141 due to insufficient friction between the outer wedge members 234 and the inner wall 141. When the wedge mechanism 233 is pulled upwards, as depicted in Fig. 4C, the outer wedge members 234 can be radially forced against the inner wall 141, thereby increasing the friction between outer wedge members 234 and the inner wall 141 sufficiently such that the tubing 104 can be pulled upwards together with the wedge mechanism 233. As an option, at least part of a surface of the outer wedge members 234 may have teeth or other gripping protrusions to grip into the inner wall 141 of the tubing.

It will thus be appreciated that the particular inner gripper mechanism as schematically depicted in Figs. 4B and 4C may be comprised by any inner gripper disclosed herein. Other optional features for the inner gripper, such as but not limited to the circumferential cutter, the sealing member, longitudinal cutter, and the passage may be readily applied to the inner gripper 230 of Figs. 4B-4C.

Fig. 5A shows the step of inserting the inner gripper 230 into the tubing 104’, but with another embodiment of the inner gripper 230. The particular embodiment of the inner gripper 230 is shown in more detail in

Figs. 5B and 5C, and can be readily applied to any other embodiment of the arrangement disclosed herein. In particular, part of the inner gripper 230 is in this step inserted into the tubing 104’, and the longitudinal cutter 235 is not yet inserted into the tubing 104.

The inner gripper 230 as depicted in Figs. 5B and 5C comprises any inner gripper mechanism 233 as disclosed herein. Furthermore, as an option applicable to any other inner gripper disclosed herein, the inner gripper 230 comprises a longitudinal cutter 235 for cutting through the conduit in a longitudinal direction parallel to an elongation direction of the conduit.

The longitudinal cutter 235 as depicted in Figs. 5B and 5C comprises a plurality of cutting wheels 235, but can conceivable also only comprise a single cutting wheel or even a different cutting member, such as a pair of scissors. When the longitudinal cutter 235 comprises more than one cutting wheel, two or more cutting wheels may be positioned one above the other in the longitudinal direction, but with one cutting wheel at a different pitch relative to the centreline of the conduit than the other cutting wheel.

In the front longitudinal section view of Fig. 5B, the inner gripper 230 1s being inserted into the tubing 104, but the longitudinal cutter 235 is positioned outside the tubing 104. Fig. 5C shows a schematic side view of the tubing 104 as a cutting wheel 239 cuts through the tubing 104. The cutting action splits the tubing 104 into different split parts 154. By virtue of the split parts 154, a longitudinal opening 153 can be formed, which opening 153 may allow the split parts 154 to fall around parts of the inner gripper 230.

Whenever a longitudinal cutter 235 is used, thus in any embodiment of the arrangement disclosed herein, the severing location at which the severing module forms the severed conduit section may be above or below the cutting wheel or cutting wheels 239 of the longitudinal cutter 235.

Although in the figures the longitudinal cutter 235 is shown as being inserted into the tubing 104, other longitudinal cutters are envisioned which remain outside the tubing 104. Preferably, but not necessarily, the longitudinal cutter 235 1s connected to move with the inner gripper 230, or even comprised by the inner gripper 230.

It may be generally preferred that the longitudinal cutter 235, the severing module 220 and the outer gripper 210 are dimensioned such that the longitudinal cutter 235 can pass through said severing module 220 and through the outer gripper 210.

Fig. 6 shows the well 100 after a step of pulling the upper part of the tubing 104 upward. The tubing 104’ is pulled upward by virtue of moving the inner gripper 230 upward while the inner gripper 230 engages the tubing 104’. As the tubing 104’ is moved upward, the tubing 104’ and the inner gripper 230 pass through the outer gripper 210 and the severing module 202.

As shown in Fig. 6, which is not to scale, the upper tubing section 104’ has moved upward relative to the remaining tubing section 104”. This creates a length of casing 106 in which no tubing is present anymore, and where thus no annulus 110 1s present.

In the figures, a vertically oriented tubing 104 is shown as an example of a conduit. However, embodiments and examples are also envisioned wherein the conduit is oriented generally horizontally, for example when the conduit is a pipeline. In such cases, whenever in the figures a movement upwards is mentioned, generally a movement away from the underground passage in which the conduit 1s present is implied.

Fig. 7A shows the well 100 after a step of severing the tubing 104’ using the severing module 220. The tubing 104 is severed at a severing location 224. This severing action severs a severed tubing section 104” from the upper tubing section 104’. When the severing location 224 is below the inner gripper 230, the inner gripper 230 cannot be used anymore for supporting the upper tubing section 104’. Instead the outer gripper 210 18 now used for supporting the upper tubing section 104’ — i.e. to prevent the upper tubing section 104’ from falling into the well.

Figs. 7B and 7C show a particular embodiment of the outer gripper 210 in more detail. It will be understood that this particular embodiment of the outer gripper 210 may be comprised by any embodiment of the arrangement disclosed herein.

The outer gripper 210 comprises one or more inner wedges 270 and one or more outer wedges 272. By virtue of the slanted surfaces of the one or more inner wedges 270 and one or more outer wedges 272, the tubing section 104’ can be selectively gripped or moved relative to the outer gripper 210.

Fig. 7B shows a situation where in the upper tubing section 104’ moves downward through the outer gripper 210. This may for example be the case after the severing module 220 has severed the severed tubing section 104” from the upper tubing section 104’. In this case, the inner wedges 270 frictionally engage the outer wall of the tubing section 104’.

Fig. 7C shows a situation where in the upper tubing section 104’ moves upward through the outer gripper 210. This may for example be the case when the upper tubing section 104’ is moved upward by virtue of an upward movement of the inner gripper 230, which inner gripper 230 in this case 1s engaged to the upper tubing section 104’. In this situation, the outer wall of the tubing section 104 can slip relative to the inner wedges 270 of the outer gripper.

An inner diameter of the outer gripper 210, which may be defined by the one or more inner wedges 270 and/or one or more outer wedges 272 may be sized to accommodate the outer diameter of the upper tubing section 104’. Optionally, when the upper tubing section 104’ comprises multiple segments which are connected with one or more ax1al connectors, the one or more inner wedges 270 and/or one or more outer wedges 272 may be sized to also accommodate the outer diameter of said one or more axial connectors.

Optionally, when the upper tubing section 104’ has a control line with control line clamps connected thereto, the one or more inner wedges 270 and/or one or more outer wedges 272 may be sized to also accommodate the control line and the control line clamps passing through the outer gripper 210.

Fig. 8 schematically shows a situation of the well 100 wherein the severed tubing section 104” is lifted away from the upper tubing section 104’ and/or from the severing module 220. Fig. 9 shows the well 100 of Fig. 8 after a step of moving the severed tubing section 104” relative to a centreline 107 of the tubing 104. This allows the severed tubing section 104” to be released by the inner gripper 230 and placed at a location for further transport. Instead of or additionally to lifting the severed tubing section 104” away, more generally it is preferred to move the severed tubing section 104” out of the way such that the upper tubing section 104’ can be lifted up again.

Fig. 10 shows another example of the well 100, with an arrangement 200 with a particular option which may be applied to any arrangement 200 disclosed herein. In the situation depicted in Fig. 10, the tubing 104 is formed by multiple tubing segments which are interconnected by axial connectors 119. The arrangement 200 further comprises an axial connector cutter 290 for removing axial connectors 119.

The axial connector cutter 290 may comprise one or more cutting wheels 292 for cutting through an axial connector 119, preferably without substantially cutting into the tubing. Generally, the axial connector cutter 290 may comprise any other cutting, sawing, or other destructive tool for removing an axial connector 119.

When the axial connector cutter 290 1s positioned above the outer gripper 210, it may be prevented that the part of the tubing 104 below a removed axial connector 119 falls back into the well 100 as this part of the tubing 104 may be gripped by the outer gripper 210. However, embodiments are also envisioned wherein the axial connector cutter 290 is positioned below the outer gripper 210. As an even further option, multiple axial connector cutters 290 may be provided, which may be partially positioned above and partially positioned below the outer gripper 210. The multiple cutters may for example cut into the axial connectors at different depths.

When an inner gripper 230 comprising a seal 1s used — as will be elaborated on in conjunction with Figs. 13B-13C — the seal is preferably positioned below the axial connector cutter 290. Preferably, but not necessarily, in use, the axial connector cutter 290 is positioned above the inner gripper 230.

Fig. 11 shows another example of the well 100, with an arrangement 200 with a particular option which may be applied to any arrangement 200 disclosed herein. The arrangement 200 further comprises a spool 254 onto which a control ine 152 can be wound. The control line 152 is typically connected to the tubing 104 by one or more clamps 150. The spool 254 may be connected to the arrangement frame 202, and is preferably but not necessarily supported onto the working surface 201. Alternatively, a spool separate from the arrangement 200 may be used for winding the control line 152 onto.

To prevent the control line 152 from interfering with the outer gripper 210, it may be preferred to remove the control line 152 from the tubing

104 before the tubing 104 passes through the outer gripper 210. To this end, a clamp cutter 250 may be comprised by any arrangement 200 disclosed herein. The clamp cutter 250 comprises one or more clamp cutting member 252 for removing the clamps 150 with which the control line 152 is connected to the tubing 104. Preferably, at least one of the clamp cutting members 252 is a cutting wheel or knife.

Preferably, but not necessarily, the clamp cutter 250 is positioned below the outer gripper 210. This prevents that clamps 150 or control line 152 has to pass through said outer gripper 210.

Fig. 12 again shows an example of the well 100, and 1s used to elaborate an option that the outer gripper 210 is moveable relative to the arrangement frame 202. When the outer gripper 210 is moveable relative to the arrangement frame 202, and the outer gripper 210 is moved simultaneously with the inner gripper 230, an approximately constant speed may be achieved with which the upper tubing section 104’ can be lifted up and out of the well.

In Fig. 12, a downward movement D of the inner gripper 230 is depicted, simultaneously with an upward movement U of the outer gripper 210. After the downward movement of the inner gripper 230, the inner gripper 230 can be moved up again while the outer gripper 210 can be moved down again. The stroke of the inner gripper 230 and the outer gripper 210 may generally correspond, as can the speed profile of the inner gripper 230 and the outer gripper 210 during their respective stroke.

Fig. 13A shows another example of a well 100, comprising the well cellar 102, tubing 104, casing 106, packer 108 and plug 112. The well 100 is depicted after the tubing 104 has been severed at a severing depth 114, and thus a separate upper tubing section 104’ and lower tubing section 104” have been formed. In the example of Fig. 13A, a particular inner gripper 230 is positioned inside the upper tubing section 104. Further element of the arrangement 200 comprising the inner gripper 230 have been omitted in Fig. 13A for clarity and conciseness of the figure.

The inner gripper 230 of Fig. 13A is shown in more detail in the schematic section views of Fig. 13B and Fig. 13C. It will be appreciated that the particular inner gripper 230 disclosed in conjunctions with Figs. 13A-C may be comprised by any arrangement 200 as disclosed herein.

In particular, in Figs. 13B and 13C, the inner gripper 230 is shown inserted into the tubing 104. It will be understood that only a small length of tubing 104 has been depicted for clarity of the figures. Respectively, Figs. 13B and 13C show the inner gripper 230 in a state of disengagement with the inner wall 141 of the tubing and a state wherein the inner gripper 230 engages the inner wall 141 of the tubing 104. In the state of disengagement, the inner gripper mechanism 233 can be moved relative to the inner wall 141, whereas in the state of engagement, the inner gripper mechanism 233 moves together with the inner wall 141, for example when the inner gripper is lifted upwards. Furthermore, between the states of Figs. 13B and 13C, the inner gripper 230 has been moved further into the tubing 104.

The inner gripper 230 as an option applicable to any inner gripper disclosed herein comprises a passage 237 through the inner gripper 230 through which a flow of fluid can flow and/or a wire, rope, slickline, conduit,

E-line, or any other elongated member may pass. As schematically indicated in Fig. 13A, the flow of fluid may be provided from a fluid container 300, using an optional fluid pump 302. The fluid may be any fluid, for example any liquid or mixture of liquids. The fluid may be cement, or any other plug-forming fluid. The fluid may be used to push plug-forming fluid present in the tubing 104 further down, for example by forcing a wiper plug positioned between the plug-forming fluid and the fluid supplied from the fluid container 300 further downward into the tubing 104.

To prevent a flow of fluid flow leaking upward between the inner wall 141 of the tubing 104 and the inner gripper mechanism 133, the inner gripper 230 comprising a sealing member 238 forming a fluid-tight seal between the sealing member 238 and the inner wall 141 of the tubing 104.

Preferably, the sealing member 238 can be moved relative to the inner wall 141 while maintaining the fluid-tight seal, for example when the inner gripper 230 is moved further into the tubing 104. Preferably, but not necessarily, the sealing member 238 is positioned in use below the inner gripper mechanism 133.

Fig. 14 schematically depicts a well 100 with an inner gripper 230 of an arrangement for removing a length of conduit, in particular a tubing of a well, from said well. For clarity and conciseness of the figure, the rest of the arrangement has been omitted. It will be understood that in Fig. 14, any embodiment of the arrangement as disclosed herein may be used.

In the situation depicted in Fig. 14, a schematically depicted volume of plug-forming fluid 402, such as cement, has been supplied to the upper tubing section 104’. Optionally, one or two wiper plugs 400 may also be positioned into the tubing 104, above and/or below the volume of plug-forming fluid 402.

The particular embodiment of the inner gripper 230 as depicted in

Fig. 14 but applicable also to any other of the examples disclosed herein, a flow of fluid 301 can be supplied through the passage 237 of the inner gripper 230 while the inner gripper 230 is positioned in the upper tubing section 104’.

The flow of fluid 301 can be used to force the plug-forming fluid 402 downwards. When a wiper plug 400 is positioned above the plug-forming fluid 402, which is not essential, also this wiper plug 400 can be forced further down into the upper tubing section 104’.

Whenever a flow of fluid is provided to the conduit, for example from the fluid container 300, one or more valves may be used through which said flow of fluid has to flow when flowing between the fluid container 300 and the conduit 104.

Fig. 15 shows the well 100 of Fig. 14 after the flow of fluid 301 has forced the plug-forming fluid 402 out of the upper tubing section 104’. As schematically depicted in Fig. 15, the upper tubing section 104’ has been lifted upward relative to the severing depth 114. As such, it will be understood that it is envisioned that while the flow of fluid 301 is supplied into the upper tubing section 104’, the upper tubing section 104’ is partially lifted out of the well and parts of the upper tubing section 104’ are severed from the upper tubing section 104’ for example using a severing module of any arrangement for removing a length of conduit as disclosed herein.

Preferably, but not necessarily, throughout the time that the flow of fluid 301 is supplied into the upper tubing section 104’, the inner gripper 230 maintains positioned inside the upper tubing section 104°. The inner gripper 230 may be pushed further into the upper tubing section 104’ to allow further section of the upper tubing section 104’ to be removed.

As a further option, it is envisioned that the fluid supplied into the upper tubing section 104’ may be the plug-forming fluid itself. Fig. 16 shows an example of a well 100 wherein a flow of plug-forming fluid 303 is supplied into the upper tubing section 104 through the inner gripper 230.

Optionally, a plug-forming fluid injector 410 may have already been positioned in the upper tubing section 104’, in particular near the severing depth 114, before the inner gripper 230 is positioned into the tubing 104. The injector 410 may be suspended from a wire, cable, slackline, or other suspension member which suspension member can be passed through the passage 237 through the inner gripper 230. Optionally, not depicted in the figures, a wiper plug may be positioned above the injector 410 which wiper plug may have a passage which is opened when sufficient fluid pressure is applied to the wiper plug, and/or the wiper plug may have an passage which can be mechanically opened.

Further optionally, the injector 410 can be provided with a radial vibration unit for causing vibrations in the plug-forming fluid. Additionally or alternatively, the injector 410 may be provided with a sealant reservoir filled with a sealant. The sealant may be released from the sealant reservoir for example prior to and/or during the time the plug-forming fluid exits the upper tubing section 104’.

Whenever a passage 237 1s provided through the inner gripper 230, an inner seal may be positioned in the passage 237 or over the passage 237, for example in the form of a stuffing box. Such an inner seal may form a fluid- tight seal between the inner gripper 230 and any wire, e-line, rope, conduit or other suspension member which extends through the passage 237.

Fig. 17 shows the well 100 of Fig. 16 after part of the upper tubing section 104’ has been lifted out of the well by pulling the inner gripper 230 upwards away from the well. While the upper tubing section 104’ is lifted out of the well 100, it is preferred to severe parts of the upper tubing section 104’ to limit the length of upper tubing section 104° protruding out of the well.

In the situation of Fig. 17, by virtue of the flow of plug-formmg material 303 flowing through the upper tubing section 104’, a volume of plug- forming material 402 has accumulated below the upper tubing section 104.

It can be said that the upper tubing section 104’ has acted as a conduit guiding the flow of plug-forming material 303 downward.

In general, and for example depicted in Figs. 15 and 17, because the upper tubing section 104’ has been lifted away from the lower tubing section 104”, in an increased part of the casing 106, no tubing is present. As such, in an increased part of the casing 106, there is also no annulus 110 anymore. It has been observed that this annulus 110 is hard to fill with plug- forming fluid, for example in a through tubing abandonment process. Because the methods and arrangements disclosed herein allow the height H of casing 106 of which the cross-section can be entirely filled with plug-forming fluid to be increased by removing the tubing 104 over this height H, a more reliable and secure method of abandoning the well 100 can be obtained.

It is again noted that the figures are only schematic section views, and are not drawn to scale to improve intelligibility of the figures. The plug formed by the plug-forming fluid 402 may in any of the examples shown herein be approximately 50 metres high or even higher. As such, the height

His preferably at least 40 metres or more, 50 metres or more, or even up to 100 metres. The tubing may in any of the examples shown herein have an inner diameter of approximately 5 12”.

Figure 18 schematically depicts a first embodiment of an arrangement 200 for removing a length of conduit, such as a tubing or casing {from an underground passage, such as a well. The first embodiment comprises any of the inner grippers 230 disclosed herein, any of the severing modules 220 disclosed herein, and any of the outer grippers 210 disclosed herein. The first embodiment of the arrangement 200 may optionally further comprise any of the axial connector cutters 290 disclosed herein and/or any of the clamp cutters 250 disclosed herein, respectively for example when the conduit comprises axial connectors and/or clamps connecting a control line to the conduit.

Preferably, but not necessarily, the inner gripper 230, severing module 220, outer gripper 210, optional clamp cutter 250 and optional axial connector cutter 290 are connected to a single arrangement frame 202.

However, in other embodiments, multiple separate frames may be comprised by the arrangement to which one or more of the inner gripper 230, severing module 220, outer gripper 210, optional clamp cutter 250 and optional axial connector cutter 290 may be connected, in any combination thereof. The same is applicable to the second embodiment of the arrangement 200 which is discussed in conjunction with Fig. 19.

Typical for the first embodiment of the arrangement is that conduit is removed between the inner gripper 230 and the outer gripper 210 using the severing module 202. As such, the severing module 202 is used for severing the conduit 104 when the severing module 202 is positioned between the inner gripper 230 and the outer gripper 210. In case the conduit is oriented vertically, this typically implies that the inner gripper is positioned above the severing module, and the severing module is positioned above the outer gripper. In case the conduit is oriented horizontally, for example when the conduit is a pipeline, the inner gripper can be positioned further away from the underground passage from which the conduit protrudes than the severing module, and the severing module can be positioned further away from the underground passage than the outer gripper.

After the severed conduit section is formed by the severing action, the severed conduit section can be moved away from the centreline of the conduit, for example but not necessarily by a movement of the inner gripper, the severed conduit section can be disengaged by the inner gripper, and the inner gripper can be re-inserted into the remaining conduit, for example but not necessarily beyond the outer gripper.

Figure 19 schematically depicts a second embodiment of an arrangement 200 for removing a length of conduit, such as a tubing or casing from an underground passage, such as a well. The arrangement 200 according to the second embodiment comprises any of the severing modules 220 disclosed herein, and any of the outer grippers 210 disclosed herein.

Furthermore, the arrangement 200 comprises any of the inner grippers 230 disclosed herein which are provided with any longitudinal cutter 235 as disclosed herein.

The second embodiment of the arrangement 200 may optionally further comprise any of the axial connector cutters 290 disclosed herein and/or any of the clamp cutters 250 disclosed herein, respectively for example when the conduit comprises axial connectors and/or clamps connecting a control line to the conduit.

Typical for the second embodiment of the arrangement 200 is that the conduit is removed above the inner gripper mechanism when an inner gripper mechanism is used, or at least above the longitudinal cutter. Thus,

the severing location at which the severing module severs the conduit can be positioned below the longitudinal cutter. This means that the severed conduit section 1s also positioned above the inner gripper mechanism, when the inner gripper mechanism is used. However, when the inner gripper is for example suspended from a cable or a piston rod, this cable or piston rod may still protrude through the severed conduit section. To facilitate moving the severed conduit section away from the centreline of the conduit and past the cable or piston rod, the longitudinal cutter 235 1s used to make one or more longitudinal cuts into the conduit above the inner gripper 230. When the one or more longitudinal cuts protrude further into the conduit than the severing location, the severed conduit section can be moved away from the centreline of the conduit and past the cable or piston rod.

When the conduit is removed above the inner gripper, the inner gripper may remain placed in the conduit. In particular in such cases, the inner gripper may comprise a seal 238, as for example elaborated on in conjunction with Figs. 13B and 13C. By virtue of the fluid-tight seal 238, the inner gripper may be used as a piston in the conduit. An optional passage through the inner gripper provides a fluid connection into the conduit via the inner gripper. As such, the second embodiment of the arrangement may comprise a fluid reservoir 300 in fluid communication with the conduit through the passage through the inner gripper, for example as elaborated on in conjunction with Figs. 14-17.

Figs. 20A and 20B schematically show a third embodiment of an arrangement 200 for removing a length of conduit, such as a tubing or casing from an underground passage, such as a well. The third embodiment of the arrangement 200 comprises an inner gripper 230, outer gripper 210, and severing module 220. Between the situations shown in Figs. 20A and 20B, the inner gripper 230 has been used to pull the tubing 104’ further out of the well and the severing module 220 has been used to sever the tubing 104’, thereby forming the severed conduit section 104”.

The third embodiment of the arrangement 200 comprises a particular inner gripper actuator 231 for moving the inner gripper 230 relative to the arrangement frame 202. This particular inner gripper actuator 231 may be comprised by any other arrangement as disclosed herein.

The inner gripper actuator 231 comprises a first hydraulic actuator 291 with a first piston rod 293 from which the inner gripper 230 is suspended.

The first hydraulic actuator 291 is moveable connected to the arrangement frame 202, preferably by a second hydraulic actuator 294 and a third hydraulic actuator 295. Fig. 20A shows the inner gripper 230 in the lowermost position — i.e. closest to the underground passage in which the conduit is positioned. Preferably, in the lowermost position, the inner gripper 230 can be positioned into the tubing 104 without having to manipulate the tubing 104 first. Fig. 20B shows the inner gripper 230 in the uppermost position. For example from this uppermost position, the inner gripper 230 together with the severed conduit section 104” can be moved away from the centreline of the conduit. In general, in any embodiment of the arrangement and method disclosed herein, the length of the severed conduit section 104” may be 1 metre or more, or even 2 metres or more.

For example during transport of the arrangement 200, it may be advantageous to reduce the height of the arrangement 200. For any arrangement disclosed herein, the arrangement 200 may be transported on a vehicle such as a truck or on a trailer. To reduce the height of the third embodiment of the arrangement 200, or any other embodiment of the arrangement comprising the specific inner gripper actuator 231, the inner gripper actuator 231 or part thereof may be folded downward towards the arrangement frame 202.

Although the hydraulic actuators are in Figs. 20A and 20B shown in-line with the upright member 298, embodiments of the inner gripper actuator 231 are also envisioned wherein the hydraulic actuators are rotated 90 degrees around a vertical axis relative to the orientation shown in the figures — thus with the hydraulic actuators aligned perpendicular to a transportation direction of the arrangement 200.

Independent of the particular inner gripper actuator 231, the third embodiment of the arrangement 200 further comprises a particular arrangement frame 202, which arrangement frame 202 may be readily comprised by any other arrangement 200 disclosed herein. The arrangement frame 202 comprises an upright member 298 with a connection element 297 connected to the upright member 298 such that the connection element 297 is positioned at a distance from the working surface 201 of the arrangement frame 202. The connection element 297 may be a hook connection element to which for example a hook of a hooklift, cable lift or chain lift can be connected.

As a further option, the arrangement frame comprises one or more rollers 296, preferably on an opposite side of the connection element 297. For positioning the arrangement frame 202 before use, for example over a well cellar 102 or generally adjacent to a well or other underground passage, the arrangement frame 202 can be tilted such that the arrangement frame 202 is first supported on the one or more rollers 296. The tilting may be the result of the arrangement frame 202 being lowered from a vehicle, such as a hooklift vehicle. The arrangement frame 202 may be rolled off the vehicle, lowered onto the one or more rollers 296, and subsequently lifted off the vehicle via a connection to the connection element 297. When the arrangement frame 202 does not comprise the one or more rollers 296, the arrangement frame 202 may be first lowered onto one edge of the arrangement frame 202.

It will be appreciated that any optional features disclosed herein for the arrangement, for example for the inner gripper, outer gripper, and severing module, may be readily applied to the third embodiment of the arrangement 200. Also vice versa, any optional feature disclosed in conjunction with the third embodiment of the arrangement may be readily applied to any other arrangement disclosed herein.

Although in the present disclosure specific first, second and third embodiments of the arrangement have been discussed, it should be understood that the disclosure is not limited to these three specific embodiments.

The present disclosure provides in a sixth aspect a longitudinal cutter 235 for cutting through a conduit in a longitudinal direction parallel to an elongation direction of the conduit. The longitudinal cutter 235 may be used in any of the methods disclosed herein, and may thus be comprised by any arrangement disclosed herein. However, the longitudinal cutter 235 may also be used in other methods, for example methods of cutting through a conduit in a longitudinal direction parallel to an elongation direction of the conduit.

The sixth aspect of the present disclosure thus provides a longitudinal cutter for cutting through a conduit in a longitudinal direction parallel to an elongation direction of the conduit, the longitudinal cutter comprising a cutter body, one or more cutting elements, for example cutting wheels or knifes, and a seal for forming a fluid-tight seal with an inner wall of the conduit. The longitudinal cutter according to the sixth aspect may be used in a method according to the seventh aspect, but also in any other method and arrangement disclosed herein.

As schematically depicted in Figs. 21A and 21B, the longitudinal cutter 235 comprises a cutter body 236 and one or more cutting wheels 239.

The longitudinal cutter 235 further comprises a seal 241 for forming a fluid- tight seal with the inner wall 141 of the conduit 104.

Furthermore, a passage 242 is provided through the seal 241 and optionally also through the cutter body 236. Through the passage 242, for example a flow of fluid can be provided, and/or a line, wire, rope, slickline, E- line, conduit, or other elongated member can be passed, from which in turn another component can be suspended in the conduit 104.

Embodiments of the longitudinal cutter 235 are also envisioned with a passage 242 through the seal 241 — thus with the seal and/or cutter body 236 closing off the cross-section of the conduit 104. As such, the longitudinal cutter 235 can be used as a piston for driving a fluid further down into the conduit 104.

In the schematic side view of Fig. 21B, it is indicated that the seal 241 is preferably positioned below the lowest cutting wheel 239, for example to prevent leakage of fluid through the longitudinal opening 153.

In order to longitudinally cut through the conduit 104 using the longitudinal cutter 235, the conduit 104 has to be moved relative to the cutter 235. This can be done by a movement of the conduit 104, by a movement of the cutter 235, or by a combination thereof. The seal 241 is arranged to allow this relative movement between the conduit 104 and the longitudinal cutter 235, and thus does not engage the inner wall of the 141 of the conduit to prevent this relative movement.

Figs. 22A and 22B depict a particular embodiment of the inner gripper 230, respectively partially inserted into a tubing 104 and into a casing surrounding the tubing 104. In the situation of Fig. 22B, the tubing 104 has been removed from the casing 106, such that an entire top opening 109 of the casing 106 1s accessible to insert the inner gripper 230 into. The inner gripper 230 comprises the wedge mechanism, comprising one or more inner wedge members 232 and one or more outer wedge members 234.

In the particular embodiment of the inner gripper 230 as shown in

Figs. 22A and 22B, as an option applicable to any other inner gripper disclosed herein, the inner gripper mechanism provides at least two different discrete outer dimensions. The two different discrete outer dimensions are provided by the stepped outer shape of the one or more outer wedge members 234. As such, advantageously, with the same inner gripper mechanism, conduits with a different inner diameter may be engaged.

Fig. 23A shows a horizontal conduit 1004, with a fourth embodiment of an arrangement 200 for removing a conduit from a horizontal passage. The fourth embodiment of the arrangement 200 comprise an inner gripper 1230, which can be inserted into the conduit 1004. The inner gripper 1230 is moveable using an inner gripper actuator 1231, which for example can be a hydraulic actuator. Preferably, but not necessarily, the inner gripper actuator 1231 is anchored to a further conduit section 1004’ using an anchor 1009. The anchor 1009 may for example comprise any inner gripper mechanism disclosed herein, or any other device for engaging an inner wall of the further conduit section 1004’.

To obtain access to the condut 1004, a ditch or hole 1102 in the ground may have been dug, and part of the conduit may have been removed.

This removal forms the conduit 1004, and also the further conduit section 1004’ which is generally aligned on the same centreline as the conduit 1004.

Because the conduit 1004 is held in an underground passage 1003, an outer gripper is not necessarily comprised by the fourth embodiment of the arrangement 200. The fourth embodiment of the arrangement 200 does comprises a severing module 1220. It will be understood that any option and embodiment of the inner gripper, severing module, arrangement frame disclosed in conjunction with any other embodiment of the arrangement may be readily applied to the fourth embodiment of the arrangement 200.

Using the inner gripper 1230, the conduit 1004 is pulled out of the underground passage 1003 and partially through the severing module 1220.

Using the severing module 1220, part of the conduit 1004 1s then severed from the remaining part of the conduit 1004. The severed part of the conduit 1004 can then be removed from the ditch 1102 when the inner gripper 1230 has been pulled out of the severed part of the conduit 1004. For removing the severed part of the conduit 1004, the severed part is moved out of the centreline of the remaining part of the conduit 1004 to make place for a next part of the conduit to be severed off the remaining part of the conduit 1004.

The fourth embodiment of the arrangement 200 may comprise a support for supporting the conduit from outside the conduit, for example during severing of the conduit. The support is arranged to prevent or reduce the conduit from being bent away from its centreline during severing, in particular when the severing involves cutting the conduit. The support may be formed as any outer gripper disclosed herein.

Fig. 23B shows the horizontal conduit 1004, but with a fifth embodiment of the arrangement 200. The fifth embodiment of the arrangement 200 comprises an outer gripper 1210, and a longitudinal cutter 1235 which is used to form one or more longitudinal cuts into the conduit 1004. The outer gripper 1210 is here required when there is insufficient friction between the conduit 1004 and the underground passage 1003 into which the conduit 1004 is placed. Due to insufficient friction, when the longitudinal cutter 1235 is forced further into the conduit, the conduit 1004 may inadvertently move back further into the underground passage 1003.

The fifth embodiment of the arrangement 200 requires means for moving the conduit further out of the underground passage 1003. These means may one or more moveable outer grippers and/or a moveable inner gripper. The longitudinal cutter 1235 may be stationary, and the conduit 1004 may be moved relative to the longitudinal cutter 1235. Alternatively, the longitudinal cutter 1235 is moveable relative to the underground passage 1003, for example by virtue of a longitudinal cutter actuator 1236, which may be a hydraulic actuator and/or which may be anchored to the further conduit section 1004’ by an anchor 1009.

In the fifth embodiment, optionally when an inner gripper is preferred, the longitudinal cutter 1235 may be comprised by the inner gripper and the longitudinal cutter actuator 1236 may be an inner gripper actuator.

When the fifth embodiment of the arrangement 200 comprises an inner gripper with an inner gripper mechanism, and when the severing module 1220 is used for severing the conduit 1004, the severing module is preferably positioned between the inner gripper mechanism and the longitudinal cutter 1235.

In any embodiment of the arrangement disclosed herein, the severing module 202 may be connected to move together with the inner gripper mechanism, at least when the severing module 202 is severing the conduit. Alternatively or additionally, in any embodiment of the arrangement disclosed herein, the severing module 202 may be connected to move together with the longitudinal cutter 235, at least when the severing module 202 is severing the conduit. Alternatively, the severing module 202 may be stationary while severing the conduit.

A sixth embodiment of the arrangement for removing a length of conduit, such as a tubing or casing from an underground passage, such as a well, 1s envisioned which does not necessarily comprise an inner gripper. The arrangement according to the sixth embodiment does comprise multiple outer grippers, of which at least a first outer gripper is moveable relative to the at least a second outer gripper. The arrangement according to the sixth embodiment comprises a longitudinal cutter, for example according to any embodiment of the sixth aspect.

The sixth embodiment of the arrangement can be used in a method of removing a length of conduit from an underground passage in which a fluid- tight seal is formed in the conduit, the fluid-tight seal being moved further down into the conduit as more length of the conduit is being removed.

A seventh aspect of the present disclosure thus provides a method for making a longitudinal cut in a conduit, comprising steps of forming a fluid- tight seal in the conduit, cutting through the conduit in a longitudinal direction parallel to a centreline of the conduit, thereby forming at least one longitudinal cut, and moving the fluid-tight further into the conduit as the longitudinal cut is cut further into the conduit. Preferably, the fluid-tight seal remains below the longitudinal cut.

In general, whenever a longitudinal cut is formed, for example using any longitudinal cutter disclosed herein, the cut may be formed in an outward direction from an inner wall of the conduit or in an inward direction from an outer wall of the conduit.

Throughout the present disclosure, where-ever the term tubing or casing 1s used, it will generally be understood that these term can be substituted for any other type of conduit. Thus, the methods and arrangements disclosed herein may be generally applied to any type of conduit, and any type of borehole — not necessarily a tubing or casing of a well.

Furthermore, it will be understood that different options disclosed in conjunction with a particular figure, with a particular embodiment of a method, and/or a particular embodiment of an arrangement may be readily applied to any other method and/or arrangement disclosed herein. Such option in particular relate to the arrangement frame, inner gripper, outer gripper, severing module, axial connector cutter, clamp cutter, fluid reservoir, and longitudinal cutter.

Claims

Conclusions

1. A method for removing a length of conduit (104), such as a pipe or casing from an underground passage, such as a well, the method comprising the steps of: - inserting at least part of an internal gripper (230) into the conduit; - alternately engaging the conduit with the internal gripper and an external gripper (210); - moving at least part of the conduit out of the underground passage by moving the internal gripper and/or the external gripper; wherein the method further comprises severing the conduit at a severing location, the severing location being positioned above the external gripper, thereby forming a severed conduit section which is severed from the conduit.

2. The method of claim 1, wherein at least part of the inner gripper passes through the disconnect module when the inner gripper is inserted into the conduit.

3. A method according to claim 1 or 2, further comprising moving the severed pipe section relative to a centerline of the pipe and reducing an external dimension of the inner gripper such that the inner gripper releases the inner wall of the pipe.

4. A method according to any preceding claim, wherein at least part of the inner gripper passes through the outer gripper when the inner gripper is inserted into the conduit.

5. A method according to any preceding claim, further comprising:

- cutting through the pipe in a longitudinal direction parallel to the direction of extension of the pipe.

6. A method according to claim 5, wherein a longitudinal cutter is connected to the inner gripper for cutting through the conduit in a longitudinal direction parallel to the direction of extension of the conduit, and the cutting through the conduit is carried out as the inner gripper is further advanced into the conduit.

7. A method according to any one of claims 5 to 6, wherein the rupture location is positioned between an inner gripper mechanism of the inner gripper and a longitudinal cutter.

8. Method according to any of the preceding claims, wherein the inner gripper moves simultaneously with the outer gripper, in particular in opposite directions.

9. A method according to any preceding claim, wherein the pipe is a pipe or casing of a well, and the internal gripper is lowered into a well cellar before inserting the internal gripper into the pipe or casing.

10. A method according to any preceding claim, wherein the conduit comprises at least two conduit sections connected via an axial conduit connector, the method further comprising cutting through the axial conduit connector.

11. A method according to any preceding claim, wherein a control line is connected to the conduit by one or more clamps, the method further comprising removing at least one of the clamps by a destructive action and winding the control line onto a spool.

12. A method according to any preceding claim, wherein a fluid-tight seal is formed between the inner gripper and an inner wall of the conduit.

13. A method according to any preceding claim, further comprising feeding a fluid or suspension member such as a wire, slickline, conduit, or E-line into the conduit through a passage through the internal gripper.

14. The method of claim 13, further comprising forming a fluid-tight seal between the passage and the suspension member.

15. The method of claim 13, wherein the fluid is a plug forming fluid, such as cement.

16. A method according to any one of claims 13 to 15, further comprising: - before inserting the inner gripper into the conduit, filling at least part of the conduit with a plug-forming fluid; and - after inserting the inner gripper into the conduit, introducing the fluid into the conduit to force the plug-forming fluid further into the subterranean passage.

17. A method according to any preceding claim, wherein the conduit is a horizontally oriented conduit and the inner gripper is moved by an inner gripper actuator anchored to a further conduit section.

18. Apparatus for removing a length of conduit, such as a pipe or casing, from an underground passage, such as a well, the apparatus comprising: - an inner gripper adapted to be inserted at least partly into the conduit, the inner gripper comprising an inner gripper mechanism for selectively engaging and releasing an inner wall of the conduit; - an outer gripper having a passage through which the conduit can extend, wherein the outer gripper comprises an outer gripper mechanism for selectively engaging and releasing an outer wall of the conduit; - an actuator for moving one of the inner gripper and the outer gripper relative to the other of the inner gripper and the outer gripper; and - a disconnect module for disconnecting the conduit.

19. Apparatus for removing a length of conduit, such as a pipe or casing from an underground passage, such as a well, the apparatus comprising: - at least one of an inner gripper adapted to be inserted at least partly into the conduit, the inner gripper comprising an inner gripper mechanism for selectively engaging and releasing an inner wall of the conduit and an outer gripper having a passage through which the conduit can extend, wherein the outer gripper comprises an outer gripper mechanism for selectively engaging and releasing an outer wall of the conduit; - an actuator for moving the conduit by moving the inner gripper and/or the outer gripper; - a severing module for severing the conduit; and - a longitudinal cutter for forming a longitudinal cut in the conduit in a longitudinal direction parallel to a direction of extension of the conduit.

20. The apparatus of claim 18 or 19, further comprising an axial connector cutter for removing an axial connector connecting two sections of conduit, wherein the axial connector cutter is positioned above the butengripper.

21. The apparatus of any one of claims 18 to 20, further comprising a clamp cutter for destructively removing a clamp connecting a control line to the conduit, wherein the clamp cutter is positioned above the outer gripper.

22. The apparatus of claim 21 further comprising a spool for winding a length of control line thereon.

23. The apparatus of any one of claims 18 to 22, further comprising a fluid container in fluid communication with a passage through the inner gripper.

24. Apparatus according to any of claims 18 to 23, further comprising an anchor for engaging an inner wall of a further pipe section, wherein the actuator is connected to the anchor for moving the inner gripper relative to the anchor.

25. Internal gripper for gripping a pipe, the internal gripper comprising: - an internal gripper mechanism for selectively gripping and releasing an internal wall of the pipe; and - a longitudinal cutter for cutting through the pipe in a longitudinal direction parallel to the direction of extension of the pipe

26. The internal gripper of claim 25 further comprising a seal for forming a fluid-tight seal with the conduit.

27. An inner gripper according to claim 26, wherein the inner gripper mechanism is positioned between the seal and the longitudinal cutter or the seal is positioned between the inner gripper mechanism and the longitudinal cutter.

28. An inner gripper according to any one of claims 25 to 27, further comprising a passage through the inner gripper.

29. An internal gripper according to any one of claims 25 to 28, wherein the internal gripper mechanism provides at least two different discrete external dimensions such that the internal gripper mechanism can be used to engage internal walls of pipes having two different internal diameters.

30. Longitudinal cutter for cutting through a conduit in a longitudinal direction parallel to a direction of extension of the conduit, the longitudinal cutter comprising: - a cutter body; - one or more cutting elements, for example cutting wheels or knives; and - a seal for forming a fluid-tight seal with an inner wall of the conduit.

31. The cutter of claim 31 further comprising a passage through the cutter body and the seal permitting fluid communication with the conduit through the cutter body.

32. Method for forming a longitudinal cut in a conduit, comprising the steps of: - forming a fluid-tight seal in the conduit;

- cutting through the conduit in a longitudinal direction parallel to a centre line of the conduit, thereby forming at least one longitudinal cut; and - moving the fluid-tight seal further into the conduit while cutting the longitudinal cut further into the conduit.

33. The method of claim 32, wherein the fluid-tight seal remains below the longitudinal cut.

34. A method according to claim 32 or 33, wherein the cut is formed in an outward direction from an inner wall of the conduit.

35. A method according to claim 32 or 33, wherein the cut is formed in an inward direction from an outer wall of the conduit.