Downhole tubing cutter tool, downhole tubing cutter assembly and associated methods

Abstract

A downhole tubing cutter tool (1) for running into a downhole tubular in a wellbore (70) and separating an upper portion of the downhole tubular from a lower portion of the downhole tubular, the downhole tubing cutter tool (1) comprising: - an inner tool portion (30); - an outer sleeve (20) telescopically coupled around the inner tool portion (30); and - at least one cutting arm (40) pivotably connected to the inner tool portion (30) and moveable between a retracted position (401) and an operational position (405); wherein the outer sleeve (20) is configured to be telescoped in use in an uphole direction (X1) to pivot the at least one cutting arm (40) from the retracted position (401) to the operational position (405) through an outer sleeve opening (21) in the outer sleeve (20).

Description

[0001] DOWNHOLE TUBING CUTTER TOOL, DOWNHOLE TUBING CUTTER ASSEMBLY AND ASSO¬

[0002] CIATED METHODS

[0003] TECHNICAL FIELD

[0004] The invention relates to a downhole tubing cutter tool and a downhole tubing cutter assembly for cutting a downhole tubular, and methods of using the downhole tubing cutter tool and the downhole tubing cutter assembly.

[0005] BACKGROUND

[0006] In the field of hydrocarbon exploration and production, a borehole is commonly provided with a tubing, such as a casing or a liner. There are occasions when a length of tubing needs to be removed. The removal may for example be done in preparation for setting a cement plug when a well is being abandoned, or in case of a re-completion.

[0007] Removal of the tubing may be by cutting the tubing. The tubing may be cut by explosives, which is associated with safety risks. Explosives are complicated to transport and store safely, particularly when the tubing to be cut is located in an offshore well.

[0008] Mechanical solutions for cutting a tubing within a borehole are known and have advantages over explosives.

[0009] Patent EP 2530238 Bl discloses a downhole tubing cutter tool for submerging into a casing in a wellbore and separating an upper part of the casing from a lower part of the casing. The downhole tubing cutter tool comprises a piston housing within a first housing part, the piston housing comprising a piston member. The piston member is arranged inside the piston chamber for moving a cutting arm between a retracted position and a projected position, and the piston member is capable of applying a projecting force on the cutting arm by applying hydraulic pressure to a first piston face.

[0010] Patent application WO 2023172666 Al discloses a tubing cutter assembly and a method for using a tubing cutter assembly. The tubing cutter assembly comprises a hydraulic module regulating the flow of hydraulic fluid to a cutting equipment to maintain consistent levels of force on the cutting tool. The hydraulic module comprises a solenoid, which may be dithered to drop the system pressure.

[0011] Patent document WO 2023173138 Al discloses a downhole mechanical service tool comprising a hydraulic power system capable of applying axial forces (i.e. forces along the length of the tool). A cam follower connected to a tubing cutter is moved axially by a central rod, creating a radial force that presses the tubing cutter against the inner surface of the surrounding tube.

[0012] Patent document US5791409A discloses a downhole cutting tool for use in a wellbore, the cutting tool having a mandrel and a cylindrical knife body slidably mounted coaxially on the mandrel. The mandrel can be attached to or suspended from any type of workstring. The upper ends of a plurality of knife blades are pivotably mounted at fixed points on the knife body. The knife blades are suspended therefrom over a plurality of ramps formed on the exterior of the mandrel. A pressure chamber is formed between the knife body and the mandrel. Fluid from the work string can be directed through the mandrel to the pressure chamber, to drive the knife body downwardly relative to the mandrel, causing the lower ends of the knife blades to contact the ramps on the mandrel and kick or pivot outwardly to cause the lower tip of the blade to contact the downhole material to be cut. As the mandrel is rotated, the knife blades rotate with it and cut into the material. The point at which the lower end of the blade contacts the ramp is a fulcrum point which is closer to the lower tip of the blade than to the upper end of the blade.

[0013] SUMMARY The invention has for its object to remedy or to reduce at least one of the drawbacks of the prior art, or at least provide a useful alternative to prior art.

[0014] The object is achieved through features, which are specified in the description below and in the claims that follow.

[0015] The invention is defined by the independent patent claims. The dependent claims define advantageous embodiments of the invention.

[0016] According to a first aspect the invention there is provided a downhole tubing cutter tool for running into a downhole tubular in a wellbore and separating an upper portion of the downhole tubular from a lower portion of the downhole tubular, the downhole tubing cutter tool comprising:

[0017] - an inner tool portion;

[0018] - an outer sleeve telescopically coupled around the inner tool portion; and

[0019] - at least one cutting arm pivotably connected to the inner tool portion and moveable between a retracted position and an operational position; wherein the outer sleeve is configured to be telescoped in use in an uphole direction to pivot the at least one cutting arm from the retracted position to the operational position through an outer sleeve opening in the outer sleeve.

[0020] The downhole tubular may be a casing or tubing or drill pipe or liner.

[0021] In the present disclosure, the retracted position of the at least one cutting arm is a position in which the cutting arm cannot engage with the downhole tubular.

[0022] In some examples, in the retracted position the at least one cutting arm may not protrude radially outwards beyond the outer sleeve. In some examples wherein a ring or a bull nose envelops a part of the outer sleeve, as will be explained further below, and wherein a further opening of the ring or the bull nose at least partially overlap with the outer sleeve opening, the at least one cutting arm may not protrude radially outwards beyond the ring or the bull nose in the retracted position.

[0023] In the present disclosure, the operational position of the at least one cutting arm is a position in which the cutting arm engages with the downhole tubular such that the cutting arm may operate on the downhole tubular, to for example cut the downhole tubular. In the operational position, the at least one cutting arm protrudes radially outwards beyond the outer sleeve. In some examples wherein a ring or a bull nose envelops a part of the outer sleeve, as will be explained further below, and wherein a further opening of the ring or the bull nose at least partially overlap with the outer sleeve opening, the at least one cutting arm protrudes radially outwards beyond the ring or the bull nose in the operational position.

[0024] Said another way, in the retracted position, the at least one cutting arm may not be the radially outermost part of the downhole tubing cutter tool. In the operational position, the at least one cutting arm may be the radially outermost part of the downhole tubing cutter tool.

[0025] In order to pivot the at least one arm from the retracted position to the operational position, only the outer sleeve needs to be telescoped in the uphole direction. The inner tool portion, and therefore also the pivotable connection of the at least one arm to the inner tool portion, need not move.

[0026] Preferably, the pivotable connection between the at least one cutting arm and the inner tool portion is positioned on a first end of the at least one cutting arm, which is uphole from a second end portion of the at least one cutting arm, such that when the at least one cutting arm is pivoted to the operational position, the second end of the at least one cutting arm is pivoted in the uphole direction. During cutting, the second end of the at least one cutting arm may also move gradually radially outwards while pivoted in the uphole direction. This movement of the at least one cutting arm may result in a cut through the downhole tubular that is angled in the uphole direction, instead of perpendicular to the downhole tubular. The angled cut may be advantageous if a separated lower portion of the downhole tubular moves transversely to the longitudinal axis of the well, as the angled cut may reduce the risk of the separated lower portion getting stuck or jammed on the downhole tubing cutter tool. The angled cut may also be advantageous it a separated upper portion of the downhole tubular collapses downwards due to the compression of the downhole tubular. The angled cut may reduce the risk of the separated upper portion getting stuck or jammed on the downhole tubing cutter tool.

[0027] It will be understood that "angled" may refer to a cut forming a straight surface, i.e. a straight surface not transverse to the longitudinal axis of the tubular being cut. Additionally "angled" may also refer to a curved surface where the "angle" created is the average angle of the curved surface relative to the longitudinal axis of the downhole tubular. That is to say, the cut surface left after cutting may be substantially straight or may be curved, but when "angled" it is not transverse to the longitudinal axis of the tubular being cut.

[0028] By "stuck or jammed" it is here meant that the tubular and the downhole tubing cutter tool engage in such a way that the downhole tubing cutter tool may not be easily removed from the downhole tubular. This may be problematic because other tools may not be run in the downhole tubular, or other operations may not be performed until the downhole tubing cutter tool is freed and recovered to the surface. This may be both expensive and time consuming. Furthermore, additional specialised equipment may be needed top free the downhole tubing cutter tool from the downhole tubular.

[0029] Telescoping the outer sleeve in the uphole direction to pivot the at least one cutting arm from the retracted position to the operational position may be advantageous because it may reduce the risk of the outer sleeve becoming stuck or jammed if a separated lower portion of the downhole tubular moves transversely to the longitudinal axis of the well. Said another way, telescoping of the outer sleeve in the uphole direction may move the downhole tubing cutter tool partially or entirely out of the path of the moving separated lower portion.

[0030] In an embodiment of the downhole tubing cutter tool, the outer sleeve may be configured to be telescoped in use in a downhole direction to pivot the at least one cutting arm from the operational position to the retracted position through the outer sleeve opening in the outer sleeve.

[0031] In order to pivot the at least one arm from the operational position to the retracted position, only the outer sleeve needs to be telescoped in the downhole direction. The inner tool portion and therefore also the pivotable connection of the at least one arm with the inner tool portion need not move.

[0032] This may be especially advantageous when moving the at least one cutting arm from the operational position to the retracted position. When retracting the at least one cutting arm by telescoping only the outer sleeve in the downhole direction, there may be less risk that the at least one cutting arm gets stuck between downhole tubular and the outer sleeve. The at least one cutting arm only needs to pivot radially inwards in order to move to the retracted position, with no movement in the uphole or downhole direction being necessary.

[0033] In a further embodiment of the downhole tubing cutter tool, the outer sleeve may be biased in use towards the downhole end of the downhole tubing cutter tool by a first biasing means providing a first biasing force towards the downhole end. Furthermore, the inner tool portion and the outer sleeve may be arranged together to form an annular pressure chamber between the inner tool portion and the outer sleeve such that pressure within the annular pressure chamber applies a force in the uphole direction on the outer sleeve, such that when the force on the outer sleeve created by the pressure inside the annular pressure chamber is greater than the first biasing force of the first biasing means in use, the outer sleeve may telescope in the uphole direction thereby pivoting the at least one cutting arm from the retracted position to the operational position through the outer sleeve opening.

[0034] The outer sleeve may be further configured to move the at least one cutting arm from the operational position to the retracted position in use by telescoping of the outer sleeve in the downhole direction when the force in the uphole direction on the outer sleeve created by the pressure inside the annular pressure chamber is less than the first biasing force of the first biasing means in the downhole direction.

[0035] By adjusting the pressure within the annular pressure chamber and thus the force applied to the outer sleeve in the uphole direction, it may be possible to accurately position the at least one cutting arm in the radial direction. The radial position of the at least one cutting arm may be adjusted by balancing the two opposing forces; the biasing force in the downhole direction and the force applied by the pressure in the uphole direction. Furthermore, the force applied by the at least one cutting arm on the downhole tubular may also be set by the balance between the two opposing forces. The balance may easily be achieved by adjusting the pressure within the annular pressure chamber.

[0036] The first biasing means may comprise a spring located between the outer sleeve and the inner tool portion.

[0037] The inner tool portion may comprise a first shoulder, and wherein the first biasing means is positioned between the first shoulder and the outer sleeve.

[0038] Alternatively, in another embodiment of the downhole tubing cutter tool, the inner tool portion and the outer sleeve may be arranged together to form a first and a second annular pressure chamber between the inner tool portion and the outer sleeve, with an annular portion / piston separating the first and the second annular pressure chambers, such that a first pressure inside the first annular pressure chamber applies a first force in the uphole direction on the outer sleeve, and a second pressure inside the second annular pressure chamber applies a second force in the downhole direction on the outer sleeve.

[0039] When the first force in the uphole direction is greater than the second force in the downhole direction, the outer sleeve may telescope in the uphole direction, thereby pivoting the at least one cutting arm from the retracted position to the operational position through the outer sleeve opening.

[0040] The first and second annular pressure chambers may further be arranged such that when the first force in the uphole direction is less than the second force in the downhole direction, the outer sleeve may telescope in the downhole direction, thereby pivoting the at least one cutting arm from the operational position to the retracted position through the outer sleeve opening.

[0041] In an embodiment of the invention, the pivotable connection between the at least one cutting arm comprises a first end opposite a second end, and the at least one cutting arm may be pivotably connected to the inner tool portion at the first end, and the first end may be uphole from the second end. In this embodiment, when the at least one cutting arm is pivoted to the operational position, the second end of the at least one cutting arm is pivoted in the uphole direction. During cutting, the second end of the at least one cutting arm will also move gradually radially outwards while pivoted in the uphole direction. This movement of the at least one cutting arm may result in a cut through the downhole tubular that is angled in the uphole direction, instead of perpendicular to the downhole tubular. The angled cut may be advantageous if a separated lower portion of the downhole tubular moves transversely to the longitudinal axis of the well, as the angled cut may reduce the risk of the separated lower portion getting stuck or jammed on the downhole tubing cutter tool. The angled cut may also be advantageous it a separated upper portion of the down-hole tubular collapses downwards due to the compression of the downhole tubular. The angled cut may reduce the risk of the separated upper portion getting stuck or jammed on the downhole tubing cutter tool.

[0042] In an embodiment of the downhole tubing cutter tool, the downhole end of the downhole tubing cutter tool may comprise a curved or tapered bull nose.

[0043] The curved or tapered bull nose may mitigate hangup when running in hole in use. The curved or tapered bull nose may lower the risk of a separated lower portion of the downhole tubular getting stuck or jammed on the downhole tubing cutter tool after the upper and lower portion has been separated by a cut.

[0044] In another embodiment of the downhole tubing cutter tool, the downhole tubing cutter tool may further comprise a curved or tapered ring downhole from the outer sleeve.

[0045] The curved or tapered ring may mitigate hangup when running in hole in use. The curved or tapered ring may lower the risk of a separated lower portion of the downhole tubular getting stuck or jammed on the downhole tubing cutter tool after the upper and lower portion has been separated by a cut.

[0046] The bull nose may envelop a part of the outer sleeve, and the bull nose may comprise a bull nose opening, wherein the bull nose opening and the outer sleeve opening may be at least partially aligned such that the at least one cutting arm may move between the retracted position and the operational position through the outer sleeve opening and the bull nose opening; or the ring may envelop a part of the outer sleeve, and the ring may comprise a ring opening, wherein the ring opening and the outer sleeve opening may be at least partially aligned such that the at least one cutting arm may move between the retracted position and the operational position through the outer sleeve opening and the ring opening.

[0047] The bull nose or the ring may be located at a downhole end of the outer sleeve.

[0048] The bull nose or curved or tapered ring being located at a downhole end of the outer sleeve may be advantageous in use during cutting of a downhole tubular. During cutting of the downhole tubular, the at least one cutting arm may progress radially outwards as it cuts deeper in the downhole tubular. The radially outwards movement is caused by the outer sleeve telescoping further uphole. When the bull nose or ring is located at a downhole end of the outer sleeve, the bull nose or ring also moves further uphole during cutting of the downhole tubular, meaning that the part of the downhole tubing cutting tool that is directly below the cutting arm, in the downhole direction, also moves further uphole during the cutting. This may lower the risk of a separated lower portion of the downhole tubular getting stuck or jammed on the downhole tubing cutter tool after the upper and lower portion has been separated by a cut. The tapered shape of the bull nose and ring may further lower this risk.

[0049] The bull nose may form a downhole end of the downhole tubing cutter tool. During cutting, the downhole end of the tubing cutter tool may move further uphole. This may lower the risk of a separated lower portion of the downhole tubular getting stuck or jammed on the downhole tubing cutter tool after the upper and lower portion has been separated by a cut.

[0050] In an embodiment of the invention, the outer sleeve opening may comprise a first outer sleeve opening shoulder forming the downhole side of the outer sleeve opening, the first outer sleeve opening shoulder being configured to abut a first engagement surface of the at least one cutting arm such that when the outer sleeve is telescoped in the uphole direction in use, the first outer sleeve opening shoulder pivots the at least one cutting arm from the retracted position to the operational position.

[0051] The first engagement surface may be curved. In some examples, the first engagement surface may be partially curved. In some examples, the first engagement surface may be fully curved.

[0052] In other examples of the invention, another part of the outer sleeve may be configured to abut a first engagement surface of the at least one cutting arm such that when the outer sleeve is telescoped in the uphole direction in use, the first outer sleeve opening shoulder pivots the at least one cutting arm from the retracted position to the operational position.

[0053] The outer sleeve opening may comprise a second outer sleeve opening shoulder forming the uphole side of the outer sleeve opening, the second outer sleeve opening shoulder being configured to abut a second engagement surface of the at least one cutting arm such that when the outer sleeve is telescoped in the downhole direction in use, the second outer sleeve opening shoulder pivots the at least one cutting arm from the operational position to the retracted position through the outer sleeve opening in the outer sleeve.

[0054] In another embodiment of the invention, the outer sleeve opening may comprise a pin being configured to abut a third engagement surface of the at least one cutting arm such that when the outer sleeve is telescoped in the downhole direction in use, the pin pivots the at least one cutting arm from the operational position to the retracted position through the outer sleeve opening.

[0055] The outer sleeve opening may be sized such that it is possible to assemble or disassemble the at least one cutting arm after the outer sleeve has been coupled with the inner tool portion. The pin may be removably attached to the outer sleeve. The at least one cutting arm may therefore easily be replaced by a new or other type of cutting arm without removing the outer sleeve. The pin may restrict the radially outwards movement of the at least one cutting arm. The pin may prevent the at least one cutting arm from freely moving radially outwards as the outer sleeve telescopes in the uphole direction. The pin may ensure that the at least one cutting arm does not pivot radially outwards in an uncontrolled manner. The pin may allow the at least one cutting arm to pivot radially outwards in a controlled manner as the outer sleeve telescopes in the uphole direction.

[0056] In an alternative embodiment, the outer sleeve opening may be small enough such that the second outer sleeve opening shoulder forming the uphole side of the outer sleeve opening may restrict the radially outwards movement of the at least one cutting arm. The second outer sleeve opening shoulder may prevent the at least one cutting arm from freely moving radially outwards as the outer sleeve telescopes in the uphole direction. The second outer sleeve opening shoulder may ensure that the at least one cutting arm does not pivot radially outwards in an uncontrolled manner. The second outer sleeve opening shoulder may allow the at least one cutting arm to pivot radially outwards in a controlled manner as the outer sleeve telescopes in the uphole direction.

[0057] In other embodiments of the invention, other mechanisms may be used for pivoting the at least one cutting arm from the operational position to the retracted position, such as a biasing means. The biasing means may for example be a spring, such that the at least one cutting arm is biased radially inwards.

[0058] The at least one cutting arm may be at least partially located in the outer sleeve opening when the downhole tubing cutter tool is in the retracted position.

[0059] The at least one cutting arm may be at least partially located in the bull nose opening or the ring opening when the downhole tubing cutter tool is in the retracted position.

[0060] An advantage of the at least one cutting arm being at least partially located in the bull nose opening or the ring opening may be that the outer sleeve can be configured to be telescoped a shorter distance in the uphole direction to pivot the at least one cutting arm to the operational position, compared with the at least one cutting arm being located entirely within the inner tool portion. The downhole tubing cutter tool may further comprise a proportional relief valve in fluid communication with the annular pressure chamber such that the proportional relief valve may control the change in pressure inside the annular pressure chamber in use.

[0061] The controlled change in pressure inside the annular pressure chamber by the proportional relief valve may result in a slow pivoting of the at least one cutting arm. The slow radially outwards pivoting of the at least one cutting arm may reduce the risk of jamming when the at least one cutting arm is moved from the retracted position to the operational position.

[0062] During cutting, the applied force of the cutting arm onto the tubular may be fine-tuned by adjusting the pressure inside the annular pressure chamber by the proportional relief valve.

[0063] The downhole tubing cutter tool may further comprise a flow restrictor in a fluid path between the proportional relief valve and the annular pressure chamber, such that the flow restrictor can reduce a flow of a fluid within the fluid path.

[0064] The flow restrictor may further lower the rate at which the pressure inside the annular pressure chamber is changed in use. This may further increase the fine-tuning of the pivoting of the at least one cutting arm, radially inwards or outwards, and the fine-tuning of the applied force of the at least one cutting arm onto the tubular during cutting.

[0065] The outer sleeve may further comprise a linear position sensor for monitoring the position of the outer sleeve relative to the inner tool portion.

[0066] It is possible to determine the radial position of the at least one cutting arm relative to the outer sleeve or the inner tool portion from the position of the outer sleeve relative to the inner tool portion. In this connection, the linear position sensor may monitor the cutting progress of the downhole tubular by monitoring the position of the at least one cutting arm. The inner tool portion may comprise an electrical feedthrough. The electrical feedthrough may enable an electrical coupling of a further downhole tool at a downhole end of the inner tool portion.

[0067] For example, the further downhole tool may be any known downhole tool. In this connection, the electrical feed-through may be configured to power the further downhole tool located there below. The electrical feed-through may be configured to transfer electrical power and / or electronic communications.

[0068] The electrical feedthrough may be configured to provide electrical power and / or electronic communications to one or more of: a measurement tool; a logging tool; and a plug setting tool.

[0069] The further downhole tool may be tapered, as this may lower the risk of a separated lower portion of the downhole tubular getting stuck or jammed on the downhole tubing cutter tool after the upper and lower portion has been separated by a cut.

[0070] In an embodiment of the invention, the downhole tubing cutter tool may further comprise a locking mechanism configured to selectively prevent telescoping of the outer sleeve relative to the inner tool portion, the locking mechanism being moveable between a locked position in which the outer sleeve cannot telescope relative to the inner tool portion and an unlocked position in which the outer sleeve can telescope relative to the inner tool portion.

[0071] Preventing telescoping of the outer sleeve relative to the inner tool portion may be advantageous when running the downhole tubing cutter tool downhole into the downhole tubular. If the outer sleeve engages with a part of the downhole tubular, or any other infrastructure permanently or temporarily installed in the downhole tubular, the outer sleeve may be prevented from telescoping in the uphole direction, such that the at least one cutting arm may be prevented from pivoting from the retracted position to the operational position. The locking mechanism may comprise an axially moveable annular piston comprising an oblique piston head section and a radially moveable wedge comprising an oblique wedge head section registered in form with the oblique piston head section; wherein the annular piston may be axially moveable between a proximal position and a distal position and may be biased towards the proximal position by a second biasing means providing a second biasing force; the wedge may be radially moveable between an expanded position wherein the wedge engages the outer sleeve such that the locking mechanism is in the locked position, and a collapsed position wherein the wedge does not engage the outer sleeve such that the locking mechanism is in the unlocked position, wherein the wedge may be biased towards the collapsed position by a third biasing means providing a third biasing force; and when the annular piston is in the proximal position the second biasing force may be greater than the third biasing force such that the wedge may be held in the expanded position; and when the annular piston is in the distal position, the wedge may be in the collapsed position; wherein the annular piston may comprise a piston pressure surface forming a portion of the annular pressure chamber such that pressure within the annular pressure chamber may apply a force on the piston pressure surface; such that in use when the force on the piston pressure surface created by the pressure inside the annular pressure chamber is greater than the second biasing force of the second biasing means, the annular piston may move from the proximal position to the distal position thereby allowing radial movement of the wedge from the expanded position whereby the locking mechanism is locked, to the collapsed position whereby the locking mechanism is unlocked.

[0072] Alternatively, the locking mechanism may comprise an axially moveable annular piston comprising an oblique piston head section and a radially moveable wedge comprising an oblique wedge head section registered in form with the oblique piston head section; wherein the annular piston may be axially moveable between a proximal position and a distal position and may be biased towards the proximal position by a second biasing means providing a second biasing force; the wedge may be radially moveable between an expanded position wherein the wedge engages the outer sleeve such that the locking mechanism is in the locked position, and a collapsed position wherein the wedge does not engage the outer sleeve such that the locking mechanism is in the unlocked position, wherein the wedge may be biased towards the collapsed position by a third biasing means providing a third biasing force; and when the annular piston is in the proximal position the second biasing force may be greater than the third biasing force such that the wedge may be held in the expanded position; and when the annular piston is in the distal position, the wedge may be in the collapsed position; wherein the inner tool portion and the outer sleeve may be arranged together to form a further annular pressure chamber between the inner tool portion and the outer sleeve, and wherein the annular piston may comprise a piston pressure surface forming a portion of the further annular pressure chamber such that pressure within the further annular pressure chamber may apply a force on the piston pressure surface; such that in use when the force on the piston pressure surface created by the pressure inside the further annular pressure chamber is greater than the second biasing force of the second biasing means, the annular piston may move from the proximal position to the distal position thereby allowing radial movement of the wedge from the expanded position whereby the locking mechanism is locked, to the collapsed position whereby the locking mechanism is unlocked.

[0073] The second biasing means may comprise a spring.

[0074] The third biasing means may comprise a garter spring. The outer sleeve may comprise a radially inwards facing edge that is registered to engage the wedge when the wedge is in the expanded position.

[0075] The wedge may be provided with a plurality of wedges arranged as described above. The plurality of wedges may be distributed in the annular pressure chamber.

[0076] The annular piston may be axially moveable from the proximal position to the distal position in the downhole direction, and from the distal position to the proximal position in the uphole direction.

[0077] According to a second aspect of the invention, there is provided a downhole tubing cutter assembly comprising a downhole tubing cutter tool according to the first aspect of the invention, the downhole tubing cutter tool being arranged within a bottom hole assembly.

[0078] The downhole tubing cutter assembly may comprise a means for rotating the downhole tubing cutter tool.

[0079] The means for rotating the downhole tubing cutter tool may be a motor.

[0080] The downhole tubing cutter assembly may further comprise an anchoring unit configured for anchoring the downhole tubing cutter assembly inside the wellbore.

[0081] The downhole tubing cutter assembly may further comprise a pump for pumping hydraulic fluid. The pump may be in fluid communication with the annular pressure chamber. The pump may be in fluid communication with the anchoring unit to control the anchoring unit. The pump may be in fluid communication with the proportional relief valve.

[0082] The downhole tubing cutter assembly may further comprise a connection unit coupled to the electrical feedthrough of the inner tool portion, the connection unit being configured to electrically and / or mechanically connect a further downhole tool to the downhole tubing cutter assembly.

[0083] The downhole tubing cutter assembly may further comprise a measurement tool, logging tool or a plug setting tool with a plug coupled with the connection unit. According to a third aspect of the invention, there is provided a method of deploying a cutting arm of a downhole tubing cutter tool, comprising the steps of: providing a downhole tubing cutter tool according to the first aspect of the invention; and telescoping the outer sleeve in the uphole direction to pivot the at least one cutting arm from the retracted position to the operational position. This step may further comprise checking the linear sensor to get information on the radial position of the at least one tubing cutter.

[0084] According to a fourth aspect of the invention, there is provided a method of deploying and retracting a cutting arm of a downhole tubing cutter tool, comprising the steps of: providing a downhole tubing cutter tool according to the first aspect of the invention; telescoping the outer sleeve in the uphole direction to pivot the at least one cutting arm from the retracted position to the operational position; and telescoping the outer sleeve in the downhole direction to pivot the at least one cutting arm from the operational position to the retracted position.

[0085] One or both of the step of telescoping the outer sleeve in the uphole or downhole direction may further comprise determining the radial position of the at least one cutting arm. Determining the radial position of the at least one cutting arm may be performed by checking the linear sensor to get information on the radial position of the at least one cutting arm.

[0086] According to a fifth aspect of the invention, there is provided a method of deploying a locked downhole tubing cutter tool and unlocking and deploying a cutting arm, comprising the steps of: providing a downhole tubing cutter tool according to the first aspect of the invention; and running the downhole tubing cutting tool into a downhole tubular with the locking mechanism in the locked position; unlocking the locking mechanism; and telescoping the outer sleeve in the uphole direction to pivot the at least one cutting arm from the retracted position to the operational position.

[0087] According to a sixth aspect of the invention, there is provided a method of operating a downhole tubing cutter tool, comprising the steps of: providing a downhole tubing cutter tool according to the first aspect of the invention; running the downhole tubing cutting tool into a downhole tubular with the locking mechanism in the locked position; unlocking the locking mechanism; telescoping the outer sleeve in the uphole direction to pivot the at least one cutting arm from the retracted position to the operational position; and telescoping the outer sleeve in the downhole direction to pivot the at least one cutting arm from the operational position to the retracted position.

[0088] The steps of telescoping the outer sleeve in the uphole or downhole direction may further comprise checking the linear sensor to get information on the radial position of the at least one tubing cutter.

[0089] The method of operating a downhole tubing cutter tool may further comprise the steps of locking the locking mechanism; running the downhole tubing cutting tool out of the downhole tubular with the locking mechanism in the locked position. In a seventh aspect the invention relates to a method of cutting a downhole tubular, comprising the steps of: providing a downhole tubing cutter tool according to the first aspect of the invention; running the downhole tubing cutter tool into a downhole tubular with the at least one cutting arm in the retracted position; locating the downhole tubing cutter tool at a desired cut location within the downhole tubular; telescoping the outer sleeve in the uphole direction to pivot the at least one cutting arm from the retracted position to the operational position thereby engaging the at least one cutting arm with the downhole tubular to be cut; and rotating the downhole tubing cutter tool to cut the downhole tubular.

[0090] The step of telescoping the outer sleeve in the uphole direction may further comprise determining the radial position of the at least one cutting arm. Determining the radial position of the at least one cutting arm may be performed by checking the linear sensor to get information on the radial position of the at least one cutting arm.

[0091] The step of telescoping the outer sleeve in the uphole direction may further comprise rotating the downhole tubing cutter tool.

[0092] The method may further comprise adjusting the pressure inside the annular pressure chamber to adjust the applied force of the at least one cutting arm onto the downhole tubular.

[0093] The step of rotating the downhole tubing cutter tool may further comprise adjusting parameters of the downhole tubing cutter tool to operate within a setting, the parameters being, but not limited to, RPM of the downhole tubing cutter tool, torque of the at least one cutting arm, pressure of the at least one cutting arm, current and temperature. The method may further comprise a step of stopping the rotation of the downhole tubing cutter tool. The method may further comprise a step of stopping the rotation of the downhole tubing cutter tool if unwanted vibrations or stalling are detected. The method may further comprise a step of stopping the rotation of the downhole tubing cutter tool if unwanted sensor readings are detected.

[0094] The method may further comprise adjusting the parameters to another more favourable setting, and restart rotating the downhole tubing cutter tool to resume the cutting operation.

[0095] The method may further comprise the step of rotating the downhole tubing cutter tool until a set range of the linear position sensor is met.

[0096] The method may further comprise telescoping the outer sleeve in the downhole direction to pivot the at least one cutting arm from the operational position to the retracted position.

[0097] The method may further comprise running the downhole tubing cutter tool out of the downhole tubular with the at least one cutting arm in the retracted position.

[0098] According to an eighth aspect of the invention, there is provided a method of cutting and separating a downhole tubular, comprising the steps of: providing a downhole tubing cutter tool according to the first aspect of the invention; running the downhole tubing cutter tool into a downhole tubular with the at least one cutting arm in the retracted position; locating the downhole tubing cutter tool at a desired cut location within the downhole tubular; telescoping the outer sleeve in the uphole direction to pivot the at least one cutting arm from the retracted position to the operational position thereby engaging the at least one cutting arm with the downhole tubular to be cut; and rotating the downhole tubing cutter tool to cut and separate the downhole tubular.

[0099] The step of telescoping the outer sleeve in the uphole direction may further comprise rotating the downhole tubing cutter tool.

[0100] According to a ninth aspect of the invention, there is provided a method of cutting and logging a downhole tubular, comprising the steps of: providing a downhole tubing cutter assembly according to the second aspect of the invention; running the downhole tubing cutter assembly into a downhole tubular with the at least one cutting arm in the retracted position; locating the downhole tubing cutter tool at a desired cut location within the downhole tubular; telescoping the outer sleeve in the uphole direction to pivot the at least one cutting arm from the retracted position to the operational position thereby engaging the at least one cutting arm with the downhole tubular to be cut; and rotating the downhole tubing cutter tool to cut the downhole tubular; operating the measurement tool or the logging tool to gather data about the downhole tubular.

[0101] The step of locating the downhole tubing cutter tool at a desired cut location within the downhole tubular may further comprise a step of anchoring the downhole tubing cutter assembly within the downhole tubular.

[0102] Prior to the step of anchoring, and / or during the step of anchoring, the method may comprise rotating the downhole tubing cutter tool.

[0103] The step of anchoring the downhole tubing cutter assembly may further comprise setting an anchoring pressure on anchors of the anchoring unit. The steps of anchoring the downhole tubing cutter assembly may further comprise checking that the anchoring pressure is within a set threshold. The step of anchoring the downhole tubing cutter assembly may further comprise maintaining the anchoring pressure on every anchor of the anchoring unit.

[0104] The method may further comprise stopping the method if the anchoring pressure is not within the set threshold and if it is not possible to obtain an anchoring pressure within the set threshold.

[0105] The steps of rotating the downhole tubing cutter tool to cut the downhole tubular and operating the measurement tool or the logging tool to gather data about the downhole tubular may be performed simultaneously.

[0106] The steps of telescoping the outer sleeve in the uphole direction to pivot the at least one cutting arm from the retracted position to the operational position, rotating the downhole tubing cutter tool to cut the downhole tubular and operating the measurement tool or the logging tool to gather data about the downhole tubular may be performed simultaneously.

[0107] The method according to the seventh aspect of the invention may comprise a step of rotating the downhole tubing cutter tool before telescoping the outer sleeve in the uphole direction to pivot the at least one cutting arm from the retracted position to the operational position.

[0108] The method according to the eight aspect of the invention may comprise a step of rotating the downhole tubing cutter tool before telescoping the outer sleeve in the uphole direction to pivot the at least one cutting arm from the retracted position to the operational position.

[0109] The method according to the ninth aspect of the invention may comprise a step of rotating the downhole tubing cutter tool before telescoping the outer sleeve in the uphole direction to pivot the at least one cutting arm from the retracted position to the operational position. According to a tenth aspect of the invention, there is provided a method of deploying a downhole tubing cutter assembly within a downhole tubular, comprising the steps of: providing a downhole tubing cutter assembly according to the second aspect of the invention; running the downhole tubing cutter tool assembly into a downhole tubular with the at least one cutting arm in the retracted position; locating the downhole tubing cutter assembly at a desired location within the downhole tubular; anchoring the downhole tubing cutter assembly at the desired location; telescoping the outer sleeve in the uphole direction to pivot the at least one cutting arm from the retracted position to the operational position.

[0110] According to an eleventh aspect of the invention, there is provided a method of deploying a downhole tubing cutter assembly within a downhole tubular and cutting the downhole tubular, the method comprising the steps of: providing a downhole tubing cutter assembly according to the second aspect of the invention; running the downhole tubing cutter assembly into a downhole tubular with the at least one cutting arm in the retracted position; locating the downhole tubing cutter assembly at a desired cut location within the downhole tubular; anchoring the downhole tubing cutter assembly at the desired cut location; telescoping the outer sleeve in the uphole direction to pivot the at least one cutting arm from the retracted position to the operational position thereby engaging the at least one cutting arm with the downhole tubular to be cut; and rotating the downhole tubing cutter tool to cut the downhole tubular; The method according to the ninth aspect of the invention may comprise a step of rotating the downhole tubing cutter tool prior to and / or during the step of anchoring the downhole tubing cutter assembly within the downhole tubular.

[0111] The method according to the tenth aspect of the invention may comprise a step of rotating the downhole tubing cutter tool prior to and / or during the step of anchoring the downhole tubing cutter assembly within the downhole tubular.

[0112] The method according to the eleventh aspect of the invention may comprise a step of rotating the downhole tubing cutter tool prior to and / or during the step of anchoring the downhole tubing cutter assembly within the downhole tubular.

[0113] The method according to the ninth aspect of the invention may comprise a step of rotating the downhole tubing cutter tool prior to and / or during the step of telescoping the outer sleeve in the uphole direction.

[0114] The method according to the tenth aspect of the invention may comprise a step of rotating the downhole tubing cutter tool prior to and / or during the step of telescoping the outer sleeve in the uphole direction.

[0115] The method according to the eleventh aspect of the invention may comprise a step of rotating the downhole tubing cutter tool prior to and / or during the step of telescoping the outer sleeve in the uphole direction.

[0116] Said in other words, the method according to the ninth and / or the tenth and / or the eleventh aspect of the invention, may comprise rotating the downhole tubing cutter tool after the step of locating the downhole tubing cutter tool at the desired location within the downhole tubular, and before anchoring the downhole tubing cutter assembly at the desired location. The method according to the ninth and / or the tenth and / or the eleventh aspect of the invention, may comprise rotating the downhole tubing cutter tool after the step of anchoring the downhole tubing cutter tool at the desired location, and before telescoping the outer sleeve in the uphole direction to pivot the at least one cutting arm from the retracted position to the operational position. The downhole tubing cutter tool may continue to rotate during anchoring of the downhole tubing cutter assembly. The downhole tubing cutter tool may continue to rotate during telescoping of the outer sleeve in the uphole direction to pivot the at least one cutting arm from the retracted position to the operational position.

[0117] The downhole tubing cutter tool may continue to rotate until the downhole tubular is separated into an upper portion and a lower portion.

[0118] DRAWINGS AND SPECIFIC DESCRIPTION

[0119] In the following are described examples of embodiments illustrated in the accompanying drawings, wherein:

[0120] Figure 1 shows a side view of a downhole tubing cutter tool, wherein arms of the downhole tubing cutter tool are in a retracted position;

[0121] Figure 2 shows the downhole tubing cutter tool of Figure 1 within a well;

[0122] Figure 3 shows a cross-section of the downhole tubing cutter tool of Figure 1, taken along the line A-A in Figure 1;

[0123] Figure 4 shows a detail view of detail C in Figure 3;

[0124] Figure 5 shows a cross-section of the downhole tubing cutter tool of Figure 1, wherein a locking mechanism is in an open state;

[0125] Figure 6 shows a detail view of detail D in Figure 5;

[0126] Figure 7 shows the downhole tubing cutter tool of Figure 1, wherein the arms are in an operational position;

[0127] Figure 8 shows the downhole tubing cutter tool of Figure 1 within a well, wherein the arms are in an operational position; Figure 9 shows a cross-section of the downhole tubing cutter tool of Figure 1, taken along the line B-B in Figure 7, the downhole tubing cutter tool being within a well;

[0128] Figure 10 shows the downhole tubing cutter tool of Figure 1, wherein the arms are further extended radially from the downhole tubing cutter tool;

[0129] Figure 11 shows an end view of the downhole end of the downhole tubing cutter tool of Figure 1;

[0130] Figure 12 shows a side view of an alternative downhole tubing cutter tool, wherein the outer sleeve opening comprises a pin;

[0131] Figure 13 shows a cross-section of the downhole tubing cutter tool of Figure 12, taken along the line C-C in Figure 12;

[0132] Figure 14 shows a side view of an alternative downhole tubing cutter tool further comprising a connection unit;

[0133] Figure 15 shows a cross-section of the downhole tubing cutter tool of Figure 14, taken along the line D-D in Figure 14;

[0134] Figure 16 shows a side view of an alternative downhole tubing cutter tool, wherein the outer sleeve is partially enveloped by the bull nose;

[0135] Figure 17 shows a cross-section of the downhole tubing cutter tool of Figure 16, taken along the line E-E in Figure 16;

[0136] Figure 18 shows a side view of an alternative downhole tubing cutter tool, wherein the outer sleeve is partially enveloped by the bull ring, and wherein the downhole tubing cutter tool comprises a connection unit;

[0137] Figure 19 shows a cross-section of the downhole tubing cutter tool of Figure 18, taken along the line F-F in Figure 18;

[0138] Figure 20 shows a downhole tubing cutter tool assembly; and Figure 21 shows a schematic of a hydraulic circuit of a downhole tubing cutter tool assembly.

[0139] In the figures, same or corresponding elements are indicated by same reference numbers. For clarity reasons, some elements may in some of the figures be without reference numbers.

[0140] A person skilled in the art will understand that the figures are just principal drawings. The relative proportions of individual elements may also be distorted.

[0141] Referring firstly to Figures 1 to 3, the reference number 1 refers to a downhole tool, in the form of a downhole tubing cutter tool for running into a downhole tubular 71 in a wellbore 70. The downhole tubular 71 may typically be a casing, a tubing, a liner, or a drill pipe. However, it will be understood that the downhole tubing cutter tool 1 described herein may be utilised in any type of downhole tubular other than a casing, a tubing, or a drill pipe.

[0142] The downhole tubing cutter tool 1 comprises an inner tool portion 30 and an outer sleeve 20 telescopically coupled around the inner tool portion 30 (see for example the cross-section in Figure 3). The downhole tubing cutter tool 1 further comprises at least one cutting arm 40 (see for example the cross-section in Figure 3) pivotably connected to the inner tool portion 30 and moveable between a retracted position 401 (see for example Figures 1 to 3 and 5) and an operational position 405 (see for example Figures 7 to 11), which will be described in further detail. The outer sleeve 20 is configured to be telescoped in an uphole direction XI to pivot the at least one cutting arm 40 from the retracted position 401 to the operational position 405 through an outer sleeve opening 21 in the outer sleeve 20.

[0143] The outer sleeve 20 is telescopically coupled around the inner tool portion 30. In the illustrated examples the outer sleeve 20 is coupled around the downhole end of the inner tool portion 30. In other examples (not shown) the outer sleeve 20 may not be coupled around a downhole end of the inner tool portion 30. The outer sleeve may for example be coupled around a mid-section of the inner tool portion. The outer sleeve may for example be coupled around an uphole end of the inner tool portion.

[0144] The downhole tubing cutter tool 1 comprises, in some examples (see Figures 1 to 3, 5, 7 to 10, 12, 13, 16, and 17), a bull nose 15 which is connected to the outer sleeve 20 and is moveable together with the outer sleeve 20. In the illustrated examples, the bull nose 15 is located at the downhole end 19 of the downhole tubing cutter tool 1. In other examples (see Figures 14, 15, 18, and 19) the outer sleeve 20 may not comprise a bull nose 15. In other examples (not shown) the bull nose 15 is not connected to the outer sleeve 20, or the downhole tubing cutter tool 1 does not comprise a bull nose 15.

[0145] Referring now to Figures 1 to 10, showing an example of a downhole tubing cutter tool 1. Figures 1, 2, 7, and 8 show side views of the downhole tubing cutter tool 1, while Figures 3, 5, 9 and 10 show cross-sectional views of the downhole tubing cutter tool, the said figures showing the cutting arm in different positions. Figures 4 and 6 show details of a locking mechanism 60.

[0146] The outer sleeve 20 is movable in an uphole direction XI and a downhole direction X2, relative to the inner tool portion 30. The outer sleeve 20 is biased towards the downhole end 19 of the downhole tubing cutter tool 1 by a first biasing means 23, here shown as a spring 23 positioned between a first shoulder 32 (visible in Figure 3) of the inner tool portion 30 and the outer sleeve 20. In other examples (not shown) the outer sleeve 20 may be biased towards the downhole end 19 of the downhole tubing cutter tool 1 by other biasing means. The first biasing means 23 provides a first biasing force on the outer sleeve 20 in the downhole direction X2, towards the downhole end 19 of the downhole tubing cutter tool 1.

[0147] In the illustrated examples, the inner tool portion 30 and the outer sleeve 20 are arranged together to form an annular pressure chamber 22 (visible in the cross-sectional and cross- sectional detail drawings in Figures 3 and 4) between the inner tool portion 30 and the outer sleeve 20. The outer sleeve 20 is moveable in the uphole direction XI by increasing a pressure within an annular pressure chamber 22, the pressure applying a force on the outer sleeve 20 in the uphole direction XI. When the force in the uphole direction XI caused by the pressure inside the annular pressure chamber 22 is greater than the first biasing force in the downhole direction X2, the outer sleeve 20 will telescope in the uphole direction XI.

[0148] The outer sleeve is moveable in the downhole direction X2 by decreasing the pressure within the annular pressure chamber 22. When the force in the uphole direction XI caused by the pressure inside the annular pressure chamber 22 is lower than the first biasing force in the downhole direction X2, the outer sleeve 20 will telescope in the downhole direction X2.

[0149] In other examples (not shown) the inner tool portion 30 and the outer sleeve 20 are arranged together to form a first and a second annular pressure chamber between the inner tool portion 30 and the outer sleeve 20. A first pressure inside the first annular pressure chamber applies a force on the outer sleeve 20 in the uphole direction XI, and a second pressure inside the second annular pressure chamber applies a force on the outer sleeve 20 in the downhole direction X2.

[0150] When the force in the uphole direction XI, caused by the first pressure inside the first annular pressure chamber, is greater than the force in the downhole direction X2, caused by the second pressure inside the second annular pressure chamber, the outer sleeve 20 telescopes in the uphole direction XI. Similarly, when the force in the uphole direction XI, caused by the first pressure inside the first annular pressure chamber, is less than the force in the downhole direction X2, caused by the second pressure inside the second annular pressure chamber, the outer sleeve 20 telescopes in the downhole direction X2.

[0151] In the illustrated examples of the downhole tubing cutter tool 1, the annular pressure chamber 22 is in fluid connection with a pump for hydraulic fluid (not shown), through a supply channel 53 and a channel 52, the two channels 52, 53 being positioned within the inner tool portion 30. In the presently described example, the two channels are machined as two separate channels to ease production. However, it will be understood that the two channels meet to form one continuous hydraulic fluid flow path, as can clearly be seen in Figure 3. In the illustrated examples, the inner tool portion 30 comprises further a proportional relief valve 50, connected to the hydraulic fluid flow path, between the supply channel 53 and the channel 52. The proportional relief valve 50 may enable a slow and controlled increase of pressure within the annular pressure chamber 22, leading to a slow and controlled movement of the outer sleeve 20 relative to the inner tool portion 30. In the illustrated example, the channel 52 comprises a flow restrictor 51 to further reducing the flow of the fluid flow through the channel 52, and thus further reducing the speed of the movement of the outer sleeve 20.

[0152] It will be understood that, although advantageous, the proportional relief valve 50 and the flow restrictor 51 are not essential for the invention. In other examples (not shown), the inner tool portion 30 comprises a regular relief valve, or no relief valve in the hydraulic fluid path between the pump and the annular pressure chamber 22.

[0153] In the illustrated examples, the downhole tubing cutter tool 1 comprises three cutting arms 40 (see Figure 11). In other examples (not shown), the downhole tubing cutter tool 1 may comprise more than three cutting arms 40, or less than three cutting arms 40.

[0154] In alternative downhole tools configured for performing other operations than cutting downhole tubulars, the downhole tools may be provided with one or more arms 43 for being moved in use between the retracted position and the operational position for performing a downhole operation.

[0155] The following is a detailed description of one of the cutting arms 40, but is equally applicable to the other cutting arms 40 where further cutting arms 40 are provided.

[0156] The cutting arm 40 is pivotably connected to the inner tool portion 30 at a first end 41 (see for example Figure 3). At the opposite second end 42, the cutting arm 40 comprises a blade 44. The outer sleeve 20 comprises an outer sleeve opening 21 through which the cutting arm 40 may protrude. The outer sleeve opening 21 comprises a first outer sleeve opening shoulder 215, forming the downhole side of the outer sleeve opening 21, and a second outer sleeve opening shoulder 210, forming the uphole side of the outer sleeve opening 21. In other examples (not shown) the cutting arm 40 comprises at the second end 42, in addition to or instead of the blade 44, a grinding element, or a scraping element, or other cutting elements suitable for cutting a downhole tubular 71. It will be understood that different cutting elements may be used, depending on the material of the downhole tubular 71 to be cut.

[0157] Referring to figures 1 to 11, the cutting arm 40 is moveable between a retracted position 401 (see Figures 1 to 3, and 5) and an operational position 405 (see Figures 7 to 11). In this example, when the cutting arm 40 is in the retracted position 401, the cutting arm 40 does not protrude radially outwards beyond the outer sleeve 20, so that the second end 42 of the cutting arm 40 is flush with the outer side of the outer sleeve 20, or within the outer sleeve 20, such that the cutting arm 40 cannot engage with the downhole tubular 71. In this example, when the cutting arm 40 is in the operational position 405, the cutting arm 40 protrudes radially outwards beyond the outer sleeve 20, through the outer sleeve opening 21 so as to engage the downhole tubular 71 such that the cutting arm 40 may operate on the downhole tubular 71.

[0158] When the outer sleeve 20 is fully extended in the downhole direction X2, relative to the inner tool portion 30, as shown in Figures 1 to 3, and 5, the cutting arm 40 is in the retracted position 401. In the illustrated example, a second engagement surface 435 of the cutting arm 40 is abutting the second outer sleeve opening shoulder 210. It will be understood that the second outer sleeve opening shoulder 210 may be closer to the first outer sleeve opening shoulder 215 than shown in the figures, such that the outer sleeve opening 21 may be smaller than shown in the figures. The second outer sleeve opening shoulder 210 may restrict the radially outwards movement the cutting arm 40. The second outer sleeve opening shoulder 210 may prevent the cutting arm 40 from freely moving radially outwards as the outer sleeve 20 is telescoped in the uphole direction XI to move the cutting arm 41 from the retracted position 401 to the operational position 405. This may result in a more controlled pivoting of the cutting arm 40 from the retracted position 401 to the operational position 405. The second outer sleeve opening shoulder 210 may ensure that the cutting arm 40 does not pivot radially outwards in an uncontrolled manner. The second outer sleeve opening shoulder 210 may allow the cutting arm to pivot radially outwards in a controlled manner as the outer sleeve 20 telescopes in the uphole direction XI.

[0159] In other examples (see Figures 12 to 19) the outer sleeve opening 21 comprises a removable pin 219 configured to abut a third engagement surface 437 of the cutting arm 40. In these examples, the pin 219 may restrict the radially outwards movement of the cutting arm 40. The pin 219 may prevent the cutting arm 40 from freely moving radially outwards as the outer sleeve 20 telescopes in the uphole direction XI to move the cutting arm 40 from the retracted position 401 to the operational position 405. This may result in a more controlled pivoting of the cutting arm 40 from the retracted position 401 to the operational position 405. The pin 219 may ensure that the cutting arm 40 does not pivot radially outwards in an uncontrolled manner. The pin 219 may allow the cutting arm 40 to pivot radially outwards in a controlled manner as the outer sleeve 20 telescopes in the uphole direction XI.

[0160] The pin 219 may also result in a more controlled pivoting of the cutting arm 40 from the operational position 405 to the retracted position 401, as the pivoting may start as soon as the outer sleeve 20 telescopes in the downhole direction X2, compared to the pivoting of a cutting arm 40 in an outer sleeve opening 21 of the same size without a pin 219.

[0161] The pin 219 is in the illustrated examples removably attached to the outer sleeve 20. This may enable easy replacement of a cutting arm 40 through the outer sleeve opening 20.

[0162] In other examples (not shown) the cutting arm 40 may be held in the retracted position 401 by biasing means such as a spring.

[0163] When the cutting arm 40 is in the retracted position 401, the downhole tubing cutter tool 1 may be moved within a wellbore 70 without the cutting arm 40 coming into contact with a downhole tubular 71 of the wellbore 70.

[0164] When the outer sleeve 20 is moved in the uphole direction XI relative to the inner tool portion 30, a part of the outer sleeve 20 pushes against a first engagement surface 430 of the cutting arm 40, so that the cutting arm 40 pivots around the pivot point 31 (see Figures 3, 5, 9 and 10). In the illustrated example, the part of the outer sleeve 20 is a roll pin positioned on the first outer sleeve opening shoulder 215. At the same time, the second outer sleeve opening shoulder 210 is moved in the uphole direction XI such that the cutting arm 40 may pivot radially outwards. As the part of the outer sleeve 20 pushes on the first engagement surface 430 due to the uphole movement of the outer sleeve 20, the second end 42 of the cutting arm 40 protrudes radially outwards through the outer sleeve opening 21, such that the cutting arm 40 is in the operational position 405.

[0165] In the example shown in Figures 1 to 11 and 12 to 15, the operational position 405 of the cutting arm 40 may be any position of the cutting arm 40 wherein the cutting arm 40 protrudes radially outwards beyond the outer sleeve 20, such that the cutting arm 40 may engage with the downhole tubular 71 such that the cutting arm 40 may cut the downhole tubular 71. Two operational positions 405 are shown in Figures 9 and 10, wherein the position of the cutting arm 40 is more radially outwards in Figure 10 compared to in Figure 9. The movement of the outer sleeve 20 may be stopped so that the cutting arm 40 is in an intermediate operational position 405.

[0166] In another example (not shown) a part of the bull nose 15 or the ring 16 is pushing against the first engagement surface 430 of the cutting arm 40 to pivot the cutting arm 40 radially outwards, as the outer sleeve 20 is moved in the uphole direction XI. In another example (not shown) a spring pushes the cutting arm 40 radially outwards, and the cutting arm 40 is restricted from pivoting radially outwards by for example the first outer sleeve opening shoulder 215 when the cutting arm 40 is in the retracted position 401. As the outer sleeve 20 is moved in the uphole direction XI, the first outer sleeve opening shoulder 215 may no longer restrict the cutting arm 40 from pivoting radially outwards, and the spring may push the cutting arm 40 radially outwards into the operational position 405. In alternative examples (not shown) the cutting arm 40 may be arranged to move radially outwards by another arrangement.

[0167] When the cutting arm is in the operational position 405, the cutting arm 40 may perform an operation on a downhole tubular 71 of a wellbore 70. The cutting arm 40 may for example cut the downhole tubular 71. The downhole tubing cutter tool 1 may be rotated to cut the downhole tubular 71. The downhole tubing cutter tool 1 may be rotating when the outer sleeve 20 is moved in the uphole direction XI to pivot the cutting arm 40 from the retracted position 401 to the operational position 405.

[0168] Furthermore, the outer sleeve 20 is configured to be telescoped in use in the downhole direction X2 to pivot the cutting arm 40 from the operational position 405 to the retracted position 401 through the outer sleeve opening 21.

[0169] In the example shown in Figures 1 to 3, 5, and 7 to 11, when the outer sleeve 20 telescope in the downhole direction X2 to move the cutting arm 40 from the operational position 405 to the retracted position 401, the first outer sleeve opening shoulder 215 is pushed against the second engagement surface 435 of the cutting arm 40 to pivot the cutting arm 40 radially inwards.

[0170] In the examples shown in Figures 12 to 19, when the outer sleeve 20 telescopes in the downhole direction X2 to move the cutting arm 40 from the operational position 405 to the retracted position 401, the pin 219 is pushed against the third engagement surface 437 of the cutting arm 40 to pivot the cutting arm 40 radially inwards.

[0171] The downhole tubing cutter tool 1 may be rotating when the outer sleeve 20 is moved in the downhole direction X2 to pivot the cutting arm 40 from the operational position 405 to the retracted position 401.

[0172] Referring now to Figures 16 to 19. The figures show a downhole tubing cutter tool 1. The downhole tubing cutter tool 1 will be mainly discussed in as far as it differs from the downhole tubing cutter tool 1 shown in Figures 1 to 3, 5 and 7 to 11.

[0173] The downhole tubing cutter tool 1 shown in Figures 16 to 19 comprises a larger arm 43a, here shown as a cutting arm 40. It may be advantageous to use different sized arms 43, 43a for different operations within a wellbore. For example, different type of downhole tubings may require different sized cutting arms 40 depending on the material or width of the tubing.

[0174] A bull nose 15 (see Figures 16 and 17) envelops a part of the outer sleeve 20, and comprises a bull nose opening 155. The bull nose opening 155 and the outer sleeve opening 21 are at least partially aligned such that the cutting arm 40 may move between the retracted position 401 and the operational position 405 through the outer sleeve opening 21 and the bull nose opening 155.

[0175] Alternatively, a curved or tapered ring 16 (see Figures 18 and 19) envelops a part of the outer sleeve 20, and comprises a ring opening 165. The ring opening 165 and the outer sleeve opening 21 are at least partially aligned such that the cutting arm 40 may move between the retracted position 401 and the operational position 405 through the outer sleeve opening 21 and the ring opening 165.

[0176] In the examples shown in Figures 16 to 19, when the cutting arm 40 is in the retracted position 401, the cutting arm 40 does not protrude radially outwards beyond the bull nose 15 or the ring 16, so that the second end 42 of the cutting arm 40 is flush with the outer side of the bull nose 15 or the ring 16, or within the bull nose 15, the ring 16 or the outer sleeve 20. In these examples, when the cutting arm 40 is in the operational position 405, the cutting arm 40 protrudes radially outwards beyond the bull nose 15 or the ring 16, through the bull nose opening 155 or the ring opening 165.

[0177] In some examples (see Figures 15 and 19) the inner tool portion 30 of the downhole tubing cutter tool 1 comprises an electrical feedthrough 91. The electrical feedthrough 91 may enable an electrical coupling of a further downhole tool at a downhole end of the inner tool portion 30.

[0178] Furthermore, in the illustrated examples, the downhole tubing cutter tool 1 comprises a linear position sensor 80. The linear position sensor 80 is connected to the outer sleeve 20 such that the linear position sensor 80 moves in the uphole direction XI and the downhole direction X2 along with the outer sleeve 20. The linear position sensor 80 may measure the position of the outer sleeve 20 relative to the inner tool portion 30. The linear position sensor 80 may therefore also measure the position of the cutting arm 40.

[0179] When moving the downhole tubing cutter tool in the downhole direction XI within a wellbore 70, for example when running in hole, it may be advantageous to prevent uphole movement of the outer sleeve 20 in case the outer sleeve 20 comes in contact with a part of the wellbore 70, the downhole tubular 71 or equipment installed in the wellbore 71 or on the downhole tubular 71, so that the cutting arm 40 is not moved radially outwards from the outer sleeve 20, or the bull nose 15 or the ring 16. Moving the cutting arm 40 radially outwards before it is intended to be deployed may cause damage to the cutting arm 40 or downhole infrastructure. Furthermore, moving the cutting arm 40 radially outwards before it is intended to be deployed may lead to the downhole tubing cutter tool 1 becoming stuck in the well. The illustrated examples of the downhole tubing cutter tool 1 comprises a locking mechanism 60 preventing uphole movement of the outer sleeve 20 relative to the inner tool portion 30. The locking mechanism 60 is shown in greater detail in Figure 4, showing the locking mechanism 60 in a locked position, wherein movement of the outer sleeve 20 relative to the inner tool portion 30 in the uphole direction XI is prevented. In Figure 6, the locking mechanism 60 is shown in an unlocked position wherein the outer sleeve 20 is free to move in the uphole direction XI relative to the inner tool portion 30.

[0180] Referring firstly to Figures 3 and 4. The locking mechanism 60 comprises an axially moveable annular piston 61 within the annular pressure chamber 22, and a radially moveable wedge 64 within the annular pressure chamber 22. The annular piston 61 comprises an oblique piston head section 610 registered in form with an oblique wedge head section 640 of the wedge 64. The annular piston 61 is axially moveable between a proximal position (see Figure 4) and a distal position (see Figure 6). The annular piston 61 is biased towards the proximal position by a second biasing means 62, here shown as a spring 62, providing a second biasing force. In the illustrated example, the annular piston 61 abuts a second shoulder 63 of the inner tool portion 30 in the proximal position.

[0181] The wedge 64 is radially moveable between an expanded position (see Figure 4) wherein the wedge 64 engages the outer sleeve 20, and a collapsed position (see Figure 6) wherein the wedge 60 does not engage the outer sleeve 20. In the illustrated example, the wedge 64 engages a radially inwards facing edge 66 of the outer sleeve 20 in the expanded position. When the wedge 64 is in the expanded position, the locking mechanism 60 is in a locked position, and when the wedge 64 is in the collapsed position, the locking mechanism 60 is in the unlocked position. In the unlocked position, the radially inwards facing edge 66 of the outer sleeve 20 may pass the wedge 64, in the space formed radially outwards from the wedge 64. The wedge 64 is biased towards the collapsed position by a third biasing means 65, here shown as a garter spring 65, providing a third biasing force.

[0182] When the annular piston 61 is in the proximal position the second biasing force is greater than the third biasing force such that the wedge 64 is held in the expanded position. When the annular piston 61 is in the distal position, the wedge 64 is in the collapsed position. In other words, when the annular piston 61 is in the proximal position, the locking mechanism 60 is in the locked position, and when the annular piston is in the distal position, the locking mechanism 60 is in the unlocked position.

[0183] The annular piston 61 is moved from the proximal position to the distal position by increasing the pressure inside the annular chamber 22. The annular piston 61 comprises a piston pressure surface 611 forming a portion of the annular pressure chamber 22 such that pressure within the annular pressure chamber 22 applies a force on the piston pressure surface 611. When the force on the piston pressure surface 611 created by the pressure inside the annular pressure chamber 22 is greater than the second biasing force of the second biasing means 62, the annular piston 61 will move from the proximal position to the distal position thereby allowing radial movement of the wedge 64 from the expanded position whereby the locking mechanism 60 is locked, to the collapsed position whereby the locking mechanism is unlocked 60.

[0184] In the illustrated example, the annular chamber comprises four radially moveable wedges 64 distributed within the annular pressure chamber 22.

[0185] Preferably, the second biasing force of provided by the second biasing means is less than the first biasing force provided by the first biasing means 23, such that when the pressure inside the annular pressure chamber 22 increases, the annular piston 61 moves first to the distal position such that the locking mechanism 60 is in the unlocked position. A further increase of the pressure inside the annular pressure chamber 22 will then result in the telescoping of the outer sleeve 20 in the uphole direction XI.

[0186] Figure 20 shows a downhole tubing cutter assembly 10 comprising a downhole tubing cutter tool 1 at the downhole end of the downhole tubing cutter assembly 10. The downhole tubing cutter assembly 10 is here shown as a downhole tubing cutter assembly 10 for cutting a downhole tubular 71 of a wellbore 70, wherein the downhole tubing cutter tool 1 comprises one or more cutting arms 43. The downhole tubing cutter assembly 10 comprises two anchoring units 95.

[0187] Figures 14, 15, 18 and 19 show examples of a downhole tubing cutter tool 1 arranged within a downhole tubing cutter assembly 10, wherein the downhole tubing cutter assembly 10 further comprising a connection unit 90. The connection unit 90 is coupled to the electrical feedthrough 91(shown in Figures 15 and 19) of the inner tool portion 30, and is configured to electrically and mechanically connect a further downhole tool to the downhole assembly 10. The further downhole tool may for example be a measurement tool, logging tool or a plug setting tool(not shown).

[0188] The connection unit 90 may comprise an electrical feedthrough, wherein the electrical feedthrough may be in connection with the electrical feedthrough of the inner tool portion 30 when the downhole tubing cutter assembly 10 is assembled in use. The electrical feedthrough of the connection unit 90 may for example extend to the downhole end of the connection unit 90, or extend to a side of the connection unit 90, such that the further downhole tool may be in electrical contact with the inner tool portion 30 through the connection unit 90.

[0189] The connection unit 90 may be coupled mechanically with the further downhole tool by for example threaded connections or a quick connect coupling (not shown).

[0190] When the outer sleeve 20 does not form the downhole end 19 of the downhole tubing cutter tool 1, the downhole tubing cutter tool preferably comprises a curved or tapered ring 16, as shown for example in Figures 14, 15, 18 and 19. In the illustrated examples, the curved or tapered ring 16 is connected to the outer sleeve 20 and moveable together with the outer sleeve 20. In other examples (not shown) the curved or tapered ring 16 is not connected to the outer sleeve 20, or the downhole tubing cutter tool 1 does not comprise a curved or tapered ring 16. In the following is described a method for operating a downhole tubing cutter tool assembly 10, such as a downhole tubing cutter assembly 10. The method comprises cutting a downhole tubular 71 in a wellbore 70. The downhole tubing cutter tool assembly 10 is positioned within the wellbore 70 where the downhole tubular 71 is to be cut. Positioning of the downhole tubing cutter assembly 10 within the wellbore 70 involves the standard running in hole of the downhole tubing cutter assembly 10 as will be easily understood by a person skilled in the art. During such running in hole, the cutting arms 40 are in the retracted position.

[0191] Reference is made to the schematic of a hydraulic circuit of the downhole tubing cutter assembly 10, shown in Figure 21.

[0192] When the downhole tubing cutter assembly 10 is positioned within the wellbore 70 at a desired location, a motor M is started. The motor M is configured for simultaneously rotating the downhole tubing cutter tool 1 and operating a hydraulic pump 501. The hydraulic pump 501 comprises a mechanical through shaft.

[0193] When the motor M starts, the hydraulic pump starts pumping and the first sequence valve 508 stops dumping and connects to the hydraulic circuit. This leads to an increased pressure on an input of a second sequence valve 510. The pressure may be measured by a first pressure sensor 509 on the output of the first sequence valve 508. The pressure on the input of the second sequence valve 510 is increased until the pressure reaches a preset pressure, such that the anchors 506 are deployed.

[0194] When the pressure on the input of the second sequence valve 510 reaches the pre-set pressure, the second sequence valve 510 opens, such that the hydraulic fluid may pass, while holding the pre-set pressure on the input of the second sequence valve 510. The pressure may be measured by a second pressure sensor 511 on an output of the second sequence valve 510.

[0195] The output of the second sequence valve 510 is connected to the proportional relief valve

[0196] 50. The proportional relief valve 50 in the default position dumps the hydraulic fluid to tank, such that the annular pressure chamber 22 does not experience a sufficiently elevated pressure to move the cutting arm 40 from the retracted position 401 to the operational position 405.

[0197] The motor M drives, at the same time as the hydraulic pump, a clutch 502, a first gearbox 503, and a second gearbox 504. The clutch 502, the first gearbox 503 and the second gearbox 504 are connected to the mechanical through shaft. The mechanical through shaft passes through the anchoring unit 95, comprising the anchors 506. An output of the first gearbox 503 comprises an RPM sensor 505 to detect if the clutch 502 disengages. At an output of the second gearbox 504 there is connected the downhole tubing cutter tool 1, such that the motor M drives the rotation of the downhole tubing cutter tool 1.

[0198] The first gearbox 503 and the second gearbox 504 leads to the downhole tubing cutter tool 1 rotating at an RPM less than the RPM of the motor M, and a torque that is higher than the torque of the motor M. Different gearbox ratios of the first gearbox 503 and the second gearbox 504 may be used, to get a desired RPM and torque of the downhole tubing cutter tool 1. The required diameter of the mechanical through shaft may increase as the torque increases. It may therefore be advantageous to increase torque by using two gearboxes, as it may result in the optimal RPM and torque of the downhole tubing cutter tool 1, while keeping the dimensions of the downhole tubing cutter assembly 10 manageable. In other examples (not shown), wherein a higher RPM and lower torque of the downhole tubing cutter tool 1 is desired, only one gearbox may be connected to the mechanical through shaft.

[0199] To monitor the operation, the following may be monitored: RPM of the motor M, torque load of the motor M, RPM of the mechanical through shaft by the RPM sensor 505, the anchor pressure by the first pressure sensor 509, and a cutting arm actuation pressure from the second pressure sensor 511.

[0200] When the anchor pressure, measured by the first pressure sensor 509, is stable, and the downhole tubing cutter tool 1 is rotating, the cutting arms 40 are deployed by sending an electrical control signal to the proportional relief valve 50. The proportional relief valve 50 is configured to, upon receiving the electrical control signal, direct hydraulic fluid towards the annular pressure chamber 22, the pressure of the hydraulic fluid being directed being proportional to the electrical control signal. The pressure inside the annular pressure chamber 22 controls the actuation of the cutting arms 40 as previously explained. The deployment of the cutting arms 40 may therefore be controlled by the electrical control signal. The deployment of the cutting arms 40 may be measured by the linear position sensor 80. The cutting arms 40 may be slowly moved from the retracted position 401 to the operational position 405 towards the downhole tubular 71, by increasing the electrical control signal to the proportional relief valve 50.

[0201] As the cutting arms 40 engage with the downhole tubular 71, an increase in the pressure within the annular pressure chamber 22, and thus the actuation pressure of the cutting arms 40, measured by the second pressure sensor 511, may be observed. The torque load of the motor M may also increase.

[0202] To achieve the most effective cutting, the actuation pressure of the cutting arms 40 may be controlled by adjusting the electrical control signal to the proportional relief valve 50 and the torque load of the motor M may be monitored. The progress of the cutting through the downhole tubular 71 may be monitored by the linear position sensor 80.

[0203] If a blade 44 gets stuck in the downhole tubular 71 during the cutting process, the clutch 502 may start slipping and the RPM sensor 505 may measure an RPM value that deviates from the known RPM of the motor M. Even if the clutch 502 slips, the anchors 506 may still be actuated as the hydraulic pump 501 may still be driven by the motor M. The electrical control signal to the proportional relief valve 50 may then be reduced to reduce the actuation pressure of the cutting arms 40. This may allow the downhole tubing cutter tool 1 to rotate normally again. The actuation pressure of the cutting arms 40 may then be increased again.

[0204] In another embodiment (not shown), the anchoring pressure may be set to be within a set range. The anchoring pressure may be maintained within the set range. The method may further comprise checking if the anchoring pressure is within the set range. If the anchoring pressure is not within the set range and if it is not possible to provide the anchoring pressure within the set range, the operation may be aborted. The method may comprise checking for anchoring slippage. If anchoring slippage is observed, for example if the downhole tubing cutter assembly 10 is rotating, the anchoring pressure may be increased. If a proper anchoring, without slippage, is not possible to obtain the operation may be aborted.

[0205] The downhole tubing cutter tool 1 may typically be set to rotate with an RPM within a set range, the range being optimised for the specific operation. The method may comprise checking if the RPM of the tubing cutter tool 1 rotation is within the set range. The RPM may be adjusted to achieve an RPM within the set threshold.

[0206] In the present description, the downhole tubing cutter tool is configured such that telescoping the outer sleeve in the uphole direction pivots the at least one cutting arm from the retracted position to the operational position. In an alternative configuration not described herein, the downhole tubing cutter tool may be configured such that telescoping the outer sleeve in the downhole direction pivots the at least one cutting arm from the retracted position to the operational position.

[0207] Although not described in detail in the interest of brevity, it will be understood that the downhole tubing cutter assembly may be run into the wellbore on a wireline. A person skilled in the art will understand the required arrangements to deliver tools into wellbores on wireline. It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0208] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0209] Clauses Clause 1. A downhole tool for running into a downhole tubular in a wellbore and performing a downhole operation; the downhole tool comprising: - an inner tool portion; - an outer sleeve telescopically coupled around the inner tool portion; and - at least one arm pivotably connected to the inner tool portion and moveable between a retracted position and an operational position; wherein the outer sleeve is configured to be telescoped in use in an uphole direction to pivot the at least one arm from the retracted position to the operational position through an outer sleeve opening in the outer sleeve.

[0210] Clause 2. The downhole tool according to clause 1, wherein the outer sleeve is configured to be telescoped in use in a downhole direction to pivot the at least one arm from the operational position to the retracted position through the outer sleeve opening.

[0211] Clause 3. The downhole tool according to clause 2, wherein: the outer sleeve is biased in use towards the downhole end of the downhole tool by a first biasing means providing a first biasing force towards the downhole end; the inner tool portion and the outer sleeve are arranged together to form an annular pressure chamber between the inner tool portion and the outer sleeve such that pressure within the annular pressure chamber applies a force in the uphole direction on the outer sleeve; such that when the force on the outer sleeve created by the pressure inside the annular pressure chamber is greater than the first biasing force of the first biasing means in use, the outer sleeve will telescope in the uphole direction thereby pivoting the at least one arm from the retracted position to the operational position through the outer sleeve opening.

[0212] Clause 4. The downhole tool according to clause 3, wherein the outer sleeve is configured to move the at least one arm from the operational position to the retracted position in use by telescoping of the outer sleeve in the downhole direction when the force in the uphole direction on the outer sleeve created by the pressure inside the annular pressure chamber is less than the first biasing force of the first biasing means in the downhole direction.

[0213] Clause 5. The downhole tool according to clause 3 or 4, wherein the first biasing means comprises a spring located between the outer sleeve and the inner tool portion. Clause 6. The downhole tool according to clause 5, wherein the inner tool portion comprises a first shoulder, and wherein the first biasing means is positioned between the first shoulder and the outer sleeve.

[0214] Clause 7. The downhole tool according to any preceding clause, wherein the at least one arm comprises a first end opposite a second end, and wherein the at least one arm is pivotably connected to the inner tool portion at the first end, and the first end is uphole from the second end.

[0215] Clause 8. The downhole tool according to any preceding clause, wherein the downhole end of the downhole tool comprises a curved or tapered bull nose.

[0216] Clause 9. The downhole tool according to any of clauses 1 to 7, wherein the downhole tool further comprises a curved or tapered ring downhole from the outer sleeve.

[0217] Clause 10. The downhole tool according to clause 8 or 9, wherein the bull nose envelops a part of the outer sleeve, and wherein the bull nose comprises a bull nose opening, wherein the bull nose opening and the outer sleeve opening are at least partially aligned such that the at least one arm may move between the retracted position and the operational position through the outer sleeve opening and the bull nose opening; or the ring envelops a part of the outer sleeve, and wherein the ring comprises a ring opening, wherein the ring opening and the outer sleeve opening are at least partially aligned such that the at least one arm may move between the retracted position and the operational position through the outer sleeve opening and the ring opening.

[0218] Clause 11. The downhole tool according to any of clauses 8 to 10, wherein the bull nose or the ring forms a downhole end of the outer sleeve.

[0219] Clause 12. The downhole tool according to any preceding clause, wherein the outer sleeve opening comprises a first outer sleeve opening shoulder forming the downhole side of the outer sleeve opening, the first outer sleeve opening shoulder being configured to abut a first engagement surface of the at least one arm such that when the outer sleeve is telescoped in the uphole direction in use, the first outer sleeve opening shoulder pivots the at least one arm from the retracted position to the operational position. Clause 13. The downhole tool according to clause 12, wherein the first engagement surface is curved.

[0220] Clause 14. The downhole tool according to any preceding clause, wherein the outer sleeve opening comprises a second outer sleeve opening shoulder forming the uphole side of the outer sleeve opening, the second outer sleeve opening shoulder being configured to abut a second engagement surface of the at least one arm such that when the outer sleeve is telescoped in the downhole direction in use, the second outer sleeve opening shoulder pivots the at least one arm from the operational position to the retracted position through the outer sleeve opening in the outer sleeve.

[0221] Clause 15. The downhole tool according to any of clauses 1 to 13, wherein the outer sleeve opening comprises a pin being configured to abut a third engagement surface of the at least one arm such that when the outer sleeve is telescoped in the downhole direction in use, the pin pivots the at least one arm from the operational position to the retracted position through the outer sleeve opening.

[0222] Clause 16. The downhole tool according to any preceding clause, wherein the at least one arm is at least partially located in the outer sleeve opening when the downhole tool is in the retracted position.

[0223] Clause 17. The downhole tool according to any one of clauses 10 to 16, wherein the at least one arm is at least partially located in the bull nose opening or the ring opening when the downhole tool is in the retracted position.

[0224] Clause 18. The downhole tool according to any one of clauses 3 to 17, further comprising a proportional relief valve in fluid communication with the annular pressure chamber such that the proportional relief valve may control the change in pressure inside the annular pressure chamber in use.

[0225] Clause 19. The downhole tool according to clause 18, further comprising a flow restrictor in a fluid path between the proportional relief valve and the annular pressure chamber, such that the flow restrictor can reduce a flow of a fluid within the fluid path. Clause 20. The downhole tool according to any preceding clause, wherein the outer sleeve further comprising a linear position sensor for monitoring the position of the outer sleeve relative to the inner tool portion.

[0226] Clause 21. The downhole tool according to any preceding clause, wherein the inner tool portion comprises an electrical feedthrough.

[0227] Clause 22. The downhole tool according to any preceding clause, further comprising a locking mechanism configured to selectively prevent telescoping of the outer sleeve relative to the inner tool portion, the locking mechanism being moveable between a locked position in which the outer sleeve cannot telescope relative to the inner tool portion and an unlocked position in which the outer sleeve can telescope relative to the inner tool portion.

[0228] Clause 23. The downhole tool according to clause 22, when dependent on clause 3, or any of clauses 4 to 21 when dependent on clause 3, wherein the locking mechanism comprises: an axially moveable annular piston comprising an oblique piston head section and a radially moveable wedge comprising an oblique wedge head section registered in form with the oblique piston head section; wherein the annular piston is axially moveable between a proximal position and a distal position and is biased towards the proximal position by a second biasing means providing a second biasing force; the wedge is radially moveable between an expanded position wherein the wedge engages the outer sleeve such that the locking mechanism is in the locked position, and a collapsed position wherein the wedge does not engage the outer sleeve such that the locking mechanism is in the unlocked position, wherein the wedge is biased towards the collapsed position by a third biasing means providing a third biasing force; and when the annular piston is in the proximal position the second biasing force is greater than the third biasing force such that the wedge is held in the expanded position; and when the annular piston is in the distal position, the wedge is in the collapsed position; wherein the annular piston comprises a piston pressure surface forming a portion of the annular pressure chamber such that pressure within the annular pressure chamber applies a force on the piston pressure surface; such that in use when the force on the piston pressure surface created by the pressure inside the annular pressure chamber is greater than the second biasing force of the second biasing means, the annular piston will move from the proximal position to the distal position thereby allowing radial movement of the wedge from the expanded position whereby the locking mechanism is locked, to the collapsed position whereby the locking mechanism is unlocked.

[0229] Clause 24. The downhole tool according to clause 22, when dependent on clause 3 or any of clauses 4 to 21 when dependent on clause 3, wherein the locking mechanism comprises: an axially moveable annular piston comprising an oblique piston head section and a radially moveable wedge comprising an oblique wedge head section registered in form with the oblique piston head section; wherein the annular piston is axially moveable between a proximal position and a distal position and is biased towards the proximal position by a second biasing means providing a second biasing force; the wedge is radially moveable between an expanded position wherein the wedge engages the outer sleeve such that the locking mechanism is in the locked position, and a collapsed position wherein the wedge does not engage the outer sleeve such that the locking mechanism is in the unlocked position, wherein the wedge is biased towards the collapsed position by a third biasing means providing a third biasing force; and when the annular piston is in the proximal position the second biasing force is greater than the third biasing force such that the wedge is held in the expanded position; and when the annular piston is in the distal position, the wedge is in the collapsed position; wherein the inner tool portion and the outer sleeve are arranged together to form a further annular pressure chamber between the inner tool portion and the outer sleeve, and wherein the annular piston comprises a piston pressure surface forming a portion of the further annular pressure chamber such that pressure within the further annular pressure chamber applies a force on the piston pressure surface; such that in use when the force on the piston pressure surface created by the pressure inside the further annular pressure chamber is greater than the second biasing force of the second biasing means, the annular piston will move from the proximal position to the distal position thereby allowing radial movement of the wedge from the expanded position whereby the locking mechanism is locked, to the collapsed position whereby the locking mechanism is unlocked. Clause 25. The downhole tool according to any of clauses 23 or 24, wherein the second biasing means comprises a spring.

[0230] Clause 26. The downhole tool according to any of clauses 23 to 25, wherein the third biasing means comprises a garter spring.

[0231] Clause 27. The downhole tool according to any of clauses 23 to 26, wherein the outer sleeve comprises a radially inwards facing edge that is registered to engage the wedge when the wedge is in the expanded position.

[0232] Clause 28. The downhole tool according to any of clauses 23 to 27, wherein the annular piston is axially moveable from the proximal position to the distal position in the downhole direction, and from the distal position to the proximal position in the uphole direction.

[0233] Clause 29. A downhole assembly comprising a downhole tool according to any preceding clause arranged within a bottom hole assembly.

[0234] Clause 30. A downhole assembly according to clause 29, wherein the downhole assembly comprises a means for rotating the downhole tool.

[0235] Clause 31. A downhole assembly according to clause 30, wherein the means for rotating the downhole tool is a motor.

[0236] Clause 32. The downhole assembly according to any of clauses 29 to 31, the downhole assembly further comprising an anchoring unit configured for anchoring the downhole assembly inside the wellbore.

[0237] Clause 33. The downhole assembly according to any of clauses 29 to 32, when dependent on clause 21, further comprising a connection unit coupled to the electrical feedthrough of the inner tool portion, the connection unit being configured to electrically and / or mechanically connect a further downhole tool to the downhole assembly.

[0238] Clause 34. The downhole assembly according to clause 33, further comprising a measurement tool, logging tool or a plug setting tool coupled with the connection unit. Clause 35. A method of deploying an arm of a downhole tool, comprising the steps of: providing a downhole tool according to any of clauses 1 to 21; and telescoping the outer sleeve in the uphole direction to pivot the at least one arm from the retracted position to the operational position.

[0239] Clause 36. A method of deploying and retracting an arm of a downhole tool, comprising the steps of: providing a downhole tool according to any one of clauses 2 to 21; telescoping the outer sleeve in the uphole direction to pivot the at least one arm from the retracted position to the operational position; and telescoping the outer sleeve in the downhole direction to pivot the at least one arm from the operational position to the retracted position.

[0240] Clause 37. A method of deploying a locked downhole tool and unlocking and deploying an arm, comprising the steps of: providing a downhole tool according to any of clauses 22 to 28; and running the downhole tool into a downhole tubular with the locking mechanism in the locked position; unlocking the locking mechanism; and telescoping the outer sleeve in the uphole direction to pivot the at least one arm from the retracted position to the operational position.

[0241] Clause 38. A method of operating a downhole tool, comprising the steps of: providing a downhole tool according to any of clauses 22 to 28 when dependent on clause 2; running the downhole tool into a downhole tubular with the locking mechanism in the locked position; unlocking the locking mechanism; telescoping the outer sleeve in the uphole direction to pivot the at least one arm from the retracted position to the operational position; and telescoping the outer sleeve in the downhole direction to pivot the at least one arm from the operational position to the retracted position.

[0242] Clause 39. The method according to clause 38, further comprising the steps of: locking the locking mechanism; running the downhole tool out of the downhole tubular with the locking mechanism in the locked position.

[0243] Clause 40. A method of deploying a downhole assembly within a downhole tubular, comprising the steps of providing a downhole assembly according to clause 32; running the downhole assembly into a downhole tubular with the at least one arm in the retracted position; locating the downhole assembly at a desired location within the downhole tubular; anchoring the downhole assembly at the desired location; telescoping the outer sleeve in the uphole direction to pivot the at least one arm from the retracted position to the operational position.

[0244] Clause 41. The method according to clause 40, further comprising the step of rotating the downhole tool.

[0245] Clause 42. The method according to clause 40 or 41, wherein, prior to and / or during the step of anchoring the downhole assembly within the downhole tubular, the method com- prises a step of rotating the downhole tool.

[0246] Clause 43. The method according to any of clauses 40 to 42, wherein, prior to and / or during the step of telescoping the outer sleeve in the uphole direction, the method comprises a step of rotating the downhole tool.

Claims

C l a i m s1. A downhole tubing cutter tool (1) for running into a downhole tubular (71) in a wellbore (70) and separating an upper portion of the downhole tubular (71) from a lower portion of the downhole tubular (71), the downhole tubing cutter tool (1) comprising:- an inner tool portion (30);- an outer sleeve (20) telescopically coupled around the inner tool portion (30); and- at least one cutting arm (40) pivotably connected to the inner tool portion (30) and moveable between a retracted position (401) and an operational position (405); wherein the outer sleeve (20) is configured to be telescoped in use in an uphole direction (XI) to pivot the at least one cutting arm (40) from the retracted position (401) to the operational position (405) through an outer sleeve opening (21) in the outer sleeve (20).

2. The downhole tubing cutter tool (1) according to claim 1, wherein the outer sleeve(20) is configured to be telescoped in use in a downhole direction (X2) to pivot the at least one cutting arm (40) from the operational position (405) to the retracted position (401) through the outer sleeve opening (21).

3. The downhole tubing cutter tool (1) according to claim 2, wherein: the outer sleeve (20) is biased in use towards the downhole end (19) of the downhole tubing cutter tool (1) by a first biasing means providing a first biasing force towards the downhole end (19); the inner tool portion (30) and the outer sleeve (20) are arranged together to form an annular pressure chamber (22) between the inner tool portion (30) and the outer sleeve (20) such that pressure within the annular pressure chamber (22) applies a force in the uphole direction (XI) on the outer sleevesuch that when the force on the outer sleeve (20) created by the pressure inside the annular pressure chamber (22) is greater than the first biasing force of the first biasing means in use, the outer sleeve (20) will telescope in the uphole direction (XI) thereby pivoting the at least one cutting arm (40) from the retracted position (401) to the operational position (405) through the outer sleeve opening (21).

4. The downhole tubing cutter tool (1) according to claim 3, wherein the outer sleeve(20) is configured to move the at least one cutting arm (40) from the operational position (405) to the retracted position (401) in use by telescoping of the outer sleeve (20) in the downhole direction (X2) when the force in the uphole direction (XI) on the outer sleeve (20) created by the pressure inside the annular pressure chamber (22) is less than the first biasing force of the first biasing means in the downhole direction (X2).

5. The downhole tubing cutter tool (1) according to 3 or 4, wherein the first biasing means comprises a spring (23) located between the outer sleeve (20) and the inner tool portion (30).

6. The downhole tubing cutter tool (1) according to claim 5, wherein the inner tool portion (30) comprises a first shoulder (32), and wherein the first biasing means is positioned between the first shoulder (32) and the outer sleeve (20).

7. The downhole tubing cutter tool (1) according to any preceding claim, wherein the at least one cutting arm (40) comprises a first end (41) opposite a second end (42), and wherein the at least one cutting arm (40) is pivotably connected to the inner tool portion (30) at the first end (41), and the first end (41) is uphole from the second end (42).

8. The downhole tubing cutter tool (1) according to any preceding claim, wherein the downhole end (19) of the downhole tubing cutter tool (1) comprises a curved or tapered bull nose (15).

9. The downhole tubing cutter tool (1) according to any of claims 1 to 7, wherein the downhole tubing cutter tool (1) further comprises a curved or tapered ring (16) downhole from the outer sleeve (20).

10. The downhole tubing cutter tool (1) according to claim 8 or 9, wherein the bull nose (15) envelops a part of the outer sleeve (20), and wherein the bull nose (15) comprises a bull nose opening (155), wherein the bull nose opening (155) and the outer sleeve opening (21) are at least partially aligned such that the at least one cutting arm (40) may move between the retracted position (401) and the operational position (405) through the outer sleeve opening (21) and the bull nose opening (155); or the ring (16) envelops a part of the outer sleeve (20), and wherein the ring (16) comprises a ring opening (165), wherein the ring opening (165) and the outer sleeve opening (21) are at least partially aligned such that the at least one cutting arm (40) may move between the retracted position (401) and the operational position (405) through the outer sleeve opening (21) and the ring opening (165).

11. The downhole tubing cutter tool (1) according to any of claims 8 to 10, wherein the bull nose (15) or the ring (16) is located at a downhole end of the outer sleeve (20).

12. The downhole tubing cutter tool (1) according to any preceding claim, wherein the outer sleeve opening (21) comprises a first outer sleeve opening shoulder (215) forming the downhole side of the outer sleeve opening (21), the first outer sleeve opening shoulder (215) being configured to abut a first engagement surface (430) of the at least one cutting arm (40) such that when the outer sleeve (20) is telescoped in the uphole direction (XI) in use, the first outer sleeve opening shoulder (215) pivots the at least one cutting arm (40) from the retracted position (401) to the operational position (405).

13. The downhole tubing cutter tool (1) according to claim 12, wherein the first engagement surface (430) is curved.

14. The downhole tubing cutter tool (1) according to any preceding claim, wherein the outer sleeve opening (21) comprises a second outer sleeve opening shoulder (210) forming the uphole side of the outer sleeve opening (21), the second outer sleeve opening shoulder (210) being configured to abut a second engagement surface (435) of the at least one cutting arm (40) such that when the outer sleeve (20) is telescoped in the downhole direction (X2) in use, the second outer sleeve opening shoulder (210) pivots the at least one cutting arm (40) from the operational position (405) to the retracted position (401) through the outer sleeve opening (21) in the outer sleeve (20).

15. The downhole tubing cutter tool (1) according to any of claims 1 to 13, wherein the outer sleeve opening (21) comprises a pin (219) being configured to abut a third engagement surface (437) of the at least one cutting arm (40) such that when the outer sleeve (20) is telescoped in the downhole direction (X2) in use, the pin (219) pivots the at least one cutting arm (40) from the operational position (405) to the retracted position (401) through the outer sleeve opening (21).

16. The downhole tubing cutter tool (1) according to any preceding claim, wherein the at least one cutting arm (40) is at least partially located in the outer sleeve opening (21) when the downhole tubing cutter tool (1) is in the retracted position (401).

17. The downhole tubing cutter tool (1) according to any one of claims 10 to 16, wherein the at least one cutting arm (40) is at least partially located in the bull nose opening (155) or the ring opening (165) when the downhole tubing cutter tool (1) is in the retracted position (401).

18. The downhole tubing cutter tool (1) according to any one of claims 3 to 17, further comprising a proportional relief valve (50) in fluid communication with theannular pressure chamber (22) such that the proportional relief valve (50) may control the change in pressure inside the annular pressure chamber (22) in use.

19. The downhole tubing cutter tool (1) according to claim 18, further comprising a flow restrictor (51) in a fluid path between the proportional relief valve (50) and the annular pressure chamber (22), such that the flow restrictor (51) can reduce a flow of a fluid within the fluid path.

20. The downhole tubing cutter tool (1) according to any preceding claim, the outer sleeve (20) further comprising a linear position sensor (80) for monitoring the position of the outer sleeve (20) relative to the inner tool portion (30).

21. The downhole tubing cutter tool (1) according to any preceding claim, the inner tool portion comprises an electrical feedthrough (91).

22. The downhole tubing cutter tool (1) according to any preceding claim, further comprising a locking mechanism (60) configured to selectively prevent telescoping of the outer sleeve (20) relative to the inner tool portion (30), the locking mechanism being moveable between a locked position in which the outer sleeve (20) cannot telescope relative to the inner tool portion (30) and an unlocked position in which the outer sleeve (20) can telescope relative to the inner tool portion (30).

23. The downhole tubing cutter tool (1) according to claim 22, when dependent on claim 3, or any of claims 4 to 21 when dependent on claim 3, wherein the locking mechanism (60) comprises: an axially moveable annular piston (61) comprising an oblique piston head section (610) and a radially moveable wedge (64) comprising an oblique wedge head section (640) registered in form with the oblique piston head section (610);wherein the annular piston (61) is axially moveable between a proximal position and a distal position and is biased towards the proximal position by a second biasing means (62) providing a second biasing force; the wedge (64) is radially moveable between an expanded position wherein the wedge (64) engages the outer sleeve (20) such that the locking mechanism (60) is in the locked position, and a collapsed position wherein the wedge (60) does not engage the outer sleeve (20) such that the locking mechanism (60) is in the unlocked position, wherein the wedge (60) is biased towards the collapsed position by a third biasing means (65) providing a third biasing force; and when the annular piston (61) is in the proximal position the second biasing force is greater than the third biasing force such that the wedge (64) is held in the expanded position; and when the annular piston (61) is in the distal position, the wedge (64) is in the collapsed position; wherein the annular piston (61) comprises a piston pressure surface (611) forming a portion of the annular pressure chamber (22) such that pressure within the annular pressure chamber (22) applies a force on the piston pressure surface (611); such that in use when the force on the piston pressure surface (611) created by the pressure inside the annular pressure chamber (22) is greater than the second biasing force of the second biasing means (62), the annular piston (61) will move from the proximal position to the distal position thereby allowing radial movement of the wedge (64) from the expanded position whereby the locking mechanism (60) is locked, to the collapsed position whereby the locking mechanism is unlocked (60).

24. The downhole tubing cutter tool (1) according to claim 22, when dependent on claim 3 or any of claims 4 to 21 when dependent on claim 3, wherein the locking mechanism (60) comprises:an axially moveable annular piston (61) comprising an oblique piston head section (610) and a radially moveable wedge (64) comprising an oblique wedge head section (640) registered in form with the oblique piston head section (610); wherein the annular piston (61) is axially moveable between a proximal position and a distal position and is biased towards the proximal position by a second biasing means (62) providing a second biasing force; the wedge (64) is radially moveable between an expanded position wherein the wedge (64) engages the outer sleeve (20) such that the locking mechanism (60) is in the locked position, and a collapsed position wherein the wedge (60) does not engage the outer sleeve (20) such that the locking mechanism (60) is in the unlocked position, wherein the wedge (60) is biased towards the collapsed position by a third biasing means (65) providing a third biasing force; and when the annular piston (61) is in the proximal position the second biasing force is greater than the third biasing force such that the wedge (64) is held in the expanded position; and when the annular piston (61) is in the distal position, the wedge (64) is in the collapsed position; wherein the inner tool portion (30) and the outer sleeve (20) are arranged together to form a further annular pressure chamber between the inner tool portion (30) and the outer sleeve (20), and wherein the annular piston (61) comprises a piston pressure surface forming a portion of the further annular pressure chamber such that pressure within the further annular pressure chamber applies a force on the piston pressure surface; such that in use when the force on the piston pressure surface created by the pressure inside the further annular pressure chamber is greater than the second biasing force of the second biasing means (62), the annular piston (61) will move from the proximal position to the distal position thereby allowingradial movement of the wedge (64) from the expanded position whereby the locking mechanism is locked, to the collapsed position whereby the locking mechanism is unlocked.

25. The downhole tubing cutter tool (1) according to any of claims 23 or 24, wherein the second biasing means comprises a spring (62).

26. The downhole tubing cutter tool (1) according to any of claims 23 to 25, wherein the third biasing means comprises a garter spring (65).

27. The downhole tubing cutter tool (1) according to any of claims 23 to 26, wherein the outer sleeve (20) comprises a radially inwards facing edge (66) that is registered to engage the wedge (64) when the wedge (64) is in the expanded position.

28. The downhole tubing cutter tool (1) according to any of claims 23 to 27, wherein the annular piston (61) is axially moveable from the proximal position to the distal position in the downhole direction (X2), and from the distal position to the proximal position in the uphole direction (XI).

29. A downhole tubing cutter assembly (10) comprising a downhole tubing cutter tool(1) according to any preceding claim arranged within a bottom hole assembly.

30. A downhole tubing cutter assembly (10) according to claim 29, wherein the downhole tubing cutter assembly (10) comprises a means for rotating the downhole tubing cutter tool (1).

31. A downhole tubing cutter assembly (10) according to claim 29, wherein the means for rotating the downhole tubing cutter tool (1) is a motor.

32. The downhole tubing cutter assembly (10) according to any of claims 28 to 30, the downhole tubing cutter assembly (10) further comprising an anchoring unit (95) configured for anchoring the downhole tubing cutter assembly (10) inside the wellbore (70).

33. The downhole tubing cutter assembly (10) according to any of claims 29 to 32, when dependent on claim 21, further comprising a connection unit (90) coupled to the electrical feedthrough (91) of the inner tool portion (30), the connection unit (90) being configured to electrically and / or mechanically connect a further downhole tool to the downhole tubing cutter assembly (10).

34. The downhole tubing cutter assembly (10) according to claim 33, further comprising a measurement tool, logging tool, or a plug setting tool coupled with the connection unit (90).

35. A method of deploying a cutting arm (40) of a downhole tubing cutter tool (1), comprising the steps of: a. providing a downhole tubing cutter tool (1) according to any of claims 1 to 21; and b. telescoping the outer sleeve (20) in the uphole direction (XI) to pivot the at least one cutting arm (40) from the retracted position (401) to the operational position (405).

36. A method of deploying and retracting a cutting arm (40) of a downhole tubing cutter tool (1), comprising the steps of: a. providing a downhole tubing cutter tool (1) according to any one of claim 2 to 21; b. telescoping the outer sleeve (20) in the uphole direction (XI) to pivot the at least one cutting arm (40) from the retracted position (401) to the operational position (405); and c. telescoping the outer sleeve (20) in the downhole direction (X2) to pivot the at least one cutting arm (40) from the operational position (405) to the retracted position (401).

37. A method of deploying a locked downhole tubing cutter tool (1) and unlocking and deploying a cutting arm (40), comprising the steps of: a. providing a downhole tubing cutter tool (1) according to any of claims22 to 28; and b. running the downhole tubing cutting tool (1) into a downhole tubular(71) with the locking mechanism (60) in the locked position; c. unlocking the locking mechanism (60); and d. telescoping the outer sleeve (20) in the uphole direction (XI) to pivot the at least one cutting arm (40) from the retracted position (401) to the operational position (405).

38. A method of operating a downhole tubing cutter tool (1), comprising the steps of: a. providing a downhole tubing cutter tool (1) according to any of claims22 to 28 when dependent on claim 2; b. running the downhole tubing cutting tool (1) into a downhole tubular(71) with the locking mechanism (60) in the locked position; c. unlocking the locking mechanism (60); d. telescoping the outer sleeve (20) in the uphole direction (XI) to pivot the at least one cutting arm (40) from the retracted position (401) to the operational position (405); and e. telescoping the outer sleeve (20) in the downhole direction (X2) to pivot the at least one cutting arm (40) from the operational position (405) to the retracted position (401).

39. The method according to claim 38, further comprising the steps of: f. locking the locking mechanism (60);g. running the downhole tubing cutting tool (1) out of the downhole tubular (71) with the locking mechanism (60) in the locked position.

40. A method of cutting a downhole tubular (71), comprising the steps of: a. providing a downhole tubing cutter tool (1) according to any of claims 1 to 21; b. running the downhole tubing cutter tool (1) into a downhole tubular(71) with the at least one cutting arm (40) in the retracted position (401); c. locating the downhole tubing cutter tool (1) at a desired cut location within the downhole tubular (71); d. telescoping the outer sleeve (20) in the uphole direction (XI) to pivot the at least one cutting arm (40) from the retracted position (401) to the operational position (405) thereby engaging the at least one cutting arm (40) with the downhole tubular (71) to be cut; and e. rotating the downhole tubing cutter tool (1) to cut the downhole tubular(71).

41. A method of cutting and separating a downhole tubular (71), comprising the steps of: a. providing a downhole tubing cutter tool (1) according to any of claims 1 to 21; b. running the downhole tubing cutter tool (1) into a downhole tubular(71) with the at least one cutting arm (40) in the retracted position (401); c. locating the downhole tubing cutter tool (1) at a desired cut location within the downhole tubular (71);d. telescoping the outer sleeve (20) in the uphole direction (XI) to pivot the at least one cutting arm (40) from the retracted position (401) to the operational position (405) thereby engaging the at least one cutting arm (40) with the downhole tubular (71) to be cut; and e. rotating the downhole tubing cutter tool (1) to cut and separate the downhole tubular (71).

42. The method according to any of claims 35 to 38 or 40 to 41, wherein the step of telescoping the outer sleeve (20) in the uphole direction (XI) further comprises rotating the downhole tubing cutter tool (1).

43. A method of cutting and logging a downhole tubular (71), comprising the steps of: a. providing a downhole tubing cutter assembly (10) according to claim 34; b. running the downhole tubing cutter assembly (10) into the downhole tubular (71) with the at least one cutting arm (40) in the retracted position (401); c. locating the downhole tubing cutter tool (1) at a desired cut location within the downhole tubular (71); d. telescoping the outer sleeve (20) in the uphole direction (XI) to pivot the at least one cutting arm (40) from the retracted position (401) to the operational position (405) thereby engaging the at least one cutting arm (40) with the downhole tubular (71) to be cut; and e. rotating the downhole tubing cutter tool (1) to cut the downhole tubular(71); f. operating the measurement tool or the logging tool to gather data about the downhole tubular (71).

44. The method according to claim 43, wherein step e and f are performed simultaneously.

45. The method according to claim 44, wherein step d, e and f are performed simultaneously.

46. The method according to any of claims 43 to 45, wherein step a is providing a downhole tubing cutter assembly (10) according to claim 34 when dependent on claim 32, and wherein step c comprises a step of anchoring the downhole tubing cutter assembly (10) within the downhole tubular (71).

47. A method of deploying a downhole tubing cutter assembly (10) within a downhole tubular (71), comprising the steps of: a. providing a downhole tubing cutter assembly (10) according to claim 32; b. running the downhole tubing cutter assembly (10) into a downhole tubular (71) with the at least one cutting arm (40) in the retracted position (401); c. locating the downhole tubing cutter assembly (10) at a desired location within the downhole tubular (71); d. anchoring the downhole tubing cutter assembly (10) at the desired location; and e. telescoping the outer sleeve (20) in the uphole direction (XI) to pivot the at least one cutting arm (40) from the retracted position (401) to the operational position (405).

48. A method of deploying a downhole tubing cutter assembly (10) within a downhole tubular (71) and cutting the downhole tubular (71), the method comprising the steps of: a. providing a downhole tubing cutter assembly (10) according to claim 32; b. running the downhole tubing cutter assembly (10) into a downhole tubular (71) with the at least one cutting arm (40) in the retracted position (401);c. locating the downhole tubing cutter assembly (10) at a desired cut location within the downhole tubular (71); d. anchoring the downhole tubing cutter assembly (10) at the desired location; e. telescoping the outer sleeve (20) in the uphole direction (XI) to pivot the at least one cutting arm (40) from the retracted position (401) to the operational position (405) thereby engaging the at least one cutting arm (40) with the downhole tubular (71) to be cut; and f. rotating the downhole tubing cutter tool (1) to cut the downhole tubular (71);49. The method according to any one of claims 46 to 48, wherein, prior to and / or during the step of anchoring the downhole tubing cutter assembly (10) within the downhole tubular (71), the method comprises a step of rotating the downhole tubing cutter tool (1).

50. The method according to any one of claims 43 to 49, wherein, prior to and / or during the step of telescoping the outer sleeve (20) in the uphole direction (XI), the method comprises a step of rotating the downhole tubing cutter tool (1).

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