The present invention relates to a downhole method for preparing and/or providing isolation at a predetermined position in an existing well having a top and a first well tubular metal structure arranged in a wellbore, the first well tubular metal structure having a longitudinal extension. The invention also relates to a downhole system for performing the downhole method.
In Australia and Brazil, existing wells do not perform as intended and the production of hydrocarbon-containing fluid consequently dwindles from a specific well, or a well produces a high content of water, it is necessary for the operator to abandon the well in a safe way, which is to remove the inner production string to create access before cementing. However, in some of these wells, the inner production string is surrounded by an outer production string, i.e. the completion is double-cased, and a control line or hydraulic tube may run on the outside of the inner production string. Both the inner and outer production strings need to be at least partly removed in order for the cement to gain access, and if a control line is present, the line needs to be removed as well since fluid may flow along the line in the cement and cause a leak. In order for the cement to gain access, the inner production string is pulled out and so is the control line as it is clamped to the inner production string, and subsequently the outer production string is pulled out and cement is poured down, filling up at least 30 metres of the well above a plug. This is an expensive operation as a big rig is required for pulling out such production strings.
It is an object of the present invention to wholly or partly overcome the above disadvantages and drawbacks of the prior art. More specifically, it is an object to provide an improved downhole method capable of providing abandonment of the well in a simpler, less expensive and regulatorily compliant manner.
The above objects, together with numerous other objects, advantages and features, which will become evident from the below description, are accomplished by a solution in accordance with the present invention by a downhole method for preparing and/or providing isolation at a predetermined position in an existing well having a top and a first well tubular metal structure arranged in a wellbore, the first well tubular metal structure having a longitudinal extension, comprising:
Furthermore, the downhole method may further comprise leaving the first part of the first section of the first well tubular metal structure in the well.
By the leaving the cut out first part of the first section of the first well tubular metal structure in the well, the uncased opening can be made anywhere in the well without spending time on taking the upper of the well tubular metal structure out the well first nor this first part of out the well. Thus, this method provides a much faster way of plugging and abandoning a well and this method also provides a much cheaper way of plugging and abandoning the well. Especially the cost is very important as when making the well, i.e. drilling the borehole, completing the well etc., the operator has to deposit money for the plugging and abandoning the well in the event that the operator does not have the funds to do so when needed many years later. Therefore, if the operator can present a plugging and abandoning method which cost less than conventional methods, the operator can reduce the deposit amount accordingly. Conventional method pulls out the part of the completion/well tubular metal structure being above the position where the barrier is to be set and thus spends a lot of money in doing so.
Moreover, the downhole method may further comprise:
Further, the downhole method may also comprise:
Also, the downhole method may further comprise pouring cement in the upper part onto the barrier and through the uncased opening.
In addition, separating the first section from the second section may comprise machining part of the first well tubular metal structure over a predetermined distance along the longitudinal extension.
Furthermore, the downhole method may also comprise:
Moreover, separating the first section from the second section may comprise moving the first section away from the second section after the machining.
Further, separating the first section from the second section may comprise pulling the first section out of the borehole after the machining.
Also, separating the first section from the second section may further comprise inserting the first section in the borehole at a distance from the second section.
In addition, inserting the annular barrier may be performed by the downhole tool or another downhole tool.
Furthermore, inserting the unexpanded annular barrier may be performed by mounting the unexpanded annular barrier at an end of the first section.
Moreover, the annular barrier may comprise a tubular metal part and an expandable metal sleeve connected with and surrounding the tubular metal part, providing an annular space between the tubular metal structure and the expandable metal sleeve, the tubular metal part having an expansion opening.
Additionally, the tubular metal part may have a closed end furthest away from the top of the well.
Furthermore, the tubular metal part may have ball seat for receiving a ball before pouring of cement.
Further, the annular barrier may comprise an expandable metal sleeve.
Also, a control line or hydraulic tube may extend along the longitudinal extension outside the first well tubular metal structure, and the step of separating a first section of the first well tubular metal structure from a second section may further comprise separating a first part of the control line or hydraulic tube from a second part of the control line or hydraulic tube.
In addition, a second well tubular metal structure may be arranged circumferentially to the first well tubular metal structure, and the step of separating a first section of the first well tubular metal structure from a second section may further comprise separating a first section of the second well tubular metal structure from a second section of the second well tubular metal structure by machining into and along a circumference of the second well tubular metal structure.
Furthermore, a second well tubular metal structure may be arranged circumferentially to the first well tubular metal structure, and the control line or hydraulic tube may be arranged between the first well tubular metal structure and the second well tubular metal structure, the step of separating a first section of the first well tubular metal structure from a second section further comprises separating a first section of the second well tubular metal structure from a second section of the second well tubular metal structure by machining into and along a circumference of the second well tubular metal structure.
Moreover, the step of separating the first and/or second part may be initiated to machining into and along a circumference of the first well tubular metal structure, subsequently stopping the machining when the first and/or second part is separated.
In addition, the downhole tool (machining) may be stopped or deactivated prior to moving the downhole tool a predetermined distance along the longitudinal extension above the predetermined position.
Furthermore, the predetermined position may be a first determined position, the “separating a first part of the first section of the first well tubular metal structure from a second part of the first section of the first well tubular metal structure” being performed at a second predetermined position, and the downhole tool being inactive while being moved from the first predetermined position to the second predetermined position.
Additionally, the downhole tool may be stopped when one portion of the well tubular structure has been separated from a second part of the well tubular structure.
Moreover, the first part of the control line or hydraulic tube may be separated from the second part of the control line or hydraulic tube by projecting the bit on the projection part further outwards in a radial direction.
Further, the first section of the second well tubular metal structure may be separated from a second section of the second well tubular metal structure by projecting the bit on the projectable element further outwards in a radial direction.
Also, a sleeve may be arranged circumferentially to the first well tubular metal structure, and the step of separating a first section of the first well tubular metal structure from a second section may further comprise separating a first section of the sleeve from a second section of the sleeve.
In addition, expanding the annular barrier may be performed by expanding the tubular metal part and/or the expandable metal sleeve.
Furthermore, expanding the annular barrier may be performed by means of a mandrel and/or an expandable bladder.
Moreover, the expandable metal sleeve may be radially expanded between the first section and the second section to abut the wall of the borehole.
Further, the annular barrier may have a first barrier end and a second barrier end, the first barrier end being configured to overlap the first section, and the second barrier end being configured to overlap the second section.
Also, the downhole method may further comprise providing second zonal isolation at a second predetermined position in the annulus between the wall of the borehole and the well tubular metal structure.
Additionally, the invention relates to a downhole system for performing the downhole method to provide zonal isolation at a predetermined position in a borehole and another well tubular metal structure having a longitudinal extension in an existing well, comprising:
The present invention also relates to a downhole system for performing the downhole method according to any of the preceding claims to provide zonal isolation at a predetermined position in the borehole and another well tubular metal structure having a longitudinal extension in an existing well, comprising:
Moreover, the bit may comprise a first segment of abrasive material.
In addition, the bit may be movable between a retracted position and a projected position in relation to the first housing part of the tool housing.
The downhole tool may be a downhole tubing intervention tool for submerging into a casing in a wellbore and for selectively removing material from within the casing, the tool extending in a longitudinal direction, comprising:
wherein the first segment is movable between a retracted position and a projected position in relation to the first housing part of the tool housing.
When having large-diameter wells and the outer diameter of the tool is restricted by a restriction further up the casing than where the operation is to take place, the segment needs to be projected further out than in small-diameter casings, and then there will be a high risk that vibrations will knock off pieces of the segment during the machining operation for removing material, but when the segment is made of abrasive material, new grains come forward, and the removal operation can proceed.
In other situations, the downhole tubing intervention tool is submerged into a casing which is surrounded by a sleeve or a second casing, and the downhole tubing intervention tool needs to selectively remove material from within the casing to separate both the casing and the sleeve or the second casing. This is not possible if the separation of the first casing destroys the segment as the segment then cannot separate the second casing or the sleeve. However, when the segment is of an abrasive material which, when worn, merely reduces in size and new particles in the segment are exposed, the separation operation can easily proceed with success as the segment is merely projected a bit further for compensating for the reduced size of the segment.
Thus, the segment may be an abrasive segment.
Furthermore, the segment may be a grinding segment.
Also, the segment may be a grinding stone.
Additionally, the first segment of abrasive material may be a non-chip-producing material.
Further, the first segment may be made of a non-chip-producing material.
The first segment may be hydraulically movable between a retracted position and a projected position in relation to the first housing part of the tool housing.
By having a hydraulically operated part activation assembly, the segment can be projected continuously outwards as the segment is worn so that the size-reduced segment is still able to contact the casing, thus continuing the removal operation.
In addition, the tool may further comprise a gear section arranged between the rotation unit and the first housing part.
Moreover, the at least first segment of abrasive material may comprise grains of diamond or Cubic Boron Nitride, aluminium oxide (corundum), silicon carbide, tungsten carbide or ceramic.
Further, the downhole tubing intervention tool may comprise a second segment arranged at a distance from the first segment along a circumference of the tool.
Also, the at least first segment of abrasive material may comprise a binder, such as iron, cobalt, nickel, bronze, brass, tungsten carbide, ceramic, resin, epoxy or polyester.
Furthermore, the first segment may have a base part and a projection part projecting from the base part, forming a radial tip.
In operation, the radial tip contacts the casing for selectively removing material from the casing, e.g. for separating the casing, and when the segment of an abrasive material is worn during the removal operation, the projection part of the segment is merely reduced in size, and new particles in the segment are exposed. Thus, the separation operation can easily proceed with success as the remaining part of the projection part of the segment is merely projected a bit further for compensating for the reduced size of the segment. When separating a sleeve or a second casing surrounding the first casing, the base part also becomes abrasive, removing further material from the first casing so that the projection part having separated the first casing can project further to also separate the second casing.
Additionally, the first segment may taper from a base part into a terminal end, forming a radial tip.
Moreover, the first segment may taper from a base part into a terminal end, forming a radial tip of the projection part.
Thus, the base part, the radial tip and the projection part may be of abrasive material.
Furthermore, the radial tip may form the abrasive edge.
In addition, the first segment may have a segment length along the longitudinal axis in the retracted position and a segment height perpendicular to the longitudinal axis, the radial tip having a tip length along the longitudinal axis being less than 75% of the segment length, preferably less than 60% of the segment length, and more preferably less than 50% of the segment length.
Further, the segment may have a first segment height at the base part and a second segment height at the radial tip, the second segment height being higher than the first segment height; preferably the second segment height is at least twice as high as the first segment height, and more preferably the second segment height is at least three times as high as the first segment height.
Moreover, the first segment may have a segment width extending along the circumference of the tool.
Furthermore, the segment width may be constant along the segment length.
Also, the segment width may be constant along the segment height.
In addition, the segment width may be smaller at the terminal end than at the base part.
Moreover, the radial tip may have a front face facing away from the second tool housing and a back face facing the second tool housing, and the front face may incline inwards from the terminal end so that the terminal end of the radial tip is the outermost part of the segment.
The segment may have a base face facing the first tool housing and facing away from the terminal end, and the segment may have an angle between the base face and the front face of more than 90°. In this way, the radial tip is more acute than if the front face did not incline inwards or backwards towards the back face.
Also, the tool may further comprise a projection part movable between a retracted position and a projected position in relation to the first housing part of the tool housing, the projection part having a first end and a second end, the second end being movably connected with the first housing part, and the first end being connected with the first segment, and the tool may further comprise a part activation assembly for moving the projection part between the retracted position and the projected position.
Moreover, the projection part may have several segments connected to the first end.
Additionally, the projection part may have a part extension, the segment length of the first segment extending along the part extension, and the segment height extending perpendicularly to the part extension in a radial direction of the tool.
Furthermore, the projection part may pivot between the retracted position and the projected position.
Also, the part activation assembly may comprise:
By having a hydraulically operated part activation assembly, the segment can be projected continuously outwards as the segment is worn so that the size-reduced segment is still able to contact the casing with sufficient weight on bit (WOB), thus continuing the removal operation.
In addition, the part activation assembly may comprise:
Further, the downhole tubing intervention tool may be a downhole tubing separation tool separating an upper part of the casing from a lower part of the casing by abrasively machining the casing from within.
Moreover, the downhole tubing intervention tool may further comprise an anchor section comprising at least one anchor extendable from the tool housing for anchoring the tool in the casing.
In addition, the downhole tubing intervention tool may further comprise a driving unit comprising wheels on wheel arms for propelling the tool forward in the well.
Furthermore, the downhole tubing intervention tool may also comprise a stroking unit, such as a stroking tool, providing a movement of the first segment in the projected position along a longitudinal extension of the well tubular metal structure. Thus, when the downhole tubing intervention tool is submerged into the well tubular metal structure, and the anchor section of the downhole tool is hydraulically activated to anchor the non-rotating part of the downhole tubing intervention tool in relation to the well tubular metal structure, the first segment removes, e.g. by milling or grinding, material from the well tubular metal structure along the circumference and the longitudinal extension of the well tubular metal structure. Thereby, a section of the well tubular metal structure is removed from the well tubular metal structure by grinding the well tubular metal structure into small particles, creating or re-creating annular isolation.
The section removed from the well tubular metal structure may have a length along the longitudinal extension of the well tubular metal structure of more than 0.5 metre, preferably more than 1 metre, and even more preferably more than 5 metres.
Finally, the invention also relates to a downhole system comprising a first well tubular metal structure and the abovementioned downhole tubing intervention tool for arrangement in the downhole system.
The invention and its many advantages will be described in more detail below with reference to the accompanying schematic drawings, which for the purpose of illustration show some non-limiting embodiments and in which:
All the figures are highly schematic and not necessarily to scale, and they show only those parts which are necessary in order to elucidate the invention, other parts being omitted or merely suggested.
The first segment 25 is movable between a retracted position and a projected position by means of hydraulics/hydraulic power. By having a hydraulically operated part activation assembly 11, the first segment 25 can be projected continuously outwards as the segment is worn so that the size-reduced segment is still able to contact the casing 2 with enough weight on bit (WOB), continuing the removal operation.
The downhole tubing intervention tool/downhole tool 1 further comprises a gear section 23 arranged between the rotation unit 20 and the first housing part 7 for changing the rotation of the rotatable shaft 12 so that the first housing part 7 rotates at a lower or higher speed. The downhole tubing intervention tool/downhole tool 1 is a wireline tool, i.e. the tool receives power through a wireline 24. An electrical control unit 69 is arranged between the connection to the wireline 24 and a motor 20 of the tool. The tool also comprises a compensator 60B ensuring a slight overpressure inside the tool. The electric motor both powers a pump 21 and rotates the first housing part 7 and the first segment 25. Even though not shown, the downhole tubing intervention tool/downhole tool 1 may have another motor besides the rotation unit 20 so that one motor drives the pump 21 and another rotates the first housing part 7 and the first segment 25. The downhole tubing intervention tool/downhole tool 1 may further comprise a driving unit 59, such as a downhole tractor comprising wheels 60 on wheel arms 61, for propelling the tool forward in the well in other parts of the well than in the vertical part. The downhole tubing intervention tool/downhole tool 1 is submerged into the well or casing 2 only by the wireline 24, e.g. with another kind of power supply line, such as an optical fibre, and not by tubing, such as coiled tubing, a drill pipe or similar piping.
As shown in
By the leaving the cut out first part of the first section of the first well tubular metal structure in the well, the uncased opening can be made anywhere in the well without spending time on taking the upper of the well tubular metal structure out the well first or this first part of out the well. Thus, this method provides a much faster way of plugging and abandoning a well, and this method also provides a much cheaper way of plugging and abandoning the well. Especially the cost is very important as when making the well, i.e. drilling the borehole, completing the well etc., the operator has to deposit money for the plugging and abandoning the well in the event that the operator does not have the funds to do so when needed many years later. Therefore, if the operator can present a plugging and abandoning method which costs less than conventional methods, and the operator can reduce the deposit amount accordingly. Conventional methods pull out the part of the completion/well tubular metal structure being above the position where the barrier is to be set and thus a lot of money is spent in doing so.
The separation is performed by machining into the casing using abrasive cutting, i.e. grinding, by forcing the first segment 25 against the inner face while rotating the segment and thereby providing a circumferential cut of removed material by means of a non-chip-producing operation. Thereby, the removed material of the casing 2 is only transformed into small particles and not a long chip as is the case with the known cutting tools. It is very difficult to bring such long chips left in the well to the surface, but these chips may be large enough for interacting with intervention tools or completion products later on.
When using a segment, such as an insert, of abrasive material instead of known metal cutting inserts, unintended vibrations do not hinder the machining operation from finishing. When experiencing unintended vibrations, the known metal cutting inserts are damaged as the cutting edge hits against the casing and small fragments are knocked off, the metal cutting inserts no longer having a cutting edge able to cut, and the tool needs to be retracted from the well. When having a segment of abrasive material, small knocked-off fragments will just expose new abrasive grains in the abrasive material, and the grinding process can continue. The segment thus mills or grinds into the element to be removed from the well, e.g. part of the casing wall, a nipple, a sliding sleeve, a no-go, a valve, etc.
In other situations, the downhole tubing intervention tool/downhole tool is submerged into a casing which is surrounded by a sleeve or a second casing as shown in
In
The segment/bit may be an abrasive segment or a grinding segment, such as a grinding stone. The segment of abrasive material is a non-chip-producing material. Thus, the segment is of a non-chip-producing material.
The segment 25 of abrasive material comprises grains of diamond or Cubic Boron Nitride, aluminium oxide (corundum), silicon carbide, tungsten carbide, ceramic or similar material. The segment 25 of abrasive material comprises a binder, such as iron, cobalt, nickel, bronze, brass, tungsten carbide, ceramic, resin, epoxy or polyester.
As shown in
As shown in all the
As can be seen in
The first segment 25 may also be the radial tip 25B tapering from a base part 25A arranged between the base face 77 and the radial tip 25B as shown in
In
The projection part 9 shown in
In
The downhole tubing intervention tool/downhole tool 1 may further comprise a stroking unit (not shown), such as a stroking tool, providing a movement of the first housing part 7 and the first segment 25 in the projected position along a longitudinal extension of the casing 2 or the first well tubular metal structure 2. The stroking unit is arranged between the anchoring section 22 and the first housing part 7 so as to be able to project the first housing part 7 from the anchoring section/anchor section 22. Thus, when the downhole tubing intervention tool/downhole tool 1 is submerged into the casing/first well tubular metal structure 2, and the anchoring section 22 of the downhole tubing intervention tool/downhole tool 1 is hydraulically activated to anchor the first housing part 7 of the downhole tubing intervention tool/downhole tool 1 in relation to the first well tubular metal structure 2, the first segment 25 removes material from the first well tubular metal structure 2 along a circumference and the longitudinal extension of the first well tubular metal structure 2. In that way, a section of the first well tubular metal structure 2 is removed from the first well tubular metal structure 2, thereby grinding a part of the first well tubular metal structure 2 into insignificantly small pieces/particles, creating or re-creating annular isolation. The section removed from the first well tubular metal structure 2 extends all the way around the circumference of the first well tubular metal structure 2 and may have a length along the longitudinal extension of the first well tubular metal structure 2 of more than 0.5 metre, preferably more than 1 metre, and even more preferably more than 5 metres. Thus, removing a section of the casing/first well tubular metal structure 2 provides access to the annulus surrounding the first well tubular metal structure 2 for creating or re-creating annular isolation, i.e. zone isolation in the annulus, or cement can be poured into the annulus, e.g. for Plug and Abandonment (P&A) operations, or an annular barrier may be arranged and expanded opposite the section to provide zone isolation in the annulus.
As shown in
When the projection part 9 is projected to press against an inner face of the casing 2 and is simultaneously rotated by the motor through the rotatable shaft 12, the abrasive edge 10 is capable of milling or grinding through the casing or drill pipe without producing chips, but merely particles. Thereby, it is obtained that the upper part 4 of the casing can be separated from the lower part 5 of the casing by cutting the casing from within without the use of explosives. In
For rotating a rotatable cutting head 110, the downhole tubing intervention tool/downhole tool 1 comprises the rotatable shaft 12 rotated by a motor 20. The rotatable shaft 12 extends through the second housing part 8 and the first housing part 7, and in the first housing part 7, the rotatable shaft 12 provides a rotational input for a gearing assembly 532. For moving the projection part 9 between the retracted position and the projected position, the downhole tubing intervention tool/downhole tool 1 comprises a projection part activation assembly 111. The projection part activation assembly 111 comprises a piston housing 113 arranged in the first housing part 7 and comprising a piston chamber 114. A piston member 115 is arranged inside the piston chamber 114 and engages with an activation element 55 adapted to move the projection part 9 between the retracted position and the projected position. The piston member 115 is movable in a longitudinal direction of the tool and has a first piston face 116. Hydraulic fluid from the hydraulic pump 21 is pumped through a first fluid channel 118 into the piston chamber 114, applying hydraulic pressure on the first piston face 116. The piston moves in a first direction, and the piston member 115 applies a projecting force on the projection part 9. When the piston member 115 moves in the first direction, a spring member 140 abutting the activation element 55 is compressed. To retract the projection part 9 from the projected position (indicated by dotted lines), the supply of hydraulic fluid to the piston chamber 114 is terminated, and the spring member 140 forces the piston member 115 in a second direction opposite the first direction along the longitudinal direction L of the tool.
The spring member 140 may also be arranged inside the piston housing 113, thereby providing a retraction force of the projection part 9. When the piston member 115 moves in the first direction, the spring member 140 is compressed in the piston housing 113. To retract the projection part 9 from the projected position, the supply of hydraulic fluid to the piston chamber 114 is terminated, and the spring member 140 forces the piston member 115 in a second direction opposite the first direction along the longitudinal direction L of the tool.
In
The hydraulic fluid for displacing the piston sleeve 224 is supplied by a hydraulic system separate from the hydraulic system used for supplying the hydraulic pressure for moving the projection part 9 between the retracted position and the projected position. By using two separate hydraulic systems, the projection part 9 and the anchors 221 may be operated independently of one another. For example, the projection part 9 may be retracted if problems occur during the cutting operation, without affecting the position of the tool in the well. Thus, the tool remains stationary in the well, and the projection part 9 may be projected once again to continue the interrupted cutting procedure. Had the tool not been kept stationary during retraction of the projection part 9, it would be difficult to determine the position of the initiated cutting, and the cutting procedure would have to start all over again at a new position. When having to start all over, the abrasive edge or bits 10 on the projection part 9 may have been abraded too much for the tool to be able to cut through the casing 2 at the new position, and the tool may therefore have to be retracted from the well to replace the segment of the projection part 9 in order to be able to cut all the way through the casing 2.
To ensure that the tool does not remain anchored in the well due to a power loss or malfunction of one of the hydraulic systems, the hydraulic system of the anchor section 22 comprises a timer for controlling the supply of hydraulic fluid to the piston chamber 228. When the projection part 9 is retracted, the timer registers/records the time elapsed. Depending on operation-specific parameters, the timer may be set to retract the anchors 221 at any time after retraction of the projection part 9, preferably between 15 and 180 minutes, and more preferably between 30 and 60 minutes after retraction of the projection part 9. When the set time has lapsed, the timer activates a valve which controls the pressure in the piston chamber 228. As the valve is activated, the pressure in the piston chamber 228 drops, and the piston member 115 displaces the piston sleeve 224 to retract the anchors 221. The valve control comprises a battery, and activation of the valve may be powered by the battery if the power to the tool is cut. The anchor arm 222 has an end surface facing the inner face of the casing 2 when being in the projected position, which is serrated to improve the ability of the anchor arm 222 to engage with the inner face of the casing 2. The tool comprises a second pump for driving the separate hydraulic system to activate the anchor system 22. Thus, the rotatable shaft 12 around which the piston sleeve 224 extends may have a fluid channel for supplying fluid to the projection of the projection part 9.
The downhole system 100, shown in
In
The invention also relates to a downhole method for providing isolation at a predetermined position in an existing well 101 having the top 51 and the first well tubular metal structure 2 arranged in a wellbore 3, the first well tubular metal structure having the longitudinal extension L. The downhole method comprises inserting the downhole tubing intervention tool/downhole tool 1 comprising the bit 10 on the projection part 9 in the first well tubular metal structure 2, positioning the downhole tubing intervention tool/downhole tool 1 opposite the predetermined position and separating a first section/upper part 4 of the first well tubular metal structure 2 from a second section/lower part 5 of the first well tubular metal structure 2 by machining into and along a circumference of the first well tubular metal structure 2. Then as shown in
As shown in
In
The abandonment plug 301 has a length of less than 5 metres, and preferably less than 3 metres. The abandonment plug 301 is typically arranged in a well tubular metal structure for stopping cement being poured into the well to provide a cement plug being 30-100 metres long.
As can be seen in
The abandonment plug 301 is typically connected to a workover pipe, a drill pipe (a drill pipe string), coiled tubing or similar disconnectable tubing in order to provide pressurised fluid from the surface to expand the abandonment plug 301 and disconnect when the plug has been set. In another embodiment, the abandonment plug 301 is connected to a wireline tool, as shown in
The abandonment plug 301 of
As shown in
The downhole method according to the invention is thus very useful when a control line or hydraulic tube 38 extends along the longitudinal extension outside the first well tubular metal structure 2, and then the step of separating the first section 4 of the first well tubular metal structure 2 from the second section 5 further comprises separating the first part 38A of the control line or hydraulic tube 38 from the second part 38B of the control line or hydraulic tube 38. This is performed as the projection part 9 is capable of projecting further radially outwards during the machining process and thus when needed. Thus, the first part 38A of the control line or hydraulic tube 38 is separated from the second part 38B of the control line or hydraulic tube 38 by projecting the bit 10 on the projection part 9 further outwards in the radial direction R.
The downhole method according to the invention is thus very useful when a second well tubular metal structure 2B is arranged circumferentially to the first well tubular metal structure 2, as shown in
As shown in
Even though only shown as a second well tubular metal structure 2B, a sleeve could be arranged circumferentially to the first well tubular metal structure 2 in a similar manner, and the step of separating a first section 4 of the first well tubular metal structure 2 from a second section 5 further comprises separating a first section 4 of the sleeve from a second section 5 of the sleeve by projecting the projection part 9 further radially outwards so that the bit 10/first segment 25 cuts or grinds into the sleeve.
The downhole system 100 for performing the abovementioned downhole method to provide zonal isolation at a predetermined position in the borehole 3 or another well tubular metal structure 2 having a longitudinal extension in an existing well comprises the first well tubular metal structure 2 arranged in the borehole 3, a downhole tool 1 inserted in the first well tubular metal structure and positioned opposite the predetermined position for separating several first parts of the first section 4 of the first well tubular metal structure 2 from the second section 5 of the first well tubular metal structure 2 by machining into and along a circumference of the first well tubular metal structure 2, providing an uncased opening and the barrier 220, 301, such as a plug, arranged in the uncased opening between the first section 4 and the second section 5 for providing zonal isolation at the predetermined position before cement is poured down into the first section 25 of the first well tubular metal structure 2.
By “fluid” or “well fluid” is meant any kind of fluid that may be present in oil or gas wells downhole, such as natural gas, oil, oil mud, crude oil, water, etc. By “gas” is meant any kind of gas composition present in a well, completion or open hole, and by “oil” is meant any kind of oil composition, such as crude oil, an oil-containing fluid, etc. Gas, oil and water fluids may thus all comprise other elements or substances than gas, oil and/or water, respectively.
By “casing” or “well tubular metal structure” is meant any kind of pipe, tubing, tubular, liner, string, etc., used downhole in relation to oil or natural gas production.
In the event that the tool is not submergible all the way into the casing 2, a downhole tractor can be used to push the tool all the way into position in the well.
The downhole tractor may have projectable arms having wheels, wherein the wheels contact the inner surface of the casing for propelling the tractor and the tool forward in the casing. A downhole tractor is any kind of driving tool capable of pushing or pulling tools in a well downhole, such as a Well Tractor®.
Although the invention has been described above in connection with preferred embodiments of the invention, it will be evident to a person skilled in the art that several modifications are conceivable without departing from the invention as defined by the following claims.
Number | Date | Country | Kind |
---|---|---|---|
21173677.2 | May 2021 | EP | regional |
21176239.8 | May 2021 | EP | regional |