NO20150624A1

NO20150624A1 - A shrinking tool for shrinkage and recovery of a wellbore tubular.

Info

Publication number: NO20150624A1
Application number: NO20150624A
Authority: NO
Inventors: Mohammad Ali Taghipour Khadrbeik
Original assignee: Sintef Tto As
Priority date: 2015-05-19
Filing date: 2015-05-19
Publication date: 2016-11-21
Also published as: EP3298230A1; EP3298230B1; EP3298230A4; WO2016186517A1

Description

Technical Field

[0001] The invention relates to a complete system for reducing diameter of tubular pipes more precisely it relates to a drill string system for plug and abandoning of wells, the present invention also relates to devices and

methods of such a system.

Background Art

[0002] The invention relates to a complete system for reducing diameter of

tubular pipes.

[0003] For plug and abandonment of oil wells the casing of the well has to be fully or partly removed before plugging. Removal of casing is a demanding task as the casing is normally bonded to concrete in between the underground formation and the casing.

[0004] The present invention enables casing section removal with milling only

parts of a tubular/casing.

[0005] Also for other purposes such as within water and Sewerage it is often of

interest to shrink and remove sections of pipings.

Disclosure of Invention

[0006] According to the present invention it is provided a method and tool for shrinkage and recovery of wellbore tubular, where the tool comprises at least: one forming die arranged along the axis of said wellbore tubular adapted to be pulled relative to tubular from inside. In one aspect of the invention the forming die consist of a c-shape lofted cut inside the tool body with a bigger profile diameter at the inlet and a smaller profile diameter at the outlet.

[0007] According to the invention the forming die may consist of at least one mechanical mean for guiding the tubular into the die, where the mechanical mean will be activated by mean of an actuating system.

[0008] According to another aspect of the invention the recovered tubular section may have at least one helical or straight groove along the longitudinal axis of the tubular.

[0009] Acccording to the present invention it is also provided a shrinking tool which may utilize the method s indicated above and where the shrinking tool is adjacent to a milling tool, where the milling tool is adapted to mill at least one radial groove and at least one axial or helical groove along the longitudinal axis of the tubular.

[0010] The shrinking tool may be pulled by mean of a moving tractor or other means like as wireline or drillstring from inside the tubular.

It is also disclosed a shrinking tool according where the tool comprises at least one anchoring mean for pulling one section of the tubular, where the separated section consist of at least on helical or axial groove along the longitudinal axis of the tubular. Brief description of drawings

[0011] To make the following description more readily understandable the following discussion will make reference to the accompanying drawings in which,

[0012] Figure 1 shows a perspective view of a system according to the present

invention;

[0013] FIG. 2 shows a view of the system according to the present invention;

[0014] FIG. 3 shows a cross sectional view of the system according to the

present invention ;

[0015] FIG. 4 shows a tractor according to the present invention;

[0016] FIG. 5 shows an example of a milling tool/milling section in accordance

with the present invention;

[0017] FIG. 6 shows a forming die according to the present invention;

[0018] Fig. 7 shows a cross sectional view of the entrance portion of the die form;

[0019] FIG. 8 shows the forming die and a casing section with a premade axial

groove;

[0020] Fig. 9 shows the forming die seen in figure 2;

[0021] Fig. 10 shows the forming die, a casing with a premade axial grove and a

shrinked casing;

[0022] Fig. 11 shows a casing with helical grooves and the same in shrinked

version according to one embodiment of the present invention, and

[0023] Fig. 12 shows a casing with helical grooves and the same in shrinked

version according to one embodiment of the present invention.

Detailed descripton of the present invention

[0024] The invention will now be described with reference to the accompanying drawings, which are not to scale, however it shall be understood that the drawings are only meant to facilitate the understanding of the invention and they are in no way limiting the scope of the claimed invention.

[0025] The invention relates to a system 1 for abandoning and plugging of oil wells as well as a system made for shrinking sections of tubular. The system comprises a forming die 15 which can be used in oil, gas and deep water wells, mining and underground operations. The tools enable to shrink a section of a tubular 91 and reduce the diameter. In particular it is disclosed a forming tool integrated in a drillstring 1 for shrinking of the tubular. The system 1 or drillstring 1 comprises the mentioned forming die 15, a milling section 13 including means for milling out helical or axial grooves in tubulars 92 and at least a tractor 10.

[0026] . The forming die 15 according the the present invention can be used to shrink a casing while the drillstring 1 moves axially inside the tubular. This enables to pull out and recover a section of the tubular/casing through the rest of the tubular/casing which remains in the well. In addition, the

forming die 15 reduces the de-bonding force for the tubular from the

cement/formation.

Description of the system according to the present invention

[0027] As indicated above the present invention relates to a system which is adapted to take out sections of casings or sections of pipes. The system 1 will now be described with reference to figure 1. The system 1 which is a drill string or part of a drillstring comprises a tractor 10, a milling section 13 and a forming die section 15.

[0028] The tractor 15 is the front end of the system with reference to the active travel direction that is, when the system 1 is activiely milling and shrinking tubulars or casings. Following the tractor is the milling section 13, the milling section includes at least one cutting tool 14.

[0029] Further up the drill string 1 is the forming die 15, the forming die 15 is adapted to shrink casings or tubulars which already has been prepared by the milling section 13 so that the tubulars or casing has premade axial grooves.

Description of the tractor

[0030] The tractor 10 is the propulsion unit of the drill string, it is shown in detail in figure 4. The tractor comprises two pistons 42, 43 connected with a push pull piston rod 12 therebetween. The push pull piston rod can move the end piston 42 relative to the near piston 43 and the rest of the drill string 1 in an axial direction.

[0031] Moving forward, that is in the X-direction in figure 4 starts with the near piston 43 and the end piston 42 in a retracted position, that is the distance between them are minimal, the near end piston 43 expands its anchor pads 11 to get into a fixed grip with its surrounding such as the casing. The anchor pads 13 of the end piston 42 is in a retracted position. The next step is that the end piston is moved in the x-direction by the piston rod 12. When the end piston 42 is in a maxiumum distance from the near piston 43, the end piston anchor itself to the surrounding walls or casings by expanding its anchor pads 13 radially. Following this step the near piston 43 retracts its anchor pads 11 and the end piston 42 can pull the near piston 43 with its drillstring in the x-direction thereby causing the whole drillstring including the milling section and the die form 15 to move in the x-direction.

The milling section

[0032] The milling section 13 follows the tractor and is inbetween the forming die

15 and the tractor 10.

[0033] The milling section according to a first embodiment shall provide axial grooves in piping-sections or casing sections. As the groove shall be axial the drill string 1 will not rotate around its axis A - A (fig 2). As the tractor 10 provides movement of the drill string 1 the milling section provides axial grooves. One or more side cutters 14 are integrated in the milling section 13. The one or more side cutters rotate around its axis of rotation, where the axis of rotation is substantially normal to the axis A-A and the surrounding walls.

[0034] The cutter 14 or cutters 14 can be retractable and expandable. In its expandable positon with one or more rotating cutters an axial groove will be made in the casing / surrounding tube.

The die form

[0035]

[0036] The die form 1 is shown at the opposite end of the drill string 1 shown in

figure 1, 2 and 3. The figures 6 - 10 shows the forming die 15 in detail.

[0037] According to one embodiment, the forming die has a c-shape entrance opening (fig. 7) which has similar diameter D1 as the tubular 72 in one end and a smaller diameter DB at the exit end. According to this embodiment, while axial movement of the forming dies in the tubular, the tubular is pushed into the C shaped die entrance opening 83 of the forming die 15. While the die 15 moves the tubular is fed into the c-shaped opening (fig 7) and through the die and is shrinked into a reduced diameter when exited from the exiting end of the forming die 15. Thus it shall be noted that the part 63 of the die 15 where the tubular or the casing enters into the c-shaped opening (fig 7) of the die 15 is tapered with an input diameter approximately similar to the tubing D1, and an exit dimater DB, where DB<D1. According to this embodiment, the forming die consists of a mechanical mean 15 for guiding the tubular into the opening entrance of the die. This mechanical mean is an expandable guiding arm 15 which radially expands out of the tool body when needed.

[0038] The following dimension restrictions applies:

[0039] Z1 > Z1

[0040] Z3 and Z1 are approximately of the same length.

[0041] D1 > D2

[0042]

Another embodiment of pulling means

[0043] The forming die 15 and the milling tool 13 are adapted to be pulled by a moving tractor 10 or any other means through the wellbore longitude axis. The other mean for pulling the die can be wire cable or drillstring. According to this embodiment, the milling tool 13 with actively driven side rotational cutters 14 can drill hole and mill axial, helical or radial grooves inside the tubular sidewalls.

[0044] Another embodiment of the inventionThe invention has been described with reference to figure 1-10, this system 1 includes components which together facilitates abandonment and plugging of oil wells and dismantling in Sewerage systems. IN another embodiment of the invention (fig 11 and

12), the milling tool can create at least one helical groove and at least two radial grooves inside the casing downhole in the well. One way of aciewing this is to use a rotational milling tool with one or more rotational side cutters 14. This enables to create a separated casing section from the tubular. According to this embodiment, the separated casing section with

at least one helical groove can be pulled in an axial direction which causes casing shrinkage and de-bonding from the formation cement. According to this embodiment, the separated casing can then be pulled out through the remaining casing inside the well. The separated casing section can be pulled by the moving tractor or other means, for example the drillstring or wire line.

Claims

1. A method and tool for shrinkage and recovery of wellbore tubular, where the tool comprises at least: one forming die arranged along the axis of said wellbore tubular adapted to be pulled relative to tubular from inside.

2. A shrinking tool according to claim 1,characterised in thatthe forming die consist of a c-shape lofted cut inside the tool body with a bigger profile diameter at the inlet and a smaller profile diameter at the outlet.

3. A shrinking tool according to claim 2,characterised in thatthe forming die consist at least one mechanical mean for guiding the tubular into the die, where the mechanical mean will be activated by mean of an actuating system.

4. A method for shrinkage and recovery of a tubular section according to claim 1,characterised in thatthe recovered tubular section may have at least one helical or straight groove along the longitudinal axis of the tubular.

5. A shrinking tool according to claim 1, 2 and 3,characterised in thatthe tool following a milling tool, where the milling tool is adapted to mill at least one radial groove and at least one axial or helical groove along the longitudinal axis of the tubular.

6. A shrinking tool according to claim 1, 2, 3 and 4,characterised in thatthe forming die to be pulled by mean of a moving tractor or other means like as wireline or drillstring from inside the tubular.

7. A shrinking tool according to claim 1,characterised in thatthe tool comprises at least one anchoring mean for pulling one section of the tubular, where the separated section consist of at least on helical or axial groove along the longitudinal axis of the tubular.