Large-size casing segment milling tool

Abstract

The present invention proposes a large-scale casing segment milling tool, comprising a cylindrical body with a plurality of rectangular grooves axially disposed on the outer wall of the body; a cutting tool disposed within the rectangular groove, which radially expands or retracts from the rectangular groove under the action of thrust; and a piston disposed within the body, which axially expands and contracts under the action of a fluid, wherein the axial expansion and contraction of the piston drives the cutting tool to radially expand or retract. When segment milling the outer layer of a double-layer casing, the present invention can be lowered through the inner layer of the casing, hydraulically driving the cutting tool to extend and perform the segment milling operation. After the operation is completed, the cutting tool can be retracted into the tool body and pulled through the inner layer of the casing to the wellhead.

Description

Technical Field

[0001] The invention relates to a segment milling tool, in particular to a large-size casing segment milling tool, belonging to the technical field of petroleum. Background Art

[0002] As the exploitation time of offshore oil and gas fields increases, more and more oil and gas wells are entering a non-productive state. These non-productive wells need to be abandoned immediately to permanently eliminate their potential threats to the environment.

[0003] The basic requirements for permanent abandonment of marine wells include four aspects:

[0004] (1) Seal and protect all freshwater and near-freshwater layers; (2) Seal and protect all future production layers with commercial mining value; (3) Prevent fluid leakage and outflow from the well; (4) Clear all facilities above the seabed and cut off the pipes below the mudline.

[0005] This requires milling out a certain length of casing and installing cement plugs to seal the production layer and prevent oil and gas leakage. In some cases, it is necessary to mill out all the sections of two layers of casing and then install cement plugs. Conventional casing milling technology requires milling two layers of casing strings layer by layer from the inside out. For example, when milling two layers of 9-5 / 8"×13-3 / 8" casing, the milling tool is lowered from the 9-5 / 8" casing to the target depth, and the blade section is extended to mill out a certain length of 9-5 / 8" casing; the drill is pulled to the wellhead, the milling tool is replaced, and then it is lowered from the 9-5 / 8" casing to the predetermined depth, and the tool section is extended to mill out a certain length of 13-3 / 8" casing. Tools for segment milling 9-5 / 8" casing are relatively mature. However, when segment milling 13-3 / 8" casing or larger, the segment milling tool must be able to be lowered into the inner casing (that is, the outer diameter of the tool is limited by the inner casing diameter) and extend long enough to mill off the outer casing. Conventional segment milling tools no longer fully meet these requirements. Summary of the Invention

[0006] In response to the above-mentioned technical problems existing in the prior art, the present invention proposes a large-size casing segment milling tool. When segment milling the outer casing in a double-layer casing, the tool can be lowered through the inner casing, and the hydraulically driven tool can be extended to perform segment milling operations; after the operation is completed, the tool can be retracted into the tool body and the drill can be pulled out to the wellhead through the inner casing.

[0007] The present invention provides a large-size casing segment milling tool, comprising:

[0008] A cylindrical body, wherein a plurality of rectangular grooves are provided on the outer wall of the body along the axial direction;

[0009] A tool is disposed in the rectangular groove, and the tool is radially expanded from or retracted into the rectangular groove under the action of a thrust force;

[0010] A piston is provided inside the body, and the piston expands and contracts axially under the action of a fluid;

[0011] The piston is extended and retracted in the axial direction to drive the tool to expand or retract in the radial direction.

[0012] A further improvement of the present invention is that the tool is detachably mounted in the rectangular groove, and the tool comprises a windowing tool and a grinding and milling tool;

[0013] When the outer casing is cut, the window cutter is installed in the rectangular groove; when the outer casing is milled, the milling cutter is installed in the rectangular groove.

[0014] A further improvement of the present invention is that the tool comprises a bar-shaped tool body, the upper end of the tool body is connected to the body via a driving rod, and the lower end is connected to the body via a support assembly;

[0015] The drive rod and the support assembly rotate to cause the tool body to expand or retract in the radial direction.

[0016] A further improvement of the present invention is that the outer wall of the tool body is an arc-shaped surface, and tool teeth are provided on the outer wall. The tool teeth of the windowing tool are a plurality of cutting blocks, and the tool teeth of the milling tool are milling columns.

[0017] A further improvement of the present invention is that wear-resistant strips are provided on the outer wall of the tool body.

[0018] A further improvement of the present invention is that the driving rod is a long strip structure with arc-shaped ends, the upper end of which is connected to the body via a first pin, and a plurality of saw teeth are provided on the arc surface of the upper end, and the lower end is connected to the tool body via a second pin;

[0019] Wherein, a plurality of serrations are provided on the side surface of the piston, which mesh with the serrations of the drive rod. When the piston is extended or retracted, the drive rod is driven to rotate along the first pin shaft through the serrations.

[0020] A further improvement of the present invention is that the support assembly includes an upper support rod and a lower support rod, the upper ends of the upper support rod and the lower support rod are connected to the body through a set of third pins, and the other ends are connected to the tool body through a set of fourth pins.

[0021] A further improvement of the present invention is that an annular chamber is provided on the flow channel inside the body;

[0022] The piston is a stepped tubular structure, which includes a thicker piston cylinder and a thinner piston tube. The piston cylinder is arranged in the annular chamber, and the piston tube extends into the flow channel at the lower part, and the serrations are arranged on the piston tube.

[0023] A further improvement of the present invention is that a spring is provided in the annular chamber, and the spring applies elastic force between the body and the piston.

[0024] A further improvement of the present invention is that an upper joint is provided at the upper end of the body, and a plurality of injection nozzles are radially provided on the side surface of the upper joint.

[0025] A further improvement of the present invention is that hard alloy material is built-up on the lower conical surface and the bottom surface of the body.

[0026] A further improvement of the present invention is that a throttle nozzle is provided at the end of the piston tube.

[0027] Compared with the prior art, the advantages of the present invention are:

[0028] The large-size casing segment milling tool described in the present invention can be lowered through the inner casing when segment milling the outer casing in a double-layer casing, and the hydraulically driven cutter can be extended to perform the segment milling operation; after the operation is completed, the cutter can be retracted into the tool body and the drill can be pulled out to the wellhead through the inner casing. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0030] Figure 1 FIG2 is a schematic structural diagram of a large-size casing segment milling tool according to an embodiment of the present invention;

[0031] Figure 2 yes Figure 1 Left view of;

[0032] Figure 3 yes Figure 1 Cross-sectional view at AA in the middle;

[0033] Figure 4 yes Figure 1 Cross-sectional view at the middle BB;

[0034] Figure 5 yes Figure 2 Cross-sectional view at CC;

[0035] Figure 6 yes Figure 2 Cross-sectional view at DD in the middle;

[0036] Figure 7 Shown is an axonometric view of a window opening tool according to an embodiment of the present invention;

[0037] Figure 8 yes Figure 7 Axonometric view of the center window cutter body;

[0038] Figure 9 The above is an axonometric view of a milling tool according to an embodiment of the present invention;

[0039] Figure 10 yes Figure 9 Axonometric drawing of the milling tool body;

[0040] Figure 11 The above is an axonometric view of a drive rod according to an embodiment of the present invention;

[0041] Figure 12 Shown is an axonometric view of an upper support rod and a lower support rod according to an embodiment of the present invention;

[0042] Figure 13 FIG2 is a schematic diagram showing the working state of a large-size casing segment milling tool according to an embodiment of the present invention, showing the state when the outer casing is cut open;

[0043] Figure 14 FIG2 is a schematic diagram showing the working state of a large-size casing segment milling tool according to an embodiment of the present invention, showing the state when milling the outer casing.

[0044] In the drawings, like components are denoted by like reference numerals, but the drawings are not necessarily drawn to scale.

[0045] The meanings of the reference numerals in the accompanying drawings are as follows:

[0046] 1. Ontology,

[0047] 2. Cutting tools,

[0048] 3. Piston,

[0049] 11. Rectangular groove,

[0050] 12. Upper joint,

[0051] 13. Cemented carbide materials,

[0052] 14. Injection nozzle,

[0053] 15. Spring,

[0054] 16. Sealing ring,

[0055] 21. Window cutter,

[0056] 22. Grinding and milling tools,

[0057] 23. Tool teeth,

[0058] 24. Wear-resistant strips,

[0059] 25. Drive rod,

[0060] 26. Upper support rod,

[0061] 27. Lower support rod,

[0062] 211. Window cutter body,

[0063] 212, cutting block,

[0064] 213. The first rectangular groove,

[0065] 214. The second rectangular groove,

[0066] 221. Milling tool body,

[0067] 222, milling column,

[0068] 223. The third rectangular groove,

[0069] 224, the fourth rectangular slot,

[0070] 251, sawtooth,

[0071] 252, the first pin,

[0072] 253, second pin,

[0073] 261, the third pin,

[0074] 264, the fourth pin,

[0075] 31. Piston cylinder,

[0076] 32. Piston tube,

[0077] 33. Throttle nozzle,

[0078] 41. Inner casing,

[0079] 42. Outer casing,

[0080] 43. Drill rod. DETAILED DESCRIPTION

[0081] To make the technical solutions and advantages of the present invention more clearly understood, exemplary embodiments of the present invention are further described in detail below with reference to the accompanying drawings. It should be understood that the described embodiments are only a portion of the embodiments of the present invention, and are not exhaustive. Furthermore, the embodiments and features of the embodiments of the present invention may be combined with each other unless there is a conflict.

[0082] Figure 1A large-scale casing section milling tool according to one embodiment of the present invention is schematically shown, which includes a main body 1. The main body 1 is a cylindrical structure with a flow channel arranged inside. A number of rectangular grooves 11 are radially arranged on the outer wall of the main body 1. In this embodiment, there are two groups of rectangular grooves 11, which are relatively arranged on both sides of the main body 1. A tool 2 is installed in the rectangular groove 11 for cutting the outer casing 42 or milling the outer casing. The tool 2 can be retracted or expanded. When retracted, it retracts into the rectangular groove 11 to facilitate the lowering of the tool; when expanded, it extends radially from the rectangular groove 11 and can be used for cutting or milling the casing. The large-scale casing section milling tool described in this embodiment also includes a piston 3, which expands and contracts axially under the action of the fluid, and the piston 3 expands and contracts axially to drive the tool 2 to expand or retract radially.

[0083] When using the large-size casing segment milling tool described in this embodiment, the main body 1 is connected to the drill pipe and lowered into the well. In the initial state, the tool 2 is in a state of being retracted into the rectangular groove 11. By controlling the displacement of the fluid, the pressure received by the piston 3 is controlled, thereby controlling the expansion and contraction of the piston 3. When the piston 3 is extended, the tool 2 is opened, so that the tool 2 cuts or mills the casing.

[0084] In one embodiment, the tool 2 is detachably installed in the rectangular groove 11, and the tool 2 includes a window opening tool 21 and a grinding and milling tool 22; the window opening tool 21 is installed in the rectangular groove 11 when cutting the outer casing 42, and the grinding and milling tool 22 is installed in the rectangular groove 11 when grinding the outer casing.

[0085] In the large-scale casing segment milling tool described in this embodiment, different types of cutters 2 are provided to achieve different functions. During use, the appropriate cutter 2 is selected based on actual needs. When cutting the outer casing 42, the window cutter 21 is installed in the rectangular groove 11; when milling the outer casing, the milling cutter 22 is installed in the rectangular groove 11. This allows for multiple different processing methods on the casing using a single tool.

[0086] In one embodiment, the tool 2 includes a tool body. The tool body is a bar-shaped structure, preferably a rectangular device, whose shape matches the rectangular groove 11. The outer wall is an arcuate surface. The upper end of the tool body is connected to the body 1 via a drive rod 25, and the lower end is connected to the body 1 via a support assembly. The drive rod 25 and the support assembly rotate to radially expand or retract the tool body.

[0087] When the piston 3 is extended or retracted, the driving rod 25 is driven to rotate. When the driving rod 25 rotates, the tool body is driven to expand or retract from the rectangular groove 11 .

[0088] In one embodiment, the outer wall of the tool body is an arcuate surface, on which are disposed tool teeth 23. The tool teeth 23 are removable and can be configured in various shapes and structures. Different types of tools 2 are similar in other aspects, but differ in the tool teeth 23. For example, the tool teeth 23 of the window cutter 21 are formed as a plurality of cutting blocks 212, while the tool teeth 23 of the milling tool 22 are formed as milling posts 222.

[0089] In a preferred embodiment, wear-resistant strips 24 are provided on the outer wall of the tool body.

[0090] In the large-scale casing segment milling tool according to this embodiment, the upper portion of the window cutter body 2111 is provided with several rows of spaced first rectangular slots 213. A central portion of the window cutter body 2111 is provided with a protrusion for straightening. The protrusion is provided with several second rectangular slots 214 evenly spaced along the circumference of the window cutter body 2111. The cutting blocks 212 are mounted in the first rectangular slots 213, and wear strips 24 are installed in the second rectangular slots 214.

[0091] The upper portion of the milling tool body 22 is provided with several rectangular strips evenly distributed along the circumference of the milling tool body 22. A protrusion for straightening is provided in the middle of the milling tool body 22. A plurality of spaced-apart third rectangular slots 223 are provided on one side of the rectangular strips. The protrusions are provided with several fourth rectangular slots 224 evenly distributed along the circumference of the window cutter body 2111. The milling posts 222 are positioned in the third rectangular slots 223, and the wear strips 24 are positioned in the fourth rectangular slots 224.

[0092] The cutting block 212 , the milling column 222 and the wear strip 24 are all made of cemented carbide.

[0093] In one embodiment, the drive rod 25 is an elongated structure with curved end surfaces, preferably semicircular, at both ends. The upper end of the drive rod 25 is connected to the body 1, and the lower end is connected to the tool body. In this embodiment, the upper end of the drive rod 25 is hinged to the body 1 via a first pin 252, and the lower end is hinged to the tool body via a second pin 253. The length of the drive rod 25 is aligned with the axis of the body 1, and the width is aligned with the radial direction of the body 1.

[0094] The upper arc surface of the driving rod 25 is provided with a plurality of serrations. The side surface of the piston 3 is provided with a plurality of serrations that mesh with the serrations of the driving rod 25. When the piston 3 is extended or retracted, the serrations drive the driving rod 25 to rotate along the first pin 252.

[0095] In the large-scale casing segment milling tool according to this embodiment, during the extension and retraction of the piston 3, the serrations drive the drive rod 25 to rotate about the first pin 252. Simultaneously, the drive rod 25 and the tool body rotate via the second pin 253. Thus, the movement of the piston 3 can drive the tool 2 to expand outward or retract inward.

[0096] In one embodiment, the support assembly includes an upper support rod 26 and a lower support rod 27. The upper support rods 26 are arranged in pairs on one side near the middle of the tool body, and the lower support rods 27 are arranged in pairs on one side near the lower end of the tool body. In this embodiment, two elongated grooves are respectively provided on both sides of the lower portion of the tool body for accommodating the upper support rods 26 and the lower support rods 27.

[0097] The upper end of the upper support rod 26 is hinged to the main body 1 through the third pin 261, and the lower end is hinged to the tool body through the fourth pin 264; the upper end of the lower support rod 27 is also hinged to the main body 1 through the third pin 261, and the lower end is hinged to the tool body through the fourth pin 264.

[0098] Preferably, both ends of the upper support rod 26 and the lower support rod 27 are semicircular, and the middle part is a rectangular parallelepiped, and stepped through holes are provided along the axis direction of the semicircular.

[0099] In one embodiment, an annular chamber is provided on the flow channel inside the body 1, wherein the inner diameter of the annular chamber is larger, and the inner diameter of the lower flow channel is smaller, forming a stepped channel. An annular end face is formed between the annular cavity and the lower flow channel. The piston 3 is a stepped tubular structure, which includes a thicker piston cylinder 31 and a thinner piston tube 32. The piston cylinder 31 is provided in the annular chamber, and the piston tube 32 extends into the lower flow channel, and the serrations are provided on the outer wall of the piston tube 32. A throttle nozzle 33 is provided at the end of the piston tube 32 to play a throttling role, so that pressure is generated in the upper part.

[0100] In this embodiment, a stepped hole is also formed inside the piston 3, so that upper and lower pressure difference surfaces are formed. At the same time, the throttling effect of the throttle nozzle 33 causes the pressure of the fluid to push the piston 3 to move. When the fluid flows through the inside, the force pushing the piston 3 to move can be controlled by controlling the displacement and pressure of the fluid, thereby controlling the expansion and contraction of the piston 3, and further controlling the opening or contraction of the tool 2.

[0101] In a preferred embodiment, a spring 15 is disposed within the annular chamber, and the spring 15 applies an elastic force between the body 1 and the piston 3. The lower end of the spring 15 is disposed on an annular end surface formed between the annular chamber and the lower flow channel, and the upper end is disposed on an annular boss at the upper end of the piston 3, exerting an upward elastic force on the piston 3. When the pressure caused by the displacement of the fluid is greater than the elastic force of the spring 15, the piston 3 moves downward. When the pressure is less than the elastic force of the spring 15, the spring 15 pushes the piston 3 upward.

[0102] In a preferred embodiment, an upper joint 12 is provided at the upper end of the body 1 , and a plurality of injection nozzles 14 are radially provided on the side surface of the upper joint 12 .

[0103] In one embodiment, a hard alloy material 13 is built-up on the lower conical surface and the bottom surface of the body 1 .

[0104] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and / or modifications that fall within the scope of the present invention, and changes and / or modifications made in accordance with the embodiments of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A large-size casing segment milling tool, characterized in that: include: A cylindrical body (1), wherein a plurality of rectangular grooves (11) are arranged on the outer wall of the body (1) along the axial direction, and the rectangular grooves (11) are in two groups and are arranged on two sides of the body (1) in opposite directions; A tool (2) is disposed in the rectangular groove (11), and the tool (2) is radially opened from or retracted into the rectangular groove (11) under the action of a thrust force; the tool (2) comprises a window cutter (21) and a milling tool (22); the tool (2) comprises a bar-shaped tool body, the upper end of the tool body being connected to the body (1) via a driving rod (25), and the lower end being connected to the body (1) via a supporting assembly; A piston (3) is arranged inside the body (1), and the piston (3) expands and contracts in the axial direction under the action of a fluid; The piston (3) is extended and retracted in the axial direction to drive the tool (2) to expand or retract in the radial direction; The driving rod (25) is a long strip structure with arc-shaped ends, the upper end of which is connected to the body (1) via a first pin (252), and a plurality of saw teeth are provided on the arc surface of the upper end, and the lower end is connected to the tool body via a second pin (253); The side surface of the piston (3) is provided with a plurality of saw teeth that mesh with the saw teeth of the drive rod (25). When the piston (3) is extended or retracted, the saw teeth drive the drive rod (25) to rotate along the first pin (252); The support assembly comprises an upper support rod (26) and a lower support rod (27), wherein the upper ends of the upper support rod (26) and the lower support rod (27) are connected to the body (1) via a set of third pins (261), and the other ends of the upper support rod (26) and the lower support rod (27) are connected to the tool body via a set of fourth pins (264); An annular chamber is provided on the flow channel inside the body (1); The piston (3) is a stepped tubular structure, comprising a thicker piston cylinder (31) and a thinner piston tube (32), wherein the piston cylinder (31) is arranged in an annular chamber, and the piston tube (32) extends into a flow channel at the lower portion, and the piston tube (32) is provided with serrations; A throttle nozzle (33) is provided at the end of the piston tube (32).

2. The large-size casing segment milling tool according to claim 1, characterized in that: The cutter (2) is detachably mounted in the rectangular groove (11); When cutting the outer casing (42), the window cutter (21) is installed in the rectangular groove (11); when milling the outer casing, the milling cutter (22) is installed in the rectangular groove (11).

3. The large-size casing segment milling tool according to claim 2, characterized in that: The drive rod (25) and the support assembly rotate to cause the tool body to expand or retract radially.

4. The large-size casing segment milling tool according to claim 3, characterized in that: The outer wall of the tool body is an arc-shaped surface, and tool teeth (23) are provided on the outer wall. The tool teeth (23) of the window opening tool (21) are a plurality of cutting blocks (212), and the tool teeth (23) of the milling tool (22) are milling columns (222).

5. The large-size casing segment milling tool according to claim 4, characterized in that: A wear-resistant strip (24) is provided on the outer wall of the tool body.

6. The large-size casing segment milling tool according to claim 5, characterized in that: A spring (15) is provided in the annular chamber, and the spring (15) applies elastic force between the body (1) and the piston (3).

7. The large-size casing segment milling tool according to claim 6, characterized in that: An upper joint (12) is provided at the upper end of the body (1), and a plurality of injection nozzles (14) are radially provided on the side surface of the upper joint (12).

8. The large-size casing segment milling tool according to claim 7, characterized in that: The lower conical surface and the bottom surface of the body (1) are built up with hard alloy material (13).

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