Free-section casing fracture collecting and guiding method and tool

Abstract

The invention belongs to the technical field of oil field downhole operation, and particularly relates to a free-section casing fracture collecting and guiding method and tool, the method is based on the free-section casing fracture collecting and guiding tool, and the free-section casing fracture collecting and guiding tool comprises a guide rail upper connector; the suspension piston is movably connected with the guide rail upper joint; the outer cylinder is connected with the guide rail upper joint; the suspension expanding cone is arranged between the outer cylinder and the suspension piston; the guide shell is connected with the outer cylinder; and the at least one chamfering expanding sheet is movably connected with the guide shell and the hanging expanding cone. By means of the free section casing fracture collecting and guiding method and tool, the problem that after a casing is cut off and deviates, a conventional tool cannot make contact with a fracture can be solved, the success rate of complex casing taking is effectively increased, and technical support is provided for efficient treatment of a shallow casing damage well of an oil field.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield downhole operations, and relates to a free-section casing fracture recovery tool and method, and in particular to a free-section casing fracture recovery method and tool used in the process of oil and water well repair operations. Background Art

[0002] During the production process of oil and water wells, due to fluid corrosion, surface subsidence and other reasons, the shallow oil layer casing is lost or deformed. The most thorough repair method is to replace the casing, remove the damaged part and the upper oil layer casing, and replace it with a new casing. Due to factors such as severe casing deformation and large horizontal displacement of the wellbore, some wells are affected by factors such as casing milling before the casing milling reaches the change point, and the casing is cut off. After the casing is cut off, the fracture is easy to be offset, making it difficult to recover. Figure 1 , Figure 2 shown.

[0003] In other words, using conventional casing milling technology, if there is casing breakage or offset, due to factors such as tubing rigidity and wellbore guidance, it is difficult for the casing milling and pulling tools to reach the broken casing at the bottom, and the original casing channel cannot be retrieved.

[0004] Based on this, the existing technology still needs to be improved. Summary of the invention

[0005] The purpose of the present invention is to address the deficiencies in the prior art and provide a method and tool for retrieving the fracture of a free-section casing. After the pipe string is lowered below the surface casing, the side of the offset casing is locally damaged by multiple retrieving mechanisms, and the casing is retracted using radial force, thereby solving the problem that the fracture of the free-section casing cannot be retrieved and ensuring the successful completion of the casing replacement operation.

[0006] According to one aspect of the present invention, a method for drawing a free-segment casing fracture is provided, wherein the method is based on a free-segment casing fracture drawing tool, wherein the free-segment casing fracture drawing tool comprises a guide rail joint; a suspension piston movably connected to the guide rail joint; an outer cylinder connected to the guide rail joint; a suspension expansion cone disposed between the outer cylinder and the suspension piston; a guide housing connected to the outer cylinder; and at least one chamfered expansion sheet movably connected to the guide housing and the suspension expansion cone, and the method comprises the following steps:

[0007] a. Lower the pipe string with the free-section casing fracture receiving tool at the bottom to below the surface casing until it is above the fracture position of the oil layer casing, and move the chamfered expansion piece radially under the action of hydraulic pressure so that the maximum outer diameter of the free-section casing fracture receiving tool exceeds the inner diameter of the surface casing;

[0008] b. Rotate the pipe string so that the bottom of the chamfered expansion piece cuts the side of the offset casing to locally damage the contact part through milling; continue to lower the pipe string, and while milling, the radial force generated causes the casing body to be drawn toward the center through cutting;

[0009] c. Lift the pipe column to retract the chamfered expansion piece, so that the maximum outer diameter of the free section casing fracture retracting tool is reduced to less than the inner diameter of the surface casing, and continue to lift the tool;

[0010] d. Use a sleeve milling tool whose outer diameter is smaller than the inner diameter of the surface casing to replace the sleeve.

[0011] In an embodiment of the present invention, the maximum outer diameter of the free section casing fracture drawing tool satisfies the following formula:

[0012] When the surface casing does not have deformation: W≤Dsc-10mm;

[0013] When the surface casing is deformed: W≤Dsc-20mm,

[0014] Wherein, Dsc is the inner diameter of the surface casing; W is the maximum outer diameter of the free section casing fracture recovery tool.

[0015] In an embodiment of the present invention, in step a, the radial movement of the chamfered expansion piece under the action of hydraulic pressure includes: by throwing a ball sitting on the top ball seat of the suspension piston, pressing and pushing the suspension piston downward, thereby pushing the suspension expansion cone downward, so that their contact surfaces enter a circulation position, and at the same time, the suspension expansion cone pushes the chamfered expansion piece through its second guide rail, so that it moves radially along the third guide rail of the guide housing.

[0016] In an embodiment of the present invention, the bottom of the chamfered diameter-expanding piece is provided with an inwardly inclined surface, and the inclined surface is paved with a high-strength alloy.

[0017] In an embodiment of the present invention, in step b, the step of making the bottom of the chamfered expanding piece cut the side of the offset sleeve to locally damage the contact portion by grinding and milling comprises: making the high-hardness alloy at the bottom of the chamfered expanding piece contact the side of the offset sleeve, and producing a notch on the side of the sleeve by grinding and milling to locally damage the contact portion.

[0018] In an embodiment of the present invention, in step b, three chamfered diameter-expanding sheets are arranged around the circumference of the pipe column.

[0019] In an embodiment of the present invention, in step c, the recovery of the chamfered expanding piece includes: the joint on the guide rail drives the suspension piston that is at the end of the stroke to move upward, the relative position of the suspension piston and the suspension expanding cone enters a locked position, and the suspension expanding cone moves upward; the chamfered expanding piece is squeezed by the upper unexpanded formation to achieve recovery.

[0020] In an embodiment of the present invention, a conversion groove is provided on the contact surface between the suspension piston and the suspension expansion cone, and the conversion groove includes a first conversion groove and a second conversion groove, wherein the first conversion groove provides a mud circulation channel, and the second conversion groove provides a lifting and hanging card function.

[0021] In an embodiment of the present invention, the locking position is the second conversion slot.

[0022] According to another aspect of the present invention, a free-segment casing fracture retrieval tool is provided, which includes: a guide rail joint; a hanging piston movably connected to the guide rail joint; an outer cylinder connected to the guide rail joint; a hanging expansion cone arranged between the outer cylinder and the hanging piston; a guide shell connected to the outer cylinder; and at least one chamfered expansion piece movably connected to the guide shell and the hanging expansion cone.

[0023] In an embodiment of the present invention, a conversion groove is provided on the contact surface between the suspension piston and the suspension expansion cone, and the conversion groove includes a first conversion groove and a second conversion groove, wherein the first conversion groove provides a mud circulation channel, and the second conversion groove provides a lifting and hanging card function.

[0024] In an embodiment of the present invention, a plurality of chamfered expansion pieces movably connected to the guide housing and the suspended expansion cone are arranged along the circumference.

[0025] In an embodiment of the present invention, the bottom of the chamfered diameter-expanding piece is provided with an inwardly inclined surface, and the inclined surface is paved with a high-strength alloy.

[0026] In an embodiment of the present invention, an outer wall of the guide rail upper joint is provided with a step, and the outer cylinder is connected to the guide rail upper joint via the step.

[0027] In an embodiment of the present invention, a first guide rail is provided on the inner side of the guide rail upper joint, and the first guide rail is connected to a part of the suspension piston and allows the part to move axially along the first guide rail.

[0028] In an embodiment of the present invention, the outer cylinder is a sealed outer cylinder, and the outer wall of the outer cylinder is connected to the guide housing via threads.

[0029] In an embodiment of the present invention, the suspension expansion cone is sleeved between the suspension piston and the outer cylinder, and sealing mechanisms are provided inside and outside the upper step of the suspension expansion cone, and a conical surface is provided at the bottom of the suspension expansion cone.

[0030] In an embodiment of the present invention, the conical surface includes a second guide rail, which connects the first part of the chamfered expansion piece and allows the first part to move along the second guide rail, and the first part and the second guide rail are installed by keyway cooperation.

[0031] In an embodiment of the present invention, the upper portion of the guide shell forms a sealed connection with the outer cylinder, and a third guide rail is provided at the bottom of the guide shell, the third guide rail is connected to the second portion of the chamfered expansion piece and allows the second portion to move radially outward along the third guide rail, and the second portion and the third guide rail are installed by keyway cooperation.

[0032] The present invention can solve the problem that conventional tools cannot access the fracture after the casing is cut off, effectively improve the success rate of complex casing removal, and provide technical support for the efficient treatment of shallow casing damaged wells in oil fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of the sleeve milling and offset cutting of the sleeve is shown;

[0034] Figure 2 A schematic diagram of horizontal displacement of the wellbore is shown;

[0035] Figure 3 A schematic cross-sectional view of a free-segment casing fracture collecting tool according to an embodiment of the present invention is shown;

[0036] Figure 4 A bottom view of a free-segment casing fracture collecting tool according to an embodiment of the present invention is shown;

[0037] Figure 5 A schematic flow chart of a method for drawing in a free-segment casing fracture according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0038] It should be understood that the embodiments of the present invention shown in the exemplary embodiments are only illustrative. Although only a few embodiments are described in detail in the present invention, it is easy for those skilled in the art to appreciate that multiple modifications are feasible without actually departing from the teaching of the subject matter of the present invention. Accordingly, all such modifications should be included within the scope of the present invention. Without departing from the gist of the present invention, other replacements, modifications, changes and deletions may be made to the design, operating conditions and parameters of the following exemplary embodiments.

[0039] According to one aspect of the present invention, a free-segment casing fracture recovery tool is provided. Figure 3As shown, it comprises: a guide rail joint 1; a suspension piston 2 movably connected to the guide rail joint 1; an outer cylinder 3 connected to the guide rail joint 1; a suspension expansion cone 4 disposed between the outer cylinder 3 and the suspension piston 2; a guide housing 5 connected to the outer cylinder 3; and at least one chamfered expansion piece 6 movably connected to the guide housing 5 and the suspension expansion cone 4. Figure 4 As shown, the free section casing fracture retraction tool may be generally cylindrical.

[0040] In an embodiment of the present invention, a step 11 is provided on the outer wall of the guide rail joint 1, and the outer tube 3 has a shape adapted to the step 11, and can be connected to the guide rail joint 1 through the step 11. In one embodiment, an external thread can be provided on the step 11, and an internal thread is provided inside the outer tube 3, so that the outer tube 3 and the guide rail joint 1 can be connected by threads. A first guide rail 12 is provided on the inner side of the guide rail joint 1, and the first guide rail 12 connects a part of the suspension piston 2 and allows this part to move axially along the first guide rail 12. In one embodiment, the first guide rail 12 is provided at the bottom of the guide rail joint 1, and forms an axial movement fit with the key on the upper part of the suspension piston 2. It should be understood that the upper part, bottom part or lower part mentioned here and in other parts is based on the direction of the free section casing fracture retrieval tool entering the well as a reference, for example, in Figure 3 In the figure, the left side represents the upper part of the free section casing fracture recovery tool, and the right side represents the bottom or lower part of the free section casing fracture recovery tool, that is, the bottom or lower part is lowered into the well before the upper part. In addition, the axial and radial directions mentioned here and in other parts are based on the axial and radial directions of the free section casing fracture recovery tool.

[0041] In the embodiment of the present invention, the outer cylinder 3 is a sealed outer cylinder, and the outer wall of the outer cylinder 3 is connected to the guide housing 5 through threads, so as to facilitate installation and disassembly.

[0042] In an embodiment of the present invention, the suspension expansion cone 4 is sleeved between the suspension piston 2 and the outer tube 3, and sealing mechanisms (such as sealing strips, sealing rings or sealing with sealant) are provided inside and outside the upper step of the suspension expansion cone 4.

[0043] In the embodiment of the present invention, a conical surface 41 is provided at the lower part of the suspension expansion cone 4. A second guide rail 42 corresponding to the chamfered expansion piece 6 is provided on the conical surface 41, and its direction is inclined downward. The second guide rail 42 connects the first part 61 of the chamfered expansion piece 6 and allows the first part 61 to move along the second guide rail 42, and the first part 61 and the second guide rail 42 are installed by keyway matching. The bottom of the chamfered expansion piece 6 is provided with an inward inclined surface (not shown in the figure), and the inclined surface is paved with high-strength alloy.

[0044] In an embodiment of the present invention, the upper portion of the guide shell 5 forms a sealed connection with the outer cylinder 3, and a third guide rail 51 is provided at the bottom of the guide shell 5, the third guide rail 51 is connected to the second portion 62 of the chamfered expansion piece 6 and allows the second portion 62 to move radially outward along the third guide rail 51, and the second portion 62 is installed with the third guide rail 51 by keyway cooperation.

[0045] In an embodiment of the present invention, a conversion groove is provided on the contact surface between the suspension piston 2 and the suspension expansion cone 4, and the conversion groove includes a first conversion groove and a second conversion groove, wherein the first conversion groove provides a mud circulation channel, and the second conversion groove provides a lifting and hanging card function.

[0046] In an embodiment of the present invention, the chamfered diameter expansion piece 6 can constitute a retracting mechanism, and a plurality of chamfered diameter expansion pieces 6 movably connected to the guide housing 5 and the suspension diameter expansion cone 4 are arranged along the circumference. In an embodiment, three chamfered diameter expansion pieces 6 can be provided to form three groups of retracting mechanisms, such as Figure 4 shown.

[0047] In the embodiment of the present invention, a ball seat is arranged on the top of the suspension piston 2, and the ball seat can receive and accommodate a ball for applying hydraulic pressure.

[0048] The free section casing fracture drawing tool described in the present invention can push the suspension piston 2 and the suspension expansion cone 4 downward under the action of hydraulic pressure, so that their contact surfaces enter the circulation position. At the same time, the expansion cone pushes the chamfered expansion sheet 6 through the axial guide rail, so that it moves along the radial guide rail of the fixed guide shell 5, so that the maximum outer diameter of the inner chamfered drawing mechanism at the bottom exceeds the inner diameter of the surface casing, thereby locally destroying the offset casing and drawing it toward the center.

[0049] According to another aspect of the present invention, a method for drawing a free-segment casing fracture is provided. Figure 5 Said, it comprises the following steps:

[0050] a. Lower the pipe string with the free-section casing fracture recovery tool at the bottom to below the surface casing until it is above the fracture position of the oil layer casing, and move the chamfered expansion piece radially under the action of hydraulic pressure so that the maximum outer diameter of the free-section casing fracture recovery tool exceeds the inner diameter of the surface casing, wherein the free-section casing fracture recovery tool can be the free-section casing fracture recovery tool mentioned in the aforementioned embodiment.

[0051] b. Rotate the pipe string so that the bottom of the chamfered expansion piece cuts the side of the offset casing to locally damage the contact part through milling; continue to lower the pipe string, and while milling, the radial force generated causes the casing body to be drawn toward the center through cutting;

[0052] c. Lift the pipe column to retract the chamfered expansion piece, so that the maximum outer diameter of the free section casing fracture retracting tool is reduced to less than the inner diameter of the surface casing, and continue to lift the tool;

[0053] d. Use a sleeve milling tool whose outer diameter is smaller than the inner diameter of the surface casing to replace the sleeve.

[0054] In an embodiment of the present invention, the maximum outer diameter of the free-section casing fracture drawing tool satisfies the following formula:

[0055] When the surface casing does not have deformation: W≤Dsc-10mm;

[0056] When the surface casing is deformed: W≤Dsc-20mm,

[0057] Wherein, Dsc is the inner diameter of the surface casing, in mm; W is the maximum outer diameter of the free section casing fracture recovery tool, in mm.

[0058] In the embodiment of the present invention, in step a, the radial movement of the chamfered expansion piece 6 under the action of hydraulic pressure includes: by throwing a ball to sit on the top ball seat of the suspension piston 2, pressing and pushing the suspension piston 2 downward, thereby pushing the suspension expansion cone 4 downward, so that their contact surfaces enter the circulation position, and at the same time, the suspension expansion cone 4 pushes the chamfered expansion piece 6 through its second guide rail 42, so that it moves radially along the third guide rail 51 of the guide shell 5. In one embodiment, step a specifically includes: lowering the free section casing fracture collection tool below the surface casing, entering the formation (free section without casing and cementing cement), and continuing to go down to above the fracture position of the oil layer casing; hydraulically pushing the suspension piston 2 and the suspension expansion cone 4 downward in turn, so that their contact surfaces enter the circulation position, and at the same time, the suspension expansion cone 4 pushes the chamfered expansion piece 6 through the axial guide rail, so that it moves along the radial guide rail of the fixed guide shell 5, so that the maximum outer diameter of the inner chamfer collection mechanism at the bottom exceeds the inner diameter of the surface casing.

[0059] In an embodiment of the present invention, in step b, making the bottom of the chamfered expansion piece 6 cut the side of the offset casing to locally damage the contact portion by milling includes: making the high-hardness alloy at the bottom of the chamfered expansion piece 6 contact the side of the offset casing, and making a notch on the side of the casing by milling to locally damage the contact portion. In one embodiment, step b specifically includes: rotating the pipe column, so that the high-hardness alloy at the bottom of the chamfered expansion piece 6 contacts the side of the offset casing, and locally damaging the contact portion by milling; continuing to lower the pipe column, while the inner chamfered retracting mechanism at the bottom generates a radial component force during milling, so that the casing body is retracted toward the center by cutting.

[0060] In an embodiment of the present invention, in step b, a plurality of chamfered diameter-expanding pieces 6 are arranged around the circumference of the pipe string. In an embodiment, the retracting mechanism can be modularized, and three retracting mechanisms are arranged along the circumference.

[0061] In an embodiment of the present invention, in step c, recovering the chamfered and expanded diameter piece 6 includes: causing the upper joint 1 of the guide rail to drive the suspension piston 2, which is already at the end of the stroke, to move upward, the relative position of the suspension piston 2 and the suspension expansion cone 4 enters a locking position, and the suspension expansion cone 4 moves upward; the chamfered and expanded diameter piece 6 is squeezed by the upper unexpanded formation to achieve recovery. In one embodiment, step c specifically includes: lifting the tubing string, the suspension piston 2 is already at the end of the stroke, the upper joint 1 of the guide rail drives the suspension piston 2 upward, the relative position of the suspension piston 2 and the suspension expansion cone 4 enters a locking position, and the suspension expansion cone 4 moves upward; the chamfered and expanded diameter piece 6 is squeezed by the upper unexpanded formation to achieve recovery, so that the maximum outer diameter of the tool is reduced to less than the inner diameter of the surface casing, and the tool is continuously lifted up and removed.

[0062] In an embodiment of the present invention, step d specifically includes: using a casing milling tool whose outer diameter is smaller than the inner diameter of the surface casing, casing milling the casing fracture that has been retracted and centered, placing it in the casing milling barrel, and using a grinding tool to trim the casing fracture until the tracer string can be lowered; removing the casing, and lowering a new casing to connect it back.

[0063] The free-section casing fracture retrieval tool and method described in the embodiment of the present invention can effectively solve the problem that conventional tools cannot contact the fracture after the casing is cut and deviated, effectively improve the success rate of complex casing removal, and provide technical support for the efficient management of shallow casing damaged wells in oil fields.

[0064] The present invention is further described below by specific examples:

[0065] The inner diameter of the surface casing is 320mm, the depth is 100m, the outer diameter of the oil layer casing is 139.7mm. The oil layer casing is severely twisted and deformed near the well depth of 160m, and it broke during the casing milling process and was offset to one side, so that the pipe string could not touch the casing.

[0066] The embodiment of the present invention provides a method and tool for drawing the fracture of a free-segment casing:

[0067] (1) The casing has no deformation and the maximum outer diameter of the free section casing fracture retracting tool is 300 mm.

[0068] (2) Use a 300mm outer diameter milling shoe or grinding shoe to process to a well depth of 158m. The bottom of the drill pipe is equipped with a free section casing fracture recovery tool. The guide shell 5 of the tool is provided with 3 sets of recovery mechanisms along the circumference. Go down to a well depth of 156m, and by throwing a ball to sit on the ball seat at the top of the suspension piston 2, the suspension piston 2 is pushed downward by pressure, and the suspension expansion cone 4 is further pushed downward. During the downward process, the contact surfaces of the two mechanisms enter the circulation position, and at the same time, the suspension expansion cone 4 pushes the chamfered expansion sheet 6 through the axial guide rail, so that it moves along the radial guide rail of the fixed guide shell 5. After expansion, the outer diameter of the tool is 340mm.

[0069] (3) The pipe string is rotated, and the free section casing fracture recovery tool cuts the formation and continues to be lowered. The high-hardness alloy at the bottom of the chamfer expansion piece contacts the side of the offset casing, and a notch is generated on the side of the casing through milling. The lowering and milling is continued, and the inner chamfer recovery mechanism at the bottom generates a radial force while milling, so that the casing body is cut and recovered toward the center, and the casing is processed downward by 1m.

[0070] (4) Lift the pipe string. The suspension piston 2 is at the end of its stroke. The joint 1 on the guide rail drives the suspension piston 2 upward. The relative position of the suspension piston 2 and the suspension expansion cone 4 enters the second conversion groove, and the suspension expansion cone 4 is hung and moved upward. The chamfered expansion piece 6 is squeezed by the upper unexpanded stratum to achieve recovery, so that the maximum outer diameter of the tool is reduced to within 320 mm, and the tool is continuously lifted up.

[0071] (5) Use a 300 mm outer diameter milling tool to mill the casing fracture that has been pulled in the center, put it into the milling barrel, put a flat-bottomed grinding shoe on the bottom of the drill pipe in the milling barrel, and trim the casing fracture until the tracer string can be lowered; remove the casing and lower a new D139.7 mm casing to connect it back.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of implementation of the present invention. If the present invention is modified or replaced by equivalents without departing from the spirit and scope of the present invention, it should be included in the protection scope of the claims of the present invention.

Claims

1. A method for collecting the fracture of a free-section casing, characterized in that: The method is based on a free-section casing fracture receiving tool, wherein the free-section casing fracture receiving tool comprises a guide rail joint; a suspension piston movably connected to the guide rail joint; an outer cylinder connected to the guide rail joint; a suspension expansion cone arranged between the outer cylinder and the suspension piston; a guide shell connected to the outer cylinder; and at least one chamfered expansion piece movably connected to the guide shell and the suspension expansion cone, and the method comprises the following steps: a. Lower the pipe string with the free-section casing fracture receiving tool at the bottom to below the surface casing until it is above the fracture position of the oil layer casing, and move the chamfered expansion piece radially under the action of hydraulic pressure so that the maximum outer diameter of the free-section casing fracture receiving tool exceeds the inner diameter of the surface casing; b. Rotate the pipe string so that the bottom of the chamfered expansion piece cuts the side of the offset casing to locally damage the contact part through milling; continue to lower the pipe string, and while milling, the radial force generated causes the casing body to be drawn toward the center through cutting; c. Lift the pipe column to retract the chamfered expansion piece, so that the maximum outer diameter of the free section casing fracture retracting tool is reduced to less than the inner diameter of the surface casing, and continue to lift the tool; d. Use a sleeve milling tool whose outer diameter is smaller than the inner diameter of the surface casing to replace the sleeve.

2. The method according to claim 1, characterized in that The bottom of the chamfered diameter-expanding piece is provided with an inwardly inclined surface, and the inclined surface is paved with a high-strength alloy.

3. The method according to claim 2, characterized in that In step b, the step of making the bottom of the chamfered and expanded piece cut the side of the offset sleeve to locally damage the contact portion by grinding and milling comprises: making the high-hardness alloy at the bottom of the chamfered and expanded piece contact the side of the offset sleeve, and producing a notch on the side of the sleeve by grinding and milling to locally damage the contact portion.

4. The method according to claim 1, characterized in that: In step c, the recovery of the chamfered expanding piece includes: the joint on the guide rail drives the suspension piston that is at the end of the stroke to move upward, the relative position of the suspension piston and the suspension expanding cone enters a locked position, and the suspension expanding cone moves upward; the chamfered expanding piece is squeezed by the upper unexpanded formation to achieve recovery.

5. The method according to claim 4, characterized in that The contact surface between the suspension piston and the suspension expansion cone is provided with a conversion groove, and the conversion groove includes a first conversion groove and a second conversion groove, wherein the first conversion groove provides a mud circulation channel, and the second conversion groove provides a lifting and hanging card function.

6. The method according to claim 5, characterized in that The locking position is the second conversion slot.

7. A free-section casing fracture retracting tool, characterized in that: include: Joint on guide rail; A suspension piston movably connected to the upper joint of the guide rail; An outer cylinder connected to the joint on the guide rail; A suspension expansion cone disposed between the outer cylinder and the suspension piston; A guide housing connected to the outer cylinder; as well as At least one chamfered expansion piece is movably connected to the guide housing and the suspension expansion cone.

8. The free-section casing fracture drawing tool according to claim 7, characterized in that: The contact surface between the suspension piston and the suspension expansion cone is provided with a conversion groove, and the conversion groove includes a first conversion groove and a second conversion groove, wherein the first conversion groove provides a mud circulation channel, and the second conversion groove provides a lifting and hanging card function.

9. The free-section casing fracture drawing tool according to claim 7, characterized in that: A plurality of chamfered expansion pieces movably connected to the guide housing and the suspension expansion cone are arranged along the circumference.

10. The free-section casing fracture drawing tool according to claim 7, characterized in that: The bottom of the chamfered diameter-expanding piece is provided with an inwardly inclined surface, and the inclined surface is paved with a high-strength alloy.

Images