An electrically driven cutting tool and method for cutting a downhole tubular string

Abstract

This invention discloses an electrically driven downhole pipe string cutting tool and method. The cutting tool includes: a control system for receiving work signals from a ground control terminal and controlling the operation of an anchoring device and a cutting device according to the work signals; an anchoring device including an anchoring cylinder and an anchoring block, the anchoring cylinder driving the anchoring block to fix the cutting tool to the inner wall of the pipe string; and a cutting device including a pusher cylinder, a rotary motor, and multiple cutter bars, the pusher cylinder driving the multiple cutter bars to extend outwards or retract inwards; and the rotary motor driving the multiple cutter bars to rotate and cut the pipe string. This invention uses a mechanical cutting method, reducing environmental pollution. Its simple mechanical structure makes it easy to assemble and disassemble, saving time and manufacturing costs. The anchoring and cutting processes have high stability and reliability. Furthermore, the control system allows for adjustment of the cutting mode and cutting progress, and can be used for emergency stops in case of unexpected situations, improving work efficiency.

Description

Technical Field

[0001] This invention belongs to the field of well workover downhole tool technology, and specifically relates to an electrically driven downhole pipe string internal cutting tool and method. Background Technology

[0002] During well workover in oil and gas wells, various problems often arise that require lifting the tubing string for inspection. However, the tubing string often encounters obstruction or even jamming during the lifting process. Traditional methods of forcefully unblocking or moving the tubing string to release it are inefficient and increasingly unsuitable for operational needs. Therefore, new solutions are needed. Nowadays, the most commonly used method in well workover is to cut the tubing string and then lift it up.

[0003] Currently, there are three main methods for cutting pipe strings: shaped charge cutting, mechanical cutting, and chemical cutting. Shaped charge cutting utilizes the immense energy generated by an explosion to blast the pipe string. This method requires precise control over the location of the blast point and the type of explosive armor, but the pipe string break is irregular, and the explosives are strictly controlled products. Chemical cutting uses the chemical substances released by the reaction to corrode the pipe string, thus achieving the cut. The biggest drawback of this method is that the chemical substances cannot be recovered after cutting, causing pollution to the wellbore environment. Mechanical cutting uses electricity or hydraulic power to directly physically destroy the pipe string through mechanical operations, achieving the cut. This method allows for continuous cutting, is easy to control, and has no environmental impact. The cutting operation mode and cutting progress can be manually or automatically adjusted through a control system. However, the current problem is that the space in the wellbore is limited, and factors such as the structure of the cutting tool, the operation mode, and the cutting power need to be carefully considered. Therefore, the invention of a stable and efficient cutting tool is an urgent need in the current pipe string cutting field. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides an electrically driven downhole pipe string internal cutting tool and method, which has high stability and reliability, does not generate additional chemical substances, reduces environmental pollution, and has a simple mechanical structure that is easy to assemble and disassemble, saving time and manufacturing costs.

[0005] An electrically driven downhole pipe string cutting tool includes: a control system for receiving operation signals from a surface control terminal and controlling the operation of an anchoring device and a cutting device according to the operation signals; the anchoring device includes an anchoring cylinder and an anchoring block, the anchoring cylinder being used to drive the anchoring block to fix the cutting tool to the inner wall of the pipe string; the cutting device includes a pusher cylinder, a rotary motor, and multiple cutter bars, the pusher cylinder being used to drive the multiple cutter bars to extend outward or retract inward; the rotary motor being used to drive the multiple cutter bars to rotate and cut the pipe string.

[0006] Furthermore, the cutting device also includes a guide cone, a guide cone connecting shaft, a tool gear shaft holder, and a tool gear shaft; wherein, the guide cone is detachably connected to the tool gear shaft holder via the guide cone connecting shaft, there is a gap between the guide cone and the tool gear shaft holder, a blind hole is provided at a position off the axial center line of the guide cone, one end of the tool gear shaft is rotatably connected to the blind hole, and a plurality of tool bars are fixed on the tool gear shaft and disposed in the gap.

[0007] Furthermore, the cutting device also includes a long-lead splined bushing, an internal splined transmission component, a push rod, a bushing head, a bushing body, a splined shaft, and a tool gear shaft suspension. The tool gear shaft support is fixedly connected to the tool gear shaft suspension, and the tool gear shaft suspension is fixedly connected to the first end of the long-lead splined bushing. The tool gear shaft suspension has a through hole in the middle. The first end of the splined shaft meshes with one end of the tool gear shaft. The second end of the splined shaft passes through the through hole and connects to the first end of the bushing body inside the long-lead splined bushing. The long-lead splined bushing constrains the bushing body to slide linearly within it. The second end of the bushing body is connected to the bushing head, which is fixed to one end of the push rod. The other end of the push rod is fixedly connected to the internal splined transmission component. The first end of the internal splined transmission component meshes with the second end of the long-lead splined bushing. The second end of the internal splined transmission component is fixedly connected to the first end of the rotary motor, and the second end of the rotary motor is connected to the pusher cylinder.

[0008] Furthermore, the cutting device also includes a cutting head housing and an annular groove slide rail; wherein, the annular groove slide rail is fixedly connected to the cutting head housing, the long lead spline bushing is rotatably connected to the annular groove slide rail, and the annular groove slide rail is used to support the long lead spline bushing.

[0009] Furthermore, the cutting device also includes a transmission retainer housing and a transmission retainer; wherein, the internal spline transmission member is rotatably connected to the transmission retainer, the transmission retainer is used to support the internal spline transmission member, the transmission retainer is fixed on the transmission retainer housing, and the transmission retainer housing is slidable inside the cutting head housing.

[0010] Furthermore, the cutting device also includes a sealing collar; wherein the sealing collar is fixed on the long lead spline bushing, and the sealing collar is used for sealing between the long lead spline bushing and the cutting head housing.

[0011] Furthermore, the anchoring device also includes an anchoring push block, an anchoring movable push block, an anchoring connecting hinge, an anchoring plate, and an anchoring movable push block end cap; wherein, the first end of the anchoring movable push block is hinged to the second end of the anchoring plate through the anchoring connecting hinge, the second end of the anchoring movable push block is fixed on the anchoring movable push block end cap, the first end of the anchoring plate is hinged to the second end of the anchoring push block through the anchoring connecting hinge, the anchoring block is fixed to the outer end face of the anchoring plate, and the anchoring movable push block end cap is fitted onto the shaft of the anchoring electric cylinder.

[0012] Furthermore, the anchoring device also includes an inner cylinder of the anchoring push block and an anchoring central shaft; wherein, the first end of the inner cylinder of the anchoring push block is connected to the first end of the anchoring push block through the end cap of the anchoring push block, the second end of the inner cylinder of the anchoring push block abuts against the first end of the anchoring central shaft, the first end of the inner cylinder of the anchoring movable push block is fitted onto the second end of the anchoring central shaft, the second end of the inner cylinder of the anchoring movable push block is connected to the end cap of the anchoring movable push block, and the anchoring movable push block is fitted onto the inner cylinder of the anchoring movable push block.

[0013] Furthermore, multiple anchor blocks are provided, and the anchor blocks are made of elastic material.

[0014] Furthermore, a spring is provided between the anchoring piece and the anchoring center axis.

[0015] Furthermore, the control system includes a driver subsection, a control subsection, a communication subsection, and an armored cable, and the anchoring device includes a first anchoring device and a second anchoring device with identical structures; wherein, the cutting device, the first anchoring device, the driver subsection, the second anchoring device, the control subsection, the communication subsection, and the armored cable are connected in sequence.

[0016] This invention also provides a method for electrically driven downhole pipe string cutting, comprising the following steps: a control system receives a work signal from a ground control terminal; the control system controls the anchoring cylinder of the anchoring device to actuate, the anchoring cylinder driving the anchoring block to fix the cutting tool to the inner wall of the pipe string; the control system controls the pusher cylinder of the cutting device to actuate, the pusher cylinder driving multiple cutter bars to unfold outward; the control system controls the rotary motor of the cutting device to actuate, the rotary motor driving multiple cutter bars to rotate and cut the pipe string; after cutting is completed, the control system controls the pusher cylinder to actuate, the pusher cylinder driving multiple cutter bars to retract inward; the control system controls the anchoring cylinder to actuate, the anchoring cylinder driving the anchoring block to retract.

[0017] The beneficial effects of this invention are:

[0018] 1. This invention is a mechanical electric cutting method, which will not cause damage to the casing or environmental pollution like explosive cutting or chemical cutting.

[0019] 2. This invention directly physically destroys the pipe string through mechanical operations to cut the downhole pipe string. This method can cut continuously, is easy to control, and has no impact on the environment. The cutting operation mode and cutting progress can be adjusted manually or automatically through the control system.

[0020] 3. The anchoring and cutting processes of this invention exhibit high stability and reliability. During anchoring, the anchoring electric cylinder pushes forward, causing the anchoring moving block to move forward. Due to the characteristics of the four-bar linkage, the anchoring connecting hinge rotates, causing the anchoring plate to extend outward. The anchoring block contacts the inner wall of the pipe, thus achieving anchoring. The structure is simple and reliable. During cutting, the pusher electric cylinder drives the rotary motor, causing the push rod to push the bushing head and bushing body forward. Since the bushing body and the spline shaft are in a helical spline fit, the spline shaft rotates, converting the axial force into a circumferential rotational force. This force is then transmitted through gears, causing the tool gear shaft to rotate and driving the tool bar to extend outward, achieving cutting. Simultaneously, the rotary motor rotates, causing the internal spline transmission component to rotate. This rotation is transmitted downwards, causing the tool to rotate and thus cutting the pipe string.

[0021] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A schematic diagram of the overall structure of an electrically driven downhole pipe string cutting tool according to an embodiment of the present invention is shown;

[0024] Figure 2a A schematic diagram of the installation of the bushing body and the splined shaft according to an embodiment of the present invention is shown;

[0025] Figure 2b A schematic diagram of the installation of the pusher electric cylinder and the rotary motor according to an embodiment of the present invention is shown;

[0026] Figure 2c A schematic diagram of the installation of the anchoring hinge and anchor plate according to an embodiment of the present invention is shown;

[0027] Figure 2d A schematic diagram of the installation of the anchor housing and the driver section according to an embodiment of the present invention is shown;

[0028] Figure 2e A schematic diagram of the installation of the anchoring cylinder end cap and the cylinder fixing sleeve according to an embodiment of the present invention is shown;

[0029] Figure 2f A schematic diagram of the installation of the control section and anchoring push block according to an embodiment of the present invention is shown;

[0030] Figure 2g A schematic diagram of the installation of the control section and communication section according to an embodiment of the present invention is shown;

[0031] Figure 3 An isometric view of a tool holder according to an embodiment of the present invention is shown;

[0032] Figure 4 An isometric view of a splined shaft according to an embodiment of the present invention is shown;

[0033] Figure 5 An isometric view of an anchoring device according to an embodiment of the present invention is shown.

[0034] In the diagram: 1. Draw cone; 2. Tool holder; 3. Tool gear shaft holder; 4. Tool gear shaft; 5. Sealing ring; 6. Cutting head housing; 7. Long lead spline bushing; 8. Annular groove slide rail; 9. Internal spline transmission component; 10. Transmission cage housing; 11. Transmission cage; 12. Rotary motor; 13. Electric cylinder housing; 14. Pusher electric cylinder; 15. Electric cylinder fixed end cover; 16. Anchoring push block; 17. Anchoring push block inner cylinder; 18. Anchoring push block end cover; 19. Push rod; 20. Bushing head; 21. Bushing body 22. Splined shaft; 23. Tool gear shaft suspension; 24. Lead-in cone connecting shaft; 25. Anchor housing; 26. Anchor center shaft; 27. Anchor connecting hinge; 28. Anchor block; 29. ​​Anchor plate; 30. Anchor moving push block; 31. Anchor moving push block inner cylinder; 32. Anchor moving push block end cover; 33. Anchor electric cylinder; 34. Anchor electric cylinder end cover; 35. Electric cylinder fixing sleeve; 36. Driver short section; 37. Control short section; 38. Communication short section; 39. Armored cable; 40. Tool; 41. Mounting hole. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] It should be noted that, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself. The terms "first" and "second," etc., are used for descriptive purposes only.

[0037] This invention provides an electrically driven downhole pipe string internal cutting tool and method that uses mechanical cutting to reduce environmental pollution.

[0038] Please see Figure 1 , Figure 1 A schematic diagram of the overall structure of an electrically driven downhole pipe string cutting tool according to an embodiment of the present invention is shown.

[0039] An electrically driven downhole pipe string cutting tool includes a cutting device, an anchoring device, and a control system. The control system is used to receive operation signals from a ground control terminal and control the anchoring device and the cutting device to operate according to the operation signals.

[0040] Specifically, the control system includes a driver section 36, a control section 37, a communication section 38, and an armored cable 39.

[0041] Control section 37 and communication section 38 are connected to the ground control terminal via armored cable 39. The ground control terminal includes communication equipment and power supply equipment, wherein the power supply equipment is used to transmit power to the cutting tool via armored cable 39, and the communication equipment enables bidirectional transmission of signals between the ground and the well bottom via armored cable 39.

[0042] Surface equipment also includes logging winches, which are used for lowering and retrieving cutting tools from the well.

[0043] Please see Figure 2a and Figure 2c , Figure 2a A schematic diagram of the installation of the bushing body and the splined shaft according to an embodiment of the present invention is shown. Figure 2c A schematic diagram of the installation of the anchoring connection hinge and anchoring plate according to an embodiment of the present invention is shown.

[0044] Specifically, the anchoring device includes an anchoring electric cylinder 33 and an anchoring block 28, and the cutting device includes a pusher electric cylinder 14, a rotary motor 12, and multiple cutter bars 2. The anchoring electric cylinder 33 is used to drive the anchoring block 28 to fix the cutting tool to the inner wall of the pipe string; the pusher electric cylinder 14 is used to drive the multiple cutter bars 2 to extend outward or retract inward; the rotary motor 12 is used to drive the multiple cutter bars 2 to rotate and cut the pipe string.

[0045] The embodiments of the present invention belong to mechanical electric cutting, which will not cause damage to the casing or environmental pollution like explosive cutting or chemical cutting.

[0046] For example, two anchoring devices are provided, and the cutting device, the first anchoring device, the driver section 36, the second anchoring device, the control section 37, and the communication section 38 are connected in sequence.

[0047] Please see Figure 2a and Figure 2b , Figure 2b A schematic diagram of the installation of the pusher electric cylinder and the rotary motor according to an embodiment of the present invention is shown.

[0048] Furthermore, the cutting device also includes a pilot cone 1, a tool gear shaft holder 3, a tool gear shaft 4, a sealing ring 5, a cutting head housing 6, a long lead spline bushing 7, an annular groove slide rail 8, an internal spline transmission component 9, a transmission retainer housing 10, a transmission retainer 11, an electric cylinder housing 13, an electric cylinder fixed end cover 15, a push rod 19, a bushing head 20, a bushing body 21, a spline shaft 22, a tool gear shaft suspension 23, and a pilot cone connecting shaft 24.

[0049] The long lead spline bushing 7, the annular groove slide rail 8, the internal spline transmission component 9, the transmission retainer housing 10, the transmission retainer 11, the rotary motor 12, the push rod 19, the bushing head 20, and the bushing body 21 are all located inside the cutting head housing 6.

[0050] The guide cone 1 is detachably connected to the tool gear shaft holder 3 via the guide cone connecting shaft 24. There is a gap between the guide cone 1 and the tool gear shaft holder 3. The guide cone 1 is provided with a blind hole at a position off the axial center line. One end of the tool gear shaft 4 is rotatably connected to the blind hole. The other end of the tool gear shaft 4 extends into the tool gear shaft holder 3 and meshes with the first end of the spline shaft 22. Multiple tool holders 2 are fixed on the tool gear shaft 4 and are set in the gap between the guide cone 1 and the tool gear shaft holder 3.

[0051] Please see Figure 3 , Figure 3 An isometric view of a tool holder according to an embodiment of the present invention is shown. The tool holder 2 is provided with a tool 40 and a mounting hole 41. The tool holder 2 is detachably connected to the tool gear shaft 4 through the mounting hole 41.

[0052] In this embodiment of the invention, a guide cone 1 is provided at the front end of multiple cutter bars 2 to protect the cutter bars 2 when the cutting tool is lowered into the well. A gap is left between the guide cone 1 and the tool gear shaft 3 to store the cutter bars 2. When the cutter bars 2 are not performing cutting operations, such as when they are lowered into the well or when they are retrieved, the cutter bars 2 are retracted into the gap between the guide cone 1 and the tool gear shaft 3. This prevents the protruding part of the cutter bars 2 from colliding with the pipe wall and damaging the pipe string when the cutting tool is lowered into the well or when it is retrieved, which would be inconvenient for operation. It also prevents the cutter bars 2 from protruding and scratching the operators during loading and unloading.

[0053] The tool gear shaft holder 3 is fixedly connected to the tool gear shaft suspension 23. The tool gear shaft suspension 23 is fixedly connected to the first end of the long lead spline bushing 7. The tool gear shaft suspension 23 has a through hole in the middle. The second end of the spline shaft 22 passes through the through hole and connects to the first end of the bushing body 21 inside the long lead spline bushing 7. The bushing body 21 can slide linearly inside the long lead spline bushing 7.

[0054] Please see Figure 4 , Figure 4 An isometric view of a spline shaft according to an embodiment of the present invention is shown.

[0055] The spline shaft 22 and the bushing body 21 are a helical spline pair, wherein the bushing body 21 is constrained by the long lead spline bushing 7 to only move linearly, and the spline shaft 22 is constrained by the tool gear shaft holder 3 and the tool gear shaft suspension 23 to only rotate.

[0056] The annular groove slide rail 8 is fixedly connected to the cutting head housing 6, and the long lead spline bushing 7 is rotatably connected to the annular groove slide rail 8. The annular groove slide rail 8 is used to support the long lead spline bushing 7. The sealing ring 5 is fixed on the long lead spline bushing 7 and is used for sealing between the long lead spline bushing 7 and the cutting head housing 6. It is suitable for downhole pressurized operations.

[0057] The second end of the bushing body 21 is connected to the bushing head 20. The bushing head 20 is fixed to one end of the push rod 19. The other end of the push rod 19 is fixedly connected to the internal spline transmission component 9. The first end of the internal spline transmission component 9 meshes with the second end of the long lead spline bushing 7. The second end of the internal spline transmission component 9 passes through the transmission retainer 11 and is fixedly connected to the first end of the rotary motor 12. The second end of the internal spline transmission component 9 is rotatably connected to the transmission retainer 11. The transmission retainer 11 is used to support the internal spline transmission component 9. The transmission retainer 11 is fixed on the transmission retainer housing 10. The transmission retainer housing 10 can slide inside the cutting head housing 6.

[0058] The second end of the rotary motor 12 is connected to the pusher cylinder 14. The cylinder fixing end cover 15 fixes the pusher cylinder 14 inside the cylinder housing 13. The first end of the cylinder housing 13 is connected to the cutting head housing 6.

[0059] The first anchoring device and the second anchoring device have the same structure. The structure of the anchoring device will be described below by way of example, taking the first anchoring device as an example.

[0060] Figure 2c and Figure 2d , Figure 2d A schematic diagram of the installation of the anchor housing and the driver section according to an embodiment of the present invention is shown.

[0061] Specifically, the first anchoring device also includes an anchoring push block 16, an anchoring push block inner cylinder 17, an anchoring push block end cap 18, an anchoring outer shell 25, an anchoring central shaft 26, an anchoring connecting hinge 27, an anchoring plate 29, an anchoring movable push block 30, an anchoring movable push block inner cylinder 31, an anchoring movable push block end cap 32, an anchoring electric cylinder end cap 34, and an electric cylinder fixing sleeve 35.

[0062] The first end of the anchoring push block 16 is connected to the second end of the electric cylinder housing 13, and the second end of the anchoring push block 16 is connected to the first end of the anchoring housing 25. The first end of the anchoring push block inner cylinder 17 is fixedly connected to the first end of the anchoring push block 16 through the anchoring push block end cap 18. The second end of the anchoring push block inner cylinder 17 abuts against the first end of the anchoring central shaft 26 inside the anchoring housing 25. The first end of the anchoring movable push block inner cylinder 31 is fitted onto the second end of the anchoring central shaft 26, and the second end of the anchoring movable push block inner cylinder 31 is connected to the anchoring movable push block end cap 32. The anchoring movable push block end cap 32 is fitted onto the shaft of the anchoring electric cylinder 33. The anchoring push block 30 is fitted onto the inner cylinder 31 of the anchoring push block. The first end of the anchoring push block 30 is hinged to the second end of the anchoring plate 29 via the anchoring connection hinge 27. The second end of the anchoring push block 30 is fixed to the end cap 32 of the anchoring push block. The first end of the anchoring plate 29 is hinged to the second end of the anchoring push block 16 via the anchoring connection hinge 27. Multiple anchoring blocks 28 are fixed on the outer end face of the anchoring plate 29. The anchoring shell 25 has an opening at the position of the anchoring plate 29. The anchoring plate 29, the anchoring connection hinge 27, the anchoring push block 16, and the anchoring push block 30 will form a four-bar linkage.

[0063] Furthermore, the anchor block 28 is made of an elastic material, such as rubber. A spring is provided between the anchor plate 29 and the anchoring center shaft 26. The anchor block 28, being made of an elastic material, is used for shock absorption during anchoring operations. The spring between the anchor plate 29 and the anchoring center shaft 26 prevents the anchor plate 29 and the anchoring connecting hinge 27 from becoming collinear, which could cause the anchoring device to jam. It should be noted that when the anchor plate 29 and the anchoring connecting hinge 27 are collinear, this is the dead point of the four-bar linkage consisting of the anchor plate 29, the anchoring connecting hinge 27, the anchoring push block 16, and the anchoring moving push block 30, at which point the four-bar linkage will jam.

[0064] Please see Figures 2e-2g , Figure 2e A schematic diagram of the installation of the anchoring cylinder end cap and the cylinder fixing sleeve according to an embodiment of the present invention is shown; Figure 2f A schematic diagram of the installation of the control section and anchoring push block according to an embodiment of the present invention is shown; Figure 2g A schematic diagram of the installation of the control section and communication section according to an embodiment of the present invention is shown.

[0065] Anchoring cylinder 33 is connected to anchoring cylinder end cap 34, and cylinder fixing sleeve 35 is connected to anchoring cylinder end cap 34, fixing anchoring cylinder 33 inside anchoring housing 25. The second end of anchoring housing 25 is connected to the first end of actuator subsection 36, the second end of actuator subsection 36 is connected to the first end of second anchoring device, the second end of second anchoring device is connected to the first end of control subsection 37, and the second end of control subsection 37 is connected to communication subsection 38. Communication subsection 38 is connected to ground control terminal via armored cable 39.

[0066] When the cutting tool of this invention is used, cutting is achieved through anchoring, rotation, and feed movements, as detailed below:

[0067] Please see Figure 5 , Figure 5 An isometric view of an anchoring device according to an embodiment of the present invention is shown.

[0068] Anchoring motion: The anchoring electric cylinder 33 pushes forward to move the anchoring push block 30 forward. Due to the characteristics of the four-bar linkage, it will drive the anchoring connecting hinge 27 to rotate, causing the anchoring plate 29 to extend outward and the anchoring block 28 to contact the inner wall of the pipe, thereby achieving anchoring.

[0069] Rotary cutting motion: The rotation of the rotary motor 12 drives the internal spline transmission component 9 to rotate, and the rotation is transmitted downwards to make the cutter 40 rotate, thereby cutting the pipe string.

[0070] Feed motion: The push rod 19 pushes the bushing head 20 and bushing body 21 forward. Since the bushing body 21 and the spline shaft 22 are in a helical spline fit, the spline rotates. Through gear transmission, the tool gear shaft 4 is driven, which drives the tool holder 2 to extend outward.

[0071] The cutting tool of this invention has a simple mechanical structure, is easy to assemble and disassemble, and can save time and manufacturing costs.

[0072] Based on the aforementioned electrically driven downhole tubing string internal cutting tool, this invention also provides an electrically driven downhole tubing string internal cutting method, comprising the following steps:

[0073] S1. Tool entry into the well: After the armored cable 39 is connected to the cutting tool, the cutting tool is lowered to the target well depth.

[0074] In practice, the cutting tool is lowered to the target well depth using a logging winch.

[0075] S2, Anchoring: The control system controls the anchoring electric cylinder 33 of the anchoring device to rotate forward, and the anchoring electric cylinder 33 drives the anchoring block 28 to fix the cutting tool on the inner wall of the pipe string.

[0076] In practice, the control terminal on the ground sends an operation signal to the cutting tool at the bottom of the well via the armored cable 39. After receiving the signal, the cutting tool first starts the anchoring cylinder 33 according to the built-in program of the control system, and extends the anchoring block 28 outward to complete the fixation of the cutting tool relative to the pipe string.

[0077] The anchoring electric cylinder 33 pushes forward, causing the anchoring moving block 30 to move forward. Due to the characteristics of the four-bar linkage, it will drive the anchoring connecting hinge 27 to rotate, causing the anchoring plate 29 to extend outward. The anchoring block 28 contacts the inner wall of the pipe, thereby achieving anchoring.

[0078] S3. Cutting: The control system controls the pusher cylinder 14 of the cutting device to rotate forward, and the pusher cylinder 14 drives multiple cutter bars 2 to unfold outward; the control system controls the rotary motor 12 of the cutting device to rotate, and the rotary motor 12 drives multiple cutter bars 2 to rotate to cut the pipe string.

[0079] In practice, the rotary motor 12 and the pusher cylinder 14 of the cutting device are started. The pusher cylinder 14 slowly extends multiple cutter bars 2 to the inner wall of the oil pipe. At this time, the speed of the rotary motor 12 is increased to the rated speed according to the control program, and the oil pipe is cut according to the cutting program.

[0080] The pusher cylinder 14 drives the rotary motor 12, which in turn pushes the push rod 19 to push the bushing head 20 and the bushing body 21 forward. Since the bushing body 21 and the spline shaft 22 are in a helical spline fit, the spline shaft 22 rotates. Through gear transmission, the tool gear shaft 4 is driven, which drives multiple tool bars 2 to extend outward. At the same time, the rotary motor 12 rotates, which drives the inner spline transmission component 9 to rotate. The rotation is transmitted downward, causing multiple tool bars 2 to rotate, thereby cutting the tube string.

[0081] S4. Retracting the blade: After the cutting is completed, the control system controls the pusher cylinder 14 to reverse, and the pusher cylinder 14 drives multiple blade rods 2 to retract inward.

[0082] In practice, after the cutting is completed, the rotation speed of the rotary motor 12 is reduced, and at the same time the pusher cylinder 14 reverses, retracting the multiple cutter bars 2 inward to their initial positions.

[0083] S5. Anchor release: The control system controls the anchoring cylinder 33 to reverse, and the anchoring cylinder 33 drives the anchoring block 28 to retract.

[0084] S6. Tool Retrieval: Retrieve the cutting tool to the surface.

[0085] In practice, the cutting tool is retrieved to the surface using a logging winch.

[0086] This invention uses mechanical operations to directly physically destroy the pipe string, thereby cutting the downhole pipe string. This method allows for continuous cutting, is easy to control, and has no impact on the environment. The cutting operation mode and its progress can be manually or automatically adjusted through the control system. It can be stopped immediately in case of an emergency, greatly improving work efficiency. It has high stability and reliability, does not generate additional chemical substances, and reduces environmental pollution.

[0087] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electrically driven downhole pipe string internal cutting tool, characterized in that, include: The control system is used to receive the operation signal from the ground control terminal and control the anchoring device and the cutting device to operate according to the operation signal. The anchoring device includes an anchoring electric cylinder and an anchoring block. The anchoring electric cylinder is used to drive the anchoring block to fix the cutting tool to the inner wall of the pipe string. The cutting device includes a pusher cylinder, a rotary motor, and multiple cutter bars. The pusher cylinder is used to drive the multiple cutter bars to extend outward or retract inward. The rotary motor is used to drive the multiple cutter bars to rotate and cut the tube string. The cutting device further includes a guide cone, a guide cone connecting shaft, a tool gear shaft holder, and a tool gear shaft; wherein, the guide cone is detachably connected to the tool gear shaft holder via the guide cone connecting shaft, there is a gap between the guide cone and the tool gear shaft holder, a blind hole is provided at a position off the axial center line of the guide cone, one end of the tool gear shaft is rotatably connected to the blind hole, and a plurality of tool bars are fixed on the tool gear shaft and disposed in the gap; The cutting device further includes a long-lead splined bushing, an internal splined transmission component, a push rod, a bushing head, a bushing body, a splined shaft, and a tool gear shaft suspension. The tool gear shaft support is fixedly connected to the tool gear shaft suspension, and the tool gear shaft suspension is fixedly connected to the first end of the long-lead splined bushing. The tool gear shaft suspension has a through hole in the middle. The first end of the splined shaft meshes with one end of the tool gear shaft. The second end of the splined shaft passes through the through hole and connects to the first end of the bushing body inside the long-lead splined bushing. The long-lead splined bushing constrains the bushing body to slide linearly within it. The second end of the bushing body is connected to the bushing head, which is fixed to one end of the push rod. The other end of the push rod is fixedly connected to the internal splined transmission component. The first end of the internal splined transmission component meshes with the second end of the long-lead splined bushing. The second end of the internal splined transmission component is fixedly connected to the first end of the rotary motor, and the second end of the rotary motor is connected to the pusher cylinder.

2. The electrically driven downhole pipe string cutting tool according to claim 1, characterized in that, The cutting device also includes a cutting head housing and an annular groove slide rail; The annular groove slide rail is fixedly connected to the cutting head housing, and the long lead spline bushing is rotatably connected to the annular groove slide rail. The annular groove slide rail is used to support the long lead spline bushing.

3. The electrically driven downhole pipe string cutting tool according to claim 2, characterized in that, The cutting device also includes a transmission retainer housing and a transmission retainer; The internal spline drive component is rotatably connected to the drive cage, the drive cage is used to support the internal spline drive component, the drive cage is fixed on the drive cage housing, and the drive cage housing can slide inside the cutting head housing.

4. The electrically driven downhole pipe string cutting tool according to claim 2 or 3, characterized in that, The cutting device also includes a sealing collar; The sealing collar is fixed on the long lead spline bushing and is used to seal the space between the long lead spline bushing and the cutting head housing.

5. The electrically driven downhole pipe string cutting tool according to claim 1, characterized in that, The anchoring device also includes an anchoring push block, an anchoring movable push block, an anchoring connecting hinge, an anchoring plate, and an anchoring movable push block end cap; The first end of the anchoring push block is hinged to the second end of the anchoring plate via the anchoring connection hinge. The second end of the anchoring push block is fixed on the end cap of the anchoring push block. The first end of the anchoring plate is hinged to the second end of the anchoring push block via the anchoring connection hinge. The anchoring block is fixed on the outer end face of the anchoring plate. The end cap of the anchoring push block is fitted onto the shaft of the anchoring electric cylinder.

6. The electrically driven downhole pipe string cutting tool according to claim 5, characterized in that, The anchoring device also includes an inner cylinder of the anchoring push block and an anchoring center shaft; Wherein, the first end of the inner cylinder of the anchoring push block is connected to the first end of the anchoring push block through the end cap of the anchoring push block, the second end of the inner cylinder of the anchoring push block abuts against the first end of the anchoring central shaft, the first end of the inner cylinder of the anchoring movable push block is fitted onto the second end of the anchoring central shaft, the second end of the inner cylinder of the anchoring movable push block is connected to the end cap of the anchoring movable push block, and the anchoring movable push block is fitted onto the inner cylinder of the anchoring movable push block.

7. The electrically driven downhole pipe string cutting tool according to any one of claims 1-3, 5 and 6, characterized in that, Multiple anchor blocks are provided, and the anchor blocks are made of elastic material.

8. The electrically driven downhole pipe string cutting tool according to claim 6, characterized in that, A spring is provided between the anchoring plate and the anchoring center axis.

9. The electrically driven downhole pipe string cutting tool according to any one of claims 1-3, 5, 6 and 8, characterized in that, The control system includes a driver section, a control section, a communication section, and an armored cable; the anchoring device includes a first anchoring device and a second anchoring device with identical structures. The cutting device, the first anchoring device, the driver sub-section, the second anchoring device, the control sub-section, the communication sub-section, and the armored cable are connected in sequence.

10. A method for cutting inside an electrically driven downhole tubing string, characterized in that, Based on the electrically driven downhole tubing string cutting tool according to any one of claims 1-9, the method includes the following steps: The control system receives operation signals from the ground control terminal; The control system controls the anchoring electric cylinder of the anchoring device to move, and the anchoring electric cylinder drives the anchoring block to fix the cutting tool to the inner wall of the pipe string; The control system controls the action of the pusher cylinder of the cutting device, which drives multiple cutter bars to extend outward. The control system controls the operation of the rotary motor of the cutting device, and the rotary motor drives multiple cutter bars to rotate and cut the tube string; After the cutting is completed, the control system controls the pusher cylinder to move, and the pusher cylinder drives multiple cutter bars to retract inward; The control system controls the movement of the anchoring electric cylinder, which in turn drives the anchoring block to retract.

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