A pre-set downhole choke electric fishing tool and fishing method thereof

Abstract

The present invention provides a pre-set downhole throttle electric salvage tool and a salvage method thereof, comprising an upper joint, an outer tube, a lower joint, a lower pressure cap and a working outer tube connected in sequence from top to bottom, the lower end face of the lower pressure cap abuts against a press sleeve, the outer wall of the press sleeve is provided with a claw seat, the claw seat is embedded with a claw, a motor is installed in the outer tube, a screw rod is passed through and rotatably connected in the hollow rotor shaft of the motor, the screw rod is connected to a central push rod, and the central push rod can be inserted into the throttle to unseal the throttle. The present invention relies on the forward and reverse rotation of the motor to provide power, drive the up and down reciprocating motion of the central push rod of the throttle until the central push rod enters the inside of the pre-set downhole throttle, and realizes the unsealing of the pre-set downhole throttle in service; the inner cavity of the outer tube can be used as a storage space for lubricating grease, and the lubricating grease stored therein can be squeezed between the oil pipe and the throttle during the salvage process, reducing the salvage friction resistance and improving the success rate of salvage.

Description

Technical Field

[0001] The invention belongs to the field of downhole operation tools, and in particular relates to a preset downhole choke electric fishing tool and a fishing method thereof. Background Art

[0002] At present, downhole throttling technology has become one of the key technologies for the development of low-pressure and low-yield gas fields. It is widely used in the early stage of gas well production. It has the important function of low-pressure gas gathering and is an important means for the economical and efficient development of low-pressure and low-yield gas fields. Therefore, the pre-set downhole throttling device is widely used in the early stage of low-pressure and low-yield gas field development. Its main feature is that when the production tubing is lowered, the pre-set working cylinder is connected at an appropriate position, and the pre-set working cylinder is lowered into the gas well along with the production tubing. When production is needed, the downhole throttling device is placed in the pre-set working cylinder to seal it, so as to achieve the purpose of throttling and pressure reduction production of gas wells.

[0003] However, in the later stage of gas field production, the formation water infiltrates into the wellbore, resulting in a decrease in production. It is necessary to adopt technical measures such as drainage and gas production, so the choke needs to be salvaged. However, during the production of the gas field, due to reasons such as sand production, scaling, and corrosion, some wells have problems such as difficulty in salvaging downhole chokes and low success rate. If the downhole choke cannot be salvaged in time, some low-pressure water-producing gas wells may not be able to implement drainage and gas production measures such as bubble drainage, velocity string, and plunger gas lift, resulting in low gas well production or well shutdown. In order to finally remove the choke, measures such as well pressure lifting or pressure lifting are required, and these measures are not only expensive, but also have the risk of stuck drill and high well control safety. Summary of the invention

[0004] The embodiment of the present invention provides a preset downhole choke electric fishing tool and a fishing method thereof, the first purpose of which is to solve the problem of high cost of existing choke fishing measures; the second purpose of which is to solve the problem of drill sticking risk of existing choke fishing measures.

[0005] In order to solve the above technical problems, the present invention provides a preset downhole choke electric fishing tool, comprising an upper joint, an outer tube, a lower joint, a lower pressure cap and a working outer tube connected in sequence from top to bottom, the lower end surface of the lower pressure cap abuts against a pressing sleeve, the outer wall of the pressing sleeve is provided with a claw seat, and the claw seat is embedded with a claw;

[0006] A motor is installed in the outer cylinder, a screw is screwed through the hollow rotor shaft of the motor, the lower end of the screw is coaxially fixed to the center push rod, a sheath is sleeved on the center push rod, the outer wall of the sheath is connected to the inner wall of the lower joint, and the lower joint is fixed to the lower pressure cap by a shear pin;

[0007] Among them, a large spring in a compressed state is housed in a cavity formed by the outer wall of the sleeve, the inner wall of the lower pressure cap and the upper end surface of the pressing sleeve, and a small spring in a compressed state is housed in a cavity formed by the outer wall of the pressing sleeve, the inner wall of the working outer cylinder and the upper end surface of the claw seat, and the elastic force of the small spring is smaller than that of the large spring.

[0008] Furthermore, solid grease is stored in the outer cylinder, and the solid grease is squeezed into the oil pipe and the preset downhole choke under the up and down reciprocating motion of the central push rod.

[0009] Preferably, the lower pressure cap is a hollow cylindrical structure, and the middle section of the inner wall of the hollow cylinder extends radially toward the center axis to form a circle of annular bosses, and the bottom end face of the lower joint abuts against the upper surface of the annular boss. The lower surface of the annular boss, the inner wall of the hollow cylinder below the annular boss, the upper end face of the pressing sleeve and the outer wall of the sleeve form an annular cavity, and the large spring is compressed and placed in the annular cavity.

[0010] Furthermore, a straightening block is provided in the outer tube, the straightening block is sleeved at the connection between the screw rod and the center push rod, and the straightening block is located below the fixing seat, and the fixing seat and the straightening block are connected by screws.

[0011] Preferably, the fixing seat is composed of two semi-annular structures joined together, and the inner wall of the circular ring structure formed by the joining is screwed to the screw rod.

[0012] Furthermore, the motor is a stepping motor capable of forward and reverse rotation.

[0013] The present invention also protects a salvaging method of a preset downhole choke electric salvaging tool:

[0014] The motor is connected through the logging cable and the preset downhole choke electric fishing tool is lowered to the top of the preset downhole choke, and then the preset downhole choke electric fishing tool is lifted up, the claws grab the preset downhole choke fishing neck, the motor drives the center push rod to move down through the screw rod, the center push rod is inserted into the center hole of the preset downhole choke, and the choke is forced to be unsealed, and the preset downhole choke electric fishing tool is lifted up to take out the preset downhole choke.

[0015] Further, the claws grasping the fishing neck of the preset downhole choke specifically include:

[0016] The preset downhole choke electric fishing tool is lowered until the claw touches the preset downhole choke fishing neck. The claw moves upward under the upward thrust of the preset downhole choke, the claw seat continuously squeezes the small spring, and the claw opens and grabs the fishing neck under the upward thrust of the fishing neck.

[0017] Furthermore, if the preset downhole choke fails to be unsealed, the hand is automatically released by the rotation of the motor or by the upward shock of the logging cable, so that the shear pin is disconnected and the elastic force of the large spring is released. Since the elastic force of the large spring is greater than the elastic force of the small spring, the pressing sleeve moves downward, the claw seat moves downward with the pressing sleeve, and the claw releases the fishing neck. At this time, the electric fishing tool for the preset downhole choke can be taken out.

[0018] Furthermore, during the salvage process, the forward and reverse rotation of the motor drives the central push rod to move up and down, squeezing the solid grease downward to lubricate the inner wall of the oil pipe and the outer surface of the preset downhole choke.

[0019] The beneficial effects of the present invention are as follows:

[0020] (1) The electric fishing tool for the preset downhole choke relies on the forward and reverse rotation of the motor to provide power, driving the up and down reciprocating movement of the center push rod of the choke until the center push rod enters the inside of the preset downhole choke (the original position of the tool), thereby unsealing the preset downhole choke in service.

[0021] (2) The inner cavity of the outer cylinder can be used as a storage space for lubricating grease. During the salvage process, the lubricating grease stored therein can be squeezed into the space between the oil pipe and the throttle, thereby reducing the friction resistance of salvage and improving the success rate of salvage.

[0022] (3) The electric fishing tool for the preset downhole choke has a simple structure, is easy to operate, and has a two-way release function. It can meet the safe, reliable, low-cost fishing technology and economic requirements for the fishing of preset downhole chokes in gas fields.

[0023] In order to make the above contents of the present invention more clearly understood, preferred embodiments are given below and described in detail in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a front view of a preset downhole choke electric fishing tool.

[0025] Figure 2 yes Figure 1 A partial enlarged view of middle A.

[0026] Description of reference numerals:

[0027] 1. Upper joint; 2. Outer cylinder; 3. Motor; 4. Screw; 5. Fixed seat; 6. Straightening block; 7. Lower joint; 8. Shear pin; 9. Lower pressure cap; 10. Large spring; 11. Pressing sleeve; 12. Center push rod; 13. Small spring; 14. Claw seat; 15. Working outer cylinder; 16. Sheath; 17. Claw. DETAILED DESCRIPTION

[0028] The following describes the implementation of the present invention through specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0029] It should be noted that, in the present invention, the up, down, left and right in the figure are regarded as the up, down, left and right of the preset downhole choke electric fishing tool described in this specification.

[0030] The exemplary embodiments of the present invention are now described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0031] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0032] First embodiment:

[0033] The first embodiment of the present invention relates to a pre-set downhole choke electric fishing tool, see Figure 1 , including an upper joint 1, an outer tube 2, a lower joint 7, a lower pressing cap 9 and a working outer tube 15 connected in sequence from top to bottom, the lower end surface of the lower pressing cap 9 abuts against a pressing sleeve 11, the outer wall of the pressing sleeve 11 is provided with a claw seat 14, and the claw seat 14 is embedded with a claw 17;

[0034] A motor 3 is installed in the outer cylinder 2, a screw rod 4 is screwed through the hollow rotor shaft of the motor 3, the lower end of the screw rod 4 is coaxially fixed to the center push rod 12, a sheath 16 is sleeved on the center push rod 12, the outer wall of the sheath 16 is connected to the inner wall of the lower joint 7, and the lower joint 7 is fixed to the lower pressure cap 9 by a shear pin 8;

[0035] Among them, the cavity formed by the outer wall of the sleeve 16, the inner wall of the lower pressure cap 9 and the upper end surface of the pressing sleeve 11 contains a large spring 10 in a compressed state and is sleeved on the sleeve 16; the cavity formed by the outer wall of the pressing sleeve 11, the inner wall of the working outer cylinder 15 and the upper end surface of the claw seat 14 contains a small spring 13 in a compressed state and is sleeved on the pressing sleeve 11, and the elastic force of the small spring 13 is smaller than the elastic force of the large spring 10.

[0036] The working principle of the preset downhole choke electric fishing tool is as follows:

[0037] Salvage process: connect the motor 3 through the logging cable and lower the preset downhole choke electric salvage tool to the top of the preset downhole choke, then lift the preset downhole choke electric salvage tool, the claw 17 grabs the salvage neck of the preset downhole choke, the motor 3 drives the central push rod 12 to move downward through the screw rod 4, the central push rod 12 is inserted into the central hole of the preset downhole choke, forcing the choke to be unsealed, and the preset downhole choke electric salvage tool can be lifted to take out the preset downhole choke.

[0038] Unsealing process: lower the preset downhole choke electric fishing tool until the claw 17 touches the preset downhole choke fishing neck, the claw 17 moves upward under the upward thrust of the preset downhole choke, the claw seat 14 continues to squeeze the small spring 13, the claw 17 is pushed upward by the fishing neck and opens to grab the fishing neck.

[0039] Operation after unsealing failure: If the preset downhole choke fails to be unsealed, the shear pin 8 is disconnected by the rotation of the motor 3 or by the upward shock of the logging cable, and the elastic force of the large spring 10 is released. Since the elastic force of the large spring 10 is greater than the elastic force of the small spring 13, the pressing sleeve 11 moves downward, the claw seat 14 moves downward with the pressing sleeve 11, and the claw 17 releases the fishing neck. At this time, the electric fishing tool for the preset downhole choke can be taken out.

[0040] The logging cable is connected to the motor 3 to supply power to the motor 3, so that its hollow rotor shaft rotates, and then the screw rod 4 in the hollow rotor shaft rotates. Since the screw rod 4 and the fixing seat 5 form a screw nut pair, the screw rod 4 converts the rotational motion into linear motion, and the center push rod 12 below it also reciprocates up and down until the center push rod 12 is inserted into the center hole of the preset downhole choke, thereby realizing the electric unsealing of the preset downhole choke.

[0041] Second implementation method:

[0042] This embodiment relates to a pre-set downhole choke electric fishing tool, see Figure 1 , including an upper joint 1, an outer tube 2, a lower joint 7, a lower pressing cap 9 and a working outer tube 15 connected in sequence from top to bottom, the lower end surface of the lower pressing cap 9 abuts against a pressing sleeve 11, the outer wall of the pressing sleeve 11 is provided with a claw seat 14, and the claw seat 14 is embedded with a claw 17;

[0043] A motor 3 is installed in the outer cylinder 2, a screw rod 4 is screwed through the hollow rotor shaft of the motor 3, a fixing seat 5 fixed to the inner wall of the outer cylinder 2 is screwed on the screw rod 4, the lower end of the screw rod 4 is coaxially fixed to the center push rod 12, a sheath 16 is sleeved on the center push rod 12, the outer wall of the sheath 16 is connected to the inner wall of the lower joint 7, and the lower joint 7 is fixed to the lower pressure cap 9 by a shear pin 8;

[0044] Among them, see Figure 2The cavity formed by the outer wall of the sleeve 16, the inner wall of the lower pressure cap 9 and the upper end surface of the pressing sleeve 11 contains a large spring 10 in a compressed state and sleeved on the sleeve 16; the cavity formed by the outer wall of the pressing sleeve 11, the inner wall of the working outer cylinder 15 and the upper end surface of the claw seat 14 contains a small spring 13 in a compressed state and sleeved on the pressing sleeve 11, and the elastic force of the small spring 13 is less than the elastic force of the large spring 10.

[0045] Solid grease is stored in the outer tube 2, and the solid grease is squeezed into the oil pipe and the preset downhole choke under the up and down reciprocating motion of the center push rod 12. Specifically, during the salvage process, the forward and reverse rotation of the motor 3 drives the center push rod 12 to move up and down, and the solid grease is squeezed and slowly moves downward to lubricate the salvage tool. When it moves below the salvage tool, it is gradually squeezed into the choke grasped by the claw 17 and the oil pipe, lubricating the outer surface of the choke and the inner wall of the oil pipe, thereby reducing the salvage friction resistance and improving the salvage success rate.

[0046] like Figure 1 As shown, the lower pressure cap 9 is a hollow cylindrical structure, and the middle section of the inner wall of the hollow cylinder extends radially toward the central axis to form a circle of annular bosses, and the bottom end face of the lower joint 7 abuts against the upper surface of the annular boss. The lower surface of the annular boss, the inner wall of the hollow cylinder below the annular boss, the upper end face of the pressing sleeve 11 and the outer wall of the sleeve 16 form an annular cavity, and the large spring 10 is compressed and placed in the annular cavity.

[0047] In order to ensure a stable connection between the screw rod 4 and the center push rod 12 and reduce eccentric wear, a straightening block 6 is further provided in the outer tube 2. The straightening block 6 is sleeved at the connection between the screw rod 4 and the center push rod 12. Above the straightening block 6 is a fixing seat 5 sleeved on the screw rod 4 and fixed to the inner wall of the outer tube 2. The fixing seat 5 and the straightening block 6 are connected by screws.

[0048] For the convenience of assembly and disassembly, preferably, the fixing seat 5 is composed of two semi-annular structures joined together, and the inner wall of the circular ring structure formed by the joining is screwed to the screw rod 4 .

[0049] In this embodiment, the motor 3 is a stepper motor capable of forward and reverse rotation, such as a ball screw stepper motor or a through screw stepper motor.

[0050] Third embodiment:

[0051] This embodiment provides a salvaging method of a preset downhole choke electric salvaging tool:

[0052] The motor 3 is connected through the logging cable and the preset downhole choke electric fishing tool is lowered to the top of the preset downhole choke, and then the preset downhole choke electric fishing tool is lifted up, the claw 17 grabs the preset downhole choke fishing neck, the motor 3 drives the central push rod 12 to move downward through the screw rod 4, and the central push rod 12 is inserted into the central hole of the preset downhole choke, forcing the choke to be unsealed, and the preset downhole choke electric fishing tool is lifted up to take out the preset downhole choke.

[0053] The preset downhole choke electric fishing tool comprises an upper joint 1, an outer tube 2, a lower joint 7, a lower pressure cap 9 and a working outer tube 15 which are connected in sequence from top to bottom. The lower end surface of the lower pressure cap 9 abuts against a pressing sleeve 11. The outer wall of the pressing sleeve 11 is provided with a claw seat 14. The claw seat 14 is embedded with a claw 17.

[0054] A motor 3 is installed in the outer cylinder 2, a screw rod 4 is screwed through the hollow rotor shaft of the motor 3, a fixing seat 5 fixed to the inner wall of the outer cylinder 2 is screwed on the screw rod 4, the lower end of the screw rod 4 is coaxially fixed to the center push rod 12, a sheath 16 is sleeved on the center push rod 12, the outer wall of the sheath 16 is connected to the inner wall of the lower joint 7, and the lower joint 7 is fixed to the lower pressure cap 9 by a shear pin 8;

[0055] Among them, the cavity formed by the outer wall of the sleeve 16, the inner wall of the lower pressure cap 9 and the upper end surface of the pressing sleeve 11 contains a large spring 10 in a compressed state and is sleeved on the sleeve 16; the cavity formed by the outer wall of the pressing sleeve 11, the inner wall of the working outer cylinder 15 and the upper end surface of the claw seat 14 contains a small spring 13 in a compressed state and is sleeved on the pressing sleeve 11, and the elastic force of the small spring 13 is smaller than the elastic force of the large spring 10.

[0056] Fourth embodiment:

[0057] This embodiment provides a salvaging method of a preset downhole choke electric salvaging tool:

[0058] The motor 3 is connected through the logging cable and the preset downhole choke electric fishing tool is lowered to the top of the preset downhole choke, and then the preset downhole choke electric fishing tool is lifted up, the claw 17 grabs the preset downhole choke fishing neck, the motor 3 drives the central push rod 12 to move downward through the screw rod 4, and the central push rod 12 is inserted into the central hole of the preset downhole choke, forcing the choke to be unsealed, and the preset downhole choke electric fishing tool is lifted up to take out the preset downhole choke.

[0059] The claw 17 grasps the fishing neck of the preset downhole choke and specifically includes:

[0060] The preset downhole choke electric fishing tool is lowered until the claw 17 touches the preset downhole choke fishing neck. The claw 17 moves upward under the upward thrust of the preset downhole choke, and the claw seat 14 continues to squeeze the small spring 13. The claw 17 is pushed upward by the fishing neck and opens to grab the fishing neck.

[0061] If the preset downhole choke fails to be unsealed, the motor 3 is automatically released through rotation or the logging cable is vibrated upward to disconnect the shear pin 8, and the elastic force of the large spring 10 is released. Since the elastic force of the large spring 10 is greater than the elastic force of the small spring 13, the pressing sleeve 11 moves downward, the claw seat 14 moves downward with the pressing sleeve 11, and the claw 17 releases the fishing neck. At this time, the electric fishing tool for the preset downhole choke can be taken out.

[0062] There are two ways of releasing, namely, automatic releasing by a motor or releasing by upward shock. Therefore, this embodiment has a two-way releasing function, which can meet the requirements of safe, reliable, low-cost salvage technology and economy for salvaging pre-set downhole chokes in gas fields.

[0063] During the salvage process, the central push rod 12 is driven to move up and down by the forward and reverse rotation of the motor 3, squeezing the solid grease downward to lubricate the inner wall of the oil pipe and the outer surface of the preset downhole choke.

[0064] During the salvaging process, the forward and reverse rotation of the motor 3 drives the central push rod 12 to move up and down reciprocatingly, and the solid grease is squeezed and slowly moves downward to lubricate the salvaging tool. When it moves below the salvaging tool, it is gradually squeezed into the throttle captured by the claw 17 and the oil pipe, lubricating the outer surface of the throttle and the inner wall of the oil pipe, reducing the salvage friction resistance and improving the success rate of salvage.

[0065] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present invention, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A salvaging method of a preset downhole choke electric salvage tool, which uses the preset downhole choke electric salvage tool to achieve salvage, characterized in that: The preset downhole choke electric fishing tool comprises an upper joint (1), an outer tube (2), a lower joint (7), a lower pressure cap (9) and a working outer tube (15) which are connected in sequence from top to bottom, wherein the lower end surface of the lower pressure cap (9) abuts against a pressing sleeve (11), the outer wall of the pressing sleeve (11) is provided with a claw seat (14), and the claw seat (14) is embedded with a claw (17); A motor (3) is installed in the outer cylinder (2), a screw rod (4) is threadedly connected to the hollow rotor shaft of the motor (3), the lower end of the screw rod (4) is coaxially fixed to a center push rod (12), a sheath (16) is sleeved on the center push rod (12), the outer wall of the sheath (16) is connected to the inner wall of the lower joint (7), and the lower joint (7) is fixed to the lower pressure cap (9) by a shear pin (8); The outer wall of the sleeve (16), the inner wall of the lower pressure cap (9) and the upper end surface of the pressing sleeve (11) form a cavity in which a large spring (10) sleeved on the sleeve (16) in a compressed state is contained; the outer wall of the pressing sleeve (11), the inner wall of the working outer cylinder (15) and the upper end surface of the claw seat (14) form a cavity in which a small spring (13) sleeved on the pressing sleeve (11) in a compressed state is contained, and the elastic force of the small spring (13) is smaller than the elastic force of the large spring (10); Solid lubricating grease is stored in the outer cylinder (2), and the solid lubricating grease is squeezed into the oil pipe and the preset downhole choke under the up and down reciprocating motion of the central push rod (12); Salvage methods include: The motor (3) is connected via a logging cable and the preset downhole choke electric fishing tool is lowered to the top of the preset downhole choke, and then the preset downhole choke electric fishing tool is lifted up, the claw (17) grabs the fishing neck of the preset downhole choke, the motor (3) drives the central push rod (12) to move downward through the screw rod (4), and the central push rod (12) is inserted into the central hole of the preset downhole choke, forcing the choke to be unsealed, and the preset downhole choke electric fishing tool is lifted up to remove the preset downhole choke; The claw (17) grasps the fishing neck of the preset downhole choke and specifically comprises: The preset downhole choke electric fishing tool is lowered until the claw (17) touches the fishing neck of the preset downhole choke, the claw (17) is pushed upward by the preset downhole choke and moves upward, the claw seat (14) continuously squeezes the small spring (13), and the claw (17) is pushed upward by the fishing neck and opens to grab the fishing neck; If the preset downhole choke fails to be unsealed, the motor (3) is automatically released or the logging cable is vibrated upward to release the hand, so that the shear pin (8) is disconnected and the elastic force of the large spring (10) is released. Since the elastic force of the large spring (10) is greater than the elastic force of the small spring (13), the pressing sleeve (11) moves downward, the claw seat (14) moves downward with the pressing sleeve (11), and the claw (17) releases the fishing neck. At this time, the electric fishing tool for the preset downhole choke can be taken out; During the salvaging process, the central push rod (12) is driven to move up and down reciprocatingly by the forward and reverse rotation of the motor (3), thereby squeezing the solid lubricating grease downward to lubricate the inner wall of the oil pipe and the outer surface of the preset downhole choke.

2. The salvaging method of the preset downhole choke electric salvaging tool according to claim 1, characterized in that: The lower pressure cap (9) is a hollow cylindrical structure, the middle section of the inner wall of the hollow cylinder extends radially toward the central axis to form a circle of annular bosses, the bottom end surface of the lower joint (7) abuts against the upper surface of the annular boss, the lower surface of the annular boss, the inner wall of the hollow cylinder below the annular boss, the upper end surface of the pressing sleeve (11) and the outer wall of the sleeve (16) form an annular cavity, and the large spring (10) is compressed and placed in the annular cavity.

3. The salvaging method of the preset downhole choke electric salvaging tool according to claim 1, characterized in that: A straightening block (6) is also provided in the outer cylinder (2). The straightening block (6) is sleeved at the connection between the screw rod (4) and the center push rod (12). Above the straightening block (6) is a fixing seat (5) sleeved on the screw rod (4) and fixed to the inner wall of the outer cylinder (2). The fixing seat (5) and the straightening block (6) are connected by screws.

4. The salvaging method of the preset downhole choke electric salvaging tool according to claim 3, characterized in that: The fixing seat (5) is composed of two semi-annular structures joined together, and the inner wall of the circular ring structure formed by the joining is screwed to the screw rod (4).

5. The salvaging method of the preset downhole choke electric salvaging tool according to claim 1, characterized in that: The motor (3) is a stepping motor capable of forward and reverse rotation.

Images