Small diameter downhole electrically driven hydraulic drop tool

Abstract

The application discloses a small-diameter downhole electrically-driven hydraulic delivery tool, which comprises a circuit control system, a power mechanism and a piston pump mechanism connected in sequence; the circuit control system comprises a circuit sealing cylinder, a cable joint assembly and a circuit control assembly; the power mechanism comprises a main sealing cylinder, a power motor, a fixed bushing, a rotating screw, a lead push cylinder and a sliding block; the piston pump mechanism comprises a piston pump cylinder, an excess joint, a sliding sealing assembly, a piston rod and a piston; a ground system supplies power to the power motor through a cable, the cable joint assembly and the circuit control assembly, and the circuit control assembly controls the power motor; after the power motor is started, the rotating screw is rotated, the lead push cylinder is driven to slide up and down under the limitation of the cooperation of the sliding block and the lead rail groove, and then the piston is driven to slide up and down through the piston rod, so that high-pressure liquid is provided to a setting mechanism to complete setting work. The application has simple and compact structure, can be repeatedly used and can solve the problem that the bridge-plugging tool cannot be delivered under abnormal conditions.

Description

Technical Field

[0001] This invention relates to the field of oil and gas development technology, and in particular to a small-diameter downhole electro-hydraulic delivery tool. Background Technology

[0002] Currently, the commonly used small-diameter (through tubing) bridge plug delivery tools mainly come in two forms: continuous tubing transmission hydraulic setting tools and cable transmission electric drive. However, both of these forms have their shortcomings.

[0003] The existing coiled tubing transfer bridge plug setting method involves injecting liquid into the tubing to pressurize and push a piston to compress the rubber sleeve, open the slips, and lock the plug onto the casing wall. Continued pressure is applied to break the release bolt, allowing the delivery tool to be deployed and set. Its drawbacks include high cost, long operation time, low efficiency, and difficulty in depth control.

[0004] When the cable-driven motor's rotating shaft clamps the bridge plug for setting, power is supplied via a cable, and a geared motor generates torque. A screw transmission mechanism then converts this torque into tension to achieve setting and release. Its drawbacks include: requiring a large stroke and high tension to break the bridge plug's release ring, high motor power requirements, and a susceptibility to motor failure.

[0005] Chinese utility model patent (application number: 201320568874, application date: 2013.09.13) discloses an electro-hydraulic bridge plug setting device, including an upper power pumping device, a fixed-axis gear train transmission mechanism, and a lower continuous pressurization device. Its upper electro-hydraulic part only provides hydraulic pressure to drive the piston stroke and form a push-pull force. Therefore, it is not a strictly speaking electro-hydraulic bridge plug setting tool; it still relies on breaking the bridge plug release bolt to release the bridge plug. It still suffers from drawbacks such as requiring a large stroke and high pulling force to break the release ring of the bridge plug. Furthermore, because it requires a large-diameter reservoir, a reduction gearbox, a throttle positioner, and a multi-stage hydraulic cylinder, it cannot be used as a tool for delivering small-diameter bridge plugs through oil pipes.

[0006] Therefore, in order to overcome the above-mentioned shortcomings, it is urgent to improve the existing delivery and setting method. Hence, a small-diameter downhole electro-hydraulic delivery device is proposed. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a small-diameter downhole electro-hydraulic delivery tool to solve the problem of not being able to deliver bridging tools when there are production tubing strings in the wellbore, pressure at the wellhead, and alternating blowouts during oil and gas well operations.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] A small-diameter downhole electro-hydraulic delivery tool includes a circuit control system, a power mechanism, and a piston pump mechanism connected sequentially from top to bottom.

[0010] The circuit control system includes a circuit sealing cylinder, a cable connector assembly, and a circuit control assembly; the cable connector assembly is fixed at the upper end of the circuit sealing cylinder and connected to a cable; the circuit control assembly is fixed in the inner cavity of the circuit sealing cylinder and electrically connected to the cable connector assembly.

[0011] The power mechanism includes a main sealing cylinder, a power motor, a fixed bushing, a rotating screw, a lead thrust cylinder, and a slider. The upper end of the main sealing cylinder is sealed to the lower end of the circuit sealing cylinder. The power motor is fixed in the upper part of the inner cavity of the main sealing cylinder and electrically connected to the circuit control assembly. The fixed bushing is fixed in the middle and lower part of the inner cavity of the main sealing cylinder. A lead groove is axially formed on the outer wall of the fixed bushing. The upper end of the lead groove is set as the upper positioning point, and the lower end of the lead groove is set as the lower positioning point. The rotating screw is rotatably placed in the inner cavity of the lead thrust cylinder and the two are connected by transmission. The upper end of the rotating screw is coaxially connected to the output shaft of the power motor. The lead thrust cylinder is slidably placed coaxially in the inner cavity of the fixed bushing. The slider is fixed on the outer wall of the lead thrust cylinder and is slidably placed in the lead groove.

[0012] The piston pump mechanism includes a piston pump barrel, an adapter joint, a sliding seal assembly, a piston rod, and a piston. The upper end of the piston pump barrel is sealed to the lower end of the main sealing cylinder through the adapter joint, and a setting mechanism is sealed to the lower end of the piston pump barrel. The sliding seal assembly is sealed to the inner cavity of the adapter joint. The piston rod can slide up and down through the sliding seal assembly, and the two are connected by a sliding seal. The upper end of the piston rod is fixed to the lower end of the lead thrust cylinder, and the piston is fixed to the lower end of the piston rod. The piston can slide up and down into the inner cavity of the piston pump barrel, and the two are connected by a sliding seal. The piston divides the inner cavity of the piston pump barrel into an upper piston cavity and a lower piston cavity. A balance hole communicating with the outside is opened on the outer periphery of the upper piston cavity, and a liquid inlet one-way valve is opened on the outer periphery of the lower piston cavity. The liquid inlet one-way valve only allows liquid to flow into the lower piston cavity from the outside in one direction.

[0013] The ground system supplies power to the power motor via the cable, the cable connector assembly, and the circuit control assembly. The circuit control assembly controls the power motor's start-up, shutdown, forward rotation, and reverse rotation. After the power motor starts, it drives the rotary screw to rotate, causing the lead thrust cylinder to slide up and down under the constraint of the slider and the lead rail groove. This, in turn, drives the piston rod to slide up and down, providing high-pressure liquid to the setting mechanism to complete the setting work. When the slider touches the upper or lower positioning point, the current load increases, and the circuit control assembly controls the power motor to change the rotation direction of the output shaft.

[0014] Furthermore, a conversion connector is used to achieve a sealed connection between the circuit sealing cylinder and the main sealing cylinder.

[0015] Furthermore, the output shaft of the power motor is arranged downwards and is coaxially connected to the rotating lead screw via a coupling and a lead screw connecting shaft. A thrust bearing is also provided at the joint between the coupling and the lead screw connecting shaft.

[0016] Furthermore, there are two guide rail grooves symmetrically formed in the middle of the outer wall of the fixed bushing, and correspondingly, there are two sliders that are used in a one-to-one correspondence with the two guide rail grooves.

[0017] Furthermore, the upper end of the transition joint is provided with two threads of different diameters, which are used to connect the main sealing cylinder and the fixed bushing respectively. The transition joint also forms a sealed connection with the main sealing cylinder through a sealing ring. The lower end of the transition joint is provided with threads and a sealing ring on the inner diameter and the outer diameter respectively. The threads and sealing ring on the inner diameter are used to connect and seal the sliding sealing assembly, and the threads and sealing ring on the outer diameter are used to connect and seal the piston pump cylinder.

[0018] Furthermore, the upper end of the fixed bushing is connected to the main body of the power motor by bolts.

[0019] Furthermore, a set of sliding seals is provided on the inner diameter of the sliding seal assembly for sealing and sliding of the piston rod.

[0020] Furthermore, the piston is provided with a balanced one-way valve, which is closed during the downward stroke of the piston and opened during the upward stroke of the piston, so that liquid is allowed to flow unidirectionally from the upper piston chamber to the lower piston chamber only during the upward stroke of the piston.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. The delivery tool provided by this invention has a simple and compact structure and low cost, and can meet the requirements for manufacturing small diameter tools, so as to solve the problem of not being able to deliver bridge plug tools under abnormal conditions;

[0023] 2. The delivery tool provided by this invention can perform pressurized operations and in-situ pumping;

[0024] 3. The delivery tool provided by this invention allows the sealing mechanism to be separated from the sealing mechanism and removed after it is anchored and sealed, thus enabling repeated use;

[0025] 4. The delivery tool provided by the present invention can be optimized and / or improved according to actual needs, and can realize delivery through oil pipes, such as delivery of packers, opening and cutting positioning tools, etc. Attached Figure Description

[0026] To make the advantages of the invention more readily apparent, the invention briefly described above will be described in more detail with reference to the specific embodiments shown in the accompanying drawings. It will be understood that these drawings depict only typical embodiments of the invention and should not be construed as limiting its scope of protection. The invention is described and explained with reference to the drawings to provide additional features and details.

[0027] Figure 1a This is a schematic diagram of the upper part of a small-diameter downhole electro-hydraulic delivery tool provided in an embodiment of the present invention;

[0028] Figure 1b This is a schematic diagram of the lower half of a small-diameter downhole electro-hydraulic delivery tool provided in an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the structure of a fixed bushing and a lead thrust cylinder in a small-diameter downhole electro-hydraulic delivery tool provided in an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the rotating lead screw in a small-diameter downhole electro-hydraulic delivery tool provided in an embodiment of the present invention;

[0031] Figure 4 This is a partial structural diagram of the piston pump mechanism in a small-diameter downhole electro-hydraulic delivery tool provided in an embodiment of the present invention.

[0032] The attached figures are labeled as follows: 1. Cable connector assembly; 2. Circuit sealing cylinder; 3. Circuit control assembly; 4. Adapter connector; 5. Power motor; 6. Main sealing cylinder; 7. Output shaft; 8. Coupling; 9. Thrust bearing; 10. Lead screw connecting shaft; 11. Upper positioning point; 12. Slider; 13. Lead rail groove; 14. Lead thrust cylinder; 15. Rotating lead screw; 16. Lower positioning point; 17. Piston rod connecting buckle; 18. Piston rod; 19. Fixed bushing; 20. Transition joint; 21. Sliding seal assembly; 22. Balance hole; 23. Piston; 24. Piston pump cylinder; 25. Inlet check valve; 26. Pump outlet connector; 27. Balance check valve. Detailed Implementation

[0033] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with embodiments of the invention.

[0034] To fully understand the embodiments of the present invention, detailed structures will be presented in the following description. Obviously, the implementation of the embodiments of the present invention is not limited to the specific details familiar to those skilled in the art. Preferred embodiments of the present invention are described in detail below; however, in addition to these detailed descriptions, the present invention may have other embodiments.

[0035] In the description of this invention, the term "A and / or B" refers to all possible combinations of A and B, such as only A, only B, or A and B. The terms "at least one A or B" or "at least one of A and B" have a similar meaning to "A and / or B" and can include only A, only B, or A and B. The singular terms "a" or "this" can also include plural forms. The terms "inner side," "outer side," "longitudinal," "lateral," "upper," "lower," "top," "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the invention and not to require the invention to be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0036] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings:

[0037] like Figure 1a , Figure 1b as well as Figures 2 to 4 As shown, an embodiment of the present invention provides a small-diameter downhole electro-hydraulic delivery tool, which mainly includes a circuit control system, a power mechanism, and a piston pump mechanism connected in sequence from top to bottom.

[0038] like Figure 1a and Figure 1b As shown, in this embodiment, the circuit control system includes a cable connector assembly 1, a circuit sealing cylinder 2, a circuit control assembly 3, and a conversion connector 4.

[0039] The cable connector assembly 1 is sealed and fixed at the upper end of the circuit sealing cylinder 2. A cable is externally connected to the upper part of the cable connector assembly 1, connecting to the surface system. The upper part of the cable connector assembly 1 can also be connected to commonly used equipment such as gamma meters, magnetic locators, and hollow energized weighted rods. The cable serves three purposes: first, to supply power to the downhole power mechanism; second, to transmit signals; and third, to transport the delivery tool provided in this embodiment. The gamma meter and magnetic locator are used for depth calibration and to determine the depth position. The lower part of the cable connector assembly 1 is electrically connected to the circuit control assembly 3, which is electrically connected to the power motor 5 in the power mechanism. The surface system can supply power to the power motor 5 via the cable, cable connector assembly 1, and circuit control assembly 3.

[0040] The circuit sealing cylinder 2 is sealed to the upper part of the main sealing cylinder 6 in the power mechanism via the conversion connector 4.

[0041] The circuit control assembly 3 is fixed in a sealed and insulated cavity consisting of the circuit sealing cylinder 2 and the conversion connector 4. The circuit control assembly 3 is electrically connected to the power motor 5 and is mainly used to control the starting, stopping, forward rotation, and reverse rotation of the power motor 5.

[0042] like Figure 1a , Figure 1b , Figure 2 and Figure 3 As shown, in this embodiment, the power mechanism includes a power motor 5, a main sealing cylinder 6, a coupling 8, a thrust bearing 9, a lead screw connecting shaft 10, a slider 12, a lead rail groove 13, a lead thrust cylinder 14, a rotating lead screw 15, and a fixed bushing 19.

[0043] The upper end of the main sealing cylinder 6 is connected to the adapter 4 via threads, and the lower end is connected to the transition joint 20 in the piston pump mechanism via threads, forming the main body.

[0044] The fixed bushing 19 is fixed in the middle and lower part of the inner cavity of the main sealing cylinder 6. The lower end of the fixed bushing 19 is connected to the transition joint 20 by threads, and the upper end is connected to the power motor 5 by bolts.

[0045] The power motor 5 is fixed in the upper part of the inner cavity of the main sealing cylinder 6 and electrically connected to the circuit control assembly 3. The output shaft 7 of the power motor 5 is arranged downward and is coaxially connected to the rotating lead screw 15 through a coupling 8 and a lead screw connecting shaft 10. A thrust bearing 9 is also provided at the joint of the coupling 8 and the lead screw connecting shaft 10. The power motor 5 is a low-power DC motor, which is powered by the ground system through cables to provide power to the piston pump mechanism.

[0046] The rotary lead screw 15 is rotatably inserted into the inner cavity of the lead thrust cylinder 14 and the two are connected in a transmission manner. The upper end of the rotary lead screw 15 is coaxially connected to the output shaft 7 of the power motor 5.

[0047] The lead thrust cylinder 14 is slidably and coaxially inserted into the inner cavity of the fixed bushing 19. The lower end of the lead thrust cylinder 14 is connected to the piston rod 18 through the piston rod connecting buckle 17, and a slider 12 that limits the sliding direction is installed on the upper outer wall of the lead thrust cylinder 14.

[0048] A guide groove 13 is provided axially on the outer wall of the fixed bushing 19. Preferably, there are two guide grooves 13 symmetrically formed in the middle of the outer wall of the fixed bushing 19. Correspondingly, there are two sliders 12, which are placed in the two guide grooves 13 and can slide up and down along the guide grooves 13. By using the sliders 12 and the guide grooves 13 in cooperation, the sliding direction of the guide thrust cylinder 14 can be limited to vertical linear motion.

[0049] The upper end of the guide rail groove 13 is designated as the upper positioning point 11, and the lower end of the guide rail groove 13 is designated as the lower positioning point 16. These are used to automatically control the rotation of the output shaft 7 of the power motor 5 to change the movement direction of the guide thrust cylinder 14. Specifically, when the slider 12 touches the upper positioning point 11 or the lower positioning point 16, the current load increases, and the circuit control assembly 3 controls the power motor 5 to change the rotation direction of the output shaft 7, thereby achieving automatic switching of the movement direction of the guide thrust cylinder 14, so that the guide thrust cylinder 14 automatically reciprocates in a vertical linear motion.

[0050] like Figure 1a , Figure 1b and Figure 4 As shown, in this embodiment, the piston pump mechanism includes a piston pump cylinder 24, an overfitting joint 20, a sliding seal assembly 21, a piston rod 18, a piston 23, a balance hole 22, an inlet check valve 25, and a balance check valve 27.

[0051] The piston pump barrel 24 is a cylindrical body with a polished inner diameter. The upper end of the piston pump barrel 24 is sealed to the lower end of the main sealing barrel 6 through an adapter 20. The lower end of the piston pump barrel 24 is provided with a pump outlet connector 26 for sealing connection with the setting mechanism (the setting mechanism includes a release connector and a setting bridge plug or rubber plug). Specifically, the upper end of the adapter 20 is provided with two threads of different diameters, which are used to connect the main sealing barrel 6 and the fixed bushing 19 respectively. The adapter 20 is also sealed to the main sealing barrel 6 through a sealing ring. The lower end of the adapter 20 is provided with threads and a sealing ring on the inner and outer diameters respectively. The threads and sealing ring on the inner diameter are used to connect and seal the sliding sealing assembly 21, and the threads and sealing ring on the outer diameter are used to connect and seal the piston pump barrel 24.

[0052] The sliding seal assembly 24 is sealed in the inner cavity of the transition joint 20. A set of sliding seals is provided on the inner diameter of the sliding seal assembly 24 to facilitate the smooth piston rod 18 to slide in a sealed manner within it.

[0053] The piston rod 18 can slide up and down through the sliding seal assembly 24 and the two are connected by a sliding seal. The upper end of the piston rod 18 is connected to the piston rod connecting buckle 17 at the lower end of the lead thrust cylinder 14, and the lower end of the piston rod 18 is fixed with a piston 23.

[0054] The piston 23 is slidably inserted into the inner cavity of the piston pump cylinder 24, and the two are connected by a sliding seal. The piston 23 divides the inner cavity of the piston pump cylinder 24 into an upper piston cavity and a lower piston cavity. The outer periphery of the upper piston cavity is provided with a balance hole 22 communicating with the outside for liquid inlet and outlet and for balancing the piston 23. Preferably, there are multiple balance holes 22 and they are evenly distributed circumferentially. The outer periphery of the lower piston cavity is provided with a liquid inlet check valve 25. The liquid inlet check valve 25 only allows liquid to flow into the lower piston cavity from the outside in one direction for liquid inlet into the lower piston cavity. The liquid inlet check valve 25 can also balance the pressure of the inner and outer cavities of its lower setting mechanism. Preferably, there are multiple liquid inlet check valves 25 and they are evenly distributed circumferentially. The piston 23 is also provided with a balance one-way valve 27. The balance one-way valve 27 is a one-way valve that is closed during the downward stroke of the piston 23 and open during the upward stroke of the piston 23. During the upward stroke of the piston 23, the balance one-way valve 27 only allows liquid to flow from the upper piston chamber to the lower piston chamber in one direction, so as to balance the piston 23 when the piston returns. Preferably, there can be multiple balance one-way valves 27 and they are evenly distributed around the circumference.

[0055] The principle of this embodiment is as follows:

[0056] After power is applied, the power motor 5 starts and drives the rotating screw 15 to rotate, which in turn drives the lead thrust cylinder 14 to move. Under the constraint of the slider 12 and the lead rail groove 13, the lead thrust cylinder 14 performs linear reciprocating motion. Since the piston rod 18 is connected to the lead thrust cylinder 14, the piston rod 18 will perform linear reciprocating motion together with the lead thrust cylinder 14, and drive the piston 23 to perform linear reciprocating motion in the piston pump cylinder 24. Through the linear reciprocating motion of the piston 23, external liquid will be drawn into the lower piston chamber and form high-pressure liquid. At the same time, the high-pressure liquid can be pumped to the setting mechanism to expand the bridge plug or rubber plug in the setting mechanism to complete the setting work, and can also provide sufficient hydraulic pressure to shear the pin release tool.

[0057] Application example:

[0058] Taking the delivery of a "small-diameter hydraulic expansion plug" through the tubing as an example, the method of using a small-diameter downhole electro-hydraulic delivery tool provided by this invention is illustrated as follows:

[0059] a. Install wellhead equipment, including blowout preventers; determine the wellhead equipment based on the pressure inside the well.

[0060] b. The tubing structure is lowered into the well via cable. The tubing structure, from bottom to top, consists of: biodegradable expansion plug + release connector + small-diameter downhole electric-driven hydraulic delivery device + magnetic positioner / gamma meter + hollow energized weight rod + cable. Based on the measured magnetic positioning data / gamma data, it is lowered to the predetermined depth in the well.

[0061] c. The surface system starts with current, which causes the power motor in the well to rotate and drive the plunger pump mechanism to pump the filtered well fluid into the capsule, causing the rubber stopper to expand and seal. The slips attached to the rubber stopper are fixed to the casing wall, and the expansion of the rubber stopper seals the wellbore.

[0062] d. When the pressure rises to a certain value, due to the area difference, the release connector shears the pin, forming a release, so that the part above the release connector is separated from the anchored and set biodegradable expansion plug, and then pulled out with the cable.

[0063] The delivery tool provided by this invention has a simple and compact structure, low cost, and can meet the requirements for small diameter manufacturing. Its maximum diameter is designed to be no greater than 65mm, and it can be lowered into the well through 3-1 / 2" tubing (production tubing), solving the problem of not being able to deliver bridging tools under abnormal conditions. Furthermore, the delivery tool provided by this invention can perform pressurized operations and in-situ pumping. In addition, the delivery tool provided by this invention allows the setting mechanism to be separated and removed after anchoring and sealing, thus enabling repeated use. Moreover, the delivery tool provided by this invention can be optimized and / or improved according to actual needs, enabling delivery through tubing, such as packers, perforators, and cutting and positioning tools.

[0064] In summary, the content of this invention is not limited to the above-described embodiments. Those skilled in the art can propose other embodiments within the technical guiding principles of this invention, but these embodiments are all included within the scope of this invention.

Claims

1. A small-diameter downhole electrically driven hydraulic delivery tool, characterized in that, It includes a circuit control system, a power mechanism, and a piston pump mechanism connected sequentially from top to bottom; The circuit control system includes a circuit sealing cylinder, a cable connector assembly, and a circuit control assembly; the cable connector assembly is fixed at the upper end of the circuit sealing cylinder and connected to a cable; the circuit control assembly is fixed in the inner cavity of the circuit sealing cylinder and electrically connected to the cable connector assembly. The power mechanism includes a main sealing cylinder, a power motor, a fixed bushing, a rotating screw, a lead thrust cylinder, and a slider. The upper end of the main sealing cylinder is sealed to the lower end of the circuit sealing cylinder. The power motor is fixed in the upper part of the inner cavity of the main sealing cylinder and electrically connected to the circuit control assembly. The fixed bushing is fixed in the middle and lower part of the inner cavity of the main sealing cylinder. A lead groove is axially formed on the outer wall of the fixed bushing. The upper end of the lead groove is set as the upper positioning point, and the lower end of the lead groove is set as the lower positioning point. The rotating screw is rotatably placed in the inner cavity of the lead thrust cylinder and the two are connected by transmission. The upper end of the rotating screw is coaxially connected to the output shaft of the power motor. The lead thrust cylinder is slidably placed coaxially in the inner cavity of the fixed bushing. The slider is fixed on the outer wall of the lead thrust cylinder and is slidably placed in the lead groove. The piston pump mechanism includes a piston pump barrel, an adapter joint, a sliding seal assembly, a piston rod, and a piston. The upper end of the piston pump barrel is sealed to the lower end of the main sealing cylinder through the adapter joint, and a setting mechanism is sealed to the lower end of the piston pump barrel. The sliding seal assembly is sealed to the inner cavity of the adapter joint. The piston rod can slide up and down through the sliding seal assembly, and the two are connected by a sliding seal. The upper end of the piston rod is fixed to the lower end of the lead thrust cylinder, and the piston is fixed to the lower end of the piston rod. The piston can slide up and down into the inner cavity of the piston pump barrel, and the two are connected by a sliding seal. The piston divides the inner cavity of the piston pump barrel into an upper piston cavity and a lower piston cavity. A balance hole communicating with the outside is opened on the outer periphery of the upper piston cavity, and a liquid inlet one-way valve is opened on the outer periphery of the lower piston cavity. The liquid inlet one-way valve only allows liquid to flow into the lower piston cavity from the outside in one direction. The ground system supplies power to the power motor via the cable, the cable connector assembly, and the circuit control assembly. The circuit control assembly controls the power motor's start-up, shutdown, forward rotation, and reverse rotation. After the power motor starts, it drives the rotary screw to rotate, causing the lead thrust cylinder to slide up and down under the constraint of the slider and the lead rail groove. This, in turn, drives the piston rod to slide up and down, providing high-pressure liquid to the setting mechanism to complete the setting work. When the slider touches the upper or lower positioning point, the current load increases, and the circuit control assembly controls the power motor to change the rotation direction of the output shaft.

2. The small-diameter downhole electro-hydraulic delivery tool according to claim 1, characterized in that, A conversion connector is used to achieve a sealed connection between the circuit sealing cylinder and the main sealing cylinder.

3. The small-diameter downhole electro-hydraulic delivery tool according to claim 1, characterized in that, The output shaft of the power motor is arranged downward and is coaxially connected to the rotating screw through a coupling and a lead screw connecting shaft. A thrust bearing is also provided at the joint between the coupling and the lead screw connecting shaft.

4. The small-diameter downhole electro-hydraulic delivery tool according to claim 1, characterized in that, The guide rail grooves are two in number and symmetrically formed in the middle of the outer wall of the fixed bushing. Correspondingly, there are two sliders, which are used in a one-to-one correspondence with the two guide rail grooves.

5. The small-diameter downhole electro-hydraulic delivery tool according to claim 1, characterized in that, The upper end of the transition joint is provided with two threads of different diameters, which are used to connect the main sealing cylinder and the fixed bushing respectively. The transition joint also forms a sealed connection with the main sealing cylinder through a sealing ring. The lower end of the transition joint is provided with threads and a sealing ring on the inner diameter and the outer diameter respectively. The threads and sealing ring on the inner diameter are used to connect and seal the sliding sealing assembly, and the threads and sealing ring on the outer diameter are used to connect and seal the piston pump cylinder.

6. The small-diameter downhole electro-hydraulic delivery tool according to claim 4, characterized in that, The upper end of the fixed bushing is connected to the main body of the power motor by bolts.

7. The small-diameter downhole electro-hydraulic delivery tool according to claim 1, characterized in that, The inner diameter of the sliding seal assembly is provided with a set of sliding seals for sealing and sliding of the piston rod.

8. The small-diameter downhole electro-hydraulic delivery tool according to claim 1, characterized in that, The piston is equipped with a balance one-way valve, which is closed during the downward stroke of the piston and opened during the upward stroke of the piston, so that liquid can only flow from the upper piston chamber into the lower piston chamber in one direction during the upward stroke of the piston.

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