Downhole lifting device and method for composite material continuous pipe joint

Abstract

The invention provides an underground lifting device and method for a composite continuous pipe joint, relates to the field of underground water injection and oil extraction, and aims to solve the problem that an existing lifting device for a composite continuous pipe is difficult to stably butt the composite continuous pipe. The lifting sliding block can extend out under the driving of the piston rod so as to be matched with a clamping groove in an upper connector of the composite continuous pipe to achieve clamping connection, and by means of the lifting sliding block which can slide in the radial direction and is controlled by the piston rod, in the underground complex environment, when the lifting device is lowered, the lifting sliding block can be pulled out to be matched with a clamping groove in the upper connector of the composite continuous pipe. The lifting sliding block is accurately clamped with the clamping groove in the upper connector of the composite continuous pipe, the accuracy of capturing the position of the connector is improved, and compared with an existing device, the device has higher pertinence and accuracy. The oil duct arranged on the lifting lug can be conveniently matched with an oil pipe to be connected into an external hydraulic source, the lifting lug is matched with the lifting rope to receive the lifting effect, and the lifting operation requirement of the composite pipe is met.

Description

Technical Field

[0001] The invention relates to the field of downhole water injection and oil production, and in particular to a downhole pulling device and method for a composite material continuous pipe joint. Background Art

[0002] Downhole oil pipes and water injection pipes are one of the key oil production equipment in the development of oil and gas fields, and they play the role of connecting the reservoir with the ground facilities. The production liquid in the underground reservoir passes through the downhole oil pipe upward into the ground gathering and transportation system; the ground high-pressure water passes through the downhole water injection pipe to supplement the pressure of the underground reservoir. With the continuous development and innovation of oil and gas extraction technology, low-density and corrosion-resistant composite continuous pipes are gradually replacing traditional metal pipes for downhole oil production and water injection operations. Composite continuous pipes are connected by joint devices. When the pipe is lifted from the well, it often gets stuck. The traditional pipe lifting device usually acts on the pipe body, which easily causes the lifting force to exceed the allowable lifting force, resulting in the phenomenon of the pipe and the joint device falling off. The part of the pipe that falls off falls into the oil production or water injection well, which will inevitably hinder the oil production process and even block the oil well or water injection well, resulting in huge economic losses.

[0003] A Chinese patent (publication number CN204126584U, publication date 20150128) discloses an oil and water well maintenance and salvage operation device, but it adopts a magnetic suction method to achieve suction, and then uses a grab hook to achieve hooking, but it is not suitable for the pulling process of the composite continuous pipe of the oil well or water injection well. The length of the composite continuous pipe joint accounts for a very small proportion of the total length of the pipe. At the same time, the downhole environment is complex. The current composite pipe pulling device is difficult to accurately capture the position of the joint, and fails to solve the problem of joint detachment during the downhole pulling operation of the composite continuous pipe. Summary of the invention

[0004] The purpose of the present invention is to address the defects of the prior art and provide a downhole pulling device and method for a composite continuous pipe joint. The device is equipped with a lifting rod that can be inserted into the composite continuous pipe. A radially sliding lifting slider is provided on the lifting rod. The lifting slider can be extended under the drive of a piston rod to cooperate with a clamping groove in the joint on the composite continuous pipe to achieve clamping and realize lifting operations. The oil channel provided on the lifting ear is convenient for cooperating with the oil pipe to connect to an external hydraulic source. The lifting ear cooperates with the lifting rope to accept the lifting effect, thereby meeting the lifting operation requirements of the composite pipe.

[0005] The first object of the present invention is to provide a downhole pulling device for a composite material continuous pipe joint, which adopts the following scheme:

[0006] The invention comprises a lifting component, wherein the lifting component comprises:

[0007] The lifting rod is provided with mounting grooves and piston cavities at intervals along the axial direction. Two lifting sliders that can slide radially along the lifting rod are slidably installed in the mounting grooves. A rebound member is connected between the two lifting sliders. A piston rod is slidably fitted in the piston cavity. The piston rod can be inserted into or withdrawn from between the lifting sliders, so that the lifting sliders are extended out of the circumference of the lifting rod or retracted.

[0008] The lifting lug has one end connected to the lifting rod and the other end connected to the lifting rope. An oil passage connected to the piston cavity is arranged inside the lifting lug, and the oil passage is connected to an external hydraulic source through an oil pipe.

[0009] Furthermore, the two lifting sliders are symmetrically distributed relative to the axis of the lifting rod, and guide pins that slidably match the lifting sliders are provided in the installation groove. The lifting sliders protrude from the peripheral surface of the lifting rod to clamp the composite continuous pipe.

[0010] Furthermore, one end of the piston rod slides in the piston cavity, and the other end protrudes out of the piston cavity and faces between the two lifting sliders. An elastic member is installed between the piston rod and the lifting rod, and the compression and rebound directions of the elastic member are parallel to the axis of the piston rod.

[0011] Furthermore, the mounting grooves are distributed radially along the lifting rod, the resilient members are distributed radially along the lifting rod, and the ends of the resilient members are fixed to the lifting slider via stop pins.

[0012] Furthermore, the lifting eye is coaxially distributed with the lifting rod, a pair of threads connected with the oil passage is installed on the lifting eye, and the oil pipe is connected to the oil passage as two-way through the pair of threads.

[0013] Furthermore, the lifting ear is provided with a lifting hole, and the lifting rope is connected to the lifting hole.

[0014] Furthermore, the oil pipes are distributed along the suspension ropes.

[0015] Furthermore, it also includes a joint, which includes a joint inner core and a joint outer sleeve. One end of the joint inner core is inserted into the composite continuous tube, and the other end extends to the outside of the composite continuous tube. The joint outer sleeve is sleeved on the outside of the composite continuous tube, and one axial end extends to the outside of the joint inner core and is fixed. The joint inner core is provided with a central channel for the lifting rod to pass through, and an annular groove is opened on the central channel to cooperate with the lifting slider to form a clamping connection.

[0016] The second object of the present invention is to provide a working method of the downhole pulling device for composite material continuous pipe joint as described in the first object, comprising:

[0017] The lifting assembly is gradually lowered along the shaft so that the end of the lifting rod away from the lifting ear gradually approaches the composite coiled tubing;

[0018] One end of the lifting rod is inserted into the top hole of the composite material tube, and the oil pipe is used to pressurize the piston cavity through the oil channel to move the piston rod;

[0019] The piston rod is inserted between the two lifting sliders, so that the lifting slider slides radially and protrudes outside the peripheral surface of the lifting rod, and the portion of the lifting slider protruding outside the lifting rod is engaged with the groove on the composite material pipe, so that the lifting rod is connected to the composite material pipe;

[0020] Operate the lifting lug and pull the composite material pipe to adjust its position.

[0021] Furthermore, it also includes:

[0022] The oil pipe releases the pressure of the piston chamber through the oil channel, and the piston rod is withdrawn from between the two lifting sliders, so that the lifting slider is retracted into the peripheral surface of the lifting rod, and the clamping connection with the clamping groove is released;

[0023] Operate the lifting lug and adjust the lifting rod to separate from the composite material pipe.

[0024] Compared with the prior art, the present invention has the following advantages and positive effects:

[0025] In view of the problem that the current lifting device of the composite continuous pipe is difficult to stably dock with the composite continuous pipe, a lifting rod that can be inserted into the composite continuous pipe is configured, and a radially sliding lifting slider is set on the lifting rod. The lifting slider can be extended under the drive of the piston rod to cooperate with the card slot in the joint of the composite continuous pipe to achieve a card connection. With the help of the lifting slider that can slide radially on the lifting rod and is controlled by the piston rod, when the lifting device is lowered in a complex underground environment, the lifting slider can be accurately connected with the card slot in the joint of the composite continuous pipe, which improves the accuracy of capturing the joint position and is more targeted and accurate than previous devices. The oil channel set on the lifting ear facilitates the connection of the oil pipe to the external hydraulic source, and the lifting ear cooperates with the lifting rope to receive the lifting effect, meeting the lifting operation requirements of the composite pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0027] Figure 1 It is a schematic diagram of the downhole pulling device of the composite material continuous pipe joint in Examples 1 and 2 of the present invention.

[0028] Figure 2 for Figure 1 Schematic diagram of the cross section at BB in the middle.

[0029] Figure 3 Schematic diagram of the lifting rod in Examples 1 and 2 of the present invention.

[0030] Figure 4 for Figure 3 Schematic diagram of the cross section at AA in the middle.

[0031] Figure 5It is a schematic diagram of the lifting slider matched with the lifting rod in Examples 1 and 2 of the present invention.

[0032] Figure 6 Schematic diagram of the joint on the composite material continuous pipe in Examples 1 and 2 of the present invention.

[0033] Among them, 1. lifting rod; 2. lifting slider; 3. piston rod; 4. guide pin; 5. elastic part; 6. lifting ear; 7. thread; 8. tension spring; 9. oil pipe; 10. lifting rope; 11. stop pin; 12. joint inner core; 13. joint outer sleeve; 14. composite continuous pipe; 15. slot. DETAILED DESCRIPTION

[0034] Example 1

[0035] In a typical embodiment of the present invention, Figure 1-Figure 6 As shown, a downhole pulling device for a composite material continuous pipe joint is provided.

[0036] The length of the composite continuous pipe joint accounts for a very small proportion of the total length of the pipe. In addition, the downhole environment is complex, which makes it difficult for the current composite pipe lifting device to accurately capture the position of the joint, and fails to solve the problem of joint falling off during the downhole lifting operation of the composite continuous pipe. Based on this, the present embodiment provides a downhole lifting device for the composite continuous pipe joint, which can achieve a relatively accurate connection with the slot 15 in the joint of the composite continuous pipe 14 through the lifting slider 2 set on the lifting rod 1 and the piston rod 3 and other structures matched therewith, as well as the lifting ear 6 and the oil channel design, so as to solve the problem of difficulty in accurately capturing the joint position and the easy falling off of the joint, so that it can better adapt to the lifting operation requirements of the composite continuous pipe 14 in the oil well or water injection well.

[0037] like Figure 1 As shown, the downhole pulling device of the composite continuous pipe joint mainly includes a pulling assembly and a joint installed on the composite continuous pipe 14, wherein the pulling assembly includes a pulling rod 1, a lifting ear 6 and a lifting rope 10 connected in sequence, the pulling rod 1 can be detachably matched with the joint on the composite continuous pipe 14, and the lifting ear 6 serves as a connecting piece between the pulling rod 1 and the lifting rope 10, and can transmit the pulling effect applied by the lifting rope 10 to the pulling rod 1.

[0038] Specifically, Figure 2 As shown, the lifting rod 1 is provided with mounting grooves and piston cavities spaced apart along its axial direction. Two lifting sliders 2 are slidably mounted in the mounting grooves, and the two lifting sliders 2 can slide along the radial direction of the lifting rod 1, and a resilient member is connected between them. The function of the resilient member is to assist the lifting slider 2 to return to its initial state after the lifting slider 2 has completed the action of probing out of the clamping joint, so as to facilitate the insertion of one end of the lifting rod 1 into the joint for mating and the removal from the joint after the mating is released.

[0039] like Figure 3 and Figure 4 As shown, the piston cavity slides with the piston rod 3, and the piston rod 3 can adjust its position by moving in the piston cavity, so that one end of the piston rod 3 can be inserted into or withdrawn from between the lifting sliders 2. When the piston rod 3 is inserted into between the two lifting sliders 2, the gap between the two lifting sliders 2 is increased, thereby pushing the lifting slider 2 to slide radially outward along the lifting rod 1, and controlling the lifting slider 2 to extend out of the circumference of the lifting rod 1; when the piston rod 3 is retracted from between the two lifting sliders 2, the gap between the two lifting sliders 2 is reduced, and the lifting slider 2 is retracted to within the circumference of the lifting rod 1, avoiding the formation of a protruding structure on the circumference of the lifting rod 1, thereby realizing operations such as clamping or disengaging with the clamping groove 15 in the joint of the composite continuous pipe 14.

[0040] like Figure 2 As shown, one end of the lifting lug 6 is connected to the lifting rod 1, and the other end is connected to the lifting rope 10, which plays the role of connecting and transmitting the pulling force. The lifting lug 6 is provided with an oil passage connected to the piston cavity, which can be connected to an external hydraulic source through an oil pipe 9, so that the external hydraulic source can provide power support for the operation of the entire lifting assembly, thereby driving the piston rod 3 to move, etc., to complete the motion control of the lifting slider 2.

[0041] With the help of the lifting slider 2 on the lifting rod 1 which can slide radially and is controlled by the piston rod 3, in a complex underground environment, when the lifting device is lowered, the lifting slider 2 can be accurately engaged with the slot 15 in the joint on the composite continuous pipe 14, thereby improving the accuracy of capturing the joint position and being more targeted and accurate than previous devices.

[0042] After the lifting slider 2 is engaged with the joint slot 15, the joint can be effectively prevented from falling off during the lifting operation, ensuring the stability of the lifting process, ensuring that the composite coiled tube 14 can be smoothly lifted, and meeting the actual needs of the composite material tube lifting operation. The oil channel set inside the lifting lug 6 can be connected to an external hydraulic source, and the piston rod 3 and other components can be driven by hydraulic pressure to move, making the motion control of the entire lifting device more flexible and reliable, and can better adapt to various working conditions of underground operations, ensuring the smooth implementation of the lifting operation.

[0043] like Figure 4 and Figure 5 As shown, two lifting sliders 2 are symmetrically distributed relative to the axis of the lifting rod 1, and a guide pin 4 that slides and fits the lifting slider 2 is provided in the installation groove. The lifting slider 2 protrudes out of the circumference of the lifting rod 1 to clamp the composite continuous pipe 14, so that when clamping with the joint of the composite continuous pipe 14, a force can be applied from two relatively even sides to ensure the stability of the clamping and the balance of the force. This avoids the situation that the clamping is not firm or the joint of the composite continuous pipe 14 is damaged due to uneven force on one side, which helps to achieve the lifting operation more accurately and smoothly.

[0044] The guide pin 4 provided in the installation groove is in sliding cooperation with the lifting slider 2, which provides precise guidance for the radial sliding of the lifting slider 2 along the lifting rod 1. It limits the unnecessary shaking or deviation of the lifting slider 2 in other directions, ensures that each extension or retraction of the lifting slider 2 can be carried out according to the predetermined trajectory, prevents the lifting slider 2 from falling out of the installation groove when moving, and improves the accuracy and reliability of the entire device in the capture and clamping operations.

[0045] like Figure 2 As shown, one end of the piston rod 3 slides in the piston cavity, and the other end protrudes out of the piston cavity and faces between the two lifting sliders 2. The sliding fit ensures that the piston rod 3 can smoothly perform linear motion in the piston cavity, so that it can stably protrude into or withdraw from between the lifting sliders 2, and effectively control the protrusion or retraction of the lifting slider 2. The action of protruding out of the piston cavity and facing between the two lifting sliders 2 allows the piston rod 3 to directly interact with the lifting slider 2 and drive the action of the lifting slider 2.

[0046] In this embodiment, the end of the piston rod 3 can be wedge-shaped. When the piston rod 3 moves between the lifting slider 2, the wedge-shaped structure can gradually push the lifting slider 2 outward. For example, the inclined surface of the wedge contacts the lifting slider 2. As the piston rod 3 advances, the action of the inclined surface will push the lifting slider 2 radially outward along the lifting rod 1, so that it protrudes out of the circumference of the lifting rod 1. The advantage of this structure is that the axial movement of the piston rod 3 can be effectively converted into the radial movement of the lifting slider 2, and the wedge-shaped structure has good guidance and can more accurately control the protrusion direction of the lifting slider 2; the end of the piston rod 3 can also be hemispherical. The hemispherical surface is smooth, and when it contacts the lifting slider 2, the friction can be reduced. When the piston rod 3 is pushed forward, the hemispherical end can generate an outward component force on the lifting slider 2, so that the lifting slider 2 slides radially. This structure is relatively flexible during movement and can adapt to a certain degree of position deviation of the lifting slider 2. Even if the initial position of the lifting slider 2 is slightly different, the hemispherical end can better contact and push it.

[0047] A groove with an inclined surface is provided on the side of the lifting slider 2 facing the piston rod 3. When the end of the piston rod 3 is in a wedge-shaped or hemispherical shape, the inclined surface of the groove can cooperate therewith. For example, when the wedge-shaped structure at the end of the piston rod 3 is inserted into the groove, the axial force of the piston rod 3 can be decomposed into a radial outward force of the lifting slider 2 through the interaction of the inclined surfaces, so that the lifting slider 2 can be extended. This groove structure with an inclined surface can enhance the matching accuracy between the lifting slider 2 and the piston rod 3 and improve the force transmission efficiency.

[0048] In this embodiment, the lifting slider 2 is made of Cr12MoV high-carbon high-chromium alloy tool steel through quenching treatment and is divided into two pieces. The middle of the two lifting sliders 2 is respectively provided with slots that penetrate the sliders and are symmetrical about the geometric center line of the sliders. There are a total of four slots. The size of the four slots is sufficient for the elastic member 5 to pass through. There are four small grooves similar in shape to the stop pin 11 near the slots to facilitate the subsequent fixation of the stop pin 11. The moving direction of the lifting slider 2 is determined by the guidance of the guide pin 4. The two lifting sliders 2 are respectively provided with grooves suitable for the guidance of the guide pin 4. The movement of the lifting slider 2 requires the drive of the piston rod 3. The two lifting sliders 2 have two grooves suitable for the passage of the piston rod 3 at the bottom of the side facing the piston rod 3, which facilitates the piston rod 3 to squeeze the two lifting sliders 2 apart.

[0049] The guide pins 4 are made of Cr12MoV high-carbon high-chromium alloy tool steel through quenching treatment, and the movement of the lifting slider 2 is guided by four guide pins 4 of appropriate sizes.

[0050] like Figure 2 As shown, an elastic member 5 is installed between the piston rod 3 and the lifting rod 1, and the compression and rebound directions of the elastic member 5 are parallel to the axis of the piston rod 3; when the piston rod 3 pushes the lifting slider 2 to extend, the elastic member 5 will be compressed to store a certain amount of elastic potential energy; and when the lifting slider 2 needs to be retracted, the rebound force of the elastic member 5 can assist the piston rod 3 to return to its original position, and can also play a buffering role, ensuring that the movement process of the entire lifting slider 2 and the piston rod 3 is more stable and controllable, and also helps to extend the service life of related parts of the device. The elastic member 5 can be a compression spring, a disc spring, etc. The disc spring is made of spring steel, which mainly bears the compression force and the rebound process is relatively gentle. Two disc springs are welded to the corresponding positions of the piston rod 3 respectively.

[0051] like Figure 2 As shown, the installation groove is distributed radially along the lifting rod 1, the resilient member is distributed radially along the lifting rod 1, the end of the resilient member is fixed to the lifting slider 2 by the stop pin 11, and the installation groove and the resilient member are both distributed radially along the lifting rod 1, and the layout structure is consistent with the radial sliding action of the lifting slider 2. The installation groove provides a spatial basis for the installation and sliding of the lifting slider 2, and the distribution of the resilient member along this direction can better play a role in the radial action process of the lifting slider 2, ensuring that the lifting slider 2 can smoothly rebound and reset along the radial direction after completing the clamping action, etc., to maintain the normal working state of the entire device.

[0052] The end of the resilient member is fixed to the lifting slider 2 by a stop pin 11. The stop pin 11 ensures the stability of the connection between the resilient member and the lifting slider 2, and prevents the resilient member from loosening or falling off during the frequent sliding of the lifting slider 2 and the operation of the device, thereby ensuring that the resilient member can continuously and effectively provide a rebound force for the lifting slider 2. The resilient member can be a tension spring 8, an elastic rope, etc. The tension spring 8 is made of spring steel, and the length of the four tension springs 8 is consistent with the total thickness of the lifting slider 2 and has standard hooks at both ends, which are inserted into the notch of the lifting slider 2 and fixed with the stop pin 11.

[0053] In this embodiment, the stop pin 11 is made of Cr12MoV high-carbon high-chromium alloy tool steel through quenching treatment, and its size is adapted to the small groove already made in the lifting slider 2. The four stop pins 11 are respectively fixed to the hooks at both ends of the four tension springs 8.

[0054] like Figure 2 As shown, the lifting ear 6 is coaxially distributed with the lifting rod 1, and a pair of threads 7 connected to the oil channel is installed on the lifting ear 6. The oil pipe 9 is connected to the oil channel through the pair of threads 7 as two-way. The coaxial distribution of the lifting ear 6 and the lifting rod 1 makes the force transmission of the entire lifting device more uniform and reasonable when subjected to force, avoiding adverse effects such as additional bending moment caused by eccentric force, and ensuring the structural stability during the lifting operation.

[0055] The threaded connector 7 installed on the lifting lug 6 and connected to the oil channel provides a convenient and reliable connection method for the oil pipe 9 to access the oil channel, which is equivalent to playing the role of a two-way connection, so that the external hydraulic source can be smoothly connected to the oil channel in the lifting lug 6 through the oil pipe 9 and the threaded connector 7, thereby providing power support for the hydraulic drive part of the device.

[0056] The lifting hole provided on the lifting ear 6 serves as the connection part of the lifting rope 10, which has a simple and practical structure and provides a connection point for the entire device to receive external lifting action. It is connected to the external lifting equipment through the lifting rope 10, and the lifting force is transmitted to the lifting rod 1 and other components to realize the lifting operation of the composite continuous pipe 14.

[0057] The lifting lug 6 is made of Cr12MoV high-carbon high-chromium alloy tool steel after quenching treatment, and is installed on the lifting rod 1 for lifting force. There are two lifting holes at the rear end of the lifting lug 6 suitable for the high-strength lifting rope 10 to pass through. There is an oil channel parallel to the long side inside the lifting lug 6, which plays the role of conveying hydraulic oil, and there is a threaded interface suitable for the external thread access of the thread 7 inside the channel on the side connected to the flexible oil pipe 9. After the piston rod 3 is placed on the lifting rod 1, the lifting lug 6 and the lifting rod 1 are welded.

[0058] The thread 7 is made of iron-based alloy (corrosion-resistant stainless steel) material, with internal joints at both ends, circular external threads at both ends, and the thread sizes and sealing forms at both ends are exactly the same, and the middle part is cylindrical. There is a channel parallel to the axis of the long side inside the thread 7, and the channel of appropriate size plays the role of conveying hydraulic oil. The lifting lug 6 is connected to the flexible oil pipe 9 assembly through the thread 7.

[0059] In this embodiment, the lifting rod 1 is made of Cr12MoV through quenching treatment. Cr12MoV is a high-carbon, high-chromium alloy tool steel. After heat treatment, it has very high hardness and abrasiveness, strong hardenability and good dimensional stability. The manufactured lifting rod 1 has the characteristics of high precision and long service life, and meets the requirements of underground lifting operations.

[0060] The distribution of the oil pipe 9 along the lifting rope 10 makes the arrangement of the oil pipe 9 more regular and orderly, and avoids the oil pipe 9 from swinging or entangled in the complex environment underground. At the same time, the distribution along the lifting rope 10 also makes it easier for the oil pipe 9 to be relatively close to the connecting structures such as the thread 7 on the lifting ear 6, which facilitates the access of the oil pipe 9 to the oil channel. In addition, during the lowering or lifting process of the entire lifting device, the oil pipe 9 can move synchronously with the lifting rope 10, reducing the interference factors caused by the movement of the oil pipe 9 itself, which is conducive to the smooth progress of the entire lifting operation.

[0061] The oil pipe 9 adopts a small-diameter flexible oil pipe 9, and a corresponding threaded interface is provided at the end. The flexible oil pipe 9 is made of composite materials, and the interface is made of Cr12MoV high-carbon high-chromium alloy tool steel through quenching treatment. The interface is set at the front end of the flexible oil pipe 9 and is suitable for external thread access of the wire 7. The lifting rope 10 is wound by a high-strength aramid bundle and passes through the lifting hole at the rear end of the lifting ear 6.

[0062] like Figure 1 and Figure 6 As shown, it also includes a joint, which includes a joint core 12 and a joint sleeve 13. One end of the joint core 12 is inserted into the composite continuous tube 14, and the other end extends to the outside of the composite continuous tube 14. The joint sleeve 13 is sleeved on the outside of the composite continuous tube 14, and one axial end extends to the outside of the joint core 12 and is fixed. The joint core 12 is provided with a central channel for the lifting rod 1 to penetrate, and an annular groove 15 is opened on the central channel to cooperate with the lifting slider 2 to form a clamping connection.

[0063] The joint adopts a composite structure of a joint inner core 12 and a joint outer sleeve 13. The inner core is inserted into the composite continuous pipe 14 and extends a portion thereof. The outer sleeve is sleeved outside the composite continuous pipe 14 and one end thereof extends outside the inner core and is fixed. This structure enhances the firmness and integrity of the connection between the joint and the composite continuous pipe 14, can better withstand the tensile force and other forces during the pulling process, and also protects the end of the composite continuous pipe 14.

[0064] Specifically, the joint inner core 12 and the joint outer shell 13 are made of Cr12MoV high carbon high chromium alloy tool steel through quenching treatment. The joint inner core 12 and the joint outer shell 13 have teeth to prevent pulling out. Through the action of the crimping machine, the joint inner core 12 and the joint outer shell 13 can be radially sealed and connected with the composite pipe. There is a slot 15 of suitable size inside the joint to facilitate the joint of the modified composite continuous pipe 14 and the lifting assembly to perform the lifting operation together.

[0065] The joint inner core 12 is provided with a central channel for the lifting rod 1 to pass through and an annular groove 15 on the channel, and the annular groove 15 can achieve precise matching with the lifting assembly. The lifting rod 1 can be smoothly inserted along the central channel, and the lifting slider 2 can be just engaged with the annular groove 15. Through this engagement method, the lifting device is closely connected to the composite continuous pipe 14 joint, so that the lifting device can effectively transfer the lifting force to the composite continuous pipe 14, realizing stable underground lifting operations, and solving the previous problems of difficulty in accurately capturing the joint position and the joint being easy to fall off.

[0066] Example 2

[0067] In another typical embodiment of the present invention, Figure 1-Figure 6 As shown, a working method of a downhole pulling device for a composite material continuous pipe joint is provided, using the downhole pulling device for a composite material continuous pipe joint as in Example 1.

[0068] A working method of a downhole pulling device for a composite material continuous pipe joint, comprising:

[0069] The lifting assembly is gradually lowered along the shaft, so that the end of the lifting rod 1 away from the lifting ear 6 gradually approaches the composite coiled tubing 14;

[0070] One end of the lifting rod 1 is inserted into the top hole of the composite material tube, and the oil pipe 9 is used to pressurize the piston cavity through the oil channel to move the piston rod 3;

[0071] The piston rod 3 is inserted between the two lifting sliders 2, so that the lifting slider 2 slides radially and protrudes outside the circumference of the lifting rod 1, and the portion of the lifting slider 2 protruding outside the lifting rod 1 is engaged with the groove 15 on the composite material pipe, so that the lifting rod 1 is connected to the composite material pipe;

[0072] Operate the lifting lug 6 to pull the composite material pipe to adjust its position;

[0073] The oil pipe 9 releases the pressure of the piston chamber through the oil passage, and the piston rod 3 is withdrawn from between the two lifting sliders 2, so that the lifting slider 2 is retracted into the circumference of the lifting rod 1, and the clamping connection with the clamping groove 15 is released;

[0074] Operate the lifting lug 6 to adjust the lifting rod 1 to separate from the composite material pipe.

[0075] Specific, combined Figure 1-Figure 6 , the working method of the downhole pulling device for the composite continuous pipe joint is described in detail.

[0076] Lowering and pulling component stage:

[0077] The lifting assembly is gradually lowered along the shaft, so that the end of the lifting rod 1 away from the lifting ear 6 gradually approaches the composite coiled tubing 14 .

[0078] The initial step of the entire lifting operation is to gradually lower the lifting assembly so that the lifting rod 1 can accurately approach the composite coiled tubing 14 to prepare for subsequent docking and lifting operations. Due to the complex underground environment, gradual lowering helps to accurately position and avoid missing the composite coiled tubing 14 or causing unnecessary collisions due to reasons such as too fast lowering speed.

[0079] The lowering process needs to control the speed and verticality of the lowering, etc. To ensure that the lifting rod 1 can smoothly approach the composite coiled tubing 14, it is necessary to use some downhole monitoring equipment or markings to assist in determining the relative position between the lifting rod 1 and the composite coiled tubing 14 to ensure that the entire process proceeds smoothly and orderly.

[0080] Inserting the lifting rod 1 into the top hole of the composite material pipe is a key pre-action to achieve the connection between the lifting device and the composite continuous pipe 14. Then, the oil pipe 9 is used to pressurize the piston cavity through the oil channel to drive the piston rod 3 to move, thereby driving the lifting slider 2 to extend and engage with the groove on the composite continuous pipe 14, so that the reliable connection between the lifting device and the composite continuous pipe 14 is cleverly achieved, solving the problem of accurately capturing the joint position, and laying the foundation for subsequent stable lifting.

[0081] When inserting the lifting rod 1, the insertion accuracy must be ensured, and the parameters such as the insertion depth need to be determined according to the specific specifications of the composite coiled tube 14. In the process of pressurizing the piston chamber, the pressure must be accurately controlled. Too little pressure will easily cause the lifting slider 2 to fail to fully extend and complete the clamping. Too much pressure will easily damage the device components or cause the lifting slider 2 to extend excessively, affecting the subsequent lifting stability. At the same time, it is also necessary to monitor the clamping condition of the lifting slider 2 and the groove in real time to ensure that the docking is firm.

[0082] After the pulling device is successfully docked with the composite coiled tubing 14, the position of the composite coiled tubing 14 in the well can be adjusted by operating the lifting lug 6 to pull the composite coiled tubing 14, for example, to place it on a more suitable pulling path, or to correct some position deviations caused by the complex environment in the well, so as to facilitate subsequent operations such as smoothly pulling the composite coiled tubing 14 to the ground.

[0083] When operating the lifting lug 6, the pulling force should be applied slowly and steadily to avoid the joint being impacted and loosened or the composite coiled tubing 14 being damaged due to excessive pulling force. At the same time, the pulling direction and strength should be reasonably adjusted in consideration of the actual space conditions underground and obstacles around the composite coiled tubing 14.

[0084] When the lifting of the composite coiled tube 14 is completed or the lifting device needs to be readjusted, it is necessary to release the connection between the lifting device and the composite coiled tube 14. By relieving the pressure in the piston chamber, the piston rod 3 is withdrawn, and the lifting slider 2 is retracted, the clamping can be released smoothly, and then the lifting lug 6 is operated to separate the lifting rod 1 from the composite coiled tube 14, so that the entire lifting device can be put into use again or perform corresponding maintenance operations.

[0085] During the pressure relief process, the speed and degree of pressure relief must also be controlled to ensure that the lifting slider 2 can be retracted smoothly to prevent abnormal situations such as collision between components due to excessive pressure relief. When operating the lifting lug 6 to disengage the lifting rod 1, it is also necessary to operate carefully to avoid unnecessary scratches, collisions, and other damages to the composite coiled tubing 14 and the lifting device.

[0086] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A downhole pulling device for composite material continuous pipe joint, characterized in that: The invention comprises a lifting component, wherein the lifting component comprises: The lifting rod is provided with mounting grooves and piston cavities at intervals along the axial direction. Two lifting sliders that can slide radially along the lifting rod are slidably installed in the mounting grooves. A rebound member is connected between the two lifting sliders. A piston rod is slidably fitted in the piston cavity. The piston rod can be inserted into or withdrawn from between the lifting sliders, so that the lifting sliders are extended out of the circumference of the lifting rod or retracted. The lifting lug has one end connected to the lifting rod and the other end connected to the lifting rope. An oil passage connected to the piston cavity is arranged inside the lifting lug, and the oil passage is connected to an external hydraulic source through an oil pipe.

2. The downhole pulling device for composite continuous pipe joint according to claim 1, characterized in that: The two lifting sliders are symmetrically distributed relative to the axis of the lifting rod, and guide pins that slidably match the lifting sliders are arranged in the installation groove. The lifting sliders protrude from the peripheral surface of the lifting rod to clamp the composite continuous pipe.

3. The downhole pulling device for composite continuous pipe joint according to claim 2, characterized in that: One end of the piston rod slides in the piston cavity, and the other end protrudes out of the piston cavity and faces between the two lifting sliders. An elastic member is installed between the piston rod and the lifting rod, and the compression and rebound directions of the elastic member are parallel to the axis of the piston rod.

4. The downhole pulling device for composite continuous pipe joint according to claim 1, characterized in that: The mounting grooves are distributed radially along the lifting rod, the resilient members are distributed radially along the lifting rod, and the ends of the resilient members are fixed to the lifting slider via stop pins.

5. The downhole pulling device for composite continuous pipe joint according to claim 1, characterized in that: The lifting lug is coaxially distributed with the lifting rod, and a pair of threads connected with the oil passage is installed on the lifting lug, and the oil pipe is connected to the oil passage as two-way through the pair of threads.

6. The downhole pulling device for composite continuous pipe joint according to claim 1 or 5, characterized in that: The lifting ear is provided with a lifting hole, and the lifting rope is connected to the lifting hole.

7. The downhole pulling device for composite continuous pipe joint according to claim 6, characterized in that: The oil pipes are distributed along the suspension ropes.

8. The downhole pulling device for composite continuous pipe joint according to claim 1, characterized in that: It also includes a joint, which includes a joint inner core and a joint outer sleeve. One end of the joint inner core is inserted into the composite continuous tube, and the other end extends to the outside of the composite continuous tube. The joint outer sleeve is sleeved on the outside of the composite continuous tube, and one axial end extends to the outside of the joint inner core and is fixed. The joint inner core is provided with a central channel for the lifting rod to pass through, and an annular groove is opened on the central channel to cooperate with the lifting slider to form a clamping connection.

9. A method for operating a downhole pulling device for a composite material continuous pipe joint, using the downhole pulling device for a composite material continuous pipe joint as claimed in any one of claims 1 to 8, characterized in that: include: The lifting assembly is gradually lowered along the shaft so that the end of the lifting rod away from the lifting ear gradually approaches the composite coiled tubing; One end of the lifting rod is inserted into the top hole of the composite material tube, and the oil pipe is used to pressurize the piston cavity through the oil channel to move the piston rod; The piston rod is inserted between the two lifting sliders, so that the lifting slider slides radially and protrudes outside the peripheral surface of the lifting rod, and the portion of the lifting slider protruding outside the lifting rod is engaged with the groove on the composite material pipe, so that the lifting rod is connected to the composite material pipe; Operate the lifting lug and pull the composite material pipe to adjust its position.

10. The working method of the downhole pulling device of composite material continuous pipe joint according to claim 9, characterized in that: Also includes: The oil pipe releases the pressure of the piston chamber through the oil channel, and the piston rod is withdrawn from between the two lifting sliders, so that the lifting slider is retracted into the peripheral surface of the lifting rod, and the clamping connection with the clamping groove is released; Operate the lifting lug and adjust the lifting rod to separate from the composite material pipe.

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