A retractable connecting nipple for downhole instruments

Abstract

The present invention relates to the technical field of oilfield drilling, and specifically discloses a telescopic connecting short section for downhole instruments. The problem that the existing connecting short section drives the installed downhole instruments to get stuck easily in a curved well. The present invention comprises a first connector, the first connector is installed with a first joint, a second connector is slidably provided on the side of the first connector away from the first joint, the second connector is fixed with a fixing sleeve slidably connected to the first connector, a second joint is installed on the side of the second connector away from the first joint, a first spring is provided between the second connector and the first connector, and a limiting mechanism for locking the first connector and the second connector is provided on the first connector. The present invention facilitates the smooth movement of the downhole instruments carried by the device in the well through the telescopic connection between the first connector and the second connector, and facilitates the smooth passage of the first connector and the second connector through the curved well.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield drilling, in particular to a telescopic connecting nipple for downhole instruments. Background Art

[0002] In the field of oil drilling and geological exploration, the comprehensive use of downhole instruments and connecting pup joints is the key to achieving efficient drilling operations. The continuous development and optimization of these tools and technologies have provided strong support for the exploration and development of oil and gas resources. By rationally selecting and using downhole instruments and connecting pup joints, the efficiency and safety of drilling operations can be significantly improved, thereby promoting the development of the oil and gas industry.

[0003] However, in the process of connecting the downhole instrument to enter the wellbore, the existing connecting short section is easily stuck due to the influence of the curved wellbore during the process of lowering into the well. After the jam, the operator is often required to reciprocate the connecting short section and the downhole instrument through external equipment to move them up and down, which slows down the lowering speed of the connecting short section and the downhole instrument, affecting the detection efficiency of the downhole instrument to the specified depth. At the same time, when the connecting short section is stuck in the curved wellbore, it affects the subsequent use of the wellbore and causes the loss of the downhole instrument. Summary of the invention

[0004] In order to solve the problems raised in the above background technology, the present invention provides a telescopic connecting nipple for downhole instruments.

[0005] The technical solution of the present invention is: a telescopic connecting short section for downhole instruments, including a first connector, a first connector is installed with a first joint, a second connector is slidably arranged on the side of the first connector away from the first joint, the second connector is fixed with a fixing sleeve slidably connected to the first connector, a second joint is installed on the side of the second connector away from the first joint, a first spring is arranged between the second connector and the first connector, and a limiting mechanism for locking the first connector and the second connector is arranged on the first connector.

[0006] Furthermore, the limiting mechanism includes a first fixing ring, which is fixed in the first connecting body and slidably connected to the second connecting body. The first fixing ring is slidably provided with a sliding column, and a second spring is installed between the sliding column and the first fixing ring. The side of the sliding column away from the first fixing ring is hemispherical, and the second connecting body is provided with a blind hole, and the hemispherical end of the sliding column is limitedly matched with the blind hole of the second connecting body.

[0007] Furthermore, the second connecting body is provided with a centrally symmetrical vertical groove, and a centrally symmetrical convex column is fixedly connected to the inner side of the first fixing ring, and the convex column is located in the adjacent vertical groove and slides.

[0008] Furthermore, the second connector is provided with a centrally symmetrical wave groove, the wave groove is connected with the adjacent vertical groove, and the wave groove is slidably matched with the adjacent convex column.

[0009] Furthermore, it also includes a supporting mechanism for supporting the first joint and the second joint, the supporting mechanism is arranged on the first connecting body, the supporting mechanism includes two groups of symmetrically distributed telescopic rods, the two groups of telescopic rods are respectively embedded in the first connecting body and the fixed sleeve, each group of the telescopic rods includes two symmetrical ones, the telescopic ends of each group of the telescopic rods are commonly fixed with a second fixing ring, the two second fixing rings are respectively in contact and cooperate with the first joint and the second joint, and the first connecting body is provided with a trigger component for controlling the movement of the two second fixing rings.

[0010] Furthermore, the opposite ends of the first connector and the second connector are both provided with spherical surfaces, and the first connector and the second connector are spherically connected to the first joint and the second joint respectively.

[0011] Furthermore, the trigger assembly includes symmetrical sliding blocks, which are symmetrically arranged on the first connecting body, symmetrical third springs are installed between the sliding blocks and the first connecting body, and the symmetrical sliding blocks are in contact and cooperation with the second connecting body. The first connecting body is fixedly connected with a symmetrically distributed fixed shell, and a sliding push rod is slidably arranged in the fixed shell, and the sliding push rod is in contact and cooperation with adjacent sliding blocks. A fourth spring is installed between the sliding push rod and the adjacent fixed shell, and the fixed shell is connected to the cavities on the two adjacent telescopic rods through two pipes, and all the fixed shells, all the cavities of the telescopic rods and the pipes connected thereto are filled with liquid.

[0012] Furthermore, the cross section of the sliding block in the direction of the center line of the adjacent sliding push rod is rhombus-shaped.

[0013] Furthermore, it also includes a locking mechanism for locking the first connector and the second connector respectively with the first joint and the second joint, the locking mechanism is arranged on the first joint and the second joint, the locking mechanism includes two symmetrical limiting columns, the two limiting columns are respectively slidably arranged in the first joint and the second joint, a fifth spring is respectively installed between the first joint and the second joint and the adjacent limiting columns, the ball ends of the first connector and the second connector are both provided with blind holes, the blind holes of the first connector and the blind holes of the second connector are respectively matched with the adjacent limiting columns.

[0014] Furthermore, the limiting column is threadedly provided with a threaded rod, the first joint and the second joint are both provided with a blind hole, and the first joint and the blind hole and the blind hole of the second joint are respectively limitedly matched with the adjacent threaded rod.

[0015] Compared with the prior art, the present invention has the following advantages: the present invention facilitates the smooth movement of the downhole instrument carried by the device in the wellbore through the telescopic connection between the first connector and the second connector, and facilitates the smooth passage of the first connector and the second connector through the curved wellbore. The limiting function of the sliding column and the second connector is used to improve the connection stability between the first connector and the second connector, avoid the vibration of the connected downhole instrument caused by the reciprocating contraction between the first connector and the second connector, and improve the working stability of the downhole instrument connected by the first joint. The ball joint between the first connector and the first joint and the ball joint between the second connector and the second joint are used to further improve the smoothness of the movement of the device in the arc wellbore. The cooperation of the two limiting columns with the blind holes on the first connector and the blind holes on the second connector is used to facilitate the operator to select the working mode of the device according to the wellbore status, and help the device drive the downhole instrument to move quickly to the designated position. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0017] Figure 2 is a cross-sectional view of the first connector and the fixing sleeve of the present invention;

[0018] Figure 3 is a cross-sectional view of the second connector and the first fixing ring of the present invention;

[0019] Figure 4 is a cross-sectional view of the limiting mechanism of the present invention;

[0020] Figure 5 It is a three-dimensional structural schematic diagram of the support mechanism of the present invention;

[0021] Figure 6 is a cross-sectional view of the trigger assembly of the present invention;

[0022] Figure 7 It is a cross-sectional view of the locking mechanism of the present invention.

[0023] Markings in the accompanying drawings: 1. first connector, 2. first joint, 3. second connector, 4. fixing sleeve, 5. second joint, 6. first spring, 7. first fixing ring, 8. sliding column, 9. second spring, 10. vertical groove, 11. convex column, 12. wave groove, 13. telescopic rod, 14. second fixing ring, 15. sliding block, 16. third spring, 17. fixing shell, 18. sliding push rod, 19. fourth spring, 20. limiting column, 21. fifth spring, 22. threaded rod. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] When the existing connecting pup joint carries the installed downhole instrument and moves in the wellbore, the downhole instrument and the connecting pup joint are easily stuck in the curved wellbore due to the curvature of the wellbore and the unevenness of the wellbore wall, which affects the moving speed of the connecting pup joint and the downhole instrument in the wellbore, thereby causing the detection efficiency of the downhole instrument to a specified depth to be reduced.

[0026] The present invention designs a connecting nipple which can help an existing connecting nipple and a downhole instrument to move smoothly in a well.

[0027] Embodiment 1: A retractable connecting nipple for a downhole instrument, see Figure 1 and Figure 2 As shown, it includes a first connector 1, a first joint 2 is installed at the lower part of the first connector 1, the first joint 2 is used to connect the downhole instrument, a second connector 3 is slidably arranged on the upper part of the first connector 1, a fixing sleeve 4 slidably connected to the first connector 1 is fixedly connected to the upper part of the second connector 3, a second joint 5 is installed on the upper part of the second connector 3, the second joint 5 is used to connect the drilling tool deep in the wellbore, a first spring 6 is arranged between the second connector 3 and the first connector 1, and a limiting mechanism for locking it and the second connector 3 is arranged on the first connector 1. The elastic force of the first spring 6 is used to control the expansion and contraction changes between the second connector 3 and the first connector 1, so as to help the device pass through a slightly stuck part.

[0028] See also Figure 2-Figure 4As shown, the limiting mechanism includes a first fixing ring 7, the first fixing ring 7 is fixedly connected to the inner surface of the first connecting body 1, and the first fixing ring 7 is slidably connected to the second connecting body 3, a sliding column 8 is slidably arranged on the left part of the first fixing ring 7, a second spring 9 is installed between the sliding column 8 and the first fixing ring 7, the right side of the sliding column 8 is hemispherical, the second connecting body 3 is provided with a blind hole, the hemispherical end of the sliding column 8 is limitedly matched with the blind hole of the second connecting body 3, so that the second connecting body 3 is fixed relative to the first connecting body 1, so that the device can carry the downhole instrument stably in the smooth vertical well, and the second connecting body 3 is provided with a center There are two symmetrical vertical grooves 10, and two centrally symmetrical protrusions 11 are fixedly connected to the inner side of the first fixing ring 7. The protrusions 11 are located in adjacent vertical grooves 10 and slide. The second connector 3 is provided with a centrally symmetrical wave groove 12. The wave groove 12 is connected to the adjacent vertical grooves 10. The wave groove 12 slides with the adjacent protrusions 11. The protrusions 11 move in the adjacent vertical grooves 10 and the wave grooves 12 to make the second connector 3 reciprocate relative to the first connector 1. The reciprocating rotation of the second connector 3 helps it and the downhole instrument to pass through the jam smoothly, so that the downhole instrument can be quickly moved to the specified depth for detection.

[0029] After completing the drilling operation, the operator takes out the drilling tool while checking the detailed data in the wellbore, and then takes out the drill bit and other equipment connected to the drilling tool, and then connects the second joint 5 to the drilling tool, and connects the downhole instrument used to the first joint 2 to complete the installation of the device.

[0030] After the installation of the device is completed, the operator controls the drill bit to move downward through the external equipment, places the downhole instrument connected to the first joint 2 underground, and the downhole instrument works to monitor the downhole data. When the downhole instrument gets stuck in the curved section in the wellbore, as the drill bit continues to move downward, the jamming force acts between the first connector 1 and the second connector 3 through the first joint 2. When the force is greater than the limiting force of the sliding column 8 on the second connector 3, the first connector 1 and the second connector 3 undergo relative contraction and deformation. The contraction between the first connector 1 and the second connector 3 causes the sliding column 8 to retract into the first fixing ring 7 and compress the second spring 9. The contraction between the first connector 1 and the second connector 3 compresses the first spring 6 to deform. At the same time, the two protrusions 11 slide in the two vertical grooves 10 to shorten the distance between the first joint 2 and the second joint 5, so as to facilitate the downhole instrument and the device to pass through the wellbore portion smoothly.

[0031] After the protruding column 11 moves from the adjacent vertical groove 10 to the adjacent wave groove 12, if the downhole instrument becomes loose in the wellbore, the drilling tool will drive the device and the downhole instrument through the curved wellbore, and then, under the action of the elastic force stored in the first spring 6, expansion and reset occur between the first connector 1 and the second connector 3, and under the action of the elastic force of the second spring 9, the sliding column 8 is reinserted into the blind hole of the second connector 3.

[0032] After the boss 11 moves from the adjacent vertical groove 10 to the adjacent wave groove 12, if the downhole instrument has not loosened in the shaft, the force during the jamming continues to cause the first connector 1 and the second connector 3 to continue to contract, and the boss 11 will move in the adjacent wave groove 12. Under the limiting and squeezing effect of the wave groove 12, the two bosses 11 drive the downhole instrument to reciprocate through the first fixing ring 7, the first connector 1 and the first joint 2. The rotation of the downhole instrument facilitates its smooth passage through the curved shaft, thereby improving the flow of the device in the process of carrying the downhole instrument into the shaft.

[0033] After the device successfully passes through the curved wellbore, the first connector 1 and the second connector 3 expand and reset under the action of the elastic force stored in the first spring 6, and the subsequent drilling tool drives the downhole instrument to continue to move through the device. When the downhole instrument gets stuck again, the above operation can be repeated. After the downhole instrument completes data collection, the operator takes out the device and the downhole instrument through external equipment.

[0034] Example 2: Based on Example 1, refer to Figure 2 and Figure 5 As shown, it also includes a supporting mechanism for supporting the first joint 2 and the second joint 5, the supporting mechanism is arranged on the first connector 1, and the opposite ends of the first connector 1 and the second connector 3 are provided with spherical surfaces, the first connector 1 and the second connector 3 are respectively ball-connected with the first connector 2 and the second connector 5, the supporting mechanism includes two groups of telescopic rods 13 symmetrically distributed up and down, the two groups of telescopic rods 13 are respectively embedded in the lower part of the first connector 1 and the upper part of the fixed sleeve 4, each group of telescopic rods 13 includes two symmetrical front and back, and the telescopic ends of each group of telescopic rods 13 are commonly fixed with a second fixing ring 14, the outer diameter of the second fixing ring 14 is smaller than the outer diameter of the second connector 5, the two second fixing rings 14 are respectively in contact with the first connector 2 and the second connector 5, a trigger assembly for controlling the movement of the two second fixing rings 14 is provided on the first connector 1, and the first connector 2 and the second connector 5 are respectively ball-connected with the first connector 1 and the second connector 3, so that the connecting short section is convenient for bending through the curved well and avoiding jamming in the curved well of the device.

[0035] See also Figure 5 and Figure 6As shown, the trigger assembly includes two sliding blocks 15 that are symmetrical in front and back, and the two sliding blocks 15 are both slidably arranged in the first connecting body 1. The cross-section of the sliding block 15 in the direction of the center line of the adjacent sliding push rod 18 is rhombus-shaped. Two third springs 16 that are symmetrical in left and right are installed between the sliding block 15 and the first connecting body 1. The two sliding blocks 15 are both in contact with the lower part of the second connecting body 3. Two fixed shells 17 that are symmetrically distributed in front and back are fixed to the first connecting body 1. The inner lower parts of the two fixed shells 17 are both slidably arranged with sliding push rods 18, and the sliding push rods 18 are in contact with the adjacent sliding blocks 15. In coordination, a fourth spring 19 is installed between the sliding push rod 18 and the adjacent fixed shell 17. In the initial state, the third spring 16 and the fourth spring 19 are both in a compressed state. The fixed shell 17 is connected to the cavities on the upper and lower adjacent telescopic rods 13 through two pipes. The cavities of all the fixed shells 17 and all the telescopic rods 13 and the pipes connected thereto are filled with liquid. The sliding block 15 is used to buffer the resetting process of the second connector 3, and at the same time, the first joint 2, the second joint 5, the first connector 1 and the second connector 3 are restored to straightness, thereby ensuring that the downhole instrument is located in the middle of the well.

[0036] When the downhole instrument gets stuck in the well, the above operation is repeated to cause the first connector 1 and the second connector 3 to contract, wherein the second connector 3 moves to release the limit on the two sliding blocks 15, and then under the elastic force of the third spring 16, the two sliding blocks 15 move closer to each other, and the sliding blocks 15 move to release the limit on the adjacent sliding push rods 18, and then under the elastic force of the two fourth springs 19, the two sliding push rods 18 move downward, and the sliding push rods 18 move downward to draw the liquid in the chambers of the two adjacent telescopic rods 13 into the corresponding fixed shells 17, and as the liquid in the chambers of the telescopic rods 13 flows, its telescopic end drives the adjacent second fixed rings 14 to move, and the two second fixed rings 14 move away from the first joint 2 and the second joint 5 respectively, and subsequently under the action of the jamming resistance, the first joint 2 and the second joint 5 rotate relative to the first connector 1 and the second connector 3, so that the device can drive the downhole instrument to smoothly pass through the curved part of the well, so that the downhole instrument can be quickly moved down to the designated position.

[0037] When the first joint 2 and the second joint 5 are still in a stuck state after bending, the two protrusions 11 are moved in the two wave grooves 12, and the above-mentioned reciprocating rotation of the first connector 1 is repeated to prevent the device and the downhole instrument from getting stuck in the well.

[0038] After the device successfully passes through the stuck part, under the action of the elastic force stored in the first spring 6, the first connector 1 and the second connector 3 expand. In this process, the two sliding blocks 15 buffer the second connector 3 to reduce the vibration of the device. Subsequently, the second connector 3 squeezes the two sliding blocks 15 to move in the opposite direction to reset. The sliding block 15 moves to compress the third spring 16. The sliding block 15 moves and squeezes the sliding push rod 18 to move upward at the same time. The two sliding push rods 18 move upward to extend the telescopic ends of the four telescopic rods 13 through the liquid to reset. The telescopic ends of the four telescopic rods 13 move to control the two second fixing rings 14 to move and squeeze the first joint 2 and the second joint 5, so that the first joint 2 and the second joint 5 swing in the opposite direction to reset, thereby keeping the downhole instrument connected to the first joint 2 centered in the wellbore, thereby improving the stability of the movement of the device and the downhole instrument in the wellbore.

[0039] Embodiment 3: Based on Embodiment 2, refer to Figure 2 and Figure 7 As shown, it also includes a locking mechanism, which is arranged on the first joint 2 and the second joint 5. The locking mechanism is used to lock the first connector 1 and the second connector 3 with the first joint 2 and the second joint 5 respectively. The locking mechanism includes two upper and lower symmetrical limit columns 20, and the two limit columns 20 are respectively slidably arranged on the left part of the first joint 2 and the left part of the second joint 5. A fifth spring 21 is installed between the first joint 2 and the second joint 5 and the adjacent limit columns 20. In the initial state, the fifth spring 21 is in a compressed state. The ball ends of the first connector 1 and the second connector 3 are both provided with blind holes. The blind holes of the first connector 1 and the blind holes of the second connector 3 are respectively limited with the adjacent limit columns 20. The limit columns 20 are threadedly provided with threaded rods 22. The first connector 2 and the second connector 5 are both provided with blind holes. The first connector 2 and the blind holes of the second connector 5 are respectively limited with the adjacent threaded rods 22. By controlling the locking and separation of the two ball joints, it is convenient for the present connecting short section to move in different wells, so that the downhole instrument connected to the present connecting short section is in the middle of the well.

[0040] When the wellbore into which the downhole instrument is dropped is a vertical wellbore, the operator rotates the two threaded rods 22 through an external tool to disengage the two threaded rods 22 from the blind holes on the first joint 2 and the blind holes on the second joint 5, respectively. Then the operator rotates the first joint 2 and the second joint 5 to make the blind holes on the first joint 2 and the second joint 5 face the adjacent limiting columns 20. Then, under the elastic force of the two fifth springs 21, the two limiting columns 20 are respectively inserted into the blind holes of the first joint 2 and the second joint 5, so that the first connector 1 and the second connector 3 are respectively in a fixed state with the first joint 2 and the second joint 5, ensuring that when the first joint 2 drives the downhole instrument to move downward, the downhole instrument is located in the middle of the wellbore, thereby reducing the scratching of the wellbore on the downhole instrument.

[0041] When the wellbore where the downhole instrument is dropped has an arc-shaped wellbore, the operator pulls the two limit columns 20, and the limit columns 20 move to compress the connected fifth spring 21, and the two limit columns 20 move out of the blind hole of the first connector 1 and the blind hole of the second connector 3 respectively, so that the first connector 1 and the second connector 3 are in a ball-jointed state with the first joint 2 and the second joint 5 respectively, and then the operator rotates the two threaded rods 22 in the opposite direction, so that the two threaded rods 22 are respectively inserted into the blind hole of the first joint 2 and the blind hole of the second joint 5, and the above operation can be repeated during the subsequent downhole process of the device.

[0042] It should be pointed out that the above preferred embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A telescopic connecting nipple for downhole instruments, characterized in that: The invention comprises a first connecting body (1), the first connecting body (1) being provided with a first joint (2), a second connecting body (3) being slidably provided on a side of the first connecting body (1) away from the first joint (2), the second connecting body (3) being fixedly connected with a fixing sleeve (4) slidably connected to the first connecting body (1), a second joint (5) being provided on a side of the second connecting body (3) away from the first joint (2), a first spring (6) being provided between the second connecting body (3) and the first connecting body (1), and a limiting mechanism for locking the first connecting body (1) and the second connecting body (3); The limiting mechanism comprises a first fixing ring (7), the first fixing ring (7) is fixedly connected to the first connecting body (1), and the first fixing ring (7) is slidably connected to the second connecting body (3), the first fixing ring (7) is slidably provided with a sliding column (8), a second spring (9) is installed between the sliding column (8) and the first fixing ring (7), the side of the sliding column (8) away from the first fixing ring (7) is hemispherical, the second connecting body (3) is provided with a blind hole, and the hemispherical end of the sliding column (8) is limitedly matched with the blind hole of the second connecting body (3); The second connecting body (3) is provided with a centrally symmetrical vertical groove (10), and a centrally symmetrical convex column (11) is fixedly connected to the inner side of the first fixing ring (7), and the convex column (11) is located in an adjacent vertical groove (10) and slides; The second connecting body (3) is provided with a centrally symmetrical wave groove (12), the wave groove (12) is connected to the adjacent vertical groove (10), and the wave groove (12) is slidably matched with the adjacent convex column (11).

2. The telescopic connecting nipple for downhole instruments according to claim 1, characterized in that: The invention also comprises a supporting mechanism for supporting the first joint (2) and the second joint (5), the supporting mechanism being arranged on the first connecting body (1), the supporting mechanism comprising two groups of telescopic rods (13) which are symmetrically distributed, the two groups of telescopic rods (13) being respectively embedded in the first connecting body (1) and the fixing sleeve (4), each group of telescopic rods (13) comprising two symmetrical ones, the telescopic ends of each group of telescopic rods (13) being commonly fixedly connected with a second fixing ring (14), the two second fixing rings (14) being respectively in contact with and cooperating with the first joint (2) and the second joint (5), and the first connecting body (1) being provided with a triggering assembly for controlling the movement of the two second fixing rings (14).

3. The telescopic connecting nipple for downhole instruments according to claim 2 is characterized in that: The first connector (1) and the second connector (3) are both provided with spherical surfaces at their opposite ends, and the first connector (1) and the second connector (3) are spherically connected to the first joint (2) and the second joint (5) respectively.

4. The telescopic connecting nipple for downhole instruments according to claim 3 is characterized in that: The trigger assembly comprises symmetrical sliding blocks (15), which are symmetrically arranged on the first connecting body (1), symmetrical third springs (16) are installed between the sliding blocks (15) and the first connecting body (1), and the symmetrical sliding blocks (15) are in contact with the second connecting body (3). The first connecting body (1) is fixedly connected to symmetrically distributed fixed shells (17), and sliding push rods (18) are slidably arranged in the fixed shells (17). The sliding push rods (18) are in contact with adjacent sliding blocks (15), and fourth springs (19) are installed between the sliding push rods (18) and adjacent fixed shells (17). The fixed shells (17) are connected to cavities on two adjacent telescopic rods (13) through two pipes, and the cavities of all the fixed shells (17), all the telescopic rods (13) and the pipes connected thereto are filled with liquid.

5. The telescopic connecting nipple for downhole instruments according to claim 4 is characterized in that: The cross section of the sliding block (15) in the direction of the center line of the adjacent sliding push rod (18) is rhombus-shaped.

6. The telescopic connecting nipple for downhole instruments according to claim 4, characterized in that: The invention also comprises a locking mechanism for locking the first connector (1) and the second connector (3) with the first joint (2) and the second joint (5) respectively. The locking mechanism is arranged on the first joint (2) and the second joint (5). The locking mechanism comprises two symmetrical limiting posts (20). The two limiting posts (20) are slidably arranged in the first joint (2) and the second joint (5) respectively. A fifth spring (21) is installed between the first joint (2) and the second joint (5) and the adjacent limiting posts (20). The ball ends of the first connector (1) and the second connector (3) are both provided with blind holes. The blind holes of the first connector (1) and the second connector (3) are respectively matched with the adjacent limiting posts (20) for limiting.

7. The telescopic connecting nipple for downhole instruments according to claim 6 is characterized in that: The limiting column (20) is threadedly provided with a threaded rod (22), the first joint (2) and the second joint (5) are both provided with blind holes, and the first joint (2) and the blind hole and the blind hole of the second joint (5) are respectively limitedly matched with adjacent threaded rods (22).

Images