Test short section with automatic compensation of axial displacement of swivel neck

Abstract

The present application belongs to the technical field of ground test auxiliary device, and discloses a test rotary buckle axial displacement automatic compensation short section, which comprises an upper joint and a lower joint, the upper joint has a first axial channel, and the second axial channel of the lower joint is communicated; one end of the upper joint has a female buckle, and one end of the lower joint has a male buckle, which are respectively used for connecting the upper buckle device and the base of the testing machine; the inner wall of the other end of the upper joint has an inner cross coarse thread, one end of the inner cross coarse thread towards the female buckle is provided with an upper hydraulic bearing body, the outer wall of the other end of the lower joint has an outer cross coarse thread, one end of the outer cross coarse thread towards the male buckle is provided with a lower hydraulic bearing body, the outer cross coarse thread is arranged in the inner cross coarse thread and is matched with the inner cross coarse thread to be screwed to form an X-shaped load coupler, and the X-shaped load coupler is provided with a hydraulic channel which is communicated with the first axial channel and the second axial channel. The present application realizes axial displacement compensation and solves the problem of easy damage of thread screw.

Description

Technical Field

[0001] This invention relates to the field of ground test auxiliary device technology, and in particular to a test screw-lock axial displacement automatic compensation short section. Background Technology

[0002] In the field of petroleum technology, full-condition surface simulation testing of downhole tools is an important component of surface simulation testing. During surface simulation testing, multi-functional testing machines are needed to connect or disconnect downhole tool strings. Typically, shorter tubing strings are fixed at one end, and axial displacement occurs when the other end is screwed in. If this axial displacement is not compensated and released, it can generate significant axial forces. Due to the different thread pitches at the two ends of the tubing string, the axial displacement generated by the same number of turns is different. Most testing machines struggle to compensate for the axial force load caused by this axial displacement in a timely manner. Large axial loads can damage the threads or the screwing device, and even cause personnel injury. Therefore, it is necessary to research an automatic axial displacement compensation sub for testing screwing, which synchronously releases the axial load during the screwing process, compensates for changes in axial displacement, reduces thread damage to the tool, and extends the service life of the screwing device. Summary of the Invention

[0003] The purpose of this invention is to provide an experimental twisted thread axial displacement automatic compensation short section to solve the problem of easy damage to the thread caused by the failure to compensate for the axial displacement generated by the twisted thread.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] The test screw-lock axial displacement automatic compensation short section includes:

[0006] The upper connector has a first axial channel; one end of the upper connector has a female thread for connecting to the upper threading device of the testing machine; the inner wall of the other end of the upper connector has an internal cross coarse thread, and the end of the internal cross coarse thread facing the female thread is provided with an upper hydraulic bearing body;

[0007] The lower connector has a second axial channel, which is coaxially connected to the first axial channel; one end of the lower connector has a male thread for connecting to the downhole tool string to be tested; the outer wall of the other end of the lower connector has an external cross coarse thread, and a lower hydraulic bearing body is provided at the end of the external cross coarse thread facing the male thread;

[0008] The external cross coarse thread passes through the internal cross coarse thread and engages with the internal cross coarse thread to form an X-type load coupler. The X-type load coupler is provided with a hydraulic channel, and the two ends of the hydraulic channel are respectively connected to the first axial channel and the second axial channel.

[0009] Optionally, the upper hydraulic bearing body has an upper hydraulic channel, the inner cross coarse thread has an upper hydraulic chamber, and the two ends of the upper hydraulic channel are respectively connected to the first axial channel and the upper hydraulic chamber.

[0010] Optionally, the lower hydraulic support body has a lower hydraulic channel, the outer cross coarse thread has a lower hydraulic chamber, the two ends of the lower hydraulic channel are respectively connected to the lower hydraulic chamber and the second axial channel, and the upper hydraulic chamber and the lower hydraulic chamber are connected through the gap between the outer cross coarse thread and the inner cross coarse thread.

[0011] Optionally, the upper connector further includes an elastic support body located between the female buckle and the upper hydraulic support body.

[0012] Optionally, the lower connector includes:

[0013] The body has the male thread at one end and the internal thread at the other end;

[0014] The tubing has an external thread at one end for connection with the internal thread, and an external cross thread at the other end for connection with the upper connector.

[0015] Optionally, the lower connector further includes an adjustable limiting mechanism, which is engaged with one end of the body opposite to the male thread. The adjustable limiting mechanism has the internal thread, and one end of the pipe column with the external thread is threaded to the adjustable limiting mechanism.

[0016] Optionally, the upper hydraulic chamber and the lower hydraulic chamber are arranged along the axial direction of the upper connector, and the upper hydraulic chamber and the lower hydraulic chamber are staggered around the axial direction.

[0017] Optionally, the inner diameters of the upper hydraulic channel and the lower hydraulic channel are both smaller than the inner diameters of the first axial channel and the second axial channel.

[0018] Optionally, the X-type load coupler and the lower hydraulic bearing body have a torque transmission section.

[0019] Optionally, the test swivel joint with automatic axial displacement compensation also includes a hydraulic sensor, the probe of which is located within the hydraulic channel.

[0020] The beneficial effects of this invention are:

[0021] The experimental rotary joint for automatic axial displacement compensation of this invention features an internally crossed coarse thread on the inner wall of the upper connector and an externally crossed coarse thread on the outer wall of the lower connector. This allows the upper and lower connectors to be connected via the threaded engagement of the internally and externally crossed coarse threads, forming an X-type load coupler. The coarse thread, compared to the fine threads of the male and female threads, facilitates overcoming thread self-locking. When the upper threading device of the testing machine is threaded into the female thread, the axial expansion and contraction of the X-type load coupler compensates for axial displacement. A hydraulic channel is provided between the first and second axial channels for connection. When the axial load changes, hydraulic action causes axial load transfer between the elastic bearing and the X-type load coupler, resulting in a change in the axial length or distance between the elastic bearing and the lower connector, thereby achieving axial displacement compensation. This maximizes the release of axial force on the tubing caused by axial displacement movement and solves the problem of easy damage to the threaded joint. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the experimental screw-lock axial displacement automatic compensation short section of the present invention.

[0023] In the picture:

[0024] 1. Upper connector; 101. First axial channel; 102. Female thread; 2. Lower connector; 201. Second axial channel; 202. Male thread; 3. Elastic bearing body; 4. Upper hydraulic bearing body; 5. Upper hydraulic channel; 6. Upper hydraulic chamber; 7. X-type load coupler; 8. Lower hydraulic chamber; 9. Lower hydraulic channel; 10. Torque transmission section; 11. Lower hydraulic bearing body; 12. Adjustable limit mechanism. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0026] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0029] This invention provides an automatic axial displacement compensation short section for test screw threads, used to avoid damage to the tool threads during the test screw threading process and improve the stress state of the upper screw threading device. For example... Figure 1 As shown, a test swivel joint axial displacement automatic compensation short section of this embodiment includes an upper connector 1 and a lower connector 2. The upper connector 1 has a first axial channel 101, and the lower connector 2 has a second axial channel 201. When the upper connector 1 and the lower connector 2 are connected, the second axial channel 201 is coaxially connected with the first axial channel 101 for drilling fluid flow, so as to conduct a full-condition simulation test of the downhole tool string. One end of the upper connector 1 has a female thread 102 for connecting to the upper threading device of the testing machine, and one end of the lower connector 2 has a male thread 202 for connecting to the downhole tool string to be tested. It should be noted that during the test installation of the downhole tool string, the downhole tool string needs to be installed between the base of the testing machine and the upper threading device. Due to the different thread pitches at both ends of the downhole tool string, the testing machine has difficulty compensating for the axial force load caused by axial displacement, which can easily cause thread damage and affect the service life of the upper threading device. Therefore, in this embodiment, a test thread axial displacement automatic compensation short section is set between the downhole tool string to be tested and the upper threading device of the testing machine to compensate for the axial displacement of the thread. Therefore, the female thread 102 and male thread 202 are respectively connected to the corresponding connector tools at both ends. It is understood that the female thread 102 and male thread 202 are interchangeable. The use of a female thread 102 on the upper connector 1 and a male thread 202 on the lower connector 2 in this embodiment is merely an example and not a limitation.

[0030] The inner wall of the other end of the upper connector 1 has an inner cross coarse thread, and the end of the inner cross coarse thread facing the female thread 102 is provided with an upper hydraulic bearing body 4; the outer wall of the other end of the lower connector 2 has an outer cross coarse thread, and the end of the outer cross coarse thread facing the male thread 202 is provided with a lower hydraulic bearing body 11; the outer cross coarse thread passes through the inner cross coarse thread and is tightened with the inner cross coarse thread to form an X-type load coupler 7. The X-type load coupler 7 is provided with a hydraulic channel, and the two ends of the hydraulic channel are respectively connected to the first axial channel 101 and the second axial channel 201.

[0031] The experimental rotary joint for automatic axial displacement compensation of the present invention uses an internal cross-coarse thread on the inner wall of the upper connector 1 and an external cross-coarse thread on the outer wall of the lower connector 2. This allows the upper connector 1 and the lower connector 2 to be connected by the threaded engagement of the internal and external cross-coarse threads, forming an X-type load coupler 7. The coarse thread is relative to the fine threads of the male thread 202 and the female thread 102. The cross-coarse thread connection helps to overcome thread self-locking. When the upper threading device of the testing machine is threaded to the female thread 102, the X-type load coupler 7 achieves axial displacement compensation through axial expansion and contraction. A hydraulic channel is set between the first axial channel 101 and the second axial channel 201 for connection. When the axial load changes, the hydraulic action causes the elastic bearing 3 and the X-type load coupler 7 to transfer the axial load. The axial length or distance between the elastic bearing 3 and the lower connector 2 changes, thereby achieving axial displacement compensation and maximizing the release of axial force caused by axial displacement movement, thus solving the problem of easy damage to the thread. Among them, the internal cross coarse thread and the external cross coarse thread are generally cross threads with a mating relationship, and can be T-type threads.

[0032] Optionally, the upper hydraulic bearing body 4 has an upper hydraulic channel 5, and the inner cross coarse thread has an upper hydraulic chamber 6. The two ends of the upper hydraulic channel 5 are respectively connected to the first axial channel 101 and the upper hydraulic chamber 6.

[0033] like Figure 1 In the illustrated embodiment, the upper hydraulic channel 5 comprises multiple segments. The first segment connects the axial through-hole of the upper hydraulic support 4 with the first axial channel 101. The second segment connects the radial through-hole of the upper hydraulic support 4 with the axial through-hole. The third segment connects the upper hydraulic chamber 6 with the through-hole on the pipe wall of the upper connector 1. Liquid within the first axial channel 101 can enter the upper hydraulic chamber 6 through the upper hydraulic channel 5, forming axial hydraulic pressure. This hydraulic pressure helps reduce hard contact between metal parts, acting as a buffer. The upper hydraulic channel 5 can be constructed in a manner not limited to the three-segment design described above; liquid communication can also be achieved by installing pipelines.

[0034] Optionally, the lower hydraulic support body 11 has a lower hydraulic channel 9 and an outer cross coarse thread with a lower hydraulic chamber 8. The two ends of the lower hydraulic channel 9 are respectively connected to the lower hydraulic chamber 8 and the second axial channel 201. The upper hydraulic chamber 6 and the lower hydraulic chamber 8 are connected through the gap between the outer cross coarse thread and the inner cross coarse thread.

[0035] When the axial load changes, the hydraulic changes in the upper hydraulic chamber 6 and the lower hydraulic chamber 8 are fed back to the upper hydraulic support body 4 and the lower hydraulic support body 11 through the upper hydraulic channel 5 and the lower hydraulic channel 8, respectively, thereby driving the axial length to change and reduce the axial load.

[0036] Optionally, the upper connector 1 also includes an elastic support 3, which is located between the female buckle 102 and the upper hydraulic support 4.

[0037] In this embodiment, the elastic support 3 is made of a highly elastic and rigid material. The elastic support 3 can abut against the upper hydraulic support 4. The elastic support 3 is provided with an axial through hole to communicate with the upper hydraulic support 4 and the first axial through hole 101. Through the buffering and compensation structure of the elastic support 3, axial displacement can be further compensated, and the axial force of the tubing with axial displacement motion parameters can be released to the maximum extent.

[0038] Optionally, the lower connector 2 includes a body and a tubing. One end of the body has a male thread 202 and the other end has an internal thread. One end of the tubing has an external thread for connecting with the internal thread, and the other end of the tubing has an external cross coarse thread for connecting to the upper connector 1.

[0039] It is understood that in this embodiment, by setting the lower connector 2 as a combination of the body and the pipe column, it is convenient to realize the threaded connection between the pipe column and the body, thus having the advantage of being replaceable. The threaded connection between the pipe column and the body can realize the adjustment of the height of the pipe column relative to the body, thereby realizing the adjustment of the axial distance between the pipe column and the upper connector 1, that is, the adjustment of the relative displacement length between the upper connector 1 and the lower connector 2, so as to meet the needs of different working conditions.

[0040] Optionally, the lower connector 2 also includes an adjustable limiting mechanism 12, which is engaged with one end of the main body away from the male thread 202. The adjustable limiting mechanism 12 has an internal thread, and the end of the pipe column with an external thread is threaded to the adjustable limiting mechanism 12.

[0041] like Figure 1As shown, in this embodiment, the adjustable limiting mechanism 12 is a nut. Taking the nut as an example, the nut is circumferentially limited and locked into the body. One end of the tube column is threadedly connected to the nut. When the tube column and the nut are threadedly connected and rotated, the height position of the tube column relative to the nut changes, and then the position of the outer cross coarse thread at the other end relative to the inner cross coarse thread changes, so that the displacement relationship between the upper connector 1 and the lower connector 2 can be adjusted to adapt to different working conditions.

[0042] Optionally, the upper hydraulic chamber 6 and the lower hydraulic chamber 8 are arranged along the axial direction of the upper connector 1, and the upper hydraulic chamber 6 and the lower hydraulic chamber 8 are arranged alternately around the axis.

[0043] like Figure 1 As shown, in this embodiment, the upper connector 1 and the lower connector 2 are coaxial after connection. The upper hydraulic chamber 6 and the lower hydraulic chamber 8 are preferably set on the protruding structure of the external cross coarse thread and the internal cross coarse thread, thus having the characteristic of staggered arrangement. They penetrate through the thickness direction and are connected by openings on the side. The diameter of the upper hydraulic chamber 6 and the lower hydraulic chamber 8 is larger than the diameter of the upper hydraulic channel 5, and the length of the lower hydraulic chamber 8 is greater than the length of the upper hydraulic chamber 6. At the upper hydraulic chamber 6 and the lower hydraulic chamber 8, when the screw rotation generates axial force, the hydraulic pressure changes, which helps to buffer the axial force and improve safety.

[0044] Optionally, the inner diameters of the upper hydraulic channel 5 and the lower hydraulic channel 9 are both smaller than the inner diameters of the first axial channel 101 and the second axial channel 201.

[0045] In this embodiment, the first axial channel 101 and the second axial channel 201 have the same inner diameter. After the upper connector 1 and the lower connector 2 are connected, the first axial channel 101 and the second axial channel 201 are coaxially connected. The inner diameters of the upper hydraulic channel 5 and the lower hydraulic channel 9 are both smaller than the inner diameter of the first axial channel 101 or the second axial channel 201, which is beneficial to forming a higher liquid pressure in the hydraulic channel for buffering or releasing axial force. It should be noted that the number of upper hydraulic channels 5 and lower hydraulic channels 9 can be set in multiples as needed, and the number of upper hydraulic chambers 6 and lower hydraulic chambers 8 can also be set in multiples. Preferably, the upper hydraulic channels 5 and upper hydraulic chambers 6 are arranged in a one-to-one correspondence, and the lower hydraulic chambers 8 and lower hydraulic channels 9 are arranged in a one-to-one correspondence.

[0046] Optionally, the X-type load coupler 7 has a torque transmission section 10 between it and the lower hydraulic bearing 11.

[0047] like Figure 1As described above, when the upper connector 1 and the lower connector 2 are connected, an X-type load coupler 7 is formed. The length of the externally crossed coarse thread on the tubing is greater than the length of the X-type load coupler 7. Therefore, in the axial direction, a section of the externally crossed coarse thread is left unsupported at the end of the tubing facing the male thread 202, called the torque transmission section 10. The X-type load coupler 7 forms a semi-suspended structure. When the axial load changes, the upper hydraulic chamber 6 and the lower hydraulic chamber 8 sense the change and feed it back to the upper hydraulic support body 4 and the lower hydraulic support body 11 through the upper hydraulic channel 5 and the lower hydraulic channel 9 and their flow-limiting adjustment mechanisms, respectively. This drives a change in the axial length to reduce the axial load. Furthermore, the buffering and compensation structure of the elastic support body 3 further compensates for axial displacement, maximizing the release of the axial force of the tubing due to axial displacement motion parameters.

[0048] Optionally, the test swivel joint with automatic axial displacement compensation also includes a hydraulic sensor, with the sensor probe located within the hydraulic channel.

[0049] In this embodiment, the probe of the hydraulic sensor is preferably placed in the upper hydraulic chamber 6 and / or the lower hydraulic chamber 8 to sense changes in axial load.

[0050] The test screw-lock axial displacement automatic compensation short section provided by the present invention has a simple structure, is easy to use, requires no cumbersome manual adjustment, is beneficial to equipment and personnel safety, and improves work efficiency.

[0051] In a preferred embodiment of the present invention, coarse thread refers to a coarse-pitch thread, and fine thread refers to a fine-pitch thread.

[0052] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An experimental rotary joint with automatic axial displacement compensation, characterized in that, include: The upper connector (1) has a first axial channel (101); one end of the upper connector (1) has a female thread (102) for connecting the upper thread device of the testing machine; the inner wall of the other end of the upper connector (1) has an internal cross coarse thread, and the end of the internal cross coarse thread facing the female thread (102) is provided with an upper hydraulic bearing body (4). The lower connector (2) has a second axial channel (201) which is coaxially connected to the first axial channel (101); one end of the lower connector (2) has a male thread (202) for connecting to the downhole tool string to be tested; the outer wall of the other end of the lower connector (2) has an external cross coarse thread, and the end of the external cross coarse thread facing the male thread (202) is provided with a lower hydraulic support body (11); The external cross coarse thread passes through the internal cross coarse thread and is tightened with the internal cross coarse thread to form an X-type load coupler (7). The X-type load coupler (7) is provided with a hydraulic channel. The two ends of the hydraulic channel are respectively connected to the first axial channel (101) and the second axial channel (201). The upper hydraulic support body (4) has an upper hydraulic channel (5), and the inner cross coarse thread has an upper hydraulic chamber (6). The two ends of the upper hydraulic channel (5) are respectively connected to the first axial channel (101) and the upper hydraulic chamber (6). The lower hydraulic support body (11) has a lower hydraulic channel (9), and the outer cross coarse thread has a lower hydraulic chamber (8). The two ends of the lower hydraulic channel (9) are respectively connected to the lower hydraulic chamber (8) and the second axial channel (201). The upper hydraulic chamber (6) and the lower hydraulic chamber (8) are connected through the gap between the outer cross coarse thread and the inner cross coarse thread.

2. The test screw-lock axial displacement automatic compensation short section according to claim 1, characterized in that, The upper connector (1) also includes an elastic support (3), which is located between the female buckle (102) and the upper hydraulic support (4).

3. The test screw-lock axial displacement automatic compensation short section according to claim 1, characterized in that, The lower connector (2) includes: The body has the male buckle (202) at one end and an internal thread at the other end; The tubing has an external thread at one end for connection with the internal thread, and an external cross thread at the other end for connection with the upper connector (1).

4. The test screw-lock axial displacement automatic compensation short section according to claim 3, characterized in that, The lower connector (2) further includes an adjustable limiting mechanism (12), which is engaged with the end of the body opposite to the male buckle (202). The adjustable limiting mechanism (12) has the internal thread, and the end of the pipe column with the external thread is threaded to the adjustable limiting mechanism (12).

5. The test screw-lock axial displacement automatic compensation short section according to claim 1, characterized in that, The upper hydraulic chamber (6) and the lower hydraulic chamber (8) are arranged along the axial direction of the upper connector (1), and the upper hydraulic chamber (6) and the lower hydraulic chamber (8) are arranged alternately around the axial direction.

6. The test screw-lock axial displacement automatic compensation short section according to claim 1, characterized in that, The inner diameters of the upper hydraulic channel (5) and the lower hydraulic channel (9) are both smaller than the inner diameters of the first axial channel (101) and the second axial channel (201).

7. The test screw-lock axial displacement automatic compensation short section according to any one of claims 1-6, characterized in that, The X-type load coupler (7) and the lower hydraulic bearing (11) have a torque transmission section (10).

8. The test screw-lock axial displacement automatic compensation short section according to any one of claims 1-6, characterized in that, It also includes a hydraulic sensor, the probe of which is located within the hydraulic channel.

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