CN106812519B - Test device for downhole tools and test system for downhole tools - Google Patents

Abstract

The invention discloses a testing device for a downhole tool and a testing system for the downhole tool, wherein the testing device for the downhole tool comprises an external mechanism and a central rod; the central rod penetrates through the external mechanism and can move in the vertical direction relative to the external mechanism; the well core rod with be formed with first cavity between the exterior mechanism, the exterior mechanism be provided with the first opening of first cavity intercommunication, well core rod is provided with the second cavity, the upper portion of second cavity is sealed, the lower part of well core rod's second cavity is opened, well core rod's lower part is used for being connected with downhole tool, be provided with on the well core rod with the second opening of first cavity with the second cavity intercommunication. By adopting the structure, the underground tool can be tested under more underground conditions.

Description

Test device for downhole tools and test system for downhole tools

technical field

The invention relates to the field of oil and gas field exploitation, in particular to a test device for downhole tools and a test system for downhole tools.

Background technique

In the field of oil production, especially in the process of heavy oil recovery, high-temperature-resistant downhole tools are indispensable in steam huff and puff, steam flooding, SAGD, combustion oil layer, and steam injection-assisted thermal recovery technology, and their quality directly affects Success or failure of heavy oil development process measures. In recent years, more and more types of downhole tools are used in various oil fields, and the requirements are getting higher and higher, especially the downhole tools with high temperature resistance and lifting and lowering action are used more and more frequently.

At present, the medium heating and circulation system of the indoor high temperature simulation test system and the wellbore of the test well are generally rigid and fixed, which cannot meet the high temperature simulation test of downhole tools with lifting and lowering action. Therefore, it is inevitable to upgrade and transform on the basis of the current test conditions.

In order to meet the high-temperature simulation test requirements of downhole tools with lifting and lowering action, Chinese patent ZL201220740708.7, titled "Oilfield Downhole Tool Test Wellhead Device" discloses a test device, but the device is not suitable for the action test of downhole tools.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a test device for downhole tools and a test system for downhole tools, which can test downhole tools under more downhole conditions.

The embodiment of the present application discloses a test device for a downhole tool, which includes an external mechanism and a center rod; the center rod is penetrated in the external mechanism, and the center rod can move in a vertical direction relative to the external mechanism ; A first chamber is formed between the central rod and the external mechanism, the external mechanism is provided with a first opening communicating with the first chamber, the central rod is provided with a second chamber, so The upper part of the second chamber is sealed, the lower part of the second chamber of the center rod is open, the lower part of the center rod is used to connect with downhole tools, and the center rod is provided with the first chamber and the The second chamber communicates with the second opening.

Preferably, the test device for the downhole tool includes a first sealing unit, the first sealing unit is provided between the center rod and the outer mechanism, and the first sealing unit is located in the first chamber above and used to seal the first chamber.

Preferably, the test device for the downhole tool includes a second sealing unit, the second sealing unit is provided between the center rod and the outer mechanism, and the second sealing unit is located in the first chamber below and used to seal the first chamber.

Preferably, the outer mechanism includes an outer tube, an upper portion of the outer tube has a first step portion extending toward the center rod, and the first sealing unit includes a first step portion disposed on the first step portion and the center rod. the first seal between them.

Preferably, the first sealing part is a perfluoroether rubber ring.

Preferably, the first sealing unit includes a second sealing portion disposed between the outer tube and the central rod, and the second sealing portion is pressed against the upper end surface of the first step portion.

Preferably, the test device for the downhole tool comprises a first pressing ring sleeved between the central rod and the outer pipe, and the lower part of the first pressing ring abuts against the second sealing part .

Preferably, the outer wall of the second sealing portion is located outside the outer wall of the first sealing portion.

Preferably, the second sealing portion is a graphite fiber sealing ring.

Preferably, the cross section of the second sealing portion is rectangular.

Preferably, the test device for downhole tools includes a first sealing mechanism, the first sealing mechanism is sleeved on the central rod and fixed with the outer pipe, the first sealing mechanism, the central rod And a first space is formed between the upper ends of the outer tube, the outer tube is provided with a first flow channel, one end of the first flow channel is communicated with the first space, and the other end of the first flow channel is connected with the first flow channel. A header is connected.

Preferably, the first flow channel is L-shaped, the upper port of the first flow channel is in communication with the first space, and the lower port of the first flow channel is located on the outer side wall of the outer tube, and is connected to the first space. A header is connected.

Preferably, the outer mechanism includes an outer tube, a lower portion of the outer tube has a second step portion extending toward the center rod, and the second sealing unit includes a second step portion disposed on the second step portion and the center rod the third seal between them.

Preferably, the third sealing part is a perfluoroether rubber ring.

Preferably, the second sealing unit includes a fourth sealing portion disposed between the outer tube and the central rod, and the fourth sealing portion is pressed against the lower end surface of the second step portion.

Preferably, the test device for the downhole tool includes a second pressing ring sleeved on the outside of the central rod, and the upper part of the second pressing ring abuts against the lower end surface of the fourth sealing part.

Preferably, the outer wall of the fourth sealing portion is located outside the outer wall of the third sealing portion.

Preferably, the fourth sealing portion is a graphite fiber sealing ring.

Preferably, the cross section of the fourth sealing portion is rectangular.

Preferably, the external mechanism includes an outer pipe, a flange seat and a second sealing mechanism, the second sealing mechanism is sleeved on the lower end of the outer pipe, and the second sealing mechanism is connected to the flange seat , the first chamber is formed between the outer tube and the center rod, the flange seat is sleeved outside the center rod, and a second cavity is arranged between the flange seat and the center rod Three sealed units.

Preferably, the inner wall of the flange seat has a third step portion extending toward the central rod, and the third sealing unit includes a fifth sealing portion disposed between the third step portion and the central rod .

Preferably, the fifth sealing part is a perfluoroether rubber ring.

Preferably, the third sealing unit includes a sixth sealing portion disposed between the flange seat and the central rod, and the sixth sealing portion is pressed against the upper end surface of the third step portion.

Preferably, the third sealing unit includes a third pressing ring that is pressed against the upper end surface of the sixth sealing portion and sleeved outside the central rod.

Preferably, a second space is formed between the flange seat, the center rod, the second sealing mechanism and the outer tube, a second flow channel is opened on the flange seat, and the second The flow channel is L-shaped, the upper port of the second flow channel is located on the upper end surface of the flange seat, and the lower port of the second flow channel is located on the outer side wall of the flange seat, and is connected with the second liquid collection. tube connection.

Preferably, the test device for the downhole tool includes a connecting sleeve, and the connecting sleeve is respectively connected with the upper part of the center rod and the first sealing mechanism through threads.

The embodiment of the present application discloses a test system for downhole tools, including the above-mentioned test device for downhole tools and a tubing string, wherein the upper end of the tubing string is connected to the central rod and is connected to the central rod The lower end of the tubing string is used to connect with the downhole tool.

Preferably, the test system for the downhole tool includes a circulation control device, a downhole tool, a test wellbore, the second opening, the tubing string, the downhole tool, the test wellbore, the circulation control device, and The first openings communicate with each other to form a circulation pipeline.

By adopting the above structure, the present invention is suitable for a wide range of temperature field (0°C to 350°C) and an actionable downhole tool, so that the downhole tool can be tested under more downhole conditions.

Description of drawings

FIG. 1 is a schematic structural diagram of a test device for downhole tools in the present application.

FIG. 2 is a partial schematic view of the upper half of FIG. 1 .

FIG. 3 is a partial schematic view of the lower half of FIG. 1 .

FIG. 4 is a schematic structural diagram of a test system for downhole tools in the present application.

Reference numerals for the above drawings:

1. Coupling; 2. Connecting sleeve; 3. The first sealing seat; 4. The first fastening sleeve; 5. The first pressing ring; 6. The second sealing part; 7. The first sealing part; 8. The circulation Interface; 9. Outer tube; 10. Center rod; 11. Third sealing part; 12. Fourth sealing part; 13. Second pressing ring; 14. Second sealing seat; 15. Connecting screw; 16. Snap ring ; 17, the second fastening sleeve; 18, the third compression ring; 19, the sixth sealing part; 20, the fifth sealing part; 21, the flange seat; 22, the first connector; 23, the first liquid collection pipe; 24, the second connector; 25, the second header; 26, the oil receiving cylinder; 27, the first chamber; 28, the second chamber; 29, the first opening; 30, the second opening; 31 32, the second step; 33, the third step; 34, the first space; 35, the second space; 36, the circulation control device; 37, the tubing string; 38, the downhole tool; 39 , test wellbore; 40, the first flow channel; 41, the second flow channel.

Detailed ways

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, and the protection scope of the present invention can be more clearly defined.

Referring to FIG. 1 , an embodiment of the present application discloses a test device for a downhole tool 38 , including an external mechanism and a center rod 10 . The central rod 10 passes through the outer mechanism. The central rod 10 is movable in a vertical direction relative to the outer mechanism. A first chamber 27 is formed between the central rod 10 and the outer mechanism. The lower portion of the center rod 10 is used for connection with a downhole tool 38 . The lower portion of the central rod 10 is provided with a second chamber 28 capable of applying the fluid flowing therein to the downhole tool 38 . The external mechanism is provided with a first opening 29 communicating with the first chamber 27 . The center rod 10 is provided with a second opening 30 which communicates the first chamber 27 and the second chamber 28 .

Specifically, the external mechanism may include an outer tube 9 . The outer tube 9 extends in the vertical direction (ie, the longitudinal direction of the paper in FIG. 1 ). The central rod 10 is movable relative to the outer tube 9 in the vertical direction. A substantially annular first chamber 27 is formed between the outer side wall of the central rod 10 and the inner side wall of the outer tube 9 . A first opening 29 is opened on the wall surface of the outer tube 9 , and the first opening 29 communicates with the first chamber 27 . Preferably, the first opening 29 can be provided with a circulation interface 8, which can be connected with other connecting pieces.

A second chamber 28 may be provided on the central rod 10 . The upper part of the second chamber 28 of the center rod 10 is sealed. The lower part of the second chamber 28 of the center rod 10 is open. A second through opening 30 is provided on the wall surface of the central rod 10 . The second opening 30 may communicate the first chamber 27 and the second chamber 28 .

After the fluid enters the first chamber 27 from the first opening 29 , then enters the second chamber 28 from the second opening 30 , and then flows from the lower part of the second chamber 28 to the downhole tool 38 and acts on the downhole tool 38 . Therefore, in the embodiments of the present application, the temperature and pressure acting on the downhole tool 38 can be controlled by the fluid, so as to simulate the working situation of the downhole tool under various conditions.

Referring to FIG. 4 , preferably, the second opening 30 can be formed through the tubing string 37 , the downhole tool 38 , the test wellbore 39 , the circulation control device 36 and the first opening 29 circulation line. The fluid circulates in the circulation line, thereby repeatedly heating the downhole tool 38 and the fluid.

When the fluid reaches a certain temperature and the downhole tool 38 needs to be lifted and lowered, a lifting device can be used to apply an upper and lower load to the center rod 10. At this time, the lifting and lowering work can be performed simultaneously with the circulating heating.

When the fluid reaches the sealing test temperature, the heating of the fluid can be stopped. The circulation control device 36 is disconnected from the test wellbore 39 and self-circulation is performed, and the downhole tool 38 is sealed and tested to the tubing string 37 and the test wellbore 39 through the first opening 29 by the squeezing system.

As shown in FIG. 1 and FIG. 2 , in this embodiment, the test device for the downhole tool 38 includes a first sealing unit, and the first sealing unit is arranged between the center rod 10 and the external mechanism , the first sealing unit is located above the first chamber 27 and is used to seal the first chamber 27 so that the fluid will not overflow from the top of the first chamber 27 .

The upper portion of the outer tube 9 has a first stepped portion 31 extending toward the central rod 10 . The first sealing unit may include a first sealing portion 7 disposed between the first step portion 31 and the center rod 10 . In this embodiment, the first sealing portion 7 is a rubber ring. Specifically, the first sealing portion 7 is an O-shaped perfluoroether rubber ring. The second sealing part 6 is a graphite fiber sealing ring with a rectangular cross section.

The first sealing part 7 can ensure that the center rod 10 moves relative to the outer pipe 9 under a preset pressure range, and ensures that the upper part of the center rod 10 and the outer pipe 9 are at a relatively high pressure (for example, not greater than 5.0MPa). case sealed.

The first sealing unit may further include a second sealing portion 6 disposed between the outer tube 9 and the central rod 10 , and the second sealing portion 6 is pressed against the first step portion 31 . end face. The outer wall of the second sealing portion 6 is located outside the outer wall of the first sealing portion 7 . When the first sealing part 7 leaks, the second sealing part 6 can still ensure the sealing between the central rod 10 and the outer tube 9 .

The second sealing part 6 can ensure that the center rod 10 is relatively stationary with the outer pipe 9, and the upper part of the center rod 10 and the outer pipe 9 can be sealed under a relatively high pressure (for example, not more than 26.0MPa). .

Preferably, the test device for the downhole tool 38 includes a first pressing ring 5 , the first pressing ring 5 is sleeved outside the central rod 10 , and the outer wall of the first pressing ring 5 is connected to the The inner wall of the upper end of the outer tube 9 is threadedly connected, and the lower part of the first pressing ring 5 abuts against the second sealing part 6 . The first pressing ring 5 can press the second sealing part 6 against the first step part 31 , so as to seal the center rod 10 and the outer tube 9 as much as possible.

More preferably, the test device for the downhole tool 38 includes a first sealing mechanism, and the first sealing mechanism is sleeved on the central rod 10 and fixed with the upper end of the outer pipe 9 . Specifically, in this embodiment, the first sealing mechanism includes a first fastening sleeve 4 and a first sealing seat 3 sleeved outside the central rod 10 . The first sealing seat 3 passes through the first fastening sleeve 4 . The first fastening sleeve 4 is fixed on the upper end of the outer tube 9 through threads, so that the lower end of the first sealing seat 3 can be tightly pressed against the fluorine rubber ring at the upper end of the outer tube 9 . Preferably, a fluorine rubber ring is arranged between the first sealing seat 3 and the central rod 10 .

A first space 34 is formed between the first sealing mechanism, the central rod 10 and the outer tube 9. A first flow channel 40 is opened on the upper part of the outer tube 9. The first space 34 is in communication, and the other end of the first flow channel 40 is in communication with the first liquid collecting pipe 23 .

Preferably, the first flow channel 40 is L-shaped, the upper port of the first flow channel 40 communicates with the first space 34 , and the lower port of the first flow channel 40 is located on the outer side wall of the upper end of the outer tube 9 and communicate with the first liquid collecting pipe 23 .

When the first sealing unit fails, the fluid can enter the first space 34 and enter the upper port of the first flow channel 40 , and then overflow from the lower port of the first flow channel 40 into the first header 23 . When it is observed that there is still or a certain flow of fluid in the first liquid collecting pipe 23, it can be found that the first sealing unit fails. Then, the sealing performance of the test device can be improved by adjusting the pressure of the first pressing ring 5 on the second sealing part 6 .

1 and 3, the test device for the downhole tool 38 includes a second sealing unit, the second sealing unit is arranged between the center rod 10 and the external mechanism, the second sealing unit The unit is located below the first chamber 27 and is used to seal the first chamber 27 so that the fluid cannot escape from below the first chamber 27 .

The lower portion of the outer tube 9 has a second step portion 32 extending toward the center rod 10 , and the second sealing unit may include a third step portion 32 disposed between the second step portion 32 and the center rod 10 . Sealing part 11 . The third sealing part 11 is a perfluoroether rubber ring. The third sealing part 11 can ensure that the center rod 10 moves relative to the outer tube 9 under a preset pressure range, and a relatively high pressure (for example, not more than 5.0 MPa) is maintained between the middle part of the central rod 10 and the outer tube 9 . case sealed.

The second sealing unit may include a fourth sealing portion 12 disposed between the outer tube 9 and the central rod 10 , and the fourth sealing portion 12 is pressed against the lower end surface of the second step portion 32 .

The test device used for the downhole tool 38 includes a second pressing ring 13 sleeved on the outside of the central rod 10 , and the outer wall of the second pressing ring 13 is threadedly connected to the inner wall of the lower end of the outer pipe 9 . The second pressing ring 13 can press the fourth sealing portion 12 against the second step portion 32 , so as to seal the center rod 10 and the outer tube 9 as much as possible.

The outer wall of the fourth sealing portion 12 is located outside the outer wall of the third sealing portion 11 . The fourth sealing portion 12 is a graphite fiber sealing ring with a rectangular cross section. When the third sealing part 11 leaks, the fourth sealing part 12 can still ensure the sealing between the central rod 10 and the outer tube 9 .

The fourth sealing part 12 can ensure that the center rod 10 is relatively stationary with the outer pipe 9, and the middle part of the center rod 10 and the outer pipe 9 can be sealed under a relatively high pressure (for example, not more than 26.0MPa). .

1 and 3, the external mechanism includes an outer pipe 9, a flange seat 21 and a second sealing mechanism, the second sealing mechanism is sleeved on the lower end of the outer pipe 9, the second sealing mechanism The sealing mechanism is connected with the flange seat 21, the first chamber 27 is formed between the outer tube 9 and the center rod 10, the flange seat 21 is sleeved outside the center rod 10, A third sealing unit is arranged between the flange seat 21 and the center rod 10 .

When the second or third sealing unit fails, after the fluid enters the second space, the second sealing mechanism can make the fluid enter the second liquid collecting pipe, and prevent the fluid from splashing around. Specifically, in this embodiment, the second sealing mechanism includes a second fastening sleeve 17 and a second sealing seat 14 sleeved outside the outer tube 9 . The second sealing seat 14 is sleeved on the outer wall of the lower end of the outer tube 9 . The second sealing seat 14 passes through the second fastening sleeve 17 . The second fastening sleeve 17 is fixed on the flange seat 21 through threads. The lower end of the outer tube 9 and the upper end surface of the flange seat 21 are fixedly connected by connecting screws 15 and snap rings 16 .

The inner wall of the flange seat 21 has a third step portion 33 extending toward the center rod 10 , and the third sealing unit includes a fifth step portion 33 disposed between the third step portion 33 and the center rod 10 . Sealing part 20 . The fifth sealing part 20 is a perfluoroether rubber ring. The fifth sealing part 20 can ensure that the center rod 10 moves relative to the outer tube 9 under the preset pressure range, and ensures that the lower part of the center rod 10 and the flange seat 21 are at a relatively high pressure (for example, no more than 5.0MPa). ) is sealed.

The third sealing unit may include a sixth sealing portion 19 disposed between the flange seat 21 and the center rod 10 , and the sixth sealing portion 19 is pressed against the third step portion 33 . end face. The sixth sealing part 19 can ensure that the center rod 10 is relatively stationary with the outer tube 9, and the lower part of the center rod 10 and the flange seat 21 can be ensured under a relatively high pressure (for example, no more than 26.0MPa) seal. When the fifth sealing part 20 leaks, the sixth sealing part 19 can still ensure the sealing between the central rod 10 and the flange seat 21 . The test device used for the downhole tool 38 includes pressing against the upper end surface of the third step portion 33 , and the outer wall of the third pressing ring 18 is threadedly connected to the inner wall of the upper end of the flange seat 21 . The third pressing ring 18 can press the sixth sealing portion 19 against the third step portion 33 to seal the center rod 10 and the flange seat 21 as much as possible.

A second space 35 is formed between the upper end of the flange seat 21 , the lower end of the outer tube 9 , the central rod 10 and the second sealing mechanism, and a second flow channel 41 is opened on the flange seat 21 , the second flow channel 41 is L-shaped, the upper port of the second flow channel 41 is located on the upper end surface of the flange seat 21 , and the lower port of the second flow channel 41 is located in the flange seat 21 The outer side wall of the pipe is in communication with the second liquid collecting pipe 25 . When the second sealing unit or the third sealing unit fails, the fluid can enter the second space 35 and enter one end of the second flow channel 41 , and then overflow from the other end of the first flow channel 40 into the second liquid header 25 . When it is observed that there is still or a certain flow of fluid in the second liquid collecting pipe 25, it can be found that the second sealing or the third sealing unit fails. Then, the pressing force of the second pressing ring 13 or the third pressing ring 18 to the third sealing part 11 or the sixth sealing part 19 can be adjusted by the second sealing mechanism.

The installation method of the test device for the downhole tool 38 in the present application is generally as follows: the lower end of the outer pipe 9 is seated on the upper end surface of the flange seat 21, and the snap ring 16 is inserted into the outer edge of the lower end of the outer pipe 9. Then use the connecting screw 15 to fix the snap ring 16 with the circumferential wire hole on the upper end face of the flange seat 21, and then seat the second sealing seat 14 on the "O" type fluorine rubber ring on the upper end face of the flange seat 21, and then use the second sealing seat 14. The inner wall thread of the two fastening sleeves 17 is connected and fixed with the outer wall thread at the upper end of the flange seat 21; The buckle is connected with the upper end thread of the outer wall of the first sealing seat 3, wherein the function of the connecting sleeve 2 is to prevent the central rod 10 from being pulled out from the connecting body of the outer tube 9 and the flange seat 21 and to facilitate the rotation of the central rod 10 when applying hoisting. Moving up and down. The first liquid collecting pipe 23 is connected to the "L"-shaped round hole that communicates with the upper end face of the outer pipe 9 and its outer wall through the first connecting head 22, and the second liquid collecting pipe 25 is connected to the second liquid collecting pipe 25 through the second connecting head 24. The buckle is connected to the "L"-shaped round hole communicating with the upper end face of the flange seat 21 and its outer wall, and an oil receiving cylinder 26 is placed under the two liquid collecting pipe outlets.

When it is observed that there is fluid flowing into the oil receiving cylinder 26, stop the operation of the test system, determine the leakage point, unfasten the first fastening sleeve 4 or the second fastening sleeve 17, and push up the first sealing seat 3 and the second sealing seat respectively. 14. Expose the first pressing ring 5, the second pressing ring 13 and the third pressing ring 18, and readjust the pressing force of the first pressing ring 5, the second pressing ring 13 and the third pressing ring 18 .

The test device for the downhole tool 38 includes a connecting sleeve 2, and the connecting sleeve 2 is respectively connected with the upper part of the center rod and the first sealing mechanism through threads. A coupling 1 is arranged between the connecting sleeve 2 and the central rod 10 . In the process of hoisting the test device on the high temperature simulation test wellhead, in order to prevent the central rod 10 from being pulled out from the connection body of the outer pipe 9 and the flange seat 21, the connecting sleeve 2 can be used to make the central rod 10 and the first sealing seat in the form of ordinary threads. 3 connections. In the normal test operation, when the center rod 10 moves up and down, the connecting sleeve 2 needs to be rotated upwards, so that the connecting sleeve 2 can be separated from the first sealing seat 3 .

When the test device used for the downhole tool 38 in the embodiment of the present application is implemented and applied, its specific working process is as follows:

Connect the downhole tool 38 and the tubing string 37 with the lifting and lowering action ready for the high temperature simulation test to the central rod 10 in the test device that has completed the final assembly, hoist it with a hoisting tool, and lift the downhole tool 38 and the tubing string 37 Put it into the high temperature simulation test well, and at the same time put the flange seat 21 on the wellhead flange and fix it with wellhead bolts; then use the clamp to connect and fix the circulation interface 8 with a circulation pipeline of the medium circulation system of the high temperature simulation test well .

The medium circulation heating of the high-temperature simulation test well begins, and the medium circulation path is the circulation interface 8, the first chamber 27 between the outer pipe 9 and the central rod 10, the second opening 30 of the central rod 10, the first chamber 27 between the outer pipe 9 and the central rod 10, and the first The second chamber 28, the tubing string 37, the downhole tool 38, and the test wellbore 39 then flow into the out-hole circulation system.

When the circulating medium reaches a certain temperature and the downhole tool 38 needs to be lifted and lowered, the connecting sleeve 2 can be rotated upward to disengage from the first sealing seat 3, and the lifting frame connected with the coupling 1 can be used to apply up and down loads to the center rod 10. At this time, the lifting and lowering action and the medium circulation heating can be carried out at the same time.

When the circulating medium reaches the sealing test temperature, the medium heating is stopped, and the valve between the out-well circulation system and the test well is closed to realize the self-circulation of the heating furnace. The first chamber 27 , the second chamber 28 of the center rod 10 , the tubing string 37 or the press-up system directly passes through the test wellbore 39 to perform a seal test on the downhole tool 38 .

During the sealing test, if it is found that the first liquid collecting pipe 23 or the second liquid collecting pipe 25 has a medium flowing into the oil receiving cylinder 26, stop pressing, and let the medium flow out of the first fastening sleeve 44 or the first fastening sleeve 44 near the liquid collecting pipe or the second liquid collecting pipe. The two fastening sleeves 17 are unbuckled, and the first sealing seat 3 or the second sealing seat 14 is pushed up respectively to expose the first pressing ring 5, the second pressing ring 13 or the third pressing ring 18, and the first pressing ring 5, the second pressing ring 13 or the third pressing ring 18 is exposed. The pressing force of the tightening ring 5, the second pressing ring 13 or the third pressing ring 18, and then the above-mentioned components are repositioned, and the pressing and sealing test is continued.

After the sealing test is completed, stop pressing, wait for the medium in the test system to cool, open all valves at a certain temperature, and let the medium flow back to the oil storage tank.

When the test device used for the test wellbore 39 and the downhole tool 38 returns to normal temperature, remove the lifting frame, rotate the connecting sleeve 2 downward to connect it with the first sealing seat 3, remove the wellhead bolt, and use the lifting tool to connect the test device and the tubing. The pipe string 37 and downhole tool 38 are lifted out of the test wellbore 39 .

Referring to FIG. 4 , the embodiment of the present application discloses a test system for downhole tool 38 , including the above-mentioned test device for downhole tool 38 and a tubing string 37 , the upper end of the tubing string 37 is connected to the The center rod 10 is connected and communicated with the second chamber 28 of the center rod 10 , and the lower end of the tubing string 37 is used for connecting with the downhole tool 38 .

Preferably, the second opening 30 can form a circulation pipeline through the tubing string 37 , the downhole tool 38 , the test wellbore 39 , the circulation control device 36 and the first opening 29 .

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments may be referred to each other.

The above-mentioned embodiments are only intended to illustrate the technical concept and characteristics of the present invention, and the purpose thereof is to enable those who are familiar with the art to understand the content of the present invention and implement them accordingly, and cannot limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be included within the protection scope of the present invention.

Claims (28)

1. A test rig for a downhole tool comprising an external mechanism and a central rod; the central rod penetrates through the external mechanism and can move in the vertical direction relative to the external mechanism; the underground tool is characterized in that a first cavity is formed between the central rod and the external mechanism, the external mechanism is provided with a first opening communicated with the first cavity, the central rod is provided with a second cavity, the upper portion of the second cavity is sealed, the lower portion of the second cavity of the central rod is open, the lower portion of the central rod is used for being connected with an underground tool, and the central rod is provided with a second opening communicated with the first cavity and the second cavity.

2. The testing device for a downhole tool according to claim 1, comprising a first sealing unit arranged between the central rod and the external means, the first sealing unit being located above the first chamber and sealing the first chamber.

3. The testing device for a downhole tool according to claim 1, comprising a second sealing unit arranged between the central rod and the external means, the second sealing unit being located below the first chamber and sealing the first chamber.

4. The trial for a downhole tool of claim 2, wherein the external mechanism comprises an outer tube having an upper portion with a first step extending toward the central rod, the first sealing unit comprising a first sealing portion disposed between the first step and the central rod.

5. The downhole tool testing device of claim 4, wherein the first seal is a perfluoroether rubber ring.

6. The testing device for a downhole tool according to claim 4, wherein the first sealing unit comprises a second sealing portion provided between the outer tube and the central rod, the second sealing portion being pressed against an upper end surface of the first step portion.

7. The downhole tool testing device of claim 6, comprising a first compression ring disposed between the central rod and the outer tube, a lower portion of the first compression ring abutting the second sealing portion.

8. The trial of claim 7 wherein the outer wall of the second seal is positioned outside the outer wall of the first seal.

9. A test rig for a downhole tool according to claim 6, wherein the second sealing portion is a graphite fibre sealing ring.

10. A test rig for a downhole tool according to claim 6, wherein the second sealing portion is rectangular in cross-section.

11. The testing device of claim 7, wherein the testing device comprises a first sealing mechanism, the first sealing mechanism is sleeved on the central rod and fixed with the outer tube, a first space is formed among the first sealing mechanism, the central rod and the upper end of the outer tube, the outer tube is provided with a first flow passage, one end of the first flow passage is communicated with the first space, and the other end of the first flow passage is communicated with a first liquid collecting tube.

12. The testing device for a downhole tool according to claim 11, wherein the first flow passage is L-shaped, an upper port of the first flow passage communicates with the first space, and a lower port of the first flow passage is located on an outer side wall of the outer tube and communicates with the first header pipe.

13. A test rig for a downhole tool according to claim 3, wherein the external means comprises an outer tube having a lower portion with a second step extending towards the central rod, the second sealing unit comprising a third sealing portion arranged between the second step and the central rod.

14. The downhole tool testing device of claim 13, wherein the third seal is a perfluoroether rubber ring.

15. The testing device for a downhole tool according to claim 13, wherein the second sealing unit comprises a fourth sealing portion provided between the outer tube and the central rod, the fourth sealing portion being pressed against a lower end surface of the second step portion.

16. The downhole tool testing device of claim 15, comprising a second compression ring disposed about the central rod, an upper portion of the second compression ring abutting a lower end surface of the fourth sealing portion.

17. A test rig for a downhole tool according to claim 16, wherein the outer wall of the fourth seal is located outside the outer wall of the third seal.

18. A test rig for a downhole tool according to claim 15, wherein the fourth sealing portion is a graphite fibre sealing ring.

19. A test rig for a downhole tool according to claim 15, wherein the fourth seal is rectangular in cross-section.

20. The testing device for the downhole tool according to claim 1, wherein the external mechanism comprises an outer tube, a flange seat, and a second sealing mechanism, the second sealing mechanism is sleeved on a lower end portion of the outer tube, the second sealing mechanism is connected with the flange seat, the first chamber is formed between the outer tube and the central rod, the flange seat is sleeved outside the central rod, and a third sealing unit is arranged between the flange seat and the central rod.

21. The trial of claim 20 wherein the inner wall of the flange seat has a third step extending towards the central stem, the third seal unit comprising a fifth seal disposed between the third step and the central stem.

22. The downhole tool testing device of claim 21, wherein the fifth seal is a perfluoroether rubber ring.

23. The testing device for a downhole tool according to claim 21, wherein the third sealing unit comprises a sixth sealing portion provided between the flange seat and the central rod, the sixth sealing portion being pressed against an upper end surface of the third step portion.

24. The testing device for a downhole tool according to claim 23, wherein the third sealing unit comprises a third compression ring pressed against the upper end surface of the sixth sealing portion and sleeved on the center rod.

25. The testing device of claim 23, wherein a second space is formed between the flange seat, the central rod, the second sealing mechanism and the outer tube, a second flow channel is formed in the flange seat, the second flow channel is L-shaped, an upper port of the second flow channel is located on an upper end face of the flange seat, and a lower port of the second flow channel is located on an outer side wall of the flange seat and is communicated with a second liquid collecting tube.

26. A testing device for a downhole tool according to claim 11, comprising a nipple threadedly connected to an upper part of the central rod and the first sealing means, respectively.

27. A testing system for a downhole tool, comprising a testing device for a downhole tool according to any of claims 1-26 and a tubing string connected at an upper end to the central rod and communicating with the second chamber of the central rod, the tubing string being adapted at a lower end for connection to a downhole tool.

28. The system of claim 27, wherein the testing system comprises a circulation control device, a downhole tool, a test wellbore, and wherein the second opening, the tubing string, the downhole tool, the test wellbore, the circulation control device, and the first opening communicate to form a circulation circuit.

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