Packer-screen tube assembly

Abstract

This invention belongs to the field of petroleum exploration and development technology, and discloses a packer-screen tube combination device. The screen tube in the combination device includes a mandrel, a reset mechanism, and an outer cylinder. The outer cylinder has a first flow channel, and the mandrel has a second flow channel. The mandrel can move downward along the axis under pressure. The reset mechanism can make the mandrel move upward after depressurization and provide two different stroke endpoints for any two adjacent upward movements of the mandrel. The two stroke endpoints are the first endpoint and the second endpoint. When the mandrel moves to the first endpoint, the second flow channel is connected to the first flow channel. When the mandrel moves to the second endpoint, the second flow channel is offset from the first flow channel. By applying pressure to the mandrel, the screen tube can be opened and closed multiple times.

Description

Technical Field

[0001] This invention relates to the field of petroleum exploration and development technology, and in particular to a packer-screen tube combination device. Background Technology

[0002] Traditional downhole testing techniques utilize multi-flow test valves from Johnston or LPR-N valves and selective test valves from Halliburton to achieve negative pressure perforation and multiple well opening / closing operations. However, these techniques have the following drawbacks in low-permeability reservoir testing: traditional test valves can only be placed above the packer, far from the reservoir, resulting in a long test pocket; in low-permeability reservoirs, fluid production is low and pressure recovery is slow, and the aforementioned traditional techniques sometimes struggle to overcome the wellbore reservoir effect in low-permeability or specially permeable reservoirs, leading to partial... The absence of radial flow during well shut-in makes it impossible to interpret formation parameters and obtain qualified formation fluid samples, affecting the oil testing conclusions and the accurate characterization of formation fluids. Traditional downhole testing valves such as multi-flow test valves, LPR-N valves, and selective test valves have disadvantages such as complex structure, high operational difficulty, and high labor intensity. They require a large number of skilled personnel, resulting in high testing costs and high failure rates. When using traditional test valves for well testing, after the oil testing is completed, it is necessary to kill the well, retrieve the test string, and then run a separate completion string for production.

[0003] Chinese invention patent CN201510237285.5 discloses a packer-multiple-operable screen tube combination device. Using this packer-multiple-operable screen tube combination device to form a well test string, the opening and closing of the production channel for fluid entry and exit from the well test string can be controlled without a test valve. It has a simple structure and low cost. However, the device has shortcomings: it uses several screen tube sub-units, lacks a reset mechanism, and has a limited total number of opening and closing operations, with no more than two well openings and two well closings each, making it difficult to meet the needs of multiple well openings and closings during well testing and completion operations. Summary of the Invention

[0004] The purpose of this invention is to provide a packer-screen assembly that allows for unlimited well opening and closing times, thus meeting the needs of multiple well opening and closing operations during well testing and completion.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A packer-screen tube assembly includes a pressure transmitting joint, a packer, and a screen tube connected in sequence, and also includes a pressure transmitting tube, the two ends of which are respectively inserted into the pressure transmitting joint and the screen tube.

[0007] The pressure transmitting joint has a first production channel and a first pressurizing channel that are not interconnected, and the pressure transmitting pipe is connected to the first pressurizing channel.

[0008] The screen tube includes a mandrel, an outer cylinder, and a reset mechanism. The outer cylinder has a second production channel and a second pressurizing channel that are not interconnected. The second production channel is connected to the first production channel, and the second pressurizing channel is connected to the pressure transmission tube. The outer cylinder also has a first guide channel connecting its inner wall and its outer wall. The mandrel is located inside the outer cylinder and is connected to the second production channel. The mandrel also has a second guide channel connecting its inner wall and its outer wall. An axially spaced pressurizing chamber and an air chamber are formed between the mandrel and the outer cylinder. The pressurizing chamber can communicate with the second pressurizing channel and pushes the mandrel downward along the axial direction when pressurized. The air chamber contains enclosed air.

[0009] The reset mechanism enables the mandrel to move upward and provides two different travel endpoints for two consecutive upward movements of the mandrel. The two travel endpoints are a first endpoint and a second endpoint. When the mandrel moves to the first endpoint, the second guide channel is connected to the first guide channel. When the mandrel moves to the second endpoint, the second guide channel is offset from the first guide channel.

[0010] Preferably, the reset mechanism includes a shift sleeve, a pin, and a reset spring. The shift sleeve is sleeved on the spindle and is axially limited with the spindle. The shift sleeve is provided with a shift groove. One end of the pin is fixed to the outer cylinder, and the other end is inserted into the shift groove. One end of the reset spring abuts against the spindle, and the other end abuts against the outer cylinder.

[0011] The transposition groove is formed by connecting a first Y-shaped groove and a second Y-shaped groove arranged in a circumferentially staggered manner. Both the first Y-shaped groove and the second Y-shaped groove include a first branch, a second branch, and a third branch. The first branch extends along the axial direction of the transposition sleeve. The second branch and the third branch are both L-shaped and connected to the first branch. One end of the second branch connected to the first branch extends along the axial direction of the transposition sleeve, and the other end of the second branch is inclined away from the third branch. One end of the third branch connected to the first branch is inclined away from the first branch, and the other end of the third branch extends along the axial direction of the transposition sleeve. The second and third branches of adjacent first Y-shaped grooves and second Y-shaped grooves are connected. The length of the first branch of the first Y-shaped groove is less than the length of the first branch of the second Y-shaped groove. The end of the first branch of the second Y-shaped groove away from the second branch and the third branch is the second endpoint, and the end of the first branch of the first Y-shaped groove away from the second branch and the third branch is the first endpoint.

[0012] Preferably, the outer cylinder includes an upper connector, a lower connector, and a cylinder body. The front end of the upper connector is connected to the packer, the rear end of the upper connector is inserted into the cylinder body and connected to the cylinder body, and the front end of the lower connector is inserted into the cylinder body and connected to the cylinder body.

[0013] Preferably, the upper connector includes a fixed connector, a protective connector, a shear connector, and a rupture disc connector. The fixed connector is connected to the packer. The shear connector and the protective connector are respectively sealed to the inner and outer sides of the fixed connector. The front end of the mandrel is inserted into the shear connector. The shear connector and the protective connector form an annular space. The front end of the rupture disc connector is sandwiched between the shear connector and the protective connector and is sealed to both. The rear end of the rupture disc connector is sandwiched between the mandrel and the outer cylinder and is sealed to both. The rupture disc connector, the shear connector, and the mandrel together form the pressurizing chamber. The air chamber is formed by the rupture disc connector and the mandrel. The rupture disc is disposed in the mounting hole opened in the rupture disc connector. The two sides of the mounting hole correspond to the pressurizing chamber and the annular space, respectively. A connecting channel is opened in the fixed connector. One end of the connecting channel communicates with the pressure transmission pipe, and the other end communicates with the annular space. The annular space, the connecting channel, and the mounting hole together constitute the second pressurizing channel.

[0014] Preferably, the mandrel is provided with a first retaining ring and a second retaining ring spaced apart along the axial direction, and the shifting sleeve is sleeved on the mandrel and located between the first retaining ring and the second retaining ring.

[0015] Preferably, the mandrel is segmented, including a power shaft segment and a reset shaft segment connected axially, the pressurization chamber and the air chamber are enclosed by the power shaft segment and the outer cylinder, and the second flow guide channel, the first retaining ring and the second retaining ring are disposed in the reset shaft segment.

[0016] Preferably, the connection channel includes a radial channel and an axial channel. One end of the radial channel passes through the wall of the fixed joint and is sealed with a threaded plug. The other end of the radial channel is connected to the pressure transmission pipe. One end of the axial channel is connected to the radial channel, and the other end is connected to the annular space.

[0017] Preferably, a rupture disc is provided in the second pressurization channel.

[0018] Preferably, a shear pin is also provided between the mandrel and the outer cylinder.

[0019] The beneficial effects of the present invention are as follows: The packer-screen assembly of the present invention is provided with a reset mechanism and a power chamber. By pressurizing the power chamber, the mandrel is moved downward. After depressurization, the reset mechanism can move the mandrel upward and provide two different stroke endpoints for any two adjacent upward movements of the mandrel, namely the first endpoint and the second endpoint. When the mandrel moves upward to the first endpoint, the second guide channel is connected to the first guide channel. When the mandrel moves upward to the second endpoint, the second guide channel is staggered from the first guide channel, corresponding to the open and closed states of the screen pipe, respectively. This realizes unlimited well opening and closing near the reservoir, improves the quality of oil testing data, and the pressure of each opening and closing operation does not need to be increased compared to the previous operation, thus reducing the pressure requirements on the casing. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the packer-screen tube combination device in an embodiment of the present invention;

[0021] Figure 2 yes Figure 1 Enlarged structural diagram at point A;

[0022] Figure 3 yes Figure 1 Enlarged structural diagram at point B;

[0023] Figure 4 yes Figure 1 Enlarged structural diagram at point C;

[0024] Figure 5 yes Figure 1 Enlarged structural diagram at point D;

[0025] Figure 6 yes Figure 1 Enlarged structural diagram at point E;

[0026] Figure 7 This is a schematic diagram of the pressure transmission connector in an embodiment of the present invention;

[0027] Figure 8 This is a schematic diagram of the upper connector in an embodiment of the present invention;

[0028] Figure 9 This is a schematic diagram of the transposition sleeve in an embodiment of the present invention.

[0029] In the diagram: 1. Pressure transmission connector; 11. Plug; 2. Packer; 3. Screen tube; 31. Outer cylinder; 311. Upper connector; 3111. Fixed connector; 3112. Shear connector; 3113. Protective connector; 3114. Rupture disc connector; 3115. Rupture disc; 312. Cylinder body; 3121. Transposition cylinder section; 3122. Spring cylinder section; 313. Lower connector; 32. Spindle; 321. Power shaft section; 322. Reset shaft section; 3221. First retaining ring; 3222. Second retaining ring; 33. Reset spring; 34. Transposition sleeve; 341. Transposition groove; 3411. First branch; 3412. Second branch; 3413. Third branch; 35. Pin; 36. Shear pin; 4. Pressure transmission tube;

[0030] a. First pressurization channel; b. First production channel; c. Second production channel; d. First flow guide channel; e. Second flow guide channel; f. Annular space; g. Pressurization chamber; h. Air chamber; i. Connecting channel; j. Mounting hole. Detailed Implementation

[0031] 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.

[0032] 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.

[0033] 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.

[0034] In the description of this embodiment, the terms "upper," "lower," "left," and "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.

[0035] Figures 1-9 The diagram shows a packer-screen tube assembly proposed in an embodiment of the present invention. This assembly includes a pressure-transmitting connector 1, a packer 2, a pressure-transmitting tube 4, and a screen tube 3. The pressure-transmitting connector 1, packer 2, and screen tube 3 are connected in series from front to rear (front end refers to the end closest to the wellhead, rear end refers to the end furthest from the wellhead). The two ends of the pressure-transmitting tube 4 pass through the pressure-transmitting connector 1 and the screen tube 3 respectively and are sealed to them. The pressure-transmitting connector 1 has a first production channel b and a first pressurization channel a that are not interconnected. The pressure-transmitting tube 4 is connected to the first pressurization channel a. The screen tube 3 includes a mandrel 32, an outer cylinder 31, and a reset mechanism. The outer cylinder 31 has independently connected... The second production channel c and the second pressurization channel are connected. The second production channel c is connected to the first production channel b. The second pressurization channel is connected to the pressure transmission pipe 4. The outer cylinder 31 is also provided with a first guide channel d that connects its inner wall and its outer wall. The mandrel 32 is located inside the outer cylinder 31 and is connected to the second production channel c. The mandrel 32 is also provided with a second guide channel e that connects its inner wall and its outer wall. The mandrel 32 and the outer cylinder 31 form an axially spaced pressurization chamber g and a closed air chamber h. The pressurization chamber g can be connected to the second pressurization channel and then connected to the outside of the pressure transmission joint 1 through the pressure transmission pipe 4 and the first pressurization channel a. Air is trapped inside the air chamber h.

[0036] After pressurized fluid is injected into the pressurized chamber g, the mandrel 32 can move downward along the axis. After depressurization, the reset mechanism can make the mandrel 32 move upward, and provide two different stroke endpoints for two adjacent upward movements of the mandrel 32, namely the first endpoint and the second endpoint. When the mandrel 32 moves to the first endpoint, the second guide channel e on the mandrel 32 is connected to the first guide channel d on the outer cylinder 31. When the mandrel 32 moves to the second endpoint, the second guide channel e on the mandrel 32 is offset from the first guide channel d on the outer cylinder 31.

[0037] The mandrel 32 of the aforementioned packer-screen tube combination device pressurizes the pressurizing chamber g through the first pressurizing channel a, the pressure transmission tube 4, and the second pressurizing channel, causing the mandrel 32 to move downward. When the pressurization is canceled, the reset mechanism can drive the mandrel 32 upward. The mandrel 32 is provided with two stroke endpoints. When the mandrel 32 travels to the first endpoint, the second guide channel e on the mandrel 32 connects with the first guide channel d on the outer cylinder 31, and the screen tube 3 opens. When the mandrel 32 travels to the second endpoint, the second guide channel e on the mandrel 32 is offset from the first guide channel d on the outer cylinder 31, and the screen tube 3 closes. Since the stroke endpoints of the mandrel 32 are different in two consecutive trips, the screen tube 3 can switch between open and closed states after the mandrel 32 is subjected to force each time. In other words, by applying a downward external force to the centrifugal shaft 32, the screen pipe 3 can be switched from open to closed or from closed to open. The screen pipe 3 can be opened or closed an unlimited number of times, allowing the fluid in the formation to flow out to the surface through the centrifugal shaft 32. This meets the needs of multiple well opening and closing operations during oil testing and production. Moreover, the high pressure of the annulus required for multiple opening and closing does not need to be increased step by step, and the pressure bearing capacity requirement of the casing above the packer is low.

[0038] refer to Figure 5 As shown, the reset mechanism includes a shift sleeve 34, a pin 35, and a reset spring 33. The shift sleeve 34 is sleeved on the spindle 32 and is axially limited with the spindle 32. The shift sleeve 34 is provided with a shift groove 341. One end of the pin 35 is fixedly connected to the outer cylinder 31, and the other end is inserted into the shift groove 341 and can move along the extension direction of the shift groove 341. One end of the reset spring 33 is connected to the spindle 32, and the other end is connected to the outer cylinder 31 to provide reset power for the spindle 32.

[0039] refer to Figure 9As shown, the transposition groove 341 is formed by connecting a first Y-shaped groove and a second Y-shaped groove arranged in a circumferentially staggered manner. Both the first and second Y-shaped grooves include a first branch 3411, a second branch 3412, and a third branch 3413. The first branch 3411 extends along the axial direction of the transposition sleeve 34. The second branch 3412 and the third branch 3413 are both L-shaped and connected to the first branch 3411. The end of the second branch 3412 connected to the first branch 3411 extends along the axial direction of the transposition sleeve 34, while the other end is inclined away from the third branch 3413. The end of the third branch 3413 connected to the first branch 3411 is also inclined away from the first branch 3411. The other end extends along the axial direction of the transposition sleeve 34. The second branches 3412 and the third branch 3413 of the adjacent first Y-shaped groove and second Y-shaped groove are connected. The difference is that the length of the first branch 3411 of the first Y-shaped groove is less than the length of the first branch 3411 of the second Y-shaped groove. When the pin 35 moves to the end of the first branch 3411 of the first Y-shaped groove away from the second branch 3412 and the third branch 3413, the spindle 32 is at the first end point. When the pin 35 moves to the end of the first branch 3411 of the second Y-shaped groove away from the second branch 3412 and the third branch 3413, the spindle 32 is at the second end point. At this time, the second guide channel e is located above the first guide channel d.

[0040] When the shift sleeve 34 moves downward with the spindle 32 under the action of external force, overcoming the elastic force of the return spring 33, the pin 35 moves upward relative to it. It enters the third branch 3413 of the adjacent first Y-shaped groove from the first branch 3411 of the second Y-shaped groove via the guidance of the second branch 3412. After depressurization, under the elastic force of the return spring 33 and the guidance of the third branch 3413, the pin 35 enters the first branch 3411 of the first Y-shaped groove and moves to the end of the first branch 3411 away from the second branch 3412 and the third branch 3413. The spindle 32 travels to the first endpoint, the first guide channel d and the second guide channel e are connected, and the screen tube 3 is opened. To close the screen tube 3, simply... When an external force is applied to the mandrel 32, the shifting sleeve 34, under the action of the external force, overcomes the elastic force of the return spring 33 and moves downward with the mandrel 32. Meanwhile, the pin 35 moves upward relative to the mandrel 32, entering the third branch 3413 of the adjacent second Y-shaped groove from the first branch 3411 of the first Y-shaped groove through the guidance of the second branch 3412. After pressure relief, under the elastic force of the return spring 33 and the guidance of the third branch 3413, the pin 35 enters the first branch 3411 of the second Y-shaped groove and moves to the end of the first branch 3411 away from the second branch 3412 and the third branch 3413. The mandrel 32 travels to the second endpoint, the first guide channel d and the second guide channel e close, and the screen tube 3 closes. In practical applications, simply repeating the above operation allows the screen tube 3 to be opened and closed an unlimited number of times.

[0041] In other embodiments, the reset mechanism can also be designed with reference to the structural principle of a ballpoint pen. Ballpoint pens are existing technology and will not be described further here.

[0042] refer to Figure 1 and Figure 7 As shown, the first production channel b extends axially through the pressure transmission joint 1. One end of the first pressurizing channel a is connected to the pressure transmission pipe 4 inserted into the pressure transmission joint 1, and the other end is connected to the outer wall of the pressure transmission joint 1, so as to transmit the pressure of the annulus formed between the packer-screen pipe assembly and the wellbore after the packer-screen pipe assembly is lowered into the well to the pressure transmission pipe 4. Exemplarily, a threaded blind hole is provided in the pressure transmission joint 1, the first pressurizing channel a is connected to the threaded blind hole, and the pressure transmission pipe 4 is inserted into the threaded blind hole and sealed and screwed into the pressure transmission joint 1.

[0043] refer to Figure 1 and Figure 6 As shown, the outer cylinder 31 includes an upper connector 311, a lower connector 313, and a cylinder body 312. The front end of the upper connector 311 is connected to the packer 2, and the rear end is inserted into the cylinder body 312 and connected to it. The front end of the lower connector 313 is inserted into the cylinder body 312 and connected to it, and the rear end is used to connect to other functional tubing. One end of the return spring 33 abuts against the front end face of the lower connector 313, and the other end abuts against the first retaining ring 3222. The first flow guide channel d is also opened on the lower connector 313.

[0044] Furthermore, the upper connector 311 includes a fixed connector 3111, a protective connector 3113, a shearing connector 3112, and a rupture disc connector 3114. The front end of the fixed connector 3111 is sealed and screwed to the packer 2. A stepped blind cavity is formed at the end of the fixed connector 3111 near the packer 2, divided into a large-diameter section and a small-diameter section. The second production channel c is located within the fixed connector 3111, with one end connected to the large-diameter section and the other end connected to the end face of the fixed connector 3111 away from the packer 2. The second pressurization channel is connected to the small-diameter section. The pressure transmission pipe 4 passes through the large-diameter section and is inserted into the small-diameter section, sealingly connecting to the fixed connector 3111, thereby preventing communication between the second production channel c and the second pressurization channel. The shearing connector 3112 and the protective connector 3113 are... The inner and outer sides of the fixed joint 3111 are sealed and screwed together. The shear joint 3112 and the protective joint 3113 enclose and form an annular space f. The front end of the rupture disc joint 3114 is sandwiched between the shear joint 3112 and the protective joint 3113 and is sealed and connected to the shear joint 3112 and the protective joint 3113 to block the rear end of the annular space f. The rear end of the rupture disc joint 3114 is sandwiched between the mandrel 32 and the outer cylinder 31 and is sealed and connected to the mandrel 32 and the outer cylinder 31. The front end of the mandrel 32 is inserted into the shear joint 3112. The inner wall surface of the rupture disc joint 3114, the end face of the shear joint 3112 and the outer wall surface of the mandrel 32 together enclose and form the pressurized chamber g. The air chamber h is formed by the rupture disc joint 3114 and the mandrel 32. The rupture disc 3115 is disposed within the mounting hole of the rupture disc connector 3114. The two sides of the mounting hole correspond to the pressurization chamber g and the annular space f, respectively. A connecting channel i is provided within the fixed connector 3111. One end of the connecting channel i communicates with the pressure transmission pipe 4, and the other end communicates with the annular space f. The annular space f, the connecting channel i, and the mounting hole together constitute the second pressurization channel. Since the second pressurization channel communicates with the pressure transmission pipe 4, and the pressure transmission pipe 4 communicates with the first pressurization channel a, the second pressurization channel can communicate with the first pressurization channel a after the rupture disc 3115 ruptures. Based on the above configuration, when installing the rupture disc 3115, it is only necessary to create a radially penetrating mounting hole on the rupture disc connector 3114, and then install the rupture disc 3115 into the mounting hole.

[0045] refer to Figure 5As shown, to achieve axial positioning of the mandrel 32 and the transposition sleeve 34, the mandrel 32 is provided with a first retaining ring 3221 and a second retaining ring 3222 spaced apart along the axial direction. The second retaining ring 3222 is located at the end of the first retaining ring 3221 away from the upper connector 311. The transposition sleeve 34 is sleeved on the mandrel 32 and located between the first retaining ring 3221 and the second retaining ring 3222. For ease of installation, one of the first retaining ring 3221 and the second retaining ring 3222 is detachably connected to the mandrel 32, while the other can be integrally formed with the mandrel 32. For example, to facilitate assembly, the mandrel 32 is segmented, including a power shaft segment 321 and a reset shaft segment 322 connected axially. The pressurization chamber g and the air chamber h are both enclosed by the power shaft segment 321 and the outer cylinder 31. The second flow channel e, the first retaining ring 3221 and the second retaining ring 3222 are disposed in the reset shaft segment 322. The split mandrel 32 can reduce the difficulty of inserting the mandrel 32 into the outer cylinder 31.

[0046] refer to Figure 2 and Figure 8 As shown, to reduce the processing difficulty of the connecting channel i, the connecting channel i includes a radial channel and an axial channel. One end of the radial channel penetrates the wall of the fixed joint 3111 and is sealed with a plug 11, while the other end is connected to the pressure transmission pipe 4. One end of the axial channel is connected to the radial channel, and the other end is connected to the annular space f. During processing, the radial channel and the axial channel can be processed along the radial and axial directions of the fixed joint 3111 respectively, and then the plug 11 is inserted into the end of the radial channel that penetrates the wall of the fixed joint 3111.

[0047] A shear pin 36 is radially provided between the mandrel 32 and the outer cylinder 31. When the pressure difference between the mandrel 32 and the outer cylinder 31 is greater than the shear force that the shear pin 36 can withstand, the shear pin 36 is sheared, and the mandrel 32 and the outer cylinder 31 can move axially. This can prevent the axial displacement between the mandrel 32 and the outer cylinder 31 caused by excessive pressure in the mandrel 32 during the well-running process.

[0048] refer to Figure 5 As shown, in this embodiment, the cylinder 312 is configured in two parts, including a transposition cylinder section 3121 and a spring cylinder section 3122 connected axially. A pin 35 is fixed to the transposition cylinder section 3121, and a return spring 33 is mounted between the spring cylinder section 3122 and the spindle 32. The rear end of the transposition cylinder section 3121 is inserted into the spring cylinder section 3122 and screwed thereon. The separate cylinder 312 configuration further reduces the assembly difficulty of the entire assembly device.

[0049] 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. A packer-screen tube assembly, comprising a pressure-transmitting connector (1), a packer (2), and a screen tube (3) connected in sequence, and further comprising a pressure-transmitting tube (4), wherein both ends of the pressure-transmitting tube (4) are respectively inserted into the pressure-transmitting connector (1) and the screen tube (3), characterized in that: The pressure transmission connector (1) has a first production channel (b) and a first pressurization channel (a) that are not interconnected, and the pressure transmission pipe (4) is connected to the first pressurization channel (a). The screen tube (3) includes a mandrel (32), an outer cylinder (31), and a reset mechanism. The outer cylinder (31) has a second production channel (c) and a second pressurizing channel that are not interconnected. The second production channel (c) is connected to the first production channel (b). The second pressurizing channel is connected to the pressure transmission tube (4). The outer cylinder (31) is also provided with a first guide channel (d) that connects its inner wall and its outer wall. The mandrel (32) is located inside the outer cylinder (31) and is connected to the second production channel (c). The mandrel (32) is also provided with a second guide channel (e) that connects its inner wall and its outer wall. The mandrel (32) and the outer cylinder (31) form an axially spaced pressurizing chamber (g) and an air chamber (h). The pressurizing chamber (g) can be connected to the second pressurizing channel and pushes the mandrel (32) downward along the axial direction when pressurized. The air chamber (h) contains air. The mandrel (32) is periodically pressurized and depressurized. The reset mechanism enables the mandrel (32) to move upward and provides two different stroke endpoints for two adjacent upward movements of the mandrel (32). The two stroke endpoints are the first endpoint and the second endpoint. When the mandrel (32) moves to the first endpoint, the second guide channel (e) is connected to the first guide channel (d). When the mandrel (32) moves to the second endpoint, the second guide channel (e) is offset from the first guide channel (d). The reset mechanism includes a shift sleeve (34), a pin (35), and a reset spring (33). The shift sleeve (34) is sleeved on the spindle (32) and is axially limited to the spindle (32). The shift sleeve (34) is provided with a shift groove (341). One end of the pin (35) is fixed to the outer cylinder (31), and the other end is inserted into the shift groove (341). One end of the reset spring (33) abuts against the spindle (32), and the other end abuts against the outer cylinder (31). The transposition groove (341) is formed by connecting a first Y-shaped groove and a second Y-shaped groove arranged in a circumferentially staggered manner. Both the first Y-shaped groove and the second Y-shaped groove include a first branch (3411), a second branch (3412), and a third branch (3413). The first branch (3411) extends along the axial direction of the transposition sleeve (34). The second branch (3412) and the third branch (3413) are both L-shaped and connected to the first branch (3411). One end of the second branch (3412) connected to the first branch (3411) extends along the axial direction of the transposition sleeve (34), and the other end of the second branch (3412) is inclined away from the third branch (3413). The third branch (3413) is connected to the first branch (3411). One end of the connection is inclined away from the first branch (3411), and the other end of the third branch (3413) extends along the axial direction of the transposition sleeve (34). The second branch (3412) and the third branch (3413) of the adjacent first Y-shaped groove and second Y-shaped groove are connected. The length of the first branch (3411) of the first Y-shaped groove is less than the length of the first branch (3411) of the second Y-shaped groove. The end of the first branch (3411) of the second Y-shaped groove away from the second branch (3412) and the third branch (3413) is the second endpoint. The end of the first branch (3411) of the first Y-shaped groove away from the second branch (3412) and the third branch (3413) is the first endpoint.

2. The packer-screen tube assembly according to claim 1, characterized in that, The outer cylinder (31) includes an upper connector (311), a lower connector (313), and a cylinder body (312). The front end of the upper connector (311) is connected to the packer (2), the rear end of the upper connector (311) is inserted into the cylinder body (312) and connected to the cylinder body (312), and the front end of the lower connector (313) is inserted into the cylinder body (312) and connected to the cylinder body (312).

3. The packer-screen tube assembly according to claim 2, characterized in that, The upper connector (311) includes a fixed connector (3111), a protective connector (3113), a shear connector (3112), and a rupture disc connector (3114). The fixed connector (3111) is connected to the packer (2). The shear connector (3112) and the protective connector (3113) are respectively sealed to the inner and outer sides of the fixed connector (3111). The front end of the mandrel (32) is inserted into the shear connector (3112). The shear connector (3112) and the protective connector (3113) form an annular space (f). The front end of the rupture disc connector (3114) is sandwiched between the shear connector (3112) and the protective connector (3113) and is sealed to the shear connector (3112) and the protective connector (3113). The rear end of the rupture disc connector (3114) is sandwiched between the shear connector (3112) and the protective connector (3113). The mandrel (32) and the outer cylinder (31) are sealed together and sealed to each other. The rupture disc joint (3114), the shear joint (3112) and the mandrel (32) together form the pressurizing chamber (g). The air chamber (h) is formed by the rupture disc joint (3114) and the mandrel (32). The rupture disc (3115) is disposed in the mounting hole opened in the rupture disc joint (3114). The two sides of the mounting hole correspond to the pressurizing chamber (g) and the annular space (f) respectively. A connecting channel (i) is opened in the fixed joint (3111). One end of the connecting channel (i) is connected to the pressure transmission pipe (4) and the other end is connected to the annular space (f). The annular space (f), the connecting channel (i) and the mounting hole together constitute the second pressurizing channel.

4. The packer-screen tube assembly according to claim 3, characterized in that, The spindle (32) is provided with a first retaining ring (3221) and a second retaining ring (3222) spaced apart along the axial direction. The shift sleeve (34) is sleeved on the spindle (32) and located between the first retaining ring (3221) and the second retaining ring (3222).

5. The packer-screen tube assembly according to claim 4, characterized in that, The mandrel (32) is segmented, including a power shaft segment (321) and a reset shaft segment (322) connected along the axial direction. The pressurization chamber (g) and the air chamber (h) are enclosed by the power shaft segment (321) and the outer cylinder (31). The second flow channel (e), the first retaining ring (3221) and the second retaining ring (3222) are disposed on the reset shaft segment (322).

6. The packer-screen tube assembly according to claim 3, characterized in that, The connecting channel (i) includes a radial channel and an axial channel. One end of the radial channel passes through the wall of the fixed joint (3111) and is sealed with a threaded plug (11). The other end of the radial channel is connected to the pressure transmission pipe (4). One end of the axial channel is connected to the radial channel, and the other end is connected to the annular space (f).

7. The packer-screen tube assembly according to claim 1, characterized in that, A rupture disc (3115) is provided in the second pressurization channel.

8. The packer-screen tube assembly according to claim 1, characterized in that, A shear pin (36) is also provided between the mandrel (32) and the outer cylinder (31).

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