While-drilling negative pressure test packer

Abstract

The invention relates to a while-drilling negative pressure test packer. In the packer, a connecting sleeve, a sealing sleeve, an extension sleeve, a torque transmission sleeve and a spline sleeve are sequentially arranged on a mandrel in a sleeving manner; the connecting sleeve is matched and connected with the mandrel through a first spline structure; the anti-abrasion sleeve, the packing assembly and the guide ring are sequentially arranged on the connecting sleeve in a sleeving mode, and the anti-abrasion sleeve is connected with the connecting sleeve; the spline sleeve is in matched connection with the mandrel through a second spline structure, the sealing sleeve is connected with the extension sleeve, the torque transmission sleeve is connected with the spline sleeve, and the extension sleeve is connected with the torque transmission sleeve; the upper part of the support sleeve is connected with the guide ring; a first boss is arranged in the middle of the spline sleeve, and a first preset distance is formed between the step surface of the first boss and the bottom end of the supporting sleeve; the spline sleeve is connected with the positioning sleeve; the limiting block is arranged on the mandrel and is clamped between the positioning sleeve and the ball seat mechanism; the positioning sleeve is connected with the lower joint assembly; the ball seat mechanism is connected with the lower connector assembly through a shear pin.

Description

TECHNICAL FIELD

[0001] The present application relates to a negative pressure testing packer while drilling. BACKGROUND

[0002] During the process of drilling and well completion, the casing pressure test, the functionality of the liner hanger and the evaluation of cementing quality are very important. The service companies and related standards of major oil companies at home and abroad have clear provisions for pressure test. The test operation is usually carried out under the condition that the kill fluid column pressure is greater than the formation pressure. Negative pressure test is to make the liner or casing bear negative pressure during the pressure test, and the operation is carried out under the condition that the kill fluid static column pressure is less than the formation pressure, to verify the sealing of cement and casing. During the whole life cycle of the oil and gas well, including drilling, well completion, testing, production and later abandonment operation, if the external pressure of the liner or casing is higher than the internal pressure or the liner cementing operation is suspected to be unsuccessful, the liner including the overlap section needs to be subjected to negative pressure test to verify the integrity of the oil and gas well.

[0003] The negative pressure testing packer used in the conventional technology usually adopts a rotation and downward pressing setting mode to form a seal during drilling and well completion, so as to carry out various operations. Taking the RTTS packer as an example, after the packer is sent to a predetermined position in the casing, the working string is lifted and right-rotated, so that the protrusion on the lower mandrel is away from the locking position of the "J" type groove and slides to a straight groove, and then the string is slowly lowered. Due to the fact that the friction blocks of the packer are tightly attached to the inner wall of the casing, under the support of the friction blocks, the slip sleeve pushes the mechanical slips to open and tightly bite the inner wall of the casing, and the drill weight on the upper part of the packer is pressed downward to the rubber cylinder through the top shoe to make the rubber cylinder expand under pressure, so as to seal the oil jacket annulus, and the setting is completed. SUMMARY

[0004] In order to realize running, complete well flushing, circulation, negative pressure test and other operations. In order to realize the negative pressure testing packer running with the downhole drill string combination once, multiple setting. The present application provides a negative pressure testing packer while drilling. The technical scheme provided by the present application is as follows:

[0005] In a first aspect, the present application provides a negative pressure testing packer while drilling, comprising: an upper joint assembly, a mandrel, a connecting sleeve, a packer assembly, an anti-wear sleeve, a guide ring, a support sleeve, a sealing sleeve, an extension sleeve, a torque transmission sleeve, a spline sleeve, a positioning sleeve, a limiting block, a ball seat mechanism, a shear pin, a lower joint assembly;

[0006] The upper joint assembly is connected with the mandrel;

[0007] The connecting sleeve, the sealing sleeve, the extension sleeve, the torque transmission sleeve and the spline sleeve are sequentially sleeved on the mandrel;

[0008] The connecting sleeve is connected with the core shaft through a first spline structure;

[0009] The wear-resistant sleeve, the packoff assembly and the guide ring are sequentially sleeved on the connecting sleeve, and the wear-resistant sleeve is connected with the connecting sleeve;

[0010] The spline sleeve is connected with the core shaft through a second spline structure, the sealing sleeve is connected with the extension sleeve, the torque transmission sleeve is connected with the spline sleeve, and the extension sleeve is connected with the torque transmission sleeve;

[0011] The support sleeve is sleeved on the sealing sleeve and the extension sleeve, and the upper part of the support sleeve is connected with the guide ring;

[0012] The middle part of the spline sleeve has a first boss, and a first preset distance is formed between the step surface of the first boss and the bottom end of the support sleeve;

[0013] The spline sleeve is connected with the positioning sleeve;

[0014] The upper end of the ball seat mechanism is sealingly connected with the core shaft;

[0015] The limiting block is arranged on the core shaft and is clamped between the positioning sleeve and the ball seat mechanism;

[0016] The positioning sleeve is connected with the lower joint assembly;

[0017] The ball seat mechanism and the lower joint assembly are connected through a shear pin;

[0018] The lower end of the ball seat mechanism is accommodated in the lower joint assembly.

[0019] In one or some embodiments, the lower end of the core shaft is provided with a plurality of limiting holes at intervals along the outer periphery, and correspondingly, the inner wall of the positioning sleeve is provided with a plurality of limiting grooves at intervals along the axial direction;

[0020] The limiting block is accommodated in the limiting hole, and one end of the limiting block is clamped in the limiting groove, and the other end of the limiting block abuts against the ball seat mechanism.

[0021] In one or some embodiments, the lower joint assembly comprises a short joint and a lower joint;

[0022] The positioning sleeve, the short joint and the lower joint are sequentially connected;

[0023] The ball seat mechanism and the short joint are connected through a shear pin;

[0024] The lower part of the ball seat mechanism is accommodated in the upper end of the lower joint and abuts against the inner wall of the lower joint.

[0025] The inner wall of the lower connector expands to form an expansion section, so that the ball seat mechanism opens in the expansion section after moving downward.

[0026] In one or more embodiments, the ball seat mechanism includes a sliding sleeve and a pawl;

[0027] The upper end of the sliding sleeve extends into the mandrel and is sealed to the mandrel;

[0028] One end of the limiting block is engaged with the limiting groove, and the other end abuts against the sliding sleeve;

[0029] The lower part of the sliding sleeve is connected to the short connector by a shear pin.

[0030] The lower end of the sliding sleeve is connected to the pawl, and the lower part of the pawl is accommodated in the upper end of the lower connector and abuts against the inner wall of the lower connector.

[0031] The inner wall of the lower connector expands to form a pawl expansion portion, so that the pawl opens at the pawl expansion portion after moving downward.

[0032] In one or more embodiments, the ball seat mechanism further includes a steel sleeve that is received within the pawl.

[0033] In one or more embodiments, the drilling negative pressure test packer further includes a non-load-bearing sealing piston;

[0034] The lower part of the mandrel is provided with a second boss;

[0035] The non-load-bearing sealing piston is sleeved on the mandrel and located between the stepped surface of the second boss and the limiting block. The outer wall of the non-load-bearing sealing piston abuts against the inner wall of the positioning sleeve.

[0036] In one or more embodiments, the first spline structure includes a short key block, a first keyway disposed on the inner wall of the connecting sleeve, and a second keyway disposed on the outer wall of the mandrel.

[0037] The short key blocks engage with the first keyway and the second keyway, respectively.

[0038] In one or more embodiments, the second spline structure includes a spline groove disposed on the inner wall of the spline sleeve, and a spline block with a corresponding protrusion disposed on the outer wall of the mandrel.

[0039] The spline block is fitted into the spline groove, and the length of the spline groove is greater than the length of the spline block.

[0040] In one or more embodiments, the upper connector assembly includes an upper connector and an upper stabilizer;

[0041] The upper connector is connected to the mandrel;

[0042] The upper stabilizer is fitted onto the upper connector.

[0043] In one or more embodiments, the upper centralizer is a spiral centralizer.

[0044] In one or more embodiments, the sealing assembly includes a short rubber tube, two retaining rings, and two long rubber tubes;

[0045] The two long rubber tubes are located on the upper and lower sides of the short rubber tube, and the two retaining rings are located between the short rubber tube and the upper long rubber tube, and between the short rubber tube and the lower long rubber tube, respectively.

[0046] In one or more embodiments, a limiting boss is provided at the lower end of the extension sleeve, and correspondingly, a torque transmission groove is provided at the upper end of the torque transmission sleeve.

[0047] The limiting boss is accommodated in the torsion transmission groove.

[0048] In one or more embodiments, the sidewall of the support sleeve is provided with an elongated slot, and the upper end of the torque transmission sleeve protrudes outward to form a torque transmission protrusion.

[0049] The torsion transmission bump is accommodated within the elongated slot, the length of which is greater than the length of the torsion transmission bump.

[0050] In one or more embodiments, the connecting sleeve is provided with a first flow hole, which is located above the anti-wear sleeve;

[0051] An annular channel is formed between the connecting sleeve and the mandrel;

[0052] The position of the long slot hole of the support sleeve corresponds to that of the sealing sleeve;

[0053] A flow channel is formed between the lower end of the connecting sleeve and the upper end of the sealing sleeve.

[0054] In one or more embodiments, the middle part of the connecting sleeve protrudes outward to form a first limiting step, and the inner wall of the upper end of the guide ring protrudes inward to form a second limiting step.

[0055] The step surfaces of the first limiting step and the second limiting step are matched.

[0056] Based on the above technical solution, the beneficial effects of the present invention compared with the prior art are as follows:

[0057] The negative pressure test packer for drilling provided in this embodiment of the invention can transmit the torque driving the mandrel to the connecting sleeve, wear-resistant sleeve, packer assembly, guide ring, support sleeve, sealing sleeve, extension sleeve, torque transmission sleeve, spline sleeve, positioning sleeve, and lower connector assembly through the first spline structure and the second spline structure. Furthermore, the mandrel can drive the limiting block and ball seat mechanism to rotate synchronously. Therefore, after the tool is run into the wellbore during drilling, the shear pin will not be sheared off when the drill string rotates during processes such as drill plug, wellbore cleaning, and circulation flushing. At the same time, by setting a limiting block on the mandrel, the limiting block is engaged between the positioning sleeve and the ball seat mechanism. Before the shear pin is sheared off and the setting function is activated, the axial movement of the mandrel is restricted by the limiting block, ensuring that the negative pressure test packer for drilling will not set prematurely when the drill string rotates. During the initial setting, the setting function is activated by shearing the shear pin through a ball-dropping pressure-pressurizing method. Releasing the drill string's suspended weight drives the mandrel and limit block to move axially. The mandrel then drives the wear-resistant sleeve to press down on the packer assembly, achieving setting and negative pressure testing. Unsealing is achieved by lifting the drill string. Therefore, multiple negative pressure tests can be performed with a single drilling run, avoiding the hassle of multiple trips to and from the drill string, reducing the time spent on tripping and assembling drill strings, improving operational efficiency while reducing operational costs and risks. Using this downhole negative pressure test packer facilitates effective evaluation of cementing quality and the sealing performance of the liner after setting during drilling and completion.

[0058] The negative pressure test packer provided in this embodiment of the invention has a first preset distance between the stepped surface of the first boss and the bottom end of the support sleeve. By releasing the drill string weight, the mandrel can be driven to move the limiting block, connecting sleeve, anti-wear sleeve, packer assembly, guide ring and support sleeve axially simultaneously by the first preset distance. Releasing the limiting block releases the axial position restriction on the mandrel, thereby enabling the mandrel to drive the anti-wear sleeve to press down on the packer assembly for setting. By lifting the drill string, the mandrel drives the anti-wear sleeve to move upward, releasing the pressure on the packer assembly and unsealing it.

[0059] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained in accordance with the structures particularly pointed out in the description, claims and drawings.

[0060] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0061] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0062] Figure 1 A schematic diagram of the structure of the drilling negative pressure test packer provided in an embodiment of the present invention. Figure 1 ;

[0063] Figure 2 for Figure 1 Schematic diagram of the AA cross-sectional structure of the packer used for negative pressure testing during drilling;

[0064] Figure 3 for Figure 2 A partially enlarged schematic diagram of part B of the packer used in the mid-drilling negative pressure test;

[0065] Figure 4 for Figure 2 A partially enlarged schematic diagram of section C of the packer used in the mid-drilling negative pressure test;

[0066] Figure 5 for Figure 2 A partially enlarged schematic diagram of section D of the packer used for negative pressure testing during drilling;

[0067] Figure 6 for Figure 2 Schematic diagram of the EE cross-sectional structure of the packer used for negative pressure testing during drilling;

[0068] Figure 7 This is a schematic diagram of the setting state structure of the packer for the negative pressure test during drilling provided in an embodiment of the present invention;

[0069] Figure 8 for Figure 7 A schematic diagram of the FF cross-sectional structure of the packer used for drilling negative pressure testing.

[0070] In the picture:

[0071] 1. Upper connector; 2. Upper stabilizer; 3. Fastening screw; 4. Short keyway; 5. Connecting sleeve; 501. First keyway; 502. First flow hole; 6. Anti-wear sleeve; 7. Mandrel; 701. Second keyway; 702. Spline block; 703. Limiting hole; 704. Second boss; 8. Long rubber sleeve; 9. Retaining ring; 10. Short rubber sleeve; 11. Guide ring; 12. Support sleeve; 1201. Long slot hole; 13. Sealing sleeve; 14. Extension sleeve; 1401. Limiting boss; 15. Torque transmission Sleeve; 1501, Torque transmission groove; 1502, Torque transmission protrusion; 16, Spline sleeve; 1601, First boss; 1602, Spline groove; 17, Positioning sleeve; 1701, Limiting groove; 18, Non-load-bearing sealing piston; 19, Limiting block; 20, Sliding sleeve; 21, Shear pin; 22, Sealing screw; 23, Short connector; 24, Lower connector; 2401, Pawl expansion; 25, Pawl; 26, Steel sleeve; 27, Unlocking ball; 28, Lower stabilizer; 29, Annular channel. Detailed Implementation

[0072] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0073] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0074] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, 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 invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0075] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral connection; 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; and they can refer to the internal communication 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.

[0076] Currently, negative pressure testing packers use a rotational and downward-pressurized setting method. Rotation of the drilling tool can cause the packer to set prematurely, preventing it from being run along with other downhole tools. During drilling and completion, if negative pressure testing is required, the packer must be run back in after tripping the drill string, involving multiple trips to change different downhole tool combinations. This results in significant time, manpower, and material costs, failing to meet the inventor's expectations. To enable the packer to be run along with other downhole tools, allowing for multiple negative pressure tests with a single run throughout the entire oil and gas well's lifecycle, thus improving operational efficiency, the inventor further developed this invention.

[0077] Example 1

[0078] This invention provides a packer for testing negative pressure while drilling. (Refer to...) Figures 1 to 8 As shown, the packer for the drilling negative pressure test includes: an upper connector assembly (not shown in the figure), a mandrel 7, a connecting sleeve 5, a packer assembly (not shown in the figure), an anti-wear sleeve 6, a guide ring 11, a support sleeve 12, a sealing sleeve 13, an extension sleeve 14, a torque transmission sleeve 15, a spline sleeve 16, a positioning sleeve 17, a limit block 19, a ball seat mechanism (not shown in the figure), a shear pin 21, and a lower connector assembly (not shown in the figure). Wherein:

[0079] The upper connector assembly (not shown in the figure) is connected to the spindle 7;

[0080] The connecting sleeve 5, sealing sleeve 13, extension sleeve 14, torque transmission sleeve 15, and spline sleeve 16 are sequentially sleeved on the mandrel 7.

[0081] The connecting sleeve 5 and the spindle 7 are connected by a first spline structure;

[0082] The wear-resistant sleeve 6, the sealing assembly, and the guide ring 11 are sequentially sleeved on the connecting sleeve 5, and the wear-resistant sleeve 6 is connected to the connecting sleeve 5;

[0083] The spline sleeve 16 is connected to the mandrel 7 through a second spline structure. The sealing sleeve 13 is connected to the extension sleeve 14, the torque transmission sleeve 15 is connected to the spline sleeve 16, and the extension sleeve 14 is connected to the torque transmission sleeve 15.

[0084] The support sleeve 12 is sleeved on the sealing sleeve 13 and the extension sleeve 14, and the upper part of the support sleeve 12 is connected to the guide ring 11.

[0085] The spline sleeve 16 has a first boss 1601 in the middle, and there is a first preset distance between the stepped surface of the first boss 1601 and the bottom end of the support sleeve 12.

[0086] The splined sleeve 16 is connected to the positioning sleeve 17;

[0087] The upper end of the ball seat mechanism is sealed to the spindle 7;

[0088] The limiting block 19 is disposed on the spindle 7 and is engaged between the positioning sleeve 17 and the ball seat mechanism;

[0089] The positioning sleeve 17 is connected to the lower connector assembly;

[0090] The ball seat mechanism and the lower connector assembly are connected by a shear pin 21;

[0091] The lower end of the ball seat mechanism is accommodated in the lower connector assembly.

[0092] In this embodiment of the invention, the packer for the drilling negative pressure test uses the top of the liner hanger's return sleeve as its positioning and bearing surface. When the drilling negative pressure test tool is lowered to the top of the liner hanger and initial setting is required, refer to... Figures 1 to 6 As shown, a ball is thrown, and once the unlocked ball 27 falls into the ball seat mechanism, the shear pin 21 between the ball seat mechanism and the lower connector assembly is pressed and severed. The ball seat mechanism then disengages from the spindle 7 and moves downwards into the lower connector assembly. (Refer to...) Figure 7 and Figure 8 As shown, since there is a first preset distance between the stepped surface of the first boss 1601 and the bottom end of the support sleeve 12, by releasing the drill string's suspended weight, the mandrel 7 can be driven to move the limiting block 19, connecting sleeve 5, anti-wear sleeve 6, packer assembly, guide ring 11, and support sleeve 12 axially downwards by the first preset distance. Releasing the limiting block 19 releases the axial upward position restriction on the mandrel 7. At this time, the setting function of the packer during drilling negative pressure testing is activated, meaning it can be pressed down for setting. Under the action of the drill string's gravity, the mandrel 7 can drive the anti-wear sleeve 6 to press down on the packer assembly for setting. By lifting (overlifting) the drill string, the mandrel 7 drives the anti-wear sleeve 6 upwards to release the pressure on the packer assembly and release it from the seal.

[0093] In this embodiment of the invention, the spindle 7 and the connecting sleeve 5 are connected by a spline engagement of a first spline structure, which transmits the torque driving the spindle 7 to the connecting sleeve 5, the anti-wear sleeve 6, and the sealing assembly. The spindle 7 and the spline sleeve 16 are connected by a spline engagement of a second spline structure, which transmits the torque driving the spindle 7 to the guide ring 11, the support sleeve 12, the sealing sleeve 13, the extension sleeve 14, the torque transmission sleeve 15, the positioning sleeve 17, and the lower connector assembly. The torque generated by the rotation of the drilling tool during drilling and completion operations creates a torque-prone end in the overall structure of the negative pressure test packer. Therefore, torque transmission during operation is crucial. To ensure multiple setting capabilities, the inventors employed the aforementioned technical means, setting up two sets of spline structures to transmit torque from the upper to the lower part, ensuring synchronous torque transmission. This allows all components of the negative pressure test packer to rotate synchronously, effectively distributing the torque across vulnerable structures such as the mandrel 7, improving torque transmission efficiency, and preventing excessive downhole torque that could cause breakage of these weak structures. Furthermore, due to the synchronous torque transmission and the absence of relative rotation between components, damage to the internal seals of the tool is reduced, thus extending the tool's service life.

[0094] In one specific embodiment, reference is made to Figure 2 and Figure 3 As shown, in the packer for the drilling negative pressure test, the first spline structure includes a short key block 4, a first keyway 501 disposed on the inner wall of the connecting sleeve 5, and a second keyway 701 disposed on the outer wall of the mandrel 7. The short key block 4 engages with the first keyway 501 and the second keyway 701 respectively. By engaging the short key block 4 with the first keyway 501 and the second keyway 701 respectively, not only can the torque of the mandrel 7 be transmitted to the connecting sleeve 5, but also, through the axial limiting effect of the short key block 4, the connecting sleeve 5 and the mandrel 7 can move synchronously in the axial direction, ensuring a tight connection between the mandrel 7 and the connecting sleeve 5.

[0095] In one specific embodiment, reference is made to Figures 2 to 4As shown, in the drilling negative pressure test packer, the second spline structure includes a spline groove 1602 disposed on the inner wall of the spline sleeve 16, and a spline block 702 correspondingly protruding on the outer wall of the mandrel 7. The spline block 702 is fitted into the spline groove 1602, and the length of the spline groove 1602 is greater than the length of the spline block 702. By setting the spline block 702 to be fitted into the spline groove 1602, the torque of the mandrel 7 can be transmitted to the spline sleeve 16. By setting the length of the spline groove 1602 to be greater than the length of the spline block 702, the spline block 702 can move up and down within the spline groove 1602 when the mandrel 7 moves axially, without obstruction when the mandrel 7 moves downward the aforementioned first preset distance.

[0096] In this embodiment of the invention, the inventors considered that relying solely on the shear pin 21 as a means of preventing premature tool setting is problematic in complex downhole conditions. The shear pin 21 is easily sheared during drilling operations, leading to premature tool setting. Therefore, the inventors proposed setting a limiting block 19 on the mandrel 7, which is engaged between the positioning sleeve 17 and the ball seat mechanism. The mandrel 7 drives the limiting block 19 and the ball seat mechanism to rotate synchronously. During drilling plug cleaning, wellbore cleaning, and circulating well washing processes, the shear pin 21 is less likely to be sheared during the packer rotation under negative pressure testing. Before the shear pin 21 is sheared and the setting function is activated, the limiting block 19 restricts the axial up-and-down movement of the mandrel 7, ensuring that the packer does not set prematurely during drill string rotation.

[0097] In this embodiment of the invention, the setting function is activated by shearing the shear pin 21 through ball-dropping and pressure-pressurizing. Releasing the drill string's suspended weight drives the mandrel 7 and the limiting block 19 to move axially. The mandrel 7 then drives the wear-resistant sleeve 6 to press down on the packer assembly, achieving setting and negative pressure testing. Unsealing is achieved by lifting (overlifting) the drill string. Therefore, multiple negative pressure tests can be performed with a single drilling run, avoiding the hassle of multiple trips to and from the drill string, reducing the time spent on tripping and drilling string assembly, improving operational efficiency while reducing operational costs and risks. Using this downhole negative pressure test packer facilitates effective evaluation of cementing quality and the sealing performance of the tailpipe after setting during drilling and completion.

[0098] In this embodiment of the invention, the downhole negative pressure test packer is connected to the drill pipe or other functional downhole drilling tools of the well washing test string via an upper connector assembly and a lower connector assembly. The upper connector assembly is used to connect the upper string, and the lower connector assembly is used to connect the lower string.

[0099] In this embodiment of the invention, the anti-wear sleeve 6 and the connecting sleeve 5 can be connected by threads. In order to ensure the connection stability between the anti-wear sleeve 6 and the connecting sleeve 5, a fastening screw 3 is also fixed on the anti-wear sleeve 6 to prevent the threads between the anti-wear sleeve 6 and the connecting sleeve 5 from coming off.

[0100] In this embodiment of the invention, the support sleeve 12 and the guide ring 11 can be connected by threads. In order to ensure the connection stability between the support sleeve 12 and the guide ring 11, a fastening screw 3 is also fixed on the support sleeve 12 to prevent the threads between the support sleeve 12 and the guide ring 11 from coming off.

[0101] In this embodiment of the invention, the sealing sleeve 13 and the extension sleeve 14 can be connected by threads. In order to ensure the connection stability between the sealing sleeve 13 and the extension sleeve 14, a fastening screw 3 is also fixed on the sealing sleeve 13 to prevent the threads between the sealing sleeve 13 and the extension sleeve 14 from coming off.

[0102] In one specific embodiment, reference is made to Figure 2 As shown, in order to ensure the sealing effect between the sealing sleeve 13 and the mandrel 7, an internal sealing structure can be provided between the sealing sleeve 13 and the mandrel 7. The sealing structure may include an O-ring and a retaining ring.

[0103] In an alternative embodiment, refer to Figure 2 and Figure 5 As shown, in the negative pressure test packer during drilling, the lower end of the mandrel 7 is provided with a plurality of limiting holes 703 at intervals along the outer periphery, and correspondingly, the inner wall of the positioning sleeve 17 is provided with a plurality of limiting grooves 1701 at intervals along the axial direction.

[0104] The limiting block 19 is accommodated in the limiting hole 703, and one end of the limiting block 19 is engaged with the limiting groove 1701, while the other end of the limiting block 19 abuts against the ball seat mechanism.

[0105] In this embodiment of the invention, multiple limiting holes 703 are provided at the lower end of the mandrel 7, and each limiting block 19 is respectively set in the corresponding hole. In addition, multiple limiting grooves 1701 with the same number of limiting holes 703 are provided on the inner wall of the positioning sleeve 17. The limiting block 19 is limited in the limiting groove 1701 by the pressing of the ball seat mechanism. Thus, the limiting groove 1701 can limit the limiting block 19, thereby preventing the axial movement of the mandrel 7. Before setting, the positional relationship between the mandrel 7 and the limiting block 19, the sealing assembly, the guide ring 11, the support sleeve 12, the sealing sleeve 13, the extension sleeve 14, the torque transmission sleeve 15, the spline sleeve 16, the positioning sleeve 17, the ball seat mechanism, the shear pin 21 and the lower connector assembly remains unchanged, thereby realizing the function of preventing premature setting.

[0106] In one specific embodiment, it may be, referring to Figure 2 and Figure 6 As shown, the ball seat mechanism includes a sliding sleeve 20 and a pawl 25. The upper end of the sliding sleeve 20 extends into the spindle 7 and is sealed to the spindle 7. One end of the limiting block 19 is engaged with the limiting groove 1701, and the other end abuts against the sliding sleeve 20. Furthermore, the lower part of the sliding sleeve 20 is connected to the ball seat mechanism via a shear pin 21. The lower end of the sliding sleeve 20 is connected to the pawl 25, and the lower part of the pawl 25 is accommodated in the upper end of the lower connector 24 and abuts against the inner wall of the lower connector 24. (Refer to...) Figure 1 and Figure 6 As shown, after the drilling negative pressure test tool is lowered to the top of the liner hanger, when the initial setting is required, a ball is dropped. Once the unlocking ball 27 falls into the pawl 25, the pressure shearing pin 21 between the sliding sleeve 20 and the lower connector assembly is broken. The ball seat mechanism disengages from the mandrel 7 and moves downwards into the lower connector assembly. (Refer to...) Figure 7 and Figure 8 As shown, by releasing the drill string suspension weight and releasing the limiting block 19, the axial upward position restriction on the mandrel 7 is released. At this time, the setting function of the packer during drilling negative pressure testing is activated. Under the action of the drill string gravity, the mandrel 7 can drive the wear-resistant sleeve 6 to press down on the packer assembly for setting. By lifting (overlifting) the drill string, the mandrel 7 drives the wear-resistant sleeve 6 upward to release the pressure on the packer assembly and unseal it.

[0107] In an alternative embodiment, refer to Figure 1 and Figure 2 As shown, in the packer for the drilling negative pressure test, the packer assembly includes a short rubber sleeve 10, two retaining rings 9, and two long rubber sleeves 8. The two long rubber sleeves 8 are located on the upper and lower sides of the short rubber sleeve 10, and the two retaining rings 9 are respectively located between the short rubber sleeve 10 and the upper long rubber sleeve 8, and between the short rubber sleeve 10 and the lower long rubber sleeve 8. (Refer to...) Figure 7 and Figure 8 As shown, by using the long rubber sleeve 8 and the short rubber sleeve 10 together, when the mandrel 7 drives the anti-wear sleeve 6 to press down under the gravity of the drill string, the long rubber sleeve 8 and the short rubber sleeve 10 can deform to different degrees. By combining the three rubber sleeves, the uniformity of the force during extrusion is improved, better sealing contact with the casing is ensured, and the fit between the rubber sleeve and the casing is increased, thereby achieving efficient setting, ensuring the setting effect, improving the setting success rate, and ensuring the functionality of multiple setting operations with a single well entry.

[0108] In this embodiment of the invention, the short rubber sleeve 10, the two retaining rings 9, and the two long rubber sleeves 8 are disposed between the anti-wear sleeve 6 and the guide ring 11. The anti-wear sleeve 6 and the guide ring 11 can restrict the position of the short rubber sleeve 10, the two retaining rings 9, and the two long rubber sleeves 8. Furthermore, during the drilling and completion process, before the short rubber sleeve 10 and the two long rubber sleeves 8 are squeezed, the outer diameter of the anti-wear sleeve 6 and the guide ring 11 is larger than the outer diameter of the short rubber sleeve 10 and the two long rubber sleeves 8, thus effectively protecting the short rubber sleeve 10 and the two long rubber sleeves 8 from wear.

[0109] In this embodiment of the invention, the materials of the short rubber sleeve 10 and the long rubber sleeve 8 can be selected according to the usage environment of the packer for the negative pressure test during drilling. For example, in a high temperature and high pressure environment, a rubber material resistant to high temperature and high pressure can be used, while in a normal temperature and normal pressure environment, a rubber material resistant to normal temperature and normal pressure can be used to save costs.

[0110] In this embodiment of the invention, in order to further improve the sealing effect, when selecting the materials of the short rubber tube 10 and the long rubber tube 8, the hardness of the material of the long rubber tube 8 can be less than that of the material of the short rubber tube 10. As a result, when subjected to compression, the long rubber tube 8 deforms more, while the short rubber tube 10 deforms less. This can provide support for the long rubber tubes 8 on both sides, improve the sealing effect of the two long rubber tubes 8, and increase the success rate of sealing.

[0111] In an alternative embodiment, refer to Figure 1 and Figure 2 As shown, in the packer for the drilling negative pressure test, the middle part of the connecting sleeve 5 protrudes outward to form a first limiting step (not shown in the figure), and the inner wall of the upper end of the guide ring 11 protrudes inward to form a second limiting step (not shown in the figure). The step surface between the second limiting step and the first limiting step matches. By matching the step surface between the second limiting step and the first limiting step, the guide ring 11 and the support sleeve 12 can be hung on the connecting sleeve 5. Thus, when the drill string is released, the guide ring 11 and the support sleeve 12 can follow the mandrel 7 and the connecting sleeve 5 to move the first preset distance. When the mandrel 7 and the connecting sleeve 5 continue to descend, the anti-wear sleeve 6 squeezes the short rubber sleeve 10 and the two long rubber sleeves 8 to achieve a setting seal. After the negative pressure test is completed, the drill bit is lifted, and the mandrel 7, connecting sleeve 5 and anti-wear sleeve 6 move upward. The aforementioned short rubber sleeve 10 and two long rubber sleeves 8 return to their original state. When the mandrel 7 and connecting sleeve 5 continue to move upward, the connecting sleeve 5 can drive the guide ring 11 and support sleeve 12 to move upward to the first preset distance.

[0112] In an alternative embodiment, refer to Figure 1 and Figure 2 As shown, in the packer for the drilling negative pressure test, the lower connector assembly includes a short connector 23 and a lower connector 24. Wherein:

[0113] The positioning sleeve 17, the short connector 23, and the lower connector 24 are connected in sequence. The ball seat mechanism is connected to the short connector 23 by a shear pin 21. The lower part of the ball seat mechanism is accommodated in the upper end of the lower connector 24 and abuts against the inner wall of the lower connector 24. The inner wall of the middle part of the lower connector 24 expands to form an expansion portion, so that the ball seat mechanism opens in the expansion portion after moving downward.

[0114] In one specific embodiment, reference is made to Figure 1 and Figure 2 As shown, the lower connector assembly may further include a lower stabilizer 28, which is disposed on the outer wall of the lower connector 24. Furthermore, the upper end face of the lower stabilizer 28 can abut against the lower end face of the short connector 23, and the lower end face of the lower stabilizer 28 is an annular surface.

[0115] In this embodiment of the invention, the packer for the negative pressure test while drilling uses the top of the liner hanger as the positioning and bearing surface. If the packer for the negative pressure test while drilling is misaligned or tilted at the top of the liner hanger, it will cause the packer assembly to deviate during setting, affecting the sealing performance between it and the wellbore, resulting in incomplete setting. This will lead to excessive errors in the negative pressure test, or even inaccurate negative pressure test results, requiring resetting and retesting. This not only wastes time but also significantly increases the economic cost of the negative pressure test. Based on this, the inventors proposed setting the lower end face of the lower stabilizer 28 as an annular surface. When the drilling negative pressure test tool is lowered to the top of the tee box, the annular surface at the lower end of the lower stabilizer 28 serves as the main bearing surface for the drilling negative pressure test packer to sit on the top of the tee box. This increases the contact area between the lower stabilizer 28 and the top of the tee box, preventing the drilling negative pressure test packer from sitting crookedly or tilted, and avoiding misalignment of the packer assembly during setting. This better ensures the integrity and effectiveness of the setting, reduces the error of the negative pressure test, improves the efficiency of the negative pressure test, and saves costs.

[0116] In this embodiment of the invention, the positioning sleeve 17 and the short connector 23 can be connected by threads. In order to ensure the connection stability between the positioning sleeve 17 and the short connector 23, a fastening screw 3 is also fixed on the positioning sleeve 17 to prevent the threads between the positioning sleeve 17 and the short connector 23 from coming off.

[0117] In this embodiment of the invention, the lower connector 24 and the short connector 23 can be connected by threads. In order to ensure the connection stability between the lower connector 24 and the short connector 23, a fastening screw 3 is also fixed on the short connector 23 to prevent the threads between the lower connector 24 and the short connector 23 from coming off.

[0118] In one specific embodiment, reference is made to Figure 2As shown, in order to ensure the sealing effect between the lower connector 24 and the short connector 23, an internal sealing structure can be provided between the lower connector 24 and the short connector 23. The sealing structure may include an O-ring and a retaining ring.

[0119] In this embodiment of the invention, the lower stabilizer 28 and the lower connector 24 can be connected by threads. In order to ensure the connection stability between the lower stabilizer 28 and the lower connector 24, a fastening screw 3 is also fixed on the lower stabilizer 28 to prevent the threads between the lower stabilizer 28 and the lower connector 24 from coming loose.

[0120] In an alternative embodiment, refer to Figure 1 and Figure 2 As shown, in the packer for the negative pressure test while drilling, the upper connector assembly includes an upper connector 1 and an upper centralizer 2;

[0121] The upper connector 1 is connected to the spindle 7;

[0122] The upper stabilizer 2 is fitted onto the upper connector 1.

[0123] In one specific embodiment, reference is made to Figure 2 As shown, an internal sealing structure can be provided between the upper connector 1 and the spindle 7. This sealing structure may include an O-ring and a retaining ring. The upper connector 1 and the spindle 7 can be connected by threads. To ensure the stability of the connection between the upper connector 1 and the spindle 7, a fastening screw 3 is also fixed on the upper connector 1 to prevent the threads between the upper connector 1 and the spindle 7 from coming off. To ensure the stability of the connection between the upper connector 1 and the upper stabilizer 2, a fastening screw 3 is also fixed on the upper stabilizer 2 to prevent the threads between the upper connector 1 and the upper stabilizer 2 from coming off.

[0124] In one specific embodiment, reference is made to Figure 1 As shown, the upper centralizer 2 and the lower centralizer 28 can be spiral-type centralizers. This structural design not only helps to centralize the packer during drilling negative pressure testing, but also, when the packer rotates, the sharp edges of the spiral structure of the centralizer can help to break up the residual cement after cementing. Furthermore, the spiral structure generates vortices when rotating, which makes it easier to carry and return downhole foreign objects (such as cement blocks, rock cuttings, etc.), thus facilitating the return of downhole foreign objects and impurities.

[0125] As described above, the ball seat mechanism includes a sliding sleeve 20 and a pawl 25. The upper end of the sliding sleeve 20 extends into the spindle 7 and is sealed to the spindle 7. One end of the limiting block 19 is engaged with the limiting groove 1701, and the other end abuts against the sliding sleeve 20. Based on this, refer to Figure 2 and Figure 6As shown in this embodiment of the invention, the lower part of the sliding sleeve 20 is connected to the short connector 23 by a shear pin 21. A sealing screw 22 is provided on the short connector 23 to cooperate with the shear pin 21, which can prevent fluid communication between the inside and outside of the pipe. Furthermore, it can prevent the shear pin 21 from disengaging and falling off due to vibration during installation or use in complex downhole environments. The lower end of the sliding sleeve 20 is connected to the pawl 25. The lower part of the pawl 25 is accommodated in the upper end of the lower connector 24 and abuts against the inner wall of the lower connector 24. The inner wall of the lower connector 24 expands to form a pawl expansion portion 2401, so that the pawl 25 opens in the pawl expansion portion 2401 after moving downwards.

[0126] In this embodiment of the invention, the sliding sleeve 20 and the pawl 25 can be connected by threads. In order to ensure the connection stability between the sliding sleeve 20 and the pawl 25, a fastening screw 3 is also fixed on the sliding sleeve 20 to prevent the threads between the sliding sleeve 20 and the pawl 25 from coming off.

[0127] In one specific embodiment, reference is made to Figure 2 and Figure 6 As shown, the ball seat mechanism may also include a steel sleeve 26, which is accommodated within the pawl 25.

[0128] Reference Figures 1 to 6 As shown, during the initial setting, a ball is dropped. Once the unlocking ball 27 falls into the pawl 25 and seals the lower end of the steel sleeve 26, due to the sealing effect of the steel sleeve 26, the fluid enters the steel sleeve 26 from the central channel of the downhole drilling tool through the upper connector 1 and the mandrel 7 of the downhole negative pressure test packer for pressurization. As the pressure increases to the shearing pressure of the shear pin 21, the shear pin 21 between the sliding sleeve 20 and the lower connector assembly is sheared off. The sliding sleeve 20 disengages from the mandrel 7 and moves downward, driving the pawl 25 and the steel sleeve 26 to move downward simultaneously within the lower connector 24. When the lower end of the pawl 25 reaches the pawl expansion portion 2401 of the lower connector 24, the end of the pawl 25 opens in the pawl expansion portion 2401, and the unlocking ball 27 continues to descend and exit the downhole negative pressure test packer. Usually, a ball catcher is installed in the tubing string below the packer in the downhole drilling tool. A flow passage is set in the ball catcher, which will not affect the circulation of fluid in the central channel of the drilling tool. Next, refer to Figure 7 and Figure 8As shown, by releasing the drill string's suspension weight and the limiting block 19, the axial upward position restriction on the mandrel 7 is released. At this time, the setting function of the packer for the drilling negative pressure test is activated. Under the action of the drill string's gravity, the mandrel 7 can drive the anti-wear sleeve 6 to press down the short rubber sleeve 10 and the two long rubber sleeves 8 for setting. After setting, the negative pressure test can be performed. Furthermore, after the negative pressure test is completed, by lifting (overlifting) the drill string, the mandrel 7 drives the anti-wear sleeve 6 upward, releasing the pressure on the short rubber sleeve 10 and the two long rubber sleeves 8, thus unsealing them.

[0129] In one specific embodiment, reference is made to Figure 2 and Figure 5 As shown, the packer for the drilling negative pressure test also includes a non-load-bearing sealing piston 18. The lower part of the mandrel 7 is provided with a second boss 704; the non-load-bearing sealing piston 18 is sleeved on the mandrel 7 and located between the stepped surface of the second boss 704 and the limiting block 19, with the outer wall of the non-load-bearing sealing piston 18 abutting against the inner wall of the positioning sleeve 17. The sealing effect achieved by the non-load-bearing sealing piston 18 prevents fluid exchange between the inside and outside of the pipe.

[0130] In an alternative embodiment, refer to Figure 2 and Figure 4 As shown, in the packer for the negative pressure test during drilling, the lower end of the extension sleeve 14 is provided with a limiting boss 1401, and correspondingly, the upper end of the torque transmission sleeve 15 is provided with a torque transmission groove 1501; the limiting boss 1401 is accommodated in the torque transmission groove 1501. Through the cooperation of the limiting boss 1401 and the torque transmission groove 1501, torque transmission between the extension sleeve 14 and the torque transmission sleeve 15 can be realized. When the mandrel 7 drives the spline sleeve 16 and the torque transmission sleeve 15 to rotate, the side wall of the torque transmission groove 1501 abuts against the limiting boss 1401, thereby realizing the transmission of force and driving the extension sleeve 14 to rotate synchronously.

[0131] In an alternative embodiment, refer to Figure 2 and Figure 4As shown, in the packer for the negative pressure test during drilling, the side wall of the support sleeve 12 is provided with an elongated slot 1201, and the upper end of the torque transmission sleeve 15 protrudes outward to form a torque transmission protrusion 1502. The torque transmission protrusion 1502 is accommodated in the elongated slot 1201, and the length of the elongated slot 1201 is greater than the length of the torque transmission protrusion 1502. Through the cooperation of the torque transmission protrusion 1502 and the elongated slot 1201, torque transmission between the support sleeve 12 and the torque transmission sleeve 15 can be realized. When the mandrel 7 drives the spline sleeve 16 and the torque transmission sleeve 15 to rotate, the torque transmission protrusion 1502 abuts against the side wall of the elongated slot 1201, thereby realizing the transmission of force and driving the support sleeve 12 to rotate synchronously, so that the support sleeve 12 can drive the guide ring 11 to rotate. Furthermore, when the setting tool is activated for the first time and the drill string is released, the mandrel 7 drives the limiting block 19, connecting sleeve 5, anti-wear sleeve 6, sealing assembly, guide ring 11, and support sleeve 12 to move axially downward a first preset distance. At this time, the torsion transmission protrusion 1502 can move relatively upward within the long slot 1201 without hindering the movement of the support sleeve 12, so that the support sleeve 12 can abut against the upper end face of the spline sleeve 16.

[0132] In this embodiment of the invention, reference is made to Figure 5 As shown, the torque transmission groove 1501 and the torque transmission protrusion 1502 are located on the inner and outer sidewalls of the upper end of the torque transmission sleeve 15, respectively.

[0133] In an alternative embodiment, refer to Figure 1 and Figure 2 As shown, in the drilling negative pressure test packer, the connecting sleeve 5 is provided with a first flow hole 502, which is located above the anti-wear sleeve 6. An annular channel 29 is formed between the connecting sleeve 5 and the mandrel 7. The position of the elongated slot 1201 of the support sleeve 12 corresponds to that of the sealing sleeve 13. A flow channel (not shown in the figure) is formed between the lower end of the connecting sleeve 5 and the upper end of the sealing sleeve 13. By setting the first flow passage 502, forming an annular channel 29 between the connecting sleeve 5 and the mandrel 7, and forming a flow passage between the connecting sleeve 5 and the sealing sleeve 13, the high-density liquid in the annulus between the casing and the drill bit can enter the tool through the long slot 1201 of the supporting sleeve 12, flow through the flow passage between the connecting sleeve 5 and the sealing sleeve 13, and the annular channel 29 between the connecting sleeve 5 and the mandrel 7 in sequence, and finally be discharged from the first flow passage 502. This allows the high-density liquid to not only move upward from the casing annulus but also move upward through the flow passage inside the tool, thereby ensuring the flow rate in the casing annulus. This reduces the negative pressure in the drill bit, thereby reducing the surface pump pressure.

[0134] In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. The terms "upper," "lower," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0135] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other. This invention is not limited to any single aspect, nor to any single embodiment, nor to any combination and / or substitution of these aspects and / or embodiments. Each aspect and / or embodiment of this invention can be used alone, or in combination with one or more other aspects and / or other embodiments.

[0136] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A negative pressure testing packer while drilling, characterized in that, The application relates to a sealing piston. The sealing piston comprises an upper joint assembly, a mandrel, a connecting sleeve, a sealing assembly, an anti-abrasion sleeve, a guide ring, a supporting sleeve, a sealing sleeve, an extending sleeve, a torque transmission sleeve, a spline sleeve, a positioning sleeve, a limiting block, a ball seat mechanism, a shear pin, a lower joint assembly; The upper joint assembly is connected with the mandrel; The connecting sleeve, the sealing sleeve, the extending sleeve, the torque transmission sleeve and the spline sleeve are sequentially sleeved on the mandrel; The connecting sleeve is connected with the mandrel through a first spline structure; The anti-abrasion sleeve, the sealing assembly and the guide ring are sequentially sleeved on the connecting sleeve, and the anti-abrasion sleeve is connected with the connecting sleeve; The spline sleeve is connected with the mandrel through a second spline structure, the sealing sleeve is connected with the extending sleeve, the torque transmission sleeve is connected with the spline sleeve, and the extending sleeve is connected with the torque transmission sleeve; The supporting sleeve is sleeved on the sealing sleeve and the extending sleeve, and the upper portion of the supporting sleeve is connected with the guide ring; The middle portion of the spline sleeve is provided with a first boss, and a first preset distance is formed between the step surface of the first boss and the bottom end of the supporting sleeve; The spline sleeve is connected with the positioning sleeve; The upper end portion of the ball seat mechanism is sealingly connected with the mandrel; The limiting block is arranged on the mandrel and is clamped between the positioning sleeve and the ball seat mechanism; The positioning sleeve is connected with the lower joint assembly; The ball seat mechanism is connected with the lower joint assembly through a shear pin; The lower end portion of the ball seat mechanism is accommodated in the lower joint assembly.

2. The under-reamed negative pressure test packer of claim 1, wherein, A plurality of limiting holes are arranged on the lower end portion of the mandrel along the outer periphery, and correspondingly, a plurality of limiting grooves are arranged on the inner wall of the positioning sleeve along the axial direction; The limiting block is accommodated in the limiting hole, and one end of the limiting block is clamped in the limiting groove, and the other end of the limiting block abuts against the ball seat mechanism.

3. The under-reamed negative pressure test packer of claim 2, wherein, The lower joint assembly comprises a short joint and a lower joint; The positioning sleeve, the short joint and the lower joint are sequentially connected; The ball seat mechanism is connected with the short joint through a shear pin; The lower portion of the ball seat mechanism is accommodated in the upper end portion of the lower joint and abuts against the inner wall of the lower joint; The inner wall of the middle portion of the lower joint is expanded to form an expansion portion, so that the ball seat mechanism is opened in the expansion portion after moving downward.

4. The under-reamed negative pressure test packer of claim 3, wherein, The ball seat mechanism comprises a sliding sleeve and a pawl; The upper end portion of the sliding sleeve extends into the mandrel and is sealingly connected with the mandrel; One end of the limiting block is clamped in the limiting groove, and the other end abuts against the sliding sleeve; The lower portion of the sliding sleeve is connected with the short joint through a shear pin; The lower end portion of the sliding sleeve is connected with the pawl, and the lower portion of the pawl is accommodated in the upper end portion of the lower joint and abuts against the inner wall of the lower joint; The inner wall of the middle portion of the lower joint is expanded to form a pawl expansion portion, so that the pawl is opened in the pawl expansion portion after moving downward.

5. The under-reamed negative pressure test packer of claim 4, wherein, The ball seat mechanism further comprises a steel sleeve, and the steel sleeve is accommodated in the pawl.

6. The under-reamed negative pressure test packer of any of claims 2-5, wherein, The application further relates to a non-load-bearing sealing piston. The lower portion of the mandrel is provided with a second boss. The non-load-bearing sealing piston is sleeved on the mandrel and located between the stepped surface of the second boss and the limiting block, and the outer wall of the non-load-bearing sealing piston abuts against the inner wall of the positioning sleeve.

7. The under-reamed negative pressure test packer of claim 1, wherein, The first spline structure comprises a short key block, a first key groove arranged on the inner wall of the connecting sleeve, and a second key groove arranged on the outer wall of the mandrel correspondingly; The short key block is engaged with the first key groove and the second key groove respectively.

8. The under-reamed negative pressure test packer of claim 1, wherein, The second spline structure comprises a spline groove arranged on the inner wall of the spline sleeve, and a spline block arranged on the outer wall of the mandrel correspondingly; The spline block is embedded in the spline groove, and the length of the spline groove is greater than the length of the spline block.

9. The under-reamed negative pressure test packer of claim 1, wherein, The upper joint assembly comprises an upper joint and an upper centralizer; The upper joint is connected with the mandrel; The upper centralizer is sleeved on the upper joint.

10. The under-reamed negative pressure test packer of claim 9, wherein, The upper centralizer is a spiral centralizer.

11. The under-reamed negative pressure test packer of claim 1, wherein, The pack-off assembly comprises a short rubber sleeve, two stop rings and two long rubber sleeves; The two long rubber sleeves are located on the upper and lower sides of the short rubber sleeve, and the two stop rings are respectively located between the short rubber sleeve and the upper long rubber sleeve and between the short rubber sleeve and the lower long rubber sleeve.

12. The under-reamed negative pressure test packer of claim 1, wherein, The lower end of the extension sleeve is provided with a limiting boss, and correspondingly, the upper end of the torque transmission sleeve is provided with a torque transmission groove; The limiting boss is accommodated in the torque transmission groove.

13. The under-reamed negative pressure test packer of claim 12, wherein, The side wall of the support sleeve is provided with a long slot hole, and the upper end of the torque transmission sleeve is outwardly protruded to form a torque transmission protruding block; The torque transmission protruding block is accommodated in the long slot hole, and the length of the long slot hole is greater than the length of the torque transmission protruding block.

14. The under-reamed negative pressure test packer of claim 13, wherein, The connecting sleeve is provided with a first flow hole above the anti-wear sleeve; The connecting sleeve and the mandrel form an annular channel therebetween; The position of the long slot hole of the support sleeve corresponds to the sealing sleeve; The lower end of the connecting sleeve and the upper end of the sealing sleeve form a flow channel therebetween.

15. The under-reamed negative pressure test packer of claim 1, wherein, The middle part of the connecting sleeve is outwardly protruded to form a first limiting step, and the inner wall of the upper end of the guide ring is inwardly protruded to form a second limiting step; The stepped surfaces between the first limiting step and the second limiting step are matched.

Images