Drilling tool assembly with filtering function and drilling tool

Abstract

The utility model discloses a drilling tool assembly with a filtering function and a drilling tool, and belongs to the technical field of drilling equipment, the drilling tool assembly comprises a first connecting seat, a second connecting seat and a flexible connecting structure, and the flexible connecting structure comprises a plurality of elastic rods; the first connecting base and the second connecting base are coaxial, and the elastic rods are arranged on the outer side of the axis and distributed around the axis at intervals. The upper end of each elastic rod is fixedly connected with the lower end of the first connecting seat, and the lower end is fixedly connected with the upper end of the second connecting seat; the device further comprises an outer sleeve and an inner sleeve, an annular cavity is defined by the inner side of the outer sleeve and the outer side of the inner sleeve, and the elastic rod is arranged in the annular cavity. The drilling tool comprises a drill rod assembly, a drill bit assembly and the drilling tool assembly. The structure provided by the scheme not only is simple, but also can effectively optimize the vibration possibly generated by the drilling tool in the drilling operation process and the stability of underground slurry.

Description

Technical Field

[0001] This utility model relates to the field of drilling equipment technology, and in particular to a drilling tool assembly and drilling tool with filtering function. Background Technology

[0002] During drilling, drill bits and drill strings may encounter various unstable factors that can cause drill string vibration, thereby affecting the stability of the downhole mud. This downhole mud instability can even interfere with the wireless signal transmission of electronic equipment, preventing relevant downhole electronic equipment from effectively transmitting detection results to the surface via wireless signals. These unstable factors include abrupt changes in lithology, stick-slip phenomena, and uneven feed. Abrupt changes in lithology refer to a sudden change in the rock type and physical properties of the formation during drilling. This change may reduce the cutting efficiency of the drill bit, increase drilling difficulty, and cause drill string vibration. Stick-slip is a dynamic instability phenomenon that typically occurs under conditions of high drill bit speed and low drilling pressure. In this situation, the drill bit may experience periodic acceleration and deceleration, leading to drill string vibration. Uneven feed refers to inconsistent drill pipe advance speeds during drilling, generally caused by improper operation or other mechanical problems. This uneven feed causes the drill string to be subjected to additional stress and vibration.

[0003] To address the issue of effectively uploading relevant downhole measurement data via wireless signals during drilling, existing solutions include methods for processing wireless data, selecting suitable drill bits and drilling tools, and optimizing mud characteristics. These data processing methods generally rely on advanced monitoring and control systems, requiring advanced technology and sophisticated upgrades. Therefore, in typical drilling operations, when drill string vibration and downhole mud fluctuations significantly impact the wireless signal transmission of electronic equipment, the most efficient and timely solutions typically involve selecting suitable drill bits and drilling tools and optimizing mud characteristics. Regarding drill bits and drilling tools for this problem, the prior art discloses a technical solution with patent application number CN202321336955.5.

[0004] In response to the aforementioned issues that drill bits and drill strings may encounter various unstable factors during drilling, which may lead to drill string vibration and downhole mud fluctuations, thereby affecting the wireless signal transmission of downhole electronic equipment, it is necessary to further enrich the structural forms of drill bits and drill strings so that users can solve related problems through drill bit and drill string selection when needed. Utility Model Content

[0005] To address the issue of the aforementioned variety of drill string structures, this utility model provides a drill string assembly and drill string with filtering function. The structure provided by this solution is not only simple, but also effectively optimizes the vibration that may be generated by the drill string and the stability of the downhole mud during drilling operations.

[0006] To address the above problems, this utility model provides a drill bit assembly and drill bit with filtering function, which solves the problems through the following technical points: A drill bit assembly with filtering function includes a first connecting seat for connecting drill rod, a second connecting seat for connecting drill bit, and a flexible connecting structure for flexibly connecting the first connecting seat and the second connecting seat, wherein the flexible connecting structure includes multiple elastic rods;

[0007] The first connecting seat and the second connecting seat are coaxial, and the elastic rods are disposed outside the axis and arranged at intervals around the axis;

[0008] Each elastic rod is fixedly connected at its upper end to the lower end of the first connecting seat and at its lower end to the upper end of the second connecting seat.

[0009] It also includes an outer sleeve disposed on the outside of the elastic rod and an inner sleeve disposed on the inside of the elastic rod, the inner side of the outer sleeve and the outer side of the inner sleeve forming an annular cavity, and the elastic rod is disposed in the annular cavity;

[0010] Both the outer sleeve and the inner sleeve have one end fixed to either the first connecting seat or the second connecting seat, and the other end is slidably connected to the other, with the sliding direction of the sliding connection being parallel to the axis.

[0011] The above-mentioned drill string assembly is used as a component of the drill string. Specifically, the lower end of the drill pipe assembly on the drill string is fixedly connected to the upper end of the first connecting seat, and the upper end of the drill bit assembly on the drill string is fixedly connected to the lower end of the second connecting seat. This drill string assembly serves as a flexible connection component between the drill pipe assembly and the drill bit assembly, playing the role of flexibly connecting the drill pipe and the drill bit. When sudden changes in lithology, stick-slip phenomena, uneven drilling occur during the drilling process, the flexible connection structure plays a flexible connection role, thereby optimizing the stability of the downhole mud and ensuring that the downhole electronic equipment can effectively transmit detection results through wireless signals.

[0012] In this design, the outer sleeve and inner sleeve form an annular cavity to prevent particulate matter inside the pipe from contacting the elastic rod during drilling and affecting its normal deformation, thus ensuring the reliability of the design. The outer sleeve and inner sleeve are configured such that one end is fixedly connected to one of the two components, while the other end is slidably connected to the other. This allows the elastic rod to undergo axial compression deformation and circumferential torsional deformation during drill pipe compression and rotation. For example, if both the outer sleeve and inner sleeve are fixed to the upper end of the second connecting seat, with the outer sleeve loosely fitted outside the first connecting seat and the inner sleeve loosely fitted inside, the fixed connection allows the outer sleeve and inner sleeve to move synchronously up and down with the second connecting seat. The sliding connection allows the outer sleeve and inner sleeve to slide axially and rotate circumferentially relative to the first connecting seat as the elastic rod deforms, ensuring a flexible connection between the first and second connecting seats.

[0013] In summary, this solution suspends the drill bit at the lower end of the drill pipe using the first connecting seat, the elastic rod, and the second connecting seat. With a simple drill string assembly structure, when applied to drilling operations, the drill pipe transmits torque through the elastic rod. During torque transmission, the axial deformation of the elastic rod and the torsional deformation in the circumferential direction of the drill string achieve flexible torque transmission. When unstable factors causing drill string vibration and downhole mud fluctuations occur during drilling, the elastic rod releases or stores axial force and torque, reducing the vibration on the drill string and its impact on downhole mud fluctuations. This reduces or avoids signal distortion during wireless signal transmission by electronic devices, improving the accuracy of drilling data acquisition and the robustness of the drilling system. Furthermore, this solution is characterized by its simple, compact, reliable structure and low operating cost.

[0014] In one specific embodiment, the outer sleeve is a cylindrical structure whose lower end is fixedly connected to the second connecting seat by a connecting bolt. The lower end of the outer sleeve is provided with a stepped hole with an outer diameter larger than the inner diameter. The upper end of the second connecting seat is provided with an internal threaded hole. The connecting bolt passes through the outer sleeve through the stepped hole and forms a bolted connection with the second connecting seat through the internal threaded hole.

[0015] In the above scheme, the end of the outer sleeve used for fixed connection with the two is set as the lower end. Specifically, the lower end of the outer sleeve is fixedly connected to the upper end of the second connecting seat. In this way, for sealing the medium inside the pipe, the second sealing element set at the lower end of the outer sleeve as an axial sealing element can be a static sealing element. When dealing with the upward flowing fluid medium outside the pipe, this structure can effectively avoid severe wear caused by abrasive particles entering between the relatively moving surfaces when the outer sleeve and the second connecting seat move relative to each other. The use of stepped holes and internal threaded holes to install the connecting bolts, and the use of connecting bolts with caps embedded in the stepped holes, can effectively ensure the connection reliability of the outer sleeve and reduce the size parameters of the drill assembly. During assembly, the outer sleeve is installed after the two ends of the elastic rod are connected to the first and second connecting seats, which makes this scheme also simple to assemble.

[0016] In one specific embodiment, the inner sleeve is a cylindrical structure integrally formed at the lower end of the first connecting seat and coaxial with the first connecting seat. The lower end of the inner sleeve is inserted into the upper end of the second connecting seat, and the inner sleeve and the second connecting seat form a sliding fit relationship.

[0017] The above solution provides a specific inner sleeve structure, namely, the inner sleeve and the first connecting seat are integrally formed into a single structure. The inner sleeve moves synchronously with the first connecting seat. When the elastic rod deforms, the sliding fit relationship allows the inner sleeve to have a degree of freedom of movement relative to the second connecting seat.

[0018] In one specific embodiment, the inner sleeve is a cylindrical structure integrally formed on the upper end of the second connecting seat and coaxial with the second connecting seat. The upper end of the inner sleeve is inserted into the lower end of the first connecting seat, and the inner sleeve and the first connecting seat form a sliding fit relationship.

[0019] The above solution provides a specific inner sleeve structure, namely, the inner sleeve and the second connecting seat are integrally formed into a single structure. The inner sleeve moves synchronously with the second connecting seat. When the elastic rod deforms, the sliding fit relationship allows the inner sleeve to have a degree of freedom of movement relative to the first connecting seat.

[0020] In one specific embodiment, a first sealing element is provided between the outer sleeve and the first connecting seat, and the first sealing element serves as an axial sealing element for the gap between the outer sleeve and the first connecting seat;

[0021] A second sealing element is provided between the outer sleeve and the second connecting seat, and the second sealing element serves as an axial sealing element for the gap between the outer sleeve and the second connecting seat.

[0022] The above solution is as follows: the leakage gap between the upper end of the outer sleeve and the first connecting seat is sealed by the first sealing element, and the leakage gap between the lower end of the outer sleeve and the second connecting seat is sealed by the second sealing element, so that a fluid channel closed to the outside can be formed on the inside of the drill bit.

[0023] In one specific embodiment, of the first connecting seat and the second connecting seat, the one that forms a sliding connection with the outer sleeve is: the one that forms a clearance fit with the outer sleeve; and the axial seal between the one and the outer sleeve is a stuffing gland seal.

[0024] The above solution is as follows: Of the first connecting seat and the second connecting seat, the one used to form a sliding connection with the outer sleeve is clearance-fitted with the outer sleeve. Under the action of the axial seal of the stuffing box seal, the relative position of the outer sleeve and the connecting seat in the radial direction of the drill assembly is limited by the axial seal while achieving axial sealing. Compared with the traditional use of O-rings as axial seals, the stuffing box increases the support area between the outer sleeve and the connecting seat, thereby ensuring the coaxiality of the outer sleeve and the connecting seat and avoiding contact wear between the outer sleeve and the connecting seat.

[0025] In one specific embodiment, the inner sleeve is provided with a connecting hole, the outer opening of the connecting hole is connected to the annular cavity, the inner opening of the connecting hole is connected to the inner hole of the inner sleeve, and a filter screen is installed in the connecting hole.

[0026] In the above scheme, the connecting hole is used as a pressure equalization hole between the annular cavity and the inner side of the inner sleeve. This reduces the resistance of the medium entering and exiting the annular cavity when dealing with unstable factors, and avoids the occurrence of hydraulic buffering within the annular cavity affecting the response speed of the elastic rod to unstable factors. The filter screen is used to prevent particulate impurities from entering the annular cavity, thus avoiding the problem of hindering the normal deformation of the elastic rod.

[0027] The preferred application is to have multiple connecting holes. This enhances the pressure equalization capability inside and outside the inner sleeve by using multiple connecting holes. Compared to a single connecting hole, the smaller size of a single connecting hole is beneficial to ensuring the service life of the filter screen, provided that the total connectivity of the connecting holes is consistent.

[0028] In one specific embodiment, the connecting hole is provided on the end of the inner sleeve used for fixed connection with the first connecting seat or the second connecting seat.

[0029] In the above scheme, if the inner sleeve is connected to the second connecting seat, the connecting hole is set at the lower end of the inner sleeve. In this way, as the inner sleeve moves upward relative to the first connecting seat with the second connecting seat, even if the length of the annular cavity is compressed, the position of the connecting hole ensures that the connecting position is still located at the lower end of the annular cavity. Therefore, this scheme can effectively ensure the pressure equalization capability of the connecting hole during use.

[0030] In one specific embodiment, the elastic rod includes a helical spring and studs. Both ends of the helical spring are provided with studs coaxial with the helical spring, and the two ends of the helical spring are respectively fixedly connected to the first connecting seat and the second connecting seat through the studs.

[0031] The above solution provides a specific elastic rod structure, wherein the axial extension and torsional deformation of the elastic rod are located on the helical spring, and the studs at both ends of the elastic rod are used to connect with the first connecting seat and the second connecting seat, respectively. In practical application, it is only necessary to configure the threads on the studs at both ends of the elastic rod to be opposite in direction, and to configure the screw holes at the lower end of the first connecting seat and the upper end of the second connecting seat, respectively, to form a simple and reliable fit between the elastic rod and the first and second connecting seats.

[0032] Preferably, the elastic rods are assembled one by one between the first connecting seat and the second connecting seat. During assembly, care is taken to ensure that each elastic rod undergoes uniform elastic deformation. Preferably, to ensure the coaxiality of the first connecting seat and the second connecting seat, the elastic rods are evenly distributed in a ring relative to the axis of the drill assembly. At the same time, to protect the threads on the screw holes and studs, each stud is equipped with a lock nut. The specific method of using the lock nut is to lock the corresponding stud on the first connecting seat and the second connecting seat by using the lock nut after the elastic rod is screwed into the screw hole, so as to optimize the stress on the threads when the drill assembly is used.

[0033] In one specific embodiment, the above-mentioned drill assembly is used as a component of a drill tool, specifically: a drill tool with filtering function, including a drill pipe assembly, a drill bit assembly, and any of the above-mentioned drill tool assemblies, wherein the lower end of the drill pipe assembly is fixedly connected to the upper end of the first connecting seat, and the upper end of the drill bit assembly is fixedly connected to the lower end of the second connecting seat.

[0034] This utility model has the following beneficial effects:

[0035] In this solution, the drill bit can be suspended at the lower end of the drill pipe through the first connecting seat, the elastic rod, and the second connecting seat. With a simple drill string assembly structure, when used in drilling operations, the drill pipe transmits torque through the elastic rod. During the torque transmission process, the axial deformation of the elastic rod and the torsional deformation in the circumferential direction of the drill string achieve flexible torque transmission. When unstable factors that cause drill string vibration and downhole mud fluctuation occur during the drilling process, the axial force and torque are released or stored through the elastic rod, reducing the vibration generated on the drill string and the impact on downhole mud fluctuation. This reduces or avoids the problem of signal distortion during wireless signal transmission of electronic equipment, thereby improving the accuracy of drilling operation data acquisition and the robustness of the drilling system. At the same time, this solution also features a simple, compact, reliable, and low-cost structure. Attached Figure Description

[0036] Figure 1 This is a structural cross-sectional view of a specific embodiment of a drill bit assembly with filtering function according to the present invention;

[0037] Figure 2 for Figure 1 Enlarged view of the circled part in section A.

[0038] The markings in the diagram are as follows: 1. First connecting seat, 2. First sealing element, 3. Outer sleeve, 4. Inner sleeve, 5. Elastic rod, 6. Connecting hole, 7. Second sealing element, 8. Connecting bolt, 9. Second connecting seat. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to the embodiments, but the present invention is not limited to the following embodiments:

[0040] Example 1:

[0041] like Figure 1 and Figure 2 As shown in the provided embodiment, a drill bit assembly with filtering function includes a first connecting seat 1 for connecting drill rod, a second connecting seat 9 for connecting drill bit, and a flexible connecting structure for flexibly connecting the first connecting seat 1 and the second connecting seat 9, wherein the flexible connecting structure includes multiple elastic rods 5.

[0042] The first connecting seat 1 and the second connecting seat 9 are coaxial, and the elastic rods 5 are arranged on the outside of the axis and spaced apart around the axis;

[0043] Each elastic rod 5 has the following configuration: its upper end is fixedly connected to the lower end of the first connecting seat 1, and its lower end is fixedly connected to the upper end of the second connecting seat 9.

[0044] It also includes an outer sleeve disposed on the outside of the elastic rod 5 and an inner sleeve 4 disposed on the inside of the elastic rod 5. The inner side of the outer sleeve 3 and the outer side of the inner sleeve form an annular cavity, and the elastic rod 5 is disposed in the annular cavity.

[0045] Both the outer sleeve 3 and the inner sleeve 4 have one end fixed to either the first connecting seat 1 or the second connecting seat 9, and the other end forms a sliding connection with the other, wherein the sliding direction of the sliding connection is parallel to the axis.

[0046] The above-mentioned drill string assembly is used as a component of the drill string. Specifically, the lower end of the drill pipe assembly on the drill string is fixedly connected to the upper end of the first connecting seat 1, and the upper end of the drill bit assembly on the drill string is fixedly connected to the lower end of the second connecting seat 9. This drill string assembly serves as a flexible connection component between the drill pipe assembly and the drill bit assembly, playing the role of flexibly connecting the drill pipe and the drill bit. When the drilling process encounters situations such as sudden changes in lithology, stick-slip phenomenon, or uneven drilling feed, the flexible connection structure plays a flexible connection role, thereby optimizing the stability of the downhole mud and ensuring that the downhole electronic equipment can effectively transmit detection results through wireless signals.

[0047] In this design, the outer sleeve 3 and the inner sleeve 4 form an annular cavity to prevent particulate matter inside the pipe from contacting the elastic rod 5 during drilling and affecting its normal deformation, thus ensuring the reliability of the design. The outer sleeve 3 and the inner sleeve 4 are configured such that one end is fixedly connected to one of the two, while the other end forms a sliding connection with the other. This allows the elastic rod 5 to undergo axial compression deformation and torsional deformation around the drill pipe during compression and rotation. For example, if the outer sleeve 3 and the inner sleeve 4 are both fixed to the upper end of the second connecting seat 9, with the outer sleeve 3 loosely fitted outside the first connecting seat 1 and the inner sleeve 4 loosely fitted inside the first connecting seat 1, then the fixed connection allows the outer sleeve 3 and the inner sleeve 4 to move synchronously up and down with the second connecting seat 9. The sliding connection allows the outer sleeve 3 and the inner sleeve 4 to slide axially and rotate circumferentially relative to the first connecting seat 1 as the elastic rod 5 deforms, ensuring a flexible connection between the first connecting seat 1 and the second connecting seat 9.

[0048] In summary, this solution allows the drill bit to be suspended at the lower end of the drill pipe via the first connecting seat 1, the elastic rod 5, and the second connecting seat 9. With a simple drill string assembly structure, when used in drilling operations, the drill pipe transmits torque through the elastic rod 5. During torque transmission, the axial deformation of the elastic rod 5 and the torsional deformation in the circumferential direction of the drill string enable flexible torque transmission. When unstable factors causing drill string vibration and downhole mud fluctuations occur during the drilling process, the elastic rod 5 releases or stores axial force and torque, reducing the vibration on the drill string and its impact on downhole mud fluctuations. This reduces or avoids signal distortion during wireless signal transmission by electronic devices, improving the accuracy of drilling data acquisition and the robustness of the drilling system. Furthermore, this solution is characterized by its simple, compact, reliable structure and low operating cost.

[0049] More specifically, the outer sleeve 3 is a cylindrical structure whose lower end is fixedly connected to the second connecting seat 9 by a connecting bolt 8. The lower end of the outer sleeve 3 is provided with a stepped hole with an outer diameter larger than the inner diameter. The upper end of the second connecting seat is provided with an internal threaded hole. The connecting bolt 8 passes through the outer sleeve 3 through the stepped hole and forms a bolted connection with the second connecting seat through the internal threaded hole.

[0050] In the above scheme, the end of the outer sleeve 3 used for fixed connection with the two is set as the lower end. Specifically, the lower end of the outer sleeve 3 is fixedly connected to the upper end of the second connecting seat 9. In this way, for the sealing of the medium inside the pipe, the second sealing element 7, which is set at the lower end of the outer sleeve 3 as an axial sealing element, can be a static sealing element. When dealing with the upward flowing fluid medium outside the pipe, this structure can effectively avoid severe wear caused by abrasive particles entering between the relatively moving surfaces when the outer sleeve 3 and the second connecting seat 9 move relative to each other. The connecting bolts 8 are installed by using stepped holes and internal threaded holes, and the connecting bolts 8 with caps embedded in the stepped holes can effectively ensure the connection reliability of the outer sleeve 3 and reduce the size parameters of the drill assembly. During assembly, the outer sleeve 3 is installed after the two ends of the elastic rod 5 are connected to the first connecting seat 1 and the second connecting seat 9, which makes this scheme also simple to assemble.

[0051] More specifically, the inner sleeve 4 is an integrally formed cylindrical structure at the lower end of the first connecting seat 1 and coaxial with the first connecting seat 1. The lower end of the inner sleeve 4 is inserted into the upper end of the second connecting seat 9, and the inner sleeve 4 and the second connecting seat 9 form a sliding fit relationship.

[0052] The above solution provides a specific structural form of the inner sleeve 4, that is, the inner sleeve 4 and the first connecting seat 1 are integrally formed into a single structure. The inner sleeve 4 moves synchronously with the first connecting seat 1. When the elastic rod 5 deforms, the sliding fit relationship allows the inner sleeve 4 to have a degree of freedom of movement relative to the second connecting seat 9.

[0053] More specifically, as a parallel scheme of the inner sleeve 4 structure, the inner sleeve 4 is a cylindrical structure integrally formed on the upper end of the second connecting seat 9 and coaxial with the second connecting seat 9. The upper end of the inner sleeve 4 is inserted into the lower end of the first connecting seat 1, and the inner sleeve 4 and the first connecting seat 1 form a sliding fit relationship.

[0054] The above solution provides a specific structural form of the inner sleeve 4, that is, the inner sleeve 4 and the second connecting seat 9 are integrally formed into a single structure. The inner sleeve 4 moves synchronously with the second connecting seat 9. When the elastic rod 5 deforms, the sliding fit relationship allows the inner sleeve 4 to have a degree of freedom of movement relative to the first connecting seat 1.

[0055] More specifically, a first sealing element 2 is provided between the outer sleeve 3 and the first connecting seat 1, and the first sealing element 2 serves as an axial sealing element for the gap between the outer sleeve 3 and the first connecting seat 1;

[0056] A second sealing element 7 is provided between the outer sleeve 3 and the second connecting seat 9, and the second sealing element 7 serves as an axial sealing element for the gap between the outer sleeve 3 and the second connecting seat 9.

[0057] The above solution is as follows: the leakage gap between the upper end of the outer sleeve 3 and the first connecting seat 1 is sealed by the first sealing element 2, and the leakage gap between the lower end of the outer sleeve 3 and the second connecting seat 9 is sealed by the second sealing element 7, so that a fluid channel closed to the outside can be formed on the inside of the drill bit.

[0058] More specifically, of the first connecting seat 1 and the second connecting seat 9, the one that forms a sliding connection with the outer sleeve 3 is: the one that forms a clearance fit with the outer sleeve 3; and the axial seal between the one and the outer sleeve 3 is a stuffing gland seal.

[0059] The above solution is as follows: of the first connecting seat 1 and the second connecting seat 9, the one used to form a sliding connection with the outer sleeve 3 is clearance-fitted with the outer sleeve 3, and under the action of the axial seal of the stuffing box seal, the relative position of the outer sleeve 3 and the other one in the radial direction of the drill assembly is limited by the axial seal while achieving axial sealing. Compared with the traditional use of O-rings as axial seals, the stuffing box increases the support area between the outer sleeve 3 and the other one, so as to ensure the coaxiality of the outer sleeve 3 and the other one and avoid contact wear between the outer sleeve 3 and the other one.

[0060] More specifically, the inner sleeve 4 is provided with a connecting hole 6, the outer opening of the connecting hole 6 is connected to the annular cavity, the inner opening of the connecting hole 6 is connected to the inner hole of the inner sleeve 4, and a filter screen is installed in the connecting hole 6.

[0061] In the above scheme, the connecting hole 6 is used as a pressure equalization hole between the annular cavity and the inner sleeve 4. This reduces the resistance of the medium entering and exiting the annular cavity when dealing with unstable factors, and avoids the occurrence of hydraulic buffering within the annular cavity affecting the response speed of the elastic rod 5 to unstable factors. The filter screen is used to prevent particulate impurities from entering the annular cavity, thus avoiding the problem of hindering the normal deformation of the elastic rod 5.

[0062] The preferred application is to have multiple connecting holes 6. This way, multiple connecting holes 6 can enhance the pressure equalization capability inside and outside the inner sleeve 4. Compared to a single connecting hole 6, the smaller size of a single connecting hole 6 is beneficial to ensuring the service life of the filter screen, provided that the total connectivity of the connecting holes 6 is consistent.

[0063] More specifically, the connecting hole 6 is provided on one end of the inner sleeve 4 for fixed connection with the first connecting seat 1 or the second connecting seat 9.

[0064] In the above scheme, if the inner sleeve 4 is connected to the second connecting seat 9, the connecting hole 6 is set at the lower end of the inner sleeve 4. In this way, as the inner sleeve 4 moves upward relative to the first connecting seat 1 with the second connecting seat 9, even if the length of the annular cavity is compressed, the position of the connecting hole 6 ensures that the connecting position is still located at the lower end of the annular cavity. Therefore, this scheme can effectively ensure the pressure equalization capability of the connecting hole 6 during use.

[0065] More specifically, the elastic rod 5 includes a helical spring and studs. Both ends of the helical spring are provided with studs coaxial with the helical spring. The two ends of the helical spring are respectively fixedly connected to the first connecting seat 1 and the second connecting seat 9 through the studs.

[0066] The above solution provides a specific structural form of the elastic rod 5, namely, the position on the elastic rod 5 where axial extension and torsional deformation occur is located on the helical spring, and the structures at both ends of the elastic rod 5 for connecting with the first connecting seat 1 and the second connecting seat 9 are the studs. In specific applications, it is only necessary to configure the threads on the studs at both ends of the elastic rod 5 to be opposite in direction, and to configure the screw holes at the lower end of the first connecting seat 1 and the upper end of the second connecting seat 9, respectively, to form a simple and reliable mating relationship between the elastic rod 5 and the first connecting seat 1 and the second connecting seat 9.

[0067] Preferably, the elastic rods 5 are assembled one by one between the first connecting seat 1 and the second connecting seat 9. During assembly, care should be taken to ensure that each elastic rod 5 undergoes uniform elastic deformation. Preferably, to ensure the coaxiality of the first connecting seat 1 and the second connecting seat 9, the elastic rods 5 are evenly distributed in a ring relative to the axis of the drill assembly. At the same time, to protect the threads on the screw holes and studs, each stud is equipped with a locking nut. The specific method of using the locking nut is to lock the corresponding stud on the first connecting seat 1 and the second connecting seat 9 by locking the elastic rod 5 into the screw hole after it is screwed in, so as to optimize the stress on the threads when the drill assembly is used.

[0068] As a specific application, the above-mentioned drill assembly is used as a component of a drill tool, specifically: a drill tool with filtering function, including a drill pipe assembly, a drill bit assembly, and any of the above-mentioned drill tool assemblies, wherein the lower end of the drill pipe assembly is fixedly connected to the upper end of the first connecting seat 1, and the upper end of the drill bit assembly is fixedly connected to the lower end of the second connecting seat 9.

[0069] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific embodiments of the present invention are limited to these descriptions. For those skilled in the art, other embodiments derived without departing from the technical solution of the present invention should be included within the protection scope of the present invention.

Claims

1. A drilling assembly with filtering function, comprising a first connecting seat (1) for connecting a drill pipe, a second connecting seat (9) for connecting a drill bit, and a flexible connecting structure for achieving flexible connection between the first connecting seat (1) and the second connecting seat (9), characterized in that, The flexible connecting structure comprises a plurality of elastic rods (5); The first connecting seat (1) and the second connecting seat (9) are coaxial, and the elastic rods (5) are arranged outside the axis and are spaced around the axis; Each elastic rod (5) is fixedly connected at the upper end to the lower end of the first connecting seat (1) and fixedly connected at the lower end to the upper end of the second connecting seat (9); Further comprising an outer sleeve (3) arranged outside the elastic rods (5) and an inner sleeve (4) arranged inside the elastic rods (5), the inner side of the outer sleeve (3) and the outer side of the inner sleeve (4) form an annular cavity, and the elastic rods (5) are arranged in the annular cavity; The outer sleeve (3) and the inner sleeve (4) are both fixed at one end to either one of the first connecting seat (1) and the second connecting seat (9) and are in sliding connection with the other one at the other end, and the sliding direction of the sliding connection is parallel to the axis.

2. A drill tool assembly having a filter function according to claim 1, characterized in that, The outer sleeve (3) is a cylindrical structure fixedly connected at the lower end to the second connecting seat (9) through a connecting bolt (8), the lower end of the outer sleeve (3) is provided with a stepped hole with an outer end diameter larger than an inner end diameter, the upper end of the second connecting seat (9) is provided with an inner threaded hole, the connecting bolt (8) passes through the outer sleeve (3) through the stepped hole and forms a bolt connection with the second connecting seat (9) through the inner threaded hole.

3. A drill tool assembly having a filter function according to claim 1, wherein, The inner sleeve (4) is a cylindrical structure integrally formed at the lower end of the first connecting seat (1) and coaxial with the first connecting seat (1), the lower end of the inner sleeve (4) is inserted into the upper end of the second connecting seat (9), and the inner sleeve (4) is in sliding fit with the second connecting seat (9).

4. The drill tool assembly of claim 1, wherein, The inner sleeve (4) is a cylindrical structure integrally formed at the upper end of the second connecting seat (9) and coaxial with the second connecting seat (9), the upper end of the inner sleeve (4) is inserted into the lower end of the first connecting seat (1), and the inner sleeve (4) is in sliding fit with the first connecting seat (1).

5. The drill tool assembly of claim 1, wherein, A first sealing member (2) is arranged between the outer sleeve (3) and the first connecting seat (1), and the first sealing member (2) is an axial sealing member for the gap between the outer sleeve (3) and the first connecting seat (1); A second sealing member (7) is arranged between the outer sleeve (3) and the second connecting seat (9), and the second sealing member (7) is an axial sealing member for the gap between the outer sleeve (3) and the second connecting seat (9).

6. A drill tool assembly having a filter function according to claim 5, wherein, Among the first connecting seat (1) and the second connecting seat (9), the one in sliding connection with the outer sleeve (3) is in gap fit with the outer sleeve (3), and the axial sealing member between the one and the outer sleeve (3) is a packing gland sealing member.

7. A drill tool assembly having a filter function according to any one of claims 1 to 6, characterized in that, A communication hole (6) is arranged on the inner sleeve (4), the hole opening outside the communication hole (6) is connected to the annular cavity, the hole opening inside the communication hole (6) is connected to the inner hole of the inner sleeve (4), and a filter screen is installed in the communication hole (6).

8. A drill tool assembly having a filter function according to claim 7, characterized in that, The communication hole (6) is arranged on the end of the inner sleeve (4) for fixed connection with the first connecting seat (1) or the second connecting seat (9).

9. A drill tool assembly having a filter function according to any one of claims 1 to 6, characterized in that, The elastic rod (5) comprises a coil spring and studs, both ends of the coil spring are provided with the studs coaxial with the coil spring, and both ends of the coil spring are fixedly connected with the first connecting seat (1) and the second connecting seat (9) through the studs.

10. A drilling tool having a filtering function, comprising a drill pipe assembly, a drill bit assembly, characterized in that, The drill tool assembly also comprises the drill rod assembly, the lower end of the drill rod assembly is fixedly connected with the upper end of the first connecting seat (1), and the upper end of the drill bit assembly is fixedly connected with the lower end of the second connecting seat (9).

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