A downhole drilling tool for drilling a well

Abstract

The utility model discloses a downhole drilling tool for drilling, relates to drilling tool technical field, including the outer body, the outer body's middle part outer peripheral surface is equipped with a plurality of guide flow grooves, and the side blade of adjacent guide flow groove is formed, and the outer body is equipped with the step hole, the valve body is embedded in the step hole, and its bottom abuts on the step surface of step hole, the first through -hole, the second through -hole, the third through -hole and the fourth through -hole are provided in the valve body, the valve seat is fixedly installed in the fourth through -hole through the connecting component, the valve seat top is equipped with the counterbore, and the flow channel for fluid flow is equipped on valve seat bottom, and the flow channel is used for connecting the third through -hole and the fourth through -hole, the valve core sets up in the counterbore, and the elastic member is equipped between the valve core and the valve seat, wherein the upper end surface of valve core is spherical sealing surface, and the inner wall of third through -hole is equipped with the ring taper sealing surface cooperation with spherical sealing surface. The above -mentioned downhole drilling tool for drilling realizes the technical effect of realizing sand cleaning and one -way non -return simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of drilling tools technology, and in particular to a downhole drilling tool for drilling. Background Technology

[0002] In oil and gas drilling, as oilfield development extends to deeper, ultra-deeper formations and complex well structures, directional wells and extended-reach horizontal wells are becoming increasingly common. However, these well types are prone to two typical downhole problems during drilling: first, cuttings particles are deposited at the lower edge of the wellbore due to gravity, forming a stable cuttings bed; second, when traversing water-sensitive or plastic formations, the wellbore is prone to narrowing or collapse. Both of these conditions lead to a significant reduction in the annulus cross-section, resulting in a series of complex situations such as stuck pipe, abnormally high pump pressure, decreased drilling fluid proppant carrying capacity, and increased drill string friction, seriously threatening drilling safety and efficiency.

[0003] Currently, two separate tools are typically used on-site to address this issue: one is to install a sand-cleaning connector to scrape the wellbore, thereby disrupting the cuttings bed and promoting sand return; the other is to install a check valve in high-pressure, blowout-prone formations to ensure that the drilling fluid can only flow downwards in one direction, preventing well kicks or blowouts caused by formation fluid backflow when the pump is stopped. Therefore, in complex well sections facing both large displacement and high-pressure risks, it is often necessary to install a sand-cleaning connector and a check valve in series.

[0004] However, downhole tools follow the basic principle that "the simpler the structure, the safer it is." Each additional tool introduces two threaded connections, which not only increases the risk of drill string breakage and derailment, but also increases the difficulty of handling downhole faults. At the same time, the additional connection operations also prolong the tripping time and reduce the efficiency of the operation.

[0005] Therefore, how to develop a new type of downhole drilling tool that integrates sand removal and one-way check function, while ensuring operational safety and achieving structural simplification and efficiency improvement, has become an urgent technical problem that needs to be solved by those skilled in the art. Utility Model Content

[0006] The purpose of this utility model is to provide a downhole drilling tool that solves the technical problems of existing downhole tools being prone to drill string breakage and disengagement, while also prolonging tripping and tripping times.

[0007] To achieve the above objectives, this utility model provides a downhole drilling tool for drilling, comprising:

[0008] The outer body has upper and lower connectors for connecting the drill string at its upper and lower ends respectively; multiple guide grooves are provided on the outer circumferential surface of the middle part of the outer body, and side cutter wings are formed between adjacent guide grooves; the outer body has a through stepped hole along the axial direction.

[0009] The valve body is fitted into the stepped hole, and its bottom abuts against the stepped surface of the stepped hole; the valve body is provided with a first through hole, a second through hole, a third through hole and a fourth through hole in sequence along the axial direction;

[0010] A valve seat is fixedly installed in the fourth through hole via a connecting assembly. The valve seat has a countersunk hole at the top and a flow channel for fluid flow at the bottom, which connects the third through hole and the fourth through hole.

[0011] A valve core is disposed in the countersunk hole, and an elastic element is provided between the valve core and the valve seat, allowing the valve core to move axially within the countersunk hole;

[0012] The diameter of the third through hole is larger than that of the second through hole. The upper end face of the valve core is a spherical sealing surface. The inner wall of the third through hole is provided with an annular cone sealing surface that mates with the spherical sealing surface. When the spherical sealing surface and the annular cone sealing surface are in contact with each other, they form a sealing pair.

[0013] Preferably, the valve body and the stepped hole are connected by an interference fit.

[0014] Preferably, the diameter of the fourth through hole is larger than the diameter of the third through hole; the valve seat includes an integrally formed first housing and a second housing, wherein the flow channel is disposed on the second housing, the countersunk hole is disposed in the first housing, and the upper end of the second housing abuts against the hole step between the third through hole and the fourth through hole.

[0015] Preferably, the connecting component includes a retaining ring, which is fitted into the fourth through hole in an interference fit manner, and the upper end of the retaining ring abuts against the bottom end of the first housing.

[0016] Preferably, the second housing has an annular groove on its middle outer circumferential surface and a blind hole at its bottom end that communicates with the fourth through hole; the flow channel includes a vertical flow channel and a radial flow channel, wherein the vertical flow channel is used to connect the third through hole and the annular groove, and the radial flow channel is used to connect the annular groove and the blind hole.

[0017] Preferably, the bottom of the valve core is a stepped shaft, which is installed in the countersunk hole. The elastic element is a compression spring, with one end of the compression spring abutting against the shoulder of the stepped shaft and the other end abutting against the bottom surface of the countersunk hole.

[0018] Preferably, the plurality of the guide grooves are evenly arranged circumferentially in the middle of the outer body.

[0019] Preferably, the surface of the side blade is provided with carbide teeth.

[0020] Preferably, the outer body, the upper connector, and the lower connector are integrally formed.

[0021] Preferably, the upper connector has a tapered threaded hole for connecting with the drill string, and the lower connector has a tapered thread on its outer periphery for connecting with the drill string.

[0022] Compared with the above-mentioned background technology, the present invention provides a downhole drilling tool that simultaneously achieves sand removal and turbulence control and one-way check flow, reduces the number of threaded connections, lowers the risk of breakage and the probability of complex failures, shortens on-site assembly time, and improves drilling efficiency. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 A front view of a downhole drilling tool for drilling provided in an embodiment of this utility model;

[0025] Figure 2 This is a schematic diagram of the downhole drilling tool with elastic element under normal conditions provided in the embodiment of this utility model;

[0026] Figure 3 This is a schematic diagram of a downhole drilling tool under the compressed state of an elastic element, as provided in an embodiment of this utility model.

[0027] Figure 4 for Figure 2 A magnified view of a portion of the image;

[0028] Figure 5 for Figure 3 A magnified view of a portion of the image.

[0029] in:

[0030] 1-Outer body, 2-Valve body, 3-Valve seat, 4-Valve core, 5-Elastic element, 6-Retaining ring;

[0031] 11-Guide groove, 12-Stepped hole, 21-First through hole, 22-Second through hole, 23-Third through hole, 24-Fourth through hole, 31-Flow channel, 32-First shell, 33-Second shell. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0033] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] See Figures 1-5 This application provides a downhole drilling tool for drilling, including an outer body 1, with upper and lower connectors for connecting the drill string at its upper and lower ends respectively; multiple guide grooves 11 are provided on the outer circumferential surface of the middle part of the outer body 1, and side blades are formed between adjacent guide grooves 11; the outer body 1 has a through stepped hole 12 along the axial direction; a valve body 2 is embedded in the stepped hole 12, and its bottom abuts against the stepped surface of the stepped hole 12; a first through hole 21, a second through hole 22, a third through hole 23 and a fourth through hole 24 are sequentially arranged in the valve body 2 along the axial direction; and a valve seat 3 is fixed by a connecting assembly. Installed in the fourth through hole 24, the valve seat 3 has a countersunk hole at the top and a flow channel 31 for fluid flow at the bottom, which connects the third through hole 23 and the fourth through hole 24; the valve core 4 is set in the countersunk hole, and an elastic element 5 is provided between the valve core 4 and the valve seat 3, allowing the valve core 4 to move axially within the countersunk hole; the diameter of the third through hole 23 is larger than the diameter of the second through hole 22, the upper end face of the valve core 4 is a spherical sealing surface, and the inner wall of the third through hole 23 is provided with an annular cone sealing surface that mates with the spherical sealing surface. When the spherical sealing surface and the annular cone sealing surface are in contact with each other, they form a sealing pair.

[0035] Specifically, the outer body 1 is a hollow cylindrical structure with standard drill string threads, i.e., upper and lower connectors, at its upper and lower ends, respectively, for connecting with the drill string to transmit torque, axial tension, and pressure. Multiple guide grooves 11 are provided on the outer circumferential surface of the middle part of the outer body 1, and side blades are formed between adjacent guide grooves 11 to disturb the annular flow field, scrape the well wall, destroy the cuttings bed, and promote sand return during rotation. The outer diameter of the outer circumferential surface of the middle part of the outer body 1 is slightly larger than the outer diameter of the two ends of the outer body 1.

[0036] The outer body 1 has a through stepped hole 12 along the axial direction. The upper through hole of the stepped hole 12 is larger than the lower through hole, thus forming a stepped surface.

[0037] The valve body 2 is a cylindrical component embedded in the stepped hole 12. Its bottom abuts against the stepped surface of the stepped hole 12 to achieve axial positioning. The valve body 2 is provided with the following through holes in sequence along the axial direction: a first through hole 21, which is the upper inlet; a second through hole 22, which is the transition section and has a smaller diameter; a third through hole 23, which is the sealing section and has a larger diameter than the second through hole 22; and a fourth through hole 24, which is the lower outlet section.

[0038] The valve seat 3 is fixedly installed in the fourth through hole 24 by a connecting assembly. The top of the valve seat 3 is provided with a countersunk hole to accommodate the valve core 4. The bottom of the valve seat 3 is provided with multiple flow channels, which connect the third through hole 23 and the fourth through hole 24 to form a drilling fluid downward channel. The valve core 4 is placed in the countersunk hole at the top of the valve seat 3 and can slide axially therein. An elastic element 5 is provided between the valve core 4 and the valve seat 3. Under normal conditions, the valve core 4 is pushed upward. The upper end face of the valve core 4 is a spherical sealing surface. The inner wall of the third through hole 23 is provided with a matching annular cone sealing surface. When the two are in contact, a reliable sealing pair is formed to block the upward flow of drilling fluid.

[0039] The workflow of a downhole drilling tool for drilling is as follows:

[0040] The hydraulic pump starts, and high-pressure drilling fluid enters the stepped hole 12 of the outer body 1 from the top of the drill string;

[0041] Drilling fluid acts on the upper surface of valve core 4 through the first through hole 21 and the second through hole 22. The hydraulic pressure overcomes the elastic force of the elastic element 5 and pushes valve core 4 downward. After valve core 4 moves downward, its spherical sealing surface disengages from the annular cone sealing surface of the third through hole 23, and the seal is released.

[0042] The drilling fluid continues to flow through the third through hole 23, flow channel 31, fourth through hole 24 and step hole 12 to the drill bit;

[0043] At the same time, the drill string rotates as a whole, causing the outer body 1 to rotate. The guide channel 11 disturbs the annular fluid, changing it from laminar flow to strong turbulence. The side blades scrape the rock cuttings bed deposited on the lower side of the well wall to prevent diameter reduction and stuck drill bit, and enhance the sand carrying capacity.

[0044] When the pump stops, the drilling fluid stops flowing downwards, the elastic element 5 returns to its original length, and pushes the valve core 4 upwards to its limit position. The spherical sealing surface of the valve core 4 fits tightly with the annular cone sealing surface of the third through hole 23 to form a sealing pair. The internal flow channel of the drill string is cut off, preventing the fluid in the well, including the formation fluid, from flowing back upwards. The upward-flowing fluid acts on the lower end of the valve core 4, superimposed with the upward thrust of the elastic element 5, making the valve core 4 press more tightly against the annular cone sealing surface. The sealing pair is further tightened to ensure absolute check flow and effectively prevent overflow, well kick, or even blowout.

[0045] The beneficial effects of the downhole drilling tool provided in this application are as follows: a single tool can simultaneously achieve sand removal and turbulence control and one-way check flow, reduce the number of threaded connections, reduce the risk of breakage and the probability of complex failures, shorten the on-site assembly time, and improve drilling efficiency.

[0046] Based on the above embodiments, the valve body 2 and the stepped hole 12 in the outer body 1 are connected by an interference fit. Specifically, the outer cylindrical surface of the valve body 2 and the inner wall of the corresponding installation section in the stepped hole 12 are designed with a preset interference. By pressing and heat fitting, the valve body 2 is firmly embedded in the stepped hole 12, and its bottom end face is tightly abutted against the step surface of the stepped hole 12 to achieve axial positioning.

[0047] Based on the above embodiments, see Figure 4 and Figure 5 The diameter of the fourth through hole 24 is larger than that of the third through hole 23; the valve seat 3 includes an integrally formed first housing 32 and a second housing 33, wherein the flow channel 31 is provided on the second housing 33, the countersunk hole is provided in the first housing 32, and the upper end of the second housing 33 abuts against the hole step between the third through hole 23 and the fourth through hole 24. The connecting component includes a retaining ring 6, which is embedded in the fourth through hole 24 in an interference fit manner, and the upper end of the retaining ring 6 abuts against the bottom end of the first housing 32.

[0048] Specifically, the diameter of the fourth through hole 24 is larger than that of the third through hole 23, forming a downward-facing inner hole step surface between them. This inner hole step surface serves as the axial positioning reference for the valve seat 3.

[0049] The valve seat 3 adopts an integral molding structure, including an upper first housing 32 and a lower second housing 33. The second housing 33 can be inserted into the fourth through hole 24 by interference fit. The two are continuously formed as an integral part along the axial direction without welding or threaded connection, ensuring structural strength and sealing reliability. The first housing 32 has a countersunk hole inside for accommodating the valve core 4. The countersunk hole matches the outer circle of the valve core 4 and provides axial sliding guidance for the valve core 4. The second housing 33 is machined with multiple flow channels 31 for connecting the third through hole 23 and the fourth through hole 24 to form a lateral flow path for drilling fluid to flow downward.

[0050] During assembly, the upper end face of the second housing 33 abuts against the inner hole step between the third through hole 23 and the fourth through hole 24, thereby achieving axial positioning of the upper part of the valve seat 3.

[0051] To further secure the valve seat 3 and prevent it from axially moving under the impact of high-pressure fluid, a connecting assembly is provided. This connecting assembly includes a retaining ring 6, which is embedded in the inner wall of the fourth through hole 24 with an interference fit. The upper end face of the retaining ring 6 abuts against the bottom end face of the first housing 32, thereby applying an upward constraint force to the valve seat 3. Together with the upper inner hole step, it clamps the valve seat 3 to achieve bidirectional axial limiting.

[0052] The retaining ring 6 can be an elastic metal ring, a C-shaped retaining ring, or an interference ring with a custom cross-section. Its outer diameter is slightly larger than the inner diameter of the fourth through hole 24. It is embedded through a press-fit process to ensure that it will not fall off during long-term service.

[0053] Based on the above embodiments, the second housing 33 has an annular groove on its middle outer peripheral surface and a blind hole at its bottom end that communicates with the fourth through hole 24; the flow channel 31 includes a vertical flow channel and a radial flow channel, wherein the vertical flow channel is used to connect the third through hole 23 and the annular groove, and the radial flow channel is used to connect the annular groove and the blind hole.

[0054] Specifically, an annular groove 34 is provided on the outer peripheral surface of the middle part of the second housing 33 to form a buffer cavity surrounding the outer wall of the second housing 33;

[0055] Meanwhile, the bottom end of the second housing 33 is provided with a blind hole 35 that communicates with the fourth through hole 24. The blind hole 35 is an axially closed cavity with only the lower end open, and its opening end communicates with the internal space of the fourth through hole 24.

[0056] Accordingly, the flow channel 31 includes a vertical flow channel, which is opened on the upper side wall of the second housing 33, for guiding the drilling fluid from the upper third through hole 23 to the annular groove 34, realizing the transition of fluid from the axial direction to the circumferential direction, and a radial flow channel 31b, which is opened on the lower side wall of the second housing 33, connecting the annular groove 34 and the blind hole 35 at the bottom, so that the fluid enters the blind hole 35 from the annular groove through the radial path, and finally flows out downward into the fourth through hole 24.

[0057] Based on the above embodiments, the bottom of the valve core 4 is a stepped shaft, which is installed in the countersunk hole. The elastic element 5 is a compression spring, with one end of the compression spring abutting the shoulder of the stepped shaft and the other end abutting the bottom surface of the countersunk hole.

[0058] Specifically, the bottom of the valve core 4 is designed as a stepped shaft structure, with the upper end of the compression spring abutting against the shoulder 41 of the stepped shaft; the lower end of the compression spring abutting against the bottom surface of the countersunk hole, i.e., the closed end of the countersunk hole of the first housing 32.

[0059] Under the preload of the compression spring, the valve core 4 is normally pushed upward to its limit position, so that the spherical sealing surface fits tightly with the annular cone sealing surface of the inner wall of the third through hole 23, achieving a reliable seal in the closed state.

[0060] Based on the above embodiments, multiple guide channels 11 are evenly arranged circumferentially in the middle of the outer body 1, and the guide channels 11 can be symmetrically arranged on the outer periphery of the middle of the outer body 1, and the surface of the side blade is provided with carbide teeth.

[0061] Specifically, multiple guide channels 11 are evenly arranged circumferentially on the outer peripheral surface of the middle part of the outer body 1, preferably 6 channels, with one channel arranged at an equal angle, to ensure the symmetry and stability of the flow field disturbance when the drill bit rotates, and to avoid the wellbore irregularity or increased tool vibration caused by eccentric scouring.

[0062] Furthermore, the guide grooves 11 are not only evenly distributed circumferentially, but can also be symmetrically arranged in the height direction (i.e., axial direction) of the outer peripheral surface of the middle part of the outer body 1. Specifically, multiple guide grooves 11 are arranged in pairs along the axial direction of the outer body 1. For example, two sets of guide grooves are symmetrically opened above and below with the cross-section of the middle part of the tool as the symmetry reference, or a single guide groove itself has a V-shaped symmetrical structure with mirror symmetry in the axial section.

[0063] In addition, each side blade is inlaid or welded with cemented carbide teeth. The cemented carbide teeth can be made of tungsten carbide and their shapes include, but are not limited to, conical teeth, ball teeth, and rectangular teeth. During the rotation of the drill string, the cemented carbide teeth actively cut into and break the compacted cuttings bed, improve sand removal efficiency, and delay the wear of the side blades, ensuring that the tool works effectively throughout the entire well section.

[0064] Based on the above embodiments, the outer body 1, the upper connector, and the lower connector are integrally formed. The upper connector has a tapered threaded hole for connecting with the drill string, and the lower connector has a tapered thread on its outer periphery for connecting with the drill string. Based on the above embodiments, in order to further improve the overall structural strength, sealing reliability and fatigue resistance, the outer body 1, the upper connector, and the lower connector adopt an integrally formed structure, that is, the three are forged from the same metal blank, such as high-strength alloy steel.

[0065] The upper connector is located at the top of the outer body 1, and its interior has a tapered threaded hole for a high-torque, high-sealing tapered thread connection with the male end of the upper drill string. The tapered surface fit can effectively transmit axial tensile force, compressive load, and rotational torque, and form a metal-to-metal sealing pair in the pre-tightened state to prevent high-pressure drilling fluid leakage.

[0066] The lower connector is located at the bottom of the outer body 1, and its outer circumference is provided with a tapered external thread for engaging with the female thread end of the drill string below, such as the drill bit connector or the lower drill collar.

[0067] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0068] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A downhole drilling tool for drilling, characterized in that, include: The outer body (1) has an upper connector and a lower connector for connecting the drill string at its upper and lower ends respectively; the outer circumferential surface of the middle part of the outer body (1) is provided with multiple guide grooves (11), and side blades are formed between adjacent guide grooves (11); the outer body (1) is provided with a through stepped hole (12) along the axial direction. The valve body (2) is fitted into the stepped hole (12), and its bottom abuts against the stepped surface of the stepped hole (12); the valve body (2) is provided with a first through hole (21), a second through hole (22), a third through hole (23) and a fourth through hole (24) in sequence along the axial direction. Valve seat (3), the valve seat (3) is fixedly installed in the fourth through hole (24) by a connecting assembly. The valve seat (3) has a countersunk hole at the top and a flow channel (31) for fluid flow at the bottom. The flow channel (31) is used to connect the third through hole (23) and the fourth through hole (24). A valve core (4) is disposed in the countersunk hole, and an elastic element (5) is provided between the valve core (4) and the valve seat (3). The valve core (4) can move axially within the countersunk hole. The diameter of the third through hole (23) is larger than that of the second through hole (22). The upper end face of the valve core (4) is a spherical sealing surface. The inner wall of the third through hole (23) is provided with an annular cone sealing surface that cooperates with the spherical sealing surface. When the spherical sealing surface and the annular cone sealing surface are in contact with each other, they form a sealing pair.

2. The downhole drilling tool for drilling according to claim 1, characterized in that, The valve body (2) and the stepped hole (12) are connected by an interference fit.

3. The downhole drilling tool for drilling according to claim 2, characterized in that, The diameter of the fourth through hole (24) is larger than that of the third through hole (23); the valve seat (3) includes an integrally formed first housing (32) and a second housing (33), wherein the flow channel (31) is provided on the second housing (33), the countersunk hole is provided in the first housing (32), and the upper end of the second housing (33) abuts against the hole step between the third through hole (23) and the fourth through hole (24).

4. The drilling tool for well drilling according to claim 3, characterized in that, The connecting component includes a retaining ring (6), which is fitted into the fourth through hole (24) in an interference fit manner, and the upper end of the retaining ring (6) abuts against the bottom end of the first housing (32).

5. The drilling tool for well drilling according to claim 4, characterized in that, The second housing (33) has an annular groove on its middle outer circumferential surface and a blind hole at its bottom end that communicates with the fourth through hole (24); the flow channel (31) includes a vertical flow channel and a radial flow channel, wherein the vertical flow channel is used to connect the third through hole (23) with the annular groove, and the radial flow channel is used to connect the annular groove with the blind hole.

6. The downhole drilling tool for drilling according to claim 1, characterized in that, The bottom of the valve core (4) is a stepped shaft, which is installed in the countersunk hole. The elastic element (5) is a compression spring, with one end of the compression spring abutting the shoulder of the stepped shaft and the other end abutting the bottom surface of the countersunk hole.

7. The drilling downhole tool according to any one of claims 1-6, characterized in that, Multiple flow channels (11) are evenly arranged circumferentially in the middle of the outer body (1).

8. The downhole drilling tool for drilling according to claim 7, characterized in that, The surface of the side blade is provided with carbide teeth.

9. The downhole drilling tool for drilling according to claim 8, characterized in that, The outer body (1) is integrally formed with the upper connector and the lower connector.

10. The downhole drilling tool for drilling according to claim 9, characterized in that, The upper connector has a tapered threaded hole for connecting with the drill string, and the lower connector has a tapered thread on its outer periphery for connecting with the drill string.

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