Well hole finding tool, well drilling device and well drilling method
By designing a wellbore eye search tool with a pivot bearing and a scraper head, the problem of the new wellbore easily being cut out when the old wellbore is shaking is solved, and efficient eye search and eye expansion is achieved, reducing construction costs.
Patent Information
- Application Number
- CN202311740292.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-18
- Publication Date
- 2025-06-20
AI Technical Summary
During the drilling process, due to formation collapse and long-term bubble invasion, it is difficult to identify the old wellbore by the impregnation cone, and it is easy to flush out new wellbores, increasing the construction difficulty and cost.
Design a wellbore eye search tool, including upper joint, lower joint, align bearing and scraper head, through align bearing, transfer rotation torque and axial pressure to the scraper head, and adjust the axis offset of the scraper head to ensure that the scraper head automatically rotates away from a higher position and explores along the low side of the wellbore.
It effectively reduces the possibility of rushing out a new wellbore, improves eye search efficiency, reduces operating costs, and achieves one-time drilling for rushing, eye searching, eye searching and eye expansion.
Smart Images
Figure CN120175239A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of wellbore reaming, and specifically relates to a wellbore eye-finding tool, a drilling device, and a drilling method. Background Art
[0002] Reaming refers to the process of ensuring the roundness of the wellbore during drilling. In the existing wellbore, in order to repair the wellbore wall and remove the debris attached to the wellbore wall to make the wellbore unobstructed, the drill string is rotated and lowered or lifted while circulating. During the construction of gas storage reservoirs of the oil and gas reservoir type, some old wells are scrapped or decommissioned due to casing damage, or serious engineering accidents such as formation collapse, well leakage, and fish falling during later construction, resulting in ineffective sealing of the reservoir or caprock of the gas storage reservoir and forming potential safety hazards. These old wells need to be reamed using wellbore flushing and reaming technology before plugging.
[0003] Currently, the main eye-finding tool for downhole open-hole wellbores is a reaming cone. Due to the long time since the old wells to be plugged, affected by formation wellbore wall collapse and landfill, and long-term soaking of downhole liquids, it is difficult for the reaming cone to identify the old wellbore during the reaming process, and it is easy to create a new wellbore. Once a new wellbore is reamed, it will greatly increase the difficulty of subsequent returning to the old wellbore and plugging, extend the construction period, and increase the operation cost. Summary of the Invention
[0004] In order to reduce the possibility of creating a new wellbore during reaming along the old wellbore, thereby improving the eye-finding efficiency and reducing the operation cost, this application proposes a wellbore eye-finding tool, a drilling device, and a drilling method.
[0005] In a first aspect, this application discloses a wellbore eye-finding tool, which includes an upper sub, a lower sub, an aligning bearing, and a scraping head;
[0006] The inner cavities of the upper sub, the lower sub, and the scraping head form a drilling fluid passage;
[0007] One end of the lower sub is connected to the upper sub, and the other end abuts against the first end face of the aligning bearing for limiting the aligning bearing;
[0008] The aligning bearing is connected to the scraping head;
[0009] The aligning bearing is used to transfer the rotational torque, axial and radial pressures of the upper sub to the scraping head, and adjust the offset angle between the axis of the upper sub and the axis of the scraping head, so that the scraping head is offset to the low side direction of the wellbore.
[0010] The tool further includes an anti-drop sleeve;
[0011] The anti - dropping sleeve is connected to the scraping head and abuts against the second end face of the self - aligning bearing, and is used for axially limiting the self - aligning bearing.
[0012] Optionally, the scraping head includes a connecting portion and a cleaning head;
[0013] The connecting portion is connected to the anti - dropping sleeve and the self - aligning bearing;
[0014] The cleaning head extends outside the lower sub, and the bottom of the outer side wall of the cleaning head is in a downward - convex arc shape.
[0015] Optionally, the cleaning head includes a plurality of cleaning claws;
[0016] The plurality of cleaning claws are evenly spaced along the circumferential direction of the cleaning head;
[0017] The cleaning claws are used to form a circular arc bottom surface so that the scraping head automatically rotates away from a higher position and probes along the lower side of the wellbore.
[0018] Optionally, each end of the cleaning claw has a cleaning tooth;
[0019] The cleaning teeth are used to scrape out mudstone cuttings during rotary drilling.
[0020] Optionally, the connecting assembly further includes a lower sub;
[0021] One end of the lower sub is connected to the upper sub, and the other end abuts against the self - aligning bearing to limit the self - aligning bearing.
[0022] Optionally, a plurality of protruding strips are provided on the outer side wall of the upper sub, and reaming teeth are provided on each protruding strip;
[0023] The reaming teeth are used to scrape and ream the wellbore wall during rotary drilling.
[0024] Optionally, the outer diameter of the protruding strip gradually decreases from top to bottom.
[0025] Optionally, the plurality of protruding strips are spirally distributed.
[0026] Optionally, drilling fluid channels are provided inside the upper sub, the lower sub and the scraping head;
[0027] The drilling fluid channels are interconnected with each other.
[0028] Optionally, the inner diameter of the drilling fluid channel in the scraping head is smaller than the inner diameters of the drilling fluid channels in the upper sub and the lower sub.
[0029] Optionally, the connecting assembly further includes a first seal and a second seal;
[0030] The first seal and the second seal are respectively located on two axial sides of the self-aligning bearing to seal the self-aligning bearing.
[0031] In a second aspect, the present application discloses a drilling device, and the device includes the wellbore eye-finding tool as described in the first aspect.
[0032] In a third aspect, the present application discloses a drilling method, which uses the wellbore eye-finding tool as described in the first aspect, and the method includes:
[0033] Lower the tool into the well;
[0034] Pump drilling fluid into the tool, and after the drilling fluid is pressurized, it sprays out from the scraping head to achieve eye flushing;
[0035] Under the action of gravity and the self-aligning bearing, the scraping head slides towards the lower side of the wellbore after scouring to achieve eye finding;
[0036] The cleaning claws scrape out impurities such as mudstone cuttings at the bottom of the wellbore to achieve hole reaming;
[0037] The protruding strip on the outside of the upper sub further enlarges the wellbore that has been reamed to achieve hole enlargement.
[0038] Based on the above technical solutions, the beneficial effects of the present application compared with the prior art are as follows:
[0039] 1. The eye-finding tool in the embodiment of the present application is suitable for the construction of finding eyes in old wellbores of oil fields. The tool uses a self-aligning bearing, and the scraping head is connected to the upper sub through the self-aligning bearing. Since the self-aligning bearing has an axis adjustment function, during use, under the action of the gravity of the drill string, the drilling fluid sprays out through the drilling fluid channel in the eye-finding tool, flushing open part of the wellbore below the drill string. The eye-finding scraping head deflects towards the lower side of the wellbore under the action of the self-aligning bearing and gravity, that is, the scraping head automatically rotates away from the higher position and advances along the lower side of the wellbore, so that the eye-finding tool always drills along the old wellbore, reducing the possibility of flushing and reaming a new wellbore, and ensuring that no wellbore is lost and no new wellbore is formed during the old wellbore eye finding; while the drill string rotates, the eye-finding tool completes the work of flushing, reaming, and finding eyes, achieving one-trip drilling for flushing eyes, finding eyes, and reaming eyes, improving the operation efficiency.
[0040] 2. In the eye-finding tool in the embodiment of the present application, the bottom of the cleaning head of the scraping head is arc-shaped, which is beneficial to reducing the resistance of the scraping head sliding towards the lowest part of the wellbore under the action of the drilling pressure and its own gravity, bringing the scraping head into the old wellbore, so that the drill string assembly always drills along the old wellbore, further reducing the possibility of flushing and reaming a new wellbore.
[0041] 3. In the eye-finding tool according to the embodiments of the present application, as the eye-finding depth increases, the spiral protruding strip on the outer part of the tool upper sub and the reaming teeth embedded thereon further trim the wellbore that has been reamed, so that the size of the found wellbore is further enlarged, smooth, and punching, eye-finding, reaming, and reaming are completed in one trip of drilling, creating conditions for the subsequent drill string assembly to pass through and subsequent construction. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Figure 1 is the overall schematic diagram in the embodiments of the present application;
[0043] Figure 2 is Figure 1 the schematic cross-sectional view along A-A in;
[0044] Figure 3 is Figure 1 the schematic cross-sectional view along B-B in;
[0045] DESCRIPTION OF THE REFERENCE NUMERALS:
[0046] 1. Upper sub; 2. Protruding strip; 21. Reaming tooth; 3. Anti-falling sleeve; 4. First seal; 5. Lower sub; 6. Alignment bearing; 7. Second seal; 8. Scraping head; 81. Connecting part; 82. Cleaning head; 83. Cleaning claw; 84. Cleaning tooth. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0047] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.
[0048] The exemplary embodiments will be described in detail herein, and examples thereof are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.
[0049] In the description of the present disclosure, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying 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 a limitation to the present disclosure. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.
[0050] In the description of the present disclosure, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood according to specific situations.
[0051] The inventor found that when reaming and scouring an old wellbore, due to the instability of the drilling pressure and the influence of various impurities in the wellbore, it is easy to dig out a new wellbore when using a tool to search for and ream the old wellbore. Once a new wellbore is reamed and scoured, it will greatly increase the difficulty of subsequent returning to the old wellbore and plugging, extend the construction period, and increase the operation cost. To solve the above problems, the inventor further developed and proposed a wellbore searching tool, a drilling device, and a drilling method.
[0052] In a first aspect, an embodiment of the present application discloses a wellbore searching tool. Referring to Figures 1-3 , the tool includes a lower sub 5, an alignment bearing 6, and a scraping head 8; the inner cavities of the upper sub 1, the lower sub 5, and the scraping head 8 form a drilling fluid passage; one end of the lower sub 5 is connected to the upper sub 1, and the other end abuts against the first end face of the alignment bearing 6 for limiting the alignment bearing 6; the alignment bearing 6 is connected to the scraping head 8; the alignment bearing 6 is used to transmit the rotational torque and axial and radial pressure of the upper sub 1 to the scraping head 8, and adjust the offset angle between the axis of the upper sub 1 and the axis of the scraping head 8, so that the scraping head 8 automatically rotates away from the higher position and deflects towards the low side direction of the wellbore.
[0053] During the use of the eye-finding tool in the embodiments of the present application, under the action of the gravity of the drill string, the drilling fluid is ejected through the drilling fluid passage in the eye-finding tool, flushing open a part of the wellbore below the drill string. The tool uses a self-aligning bearing 6, and the scraping head 8 is further connected to the upper sub 1 through the self-aligning bearing 6 and the lower sub 5. Since the self-aligning bearing 6 can adjust the offset between the axis of the scraping head 8 and the axis of the upper sub 1 within 3°, the scraping head 8 can rotate away from a higher position under the action of the drilling pressure and its own gravity and slide to the lower side of the old wellbore, so as to continue to bring the scraping head 8 into the old wellbore, so that the eye-finding tool always drills along the old wellbore, reducing the possibility of flushing and cutting a new wellbore. While the drill string rotates, the eye-finding tool completes the operations of flushing, cutting, and eye-finding, realizing one-trip drilling for flushing, eye-finding, cutting, and reaming, improving the operation efficiency and reducing the operation cost.
[0054] In an optional embodiment, referring to Figure 1 、 Figure 2 , the upper sub 1 is in the shape of a circular tube, and a plurality of circular holes with different diameters are provided on its inner side to form a drilling fluid passage. Specifically, the aperture size of the circular holes gradually decreases from the end far away from the scraping head 8 to the end close to the scraping head 8, so that the pressure of the drilling fluid increases when flowing through the upper sub 1 to improve the spraying speed of the drilling fluid.
[0055] In an optional embodiment, referring to Figure 1 , the eye-finding tool in the present application further includes an anti-falling sleeve 3. The anti-falling sleeve 3 is connected to the scraping head 8 and abuts against the second end face of the self-aligning bearing 6, so that the anti-falling sleeve 3 and the lower sub 5 jointly limit the self-aligning bearing 6 on the inner and outer sides of the self-aligning bearing 6 respectively. Specifically, the anti-falling sleeve 3 is threadedly connected to the scraping head 8.
[0056] In an optional embodiment, referring to Figure 1 , the upper part of the lower sub 5 is threadedly connected to the outer side of the upper sub 1, and the lower sub 5 is also in the shape of a circular tube. The lower end of the lower sub 5 has a step, and the step abuts against the self-aligning bearing 6 to axially limit the self-aligning bearing 6.
[0057] In an optional embodiment, referring to Figure 1 、 Figure 3 , the scraping head 8 includes a connecting portion 81 and a cleaning head 82. Among them, the connecting portion 81 is in the shape of a thin neck and extends into the lower sub 5, and the connecting portion 81 is connected to the anti-falling sleeve 3 and the self-aligning bearing 6. It should be noted that when installing the self-aligning bearing 6, first connect the connecting portion 81 of the scraping head 8, the self-aligning bearing 6 and the anti-falling sleeve 3 in sequence, then install the lower sub 5 to abut against the lower end face of the self-aligning bearing 6, and finally tighten the lower sub 5 and the upper sub 1. The self-aligning bearing 6 in the present application can adjust the offset between the axes of the upper sub 1 and the scraping head 8 by 1-3°, without affecting the transmission of torque and axial and radial pressures.
[0058] In an optional embodiment, referring toFigure 1 In the embodiment of the present application, the cleaning head 82 of the scraping head 8 extends outside the upper sub 1. The cleaning head 82 specifically includes a plurality of cleaning claws 83, and the plurality of cleaning claws 83 are evenly spaced along the circumferential direction of the cleaning head 82, thereby forming an arc-shaped wall surface, which is beneficial to reducing the resistance of the scraping head 8 sliding to the lowest part of the wellbore under the action of the drilling pressure and its own gravity, bringing the scraping head into the old wellbore, enabling the hole finding tool to always drill along the old wellbore, and reducing the possibility of punching out a new wellbore. At the same time, it is also beneficial to form a downwardly convex arc plane after each reaming, facilitating hole finding.
[0059] It should be noted that referring to Figure 1 , the bottom of the outer wall of the cleaning head 82 is in a downwardly convex arc shape. The shape of the cleaning head 82 can be spherical, or uneven ellipsoidal, or the upper part can be of other shapes and the bottom is ellipsoidal, etc., as long as its bottom is in a downwardly convex arc shape.
[0060] Specifically, referring to Figure 3 In this embodiment, the number of cleaning claws 83 is four, and each cleaning claw 83 is arc-shaped, and has the function of reaming while finding the hole. The four cleaning claws 83 respectively converge from the four surrounding directions on one side of the cleaning head 82 towards the center of the end, and enclose a small hole, which is communicated with its inner cavity for the drilling fluid to spray out. Further, there are cleaning teeth 84 at the end, and the cleaning teeth 84 are used to scrape out impurities such as mudstone cuttings at the bottom of the wellbore side. The cleaning teeth 84 can specifically be pointed cone-shaped or square cemented carbide teeth. The cleaning teeth 84 can be specifically distributed on both the inner and outer sides of the cleaning claws 83.
[0061] During the actual hole finding process, the upper sub 1 transmits the rotational torque generated by the upper drill string to the cleaning head 82 through the alignment bearing 6. When the cleaning head 82 rotates, it can break through the relatively soft bottom of the old wellbore through the cleaning teeth 84 and scrape out the mudstone cuttings and the like at the bottom of the wellbore side. Since the bottom surface of the wellbore formed by the cleaning claws 83 after each hole finding is arc-shaped, when finding the hole next time, the scraping head 8 sinks into the wellbore depression under the action of gravity, so that it advances downward along the lower edge of the old wellbore each time.
[0062] In an alternative embodiment, since the scraping head 8 is also hollow, a drilling fluid passage for the drilling fluid to flow through is also formed inside it. The drilling fluid passages inside the upper sub 1, the lower sub 5, and the scraping head 8 are interconnected. Among them, the inner diameter of the drilling fluid passage in the scraping head 8 is smaller than the inner diameters of the drilling fluid passages in the upper sub 1 and the lower sub 5. Further, it can be that the inner diameters of the drilling fluid passages in the upper sub 1, the lower sub 5, and the scraping head 8 decrease in sequence. Therefore, when the drilling fluid passes through the drilling fluid passage, the flow rate increases and it sprays out, with a strong impact force, which can wash away the floating soil in the lower wellbore, and the floating soil returns to the ground with the drilling fluid circulation.
[0063] When the wellbore is flushed by the drilling fluid, the floating soil in the old wellbore underground is easier to be flushed open than other positions. Even if a part of other positions is flushed open, they are still higher than the position of the old wellbore. Under the action of gravity and the aligning bearing 6, the scraping head 8 can deviate from the axis 1 of the upper sub 1 by 1-3° during rotation and shift to the low side direction of the wellbore.
[0064] In an alternative embodiment, referring to Figure 1 and Figure 2 , a plurality of protruding strips 2 distributed in a spiral shape are provided on the outer side wall of the upper sub 1. The thickness of the protruding strips 2 gradually decreases from top to bottom. Each protruding strip 2 is provided with reaming teeth 21 for scraping and reaming the wellbore wall. Specifically, the reaming teeth 21 are also cemented carbide teeth. In order to achieve reaming, the size of the reaming teeth 21 is slightly larger than the size of the cleaning teeth 84. Specifically, the number of the protruding strips 2 can be 5. As the depth of the wellbore finding increases, the 5 protruding strips 2 on the outside of the upper sub 1 and the cemented carbide blocks embedded on them scrape and ream the wall of the old wellbore, further expanding the old wellbore, facilitating the passage of the upper drill string and wellbore cleaning, and creating conditions for the later construction.
[0065] In an alternative embodiment, referring to Figure 1 , the connection assembly further includes an anti-drop sleeve 3. The anti-drop sleeve 3 is specifically in a cylindrical shape and is embedded between the upper sub 1 and the scraping head 8. And the inner side of the anti-drop sleeve 3 is threadedly connected to the scraping head 8. The anti-drop sleeve 3 can be made of rubber material, and by generating frictional force with the upper sub 1 and transmitting frictional force to the scraping head 8, the purpose of preventing the scraping head 8 from falling off is achieved.
[0066] In an alternative embodiment, referring to Figure 1 , the connection assembly further includes a first seal 4 and a second seal 7. The first seal 4 and the second seal 7 are respectively located on both axial sides of the aligning bearing 6 to seal the aligning bearing 6. Specifically, the first seal 4 is provided between the anti-drop sleeve 3 and the upper sub 1, and the second seal 7 is provided between the lower sub 5 and the scraping head 8. The first seal 4 and the second seal 7 can be gaskets, sealing rings or sealing rings, etc.
[0067] In the second aspect, the wellbore finding tool in the embodiments of the present application can function as a part of the drilling device. The drilling device may specifically include the wellbore finding tool of the present application, as well as an upper drill string and a power unit. The power unit provides rotational drive to drive the drill string and the wellbore finding tool to work. Specifically, a drill pipe thread is provided at the end of the upper sub 1 of the wellbore finding tool. After the tool is assembled, it is connected to the upper drill string through the upper drill pipe thread. The tool is lowered into the well together with the drill string and rotates together with the drill string. At the same time, the size of the drilling fluid passage of the wellbore finding tool is designed to be smaller than the inner diameter of the upper drill string, and the drilling fluid flows faster and jets out when passing through the wellbore finding tool.
[0068] Thirdly, when the eye-finding tool in the embodiments of the present application is actually under construction, the work of punching eyes, finding eyes, scribing eyes and reaming eyes is completed according to the following process: First, lower the eye-finding tool into the well together with the upper drill string, and start the power unit to drive the tool to rotate; then pump drilling fluid into the eye-finding tool, and after the drilling fluid is pressurized through the drilling fluid passage, it is ejected from the cleaning head 82 at a relatively high speed to wash away the floating soil in the lower wellbore. The floating soil returns to the ground with the drilling fluid circulation to achieve punching eyes; further, the scraping head 8 slides towards the low side of the scoured wellbore under the action of gravity and the centering bearing 6 to achieve eye-finding; furthermore, the cleaning claws 83 scrape out impurities such as mudstone cuttings at the bottom of the well to achieve scribing eyes and form a downwardly concave plane, so that the scraping head 8 probes downward along the low side of the old wellbore every time. Finally, as the eye-finding depth increases, the spiral protruding strip 2 outside the tool upper sub 1 and the reaming teeth 21 embedded thereon further trim the wellbore that has been scribed, so that the size of the found wellbore is further enlarged and smoothed to achieve reaming eyes, creating conditions for the subsequent drill string assembly to pass through and subsequent construction.
[0069] During the construction process of punching, scribing and finding eyes, in order to improve the accuracy of eye-finding, the eye-finding wellbore trajectory can be compared with the old well trajectory in real time through the recognition terminal to ensure that the eye-finding trajectory advances in the old wellbore. When it is found that the punching and scribing speed significantly decreases or the drilling pressure significantly increases or decreases, lift out the drill string assembly and check whether the cleaning claws 83 at the lower part of the tool, the inner cavity of the scraping head 8, the centering bearing 6 are blocked, whether the tool is broken, whether the thread slips, and whether the reaming teeth 21 on the cleaning claws 83 and the protruding strip 2 are cut off. If there are problems, pull out the drill string and replace the tool to continue eye-finding.
[0070] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for describing the above embodiments, but those of ordinary skill in the art should recognize that the various embodiments can be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the manner in which this term is covered is similar to the term "including", as "including" is interpreted as a transitional term in the claims. In addition, any term "or" used in the claims or the specification is intended to mean "non-exclusive or".
Claims
1. A wellbore eye-finding tool, characterized in that, The tool includes an upper sub (1), a lower sub (5), an aligning bearing (6), and a scraping head (8); The inner cavities of the upper sub (1), the lower sub (5), and the scraping head (8) form a drilling fluid passage; One end of the lower sub (5) is connected to the upper sub (1), and the other end abuts against the first end face of the aligning bearing (6) for limiting the aligning bearing (6); The aligning bearing (6) is connected to the scraping head (8); The aligning bearing (6) is used to transfer the rotational torque, axial and radial pressures of the upper sub (1) to the scraping head (8), and adjust the offset angle between the axis of the upper sub (1) and the axis of the scraping head (8), so that the scraping head (8) is offset to the low side direction of the wellbore.
2. The wellbore eye-finding tool according to claim 1, characterized in that, The tool further includes an anti-drop sleeve (3); The anti-drop sleeve (3) is connected to the scraping head (8) and abuts against the second end face of the aligning bearing (6) for axially limiting the aligning bearing (6).
3. The wellbore eye-finding tool according to claim 2, characterized in that, The scraping head (8) includes a connecting portion (81) and a cleaning head (82); The connecting portion (81) is connected to the anti-drop sleeve (3) and the aligning bearing (6); The cleaning head (82) extends outside the lower sub (5), and the bottom of the outer side wall of the cleaning head (82) is in a downwardly convex arc shape.
4. The wellbore eye-finding tool according to claim 3, characterized in that, The cleaning head (82) includes a plurality of cleaning claws (83); The plurality of cleaning claws (83) are evenly spaced along the circumferential direction of the cleaning head (82); The cleaning claws (83) are used to form an arc-shaped wall surface to reduce the resistance of the scraping head (8) offset to the low side direction of the wellbore.
5. The wellbore eye-finding tool according to claim 4, characterized in that, Each end of the cleaning claw (83) has a cleaning tooth (84); The cleaning tooth (84) is used to scrape out mudstone cuttings during rotary drilling.
6. The wellbore eye-finding tool according to claim 1, characterized in that, A plurality of protruding strips (2) are provided on the outer side wall of the upper sub (1), and reaming teeth (21) are provided on each protruding strip (2); During rotary drilling, the reaming teeth (21) scrape and ream the wellbore wall of the wellbore.
7. The wellbore eye-finding tool according to claim 6, characterized in that, The outer diameter of the protruding strip (2) gradually decreases from top to bottom.
8. The wellbore eye-finding tool according to claim 6 or 7, characterized in that, The plurality of protruding strips (2) are spirally distributed.
9. The wellbore eye-finding tool according to claim 1, characterized in that, The inner diameter of the drilling fluid passage in the scraping head (8) is smaller than the inner diameters of the drilling fluid passages in the upper sub (1) and the lower sub (5).
10. The wellbore eye-finding tool according to claim 1, characterized in that, The connection assembly further includes a first seal (4) and a second seal (7); The first seal (4) and the second seal (7) are respectively located on both axial sides of the aligning bearing (6) to seal the aligning bearing (6).
11. A drilling device, characterized in that, The device includes the wellbore eye-finding tool according to any one of claims 1-10.
12. A drilling method, characterized in that, Using the wellbore eye-finding tool according to any one of claims 6-10, the method includes: Lowering the tool into the well; Pumping drilling fluid into the tool, and the drilling fluid is ejected from the scraping head after being pressurized through the drilling fluid to achieve hole flushing; The scraping head slides towards the low side of the scoured wellbore under the action of gravity and the aligning bearing to achieve eye finding; The cleaning claws scrape out impurities such as mudstone cuttings at the bottom of the well to achieve hole truing; The protruding strips outside the upper sub further expand the already trued wellbore to achieve reaming.