Directional drilling tool structure, drilling system and tool face placement method

Abstract

The application provides a directional drilling tool structure, a drilling system and a tool face placement method. The tool structure comprises a stabilizer arranged at a bending point of a tool body. The stabilizer comprises a plurality of stabilizer blocks distributed in the circumferential direction of the tool body and protruding outward from the tool body. The plurality of stabilizer blocks comprise a first stabilizer block located at the bending point and facing away from the bending direction, and a second stabilizer block and a third stabilizer block located on both sides of the cross section of the tool body as a tool face. The second stabilizer block and the third stabilizer block have the same protrusion height relative to the tool body and are higher than the protrusion height of the first stabilizer block relative to the tool body. According to the technical scheme of the application, the stabilizer of the screw drill for directional drilling is designed, and the protrusion of the stabilizer block is designed in terms of structure and size, thereby increasing the contact area between the tool body and the wellbore and strengthening the stability of the center of gravity, and the stable placement of the tool face in the directional drilling process is realized.

Description

Technical Field

[0001] This invention relates to the field of directional drilling technology, and particularly to directional drilling tool structures, drilling systems, and tool face placement methods. Background Technology

[0002] Currently, the placement of the tool face during directional drilling primarily considers the reverse twist angle of the screw drill string. This means the actual drilled tool face equals the placed tool face minus the reverse twist angle of the screw drill string. During directional drilling, the tool face angle is stabilized within the design range by controlling the drilling pressure. While this method is widely used and practical in simple two-dimensional directional drilling operations such as increasing and decreasing directional angle, it does not consider the impact of factors such as the drill bit and drill string assembly structure on the tool face placement.

[0003] With the development of unconventional oil and gas resources, the "well factory" development model has made 3D directional / horizontal wells the main well type. Conventional tool face placement methods can no longer meet the needs of 3D well directional drilling. For example, in actual production, it was found that during the drilling of a target wellbore with a diameter of Φ215.9mm, when using a conventional screw drill string assembly for full azimuth directional drilling at a well inclination of 41°, the tool face could not be placed in place, forcing the drilling to be pulled out and replaced with a rotary steerable drill string assembly to drill the full azimuth directional section of the well.

[0004] The specific problems in the above-mentioned well drilling process are as follows: the tool face is not positioned properly. After moving the drill string up and down, the drill string is rotated to the preset tool face and then the drill string is lowered to the bottom of the well. Even when drilling with low drill pressure, the tool face fluctuates abnormally and jumps irregularly. It often rotates 1 to 2 times or even more. The tool face cannot be stabilized near the design value and directional drilling cannot be carried out.

[0005] Therefore, it is necessary to study a directional drilling tool structure, drilling system, and tool face placement method, and to address the problem of unstable tool face placement during directional drilling by considering factors such as drill bit and tool assembly structure. Summary of the Invention

[0006] To address the problem of unstable tool face placement in the existing technology and the resulting impact on normal directional drilling operations, this application proposes a directional drilling tool structure, drilling system, and tool face placement method.

[0007] In a first aspect, the present invention proposes a directional drilling tool structure, including a stabilizer disposed at the bending point of the drill tool body. The stabilizer includes a plurality of stabilizing blocks distributed circumferentially along the drill tool body and protruding outward from the drill tool body. The plurality of stabilizing blocks include a first stabilizing block located on the back side away from the bending direction at the bending point, and a second stabilizing block and a third stabilizing block located on both sides of the cross-section of the drill tool body as a tool face.

[0008] The second and third stabilizing blocks have the same height relative to the drill body and are greater than the height of the first stabilizing block relative to the drill body.

[0009] In one embodiment, the difference between the height of the second stabilizing block protruding relative to the drill string body and the height of the first stabilizing block protruding relative to the drill string body is 1-1.5 mm. With this embodiment, the drill string corresponding to the stabilizer is typically used in wellbores with a mainstream diameter of Φ215.9 mm. Considering the dimensions of the wellbore and the drill string itself, it is optimal for the height of the second (third) stabilizing block protruding relative to the drill string body to be 1-1.5 mm higher than the corresponding height of the first stabilizing block.

[0010] In one embodiment, the second and third stabilizing blocks are symmetrically positioned with respect to the cross-section of the drill string body as the tool face. This embodiment ensures stable contact between the drill string body and the wellbore regardless of the direction in which the drill string body is oriented.

[0011] In one embodiment, the second stabilizing block and the third stabilizing block have the same circumferential length, and the ratio between the second stabilizing block and the third stabilizing block and the first stabilizing block has the same circumferential length is (2-2.5):3.

[0012] In one embodiment, the stabilizer further includes an outer sleeve fitted at the bending point of the drill bit body, and the stabilizing block is disposed on the outer peripheral surface of the outer sleeve. In this embodiment, the stabilizing block is constructed on the outer peripheral surface of the outer sleeve, and the outer sleeve has a mounting hole at its center, the size of which matches the screw of the drill bit. Therefore, the outer sleeve can be fixedly fitted onto the screw, facilitating the overall installation of the stabilizer.

[0013] In one embodiment, the stabilizer includes at least three stabilizing blocks, and the number of the second and third stabilizing blocks in the stabilizer is the same. In this embodiment, since the stabilizing blocks on the stabilizer need to cover three locations—the back side and both sides—at the bend point of the drill body, at least three stabilizing blocks are required to ensure stability during drilling in all directions.

[0014] In one embodiment, the end of the drill bit at the end of the drill body is provided with a limiting structure, the limiting structure including a limiting protrusion protruding outward from the surface of the drill bit, the height of the limiting protrusion being less than the height of the cutting teeth at the end of the drill bit. Through this embodiment, while maximizing the overall attack capability of the drill bit, the axial attack capability of the drill bit is appropriately reduced, the lateral attack force ratio is increased, torque is controlled, the tool face is stabilized, and the build-up rate is improved.

[0015] In one embodiment, the drill bit is a PDC drill bit, and the crown of the transition portion between the end face and the side face of the drill bit has a double-arc shape. This embodiment optimizes the drill bit crown shape to a double-arc shape to improve the drill bit's directional performance.

[0016] Secondly, the present invention provides a method for arranging directional drilling tool faces, applied to the aforementioned directional drilling tool structure, comprising:

[0017] The drilling stages of directional drilling are determined, including the inclination increase stage, the inclination decrease stage, and the azimuth twist stage;

[0018] According to the drilling stage and the target drilling direction, adjust the corresponding stabilizing block in the stabilizer on the drill string body to correspond to the low side or high side of the wellbore;

[0019] Specifically, during the directional increase stage, the first stabilizing block on the drill string body is adjusted to correspond to the bottom edge of the wellbore; during the directional decrease stage, the first stabilizing block on the drill string body is adjusted to correspond to the high edge of the wellbore; during the azimuth adjustment stage, the second or third stabilizing block on the drill string body is adjusted to correspond to the bottom or high edge of the wellbore according to the target drilling direction.

[0020] Thirdly, the present invention proposes a directional drilling system, which includes the aforementioned directional drilling tool structure, and thus possesses all the technical effects it has.

[0021] The above-mentioned technical features can be combined in various suitable ways or replaced by equivalent technical features, as long as the purpose of the present invention can be achieved.

[0022] The directional drilling tool structure, drilling system, and tool face placement method provided by this invention have at least the following advantages compared with the prior art:

[0023] This invention provides a directional drilling drill string structure, drilling system, and tool face placement method. It designs a stabilizer for the screw drill string in directional drilling and designs the structure and size of the stabilizing block protrusion in the stabilizer, which increases the contact area between the drill string body and the wellbore and enhances the stability of the center of gravity, thereby achieving stable placement of the tool face during directional drilling. Attached Figure Description

[0024] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0025] Figure 1 A schematic diagram of the stabilizer in the drill bit structure of the present invention is shown.

[0026] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not to scale.

[0027] Figure label:

[0028] 1-Stabilizer, 11-First stabilizer, 12-Second stabilizer, 13-Third stabilizer, 14-Cover. Detailed Implementation

[0029] In current directional drilling technology, the tool face placement during directional drilling primarily considers the reverse twist angle of the screw drill string. That is, the actual drilled tool face equals the placed tool face minus the reverse twist angle of the screw drill string. During directional drilling, the tool face angle is stabilized within the design range by controlling the drilling pressure. While this method is widely used and practical in simple two-dimensional directional drilling operations such as increasing and decreasing azimuth, it does not consider the influence of factors such as the drill bit and drill string assembly structure on the tool face placement.

[0030] With the development of unconventional oil and gas resources, the "well factory" development model has made 3D directional / horizontal wells the main well type. Conventional tool face placement methods can no longer meet the needs of 3D well directional drilling. For example, in actual production, it was found that during the drilling of a target wellbore with a diameter of Φ215.9mm, when using a conventional screw drill string assembly for full azimuth directional drilling at a well inclination of 41°, the tool face could not be placed in place, forcing the drilling to be pulled out and replaced with a rotary steerable drill string assembly to drill the full azimuth directional section of the well.

[0031] The specific problems in the above-mentioned well drilling process are as follows: the tool face is not positioned properly. After moving the drill string up and down, the drill string is rotated to the preset tool face and then the drill string is lowered to the bottom of the well. Even when drilling with low drill pressure, the tool face fluctuates abnormally and jumps irregularly. It often rotates 1 to 2 times or even more. The tool face cannot be stabilized near the design value and directional drilling cannot be carried out.

[0032] Therefore, this invention proposes a directional drilling tool structure, drilling system, and tool face placement method to solve the above problems, and provides a detailed description in an irregular embodiment.

[0033] The invention will now be further described with reference to the accompanying drawings.

[0034] Example 1

[0035] The present invention provides a directional drilling tool structure, which includes a stabilizer 1 disposed at the bending point of the drill body. The stabilizer 1 includes a plurality of stabilizing blocks distributed circumferentially along the drill body and protruding outward from the drill body. The plurality of stabilizing blocks include a first stabilizing block 11 located on the back side away from the bending direction at the bending point, and a second stabilizing block 12 and a third stabilizing block 13 located on both sides of the cross section of the drill body that serves as the tool face.

[0036] Among them, the second stabilizing block 12 and the third stabilizing block 13 have the same height relative to the drill body and are greater than the height of the first stabilizing block 11 relative to the drill body.

[0037] Specifically, as shown in the attached diagram. Figure 1 As shown, the stabilizer 1 of the present invention mainly includes multiple protruding structures distributed circumferentially, which are multiple stabilizing blocks. The drill body of directional drilling usually has a certain angle, or adopts a screw that is bent at a certain angle, or adopts the form of adding a bent joint to a straight screw.

[0038] The first stabilizing block 11 of the stabilizer 1 is located on the back side away from the bending direction at the bending point of the drill body. Normally, there is one first stabilizing block 11. Its function is to stably contact the lower or higher side of the wellbore during directional drilling to increase or decrease the inclination, thereby stabilizing the entire drill string and stabilizing the directional tool face to ensure good directional drilling results.

[0039] The second stabilizing block 12 and the third stabilizing block 1 are located between the target cross-sections of the drill string body. The drill string body may have one second stabilizing block 12 and one third stabilizing block 13, or it may have multiple second stabilizing blocks 12 and three stabilizing blocks 13. The target cross-section corresponds to the cross-section of the tool face of the drill string body. The axis of the drill string body is located in the target cross-section, and the target cross-section divides the drill string body into two symmetrical parts. The protrusion heights of the second stabilizing block 12 and the third stabilizing block 13 relative to the drill string body are the same and greater than the protrusion height of the first stabilizing block 11 relative to the drill string body. The purpose of this arrangement is that during full-force azimuth directional drilling in the three-dimensional well section, the first stabilizing block 11 is located on the side of the wellbore and cannot effectively stabilize the drill string. Meanwhile, the second stabilizing block 12 or the third stabilizing block 13 (determined according to the direction of the torsion) located at the lower or higher edge of the wellbore is located on the side of the drill bit body. Since the contact force between the second stabilizing block 12 and the third stabilizing block 13 and the wellbore is not as strong as that between the first stabilizing block 11 located on the back of the curved section, the present invention further increases the height of the second stabilizing block 12 and the third stabilizing block 13 protruding relative to the drill bit body. This can enhance the stability of the contact between the second stabilizing block 12 or the third stabilizing block 13 and the lower or higher edge of the wellbore (increase the interaction force of the contact), thereby stabilizing the placement of the drill bit body and the tool face.

[0040] Preferably, the difference between the height of the second stabilizing block 12 protruding relative to the drill body and the height of the first stabilizing block 11 protruding relative to the drill body is 1-1.5 mm.

[0041] Specifically, the stabilizer of this invention is typically used in wellbores of the mainstream size of Φ215.9mm. Considering the dimensions of the wellbore and the drill string itself, it is optimal for the second (third) stabilizing block to protrude 1-1.5mm higher than the height of the first stabilizing block relative to the drill string body. Similarly, when applying the stabilizer of this invention to wellbores of other sizes, the aforementioned height difference can be further adjusted according to the variation in wellbore size.

[0042] Furthermore, when the stabilizer 1 of the present invention is applied to a wellbore with a mainstream diameter of Φ215.9mm, the corresponding screw of the drill string is Φ172mm, the diameter of the circle containing the outer circumference of the first stabilizing block 11 is 210mm, and the diameter of the circle containing the outer circumference of the second stabilizing block 12 (third stabilizing block 13) is 212mm. Based on this dimensional relationship, the total protrusion height of the stabilizing block relative to the outer surface of the screw can be determined.

[0043] Preferably, the distribution positions of the second stabilizing block 12 and the third stabilizing block 13 are symmetrical about the cross-section of the drill body as the tool face.

[0044] Specifically, as shown in the attached diagram. Figure 1 As shown, the distribution, shape, and size of the second stabilizing block 12 and the third stabilizing block 13 are symmetrical about the cross-section of the drill bit body as the tool face (including the case where there is one or more of the second stabilizing block 12 and the third stabilizing block 13 respectively). In this way, the drill bit body has stable contact with the wellbore regardless of which direction it is tortuous.

[0045] Furthermore, the second stabilizing block 12 and the third stabilizing block 13 have the same length extending in the circumferential direction, and the ratio between them and the length extending in the axial direction of the first stabilizing block 11 is (2-2.5):3.

[0046] Furthermore, the stabilizer 1 also includes an outer sleeve 14 fitted at the bending point of the drill body, and a stabilizing block is disposed on the outer peripheral surface of the outer sleeve 14.

[0047] Specifically, as shown in the attached diagram. Figure 1 As shown, the outer jacket 14 serves as the main body of the stabilizer 1, and the stabilizing block is constructed on the outer peripheral surface of the outer jacket 14. The outer jacket 14 has a mounting hole in the center, the size of which matches the screw of the drill bit, so that the outer jacket 14 can be fixedly fitted onto the screw, which facilitates the overall installation of the stabilizer 1.

[0048] Furthermore, the stabilizer 1 includes at least three stabilizing blocks, and the number of second stabilizing blocks 12 and third stabilizing blocks 13 in the stabilizer 1 is the same.

[0049] Specifically, as shown in the attached diagram. Figure 1As shown, the stabilizer 1 requires at least three stabilizer blocks to cover three locations: the back side and both sides of the drill bit body's bending point, ensuring stability during drilling in all directions. The number of stabilizer blocks can be increased as needed, for example, to five: one first stabilizer block 11, two second stabilizer blocks 12, and two third stabilizer blocks 13.

[0050] Example 2

[0051] The present invention provides a directional drilling tool structure, which includes a stabilizer 1 disposed at the bending point of the drill body. The stabilizer 1 includes a plurality of stabilizing blocks distributed circumferentially along the drill body and protruding outward from the drill body. The plurality of stabilizing blocks include a first stabilizing block 11 located on the back side away from the bending direction at the bending point, and a second stabilizing block 12 and a third stabilizing block 13 located on both sides of the cross section of the drill body that serves as the tool face.

[0052] Among them, the second stabilizing block 12 and the third stabilizing block 13 have the same height relative to the drill body and are greater than the height of the first stabilizing block 11 relative to the drill body.

[0053] Specifically, as shown in the attached diagram. Figure 1 As shown, the stabilizer 1 of the present invention mainly includes multiple protruding structures distributed circumferentially, which are multiple stabilizing blocks. The drill body of directional drilling usually has a certain angle, or adopts a screw that is bent at a certain angle, or adopts the form of adding a bent joint to a straight screw.

[0054] The first stabilizing block 11 of the stabilizer 1 is located on the back side away from the bending direction at the bending point of the drill body. Normally, there is one first stabilizing block 11. Its function is to stably contact the lower or higher side of the wellbore during directional drilling to increase or decrease the inclination, thereby stabilizing the entire drill string and stabilizing the directional tool face to ensure good directional drilling results.

[0055] The second stabilizing block 12 and the third stabilizing block 1 are located between the target cross-sections of the drill string body. The drill string body may have one second stabilizing block 12 and one third stabilizing block 13, or it may have multiple second stabilizing blocks 12 and three stabilizing blocks 13. The target cross-section corresponds to the cross-section of the tool face of the drill string body. The axis of the drill string body is located in the target cross-section, and the target cross-section divides the drill string body into two symmetrical parts. The protrusion heights of the second stabilizing block 12 and the third stabilizing block 13 relative to the drill string body are the same and greater than the protrusion height of the first stabilizing block 11 relative to the drill string body. The purpose of this arrangement is that during full-force azimuth directional drilling in the three-dimensional well section, the first stabilizing block 11 is located on the side of the wellbore and cannot effectively stabilize the drill string. Meanwhile, the second stabilizing block 12 or the third stabilizing block 13 (determined according to the direction of the torsion) located at the lower or higher edge of the wellbore is located on the side of the drill bit body. Since the contact force between the second stabilizing block 12 and the third stabilizing block 13 and the wellbore is not as strong as that between the first stabilizing block 11 located on the back of the curved section, the present invention further increases the height of the second stabilizing block 12 and the third stabilizing block 13 protruding relative to the drill bit body. This can enhance the stability of the contact between the second stabilizing block 12 or the third stabilizing block 13 and the lower or higher edge of the wellbore (increase the interaction force of the contact), thereby stabilizing the placement of the drill bit body and the tool face.

[0056] Preferably, the difference between the height of the second stabilizing block 12 protruding relative to the drill body and the height of the first stabilizing block 11 protruding relative to the drill body is 1-1.5 mm.

[0057] Specifically, the drill string corresponding to the stabilizer 1 of the present invention is typically applied to wellbores of the mainstream size of Φ215.9mm. Considering the size of the wellbore and the drill string itself, it is optimal for the second stabilizing block 12 (third stabilizing block 13) to protrude 1-1.5mm higher than the height corresponding to the first stabilizing block 11. Similarly, when applying the stabilizer 1 of the present invention to wellbores of other sizes, the above-mentioned height difference can be further adjusted according to the size variation of the wellbore.

[0058] Furthermore, when the stabilizer of the present invention is applied to a wellbore with a mainstream diameter of Φ215.9mm, the corresponding screw of the drill string is Φ172mm, the diameter of the circle containing the outer circumference of the first stabilizing block is 210mm, and the diameter of the circle containing the outer circumference of the second (third) stabilizing block is 212mm. Based on this dimensional relationship, the total protrusion height of the stabilizing block relative to the outer surface of the screw can be determined.

[0059] Preferably, the distribution positions of the second stabilizing block 12 and the third stabilizing block 13 are symmetrical about the cross-section of the drill body as the tool face.

[0060] Specifically, as shown in the attached diagram. Figure 1As shown, the distribution, shape, and size of the second stabilizing block 12 and the third stabilizing block 13 are symmetrical about the cross-section of the drill bit body as the tool face (including the case where there is one or more of the second stabilizing block 12 and the third stabilizing block 13 respectively). In this way, the drill bit body has stable contact with the wellbore regardless of which direction it is tortuous.

[0061] Furthermore, the second stabilizing block 12 and the third stabilizing block 13 have the same length extending in the circumferential direction, and the ratio between them and the length extending in the axial direction of the first stabilizing block 11 is (2-2.5):3.

[0062] Furthermore, the stabilizer 1 also includes an outer sleeve 14 fitted at the bending point of the drill body, and a stabilizing block is disposed on the outer peripheral surface of the outer sleeve 14.

[0063] Specifically, as shown in the attached diagram. Figure 1 As shown, the outer jacket 14 serves as the main body of the stabilizer 1, and the stabilizing block is constructed on the outer peripheral surface of the outer jacket 14. The outer jacket 14 has a mounting hole in the center, the size of which matches the screw of the drill bit, so that the outer jacket 14 can be fixedly fitted onto the screw, which facilitates the overall installation of the stabilizer 1.

[0064] Furthermore, the stabilizer 1 includes at least three stabilizing blocks, and the number of second stabilizing blocks 12 and third stabilizing blocks 13 in the stabilizer 1 is the same.

[0065] Specifically, as shown in the attached diagram. Figure 1 As shown, the stabilizer 1 requires at least three stabilizer blocks to cover three locations: the back side and both sides of the drill bit body's bending point, ensuring stability during drilling in all directions. The number of stabilizer blocks can be increased as needed, for example, to five: one first stabilizer block 11, two second stabilizer blocks 12, and two third stabilizer blocks 13.

[0066] Furthermore, the end of the drill bit (not shown in the figure) at the end of the drill body is provided with a limiting structure, which includes a limiting protrusion protruding outward from the surface of the drill bit, and the height of the limiting protrusion is less than the height of the cutting teeth at the end of the drill bit.

[0067] The drill bit uses a PDC drill bit, and the crown of the crown, which serves as the transition between the end face and the side face of the drill bit, has a double-circular arc shape.

[0068] Specifically, the drill bit is located at the end of the drill body. A limiting protrusion at the drill bit end serves as a restrictive structure to limit the depth of penetration of the cutting teeth. While maximizing the overall aggressiveness of the drill bit, this design appropriately reduces its axial aggressiveness, increases the lateral attack force ratio, controls torque, stabilizes the tool face, and improves the build-up rate. The drill bit crown shape is optimized to a double-arc design to improve its directional performance.

[0069] Furthermore, the drill bit includes a connector and a gauge. For example, a PDC drill bit used in a Φ215.9mm wellbore has a total length of 254mm, a connector length of 125mm, and a gauge length of 76.2mm.

[0070] Furthermore, the drill string body also includes a drill pipe section. In this invention, a Φ165mm non-magnetic drill collar + 1-2 Φ165mm drill collars are used in the directional drilling assembly for a Φ215.9mm wellbore to increase drill string rigidity and improve tool face stability. Simultaneously, to reduce the high wellbore friction caused by the drill collars during directional drilling, a hydraulic vibrator is added to the upper part of the drill string assembly to reduce wellbore friction, improve drilling pressure transmission efficiency, ensure constant drill bit force, and enhance tool face stability.

[0071] Example 3

[0072] Taking a target wellbore of Φ215.9mm as an example, an embodiment of the present invention provides a directional drilling tool structure, as detailed below:

[0073] Drill bit: A PDC drill bit with 6 blades and 16mm cutting teeth, which has the following characteristics:

[0074] (1) An ultra-short integrated design is adopted in terms of length, including the joint and gauge protection design, to improve the directional stability and build-up rate of the drill bit. The PDC drill bit used in a Φ215.9mm wellbore has a total length of 254mm, a joint length of 125mm, and a gauge protection length of 76.2mm. (2) The drill bit core is designed with a limiting structure to appropriately reduce the axial attack of the drill bit while ensuring the overall attack capability of the drill bit as much as possible, thereby increasing the lateral attack force ratio, controlling torque, stabilizing the tool face, and improving the build-up rate. (3) The drill bit crown shape is optimized to a double arc shape to improve the directional performance of the drill bit. (4) The drill bit force balance is optimized to improve the working stability of the drill bit. (5) The shoulder side-cutting capability is strengthened to improve the build-up capability of the drill bit.

[0075] Stabilizer: A stabilizer is installed at the bottom of the Ф172mm 1.5° screw drill bit. The outer diameter of the first stabilizing block of the stabilizer is Ф210mm, and the outer diameters of the second and third stabilizing blocks of the stabilizer are Ф212mm and the circumferential length is 140mm.

[0076] Drill string assembly: Ф215.9mm PDC drill bit + Ф172mm 1.5° screw drill string + float valve + Ф165mm non-magnetic drill collar × 1 + Ф165mm drill collar × 3 + Ф127mm heavy-duty drill pipe × 9 + Ф172mm hydraulic oscillator + Ф127mm heavy-duty drill pipe × 29 + Ф127mm drill pipe.

[0077] Using the above-mentioned screw-guided drill string assembly in a target wellbore of Φ215.9mm, azimuth directional drilling was carried out at a full twist at an inclination of about 41°. The tool face could be placed in place in 20 minutes, and the tool face remained basically stable during pressurized directional drilling. The azimuth change rate reached 7.02° / 30m, which met the wellbore trajectory design requirements.

[0078] Example 4

[0079] An embodiment of the present invention provides a method for arranging directional drilling tool faces, applied to the above-described directional drilling tool structure, comprising:

[0080] Determine the drilling stages for directional drilling, which include the inclination increase stage, the inclination decrease stage, and the azimuth change stage.

[0081] Adjust the corresponding stabilizing blocks in the stabilizers on the drill string body to align with the lower or higher edge of the wellbore, depending on the drilling stage and the target drilling direction.

[0082] Specifically, during the directional increase stage, the first stabilizing block on the drill string body is adjusted to correspond to the bottom edge of the wellbore; during the directional decrease stage, the first stabilizing block on the drill string body is adjusted to correspond to the high edge of the wellbore; and during the azimuth change stage, the second or third stabilizing block on the drill string body is adjusted to correspond to the bottom or high edge of the wellbore according to the target drilling direction.

[0083] Example 5

[0084] An embodiment of the present invention provides a directional drilling system, which includes the above-described directional drilling tool structure, and thus possesses all the technical effects thereof.

[0085] In the description of this invention, it should be understood that the terms "upper", "lower", "bottom", "top", "front", "rear", "inner", "outer", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0086] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A directional drilling tool structure, characterized in that, The device includes a stabilizer located at the bend point of the drill body. The stabilizer includes a plurality of stabilizing blocks distributed circumferentially along the drill body and protruding outward from the drill body. The plurality of stabilizing blocks include a first stabilizing block located on the back side away from the bend direction at the bend point, and a second stabilizing block and a third stabilizing block located on both sides of the cross-section of the drill body that serves as a tool face. Wherein, the second stabilizing block and the third stabilizing block protrude at the same height relative to the drill body and are greater than the height of the first stabilizing block protruding relative to the drill body; The stabilizer also includes an outer sleeve fitted at the bending point of the drill body, and the stabilizing block is disposed on the outer peripheral surface of the outer sleeve.

2. The directional drilling tool structure according to claim 1, characterized in that, The difference between the height of the second stabilizing block protruding relative to the drill body and the height of the first stabilizing block protruding relative to the drill body is 1-1.5 mm.

3. The directional drilling tool structure according to claim 1, characterized in that, The second and third stabilizing blocks are symmetrical about the cross-section of the drill body as the tool face.

4. The directional drilling tool structure according to claim 3, characterized in that, The second stabilizing block and the third stabilizing block have the same circumferential length, and the ratio between the second stabilizing block and the third stabilizing block and the first stabilizing block has the same circumferential length is (2-2.5):

3.

5. The directional drilling tool structure according to any one of claims 1 to 4, characterized in that, The stabilizer includes at least three stabilizer blocks, and the number of the second stabilizer blocks and the third stabilizer blocks in the stabilizer are the same.

6. The directional drilling tool structure according to any one of claims 1 to 4, characterized in that, The drill bit at the end of the drill body is provided with a limiting structure, which includes a limiting protrusion protruding outward from the surface of the drill bit. The height of the limiting protrusion is less than the height of the cutting teeth at the end of the drill bit.

7. The directional drilling tool structure according to claim 6, characterized in that, The drill bit is a PDC drill bit, and the crown of the crown portion, which serves as the transition between the end face and the side face of the drill bit, has a double-circular arc shape.

8. A method for arranging directional drilling tool faces, applied to the directional drilling tool structure as described in any one of claims 1 to 7, characterized in that, include: The drilling stages of directional drilling are determined, including the inclination increase stage, the inclination decrease stage, and the azimuth twist stage; According to the drilling stage and the target drilling direction, adjust the corresponding stabilizing block in the stabilizer on the drill string body to correspond to the low side or high side of the wellbore; Specifically, during the directional increase stage, the first stabilizing block on the drill string body is adjusted to correspond to the bottom edge of the wellbore; during the directional decrease stage, the first stabilizing block on the drill string body is adjusted to correspond to the high edge of the wellbore; during the azimuth adjustment stage, the second or third stabilizing block on the drill string body is adjusted to correspond to the bottom or high edge of the wellbore according to the target drilling direction.

9. A directional drilling system, characterized in that, It includes the directional drilling tool structure as described in any one of claims 1 to 7.

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