Rotary guiding short section and well drilling control method

Abstract

The invention discloses a rotary guiding short section and a well drilling control method, and solves the technical problems that an existing rotary guiding system is single in function, and vertical well drilling and vertical well deflecting need multiple times of drilling. The rotary guiding short section comprises a short section main body used for being connected with drilling equipment; the pushing assembly is arranged on the nipple main body and is used for controlling the drilling direction; the acceleration sensing and measuring assembly is arranged on the nipple main body and is used for measuring well deviation and a gravity tool surface of the drilling equipment; the fluxgate sensing measurement assembly is arranged on the nipple main body and is used for measuring well deviation and a magnetic tool surface of drilling equipment; and the transmission control assembly is arranged on the nipple main body. According to the drilling equipment, the functions of vertical drilling, vertical well deflecting and directional drilling can be achieved at the same time, function switching can be conducted automatically, the functions of vertical drilling, vertical well deflecting and one-time drilling of a three-dimensional directional well are achieved, the number of times of tripping of the drilling equipment is reduced, and therefore the drilling time efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of oil drilling technology, specifically relating to a rotary steering sub and a drilling control method. Background Technology

[0002] Rotary steering systems are an advanced drilling guidance technology that can control the wellbore trajectory while the drill string rotates continuously. Compared with traditional sliding steering methods (such as curved housing motors), rotary steering systems have significant advantages in efficiency, accuracy, and wellbore quality. They are widely used in complex operations such as modern directional drilling, horizontal wells, and extended reach wells. Vertical drilling and vertical well deflection are typical application scenarios for rotary steering systems.

[0003] During vertical drilling operations, the well inclination angle must always be kept within 1°. During vertical well directional drilling operations, the wellbore trajectory must be directional from the vertical state according to the predetermined azimuth angle. If the directional angle does not meet expectations, the wellbore trajectory needs to be continuously corrected until the trajectory reaches the predetermined azimuth and well inclination.

[0004] However, existing drilling equipment typically requires separate trips for both vertical drilling and directional drilling. This is mainly because existing directional drilling, vertical drilling, and directional drilling tools have limited functionality and structural design, and cannot support single-trip drilling for directional drilling, vertical drilling, and three-dimensional directional drilling. In addition, existing rotary steering systems are mainly designed for a single mode (such as vertical drilling only or directional drilling only) and lack dynamic switching capabilities, which need to be improved. Summary of the Invention

[0005] To address all or part of the aforementioned problems, the present invention aims to provide a rotary guide sub and a drilling control method that can simultaneously perform vertical drilling, vertical well directional drilling, and directional drilling, and can autonomously switch between functions. It has the functions of vertical drilling, vertical well directional drilling, and three-dimensional directional drilling in one trip, reducing the number of trips of drilling equipment and thus improving drilling efficiency.

[0006] In a first aspect, the present invention provides a rotary guide sub, comprising: The short section body is used for connection to drilling equipment; The push-assist assembly is mounted on the short section body and is used to control the drilling direction; An acceleration sensing and measurement assembly is mounted on the main body of the short section and is used to measure the well inclination and gravity tool face of the rotary guide short section; A fluxgate sensor measurement assembly is mounted on the main body of the short section and is used to measure the well inclination and magnetic tool face of the rotary guide short section; The transmission control assembly is located on the main body of the short section.

[0007] Optionally, the push assembly includes a first pusher, a second pusher, and a third pusher, and the first pusher, the second pusher, and the third pusher are arranged at 120° intervals along the circumferential direction of the short section body.

[0008] Optionally, the acceleration sensing and measurement assembly includes a triaxial accelerometer and a first signal processing circuit. The triaxial accelerometer is used to measure the well inclination and gravity tool face of the rotary guide section, and the first signal processing circuit is connected to the transmission control assembly.

[0009] Optionally, the fluxgate sensing and measurement assembly includes a three-axis fluxgate sensor and a second signal processing circuit. The three-axis fluxgate sensor is used to measure the well inclination and magnetic tool face of the rotary guide sub. The second signal processing circuit is connected to the transmission control assembly.

[0010] Optionally, the triaxial accelerometer and the triaxial fluxgate sensor are arranged in a staggered manner along the circumference of the short section body.

[0011] Secondly, the present invention provides a drilling control method using a rotary steering sub, comprising the following steps: S1 connects the rotary guide sub to the drilling equipment; S2 controls the drilling equipment to be lowered into the wellbore; S3 controls the drilling equipment to perform vertical drilling operations or directional drilling operations.

[0012] Optionally, in S3, if vertical drilling operations are required: The external control system sends corresponding command information to the transmission control assembly, and the transmission control assembly sets the guide angle of the rotary guide segment to 180°. When the rotary guide segment forms an arbitrary well inclination angle, acceleration components will be generated in the X and Y directions of the rotary guide segment. The acceleration sensing and measurement assembly can then measure the gravity tool face. At this time, the transmission control assembly controls the push assembly to generate a 180° vector resultant force, adjusting the drilling trajectory towards a vertical state to ensure that the drilling equipment drills vertically.

[0013] Optionally, in S3, if a vertical well drilling operation is required: The external control system sends corresponding command information to the transmission control assembly, and the transmission control assembly sets the guide angle of the rotary guide segment to a preset value A0. At the same time, it determines the well inclination θ of the rotary guide segment and measures the orientation information of the rotary guide segment according to the acceleration sensor measurement assembly or the fluxgate sensor measurement assembly. It then coordinates with the push assembly to control the drilling direction to ensure that the drilling equipment drills along the preset trajectory.

[0014] Optionally, if the well inclination θ of the rotary guide sub is ≥1°, the gravity tool face is measured by the acceleration sensor measurement assembly, and the drilling direction is controlled by the push assembly to ensure that the drilling equipment drills along the preset trajectory.

[0015] Optionally, if the well inclination θ of the rotary guide sub is less than 1°, the magnetic tool face is measured by the fluxgate sensor assembly, and the drilling direction is controlled by the push assembly to ensure that the drilling equipment drills along the preset trajectory. Once the wellbore inclination of the rotary guide section reaches the set threshold, the system switches to the acceleration sensor measurement assembly to measure the gravity tool face, and then enters the three-dimensional trajectory control mode.

[0016] As can be seen from the above technical solution, the rotary guide sub and drilling control method provided by the present invention have the following advantages: This rotary steering sub and drilling control method can simultaneously realize vertical drilling, vertical well directional drilling and directional drilling functions, and can autonomously switch functions. It has the function of drilling vertical drilling, vertical well directional drilling and three-dimensional directional well in one trip, reducing the number of trips of drilling equipment and thus improving drilling efficiency.

[0017] Other features and advantages of the present invention will be set forth in the following description. Attached Figure Description

[0018] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

[0019] Figure 1 This is a schematic diagram of the overall structure of the rotary guide section in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the push-in assembly in Embodiment 1 of the present invention; Figure 3 This is a cross-sectional view of the rotary guide section in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the guiding force control principle in Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the guiding force control principle in Embodiment 1 of the present invention; Figure 6 This is a flowchart of the drilling control method in Embodiment 2 of the present invention; Figure 7 This is a schematic diagram of the vertical tilting measurement principle in Embodiment 2 of the present invention.

[0020] Explanation of reference numerals in the attached figures: 1. Short section main body; 2. Push-back assembly; 21. First push-back device; 22. Second push-back device; 23. Third push-back device; 3. Acceleration sensing and measurement assembly; 31. Three-axis accelerometer sensor; 32. First signal processing circuit; 4. Fluxgate sensing and measurement assembly; 41. Three-axis fluxgate sensor; 42. Second signal processing circuit. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be arbitrarily combined with each other.

[0022] Example 1 like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 The figure shown is Embodiment 1 of the present invention. This embodiment discloses a rotary guide sub, including a sub body 1, a push assembly 2, an acceleration sensing and measurement assembly 3, a fluxgate sensing and measurement assembly 4, and a transmission control assembly. The sub body 1 is used to connect with drilling equipment, and the push assembly 2 is disposed on the sub body 1 and used to control the drilling direction.

[0023] Accelerometer sensor assembly 3 and fluxgate sensor assembly 4 are respectively mounted on the main body 1 of the short section. Accelerometer sensor assembly 3 is used to measure the well inclination and gravity tool face of the drilling equipment, and fluxgate sensor assembly 4 is used to measure the well inclination and magnetic tool face of the drilling equipment.

[0024] The transmission control assembly is located inside the main body 1 of the short section (not shown in the figure). The transmission control assembly is connected to the push assembly 2, the acceleration sensing and measurement assembly 3 and the fluxgate sensing and measurement assembly 4 respectively. At the same time, the transmission control assembly is wirelessly connected to the external control system or connected via cable.

[0025] In this embodiment, the transmission control assembly is used to transmit the measurement information of the acceleration sensing and measurement assembly 3 and the fluxgate sensing and measurement assembly 4 to the external control system. At the same time, the transmission control assembly can also receive the instruction information issued by the external control system and control the push assembly 2 to perform push and retract leg actions.

[0026] In one embodiment, such as Figure 1 , Figure 2 As shown, the push assembly 2 includes a first pusher 21, a second pusher 22 and a third pusher 23, and the first pusher 21, the second pusher 22 and the third pusher 23 are arranged at 120° intervals along the circumferential direction of the short section body 1.

[0027] In one embodiment, such as Figure 1 As shown, the acceleration sensing and measurement assembly 3 includes a triaxial acceleration sensor 31 and a first signal processing circuit 32. The triaxial acceleration sensor 31 is used to measure the well inclination and gravity tool face of the drilling equipment, and the first signal processing circuit 32 is connected to the transmission control assembly.

[0028] In one embodiment, such as Figure 1 As shown, the fluxgate sensing and measurement assembly 4 includes a three-axis fluxgate sensor 41 and a second signal processing circuit 42. The three-axis fluxgate sensor 41 is used to measure the well inclination and magnetic tool face of the drilling equipment, and the second signal processing circuit 42 is connected to the transmission control assembly.

[0029] In one embodiment, such as Figure 1 , Figure 3 As shown, the triaxial accelerometer 31 and the triaxial fluxgate sensor 41 are arranged in a staggered manner along the circumference of the short section body 1, that is, the triaxial accelerometer 31 and the triaxial fluxgate sensor 41 form a fixed included angle.

[0030] In this embodiment, the first pusher 21, the second pusher 22, and the third pusher 23 are all hydraulic pushers, meaning that the extension and retraction of the pusher arms are controlled hydraulically. The transmission control assembly includes a transmission module, a receiving module, and a control module. The control module can control the extension and retraction of the pusher arms of the first pusher 21, the second pusher 22, and the third pusher 23. The receiving module is used to receive instruction information from an external control system, and the transmission module is used to transmit information. This is prior art and will not be described in detail here.

[0031] like Figure 4 , Figure 5 The diagram illustrates the guiding force control principle of the rotary guide section, where: X-tool high edge axis: The guide sleeve reference axis determined by the centerline axis of the tool and the centerline position of the first pusher 21, used to indicate the deflection angle of the guide sleeve; P-gravity high-side axis: The axis in the opposite direction of the vertical gravity direction, a fixed coordinate axis that does not rotate with the guide sleeve; α-Tool height angle: The angle between the tool height axis and the gravity height axis (-g direction), measured by the near-bit inertial module; β tool guide angle: the deflection angle of the resultant force vector relative to the tool's high-side axis; θ-guide angle: The deflection angle of the guide force vector relative to the gravity high side axis (-g direction).

[0032] It is important to note that, Figure 5 In the diagram, P1 refers to the direction of the first pusher, P2 refers to the direction of the second pusher, P3 refers to the direction of the second pusher, and rib #1 refers to the first pusher.

[0033] In this embodiment, the triaxial accelerometer 31 can simultaneously detect X, Y, and Z-axis accelerations for real-time measurement of the wellbore inclination and gravity tool face of the rotating guide sub. The gravity tool face refers to the area with the direction of gravity as a reference. Generally, the triaxial accelerometer 31 determines the wellbore inclination and gravity tool face by measuring the component distribution of gravitational acceleration in the drill string coordinate system. In a static state, the triaxial accelerometer 31 calculates the wellbore inclination angle by detecting the angle between the gravity direction and the drill string axis, while the gravity tool face is determined by the projection direction of gravity onto the transverse plane of the drill string.

[0034] The coordinate system (X, Y, Z) of the triaxial accelerometer 31 is bound to the drill string, wherein: Z-axis: Along the drill string axis (pointing towards the drill bit); X and Y axes: perpendicular to the Z axis and orthogonal to each other (usually the X axis points to the tool face reference direction).

[0035] In this embodiment, the principle of the triaxial fluxgate sensor 41 in measuring the wellbore inclination and magnetic tool face of the rotary guide sub is mainly based on the detection of the geomagnetic field direction. The triaxial fluxgate sensor 41 uses a high-sensitivity magnetic core material, which can accurately sense the distribution of the geomagnetic field in the drill string coordinate system. When the drill string tilts, the components of the geomagnetic field on each axis of the sensor will change. By analyzing the relative magnitude and direction relationship of these magnetic field components, the tilt angle of the drill string (wellbore inclination) and the azimuth angle of the tool face relative to magnetic north (magnetic tool face) can be determined.

[0036] In this embodiment, when drilling vertically, the wellbore trajectory is required to be as vertical as possible, and the well deviation is usually required to be less than 1°. At this time, a triaxial accelerometer 31 can be used to measure the well deviation of the rotary guide sub and the real-time gravity tool face in real time. The resultant direction of the guide force is set to 180°. No matter which direction the rotary guide is skewed from, the set 180° gravity tool face angle can always keep the rotary guide in a declination state, that is, always adjust and approach the vertical state.

[0037] In this embodiment, when creating an directional borehole, the rotary guide sub is required to create the directional borehole in a specified orientation. The accelerometer can only acquire the borehole inclination and gravity tool face, but cannot acquire the orientation information. The azimuth angle of the directional borehole is uncertain, making it impossible to create the directional borehole in a specific orientation. Therefore, the triaxial fluxgate sensor 41 is used to measure the borehole inclination and magnetic tool face of the rotary guide sub to obtain the orientation information of the drill string, ensuring that the drill string can create the directional borehole in a specific orientation.

[0038] Example 2 like Figure 6 , Figure 7 The following is an embodiment 2 of the present invention, which discloses a drilling control method using the rotary guide sub from embodiment 1. The drilling control method includes the following steps: S1 connects the rotary guide sub to the drilling equipment; S2 controls the drilling equipment to be lowered into the wellbore; S3 controls the drilling equipment to perform vertical drilling operations or directional drilling operations.

[0039] In S3, if vertical drilling operations are required: The external control system sends corresponding command information to the transmission control assembly, and the transmission control assembly sets the guide angle of the rotary guide segment to 180°. When the rotary guide segment forms any small well inclination angle, acceleration components will be generated in the X and Y directions of the rotary guide segment. The acceleration sensing and measurement assembly 3 can measure the gravity tool face. At the same time, the transmission control assembly controls the push assembly 2 to generate a 180° vector resultant force, adjusting the drilling trajectory towards a vertical state, that is, always in the command of declination reduction, so as to ensure that the drilling equipment drills vertically.

[0040] In S3, if a vertical wellbore drilling operation is required: The external control system sends corresponding command information to the transmission control assembly, and the transmission control assembly sets the guide angle of the rotary guide sub to a preset value A0, while determining the well inclination θ of the rotary guide sub. If the well inclination θ of the rotary guide sub is ≥1°, the gravity tool face is measured by the acceleration sensor assembly 3, and the drilling direction is controlled by the push assembly 2 to ensure that the drilling equipment drills along the preset trajectory.

[0041] If the well inclination θ of the rotary guide sub is less than 1°, the magnetic tool face is measured by the fluxgate sensor assembly 4, and the drilling direction is controlled by the push assembly 2 to ensure that the drilling equipment drills along the preset trajectory. After the well inclination of the rotary guide sub reaches the set threshold, the system switches to the acceleration sensor assembly 3 to measure the gravity tool face, and then enters the three-dimensional trajectory control mode.

[0042] Existing rotary steerable drilling systems cannot identify the position of the tool height edge and the first pusher 21 when the well inclination is less than 5°, and therefore cannot determine the pushing direction. Therefore, before using rotary steerable drilling, a pre-inclination wellbore with an inclination greater than 5° must be drilled using a mud motor, which greatly limits the application of rotary steerable drilling.

[0043] Therefore, this application uses a triaxial fluxgate sensor 41 to measure the angle between the near-bit fluxgate and the Earth's magnetic axis in real time, thereby determining the position of the first pusher 21 and thus the directional drilling azimuth. The azimuth of the first pusher 21 can be measured using the near-bit azimuth module. Then, based on the designed directional drilling direction, the direction of the guiding force can be set to be completely opposite to the directional drilling direction. The magnitude of the force is generally set to 100% to ensure that the drill bit can drill along the predetermined direction.

[0044] As can be seen from the above, this rotary steering sub and drilling control method can achieve autonomous switching between vertical drilling, vertical well directional drilling and directional drilling functions. It has the function of drilling vertical drilling, vertical well directional drilling and three-dimensional directional drilling in one trip, reducing the number of trips of drilling equipment, thereby improving drilling efficiency. It is especially suitable for offshore, deep well and unconventional oil and gas development, and is an important development direction for future intelligent drilling equipment.

[0045] Furthermore, this rotary guide section employs independent signal processing circuits, ensuring that the signal acquisition and processing of the two types of sensors do not interfere with each other. This improves the response speed and accuracy of well inclination and tool face measurements, providing data support for function switching. Simultaneously, the two sensors are arranged in a circumferentially staggered configuration, avoiding signal blind spots and ensuring accurate acquisition of azimuth information in various scenarios, whether the well inclination is extremely small (θ < 1°) or large (θ ≥ 1°).

[0046] Furthermore, in directional well operations, traditional build-up methods cannot determine the direction of the well deviation. The rotary steerable can create an deviation from any direction. When the well deviation exceeds a certain threshold, or after the upper probe measures the specific direction, trajectory correction is required, which wastes a significant amount of well section, manpower, resources, and time. Compared to traditional build-up methods, this method can ensure that the rotary steerable can create a deviation in the expected direction, greatly saving well section, manpower, resources, and time.

[0047] It should be noted that, unless otherwise stated, the technical or scientific terms used in this invention should have the ordinary meaning as understood by one of ordinary skill in the art.

[0048] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A rotary guide sub, characterized in that, include: The short section body (1) is used for connection with drilling equipment; The push assembly (2) is mounted on the short section body (1) and is used to control the drilling direction; An acceleration sensing and measurement assembly (3) is mounted on the main body (1) of the short section and is used to measure the well inclination and gravity tool face of the rotary guide short section; The fluxgate sensor measurement assembly (4) is mounted on the main body (1) of the short section and is used to measure the well inclination and magnetic tool face of the rotary guide short section; The transmission control assembly is mounted on the main body (1) of the short section; The acceleration sensing and measurement assembly (3) includes a triaxial acceleration sensor (31) and a first signal processing circuit (32). The triaxial acceleration sensor (31) is used to measure the well inclination and gravity tool face of the rotary guide sub. The first signal processing circuit (32) is connected to the transmission control assembly. The fluxgate sensing and measurement assembly (4) includes a three-axis fluxgate sensor (41) and a second signal processing circuit (42). The three-axis fluxgate sensor (41) is used to measure the well inclination and magnetic tool face of the rotary guide section. The second signal processing circuit (42) is connected to the transmission control assembly. The triaxial accelerometer (31) and the triaxial fluxgate sensor (41) are arranged in a staggered manner along the circumference of the short section body (1).

2. The rotary guide sub according to claim 1, characterized in that, The push assembly (2) includes a first pusher (21), a second pusher (22) and a third pusher (23), and the first pusher (21), the second pusher (22) and the third pusher (23) are arranged at 120° intervals along the circumferential direction of the short section body (1).

3. A drilling control method, using the rotary guide sub as described in claim 1 or 2, characterized in that, Includes the following steps: S1 connects the rotary guide sub to the drilling equipment; S2 controls the drilling equipment to be lowered into the wellbore; S3 controls the drilling equipment to perform vertical drilling operations or directional drilling operations.

4. The drilling control method according to claim 3, characterized in that, In S3, if vertical drilling operations are required: The external control system sends corresponding instruction information to the transmission control assembly, and the transmission control assembly gives the guide angle of the rotary guide short section to 180°. When the rotary guide short section forms an arbitrary well inclination angle, the X and Y directions of the rotary guide short section will produce acceleration components. The acceleration sensing and measurement assembly (3) can measure the gravity tool face. At this time, the transmission control assembly controls the push assembly (2) to generate a 180° vector resultant force, and adjusts the drilling trajectory to a vertical state to ensure that the drilling equipment drills vertically.

5. The drilling control method according to claim 3, characterized in that, In S3, if a vertical wellbore drilling operation is required: The external control system sends corresponding instruction information to the transmission control assembly, and the transmission control assembly sets the guide angle of the rotary guide sub to a preset value A0. At the same time, it determines the well inclination θ of the rotary guide sub and measures the orientation information of the rotary guide sub according to the acceleration sensor measurement assembly (3) or the fluxgate sensor measurement assembly (4). It then coordinates with the push assembly (2) to control the drilling direction to ensure that the drilling equipment drills along the preset trajectory.

6. The drilling control method according to claim 5, characterized in that, If the well inclination θ of the rotary guide sub is greater than or equal to 1°, the gravity tool face is measured by the acceleration sensor assembly (3), and the drilling direction is controlled by the push assembly (2) to ensure that the drilling equipment drills along the preset trajectory.

7. The drilling control method according to claim 5, characterized in that, If the well inclination θ of the rotary guide sub is less than 1°, the magnetic tool face is measured by the fluxgate sensor assembly (4), and the drilling direction is controlled by the push assembly (2) to ensure that the drilling equipment drills along the preset trajectory. Once the well inclination of the rotary guide section reaches the set threshold, switch to the acceleration sensor measurement assembly (3) to measure the gravity tool surface, and then enter the three-dimensional trajectory control mode.

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