Drilling tool face angle and rotating speed measuring device and method for eliminating centrifugal force influence

Abstract

The invention belongs to the technical field of sensor measurement, and particularly relates to a drilling tool face angle and rotating speed measuring device and method for eliminating centrifugal force influence, the center of a rotating body of the drilling tool face angle and rotating speed measuring device is provided with axial slurry circulation, and two single-axis acceleration sensors are arranged on a mounting plane perpendicular to a central axis in the rotating body by taking the central axis as a reference. The distances from the sensing centers of the two sensors to the central axis are equal, and the connecting lines of the sensing centers of the two sensors and the central axis are perpendicular to each other. The sensitive axis directions of the two sensors are in the mounting plane, are perpendicular to the connecting line of the sensing center and the central axis, and are perpendicular to each other. According to the layout, the sensitive shafts of the sensor are all along the tangential direction of the mounting point, the radial centrifugal acceleration is'desensitized ', only the gravity acceleration component is responded, the interference of the centrifugal force generated by high-speed rotation on the measurement of the face angle and the rotating speed of a gravity tool is eliminated from the hardware level, and the problem that the sensor cannot be mounted at the axis due to the existence of a central channel is solved.

Description

Technical Field

[0001] This invention belongs to the field of sensor measurement technology, specifically a drilling tool face angle and rotation speed measuring device and method for eliminating the influence of centrifugal force. Background Technology

[0002] The statements in this section merely refer to the background art related to this invention and do not necessarily constitute prior art.

[0003] In drilling projects for resources such as oil and natural gas, rotary steerable drilling systems are a core technology for achieving precise trajectory control and improving drilling efficiency and success rates. This system relies on real-time, accurate measurement of the downhole tool's attitude. The gravity tool facet angle is a key parameter determining the drilling direction (wellbore azimuth), while the drill pipe rotation speed provides fundamental information for monitoring drilling conditions and adjusting steerable forces. Currently, the industry commonly uses accelerometer-based measurement schemes to obtain these parameters.

[0004] The traditional ideal design is to mount a dual-axis or tri-axis accelerometer module directly on the geometric center axis of the drill pipe. When the sensor is located at the center of rotation, it rotates with the drill pipe, sensing only the projected components of the Earth's gravitational acceleration on each of the sensor's sensitive axes, without being affected by the centrifugal acceleration caused by rotation. Therefore, it can accurately calculate the gravity tool facet angle and rotational speed.

[0005] However, there are inherent contradictions in the structural design of specialized downhole tools such as rotary steerable tools and turbine drills. To transport drilling fluid to cool the drill bit and carry cuttings, a mud circulation channel must be reserved in the central area of ​​the tool. This central channel occupies the space that should be used to install sensor modules, preventing the accelerometer from being placed at the center of rotation of the drill pipe and forcing it to be offset and installed at a non-central position around the center bore.

[0006] When an accelerometer is installed off-center, in addition to sensing gravitational acceleration, it will inevitably be subject to a superimposed interference from centrifugal acceleration, which is proportional to the square of the rotational angular velocity and directed outward along the radius of the installation point. The intensity of this centrifugal force signal is typically much greater than the gravitational acceleration component and is related to the square of the rotational speed; its interference amplitude is far beyond that of ordinary vibration noise. Even more serious is the fact that in actual drilling operations, the drill string also endures complex, multi-frequency, wide-amplitude, and non-stationary vibrations generated by formation interactions, drilling fluid turbulence, and mechanical collisions. These vibrational accelerations and centrifugal accelerations intertwine and couple in the time and frequency domains, forming an extremely complex interference background. Summary of the Invention

[0007] This invention provides a drilling tool face angle and rotation speed measurement device and method that eliminates the influence of centrifugal force. By symmetrically installing two single-axis accelerometers on the periphery of the rotating shaft and making their sensitive axes perpendicular to their respective radii in the cross-section, the interference of radial centrifugal acceleration is completely shielded at the sensor level, and the sensor is only sensitive to the gravitational acceleration component, thereby accurately calculating the gravity tool face angle and rotation speed.

[0008] The first aspect of the present invention discloses a drilling tool face angle and rotation speed measuring device for eliminating the influence of centrifugal force, including a rotating body (1), a first single-axis accelerometer (4a) and a second single-axis accelerometer (4b); the rotating body (1) has an axial mud circulation hole (2) at its center; the first single-axis accelerometer (4a) and the second single-axis accelerometer (4b) are located in an annular region coaxial with the mud circulation hole (2) inside the rotating body (1), and the sensing centers of the two sensors are equidistant from the central axis of the rotating body (1); In the mounting plane perpendicular to the central axis: The lines connecting the sensing center of the first single-axis accelerometer (4a), the sensing center of the second single-axis accelerometer (4b), and the central axis are perpendicular to each other; The sensitive axis direction of the first single-axis accelerometer (4a) is located in the mounting plane and is perpendicular to the line connecting the sensing center and the central axis of the first single-axis accelerometer (4a). The sensitive axis direction of the second single-axis accelerometer (4b) is located in the mounting plane and is perpendicular to the line connecting the sensing center and the central axis of the second single-axis accelerometer (4b). The sensitive axis direction of the first single-axis accelerometer (4a) is perpendicular to the sensitive axis direction of the second single-axis accelerometer (4b).

[0009] Furthermore, the first single-axis accelerometer (4a) and the second single-axis accelerometer (4b) are arranged symmetrically inside the rotating body (1) and are located in the annular chamber wall or mounting base surrounding the mud circulation hole (2).

[0010] Furthermore, it also includes a first A / D conversion module and a second A / D conversion module. The output terminal of the first single-axis accelerometer (4a) is connected to the input terminal of the first A / D conversion module, and the output terminal of the second single-axis accelerometer (4b) is connected to the input terminal of the second A / D conversion module.

[0011] Furthermore, it also includes a central processing unit, the input of which is connected to the output of the first A / D conversion module and the second A / D conversion module, for receiving and processing measurement data from the two single-axis accelerometers (4a, 4b).

[0012] Furthermore, it also includes a third single-axis accelerometer, the sensitive axis of which is parallel or antiparallel to the central axis of the rotating body (1), and is used to measure the acceleration component along the central axis.

[0013] Furthermore, the central processing unit is configured to: based on the measurements from the first single-axis accelerometer (4a) Gy The measured values ​​of the second uniaxial accelerometer (4b) Gz According to the formula i =atan2( Gy, Gz Calculate the face angle of the gravity tool. i , where atan2 is the arctangent function in the fourth quadrant.

[0014] Furthermore, the central processing unit is also configured to calculate the gravity tool facet angle based on times t1 and t2 respectively. i 1 and i 2. Obtain the continuous angular change Δ through angular unwinding processing. i And according to the formula: Rotational speed = Δ i / [360×(t2 t1)], calculate the instantaneous rotational speed or average rotational speed of the rotating body (1).

[0015] Furthermore, the projections of the sensitive axis directions of the first single-axis accelerometer (4a) and the second single-axis accelerometer (4b) onto the mounting plane coincide with the circumferential tangent directions at the sensing centers of the first single-axis accelerometer (4a) and the second single-axis accelerometer (4b), respectively.

[0016] Furthermore, the device is applied to rotary steerable drilling tools, turbine drills, or other downhole power drills with a central circulation channel.

[0017] The second aspect of the present invention discloses a method for measuring the face angle and rotational speed of drilling tools to eliminate the influence of centrifugal force, comprising the following steps; Acquire the measurement signal from the first uniaxial accelerometer (4a). Gy Measurement signal of the second uniaxial accelerometer (4b) Gz The two sensors are arranged such that their sensing axes are perpendicular to each other in a plane perpendicular to the axis of rotation, and both are perpendicular to the line connecting their respective sensing centers to the axis of rotation. based on Gy and Gz Calculate the gravity tool face angle at the current moment. i The calculation formula is: θ= atan2 (Gy,Gz) Calculate the face angle of the gravity tool i where atan2 is the arctangent function in the fourth quadrant; Record the gravity tool face angle values ​​at multiple consecutive moments, and perform angle unwinding processing on the tool face angle values ​​at adjacent moments to obtain a continuous and non-jumping relative rotation angle Δ. i According to the relative rotation angle Δ i Calculate the rotational speed of the rotating body (1) based on the corresponding time interval Δt.

[0018] Compared with existing technologies, one or more of the above technical solutions have the following beneficial effects: By symmetrically mounting two single-axis accelerometers around the rotating shaft, with their sensitive axes perpendicular to their respective radii within the cross-section, the sensitive axes of the two single-axis accelerometers are orthogonal to the direction of the centrifugal force at the hardware level. This isolates the interference of strong centrifugal acceleration on gravity measurements, allowing the sensors to be sensitive only to the gravitational acceleration component, thereby accurately calculating the gravity tool facet angle and rotational speed. This layout allows the sensor module to obtain a pure gravity signal equivalent to that installed at the ideal rotation center, even when it must be mounted off-center from the rotation center. This resolves the technical contradiction that traditional axial mounting schemes cannot be used due to the space occupied by the drilling fluid center channel. Attached Figure Description

[0019] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0020] Figure 1 This is a schematic diagram of the drilling tool face angle and rotation speed measurement process for eliminating the influence of centrifugal force, provided for one or more embodiments of the present invention.

[0021] In the diagram: 1. Rotary guide head (drill rod), 2. Mud circulation hole (location where it is inconvenient to install an accelerometer), 3. Diameter, 4. Single-axis accelerometer, 5. Axial direction of the accelerometer, 6. A / D conversion module, 7. Output signal, 8. CPU. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0024] The tool face angle refers to the rotation angle of the bending direction (or pushing direction) of the drill bit used for guidance relative to a certain reference. When gravity is used as the reference, it is called the gravity tool face angle, and when the Earth's magnetic north pole is used as the reference, it is called the magnetic tool face angle.

[0025] The gravity tool face angle refers to the angle between the direction of the drill bit's guide bend and the vertical line of Earth's gravity (i.e., the "downward" direction).

[0026] The rotary guide head (drill pipe) 1 is the core rotating component of the downhole tool. It is usually a cylindrical metal component with its central axis serving as the reference axis for the rotation of the drill string and also the optimal installation position for the sensor under ideal conditions.

[0027] The mud circulation hole 2 is a large-diameter circular hole that runs along the central axis of the rotary guide head 1. Drilling mud flows through the mud circulation hole 2, providing power to the drill bit and carrying cuttings back to the surface. Because the mud circulation hole 2 completely occupies the physical space at the center of the tool, it is impossible to install hardware such as measuring sensors on the central axis of rotation. To address this issue, conventional solutions "make way" for all electronic components (including sensors) that need to be installed, placing them in the annular area or sidewalls surrounding the central hole.

[0028] This solution provides a drilling tool face angle and rotation speed measurement device and method to eliminate the influence of centrifugal force. By symmetrically installing two single-axis accelerometers on the periphery of the rotating shaft and making their sensitive axes perpendicular to their respective radii in the cross-section, the interference of radial centrifugal acceleration is completely shielded at the sensor level, and the sensor is only sensitive to the gravitational acceleration component, thereby accurately calculating the gravity tool face angle and rotation speed.

[0029] A drilling tool face angle and rotation speed measuring device to eliminate the influence of centrifugal force, including; Rotating body 1, with an axial mud circulation hole 2 at its center; The first single-axis accelerometer (4a) and the second single-axis accelerometer (4b) are located on two mutually perpendicular diameters 3 within the radial section of the rotating body 1, and the distances from the two single-axis accelerometers to the central axis (i.e., the center) of the rotating body 1 are equal. The sensitive axis direction of the first single-axis accelerometer (4a) is perpendicular to the first radius direction formed by the line connecting its own position and the center of the circle; The sensitive axis direction of the second single-axis accelerometer (4b) is perpendicular to the direction of the second radius formed by the line connecting its own position and the center of the circle; The sensitive axis direction of the first single-axis accelerometer (4a) is perpendicular to the sensitive axis direction of the second single-axis accelerometer (4b).

[0030] like Figure 1As shown, when it is inconvenient to install a dual-axis accelerometer at the center of the rotary guide head 1 in the mud circulation hole 2, two single-axis sensors 4 (first single-axis accelerometer 4a and second single-axis accelerometer 4b) are installed on the two mutually perpendicular diameters 3 of the rotary guide head 1. The distance between the two single-axis sensors 4 and the center of the cross section of the rotary guide head 1 is equal, and the sensitive axis direction (i.e., axial direction 5) of the single-axis sensor 4 is perpendicular to the diameter 3 of the rotary guide head 1.

[0031] The output signals of the two single-axis sensors 4 are respectively connected to the two corresponding A / D conversion modules 6. The output signals 7 of the two A / D conversion modules 6 are connected to the same CPU 8. The CPU 8 calculates the gravity tool face angle and rotation speed through the loaded algorithm.

[0032] CPU8 calculates the gravity tool face angle and rotation speed using a loaded algorithm, specifically: The direction of the drill pipe's axial direction toward the ground is defined as the X-axis of the three-dimensional coordinate system. On a plane at a 90-degree angle to the X-axis, the direction of a fixed marker (e.g., the direction of the directional drilling tool) is defined as the Y-axis. The direction 90 degrees away from both the X and Y axes is defined as the Z-axis. A single-axis accelerometer (single-axis sensor 4) must be installed in both the Y and Z axes; the X-axis accelerometer is optional. Its primary function is not to directly calculate the gravity tool face angle or rotational speed, but rather to monitor acceleration along the drill pipe's axial direction. For example, it can be used to identify strong axial impacts and vibrations, or to assist in distinguishing complex motion patterns of the drill string in certain algorithms. For basic rotational speed measurement, the rotational direction and speed can be reliably determined by continuously reading the tool face angle sequence calculated by the Y' and Z' axis sensors.

[0033] When the projection of the gravity vector onto the mounting plane points exactly in the positive direction of the reference Z' axis (i.e., the direction of the sensitive axis of sensor 4b is in the same direction as it), the tool face angle is defined as 0 degrees. At this time, the output of sensor 4a is 0, and the output of sensor 4b is the maximum positive value.

[0034] Based on the above sensor layout, the output signal of the first sensor (4a) Gy The output signal of the second sensor (4b) Gz , which is the projection component of gravitational acceleration in two orthogonal directions within the plane of the drill tool.

[0035] Gravity tool face angle i The result can be obtained by calculating the ratio between these two components, as shown in the following formula: ; ; ; Alternatively, the four-quadrant arctangent function can be used: θ= atan2( Gy , Gz ); in, Gy This is the real-time output value of the first single-axis accelerometer (4a) mounted on the reference Y' axis. This value represents the projected component of gravitational acceleration along the sensitive axis of sensor 4a at the current toolface angle θ, in g or m / s². 2 .

[0036] Gz This is the real-time output value of the second single-axis accelerometer (4b) mounted on the reference Z' axis. This value represents the projected component of gravitational acceleration along the sensitive axis of sensor 4b at the current toolface angle θ, in g or m / s². 2 .

[0037] This is the magnitude of the projection of the gravitational acceleration vector onto the current measurement plane. Ideally (without interference and with accurate sensor calibration), this value should be constant at 1g. In practical applications, this value can be used to verify data validity (e.g., to determine if the sensor is malfunctioning or experiencing abnormal interference). The positive direction of the angle is the tool face angle when the drill bit rotates clockwise (viewing angle: from the drill bit along the axis towards the breech). i As a result, it increases.

[0038] At a certain moment, after measuring the tool face angle, the data is recorded. After waiting for a short period of time (a seconds), the tool face angle is measured again, and the two tool face angles are subtracted. It is important to note that the tool face angle is an angle value with a period of 360°. When calculating the angle difference b, phase unwinding processing is required to ensure that the true angle increment of continuous rotation is obtained (for example, a rotation from 350° to 10° should be calculated as a rotation of 20°, not -340°). The processed angle difference b is the angle by which the drill pipe rotated within a seconds.

[0039] Since one revolution is 360 degrees, the number of revolutions in 'a' seconds is equal to b / 360. Therefore, the rotational speed per second is (b / 360) / a. To convert this to the commonly used RPM (revolutions per minute), we need to multiply by 60. After simplification, we get the formula: Rotational speed RPM = b / (6a) When the drill pipe rotates at high speed, if the Y-axis and Z-axis accelerometers are installed at the center point of the rotation, the centrifugal force sensed by the sensors is small enough that its influence can be ignored, provided the two sensors are close enough to the center. However, due to physical limitations, sensors may not be able to be installed at the center of the drill pipe, requiring them to be installed off-center. In this case, if a multi-axis accelerometer is used, the Y-axis and Z-axis are often installed at the same point. Since Y and Z differ by 90 degrees, if one axis is in the same or opposite direction to the centrifugal force, the other axis will necessarily be perpendicular to it. The sensor in the same or opposite direction to the centrifugal force will increase or decrease the value of the centrifugal force, the magnitude of which depends on the rotational speed. However, since the other sensor perpendicular to the centrifugal force is not affected by it, the calculated tool face angle will be inaccurate. Therefore, this method uses two independent accelerometers, not installed in the same location, but in two locations, both perpendicular to the centrifugal force, with a 90-degree difference between them, serving as the Y-axis and Z-axis respectively. Because the sensors are perpendicular to the centrifugal force, the magnitude of the centrifugal force cannot affect the values ​​of the two accelerometers.

[0040] This design selects a cross-section perpendicular to the axis of the rotary guide head 1 as the mounting plane. Typically, this plane is located within a protected and structurally stable section of the tool. Figure 1 This cross-section is shown. On this cross-section, with the mud circulation hole 2 (i.e., center O) as the center, two virtual, mutually perpendicular reference diameters are drawn (for example, denoted as the reference Y' axis and the reference Z' axis, i.e., ...). Figure 1 The two reference diameters (3 in the figure) are the reference lines for sensor positioning, but the sensor is not installed on these two lines, but in a position related to them.

[0041] Specifically: On the mounting plane, with the center O as the origin, two virtual perpendicular reference lines are drawn (for example, referred to as reference line Y' and reference line Z', respectively). The first sensor (sensor 4a) is mounted on the positive (or negative) direction of reference line Y', at a position (point A) a specific radius value R away from the center O. R>0, meaning it is off-center.

[0042] The sensitive axis of sensor 4a is set to be perpendicular to radius OA within the mounting plane. A second sensor (sensor 4b) is mounted on the positive (or negative) direction of the baseline Z', at a position (point B) with the same radius R from the center O. That is, the distances from points A and B to the center of the circle are strictly equal.

[0043] The sensitive axis direction of sensor 4b is set to be perpendicular to radius OB in the mounting plane. Furthermore, the sensitive axis direction of sensor 4b is perpendicular to the sensitive axis direction of sensor 4a in the mounting plane.

[0044] With this arrangement, the sensitive axes of both sensors point tangentially to the circumference.

[0045] A single-axis accelerometer has only one sensitive axis and can only accurately measure acceleration, deceleration, or gravitational components along the sensitive axis. In most cases, to measure centrifugal force, the sensor's sensitive axis is aligned with the center (along the radial direction) because centrifugal force points outward along the radial direction. However, this design sets the sensitive axis of each single-axis accelerometer 4 to be perpendicular to the radial direction at 90 degrees (i.e., "axial direction 5 is perpendicular to the diameter 3 of the rotating guide head 1"). This prevents the centrifugal force transmitted along the radial direction from being captured by the single-axis accelerometer 4, resulting in a measured value of 0. Meanwhile, the downward-pointing gravity continuously passes by the side of the sensor 4 as the drill pipe rotates, allowing the sensor 4 to capture changes in its component. Subsequently, the gravity tool face angle and drill pipe rotation speed are calculated using appropriate algorithms.

[0046] Therefore, the sensor layout in this scheme makes the combined signal output from the two sensors mathematically equivalent to the output of a single biaxial accelerometer mounted at the center O and unaffected by centrifugal force, thus achieving measurement accuracy. The above analysis is based on an ideal geometric model where the sensor's sensitive axis is strictly perpendicular to the installation radius. In actual manufacturing and installation, strict control of alignment accuracy is necessary to minimize angular deviations, or calibration methods should be used to compensate for residual centrifugal interference introduced by minor deviations to ensure measurement accuracy.

[0047] In practical applications, two single-axis accelerometers 4 are integrated and installed in a sealed instrument chamber inside the rotary guide head 1. This instrument chamber is typically a cylindrical or annular metal pressure-bearing shell, with its central axis coinciding with the central axis of the rotary guide head 1 to ensure the stability of the internal mounting reference. A mud circulation hole 2 passes through the central axis of this instrument chamber. The two sensors are fixed to the inner wall of the instrument chamber via rigid mounting bases, ensuring that their sensitive axis directions precisely meet the spatial geometry designed in this scheme. The instrument chamber provides a stable working environment isolated from high-pressure, corrosive drilling mud for the sensors and subsequent signal processing circuitry.

[0048] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A drilling tool face angle and rotational speed measuring device that eliminates the effects of centrifugal force, characterized in that, The device comprises a rotating body (1), a first single-axis acceleration sensor (4a) and a second single-axis acceleration sensor (4b); the rotating body (1) is provided with a mud circulating hole (2) in the axial direction; the first single-axis acceleration sensor (4a) and the second single-axis acceleration sensor (4b) are located in the annular area coaxial with the mud circulating hole (2) in the rotating body (1), and the distances from the sensing centers of the two to the central axis of the rotating body (1) are equal; In the installation plane perpendicular to the central axis: The connecting lines of the sensing center of the first single-axis acceleration sensor (4a), the sensing center of the second single-axis acceleration sensor (4b) and the central axis are perpendicular to each other; The sensitive axis direction of the first single-axis acceleration sensor (4a) is located in the installation plane and is perpendicular to the connecting line of the sensing center of the first single-axis acceleration sensor (4a) and the central axis; The sensitive axis direction of the second single-axis acceleration sensor (4b) is located in the installation plane and is perpendicular to the connecting line of the sensing center of the second single-axis acceleration sensor (4b) and the central axis; The sensitive axis direction of the first single-axis acceleration sensor (4a) is perpendicular to the sensitive axis direction of the second single-axis acceleration sensor (4b).

2. The drilling tool face angle and rotational speed measurement device that eliminates the effects of centrifugal force of claim 1, wherein, The first single-axis acceleration sensor (4a) and the second single-axis acceleration sensor (4b) are symmetrically arranged inside the rotating body (1) and are located in the annular bulkhead or the installation base around the mud circulating hole (2).

3. The drilling tool face angle and rotational speed measurement device that eliminates the effects of centrifugal force of claim 1, wherein, Further comprising a first A / D conversion module and a second A / D conversion module, the output end of the first single-axis acceleration sensor (4a) is connected to the input end of the first A / D conversion module, and the output end of the second single-axis acceleration sensor (4b) is connected to the input end of the second A / D conversion module.

4. The drilling tool face angle and rotational speed measurement device that eliminates the effects of centrifugal force of claim 1, wherein, Further comprising a central processing unit, the input end of the central processing unit is connected to the output ends of the first A / D conversion module and the second A / D conversion module, for receiving and processing the measurement data of the two single-axis acceleration sensors.

5. The drilling tool face angle and rotational speed measurement device that eliminates the effects of centrifugal force of claim 4, wherein, a central processing unit configured to calculate a gravity tool face angle Gy based on a measurement value of the first single-axis acceleration sensor (4a) Gz and a measurement value of the second single-axis acceleration sensor (4b) θ according to the formula Gy, Gz =atan2( θ ), wherein atan2 is a four-quadrant arctangent function.

6. The drilling tool face angle and rotational speed measurement device that eliminates the effects of centrifugal force of claim 4, wherein, The central processing unit is also configured to calculate the gravity tool facet angle based on times t1 and t2 respectively. θ 1 and θ 2. Obtain the continuous angular change Δ through angular unwinding processing. θ And according to the formula: Rotational speed = Δ θ / [360×(t2 t1)], calculate the instantaneous rotational speed or average rotational speed of the rotating body (1).

7. The drilling tool face angle and rotational speed measurement device that eliminates the effects of centrifugal force of claim 1 wherein, Further comprising a third single-axis acceleration sensor, the sensitive axis direction of the third single-axis acceleration sensor is parallel or antiparallel to the central axis of the rotating body (1), for measuring the acceleration component in the direction of the central axis.

8. The drilling tool face angle and rotational speed measurement device that eliminates the effects of centrifugal force of claim 1 wherein, The projections of the sensitive axis directions of the first single-axis acceleration sensor (4a) and the second single-axis acceleration sensor (4b) in the installation plane are respectively coincident with the circumferential tangent directions at the respective sensing centers of the first single-axis acceleration sensor (4a) and the second single-axis acceleration sensor (4b).

9. The drilling tool face angle and rotational speed measurement device that eliminates the effects of centrifugal force of claim 1 wherein, The device is applied to a rotary steering drilling tool, a turbine drilling tool or other downhole power drilling tools with a central circulating channel.

10. A method for measuring the face angle and rotational speed of a drilling tool, free from the influence of centrifugal forces, based on the device according to any one of claims 1 to 9, characterized in that, The device comprises the following steps: acquiring a measurement signal of a first single-axis acceleration sensor (4a) Gy and a measurement signal of a second single-axis acceleration sensor (4b) Gz the arrangement of the two sensors satisfying that their sensitive axes are mutually perpendicular in a plane perpendicular to the rotation axis and both are perpendicular to the line connecting the respective sensing center to the rotation axis; Based on Gy and Gz , the gravity toolface angle at the current time is calculated θ , the calculation formula is θ= atan2 (Gy, Gz) Calculate the gravity toolface angle θ , wherein atan2 is the four quadrant arctangent function; The gravity tool face angle values at a plurality of continuous time points are recorded, the tool face angle values at adjacent time points are angle unwound to obtain continuous relative rotation angles Δ θ ; and the rotation speed of the rotating body (1) is calculated according to the relative rotation angles Δ θ and corresponding time intervals Δt.

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