Error correction method and system for inclinometer while drilling

Abstract

The invention relates to the technical field of directional drilling, in particular to an error correction method and system for an inclinometer while drilling, and the method comprises the steps: obtaining a tool rotating speed change rule parameter and amplitude and frequency parameters of a vibration signal according to rotation and vibration data collected by a sensor group; according to the amplitude and frequency parameters of the vibration signals, the vibration signals are sampled through a band elimination filter with the self-adaptive center frequency, Fourier analysis is carried out, the frequency of interference signals is found out, and the vibration interference signals are eliminated by changing the center frequency of the band elimination filter in real time; according to the while-drilling inclinometer, various problems of conventional static measurement can be solved, the real-time accurate measurement technology is achieved without stopping drilling or stopping a pump in the drilling process, the static time of a drilling tool is shortened, the drilling risk is reduced, the complete drilling depth is rapidly achieved, meanwhile, the vibration and centripetal acceleration of a product are eliminated, and the drilling efficiency is improved. And the detection accuracy of the position of the drilling tool in the well rotating process is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of directional drilling, and in particular to an error correction method and system for a while-drilling inclinometer. Background Art

[0002] In the oil and gas industry, the advancement of drilling technology has led to a shift in wellbore structure from vertical wells to directional wells and horizontal wells. At the same time, vertical wells are also facing the challenge of preventing deflection and drilling straight. In the context of pursuing drilling speed increase, cost reduction and efficiency improvement, wellbore control, trajectory accuracy and transmission efficiency of directional instruments have become key factors.

[0003] The inclinometer probe in the directional instrument is responsible for wellbore control and data transmission. One of its main functions is to measure wellbore geometric parameters. Directional well engineers adjust the actual drilling wellbore trajectory based on the real-time uploaded inclinometer data to achieve the expected trajectory effect; however, each measurement usually takes 10 minutes or even longer, and the slight movement of the drill bit will seriously affect the measurement accuracy. Secondly, if the circulation equipment is in poor condition, the measurement may fail and need to be re-measured. In addition, long-term drill bit static will cause drill cuttings to accumulate, increasing the risk of wellbore blockage and drill stuck.

[0004] In order to solve these problems, inclinometers while drilling were developed. However, in actual use, external vibrations and the misalignment of the instrument and the drill bit will cause vibrations and centrifugal forces, which will greatly affect the accuracy of directional detection.

[0005] Therefore, in order to solve the above problems, we propose that the purpose of the present invention is to provide an error correction method and system for a while drilling inclinometer. Summary of the invention

[0006] The purpose of the present invention is to solve the shortcomings of the prior art, such as external vibration and the installation of the instrument and the drill bit being out of axial alignment, which will cause vibration and centrifugal force, thereby greatly affecting the direction detection accuracy, and to propose an error correction method and system for a while-drilling inclinometer.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] An error correction method for a while drilling inclinometer is designed, including:

[0009] According to the rotation and vibration data collected by the sensor group, the parameters of the tool speed change law and the amplitude and frequency parameters of the vibration signal are obtained;

[0010] According to the amplitude and frequency parameters of the vibration signal, the vibration signal is sampled through a band-stop filter with adaptive center frequency, and Fourier analysis is performed to find out the frequency of the interference signal. The vibration interference signal is eliminated by changing the center frequency of the band-stop filter in real time.

[0011] According to the parameters of the tool speed change law, the real-time speed of the sensor group is calculated by collecting the magnetic component, and the acceleration component of the sensor group in the dynamic process is collected. Calibration and compensation are performed through the algorithm to eliminate the influence of centripetal acceleration.

[0012] Furthermore, the sensor group includes three three-axis accelerometer sensors whose central axes are 90° to each other and three three-axis fluxgate sensors whose central axes are 90° to each other; wherein the three three-axis accelerometer sensors are respectively denoted as Ax, Ay and Az, and the three three-axis fluxgate sensors are respectively denoted as Mx, My and Mz.

[0013] Furthermore, the filtering function of the digital filter is realized by the center frequency adaptive band-stop filter;

[0014] When eliminating the vibration interference signal, the acceleration signals of Ax, Ay and Az are first collected by ADC and converted into digital quantities, and Fourier analysis is performed to analyze the signal amplitude and frequency. According to the obtained amplitude and frequency results, the center frequency of the band group filter is adjusted; then the digital quantity corresponding to the three-axis accelerometer sensor is brought into the band-stop filter to obtain the accelerometer result of eliminating the vibration interference signal.

[0015] Further, the center frequency adaptive band-stop filter is a 4th-order FIR band-stop filter, and its center frequency and stopband width are initially designed to be 50 Hz and 20 Hz;

[0016] The output calculation formula of the 4th order FIR band stop filter is:

[0017]

[0018] Where y(n) is the output signal after filtering; x(nk) is the input signal at the nkth moment; h(k) is the band-stop filter coefficient, k = 0, 1, 2, 3, 4; n is the index of the output sequence y(n).

[0019] Furthermore, when eliminating the influence of centripetal acceleration, the original magnetic data of Mx, My and Mz are collected at high speed by ADC to calculate the real-time speed r of the sensor, and the original acceleration data ax collected by ADC is used to calculate the current centripetal acceleration value fx through Fourier algorithm. r ; According to the formula gx = ax-fx r Get the accelerometer component value gx after eliminating the influence of centripetal force.

[0020] Furthermore, before the sensor group collects rotation and vibration data, it also includes a dynamic parameter calibration step and a dynamic parameter verification step, and the dynamic parameter calibration step and the dynamic parameter verification step are used to correct the influence of rotation measurement on the sensor measurement accuracy.

[0021] Furthermore, the dynamic parameter calibration step includes:

[0022] Install the instrument to be calibrated on the turntable and adjust the turntable to keep the well inclination angle at 0°±Δθ;

[0023] Under the 0° well inclination state, the rotary table speed was set to 20RPM, 40RPM, 60RPM and 80RPM respectively, and the output data of the three-axis accelerometer was collected synchronously at each speed. No less than 10,000 sets of data were continuously recorded under each speed condition to complete the data collection;

[0024] Adjust the turntable well inclination angle to 45°±Δθ and repeat the data acquisition process;

[0025] Adjust the turntable well inclination angle to 90°±Δθ and repeat the data acquisition process;

[0026] Adjust the turntable well inclination angle to 135°±Δθ and repeat the data acquisition process;

[0027] All data are analyzed and calculated, and then the calculation results are brought into the firmware program of the product, thus completing the dynamic calibration, wherein the Δθ is the allowable error.

[0028] Furthermore, the dynamic parameter verification step includes:

[0029] Install the product on the rotary table, adjust the well inclination to maintain 0°±Δθ, and record the current well inclination value INCs;

[0030] The rotation speed is set to 20RPM, 40RPM, 60RPM and 80RPM respectively, and the well inclination values ​​INC20, INC40, INC60 and INC80 at different rotation speeds are recorded. The well inclination value recorded under rotation and the well inclination value INCs under static state are subtracted to obtain the dynamic well inclination measurement accuracy;

[0031] Adjust the well inclination to maintain 45°±Δθ, and record the current well inclination value INCs and azimuth value AZIs;

[0032] The rotation speed is set to 20RPM, 40RPM, 60RPM and 80RPM respectively, and the well inclination values ​​INC20, INC40, INC60 and INC80 at different rotation speeds are recorded. The azimuth values ​​AZI20, AZI40, AZI60 and AZI80 at different rotation speeds are recorded. The well inclination value recorded under rotation is subtracted from the well inclination value INCs under static state to obtain the well inclination measurement accuracy under dynamic state; the azimuth value recorded under rotation is subtracted from the azimuth value AZIs under static state to obtain the azimuth measurement accuracy under dynamic state;

[0033] Adjust the well inclination to maintain 90°±Δθ, record the current well inclination value INCs and azimuth value AZIs, and repeat the steps of dynamic azimuth measurement accuracy;

[0034] Adjust the well inclination to maintain 135°±Δθ, record the current well inclination value INCs and azimuth value AZIs, and repeat the dynamic lower azimuth measurement accuracy step, where Δθ is the allowable error.

[0035] Furthermore, the turntable is a non-magnetic turntable with heating and rotating functions, the maximum heating temperature is 200° C., and the maximum rotating speed is 400 rpm.

[0036] In addition, the present invention also proposes an error correction system for a while drilling inclinometer, which comprises:

[0037] Sensor unit: used to collect rotation and vibration data;

[0038] A data processing unit; used to obtain parameters of tool speed variation law and amplitude and frequency parameters of vibration signals according to rotation and vibration data;

[0039] Vibration elimination unit: It is used to sample the vibration signal at high speed according to the amplitude and frequency parameters of the vibration signal through a band-stop filter with adaptive center frequency, and perform Fourier analysis to find out the frequency of the interference signal, change the center frequency of the band-stop filter in real time, and eliminate the vibration interference signal;

[0040] Centripetal acceleration elimination unit: It is used to calculate the real-time rotation speed of the sensor group according to the parameters of the tool rotation speed change law by collecting the magnetic component, and collect the acceleration component of the sensor group in the dynamic process, and calibrate and compensate through the algorithm to eliminate the influence of centripetal acceleration.

[0041] The present invention proposes an error correction method and system for an inclinometer while drilling, and the beneficial effects are as follows: the inclinometer while drilling of the present invention can solve various problems faced by conventional static measurement, and can achieve real-time and accurate measurement without stopping drilling or pumping during the drilling process. This method saves measurement time and reduces the stationary time of the drill bit, thereby reducing the drilling risk and quickly reaching the completed drilling depth. At the same time, by eliminating the vibration and centripetal acceleration of the product, the measurement accuracy is greatly improved, and the accuracy of the drill bit position detection during the well rotation process is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a flow chart of the steps of the present invention;

[0043] Figure 2 It is a flow chart of the dynamic parameter calibration steps of the present invention;

[0044] Figure 3 It is a flow chart of the dynamic parameter verification steps of the present invention. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0046] Embodiment 1

[0047] Reference Figure 1 An embodiment of the present invention discloses an error correction method for an inclinometer while drilling. Of course, the inclinometer described in the present invention is installed inside the drilling tool. When the drill bit is drilling, the azimuth, well inclination and tool face angle of the drill bit are monitored in real time through the inclinometer, and redundant errors in monitoring are eliminated through the method. Specifically, the method includes:

[0048] Step 100, based on the rotation and vibration data collected by the sensor group, obtain the tool speed change law parameters and the amplitude and frequency parameters of the vibration signal. The sensor group in this embodiment includes three three-axis accelerometer sensors with three central axes at 90° to each other and three-axis fluxgate sensors with three central axes at 90° to each other; wherein the three three-axis accelerometer sensors are respectively denoted as Ax, Ay and Az, and the three three-axis fluxgate sensors are respectively denoted as Mx, My and Mz.

[0049] When the drill bit rotates, the acceleration and geomagnetic signals measured by the sensor group change in the form of sinusoidal signals. When the rotation speed reaches 300 rpm, the frequency is 5 Hz. The accelerometer and fluxgate should be able to accurately measure at a frequency of 5 Hz, and the signal amplitude should not be significantly attenuated. Therefore, in this embodiment, an accelerometer and fluxgate sensor with a bandwidth of more than 200 Hz are selected;

[0050] In addition, the accelerometer and fluxgate convert the fast-changing acceleration signal and geomagnetic signal into a fast-changing voltage signal. The acquisition circuit needs to ensure that the signals of the three accelerometers and three fluxgate sensors are collected and converted at the same time to ensure that the six sensor components reflect the same position.

[0051] In this embodiment, the sensor uses a 24-bit synchronous sampling analog-to-digital converter (ADC), such as a high-performance analog-to-digital converter of model AD7771, which can simultaneously collect the voltage signals of 6 sensor components with high precision, ensuring that the original data of each component can be accurately measured when the sensor rotates, laying a foundation for subsequent data processing;

[0052] Step 200: based on the amplitude and frequency parameters of the vibration signal, the vibration signal is sampled through a band-stop filter with a center frequency adaptive, and Fourier analysis is performed to find out the frequency of the interference signal, and the vibration interference signal is eliminated by changing the center frequency of the band-stop filter in real time;

[0053] Obviously, large vibrations are inevitable during the drilling process, and the acceleration generated by the vibrations will also cause changes in the accelerometer output, resulting in sensor measurement errors;

[0054] The vibration acceleration is an AC signal, and the gravity acceleration signal under rotation is also an AC signal, and the frequency of the vibration acceleration signal is not fixed, which determines that it is impossible to eliminate the vibration acceleration signal and retain the gravity acceleration signal through a simple low-pass filter;

[0055] In order to effectively eliminate the interference of vibration acceleration signals, the present invention adopts a band-stop filter with adaptive center frequency. First, the vibration signal is sampled at high speed and Fourier analysis is performed to find the frequency of the interference signal, and the filter frequency is changed in real time to effectively eliminate the vibration interference signal.

[0056] Specifically, in this embodiment, the filtering function of the digital filter is realized by the center frequency adaptive band-stop filter;

[0057] When eliminating the vibration interference signal, first collect the acceleration signals of Ax, Ay and Az through ADC and convert them into digital quantities, and perform Fourier analysis to analyze the signal amplitude and frequency. According to the obtained amplitude and frequency results, adjust the center frequency of the band group filter, and then bring the digital quantity corresponding to the three-axis accelerometer sensor into the band stop filter to obtain the accelerometer result of eliminating the vibration interference signal;

[0058] In addition, the center frequency adaptive band stop filter is a 4th order FIR band stop filter, and its center frequency and stop band width are initially designed to be 50 Hz and 20 Hz;

[0059] The output calculation formula of the 4th order FIR band stop filter is:

[0060]

[0061] Where y(n) is the output signal after filtering; x(nk) is the input signal at the nkth moment; h(k) is the band-stop filter coefficient k = 0, 1, 2, 3, 4; n is the index of the output sequence y(n), indicating that the output of the filter at time point n is being calculated.

[0062] Based on the above embodiment, due to the limitation of the structure and installation method of the accelerometer itself, it is impossible to completely coincide the measurement center with the rotation axis. Therefore, when the sensor rotates, centripetal acceleration is generated on the measurement axis of the accelerometer, which is superimposed on the gravity acceleration and affects the measurement result.

[0063] Since the magnitude of the centripetal acceleration is related to the rotation radius and rotation speed of the accelerometer measurement center, the rotation radius is fixed on the same sensor, and the centripetal acceleration can be measured by only measuring the real-time rotation speed of the sensor;

[0064] Step 300: According to the parameters of the tool speed variation law, by collecting the magnetic component, the real-time speed of the sensor group is calculated and the acceleration component of the sensor group in the dynamic process is collected, and calibration and compensation are performed through the algorithm to eliminate the influence of the centripetal acceleration.

[0065] The speed of the sensor is measured by magnetic sensors on the X and Y axes. Since magnetic sensors are not affected by vibration and centripetal acceleration, they are an ideal way to measure speed.

[0066] In an optional embodiment, when eliminating the influence of centripetal acceleration, the present invention collects the magnetic raw data of Mx, My and Mz at high speed through ADC, calculates the real-time speed r of the sensor, and calculates the current centripetal acceleration value fx through Fourier algorithm using the sensor acceleration raw data ax collected by ADC. r ; According to the formula gx = ax-fx r Get the accelerometer component value gx after eliminating the influence of centripetal force.

[0067] Although high dynamic response accelerometers and fluxgate sensors are selected, their signal sensitivity will change slightly during rotation measurement. This change will still affect the measurement accuracy of the sensor. In order to eliminate this effect, the dynamic parameters of the sensor under rotation must be calibrated.

[0068] Specifically, before the sensor group collects rotation and vibration data, it also includes a dynamic parameter calibration step 400 and a dynamic parameter verification step 500, and the dynamic parameter calibration step 400 and the dynamic parameter verification step 500 are used to correct the influence of rotation measurement on the sensor measurement accuracy.

[0069] Reference Figure 2 Based on the above embodiment, the dynamic parameter calibration step 400 in the present invention includes:

[0070] Step 401, installing the instrument to be calibrated on a turntable, and adjusting the turntable to keep the well inclination angle at 0°±Δθ;

[0071] Step 402, in the well inclination state of 0°, the rotary table speed is set to 20RPM, 40RPM, 60RPM and 80RPM respectively, and the output data of the three-axis accelerometer is synchronously collected at each speed. No less than 10,000 sets of data are continuously recorded under each speed condition to complete the data collection;

[0072] Step 403, adjusting the turntable well inclination angle to 45°±Δθ, and repeating the data acquisition process in step 402;

[0073] Step 404, adjust the turntable well inclination angle to 90°±Δθ, and repeat the data acquisition process of step 402;

[0074] Step 405, adjust the turntable well inclination angle to 135°±Δθ, and repeat the data acquisition process in step 402;

[0075] Step 406: Analyze and calculate all data, and then bring the calculation results into the firmware program of the product, thus completing the dynamic calibration, wherein the Δθ is the allowable error.

[0076] The calibration data collection example is as follows:

[0077]

[0078] Under static offset calibration, at 0° well inclination, the theoretical value of the Z axis should be 980mV (corresponding to 1g gravity), and the measured average value is 980.12mV. The offset needs to be compensated:

[0079] Calibration = Z original - 0.12.

[0080] Reference Figure 3 Based on the above embodiment, the dynamic parameter verification step 500 in the present invention includes:

[0081] Step 501, install the product on the turntable, adjust the well inclination to maintain 0°±Δθ, and record the current well inclination value INCs;

[0082] Step 502, the rotation speed is set to 20RPM, 40RPM, 60RPM and 80RPM respectively, and the well inclination values ​​INC20, INC40, INC60 and INC80 at different rotation speeds are recorded, and the well inclination value recorded under rotation is subtracted from the well inclination value INCs under static state, so as to obtain the dynamic well inclination measurement accuracy;

[0083] Step 503, adjust the well inclination to maintain 45°±Δθ, and record the current well inclination value INCs and azimuth value AZIs;

[0084] Step 504, the rotation speed is set to 20RPM, 40RPM, 60RPM and 80RPM respectively, the well inclination values ​​INC20, INC40, INC60 and INC80 at different rotation speeds are recorded, and the azimuth values ​​AZI20, AZI40, AZI60 and AZI80 at different rotation speeds are recorded, and the well inclination value recorded under rotation is subtracted from the well inclination value INCs under static state to obtain the well inclination measurement accuracy under dynamic state; the azimuth value recorded under rotation is subtracted from the azimuth value AZIs under static state to obtain the azimuth measurement accuracy under dynamic state;

[0085] Step 505, adjust the well inclination to maintain 90°±Δθ, record the current well inclination value INCs and azimuth value AZIs, and repeat the dynamic lower azimuth measurement accuracy step;

[0086] Step 506, adjust the well inclination to maintain 135°±Δθ, record the current well inclination value INCs and azimuth value AZIs, and repeat the dynamic lower azimuth measurement accuracy step, wherein Δθ is the allowable error.

[0087] Dynamic parameter verification example (steps 500-506);

[0088] Among them, the dynamic accuracy verification table of well inclination angle is as follows:

[0089]

[0090]

[0091] The azimuth dynamic accuracy verification table is as follows:

[0092]

[0093] Well inclination error trend: The error is positively correlated with the rotation speed (such as +0.17° at 80RPM), and needs to be compensated by the firmware formula:

[0094] INC calibration = INC original - 0.002·RPM;

[0095] Azimuth error distribution: The error increases with the increase of well inclination (such as -0.5° at 135°). The compensation formula is:

[0096] AZIcalibration = AZIoriginal·(1+0.0001·INC);

[0097] Model verification shows that after compensation, the well inclination error is reduced to ≤0.05°, and the azimuth error is ≤0.2°, meeting the requirements of high-precision measurement while drilling.

[0098] In a specific embodiment, the Δθ angle deviation range of the present invention does not exceed ±1°, and the azimuth adjustment resolution of the turntable during the test reaches 0.1°

[0099] It should be noted that the turntable described in the present invention is a non-magnetic turntable with heating and rotating functions, the maximum heating temperature is 200°C, the maximum rotating speed is 400rpm, and it is controlled by a servo motor, with high speed stability and accuracy. The well inclination and azimuth of the turntable can also be adjusted, and the dynamic parameters of the sensor can be comprehensively tested under different temperature points, different angles and speed conditions.

[0100] In summary, the inclinometer while drilling of the present invention can solve the various problems faced by conventional static measurements. It can achieve real-time and accurate measurement without stopping the drill or the pump during the drilling process. This method saves measurement time and reduces the drill bit stationary time to reduce drilling risks and quickly reach the completed drilling depth. At the same time, by eliminating the vibration and centripetal acceleration of the product, the measurement accuracy is greatly improved, and the accuracy of drill bit position detection during the well rotation process is improved.

[0101] Embodiment 2

[0102] In this embodiment, an error correction system for a while drilling inclinometer is also disclosed. According to the figure, the system includes:

[0103] Sensor unit: used to collect rotation and vibration data. In this embodiment, the sensor group includes three three-axis accelerometer sensors whose central axes are 90° to each other and three-axis fluxgate sensors whose central axes are 90° to each other; wherein the three three-axis accelerometer sensors are respectively denoted as Ax, Ay and Az, and the three three-axis fluxgate sensors are respectively denoted as Mx, My and Mz;

[0104] A data processing unit; used to obtain tool speed change law parameters and amplitude and frequency parameters of the vibration signal based on the rotation and vibration data. The data processing unit described in this embodiment may include a circuit module, a CPU and a center frequency adaptive band-stop filter;

[0105] Vibration elimination unit: It is used to sample the vibration signal at high speed according to the amplitude and frequency parameters of the vibration signal through a band-stop filter with adaptive center frequency, and perform Fourier analysis to find out the frequency of the interference signal, change the center frequency of the band-stop filter in real time, and eliminate the vibration interference signal;

[0106] In this embodiment, the filtering function of the digital filter is realized by the center frequency adaptive band-stop filter;

[0107] When eliminating the vibration interference signal, first collect the acceleration signals of Ax, Ay and Az through ADC and convert them into digital quantities, and perform Fourier analysis to analyze the signal amplitude and frequency. According to the obtained amplitude and frequency results, adjust the center frequency of the band group filter, and then bring the digital quantity corresponding to the three-axis accelerometer sensor into the band stop filter to obtain the accelerometer result of eliminating the vibration interference signal;

[0108] Centripetal acceleration elimination unit: used to calculate the real-time rotation speed of the sensor group and collect the acceleration component of the sensor group in the dynamic process according to the parameters of the tool rotation speed change law, and calibrate and compensate through the algorithm to eliminate the influence of centripetal acceleration;

[0109] Specifically, in this embodiment, the ADC collects the magnetic raw data of Mx, My and Mz at high speed to calculate the real-time speed r of the sensor, and the sensor acceleration raw data ax collected by the ADC is used to calculate the current centripetal acceleration value fx through the Fourier algorithm. r .

[0110] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for error correction of a while drilling inclinometer, characterized in that ,include: According to the rotation and vibration data collected by the sensor group, the parameters of the tool speed change law and the amplitude and frequency parameters of the vibration signal are obtained; According to the amplitude and frequency parameters of the vibration signal, the vibration signal is sampled through a band-stop filter with adaptive center frequency, and Fourier analysis is performed to find out the frequency of the interference signal. The vibration interference signal is eliminated by changing the center frequency of the band-stop filter in real time. According to the parameters of the tool speed change law, the real-time speed of the sensor group is calculated by collecting the magnetic component, and the acceleration component of the sensor group in the dynamic process is collected. Calibration and compensation are performed through the algorithm to eliminate the influence of centripetal acceleration.

2. The error correction method for the inclinometer while drilling instrument according to claim 1, characterized in that: The sensor group includes three three-axis accelerometer sensors whose central axes are 90° to each other and three three-axis fluxgate sensors whose central axes are 90° to each other; wherein the three three-axis accelerometer sensors are respectively denoted as Ax, Ay and Az, and the three three-axis fluxgate sensors are respectively denoted as Mx, My and Mz.

3. The error correction method for the while drilling inclinometer according to claim 2, characterized in that: The filtering function of the digital filter is realized by the center frequency adaptive band-stop filter; When eliminating the vibration interference signal, the acceleration signals of Ax, Ay and Az are first collected by ADC and converted into digital quantities, and Fourier analysis is performed to analyze the signal amplitude and frequency. According to the obtained amplitude and frequency results, the center frequency of the band group filter is adjusted; then the digital quantity corresponding to the three-axis accelerometer sensor is brought into the band-stop filter to obtain the accelerometer result of eliminating the vibration interference signal.

4. The error correction method for an inclinometer while drilling instrument according to claim 3, characterized in that: The center frequency adaptive band-stop filter is a 4th-order FIR band-stop filter, and its center frequency and stopband width are initially designed to be 50 Hz and 20 Hz; The output calculation formula of the 4th order FIR band stop filter is: Where y(n) is the output signal after filtering; x(nk) is the input signal at the nkth moment; h(k) is the band-stop filter coefficient, k = 0, 1, 2, 3, 4; n is the index of the output sequence y(n).

5. The error correction method for an inclinometer while drilling instrument according to claim 2, characterized in that: When eliminating the influence of centripetal acceleration, the original magnetic data of Mx, My and Mz are collected at high speed by ADC to calculate the real-time speed r of the sensor, and the original acceleration data ax collected by ADC is used to calculate the current centripetal acceleration value fx through Fourier algorithm. r ; According to the formula gx = ax-fx r Get the accelerometer component value gx after eliminating the influence of centripetal force.

6. The error correction method for an inclinometer while drilling instrument according to claim 1, characterized in that: Before the sensor group collects rotation and vibration data, it also includes a dynamic parameter calibration step and a dynamic parameter verification step, and the dynamic parameter calibration step and the dynamic parameter verification step are used to correct the influence of rotation measurement on the measurement accuracy of the sensor.

7. The error correction method for an inclinometer while drilling instrument according to claim 6, characterized in that: The dynamic parameter calibration step comprises: Install the instrument to be calibrated on the turntable and adjust the turntable to keep the well inclination angle at 0°±Δθ; Under the 0° well inclination state, the rotary table speed was set to 20RPM, 40RPM, 60RPM and 80RPM respectively, and the output data of the three-axis accelerometer was collected synchronously at each speed. No less than 10,000 sets of data were continuously recorded under each speed condition to complete the data collection; Adjust the turntable well inclination angle to 45°±Δθ and repeat the data acquisition process; Adjust the turntable well inclination angle to 90°±Δθ and repeat the data acquisition process; Adjust the turntable well inclination angle to 135°±Δθ and repeat the data acquisition process; All data are analyzed and calculated, and then the calculation results are brought into the firmware program of the product, thus completing the dynamic calibration, wherein the Δθ is the allowable error.

8. The error correction method for an inclinometer while drilling instrument according to claim 7, characterized in that: The dynamic parameter verification step includes: Install the product on the rotary table, adjust the well inclination to maintain 0°±Δθ, and record the current well inclination value INCs; The rotation speed is set to 20RPM, 40RPM, 60RPM and 80RPM respectively, and the well inclination values ​​INC20, INC40, INC60 and INC80 at different rotation speeds are recorded. The well inclination value recorded under rotation and the well inclination value INCs under static state are subtracted to obtain the dynamic well inclination measurement accuracy; Adjust the well inclination to maintain 45°±Δθ, and record the current well inclination value INCs and azimuth value AZIs; The rotation speed is set to 20RPM, 40RPM, 60RPM and 80RPM respectively, and the well inclination values ​​INC20, INC40, INC60 and INC80 at different rotation speeds are recorded. The azimuth values ​​AZI20, AZI40, AZI60 and AZI80 at different rotation speeds are recorded. The well inclination value recorded under rotation is subtracted from the well inclination value INCs under static state to obtain the well inclination measurement accuracy under dynamic state; the azimuth value recorded under rotation is subtracted from the azimuth value AZIs under static state to obtain the azimuth measurement accuracy under dynamic state; Adjust the well inclination to maintain 90°±Δθ, record the current well inclination value INCs and azimuth value AZIs, and repeat the steps of dynamic azimuth measurement accuracy; Adjust the well inclination to maintain 135°±Δθ, record the current well inclination value INCs and azimuth value AZIs, and repeat the dynamic lower azimuth measurement accuracy step, where Δθ is the allowable error.

9. The error correction method of the inclinometer while drilling instrument according to claim 7 or 8, characterized in that: The turntable is a non-magnetic turntable with heating and rotating functions, the maximum heating temperature is 200° C., and the maximum rotating speed is 400 rpm.

10. An error correction system for a while drilling inclinometer, characterized in that: include: Sensor unit: used to collect rotation and vibration data; Data processing unit; Used to obtain tool speed change law parameters and amplitude and frequency parameters of vibration signals based on rotation and vibration data; Vibration elimination unit: It is used to sample the vibration signal at high speed according to the amplitude and frequency parameters of the vibration signal through a band-stop filter with adaptive center frequency, and perform Fourier analysis to find out the frequency of the interference signal, change the center frequency of the band-stop filter in real time, and eliminate the vibration interference signal; Centripetal acceleration elimination unit: It is used to calculate the real-time rotation speed of the sensor group according to the parameters of the tool rotation speed change law by collecting the magnetic component, and collect the acceleration component of the sensor group in the dynamic process, and calibrate and compensate through the algorithm to eliminate the influence of centripetal acceleration.

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