CN111878068B

CN111878068B - High-temperature solid-state resonance gyroscope and drilling measurement system composed of same

Info

Publication number: CN111878068B
Application number: CN202010393251.6A
Authority: CN
Inventors: 薛旭
Original assignee: Institute of Geology and Geophysics of CAS
Current assignee: Beijing Zhongke Hangxin Technology Co ltd
Priority date: 2020-05-11
Filing date: 2020-05-11
Publication date: 2021-06-29
Anticipated expiration: 2040-05-11
Also published as: CN111878068A

Abstract

The invention provides a high-temperature miniaturized resonant gyroscope which comprises a harmonic oscillator, a circuit board, a piezoelectric element, a supporting base, a shell and a binding post, wherein the harmonic oscillator is arranged in the shell and connected with the supporting base; the invention also provides an inertial navigation system, which comprises a three-axis gyroscope, a three-axis accelerometer and a shock absorber, wherein the gyroscope is fixedly connected with the shock absorber, and the gyroscope adopts the high-temperature resonant gyroscope. The invention also provides a well drilling measuring system and a well drilling measuring method, wherein the system has the environmental adaptability capability of resisting high temperature, strong vibration and large impact and has the advantage of small volume of well drilling measurement; the method is used in the measuring system, and the measurement of the underground position can be accurately carried out.

Description

High-temperature solid-state resonance gyroscope and drilling measurement system composed of same

Technical Field

The invention relates to the technical field of underground azimuth measurement while drilling, in particular to a drilling measurement system adopting a high-temperature solid-state resonant gyroscope and a high-temperature solid-state resonant gyroscope.

Background

The MWD (measurement while drilling) tool, one of the most central guided drilling instruments, has been rapidly developed and successfully applied in the last thirty years, and benefits from the technical breakthrough of the combination of the quartz flexible accelerometer and the fluxgate in the field of oil and gas resource development and application, particularly the adaptability to the underground high-temperature and severe vibration environment and the precision guarantee in the severe environment, so that the quartz flexible accelerometer and the fluxgate become the standard configuration of the guided drilling, and the application range of the quartz flexible accelerometer and the fluxgate covers a vertical well, a large inclination angle and a horizontal well. The combination of the two sensors defines the specification requirement of MWD to a certain extent, and especially, on the premise of ensuring the precision, the combination of reliability and service life under vibration and impact is considered.

In US 6,453,239B 1, Schlumberger company describes in detail the design of a hemispherical gyroscope (while drilling) -based measurement system, which consists of a three-axis hemispherical gyroscope and a three-axis quartz flexible accelerometer, wherein, the gyroscope adopts a 'two-component' structure scheme (see figure 2(b)), the harmonic oscillator adopts a 42-degree inclined installation mode, the three-axis gyroscope adopts a 120-degree inclined angle installation mode, the axial outer diameter dimension of the gyroscope is ensured, the method makes full use of the advantages of high precision, strong environmental adaptability and the like of the hemispherical gyroscope, designs various application scenes, comprises multi-point gyro measurement while drilling, multi-point gyro cable measurement, continuous navigation measurement with zero-speed correction capability, continuous cable measurement based on cable length correction and the like, and applies the Coriolis vibration gyroscope to a measurement while drilling system. However, in this patent, there are problems including, but not limited to:

the fused quartz hemispherical gyroscope has high price and high processing difficulty; by adopting a capacitance detection and feedback mode, a large voltage (such as a reported 300V voltage) is required to realize a force balance mode; the stability and the environmental adaptability under the high-temperature application environment are realized; the power consumption is large.

At present, with the gradual extension of the world exploration field to complex areas and special environments, the development difficulty and the development cost are greatly increased, the exploration and development situation promotes the evolution and the development of well types, and the proportion of complex structure wells such as extended reach wells, ultra-thin oil layer horizontal wells, multilateral wells and the like in the exploration and development of oil and gas fields is larger and larger. With the development of the steering drilling technology represented by the rotary steering technology, especially in deep and ultra-deep steering drilling applications, the requirement for the control accuracy of the well track is continuously increased, and the existing attitude measurement technical means face the following problems and challenges:

1) magnetic field interference problem: the MWD system based on the magnetic sensor measures the earth magnetic field by using the magnetic sensor to calculate the azimuth angle, and the magnetic interference from the stratum ore body, the magnetic interference of a drill rod, the solar wind, the magnetic storm and the like can influence the measurement of the earth magnetic field in the measurement process;

2) near bit measurement problem: the method is limited by the magnetic interference of a drill bit and the length of a non-magnetic drill collar, the conventional MWD attitude measurement system cannot be directly installed at a position close to the drill bit and is generally at least 10-15 m away from the drill bit, so that the current attitude of the drill bit and position information obtained by conversion can be obtained only after the drill bit drills into 10-15 m, if a well track deviates from the original design, the cost of correction after discovery is very high, and particularly the hard formation track with slow drilling speed is corrected;

3) problems with the measurement of the orientation of a rotary steerable tool: the rotary-steering near-bit azimuth measurement is always an important direction for research and development in the field, and relatively speaking, due to the fact that the rotary-steering near-bit azimuth measurement is directly and fixedly connected to the near-bit position and severe environments such as high temperature, large impact and strong vibration, the application of the rotary-steering near-bit azimuth measurement is most challenging to the comprehensive performance requirements of the gyroscope.

4) The problem of windowing of casing in cabled measurement mode: the positioning windowing in the casing is an early application of a gyroscope in the field of petroleum drilling, mainly aiming at cluster wells and horizontal well directional drilling, a cable gyroscope inclinometer is usually adopted to complete windowing positioning, so that trial and error windowing is avoided, the time cost is saved, and the time cost of cable measurement is still not negligible; in addition, after the bushing is windowed, the bushing is still in a magnetic interference environment for a period of time, the orientation measurement is still in a 'blind area' of the fluxgate, the gyroscope is required to realize accurate orientation measurement before the fluxgate effectively works, and the cable measurement mode cannot effectively solve the application.

5) The demand of oil exploration and development for high-end gyroscopes is: the gyroscope can meet the requirements of high temperature and strong vibration, has small volume and high precision, and can normally work under the standard constructed by magnetic measurement MWD.

Disclosure of Invention

The invention combines the solid-state gyroscope technology of HT-CVG (high temperature Coriolis vibration gyroscope) with deep-layer and ultra-deep-layer guiding Drilling application, provides a Measurement while Drilling gyroscope and a Measurement system (Gyro Measurement while Drilling, herein abbreviated as GMD) thereof, realizes the integrated design of system level, sensor level and element level, and meets the application requirements of directional well Measurement, rotary guiding system and the like.

According to a first aspect of the invention, a high-temperature miniaturized resonant gyroscope is provided, the gyroscope comprises a harmonic oscillator, a circuit board, a piezoelectric element, a supporting base, a shell and a binding post, the harmonic oscillator is arranged in the shell and connected with the supporting base, the piezoelectric element is connected with the binding post through a metal conductor, the circuit board realizes signal transmission, and the gyroscope element is fixedly connected with key process points through high-temperature materials and a high-temperature process.

Further, the gyroscope is a small-sized gyroscope capable of operating at a high temperature of 125 ℃ or higher.

Further, the gyroscope can operate at a high temperature of 185 ℃.

Furthermore, the key process points of the fixed connection include the fixed connection points between the piezoelectric element and the harmonic oscillator, between the wiring terminal and the piezoelectric element, between the wiring terminal and the circuit board, between the support base and the harmonic oscillator, and between the shell and the support base.

Furthermore, a welding point is arranged at the top of the shell of the harmonic oscillator, and sealing welding is realized by adopting a high-temperature resistant material.

Further, the high temperature material includes Sn-Ag, Sn-Cu or Sn-Ag-CU alloy.

Further, the diameter of the gyroscope is not more than 30 mm.

Furthermore, a support base of the gyroscope is fixedly connected with the harmonic oscillator, and the bottom of the support base is in a conical design and is fixedly connected with an external structure through a pressing block.

Further, the external structure is an IMU.

Furthermore, the harmonic oscillator also comprises a transition circuit board, a plurality of round holes are formed in the top of the harmonic oscillator, and the conductive metal wire is fixedly connected with the wiring terminal through the round holes.

Further, the piezoelectric element is arranged on the side wall or the bottom of the harmonic oscillator.

Further, the harmonic oscillator adopts the full symmetric structure, and the harmonic oscillator of full symmetric structure includes support column and full symmetric shell, the support base includes bottom and cyclic annular supporting part, the support column is located the cyclic annular supporting part of support base inside, the full symmetric shell is located the cyclic annular supporting part outside of support base, the full symmetric shell adopts the structural style of internal diameter such as, external diameter varies.

Further, the circuit board is located at the lower part of the support base.

Furthermore, a high-temperature resistant vibration absorber is arranged on the periphery of the gyroscope.

Further, the support base and the high temperature resistant vibration absorber are fixedly connected into the IMU.

According to a second aspect of the present invention, there is provided an inertial navigation system, the system comprising a three-axis gyroscope, a three-axis accelerometer and a damper, the gyroscope being fixedly connected to the damper, the gyroscope being a high temperature resonant gyroscope according to the first aspect of the present invention.

Further, the accelerometer is a high temperature quartz flexible accelerometer or a high temperature MEMS accelerometer.

Further, the inertial navigation system further comprises a sensor sensitive to geomagnetism.

According to a third aspect of the present invention there is provided a borehole measurement system comprising an inertial navigation system according to the second aspect of the present invention, the measurement system further comprising:

other sensor unit combinations, wherein the other sensor unit combinations comprise temperature sensors and angle measuring sensors;

the signal acquisition and processing unit acquires intermediate control variables from the combination of the inertial navigation system and other sensor units and the control and calibration unit, and completes signal processing and parameter compensation in the processing unit;

the control and calibration unit is used for controlling and calibrating the rotation of the positions of the gyroscope and the measurement system, and comprises but is not limited to a gyroscope closed-loop control and calibration circuit and a control circuit for rotation modulation;

the system comprises a state monitoring unit and a GMD output unit, wherein the state monitoring unit processes signals from a vibration monitoring sensor or an accelerometer; the GMD output unit comprises an MWD standard interface and is used for outputting the processed signal of the signal acquisition and processing unit;

the power supply unit is used for supplying power to the inertial navigation system, the other sensor unit combination, the signal acquisition and processing unit, the control and calibration unit, the state monitoring unit and the GMD output unit;

and the shell structure is used for accommodating the inertial navigation system and the units.

Further, the system also comprises a rotating unit, and the rotating unit drives the measuring system to rotate.

Further, the signal processing is performed in an ARM core processor or other core processors, and includes but is not limited to a full parameter compensation module, a self-calibration and self-calibration module, an initial alignment module, a continuous measurement while drilling module, and a filtering module.

According to a fourth aspect of the present invention there is provided a borehole measurement method for use in a measurement system according to the third aspect of the present invention, the method comprising the steps of:

s1) the measuring system receives a ground drill stopping instruction and then judges whether the drill collar is static, if yes, rough alignment is started at the position, and if not, the measuring system continues to wait;

s2), finishing coarse alignment, and taking the azimuth angle, the inclination angle and the tool face angle information output by the measuring system when the coarse alignment is finished as a new coordinate vector;

s3), entering a fine alignment process, and estimating new azimuth angle, well inclination angle and tool face angle information according to the speed observed quantity and the earth rotation angular rate observed quantity;

s4) measuring the starting rotation position of the system and acquiring the output of the angle measurement sensor in real time;

s5) at the second position, entering a fine alignment process, and estimating new azimuth angle, inclination angle and tool face angle information by using the velocity vector and velocity observed quantity, the earth rotation angular rate vector and the earth rotation angular rate observed quantity;

s6) finally calculating the azimuth angle, the inclination angle and the tool face angle according to the information of the azimuth angle, the inclination angle and the tool face angle of the first position and the second position, estimating the zero offset error of the gyroscope and the accelerometer, feeding the zero offset error back to an output model of the inertial instrument, and correcting the zero offset error;

s7), the alignment is finished, the error is updated, and the data is stored.

Further, in step S1), after an external instruction is received to obtain a drill stop instruction, the magnitude of mud vibration is determined by an output signal of the vibration monitoring sensor filter acquired by the state monitoring unit or an accelerometer output signal in the inertial navigation system, and it is determined whether to start to perform coarse alignment by a set threshold.

Further, the coarse alignment is to directly use the output information of the gyroscope and the output information of the accelerometer mounted on the carrier to obtain the azimuth angle, the inclination angle and the tool face angle information of the carrier by an analytic method.

The invention has the beneficial effects that:

according to the high-temperature resonant gyroscope provided by the invention, on the basis of the existing metal resonant gyroscope, through researching material characteristics, an assembly process, a structural design, an integrated vibration reduction process and the like of the optimized core components, adopting high-temperature resistant materials and processes and carrying out vibration reduction design, the high-temperature resonant gyroscope can bear the work of a high-temperature environment (above 125 ℃) when applied in a strong vibration environment;

the invention also provides a miniaturized high-temperature resonant gyroscope, which is designed to be similar to the shape design of a cone, can be directly fixedly connected in an external pressing block mode, avoids the installation of a flange plate or a screw, saves the installation space and can greatly reduce the volume;

according to the inertial navigation system provided by the invention, the structure is optimized, and the inertial navigation system has the advantages of meeting the requirements of high temperature and strong vibration and having small volume.

The drilling measurement system provided by the invention has the capability of resisting environment adaptability under high temperature, strong vibration and large impact, and in addition, the precision under the environment is ensured; the trend in oil drilling is to slim hole wells, and therefore the size of the gyroscopes provided in the present invention can also meet their demanding requirements.

According to the drilling measurement method provided by the invention, the method is used in the measurement system, and the azimuth measurement can be accurately carried out.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a prior art "bath pan" curve for a reliable design;

fig. 2 is a schematic structural diagram of a hemispherical gyroscope of the prior art, in which: FIG. 2(a) is a schematic structural diagram of a "three-part" hemispherical gyroscope, and FIG. 2(b) is a schematic structural diagram of a "two-part" hemispherical gyroscope;

FIG. 3 is a schematic diagram of a HT-CVG according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a second HT-CVG according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a triple HT-CVG according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a four HT-CVG according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a five HT-CVG according to an embodiment of the present invention;

FIG. 8 is a first schematic structural diagram of a harmonic oscillator according to the present invention;

FIG. 9 is a second schematic structural diagram of a harmonic oscillator according to the present invention;

FIG. 10 is a schematic diagram of a harmonic oscillator according to a third embodiment of the present invention;

fig. 11 is a fourth schematic structural diagram of a harmonic oscillator of the present invention;

FIG. 12 is a graph of the original zero-offset output of room temperature heating to 150 ℃;

FIG. 13 is an Allan variance test curve for a high temperature gyroscope (numbered 022215A);

FIG. 14 is an Allan variance test curve for a high temperature gyroscope (numbered 022269B);

FIG. 15 is a schematic view of the mounting of a sensing unit of a three-axis gyroscope;

FIG. 16 is a schematic view of the installation relationship of the high temperature sensitive unit and the damper;

FIG. 17 is a schematic view of a directional well horizontal well of the present invention;

FIG. 18 is a block diagram of the system architecture of the present invention;

FIG. 19 is a flow chart of a drilling inertial navigation measurement method according to the present invention;

FIG. 20 is a graph of coarse alignment one-shot simulation results under high temperature and strong vibration environments according to the present invention.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

Fig. 1 is a graph of a classical bathtub designed for reliability, which is a mathematical model established based on an exponential function and divides the time of occurrence of a fault into an early fault period, an occasional fault period and a wear fault period, wherein the early fault period refers to that a product fails early, mainly due to factors such as process defects, and a series of tests conducted before the product leaves a factory, such as vibration, impact, temperature cycle, multiple power-on and power-off, are all used for eliminating the early fault of a gyroscope as soon as possible, so that the product delivered to a user enters a stable occasional fault period section. For the life or MTBF of a GMD (gyroscopic Measurement while Drilling) gyroscope, referring to a period of occasional failure, i.e. a region where the slope of the curve is fixed, the MTBF of a product during the period of occasional failure can be defined as:

MTBF＝T/R (1)

where T refers to the total operating time and R refers to the number of failed components. Then the probability of a particular product surviving during the working time period t is:

P(t)＝e^-t/MTBF (2)

in the development process of gyroscopes, from the initial floating gyroscope to the dynamically tuned gyroscope and to the later developed optical gyroscopes (laser gyroscopes and fiber optic gyroscopes), to the current coriolis vibration gyroscopes, the number of components of the gyroscope is reduced, on the one hand, the manufacturing cost of the gyroscope is reduced, on the other hand, the MTBF of the gyroscope is greatly increased, which is very important for GMD applications. The small size, high precision, high reliability and low cost are the basic requirements of the GMD application, and from this point of view, the coriolis vibration gyroscope represented by the solid-state resonator gyroscope is the most preferable technical solution for the current stage GMD application.

In the aforementioned US patent 6,453,239B 1, Schlumberger company introduced in detail the design scheme of a hemispherical gyroscope (while drilling) -based measurement system, which consists of a three-axis hemispherical gyroscope and a three-axis quartz flexible accelerometer, wherein the gyroscope adopts a "two-component" structure scheme, the harmonic oscillator adopts a 42 ° tilt installation mode, and the three-axis gyroscope adopts a 120 ° tilt installation mode.

The materials commonly used for the resonator of the resonant gyroscope comprise isotropic fused silica, elastic alloy, silicon (MEMS) and the like, and the commonly used shapes are as follows: hemispherical, cylindrical, annular, disc-shaped, etc., the thin shell resonator is thin walled, easily deformable, and the resonance frequency of the resonator, which is determined by its material and shape, is repetitive and stable. The most common harmonic oscillators have three modes of operation: the mode n is 0, in which the resonator performs tension-compression vibration, the mode n is 1, at this time, the mode shape of the resonator performs displacement translation, and the mode n is 2 of bending vibration, where the mode n is 2 is the most stable, and the mode n is 2 is generally selected as the mode shape of the resonator.

When the harmonic oscillator is excited, the mode shape is a standing wave form, and when the harmonic oscillator has no input of angular velocity, antinodes are located on four axes of the symmetrical harmonic oscillator, and when the harmonic oscillator rotates around the symmetrical axis at the angular velocity Ω, the antinode axes cause rotation (precession) of the antinode axes (standing waves) relative to the harmonic oscillator in an inertial space under the action of coriolis inertial force.

Under the action of inertial force, the four-antinode precession angle phi of harmonic oscillator vibration₁Physical rotation angle phi with harmonic oscillator₀There is a fixed hysteresis, i.e. phi₁＝κΦ₀And kappa is called a Blaine factor, the value of the Blaine factor is only related to the material and the shape of the harmonic oscillator, the position of the azimuth angle of the four-antinode vibration mode is detected in real time through the pickup electrode, and the rotation angle of the gyroscope is calculated according to the precession angle of the vibration mode, and the mode is called a full-angle working mode. The precession of the harmonic oscillator is suppressed by applying feedback control such that the four-antinode mode overcomes the coriolis force while remaining suppressed from the case at all times, and the input angular rate is calculated by applying a feedback force, referred to as a depth negative feedback mode or rate mode.

As shown in fig. 2, the structure of the commonly used hemispherical gyroscope is shown, fig. 2(a) is a schematic structural diagram of a "three-component" hemispherical gyroscope, and the core components are a driving electrode, a harmonic oscillator and a measuring electrode; fig. 2(b) is a schematic structural diagram of a "two-component" hemispherical gyroscope, i.e., the core components are the driving and detecting multiplexing electrodes and the harmonic oscillators.

The high-temperature HT-CVG (high-temperature Coriolis vibration gyroscope) adopted by the invention is also a vibration gyroscope based on the Coriolis effect, a contact electrode configuration scheme is adopted, the non-contact electrode configuration is different from that of a spherical electrode or a flat electrode, the piezoelectric ceramic (PZT) excitation efficiency is higher, and the requirements on alignment and assembly are reduced. As shown in fig. 3, which is a schematic structural diagram of an HT-CVG, the high-temperature CVG (abbreviated as HT-CVG) mainly includes: harmonic oscillator 1, piezoelectric ceramics (PZT)2, a supporting base 3, a shell 4, a circuit board 5, a binding post 6, a conductive metal wire 7 and a sealing material 8. The binding post 6 is divided into an internal binding post and an external binding post, wherein the internal binding post is a binding post fixedly connected with the piezoelectric ceramic through a metal wire, and the external binding post is a binding post electrically connected with the circuit board and led out to the outside.

Wherein, the harmonic oscillator can adopt a full-symmetry structure, such as a cylinder, a hemisphere and a combination of related symmetrical structures, such as cylinders with unequal diameters; the harmonic oscillator with the fully symmetrical shape comprises a support column and a fully symmetrical shell, wherein the support column is positioned inside the annular support part of the support base 3, the fully symmetrical shell is positioned outside the annular support part of the support base 3, and the fully symmetrical shell can adopt a structural form with equal inner diameter and unequal outer diameter (the signal-to-noise ratio of the harmonic oscillator can be improved); referring to fig. 8-11, the structures of various harmonic oscillators are shown, wherein the fully symmetric outer shell of the harmonic oscillator in fig. 8 is a cylinder with unequal diameters, and the supporting column is arranged inside the cylindrical fully symmetric outer shell; the fully symmetric outer shell of the harmonic oscillator in fig. 9 is a cylinder with unequal diameters, and the supporting column is arranged at the top of the cylindrical fully symmetric outer shell with unequal diameters; fig. 10 shows the full-symmetric case of the harmonic oscillator as a variable-diameter cylinder with the supporting posts at the top of the variable-diameter cylinder; fig. 11 the resonator support posts are inside the cylindrical core and the resonators are provided with a plurality of lead holes.

Wherein the piezoelectric ceramics 2 can be arranged on the side wall or the bottom of the full-symmetrical housing (when the harmonic oscillator is inverted, called the top, and is consistent here without affecting the characteristic description), and the supporting base 3 comprises a bottom part and a supporting part.

In the first to fourth embodiments (see fig. 3 to 6), the support portion is annular and is disposed above the bottom portion; in the fifth embodiment (see fig. 7), an annular transition circuit board is arranged on the top of the annular supporting part; the fully symmetrical harmonic oscillator structure is fixed on the upper part of the supporting base and matched with the supporting base, the fully symmetrical harmonic oscillator comprises a fully symmetrical shell and a supporting column, as an embodiment, a conductive metal wire (line) is fixedly connected with a binding post through a round hole at the top of the harmonic oscillator, and in the embodiment, a transition circuit board is additionally arranged between the harmonic oscillator and the supporting base; a silk screen printing layer can be designed in the transition circuit board to realize interconnection of internal signals, and preferably, 8 piezoelectric ceramic electrodes are subjected to internal electric connection and integration, so that four or more piezoelectric ceramic electrodes are led out, 8 piezoelectric ceramic electrodes are not required to be led out, and the process difficulty is reduced.

In the first and second embodiments, the piezoelectric ceramic 2 is fixed at the bottom of the fully symmetric shell of the harmonic oscillator 1, and forms a lever effect with the cylindrical shell with unequal outer diameters, so that the driving sensitivity is improved; the resonator is externally provided with a shell 4, and the shell 4 and the support base 3 are sealed, and as an embodiment, laser welding sealing can be adopted. In the third and fourth embodiments, the piezoelectric ceramics 2 are located on the side walls of the fully symmetric housing of the harmonic oscillator 1; in the fourth and fifth embodiments, the resonator shell is a variable diameter resonator shell.

In the first to fourth embodiments, the conductive wire 7 connects the piezoelectric ceramic 2 and the post 6. The circuit board 5 is located below the support base 3 and the top of the housing 4 is sealed with a sealing material 8.

In addition, in the first embodiment, the bottom of the supporting base 3 is fixed by screws or flanges;

in the second to fifth embodiments, the bottom of the support base is designed in a conical shape (the bottom of the support base is shown to be conical with an inclined edge), and at present, a small-size borehole is a trend, and the measurement instrument is required to have a very small size, for example, as the size of MWD, the current specifications are phi 48mm and phi 36mm, for the traditional installation through a positioning hole or a flange, due to size limitation, the appearance design similar to the conical shape is designed, and the measurement instrument can be directly fixedly connected in an external pressing block mode, so that the installation of the flange or a screw is avoided, the installation space is saved, and the volume can be greatly reduced.

The harmonic oscillator of the HT-CVG is made of a high-Q-value alloy material, and compared with quartz CVG which adopts a fused quartz material as a harmonic oscillator material, the cost is lower; the harmonic oscillator processing technology is a cylindrical structure and is simple, and quartz CVG adopts a hemispherical structure, so that the operation is complex and certain processing cost is caused.

The HT-CVG adopts a piezoelectric (low voltage 5V) excitation and detection mode, and compared with a quartz CVG adopting a capacitance (high voltage 300V) excitation and detection mode, the voltage is lower.

The vacuum packaging mode of the HT-CVG is medium vacuum degree, and a getter is not needed, while the quartz CVG adopts extremely high vacuum degree and needs a getter.

The static/dynamic balance in HT-CVG is achieved by grinding the removed mass (conventional process), while quartz CVG is achieved by plasma (complex process), which is complex to operate and more costly.

As shown in Table 1, given the typical characteristic comparison of HT-CVG to quartz HRG, it can be seen that HT-CVG has the potential for low cost and high reliability.

TABLE 1 characteristic comparison of HT-CVG with Quartz HRG

Because the harmonic oscillator material is inhomogeneous and the quality unbalance error is brought by the processing error, the harmonic oscillator Q value is influenced by the important factor, and the energy loss brought by the unbalanced quality dm is as follows:

the parasitic quality factor due to mass imbalance is expressed as:

wherein, ω is_dmNatural frequency of vibration, Q, of the unbalanced mass_dmIs its quality factor, ω_xThe natural frequency of a harmonic oscillator is referred to, E' refers to energy leakage of unbalanced mass, and dm/m is 10 in the prior art^-3The unbalanced mass can reduce the comprehensive quality factor of the harmonic oscillator by one order of magnitude, so that the driving energy of the harmonic oscillator is maintained to be improved by one order of magnitude, and the generated control error is increased by one order of magnitude.

Energy dissipation caused by material non-ideality and processing error is bidirectional, on one hand, energy is transmitted and dissipated outwards through the base, on the other hand, external energy is easily transmitted to the harmonic oscillator through the base, for an ideal harmonic oscillator, the antinode and node full symmetry characteristics counteract and isolate external energy interference, and in one oscillation cycleIn the meantime, the force or moment acting on the support body is zero, and when non-ideal factors such as mass unbalance exist, energy leakage of the harmonic oscillator is caused, and meanwhile, the support body cannot completely isolate external vibration. When there is an external input vibration disturbance, an additional force f is generated by the unbalanced mass coupling_dm，f_dmIs due to the force transmitted to the harmonic oscillator by the external vibration:

wherein gamma is_aRefers to the external vibration acceleration, and therefore the unbalanced mass dm is a main source of the gyro vibration rectification error. As an inertial device applied to GMD, in a high-temperature vibration environment in a well, energy dissipation due to mass imbalance is easy to interfere with harmonic oscillators from the outside, which is also an important factor limiting GMD measurement accuracy, especially accuracy in a continuous measurement mode.

Therefore, to achieve a higher Q value, the above four factors need to be considered, wherein the material characteristics and the stability of the resonator are intrinsic basic factors determining the quality factor, and the processing accuracy of the resonator is a determining factor determining the energy loss of the resonator. The energy loss of the harmonic oscillator brings zero offset error (Bias) on one hand, and the stability of the energy loss is the key for determining the stability (Bias Drift) of the zero offset on the other hand, so that the energy loss is reduced, the comprehensive quality factor of the harmonic oscillator is improved, the requirement for external control energy for maintaining the stable amplitude vibration of the harmonic oscillator is reduced, and the error brought by a controller is reduced.

In addition to the structural design, the invention aims to provide a high-temperature Coriolis vibration gyro (HT-CVG) which can bear the work of a high-temperature environment (above 125 ℃).

Specifically, on the basis of the existing metal resonant gyroscope, the application of the metal resonant gyroscope to high temperature is realized by researching the material characteristics, the assembly process, the integrated vibration reduction process and the like of the optimized core components.

The invention realizes the prototype development of the HT-CVG high-temperature gyroscope, and researches a related self-calibration method aiming at the full-well inclination measurement application of GMD.

In this embodiment, the process of the HT-CVG is modified, particularly with respect to the improvement of key process points within the HT-CVG and the improvement of process points between the HT-CVG and the high temperature resistant damper.

Wherein key process points include, but are not limited to: welding spots are arranged between the harmonic oscillator and the supporting base to realize fixed connection; welding spots are arranged between the piezoelectric ceramics and the cylindrical harmonic oscillator to realize fixed connection; welding spots are arranged between the internal wiring terminal and the internal circuit substrate to realize solid connection; welding spots are arranged between the supporting base and the internal circuit substrate to realize fixed connection; welding spots are arranged between the internal binding posts and the circuit board to realize solid connection; welding spots are arranged between the external binding post and the circuit board to realize the fixed connection; in another embodiment, the above-mentioned fixing manner may be performed by a glue bonding manner instead of using welding spots.

Furthermore, the top of the shell is provided with a welding point, and welding is realized through sealing welding flux in a vacuum environment.

Specifically, as shown in table 2:

TABLE 2 description of the components of the high temperature header Key Process Point interconnect

In the embodiment, the process parameters of the high-temperature glue or the high-temperature solder are optimized, so that the components of the harmonic oscillator and the HT-CVG formed by the components can work normally in a high-temperature environment.

The welding process of each key part in table 2 is the basis for determining whether the high-temperature CVG gyroscope can work normally and stably, and the long-term stability, excellent repeatability, excellent vibration characteristics (low vibration rectification error) and high MTBF (mean time between failure) of the high-temperature CVG gyroscope are realized according to the environmental requirements of high temperature, strong vibration, large impact and the like

Different solders are adopted to realize the interconnection of the key components, and a high-temperature process is also required to be considered, wherein the high-temperature process comprises the selection of process parameters of the solders, and the following factors are generally required to be considered:

1. melting point of solder

Because the CVG gyroscope works in a high-temperature environment for a long time, the temperature is as high as 150 ℃ and even 185 ℃ at 4000 meters or even 8000 meters. The traditional solder has lower melting point, easy coarsening of the structure at high temperature and reduced mechanical property, and can not meet the use requirement.

2. Shear strength of solder

The shear strength is the key to determine whether the CVG gyroscope can survive under strong vibration and large impact, and especially at high temperature, the shear strength of the solder becomes poor;

3. creep and thermal fatigue resistance of solder: long term stability and repeatability of the gyroscope can be affected.

The traditional SnPb or 62Sn36Pb2Ag solder has low melting point, easily coarsened structure at 150 ℃ and reduced mechanical property, and can not meet the requirements. In addition, in the prior art, the gyroscope is mostly applied to ground or space applications, and only needs to meet a high-temperature use environment of 65 ℃ or not higher than 85 ℃, and cannot meet the requirements of working in a high-temperature environment (especially at a temperature of more than 185 ℃), and in addition, in a measurement while drilling mode, a long-time strong vibration and large impact environment cannot be met by the prior art, so that the severe application environment cannot be met by the prior art.

The welding of the harmonic oscillator and the base belongs to metal materials, in one embodiment of the invention, Ag-doped Sn materials can be adopted, such as Sn96.5Ag3.5, the melting point of the Sn-Ag-Cu alloy is 221 ℃, 38 ℃ higher than that of the traditional Sn-Pb alloy, in addition, Sn-Ag-CU alloy generated by extending from Sn-Ag and Sn-Cu is eutectic phase, the melting point can reach 217 ℃, and the Sn-Ag-CU alloy can also be used as the welding material of the harmonic oscillator and the base. In another embodiment, the creep resistance of Sn-Ag or Sn-Ag-CU alloy is better than that of the traditional solder, and can be used as a preferred solder for the harmonic oscillator and the base.

In the embodiment of the invention, a scheme of adopting contact type piezoelectric ceramic to drive and measure is adopted, so that the driving efficiency and the detection sensitivity are improved; unlike a non-contact electrode configuration, which is either a spherical electrode or a flat electrode, piezoelectric ceramic (PZT) actuation is more efficient and alignment and assembly requirements are reduced.

The fully-symmetrical (such as cup-shaped and cylindrical) harmonic oscillator mass block is fixedly connected to the supporting base, in one embodiment, the mass block is excited by piezoelectric ceramics to resonate, the harmonic oscillator resonates according to a stable amplitude and a stable frequency through a control circuit, when an external input angular rate exists, the standing wave of the harmonic oscillator is made to precess by the Coriolis force generated by the vibration amplitude of the harmonic oscillator, so that a mode along the direction of 45 degrees is excited, and the external input angular rate can be obtained by detecting the vibration amplitude in the direction. In order to reduce the energy consumption of the harmonic oscillator, the harmonic oscillator is sealed in the vacuum cavity through the shell.

In order to meet the reliability and precision of the solid-state gyroscope in a high-temperature environment, the piezoelectric ceramics need to be bonded to the surface of the harmonic oscillator by high-temperature welding glue or at high temperature, the harmonic oscillator and the base are processed and assembled by adopting a high-temperature resistant process, and the internal wiring circuit board adopts a high-temperature resistant PCB or a ceramic substrate; the shell and the base are sealed by adopting a high-temperature-resistant welding process, such as a laser welding process.

In the test, the gyroscope is placed in a heating device, the temperature is increased from room temperature to 150 ℃, then the gyroscope is naturally cooled, the original output of the zero-offset curve of the gyroscope in the process is shown in figure 12, and the gyroscope works normally in the sampling process of 18 hours.

On the basis of this test, the following were respectively: carrying out fixed-point temperature tests at room temperature, 90 ℃, 125 ℃ and 150 ℃, preserving heat for 1h at each temperature point, collecting data at each constant temperature point after the temperature is stable, and calculating Allan variance; and tested the gyroscope performance test at 185 ℃. FIG. 13 shows the test data for a high temperature gyroscope, numbered 022215A, with random angular walk remaining substantially unchanged and zero bias instability parameter increasing with increasing temperature, at 0.04deg/h at room temperature and 0.09deg/h at 150 deg.C in a high temperature environment ranging from room temperature to 150 deg.C.

A further gyroscope, numbered 022269B, was then subjected to a higher temperature test in which a 185 ℃ high temperature test was added and the Allan variance curve at each temperature point is shown in figure 7.

As can be seen from FIG. 14, the random angular walk values of the high temperature gyroscope numbered 022269B at various temperature points are substantially unchanged, and in addition, the parameter distribution of zero bias instability is relatively concentrated from room temperature to high temperature of 185 ℃, the zero bias instability changes from 0.03deg/h to about 0.05deg/h, and the trend term drift is better suppressed.

The test of a plurality of high-temperature gyroscopes is carried out, and the test data shows that the random walk value of the angle is not obviously changed at different temperatures from low temperature to high temperature, and the ARW value at each temperature point is smaller than that at each temperature point

The zero-bias instability index worsens with increasing temperature, and in general is less than 0.1deg/h at each temperature point.

As shown in fig. 15, the gyroscope in the GMD of the present invention is arranged in a manner that three-axis gyroscopes with high temperature resistant vibration dampers are independently and detachably mounted in the GMD frame, preferably, the three-axis gyroscopes are arranged at 90 degrees to each other, which comprehensively considers the heat dissipation design, vibration characteristics and convenience of testing and maintenance. In other embodiments, the coordinate system may be solved in a calibrated manner if the three-axis gyroscope is not in a 90 degree setting.

FIG. 16 shows the relative positions of the vibration damper and gyroscope, in this embodiment the base of the gyroscope is conical in shape and is secured to the IMU by the vibration damper, which in one embodiment is a high temperature resistant vibration damper.

Referring to fig. 16, a resonator 15 and a pressing block 11 are arranged in a probe 14, wherein a damper 12 is arranged on the periphery of the resonator 15, and the damper 12 is fixedly connected with the conical outer part of the support base of the gyroscope, and can completely surround the gyroscope or partially surround the gyroscope; the pressing block 11 is connected with the probe 14 through a pressing block screw 13.

For the coriolis vibration gyroscope, the zero offset stability and repeatability of the gyroscope under high temperature and strong vibration are core factors influencing the GMD orientation measurement accuracy, and the non-strict isotropy (generating unbalanced mass) of the harmonic oscillator is a main factor generating vibration rectification errors. Because the unbalanced mass of the harmonic oscillator can cause energy leakage, on one hand, the amplitude of the energy of the harmonic oscillator is increased, and control errors are brought, and on the other hand, the normal operation of the harmonic oscillator is influenced by external vibration interference, so that vibration rectification errors are brought. By designing the high-temperature resistant vibration absorber of the GMD, the vibration energy exchange between the outside and the harmonic oscillator is reduced, so that the purpose of reducing the vibration rectification error of the gyroscope is achieved. The shock absorber and the HT-CVG are in a pressing block mode, and the shock absorber is a bearing part, so that external vibration energy is attenuated.

In the field of application of oil drilling and directional drilling measurement, the application of gyroscopes mainly belongs to two major categories, one category is static point measurement, and measurement of the geographical North direction is realized mainly through the sensitive ground speed horizontal component of the gyroscopes, which is called a North-seeking gyroscope (True North Finder) or a Gyro-Compass (Gyro-Compass) mode; the other is continuous measurement, and attitude and azimuth information is measured in real time by adopting a standard inertial navigation algorithm according to the result of initial alignment (north finding), so that the well track is fitted.

The mode division of realizing mainly includes the mode along with the drilling and has the cable mode, along with the drilling mode, the combination of the gyroscope is fixedly connected with drilling tool, when the drilling tool is in the static position (for example when the rotary steering tool begins to change the pole), the combination of the gyroscope begins to work, generally adopt and seek the north mode, realize the fast north orientation and measure, when the drilling tool is crept into the work, the combination of the gyroscope is in the dormant state at this moment, creep into along with the drilling tool together, therefore, the gyroscope guarantees to survive under high temperature, strong vibration and big impact, it can guarantee the measuring accuracy after opening the working mode; under the cable logging mode, the gyroscope generally works independently, the well trajectory is measured mainly aiming at the cable logging application, the efficiency is low, and the working environment of the gyroscope is moderate compared with that of the gyroscope while drilling.

In addition, the gyroscope is divided into a platform type and a strap-down type from a fixed connection mode of the gyroscope, the gyroscope is located in one measuring element in a rate stabilizing loop in a platform type working mode, an inertial space is established in the rate stabilizing loop, accordingly, the accelerometer or other sensors complete measurement of attitude and azimuth relative to the inertial space, the gyroscope and the accelerometer are directly and fixedly connected to a measuring tool in the strap-down type, and measurement of azimuth and attitude information is achieved through a north-seeking algorithm or a strap-down algorithm.

In the above various application modes, except for a sensor with a gyroscope as a core, an accelerometer component is required to calculate a tool face angle and a well inclination angle by sensing the earth gravity component, and the two key drilling parameters are the premise of calculating an azimuth angle, so that the accelerometer and the gyroscope are equally important, and a quartz flexible accelerometer is commonly used at present and widely applied to MWD based on magnetic measurement.

For directional well measurement, especially for the development of the horizontal well shown in fig. 17, it is required that the gyroscope not only has high accuracy, but also, more importantly, has the ability of environmental adaptability to withstand high temperature, strong vibration and large impact, and in addition, ensures accuracy under the above environment. In addition, the trend of oil drilling is to use small-bore wells, and therefore, the size requirement of the gyroscope is also severe.

FIG. 18 shows the structure of a directional well drilling azimuth measurement system, according to one embodiment of the present invention. The inertial navigation unit comprises a triaxial high-temperature gyroscope and a triaxial high-temperature accelerometer, and is fixedly connected into a skeleton structure of the GMD in a strapdown mode by respectively adopting an orthogonal installation (or non-orthogonal mode, and the initial installation angle and a corresponding conversion coordinate system need to be calibrated), wherein the high-temperature accelerometer can select two schemes of a high-temperature quartz flexible accelerometer and a high-temperature MEMS accelerometer; in another embodiment, the inertial navigation unit further comprises a three-axis high temperature gyroscope, a three-axis high temperature accelerometer, and a fluxgate.

As shown in fig. 18, the probe structure includes, in addition to the inertial navigation unit, a housing structure, a combination of other sensor units, a signal acquisition and processing unit, a control and calibration unit, a power supply unit, a state monitoring unit, and a GMD output unit.

The shell structure comprises a rotating unit, a framework and a pressure-resistant pipe; in one embodiment, the rotary unit rotates in two fixed positions, but also between more positions (four positions).

Other sensor unit combinations include, but are not limited to: temperature sensors, angle sensors, etc.

The signal acquisition and processing unit acquires intermediate control variables (such as the vibration amplitude of the gyroscope, the phase of the gyroscope, the temperature and the like as an example) from the control and calibration unit, and completes calibration and parameter compensation in the processing unit.

The method specifically comprises the following steps:

a signal acquisition unit: the method comprises the steps of collecting a gyro signal, an accelerometer signal, a sensor signal sensitive to geomagnetism, a vibration monitoring signal, a temperature signal, an angle signal and the like; further comprising a signal processing unit: the signal processing unit is carried out in an ARM core processor or other core processors and comprises but is not limited to a full-parameter compensation module, a self-calibration and self-calibration module, an initial alignment module, a continuous measurement-while-drilling module, a filtering (such as an anti-aliasing filter) module and the like.

The full-parameter compensation module is used for realizing parameter compensation by acquiring a plurality of observation points in the gyroscope and the accelerometer and by error modeling and related algorithms, and specifically comprises the step of compensating drift errors of the gyroscope or the accelerometer caused by temperature, vibration and the like.

The self-calibration and self-calibration module fully utilizes the full-symmetry characteristic of the high-temperature gyroscope, collects key monitoring points in the gyroscope in real time through externally fed excitation signals, calibrates the zero offset drift error of the gyroscope in the processor through an algorithm, and calibrates the scale factor error of the gyroscope.

The initial alignment module is used for respectively sensing the earth rotation angular rate information and the gravity acceleration information by the gyroscope and the accelerometer under the static base, calculating initial values of an azimuth angle, a well inclination angle and a tool face angle by a coarse alignment algorithm, and then calculating the azimuth angle, the well inclination angle and the tool face angle of the GMD by adopting a Kalman optimal estimation algorithm in combination with external auxiliary information such as zero-speed correction information and the like.

The continuous measurement while drilling module is used for outputting azimuth information, inclination angle information and tool face angle information in GMD continuous working in real time through a related algorithm on the basis of an initial azimuth angle, inclination angle and tool face angle obtained through initial alignment calculation, and further calculating well track information.

The filtering module is used for outputting real-time acquired multi-dimensional sensor signals (accelerometer, gyroscope, magnetic sensor and other sensor signals) to an ADC module in the signal acquisition and processing unit through a filter, usually an anti-aliasing filter, so as to realize analog-to-digital conversion.

Control and calibration units include, but are not limited to: a gyro control and calibration circuit and a control circuit for rotation modulation. Wherein, the method comprises closed-loop control of the gyroscope; in addition, the control and calibration unit and the signal acquisition and processing unit jointly control the rotation unit to drive an inertial navigation system consisting of a three-axis accelerometer and a three-axis gyroscope to carry out rotation modulation (or rotation position), so that zero offset error elimination or inhibition of the accelerometer and the gyroscope is realized.

The rotating unit includes a rotational position drive mechanism.

Wherein, the filtering module also comprises a vibration monitoring filter circuit.

In one embodiment, the vibration monitoring filter circuit is a band-pass circuit, the cut-off frequencies of-3 dB are 8Hz and 15KHz respectively, and the vibration monitoring frequency band is insensitive to signals below 8Hz because the working frequency band is low and close to direct current when the GMD is normal; the self-vibration frequency of the gyroscope is close to 8KHz, the bandwidth of the quartz flexible accelerometer is 100Hz, the cut-off frequency of a high frequency band is set to be 15KHz, and in the GMD working process, because the possible impact magnitude is large and the acquired frequency range is wide, the open-loop silicon-based MEMS or piezoelectric accelerometer can be preferably selected, and the wide range and the wide bandwidth are considered.

The power supply unit comprises a power supply for the inertial navigation unit, the signal acquisition and processing unit, the control and calibration unit, the rotation unit, the state monitoring unit, the GMD output unit and other sensor combination units.

In the state monitoring unit and the GMD output unit, the state monitoring unit comprises a vibration monitoring sensor and performs related algorithm processing on signals of the vibration monitoring sensor or an accelerometer; the GMD output unit comprises an MWD standard interface, and the signal acquisition and processing unit outputs a result to the GMD output unit.

The measurement system is used in the drilling engineering shown in fig. 17, is used for directional drilling of a directional well, measurement of a well track and the like, can be installed in a drill collar in a Measurement While Drilling (MWD) mode, and can also be used in a wireline logging mode.

As an example, in the context of Measurement While Drilling (MWD) applications, the measurement method of the system is shown in fig. 19. The method comprises the following steps:

1) the measuring system (probe) receives a ground drilling stopping instruction, and the sensor judges whether the drill collar is static or not so as to avoid the influence of interference factors such as a slurry pump on the measuring precision. If so, coarse alignment is started at that position (i.e., the first position), and if not, waiting continues.

When an external instruction is received, after a drill stopping instruction is obtained, firstly, a state monitoring unit carries out relevant algorithm operation on signals acquired and filtered by a vibration monitoring sensor or an accelerometer in an inertial navigation system, the size of mud vibration is judged, and whether coarse alignment is started or not and whether Kalman optimal estimation can be started or not is judged through a set threshold value.

The external (e.g., job site) initial alignment command is mainly a command from the GMD system level, and at this time, the job site determines that the drill collar is in a drill-stop state.

The method comprises the steps of performing instruction interpretation on an accelerometer or a vibration monitoring sensor, namely, after receiving an external instruction, performing interpretation through a state monitoring unit, interpreting whether interference factors such as mud and the like exist underground or not, outputting through a filter of the sensor, setting a threshold value judging program through the state monitoring unit, and performing coarse alignment when a shaking value is smaller than a set value.

The coarse alignment is to directly use the output information of a gyroscope and the output information of an accelerometer which are arranged on a carrier to obtain the information of an azimuth angle, a well-angle and a tool face angle of the carrier by an analysis method;

2) and finishing coarse alignment, and taking the azimuth angle, the inclination angle and the tool face angle information output by the system at the end of the coarse alignment as a new coordinate vector.

The system outputs the output of the coarse alignment calculation.

3) And entering a fine alignment process, and estimating the information of the azimuth angle, the well angle and the tool face angle after data fusion according to external observation vectors such as the speed observation quantity and the earth rotation angular rate observation quantity and an optimal estimation algorithm such as a Kalman algorithm.

4) And starting to rotate the position, and acquiring the output of the angle measuring sensor in real time.

5) And at the second position, entering a fine alignment process, and estimating new azimuth angle, well angle and tool face angle information.

6) And finally calculating the accurate azimuth angle, the inclination angle and the tool face angle after the optimal estimation according to the azimuth angle, the inclination angle and the tool face angle information of the first position and the second position, estimating the zero offset error of the gyroscope and the accelerometer, and feeding the zero offset error back to an output model of the inertial instrument for correction.

7) And after the alignment is finished, updating the error and storing the data.

Among the above methods, there are various methods for coarse alignment of strapdown inertial navigation: directly using components of the gravity acceleration and the earth rotation angular rate as input to solve, and adopting an Euler angle method to solve (an analytic method); or a double-vector attitude determination principle attitude matrix method is adopted, and in addition, an inertial system alignment method under a shaking base can also be adopted. In any coarse alignment mode, final limit accuracy analysis is almost consistent, that is, the azimuth alignment accuracy is mainly related to the drift error of an equivalent east gyroscope, the horizontal attitude accuracy depends on the accelerometer drift error of a horizontal axis, and various coarse alignment methods only have differences from the inhibition capability, the calculated amount and the like of external environment interference.

Because the geographical position of the drilling construction site is known, the components of the rotational angular velocity vector of the earth in a geographical coordinate system and the gravity vector can be accurately obtained at the moment, and the following formula is shown:

wherein g, ω_ieL respectively represents the magnitude of the local gravitational acceleration, the magnitude of the angular rotation rate of the earth and the local latitude, and the north component omega of the angular rotation rate of the earth is recorded_N＝ω_iecosL and the sky component ω_U＝ω_iesinL。

In the course of coarse alignment of the static base, the gyroscope and the accelerometer in the GMD system respectively measure the projections of the gravity vector and the rotational angular velocity of the earth under a carrier system, the influence of slurry shaking interference is ignored, and the measurement values of the three-component gyroscope and the three-component acceleration on the carrier are as follows:

wherein the content of the first and second substances,

the rough alignment time is generally very short, the measurement value of the inertial instrument is generally a smooth mean value within a period of time, when the inertial instrument has no obvious trend item drift error, the longer the smoothing time is, better precision can be obtained, under the condition of comprehensively considering the rough alignment time and the alignment precision, the judgment and analysis can be carried out on Allan variance test data according to the smoothing time, and the optimal smoothing time is selected according to the time of the Allan variance bottoming.

From the equations (6) and (7), the pitch angle (inclination angle) can be obtained:

determining the roll angle (tool face angle):

is obtained by

And

by substituting equation (6):

the solution heading angle (azimuth) is:

equations (9), (10) and (12) constitute the basic algorithm of the euler angle coarse alignment, and the ultimate accuracy of the euler analysis method static base alignment is analyzed below.

Consider the zero offset error of the accelerometer and gyroscope:

in the formula (13), the reaction mixture is,

zero offset error, epsilon, of accelerometers under separate surface-loading system and navigation system^b、εⁿSeparate meter carrier system and guideZero offset error of the gyroscope under the navigation system.

When solving the differential in one direction, making the angle in the other two directions zero, respectively differentiating the two sides of (9), (10) and (12) and neglecting the second-order small quantity to obtain:

equations (14), (15) and (16) determine the ultimate accuracy of the static base alignment. Attitude alignment accuracy under static base conditions depends primarily on east and north accelerometer drift errors, while azimuth alignment accuracy depends primarily on east gyro drift errors and east accelerometer drift errors.

In high temperature and strong vibration environments, the results of the coarse alignment one-time simulation are shown in fig. 20 when considering the repetitive drift errors of successive starts of the gyroscope and accelerometer.

The invention provides a model of an inertial instrument and an optimal estimation theory based on Kalman:

firstly, an error model of an inertial instrument is given, scale factor errors and installation errors are ignored under a static base, and an output model of a gyroscope in a carrier coordinate system can be expressed as follows:

wherein

Mean, omega, of gyroscope sample outputs^bIs the real angular rate input value of the gyroscope, epsilon₀Is the constant drift of the gyroscope, epsilon_rFor slowly varying drift, epsilon_wIs a fast-varying drift.

ε₀The method mainly comprises the following steps of (1) sequentially starting repetitive errors which can be expressed by random constants, wherein an error model is as follows:

slowly varying drift epsilon_rThe trend term, representing the gyroscope, characterizes the rate ramp term in the Allan variance, which can be described generally by a first order Markov process, i.e.:

in the formula (19), τ_gTime of relevance for Markov Process, w_rIs white noise.

The method can restrain the trend term error related to the gyroscope and time through comprehensive error compensation, and can keep longer time after the Allan variance of the gyroscope is in touch-down time, so that the Markov related time is longer in practice, and can be ignored in the alignment time, and the output model of the gyroscope can be simplified as follows:

wherein, the zero offset error of the gyroscope is as follows:

ε＝ε₀+ε_w (21)

the term ε associated with white noise is generally expressed as an angular random walk coefficient ARW_w。

Also, the accelerometer output model can be simplified as:

wherein the content of the first and second substances,

mean value of accelerometer sample output, f^bIs the true acceleration value of the accelerometer,

in order for the accelerometer to drift in a constant value,

is a white noise random error.

The method mainly comprises the following steps of (1) repeatedly starting the accelerometer, wherein the repeated error can be expressed by a random constant, and an error model is as follows:

define the zero offset error of the accelerometer as:

the term related to white noise is typically expressed in terms of a Power Spectral Density (PSD) value within a certain bandwidth of the accelerometer

The gyroscope output model and the accelerometer output model are collectively referred to as an output model of the inertial instrument.

The method of fine alignment comprises the following steps:

the navigation coordinate system is taken as a northeast geographical coordinate system, a 12-dimensional inertial navigation system precise alignment mathematical model is established, and the state variables of the Kalman filter are as follows:

in formula (25), each is: speed error δ vⁿStrapdown inertial navigation mathematic platform misalignment angle phiⁿConstant drift of high-temperature gyroscope

Zero offset from the constant of the high temperature accelerometer

And

the method is mainly brought by the repeated starting error of the high-temperature inertial instrument, and according to an error model of the strapdown inertial navigation system under a static base and neglecting a small amount of errors, the state equation is obtained as follows:

in the above formula, the first and second carbon atoms are,

in the formula (27)

The method is characterized in that random white noise of an accelerometer and a gyroscope in a carrier coordinate system (b system) is respectively generated, after comprehensive temperature compensation and elimination of the norm-up factor, the output of an inertial instrument can be represented as zero-mean normal distribution, and in practical application, all model coefficients are solved by Allan variance and used as prior values estimated by an inertial instrument model.

Output speed v of static carrier and navigation calculation when GMD system static base is alignedⁿI.e. the velocity error deltavⁿWill delta vⁿAs a measurement value, the measurement equation is:

Z_v＝δvⁿ＝[0_3×3 I_3×3 0_3×3 0_3×3]X+V_v (28)

wherein, V_vNoise is measured for the velocity in the navigation coordinate system.

The embodiments of the present application are described in detail above. As used in the specification and claims, certain terms are used to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. "substantially" means within an acceptable error range, and a person skilled in the art can solve the technical problem within a certain error range to substantially achieve the technical effect. The description which follows is a preferred embodiment of the present application, but is made for the purpose of illustrating the general principles of the application and not for the purpose of limiting the scope of the application. The protection scope of the present application shall be subject to the definitions of the appended claims.

It should be understood that the term "and/or" as used herein is merely one type of association that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

The foregoing description shows and describes several preferred embodiments of the present application, but as aforementioned, it is to be understood that the application is not limited to the forms disclosed herein, but is not to be construed as excluding other embodiments and is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the application as described herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the application, which is to be protected by the claims appended hereto.

Claims

1. A high-temperature miniaturized resonant gyroscope comprises a harmonic oscillator, a circuit board, a piezoelectric element, a supporting base, a shell and a wiring terminal, wherein the harmonic oscillator is arranged in the shell and connected with the supporting base; the gyroscope is characterized in that the gyroscope element is fixedly connected by adopting a high-temperature material and a high-temperature welding process at a key process point;

the key process points of the fixed connection comprise fixed connection points positioned between the piezoelectric element and the harmonic oscillator, between the wiring terminal and the piezoelectric element, between the wiring terminal and the circuit board, between the support base and the harmonic oscillator and between the shell and the support base;

the supporting base of the gyroscope is fixedly connected with the harmonic oscillator, and the bottom of the supporting base is in a conical design and is fixedly connected with an external structure through a pressing block;

a transition circuit board is arranged between the harmonic oscillator and the supporting base, and a silk-screen layer is arranged inside the transition circuit board to realize interconnection of internal signals;

the transition circuit board is connected with the wiring terminal.

2. A high temperature miniaturized resonator gyroscope according to claim 1, characterized in that the gyroscope is a small-sized gyroscope capable of operating at high temperatures above 125 ℃.

3. A high temperature miniaturized resonant gyroscope of claim 2, wherein the gyroscope is capable of operating at a high temperature of 185 ℃.

4. The high-temperature miniaturized resonant gyroscope of claim 1, wherein the top of the housing of the resonator is provided with a welding point, and the welding point is made of high-temperature materials.

5. A high temperature miniaturized resonator gyroscope according to claim 1, wherein the high temperature material comprises Sn-Ag, Sn-Cu or Sn-Ag-Cu alloys.

6. A high temperature miniaturized resonant gyroscope according to claim 1, wherein the gyroscope has a diameter of no more than 30 mm.

7. The high-temperature miniaturized resonant gyroscope of claim 1, wherein the piezoelectric element is disposed on a sidewall or a bottom of the resonator.

8. A high temperature miniaturized resonant gyroscope according to claim 1, wherein the gyroscope is peripherally provided with a high temperature resistant damper.

9. A high temperature miniaturized resonant gyroscope according to claim 1, wherein the support base and the high temperature resistant vibration damper are fixedly coupled into the IMU.

10. An inertial navigation system comprising a three-axis gyroscope, a three-axis accelerometer and a damper, the gyroscope being fixedly connected to the damper, the gyroscope being a high temperature miniaturized resonant gyroscope according to any of claims 1 to 9.

11. The inertial navigation system of claim 10, wherein the accelerometer is a high temperature quartz flexible accelerometer or a high temperature MEMS accelerometer.

12. The inertial navigation system of claim 10, further comprising a sensor sensitive to geomagnetism.

13. A drilling measurement system comprising an inertial navigation system according to any one of claims 10 to 12, the measurement system further comprising:

14. The borehole measurement system according to claim 13, further comprising a rotation unit that drives the measurement system in rotation.

15. The system of claim 13, wherein the signal processing is performed in an ARM core processor or other core processor, including but not limited to a full parametric compensation module, a self calibration and calibration module, an initial alignment module, and a continuous measurement while drilling module, a filtering module.

16. A method of borehole measurement, for use in a measurement system according to any of claims 13-15, the method comprising the steps of:

s5) after rotation, entering a fine alignment process, and estimating new azimuth angle, inclination angle and tool face angle information by using the velocity vector and velocity observed quantity, the earth rotation angular rate vector and the earth rotation angular rate observed quantity;

s6) finally calculating the azimuth angle, the inclination angle and the tool face angle according to the azimuth angle, the inclination angle and the tool face angle information of the position before rotation and the position after rotation, estimating the zero offset error of the gyroscope and the accelerometer, feeding the zero offset error back to an output model of the inertial instrument, and correcting the zero offset error;

s7), the alignment is finished, the error is updated, and the data is stored.

17. The borehole surveying method according to claim 16, wherein, in step S1), after the external command is received as the drill stop command, the magnitude of the mud vibration is determined by the output signal of the vibration monitoring sensor filter acquired by the state monitoring unit or the accelerometer output signal in the inertial navigation system, and whether to start to perform the coarse alignment is determined by the set threshold.

18. The borehole survey method according to claim 16, wherein the coarse alignment is performed by directly using the gyroscope output information and the accelerometer output information mounted on the carrier to obtain the azimuth angle, the inclination angle, and the toolface angle of the carrier by an analytic method.

19. The method of claim 16, wherein the fine alignment process uses an optimal estimation algorithm to perform data fusion calculation to obtain new azimuth, elevation angle, and toolface angle information.