CN101265804B - Well drilling high precision gradient meter sensor perpendicular installation error compensation process - Google Patents

Abstract

The invention relates to a method for compensating the quadrature installation error of a high precise inclinometer sensor used for well drilling, which is characterized in that the method uses C language for programming and running on the computer. The method has a compensation method that those errors are eliminated via software algorithm only by one time measuring the deflection angle between the installation axle and the theoretic axis after installing the acceleration sensor and the magnetic sensor that are correctively chosen and adjustment and calibration which guarantees quadrature is not needed. The method has the advantages that only one-time measurement of the deflection angle between the installation axle and the theoretic axis can eliminate those errors via software algorithm, thus providing a convenient method for re-demarcating when the users repair the inclinometer.

Description

The compensation method of the high precision gradient meter sensor quadrature alignment error that a kind of drilling well is used

Technical field

The present invention relates to the compensation method of the high precision gradient meter sensor quadrature alignment error that a kind of drilling well uses, be used for the oil exploration field, belong to the high precision gradient meter technical field.

Background technology

The inclinometer that existing drilling well is used is usually with 3 acceleration of gravity sensors and 3 fluxgate sensors, through the quadrature installation, measures the parameters such as angle of slope and azimuth at measuring point place; Because acceleration of gravity is of a great variety; Performance difference is big, and high precision gradient meter not only requires height to sensor performance, and the pair of orthogonal verticality requires high; During installation operating personnel are required height, waste time and energy.

The basic principle of inclinometer be utilize earth gravitational field and the magnetic field component value on three coordinate axes calculate the attitude parameter such as angle of slope, azimuth at tested place.

Convenient for describing later on, in northwest (NW) sky coordinate system (north is magnetic north, is to turn clockwise), the angle of slope representes that with γ the azimuth representes that with α the gravity tool-face is used θ _G, the Magnetic tools face is used θ _M, g _x, g _y, g _zBe three components of acceleration of gravity; M _x, M _yM _zBe three components of earth magnetism.The utilization coordinate transform test philosophy of can deriving:

$\mathrm{\γ}={\mathrm{tg}}^{-1}\frac{\sqrt{g_x^2+g_y^2}}{g_z}$

$\mathrm{\α}={\mathrm{tg}}^{-1}\frac{(g_x{M}_y-g_y{M}_x)\sqrt{g_x^2+g_y^2+g_z^2}}{M_z(g_x^2+g_y^2)+g_z(g_x{M}_x+g_y{M}_y)}$

${\mathrm{\θ}}_G={\mathrm{tg}}^{-1}\frac{g_y}{g_x}$

${\mathrm{\θ}}_M={\mathrm{tg}}^{-1}\frac{M_y}{M_x}$

Because the quadrature alignment error is to cause inclinometer to produce the measuring system main error; Generally can attitude be installed through the adjustment sensor; Reach and reduce the caused error of nonopiate installation, shortcoming is to waste time and energy, and causes puzzlement for user's maintenance from now on.

Summary of the invention

The purpose of this invention is to provide a kind of can the elimination because the compensation method of the high precision gradient meter sensor quadrature alignment error that the drilling well of acceleration transducer and the incorrect measure error that produces of Magnetic Sensor installation is used.

For realizing above purpose, technical scheme of the present invention provides the compensation method of the high precision gradient meter sensor quadrature alignment error that a kind of drilling well uses, and it is characterized in that, program with the C language, operation on computers, its compensation method is:

The first step. select noise error less than 3 acceleration transducers of 0.1mg and noise error 3 Magnetic Sensor CFG-S less than 1nT;

Second step. in 3 acceleration transducers and 3 Magnetic Sensors that high precision gradient meter difference installation steps 1 are selected, per three sensor pairwise orthogonals;

The 3rd step. mounted high precision gradient meter is installed on the three-axle table; Timing places vertical direction with the arbitrary sensor in 3 acceleration transducers earlier; Even the X axle acceleration sensor overlaps with coordinate system Z axle on the three-axle table; Make the output of X axle acceleration sensor maximum, the reading x of 3 acceleration transducers of record _M1, y _M1, z _M1The Y axle acceleration sensor is overlapped with coordinate system Z axle on the three-axle table, make the output of Y axle acceleration sensor maximum, the reading x of 3 acceleration transducers of record _M4, y _M4, z _M4

The 4th step. make X axle acceleration sensor two angles of deflection respectively in 0-90 degree scope again, write down the reading of respective sensor after each deflection, x _M2, y _M2, z _M2x _M3, y _M3, z _M3

The 5th step. respectively to 3 acceleration sensings and 3 Magnetic Sensors, obtain each with theoretical axle between deflection angle, i.e. penalty coefficient, thus eliminate nonopiate influence, specifically formula is following:

x _R＝x _m+φ _xyy _m+φ _xzz _m

y _R＝y _m+φ _yxx _m+φ _yzz _m

z _R＝z _m+φ _zxx _m+φ _zyy _m

Wherein, φ _Xy, φ _Xz, φ _Yx, φ _Xz, φ _Zx, φ _ZyThe expression penalty coefficient, x _R, y _R, z _RThe expression actual value, x _m, y _m, z _mThe expression measured value;

The 6th step. each sensor respectively has two quadrature compensation coefficients; Be that the X axle acceleration sensor need be measured respectively to the Y axle with to the quadrature compensation coefficient of Z axle; The Y axle acceleration sensor need be measured respectively to the X axle with to the quadrature compensation coefficient of Z axle, and the Z axle acceleration sensor need be measured respectively to the X axle with to the quadrature compensation coefficient of Y axle; Equally; The X axial magnetic sensor need be measured respectively to the Y axle with to the quadrature compensation coefficient of Z axle; The Y axial magnetic sensor need be measured respectively to the X axle with to the quadrature compensation coefficient of Z axle; The Z axial magnetic sensor need be measured respectively to the X axle with to the quadrature compensation coefficient of Y axle, therefore has 12 quadrature compensation coefficients, and in computer, preserves these 12 quadrature compensation coefficients;

The 7th step. suppose that three angles between the acceleration transducer are α, β, γ, then above-mentioned coefficient φ _Xy, φ _Xz, φ _Yx, φ _Xz, φ _Zx, φ _ZyBe respectively:

φ _xy＝φ _yx＝cosα

φ _xz＝φ _zx＝cosβ

φ _yz＝φ _zy＝cosγ

Obtain three angle, β, values of γ between the acceleration transducer;

The 8th step. eliminate the nonopiate influence of acceleration transducer according to the angle between 3 acceleration transducers, β, γ.

The present invention is through correct acceleration transducer and the Magnetic Sensor selected; After installing acceleration transducer and Magnetic Sensor; No longer need guarantee the adjustment of quadrature, only need the deflection angle between single-time measurement installation shaft and the theoretical axle, just can eliminate these errors through software algorithm.

Advantage of the present invention is the deflection angle that only needs between single-time measurement installation shaft and the theoretical axle, just can eliminate these errors through software algorithm, and the method that makes things convenient for of demarcation again is provided when safeguarding inclinometer for the user.

Description of drawings

Fig. 1 is a quadrature compensation coefficient determination schematic flow sheet;

The specific embodiment

Below in conjunction with accompanying drawing and embodiment the present invention is described further.

Embodiment

As shown in Figure 1, be quadrature compensation coefficient determination schematic flow sheet, because the output of inclinometer is the result under a plurality of sensor combination, the factor that therefore influences the deviational survey output accuracy is many, and relation is quite complicated, will consider that thus the problem that solves is following:

1, the influence of single-sensor

Learn through theoretical the derivation,

1) if to satisfy when the angle of slope be 0.7～3 °, the requirement of azimuth test error in ± 5 ° need to guarantee that the full test error of acceleration transducer must be less than 0.6mg, the full test error of magnetic azimuth sensor must be less than 1 ‰ earth's magnetic fields, about 50nT; Annotate: the starting point of small inclination is 0.7 °, rather than in the standard 0 °.

2) if will satisfy when 3.1～5 ° at angle of slope; The requirement of azimuth test error in ± 1 °; Need to guarantee that the full test error of acceleration transducer must be less than 0.5mg, the full test error of magnetic azimuth sensor must be less than 0.5 ‰ earth's magnetic fields, about 25nT;

3) if to satisfy when the angle of slope greater than 5 ° (referring in 90 ° of scopes); The requirement of azimuth test error in ± 0.5 °; The full test error that guarantees acceleration transducer must be less than 0.4mg, and the full test error of magnetic azimuth sensor must be less than 0.1 ‰ earth's magnetic fields, about 5nT;

4) above calculating only to the magnetic dip angle scope in China area, promptly in-70～70 ° of zones, if having higher magnetic dip angle zone, still guarantee above-mentioned precision, needs further to improve the sensor index.

According to above analysis, a kind of acceleration transducer FLEX15001 noise error of selecting for use is less than 0.1mg, and fluxgate sensor CFG-S is less than 1nT, thereby on principle, fully satisfied above technical requirement, constituted the primary condition of high precision gradient meter.

At high precision gradient meter 3 acceleration transducers and 3 Magnetic Sensors are installed respectively, per three sensor pairwise orthogonals.

2, sensor three-dimensional orthogonal alignment error

The principle of inclinometer is based on per three sensors in twos on the strict orthogonal basis, and in the manufacture process of reality, is difficult to guarantee strict orthogonal between the sensor; Therefore bring alignment error, often become the major obstacle that inclinometer improves precision, for this reason; We adopt three attitude deflections to survey the method for offset angle through the checking of mathematical derivation and test of many times, obtain each with theory spool between deflection angle; Be penalty coefficient, thereby eliminate nonopiate influence that concrete formula is following:

x _R＝x _m+φ _xyy _m+φ _xzz _m

y _R＝y _m+φ _yxx _m+φ _yzz _m

z _R＝z _m+φ _zxx _m+φ _zyy _m

Wherein, φ _Xy, φ _Xz, φ _Yx, φ _Xz, φ _Zx, φ _ZyDeng expression penalty coefficient, x _R, y _R, z _RDeng expression actual value, x _m, y _m, z _mDeng the expression measured value.

Suppose that three angles between the sensor are α, β, γ, then above-mentioned coefficient φ _Xy, φ _Xz, φ _Yx, φ _Xz, φ _Zx, φ _ZyBe respectively:

φ _xy＝φ _yx＝cosα

φ _xz＝φ _zx＝cosβ

φ _yz＝φ _zy＝cosγ

Timing places vertical direction with arbitrary sensor, makes its respectively two angles of deflection again, writes down the reading of respective sensor after each deflection, can list system of linear equations and solve above coefficient.

Application example:

Certain installs the incorrect sensor of possibility, proofreaies and correct according to above-mentioned flow process:

At first make the X axle acceleration sensor vertical,, write down three sensor readings even the output of X axle acceleration sensor is maximum

x _m1＝9.80，y _m1＝2.90，z _m1＝1.42；

Make the X axle acceleration sensor around vertical direction difference deflection 30,60 degree, write down following three sensor readings of each attitude

x _m2＝8.48，y _m2＝0.35，z _m2＝1.42；

x _m3＝4.90，y _m3＝0.38，z _m3＝0.99；

The system of linear equations that obtains is:

Finding the solution above-mentioned equation group obtains:

$\left\{\begin{array}{c}\cos \mathrm{\α}=\frac{\frac{1}{2}{x}_{m1}{z}_{m2}+\frac{\sqrt{3}}{2}{x}_{m3}{z}_{m1}+x_{m2}{z}_{m3}-x_{m3}{z}_{m2}-\frac{\sqrt{3}}{2}{x}_{m1}{z}_{m3}-\frac{1}{2}{x}_{m2}{z}_{m1}}{\frac{1}{2}{x}_{m1}{z}_{m2}-\frac{\sqrt{3}}{2}{y}_{m3}{z}_{m1}-y_{m2}{z}_{m3}+y_{m3}{z}_{m2}+\frac{\sqrt{3}}{2}{y}_{m1}{z}_{m3}+\frac{1}{2}{y}_{m2}{z}_{m1}}\\ \cos \mathrm{\β}=\frac{\frac{1}{2}{x}_{m2}{y}_{m1}+\frac{\sqrt{3}}{2}{x}_{m1}{y}_{m3}+x_{m3}{y}_{m2}-x_{m2}{y}_{m3}-\frac{\sqrt{3}}{2}{x}_{m3}{y}_{m1}-\frac{1}{2}{x}_{m1}{y}_{m2}}{\frac{1}{2}{x}_{m1}{z}_{m2}-\frac{\sqrt{3}}{2}{y}_{m3}{z}_{m1}-y_{m2}{z}_{m3}+y_{m3}{z}_{m2}+\frac{\sqrt{3}}{2}{y}_{m1}{z}_{m3}+\frac{1}{2}{y}_{m2}{z}_{m1}}\end{array}\right.$

Make the Y axle acceleration sensor vertical, write down three sensor readings

x _m4＝0.71，y _m4＝9.79，z _m4＝0.001；

The Y axle acceleration sensor is overlapped with coordinate system Z axle, write down three sensor readings x _M4, y _M4, z _M4

The linear equation that obtains is:

g＝y _m4+x _m4cosα+z _m4cosγ

Utilize a last solution of equations to obtain:

$\cos \mathrm{\γ}=\frac{g-y_{m4}-x_{m4}\cos \mathrm{\α}}{z_{m4}}$

Obtain according to above-mentioned solution formula:

φ _xy＝φ _yx＝0.017

φ _xz＝φ _zx＝0.035

φ _yz＝φ _zy＝10 ^-4

Obtaining three angles between the sensor at last is α, β, γ, eliminates nonopiate influence according to angle, β, γ.

Claims (1)

1. the compensation method of the high precision gradient meter sensor quadrature alignment error used of a drilling well is characterized in that, program with the C language, operation on computers, its compensation method is:

The first step. select noise error less than 3 acceleration transducers of 0.1mg and noise error 3 Magnetic Sensor CFG-S less than 1nT;

Second step. in 3 acceleration transducers and 3 Magnetic Sensors that high precision gradient meter difference installation steps 1 are selected, per three sensor pairwise orthogonals;

The 3rd step. mounted high precision gradient meter is installed on the three-axle table; Timing places vertical direction with the arbitrary sensor in 3 acceleration transducers earlier; Even the X axle acceleration sensor overlaps with coordinate system Z axle on the three-axle table; Make the output of X axle acceleration sensor maximum, the reading x of 3 acceleration transducers of record _M1, y _M1, z _M1The Y axle acceleration sensor is overlapped with coordinate system Z axle on the three-axle table, make the output of Y axle acceleration sensor maximum, the reading x of 3 acceleration transducers of record _M4, y _M4, z _M4

The 4th step. make X axle acceleration sensor two angles of deflection respectively in 0-90 degree scope again, write down the reading of respective sensor after each deflection, x _M2, y _M2, z _M2x _M3, y _M3, z _M3

The 5th step. respectively to 3 acceleration transducers and 3 Magnetic Sensors, obtain each with theoretical axle between deflection angle, i.e. penalty coefficient, thus eliminate nonopiate influence, specifically formula is following:

x _R＝x _m+φ _xyy _m+φ _xzz _m

y _R＝y _m+φ _yxx _m+φ _yzz _m

z _R＝z _m+φ _zxx _m+φ _zyy _m

Wherein, φ _Xy, φ _Xz, φ _Yx, φ _Xz, φ _Zx, φ _ZyThe expression penalty coefficient, x _R, y _R, z _RThe expression actual value, x _m, y _m, z _mThe expression measured value;

The 6th step. each sensor respectively has two quadrature compensation coefficients; Be that the X axle acceleration sensor need be measured respectively to the Y axle with to the quadrature compensation coefficient of Z axle; The Y axle acceleration sensor need be measured respectively to the X axle with to the quadrature compensation coefficient of Z axle, and the Z axle acceleration sensor need be measured respectively to the X axle with to the quadrature compensation coefficient of Y axle; Equally; The X axial magnetic sensor need be measured respectively to the Y axle with to the quadrature compensation coefficient of Z axle; The Y axial magnetic sensor need be measured respectively to the X axle with to the quadrature compensation coefficient of Z axle; The Z axial magnetic sensor need be measured respectively to the X axle with to the quadrature compensation coefficient of Y axle, therefore has 12 quadrature compensation coefficients, and in computer, preserves these 12 quadrature compensation coefficients;

The 7th step. suppose that 3 angles between the acceleration transducer are α, β, γ, then above-mentioned coefficient φ _Xy, φ _Xz, φ _Yx, φ _Xz, φ _Zx, φ _ZyBe respectively:

φ _xy＝φ _yx＝cosα

φ _xz＝φ _zx＝cosβ

φ _yx＝φ _zy＝cosγ

Obtain 3 angle, β, values of γ between the acceleration transducer;

The 8th step. eliminate the nonopiate influence of acceleration transducer according to the angle between 3 acceleration transducers, β, γ.

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