CN202100251U - Nine-accelerometer continuous inclinometer - Google Patents

Abstract

The utility model relates to a nine-accelerometer continuous inclinometer for measuring tracks of oil and gas wells, which comprises a sensor function unit, a signal conditioning and data collecting unit and a controlling and data processing unit. The sensor function unit is accessed into the controlling and data processing unit through the signal conditioning and data collecting unit. The sensor function unit comprises at least three accelerometer groups, and the accelerometer groups are arranged together coaxially. The nine-accelerometer continuous inclinometer has the advantages of being low in cost, not restricted by on-site environment, long in service life, strong in shock-proof and impact-proof performance, simple in structure, high in reliability, fast in reaction and low in power consumption.

Description

A kind of nine accelerometer continuous inclinometers

Technical field

The utility model belongs to mining industry Exploration Domain such as oil, natural gas, relates to a kind of survey tool of oil gas well, relates in particular to a kind of nine used when measuring oil gas well track accelerometer continuous inclinometers.

Background technology

In the process of drilling well, window sidetracking and the horizontal well of fetching water, need to understand well track, guarantee that the quality of drilling engineering meets design requirement, the deviational survey instrument occurs based on this kind purpose just.Deviational survey instrument kind is many both at home and abroad, but is divided into two types generally: fluxgate inclinometer and gyrolevel.They adopt different deviational survey principles, and the scope of use is also different, the concrete introduction as follows:

It is three projection components on the coordinate axes in instrument coordinates that the fluxgate inclinometer adopts three fluxgate sensors to measure geomagnetic fieldvector usually; Adopting three accelerometer measures acceleration of gravity vectors is three projection components on the coordinate axes in instrument coordinates; Because the geomagnetic fieldvector and the acceleration of gravity vector of each geographical coordinate are known; Through coordinate transform, and utilize six measured values can calculate angle of slope, tool face azimuth and the azimuth of oil well on each point, thereby obtain well track.Fluxgate inclinometer branch is surveyed and tie-in, and anti-seismic performance and shock resistance are more intense, can be used for measurement while drilling.But the fluxgate inclinometer is subject to the influence of surrounding magnetic field, requires debugging enironment no ferromagnetic material in 3 meters, and no high-intensity magnetic field exists in 10 meters, can only be used for the measurement of open hole well, and range of application receives certain restriction.

Gyrolevel is divided into a survey gyrolevel and continuous gyrolevel.When point survey gyrolevel carries out work; Conscious well depth is divided into plurality of sections; Instrument is stopped a few minutes on each node, measure angle of slope, tool face azimuth and the azimuth of this node, then the track of all nodes is coupled together the track that just can obtain well.Point survey gyrolevel adopts a two-degrees-of freedom gyro to measure the rotational-angular velocity of the earth vector at two of the instrument plane axial projected angle velocity components usually; Adopting three accelerometer measures acceleration of gravity vectors is three projection components on the coordinate axes in instrument coordinates; Because the rotational-angular velocity of the earth vector and the acceleration of gravity vector of each geographical coordinate are known; Through coordinate transform; And utilize five measured values and oil well local latitude can calculate angle of slope, tool face azimuth and the azimuth of oil well on each point, thereby obtain well track.Point survey gyrolevel does not receive the restriction of magnetic field environment, both can test open hole well, all right test suite pipe well; But its anti-seismic performance and shock resistance are more weak; Be not suitable for measurement while drilling, owing to adopt areal survey, certainty of measurement is lower; Survey gyrolevel in addition and before measuring, wait instrument static earlier, Measuring Time is long.

Gyrolevel need not the well depth segmentation continuously, can carry out continuous measurement to the oil gas well, but consider the variation of gyro drift, in practical applications, whenever need instrument be stopped at regular intervals, gyro is carried out zero point aim at.Gyrolevel adopts the moving optical fibre gyro of transferring gyro or three single-degree-of-freedoms of two two degrees of freedom usually continuously; Angular velocity component in the measuring apparatus coordinate system on three coordinate axes; Adopting three accelerometer measures acceleration of gravity vectors is three projection components on the coordinate axes in instrument coordinates, before measuring beginning, will adopt earlier to seek northern algorithm and seek north.Completion is sought the back, north and just can be measured, and adopts hypercomplex number strap-down navigation algorithm usually, calculates angle of slope, tool face azimuth and the azimuth of each point, thereby obtains well track.The gyrolevel Measuring Time will shorten much than some survey gyrolevel Measuring Time continuously; Certainty of measurement also improves, and does not receive the restriction of magnetic field environment, both can test open hole well; Also can the test suite pipe well; But its complex structure, anti-seismic performance and shock resistance are more weak, are not suitable for measurement while drilling.Seek northern algorithm and gyro strap-down navigation algorithm, data more complicated owing to adopt.

The fluxgate inclinometer is adopted in the measurement of open hole well at present usually, and cased well mainly adopts gyrolevel, but the fluxgate inclinometer receives the influence of magnetic field environment; Application has certain restriction, and gyrolevel receives the gyro technology limitation, anti-seismic performance and shock resistance a little less than; Cost is high, limited service life, and volume is big; Complicated operation, efficiency of measurement is lower.Along with going deep into of domestic and international gyro free strap down inertial navigation system research, being applied to the logging technique field has become possibility, and the appearance of the no gyroscopic survey instrument of employing acceierometer sensor becomes the certainty of development.

The utility model content

In order to solve the above-mentioned technical problem that exists in the background technology, the utility model provide a kind of cost low, do not receive site environment restriction, long service life, stronger anti-seismic performance and shock resistance arranged, simple in structure, reliability is high, reaction is quick, nine accelerometer continuous inclinometers of low-power consumption.

The technical solution of the utility model is: the utility model provides a kind of nine accelerometer continuous inclinometers, and its special character is: said nine accelerometer continuous inclinometers comprise sensor unit, signal condition and data acquisition unit and control and data processing unit; Said sensor cell output signal is given control and data processing unit after through signal condition and data acquisition unit; Said sensor function unit comprises three groups of accelerometer groups, coaxial being set together of said accelerometer group.

Coaxial the laterally arranging together of above-mentioned accelerometer group.

Above-mentioned accelerometer group comprises first accelerometer, second accelerometer and the 3rd accelerometer; Said first accelerometer, second accelerometer and the 3rd accelerometer are orthogonally set together.

The sensor functional unit also comprises the temperature pick up of the temperature that is used for the measuring transducer working environment.

Above-mentioned accelerometer is quartz flexible accelerometer or silicon micromechanical accelerometer.

Above-mentioned nine accelerometer continuous inclinometers also comprise communication unit, and said communication unit and control and data processing unit electrically connect.

Above-mentioned signal condition and data acquisition unit comprise operational amplifier and AD converter; Said operational amplifier and AD converter electrically connect.

Above-mentioned AD converter is 24, the AD converter of 8 passages.

It is control core and data processing unit that above-mentioned control and data processing unit are based on DSP.

The utility model has the advantages that:

The nine accelerometer continuous inclinometers that the utility model provided both can be used for the measurement of open hole well, also can be used for the measurement of cased well, promptly can be used for measurement while drilling, also can be used for the independent occasions of using such as well mark check.Because the utility model has adopted the gyro free strap down inertial navigation technology; Avoided the design of gyro control circuit in gyrolevel, control circuit is become simply, power consumption obviously reduces; Because the drift of accelerometer is obvious lower than gyro; And the appearance of high-precision accelerometer, make nine accelerometer deviational survey appearance can satisfy the certainty of measurement requirement of well track, its concrete advantage shows the following aspects:

1) measuring speed is fast.In gyrolevel, the some survey all will make instrument stop at each survey mark and measure time and effort consuming; Though the gyro continuous meter can carry out continuous measurement, because the random drift of gyro, through need instrument being stopped after a while; Calibrate, and the nine accelerometer continuous inclinometers that the utility model provided do not use gyro, and the random drift of accelerometer is much littler than the random drift of gyro; Need not calibration when test, so Measuring Time shortens a lot.

2) low in energy consumption.In gyrolevel, drive gyrorotor by motor rotating at high speed and rotate at a high speed, not only be easy to generate heat, and power consumption is big, and in nine accelerometer continuous inclinometers of no gyro, does not have this problem, power consumption obviously reduces.

3) simple in structure.In gyrolevel, use flexible gyroscope or optical fibre gyro usually, not only the gyro complex structure; And control circuit is complicated, obtain good effect, needs gyro and control circuit well to cooperate; The volume ratio of gyro is bigger in addition; Also than higher, when carrying out structure design, to consider multiple factor to the requirement of operating temperature, so the structure more complicated.In nine accelerometer continuous inclinometers of no gyro, because the volume ratio of accelerometer is less, do not need complicated control circuit, less demanding to operating temperature, so design easily on the structure, final structure is also fairly simple.

4) reliability is high.In gyrolevel, the life-span of gyro limits if having time, a little less than the impact resistance, in use has constant value drift again; The once electrification random drift, random drift such as drift makes circuit and Algorithm design more complicated day by day; And in nine accelerometer continuous inclinometers of no gyro, the not free in principle restriction of the life-span of accelerometer, impact resistance is also more intense; Random drift is much littler than gyro, and control circuit and algorithm are also fairly simple, and reliability obviously improves.

5) life-span is long.In gyrolevel, gyrorotor is around at a high speed rotation of fixed point, with rotor supports on the minimum bearing of frictional force; Because there are wearing and tearing at work in gyro; So the life-span of gyrolevel is not long, and in nine accelerometer continuous inclinometers of no gyro, the not free in principle restriction of the life-span of accelerometer; Life-span is long, safeguards simple.

6) applied range.Nine accelerometer continuous inclinometers do not receive the restriction of magnetic field environment, both can be used for open hole well, can be used for cased well yet, and because its impact resistance is more intense, promptly can be used for measurement while drilling, also can be used for completion after, well track is measured.

Description of drawings

Fig. 1 is that carrier ties up to the position view in the earth system;

Fig. 2 is the allocation plan sketch map of the nine acceleration inclinometers that provide of the utility model;

Fig. 3 is the general structure sketch map of nine acceleration gyrolevels;

Fig. 4 is that the circuit of inclinometer provided by the present invention is realized block diagram;

The specific embodiment

The principle of the utility model is: the utility model adopts the gyro free strap down inertial navigation technology; And the accelerometer of gyro free strap down inertial navigation system all is installed in the non-barycenter place of carrier; The specific force equation at the non-barycenter place of carrier is the basis of research gyro free strap down inertial navigation system, the concrete derivation as follows:

In Fig. 1, terrestrial coordinate system is O _eX _eY _eZ _e, carrier coordinate system is O _bX _bY _bZ _b, carrier movement angular velocity is ω _Nb(rad/s), establishing the carrier barycenter is R to the radius vector in the earth's core, and any 1 P (non-barycenter place) is L to the radius vector at its barycenter place on the carrier, and then the P point is that R ' is to the radius vector in the earth's core:

R′＝R+L

In inertial coodinate system, differentiate gets to following formula:

$\frac{{\mathrm{dR}}^{\′}}{\mathrm{dt}}{|}_i=V_e+{\mathrm{\ω}}_{\mathrm{nb}}\×L+{\mathrm{\ω}}_{\mathrm{ie}}\×R^{\′}$

Wherein Ve is a carrier barycenter ground speed (m/s), ω _IeBe rotational-angular velocity of the earth (rad/s).In inertial coodinate system, to the both sides differentiate of following formula, then:

$\frac{d^2{R}^{\′}}{{\mathrm{dt}}^2}{|}_i={\stackrel{\·}{V}}_e+\stackrel{\·}{{\mathrm{\ω}}_{\mathrm{nb}}}\×L+{\mathrm{\ω}}_{\mathrm{nb}}\×({\mathrm{\ω}}_{\mathrm{nb}}\×L)+(2*{\mathrm{\ω}}_{\mathrm{ie}}+{\mathrm{\ω}}_{\mathrm{en}})\×(V_e+{\mathrm{\ω}}_{\mathrm{nb}}\×L)+{\mathrm{\ω}}_{\mathrm{ie}}\×({\mathrm{\ω}}_{\mathrm{ie}}\×R^{\′})$

Wherein

Be carrier barycenter acceleration over the ground,

The carrier movement angular acceleration, ω _EnPosition angle speed for inertial navigation.

When the absolute acceleration when non-barycenter place on the carrier is

, get according to Newton's second law:

$\frac{d^2{R}^{\′}}{{\mathrm{dt}}^2}{|}_i=f+g_m$

Wherein f is a specific force, g _mBe gravitational acceleration.

If gravity acceleration g=g _m-ω _Ie* (ω _Ie* R '), then the specific force equation of the non-center of mass point P of carrier in carrier coordinate system is:

$f^b={\stackrel{\·}{V}}_e^b+\stackrel{\·}{{{\mathrm{\ω}}_{\mathrm{nb}}}^b}\×L^b+{{\mathrm{\ω}}_{\mathrm{nb}}}^b\×({{\mathrm{\ω}}_{\mathrm{nb}}}^b\×L^b)+(2*{{\mathrm{\ω}}_{\mathrm{ie}}}^b+{{\mathrm{\ω}}_{\mathrm{en}}}^b)\×(V_e^b+{{\mathrm{\ω}}_{\mathrm{nb}}}^b\×L^b)+g^b+{\▿}^b$

Wherein:

Specific force (the m/s that----records for accelerometer ²);

----is carrier barycenter acceleration (m/s over the ground ²);

----is carrier barycenter ground speed (m/s);

----is carrier angular acceleration (rad/s2);

----is carrier angular velocity (rad/s);

----is rotational-angular velocity of the earth (rad/s);

----is the position angle speed (rad/s) of inertial navigation;

----is installed in the position (m) in the carrier coordinate system for accelerometer;

----is acceleration of gravity (m/s ²);

----is zero inclined to one side (m/s of accelerometer ²).

The acceleration allocation plan of nine accelerometer deviational survey appearance is as shown in Figure 2, and nine accelerometers are divided into three groups, every group of accelerometer that comprises three mutually orthogonal installations; Installation direction is parallel to the instrument coordinates direction of principal axis; Every two adjacent groups accelerometer connects firmly G respectively at a distance of 0.6 meter with instrument _X1, G _X2With G _X3Be parallel to each other G _Y1, G _Y2With G _Y3Be parallel to each other G _Z1, G _Z2With G _Z3Coaxial each other.

Form an equation group by the specific force equation of nine accelerometers, can obtain following two equation group through resolving:

$\left\{\begin{array}{c}{\left[{\mathrm{\ω}}_x^b\right]}^2=\frac{1}{2}[\frac{f_d-f_e}{L_e-L_d}+\frac{f_g-f_h}{L_h-L_g}-\frac{f_a-f_b}{L_b-L_a}]+{\mathrm{\ϵ}}_{\mathrm{xx}}^b\\ {\left[{\mathrm{\ω}}_y^b\right]}^2=\frac{1}{2}[\frac{f_a-f_b}{L_b-L_a}+\frac{f_g-f_h}{L_h-L_g}-\frac{f_d-f_e}{L_e-L_d}]+{\mathrm{\ϵ}}_{\mathrm{yy}}^b\\ {\left[{\mathrm{\ω}}_z^b\right]}^2=\frac{1}{2}[\frac{f_d-f_e}{L_e-L_d}+\frac{f_g-f_h}{L_h-L_g}-\frac{f_a-f_b}{L_b-L_a}]+{\mathrm{\ϵ}}_{\mathrm{zz}}^b\end{array}\right.$

$\left\{\begin{array}{c}{\stackrel{\·}{\mathrm{\ω}}}_x^b=\frac{1}{L_i}[\frac{L_d{f}_e-L_e{f}_d}{L_d-L_e}-f_i]+[{\mathrm{\ϵ}}_{\mathrm{zy}}^b+{\mathrm{\ω}}_z^b{\mathrm{\ω}}_y^b]\\ {\stackrel{\·}{\mathrm{\ω}}}_y^b=\frac{1}{L_c}[\frac{L_g{f}_h-L_h{f}_g}{L_g-L_h}-f_c]+[{\mathrm{\ϵ}}_{\mathrm{xz}}^b+{\mathrm{\ω}}_x^b{\mathrm{\ω}}_z^b]\\ {\stackrel{\·}{\mathrm{\ω}}}_z^b=\frac{1}{L_f}[\frac{L_a{f}_b-L_b{f}_a}{L_a-L_b}-f_f]+[{\mathrm{\ϵ}}_{\mathrm{yx}}^b+{\mathrm{\ω}}_y^b{\mathrm{\ω}}_x^b]\end{array}\right.$

For the common employing immediate integration of resolving of angular velocity and the extraction of root, but immediate integration can cause the systematic error accumulation, and error is a unbounded.The error of the extraction of root is a bounded, yet owing to introduced the symbol decision process, under the situation of little angular velocity and little angular acceleration, causes the symbol erroneous judgement easily, and extracting operation has increased the workload of system simultaneously.Construct a kind of angular velocity aided algorithm at this, improve the angular velocity calculation accuracy.

For arbitrary axial t-1 angular velocity constantly, available following formula is represented:

${\mathrm{\ω}}_b^2(t-1)={[{\mathrm{\ω}}_b\left(t\right)-{\mathrm{\Δ\ω}}_b\left(t\right)]}^2$

$={\mathrm{\ω}}_b^2\left(t\right)-{2\mathrm{\ω}}_b\left(t\right){\mathrm{\Δ\ω}}_b\left(t\right)+{\mathrm{\Δ\ω}}_b^2\left(t\right)$

$={\mathrm{\ω}}_b^2\left(t\right)-{2\mathrm{\ω}}_b\left(t\right)\·\mathrm{\Δt}\·\stackrel{\·}{{\mathrm{\ω}}_b\left(t\right)}+{\mathrm{\Δt}}^2\·\stackrel{\·}{{\left[{\mathrm{\ω}}_b\left(t\right)\right]}^2}$

Can derive angular velocity by following formula is:

${\mathrm{\ω}}_b\left(t\right)=\frac{{\mathrm{\ω}}_b^2\left(t\right)-{\mathrm{\ω}}_b^2(t-1)+{\mathrm{\Δt}}^2\·\stackrel{\·}{{\left[{\mathrm{\ω}}_b\left(t\right)\right]}^2}}{2\·\mathrm{\Δt}\·\stackrel{\·}{{\mathrm{\ω}}_b\left(t\right)}}$

Utilize the lever arm effect of accelerometer to calculate the angular velocity information of carrier like this, utilize the strap-down navigation algorithm to calculate the movement locus of carrier then, this gyro free strap down airmanship is applied to the well logging field, just can realize measurement well track.

This instrument system comprises above ground portion and down-hole part; Above ground portion comprises computer and numerical control part; Realization is to the control of downhole instrument with to the analyzing and processing of data, and the down-hole part comprises nine acceleration continuous inclinometers, also can connect other as required and measure pipe nipple.The special feature of the utility model is to use new technology to carry out the measurement of well track, and carries out relevant structure design, therefore does simple introduction with this here as emphasis.

The general structure of nine acceleration gyrolevels is as shown in Figure 3, can this pipe nipple be divided into power unit, Sensor section and control section on the whole.Power unit is positioned at powerhouse dome, converts the direct current of single-core cable into sensor and the required low-voltage dc power supply of controller, accomplishes the modulation and demodulation process of signal simultaneously, guarantees the unimpeded of communication line.Sensor section is made up of sensor cabin one, sensor cabin two, sensor cabin three; Three mutually orthogonal accelerometers are installed in each sensor cabin; The sensitive axes of accelerometer is parallel with the coordinate axes of instrument coordinates system; And consistent with the direction of coordinate axes, whole nine accelerometers are formed the gyro free strap down navigation system.Control section is accomplished resolving of collection to sensing data, Kalman filtering, angular velocity, and the strap-down navigation algorithm resolves, and angle of slope, tool face azimuth and azimuthal finding the solution.Because gyro free strap down navigation algorithm more complicated; Amount of calculation is big; And real-time is required relatively strictness, so control chip is selected dsp chip, in addition owing to use high-precision accelerometer; Sampling precision is proposed higher requirement, this select for use high accuracy, at a high speed, the AD chip of low-power consumption.In gyrolevel,, usually power unit is placed the vacuum flask outside, and nine accelerometer continuous inclinometers adopt no gyroscopic navigation technology because power consumption is bigger; Reduced power consumption; Can all parts be put in the vacuum flask, simplify apparatus structure, improve reliability.The utility model is a kind of nine accelerometer continuous inclinometers technology of not having gyro that proposes for the deficiency that solves the inclinometer product described in the background technology; Because this technology adopts nine accelerometer allocation plans; Make the inclinometer miniaturization be achieved; The calibration process is fairly simple, and impact resistance also improves a lot.The physical circuit realization of the utility model is described below in conjunction with Fig. 4.

Nine accelerometer continuous inclinometers can be divided into four functional units on circuit is realized, i.e. sensor function unit, signal condition and data acquisition unit, control and data processing unit and communication unit.The sensor function unit is made up of nine acceleration transducers and a temperature pick up, and accomplish the specific force of three dimensions diverse location and measure, and the temperature survey of working sensor environment.Signal condition and data acquisition unit by high temperature, high-precision precision operational-amplifier and 24, at a high speed, 8 passage modulus conversion chips form, and accomplish sampling, amplification, conditioning and the collection of sensor signal, and convert thereof into data signal, accept processing.Control and data processing unit are core with DSP, accomplish the control that data are gathered, Control on Communication, and the memory function of data.Communication unit is accomplished modulation, the demodulating process of coding, decoding and the signal of data, realizes communicating by letter reliably between nine accelerometer continuous inclinometers and the ground numerical control.

Claims (9)

1. accelerometer continuous inclinometer, it is characterized in that: said nine accelerometer continuous inclinometers comprise sensor function unit, signal condition and data acquisition unit and control and data processing unit; Said sensor function unit is through signal condition and data acquisition unit Access Control and data processing unit; Said sensor function unit comprises at least three group accelerometer groups, coaxial being set together of said accelerometer group.

2. nine accelerometer continuous inclinometers according to claim 1 is characterized in that: coaxial the laterally arranging together of said accelerometer group.

3. nine accelerometer continuous inclinometers according to claim 2 is characterized in that: said accelerometer group comprises first accelerometer, second accelerometer and the 3rd accelerometer; Said first accelerometer, second accelerometer and the 3rd accelerometer are orthogonally set together.

4. nine accelerometer continuous inclinometers according to claim 3 is characterized in that: said sensor function unit also comprises the temperature pick up of the temperature that is used for the measuring transducer working environment.

5. nine accelerometer continuous inclinometers according to claim 4 is characterized in that: said accelerometer is quartz flexible accelerometer or silicon micromechanical accelerometer.

6. according to claim 1 or 2 or 3 or 4 or 5 described nine accelerometer continuous inclinometers, it is characterized in that: said nine accelerometer continuous inclinometers also comprise communication unit, and said communication unit and control and data processing unit electrically connect.

7. nine accelerometer continuous inclinometers according to claim 6, it is characterized in that: said signal condition and data acquisition unit comprise operational amplifier and AD converter; Said operational amplifier and AD converter electrically connect.

8. nine accelerometer continuous inclinometers according to claim 7 is characterized in that: said AD converter is 24, the AD converter of 8 passages.

9. nine accelerometer continuous inclinometers according to claim 8 is characterized in that: it is control core and data processing unit that said control and data processing unit are based on DSP.

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