SU1537800A1 - Ferroprobe azimuth transmitter - Google Patents

Abstract

The invention relates to field geophysics and improves the accuracy of determining the azimuth of a curved well. The sensor contains dissected flux-probes (F) 1, 2, 3, thin rods (C) 8, 9, 10, 11, 12 of which are made of a non-magnetic material with a ferromagnetic film applied on them and with excitation windings 13 and signal windings 14. Half-lengths With 8 and 10, 9 and 11, 12 are the same. At the same time C 8 and 10 are laid in the main profiled parallel grooves (P), made in the substrate of a dielectric material made in the form of a cylinder. Moreover, C, orthogonal to main C, are laid in C 9 and 11, and C 12 - in additional C, made on the side surface of the cylindrical substrate orthogonally to the main P. Windings 14 are connected in series and according to each other and with the second harmonic filter 15. The windings 13 within each pair C are interconnected in series and counter, and within one F - in series and in accordance with and through switch 16 are connected to excitation generator 17. The filter 15 is connected to the display unit 20 via a series-connected rectifier 18 and an analog-to-digital converter 19. The signal from the generator 17 is fed alternately to the windings 13 F 1, 2, 3. In the Earth’s magnetic field with an F 1 and 2 in the horizon plane The windings 14 f 1, 2, 3 are subjected to voltage, the magnitude of which determines the azimuth. 3 il.

Description

The invention relates to field geophysics and can be used to determine the azimuth of a curved well.

The purpose of the invention is to improve the accuracy of azimuth measurement.

Figure 1 shows the substrate with profiled grooves; figure 2 - scan the substrate; FIG. 3 is a structural diagram of a fluxgate azimuth sensor with one of the variants of the signal detection circuit.

The fluxgate azimuth sensor contains the first, second, and third dissected flux-probes 1–3, which are placed in the shaped grooves A – 6, made in the substrate 7 of a dielectric material made in the form of a cylinder. The first ferrosonde 1 is placed in the main profiled slots 4 parallel to each other, and the second

ferrosonde 2 is placed in parallel profiled grooves 5 orthogonal grooves A. Dissected ferrosonde 1 and 2 consist of two identical main cores made in the form of a main pair of thin rods 8 of non-magnetic material coated with a ferromagnetic film and with windings of excitation and signal windings, from an additional pair of thin rods 9 of non-magnetic material with a ferromagnetic film deposited on them and with excitation windings and signal windings laid in profiled parallel n orthogonal to the main pair of rods 8. The sensor also includes four pairs of rods 10 and 11, supplementing the main and additional pairs of rods 8 and 9, made of a nonmagnetic material with a ferromagnetic film applied on them and with excitation windings and signal windings, two pairs rods 10, complementing the main pair of rods 8, are laid in profiled grooves A, parallel to the grooves of the main pair of rods 8, and two other pairs of rods 11, complementing an additional pair of rods 9, are laid in profiled grooves 5, parallel Yelnia grooves 9 further pair of rods.

The third ferrosonde 3 consists of three pairs of rods 12, which are arranged in three pairs of additional profiled grooves 6, orthogonal to the main grooves A and 5 and made on the side

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five

0

five

before

the surfaces of the cylindrical substrate 7. Three pairs of rods 12 are made of a non-magnetic material with a ferromagnetic film deposited on them and also, like the main pair of rods 8, an additional pair of rods 9 and the complementary pairs of rods 10 and 11 contain excitation windings 13 and signal windings.

The signal windings I t of the fluxgate 3 are connected in series and according to each other, with the signal windings of the main and additional pairs of rods 8 and 9, with the signal windings of four pairs of rods 10 and 11, supplementing the main and additional pairs, and with the second harmonic filter 15.

The half-sum of the lengths of the rods 8 and 10 of the main and two pairs complementing it, the rods 9 and 11 of the additional and complementing it two pairs and three pairs of rods 12 of the third ferrosonde 3 are the same. Excitation windings 13 within each pair of rods of dissected flux-probes 1–3 are interconnected electrically in series and counter, and within one dissected ferrosonde pair of excitation windings are interconnected electrically in series and according to and through switch 16 are connected to the exciter generator 17 . The output of the second harmonic filter 15 is connected to the input of the rectifier 18, the output of which is connected to the input of the analog-to-digital converter (ADC) 19, the output of which is connected to the input of the signal indication unit 20.

In the above construction, the dissected ferrozond 1 - 3 each contain three pairs of rods. In general, the number of pairs of rods may be., - more, depending on max 50

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but the possible number of slots, 5, 6, made in the substrate 7.

Ferrozondov azimuth sensor works as follows.

Excitation generator 17 generates an excitation signal, which through switch 16 is alternately fed to excitation windings 13 of dissected flux-gates 1-3. If the sensitivity axes of dissected flux-probes 1 and 2 lie in the plane of the horizon, then in the presence of the earth’s magnetic field in the signal windings of flux-probes 1 ± 3, the voltages are defined as

and,

U2

Uj de u

lt -sinot; lc. cosci; lc.bf

U. U (i

k stresses taken from 1, 2 and 3 dismembered flux-probes;

the constant of the flux-gate, depending on the number of turns in the excitation windings and signal windings, the excitation frequency, etc. and having a dimension, Ohm; horizontal is the component of the magnetic field of the Earth, A / m; half-sum of the lengths of rods of one dissected ferrosonde, m; magnetic azimuth;

b g

- magnetic inclination, where z is the vertical component of the intensity of the Earth's magnetic field 30.

The sensitivity of dissected flux-probes in terms of the measured magnetic field is defined as

one,

 , ,

Slnrfj g-k

1 cosoi;

E Uz EN

1, -b.

n-1, (2)

Wherein

where n is the number of pairs of half-elements dismembered ferrosonde; 1 - the length of one half element of the dissected ferrosonde.

As can be seen from expressions (1) and (2), the sensitivity of such a ferrosonde is n times higher than that of a conventional ferrosonde. This makes it possible to increase the measurement accuracy of the magnetic azimuth.

The C-signal windings 1A of the partitioned ferroprobe 1 - 3 signals are alternately fed to the second harmonic filter 15, rectifier 18, ADC 19 and to the input of signal indication unit 20. The signal display unit 20 has no features. The switch 16 can be controlled automatically.

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or manually. In the latter case, the switch 16 may be a mechanical switch.

5 The azimuth calculation is made according to known formulas.

The proposed solution has an increased accuracy of azimuth measurement with an equal diameter of the sensor, due to the absence of a mechanical transducer, including internal and external gimbal frames. In addition, this design does not require time-consuming operations.

15 adjustments of three flux-probes relative to each other.

20

25

thirty

35

40

45

50

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Claims (1)

Invention Formula An azimuth ferrosonde sensor containing a substrate made of a dielectric material with main profiled slots parallel to each other, of which the first dissected ferrosonde is placed in the form of two identical main cores and two pairs of cores that supplement the main non-magnetic material made of thin rods a ferromagnetic film deposited on them and with excitation windings and signal windings, the second dissected ferrozond as an additional pair and complementing it two pairs of thin rods of non-magnetic material with a ferromagnetic film deposited on them and with excitation windings and signal windings arranged in profiled parallel grooves orthogonal to the main pair of cores, excitation generator, switch and successively interconnected second harmonic filter, straightener, analog-digital the converter and the signal indication unit, which is due to the fact that, in order to increase the accuracy of the azimuth measurement, it is equipped with a third dissected ferrosonde, the substrate is made In the form of a cylinder, on the side surface of which three pairs of additional profiled grooves are arranged orthogonal to the main grooves, the main and additional pairs of rods, and the third ferrosonde is dimensioned in additional profiled grooves in the form of three pairs of rods of nonmagnetic material coated with a ferromagnetic film and with windings excitation and signal windings, while the excitation windings of each pair are interconnected in series and oppositely and in series with the excitation windings of the other two pairs of the third flux probe and through the switch are connected to the excitation generator, and the signal windings of the third flux probe are connected in series and according to each other with sig windings of the main and additional pairs of rods, with signal windings of four pairs of rods that complement the main and additional pairs, and with a second harmonic filter The rods of the third ferrosonde are the same.