SU1452954A1 - Ferroprobe azimuth transmitter - Google Patents

Abstract

The invention relates to field geophysics and is intended to determine the magnetic azimuth of a well. The purpose of the invention is to improve the accuracy and reliability of work. The fluxgate azimuth sensor has a ring type 1 flux probe with a change of excitation winding 2 and signal windings 3, 3 of which are primary and four others are additional windings. The main windings are at an angle of 90 °. to each other. The additional windings are located at an angle of 90 °. to each other and at an angle of 45 ° to the main windings. Winding 2 is connected to a generator (D) 4, which is connected via frequency doubler 23 to clocking-in outputs of phase detectors 9, 10. Each pair is diametrically opposed to windings 3 connected in series and oppositely and connected to the corresponding inputs of switches 5, 6. The outputs of the latter through the selective amplifiers (U) 7 and 8. phase detectors 9, 10. U AND 12 are connected to the inputs of the comparators (K) 13. 14 and -nii K 15, 16. Outputs K 13 , 14 is connected; through the analog-digital transformer IT 18 to the first and second inputs of the information recording unit i J. The outputs K 15, l (i are connected to the third and fourth) inputs of block 19. The outputs K 13, 14 are connected through the element OR 20 to the suppressor 1. Inputs G 21 rectangular pulses. The output G 2l is connected to the input of the counter 22, the output of which is connected to the control inputs of the switches 5. 6 and the fifth input of a knob, -49. The ferrosonde is installed in the plane of the horizon. The voltage from the windings 3 is supplied through the commutators 5, 6 to 7, 8. The timing of the removed voltage G 4 and frequency doubler 23 is performed. The second harmonic of the signal is detected by detectors 9, 10. At the same time, with V 11, 12 cinniaeicH, the constant voltage is pronounced on the azimuth. 1 tab. 3 il. he built N

Description

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

The aim of the invention is to improve the accuracy and reliability of the sensor.

FIG. 1 shows a structural diagram of the fluxgate azimuth sensor; in fig. 2 is a schematic diagram of the possible implementation of the information recording unit; in fig. 3 shows a possible embodiment of the display panel of the information recording unit.

The fluxgate azimuth sensor contains a ferrosonde of 1 ring type with excitation winding 2 and signal windings 3 located on it, four of which are main, and four additional windings, each pair of separated signal windings having an orthogonal pair. Excitation winding 2 is connected to generator 4. Each pair of diametrically opposite signal windings is connected in series and counter and connected to the corresponding inputs of switches 5 and b, the outputs of which are connected through selective amplifiers 7 and 8, phase detectors 9 and 10, amplifiers 11 and 12 to the inputs of the comparators 13 and 14 and the sign comparators 15 and 16, and the outputs of the comparators 13 and 14 are connected via analog-to-digital converters (ADC) 17 and 18 respectively to the first and second inputs of the information recording unit 19, and the outputs iconic comparators 15 and 16 are connected directly to the third and fourth inputs of the information recording unit 19. The outputs of the comparators 13 and 14 are also connected via the OR 20 element to the prohibiting input of the rectangular impulse generator 21, which is connected via its output to the input of the counter 22, the output of which is connected to the control inputs of the switches 5 and 6 and to the fifth input of the registration unit 19 information, the generator 4 through the frequency doubler 23 is connected to the clock inputs of the phase detectors 9 and 10.

Ferrozondov azimuth sensor works as follows.

Ring ferrosonde 1 is installed in the plane of the horizon, for example, using a kinematic scheme (not shown). The winding 2 of the fluxgate 1 is powered by the generator 4. On the signal windings 3, a voltage appears that through the switches 5 and 6 goes to two independent signal conversion paths, including selective amplifiers 7 and 8, detectors 9 and 10 and amplifiers 11 and 12.

To detect the second harmonic of the signal, the voltage taken is clocked using generator 4,

0

g

frequency doubler 23 and detectors 9 and 10. A constant voltage is removed from the output of amplifiers 11 and 12, which is described by

Ufc K-Hsin (cX - CU), (1)

where K is a conversion constant, depending on the design of the fluxgate, the parameters of the transformation path; H - magnetic field strength

The earths;

with. - magnetic azimuth; ft. - the corresponding number of the signal winding pair;

9- angle between elements of dissected ferrosonde.

Consider the ratio of c and kp under which the condition | oi is satisfied. -kj) | x We choose the value of x such that the relation sin); x x holds.

In this case, the expression (1) can be rewritten as

lUfe | K-H (ot-kp). (2)

As can be seen from expression (2), the output voltage is proportional to the measured angle o (., I.e., varies linearly.

  kf- +

IVfel KN

The output signal 1. is fed to the inputs of comparators 13 and 14, having a reference voltage - + Uon and -UOT. These voltages are equal to the voltage of the signal windings excited in one pair when the horizontal component of the vector of the magnetic field of the Earth deviates from the sensitivity axis of the ferrosonde, respectively, by the angle f / 2 and - р / 2.

If the output voltage is within

-Uon U, t - + Uon,

(3)

Then the element OR 20 is triggered, the rectangular pulse generator 21 is turned off, information about the number of the signal winding is taken from counter 22, and information from the ADC 17 and 18 about the value of the output voltage is supplied to information recording unit 19.

If the output signal does not satisfy inequality (3), the generator 21 rectangular pulses and the counter 22 commutes the following two orthogonal signal windings.

In this case, we have four elements of a dissected ferrosonde. Therefore, the angle p is determined from the ratio

55

). 45 °,

where the number of elements dissected ferrosonde.

Then the measurement error due to the approximation of the sin / 2 function is

Ls. " p / 2 - sin f / 2 3423

Asking a gratuity. You can determine the required number of elements of the signal windings.

Since the azimuth varies from 0 ° to 360 °, in order to determine it unambiguously, it is necessary to use information about the signs of the polarity of voltages taken from two orthogonally located ferrosonde. For this purpose, the output signals Uft and Utt + z from amplifiers And and 12 are fed to the inputs of the sign comparators 15 and 16, the outputs of which are connected to the third and fourth inputs of the information recording unit.

The table gives the angle values.

Switches, selective amplifiers, phase detectors, amplifiers, comparators, sign comparators, ADCs, OR elements, a counter, a frequency doubler, and a square pulse generator are standard devices and therefore have no features.

Consider a possible implementation of the information recording unit.

The information recording unit can be implemented on a K155IDZ type decoder, “NOT with an open collector output type K155ЛН2” logic elements, LED ALS 311A series seven-segment indicators, AL 102B series LEDs.

The analog-to-digital converter code corresponding to the voltage removed is applied to the inputs of the HI-NC LED indicators. From digital indicators, information is read directly in the angular measure, where HI is tens of degrees, H2 is units of degrees; NZ - the tenth fractions of degrees.

The information inputs of the DD1 decoder receive a logical “O or logical” 1 signal, depending on the sign of the polarity of the voltage Ui. and Ufe + t, and the code corresponding to the number of the element being included in the dissected ferrosonde. LEDs VD1-VD16 are connected to the outputs of the decoder through the elements NOT DD2- DD4.4. The elements do NOT play the role of an inverse repeater, since the output current of the decoder is small to turn on the diodes. If the LEDs are located in the corresponding sectors of the circle (see table), then it is possible to visually fix in which sector the measured azimuth is located.

To determine the true value of the winter, either the azimuth value, taken from the LED indicators, must be added.

five

katorov to the lower corner of the sector, or subtract it from the upper boundary.

Summation is necessary in the case when the information input of the second bit of the decoder DD1 is set to logical "1 regardless of the combination of codes on other information inputs. To unambiguously determine the required arithmetic operation, a VD17 LED is connected to the second input of the decoder DD1 via the element NOT DD4.5. If the diode is lit, summation is performed; if not, subtraction. Resistors R1-R17 are selected based on the current required of the VD1-VD17 LEDs.

25

The combined use of four main and four additional signal windings, comparators, sign comparators, a counter and switches provides 2Q operation of the fluxgate in the zone of maximum sensitivity, which increases the measurement accuracy. In addition, there is no need to use a computing node, which simplifies the design and reduces Ensures reliability of the sensor.

Claims (1)

Invention Formula 0 A ferrosonde azimuth sensor containing a ring type ferrosonde with an excitation winding and four main signal windings at 90 ° with respect to one another, a frequency doubler, a generator connected to the excitation winding, two selective amplifiers and two 5 phase detectors, characterized in that, in order to increase the accuracy and reliability of operation, it is equipped with four additional signal windings located at an angle of 90 ° with respect to one another and at an angle of 45 ° with respect to the main signal winding. switches, two, amplifiers, two comparators, two sign comparators, two analog-to-digital converters, an OR element, a rectangular impulse generator, a counter and an information recording unit, each pair diametrically of the positive signal windings are connected in series and counter and connected to the corresponding inputs of the switches, the outputs of which are connected through bending amplifiers, phase detectors, amplifiers to the inputs of comparators and sign comparators, the outputs of the comparators being connected through the analog-digital converters to the first and second inputs of the registration unit information, and the outputs of the sign comparators are connected directly to the third and fourth inputs of the register block5 0 five information, the comparators' outputs are also connected via the OR element to the prohibitive input of the generator of rectangular pulses, which by its output is connected to the input of the counter, the output of which is connected to the control inputs of the switches and to the fifth input of the information recording unit, and the generator through the frequency doubler is connected to clock inputs of phase detectors. Note.k - the element number of the dissected ferrosonde, the output voltage of which satisfies condition (3); Vr - the sign of the polarity of the voltage taken from the k-ro flux-gate, Ud.2.-the sign of the polarity of the voltage taken from the flux-gate orthogonal to the k-th, VDCN) - LED, installed in the corresponding sector of the wasps, on the information recording unit . LP1 Shil 2 337.5 Vff2 oh oh Vd7s 27 (f vDg . Vd7 22S Vd5 202: 5 VD3 780 U01 . Well MD / 7 /// Fiz. 22, S wow VO 8 67.5 YD GO W072 757.5 H5