RU2013536C1 - Device for reading and recording magnetic depth marks - Google Patents

Abstract

FIELD: mining. SUBSTANCE: device has biasing generator 13, readout unit with mark application unit 2, and magnetic mark sensor in the form of two magnetomodular transducers 1 and 3. The magnetic mark sensor is connected to the input of the device. The mark readout unit is fashioned as five comparators 4-8 of first and second RS-triggers, 11 and 12, first, second, and third AND-gates 9, 10, and 14. 13 -- 3, 1 -- 8 -- 9, 8 -- 10, 3 -- 4, 3 -- 5, 3 -- 6, 3 -- 7, 4 -- 11, 14 -- 2, 5 -- 9 -- 11, 6 -- 10 -- 12 -- 14, 7 -- 12. The device allows to align the point of the readout sensor with the point of regeneration of the mark application unit directly at the center of the magnetic mark. EFFECT: enhanced accuracy of measurements, reduced expenditures for well servicing and prospecting. 3 dwg

Description

 The invention relates to measuring depths in field geophysical maintenance of boreholes.

 A device is known that contains a magnetic probe and a marking device, while to increase the noise immunity between the magnetic probe and a marking device, a threshold device and a logic unit are included to ensure that the marking device is triggered from a signal of a certain shape [1].

 A device is known that contains a magnetomodulating transducer with an excitation generator and an integrator connected to it, which is connected to a threshold unit, and a compensation unit that provides stable reading of weak marks in the presence of surrounding magnetic fields [2].

 The disadvantage of these devices is the inability to restore the initial field strength of the magnetic marks, which leads to the need for repeated measurements of the cable while reducing the field strength of the magnetic marks below the sensitivity threshold of the device.

 A device is known comprising a tag reader, a choke for demagnetizing the cable, and a tagging unit spaced along the length of the cable. The specified device allows for each rise to regenerate the labels passing through the label reader, while applying magnetic labels to the labeling unit and then erasing them after reading [3].

 The disadvantages of this device are the inability to regenerate labels during reverse movement of the cable, as well as the shift of magnetic marks on the cable at each of its descent, associated with the transfer of applied marks relative to readable ones, which reduces the accuracy of linking geophysical information to depths in the well and requires additional adjustment shifted marks when measuring the true depth of the well.

 The closest technical solution to the proposed one is a magnetic tag reader containing a tag sensor made in the form of two magnetomodulating transducers spaced half the width of the north pole of the magnetic tag and having an excitation winding fed by a pulsed current from the magnetization generator, the outputs of the magnetomodulating transducers are connected to the reader marks [4].

 However, this device has a high threshold of the lower limit of sensitivity, which narrows the range of stable reading of tags, there is no noise immunity from the effects of the electromagnet during tag regeneration. In addition, the device does not have the functionality to regenerate readable tags during field geophysical maintenance of boreholes.

 The aim of the invention is to improve the accuracy of linking field-geophysical information to the depths in the well by eliminating the displacement of magnetic marks on the cable during their regeneration.

 This goal is achieved by the fact that in the device for reading and regenerating magnetic marks when measuring the depth of the well containing the reading unit, the mark sensor is made in the form of two differential magnetomodulating transducers, the outputs of which are connected to the input of the reading unit labels, the latter is made in the form of five comparators, the first and second RS-flip-flops, the first, second and third elements And, and the inputs of the comparators are the input of the label reader, and the outputs of the first and fourth comparators are are respectively connected to the R-inputs of the first and second RS-flip-flops, the outputs of the second and third comparators are connected respectively to the first inputs of the first and second elements And, the second inputs of which are connected to the output of the fifth comparator, and the outputs of the first and second elements And are connected respectively to S- the inputs of the first and second RS-flip-flops, the outputs of which are connected respectively to the first and second inputs of the third AND element, the output of the latter is the output of the label reader and connected to the labeling unit, which is located en magnitomodulyatsionnymi between converters.

 A significant difference between the proposed device and others known in the art is the use of a differential magnetomodulation transducer consisting of two magnetomodulation transducers spaced half the width of the north pole of the magnetic mark, the location of the marking unit, including the marking elements - an electromagnet, as well as connecting the output of the tag sensor to the tag reading unit, made in the form of five comparators, the first and second about RS-flip-flops, the first, second and third elements And, and the connection of the output of the label reader with the labeling unit, and the differential output of the label sensor is connected to the inputs of the first four comparators, and the output of one of the magnetomodulating converters is connected to the input of the fifth comparator, to the other the inputs of which are supplied with different reference voltages.

 As a result of comparing the output signals of the mark sensor and the magnetomodulating transducer with the levels of the reference voltage applied to the inputs of the five comparators, the mark reading unit generates a signal combining the reading point of the mark sensor with the regeneration point of the marking unit directly in the center of the magnetic mark, which eliminates the shift of magnetic marks by cable during their regeneration and allows you to restore the initial magnetic field strength of the depth marks at each descent. This increases the accuracy of linking field-geophysical information to the depths in the well. Given the growing trend of well depths and the use of magnetized casing strings, when working in which the field strength of the depth mark due to increased mechanical and thermal influences and (or) magnetization of the casing strings decreases especially quickly, the use of the proposed device allows to reduce the cost of performing a given volume of production -geophysical works.

 In FIG. 1 is a block diagram of the proposed device; in FIG. 2 and 3 are timing diagrams of the operation of the device during reverse movement of the wireline cable.

The sensitive element of the device is a tag sensor, which is a differential magnetomodulating transducer with pulse excitation, consisting of two magnetomodulating transducers 1 and 3, spaced half the width of the north pole of the magnetic tag and having an excitation winding fed by a pulse current from the magnetization generator 13. Between the two magnetomodulating converters 1 and 3, there is a block 2 for applying labels, including an element for applying a magnetic label - an electromagnet. The output of the tag sensor is connected to the tag reader, the input of which is the inputs of the first 4, second 5, third 6, fourth 7 and fifth 8 comparators, and the differential input of the tag sensor is connected to the inputs of the comparators 4-7, to the other inputs of which reference voltages U ₁ , U ₂ , U ₃ , U ₄ . The output of the magnetomodulating transducer 1 is connected to the input of the fifth comparator 8, the second input of which is supplied with a reference voltage U ₅ . The outputs of the first 4 and fourth 7 comparators are connected respectively to the R-inputs of the first 11 and second 12 RS-flip-flops, and the outputs of the second 5 and third 6 comparators are connected respectively to the first inputs of the first 9 and second 10 elements AND, the second inputs of which are connected to the output of the fifth comparator 8. The outputs of the elements And 9 and 10 are connected respectively to the S-inputs of the first 11 and second 12 RS-flip-flops, the outputs of which are connected respectively to the first and second inputs of the third element And 14. The output of the latter is the output of the label reading unit and one temporarily connected to the input unit 2 labeling. The necessary noise immunity of the device when reading labels is achieved by choosing higher levels of comparison of the output signal of the label sensor with the reference voltages U ₁ and U ₄ supplied respectively to the inputs of the comparators 4 and 7. A characteristic feature of the output signal is the zero crossing point, the position of which relative to the transducer housing determines reading point and at the same time applying a magnetic mark. The choice of sufficiently low levels of comparison of the output signal of the label sensor with the reference voltages U ₂ and U ₃ supplied to the inputs of the comparators 5 and 6, respectively, ensures reading and simultaneously applying magnetic marks immediately after the transition of the label sensor signal through zero. A high level of comparison of the output signal of the magnetomodulating transducer 1 with the reference voltage U ₅ supplied to the input of the comparator 8 determines the sensitivity of the device. In order to exclude the application of a magnetic mark when the device is turned on, it provides for the forced reset of RS triggers 11 and 12.

 The device operates as follows.

When the label is affected by the magnetic field labels (Figs. 2 and 3, a), output signals appear on the signal windings of the magnetomodulating transducers 1 and 3, the amplitude and polarity of which depend on the position of the label relative to the transducers 1 and 3 (Figs. 2 and 3, b -at). In the case of a logging cable being lowered into the well (Fig. 2), the initial influence of the magnetic field of the mark is directed to the magnetomodulating transducer 1, as a result of which pulses of positive polarity appear at the outputs of the mark sensor and magnetomodulating transducer 1 (Fig. 2, b, c). When the amplitude of the output signal of the sensor marks the reference voltage levels U ₂ and U _{1, the} comparators 6 and 4 generate positive pulses (Fig. 2, d, e), and the output signal of the comparator 4 resets trigger 11 (Fig. 2, m). When the amplitude of the output signal of the magnetomodulating transducer 1 exceeds the reference voltage level U _{5, the} comparator 8 generates positive pulses (Fig. 2, f), which allow the output of the comparator 6 to pass through the element And 10 (Fig. 2, g). The output signal of the element And 10 sets the trigger 12 (Fig. 2, l). When the center of the mark matches the center of the mark sensor, the output of the mark sensor becomes zero. A further shift of the label relative to the center of the label sensor causes the output of the sensor labels pulses of negative polarity (Fig. 2, b). When the amplitude of the output signal of the sensor marks the reference voltage level, the comparator 5 generates positive pulses (Fig, 2, h), which, in the presence of the output signal of the comparator 8 (Fig. 2, a) pass to the output of the And 9 element (Fig. 2, k) . The output signal of the element And 9 sets the trigger 11 (Fig. 2, m). When the amplitude of the output signal of the label sensor exceeds the level of the reference voltage U ₄ , the comparator 7 generates positive pulses (Fig. 2, and), which reset the trigger 12. At the time of installation of both triggers 11 and 12 at the output of the element And 14 the signal "Tag" is generated, which is fed to the input of the labeling unit and the output of the device (Fig. 2, n).

Similarly, the device operates when lifting the wireline cable (Fig. 3). The initial effect of the magnetic field of the mark is directed to the magnetomodulating transducer 3, as a result of which pulses of negative polarity appear at the output of the mark sensor (Fig. 3, b). When the amplitude exceeds the output of the label sensor, pulses of negative polarity appear (Fig. 3, b). Exceeding the amplitude of the output signal of the sensor labels reference voltage levels U ₃ and U ₄ leads to the generation of positive pulses of the comparators 5 and 7 (Fig. 3, d, d), and the output signal of the comparator 7 resets trigger 12 (Fig. 3, l). Further exposure to the magnetic field of the label causes the appearance of the output signal of the magnetomodulating transducer 1 (Fig. 3, c). When the amplitude of the output signal of the magnetomodulating transducer 1 exceeds the reference voltage level, the comparator 8 generates positive pulses (Fig. 3, a) that allow the output of the comparator 5 to pass through the And element 9 (Fig. 3, g). The output signal of the element And 9 sets the trigger 11 (Fig. 3, m). When the center of the magnetic mark passes through the center of the mark sensor and the amplitude of the output signal of the mark sensor exceeds the level of the reference voltage U _{2, the} comparator 6 generates positive pulses (Fig. 3, h), which, passing through the element And 10 (Fig. 3, k), set trigger 12 (Fig. 3, l). When the amplitude of the output signal of the sensor marks the reference voltage level, the comparator 4 generates positive pulses (Fig. 3, and), resetting the trigger 11 (Fig. 3, m). The moment of installation of the triggers 11 and 12 generates a signal "label" at the output of the element And 14 (Fig. 3, n).

 Thus, the combination of the readout point of the mark sensor with the regeneration point of the marking unit directly in the center of the magnetic mark eliminates the shift of magnetic marks on the cable during their regeneration, and the regeneration of magnetic marks at each descent, allows you to restore the initial magnetic field strength of the depth marks, which increases the accuracy binding of field-geophysical information to the depths in the well.

Claims (1)

 DEVICE FOR READING AND REGENERATING DEPTH MAGNETIC METHODS, containing a tag sensor made in the form of two magnetomodulating transducers spaced half the width of the north pole of the magnetic tag and having an excitation winding fed by a pulsed current from a magnetization generator, the outputs of the magnetomodulating transducers two comparators, an element And and an RS-trigger, characterized in that it is equipped with a labeling unit located between the magnetomodulation converters, and the tag reader is additionally equipped with three comparators, two AND elements and a second RS-trigger, with one of the outputs of the first magnetomodulating converter connected to the first inputs of the first, second, third and fourth comparators, and the second output of the first connected to the first input of the fifth comparator and the output of the second magnetomodulating converters, reference voltages are applied to the second inputs of the comparators, the outputs of the first and fourth comparators are connected respectively to the R inputs of the first and second triggers, the outputs of the second and third comparators are connected respectively to the first inputs of the first and second circuits And, the second inputs of which are connected to the output of the fifth comparator, the outputs of the first and second circuits And are connected respectively to the S-inputs of the first and second triggers, the outputs of which connected to the inputs of the third element And, and the output of the third element And is the output of the label reader and connected to the input of the labeling unit.

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