SU1520238A1 - Apparatus for measuring the set of geophysical parameters in well - Google Patents

Abstract

The invention relates to geophysical measurements. The purpose is to increase the functionality and increase the information content by simultaneously measuring three geophysical parameters. The device contains a two-pole current source 1, a voltage-to-voltage converter 2, blocks 3 and 4 of subtraction and indication, control unit 5, a communication line with wires 11, 12, a resistive sensor 18, a choke 20 with a rectangular reversal characteristic. To achieve the goal, the device has a bridge strain gauge 13 with strain gauges 14, 15, 16, 17, eight diodes 21-28, an additional resistive sensor 19. When current is applied, the choke 20 has a high resistance, and then, as the core is saturated, it is negligible. The device has four cycles of operation. In the first cycle, a current of positive polarity is applied and the strain gauges 16, 15 of the strain gauge 13 are shunted. The current flows through the sensor 18. The voltage And is converted into code by the converter 2, fixed and fed to the input of the subtraction unit 3. In the second cycle, the throttle 20 has a low resistance and shunts the sensor 18. The voltage And _{2 is} fed to the input of the unit 3. The third and fourth cycles form the voltage And ₃ and And ₄ when changing the polarity of the current source 1. As a result of voltage subtraction, codes are formed that are proportional to the change in the resistances of the sensors 18, 19 and the strain gauge 13. The results are recorded in the display unit 4. The use of the device eliminates the influence of the communication link parameters on the measurement result, increases the information content by measuring three parameters within four cycles of the device operation. 4 il.

Description

Sh

voltage converter 2 to code, blocks 3 and subtraction and indication, control unit 5, a communication line with wires 11, 12, a resistive sensor 18, a choke 20 with a rectangular bias characteristic. To achieve the goal, the device has a bridge strain gauge 13 with strain gauges 1, 15, 16, 17, eight diodes 21-28, an additional resistive sensor 19. When current is applied, the choke 20 has a high resistance and then negligibly small as the core is saturated. The device has four cycles of operation. In the first cycle, a current of positive polarity is applied and the strain gauges 1b, 13 of the strain gauge 13 are shunted. The current flows through

ten

15

The transducer 2 is encoded into the code and fed into the input of the subtraction. In the second cycle, the other 20 has a small resistance that rutes the sensor 18. The voltage Upat to the input of the unit 3. The third and the right cycles form a voltage and when changing the polarity of the source 1 current. As a result of subtractions, codes are formed that are proportional to the change in resistances 18, 19 and the strain gauge 13. The rests are fixed in block k.

. sensor 18. The voltage U, the conversion Q operation of the device. 4 il.

Into the code by the converter 2, is fixed and is fed to the input of the subtraction unit 3. In the second cycle, the throttle 20 has a low resistance and shunts the sensor 18. The voltage Ui is fed to the input of block 3. The third and fourth cycles form the voltage Uj and even when changing the polarity of the current source 1. As a result of voltage subtraction, codes are formed that are proportional to the change in the resistances of the sensors 18, 19 and the strain gauge 13. The results are recorded in the display unit k. The use of the device allows us to exclude the influence of the communication link parameters on the measurement result, to increase the information content by measuring three parameters within four cycles of the device operation. 4 il.

35

The invention relates to remote measurements of geophysical parameters by resistive sensors and can be used to measure a set of physical quantities converted to changes in active resistance (temperature, pressure, flow, etc.) in wells using a two-wire line. communication.,

The aim of the invention is to enhance the functionality and increase the information content by simultaneously measuring three geophysical parameters.

Figure 1 shows the structural-functional diagram of a device for measuring a complex of geophysical parameters in a well; Fig. 2 is a block diagram of a voltage converter in a CODE;} Fig. 3 is a block diagram of a control unit; in Fig. (- timing charts of operation of the control unit.

A device for measuring a complex of geophysical parameters in a well includes a current source 1, a voltage-to-voltage converter 2, a subtraction unit 3, a display unit C, a control unit 5 with control outputs 6-10, a two-wire communication line with active resistance of wires 11 and 12 , the deep part of the device, containing a bridge strain gauge pressure sensor 13 with a tensor 40

45

50

55

five

ABOUT

0

five

0

five

14 to 17, the first 18 and second 19 resistive temperature sensors, a choke 20 with a rectangular magnetic reversal characteristic, and eight diodes 21 to 28. The current source 1 is connected to the wires 11 and 12 of the communication line and the inputs of the pre-phaser 2 voltage in the code, which by its outputs is connected to the inputs of the subtraction unit 3, the outputs of which are connected to the inputs of the display unit. Control unit 5 of output 6 is connected to the control unit (the input of current source 1 is connected to it, and outputs 7-10 are connected to control inputs of voltage converter 2 in code. Parallel to each of the strain gauges of the bridge tensor resistance pressure sensor 13, each of diodes 21-24 is connected, moreover, one of the points of the supply diagonal of the sensor 13 (tensome bridge) is connected to the cathode of diode 21, the anode of diode 22 and wire 11 of the two-wire communication line, and the second point of the supply diagonal of tensome bridge 13 to the cathode of diode 23, anode of diode 2k, anodes of diodes 25 and 27 , the cathodes of diodes 2b and 28. Two points KSR Control tenzomosta diagonal 13 are connected to the anodes of diodes 21 and 23 and the cathodes of diodes 22 and 2k, respectively. The second wire link 12 in the deep portion is connected to the first terminals of resistive sensors 18 and 19 and the temperature of choke 20. The second terminal of the choke 20 is connected to the cathode

five

the diode 27 and the anode of the diode 28; the second terminals of the temperature sensors 18 and 19 are connected respectively to the cathode 25 and the anode of the 26 diodes.

The voltage converter 2 in the code contains four nodes 29-32 of sample storage (VHR), four ZZ-Zb inverters and four analog-digital converters (ADC).

Block 3 subtraction contains three arithmetic logic units (not shown).

Control unit 5 includes a square-wave generator A1, splitters kZ-k frequencies, inverters 5 and logic elements AND 48-51, whose outputs 7-10 are respectively control inputs for voltage converter 2 to code, and output 6 of divider kk is the control input for current source 1.

A device for measuring a complex of geophysical parameters in a well works as follows.

The Al generator of rectangular pulses of the control unit 5 generates a sequence of rectangular pulses (Fig. 1), whose frequency

is divided into 2-kk dividers (U, U 1144) By the coincidence of the high level signals 1144 and 43 and 4t, the output of the And 48 (and.) element is generated by a pulse, controlling the VHF 29 of the voltage converter 2 to the code. By the coincidence of the pulses from the outputs of the inverters 5 and fS and the output of the divider kk, a pulse is formed at the output of the element 49 (U + g), controlling the VHD 30. By combining the pulses from the outputs of the dividers 42 and 43 (and 41 and 4z) and the inverter 47 output element And 50 (and 5c) control pulses of the water economy unit 31 are generated. When the high level signals from the outputs of inverters 45-47 coincide, at the output of the element And 51 (and 51) pulses are generated that control the control of the water economy department 32. The output signal from the splitter 44 (1) 44) is fed to the output 6 of the control unit 5 to control the bipolar current source 1.

The high level signal from output 6 (and 44.) of the control unit 5 in the communication line carries a positive current through wires 11 and 12. At the same time, the current flows through the parallel circuits formed, the first of which consists of series-connected strain gauges 14 bridge dates

0238

Yu

The sensor 13 and the diode 23 connected at a given polarity of the current in the forward direction are shunt as a result of this strain gauge 15, and the second circuit is formed from the series-connected strain gauge 17 and diode 22. For strain gauges manufactured according to the integrated technology, which include bridge pressure gauge 13 pressure, the statement about the equality of resistance of all arms of the bridge in the absence of pressure, i.e.

RI where R

R

“,

sixteen,

R R R

 R

tt,

Rn.

 R., (1)

I

, 7 - initial resistance of strain gauges 14-17 strain gauge 13 in the absence of pressure,

therefore, the resistance increments of ARp of the strain gauges, forming the shoulders of the bridge, are equal under the action of pressure. Ensuring equal DC resistance of all diodes included in the forward direction

RVII-Rs / -i-2 Pvv2.3 R VM (2)

by the method of individual selection, it can be argued that the current in each of the resulting circuits is equal to half the current I of the current source 1. Insofar as

If a choke 20 with a rectangular hysteresis loop is used, for example, wound around a ring core of iron-nickel alloys, then a small amount of current (about 0.1 mA) flows through the process of magnetization and remagnetization. its impedance is X j - 00. 8 the moment when the choke enters saturation, the resistance

it is determined by the resistance of the winding and is negligible. At the initial moment of current flow I, choke 20 begins to magnetize and all current flows through

a diode 25 connected in this case in the forward direction, and a resistive sensor 18. Thus, at the initial time, the voltage at the input of the voltage converter 2 to the code is determined by

i

I. (2R + (R + Rj,)

R vrs

(3)

de 2R - total resistance

wires 11 and 12 of the line,

R is the active resistance of a tensor resistor with a positive increment of resistance with increasing pressure

nor, which given can be written in the form

R "R„ K „+ dKo

(1) W

f4 P

R e - equivalent resistance, defined in view of (1) and (2) by the expression

R

.R t5-r

31

R

+ g

R "R

(five)

15 and Ry 5 constant resistance

the current of the diode 25, R, j is the resistance of the resistive sensor 18. The voltage U O) pulse from the output 7 of the control unit 5 is stored in the OU 29 of the voltage converter 2 into a code, and at the end of the control pulse a high level signal is generated inverter 33 enabling the ADC, which generates a parallel code on its output bus

N / k and ,,. (6) where k is the conversion factor

ADC.

At the next time point, choke 20 enters saturation, shunt resistive sensors 18 and 19 (all current I flows through choke 20). The voltage at this moment is determined by the expression

and,

one

I (| (R +

R ,,) + R

vii).,

(7) where R is constant resistance

diode current 27.

The resistance of the winding of the throttles 20, which is in saturation, can be neglected due to its insignificance. The voltage Ui (7). the pulse from the output 8 of the control unit 5 is stored in the VHD 30 of the converter 2, and at the end of the pulse, the high level of the output of the inverter 3 converts the input voltage to a parallel code in the ADC 38

Ni, k U. (8) Figure 4 shows the variation of the input voltage for the converter 2 of the voltage Ujx and marked the points at which the voltage is memorized.

The command of the control unit 5 at the output 6 (and) generates a low signal level controlling the current source 1. A current (-1) of reverse polarity, but of equal amplitude, begins to flow into the communication line. The inductor 20 begins to rebrang and the current flows through the newly formed 14: resistive sensor 19, diode 26 and parallel branches m - diode 24, strain resistor 16 and the strain gauge 15, diode 21. The voltage at the input of the voltage converter 2 into the code in this time is determined by the expression

3

R ,,).

- (2R

 j (R + R ,,) +

R V 1.6

(9) 5

where r

R

15

Vte

R 0

active resistance of resistive sensor 19, resistance to direct current of diode 26, active resistance of a strain gauge with a negative increment of resistance with increasing pressure, which, taking into account (1) and specified, can be written as

 , R ,, Re - dR

R

15

sixteen

P

E1

five

(ten)

- equivalent resistance, defined by (1) and (2) by expression

Eiv 14 E1 -

cir

(eleven)

The voltage U by the control signal and 50 from the output 9 of the control block 5 is stored in the VHI 31 of the converter 2, and then when a high level signal appears at the output of the inverter 35, this voltage is converted to the ADC 39 into a parallel code

N, k and

3

(12)

At the next moment of time, choke 20 enters saturation, the shunt of resistive dates, 4 and 18 and 19, and the voltage and at the input of converter 2 is determined by the expression

if -I (| (R + R,.) - -R

v / 28

(13)

which, on the signal Us, from the output 10 of the control unit 5 is stored in the TLI J2. and then on high signal

the level from the output of the inverter 3B is converted into Alin kO into the parallel code N k U. (1) The N – N codes received as they are converted go through their buses to the inputs of three arithmetic logic units (ALB) of the subtraction unit 3, and to the inputs of the first LPR parallel binary codes N, N are received, where N is subtracted, - N, to the inputs, the second ALB - N, N4 codes (operation N N4), and to the inputs of the third ALB - N and N codes, where subtraction

Kj. IM

as a result of the operations performed on the ALB outputs, the codes are formed respectively

Nf N - NI kU - kU

kKRvis

N, N3

- R V47 - N4

+ R,);

kU3 - kU4

 kI (R i It

  13 )

(15) (16)

NT N4 kUi - kU t

kl ((RnR vasb

E) - 2

) +

R v 21 (17)

where Ny, n, N 1 - codes, respectively: at the output of the first,

second, third

ALB.

Diodes 27 and 28 are not directly necessary for the conversion process, i.e. do not participate in achieving the stated goals of the invention. However, in their absence, expressions (15) and (16) have uncompensated terms, the change of which introduces additional error in the measurement result. In the case of their use and ensuring equality

(18

R vi5

V77

 R

Vie

 g,

(18)

what is achieved by individual and selection, the results of transformations (15) and (t6) take the form

N5 (19) ,,. (20) Using expressions (), (5)., (10) and (11) and equality (18), expression (17) transforms to

N.

kI (| (R

about + uRp +

g) - | (RO- UR p + g) + g - g) kIdR p. (21)

The obtained results are sent to the display unit k, where they can

ten

15

20

25

thirty

35

40

45

50

55

appear in units of the measured parameter with the appropriate calibration of the device. Each of the obtained results (19) - (21) depends only on its measured parameter, which is converted to the resistance of the corresponding resistive sensor, and is invariant to the parameters of the communication line.

Claims (1)

Invention Formula A device for measuring a complex of geophysical parameters in a well, comprising a first resistive temperature sensor, a choke, a two-wire communication line, a current source, a voltage converter into a code, a control unit, a subtraction unit and a display unit, the first terminals of the throttle and first resistive sensor the first wire of the communication line to the first output of the current source and the first input of the voltage converter in the code, the second input of which is connected to the second output of the current source and the second wire of the line, The output is connected via a subtraction unit to the display unit, while the outputs of the control unit are connected to the control inputs of the voltage converter and the current source, characterized in that, in order to expand the functionality and increase information by simultaneously measuring three geophysical parameters it is equipped with a second resistive temperature sensor, a bridge integrated strain gauge pressure sensor, the first - the eighth diodes, the first - the fourth diodes are connected by a bridge circuit and Connected in parallel to each of the four bridge pressure gauges, the connection point of the opposite terminals of the first and third diodes is connected to the first output of the supply diagonal of the bridge pressure sensor and the second wire of the communication line, and the connection point of the opposite terminals of the second and fourth diodes is connected to the second output the supply diagonal of the bridge pressure sensor, the conclusions of the measuring diagonal of which are connected respectively to the connecting points of the first-named terminals of the same name and the fourth diodes, the second terminal of the supply diagonal of the bridge pressure sensor is connected to the anodes of the fifth and seventh diodes and cathodes of the sixth and the eighth diode, the cathode of the fifth diode is connected to the second terminal of the first rezistivno- second temperature sensor, the anode of the sixth the diode is connected to the second output of the second resistive temperature sensor, the first output of which is connected to the first wire of the communication line, the cathode of the seventh diode is connected to the anode of the eighth diode and the second output of the throttle.