SU1133573A1 - Device for synchronizing acoustic well-logging equipment - Google Patents

Abstract

A DEVICE FOR SYNCHRONIZATION OF THE EQUIPMENT OF THE ACOUSTIC CARROT, consisting of a ground synchronization unit, the input of which is connected to the geophysical cable, and a borehole part containing a frequency divider, a delayed pulse shaping unit, an emitter excitation pulse generator, a transmitter for generating emitters, emitters, an energizer, a delayed pulse, a generator of emitters excitation pulses, a pulse emitter pulse generation unit, a switch, and a learning lead generator; two inverters, an OR element and a power amplifier, while the output of the power amplifier and the input of the frequency divider are connected to the geophysical cable, The output of the frequency divider is connected to the input of the block for generating delayed start pulses, the first two outputs of which are connected to the inputs of the generator of excitation pulses of the emitters, and one of the outputs of the latter is connected by a generator of generating pulses of the moment of excitation of the emitters to the reset input of the waiting multivibrator, whose output through the inverter is connected to one from the outputs of the power amplifier, and the input of the standby multivibrator through the second inverter is connected to the output of the OR element, whose inputs are connected to the third and the fourth output of the block for the formation of delayed start pulses, characterized in that, in order to increase the noise immunity and enhance the functionality of the device, the ground synchronization unit is made in the form of five AND elements, three OR elements, two time delay elements, two inverters, two differentiating elements , RS flip-flop, differentiator, two pulse selectors by duration, waiting for the multivib rator and turned on at the input of the ground synchronizer block of the comparator, the output (L go connected to the first input of the first element. And the output of the last connected to the inputs of the pulse selectors in duration, the outputs of the selectors are connected to the first inputs of the second and third elements And, the second inputs of which are combined and connected through a differentiator to the input of the comparator, and the outputs of the second and third eleooo From SP cops And connected to the inputs of the RS-flip-flop and through inverters with the first inputs of the fourth and fifth elements And, the second inputs of which are connected through the elements of the time delay with the outputs of the RS-flip-flop, outputs The Fourth and fifth AND gates connected to the first OR element, inputs of second OR elements are connected through differentiating the outputs RS-trigger and to the inputs of the latter via the third OR gate connected to the start input of a monostable multivibrator, whose output is connected to a second input of the first element I.

Description

The invention relates to well logging by acoustic methods. A device for acoustic logging with a borehole device containing a four-element compensation probe is known in which the channel switching of the upper and lower three-element systems of the probe and the start of the emitters are carried out from the ground control panel. The disadvantage of this device is the need to use three lived seven-wire cable. A device for acoustic logging of wells with synchronization of the operation of a downhole tool and a ground control unit is known by generating synchronization pulses in a well instrument linked to a network voltage and transmitting them via cable to a ground control unit (synchronization “from below”). In the ground control, the channel-by-channel separation of synchronization pulses is carried out on the polar basis to control the measurement process of the kinematic and dynamic parameters of elastic waves 2. However, this system is only intended to synchronize the operation of acoustic logging equipment with three-element probes and, moreover, has low accuracy when measuring interval time, since the accuracy of measurement of dynamic parameters (Ai, A; j and a)., the synchronization system does not affect. The closest in technical essence to the present invention is a device for synchronizing acoustic logging equipment consisting of a ground synchronization unit, the input of which is connected to a geophysical cable, and a downhole part containing a frequency divider, a delayed impulse generation unit, an emitter excitation pulse generator, a unit forming impulses of the moment of excitation of emitters. a standby multivibrator, two inverters, an OR element and a power amplifier, the output of the power amplifier and the frequency divider input are connected to the geophysical cable, the output of the frequency divider is connected to the input of the delayed start pulse formation unit, the first two outputs of which are connected to the inputs of the emitter excitation pulse generator, and one of the outputs of the latter is connected via a pulse shaping unit of the moment of excitation of the emitters to the reset input of the waiting multivibrator, the output of which through an inverter is connected n to one of the inputs of the power amplifier, and the input of the standby multivibrator is connected via the second inverter to the output of the OR element, whose inputs are connected to the third and fourth outputs of the block for generating delayed trigger pulses 3. In a known device, in order to increase noise immunity, the transmission of synchronization pulses and information the signal is carried out on the same two-wire communication line. Moreover, to isolate the synchronization pulses of the first and second channels of a three-element probe, the pulse pulse time is used, and the time of propagation of elastic waves is counted at the beginning of the trailing edge of these pulses, corresponding to the moment of excitation of the radiator of the downhole tool. This synchronization system can be used for the formula of the probe of the downhole tool AND AH.BFIj and with minor changes for the probes with the formula, where Hi, .Hj. Are emitters; P1, .. P2.: - receivers; A - measuring base of the probe; In - the length of the probe. The use of this synchronization system for working with four- and six-element compensation probes is possible only with an increase in the instrumental volume both in the downhole tool and in the surface console. It is necessary to have not two, but four time signs, for example, the first and second (the duration of synchronization pulses 1..and.) .. - for the three-element lower part of the compensation probe, and the third and fourth (... and G.) for the three-element the upper part, which also reduces the noise immunity of the synchronization system and complicates the circuit. In addition, false positives are possible as a result of the information signal being applied to the synchronization path. The purpose of the invention is to enhance the functionality of the synchronization system. Using only two time signs, as well as improving its noise immunity. The goal is achieved by the fact that the device for synchronization of acoustic logging equipment, consisting of a ground synchronization unit, whose input is connected to a geophysical cable and a well part containing a frequency divider, a block for generating delayed start pulses, a generator of excitation pulses of emitters, a block for generating pulse emitters, waiting for a multivibrator, two inverters, an OR element and a power amplifier; the output of the power amplifier and the input of the frequency divider are connected to the geophysical cable, the output of the frequency divider is connected to the input of the delayed generation pulse shaping unit, the first two outputs of which are connected to the inputs generator of excitation pulses of emitters, and one of the outputs of the latter is connected through a pulser forming unit of the moment of excitation of emitters with a reset input of the waiting multivibr the output of the inverter is connected to one of the outputs of the power amplifier, and the input of the standby multivibrator is connected via the second inverter to the output of the OR element, the inputs of which are connected to the third and fourth outputs of the delayed pulse formation unit; the ground synchronization unit is made in the form of five elements And, three, elements OR, two elements of time delay, two inverters, two differentiating elements, RS-flip-flop, differentiator, two pulse selectors by duration, waiting for multivibr of the comparator, the output of which is connected to the first input of the first element And, the output of the latter is connected to the inputs of the pulse selectors in duration, the outputs of the selectors are connected to the first inputs of the second and third elements And, the second inputs of which are combined and connected through a differentiator to the input of the comparator, and the outputs of the second and third elements And connected to the inputs of the RS-flip-flop and through inverters with the first inputs of the fourth and fifth elements And, the second inputs of which are connected through the elements of the time delay with the outputs of the RS-flip-flop, the outputs of the fourth and fifth elements AND are connected to the first element OR, the inputs of the second element OR through the differentiating elements are connected to the outputs of the RS-trigger, and to the inputs of the last , its multivibrator, the output of which is connected to the second input of the first element I.

Such a construction of the synchronization system makes it possible to use it both for working with three-element acoustic, probes, and for working with four- and six-element compensation probes.

FIG. 1 is a block diagram of a device for synchronizing acoustic logging equipment; in fig. 2 - time diagrams illustrating the operation of the device.

The device consists of a ground block 1 synchronization and downhole part 2, connected by a geophysical cable 3.

Synchronization unit 1 consists of comparator 4, differentiator 5, element Ib, selectors 7 and 8 pulses in duration, elements 9 and 10, RS flip-flop 11, inverters 12 and 13, elements 14 and 15 of the time delay of elements 16 and 17 , element OR 18, differentiating elements 19, and 20, elements OR 21 and 22, waiting for the multivibrator 23.

The downhole part 2 of the synchronization device includes a frequency divider 24, a block 25 for generating delayed start pulses, a generator 26 for meter excitation pulses, a block 27 for generating emitter excitation pulses, a waiting multivibrator 28; inverters 29 and 30, element OR 31, power amplifier 32.

The device works as follows.

The operation of the downhole part of the synchronization system when working with a three-element probe is no different from that described in 3, i.e. for separating the information of the first and second channels, the synchronization pulses are transmitted to the ground synchronization unit with a time of a pulsed indication: the duration T. is the indication of the first channel; the duration of CD, is a sign of the second channel, and the moment of excitation corresponds to the beginning of the trailing edge of the synchronization pulse. These. Two temporary signs can be used when working with four- and combinational element compensation probes.

Since the four- and touch-element compensation probes are two three-element probes with an oncoming observation system, in the process of borehole surveys, in order to improve the dynamic errors, it is necessary to measure the kinematic parameters (interval time), first with one three-element probe system, and then the second, those. the algorithm of operation, for example, for the most common four-element compensation probe, in which the base is formed by two receivers P. and P., is the following:

And, -Pi ... I1-Pg, .. I-Pg, ... Ig-P1, .. - 1st

cycle

I1-P1, .. I4-Pg, .. Ig-.P2, .Ig-P1 .- 2nd cycle, etc.

Therefore, in each measurement cycle, the emitter I / is triggered (for the first and second channels of one three-element system) and twice - the emitter U. {for the first and second-channel three-element counter systems).

At the same time, the highlighted first synchronization pulse with a duration of G. indicates that information is transmitted from the first channel of the three-element system, and the next after it with the same duration in a different cycle is a sign of the second channel of this system. Similarly, for another counter three-element system with a synchronization pulse duration Tj ...

Consider the operation of the device when using a four-element compensation probe in a well device. The software / time unit, which sets the cyclic operation of the downhole tool and the ground control, is a frequency divider 24 that converts the network voltage into a series of square-wave pulses (square wave), the frequency of which determines the starting frequency of the emitters (Fig. 2-33 and 34 ). The output pulses of the frequency divider 24 arrive at block 25, which forms delayed start pulses of the generator 26 (FIGS. 2-35 and 36) and start pulses of the waiting multivibrator 28. When an acoustic pulse is emitted by the output signal of the emitters excitation pulse generation unit 27, the multivibrator 28 tilts and The output pulse of rectangular shape (Fig. 2-37) is fed through, inverter 30 to power amplifier 32. After a period of time depending on the probe parameters and the characteristics of the rock being studied, an information signal is received from the receiver of the transmitted channel to the second input of the power amplifier 32, which, like the synchronization pulse, is amplified and sent to the communication line (Fig. 2-38 ).

In one measurement cycle with a four-element compensation probe, the multivibrator 28 generates successively in clock cycles two synchronization pulses with a duration ti.H two with a duration CrDfig. 2-38). It should be noted that instead of a standby multivibrator 28, an RS flip-flop can be used to generate synchronization pulses.

The synchronization pulses through the communication line (geophysical cable 3) are simultaneously fed to the inputs of the comparator 4 and the differentiator 5 of the synchronization unit (Fig. 2-39). The comparator 4 forms, from input trapezoidal pulses, which, due to distortions of the inserted communication lines, have fronts duration of about 20-30 MKS and rectangular pulses (Fig. 2-40). The output pulse of the comparator 4 through the element And 6 (at the second input logic "1) is fed to the selectors 7 and 8 pulses in duration.

The selector 7 is set up for the selection of pulses whose duration is in the t band, ±, where 4fi is the passband of the selector, and the selector 8 is on the selection of pulses with a duration z in the passband,

Therefore, when a signal with a duration C appears at their inputs, only at the output of the selector 7 a pulse appears, which is fed to the input of the element AND 9. Simultaneously from the differentiator 5, the second input of the element 9 9 is given a pulse formed from the trailing edge of the input signal (Fig. 2-41). By coincidence of the pulses element And 9 forms a pulse, tilting the RS-flip-flop 11 through the R input.

(Fig. 2-42). At output Q, a logical "1.

A positive differential is allocated by the differentiating element 19 and through the OR element 21 it arrives at the output of the synchronization unit 1 for controlling the calculation process in the measurement units of the kinematic and dynamic parameters of elastic waves over the first channel (Fig. 2-44).

The output pulse of the element AND 9 is also fed through an inverter 12 to the element AND 16,

but there is no logic at its first input despite the fact that RS-flip-flop 11 is overturned and at its output Q is a high potential. The delay in receipt of the signal from the output Q of the RS flip-flop 1 to the second input of the element And 16 is carried out by the element 14

0 time delay, made, for example, in the form of a resistive-capacitive chain, the time constant of which is chosen several times longer than the duration of the output pulse of the element 9. And therefore

The logical "1 at the first input of the element AND 16 appears already after the positive impulse disappears at the second input. At the output of the element And 16 signal. missing.

Upon arrival in the next measurement cycle of the SRI to the ground synchronization unit 1 of the second synchronization pulse with the duration ..RS-trigger I remains in the same state, and the AND 16 element generates a pulse that passes through the OR 18 element to the output of the synchronization unit 1 to control the second channel computation process (Fig. 2-45).

As indicated above, in the next two cycles of operation of the apparatus from the well part 2 of the device, synchronization pulses with a duration Sz are transmitted to the ground synchronization unit 1, which are allocated by the selector 9 (Fig. 2-43).

Upon the arrival of the first pulse, the RS flip-flop 11 tilts along the input S. At its output, R appears logical "1, the positive differential is differentiated by element 20 and through the element OR 21 enters the first control channel of the calculation of the elastic waves (Fig. 2-

0 44).

At the output of the element And 17 no signal, since the input signals due to the time delay element 15 are separated in time. The constant time of element 15 is chosen from the same considerations as 5 for element 14.

When a second synchronization pulse arrives with a duration t, the RS flip-flop 11 remains switched on by the code S. In the control channel (the output of the OR 21 element). the signal is absent, and appears at the output of the element AND 17 and through the element OR 18 is fed to the second channel of the control process for calculating the parameters of elastic waves (Fig. 2-45). In addition, the output pulse of the element 17 is the end of a cycle pulse (Fig. 2-46), indicating that all four channels of the three-element systems of the four-element compensation probe were polled and the interval time value can be output from the kinematic parameters measuring unit compensation probe D l, determined by the formula utK i-, where tl and 4t2 is the interval time measured by the counter three-element systems of the probe. The interval time uti and Atj are measured in the wave kinematic parameter measuring unit, where the first and second control channels from block 1 are sent to the synchronization pulses, which are the origin of the near and far channels of three-element systems, and the elastic wave propagation time is measured by fixing the arrival of the first arrivals of the information signal of each of the channels. Since the synchronization pulses and the information signal are transmitted at each step along the same communication link from the downhole tool to the ground control, AND 6, OR 22 and a waiting multivibrator 23 are used in order to increase the noise immunity of the control channels. through the communication line of the synchronization pulses, the output pulses of the selectors 7 and 8 through the element OR 22 tilts the waiting multivibrator 23 and a prohibition signal is sent to the second input of the element 6 And the logical signal "O. The pulse duration of the multivibrator 23 is chosen such that the synchronization path is blocked during the entire time that the information signal arrives at the ground control panel. Then, the pending multivibrator 23 returns to its original state. The prohibition signal is removed from the second input of the And 6 element, and the path is ready for the extraction of synchronization pulses. When used in a downhole tool, a chip-element compensation probe, the operation of the device in terms of the generation of synchronization pulses and their processing in the ground control unit is no different from that discussed above. When working with three-element probes, the separation of synchronization pulses along the first and second control channels is carried out from the output of the elements AND 9 and 10 (Fig. 1). The proposed device allows to significantly extend the functionality, since it can be used to work with three-element probes, four- and six-element compensating probes. In addition, the system noise immunity is improved by blocking the synchronization channel for the duration of the transmission of the information signal. Thus, the device makes it possible to unify the synchronization system of the acoustic logging equipment while reducing costs in comparison with individual systems by approximately two times.

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Claims (1)

DEVICE FOR SYNCHRONIZING ACOUSTIC LOGGING EQUIPMENT, consisting of a ground synchronization unit, the input of which is connected to a geophysical cable, and a borehole part containing a frequency divider, a unit for generating delayed triggering pulses, a generator for pulse excitation of emitters, a unit for generating pulses of the moment of excitation of emitters, a waiting multivibrator, two multivibrators an inverter, an OR element, and a power amplifier, while the output of the power amplifier and the input of the frequency divider are connected to a geophysical cable, the output a frequency amplifier is connected to the input of the delayed start pulse generation unit, the first two outputs of which are connected to the inputs of the emitter pulse generator, and one of the outputs of the last one is connected to the pulser of the emitter generation momentum pulse with the reset input of the standby multivibrator, the output of which is connected to one of the inverters the outputs of the power amplifier, and the input of the standby multivibrator through the second inverter is connected to the output of the OR element, the inputs of which are connected to the third and fourth the outputs of the unit for the formation of delayed triggering pulses, characterized in that, in order to increase the noise immunity and expand the functionality of the device, the ground synchronization unit is made in the form of five AND elements, three OR elements, two time delay elements, two inverters, two differentiating elements, RS- trigger differentiator, two selectors pulse duration, waiting multivib- _with Rhatore and installed at the input ground ® sync block comparator, whose output is connected to the first the input of the first element And, the output of the last is connected to the inputs of the pulse selectors in duration, the outputs of the selectors are connected to the first inputs of the second and third elements And, the second inputs of which are combined and connected through the differentiator to the input of the comparator, and the outputs of the second and third elements And are connected to the inputs RS -trigger and through inverters with the first inputs of the fourth and fifth elements And, the second inputs of which are connected via time delay elements with the outputs of the RS-trigger, the outputs of the fourth and fifth elements And connected They are connected to the first OR element, the inputs of the second OR element are connected through the differentiating elements to the outputs of the RS flip-flop, and the input of the standby multivibrator is connected to the inputs of the last OR element through the third element, the output of which is connected to the second input of the first element I. SU _I)) 1133573