SU757697A1 - Apparatus for transferring information from well to ground surface - Google Patents

Description

The invention relates to geophysical instrumentation and can be used in equipment in which the conversion of measurement signals into a digital code.

A device for transmitting signals converted into a digital code from a well to the surface via a geophysical cable is known. Interference immunity of transmission is achieved through the use of frequency modulation and a pilot signal that ensures synchronous operation of the nodes in the downhole tool and in the ground equipment [1].

The disadvantage of this device is the low speed information transfer.

The closest to the invention is a device for transmitting information from the well to the surface ^ through the communication line, which contains signal sensors in the downhole tool, information converters to binary code, parallel code to serial converter, control unit 25 and output stage, and in the surface part - block ground equipment control, serial code converter into parallel and recording unit [2].

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Its disadvantage is low noise immunity and speed of information transfer.

The purpose of the invention is to improve the noise immunity and speed of information transfer.

This is achieved in that the known device is introduced: a downhole tool - The relative signal modulator with ⁰ in relative phase-shift keying, the control signal generating unit and the additional input for generating a clock signal in the output stage, a ground part - a clock extracting unit, the filter adjuster amplifier - limiter, signal demodulator with relative phase shift keying and control unit of transmitted information, and in the well device the inputs of the signal modulator are connected to the output of the converter in parallel code to the control unit of the downhole tool and the output of the control signal block, the output of the signal modulator to the output stage, the auxiliary input of which is connected to the control block of the downhole tool, and in the surface part

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The filter-corrector input is connected to the communication line, its output is connected to the input of the limiting amplifier, whose output is connected to the signal demodulator input with relative phase shift keying connected to a serial-to-parallel converter, and a clock extraction unit, other inputs also connected to the communication line and the ground equipment control unit connected to the serial code-to-parallel converter and the transmitted information control unit, which is connected to the converter to the recipient of the serial code in parallel and to the registering unit, also connected to the converter of the serial code in parallel.

FIG. 1 is a block diagram of the device; in fig. 2 - time diagrams explaining his work.

The device contains (see Fig. 1) sensors of signals 1, 2 and 3, information converters from sensors 4, 5 and b into a binary code, switch 7, converter of parallel code to serial 8, control unit 9, blocking circuit 10, control circuit 11 information transfer, modulator-12 signal with relative phase shift keying, output stage 13 with an additional input for generating 14 clock signal, block for generating 15 control signals, communication line 16, filter equalizer 17, limiter 18, demodulator 19 for relative signal phases by manipulation, signal delay line 20, modulo-two adder 21, nonlinear filter 22, clock extraction unit 23, ground control unit 24, synchronization signal circuit 25, serial to parallel converter 26, transmitted information control unit 27, registering block 28 .

The device works as follows. in a way. Measurement signals from sensors 1, 2 and 3 come in as a data converter and binary code 4, 5 and 6 — binary counters for radioactive radiation pulses or analog-to-digital converters. Using the switch 7, the command "from the control unit 9, which enters via circuit 11, sends information to the parallel code to serial converter 8. During the transfer of information, the input of the signal sensors are blocked along circuit 10. Blocking, transferring information and resetting the information converters to binary code 4, 5 and b is carried out during the transmission of the sync signal, which enters the communication line 16 first.The sync signal is generated in the control unit 9 and through the circuit 14 is fed to the auxiliary input of the sync signal formation the output th stage 13. An additional input is required due to the fact that the clock signal is a pulse-like information symbol in duration and polarity, but surpasses it in amplitude.

Following the synchronization signal, an information signal (see Fig. 2c) is transmitted to the communication line 16, converted in the signal modulator with a relative phase shift keying 12. _Λ

The number of transferred binary units

Information signal registers I in the block of formation of control characters 15.

To transmit a clock pulse of one polarity and duration with information signal symbols, as well as to ensure the splitting of adjacent symbols, if the number of information pulses is even, the control symbol complements the number of units to an even value, if the number of information symbols is odd, the check symbol must complement the number of ones to an odd value.

When the device operates in equipment with a pulsed neutron generator, which is launched from the surface, a control pulse (see Fig. 2a) is sent from the control unit of the ground equipment 24 through the control circuit 25 to the control unit of the borehole device 9 (see Fig. 2a). 26) and generates a sync signal that first enters the communication line and a falling front triggering the neutron generator. On the surface, the sync signal enters the sync signal allocation unit 23, where it is distinguished by its amplitude feature and polarity.

The signal passing through the communication line (geophysical cable) is subject to distortion due to the limitation of the frequency band and various types of interference (Fig. 2d). In order to increase the signal-to-noise ratio, the signal is fed to the filter corrector 17 and further to the limiting amplifier 1 * 8 and phase demodulator 19. The signal is delayed for the duration of one character (Fig. 2e) using the delay line 20 and fed to the adder circuit modulo two 21, where the signal is formed (see Fig. 2g). Using a nonlinear filter 22, the signal is converted into a form (see FIG. 2h), from which an information signal is output by time gating in a serial-to-parallel code converter 26, which arrives at the recording unit 28.

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A series of gating pulses (see FIG. 2k) is produced in the ground equipment control unit 24, the pulses arrive after a delay time after the separation of the trailing edge of the sync pulse (see Fig. 2i). five

Information and control signals are received in the control unit of the transmitted information 27. The unit provides an assessment of the synchronization stability and the operability of the transmission device as a whole.

Claims (1)

Claim 15 20 A device for transmitting information from a well to a surface via a communication line, which contains signal sensors in a well tool, information converters to binary code, a parallel code to serial converter, a control unit and an output stage, and in the ground part - a ground equipment control unit, a serial-to-parallel converter and a recording unit, which is 25 seconds so that, in order to improve the noise immunity and information transfer rate, a signal modulator is inserted into the downhole tool with relative phase shift keying, block 30 of generation of control signals and an additional input for generating a clock signal in the output stage, a block for extracting a clock signal, filter corrector, amplifier-ogre are entered into the ground part an anichitel, a signal demodulator with relative phase shift keying and a control unit for the transmitted information; in the downhole tool, the inputs of the signal modulator are connected to the output of the parallel code to serial converter, to the control unit of the downhole tool and the output of the control signal unit, the output of the signal modulator to the output stage, the auxiliary input of which is connected to the control unit of the downhole tool, and in the surface part filter-corrector is connected to the communication line, its output is connected to the input of the amplifier-limiter, the output of which is connected to the input of the demodulator signal relative phase shift keying connected to a serial to parallel converter and the input of a sync signal extraction unit, the other inputs of which are also connected to a communication line and a ground equipment control unit connected to a serial to parallel converter and a control unit of transmitted information that is connected to a serial code converter parallel to the recording unit, also connected to the serial to parallel converter.