A comprehensive underground observation device

Abstract

The embodiment of this specification provides a downhole comprehensive observation device, including at least one data acquisition unit, which is deployed in the downhole, and is used to receive analog signals collected by at least one data measuring instrument, and convert the analog signals into digital signals; a downhole data processing unit, which is deployed in the downhole, and is used to encode the digital signals to obtain the encoded digital signals; it is used to perform voltage conversion processing on the received power supply signals, and transmit the power supply signals after voltage conversion processing to each data measuring instrument through each data acquisition unit; a ground data processing unit, which is deployed on the ground, and is used to decode the encoded digital signals to obtain digital signals, and transmit the power supply signals to the downhole data processing unit; the downhole data processing unit and the ground data processing unit are connected through a cable that multiplexes digital signals and power supply signals. The device of this embodiment can solve the data transmission and power supply problems between the downhole part and the ground part in the deep well comprehensive observation.

Description

Technical Field

[0001] One or more embodiments of the present specification relate to the field of downhole observation technology, and in particular, to a downhole comprehensive observation device. Background Art

[0002] In the underground comprehensive observation system, various data measuring instruments such as seismometers, magnetometers, strain sensors, etc. are generally laid at the bottom of the well at a depth of 300 to 3000 meters underground. The analog data measured by various data measuring instruments are transmitted to the ground equipment via cable cores. At the same time, the ground equipment inputs power to each data measuring instrument through the cable cores to power it.

[0003] In order to realize the transmission of various analog signals and power supplies, the number of cable cores is as many as dozens. Due to the excessive number of cores, the diameter of a single core is reduced, the cable resistance is increased, and the transmission loss of analog signals and power supplies on the cable is large; various measurement signals are transmitted simultaneously in the cable, and there is a lot of crosstalk between them, resulting in low quality of observation data and high power consumption. Moreover, analog signals are prone to line attenuation and line interference during long-distance transmission, especially for data measurement instruments such as seismic observation instruments that are very sensitive to external interference. Cable disturbances, core wire twisting, tension release, etc. will seriously affect the quality of observation data. Summary of the invention

[0004] In view of this, the purpose of one or more embodiments of this specification is to provide an underground comprehensive observation device to solve the observation data transmission and power supply problems of various underground data measurement instruments.

[0005] Based on the above purpose, one or more embodiments of this specification provide a downhole comprehensive observation device, including:

[0006] At least one data acquisition unit, deployed underground, for receiving analog signals acquired by at least one data measuring instrument and converting the analog signals into digital signals;

[0007] The downhole data processing unit is deployed downhole and is used to encode the digital signal to obtain the encoded digital signal; and is used to perform voltage conversion processing on the received power supply signal, and transmit the power supply signal after voltage conversion processing to each data measuring instrument through each data acquisition unit;

[0008] A ground data processing unit, deployed on the ground, is used to decode the encoded digital signal to obtain a digital signal, and is used to transmit the power supply signal to the downhole data processing unit;

[0009] The downhole data processing unit is connected to the surface data processing unit through a cable that multiplexes digital signals and power signals.

[0010] Optionally, the cable is a seven-core cable, three pairs of core wires are divided from the seven-core cable, at least one pair of core wires are used to transmit the digital signal, any three core wires are used to transmit the positive power supply signal, and the remaining three core wires are used to transmit the negative power supply signal.

[0011] Optionally, the downhole data processing unit includes:

[0012] A first encoding and decoding circuit is used to encode the digital signal to obtain a digital signal in a non-DC form;

[0013] A first signal transceiver circuit is used to transmit the non-DC digital signal to the ground data processing unit via the cable; and to receive the DC power signal transmitted by the ground data processing unit via the cable;

[0014] The ground data processing unit comprises:

[0015] a second signal transceiver circuit, receiving the non-DC digital signal through the cable; and transmitting the DC power supply signal to the downhole data processing unit through the cable;

[0016] The second encoding and decoding circuit is used to decode the non-DC digital signal to obtain the digital signal.

[0017] Optionally, the first signal transceiver circuit includes a first differential processing sub-circuit, a first drive amplifier sub-circuit, a first data transmission sub-circuit, and a first power signal transmission sub-circuit; the signal output end of the first codec circuit is connected to the signal input end of the first differential processing sub-circuit, the signal output end of the first differential processing sub-circuit is connected to the signal input end of the first drive amplifier sub-circuit, and the signal output end of the first drive amplifier sub-circuit is connected to the signal input end of the first data transmission sub-circuit; the signal output end of the first power signal transmission sub-circuit is connected to the signal input end of the voltage conversion circuit used to convert the DC power signal into voltage, the first data transmission sub-circuit is a DC blocking capacitor, and the first power signal transmission sub-circuit is an isolation inductor connected in parallel with the DC blocking capacitor and two switching diodes with opposite polarities, and the two switching diodes are connected in parallel.

[0018] Optionally, the second signal transceiver cable includes a second data transmission sub-circuit and a second power signal transmission sub-circuit, the second data transmission sub-circuit is a DC blocking capacitor, and the second power signal transmission sub-circuit is an isolation inductor connected in parallel with the DC blocking capacitor.

[0019] Optionally, the ground data processing unit further includes:

[0020] The second encoding and decoding circuit is used to encode the control instruction to obtain a control signal in a non-DC form;

[0021] The second signal transceiver circuit is used to transmit the non-DC control signal to the downhole data processing unit via the cable;

[0022] The downhole data processing unit also includes:

[0023] The first signal transceiver circuit receives the control signal in non-DC form through the cable;

[0024] The first encoding and decoding circuit is used to decode the non-DC control signal to obtain the control instruction.

[0025] Optionally, the first signal transceiver circuit includes a first filtering sub-circuit, a first amplifying sub-circuit, a first comparator, and a first data transmission sub-circuit. The signal output end of the first data transmission sub-circuit is connected to the signal input end of the first comparator through the first filtering sub-circuit and the first amplifying sub-circuit, and the signal output end of the first comparator is connected to the signal input end of the first encoding and decoding circuit.

[0026] Optionally, the non-DC digital signal and the non-DC control signal are transmitted between the downhole data processing unit and the surface data processing unit in a half-duplex mode.

[0027] Optionally, the ground data processing unit also includes a signal supplement circuit for compensating and correcting the encoded digital signal.

[0028] Optionally, the at least one data acquisition unit is connected to the downhole data processing unit via a CAN bus.

[0029] From the above description, it can be seen that the downhole comprehensive observation device provided by one or more embodiments of this specification includes at least one data acquisition unit, which is deployed in the downhole, and is used to receive the analog signal collected by at least one data measuring instrument, and convert the analog signal into a digital signal; a downhole data processing unit, which is deployed in the downhole, and is used to encode the digital signal to obtain the encoded digital signal; and is used to perform voltage conversion processing on the received power supply signal, and transmit the power supply signal after voltage conversion processing to each data measuring instrument through each data acquisition unit; a ground data processing unit, which is deployed on the ground, is used to decode the encoded digital signal to obtain a digital signal, and is used to transmit the power supply signal to the downhole data processing unit; the downhole data processing unit and the ground data processing unit are connected by a cable that multiplexes the digital signal and the power supply signal. The device of this embodiment can solve the problem of data transmission and power supply between the downhole part and the ground part, greatly reduce the number of cable cores, and ensure the accuracy and reliability of data transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate one or more embodiments of the present specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only one or more embodiments of the present specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A block diagram of the device structure of one or more embodiments of this specification;

[0032] Figure 2 This is a schematic diagram of the device structure of another embodiment of the present specification;

[0033] Figure 3 A schematic diagram of the arrangement of cable core wires according to one or more embodiments of this specification;

[0034] Figure 4 A structural block diagram of a downhole data processing unit according to one or more embodiments of the present specification;

[0035] Figure 5 A structural block diagram of a ground data processing unit according to one or more embodiments of the present specification;

[0036] Figure 6 A schematic diagram of a circuit principle of a first coding and decoding circuit according to one or more embodiments of this specification;

[0037] Figure 7 A schematic diagram of the principle of the first and second signal transceiver circuits of one or more embodiments of this specification;

[0038] Figure 8 A schematic diagram of half-duplex communication data format according to one or more embodiments of this specification;

[0039] Figures 9A-9D A schematic diagram of a simplified model of four distributed parameters of a seven-core cable of one or more embodiments of this specification;

[0040] Fig.10 A schematic diagram of a digital signal that has not been corrected by a signal compensation circuit according to one or more embodiments of the present specification;

[0041] Fig.11 A schematic diagram of a digital signal corrected by a signal compensation circuit according to one or more embodiments of the present specification;

[0042] Fig.12 A schematic diagram of the connection between the data acquisition unit and the downhole data processing unit of one or more embodiments of this specification;

[0043] Fig.13 A structural block diagram of a data acquisition unit according to one or more embodiments of the present specification. DETAILED DESCRIPTION

[0044] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0045] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in one or more embodiments of this specification should be understood by people with ordinary skills in the field to which this disclosure belongs. The "first", "second" and similar words used in one or more embodiments of this specification do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0046] like Figure 1 As shown, one or more embodiments of this specification provide a downhole comprehensive observation device, including:

[0047] At least one data acquisition unit 10, deployed underground, for receiving analog signals acquired by at least one data measuring instrument, and converting the analog signals into digital signals;

[0048] The downhole data processing unit 11 is deployed downhole and is used to encode the digital signal to obtain the encoded digital signal; and is used to perform voltage conversion processing on the received power supply signal, and transmit the power supply signal after voltage conversion processing to each data measuring instrument through each data acquisition unit 10;

[0049] A ground data processing unit 20 is deployed on the ground and is used to decode the encoded digital signal to obtain a digital signal, and to transmit the power supply signal to the downhole data processing unit 11;

[0050] The downhole data processing unit 11 is connected to the surface data processing unit 20 via a cable that multiplexes digital signals and power signals.

[0051] Combination Figure 1 , 2 As shown, in this embodiment, the downhole comprehensive observation device includes a downhole part and a ground part, wherein the downhole part includes various types of data measuring instruments, at least one data acquisition unit 10 and a downhole data processing unit 11, and the ground part includes a ground data processing unit 20. The data output end of the data measuring instrument is connected to the data input end of the data acquisition unit 10, and the data output end of the data acquisition unit 10 is connected to the data input end of the downhole data processing unit 11. The analog signal collected by the data measuring instrument is transmitted to the data acquisition unit 10, and the data acquisition unit 10 performs analog-to-digital conversion on the analog signal to obtain a digital signal, and transmits the digital signal to the downhole data processing unit 11; the downhole data processing unit 11 is connected to the ground data processing unit 20 through a cable, and the downhole data processing unit 11 encodes the digital signal to obtain an encoded digital signal, which is transmitted to the ground data processing unit 20 through the cable, and the ground data processing unit 20 decodes the encoded digital signal to obtain a digital signal, thereby obtaining the data collected by the downhole data measuring instrument, and realizing the data transmission from the downhole observation data to the ground equipment. On the other hand, the ground data processing unit 20 transmits the power signal to the downhole data processing unit 11 via a cable. The downhole data processing unit 11 performs voltage conversion processing on the power signal to obtain a voltage signal suitable for the normal operation of various data measuring instruments, and transmits the converted voltage signal to the data measuring instrument via the data acquisition unit 10 to power the data measuring instrument. The downhole comprehensive observation device of this embodiment, on the one hand, converts the analog signal collected by the data measuring instrument into a digital signal and transmits it to the ground part, which can improve the anti-interference ability of the signal and improve the quality of the observation data. On the other hand, the downhole part and the ground part are connected by a cable that multiplexes the digital signal and the power signal, which can reduce the number of cable cores, simplify the device structure, reduce costs, and reduce the difficulty of installation and maintenance.

[0052] In some embodiments, the data measuring instruments deployed underground include but are not limited to observation instruments for observing various parameters underground, such as seismic observation instruments, magnetometers, gyroscopes, stress sensors, and temperature and humidity sensors. Each type of data measuring instrument can be deployed in one or multiple units at different locations underground. The same type of data measuring instrument can be connected to the same data acquisition unit 10, or multiple types of data measuring instruments deployed at a certain location can be connected to the same data acquisition unit 10. The layout of the instruments is not specifically limited in this specification.

[0053] In the existing method, each data measurement instrument is connected to the ground equipment through the corresponding cable core wire to transmit data separately. The number of core wires is too large, the device is complicated and causes great interference. In this specification, the underground part and the ground part of the underground comprehensive observation device are connected through a cable that multiplexes digital signals and power signals. In some methods, a seven-core cable is used to realize data communication and power supply multiplexing, which can greatly reduce the number of core wires and reduce line interference. Specifically:

[0054] like Figure 3 As shown, the core wires of the seven-core armored cable are arranged clockwise as No. 1, 2, 3, 4, 5, and 6, and the middle core wire is No. 7; according to the arrangement characteristics of the seven-core cable, two core wires that are relatively parallel to each other are set as a pair, so as to be divided into 3 pairs of wires, for example, No. 1 and No. 4, No. 2 and No. 5, and No. 3 and No. 6 are divided into three pairs of core wires. On the one hand, the three pairs of core wires can be used to transmit data. When in use, the three pairs of core wires can be flexibly configured and used, for example, using three pairs of core wires to transmit data at the same time, or using one or two pairs of core wires to transmit data, or when one or two pairs of core wires fail, the other two pairs or one pair of core wires transmit data, so that data transmission has redundancy and can improve data transmission reliability. On the other hand, any three core wires of the three pairs of core wires can be used as the positive power supply to transmit the positive power supply signal, and the other three core wires can be used as the negative power supply to transmit the negative power supply signal. Line 7 is used as the positive backup power supply to form a backup power supply circuit with the outer armor of the 7-core cable.

[0055] In order to realize the multiplexing of data transmission and power supply, the digital signal transmitted in the cable is a non-DC signal, and the power supply signal is a DC power supply signal. Figure 4 , 5 As shown, the downhole data processing unit 11 includes:

[0056] The first coding and decoding circuit is used to encode the digital signal to obtain a digital signal in a non-DC form;

[0057] The first signal transceiver circuit is used to transmit the non-DC digital signal to the ground data processing unit 20 via the cable; and receive the DC power signal transmitted by the ground data processing unit 20 via the cable;

[0058] The ground data processing unit 20 includes:

[0059] The second signal transceiver circuit receives a non-DC digital signal through a cable; and transmits a DC power supply signal to the downhole data processing unit 11 through the cable;

[0060] The second encoding and decoding circuit is used for decoding the digital signal in a non-DC form to obtain a digital signal.

[0061] In this embodiment, for the data transmission part, the downhole data processing unit 11 performs analog-to-digital conversion on the analog signal collected by the data measuring instrument to obtain a digital signal, and uses the first codec circuit to encode the digital signal to obtain a non-DC digital signal, and uses the first signal transceiver circuit to transmit the non-DC digital signal to the ground data processing unit 20 via a cable. The ground data processing unit 20 receives the non-DC digital signal transmitted by the downhole data processing unit 11 through the second signal transceiver circuit, and uses the second codec circuit to decode the non-DC digital signal to obtain a digital signal. For the power supply part, the ground data processing unit 20 uses the second signal transceiver circuit to transmit the DC power signal to the downhole data processing unit 11 via a cable, and the first signal transceiver circuit of the downhole data processing unit 11 receives the DC power signal, and after voltage conversion processing is performed on the DC power signal, the converted voltage signal is further transmitted to each data measuring instrument through the data acquisition unit 10 to power each electrical device in the well. In this embodiment, by transmitting non-DC digital signals and DC power supply signals in the cable core wires, data transmission and power supply transmission multiplexing in the cable can be achieved, which greatly reduces the number of cable core wires, reduces the interference of cables on signal transmission, reduces the difficulty of device installation and maintenance, and reduces costs; and, by uniformly encoding analog signals, the crosstalk problem of different signals can be eliminated.

[0062] In some implementations, the first encoding and decoding circuit is used to encode the digital signal to obtain a digital signal in Miller code form; the second encoding and decoding circuit is used to decode the digital signal in Miller code form to obtain a digital signal. Alternatively, the first encoding and decoding circuit is used to encode the digital signal to obtain a digital signal in differential Manchester code form; the second encoding and decoding circuit is used to decode the digital signal in differential Manchester code form to obtain a digital signal. The digital signal in Miller code form and the digital signal in differential Manchester code form are both signals without DC components, and can be multiplexed with the DC power supply signal on the cable.

[0063] In some ways, combined Figure 6As shown, the encoding process of the first encoding and decoding circuit is to first convert the digital signal into NRZ code (non-return-to-zero code, bit 1 corresponds to a high level, bit 0 corresponds to a low level), and XOR the NRZ code with the bit synchronization clock BSCLK / 2, and the generated signal is used as the input of the D flip-flop, and the D flip-flop uses BSCLK as a clock to drive the output digital inversion as a clock to drive another bistable D flip-flop to generate Miller code; the decoding process is: the Miller code is input to the D end of the first D flip-flop, and the first D flip-flop outputs to the input end of the second D flip-flop, and both D flip-flops are driven by the BSCLK clock; the output end of the first D flip-flop and the output end of the second D flip-flop input an XOR gate, and the XOR gate outputs to the third D flip-flop, and the third D flip-flop outputs the decoded digital signal under the BSCLK / 2 clock drive. The encoding and decoding circuit of the Miller code can be implemented based on a circuit including circuit elements such as an XOR gate and a D flip-flop, and can also be implemented based on a CPLD or FPGA internal logic unit. The structure and principle of this encoding and decoding circuit belong to general technology, and this manual will not be described in detail.

[0064] For cables that multiplex data and power supply, the ground part and the underground part are equipped with corresponding signal transceiver circuits to send and receive non-DC digital signals and DC power supply signals.

[0065] For the downhole data processing unit 11, its first signal transceiver circuit includes a first differential processing subcircuit, a first drive amplifier subcircuit, a first data transmission subcircuit, and a first power signal transmission subcircuit. The signal output end of the first codec circuit is connected to the signal input end of the first differential processing subcircuit, the signal output end of the first differential processing subcircuit is connected to the signal input end of the first drive amplifier subcircuit, and the signal output end of the first drive amplifier subcircuit is connected to the signal input end of the first data transmission subcircuit; the non-DC digital signal output by the first codec circuit is processed into a differential digital signal by the first differential processing subcircuit, and the differential digital signal is amplified by the first drive amplifier subcircuit and then transmitted to the surface data processing unit 20 by the first data transmission subcircuit. The signal output end of the first power signal transmission subcircuit is connected to the signal input end of the voltage conversion circuit, and the first power signal transmission subcircuit receives the DC power signal transmitted by the surface data processing unit 20, and transmits the DC power signal to the voltage conversion circuit, and the voltage conversion circuit performs voltage conversion processing on the DC power signal.

[0066] like Figure 7As shown, the first data transmission sub-circuit is a DC blocking capacitor, which can realize the transmission of digital signals in non-DC form; the first power signal transmission sub-circuit is an isolation inductor connected in parallel with the DC blocking capacitor and two switching diodes with opposite polarities. The two switching diodes are connected in parallel, the isolation inductor can realize the transmission of DC power supply signals, and the switching diode can realize the interchangeability of the positive and negative poles of the power supply, that is, any one of the 6 core wires can be the positive pole or any one can be the negative pole.

[0067] For the ground data processing unit 20, its second signal transceiver circuit includes a second filtering subcircuit, a second amplifying subcircuit, a second comparator, a second data transmission subcircuit, and a second power signal transmission subcircuit. The signal output end of the second data transmission subcircuit is connected to the signal input end of the second filtering subcircuit, the signal output end of the second filtering subcircuit is connected to the signal input end of the second amplifying subcircuit, the signal output end of the second amplifying subcircuit is connected to the signal input end of the second comparator, and the signal output end of the second comparator is connected to the signal input end of the second codec circuit; the second data transmission subcircuit receives the non-DC digital signal transmitted by the downhole data processing unit 11, the non-DC digital signal is filtered by the second filtering subcircuit, amplified by the second amplifying subcircuit, and restored by the second comparator to obtain the required non-DC digital signal, and the non-DC digital signal is decoded by the second codec circuit to obtain the digital signal. The second power signal transmission subcircuit transmits the DC power signal to the downhole data processing unit 11.

[0068] like Figure 7 As shown, the second data transmission subcircuit is a DC blocking capacitor, which can realize the transmission of non-DC digital signals; the second power signal transmission subcircuit is an isolation inductor connected in parallel with the DC blocking capacitor, which can realize the transmission of DC power signal.

[0069] In this embodiment, the downhole data processing unit 11 and the ground data processing unit 20 realize the sending and receiving processing of non-DC digital signals and DC power supply signals through the first signal transceiver circuit and the second signal transceiver circuit, which can realize the multiplexing transmission and separation of non-DC digital signals and DC power supply signals in the cable core wire. In addition, through signal processing methods such as differential processing, amplification processing, and filtering processing, the signal anti-interference ability can be improved, and the accuracy of signal transmission can be guaranteed, so that the signal is suitable for long-distance transmission and suitable for data transmission and power supply in deep wells.

[0070] In some embodiments, the power supply voltage input by the ground data processing unit 20 to each electrical device in the underground part is 72-120V, which can meet the power demand of various electrical devices in the underground part.

[0071] In this embodiment, the ground data processing unit 20 can also monitor the status of the data measuring instrument underground and control the data measuring instrument.

[0072] The ground data processing unit 20 also includes:

[0073] The second encoding and decoding circuit is used to encode the control instruction to obtain a control signal in a non-DC form;

[0074] A second signal transceiver circuit is used to transmit the control signal in a non-DC form to the downhole data processing unit 11 via a cable;

[0075] The downhole data processing unit 11 also includes:

[0076] A first signal transceiver circuit receives a control signal in a non-DC form through a cable;

[0077] The first encoding and decoding circuit is used to decode the control signal in a non-DC form to obtain a control instruction.

[0078] In this embodiment, on the basis of realizing the function of transmitting the observation data collected by the data measuring instrument from the downhole part to the surface part and the surface part supplying power to the downhole part, the surface part can also realize the control function of the downhole data measuring instrument. The surface part determines the control instruction, encodes the control instruction by using the second codec circuit to obtain a control signal in a non-DC form, and sends the non-DC control signal to the downhole data processing unit 11 via the second signal transceiver circuit. The first signal transceiver circuit of the downhole data processing unit 11 receives the non-DC control signal, and decodes the non-DC control signal by using the first codec circuit to obtain the control instruction, and distributes the control instruction to the corresponding data measuring instrument via the data acquisition unit 10, so that the data measuring instrument performs the corresponding action according to the control instruction.

[0079] In some embodiments, the control instructions sent by the surface part to the downhole part include instructions for querying the instrument status, instructions for controlling the instrument to perform certain actions, parameters for configuring the instrument, timing signals for providing time information to the instrument, etc. For example, for a seismic observation instrument, the control instructions sent by the surface data processing unit 20 to the seismic observation instrument through the downhole data processing unit 11 and the data acquisition unit 10 include querying the pendulum status, unlocking the pendulum, zeroing instructions, timing signals, configuring the data transmission rate, etc.

[0080] Optionally, the ground data processing unit 20 may be provided with an instrument monitoring module, and the user may set control instructions for each data measuring instrument through the instrument monitoring module, and monitor the observation data collected by each data measuring instrument through the instrument monitoring module.

[0081] In order to realize the transmission and issuance of control instructions, the second signal transceiver circuit also includes a second differential processing sub-circuit and a second drive amplifier sub-circuit; the signal output end of the second codec circuit is connected to the signal input end of the first data transmission sub-circuit through the second differential processing sub-circuit and the second drive amplifier sub-circuit; the non-DC control signal output by the second codec circuit is processed into a differential control signal by the second differential processing sub-circuit, and the differential control signal is amplified by the second drive amplifier sub-circuit and then transmitted to the downhole data processing unit 11 through the second data transmission sub-circuit.

[0082] The first signal transceiver circuit also includes a first filtering subcircuit, a first amplifying subcircuit, and a first comparator. The signal output end of the first data transmission subcircuit is connected to the signal input end of the first comparator through the first filtering subcircuit and the first amplifying subcircuit, and the signal output end of the first comparator is connected to the signal input end of the first codec circuit; the first data transmission subcircuit receives the non-DC control signal transmitted by the ground data processing unit 20, and the non-DC control signal is filtered by the first filtering subcircuit, amplified by the first amplifying subcircuit, and restored by the first comparator to obtain the required non-DC control signal, and the non-DC control signal is decoded by the first codec circuit to obtain the control instruction.

[0083] In this embodiment, the downhole data processing unit 11 transmits the observation data collected by the data measuring instrument to the surface data processing unit 20, and the surface data processing unit 20 transmits the control command to the downhole data processing unit 11. In order to realize the two-way data transmission, the observation data and the control command are transmitted in half-duplex mode, that is, in a predetermined first time period, the downhole data processing unit 11 transmits a non-DC digital signal to the surface data processing unit 20, and in a second time period different from the first time period, the surface data processing unit 20 transmits a non-DC control signal to the downhole data processing unit 11. The half-duplex data transmission mode can realize the data communication and control functions between the downhole part and the surface part, and solve the problem of long-distance and long-line transmission at the same time, and improve the reliability of data transmission.

[0084] In some methods, a whole second can be divided into a first time period and a second time period. During the first time period, control instructions are transmitted from the surface part to the downhole part, and during the second time period, downhole observation data are transmitted from the downhole part to the surface part.

[0085] Considering the line loss in cable transmission, in order to ensure the accuracy of the received signal, the downhole data processing unit 11 also sends a signal compensation parameter for correcting the signal to the ground data processing unit 20. In half-duplex transmission, one second is divided into a first time period, a second time period and a third time period. In the first time period, the ground data processing unit 20 transmits a control instruction to the downhole data processing unit 11. In the second time period, the downhole data processing unit 11 sends a signal compensation parameter (a preset fixed coding signal, such as a hexadecimal code with a setting value of AAAAAAAA) to the ground data processing unit 20. The ground data processing unit 20 performs a cross-correlation operation on the received non-DC digital signal according to the received signal compensation parameter, and calculates the compensation coefficient of the equalization filter. After determining the compensation coefficient of the equalization filter, the signal compensation parameter may no longer be sent in the second time period. In the third time period, the downhole data processing unit 11 transmits the observation data to the ground data processing unit 20.

[0086] Combination Figure 8 As shown, optionally, starting from the whole second, one second is divided into three time periods, which are 60ms, 40ms and 900ms in chronological order; within 60ms, the ground data processing unit 20 sends a non-DC control signal to the downhole data processing unit 11, within 40ms, the downhole data processing unit 11 sends a signal compensation parameter to the ground data processing unit 20, and within 900ms, the downhole data processing unit 11 transmits a non-DC digital signal to the ground data processing unit 20.

[0087] As shown in Table 1, the data exchanged between the downhole data processing unit 11 and the ground data processing unit 20 uses a unified data format, wherein the first byte is all "0", which indicates the beginning of the data block and is used for synchronization of data transmission. The second and third bytes are identification codes, which serve as the start mark of data block transmission. The fourth byte starts as the data area, followed by a two-byte data length, and the last two bytes are the checksum.

[0088]

[0089] Table 1

[0090] Taking into account that during long-distance cable transmission, the cable will interfere with data transmission, causing signal attenuation and distortion. In order to ensure the accuracy of data transmission and reduce the bit error rate, the ground data processing unit 20 also includes a signal supplement circuit for compensating and correcting the received digital signal.

[0091] like Figures 9A-9D As shown in the figure, the distributed parameter simplified model of the seven-core cable is shown in the figure. One is a single RC network with input V i With output VO The relationship is:

[0092]

[0093] The second type is two RC networks connected in series, and the relationship between input and output is:

[0094]

[0095] The third type is three RC networks connected in series, and the relationship between input and output is:

[0096]

[0097] The fourth type is four RC networks connected in series, and the relationship between input and output is:

[0098]

[0099] If we estimate the distributed parameters of a 1000-meter seven-core cable, assuming the resistance value R = 66 ohms and the capacitance value C = 130 nanofarads, we can calculate the frequency characteristic curves of the four models, such as Fig.10 As shown, the frequency band of the cable starts to decrease at 18.55 MHz. In order to ensure the accuracy of signal transmission, a signal compensation circuit is set in the ground data processing unit 20 to perform signal compensation correction on the digital signal transmitted via the cable.

[0100] In some embodiments, the signal compensation circuit uses an equalization filter. After the ground data processing unit 20 receives the signal compensation parameters from the downhole data processing unit 11, it uses different equalization filters to calculate the correlation between the signal compensation parameters and the received non-DC digital signal. After the calculation, the equalization filter with the largest correlation corresponding to the maximum value of the correlation operation is determined, and the equalization filter is used as the equalization filter in the communication process between the downhole data processing unit 11 and the ground data processing unit 20. The equalization filter is used to compensate and correct the received non-DC digital signal, which can widen the signal band of the cable transmission by 10 times (such as Fig.11 As shown), signal compensation correction is realized to compensate for the attenuation of signal transmission caused by the cable line and improve the accuracy of data transmission.

[0101] The downhole part is described in detail below in conjunction with specific embodiments.

[0102] like Fig.12As shown, at least one data acquisition unit 10 is connected to the downhole data processing unit 11 through a CAN bus. Each data acquisition unit 10 receives the analog signal collected by the connected data measuring instrument, performs analog-to-digital conversion on the analog signal to obtain a digital signal, and uniformly transmits the digital signal to the downhole data processing unit 11 through the CAN bus; and the downhole data processing unit 11 transmits the control instruction to the corresponding data acquisition unit 10 through the CAN bus. As shown in the figure, each data acquisition unit 10 realizes serial differential transmission of digital signals through the CAN1 line and the CAN2 line. In this embodiment, after the analog signal collected by various types of data measuring instruments is converted into a digital signal by the corresponding data acquisition unit 10, the digital signal is uniformly transmitted to the downhole data processing unit 11 through the CAN bus, which can realize the uniformity, standardization, and real-time performance of data acquisition of multiple distributed data acquisition units 10, ensure the data transmission rate, and realize the integration of data acquisition of various downhole data measuring instruments, which has universality. At the same time, the downhole data processing unit 11 sends the control instructions sent by the surface part to the data acquisition unit 10 through the CAN bus, and the data acquisition unit 10 further sends the control instructions to the corresponding data measuring instrument so that the data measuring instrument performs corresponding actions according to the control instructions.

[0103] like Fig.13 As shown, the data acquisition unit 10 includes a third main control chip and an analog-to-digital conversion circuit. The signal output end of the data measuring instrument is connected to the signal input end of the analog-to-digital conversion circuit, and the signal output end of the analog-to-digital conversion circuit is connected to the signal input end of the third main control chip. The analog-to-digital conversion circuit converts the analog signal collected by the data measuring instrument into a digital signal, and transmits the digital signal to the third main control chip. The third main control chip encapsulates the digital signal according to the data transmission format of the CAN bus, and sends the encapsulated digital signal to the downhole data processing unit 11 via the CAN bus. When the ground data processing unit 20 issues a control instruction, the third main control chip transmits the control instruction to the data measuring instrument, so that the data measuring instrument performs the corresponding action according to the control instruction.

[0104] In order to distinguish the signals collected by each data measuring instrument, it is necessary to add identification information to the signals collected by each data measuring instrument. The data acquisition unit 10 also includes an identification processing circuit. The signal output end of the data measuring instrument is connected to the signal input end of the third main control chip through an analog-to-digital conversion circuit and an identification processing circuit. The analog-to-digital conversion circuit converts the analog signal collected by the data measuring instrument into a digital signal. The identification processing circuit adds identification processing to the digital signal to obtain an identification digital signal, and transmits the identification digital signal to the third main control chip. The third main control chip encapsulates the identification digital signal according to the data transmission format of the CAN bus, and then sends the encapsulated identification digital signal to the downhole data processing unit 11 via the CAN bus.

[0105] Optionally, the identification information is a device identification number of a data measuring instrument, and the signal collected by the corresponding data measuring instrument is determined according to the device identification number. In one embodiment, the identification processing circuit reads the device identification number of the data measuring instrument from a memory, and combines the device identification number with a digital signal corresponding to the data measuring instrument into an identification digital signal.

[0106] like Figure 4 As shown, the downhole data processing unit 11 includes a first main control chip, a first codec circuit, a first signal transceiver circuit, and a voltage conversion circuit. The power signal output terminal of the first signal transceiver circuit is connected to the power input terminal of the first main control chip through the voltage conversion circuit, the data input and output terminal of the first signal transceiver circuit is connected to the first signal input and output terminal of the first codec circuit, and the second signal input and output terminal of the first codec circuit is connected to the data input and output terminal of the first main control chip. The first main control chip receives the identification digital signal transmitted by the data acquisition unit 10 via the CAN bus, and the first main control chip transmits the identification digital signal to the first codec circuit for encoding processing, and the generated non-DC identification digital signal is sent to the ground data processing unit 20 via the first signal transceiver circuit; or, the first signal transceiver circuit receives the non-DC control signal transmitted by the ground data unit 20, and transmits the non-DC control signal to the first codec circuit, the first codec circuit decodes the non-DC control signal to obtain a control instruction, and transmits the control instruction to the first main control chip, the first main control chip encapsulates the control instruction according to the data format of the CAN bus, and sends the encapsulated control instruction to the data acquisition unit 10 via the CAN bus, and the data acquisition unit 10 further sends the control instruction to the corresponding data measuring instrument; at the same time, the first signal transceiver circuit receives the DC power signal transmitted by the ground data processing unit 20, the DC power signal is processed by the voltage conversion circuit into the voltage signal required by each electrical device, and the first main control chip transmits the voltage signal to each electrical device to supply power to each electrical device in the well.

[0107] like Figure 5As shown, the ground data processing unit 20 includes a second main control chip, a second codec circuit, a second signal transceiver circuit, a power supply circuit, and a signal classification circuit. The power output terminal of the second main control chip is connected to the power input terminal of the second signal transceiver circuit through the power supply circuit, the data input and output terminal of the second signal transceiver circuit is connected to the signal input and output terminal of the second codec circuit, the signal output terminal of the second codec circuit is connected to the data input terminal of the second main control chip through the classification circuit, and the control instruction output terminal of the second main control chip is connected to the signal input terminal of the second codec circuit. The DC power signal output by the power supply circuit is transmitted to the downhole data processing unit 11 through the second signal transceiver circuit to supply power to various electrical equipment in the downhole; at the same time, the second signal transceiver circuit receives the non-DC identification digital signal transmitted by the downhole data processing unit 11, and transmits the non-DC identification digital signal to the second encoding and decoding circuit, the second encoding and decoding circuit decodes the non-DC identification digital signal to obtain the identification digital signal, and transmits the identification digital signal to the signal classification circuit, the signal classification circuit classifies the digital signal according to the identification digital signal, and transmits the classified digital signal to the second main control chip; or the second main control chip transmits the control instruction to the second encoding and decoding circuit, the second encoding and decoding circuit encodes the control instruction, and the obtained non-DC control signal is transmitted to the downhole data processing unit 11 via the second signal transceiver circuit.

[0108] Optionally, the ground data processing unit 20 also includes a timing module, which is connected to the time signal input terminal of the second main control chip to provide a timing signal for the device. The ground data processing unit 20 also establishes a data connection with a remote device through a network. The ground data unit 20 transmits various types of digital signals obtained and processed as downhole observation data to the remote device, providing the remote device with downhole observation data. Optionally, the remote device is a terminal that requires downhole observation data and can further store, statistically analyze, and process the downhole observation data, such as a host computer, a remote data processing terminal, a remote network data receiving management terminal, etc.

[0109] In some embodiments, considering the harsh working environment underground, various circuit devices in the underground part use high-temperature components, which can be suitable for the high-temperature and high-pressure working environment deep underground and improve the reliability of the device.

[0110] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples. In line with the present disclosure, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the present specification as described above, which are not provided in detail for the sake of simplicity.

[0111] In addition, to simplify the description and discussion, and in order not to obscure one or more embodiments of the present specification, known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided figures. In addition, the device may be shown in the form of a block diagram so as to avoid obscuring one or more embodiments of the present specification, and this also takes into account the fact that the details of the implementation of these block diagram devices are highly dependent on the platform on which one or more embodiments of the present specification will be implemented (i.e., these details should be fully within the scope of understanding of those skilled in the art). Where specific details (e.g., circuits) are set forth to describe exemplary embodiments of the present disclosure, it is apparent to those skilled in the art that one or more embodiments of the present specification may be implemented without these specific details or with variations in these specific details. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0112] Although the present disclosure has been described in conjunction with specific embodiments of the present disclosure, many replacements, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may use the embodiments discussed.

[0113] One or more embodiments of this specification are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this specification should be included in the scope of protection of this disclosure.

Claims

1. A comprehensive underground observation device, characterized in that: include: At least one data acquisition unit, deployed underground, for receiving analog signals acquired by at least one data measuring instrument and converting the analog signals into digital signals; The downhole data processing unit is deployed downhole and is used to encode the digital signal to obtain the encoded digital signal; and is used to perform voltage conversion processing on the received power supply signal, and transmit the power supply signal after voltage conversion processing to each data measuring instrument through each data acquisition unit; A ground data processing unit, deployed on the ground, is used to decode the encoded digital signal to obtain a digital signal, and is used to transmit the power supply signal to the downhole data processing unit; Wherein, the ground data processing unit comprises: Instrument monitoring module, used to set control instructions; A second encoding and decoding circuit is used to encode the control instruction to obtain a control signal in a non-DC form; A second signal transceiver circuit, used for transmitting the non-DC control signal to the downhole data processing unit via a cable; The downhole data processing unit comprises: A first signal transceiver circuit receives the control signal in a non-DC form through a cable; A first encoding and decoding circuit is used to decode the non-DC control signal to obtain the control instruction; The downhole data processing unit is connected to the surface data processing unit through a cable that multiplexes digital signals and power signals.

2. The device according to claim 1, characterized in that The cable is a seven-core cable, from which three pairs of core wires are divided. At least one pair of core wires is used to transmit the digital signal, any three core wires are used to transmit the positive power supply signal, and the remaining three core wires are used to transmit the negative power supply signal.

3. The device according to claim 1, characterized in that The downhole data processing unit comprises: A first encoding and decoding circuit is used to encode the digital signal to obtain a digital signal in a non-DC form; A first signal transceiver circuit is used to transmit the non-DC digital signal to the ground data processing unit via the cable; and to receive the DC power signal transmitted by the ground data processing unit via the cable; The ground data processing unit comprises: a second signal transceiver circuit, receiving the non-DC digital signal through the cable; and transmitting the DC power supply signal to the downhole data processing unit through the cable; The second encoding and decoding circuit is used to decode the non-DC digital signal to obtain the digital signal.

4. The device according to claim 3, characterized in that The first signal transceiver circuit includes a first differential processing subcircuit, a first drive amplifier subcircuit, a first data transmission subcircuit, and a first power signal transmission subcircuit; the signal output end of the first codec circuit is connected to the signal input end of the first differential processing subcircuit, the signal output end of the first differential processing subcircuit is connected to the signal input end of the first drive amplifier subcircuit, and the signal output end of the first drive amplifier subcircuit is connected to the signal input end of the first data transmission subcircuit; the signal output end of the first power signal transmission subcircuit is connected to the signal input end of the voltage conversion circuit used to convert the DC power signal into voltage, the first data transmission subcircuit is a DC blocking capacitor, and the first power signal transmission subcircuit is an isolation inductor connected in parallel with the DC blocking capacitor and two switching diodes with opposite polarities, and the two switching diodes are connected in parallel.

5. The device according to claim 3, characterized in that The second signal transceiver circuit includes a second data transmission subcircuit and a second power signal transmission subcircuit, the second data transmission subcircuit is a DC blocking capacitor, and the second power signal transmission subcircuit is an isolation inductor connected in parallel with the DC blocking capacitor.

6. The device according to claim 3, characterized in that The first signal transceiver circuit includes a first filtering subcircuit, a first amplifying subcircuit, a first comparator, and a first data transmission subcircuit. The signal output end of the first data transmission subcircuit is connected to the signal input end of the first comparator through the first filtering subcircuit and the first amplifying subcircuit, and the signal output end of the first comparator is connected to the signal input end of the first encoding and decoding circuit.

7. The device according to claim 3, characterized in that The non-DC digital signal and the non-DC control signal are transmitted between the downhole data processing unit and the surface data processing unit in a half-duplex mode.

8. The device according to claim 1, characterized in that The ground data processing unit also includes a signal supplement circuit for compensating and correcting the encoded digital signal.

9. The device according to claim 1, characterized in that The at least one data acquisition unit is connected to the downhole data processing unit via a CAN bus.

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