RU2777271C1 - Seismic data collection system - Google Patents

Abstract

FIELD: seismic research.

SUBSTANCE: invention relates to the field of seismology and more specifically to a system for collecting seismic data and can be used in automated systems for collecting geophysical information, in particular in multi-channel digital telemetry seismic recording systems with wired and wireless communication lines. A seismic data collection system is proposed, containing a data collection unit, a control computer, a unit of seismic receivers, a recording unit containing a memory unit located together with a unit of seismic receivers. According to the invention, the system additionally contains concentrator units interconnected by a fiber-optic cable and with a control computer. The data acquisition unit contains cable modules and cable-free units made with the possibility of synchronous operation from the satellite signal, while the number of cable modules and cable-free units is determined by the number of seismic channels. Each of the concentrators is equipped with a controlled cable line power supply and a module for converting an optical signal into a digital signal and vice versa and has an input for connecting to a cable module, for connecting Wi-Fi antennas, for receiving a signal from a cable-free unit via a radio channel, for a GPS antenna, for connecting a battery. At the same time, each concentrator contains a processor programmed with the ability to compress signals coming from cable modules and cable-free units, and the number of concentrator units is selected depending on the number of seismic channels.

EFFECT: lengthening the line of arrangement to 2400 active seismic channels during 2D work and providing 3D mode for areal field work with a channel capacity of up to 100,000 active seismic cable and cable-free channels.

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Description

The invention relates to the field of seismology and more specifically to a seismic data acquisition system and can be used in automated systems for collecting geophysical information, in particular in multichannel digital telemetric seismic recording systems with wired and wireless communication lines for processing seismic profiles by various seismic exploration methods.

A seismic data collection system is known (see RF patent No. 2207593 according to IPC class G01V1 / 22, publ. 06/27/2003), containing a group of autonomous registration units, each of which has at least one seismic receiver connected to the inputs, a central control onboard complex and at least one information telemetry communication line, containing at least one section connecting autonomous registration units between themselves and with the central control on-board complex, moreover, the central control on-board complex contains a computer complex and at least one on-board recorder connected to the section of the information telemetry communication lines and connected to the computer complex by a serial information communication channel, moreover, at least one service data sensor or seismic receiver is connected to the inputs of the flight recorder, each autonomous recording unit contains a device for separating data streams and a recorder, and the device section The data streaming system contains the first receiver and the first transmitter connected to the information communication line, the second receiver and the second transmitter connected to the information communication line, a switch and a modem, the output of the first receiver is connected to the first input of the switch, the switching output of which is connected to the first input of the modem , the second input of which is connected to the serial information output of the registrar, characterized in that in the device for separating data streams, the second input of the switch is connected to the output of the second receiver, the first output of the switch is connected to the input of the first transmitter, the second output of the switch is connected to the input of the second transmitter, the switching input of the switch connected to the first output of the modem, the second output of which is connected to the serial information input of the registrar, the control output of which is connected to the control input of the switch, to the control input of the first receiver, to the control input of the first transmitter, to the control input ohm of the second receiver and with the control input of the second transmitter of the device for separating data streams.

The disadvantage of this system is its excessive energy saturation with on-board electronic equipment, which requires additional operator attention to track failures when the control codes do not match, while the fault location of an array several kilometers long is not automatically determined.

An information telemetric communication line containing at least one section connecting autonomous recording units to each other with the central control on-board complex is essentially only a cable seismic system using a multi-core cable, which significantly increases the total weight of the equipment.

A seismic data collection system is also known (see RF patent No. 2190241 according to class IPC G01V1 / 22, publ. 27.09.2002), containing a central control unit and seismic receiver nodes located in a certain order in the study area, each of the mentioned seismic receiver nodes contains means for presenting digital data of the seismic movement of the earth's surface at the location of the said geophone assembly. The area under study is divided into a group of sectors, each of which contains a group of seismic receiver nodes and a sector access node, each of the mentioned seismic receiver nodes contains a radiotelemetry means for receiving control signals from the central control unit through the corresponding sector access node and transmitting the mentioned digital data by command to the corresponding sector access node for their subsequent transmission to the central control unit, and the said seismic receiver nodes located in this sector are connected to the said sector access node by means of the specified radiotelemetry means, at a certain frequency different from the frequencies used in sectors adjacent to this sector, and each frequency is used in the system in several non-adjacent sectors of the specified territory. The sector access nodes are connected to said central control unit via radio communication, cable or fiber optic communication channel.

The disadvantage of this system is the limitation of the actual placement on rough terrain, since the shape and size of the sectors are determined by the range of radio transmitters, the characteristics of the territory, the presence of any obstacles and, to a lesser extent, weather conditions. Remote Data Acquisition Nodes (RDCs) located in the same sector operate on the same set of radio frequencies. In sectors adjacent to each other, different radio frequencies are used. When performing 3D work, especially when it is necessary to overcome natural obstacles, a limited set of frequency ranges can significantly reduce work productivity.

With a chaotic placement of sectors on the area, a long fiber optic line will be required, which, without special data flow regenerators, will lead to a significant slowdown of the entire volume of geophysical information or to the loss of part of it at the time it enters the main recorder.

Closest to the claimed is a data collection system for characterizing subsurface structures (see RF patent No. 2450255 according to class IPC G01N1 / 22, publ. at least one means of collecting information, containing a block of seismic receivers installed on the earth's surface with the possibility of registering seismic waves in the earth and generating a signal characterizing the recorded seismic wave emanating from subsurface structures, a recording block containing a memory block located together with the block seismic receivers, connected to it with the possibility of receiving a signal and storing in digital format information characterizing the received signal and configured to obtain the location and orientation parameter of only one block of seismic receivers, a processor associated with the block of seismic receivers and a recording unit, and a communication means located together with a seismic receiver unit and a recording unit with the possibility of direct communication with the central controller, and a seismic wave source configured to generate a seismic wave of a given magnitude and from a point with a predetermined location.

The main disadvantage is that this system does not have a real data transfer time, but writes to memory for subsequent reading to the central controller.

The technical problem of the claimed invention consists in expanding the arsenal of means of multichannel digital telemetry seismic recording systems by integrating with cable and cableless channels with an increase in the number of channels and with an increase in consumer opportunities for geophysical research in a wide temperature range from -40 to +70 degrees Celsius, with any geophones, and with any source of excitation of seismic waves and on any surface with various types of obstacles and with the ability to bypass obstacles without breaking the line of observation.

The technical result consists in extending the spacing line to 2400 active seismic channels during 2D work (such channeling is necessary when the channel grid is thickened with a seismic signal reception step of 5-10 meters) and providing a 3D mode for areal field work with a channel capacity of up to 100,000 active seismic cable and cableless channels (arrangement is determined by a specific area and, accordingly, the possibility of maximum placement of channels with a certain step along the profile lines to implement the registration technique with several groups of vibration sources simultaneously), as well as in increasing the speed of seismic information transmission via the main fiber optic cable to the central computer, bypassing obstacles without breaking the line of observation and thereby reducing the time required to complete a given amount of work.

To achieve the claimed technical result, a seismic data acquisition system containing a data acquisition unit, a control computer, a seismic receiver unit, a recording unit containing a memory unit located together with a seismic receiver unit, according to the invention, the system further comprises concentrator units interconnected by a fiber optic cable and with the control computer, the data acquisition unit contains cable modules and cableless blocks, made with the possibility of synchronous operation from the satellite signal, while the number of cable modules and cableless blocks is determined by the number of seismic channels, each of the concentrators is equipped with a controlled cable line power supply and an optical conversion module signal to a digital signal and vice versa and has an input for connecting to a cable module, for connecting Wi-Fi antennas, for receiving a signal from a wireless unit via a radio channel, for a GPS antenna, for connecting a battery, wherein each concentrator contains a processor programmed with the possibility of compressing signals coming from cable modules and cableless blocks, and the number of concentrator blocks is selected depending on the number of seismic channels.

The case of each hub block and cableless block is sealed from impact-resistant plastic with a degree of protection according to IP68.

The invention is illustrated by drawings, which show:

- in Fig. 1 - the claimed data collection system,

- in Fig. 2 - obstacle avoidance scheme,

- in Fig. 3 - hub block,

in fig. 4 - cableless block.

The positions in the drawings indicate:

1 - control computer,

2 - block of synchronization and auxiliary channels,

3 - synchronization and excitation system,

4 - industrial managed switch,

5 - entrance panel,

6 - line concentrator block,

7 - cableless block,

8 - cable module,

9 - main board,

10 - controller of the first port,

11 – second port controller,

12,13,14 - protection devices,

15 - synchronization board.

16 - analog device,

17 - controller,

18 - protection device,

19 - GPS board,

20 - battery.

The system contains a central recording complex, which contains: a control computer 1, a block for synchronization and auxiliary channels 2, a synchronization and excitation system 3, an industrial controlled switch 4, an input panel 5.

Control computer 1 provides:

- preparation of service information for ground units;

- synchronization of the processes of launching the source of excitation of seismic vibrations and registration of seismic data;

- formation of a file of times of launching a source of seismic vibrations;

- transmission of service information prepared for ground units using Wi-Fi wireless data transmission technology or wired connection;

- reception of seismic, service information and the results of self-testing of field units using wireless technology for data transmission Wi-Fi or wired connection via Ethernet;

- generating seismograms by linking the seismic data files of the registered wireless units to the corresponding start times of the excitation source;

- binding of seismograms generated in the process of sorting the registered seismic data to specific pickets, using the input SPS-File with the specified profile placement coordinates;

- recording of seismograms on the information carrier in one of the seismic data formats (SEG-Y or SEG-D);

- processing the test results and issuing a conclusion on the technical condition of the blocks and built-in batteries.

Block synchronization and auxiliary channels 2 provides synchronization of the processes of starting the source of excitation of seismic vibrations at the command of the control computer 1 and digitization of analog signals of auxiliary channels.

Synchronization and excitation system 3 is designed to work with both explosive and non-explosive pulsed excitation sources. The system is used to: synchronize the start of the launch of seismic data acquisition systems and the launch of vibration excitation sources; initiation of explosive sources of excitation of oscillations; generating signals for marking the moment and vertical time at the oscillation excitation point; transmission of moment and vertical time mark signals from the vibration excitation point to the seismic station.

The industrial managed switch 4 receives a digital information stream from the input panel and transmits it to the control computer via the Ethernet protocol, the switch power supply converts the primary supply voltage of 220 V to 48 V and transmits it to the telemetry line.

The input panel 5 serves to provide switching of the fiber optic cable of two ports coming from the hub blocks with the input of a controlled industrial switch and then via the Ethernet protocol to the control computer, provides protection of the telemetry line from static electricity and generates the supply voltage for the "digital-optics" converter.

The hub block 6 has a plastic housing manufactured with IP68 protection. The housing is equipped with connectors for connecting the battery, connectors for connecting the main fiber optic cable, connectors for cable telemetry modules 8 and connectors for installing special Wi-Fi antennas for receiving seismic data in real time from cableless units 7, as well as for reading data from the device’s memory without preliminary disassembly of the device using the Ethernet protocol, a GPS / GLONAS antenna for determining coordinates and ensuring synchronous operation of cableless units 7 by a signal from a satellite, an ESD protection device, a main board with two controllers located on it, on which electronic memory devices are placed, a module with a Wi-Fi antenna, a module with a GPS antenna, a module for converting an optical signal into a digital signal and vice versa, protection boards. The concentrator provides at least two branches of cable data collection modules, or cableless data collection units, the number of connected external batteries with a voltage of 12V - 2, the range of the built-in radio transmitting (Wi-Fi) module - 300 m, the length of the fiber-optic backbone cable - 330 m., Ethernet interface to create a flexible backbone structure (see Fig. 3).

The cableless box 7 includes a housing and a cover, which are also made of plastic with IP68 protection. At the bottom of the case, with the help of double-sided adhesive tape and a silicone plate, a rechargeable battery is fixed, fixed with a metal plate, contains an electronic part fixed in the case, which is placed on two sub-units electrically connected to each other by connectors and forming a “layer cake” type structure using metal racks. The cover has an output sealed connector, which is used to connect with seismic sensors, and a connector used to charge the battery and read the recorded information.

The structure of the cableless unit 7 also includes an antenna fixed on the cover; Block 7 is intended for recording seismic data without the use of cables and a radio channel and includes an analog device with one or three data acquisition channels, a synchronization board with a built-in high-sensitivity GPS receiver, a clock generator, a built-in test signal generator, non-volatile memory up to 32 GB, high-speed port for data transfer and battery (see Fig. 4).

The cable module 8 provides reception of signals from seismic receivers at the receiving points, their amplification, conversion into a digital 24-bit code, filtering, transmission of this data to a telemetry communication line and regeneration of information coming from neighboring modules.

The system works like this:

On the earth's surface, the system is installed (seismic receivers, concentrator blocks, wireless blocks, cable modules, fiber optic cable). The system forms observation lines, which are divided into block segments. Each hub serves only its segment of blocks. The hubs in the line are connected via a four-core cable, and between the lines with a fiber optic cable, while the first hub is connected to the on-board computer via an optical cable. As a result, the requirement for cable cross-section is reduced, synchronization signals are less distorted, and data compression is possible to increase the channel capacity of the line.

The operator turns on the power of the control computer 1 and starts the “station” program, sets the required configuration (the number of channels in the line, the number of reception lines, the quantization interval), turns on the power of the system remotely via a fiber optic cable with a special command that is sent to the circuit of the hub unit, the devices start up into operation, a controlled power supply generates a specified voltage of 48V for cable blocks of the telemetry line. The hub blocks and wireless blocks determine the coordinates of the installation site and are synchronized by the satellite signal, while the block of synchronization and auxiliary channels 2, at the command of the control computer, generates a “Start” signal for the synchronization system 3 with a duration of 100 ms and an amplitude of 5V (the effective signal level is 0 V), which is synchronized with one of the second pulses of the GPS signal. In this case, the leading (falling) edge of the “Start” signal coincides with the leading edge of the PPS signal, which the BSVK navigation receiver generates once per second when there is a connection with GPS satellites.

In block 2, the “TOM” signal is received from the excitation synchronization system 3, the time of arrival of the leading edge of the “TOM” signal is measured, and a message is transmitted to the computer with the value of the measured time with an accuracy of ± 1 μs. The moment of time corresponding to the arrival of the "KOM" signal is stored in a special file. The time of arrival of the "COM" signal is used later when constructing seismograms in the SEG-D or SEG-Y format to search for the first reading when generating seismograms from signals received from seismic receivers connected to cableless and cable blocks.

Three analog signals can be connected to the input of block 2, which are converted into digital codes in block 2 and transmitted to computer 1 as three auxiliary channels. The parameters of the auxiliary channels of block 2 are similar to the parameters of the seismic channels of cable and cableless blocks.

When a seismic source creates vibrations of the earth's surface and when reflected waves are received at the input of seismic receivers in wireless units and in cable telemetry modules, an analog-to-digital conversion of the input signal and the formation of a 24-bit word in its own format from cable and cableless seismic array units is performed.

Next, 24-bit words enter the concentrator units via a four-core cable or via a radio channel at a frequency of 2.4 GHz, the concentrator unit analyzes the incoming information for each bit, compresses the information, and transmits it via a fiber-optic cable to the DSC for subsequent recording in the memory of the control computer.

Compression is based on the fact that most of the channels in the segment have a small amplitude, and the signal amplitude of one channel can vary significantly in time.

When collecting data for its segment, the concentrator generates short sections on each channel. The site consists of a header and data. The header contains a sign of the beginning of the section, the number of samples of the section, the value of the zero offset in the section and the word length of the samples.

The compression procedure consists of the following steps:

• Defining and writing to the parcel data zero offset header.

• Determination of the maximum amplitude of readings of a section to eliminate excess discharges and determination of the minimum bit depth of readings of this section.

• Convert the 24-bit format to a format with the selected number of bits and write the number of bits to the header.

• Recording the number of plot readings in the header.

As a result of compression, the amount of data is significantly reduced, which makes it possible to install more registration units with geophones in the line, i.e. increase the bandwidth of the line. After the "compressed" data is received by the on-board computer of the seismic system, the data is unpacked and converted into a 24-bit SEG-D or SEG-Y format code.

Each hub, as shown in FIG. 1 serves one segment of the spread, which includes 60 cable channels. The number of channels (seismic receivers) is determined by the ability of the controlled power supply to generate a voltage of 48 V for cable channels. If we form a chain of cable channels and 40 hubs, we will get a line length of 2400 channels with a step of 50 meters between channels. A further increase in channelization is limited by the possibility of an excitation source that excites seismic vibrations from the earth's surface and, accordingly, the reflected wave is absorbed and does not reach the seismic receiver from the depth.

Similar restrictions on the number of geophones located along several lines, and for 3D projects.

Thus, the system makes it possible to extend the spreading lines up to 2400 seismic channels during 2D work and provide the 3D mode for areal field work up to 100,000 active seismic cable and cableless channels

The system allows not only ground placement, but also placement of cable blocks in the water, in particular, in water bodies with a depth of no more than 12 m, while hydrophones are installed instead of geophones, while the system automatically determines the location of the geophone and hydrophone.

The system implements an obstacle avoidance algorithm.

Thus, concentrator blocks provide control of cable telemetry modules and cableless seismic information blocks; synchronization of operation of concentrators and data collection units connected to them with GPS/GLONAS satellite navigation signals; receiving parameters or commands coming from the control computer and their transmission to the monitoring line in which the given concentrator is installed and further to the concentrator of the neighboring monitoring line; reception of seismic data from the branches of the observation line in which this concentrator is installed; transfer of the received data via the main line to the computer; regeneration of seismic information during data transmission between observation lines and to a computer; creation of an auxiliary trunk line for the purpose, for example, of bypassing an obstacle, by installing an additional concentrator block in the line, connected to the central recording complex; diagnosing the technical condition of data collection units connected to the concentrator unit (cable modules and cableless units) and geophones; storage of seismic and service information incoming to the concentrator units in the internal memory of the concentrator unit in the absence or temporary loss of communication with the central complex; transfer of information stored in the internal memory of the unit either to a mobile data collection device (tablet) via a radio channel, or to the central complex via a cable channel, when the interrupted connection between the central complex and the concentrator unit is restored; use of a hub block as a repeater, for example, when placed in a line to bypass an obstacle, while part of the geophysical information will pass through cable blocks.

Claims (2)

1. A seismic data acquisition system containing a data acquisition unit, a control computer, a seismic receiver unit, a recording unit containing a memory unit located together with a seismic receiver unit, characterized in that the system additionally contains concentrator units interconnected by a fiber optic cable and with control computer, the data acquisition unit contains cable modules and cableless blocks, made with the possibility of synchronous operation from the satellite signal, while the number of cable modules and cableless blocks is determined by the number of seismic channels, each of the concentrators is equipped with a controlled power supply and a module for converting an optical signal into a digital signal and vice versa and has an input for connecting to a cable module, for connecting Wi-Fi antennas, for receiving a signal from a wireless unit, for a GPS antenna, for connecting a battery, while each hub contains a processor programmed with the possibility signal compression axis from cable modules and cableless blocks, and the number of concentrator blocks is selected depending on the number of seismic channels. 2. The system according to claim 1, characterized in that the housings of each hub unit and cableless unit are sealed from impact-resistant plastic with a degree of protection according to IP68.

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