CN220043682U - Accurate synchronization system of seismic exploration source synchronizer - Google Patents

Abstract

The utility model provides an accurate synchronization system of a seismic exploration source synchronizer, which comprises an encoder and a decoder, wherein the encoder is linked with a seismic exploration instrument and is arranged on an instrument car, the decoder is arranged at each seismic source point, and the synchronization system is connected between the encoder and the seismic exploration instrument in series and comprises a delay circuit and a switch circuit; when the seismic prospecting instrument is communicated with each seismic focus point through the wireless relay station, the switch circuit is connected with the delay circuit to the system so as to correct the delay generated by the differential operation of the wireless relay station. By adopting the technology of the utility model, the starting time of the data acquisition of the seismic instrument and the detonation time of the seismic source can be ensured, and the two parts are still at the same time, and the two parts are accurately synchronous, thereby greatly improving the field construction operation efficiency of the seismic exploration and shortening the field construction operation period of the seismic exploration.

Description

Accurate synchronization system of seismic exploration source synchronizer

Technical Field

The utility model relates to the field of seismic exploration, in particular to a system for ensuring accurate synchronization of a seismic exploration source synchronizer, which solves the problem that a wireless relay station generates delay in seismic exploration source synchronization.

Background

It is well known that: the method of seismic exploration is used for searching energy sources such as petroleum, natural gas, coal and the like, and is an important means at home and abroad at present. Seismic exploration is based on the principle of echo detection. Seismic waves are excited at a point of a seismic source (including but not limited to explosive sources, non-explosive sources: such as source vehicles, air guns, electric sparks, etc.), and seismic reflections from the subsurface formation interfaces are received at a receiving point. The geometrical form and the geological attribute of each stratum are determined according to the propagation speed and the travel time of the seismic wave in each stratum medium, so that the geological structure and the geological attribute of the energy source containing petroleum, natural gas, coal and the like are searched, and the receiving of the seismic reflection wave from the stratum interface is the core of seismic exploration. The instrument station, the receiving point and the seismic source point are distributed at different places, the artificial seismic source is utilized to excite to generate seismic waves, and then the seismic reflected waves are received by the detectors and the collecting stations distributed on the ground surface of the detection area. The excitation of the seismic source, the acquisition and the reception of the seismic reflection wave information data and the transmission and reception of related working instructions are all completed by a system (seismic data acquisition system) of a seismic prospecting instrument. The system requires a very accurate set of related work orders and timing systems.

The seismic source synchronizer is an essential important device in a seismic exploration data acquisition system, and has the functions of: the starting time of the seismic prospecting instrument for collecting the seismic data and the detonation time of the seismic source are ensured to be precisely synchronous at the same time, and the TB signal synchronous precision of the seismic prospecting instrument must meet the industrial standard of the oil and gas SY/T5314-2004 of the people's republic of China: less than + -1 mS (1 mS based on the pulse timing signal provided by the time reference circuit currently in common use, the following).

In the mountain area seismic exploration operation, as shown in fig. 1, a schematic diagram of mountain area seismic exploration field construction operation is shown. The seismic source point 2 in fig. 1 forms a wireless communication blind area due to the mountain blocking between the instrument trolley and the seismic source point 2, so that the wireless communication cannot be normally performed, the wireless communication cannot be normally transmitted, and the seismic source synchronizer cannot normally work. As the seismic exploration is arranged to be shorter by 2-3 km in the past, the number of the receiving channels of the seismic channels is hundreds of channels at most, the coverage area of one exploration is only a few square kilometers, and the instrument station and each seismic source point can be communicated by adopting a method of manually placing telephone lines when the field construction operation of the seismic exploration in the mountain area is carried out. However, with the increase of the depth requirements and the increase of the precision requirements of the seismic exploration, the number of the acquisition channels of the field seismic exploration is increased to 5-10 ten thousand channels, and the coverage area of one exploration reaches tens of square kilometers, so that when the field construction operation of the seismic exploration in mountain areas is performed, the method of manually placing telephone lines is adopted to communicate the instrument trucks with each seismic source point, which is obviously impractical. Therefore, in the field construction operation of mountain area seismic exploration, the problem of synchronization between instrument stations and each seismic source point is always a difficult problem which puzzles the mountain area seismic exploration.

The wireless relay station is used for communicating the instrument station with each seismic source point, and the communication problem between the instrument station and each seismic source point is solved, but the wireless relay station adopts a different frequency differential rotation working mode to generate delay, so that the starting time of the seismic prospecting instrument for collecting the seismic data and the detonation time of the seismic source cannot accurately occur at the same moment, and synchronization is abnormal. Therefore, the problem of delay generated by the wireless relay station in the seismic exploration seismic source synchronization must be solved, and the starting time of the seismic exploration instrument for acquiring the seismic data and the detonation time of the seismic source must be ensured to be in the same time, and the two sides must be accurately synchronized.

The source synchronizer consists of two parts: the encoder and the decoder must be paired, and only the paired encoder and decoder can recognize each other because the instruction code transmitted between them corresponds to a password. The encoder and the seismic prospecting instrument are usually placed on an instrument vehicle (called an instrument station), and are in linkage with the seismic prospecting instrument in a related mode and controlled by an instrument operator; the decoder is placed at each source point and operated by an exploder. The two are separated by a certain distance, and a radio station or a telephone line is used for communication and transmitting related work orders.

When the source synchronizer works:

case 1: the same-frequency receiving and transmitting working mode is that when a seismic prospecting instrument operator works normally on the relevant seismic data acquisition equipment on the well-inspected seismic survey line and completely accords with the seismic data acquisition working conditions, the instrument operator informs an exploder on a seismic source point of all preparation works before the seismic source is excited, and if all the works before the initiation on the seismic source point are all ready, the working process of the seismic data acquisition is started. At this point a first instruction is issued by the instrument operator with the encoder: the preparation code is received only by the decoder matched with the encoder, and is transmitted to the decoder on the source excitation point through a radio station or a telephone line, an exploder on the source excitation point charges the decoder after receiving the preparation code instruction, the charging time is usually a few seconds, the purpose of the preparation code is to provide sufficient detonation charge energy for the detonation of the detonator, and after a few seconds, an instrument operator links the encoder to send a second instruction by operating the seismic prospecting instrument: the ignition command can be received by only the decoder matched with the encoder, and is transmitted to the decoder on the focus excitation point through a radio station or a telephone line, the decoder can automatically receive the ignition command under the control of an exploder on the focus excitation point, the ignition command can be automatically decoded to form a synchronous zero point, the moment is taken as a time reference point, and then the encoder and the decoder establish a time synchronous relationship, and the two parties take the synchronous zero point as the respective time reference point. And thereby each of the two parties issues an execution instruction: the decoder on the seismic source point automatically sends out an initiation command to excite the seismic source, and meanwhile, the encoder on the seismic prospecting instrument vehicle also automatically sends out a seismic data acquisition initiation command to start the seismic prospecting instrument to acquire seismic data. So far, the detonation time of the seismic source and the time of the seismic prospecting instrument for collecting the seismic data occur at the same moment, so that an accurate synchronization relationship is ensured, and the synchronization precision error is required to be less than +/-1 ms according to the seismic prospecting industry specification.

Case 2: because of the mountain blocking, when the seismic source point 2 is in a wireless communication blind area, the instrument car and the seismic source point 2 cannot be in direct radio communication, and at the moment, the instrument and the seismic source point 2 can be communicated by utilizing a wireless relay station. The wireless relay station is generally composed of: the frequency difference turntable, the duplexer, the antenna, the feeder line and the link station. Because the wireless relay station adopts a different frequency difference conversion working mode, delay is necessarily generated, so that the starting time of seismic data acquisition of a seismic instrument and the detonation time of a seismic source cannot occur at the same time, cannot be synchronized, and do not meet the industrial standard of the oil and gas SY/T5314-2004 of the people's republic of China.

Under the circumstance, the original method of manually placing telephone lines is only needed to be adopted to connect the instrument trolley with each seismic source point so as to ensure that the starting time of the seismic exploration instrument for collecting the seismic data and the detonation time of the seismic source occur at the same moment, and the two times are accurately synchronous, namely, the reason of manually placing the telephone lines in the mountain area seismic exploration work is the reason that the manual placing telephone lines are also needed. As described previously: the telephone line is difficult to put manually in mountain areas and is even broken accidentally sometimes, so that the field construction operation efficiency is greatly reduced, and the construction period is prolonged and the cost is increased.

In summary, in the field construction operation of mountain area seismic exploration, the problem of synchronization between the instrument and each seismic source point is always a difficult problem puzzling mountain area seismic exploration.

Disclosure of Invention

The utility model aims to solve the problem of synchronization between an instrument and each seismic source point in mountain seismic exploration field construction operation, and provides an accurate synchronization system of a seismic exploration seismic source synchronizer. The method can be applied to the seismic exploration fields of petroleum, natural gas, coal and the like, and can also be applied to other occasions where the differential rotation delay generated by the wireless relay station needs to be corrected.

The technical scheme of the utility model is as follows:

the utility model provides an accurate synchronization system of a seismic exploration source synchronizer, which comprises an encoder and a decoder, wherein the encoder is linked with a seismic exploration instrument and is arranged on an instrument car, the decoder is arranged at each seismic source point, and the synchronization system is connected between the encoder and the seismic exploration instrument in series and comprises a delay circuit and a switch circuit;

when the seismic prospecting instrument is communicated with each seismic focus point through the wireless relay station, the switch circuit is connected with the delay circuit to the system so as to correct the delay generated by the differential operation of the wireless relay station.

Further, the switch circuit comprises linkage switches K1, K2 and K3, one end of the linkage switch K1 is connected with a synchronous zero output end of the encoder and one end of the linkage switch K2, the other end of the linkage switch K1 is connected with a control end of the seismic prospecting instrument and one end of the linkage switch K3, and the other ends of the linkage switches K2 and K3 are respectively connected with two ends of the delay circuit;

when the linkage switch K1 is switched on, the linkage switches K2 and K3 are switched off, and at the moment, the seismic prospecting instrument receives and transmits the same frequency with each seismic focus, and the seismic prospecting instrument is in a normal working state, namely a wireless relay station is not used;

when the linkage switch K1 is turned off, the linkage switches K2 and K3 are turned on, at the moment, the earthquake prospecting instrument receives and transmits different frequencies from each earthquake focus, and the earthquake prospecting instrument is in a working state of starting the wireless relay station and is connected with the delay circuit.

Further, the delay circuit includes:

a time reference circuit for providing a pulse timing signal as a time reference, the output of the time reference circuit being connected to the input of the control gate circuit;

the control gate circuit comprises a state trigger and a control gate, namely an AND gate Y1, wherein the synchronous zero output end of the encoder is connected with the lower input end of the state trigger, the upper input end of the state trigger is connected with an RS reset signal, the output end of the state trigger is connected with the upper input end of the control gate, the lower input end of the control gate is connected with the output of the time reference circuit, and the output end of the control gate is connected with the lowest bit of the counter circuit and the lowest bit input end of the comparator circuit simultaneously in parallel to control the output of the timing pulse signal;

the counter circuit is composed of a plurality of counters and is arranged from the lowest position to the highest position; the highest output end of the low-weight bit is connected with the lowest input end of the high-weight bit, namely the highest output end of the lowest-weight counter is connected with the lowest input end of the next low-weight counter, the highest output end of the next low-weight counter is connected with the lowest input end of the next low-weight counter, and the like, the next low-weight counter is connected with the highest-weight counter, each counter is respectively connected with an RS reset signal, the reset signal is provided when the encoder is started, and each output end of each counter is respectively connected with the corresponding bit input end of the corresponding weight comparator;

the time selection circuit consists of a plurality of jumpers, connects a +5v high level or GND low level to a corresponding port of the comparator, and presets a delayed time value;

the comparator circuit is composed of a plurality of comparators and is arranged from the lowest bit to the highest bit; the output end of the comparator with low weight is connected with the input end of the comparator with high weight, and the output end of the highest-order comparator is connected with the input end of the driver circuit;

and the driver circuit is used for outputting an execution signal to a starting control end of the seismic prospecting instrument.

Further, the time reference circuit adopts a crystal oscillator; or GPS and Beidou are adopted, and the GPS and the Beidou are used as time references through a frequency divider.

Further, the time reference circuit is used for providing a pulse timing signal of 0.01ms as a time reference.

Further, the state trigger adopts an RS trigger for representing the state of synchronous zero output of the encoder; the output end of the NAND gate YF1 is connected with the upper input end of the NAND gate YF2, the output end of the NAND gate YF2 is connected with the lower input end of the NAND gate YF1, the output end of the NAND gate YF2 is simultaneously connected with the upper input end of the AND gate Y1, the lower input end of the NAND gate YF2 is used as the input end of the state trigger to be connected with the synchronous zero output end of the encoder, the upper input end of the NAND gate YF1 is used as the other input end of the state trigger to be connected with the RS reset signal, and the output end of the NAND gate YF2 is used as the output end of the state trigger to be connected with the upper input end of the control gate, namely the AND gate Y1.

Further, the counter adopts a 10-system counter or a 16-system counter; accordingly, the comparator employs a comparator consistent with a counter system.

The utility model has the beneficial effects that:

the system effectively solves the problem of delay generated by the wireless relay station in the synchronization of seismic exploration sources in mountain areas, ensures that the starting time of data acquisition of the seismic instruments and the detonation time of the sources still occur at the same moment, is accurately synchronous, and ensures that the TB signal synchronization accuracy of the system not only completely accords with the industrial standard of the oil and gas SY/T5314-2004 of the people's republic of China. The delay generated by the differential operation of the wireless relay station maintains accurate synchronization relationship and is normal after the correction of the delay circuit is added at the encoder end.

In the utility model, a time reference circuit is used for providing a pulse timing signal of 0.01ms as a time reference; the TB signal synchronization accuracy is improved from +/-1 mS to +/-0.01 mS.

According to the utility model, delay t 0-t 1 generated by the wireless relay station differential operation is corrected, namely, when the encoder sends out a synchronous zero point, a delay time is added at the encoder end, and the synchronous zero point time is also delayed from t0 to t1, wherein the time value is the time value of delay generated by the wireless relay station differential operation at the decoder end, and the time values are equal, so that the corrected synchronous zero instruction sent out by the encoder and the synchronous zero point instruction detected by the decoder end still keep an accurate synchronous relationship in time, and the starting time of the seismic exploration instrument for acquiring the seismic data and the detonation time of the seismic source are ensured to be in the same time t1, and accurate synchronization is ensured.

The system of the utility model has good application effect in the field construction operation of seismic exploration of complex terrains such as mountain areas, tibet plateau, loess plateau, tropical rain forest, beach islands, desert gobi and the like. With the trend of seismic exploration to more than one channel, large three dimensions, long survey lines and large areas, the practical use value of the utility model is more fully shown, and the current field construction operation condition of seismic exploration generally consumes less than hundreds of thousands of yuan per day, more than hundreds of thousands of yuan per day, and even higher cost. The technology of the utility model is applied to the seismic exploration field construction operation of the complex terrain, improves the efficiency of the seismic exploration field construction operation on the premise of ensuring accurate synchronization, shortens the construction period of the seismic exploration field construction operation, reduces the total cost of the seismic exploration field construction operation, saves few millions of yuan, more tens of millions of yuan and even more for one exploration project, and has considerable economic benefit.

Additional features and advantages of the utility model will be set forth in the detailed description which follows.

Drawings

The foregoing and other objects, features and advantages of the utility model will be apparent from the following more particular descriptions of exemplary embodiments of the utility model as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts throughout the exemplary embodiments of the utility model.

Fig. 1 shows a schematic diagram of a mountain area seismic exploration field construction operation in the background art.

Fig. 2 shows a schematic diagram of a system according to an embodiment of the utility model.

Fig. 3 shows a delay circuit diagram according to an embodiment of the utility model.

Fig. 4 shows a separate display of encoder and decoder synchronization zeros when actual synchronization is performed, with the upper line being encoder synchronization zeros and the lower line being decoder synchronization zeros, according to an embodiment of the present utility model.

Fig. 5 shows a diagram of encoder and decoder synchronization zero overlap display when synchronization is measured in accordance with an embodiment of the present utility model.

Description of the embodiments

Preferred embodiments of the present utility model will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present utility model are shown in the drawings, it should be understood that the present utility model may be embodied in various forms and should not be limited to the embodiments set forth herein.

As shown in fig. 2, a precise synchronization system of a seismic exploration source synchronizer, wherein the source synchronizer comprises an encoder and a decoder, the encoder is linked with a seismic exploration instrument and is arranged on an instrument trolley, and the decoder is arranged at each source point: the synchronous system is connected in series between the encoder and the seismic prospecting instrument and comprises a delay circuit and a switch circuit; when the seismic prospecting instrument is communicated with each seismic focus point through the wireless relay station, the switch circuit is connected with the delay circuit to correct the delay generated by the differential operation of the wireless relay station; the switch circuit comprises linkage switches K1, K2 and K3, one end of the linkage switch K1 is connected with the synchronous zero output end of the encoder and one end of the linkage switch K2, the other end of the linkage switch K1 is connected with the control end of the seismic prospecting instrument and one end of the linkage switch K3, and the other ends of the linkage switches K2 and K3 are respectively connected with two ends of the delay circuit;

when the linkage switch K1 is switched on, the linkage switches K2 and K3 are switched off, and at the moment, the seismic prospecting instrument receives and transmits the same frequency with each seismic focus, and the seismic prospecting instrument is in a normal working state, namely a wireless relay station is not used;

when the linkage switch K1 is turned off, the linkage switches K2 and K3 are turned on, at the moment, the earthquake prospecting instrument receives and transmits different frequencies from each earthquake focus, and the earthquake prospecting instrument is in a working state of starting the wireless relay station and is connected with the delay circuit.

As shown in fig. 3, the delay circuit added at the encoder side includes: a time reference circuit (time base for short, the same applies hereinafter), a control gate circuit, a counter circuit, a time selection circuit, a comparator circuit, and a driver circuit;

1. time reference circuit: the time reference in the utility model selects the pulse timing signal of 0.01mS, and can select a crystal oscillator with high precision and high stability, or introduces GPS and Beidou as the time reference, and the time reference is obtained by frequency division. The crystal oscillator, the GPS, the Beidou time base and the frequency divider are all conventional universal circuits. Practice proves that: the crystal oscillator with high precision and high stability is selected, so that the requirements of the precision and the stability of practical use can be met, and the manufacturing cost is low; the GPS and Beidou time base is introduced, so that the precision is higher, but the manufacturing cost is also high, and the GPS and Beidou time base can be determined according to the actual situation.

The output end of the timing pulse signal of 0.01mS provided by the time reference circuit and controlled by the control gate circuit is connected with the lowest bit input ends of the counter circuit and the comparator circuit. The timing pulse signal of 0.01mS provided by the time reference circuit and controlled by the control gate circuit is simultaneously inputted to the lowest bit of the counter circuit and the comparator circuit, respectively.

2. And a control gate circuit: the state trigger consists of a NAND gate YF1 and a NAND gate YF2, wherein the output end of the NAND gate YF1 is connected with the upper input end of the NAND gate YF2, the output end of the NAND gate YF2 is connected with the lower input end of the NAND gate YF1, and the output end of the NAND gate YF2 is also connected with the upper input end of the control gate and the upper input end of the NAND gate Y1. The synchronous zero output end of the encoder is connected with the lower input end of a state trigger (namely, the lower input end of the NAND gate YF 2), and the upper input end of the state trigger (namely, the upper input end of the NAND gate YF 1) is connected with the RS for resetting. The output end of the state trigger (i.e. the output end of the NAND gate YF 2) is connected with the upper input end of the control gate and gate Y1, and the lower input end of the control gate and gate Y1 is connected with the output end of the timing pulse of 0.01mS provided by the time reference circuit. The output of the AND gate Y1 is connected to the low-level bit of the counter circuit and the low-level bit input of the comparator circuit.

3. A counter circuit: the system consists of a plurality of counters, wherein a 10-system counter or a 16-system counter is adopted, and the arrangement is from the lowest position to the highest position; the highest output end of the low-weight bit is connected with the lowest input end of the high-weight bit, namely the highest output end of the lowest-weight counter is connected with the lowest input end of the next low-weight counter, the highest output end of the next low-weight counter is connected with the lowest input end of the next low-weight counter, and the like, the next low-weight counter is connected with the highest-weight counter, each counter is respectively connected with an RS reset signal, the reset signal is provided when the encoder is started, and each output end of each counter is respectively connected with the corresponding bit input end of the corresponding weight comparator;

taking a 10-system counter as an example, the highest output end in the lower weight bit is connected with the lowest input end in the higher weight bit, namely the highest output end (counter A3) in the bits is connected with the lowest input end (counter B0) in the ten bits, and the highest output end (counter B3) in the ten bits is connected with the lowest input end (counter C0) in the hundred bits, and so on. RS is the total clear reset provided by the encoder when it is turned on.

4. A time selection circuit: a time selection circuit is formed by a plurality of U-shaped jumpers, +5v (high level) or GND (low level) is connected to a corresponding port of the comparator, and a delayed time value is preset.

5. A comparator circuit: the utility model takes 10-system comparator as an example, the output end of low-weight bit is connected with the input end of high-weight bit, namely the output end of bit (comparator A) is connected with the input end of ten bits (comparator B), the output end of ten bits (comparator B) is connected with the input end of hundred bits (comparator C), and so on.

The input end of the comparator circuit is connected with the output end of the counter, and the other input end is selected by the selected time value through jumper connection high and low levels. When the measured delay time of a certain wireless relay station is 1.76mS, the determined count value is also 1.76 (0.01 is used as a bit), and then: c0 on comparator C (equivalent to hundred bits) is connected with +5V; c1, C2, C3 are grounded, and the binary number 0001 is 1 on hundreds of bits of 10. And (3) the same principle: b0, B1, B2 on comparator B (equivalent to ten bits) are +5v; b3 is grounded, and binary number 0111 is 7 with tens of upper bits of 10. A1 and a2 on the comparator a (corresponding to bits) are connected with +5v; a0 and A3 are grounded, and binary number 0110 is 6 on 10 bits, and the total value is 176. Since the timing pulse signal is 0.01mS, 176 is 1.76mS;

6. driver circuit: the system consists of a circuit with driving capability, and outputs an execution signal to a starting control end of the seismic prospecting instrument. The output end of the highest weight bit (comparator N) of the comparator circuit is connected with the input end of the driver circuit Q1, the output end of the driver circuit Q1 is connected with the starting control end of the seismic prospecting instrument, and the seismic prospecting instrument is started to collect seismic data.

The specific implementation method comprises the following steps:

firstly, the connection between a synchronous zero output circuit of an original encoder and a starting control end of a seismic prospecting instrument is disconnected, and the synchronous zero output circuit is reconnected through a linkage switch K1: the left end of the linkage switch K1 is connected with the synchronous zero circuit output end of the encoder, and the right end of the linkage switch K1 is connected with the starting control end of the seismic prospecting instrument.

The delay circuit is added between the synchronous zero output end of the encoder and the starting control end of the seismic prospecting instrument: the left end of the delay circuit is connected with the synchronous zero circuit output end of the encoder through a linkage switch K2, namely: the left end input end of the delay circuit is connected with the right end of the linkage switch K2, and the left end of the linkage switch K2 is connected with the synchronous zero circuit output end of the encoder; the right end of the delay circuit is connected with the starting control end of the seismic prospecting instrument through a linkage switch K3, namely: the right end output end of the delay circuit is connected with the left end of the linkage switch K3, and the right end of the linkage switch K3 is connected with the starting control end of the seismic prospecting instrument.

When K1 is connected, K2 and K3 are disconnected, and the normal working state of receiving and transmitting the same frequency is the working state without using the wireless relay station;

on the contrary, when K1 is turned off, K2 and K3 are turned on, and the receiving and transmitting different frequencies are the working states of the wireless relay station. The linkage switch K is additionally arranged on the operation panel of the encoder box body, and the gear of the linkage switch K is controlled according to whether a wireless relay station is used or not, so that the operation is extremely simple, and the use is very convenient.

Working principle of encoder-end delay circuit

The delay time of any brand and model of wireless relay station is measured (namely, different brands and different models of wireless relay stations are different in difference transfer delay time, but the delay time value is a fixed value, for example, the measured delay time of a certain brand and model of wireless relay station is 1.76 mS), taking 1.76mS as an example, the time value of a delay circuit added by an encoder end is also 1.76mS, and the two delay time values are identical.

The timing pulse of 0.01mS provided by the time reference circuit can be output to the counter circuit and the comparator circuit or when the delay circuit works, and is controlled by the control gate. As shown in the lower left side of fig. 3, the lower input of the and gate Y1 is connected to the output of the timing pulse of the time reference circuit 0.01mS, while the upper input of the and gate Y1 is connected to the output of the state flip-flop. The state trigger is an RS bistable trigger, and one input end below the RS bistable trigger (the input end below a NAND gate YF 2) is connected with the synchronous zero output of the encoder and is controlled by the synchronous zero; the upper input end of the control circuit is connected with RS reset and is controlled by the RS reset.

The timing pulse of 0.01mS provided by the time reference circuit is controlled by a control gate (AND gate Y1), which in turn is controlled by an RS trigger formed by connecting a NAND gate YF1 and a NAND gate YF2, and the state trigger (the lower input end of the NAND gate YF 2) is controlled by the synchronous zero output by the encoder. In other words, the timing pulse signal of 0.01mS provided by the time reference circuit is not outputted when the synchronization zero is not reached, and the timing pulse signal of 0.01mS provided by the time reference circuit is outputted only when the synchronization zero is reached.

In the reset phase of the total clearing RS, the output low level of the state trigger is added to one input end above the AND gate Y1, and the state is in a 0-locking state, and the timing pulse of 0.01mS is not passed. Only when the synchronous zero instruction signal of the encoder is outputted, the synchronous zero instruction signal is added to the lower input end of the state trigger, the state trigger is triggered to turn over, the high level is outputted, the synchronous zero instruction signal is added to the upper input end of the AND gate Y1, the AND gate Y1 is controlled to be in a1 door opening state, and only at the moment, the timing pulse of 0.01mS provided by the time reference circuit can be outputted to the counter circuit and the comparator circuit, namely, only at the moment, the delay circuit starts to perform timing action. In other words, the timing pulse signal of 0.01mS provided by the time reference circuit is controlled by the synchronous zero circuit, the synchronous zero is not reached, and the timing pulse signal of 0.01mS provided by the time reference circuit is not outputted. Only when the synchronization zero is reached, the timing pulse signal of 0.01mS provided by the time reference circuit is output and is input to the counter circuit and the comparator circuit respectively, namely the synchronization zero is the starting point in time.

When the count number of the timing pulse signals of 0.01mS provided by the time reference circuit reaches the count number selected in advance by the time selection circuit, namely when the preselected value is equal to the count value of the timing pulse, the comparator circuit acts to output a signal to the input end of the driver circuit Q1, then the driver circuit Q1 outputs an execution signal, and the synchronous zero after time correction is added to the starting control end of the seismic prospecting instrument, so that the starting instrument starts to collect seismic data.

As described above, if the measured delay time of the wireless relay station is 1.76mS, the determined count value is also 1.76 (0.01 as a bit), and: c0 on comparator C (equivalent to hundred bits) is connected with +5V; c1, C2, C3 are grounded, and the binary number 0001 is 1 on hundreds of bits of 10. And (3) the same principle: b0, B1, B2 on comparator B (equivalent to ten bits) are +5v; b3 is grounded, and binary number 0111 is 7 with tens of upper bits of 10. A1 and a2 on the comparator a (corresponding to bits) are connected with +5v; a0 and A3 are grounded, and binary number 0110 is 6 on 10 bits. From the above, it can be seen that: total value 176. When the number of count pulses on the timer circuit reaches 176, the comparator operates, and since one timer pulse is 0.01mS, the time value at this time is 1.76 and mS. Namely: when the count number of the timing pulses provided to the counter circuit and the comparator circuit by the time reference circuit reaches the count number determined by the time selection circuit, namely the count number is the same, the circuit acts; in contrast, when the count number of the timing pulses supplied to the counter circuit and the comparator circuit by the time reference circuit does not reach the count number determined by the time selection circuit, that is, the count number is different from the count number, the circuit does not operate.

In summary, when the differential delay of the wireless relay station is 1.76 and mS, the synchronization zero time of the decoder is 1.76 and mS later than the original synchronization zero time of the encoder, and the delay is from t0 to t1, so that the delay circuit of 1.76 and mS is added to the encoder, and the delay is also from t0 to t1. The end result is: after the delay time generated by the differential rotation of the wireless relay station is corrected, the synchronous zero point sent by the encoder end and the synchronous zero point detected by the decoder end still keep a precise synchronous relationship at the time t1, so that the starting time of the seismic prospecting instrument for collecting the seismic data and the detonation time of the seismic source are ensured, and the two parties still occur at the same time t1 and still keep precise synchronization. Because the base number of the timing pulse is 0.01mS, the synchronization accuracy of the TB signal specified by the industrial standard of the oil and gas SY/T5314-2004 is improved from +/-1 mS to +/-0.01 mS.

Circuit components and installation instructions:

1. time reference circuit: the high-precision high-stability crystal oscillator can be selected, or GPS and Beidou time base (such as Beidou satellite receiving antenna GNC2A 11) are introduced, and frequency division is performed to obtain the high-precision high-stability crystal oscillator.

2. The device used in the delay circuit:

and (3) a door controller: SN7400; a counter: SN7490 (decimal), or (SN 7493 hexadecimal); a comparator: SN7485; a driver: SN7406; a time selection circuit: and a high-low level circuit, the high level is +5V, the low level is GND ground, and the required time value is selected by the jumper.

3. Installation of a delay circuit: the delay circuit has small volume, light weight and low power consumption, can be made on a small circuit board, is arranged in the encoder box body, and is powered by the related power supply of the encoder. And the delay circuit is arranged between the synchronous zero output end of the encoder and the starting control end of the seismic prospecting instrument through the linkage switch K.

The technical indexes are as follows:

1. synchronization time accuracy: + -0.01 mS.

2. Clock stability: better than 0.1ppm.

3. The application environment is as follows: working environments such as land, hills, mountains, jungles, beach, and the like.

4. Operating temperature: -20 ℃ to 60 ℃.

Actual measurement of the synchronization effect: after the delay generated by the differential work of the wireless relay station is corrected, the synchronous zero point sent by the encoder end and the synchronous zero point detected by the decoder end still keep a precise synchronous relationship in time, and finally, the starting time of the seismic prospecting instrument for collecting the seismic data and the detonation time of the seismic source are ensured to be at the same time t1, and the two sides are precisely synchronous. In actual measurement, as shown in fig. 4, a synchronous zero separation display diagram of the encoder and the decoder is shown; as shown in FIG. 5, in the diagram of the synchronous zero superposition display of the encoder and the decoder, in FIG. 5, the encoder and the decoder are completely consistent and accurately synchronous, the synchronous accuracy is better than 0.01mS, and finally, the starting time of data acquisition of the seismic instrument and the detonation time of the seismic source are ensured, and the two parties still occur at the same time and are accurately synchronous. As can be seen from fig. 5: the synchronous precision of the TB signal not only completely accords with the industrial standard of the oil and gas SY/T5314-2004 of the people's republic of China, but also improves the synchronous precision of the TB signal from +/-1 mS to +/-0.01 mS.

The wireless communication device is one of important devices for the field construction operation of seismic exploration, good wireless communication is a basic premise for ensuring the smoothness of the field construction operation and improving the field construction operation efficiency, and the efficient field construction operation is almost impossible without good communication. Therefore, in the field construction operation of seismic exploration, a wireless communication system is generally used for communication, and the method has the advantages of high cost performance, economy, practicability, flexible operation, convenience and rapidness. However, practice has proven that: in the same frequency receiving and transmitting condition, the communication distance is limited. It is well known that: because the earth surface is an arc-shaped curved surface, the maximum communication distance of the sight distance is about 10 kilometers, and once the earth is influenced by landforms, tree forests, village houses and the like, the actual maximum communication distance is less than 10 kilometers.

After the wireless relay station is erected, the wireless communication coverage area can be greatly increased. By adopting the method, the starting time of data acquisition of the seismic instrument and the detonation time of the seismic source can be ensured, and the two parts are still synchronous at the same time, so that the method not only completely accords with the industrial standard of the oil and gas SY/T5314-2004 of the people's republic of China, but also improves the synchronization accuracy of TB signals from +/-1 mS to +/-0.01 mS. The method completely meets the field construction operation requirements of increasingly-growing seismic exploration on multiple channels, large three dimensions, long survey lines and large areas, greatly improves the field construction operation efficiency of the seismic exploration, greatly shortens the field construction period of the seismic exploration, and greatly reduces the field construction operation cost of the seismic exploration.

The foregoing description of embodiments of the utility model has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described.

Claims (7)

1. The utility model provides an accurate synchronization system of seismic exploration focus synchronizer, the focus synchronizer includes encoder and decoder, encoder and seismic exploration instrument linkage, and place on the instrument car, each earthquake source point is placed in to the decoder, its characterized in that:

the synchronous system is connected in series between the encoder and the seismic prospecting instrument and comprises a delay circuit and a switch circuit; when the seismic prospecting instrument is communicated with each seismic focus point through the wireless relay station, the switch circuit is connected with the delay circuit to the system so as to correct the delay generated by the differential operation of the wireless relay station.

2. The accurate synchronization system of the seismic source synchronizer for the seismic exploration according to claim 1, wherein the switch circuit comprises linkage switches K1, K2 and K3, one end of the linkage switch K1 is connected with a synchronous zero output end of the encoder and one end of the linkage switch K2, the other end of the linkage switch K1 is connected with a control end of the seismic exploration instrument and one end of the linkage switch K3, and the other ends of the linkage switches K2 and K3 are respectively connected with two ends of the delay circuit;

when the linkage switch K1 is switched on, the linkage switches K2 and K3 are switched off, and at the moment, the seismic prospecting instrument receives and transmits the same frequency with each seismic focus, and the seismic prospecting instrument is in a normal working state, namely a wireless relay station is not used;

when the linkage switch K1 is turned off, the linkage switches K2 and K3 are turned on, at the moment, the earthquake prospecting instrument receives and transmits different frequencies from each earthquake focus, and the earthquake prospecting instrument is in a working state of starting the wireless relay station and is connected with the delay circuit.

3. The seismic source synchronizer precision synchronization system of claim 1, wherein the delay circuit comprises:

a time reference circuit for providing a pulse timing signal as a time reference, the output of the time reference circuit being connected to the input of the control gate circuit;

the control gate circuit comprises a state trigger and a control gate, namely an AND gate Y1, wherein the synchronous zero output end of the encoder is connected with the lower input end of the state trigger, the upper input end of the state trigger is connected with an RS reset signal, the output end of the state trigger is connected with the upper input end of the control gate, the lower input end of the control gate is connected with the output of the time reference circuit, and the output end of the control gate is connected with the lowest bit of the counter circuit and the lowest bit input end of the comparator circuit simultaneously in parallel to control the output of the timing pulse signal;

the counter circuit is composed of a plurality of counters and is arranged from the lowest position to the highest position; the highest output end of the low-weight bit is connected with the lowest input end of the high-weight bit, namely the highest output end of the lowest-weight counter is connected with the lowest input end of the next low-weight counter, the highest output end of the next low-weight counter is connected with the lowest input end of the next low-weight counter, and the like, the next low-weight counter is connected with the highest-weight counter, each counter is respectively connected with an RS reset signal, the reset signal is provided when the encoder is started, and each output end of each counter is respectively connected with the corresponding bit input end of the corresponding weight comparator;

the time selection circuit consists of a plurality of jumpers, connects a +5v high level or GND low level to a corresponding port of the comparator, and presets a delayed time value;

the comparator circuit is composed of a plurality of comparators and is arranged from the lowest bit to the highest bit; the output end of the comparator with low weight is connected with the input end of the comparator with high weight, and the output end of the highest-order comparator is connected with the input end of the driver circuit;

and the driver circuit is used for outputting an execution signal to a starting control end of the seismic prospecting instrument.

4. The accurate synchronization system of the seismic source synchronizer for seismic exploration according to claim 3, wherein the time reference circuit is a crystal oscillator; or GPS and Beidou are adopted, and the GPS and the Beidou are used as time references through a frequency divider.

5. The accurate synchronization system of a seismic source synchronizer of claim 3 wherein the time reference circuit is configured to provide a pulse timing signal of 0.01ms as a time reference.

6. The accurate synchronization system of the seismic source synchronizer for seismic exploration according to claim 3, wherein the state trigger adopts an RS trigger for representing the state of synchronous zero output of the encoder; the output end of the NAND gate YF1 is connected with the upper input end of the NAND gate YF2, the output end of the NAND gate YF2 is connected with the lower input end of the NAND gate YF1, the output end of the NAND gate YF2 is simultaneously connected with the upper input end of the AND gate Y1, the lower input end of the NAND gate YF2 is used as the input end of the state trigger to be connected with the synchronous zero output end of the encoder, the upper input end of the NAND gate YF1 is used as the other input end of the state trigger to be connected with the RS reset signal, and the output end of the NAND gate YF2 is used as the output end of the state trigger to be connected with the upper input end of the control gate, namely the AND gate Y1.

7. The accurate synchronization system of the seismic source synchronizer for seismic exploration according to claim 3, wherein the counter is a 10-system counter or a 16-system counter; accordingly, the comparator employs a comparator consistent with a counter system.