Multi-channel induced polarization system for geological exploration

Abstract

The invention relates to the technical field of induced polarization detection, and discloses a multi-channel induced polarization system for geological exploration, which comprises a multi-channel acquisition module and an intelligent detection module. According to the multichannel induced polarization system for geological exploration, power supply data and current data at all time points are acquired through the multichannel acquisition module and are classified to form a data set, the intelligent detection module analyzes apparent resistivity and polarizability between an electric field and current, conductivity and charge accumulation capability of an underground medium are visually reflected, and the accuracy and the reliability of the system are improved. A monitoring period with a fixed time length is set, the change trend of apparent resistivity and polarizability is analyzed, a fluctuation index and a stability coefficient are generated, the electrical fluctuation degree and stability of the underground rock stratum are quantitatively evaluated, the multi-channel parallel detection precision is high, the intelligent detection module sets a resistance threshold value, a polarization threshold value, a fluctuation threshold value and a stability threshold value in a fixed range, and the detection accuracy is high. The method is used for judging the water saturation, mineralization components and heterogeneity of underground rock strata and outputting corresponding judgment results, and intelligent evaluation and exploration efficiency is high.

Description

Technical Field

[0001] The invention relates to the technical field of induced polarization detection, in particular to a multi-channel induced polarization system for geological exploration. Background Art

[0002] The multi-channel IP system in geological exploration is a common technology used to detect the structure, distribution, aquifers and other geological features of underground materials. The multi-channel IP system emits current or electromagnetic waves of a certain frequency and intensity to stimulate the underground medium to respond. Multiple receiving electrodes on the ground or underground simultaneously receive the electric field or current changes, record the electromagnetic response of the underground medium, and invert the resistivity, conductivity distribution and other geological parameters of the underground medium by measuring the electromagnetic wave response at different frequencies and time points, and combining the multi-channel received information. The multi-channel IP system has multiple probes working simultaneously, which can provide high-resolution data at multiple depths and directions, obtain more details, and help generate more accurate underground geological maps. The application scenarios of the multi-channel IP system include hydrogeological exploration, mineral exploration, engineering exploration and environmental geological surveys. When applied to hydrogeological exploration, it can be used to find groundwater layers and analyze the hydrological characteristics of aquifers. When applied to mineral exploration, it can discover mineral deposits and determine the distribution and depth of ore bodies. When applied to engineering exploration, it can assist in analyzing underground soil layers and determining the information required for building foundation design. When applied to environmental geological surveys, it can monitor soil pollution, groundwater pollution and other issues. The multi-channel IP system can not only provide higher exploration efficiency, accuracy, spatial resolution and adaptability, but also adapt to a variety of complex and changing geological environments.

[0003] At present, the traditional multi-channel IP system used in geological exploration has low sensitivity in areas with complex geological bodies or significant heterogeneity, and lacks the ability to analyze long-term data, making it difficult to ensure the reliability of detection results. It is usually necessary to rely on human judgment to evaluate the accuracy of the results, which makes it difficult to plan exploration work and thus affects exploration efficiency. Summary of the invention

[0004] In view of the shortcomings of the existing technology, the present invention provides a multi-channel induced polarization system for geological exploration, which has the advantages of high multi-channel parallel detection accuracy and high intelligent evaluation exploration efficiency. It solves the problem that traditional multi-channel induced polarization systems used for geological exploration lack the ability to analyze long-term data and make exploration work planning difficult.

[0005] To achieve the above object, the present invention provides the following technical solutions: a multi-channel induced polarization system for geological exploration, comprising a multi-channel acquisition module and an intelligent detection module; The multi-channel acquisition module is composed of a transmission data unit and a receiving data unit. The transmission data unit is connected to a transmitter through a network to collect a transmission data set. The transmitter is used to cyclically provide a bidirectional pulse current. The transmission data set includes power supply data at all time points. The receiving data unit is connected to a receiver through a network to collect a receiving data set. The receiver is used to measure the change of current data. The receiving data set includes current data at all time points. The intelligent detection module is composed of a current analysis unit, a trend analysis unit and a detection management unit. The current analysis unit analyzes the apparent resistivity between the electric field and the current according to the transmitted data set and the received data set. and polarizability The trend analysis unit is provided with a monitoring cycle of fixed duration. , analyze the apparent resistivity and polarizability The changing trend of and stability factor , the detection management unit sets a fixed range of resistance thresholds , polarization threshold , Fluctuation threshold and stability threshold , combined with the apparent resistivity , polarizability , Volatility Index and stability factor , determine the water saturation, mineralization composition and heterogeneity of the underground rock formation, and output the corresponding judgment results.

[0006] Preferably, the expression of the emission data set is , to They are the first to the second transmitters respectively. The power supply data of each channel includes the transmitting electrode number and the transmitting current intensity. Indicates the specific time point for obtaining the power supply data of each channel.

[0007] Preferably, the expression of the received data set is , to They are the first to the second receivers respectively. The current data received by each channel includes the measurement electrode number and secondary field potential. Indicates the specific time point for obtaining the receiving current data of each channel.

[0008] Preferably, the apparent resistivity The calculation process is as follows: According to the launch data set, The transmitting electrode pieces of each channel are numbered as , , will The transmitting electrodes of each channel are numbered as , , where the transmitter consists of a transmitting electrode sheet and emitter electrode The combination provides bidirectional pulse current; According to the received data set, The measurement electrodes of each channel are numbered as , , will The electrode number of each channel is marked as , , where the receiver consists of measuring electrodes and measuring electrodes Combination measurement of current data changes; ; ; In the formula, Indicates the emitter electrode and measuring electrodes The distance between Indicates the emitter electrode and measuring electrodes The distance between Indicates the emitter electrode and measuring electrodes The distance between Indicates the emitter electrode and measuring electrodes The distance between represents the device constant, represents the emission current, Indicates measuring electrode sheet and measuring electrodes The potential difference between them.

[0009] Preferably, the polarizability The calculation process is as follows: ; In the formula, Indicates the duration of the transmitter transmitting current, It indicates the time for the receiver to measure the secondary field potential after the transmitter stops supplying power. Indicates that after the transmitter stops supplying power, The secondary field potential difference at time , express The total field potential difference at time.

[0010] Preferably, the volatility index The calculation process is as follows: Statistical monitoring cycle The apparent resistivity at all time points , and marked as , to From the first time point to the Apparent resistivity at time point ; ; ; In the formula, Indicates monitoring cycle Internal, apparent resistivity The average value of Indicates Apparent resistivity at time point , Indicates that according to the standard deviation formula, the monitoring period is obtained Internal, apparent resistivity Volatility index.

[0011] Preferably, the stability coefficient The calculation process is as follows: Statistical monitoring cycle The polarizability at all time points , and marked as , to From the first time point to the The polarizability at each time point ; ; ; In the formula, Indicates monitoring cycle Internal polarizability The average value of Indicates The polarizability at each time point , Indicates that according to the standard deviation formula, the monitoring period is obtained Internal polarizability The stability coefficient.

[0012] Preferably, the apparent resistivity Below resistance threshold When , it indicates that the underground rock formation has high water saturation and high conductivity. Resistance threshold exceeded When , it indicates that the water saturation of the underground rock formation is low and the electrical conductivity is low.

[0013] Preferably, the polarizability Below the polarization threshold When the underground rock formation has low mineralization content and low conductivity, the polarizability Exceeding the polarization threshold When , it means that the underground rock formation has high mineralization content and high electrical conductivity.

[0014] Preferably, the volatility index Exceeding the volatility threshold or stability factor Below the stability threshold When , it indicates that the underground rock formation is highly heterogeneous and the measurement accuracy is low.

[0015] Compared with the prior art, the present invention provides a multi-channel IP system for geological exploration, which has the following beneficial effects: 1. The present invention connects the transmitter and the receiver through a multi-channel acquisition module network to obtain the power supply data and current data at all time points, and classifies them into a transmission data set and a reception data set. The intelligent detection module analyzes the apparent resistivity between the electric field and the current based on the transmission data set and the reception data set. and polarizability , intuitively reflects the conductivity and charge accumulation capacity of the underground medium, and then sets a fixed-time monitoring cycle , analyze the apparent resistivity and polarizability The changing trend of and stability factor , quantitatively evaluate the degree of electrical fluctuation and stability of underground rock formations. Areas with larger fluctuations may have stronger heterogeneity, and stable areas usually mean that the rock structure is uniform, which helps to understand the long-term electrical change trend of the underground. Multi-channel parallel detection has high accuracy.

[0016] 2. The present invention sets a fixed range of resistance thresholds through an intelligent detection module , polarization threshold , Fluctuation threshold and stability threshold , used to determine the water saturation, mineralization composition and heterogeneity of underground rock formations, apparent resistivity Below resistance threshold When , it indicates that the underground rock has high water saturation, high conductivity, and apparent resistivity Resistance threshold exceeded When , it means that the underground rock formation has low water saturation and low conductivity, which is very important for water resource exploration or environmental engineering. Below the polarization threshold When the underground rock formation has low mineralization content, low conductivity, and low polarizability Exceeding the polarization threshold When the index is high, it means that the underground rock formation has high mineralization content and high conductivity, which helps to identify mineralized layers or other valuable mineral resources. Exceeding the volatility threshold or stability factor Below the stability threshold When the underground rock layer is highly heterogeneous, the measurement accuracy is low, which helps geological prospectors make more accurate exploration decisions and intelligently evaluates the exploration efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the system flow of the present invention. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Because the traditional multi-channel IP system used for geological exploration has low sensitivity in areas with complex geological bodies or significant heterogeneity, and lacks the ability to analyze long-term data, it is difficult to ensure the reliability of the detection results. It usually needs to rely on human judgment to evaluate the accuracy of the results, which makes it difficult to plan the exploration work and thus affects the exploration efficiency. Therefore, a multi-channel IP system for geological exploration is provided. Please refer to Figure 1 , a multi-channel IP system for geological exploration, including a multi-channel acquisition module and an intelligent detection module. The DC IP instrument used in the system consists of a transmitter and a receiver, specifically a WDFZ-5T (WDFZ-10T) high-power intelligent transmitter and a WDJS-3 series digital DC IP receiver; DC IP instruments support software synchronization, quartz clock synchronization and optional GPS synchronization. Software synchronization is a traditional synchronization method, which enables WDJS-3 series instruments to work well with traditional time domain induced polarization measurement system transmitters. Quartz clock synchronization and GPS synchronization have fast measurement speeds and are particularly suitable for working in areas where conventional synchronization methods are difficult to work in, such as weak signals or strong interference. The DC IP instrument has a large-capacity data storage device of ≥1GB, which can store more than 100,000 sets of measurement values ​​without losing them even when the power is off. In addition, this series of instruments supports exporting stored data through the USB interface. After connecting to the computer with a dedicated communication line, the instrument will be automatically recognized by the computer as a general USB flash drive storage device. The operations of copying and cutting data files are exactly the same as those of ordinary USB flash drives, which is extremely convenient to use. Specifically, the power supply cycle of the DC induced polarization instrument, that is, the duration of a one-time "positive power supply-power off-negative power supply-power off", the interval at which the transmitter stores current data is a full cycle; The main technical indicators of the transmitter (WDFZ-5T—single channel) are as follows: Number of power supply output electrodes: 2; Maximum transmit power: 7200W; Maximum transmission voltage: ±1200V; Maximum emission current: 6A; Current measurement accuracy: ±0.2%±1 word; Power supply (transmission) cycle: 4s, 8s, 16s, 32s, 64s, 128s, 256s; Output waveform: positive power supply, power off, negative power supply, power off, bipolar equal width symmetrical waveform, duty cycle 1:1; Current storage time interval: 1 power supply cycle; Large-capacity data storage: can store no less than 1,000,000 sets of current data (including the year, month, day, hour, minute and other data of the measurement time), with power-off protection function; Communication interface: USB serial interface; Large screen display: 160×160 dot matrix graphic LCD; Instrument working power supply: 12V9Ah rechargeable lithium battery; DC high voltage input: 1200VDC (maximum input voltage), 6ADC (maximum current); Working temperature: -10℃~50℃; Storage temperature: -20℃~60℃; Please refer to Table 1 for the main technical specifications of the receiver;

[0020] Table 1 Main technical indicators of the receiver The multi-channel acquisition module consists of a transmission data unit and a receiving data unit. The transmission data unit connects to the transmitter through the network to collect the transmission data set. The transmitter is used to cyclically provide bidirectional pulse current. Specifically, the multi-channel transmitter can be configured according to actual needs to achieve simultaneous access to multiple power supply electrodes. When working, any one group of AB electrodes can be selected for power supply. The transmission data set includes the power supply data at all time points. The expression of the transmission data set is , to They are the first to the second transmitters respectively. The power supply data of each channel includes the transmitting electrode number and the transmitting current intensity. Indicates the specific time point for obtaining the power supply data of each channel. Multi-channel parallel acquisition can improve data acquisition efficiency and is suitable for large-scale exploration; The receiving data unit collects the receiving data set through the network connection receiver. The receiver is used to measure the change of current data. Specifically, for a receiver with 20 channels, the maximum number of time-sharing working channels of the instrument is 20 channels, and it supports up to 21 electrodes to be connected at the same time. It can automatically measure twice (odd channel measurement and even channel measurement) and output the measurement results of 20 electrode pairs. The channels are completely isolated from each other and do not interfere with each other. The receiving data set includes the current data at all time points. The expression of the receiving data set is , to They are the first to the second receivers respectively. The current data received by each channel includes the measurement electrode number and secondary field potential. Indicates the specific time point at which each channel receives the current data, providing reliable data support for the accurate assessment of underground electrical characteristics; The intelligent detection module consists of a current analysis unit, a trend analysis unit and a detection management unit. The current analysis unit analyzes the apparent resistivity between the electric field and the current based on the transmitted data set and the received data set. and polarizability ; Apparent resistivity The calculation process is as follows: According to the launch data set, The transmitting electrode pieces of each channel are numbered as , , will The transmitting electrodes of each channel are numbered as , , where the transmitter consists of a transmitting electrode sheet and emitter electrode The combination provides bidirectional pulse current; According to the received data set, The measurement electrodes of each channel are numbered as , , will The electrode number of each channel is marked as , , where the receiver consists of measuring electrodes and measuring electrodes Combination measurement of current data changes; ; ; In the formula, Indicates the emitter electrode and measuring electrodes The distance between Indicates the emitter electrode and measuring electrodes The distance between Indicates the emitter electrode and measuring electrodes The distance between Indicates the emitter electrode and measuring electrodes The distance between represents the device constant, represents the emission current, Indicates measuring electrode sheet and measuring electrodes The potential difference between them directly reflects the conductivity of the underground medium; Polarizability The calculation process is as follows: ; In the formula, Indicates the duration of the transmitter transmitting current, It indicates the time for the receiver to measure the secondary field potential after the transmitter stops supplying power. Indicates that after the transmitter stops supplying power, The secondary field potential difference at time , express The total field potential difference at the moment directly reflects the charge accumulation capacity of the underground medium; The trend analysis unit is set with a fixed-length monitoring cycle , analyze the apparent resistivity and polarizability The changing trend of and stability factor ; Volatility Index The calculation process is as follows: Statistical monitoring cycle The apparent resistivity at all time points , and marked as , to From the first time point to the Apparent resistivity at time point ; ; ; In the formula, Indicates monitoring cycle Internal, apparent resistivity The average value of Indicates Apparent resistivity at time point , Indicates that according to the standard deviation formula, the monitoring period is obtained Internal, apparent resistivity The fluctuation index is used to quantitatively evaluate the degree of electrical fluctuation of underground rock formations. Areas with larger fluctuations may have stronger heterogeneity. Stability factor The calculation process is as follows: Statistical monitoring cycle The polarizability at all time points , and marked as , to From the first time point to the The polarizability at each time point ; ; ; In the formula, Indicates monitoring cycle Internal polarizability The average value of Indicates The polarizability at each time point , Indicates that according to the standard deviation formula, the monitoring period is obtained Internal polarizability The stability coefficient can quantitatively evaluate the stability of underground rock formations. Stable areas usually mean uniform rock structures, which helps to understand the long-term electrical change trends of the underground. Multi-channel parallel detection has high accuracy. Probe Management Unit sets fixed range resistance thresholds , polarization threshold , Fluctuation threshold and stability threshold , combined with the apparent resistivity , polarizability , Volatility Index and stability factor , determine the water saturation, mineralization composition and heterogeneity of underground rock formations, apparent resistivity Below resistance threshold When , it indicates that the underground rock has high water saturation, high conductivity, and apparent resistivity Resistance threshold exceeded When , it means that the underground rock formation has low water saturation and low conductivity, which is very important for water resource exploration or environmental engineering. Below the polarization threshold When the underground rock formation has low mineralization content, low conductivity, and low polarizability Exceeding the polarization threshold When the index is high, it means that the underground rock formation has high mineralization content and high conductivity, which helps to identify mineralized layers or other valuable mineral resources. Exceeding the volatility threshold or stability factor Below the stability threshold When the underground rock layer is highly heterogeneous, the measurement accuracy is low, which helps geological prospectors make more accurate exploration decisions and intelligently evaluates the exploration efficiency.

[0021] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-channel IP system for geological exploration, characterized in that: Including multi-channel acquisition module and intelligent detection module; The multi-channel acquisition module is composed of a transmission data unit and a receiving data unit. The transmission data unit is connected to a transmitter through a network to collect a transmission data set. The transmitter is used to cyclically provide a bidirectional pulse current. The transmission data set includes power supply data at all time points. The receiving data unit is connected to a receiver through a network to collect a receiving data set. The receiver is used to measure the change of current data. The receiving data set includes current data at all time points. The intelligent detection module is composed of a current analysis unit, a trend analysis unit and a detection management unit. The current analysis unit analyzes the apparent resistivity between the electric field and the current according to the transmitted data set and the received data set. and polarizability The trend analysis unit is provided with a monitoring cycle of fixed duration. , analyze the apparent resistivity and polarizability The changing trend of and stability factor , the detection management unit sets a fixed range of resistance thresholds , polarization threshold , Fluctuation Threshold and stability threshold , combined with the apparent resistivity , polarizability , Volatility Index and stability factor , determine the water saturation, mineralization composition and heterogeneity of the underground rock formation, and output the corresponding judgment results.

2. A multi-channel IP system for geological exploration according to claim 1, characterized in that: The expression of the emission data set is , to They are the first to the second transmitters respectively. The power supply data of each channel includes the transmitting electrode number and the transmitting current intensity. Indicates the specific time point for obtaining the power supply data of each channel.

3. A multi-channel IP system for geological exploration according to claim 2, characterized in that: The expression of the received data set is: , to They are the first to the second receivers respectively. The current data received by each channel includes the measurement electrode number and secondary field potential. Indicates the specific time point for obtaining the receiving current data of each channel.

4. A multi-channel IP system for geological exploration according to claim 3, characterized in that: The apparent resistivity The calculation process is as follows: According to the launch data set, The transmitting electrode pieces of each channel are numbered as , , will The transmitting electrodes of each channel are numbered as , , where the transmitter consists of a transmitting electrode sheet and emitter electrode The combination provides bidirectional pulse current; According to the received data set, The measurement electrodes of each channel are numbered as , , will The electrode number of each channel is marked as , , where the receiver consists of measuring electrodes and measuring electrodes Combination measurement of current data changes; ； ； In the formula, Indicates the emitter electrode and measuring electrodes The distance between Indicates the emitter electrode and measuring electrodes The distance between Indicates the emitter electrode and measuring electrodes The distance between Indicates the emitter electrode and measuring electrodes The distance between represents the device constant, represents the emission current, Indicates measuring electrode sheet and measuring electrodes The potential difference between.

5. A multi-channel IP system for geological exploration according to claim 4, characterized in that: The polarizability The calculation process is as follows: ； In the formula, Indicates the duration of the transmitter transmitting current, It indicates the time for the receiver to measure the secondary field potential after the transmitter stops supplying power. Indicates that after the transmitter stops supplying power, The secondary field potential difference at time , express The total field potential difference at time.

6. A multi-channel IP system for geological exploration according to claim 5, characterized in that: The volatility index The calculation process is as follows: Statistical monitoring cycle The apparent resistivity at all time points , and marked as , to From the first time point to the Apparent resistivity at time point ; ； ； In the formula, Indicates monitoring cycle Internal, apparent resistivity The average value of Indicates Apparent resistivity at time point , Indicates that according to the standard deviation formula, the monitoring period is obtained Internal, apparent resistivity Volatility index.

7. A multi-channel IP system for geological exploration according to claim 6, characterized in that: The stability factor The calculation process is as follows: Statistical monitoring cycle The polarizability at all time points , and marked as , to From the first time point to the The polarizability at each time point ; ； ； In the formula, Indicates monitoring cycle Internal polarizability The average value of Indicates The polarizability at each time point , Indicates that according to the standard deviation formula, the monitoring period is obtained Internal polarizability The stability coefficient.

8. A multi-channel IP system for geological exploration according to claim 7, characterized in that: The apparent resistivity Below resistance threshold When , it indicates that the underground rock formation has high water saturation and high conductivity. Resistance threshold exceeded When , it indicates that the water saturation of the underground rock formation is low and the electrical conductivity is low.

9. A multi-channel IP system for geological exploration according to claim 8, characterized in that: The polarizability Below the polarization threshold When the underground rock formation has low mineralization content and low conductivity, the polarizability Exceeding the polarization threshold When , it means that the underground rock formation has high mineralization content and high electrical conductivity.

10. A multi-channel IP system for geological exploration according to claim 9, characterized in that: The volatility index Exceeding the volatility threshold or stability factor Below the stability threshold When , it indicates that the underground rock formation is highly heterogeneous and the measurement accuracy is low.

Images