Geological exploration method and device

Abstract

The present application relates to the technical field of geophysical exploration. A geological exploration method and device are provided. The method comprises the following steps: arranging a transmitter in an exploration area; determining the number M of all single frequencies and the frequency values of all single frequencies sent by the transmitter; encoding the frequency values of all single frequencies in the first channel of the transmitter according to a first preset rule to obtain an encoded first channel; encoding the remaining channels according to a second preset rule according to the encoded first channel to obtain encoded remaining channels; simultaneously supplying power to all encoded channels of the transmitter and recording the information of each single frequency of each channel; collecting the information of each measuring point by a receiver; the receiver and the transmitter are time-synchronized; and analyzing and interpreting the geology according to the information of all single frequencies of the transmitter and the information corresponding to each measuring point collected by the receiver. The method provided by the present application improves the exploration accuracy and efficiency.

Description

Technical Field

[0001] This invention relates to the field of geophysical exploration technology, specifically to a geological exploration method and apparatus. Background Technology

[0002] With the continuous growth of geological exploration demand and the development of technology, electrical exploration, as an important component of geophysical exploration methods, plays a key role in resource exploration, environmental monitoring, engineering geological surveys and other fields.

[0003] Among existing electrical exploration techniques, there is a survey method that uses single-frequency signal frequency division multiplexing. This method transmits single-frequency current signals of different frequencies on each channel through a transmitter, enabling simultaneous exploration of multiple channels, which effectively improves exploration efficiency and reduces exploration costs.

[0004] However, although this method is highly efficient, it is lacking in information and accuracy for refined electrical exploration. Therefore, it is urgent to develop new exploration technologies to significantly improve exploration results. Summary of the Invention

[0005] This invention provides a geological exploration method and apparatus to address the shortcomings of low accuracy in frequency division electrical method exploration using single-frequency signals in the prior art.

[0006] This invention provides a geological exploration method, comprising:

[0007] A transmitter is deployed in the exploration area to send frequency-converted signals to a receiver; the transmitter has N channels, where N > 1;

[0008] Determine the number M of all individual frequencies transmitted by the transmitter and the frequency value of all individual frequencies; M ≥ N;

[0009] The frequency values ​​of all single frequencies in the first channel of the transmitter are encoded according to the first preset rule to obtain the encoded first channel;

[0010] Based on the encoded first channel, the remaining channels of the transmitter are encoded according to the second preset rule to obtain the encoded remaining channels;

[0011] Power is supplied to all encoded channels of the transmitter simultaneously, and information about each single frequency of each channel is recorded;

[0012] The receiver collects measurement point information for each measurement point; the receiver is synchronized with the transmitter in time.

[0013] Based on the information from all single-frequency transmitters and the information from each measuring point collected by the receiver, the geology is analyzed and interpreted.

[0014] According to a geological exploration method provided by the present invention, the step of encoding all single-frequency values ​​in the first channel of the transmitter according to a first preset rule to obtain the encoded first channel includes:

[0015] The frequency values ​​of all single-frequency signals in the first channel Sort the frequencies in ascending order to obtain an ascending single-frequency sequence; then sort the ascending single-frequency sequence in descending order to obtain a descending single-frequency sequence; where i∈[1,M];

[0016] The ascending single-frequency sequence is concatenated with the descending single-frequency sequence to obtain the concatenated frequency sequence.

[0017] Based on the splicing frequency sequence, the first channel after encoding is determined.

[0018] According to a geological exploration method provided by the present invention, the step of encoding the remaining channels of the transmitter according to a second preset rule based on the encoded first channel to obtain the encoded remaining channels includes:

[0019] The remaining channels are encoded by advancing the splicing frequency sequence of the current channel by two frequencies relative to the splicing frequency sequence of the previous channel.

[0020] According to a geological exploration method provided by the present invention, the step of simultaneously powering all coded channels of the transmitter and recording information of each single frequency of each channel includes:

[0021] All encoded channels of the transmitter are powered simultaneously, with each channel repeatedly transmitting using its own spliced ​​frequency sequence; the transmission time for each single frequency is [duration missing]. ,and It is an integer not less than 1; The unit is seconds. The unit is Hertz;

[0022] Record the current value for each single frequency in all channels. ;in, Where p is the single-frequency value, p is the power supply point number corresponding to each channel, and q is the number corresponding to each measurement point.

[0023] According to a geological exploration method provided by the present invention, the measuring point information includes: device coefficients. and potential difference ;

[0024] The potential difference at each measuring point is collected by a receiver. include:

[0025] Record the start and end times of each single frequency in all channels of the transmitter, and synchronously record the start and end times of each single frequency received by each channel of the receiver;

[0026] By comparing the start and end times of each single frequency of the transmitter with the start and end times of each single frequency of the receiver, the signal source of each single frequency of the receiver can be determined.

[0027] Based on the signal source of each single frequency of the receiver, the potential difference at each measuring point is determined respectively. ,in For a single frequency, p is the power supply point number corresponding to each channel, and q is the number corresponding to each measurement point;

[0028] The device coefficients at each measuring point are collected by a receiver. include:

[0029] Obtain the coordinates of the power supply point corresponding to each channel of the transmitter, and the coordinates of the measuring electrode corresponding to each measuring point of the receiver;

[0030] Based on the coordinates of the power supply point and the coordinates of the measuring electrode, determine the device coefficient for the corresponding measuring point. ;

[0031] Where p is the power supply point number corresponding to each channel, and q is the number corresponding to each measurement point.

[0032] According to a geological exploration method provided by the present invention, the step of analyzing and interpreting geology based on information from all single-frequency transmitters and measurement point information corresponding to each measurement point includes:

[0033] According to the device coefficient Potential difference Current value Determine the apparent resistivity corresponding to different channels at each measuring point. ;

[0034]

[0035] Where i is the number of the single frequency. For single frequency, [1,M]; p is the power supply point number corresponding to each channel, and q is the number corresponding to each measurement point;

[0036] According to the potential difference Current value Determine the apparent frequency induced polarization parameters at each measuring point. ;

[0037]

[0038] Where i and r are the numbers of the single frequency. It is a single frequency; 1,M], 1,M], and p is the power supply point number corresponding to each channel, and q is the number corresponding to each measurement point.

[0039] Based on the apparent resistivity of each measuring point and amplitude-frequency induced polarization parameters To analyze and interpret geology.

[0040] According to a geological exploration method provided by the present invention, the frequency ratio between the single-frequency signals transmitted by each channel of the transmitter is a number greater than 1.

[0041] According to a geological exploration method provided by the present invention, the time synchronization error between the transmitter and the receiver does not exceed 100 nanoseconds; the dead time period is greater than or equal to 0.

[0042] According to a geological exploration method provided by the present invention, a dead time period is set between two adjacent frequencies transmitted by each channel; the dead time period is not less than half a cycle of the larger frequency signal among the two adjacent single-frequency signals.

[0043] The present invention also provides a geological analysis apparatus, comprising:

[0044] A deployment unit is used to deploy transmitters in the exploration area to send frequency-converted signals to receivers; the transmitters have N channels, where N > 1;

[0045] The determining unit is used to determine the number M of all single frequencies transmitted by the transmitter and the frequency value of all single frequencies; M ≥ N;

[0046] The encoding unit is used to encode the frequency values ​​of all single frequencies in the first channel of the transmitter according to the first preset rule to obtain the encoded first channel;

[0047] The encoding unit is further configured to encode the remaining channels of the transmitter according to the second preset rule based on the encoded first channel, so as to obtain the encoded remaining channels.

[0048] The power supply unit is used to simultaneously supply power to all encoded channels of the transmitter;

[0049] The recording unit is used to synchronously record information of each single frequency of each channel while power is supplied; wherein, a dead time period is set between two adjacent frequencies transmitted by each channel;

[0050] The recording unit is also used to collect measurement point information for each measurement point through a receiver; the receiver is synchronized with the transmitter in time.

[0051] The analysis unit is used to analyze and interpret the geology based on information from all single-frequency transmitters and the measurement point information corresponding to each measurement point.

[0052] The geological exploration method and apparatus provided by this invention, by employing multiple channels (N>1) to simultaneously transmit frequency conversion signals to the receiver, achieves the purpose of simultaneously acquiring geological information from multiple directions or locations, thereby improving the accuracy of geological analysis.

[0053] Moreover, this invention achieves relatively stable operation of the multi-channel frequency division electrical method transmission system, reduces sudden changes in power and current of the transmission system, lowers the hardware requirements and safety hazards of the multi-channel frequency division electrical method transmission system, reduces the weight of the multi-channel frequency division electrical method transmission system, and enhances the convenience of the multi-channel frequency division electrical method transmission system, thereby improving the exploration effect and efficiency of frequency division electrical method. Attached Figure Description

[0054] Figure 1 A flowchart of the geological exploration method provided by this invention;

[0055] Figure 2 Schematic diagram of power supply point setting in an embodiment of the present invention;

[0056] Figure 3(a) is a schematic diagram of the frequency setting of the first channel in an embodiment of the present invention;

[0057] Figure 3(b) is a schematic diagram of the second channel frequency setting according to an embodiment of the present invention;

[0058] Figure 3(c) is a schematic diagram of the frequency setting of the third channel in an embodiment of the present invention;

[0059] Figure 4 This is a structural block diagram of the geological exploration device provided by the present invention. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0061] With the continuous advancement of technology, electrical resistivity tomography (EDT), as an important branch of geophysical exploration, has seen its applications become increasingly widespread, covering multiple fields such as mineral resource exploration, groundwater resource investigation, and engineering geological survey. While pursuing higher exploration results, improving exploration efficiency has become an urgent need for the industry's development. However, current EDT technology faces bottlenecks in efficiency improvement, especially when dealing with complex geological conditions or large-scale exploration tasks, where traditional methods struggle to meet the requirements of high efficiency and accuracy. Among existing EDT technologies, single-frequency signal frequency division multiplexing (FDM) has been applied due to its unique advantages. This method transmits single-frequency current signals of different frequencies on each channel via a transmitter, enabling simultaneous multi-channel exploration, thereby improving exploration efficiency and reducing costs. Compared to conventional EDT, single-frequency signal FDM shows significant advantages in rapidly covering large areas and providing preliminary understanding of geological structures. However, single-frequency signal FDM also has significant limitations: because the transmitted current signal is single-frequency, the acquired geoelectric information is relatively limited, making it difficult to accurately reflect the complexity and details of underground geological structures. This makes the current method inadequate for refined electrical resistivity tomography (EDT) exploration, failing to meet the demand for high-precision analysis of geological structures. Specifically, single-frequency signals are susceptible to factors such as geological body heterogeneity and noise interference, resulting in insufficient accuracy of exploration results and difficulty in accurately identifying key information such as geological structures and mineral resource distribution. To address this challenge, this application employs a multi-channel frequency division multiplexing (FDM) EDT using variable-frequency signals with special coding technology to survey geological structures, achieving simultaneous multi-channel exploration while improving the richness and accuracy of exploration information.

[0062] The geological exploration method provided by this invention is described below:

[0063] Figure 1 A flowchart of the geological exploration method provided by this invention, such as Figure 1 As shown, the method includes the following steps:

[0064] Step 101: Deploy transmitters in the exploration area to send frequency-converted signals to receivers; the transmitters have N channels, where N > 1.

[0065] Specifically, within the selected geological exploration area, transmitters are placed in suitable locations according to certain rules and layout requirements. As a signal source, the transmitter generates frequency-converted signals, which are then transmitted to the receiver. The transmitter has multiple channels (N, where N is greater than 1), each capable of transmitting signals independently. This multi-channel design improves exploration efficiency and coverage, allowing for the simultaneous acquisition of geological information from multiple directions or locations.

[0066] The power supply points connected to each channel of the transmitter are located at different positions. In this application, the power supply points include: mobile power supply points and infinity power supply points. Among them, a mobile power supply point refers to a power supply point that is close to the measuring point and can generate a significant potential difference signal at the measuring point; while an infinity power supply point refers to a power supply point that is far from the measuring point and the potential difference signal generated at the measuring point is negligible.

[0067] Step 102: Determine the number M of all single frequencies transmitted by the transmitter and the frequency value of all single frequencies; M≥N.

[0068] Specifically, in traditional single-frequency signal frequency division multiplexing (FDM) methods, each channel transmits only one fixed-frequency signal. However, in this application, N > 1, therefore M is at least 2. This means that the transmitter in this application transmits at least two single-frequency signals. By increasing the number of signal frequencies, richer geoelectric information can be obtained through exploration, thereby improving the survey accuracy and overcoming the limitation of limited information in traditional single-frequency signals.

[0069] Step 103: Encode the frequency values ​​of all single frequencies in the first channel of the transmitter according to the first preset rule to obtain the encoded first channel.

[0070] Specifically, for the first channel of the transmitter, all single-frequency values ​​in the channel are encoded according to a pre-set first preset rule to obtain the encoded first channel. Encoding allows multiple frequency signals to be combined, giving the signal transmitted by this channel unique encoding characteristics. This encoded signal contains more information dimensions during transmission; therefore, when the receiver receives the encoded signal, it can reconstruct the information of each frequency signal, thus greatly increasing the amount of information transmitted per unit time.

[0071] Step 104: Based on the encoded first channel, encode the remaining channels of the transmitter according to the second preset rule to obtain the encoded remaining channels.

[0072] Specifically, after encoding the first channel, the remaining channels of the transmitter are encoded using the second preset rule based on the relevant information of the encoded first channel. By encoding the remaining channels, all channels have a unified encoding format and standard, which facilitates subsequent synchronization processing and analysis.

[0073] Step 105: Simultaneously power all encoded channels of the transmitter and record the information of each single frequency of each channel.

[0074] Specifically, after all channels have completed encoding, power is simultaneously supplied to each channel of the transmitter, causing each channel to begin sending signals according to the set encoding method.

[0075] Step 106: Collect measurement point information for each measurement point using a receiver; the receiver is synchronized with the transmitter in time.

[0076] Specifically, the receiver can receive signals transmitted by the transmitter and convert them into recordable and analyzable data. Because the receiver is time-synchronized with the transmitter, the arrival time of each signal can be accurately recorded, thereby determining information such as the signal's propagation path and propagation time.

[0077] Step 107: Analyze and interpret the geology based on the information of all single frequencies of the transmitter and the measurement point information corresponding to each measurement point.

[0078] Specifically, after acquiring information on all single-frequency signals transmitted by the transmitter and the corresponding measurement point information for each measurement point, geological analysis and interpretation are performed using this data. By analyzing the response characteristics of different frequency signals at each measurement point, information such as the electrical structure, lithological distribution, and structural features of the geological body can be inferred.

[0079] The geological exploration method provided by this invention achieves the goal of simultaneously acquiring geological information from multiple directions or locations by using multiple channels (N>1) to send frequency conversion signals to the receiver, thereby improving the accuracy of geological analysis.

[0080] Furthermore, step 103 will be described in detail below, which includes the following details:

[0081] The frequency values ​​of all single-frequency signals in the first channel Sort the frequencies in ascending order to obtain an ascending single-frequency sequence; then sort the ascending single-frequency sequence in descending order to obtain a descending single-frequency sequence; where i∈[1,M]; then concatenate the ascending single-frequency sequence with the descending single-frequency sequence to obtain a concatenated frequency sequence; and finally determine the first encoded channel based on the concatenated frequency sequence.

[0082] Specifically, all frequency values ​​corresponding to each single frequency transmitted by the transmitter. Sort in ascending order, for example, ;in 1,M]; The single-frequency sequence (i.e., spliced ​​frequency sequence) of the frequency conversion signal transmitted by the first channel of the transmitter is: Each single-frequency sequence contains 2*M single-frequency frequencies, and the single-frequency sequence is repeatedly transmitted. That is, the combination of single-frequency sequences of the frequency conversion signal transmitted by the first channel is: Because signals of different frequencies propagate at different speeds and attenuate at different rates in underground media, and because repeatedly transmitted frequency sequences exhibit low correlation with noise at the receiver but high correlation with the original signal at the transmitter, the receiver can analyze the received signal against the known transmitted frequency sequence. This allows for the effective extraction of useful signals from complex background noise, further improving exploration accuracy.

[0083] Furthermore, the following describes how to encode the remaining channels of the transmitter according to the second preset rule to obtain the encoded remaining channels, specifically including the following scheme:

[0084] The remaining channels are encoded by advancing the splicing frequency sequence of the current channel by two frequencies relative to the splicing frequency sequence of the previous channel.

[0085] Specifically, the single-frequency sequence of the frequency-converted signal transmitted by the second channel of the transmitter is two frequencies ahead of the single-frequency sequence of the frequency-converted signal transmitted by the first channel; that is, the single-frequency sequence of the frequency-converted signal transmitted by the second channel of the transmitter is selected as follows: Each single-frequency sequence contains 2*M single-frequency frequencies, and the single-frequency sequence is repeatedly transmitted. That is, the combination of single-frequency sequences of the frequency conversion signal transmitted by the second channel is: Set the single-frequency sequence of each subsequent channel in the above manner, that is, the single-frequency sequence of the frequency conversion signal sent by the j-th channel of the transmitter is 2 frequencies ahead of the single-frequency sequence of the frequency conversion signal sent by the (j-1)-th channel; until the frequency conversion signal settings of all channels are completed; where j is a natural number greater than 1.

[0086] This application pre-sets the frequency sequence of each channel by two frequencies. By comparing the received signal with the frequency sequence transmitted by each channel, the receiver can accurately identify the source channel and frequency of each signal, improving the accuracy and reliability of signal detection. Furthermore, the frequency sequences of each channel have overlapping portions, and adjacent channel frequencies overlap. This data redundancy design allows for comparison and verification during data processing. When an anomaly or interference occurs in the data of a certain channel, it can be corrected and supplemented by referring to relevant data from other channels, improving the reliability and stability of the data, and ultimately enhancing the stability of the survey.

[0087] The method provided by this invention, on the one hand, allows for the acquisition of more geoelectric information of different frequencies at the same time by having multiple channels working simultaneously with different frequency sequences for each channel. Compared with single-channel frequency-by-frequency measurement, this significantly shortens exploration time and improves exploration efficiency. On the other hand, by advancing the frequency sequences of adjacent channels by two frequencies, different frequency signals can detect geological bodies from different angles and depths when propagating underground, thereby reducing data omissions and errors and improving the stability of the survey.

[0088] Furthermore, the frequency conversion signal sent by each channel of the transmitter contains the frequencies of all selected single frequencies.

[0089] Specifically, existing single-frequency signal frequency division multiplexing (FDM) methods can only acquire limited geoelectric information, which cannot meet the needs of refined electrical exploration. This application, in order to obtain more comprehensive geoelectric information and achieve refined electrical exploration, ensures that the frequency conversion signal transmitted by each channel of the transmitter includes all selected single-frequency frequencies. This allows the receiver to receive information such as the potential difference between different frequencies by simultaneously transmitting multiple frequency signals, thereby enabling comprehensive detection of the electrical characteristics of different geological bodies at different depths based on the potential difference information.

[0090] Furthermore, step 105 will be described in detail below, which includes the following details:

[0091] All encoded channels of the transmitter are powered simultaneously, with each channel repeatedly transmitting using its own spliced ​​frequency sequence; the transmission time for each single frequency is [duration missing]. ,and It is an integer not less than 1; The unit is seconds. The unit is Hertz; record the current value for each single frequency in all channels. In each channel, the current value of the same single frequency is equal. Where p is the single-frequency value, p is the power supply point number corresponding to each channel, and q is the number corresponding to each measurement point.

[0092] Specifically, each channel of the transmitter is powered simultaneously according to the single-frequency sequence combination corresponding to the above channel, and the current value of each single-frequency of each channel is recorded. The current value of the same single frequency in each channel is equal; the current value of the same single frequency in different channels may be different, and the current value of each single frequency in each channel is recorded. The transmission time of each single frequency is also recorded. They are all equal, and The integer value of Ti*fi ensures that each single-frequency signal can be transmitted for multiple complete cycles. This guarantees that the characteristics of each frequency signal are fully represented, avoiding the loss of some signal features due to insufficient signal transmission time. Furthermore, in subsequent processing, since the transmission duration of each single-frequency signal is consistent, signals from different channels and frequencies can be sampled and processed at the same time intervals. This improves data synchronization, facilitates comparative analysis, enhances data processing efficiency and accuracy, and reduces data processing complexity. In addition, the integer value of Ti*fi guarantees that within each Ti time interval, the signal sampling points correspond to the complete signal cycle. This facilitates accurate measurement of signal parameters such as amplitude and phase at the receiving end. Such precise measurement can more accurately reflect the differences in the response of underground geological bodies to different frequency signals, thereby further improving the accuracy of geological analysis.

[0093] Moreover, by recording the current value of each single frequency of each channel, and allowing different current values ​​of the same single frequency in different channels, the response differences of underground geological bodies to different power supply channels and different frequency currents can be fully reflected, thereby accurately capturing the changes in the electrical characteristics of underground geological bodies and improving the accuracy of surveying.

[0094] Furthermore, the measuring point information of this invention includes: device coefficients. and potential difference Step 106 involves acquiring the measurement point information for each measurement point using a receiver, including: acquiring the potential difference at each measurement point using a receiver. The device coefficients for each measuring point are collected by the receiver. The potential difference at each measuring point is collected via a receiver. Specifically, the following solutions are included:

[0095] Record the start and end times of each single frequency in all channels of the transmitter, and simultaneously record the start and end times of each single frequency received by each channel of the receiver. By comparing the start and end times of each single frequency of the transmitter with those of the receiver, the signal source of each single frequency of the receiver can be determined. Based on the signal source of each single frequency of the receiver, the potential difference at each measuring point can be determined. ,in Where p is the single-frequency value, p is the power supply point number corresponding to each channel, and q is the number corresponding to each measurement point.

[0096] The device coefficients at each measuring point are collected by the receiver. This includes: acquiring the coordinates of the power supply point for each channel of the transmitter and the coordinates of the measuring electrode for each measuring point of the receiver; and determining the device coefficients for the corresponding measuring points based on the power supply point coordinates and the measuring electrode coordinates. Where p is the power supply point number corresponding to each channel, and q is the number corresponding to each measurement point.

[0097] Specifically, the transmitter records the start and end times corresponding to each single frequency transmitted by each channel; the receiver records the start and end times corresponding to each single frequency received by each channel; based on the start and end times recorded by the transmitter for each single frequency transmitted by each channel, the signal of a certain frequency at a certain moment in the frequency division multiplexing receiver is determined to originate from the corresponding mobile power supply point; the receiver, synchronized with the transmitter, collects the potential differences at different power supply points, different frequencies, and different measurement points corresponding to different channels at the measurement point. Record the coordinates of the power supply point corresponding to each channel and the measuring electrode corresponding to each measuring point, and calculate the device coefficient according to the device coefficient formula of the conduction method. calculate.

[0098] This invention synchronizes the transmitter and receiver in time and records the start and end times of each single frequency. This allows for precise determination of the source of a specific frequency signal from a mobile power supply point at a given moment, effectively avoiding signal confusion and thus further improving survey efficiency and accuracy.

[0099] Furthermore, step 106 will be explained in detail below:

[0100] According to the device coefficient Potential difference Current value Determine the apparent resistivity corresponding to different channels at each measuring point. ;

[0101]

[0102] Where i is the number of the single frequency. For single frequency, [1,M]; p is the power supply point number corresponding to each channel, and q is the number corresponding to each measurement point;

[0103] According to the potential difference Current value Determine the apparent frequency induced polarization parameters at each measuring point. ;

[0104]

[0105] Where i and r are the numbers of the single frequency. It is a single frequency; 1,M], 1,M], and p is the power supply point number corresponding to each channel, and q is the number corresponding to each measurement point.

[0106] Based on the apparent resistivity of each measuring point and amplitude-frequency induced polarization parameters To analyze and interpret geology.

[0107] The method provided by this invention combines apparent resistivity and apparent amplitude-frequency induced polarization parameters to conduct a comprehensive analysis of geological bodies from both conductivity and induced polarization effects, thereby further improving the accuracy and reliability of geological analysis.

[0108] Furthermore, the frequency ratio between the single frequencies transmitted by each channel of the transmitter is a natural number greater than 1.

[0109] Specifically, the frequency ratio between the single frequencies transmitted by each channel of the transmitter is a natural number greater than 1, that is... It is a natural number greater than 1. When the frequency ratio between adjacent frequencies is greater than 1, the mutual interference between frequencies can be effectively reduced, and the reduction of frequency interference directly improves the quality of the acquired potential difference data. This helps to calculate the apparent resistivity and apparent amplitude frequency-induced polarization parameters more accurately, thereby improving the accuracy of geological analysis and interpretation.

[0110] Furthermore, the time synchronization error between the transmitter and receiver does not exceed 100 nanoseconds.

[0111] This application improves the accuracy of receiver data acquisition by designing the time synchronization error between the transmitter and receiver to be no more than 100 nanoseconds, thereby ultimately improving the accuracy of the survey.

[0112] Furthermore, a dead time interval is set between two adjacent frequencies transmitted by each channel; this dead time interval is not less than half a cycle of the larger frequency signal among the two adjacent single-frequency signals.

[0113] Specifically, a dead time period refers to a time during which the channel does not transmit any signal. To prevent interference between signals of different frequencies, this application sets a dead time period between adjacent frequencies transmitted by each channel. Because the dead time period reduces frequency interference, the quality of the acquired potential difference data is higher. This helps to more accurately calculate apparent resistivity and apparent amplitude frequency-induced polarization parameters, thereby improving the accuracy of geological analysis and interpretation. In this embodiment of the invention, the length of the dead time period can be greater than 0 or 0, i.e., no dead time period is set. When no dead time period is set, subsequent measurement data should be filtered out for a portion of the time period to reduce interference between frequencies. Furthermore, when no dead time period is set, the transmitter can continuously transmit frequency-converted signals without inserting periods of no signal between adjacent frequencies. This helps to improve exploration efficiency.

[0114] Preferably, the length of the dead time period in this application is not less than half the cycle length of the highest frequency signal among two adjacent frequencies. When the length of the dead time period is not less than half the cycle length of the highest frequency signal among two adjacent frequencies, it can be ensured that the attenuation of the previous frequency signal is sufficiently low before the next frequency signal is transmitted, thereby avoiding or significantly reducing interference between frequencies. This helps to calculate the apparent resistivity and apparent amplitude frequency induced polarization parameters more accurately, thereby further improving the survey accuracy.

[0115] The geological exploration method of the present invention will now be described in general, and it specifically includes the following steps:

[0116] a) Determine the total number of channels N of the transmitter. (As shown in Figures 3(a)-3(c), the total number of channels N=3 in this embodiment); and transmitters are deployed in the exploration area, with each channel of the transmitter connected to a different power supply point. For example... Figure 2 As shown, Figure 2 The black dots represent measuring electrodes; the cross-shaped dots numbered A1, A2, and A3 represent moving power supply points; the cross-shaped dots numbered C1, C2, and C3 represent infinity power supply points; and the circular dots numbered O1, O2, O3, O4, O5, and O6 represent measuring points. Figure 2 In the above, points such as A1, A2, A3, C1, C2, and C3, which are close to measuring points O1, O2, O3, O4, O5, and O6 and can generate obvious potential difference signals, are considered mobile power supply points.

[0117] b) Determine the number M of all single frequencies transmitted by the transmitter, and the frequency values ​​of all single frequencies (as shown in Figures 3(a)-3(c), a three-channel frequency division multiplexing transmitter is used, with each channel transmitting 3 single frequencies, and the frequency values ​​are 0.5, 1, and 2 Hz, i.e., M=3); all frequency values Sort in ascending order, as shown in Figures 3(a)-3(c), the frequency values ​​are as follows: =0.5、 1. 2 Hz; the frequency conversion signal sent by each channel of the transmitter contains the frequencies of all selected single frequencies (i.e., the signal sent by each channel contains signals of 0.5, 1, and 2 Hz); in this embodiment, no dead time period is set, that is, the length of the dead time period is equal to 0.

[0118] c) The transmission duration of each single frequency transmitted by each channel of the transmitter is 4 seconds.

[0119] d) As shown in Figure 3(a), the single-frequency sequence of the frequency conversion signal sent by the first channel is: , 1, 0.5; The single-frequency sequence combination of the frequency conversion signal sent by the first channel is: ;

[0120] e) As shown in Figure 3(b), the single-frequency sequence of the frequency conversion signal sent by the second channel is: 1, 0.5 The single-frequency sequence combination of the frequency conversion signal sent by the second channel is as follows: ;

[0121] f) As shown in Figure 3(c), the single-frequency sequence of the frequency conversion signal sent by the third channel is: 1, 0.5, , The single-frequency sequence combination of the frequency conversion signal sent by the third channel is as follows: ;

[0122] g) Each channel of the transmitter is simultaneously powered according to the single-frequency sequence group corresponding to the above channel, and the current value of each single-frequency of each channel is recorded. ;

[0123] h) The transmitter and the frequency division multiplexing (FDM) receiver synchronize their times; as shown in Figures 3(a)-3(c), the 0.5 Hz signal from 0 to 4 seconds comes from the mobile power supply point A1 and the infinite power supply point C1 corresponding to the first channel; the 1 Hz signal from 0 to 4 seconds comes from the mobile power supply point A2 and the infinite power supply point C2 corresponding to the second channel; the 2 Hz signal from 0 to 4 seconds comes from the mobile power supply point A3 and the infinite power supply point C3 corresponding to the third channel; the 0.5 Hz signal from 4 to 8 seconds comes from the mobile power supply point A3 and the infinite power supply point C3 corresponding to the third channel; the 1 Hz signal from 4 to 8 seconds comes from the mobile power supply point A1 and the infinite power supply point C1 corresponding to the first channel; the 2 Hz signal from 4 to 8 seconds comes from the mobile power supply point A2 and the infinite power supply point C2 corresponding to the second channel; and so on, until the frequency conversion signal settings for all channels are completed;

[0124] i) Use a receiver synchronized with the transmitter to collect the potential difference of different channels at different power supply points, different frequencies, and different measurement points at different measurement points;

[0125] g) Record the coordinates of the power supply point corresponding to each channel and the measuring electrode corresponding to each measuring point, and calculate the device coefficient according to the device coefficient formula of the conduction method. calculate;

[0126] k) Based on the potential difference at the power supply point, different frequency, and different measuring point corresponding to the different channels being measured. Calculate the apparent resistivity at different power supply points, frequencies, and measurement points for different channels. And amplitude frequency induced polarization parameters For geological analysis and interpretation:

[0127] As shown in Figures 3(a)-3(c), This indicates that the signal obtained at measurement point O1 is supplied by power supply point A1 (C1 is omitted here because it is a fixed power supply point at infinity). The apparent resistivity of a signal at a Hertz frequency is calculated; where... To obtain the signal supplied by power supply point A1 at measurement point O1 (C1 is omitted here because it is a power supply point at infinity). Potential difference at Hertz frequency; The power supplied by power supply point A1 (C1 is omitted here because it is a power supply point at infinity). Current value at Hertz frequency; The device coefficients are calculated based on the coordinates of power supply point A1 and measuring point O1.

[0128] This indicates that the signal obtained at measurement point O1 is supplied by power supply point A1 (C1 is omitted here because it is a fixed power supply point at infinity). Hertz frequency and The apparent frequency induced polarization parameters of a signal with a Hertzian frequency are calculated; where... To obtain the signal supplied by power supply point A1 at measurement point O1 (C1 is omitted here because it is a power supply point at infinity). Potential difference at Hertz frequency; To obtain the signal supplied by power supply point A1 at measurement point O1 (C1 is omitted here because it is a power supply point at infinity). Potential difference at Hertz frequency.

[0129] The geological analysis apparatus provided by the present invention is described below. The geological analysis apparatus described below and the geological analysis method described above can be referred to in correspondence.

[0130] like Figure 4 As shown, the geological analysis apparatus provided by the present invention includes:

[0131] Deployment unit 401 is used to deploy a transmitter in the exploration area to send frequency-converted signals to a receiver; the transmitter has N channels, where N > 1;

[0132] Determining unit 402 is used to determine the number M of all single frequencies transmitted by the transmitter and the frequency value of all single frequencies; M≥N;

[0133] Encoding unit 403 is used to encode the frequency values ​​of all single frequencies in the first channel of the transmitter according to a first preset rule to obtain the encoded first channel;

[0134] The encoding unit 403 is further configured to encode the remaining channels of the transmitter according to the second preset rule based on the encoded first channel, so as to obtain the encoded remaining channels.

[0135] The power supply unit 404 is used to simultaneously supply power to all encoded channels of the transmitter;

[0136] Recording unit 405 is used to synchronously record information of each single frequency of each channel while power is supplied; wherein, a dead time period is set between two adjacent frequencies transmitted by each channel;

[0137] The recording unit 405 is also used to collect measurement point information of each measurement point through a receiver; the receiver is synchronized with the transmitter in time.

[0138] Analysis unit 406 is used to analyze and interpret geology based on information from all single-frequency transmitters and the measurement point information corresponding to each measurement point.

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of geological exploration, characterized in that, include: A transmitter is deployed in the exploration area to send frequency-converted signals to a receiver; the transmitter has N channels, where N > 1; Determine the number M of all individual frequencies transmitted by the transmitter and the frequency value of all individual frequencies; M≥N; The frequency values ​​of all single frequencies in the first channel of the transmitter are encoded according to the first preset rule to obtain the encoded first channel; Based on the encoded first channel, the remaining channels of the transmitter are encoded according to the second preset rule to obtain the encoded remaining channels; Power is supplied to all encoded channels of the transmitter simultaneously, and information about each single frequency of each channel is recorded; Information from each measuring point is collected using a receiver; The receiver is synchronized with the transmitter in time. Based on the information from all single-frequency transmitters and the measurement point information corresponding to each measurement point collected by the receiver, the geology is analyzed and interpreted. The step of encoding all single-frequency values ​​in the first channel of the transmitter according to a first preset rule to obtain the encoded first channel includes: The frequency values ​​of all single-frequency signals in the first channel Sort the frequencies in ascending order to obtain an ascending single-frequency sequence; then sort the ascending single-frequency sequence in descending order to obtain a descending single-frequency sequence; where i∈[1,M]; The ascending single-frequency sequence is concatenated with the descending single-frequency sequence to obtain the concatenated frequency sequence. Based on the splicing frequency sequence, determine the encoded first channel; The step of encoding the remaining channels of the transmitter according to the encoded first channel and then encoding them according to the second preset rule to obtain the encoded remaining channels includes: The remaining channels are encoded by advancing the splicing frequency sequence of the current channel by two frequencies relative to the splicing frequency sequence of the previous channel.

2. The geological exploration method according to claim 1, characterized in that, The simultaneous power supply to all encoded channels of the transmitter and the recording of information for each single frequency of each channel includes: All encoded channels of the transmitter are powered simultaneously, with each channel repeatedly transmitting using its own spliced ​​frequency sequence; the transmission time for each single frequency is [duration missing]. ,and It is an integer not less than 1; The unit is seconds. The unit is Hertz; record the current value of each single frequency in all channels ; wherein, is the single frequency, p is the corresponding power supply point number of each channel, q is the corresponding number of each measuring point.

3. The geological exploration method according to claim 2, characterized in that, The information of the measuring point includes: device coefficient and potential difference ; acquiring the potential difference of each measuring point by a receiver comprising: Record the start and end times of each single frequency in all channels of the transmitter, and synchronously record the start and end times of each single frequency received by each channel of the receiver; By comparing the start and end times of each single frequency of the transmitter with the start and end times of each single frequency of the receiver, the signal source of each single frequency of the receiver can be determined. determining the potential difference of each measuring point according to the signal source of each single frequency of the receiver wherein is the single frequency, p is the power supply point number corresponding to each channel, q is the number corresponding to each measuring point; The device coefficients at each measuring point are collected by a receiver. include: Obtain the coordinates of the power supply point corresponding to each channel of the transmitter, and the coordinates of the measuring electrode corresponding to each measuring point of the receiver; Based on the coordinates of the power supply point and the coordinates of the measuring electrode, determine the device coefficient for the corresponding measuring point. ; in, p Number the power supply point corresponding to each channel. q The corresponding number for each measuring point.

4. The geological exploration method according to claim 3, characterized in that, The geological analysis and interpretation based on information from all single-frequency transmitters and information corresponding to each measuring point includes: According to the device coefficient Potential difference Current value Determine the apparent resistivity corresponding to different channels at each measuring point. ; in, i This refers to the number of a single frequency. For single frequency, 1,M]; p Number the power supply point corresponding to each channel. q The number corresponding to each measuring point; According to the potential difference Current value Determine the apparent frequency induced polarization parameters at each measuring point. ; in, i and r This refers to the number of a single frequency. It is a single frequency; 1,M], 1,M], and ; p Number the power supply point corresponding to each channel. q The number corresponding to each measuring point; Based on the apparent resistivity of each measuring point and amplitude-frequency induced polarization parameters To analyze and interpret geology.

5. The geological exploration method according to claim 1, characterized in that, The frequency ratio between the single frequencies transmitted by each channel of the transmitter is a number greater than 1.

6. The geological exploration method according to claim 1, characterized in that, The time synchronization error between the transmitter and receiver does not exceed 100 nanoseconds.

7. The geological exploration method according to claim 1, characterized in that, A dead time interval is set between two adjacent frequencies transmitted by each channel; the dead time interval is not less than half a cycle of the larger frequency signal among the two adjacent single-frequency signals.

8. A geological analysis device, characterized in that, include: A deployment unit is used to deploy transmitters in the exploration area to send frequency-converted signals to receivers; the transmitters have N channels, where N > 1; The determining unit is used to determine the number M of all single frequencies transmitted by the transmitter and the frequency value of all single frequencies; M≥N; The encoding unit is used to encode the frequency values ​​of all single frequencies in the first channel of the transmitter according to the first preset rule to obtain the encoded first channel; The encoding unit is further configured to encode the remaining channels of the transmitter according to the second preset rule based on the encoded first channel, so as to obtain the encoded remaining channels. The power supply unit is used to simultaneously supply power to all encoded channels of the transmitter; The recording unit is used to synchronously record information of each single frequency of each channel while power is supplied; wherein, a dead time period is set between two adjacent frequencies transmitted by each channel; The recording unit is also used to collect measurement point information for each measurement point through a receiver; the receiver is synchronized with the transmitter in time. The analysis unit is used to analyze and interpret the geology based on the information of all single frequencies of the transmitter and the measurement point information corresponding to each measurement point; The encoding unit is specifically used for: The frequency values ​​of all single-frequency signals in the first channel Sort the frequencies in ascending order to obtain an ascending single-frequency sequence; then sort the ascending single-frequency sequence in descending order to obtain a descending single-frequency sequence; where i∈[1,M]; The ascending single-frequency sequence is concatenated with the descending single-frequency sequence to obtain the concatenated frequency sequence. Based on the splicing frequency sequence, determine the encoded first channel; The encoding unit is also specifically used for: The remaining channels are encoded by advancing the splicing frequency sequence of the current channel by two frequencies relative to the splicing frequency sequence of the previous channel.

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