A comprehensive electrical prospecting method and device

Abstract

A comprehensive electrical prospecting method and device provided by the present invention, the method comprising: inputting an alternating current frequency signal with a preset bandwidth into the geological object to be measured in a frequency sweep manner, receiving the voltage data recorded by the measuring electrodes, and obtaining an amplitude-frequency response curve; finding the frequency corresponding to the amplitude attenuation position according to the amplitude-frequency response curve to obtain the response frequency of the geological object to be measured; obtaining the distribution characteristics of the water-richness of the geological object to be measured according to the difference between the response frequency of the geological object to be measured and the response frequency of a single medium; the present invention determines the distribution characteristics of the water-richness of coal and rock strata according to the difference between the response frequency of the geological object to be measured and the response frequency of a single medium. At the same time, by means of frequency sweep, the frequencies required for detecting the medium are covered, avoiding the omission situation existing in the current alternating current electrical method, so as to ensure the accuracy of the underground exploration results.

Description

Technical Field

[0001] The present invention relates to the technical field of mine geophysical electrical prospecting, and particularly relates to a comprehensive electrical prospecting method and device. Background Art

[0002] Electrical methods are sensitive to low-resistance water-filled fracture zones, have a small volume effect, high longitudinal and transverse resolution, and high construction efficiency. They can be applied to the detection in coal mines, either in front of the heading face or for the detection of the sidewalls of roadways, the top and bottom plates of coal seams, etc., providing a technical means for the prediction and forecast of water hazards and water-conducting structures during the production process of coal mining enterprises.

[0003] Currently, in the active field prospecting methods of mine electrical methods in coal mines, mainly direct current electric field detection methods and alternating current electric field detection methods are used. The direct current method is based on the conductivity difference of coal, rock (water) media. Through an artificially established electric field, the electric field distribution of the medium under its influence is observed. By obtaining the supply current and measured voltage corresponding to the electric field, according to the formula:

[0004]

[0005] where ρ s is the apparent resistivity, K is the device coefficient of the measurement method and is a constant, ΔU and I correspond to the measured electrical method and the supply current, and finally, the distribution characteristics of the water-richness of the inner floor rock formation in the coal mining face are determined according to the differences in apparent resistivity at different measurement points. However, when there are multiple media mixed in the inner floor rock of the coal mining face and the conductivity is the same as that of a single medium, when using the direct current method for detection at this time, the difference in the media cannot be judged.

[0006] The alternating current method is to supply an alternating electric field of a certain frequency into the ground artificially, and at the same time observe the potential difference between the measuring electrodes M and N. When the electromagnetic effect (EM) and the induced polarization effect (IP) exist simultaneously, at this time, the potential difference has a phase shift compared with the supply current I and will change with the change of frequency. Therefore, the obtained apparent resistivity is a complex variable function of frequency, called apparent complex resistivity, and is expressed as:

[0007]

[0008] In the above formula, K is the device coefficient; i is the imaginary unit; ω = 2πf is the angular frequency, and the "~" above the measured potential difference ΔU and the supply current indicates the quantity in the frequency domain, A s and are respectively the amplitude and phase of the apparent complex resistivity.

[0009] The alternating current method of detection mainly changes the emission frequency of the artificial active field, thereby causing changes in the amplitude or phase of the apparent complex resistivity, resulting in changes in the apparent complex resistivity. By the difference in apparent complex resistivity, the distribution characteristics of the water-richness of the floor rock formation in the coal mining face are determined.

[0010] However, since different media have different responses to frequencies, when detecting a target with an alternating current field of a certain frequency, the measured medium may not respond to the emitted frequency. In this case, it is necessary to increase the number of emission frequency groups to improve the hit probability, but there will still be cases where coverage is not achieved. Summary of the Invention

[0011] To solve the above problems of the prior art, the present invention provides a comprehensive electrical prospecting method and device to ensure the accuracy of underground exploration results.

[0012] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0013] In a first aspect, the present invention provides a comprehensive electrical prospecting method, including:

[0014] Input an alternating current frequency signal with a preset bandwidth into the measured geology by means of frequency sweeping, receive the voltage data recorded by the measurement electrodes, and obtain an amplitude-frequency response curve;

[0015] Find the frequency corresponding to the amplitude attenuation position according to the amplitude-frequency response curve to obtain the response frequency of the measured geology;

[0016] Obtain the distribution characteristics of the water-richness of the measured geology according to the difference between the response frequency of the measured geology and the response frequency of a single medium.

[0017] The beneficial effect of the present invention is that: since the coal seam, the underlying rock formation and the aquifer in the coal mining face constitute a mixed medium body, and the frequency response of water is lower than that of coal and rock, therefore, when a signal higher than the water response frequency passes through this mixed medium body, the signal will be attenuated, and the higher the frequency, the more severe the attenuation. Thus, the distribution characteristics of the water-richness of the coal and rock formations are judged according to the difference between the response frequency of the measured geology and the response frequency of a single medium. At the same time, by means of frequency sweeping, the frequencies required for detecting the medium are covered, avoiding the omission situation existing in the current alternating current method, so as to ensure the accuracy of underground exploration results.

[0018] Optionally, it further includes:

[0019] Regard the measured geology as a first-order low-pass filter circuit model, and obtain the first water content ratio of the measured geology according to the response frequency f0 of the measured geology and the first-order filter formula: f = 1 / 2πRC.

[0020] According to the above description, the mixed dielectric can be equivalently regarded as a first-order low-pass filter circuit model with RC dielectric parameters. Since the water in the mixed dielectric composed of coal, rock, and water is rich in mineral ions, its conductivity is relatively good. Therefore, the change in the water content in the rock has a negligible effect on its resistance value R. The resistance values of coal and rock media are quite fixed. Therefore, it can be approximately considered that R is a constant. Water is equivalent to the electrolyte in a capacitor, and the change in water content has a relatively large effect on the capacitance value C. Therefore, according to the first-order filter formula, the response frequency f0 of the mixed dielectric is inversely proportional to the water content. The larger the water content, the smaller its f0; conversely, the larger f0 is. Therefore, the specific water content ratio relationship is inferred based on the relationship between the response frequency of the mixed dielectric and the natural response frequency of the pure dielectric.

[0021] Optionally, it further includes:

[0022] Receiving the phase data recorded by the measurement electrode to obtain a phase-frequency response curve;

[0023] Obtaining the response phase of the geological formation to be measured according to the response phase of the response frequency on the phase-frequency response curve;

[0024] The distribution characteristics of the water-richness of the geological formation to be measured obtained according to the difference between the response frequency of the geological formation to be measured and the response frequency of a single dielectric include:

[0025] Comprehensively obtaining the distribution characteristics of the water-richness of the geological formation to be measured according to the difference between the response frequency of the geological formation to be measured and the response frequency of a single dielectric and the difference between the response phase of the geological formation to be measured and the response phase of a single dielectric.

[0026] According to the above description, this embodiment also comprehensively considers the difference in phase to consider the distribution characteristics of the water-richness of the geological formation to be measured, ensuring the accuracy of the underground exploration results.

[0027] Optionally, it further includes:

[0028] According to the response phase of the geological formation to be measured and the first-order filter formula: Obtaining the second water content ratio of the geological formation to be measured;

[0029] Comprehensively obtaining the final water content ratio of the geological formation to be measured by combining the first water content ratio and the second water content ratio.

[0030] According to the above description, according to the first-order filter formula, the response phase of the mixed dielectric has a positive correlation with the water content. The larger the water content, the larger its is. Conversely The smaller it is, so the specific water content ratio relationship is inferred from the relationship between the response phase of the mixed medium and the inherent response phase of the pure medium. Then, by combining the two parameters, the water content ratio of the measured geology is obtained to ensure the accuracy of the underground exploration results.

[0031] Optionally, the amplitude attenuation position is the position where the amplitude attenuates by 2 - 5 dB.

[0032] In a second aspect, the present invention provides a comprehensive electrical prospecting device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the following is achieved:

[0033] Input an alternating frequency signal with a preset bandwidth to the measured geology in a frequency - sweeping manner, receive the voltage data recorded by the measurement electrodes, and obtain an amplitude - frequency response curve;

[0034] Find the frequency corresponding to the amplitude attenuation position according to the amplitude - frequency response curve to obtain the response frequency of the measured geology;

[0035] Obtain the distribution characteristics of the water - richness of the measured geology according to the difference between the response frequency of the measured geology and the response frequency of a single medium.

[0036] Optionally, it further includes:

[0037] Regard the measured geology as a first - order low - pass filter circuit model, and obtain the first water content ratio of the measured geology according to the response frequency f0 of the measured geology and the first - order filter formula: f = 1 / 2πRC.

[0038] Optionally, it further includes:

[0039] Receive the phase data recorded by the measurement electrodes to obtain a phase - frequency response curve;

[0040] Obtain the response phase of the measured geology according to the response phase of the response frequency on the phase - frequency response curve;

[0041] The obtaining of the distribution characteristics of the water - richness of the measured geology according to the difference between the response frequency of the measured geology and the response frequency of a single medium includes:

[0042] Comprehensively obtain the distribution characteristics of the water - richness of the measured geology according to the difference between the response frequency of the measured geology and the response frequency of a single medium and the difference between the response phase of the measured geology and the response phase of a single medium.

[0043] Optionally, it further includes:

[0044] According to the response phase of the measured geology and the first - order filter formula: Obtain the second water content ratio of the geological area to be measured;

[0045] Obtain the final water content ratio of the geological area to be measured by integrating the first water content ratio and the second water content ratio.

[0046] Optionally, the amplitude attenuation position is the position where the amplitude attenuates by 2 - 5 dB.

[0047] Among them, for the technical effects provided by the comprehensive electrical prospecting device in the second aspect, refer to the relevant descriptions of the comprehensive electrical prospecting method provided in the first aspect. Description of the Drawings

[0048] Figure 1 It is a schematic diagram of the main process of a comprehensive electrical prospecting method according to an embodiment of the present invention;

[0049] Figure 2 It is a schematic diagram of the amplitude - frequency response curve and phase - frequency response curve involved in an embodiment of the present invention;

[0050] Figure 3 It is a schematic structural diagram of a comprehensive electrical prospecting method according to an embodiment of the present invention;

[0051] Figure 4 It is a schematic structural diagram of a comprehensive electrical prospecting device according to an embodiment of the present invention.

[0052]

Description of the Reference Numerals

[0053] 1: A comprehensive electrical prospecting device;

[0054] 2: Processor;

[0055] 3: Memory. Detailed Embodiments

[0056] In order to better understand the above - mentioned technical solutions, the exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0057] Embodiment 1

[0058] Since the coal seam, the underlying rock formation and the aquifer in the coal mining face constitute a mixed medium, and the frequency response of water is lower than that of coal and rock, when a signal higher than the water response frequency passes through this mixed medium, the signal will be attenuated, and the higher the frequency, the more severe the attenuation. Therefore, the mixed medium can be equivalently considered as a first - order low - pass filter circuit model with RC dielectric parameters.

[0059] Therefore, please refer to Figures 1 to 3 , a comprehensive electrical prospecting method, including the steps of:

[0060] S1. Input an AC frequency signal with a preset bandwidth into the geological object to be measured by means of frequency sweeping, and receive the voltage data and phase data recorded by the measuring electrodes to obtain an amplitude-frequency response curve and a phase-frequency response curve;

[0061] As Figure 3 shown, where power is supplied at points A and B to input an AC frequency signal with a preset bandwidth and an initial phase of 0, and then the voltage data and phase data between points M and N are measured to obtain Figure 2 the amplitude-frequency response curve and phase-frequency response curve shown.

[0062] Among them, Figure 2 the upper one in

[0063] S2. Find the frequency corresponding to the amplitude attenuation position according to the amplitude-frequency response curve to obtain the response frequency of the geological object to be measured, and obtain the response phase of the geological object to be measured according to the response phase on the phase-frequency response curve;

[0064] In this embodiment, the amplitude attenuation position is the position where the amplitude attenuates by 3 dB. In other embodiments, the amplitude attenuation position can be the position where the amplitude attenuates by 2 - 5 dB.

[0065] Therefore, find the inflection point of the frequency response according to the amplitude-frequency response curve, that is, the frequency corresponding to the position where the amplitude begins to attenuate, and consider this frequency as the response frequency f0 of the geological object to be measured, and thereby obtain its response phase

[0066] S3. Comprehensively obtain the distribution characteristics of the water abundance of the geological object to be measured according to the difference between the response frequency of the geological object to be measured and the response frequency of a single medium and the difference between the response phase of the geological object to be measured and the response phase of a single medium;

[0067] Among them, when the medium is pure water, coal, and rock respectively, the corresponding response frequencies and phases are measured by the instrument as f 水 , f 煤 , f 岩 and Since there may be mixed media such as coal, rock, and water in the geological object to be measured, its amplitude-frequency curve is measured by the instrument, and the response frequency f0 and phase of the mixed medium are found according to step S2 According to f0, and f 水 , f 煤 , f 岩 and The relative size relationship is used to determine the distribution characteristics of the water-richness of the floor rock formation in the coal mining face.

[0068] S4. Regard the geological object to be measured as a first-order low-pass filter circuit model, and according to the response frequency f0 of the geological object to be measured and the first-order filter formula: f = 1 / 2πRC, obtain the first water content ratio of the geological object to be measured;

[0069] Among them, since the water in the mixed medium composed of three media of coal, rock and water is rich in mineral ions, its conductivity is relatively good. Therefore, the change in the amount of water in the rock has a negligible impact on its resistance value R. The resistance values of the coal and rock media are quite fixed. Therefore, it can be approximately considered that R is a constant, and water is equivalent to the electrolyte in the capacitor. The change in the amount of water has a relatively large impact on the capacitance value C. In practical applications, the corresponding relationship between the capacitance value C and the amount of water can be measured in advance for accurate calculation of the water content ratio in the follow-up.

[0070] Therefore, the first-order filter formula: f = 1 / 2πRC can be approximately considered as f0 = 1 / KC, where K is a constant. Then, the response frequency f0 of the mixed medium is inversely proportional to the water content. The larger the water content, the smaller its f0, and vice versa, the larger f0. That is, the specific water content ratio relationship is inferred through the relationship between the response frequency of the mixed medium and the inherent response frequency of the pure medium.

[0071] S5. According to the response phase of the geological object to be measured and the first-order filter formula: Obtain the second water content ratio of the geological object to be measured;

[0072] Similarly, the first-order filter formula: Can be approximately considered as Where K is a constant, then the response phase Of the mixed medium is positively correlated with the water content. The larger the water content, the larger its , And vice versa The smaller, that is, the specific water content ratio relationship is inferred through the relationship between the response phase of the mixed medium and the inherent response phase of the pure medium.

[0073] S6. Obtain the final water content ratio of the geological object to be measured by integrating the first water content ratio and the second water content ratio.

[0074] In this embodiment, the integration process of the two water content ratios includes:

[0075] (1) When the difference between the second water content ratio and the first water content ratio is within the threshold range, the measurement result of the first water content ratio is used as the standard. If it exceeds the threshold range, the difference is assigned to the first water content ratio with a preset correction coefficient;

[0076] For example, if the first water content ratio is 14.5%, the second water content ratio is 16.2%, the threshold range is 1.5%, and the preset correction coefficient is 0.3. In this embodiment, the difference between the second water content ratio and the first water content ratio is 1.7%, which is outside the threshold range. The difference value of 1.7% * 0.3 = 0.51% is assigned to the first water content ratio of 14.5%, resulting in 15.01%. If the threshold range is 2%, then the final water content ratio is directly 14.5%.

[0077] (2) When the difference between the second water content ratio and the first water content ratio is within the threshold range, the measurement result of the second water content ratio shall be used as the standard. If it exceeds the threshold range, the difference value shall be assigned to the second water content ratio with the preset correction coefficient;

[0078] For example, if the first water content ratio is 14.5%, the second water content ratio is 16.2%, the threshold range is 1.5%, and the preset correction coefficient is 0.3. In this embodiment, the difference between the second water content ratio and the first water content ratio is 1.7%, which is outside the threshold range. The difference value of 1.7% * 0.3 = 0.51% is assigned to the second water content ratio of 16.2%, resulting in 15.69%. If the threshold range is 2%, then the final water content ratio is directly 16.2%.

[0079] (3) The first water content ratio and the second water content ratio are converted according to the preset weight coefficient to obtain the final water content ratio.

[0080] For example, if the first water content ratio is 14.5% and its preset weight coefficient is 0.6, and the second water content ratio is 16.2% and its preset weight coefficient is 0.4, then the final water content ratio = 14.5% * 0.6 + 16.2% * 0.4 = 8.7% + 6.48% = 15.18%.

[0081] It should be noted that the above threshold range, preset correction coefficient, and the preset weight coefficient between the two can be adjusted according to the actual use in the process and are not limited to the above values.

[0082] Thus, this embodiment can not only judge the distribution characteristics of the water-richness of the measured geology according to the differences in the amplitude-frequency and phase-frequency curves, but also infer the specific water content ratio relationship through the relationship between the response frequency of the mixed medium and the natural response frequency of the pure medium and the relationship between the response phase of the mixed medium and the natural response phase of the pure medium, thereby solving the problem that the existing traditional methods cannot accurately calculate the water content ratio. At the same time, by means of frequency sweeping, the frequencies required for the detection medium are covered, avoiding the omission situation existing in the current alternating current method and ensuring the accuracy of the underground exploration results.

[0083] Embodiment 2

[0084] Please refer to Figure 4, A comprehensive electrical prospecting device 1, including a memory 3, a processor 2, and a computer program stored on the memory 3 and executable on the processor 2. When the processor 2 executes the computer program, it implements the steps in the first embodiment above.

[0085] Since the device / device described in the above embodiments of the present invention is the device / device adopted for implementing the method in the above embodiments of the present invention, based on the method described in the above embodiments of the present invention, those skilled in the art can understand the specific structure and variations of the device / device, and thus will not be elaborated herein. Any device / device adopted by the method in the above embodiments of the present invention falls within the scope of protection of the present invention.

[0086] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a device, or a computer program product. Therefore, the present invention can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0087] The present invention is described with reference to the flowcharts and / or block diagrams of methods, devices (apparatuses), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions.

[0088] It should be noted that in the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The present invention can be implemented by means of hardware including several different components and by means of a suitably programmed computer. In the claims listing several devices, several of these devices can be embodied by the same hardware. The use of the words first, second, third, etc. is only for convenience of description and does not indicate any order. These words can be understood as part of the component name.

[0089] In addition, it should be noted that in the description of this specification, the descriptions of terms such as "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0090] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications after learning the basic creative concepts. Therefore, the claims should be construed to include the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0091] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention should also include these modifications and variations.

Claims

1. A comprehensive electrical prospecting method, characterized in that, Including: Input an AC frequency signal with a preset bandwidth into the geological object to be measured by means of frequency sweeping, receive the voltage data and phase data recorded by the measurement electrodes, and obtain the amplitude-frequency response curve and the phase-frequency response curve; Find the frequency corresponding to the amplitude attenuation position according to the amplitude-frequency response curve to obtain the response frequency of the geological object to be measured, and obtain the response phase of the geological object to be measured according to the response phase of the response frequency on the phase-frequency response curve; Comprehensively obtain the distribution characteristics of the water-bearing property of the geological object to be measured based on the difference between the response frequency of the geological object to be measured and the response frequency of a single medium, and the difference between the response phase of the geological object to be measured and the response phase of a single medium.

2. The integrated electrical prospecting method according to claim 1, characterized in that Also including: Regard the geological object to be measured as a first-order low-pass filter circuit model, and obtain the first water content ratio of the geological object to be measured according to the response frequency f0 of the geological object to be measured and the first-order filter formula: f = 1 / 2πRC.

3. The integrated electrical prospecting method according to claim 2, characterized in that, Also including: Obtain the second water content ratio of the geological object to be measured according to the response phase of the geological object to be measured and the first-order filter formula: φ0 = arctan(2πfRC); Comprehensively obtain the final water content ratio of the geological object to be measured by combining the first water content ratio and the second water content ratio.

4. A comprehensive electrical prospecting method according to any one of claims 1 to 3, characterized in that, The amplitude attenuation position is the position where the amplitude attenuates by 2 - 5 dB.

5. A comprehensive electrical prospecting device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the computer program, it realizes the following: Input an AC frequency signal with a preset bandwidth into the geological object to be measured by means of frequency sweeping, receive the voltage data and phase data recorded by the measurement electrodes, and obtain the amplitude-frequency response curve and the phase-frequency response curve; Find the frequency corresponding to the amplitude attenuation position according to the amplitude-frequency response curve to obtain the response frequency of the geological object to be measured, and obtain the response phase of the geological object to be measured according to the response phase of the response frequency on the phase-frequency response curve; Comprehensively obtain the distribution characteristics of the water-bearing property of the geological object to be measured based on the difference between the response frequency of the geological object to be measured and the response frequency of a single medium, and the difference between the response phase of the geological object to be measured and the response phase of a single medium.

6. The integrated electrical prospecting device according to claim 5, wherein, Also including: Regard the geological object to be measured as a first-order low-pass filter circuit model, and obtain the first water content ratio of the geological object to be measured according to the response frequency f0 of the geological object to be measured and the first-order filter formula: f = 1 / 2πRC.

7. The integrated electrical prospecting device according to claim 6, characterized in that, Also including: Obtain the second water content ratio of the geological object to be measured according to the response phase of the geological object to be measured and the first-order filter formula: φ0 = arctan(2πfRC); Comprehensively obtain the final water content ratio of the geological object to be measured by combining the first water content ratio and the second water content ratio.

8. A comprehensive electrical prospecting device according to any one of claims 5 to 7, characterized in that The amplitude attenuation position is the position where the amplitude attenuates by 2 - 5 dB.

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