Underground gypsum-salt rock stratum identification method, system and equipment and storage medium

Abstract

The invention provides an underground gypsum-salt rock stratum identification method and system, electronic equipment and a storage medium, and the method comprises the steps: obtaining the magnetotelluric frequency data of an underground rock stratum, and generating a magnetotelluric frequency CYT curve; obtaining a first difference parameter CG1 according to a difference value between a maximum extreme value envelope line LOGMAX and a minimum extreme value envelope line LOGMIN of the magnetotelluric frequency CYT curve; performing trend fitting based on a magnetotelluric frequency CYT curve to obtain a fitting straight line CNN; solving a difference value between the magnetotelluric frequency CYT curve and the fitting straight line CNN to obtain a second difference parameter CG2; and based on the obtained first difference parameter CG1 and the second difference parameter CG2, performing gypsum salt rock judgment and identification on the underground target stratum. According to the method, accurate recognition of the gypsum salt rock in the clastic rock stratum can be effectively achieved, the development condition of the gypsum salt rock in the non-drilling section can be predicted in drilling, and the method plays an important role in avoiding drilling accidents.

Description

Technical Field

[0001] This invention belongs to the field of petroleum geological exploration technology, and in particular relates to a method, system, equipment and storage medium for identifying underground gypsum-salt rock strata. Background Technology

[0002] Identifying underground gypsum-salt rock strata is a crucial task in geological exploration and resource development, with profound implications for oil and gas exploration, mineral resource assessment, and geological environmental studies. Due to their unique physical and chemical properties, gypsum-salt rock strata are often closely related to the formation and distribution of oil and gas reservoirs; therefore, accurate identification of underground gypsum-salt rock strata is of great significance for guiding resource exploration and development.

[0003] However, identifying underground gypsum-salt rock strata is no easy task. First, gypsum-salt rock strata are typically buried deep underground, and their physical and geochemical characteristics often change significantly due to the covering and compaction of overlying strata, posing a significant challenge to identification. Second, the complex and varied underground geological structure means that gypsum-salt rock strata may be interspersed with other rock strata, making identification even more difficult. Furthermore, traditional geological exploration methods, such as drilling and well logging, while providing direct stratigraphic information, are costly and destructive to the formation, making them unsuitable for large-scale exploration. To overcome these difficulties, researchers are constantly exploring new methods for identifying underground gypsum-salt rock strata. Geophysical exploration techniques, such as seismic exploration, have gradually become a research hotspot. By measuring the propagation and reflection characteristics of seismic waves in underground rock strata, seismic exploration can indirectly infer the structure and properties of the strata. However, when dealing with deep and complex strata, the resolution and accuracy of seismic exploration are often limited. In such cases, well logging and seismic interpretation are relied upon. However, the resolution of seismic data is limited (about 20-30m for deep layers), and the accuracy of identifying thin gypsum-salt rocks is low. Although well logging has high accuracy, it is limited by the drilling location. If there is no well, well logging data cannot be provided, and the overall production technology needs cannot be met.

[0004] Therefore, the identification of underground gypsum-salt rock strata faces numerous challenges. How to combine multiple exploration techniques to improve identification accuracy and efficiency; how to process exploration data under complex geological conditions, reduce interpretation uncertainty, and predict the development of gypsum-salt rock in undrilled sections are all problems that need to be solved. Therefore, developing an efficient, accurate, and economical method for identifying underground gypsum-salt rock strata is of great significance for promoting the development of geological exploration and resource development. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing a method, system, device, and storage medium for identifying underground gypsum-salt rock layers. It utilizes the fact that when electromagnetic waves penetrate gypsum-salt rock layers, the sand bodies absorb the energy of the solar cells, causing a decrease in vibration frequency and resulting in asymmetric vibrations. This leads to an increase in data points within smaller layers (i.e., an increase in the number of cycles), while mudstone exhibits the opposite characteristic. By using the magnetotelluric frequency curve (CYT curve) to reflect the relationship between electromagnetic wave frequency and formation porosity, it is possible to clearly distinguish between sandstone and mudstone, thereby improving the accuracy and efficiency of identifying underground gypsum-salt rock layers.

[0006] This invention is specifically achieved through the following technical solution:

[0007] In one aspect of this invention, a method for identifying underground gypsum-salt layers is provided, the method comprising the following steps:

[0008] Step 1: Obtain magnetotelluric frequency data of underground rock strata and generate magnetotelluric frequency CYT curves;

[0009] Step 2: Based on the difference between the maximum extreme value envelope LOG_MAX and the minimum extreme value envelope LOG_MIN of the magnetotelluric frequency CYT curve, obtain the first difference parameter CG1;

[0010] Step 3: Perform trend fitting based on the magnetotelluric frequency (CYT) curve to obtain the fitted straight line CNN;

[0011] Step 4: Calculate the difference between the magnetotelluric frequency CYT curve and the fitted straight line CNN to obtain the second difference parameter CG2;

[0012] Step 5: Based on the obtained first difference parameter CG1 and second difference parameter CG2, identify the underground target strata as gypsum-salt rock.

[0013] In another aspect of the present invention, a system for identifying underground gypsum-salt rock strata corresponding to the above-described method is provided. The system includes a CYT curve acquisition module, a first calculation module, a second calculation module, and a determination and identification module.

[0014] The CYT curve acquisition module is used to acquire magnetotelluric frequency data of underground rock strata and generate magnetotelluric frequency CYT curves.

[0015] The first calculation module is used to obtain the first difference parameter CG1 based on the difference between the maximum extreme value envelope LOG_MAX and the minimum extreme value envelope LOG_MIN of the magnetotelluric frequency CYT curve;

[0016] The second calculation module is used to perform trend fitting on the magnetotelluric frequency CYT curve to obtain the fitting line CNN, and then calculate the difference between the magnetotelluric frequency CYT curve and the fitting line CNN to obtain the second difference parameter CG2.

[0017] The determination and identification module is used to determine and identify gypsum-salt rocks in the underground target strata using the obtained first difference parameter CG1 and second difference parameter CG2.

[0018] In another aspect of the present invention, based on the same inventive concept disclosed above, an electronic device is provided, including a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, the processor performs all the steps of the method for identifying underground gypsum-salt rock layers as described above.

[0019] In another aspect of the present invention, the present invention also provides a computer storage medium storing a computer program, which, when executed by the processor, is used to implement all the steps of the method for identifying underground gypsum-salt rock layers as described above.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] By using the magnetotelluric frequency curve (CYT curve) to reflect the relationship between electromagnetic wave frequency and formation porosity, it is possible to clearly distinguish between sandstone and mudstone, thereby improving the accuracy and efficiency of identifying underground gypsum-salt rock layers. At the same time, it is not limited by the drilling location and can identify underground gypsum-salt rock layers even without well logging data.

[0022] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a flowchart illustrating a method for identifying underground gypsum and salt layers.

[0025] Figure 2This is a schematic diagram of the extreme value envelope extraction of the CYT curve, which is a method for identifying underground gypsum-salt layers.

[0026] Figure 3 This is a schematic diagram of a system for identifying underground gypsum and salt layers.

[0027] Figure 4 This is a rendering of the gypsum-salt rock identification effect of the Hetan 101 well in the Hetao Basin.

[0028] Figure 5 This is another rendering of the gypsum-salt rock identification from the Hetan 101 well in the Hetao Basin.

[0029] Figure 6 This is another rendering of the gypsum-salt rock identification from the Hetan 101 well in the Hetao Basin. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In one embodiment, please refer to Figure 1 and Figure 2 , Figure 1 This is a flowchart illustrating a method for identifying underground gypsum-salt layers. Figure 2 This is a schematic diagram of CYT curve extreme value envelope extraction for a method of identifying underground gypsum-salt layers; the method includes the following steps:

[0032] Step S1: Obtain magnetotelluric frequency data of underground rock strata and generate magnetotelluric frequency CYT curves;

[0033] Furthermore, the acquisition of magnetotelluric frequency data of underground rock strata and the generation of magnetotelluric frequency CYT curves are achieved by measuring the target underground strata using a magnetotelluric field detection instrument. The specific principle is as follows: using the low-frequency electromagnetic waves of the magnetotelluric field detection instrument as the field source, when the electromagnetic waves are perpendicularly incident at any depth underground, a new electromagnetic pulse is generated and reflected to the surface. This reflected wave is a combination containing information on the comprehensive energy value of the underground. By receiving and processing these reflected waves, the comprehensive energy value of the lithology at different underground depths, i.e., the CYT(i) value, can be obtained. Based on all the CYT(i) values, a magnetotelluric frequency CYT curve is plotted.

[0034] Furthermore, the expression for the magnetotelluric frequency curve CYT is:

[0035] CYT(i)=1000*(1 / F(i)-depth(i)*5) / 0.2

[0036] In the formula, i = 1, 2, ..., M, F is the measured magnetotelluric frequency; depth is the stratum depth corresponding to the magnetotelluric frequency; M is the number of sampling points for the magnetotelluric frequency data.

[0037] Step S2: Based on the difference between the maximum extreme value envelope LOG_MAX and the minimum extreme value envelope LOG_MIN of the magnetotelluric frequency CYT curve, obtain the first difference parameter CG1;

[0038] For further details, please refer to Figure 2 In this embodiment, the maximum extremum envelope LOG_MAX and the minimum extremum envelope LOG_MIN are obtained by comparing the peak values ​​of the magnetotelluric frequency CYT curve, specifically including:

[0039] The method for extracting the maximum extremum envelope LOG_MAX is as follows:

[0040] LOG_MAX(j) = CYT(i)

[0041] CYT(i)>CYT(i-1)&&CYT(i)>CYT(i+1)

[0042] In the formula, i = 2, 3, ..., M-1; j = 1, 2, ..., N; where M is the number of sampling points of the magnetotelluric frequency data, and N represents the number of extreme points of the magnetotelluric frequency CYT curve;

[0043] The method for extracting the minimum extremum envelope LOG_MIN is as follows:

[0044] LOG_MIN(j)=CYT(i)

[0045] CYT(i) <CYT(i-1)&&CYT(i)<CYT(i+1)

[0046] In the formula, i = 2, 3, ..., M-1; j = 1, 2, ..., N; M is the number of sampling points of the magnetotelluric frequency data, and N represents the number of extreme points of the magnetotelluric frequency CYT curve;

[0047] The specific calculation method for the first difference parameter CG1 is as follows:

[0048] CG1(j)=|LOG_MAX(j)-LOG_MIN(j)|

[0049] In the formula, j = 1, 2, ..., N, and N represents the number of extreme points of the magnetotelluric frequency CYT curve.

[0050] Furthermore, in this embodiment, the number of maximum limit envelopes LOG_MAX and minimum extremum envelopes LOG_MIN extracted is the same.

[0051] Furthermore, taking the absolute value of the calculated difference CG1(j) is to ensure that the obtained first difference parameter CG1 is always positive; the first difference parameter CG1 represents the width between the maximum and minimum extreme value envelopes. When the magnetotelluric frequency CYT curve fluctuates, the greater the fluctuation amplitude, the greater the width, and the greater the value of the first difference parameter CG1.

[0052] Step S3: Perform trend fitting based on the magnetotelluric frequency CYT curve to obtain the fitted straight line CNN;

[0053] Furthermore, the trend fitting based on the magnetotelluric frequency (CYT) curve to obtain the fitted straight line CNN aims to express the changing trend of the magnetotelluric frequency (CYT) curve, making the results more accurate; the expression of the CNN is:

[0054] CNN(i) = a * depth + b

[0055] In the formula, i = 1, 2, ..., M, where M is the number of sampling points of magnetotelluric frequency data, a and b represent the fitting coefficients obtained by linear regression analysis of the magnetotelluric frequency CYT curve, depth represents the depth of the underground target stratum, CNN(i) represents the fitted value of the sampling points, and CNN represents the fitted straight line, which is drawn from all CNN(i) values.

[0056] Step S4: Calculate the difference between the magnetotelluric frequency CYT curve and the fitted straight line CNN to obtain the second difference parameter CG2;

[0057] Furthermore, the second difference parameter CG2 represents the difference between the magnetotelluric frequency (CYT) curve and the CNN fitting trend line. Specifically, the value of CG2 expresses the offset of the fitted line CNN within the CYT curve. A larger CG2 value indicates a larger offset and higher formation resistivity. If CG2 is greater than 0, it indicates that the fitted line CNN is to the right of the CYT curve, suggesting a leftward skewness and high resistivity. If CG2 is less than 0, it indicates that the fitted line CNN is to the left of the CYT curve, suggesting a rightward skewness and low resistivity. Its specific expression is as follows:

[0058] CG2(i) = CNN(i) - CYT(i)

[0059] In the formula, i = 1, 2, ..., M, where M is the number of sampling points for the magnetotelluric frequency data.

[0060] Step S5: Based on the obtained first difference parameter CG1 and second difference parameter CG2, identify the underground target strata as gypsum-salt rock.

[0061] Furthermore, the specific criteria for identifying gypsum-salt rock in the underground target strata are as follows: when the first difference parameter CG1 is less than the first judgment threshold and the second difference parameter CG2 is greater than the second judgment threshold, the current rock stratum is gypsum-salt rock.

[0062] Furthermore, the setting of the first and second judgment thresholds is based on previously determined empirical values ​​from core data calibration; in this embodiment, the first judgment threshold is preferably 500, and the second judgment threshold is preferably 50, that is: CG1<500&&CG2>50.

[0063] In one embodiment, please refer to Figure 3 , Figure 3 This is a schematic diagram of a subsurface gypsum-salt layer identification system. The system includes: a CYT curve acquisition module, a first calculation module, a second calculation module, and a judgment and identification module.

[0064] The CYT curve acquisition module is used to acquire magnetotelluric frequency data of underground rock strata and generate magnetotelluric frequency CYT curves.

[0065] The first calculation module is used to obtain the first difference parameter CG1 based on the difference between the maximum extreme value envelope LOG_MAX and the minimum extreme value envelope LOG_MIN of the magnetotelluric frequency CYT curve;

[0066] The second calculation module is used to perform trend fitting on the magnetotelluric frequency CYT curve to obtain the fitting line CNN, and then calculate the difference between the magnetotelluric frequency CYT curve and the fitting line CNN to obtain the second difference parameter CG2.

[0067] The determination and identification module is used to determine and identify gypsum-salt rocks in the underground target strata using the obtained first difference parameter CG1 and second difference parameter CG2.

[0068] In one embodiment, an electronic device is provided, including a memory and a processor. The memory stores a computer program that, when executed by the processor, causes the processor to perform all the steps of a method for identifying underground gypsum-salt rock layers as described above.

[0069] In one embodiment, a computer storage medium is provided, on which a computer program is stored, which, when executed by the processor, is used to implement all the steps of a method for identifying underground gypsum-salt rock layers as described above.

[0070] Experimental example:

[0071] In one experimental example, please refer to Figures 4-6 Taking the Hetan 101 well in the Guangming structure of the Hetao Basin as an example, the invention will be further described in detail:

[0072] The Linhe Formation of the Guangming Tectonic System in the Hetao Basin is a set of clastic strata, including conglomerate sandstone, sandstone, gypsum-salt rock, and mudstone. According to the major lithological classification, in this experimental example, conglomerate sandstone and sandstone are collectively referred to as sandstone. The reservoir space is mainly porous, with the well logging electrical characteristics of the sandstone bodies showing low natural gamma, high neutron and sonic transit time, and slightly higher resistivity. The magnetotelluric frequency (CYT) curve measures the frequency information of electromagnetic waves. The frequency of electromagnetic waves is closely related to the porosity of the formation. Sandstone bodies have well-developed porosity, while mudstones do not. Therefore, due to the developed porosity of sandstone bodies, electromagnetic wave energy is absorbed, and the vibration frequency of electromagnetic waves decreases. Instead of a symmetrical sine wave vibrating back and forth, it vibrates continuously in one direction, resulting in an increased number of data points within a small layer. The number of statistical data points is actually the number of periods, i.e., the reciprocal of the frequency. The opposite is true for mudstone. Therefore, the magnetotelluric frequency (CYT) curve shows a clear difference between sandstone and mudstone, with sandstone having a higher number of periods and mudstone a lower number of periods.

[0073] In this experimental example, firstly, the CYT-VI type magnetotelluric field lithology detection instrument was used to measure the strata and obtain the magnetotelluric frequency CYT curve. The magnetotelluric frequency CYT curve is actually a processed value and is a dimensionless parameter. The processing procedure is as follows: the measured frequency is converted into a period, the depth is multiplied by 5, the converted period value is subtracted, and then divided by 200 nanoseconds to obtain the final CYT value CYT(i). Its specific expression is as follows:

[0074] CYT(i)=1000*(1 / F(i)-depth(i)*5) / 0.2

[0075] i = 1, 2, ..., M;

[0076] In the formula, F is the measured magnetotelluric frequency; depth is the stratum depth corresponding to the magnetotelluric frequency; and M is the number of sampling points for the magnetotelluric frequency data. In the process of acquiring the magnetotelluric frequency CYT curve, no manual calculation is required; the calculation method is encapsulated within the electric field lithology detection instrument. When measuring the strata, the electric field lithology detection instrument directly obtains the CYT value and the magnetotelluric frequency CYT curve plotted from the CYT value.

[0077] After obtaining the magnetotelluric frequency (CYT) curve of well HeTan 101, the maximum extreme value envelope (LOG_MAX) and minimum extreme value envelope (LOG_MIN) of the CYT curve are extracted. Next, the difference between LOG_MAX and LOG_MIN is calculated, and the absolute value of the calculated difference is taken to obtain the first difference parameter CG1. Then, a trend fit is performed on the obtained CYT curve to obtain the fitted line CNN. In the expression of the fitted line CNN: CNN(i) = a*depth + b, the coefficients of the CYT fitted curve of well HeTan 101 are: a = 0.347, b = -465.3. Then, the difference between the CYT curve and the fitted line CNN is calculated to obtain the second difference parameter CG2. Finally, based on the obtained first difference parameter CG1 and second difference parameter CG2, it is determined whether the underground target stratum is gypsum-salt rock. The specific determination method is: if CG1 is less than 500 and CG2 is greater than 50, then it is gypsum-salt rock.

[0078] Furthermore, the HeTan 101 well has already been drilled, and the logging lithology can be used as a standard to verify the identification effect. Please refer to [link / reference needed]. Figures 4-6 , Figures 4-6 The main data source is the identification results of gypsum-salt rock in the Hetao Basin well Hetan 101. In the figure, LOG_MAX and LOG_MIN represent the maximum and minimum envelopes of the distributed magnetotelluric frequency (CYT) curve, respectively. XL is the fitting line CNN of the CYT curve, and CG1 and CG2 are the judgment parameters. The data primarily shows the gypsum-salt rock layers identified by well logging and the CYT-identified gypsum-salt rock. The identification accuracy was calculated based on the thickness percentage. The thickness of the gypsum-salt rock layer in the formation is 73.5m, and the thickness of the identified gypsum-salt rock matching section is 62.1m. Finally, the calculated identification accuracy was 84.5%.

[0079] 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 for identifying underground gypsum-salt rock strata, characterized in that, include: Acquire magnetotelluric frequency data of underground rock strata and generate magnetotelluric frequency CYT curves. The first difference parameter CG1 is obtained based on the difference between the maximum extreme value envelope LOG_MAX and the minimum extreme value envelope LOG_MIN of the magnetotelluric frequency CYT curve. Trend fitting was performed on the magnetotelluric frequency (CYT) curve to obtain the fitted straight line CNN. The difference between the magnetotelluric frequency CYT curve and the fitted straight line CNN is calculated to obtain the second difference parameter CG2. Based on the obtained first difference parameter CG1 and second difference parameter CG2, the underground target strata are identified as gypsum-salt rocks.

2. The method for identifying underground gypsum-salt rock strata as described in claim 1, characterized in that, The expression for the magnetotelluric frequency CYT curve is: CYT(i)=1000*(1 / F(i)-depth(i)*5) / 0.2 i = 1, 2, ..., M In the formula, F represents the measured magnetotelluric frequency data; depth represents the stratum depth corresponding to the magnetotelluric frequency data; and M represents the number of sampling points for the magnetotelluric frequency data.

3. The method for identifying underground gypsum-salt rock strata as described in claim 2, characterized in that: The method for extracting the maximum extremum envelope LOG_MAX is as follows: LOG_MAX(j) = CYT(i) CYT(i)>CYT(i-1)&&CYT(i)>CYT(i+1) In the formula, i = 2, 3, ..., M-1; j = 1, 2, ..., N; where M is the number of sampling points of the magnetotelluric frequency data, and N represents the number of extreme points of the magnetotelluric frequency CYT curve; The method for extracting the minimum extremum envelope LOG_MIN is as follows: LOG_MIN(j)=CYT(i) CYT(i) <CYT(i-1)&&CYT(i)<CYT(i+1) In the formula, i = 2, 3, ..., M-1; j = 1, 2, ..., N; M is the number of sampling points of the magnetotelluric frequency data, and N represents the number of extreme points of the magnetotelluric frequency CYT curve.

4. The method for identifying underground gypsum-salt rock strata as described in claim 3, characterized in that: The first difference parameter CG1 is calculated as follows: CG1(j)=|LOG_MAX(j)-LOG_MIN(j)|, where j=1,2,…,N, and N represents the number of extreme points of the magnetotelluric frequency CYT curve; The first difference parameter CG1 is the width between the maximum and minimum extreme value envelopes, and its first difference parameter CG1 is proportional to the amplitude of the fluctuation of the magnetotelluric frequency CYT curve.

5. The method for identifying underground gypsum-salt rock strata as described in claim 2, characterized in that, The trend fitting based on the magnetotelluric frequency (CYT) curve yields a fitted straight line CNN, the expression of which is: CNN(i) = a * depth + b In the formula, i = 1, 2, ..., M, where M is the number of sampling points of magnetotelluric frequency data, a and b represent the fitting coefficients obtained by linear regression analysis of the magnetotelluric frequency CYT curve, depth represents the depth of the underground target stratum, CNN(i) represents the fitted value of the sampling points, and CNN represents the fitted straight line, which is drawn from all CNN(i) values.

6. The method for identifying underground gypsum-salt rock strata as described in claim 5, characterized in that: The expression for the second difference parameter CG2 is: CG2(i)=CNN(i)-CYT(i), where i=1,2,…,M, and M is the number of sampling points for the magnetotelluric frequency data.

7. The method for identifying underground gypsum-salt rock strata as described in claim 6, characterized in that: The second difference parameter CG2 represents the difference between the magnetotelluric frequency CYT curve and the CNN fitting trend line. Specifically, the value of CG2 expresses the offset of the fitting line CNN in the magnetotelluric frequency CYT curve. The larger the value of CG2, the greater the offset and the higher the formation resistivity. If the parameter CG2 is greater than 0, it means that the fitted line CNN is to the right of the magnetotelluric frequency CYT curve, indicating that the magnetotelluric frequency CYT curve is skewed to the left and the resistivity is high. If the parameter CG2 is less than 0, it means that the fitted line CNN is to the left of the magnetotelluric frequency CYT curve, indicating that the magnetotelluric frequency CYT curve is right-skewed and the resistivity is low.

8. A method for identifying underground gypsum-salt rock strata as described in any one of claims 1 to 7, characterized in that: The specific criteria for identifying gypsum-salt rock in the underground target strata are as follows: when the first difference parameter CG1 is less than the first judgment threshold and the second difference parameter CG2 is greater than the second judgment threshold, the current rock stratum is gypsum-salt rock.

9. A system for identifying underground gypsum-salt rock strata, characterized in that, include: The CYT curve acquisition module is used to acquire magnetotelluric frequency data of underground rock strata and generate magnetotelluric frequency CYT curves. The first calculation module is used to obtain the first difference parameter CG1 based on the difference between the maximum extreme value envelope LOG_MAX and the minimum extreme value envelope LOG_MIN of the magnetotelluric frequency CYT curve. The second calculation module is used to perform trend fitting on the magnetotelluric frequency CYT curve to obtain the fitting line CNN, and then calculate the difference between the magnetotelluric frequency CYT curve and the fitting line CNN to obtain the second difference parameter CG2. The determination and identification module is used to determine and identify gypsum-salt rocks in the underground target strata using the obtained first difference parameter CG1 and second difference parameter CG2.

10. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the computer program is executed by the processor, the processor performs a method for identifying underground gypsum-salt rock layers as described in any one of claims 1 to 8.

11. A computer storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements a method for identifying underground gypsum-salt rock strata as described in any one of claims 1 to 8.

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