CN117214962A - Shale gas favorable region identification method and system based on well-ground electromagnetic multi-parameter - Google Patents
Shale gas favorable region identification method and system based on well-ground electromagnetic multi-parameter Download PDFInfo
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Abstract
The application discloses a shale gas favorable region identification method and system based on well-ground electromagnetic multi-parameter, comprising the following steps: detecting by a two/three-dimensional ground electromagnetic method in a region to be detected, acquiring ground electromagnetic data, and inverting and imaging; the ground electromagnetic data comprises a first apparent resistivity and a first apparent polarization rate; drilling holes in the region to be detected and the region outside the region to be detected to obtain a plurality of cores, and measuring a second resistivity and a second polarization rate by a laboratory method; combining the second resistivity and the second polarization rate, and carrying out corresponding correction on the first apparent resistivity and the first apparent polarization rate by adopting a weighted average method to obtain a third apparent resistivity and a third apparent polarization rate; respectively identifying and extracting the third apparent resistivity and the third apparent polarization rate by adopting cluster analysis to respectively obtain abnormal positions and space spreading forms of low apparent resistivity and high apparent polarization rate; and dividing to obtain shale gas favorable areas.
Description
Technical Field
The application relates to the technical field of shale gas exploration, in particular to a method and a system for identifying a shale gas favorable region based on well-ground electromagnetic multi-parameters.
Background
At present, shale gas exploration technical methods are in vigorous development, wherein seismic exploration is taken as a main exploration means due to high resolution capability, but most shale gas exploration areas in south areas belong to complicated mountain areas, geological conditions are complex, seismic exploration is difficult to spread and cost is extremely high. The electromagnetic exploration method has the advantages of large exploration depth, high work efficiency and low cost. Meanwhile, the shale gas reservoir has electromagnetic characteristics of low resistivity, high polarizability and the like, so that the electromagnetic exploration method is used as the supplement of area census and seismic exploration in shale gas exploration, and common methods comprise a wide-area electromagnetic method, a time-frequency electromagnetic method, a magnetotelluric method, a complex resistivity method and the like. It should be noted that the shale gas favorable region in the technology is a shale gas favorable target region.
For example, in the patent publication No.: CN105607147a, name: in a chinese patent application of a method and system for inverting shale gas reservoir resistivity, it comprises: obtaining apparent resistivity of the target area by using a wide-area electromagnetic method; collecting seismic data of a target area; and performing constraint inversion on apparent resistivity according to the seismic data to obtain a distribution change rule of the shale gas reservoir resistivity of the target area. The technology avoids multiple solutions caused by inversion by a single earthquake or electromagnetic method in the prior art, and improves the accuracy and precision of inversion of the shale gas reservoir resistivity.
And the patent publication number is as follows: CN115097107a, name: a Chinese patent of a sea-phase shale low-resistance cause type and shale gas exploration potential judging method based on new resistivity parameters evaluates the shale low-resistance cause of a single well and the exploration potential of corresponding construction units from two angles of the shale low-resistance cause type and on-site analysis gas quantity, specifically partitions the shale low-resistance cause through a new resistivity parameter and deep lateral intersection map, and enables on-site analysis gas quantity data points to be in a gas content interval of the shale low-resistance cause, so that a production unit can be helped to quickly define the shale low-resistance cause type, whether industrial productivity is achieved or not can be quickly judged, the exploration potential of similar construction units is evaluated, and the method is favorable for the production unit to quickly make decisions.
And the patent publication number is as follows: CN111188612a, name: a Chinese patent application of a rapid identification method of shale oil dessert by logging multi-parameter fusion mainly comprises the following steps: logging the shale well completion to obtain a plurality of logging curves; selecting a compensation sound wave curve, a natural gamma curve, a compensation density curve and a deep resistivity curve as sensitive logging curves; respectively carrying out linear conversion on the compensation acoustic wave curve, the natural gamma curve and the compensation density curve by a dispersion standardization method to obtain a standardized compensation acoustic wave curve, a standardized natural gamma curve and a standardized compensation density curve; selecting resistivity values of the mudstone sections with stable distribution to obtain a standardized deep resistivity curve; and obtaining a shale oil comprehensive evaluation index curve according to the standardized sensitive logging curve. The method fully integrates various logging response characteristics, and effectively improves the accuracy of evaluating desserts by using logging data.
The method is characterized in that a complex resistivity model without frequency bands and parameter inversion are further researched on the basis of rock complex resistivity experimental analysis from three-dimensional forward modeling of a well-to-ground differential electromagnetic method (BSDEM) in the complex resistivity research of the well-to-ground differential electromagnetic method and the application of the well-to-ground differential electromagnetic method in the evaluation of the oil saturation of a reservoir, the complex resistivity constraint inversion method of the BSDEM reservoir is provided, and the complex resistivity reservoir evaluation method based on the BSDEM is formed. In addition, a three-dimensional CSEM and seismic joint inversion method based on a cross gradient coupling mechanism is provided in a section of 'CSEM and seismic joint inversion research based on cross gradients', and meanwhile, self-adaptive correction is performed in inversion iteration by means of mean value clustering and regression analysis technology.
However, the above-described technique has the following problems:
first, the above techniques mostly perform exploration identification on advantageous regions of shale gas from a single method, single attribute, single parameter angle, or detect in combination with costly seismic exploration methods. Electromagnetic exploration methods cannot fully exploit their method advantages in shale gas exploration due to the multi-resolution of a single parameter and the resolution of the exploration.
Secondly, the identification accuracy of exploration and identification of the shale gas favorable region by adopting a single attribute and a single parameter angle is low. Which is limited by a certain property or a certain parameter. If the acquired information such as parameters, data and the like has local abnormal information or the acquired data has errors, the information directly causes the errors in the identification of the beneficial region.
Therefore, there is an urgent need to provide a method and a system for identifying a shale gas favorable region based on well-earth electromagnetic multi-parameters, which are simple in logic, accurate and reliable.
Disclosure of Invention
Aiming at the problems, the application aims to provide a shale gas favorable region identification method and a shale gas favorable region identification system based on well-ground electromagnetic multi-parameters, and the technical scheme adopted by the application is as follows:
in a first aspect, the present application provides a method for identifying a beneficial zone of shale gas based on well-to-earth electromagnetic multiparameters, comprising the steps of:
detecting by a two/three-dimensional ground electromagnetic method in a region to be detected, acquiring ground electromagnetic data, and inverting and imaging; the ground electromagnetic data comprise a first apparent resistivity and a first apparent polarization rate;
drilling holes in the region to be detected and the region outside the region to be detected to obtain a plurality of cores, and measuring a second resistivity and a second polarization rate by a laboratory method;
combining the second resistivity and the second polarization rate, and carrying out corresponding correction on the first apparent resistivity and the first apparent polarization rate by adopting a weighted average method to obtain a third apparent resistivity and a third apparent polarization rate;
respectively identifying and extracting the third apparent resistivity and the third apparent polarization rate by adopting cluster analysis to obtain an abnormal position and a spatial spreading form of the low apparent resistivity and an abnormal position and a spatial spreading form of the high apparent polarization rate;
and obtaining the coincidence area of the abnormal position and the space spreading form of the low apparent resistivity and the high apparent polarization, namely the shale gas favorable area.
In a second aspect, the present application provides a shale gas vantage point identification system based on well-to-earth electromagnetic multiparameters, comprising:
the ground electromagnetic data acquisition module is used for carrying out two-dimensional/three-dimensional ground electromagnetic method detection in the region to be detected, acquiring ground electromagnetic data and carrying out inversion imaging; the ground electromagnetic data comprise a first apparent resistivity and a first apparent polarization rate;
the input module is used for inputting the second resistivity and the second polarization rate; the obtaining of the second resistivity and the second polarizability comprises the following steps: drilling holes in the region to be detected and the region outside the region to be detected to obtain a plurality of cores, and measuring a second resistivity and a second polarization rate by a laboratory method;
the correction module is connected with the ground electromagnetic data acquisition module and the input module, combines the second resistivity and the second polarization rate, and carries out corresponding correction on the first apparent resistivity and the first apparent polarization rate by adopting a weighted average method to obtain a third apparent resistivity and a third apparent polarization rate;
the cluster analysis module is connected with the correction module, and performs recognition and extraction on the third apparent resistivity and the third apparent polarization rate respectively by adopting cluster analysis to obtain an abnormal position and a spatial spreading form of the low apparent resistivity and an abnormal position and a spatial spreading form of the high apparent polarization rate;
and the labeling module is connected with the cluster analysis module and used for obtaining the abnormal positions of low apparent resistivity and high apparent polarizability and the overlapping area of the spatial spreading form, namely the shale gas favorable area.
Compared with the prior art, the application has the following beneficial effects:
(1) The method starts from electromagnetic characteristics of shale gas, and adopts an electromagnetic method to obtain a first apparent resistivity and a first apparent polarization rate; and then obtaining the second resistivity and the second polarization rate by using a core taking laboratory test. The application adopts the combination of multiple methods and multiple parameters, and reduces the multiple solutions of the single method and the parameters. Meanwhile, the methods are independently processed and mutually verified, so that the identification accuracy of the electromagnetic method on shale gas exploration is further improved.
(2) According to the application, the first apparent resistivity and the first apparent polarization rate are correspondingly corrected by combining the second resistivity and the second polarization rate and adopting a weighted average method, so that the accuracy and reliability of data for cluster analysis are ensured, and the accuracy of identification is further provided.
(3) The method is characterized in that clustering analysis is adopted for electromagnetic characteristics of shale gas with low resistivity and high polarizability, and corresponding clustering centers are obtained, so that abnormal positions and spatial distribution forms with low apparent resistivity and abnormal positions and spatial distribution forms with high apparent polarizability are respectively obtained. And then intersection is calculated to obtain an accurate and reliable shale gas beneficial zone, which is accurate and reliable and has simple logic.
In conclusion, the method has the advantages of simple logic, accuracy, reliability and the like, and has high practical value and popularization value in the technical field of shale gas exploration.
Drawings
For a clearer description of the technical solutions of the embodiments of the present application, the drawings to be used in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and should not be considered as limiting the scope of protection, and other related drawings may be obtained according to these drawings without the need of inventive effort for a person skilled in the art.
FIG. 1 is a logic flow diagram of the present application.
FIG. 2 is a first apparent resistivity cross-section of the application.
FIG. 3 is a first cross-sectional view of the present application in terms of apparent polarization.
FIG. 4 is a graph of second resistivity results from an in-house test of the present application.
FIG. 5 is a graph showing the second polarizability results of the indoor test of the present application.
Fig. 6 is a graph of a vantage point range division of a shale gas of the present application.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the present application will be further described with reference to the accompanying drawings and examples, which include, but are not limited to, the following examples. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
In this embodiment, the term "and/or" is merely an association relationship describing the association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone.
The terms first and second and the like in the description and in the claims of the present embodiment are used for distinguishing between different objects and not for describing a particular sequential order of objects. For example, the first target object and the second target object, etc., are used to distinguish between different target objects, and are not used to describe a particular order of target objects.
In embodiments of the application, words such as "exemplary" or "such as" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g." in an embodiment should not be taken as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete fashion.
In the description of the embodiments of the present application, unless otherwise indicated, the meaning of "a plurality" means two or more. For example, the plurality of processing units refers to two or more processing units; the plurality of systems means two or more systems.
As shown in fig. 1 to 6, the present embodiment provides a shale gas vantage point identification method based on well-to-earth electromagnetic multiparameter, which includes the steps of:
firstly, carrying out two/three-dimensional ground electromagnetic method detection in a region to be detected, carrying out two/three-dimensional ground electromagnetic data acquisition, acquiring ground electromagnetic data, and carrying out inversion imaging; the surface electromagnetic data includes a first apparent resistivity, a first apparent polarization, as shown in fig. 2 and 3.
In this embodiment, the ground electromagnetic method may be more specifically selected, such as a time-frequency electromagnetic method, a wide-area electromagnetic method, and the like. In this case, a time-frequency electromagnetic method is preferred, and the method can perform time-frequency and frequency-domain acquisition simultaneously, and simultaneously obtain the parameters of the first apparent resistivity and the first apparent polarization, so that economic cost can be greatly saved. In this embodiment, after field data acquisition is completed, the data is preprocessed, including time-frequency conversion, normalization, denoising, and the like.
The frequency domain data is processed to obtain the apparent resistivity of the whole area. In this embodiment, the first apparent resistivity of the region to be detected is obtained according to the frequency domain data, which is expressed as:
wherein I represents an emission current; e (E) x (ω) represents electric field strength; ρ represents the first apparent resistivity of the uniform half space; r represents the distance between the measuring point and the origin of coordinates, and l represents the half length from the point A to the point B of the transmitting source; (x, y) represents coordinates of a measuring point relative to a center point of the emission source; ζ represents the coordinates of the current element in the emission source cable; phi represents the included angle between the measuring point and the origin of coordinates, and k represents the wave number; e represents the base of natural logarithms;
the expression of the wave number k is:
μ 0 ＝4π10 -7
omega represents an angular frequency; i represents a complex number unit; u (u) 0 Indicating vacuum permeability;
obtaining the first apparent resistivity of the uniform half space by adopting a numerical iteration method ρ 。
In addition, a first visual polarization rate eta is obtained from the time domain data s The expression is as follows:
wherein,representation->A secondary potential difference measured at a moment; deltaV (T) represents the total field potential difference at time T of power supply; and the moment T is the instant of power failure.
In this embodiment, the first apparent resistivity and the first apparent polarizability obtained as described above are gridded and interpolated to perform two-dimensional/three-dimensional imaging of the entire survey area.
And secondly, drilling holes in the region to be detected and the region outside the region to be detected to obtain a plurality of cores, and measuring a second resistivity and a second polarization rate by a laboratory method, wherein the second resistivity and the second polarization rate are shown in figures 4 to 5.
In this embodiment, the complex resistivity of the core sample is measured in the room by using the impedance testing instrument, and the resistivity value of each frequency point of the sample is calculated according to the real and imaginary parts of the measured complex resistivity value of the sample, where the expression is:
ρ(ω')＝Z(ω')*π*(r') 2 /L'
wherein ω' represents frequency; r' represents the radius of the core sample; l' represents the height of the core sample; z (ω') represents impedance;
and taking the real part and the imaginary part of the complex resistivity as the second resistivity of the rock core.
In this example, a dual Cole-Cole model was used to determine the second polarizability of the core, expressed as:
wherein ρ' 0 A second resistivity representing zero frequency; m is m 1 Denoted τ 1 A second polarization rate at the moment; m is m 2 Denoted τ 2 A second polarization rate at the moment; c 1 And c 2 Representing a frequency correlation coefficient which is a constant and has a value range of 0-1; i represents a complex number unit.
Combining the second resistivity and the second polarization rate, and carrying out corresponding correction on the first apparent resistivity and the first apparent polarization rate by adopting a weighted average method to obtain a third apparent resistivity and a third apparent polarization rate;
and projecting the drilling position in the second step into the two/three-dimensional result of the first step, and carrying out weighted average on the second resistivity and the second polarization value which are tested indoors in the second step, the corresponding position of the first step, the two/three-dimensional first apparent resistivity of the corresponding depth and the first apparent polarization. Here, the apparent resistivity is taken as an example:
adopts the value K of the second resistivity 2 And a value K of the first apparent resistivity 1 And obtaining a value K of the third apparent resistivity, wherein the value K is expressed as follows:
wherein a is 1 A weight coefficient corresponding to the first apparent resistivity is represented; a, a 2 And the weight coefficient corresponding to the second resistivity is represented.
In this embodiment, the weighted average result is used as a control point, and the first apparent resistivity and the first apparent polarizability in the first step are gridded and interpolated again to obtain a more accurate two/three-dimensional imaging result.
And fourthly, respectively identifying and extracting the third apparent resistivity and the third apparent polarization rate by adopting cluster analysis to obtain an abnormal position and a spatial spreading form of the low apparent resistivity and an abnormal position and a spatial spreading form of the high apparent polarization rate. In the process of identifying and extracting the third apparent resistivity and the third apparent polarization rate by adopting cluster analysis, a region corresponding to 50% of the average apparent resistivity of which the apparent resistivity is smaller than the third apparent resistivity is taken as a region corresponding to the low apparent resistivity; and taking a region corresponding to 150% of the average visual polarization rate of which the visual polarization rate is larger than the third visual polarization rate as a region corresponding to the high visual polarization rate.
In the embodiment, a K-means clustering method is selected to perform low-resistance and high-polarization anomaly identification extraction on the two/three-dimensional third apparent resistivity and the third apparent polarizability result in the third step. K mean clustering is an unsupervised real-time clustering algorithm, and is most widely used in cluster analysis due to simplicity and high efficiency of the algorithm. The algorithm adopts the distance as an evaluation index of the similarity, so that a standard measure function for evaluating the clustering performance reaches the optimal.
Here, taking the third apparent resistivity as an example, it includes the steps of:
(1) Obtaining a third apparent resistivity corresponding to a plurality of data points, and forming a data set X;
(2) Sorting the third apparent resistivity in the data set X from large to small, selecting the last K data, and taking the last K data as an initial clustering center C;
(3) Classifying the data set X according to a minimum distance algorithm to obtain a plurality of cluster types;
(4) Updating the cluster center for any cluster, and classifying until the following formula is satisfied:
wherein J (C, X) represents a standard function of the third apparent resistivity cluster;represents the ith 1 Personal clustering centerAnd the j-th third apparent resistivity X j Euclidean distance between them.
And fifthly, on the basis of the fourth step, the region meeting the characteristics of low resistivity and high polarizability can be divided into shale gas favorable regions, and the region meeting a certain characteristic can be divided into potential favorable regions.
First, according to the low resistivity and high polarizability anomalies identified in the fourth step, the position coordinates and depth information of the low resistivity and high polarizability are respectively indexed in the two/three-dimensional results through numerical indexes.
Then, the positions and depths which simultaneously meet the characteristics of low resistivity and high polarizability are divided into shale gas favorable areas.
Then, the position and depth satisfying one of the characteristics of low resistivity and high polarizability are divided into potential beneficial areas of shale gas. As shown in fig. 6.
The above embodiments are only preferred embodiments of the present application and are not intended to limit the scope of the present application, but all changes made by adopting the design principle of the present application and performing non-creative work on the basis thereof shall fall within the scope of the present application.
Claims (10)
1. The shale gas favorable region identification method based on the well-ground electromagnetic multi-parameter is characterized by comprising the following steps of:
detecting by a two/three-dimensional ground electromagnetic method in a region to be detected, acquiring ground electromagnetic data, and inverting and imaging; the ground electromagnetic data comprise a first apparent resistivity and a first apparent polarization rate;
drilling holes in the region to be detected and the region outside the region to be detected to obtain a plurality of cores, and measuring a second resistivity and a second polarization rate by a laboratory method;
combining the second resistivity and the second polarization rate, and carrying out corresponding correction on the first apparent resistivity and the first apparent polarization rate by adopting a weighted average method to obtain a third apparent resistivity and a third apparent polarization rate;
respectively identifying and extracting the third apparent resistivity and the third apparent polarization rate by adopting cluster analysis to obtain an abnormal position and a spatial spreading form of the low apparent resistivity and an abnormal position and a spatial spreading form of the high apparent polarization rate;
and obtaining the coincidence area of the abnormal position and the space spreading form of the low apparent resistivity and the high apparent polarization, namely the shale gas favorable area.
2. The method for identifying the shale gas favorable region based on the well-earth electromagnetic multi-parameter according to claim 1, wherein in the identification and extraction of the third apparent resistivity and the third apparent polarization rate by adopting cluster analysis, a region corresponding to 50% of the average apparent resistivity, of which the apparent resistivity is smaller than the third apparent resistivity, is taken as a region corresponding to the low apparent resistivity; and taking a region corresponding to 150% of the average visual polarization rate of which the visual polarization rate is larger than the third visual polarization rate as a region corresponding to the high visual polarization rate.
3. The method for identifying the shale gas favorable region based on the well-ground electromagnetic multi-parameter according to claim 1, wherein the two/three-dimensional ground electromagnetic method detection is carried out on the region to be detected, and the ground electromagnetic data are acquired; the two/three-dimensional ground electromagnetic method is a time-frequency electromagnetic method or a wide-area electromagnetic method.
4. The method for identifying the shale gas favorable region based on the well-ground electromagnetic multi-parameter according to claim 3, wherein the two/three-dimensional ground electromagnetic method is a time-frequency electromagnetic method, and frequency domain data and time domain data are acquired and obtained; further comprises:
obtaining a first apparent resistivity of the region to be detected according to the frequency domain data, wherein the first apparent resistivity is expressed as follows:
wherein I represents an emission current; e (E) x (ω) represents electric field strength; ρ represents the first apparent resistivity of the uniform half space; r represents the distance between the measuring point and the origin of coordinates, l represents the point A to point B of the emitting sourceOne half length; (x, y) represents coordinates of a measuring point relative to a center point of the emission source; ζ represents the coordinates of the current element in the emission source cable; phi represents the included angle between the measuring point and the origin of coordinates, and k represents the wave number; e represents the base of natural logarithms;
the expression of the wave number k is:
μ 0 ＝4π10 -7
omega represents an angular frequency; i represents a complex number unit; u (u) 0 Indicating vacuum permeability;
and obtaining the first apparent resistivity rho of the uniform half space by adopting a numerical iteration method.
5. The method for identifying a shale gas vantage point based on well-to-earth electromagnetic multiparameters of claim 4, further comprising: obtaining a first visual polarization rate eta from time domain data s The expression is as follows:
wherein,representation->A secondary potential difference measured at a moment; deltaV (T) represents the total field potential difference at time T of power supply; and the moment T is the instant of power failure.
6. The method for identifying a favorable region of shale gas based on well-earth electromagnetic multiparameters according to claim 1, wherein the second resistivity is measured by laboratory method, comprising the steps of:
the complex resistivity ρ (ω') of the core was measured using an impedance test instrument, expressed as:
ρ(ω')＝Z(ω')*π*(r') 2 /L'
wherein ω' represents frequency; r' represents the radius of the core sample; l' represents the height of the core sample; z (ω') represents impedance;
and taking the real part and the imaginary part of the complex resistivity as the second resistivity of the rock core.
7. The method for identifying a favorable region of shale gas based on well-land electromagnetic multiparameters according to claim 6, wherein measuring the second polarizability by laboratory method comprises:
obtaining a second polarizability of the core by adopting a double Cole-Cole model, wherein the second polarizability is expressed as follows:
wherein ρ' 0 A second resistivity representing zero frequency; m is m 1 Denoted τ 1 A second polarization rate at the moment; m is m 2 Denoted τ 2 A second polarization rate at the moment; c 1 And c 2 Representing a frequency correlation coefficient, which is a constant; i represents a complex number unit.
8. The method for identifying the shale gas favorable region based on the well-earth electromagnetic multi-parameter according to claim 1, wherein the method is characterized in that the second resistivity and the second polarization rate are combined, and the first apparent resistivity and the first apparent polarization rate are correspondingly corrected by adopting a weighted average method to obtain a third apparent resistivity and a third apparent polarization rate;
the determination of the third apparent resistivity includes the steps of:
adopts the value K of the second resistivity 2 And a value K of the first apparent resistivity 1 And obtaining a value K of the third apparent resistivity, wherein the value K is expressed as follows:
wherein a is 1 A weight coefficient corresponding to the first apparent resistivity is represented; a, a 2 And the weight coefficient corresponding to the second resistivity is represented.
9. The method for identifying the shale gas favorable region based on the well-earth electromagnetic multi-parameter according to claim 1, which is characterized in that the third apparent resistivity and the third apparent polarizability are respectively identified and extracted by adopting cluster analysis; the identification and extraction of the third apparent resistivity comprises the following steps:
obtaining a third apparent resistivity corresponding to a plurality of data points, and forming a data set X;
sorting the third apparent resistivity in the data set X from large to small, selecting the last K data, and taking the last K data as an initial clustering center C; the K is a positive integer;
classifying the data set X according to a minimum distance algorithm to obtain a plurality of cluster types;
updating the cluster center for any cluster, and classifying until the following formula is satisfied:
wherein J (C, X) represents a standard function of the third apparent resistivity cluster;represents the ith 1 Personal cluster center->And the j-th third apparent resistivity X j Euclidean distance between them.
10. A shale gas vantage point identification system based on well-to-earth electromagnetic multiparameters, comprising:
the ground electromagnetic data acquisition module is used for carrying out two-dimensional/three-dimensional ground electromagnetic method detection in the region to be detected, acquiring ground electromagnetic data and carrying out inversion imaging; the ground electromagnetic data comprise a first apparent resistivity and a first apparent polarization rate;
the input module is used for inputting the second resistivity and the second polarization rate; the obtaining of the second resistivity and the second polarizability comprises the following steps: drilling holes in the region to be detected and the region outside the region to be detected to obtain a plurality of cores, and measuring a second resistivity and a second polarization rate by a laboratory method;
the correction module is connected with the ground electromagnetic data acquisition module and the input module, combines the second resistivity and the second polarization rate, and carries out corresponding correction on the first apparent resistivity and the first apparent polarization rate by adopting a weighted average method to obtain a third apparent resistivity and a third apparent polarization rate;
the cluster analysis module is connected with the correction module, and performs recognition and extraction on the third apparent resistivity and the third apparent polarization rate respectively by adopting cluster analysis to obtain an abnormal position and a spatial spreading form of the low apparent resistivity and an abnormal position and a spatial spreading form of the high apparent polarization rate;
and the labeling module is connected with the cluster analysis module and used for obtaining the abnormal positions of low apparent resistivity and high apparent polarizability and the overlapping area of the spatial spreading form, namely the shale gas favorable area.
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