Processing method using two-dimensional time-frequency electromagnetic data

Abstract

The invention provides a processing method using two-dimensional time-frequency electromagnetic data. The processing method comprises the following steps: obtaining collected time domain electric field data of a measuring point on a measuring line, and carrying out de-noising processing to obtain a time domain electric field database after de-noising correction; obtaining a measuring point frequency domain electric field amplitude and phase database on the acquisition measuring line based on Fourier transform; obtaining frequency domain-apparent resistivity data based on the whole-area apparent resistivity definition; carrying out three-dimensional fine processing on the original data by utilizing the electrical information; carrying out time-frequency electromagnetic three-dimensional inversion; the depth domain-resistivity data obtained through time-frequency electromagnetic three-dimensional inversion are analyzed and processed; extracting a time-frequency electromagnetic three-dimensional inversion depth domain-resistivity result of a corresponding seismic survey line coordinate; and carrying out comprehensive geological interpretation application in combination with seismic data. The method for carrying out three-dimensional processing, three-dimensional inversion and application on the two-dimensional time-frequency electromagnetic data is realized, and the inversion precision and accuracy of the two-dimensional time-frequency electromagnetic data are improved.

Description

Technical Field

[0001] The present invention relates to the field of geophysical data processing and geological comprehensive interpretation technology in petroleum exploration, and in particular to a processing method using two-dimensional time-frequency electromagnetic data. Background Art

[0002] The time-frequency electromagnetic exploration method in geophysical exploration is usually an important geophysical means to study the internal electrical structure of the earth. It can detect the electrical distribution of various points from tens of meters to tens of kilometers above the ground, and plays an important role in identifying geological targets such as basin structure, basin-mountain contact relationship, and faults.

[0003] The electromagnetic signals collected by the time-frequency electromagnetic method have the advantages of anti-interference and high signal-to-noise ratio due to the use of high-power artificial sources to transmit signals. In oil exploration, they have the advantages of not being shielded by high resistance, having strong resolution for high-conductivity layers and strong lateral resolution. However, due to its volume effect and lateral effect, the resolution and accuracy of the inversion results obtained by performing two-dimensional inversion on conventional two-dimensional time-frequency electromagnetic acquisition data in complex structural areas are difficult to match with seismic data, and cannot meet the requirements of conventional gravity, magnetic, electric and seismic joint exploration and research. Summary of the invention

[0004] In view of the above problems, the present invention is proposed to provide a processing method using two-dimensional time-frequency electromagnetic data that overcomes the above problems or at least partially solves the above problems.

[0005] According to one aspect of the present invention, a processing method using two-dimensional time-frequency electromagnetic data is provided, the processing method comprising:

[0006] Step 101: Based on the collected data, the time domain electric field data of the measuring points on the collected measuring line are obtained, and denoising is performed to obtain a time domain electric field database after denoising and correction;

[0007] Step 102: Obtaining a frequency domain electric field amplitude and phase database of the measuring points on the acquisition measurement line based on Fourier transform;

[0008] Step 103: Based on the definition of the apparent resistivity of the entire area, frequency domain-apparent resistivity data is obtained;

[0009] Step 104: Using the electrical information and combining it with the apparent resistivity information of the first branch, an electrical model of the work area is established, and three-dimensional fine processing of the original data is carried out;

[0010] Step 105: Optimize inversion parameters and carry out time-frequency electromagnetic three-dimensional inversion;

[0011] Step 106: Analyze and process the depth domain-resistivity data obtained by the time-frequency electromagnetic three-dimensional inversion;

[0012] Step 107: Extract the time-frequency electromagnetic three-dimensional inversion depth domain-resistivity results corresponding to the seismic survey line coordinates; combine with the seismic data to perform comprehensive geological interpretation applications.

[0013] Optionally, the step 104: using the electrical information and combining the first branch apparent resistivity information to establish an electrical model of the work area and carry out three-dimensional fine processing of the original data specifically includes:

[0014] By using the three-dimensional processing technology of two-dimensional time-frequency electromagnetic frequency domain-apparent resistivity data, we can obtain frequency domain-apparent resistivity two-dimensional time-frequency electromagnetic data that can fully reflect the complex electrical structure.

[0015] Optionally, the step 105: optimizing inversion parameters and carrying out time-frequency electromagnetic three-dimensional inversion specifically includes: using electromagnetic three-dimensional inversion technology to obtain a time-frequency electromagnetic three-dimensional inversion resistivity-depth domain data volume.

[0016] Optionally, before the step 107: extracting, analyzing and interpreting the depth domain-resistivity data obtained by the time-frequency electromagnetic three-dimensional inversion, the following steps may be further performed:

[0017] According to the two-dimensional time-frequency electromagnetic acquisition coordinates, the depth domain-resistivity inversion results of the two-dimensional survey line are extracted from the resistivity-depth domain data volume obtained by the time-frequency electromagnetic three-dimensional inversion, and combined with the seismic data, a comprehensive interpretation of the two-dimensional time-frequency electromagnetic acquisition survey line is performed.

[0018] Optionally, the seismic data includes: geological, drilling, gravity, magnetic and seismic data.

[0019] Optionally, the step 104: using the drilling and outcrop electrical information in combination with the first branch apparent resistivity information to establish an electrical model of the work area and conduct three-dimensional fine processing of the original data specifically includes:

[0020] Using the drilling and outcrop electrical measurement data, a regional electrical model for the study area was established;

[0021] The pre-processed time-frequency electromagnetic data is subjected to three-dimensional fine pre-processing of flying spot and static displacement correction by using filtering processing method;

[0022] The data are processed in three dimensions to obtain frequency domain-apparent resistivity data that can fully reflect the complex electrical structure.

[0023] Optionally, the electrical information includes: drilling and outcrop.

[0024] Optionally, the filtering processing method specifically includes: spatial filtering method, curve translation method, and low-pass filtering.

[0025] Optionally, the step 105: optimizing inversion parameters and carrying out time-frequency electromagnetic three-dimensional inversion specifically includes:

[0026] Optimize inversion parameters and carry out time-frequency electromagnetic three-dimensional inversion;

[0027] The time-frequency electromagnetic three-dimensional inversion depth domain-resistivity data volume obtained by three-dimensional inversion.

[0028] Optionally, the analysis process in step 106 specifically includes: extraction, analysis, and interpretation.

[0029] The present invention provides a processing method using two-dimensional time-frequency electromagnetic data, the processing method comprising: step 101: based on the collected data, obtaining the time domain electric field data of the measuring points on the collected survey line, and performing denoising processing to obtain the time domain electric field database after denoising correction; step 102: obtaining the frequency domain electric field amplitude and phase database of the measuring points on the collected survey line based on Fourier transform; step 103: obtaining the frequency domain-apparent resistivity data based on the definition of the apparent resistivity of the whole area; step 104: using the electrical information, combining the first branch apparent resistivity information to establish the electrical model of the work area, and carrying out three-dimensional fine processing of the original data; step 105: optimizing the inversion parameters, and carrying out time-frequency electromagnetic three-dimensional inversion; step 106: analyzing and processing the depth domain-resistivity data obtained by the time-frequency electromagnetic three-dimensional inversion; step 107: extracting the time-frequency electromagnetic three-dimensional inversion depth domain-resistivity results corresponding to the seismic survey line coordinates; combining with the seismic data, carrying out comprehensive geological interpretation application. A method for three-dimensional processing, three-dimensional inversion and application of two-dimensional time-frequency electromagnetic data has been realized, which improves the inversion precision and accuracy of two-dimensional time-frequency electromagnetic data. It can be widely used in fine interpretation and combined gravity, magnetic, electric and seismic interpretation in oil and gas exploration.

[0030] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0032] Figure 1 A flowchart of a processing method using two-dimensional time-frequency electromagnetic data provided by an embodiment of the present invention;

[0033] Figure 2 is a graph of the electric field amplitude and phase properties of a time-frequency electromagnetic survey line in a specific embodiment of the present invention;

[0034] Figure 3 It is a frequency domain-apparent resistivity profile of a time-frequency electromagnetic survey line in two-dimensional processing in a specific embodiment of the present invention;

[0035] Figure 4 It is a frequency domain-apparent resistivity profile of a time-frequency electromagnetic survey line in three-dimensional processing in a specific embodiment of the present invention;

[0036] Figure 5 It is a three-dimensional display diagram of the depth domain-resistivity data volume of the time-frequency electromagnetic survey line in a specific embodiment of the present invention;

[0037] Figure 6 It is a three-dimensional inversion depth domain-resistivity profile of a time-frequency electromagnetic survey line in a specific embodiment of the present invention;

[0038] Figure 7 It is a three-dimensional inversion depth domain-resistivity profile of a seismic survey line in a specific embodiment of the present invention;

[0039] Figure 8 It is a frequency domain-apparent resistivity profile of a time-frequency electromagnetic survey line in two-dimensional processing in a specific embodiment of the present invention;

[0040] Fig. 9 It is a frequency domain-apparent resistivity profile of a survey line in three-dimensional processing in a specific embodiment of the present invention;

[0041] Fig.10 It is a three-dimensional display diagram of the depth domain-resistivity data volume of the time-frequency electromagnetic survey line in a specific embodiment of the present invention;

[0042] Fig.11 It is a three-dimensional inversion depth domain-resistivity profile of a time-frequency electromagnetic survey line in a specific embodiment of the present invention;

[0043] Fig.12 It is a depth domain-resistivity profile diagram of a time-frequency electromagnetic survey line three-dimensional inversion in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0044] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0045] The terms "comprises" and "having" and any variations thereof in the description embodiments, claims and drawings of the present invention are intended to cover non-exclusive inclusions, for example, including a series of steps or units.

[0046] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0047] like Figure 1 As shown, Figure 1 The present invention is a flow chart of a method for three-dimensional processing, inversion and application using two-dimensional time-frequency electromagnetic data.

[0048] Step 101, based on the collected data, the time domain electric field data of the measuring points on the collected measuring line are obtained, and conventional denoising and other processing are performed to obtain a denoised and corrected time domain electric field database;

[0049] Step 102, obtaining a frequency domain electric field amplitude and phase database of the measuring points on the acquisition measuring line based on Fourier transform;

[0050] Step 103, based on the definition of apparent resistivity of the whole area, obtaining frequency domain-apparent resistivity data;

[0051] Step 104, using the electrical information of drilling, outcrop, etc., combined with the first branch apparent resistivity information, an electrical model of the work area is established, and three-dimensional fine processing of the original data is carried out;

[0052] Step 105, optimizing inversion parameters and carrying out time-frequency electromagnetic three-dimensional inversion;

[0053] Step 106, three-dimensional inversion of time-frequency electromagnetic three-dimensional inversion depth domain-resistivity data volume obtained by three-dimensional inversion;

[0054] Step 107, extracting, analyzing and interpreting the depth domain-resistivity data obtained by the time-frequency electromagnetic three-dimensional inversion.

[0055] Step 108, extract the time-frequency electromagnetic three-dimensional inversion depth and resistivity results corresponding to the seismic line coordinates; combine geological, drilling, gravity and magnetic and seismic data to perform comprehensive geological interpretation applications.

[0056] Example 1

[0057] In step 1, the electric field data collected by two-dimensional time-frequency electromagnetic is denoised in the time domain; the time domain electric field data is used to obtain the frequency domain-electric field amplitude and phase data, such as Figure 2 As shown; Based on the definition of apparent resistivity of the whole area, the frequency domain-apparent resistivity data is obtained, such as Figure 3 As shown;

[0058] In step 2, the regional electrical model of the study area is first established using the drilling and outcrop electrical measurement data; the pre-processed time-frequency electromagnetic data are subjected to three-dimensional fine pre-processing such as flying point and static displacement correction using spatial filtering, curve translation, low-pass filtering, etc.; the above data are comprehensively processed in three-dimensional closure to obtain frequency domain-apparent resistivity data that can fully reflect the complex electrical structure, such as Figure 4shown.

[0059] In step 3, high-precision terrain data is used to establish a three-dimensional surface elevation data network in the study area; the inversion parameters are optimized, and time-frequency electromagnetic three-dimensional inversion is carried out to obtain the time-frequency electromagnetic three-dimensional depth domain-resistivity data volume, such as Figure 5 As shown;

[0060] In step 4, extract the coordinates of the two-dimensional time-frequency electromagnetic survey line and load them into the depth domain-resistivity data volume obtained by the three-dimensional time-frequency electromagnetic inversion; extract the depth domain-resistivity inversion results obtained by the three-dimensional time-frequency electromagnetic inversion of the corresponding survey line coordinates; combine geological, drilling and other data to conduct a comprehensive interpretation of the time-frequency electromagnetic acquisition survey line, such as Figure 6 As shown;

[0061] In step 5, extract the coordinates of any seismic line in the work area and load them into the depth domain-resistivity data volume of the time-frequency electromagnetic three-dimensional inversion; extract the time-frequency electromagnetic three-dimensional inversion depth and -resistivity results corresponding to the seismic line coordinates; combine geological, drilling, gravity and magnetic and seismic data to perform comprehensive geological interpretation applications, such as Figure 7 shown.

[0062] Example 2

[0063] In step 1, the electric field data collected by two-dimensional time-frequency electromagnetic is denoised in the time domain; the frequency domain-electric field amplitude and phase data are obtained using the time domain electric field data; based on the definition of the apparent resistivity of the entire area, the frequency domain-apparent resistivity data is obtained, such as Figure 8 As shown;

[0064] In step 2, the regional electrical model of the study area is first established using data from drilling and outcrop electrical measurements. The preprocessed time-frequency electromagnetic data are subjected to three-dimensional fine preprocessing such as flying point and static displacement correction using spatial filtering, curve translation, and low-pass filtering. The above data are comprehensively processed in three dimensions to obtain frequency domain-apparent resistivity data that can fully reflect the complex electrical structure, such as Fig. 9 shown.

[0065] In step 3, high-precision terrain data is used to establish a three-dimensional surface elevation data network in the study area; the inversion parameters are optimized, and the time-frequency magnetic three-dimensional inversion is carried out to obtain the time-frequency electromagnetic three-dimensional depth domain-resistivity data volume, such as Fig.10 As shown;

[0066] In step 4, extract the coordinates of the two-dimensional time-frequency electromagnetic survey line and load them into the depth domain-resistivity data volume obtained by the three-dimensional time-frequency electromagnetic inversion; extract the depth domain-resistivity inversion results obtained by the three-dimensional time-frequency electromagnetic inversion of the corresponding survey line coordinates; combine geological, drilling and other data to conduct a comprehensive interpretation of the time-frequency electromagnetic acquisition survey line, such as Fig.11 As shown;

[0067] In step 5, extract the coordinates of any seismic line in the work area and load them into the depth domain-resistivity data volume of the time-frequency electromagnetic three-dimensional inversion; extract the time-frequency electromagnetic three-dimensional inversion depth and -resistivity results corresponding to the seismic line coordinates; combine geological, drilling, gravity and magnetic and seismic data to perform comprehensive geological interpretation applications, such as Fig.12 shown.

[0068] Beneficial effects: The present invention starts from a method of using two-dimensional time-frequency electromagnetic data for three-dimensional processing, inversion and application. Through relevant analysis technology, the two-dimensional time-frequency electromagnetic acquisition data is three-dimensionally processed and three-dimensionally inverted, thereby improving the resolution and accuracy of the inversion results, laying the foundation for comprehensive interpretation of gravity, magnetic, electric and seismic data.

[0069] The above specific implementation methods further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A processing method using two-dimensional time-frequency electromagnetic data, characterized in that: The processing method comprises: Step 101: Based on the collected data, the time domain electric field data of the measuring points on the collected measuring line are obtained, and denoising is performed to obtain a time domain electric field database after denoising and correction; Step 102: Obtaining a frequency domain electric field amplitude and phase database of the measuring points on the acquisition measurement line based on Fourier transform; Step 103: Based on the definition of the apparent resistivity of the entire area, frequency domain-apparent resistivity data is obtained; Step 104: Using the electrical information and combining it with the apparent resistivity information of the first branch, an electrical model of the work area is established, and three-dimensional fine processing of the original data is carried out; Step 105: Optimize inversion parameters and carry out time-frequency electromagnetic three-dimensional inversion; Step 106: Analyze and process the depth domain-resistivity data obtained by the time-frequency electromagnetic three-dimensional inversion; Step 107: Extract the time-frequency electromagnetic three-dimensional inversion depth domain-resistivity results corresponding to the seismic survey line coordinates; combine with the seismic data to perform comprehensive geological interpretation applications.

2. A processing method using two-dimensional time-frequency electromagnetic data according to claim 1, characterized in that: The step 104: using the electrical information and combining the first branch apparent resistivity information to establish an electrical model of the work area and carry out three-dimensional fine processing of the original data specifically includes: By using the three-dimensional processing technology of two-dimensional time-frequency electromagnetic frequency domain-apparent resistivity data, we can obtain frequency domain-apparent resistivity two-dimensional time-frequency electromagnetic data that can fully reflect the complex electrical structure.

3. The method for processing two-dimensional time-frequency electromagnetic data according to claim 1, characterized in that: The step 105: optimizing inversion parameters and carrying out time-frequency electromagnetic three-dimensional inversion specifically includes: using electromagnetic three-dimensional inversion technology to obtain a time-frequency electromagnetic three-dimensional inversion resistivity-depth domain data volume.

4. A processing method using two-dimensional time-frequency electromagnetic data according to claim 2, characterized in that: The step 107: extracting, analyzing and interpreting the depth domain-resistivity data obtained by the time-frequency electromagnetic three-dimensional inversion, further includes: According to the two-dimensional time-frequency electromagnetic acquisition coordinates, the depth domain-resistivity inversion results of the two-dimensional survey line are extracted from the resistivity-depth domain data volume obtained by the time-frequency electromagnetic three-dimensional inversion, and combined with the seismic data, a comprehensive interpretation of the two-dimensional time-frequency electromagnetic acquisition survey line is performed.

5. The method for processing two-dimensional time-frequency electromagnetic data according to claim 1, characterized in that: The seismic data include: geological, drilling, gravity, magnetic and seismic data.

6. The method for processing two-dimensional time-frequency electromagnetic data according to claim 1, characterized in that: The step 104: using the drilling and outcrop electrical information, combined with the first branch apparent resistivity information to establish the work area electrical model, and carrying out three-dimensional fine processing of the original data specifically includes: Using the drilling and outcrop electrical measurement data, a regional electrical model for the study area was established; The pre-processed time-frequency electromagnetic data is subjected to three-dimensional fine pre-processing of flying spot and static displacement correction by using filtering processing method; The data are processed in three dimensions to obtain frequency domain-apparent resistivity data that can fully reflect the complex electrical structure.

7. The method for processing two-dimensional time-frequency electromagnetic data according to claim 1, characterized in that: The electrical information includes: drilling and outcrop.

8. The method for processing two-dimensional time-frequency electromagnetic data according to claim 6, characterized in that: The filtering processing method specifically includes: spatial filtering method, curve translation method, and low-pass filtering.

9. The method for processing two-dimensional time-frequency electromagnetic data according to claim 1, characterized in that: The step 105: optimizing inversion parameters and carrying out time-frequency electromagnetic three-dimensional inversion specifically includes: Optimize inversion parameters and carry out time-frequency electromagnetic three-dimensional inversion; The time-frequency electromagnetic three-dimensional inversion depth domain-resistivity data volume obtained by three-dimensional inversion.

10. The method for processing two-dimensional time-frequency electromagnetic data according to claim 1, characterized in that: The analysis process in step 106 specifically includes: extraction, analysis, and interpretation.

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