Quantitative analysis-based seismic wavelet quality control method

Abstract

The invention relates to a seismic wavelet quality control method based on quantitative analysis, and belongs to the technical field of geological exploration. Comprising the following steps: selecting a time window for shot points and detection points in a whole area according to a geological target, and then performing autocorrelation superposition on the shot points and the detection points; analyzing the wavelets obtained by autocorrelation superposition, reading the amplitude value A0 of the first negative lobe of the wavelets after autocorrelation and the second zero crossing time T2 of the wavelets, and solving the area S of each zero-phase wavelet by using S = A0 * T2; and after abnormal values are removed, drawing a shot point and detection point wavelet whole-region distribution plane graph and a histogram through the calculated area S of each wavelet, comparing the wavelet distribution range, and carrying out quantitative analysis on the wavelets. According to the method, the wavelet areas of each shot point and each detection point are calculated through an autocorrelation method, quantitative analysis and plane quality control are carried out, the fidelity of seismic data is ensured, reservoir prediction is more accurate, and powerful support is provided for exploration and development of oil and gas fields.

Description

Technical Field

[0001] The invention relates to a seismic wavelet quality control method based on quantitative analysis, belonging to the technical field of geological exploration. Background Art

[0002] In the later stages of oil and gas field development, with increasingly higher reservoir prediction accuracy and more refined requirements for seismic data, seismic wavelet consistency processing is a crucial step in seismic data processing. Conventional wavelet consistency relies on quality control using data gathers and stacked profiles. This involves determining the data frequency bands through pure wave display of gathers and frequency scanning of seismic profiles, and then using stacked profiles for overlay display to determine if the main lobe compression of the processed seismic data tends to be consistent. However, based on the principle of "point, line, and area" quality control, only point and line quality control can be performed, and it is a qualitative analysis, not a quantitative representation of the overall consistency of seismic wavelets within the seismic work area. While current seismic processing quality control is relatively complete, seismic wavelet consistency can only be qualitatively analyzed through gather and stacked profile wavelet morphology, and cannot guarantee the consistency of seismic wavelets across the entire area, thus affecting data fidelity. Summary of the Invention

[0003] To address the aforementioned problems in existing technologies, this invention discloses a seismic wavelet quality control method based on quantitative analysis. The purpose of this invention is to increase the stability of seismic wavelets by autocorrelation superposition of shot and receiver domain data, and to calculate the wavelet area using amplitude energy and main lobe compression, thereby obtaining wavelet plane distribution maps and histograms at the shot and receiver points. The resulting wavelet plane distribution maps more intuitively reflect the wavelet distribution range, allowing for more refined quality control. This further improves wavelet consistency, ensures the fidelity of seismic data, and enables more accurate reservoir prediction, providing strong support for oil and gas field exploration and development.

[0004] The technical solution adopted in this invention is: a seismic wavelet quality control method based on quantitative analysis, comprising the following steps:

[0005] Step 1: Select time windows for shot points and receiver points across the entire area based on geological targets, and then perform autocorrelation stacking on shot points and receiver points respectively;

[0006] Step 2: Analyze the wavelet obtained by autocorrelation superposition. By reading the amplitude value A0 of the first negative lobe of the wavelet after autocorrelation and the second zero-crossing time T2 of the wavelet, the area S of each zero-phase wavelet is calculated using S=A0*T2.

[0007] Step 3: After removing outliers, the area S of each wavelet is obtained to draw a plane diagram and a histogram of the wavelet distribution in the entire area of ​​the shot point and the detection point, compare the wavelet distribution range, and perform quantitative analysis on the wavelet.

[0008] Furthermore, step 1 utilizes the formula

[0009] Autocorrelation superposition is performed, where t is time in ms; N is the Nth trace of each shot point and receiver point, dimensionless; X is the trace number, dimensionless; and T is the time length of one-sided autocorrelation in ms.

[0010] Furthermore, in step 2, the amplitude value A0 is obtained by the wavelet energy strength, and the unit is db; the time T2 is read by the main lobe compression degree, and the unit is ms.

[0011] Furthermore, the criterion for judging the abnormal value in step 3 is that the second zero crossing time T2 of the wavelet exceeds two wavelet phases.

[0012] Furthermore, in step 3, with the coordinates of the shot point and receiver point as X / Y and the calculated wavelet area S as Z, the planar distribution of the wavelet area S is plotted using Geoeast software with plane attribute analysis according to the unified scale of RAINBOW color code, and a bar chart is plotted for the distribution range of S values ​​to quantitatively analyze the distribution of the wavelet in the whole area.

[0013] This invention discloses a seismic wavelet quality control method based on quantitative analysis. Its advantages are: compared to previous qualitative analyses that could not perform planar quality control, this invention considers using autocorrelation methods to increase wavelet stability through autocorrelation superposition, calculating the wavelet area of ​​each shot point and receiver point, and performing quantitative analysis and planar quality control. It can quantitatively perform "point, line, and surface" quality control, and can compare the wavelet distribution range through wavelet planar maps of shot points and receiver points, ensuring the fidelity of seismic data, making reservoir prediction more accurate, and providing strong support for oil and gas field exploration and development. Attached Figure Description

[0014] 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.

[0015] Figure 1 This is an autocorrelation overlay diagram in an embodiment of the present invention;

[0016] Figure 2 This is a model diagram of wavelet peaks and crossovers in an embodiment of the present invention;

[0017] Figure 3 1 is a plane distribution diagram and a histogram of the RAINBOW color code wavelet area S in an embodiment of the present invention.

[0018] Specific implementation methods

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0020] In order to further understand the content of the present invention, the present invention is further described below in conjunction with specific implementation methods.

[0021] Unless otherwise specified, the well logging methods used in the following embodiments are conventional methods. The present invention is described in detail below with reference to the accompanying drawings:

[0022] Example 1:

[0023] A seismic wavelet quality control method based on quantitative analysis includes the following steps:

[0024] Step 1: If Figure 1 As shown, firstly, based on the geological requirements of this processing, statistical time windows of 100ms above and below the target layer hyperbolic morphology were selected for the seismic data in both the shot zone and receiver zone, respectively, and the formula was used... Perform autocorrelation superposition, where t is time, X is the channel number, and T is the time length of the unilateral autocorrelation.

[0025] Step 2: As Figure 2 As shown in the figure, the amplitude of the first negative lobe of the wavelet, A0, and the second zero crossing of the wavelet, T2, are calculated using the wavelet obtained by autocorrelation. A larger difference in A0 values ​​indicates a larger span of wavelet energy strength, indicating poor spatial excitation energy consistency. A larger span of T2 values ​​indicates greater spatial variability of the wavelets. Finally, the area S of each autocorrelation wavelet is calculated by A0*T2. The smaller the range of S values, the better the wavelet consistency.

[0026] Step 3: If Figure 3As shown in the figure, due to noise interference in seismic data, outliers are generated when calculating wavelet area statistics, affecting the accuracy of wavelet consistency. Wavelet second zero-crossing time T2 exceeding two wavelet phases is considered an outlier and needs to be eliminated. Subsequently, the wavelet area S is calculated based on the X / Y coordinates of the shot and receiver points, and the plane distribution of the wavelet area S is plotted using the RAINBOW color scale using Geoeast software. A histogram of the S value distribution range is then plotted to quantitatively analyze the wavelet distribution across the entire region. Large differences in the plane attribute map color scale indicate poor wavelet consistency. The histogram accurately determines the distribution range of the wavelet area. A more dispersed range and large differences in values ​​further indicate poor wavelet consistency. More concentrated the plane attribute map color scale, the better the wavelet consistency. The histogram accurately determines the distribution range of the wavelet area. A smaller range indicates better wavelet consistency. Comprehensive data quality control at the "point, line, and surface" level ensures a more concentrated wavelet distribution range, maintains data spatial resolution, and improves reservoir prediction accuracy.

[0027] The above-established seismic wavelet quality control method based on quantitative analysis introduces the method of obtaining wavelet area into the wavelet consistency analysis technology for the first time. This method can more accurately calculate the wavelet distribution range of seismic data and guide the optimization of seismic data processing parameters. At present, this technology has been applied to the seismic data quality control link in the Jilin exploration area, improving the fidelity of seismic data processing, improving the accuracy of reservoir prediction, and ensuring the success rate of horizontal well drilling. It has important scientific guiding significance for the key links of seismic data processing.

[0028] Conventional wavelet consistency quality control relies on data gathers and superimposed profiles, and determines the frequency band of the data through pure wave display gathers and seismic profile frequency scanning, and uses superimposed profiles to display, to determine whether the degree of compression of the main lobe of the processed seismic data tends to be consistent. However, according to the principle of "point, line, and surface" quality control, only point and line quality control can be performed, and it is a qualitative analysis, and it cannot quantitatively reflect the overall consistency of the seismic data wavelet in the seismic work area. Therefore, it is necessary to use quantitative analysis to perform "point, line, and surface" quality control on the wavelet consistency. The present invention has the following advantages: compared with the previous qualitative analysis, which cannot perform plane quality control, the present invention considers using the wavelet area for quantitative analysis, draws a wavelet plane distribution map for the entire area, and can intuitively reflect the wavelet distribution.

[0029] Compared to previous qualitative analyses of seismic data wavelet consistency, this invention utilizes autocorrelation methods and autocorrelation stacking to increase wavelet stability. This method calculates the wavelet area at each shot and receiver point for quantitative analysis and plane quality control. This allows for quantitative "point, line, and plane" quality control, and allows for comparison of wavelet distribution ranges using shot and receiver wavelet plane plots. This ensures seismic data fidelity, improves reservoir prediction accuracy, and provides strong support for oil and gas field exploration and development. This achievement focuses on addressing the technical method for quantitatively analyzing wavelets during wavelet analysis quality control of seismic data, thereby improving seismic data processing accuracy.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A seismic wavelet quality control method based on quantitative analysis, characterized in that: The following steps are involved: Step 1: Select the time window for all the shot points and receiver points in the whole area according to the geological target, and then perform autocorrelation superposition on the shot points and receiver points respectively; Step 2: Analyze the wavelet obtained by autocorrelation superposition, and calculate the area S of each zero-phase wavelet by reading the amplitude value A0 of the first negative lobe of the wavelet after autocorrelation and the second zero-crossing time T2 of the wavelet, using S=A0*T2; Step 3: After removing the outliers, the area S of each wavelet is obtained, and the plane diagram and bar diagram of the wavelet distribution of the entire area of ​​the shot point and the detection point are drawn. The wavelet distribution range is compared and the wavelet is quantitatively analyzed.

2. A seismic wavelet quality control method based on quantitative analysis according to claim 1, characterized in that: In step 1, use the formula Perform autocorrelation stacking, where t is time in ms; N is the Nth channel of each shot point and detection point, dimensionless; X is the channel number, dimensionless; T is the time length of unilateral autocorrelation in ms.

3. A seismic wavelet quality control method based on quantitative analysis according to claim 1, characterized in that: In step 2, the amplitude value A0 is obtained by the wavelet energy strength, in db; the time T2 is read by the main lobe compression degree, in ms.

4. A seismic wavelet quality control method based on quantitative analysis according to claim 1, characterized in that: The judgment criterion of the abnormal value in step 3 is that the second zero crossing time T2 of the sub-wave exceeds two sub-wave phases.

5. The seismic wavelet quality control method based on quantitative analysis according to claim 1, characterized in that: In step 3, according to the coordinates of the shot point and the detection point as X / Y and the obtained sub-wave area S as Z, the plane distribution of the sub-wave area S is drawn according to the unified scale of the RAINBOW color scale using the plane attribute analysis of the Geoeast software, and a bar graph is drawn for the distribution range of the S value to quantitatively analyze the distribution of the sub-wave in the entire area.

6. A seismic wavelet quality control method based on quantitative analysis according to claim 1, characterized in that: In step 1, the statistical time window is selected within 100ms above and below the hyperbolic shape of the target layer.

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