Normalization method, device, computer equipment and storage medium for wave impedance curve

Abstract

The embodiment of the present invention provides a normalization method, device, computer equipment and storage medium for wave impedance curve, wherein the method includes: obtaining lithology data of drilling, dividing lithology types in the lithology data; assigning a grade to each lithology type, calibrating the grade assignment of each lithology type, and obtaining a lithology curve; normalizing the wave impedance curve by absolute value; adding the wave impedance curve after absolute value normalization and the lithology curve at the corresponding depth to obtain a normalized wave impedance curve. The scheme realizes the use of lithology curves in the process of normalizing the wave impedance curve, realizes the normalization of the wave impedance curve according to the lithology grade, so that the normalized wave impedance curve realizes the consideration of sedimentary phases and sedimentary cycles, which is conducive to improving the lithology sensitivity of the normalized wave impedance curve, and further helps to improve the accuracy of the normalized wave impedance curve.

Description

Technical Field

[0001] The present invention relates to the field of geophysical exploration technology, and in particular to a normalization method, device, computer equipment and storage medium for a wave impedance curve. Background Art

[0002] Wave impedance inversion is now basically a standard technology for comprehensive interpretation projects. Wave impedance inversion has a key link, curve standardization. Initially, the acoustic wave curve was generally standardized, and later it developed to normalize the wave impedance curve. There are basically two types of normalization methods, one is the histogram method, and the other is the mean correction method. The first method focuses on the probability distribution problem, and the second method focuses on the overall trend problem.

[0003] The normalized wave impedance curves of the above two methods are less sensitive to lithology and have errors, which is not conducive to improving the accuracy of wave impedance inversion. Summary of the invention

[0004] The embodiment of the present invention provides a normalization method for a wave impedance curve to solve the technical problem that the normalization method for a wave impedance curve in the prior art has errors. The method comprises:

[0005] Obtain the lithology data of the drilling and classify the lithology types in the lithology data;

[0006] Assign a grade to each lithology type, and perform calibration on the grade assigned to each lithology type to obtain a lithology curve;

[0007] Normalize the wave impedance curve to its absolute value;

[0008] The wave impedance curve after the absolute value is normalized and the lithology curve are added at the corresponding depth to obtain a normalized wave impedance curve.

[0009] The embodiment of the present invention also provides a wave impedance curve normalization device to solve the technical problem that the wave impedance curve normalization method in the prior art has errors. The device includes:

[0010] A data acquisition module is used to acquire the lithology data of the drilling and classify the lithology types in the lithology data;

[0011] The lithology data processing module is used to assign a grade to each lithology type, and to scale the grade assigned to each lithology type to obtain a lithology curve;

[0012] Absolute value normalization module, used to perform absolute value normalization on the wave impedance curve;

[0013] The curve normalization module is used to add the wave impedance curve after the absolute value is normalized and the lithology curve at the corresponding depth to obtain the normalized wave impedance curve.

[0014] An embodiment of the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the normalization method of any of the above-mentioned wave impedance curves is implemented to solve the technical problem that errors exist in the normalization method of the wave impedance curve in the prior art.

[0015] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program for executing any of the above-mentioned normalization methods for wave impedance curves, so as to solve the technical problem that errors exist in the normalization methods for wave impedance curves in the prior art.

[0016] In an embodiment of the present invention, it is proposed to obtain lithological data of drilling, divide the lithological types in the lithological data, assign a grade to each lithological type, and perform calibration processing on the grade assigned to each lithological type to obtain a lithological curve. Finally, the wave impedance curve after the absolute value is normalized at the corresponding depth and the lithological curve are added to obtain a normalized wave impedance curve, so that the lithological curve is used in the process of normalizing the wave impedance curve, and the wave impedance curve is normalized according to the lithological grade, so that the normalized wave impedance curve takes into account the sedimentary phase and the sedimentary cycle, which is beneficial to improve the lithological sensitivity of the normalized wave impedance curve, and then it is beneficial to improve the accuracy of the normalized wave impedance curve. Using the normalized wave impedance curve for wave impedance inversion can improve the accuracy of the wave impedance inversion result for reservoir prediction. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of the present application, and do not constitute a limitation of the present invention. In the drawings:

[0018] Figure 1 is a flow chart of a normalization method for a wave impedance curve provided by an embodiment of the present invention;

[0019] Figure 2 It is a schematic diagram of a method of changing lithology data from three columns to two columns provided by an embodiment of the present invention;

[0020] Figure 3 It is a comparison diagram before and after lithology classification provided by an embodiment of the present invention;

[0021] Figure 4 This is a comparison diagram of a wave impedance curve before and after low-frequency filtering provided by an embodiment of the present invention;

[0022] Figure 5It is a comparison diagram of a wave impedance curve after filtering and before and after numerical normalization provided by an embodiment of the present invention;

[0023] Figure 6 is a comparison diagram of a wave impedance curve provided by an embodiment of the present invention before and after being processed by the above wave impedance curve normalization method;

[0024] Figure 7 is a structural block diagram of a computer device provided by an embodiment of the present invention;

[0025] Figure 8 It is a structural block diagram of a wave impedance curve normalization device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0027] The inventors have found that the existing normalization method of wave impedance curves does not adequately consider sedimentary phases and sedimentary cycles. For example, the grain size, lithology, and sedimentary cycles of sedimentary sites such as delta plains and delta fronts are different, and different sedimentary phase sites have different lithology combinations. Therefore, whether normalized by probability distribution or overall trend, there will be errors. Some phases are very different from each other, such as deep lake phases and fan root phases, so the error will also be very large. Therefore, the normalization method of the above-mentioned wave impedance curve is proposed to improve the lithology sensitivity of the normalized wave impedance curve, thereby reducing the normalization error, and then when using the above-mentioned normalized wave impedance curve for wave impedance inversion, improve the accuracy of the wave impedance inversion result for reservoir prediction.

[0028] In an embodiment of the present invention, a normalization method for a wave impedance curve is provided, such as Figure 1 As shown, the method includes:

[0029] Step 102: Obtaining lithology data of the well, and classifying the lithology types in the lithology data;

[0030] Step 104: assigning a grade to each lithology type, and scaling the grade assigned to each lithology type to obtain a lithology curve;

[0031] Step 106: normalize the wave impedance curve to its absolute value;

[0032] Step 108: Add the wave impedance curve after the absolute value is normalized and the lithology curve at the corresponding depth to obtain a normalized wave impedance curve.

[0033] Depend on Figure 1As can be seen from the process shown, in the embodiment of the present invention, it is proposed to obtain the lithological data of the drilling, divide the lithological types in the lithological data, and assign a grade to each lithological type, and perform calibration processing on the grade assignment of each lithological type to obtain a lithological curve. Finally, the wave impedance curve after the absolute value is normalized at the corresponding depth and the lithological curve are added to obtain a normalized wave impedance curve, so that the lithological curve is used in the process of normalizing the wave impedance curve, and the wave impedance curve is normalized according to the lithological grade, so that the normalized wave impedance curve takes into account the sedimentary phase and the sedimentary cycle, which is beneficial to improve the lithological sensitivity of the normalized wave impedance curve, and then it is beneficial to improve the accuracy of the normalized wave impedance curve. Using the normalized wave impedance curve for wave impedance inversion can improve the accuracy of the wave impedance inversion result for reservoir prediction.

[0034] In a specific implementation, in the process of obtaining the lithological data of the drilling, any form of lithological data or interpreted lithological data can be obtained, and then processed to obtain lithological data including depth data. Figure 2 As shown in the figure, taking the lithology data output by Geoeast as an example, the lithology data output by Geoeast consists of three columns of data: top depth, bottom depth, and lithology data. Figure 2 As shown in Figure a, the three columns of data can be converted into two columns of data including depth and lithology data, as shown in Figure a. Figure 2 As shown in Figure b in , simplified lithology data can be obtained.

[0035] In specific implementation, after obtaining the lithology data, the lithology types in the lithology data can be divided. Specifically, the lithology can be classified according to density and velocity. The specific method of classifying the types and the degree of subdivision are not specifically limited in this application. For example, it can be divided into mudstone, silt and fine sand, coarse sand, carbonate rock, ore, igneous rock, metamorphic rock, etc.

[0036] In specific implementation, after the lithology types are divided, each lithology type is assigned a grade. In order to achieve that the size of the grade assigned can reflect the difference in lithology, in this embodiment, the grade is assigned according to the impedance of each lithology type, and the size of the impedance is proportional to the size of the grade assigned. Figure 3 As shown, Figure 3 Figure a shows the data before the lithology classification is assigned. Figure 3Figure b (the horizontal axis is the grade assignment, the vertical axis is the depth) is the data after the lithology is re-graded. The grade assignment of mudstone is 1, the grade assignment of silt and fine sand is 2, the grade assignment of coarse sand is 3, the grade assignment of carbonate rock is 4, the grade assignment of ore is 5, the grade assignment of igneous rock is 6, and the grade assignment of metamorphic rock is 7. The size of the corresponding grade assignment number is determined according to the corresponding lithology and impedance. That is, the smaller the impedance, the smaller the corresponding grade assignment value, and the larger the impedance, the larger the corresponding grade assignment value.

[0037] In specific implementation, in order to achieve a numerical level of the grade assignment within the amplitude value range of the wave impedance curve so as to be added to the wave impedance curve, in this embodiment, the grade assignment of each lithology type is multiplied by the base value of the wave impedance curve, and then the product is added to the difference between the base value and the peak value of the wave impedance curve to obtain the lithology curve. For example, the base value of the wave impedance curve is 1500, and the difference between the base value and the peak value of the wave impedance curve is 2000, then the grade assignment of each lithology type is multiplied by 1500, and then 2000 is added to obtain the lithology curve.

[0038] In specific implementation, in order to filter out frequencies below 10 Hz, in this embodiment, before the wave impedance curve is normalized to an absolute value, the wave impedance curve is subjected to high-pass filtering, such as Figure 4 As shown, Figure 4 Figure a in the figure is the original wave impedance curve. Figure 4 Figure b is the wave impedance curve after low-frequency filtering.

[0039] In specific implementation, in the process of normalizing the absolute value of the wave impedance curve, the maximum and minimum values ​​of the filtered wave impedance curve can be counted, abnormal values ​​can be eliminated, and then the amplitude can be normalized. Figure 5 As shown, Figure 5 Figure a in the figure is the wave impedance curve after low-frequency filtering. Figure 5 Figure b is the wave impedance curve after filtering and the absolute value is normalized. The wave impedance curve after filtering can be normalized to ±1000.

[0040] When implementing it, Figure 6 As shown, Figure 6 Figure a in the figure is the original wave impedance curve. Figure 6 Figure b is the wave impedance curve after being processed by the above wave impedance curve normalization method and normalized according to the lithology grade. Figure 6 Figure c is a histogram of the original wave impedance curve, and the color code is the lithology. Figure 6Figure d in the figure is a histogram of the wave impedance curve after being processed by the normalization method of the wave impedance curve and normalized by lithology level, and the color code is lithology. It can be seen that the wave impedance curve after being processed by the normalization method of the wave impedance curve and normalized by lithology level has significantly improved the sensitivity of the wave impedance curve to lithology, and the wave impedance curve can clearly distinguish lithology in any region and any sedimentary phase belt.

[0041] In this embodiment, a computer device is provided, such as Figure 7 As shown, it includes a memory 702, a processor 704 and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the normalization method of any wave impedance curve described above is implemented.

[0042] Specifically, the computer device may be a computer terminal, a server or a similar computing device.

[0043] In this embodiment, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program for executing any of the above-mentioned normalization methods for wave impedance curves.

[0044] Specifically, computer-readable storage media include permanent and non-permanent, removable and non-removable media that can be used to store information by any method or technology. Information can be computer-readable instructions, data structures, program modules or other data. Examples of computer-readable storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable storage media does not include temporary computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0045] Based on the same inventive concept, a normalization device for a wave impedance curve is also provided in an embodiment of the present invention, as described in the following embodiments. Since the principle of solving the problem by the normalization device for a wave impedance curve is similar to that of the normalization method for a wave impedance curve, the implementation of the normalization device for a wave impedance curve can refer to the implementation of the normalization method for a wave impedance curve, and the repeated parts will not be repeated. As used below, the term "unit" or "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0046] Figure 8 is a structural block diagram of a normalization device for a wave impedance curve according to an embodiment of the present invention, such as Figure 8 As shown, the device comprises:

[0047] The data acquisition module 802 is used to acquire the lithology data of the drilling well and classify the lithology types in the lithology data;

[0048] The lithology data processing module 804 is used to assign a grade to each lithology type, and to scale the grade assigned to each lithology type to obtain a lithology curve;

[0049] An absolute value normalization module 806 is used to perform absolute value normalization on the wave impedance curve;

[0050] The curve normalization module 808 is used to add the wave impedance curve after the absolute value is normalized and the lithology curve at the corresponding depth to obtain a normalized wave impedance curve.

[0051] In one embodiment, the lithology data processing module is specifically used to assign a grade according to the impedance of each lithology type, and the size of the impedance is proportional to the size of the grade assigned.

[0052] In one embodiment, the lithology data processing module is specifically used to multiply the grade of each lithology type by the base value of the wave impedance curve, and then add the product to the difference between the base value and the peak value of the wave impedance curve to obtain the lithology curve.

[0053] In one embodiment, it further includes:

[0054] The filtering module is used to perform high-pass filtering on the wave impedance curve before normalizing the absolute value of the wave impedance curve.

[0055] The embodiment of the present invention achieves the following technical effects: it proposes to obtain lithological data of drilling, classify lithological types in the lithological data, assign a grade to each lithological type, and perform calibration processing on the grade assignment of each lithological type to obtain a lithological curve. Finally, the wave impedance curve after the absolute value is normalized at the corresponding depth and the lithological curve are added to obtain a normalized wave impedance curve, so that the lithological curve is used in the process of normalizing the wave impedance curve, and the wave impedance curve is normalized according to the lithological grade, so that the normalized wave impedance curve takes into account the sedimentary phase and the sedimentary cycle, which is beneficial to improve the lithological sensitivity of the normalized wave impedance curve, and then it is beneficial to improve the accuracy of the normalized wave impedance curve. Using the normalized wave impedance curve for wave impedance inversion can improve the accuracy of the wave impedance inversion result for reservoir prediction.

[0056] Obviously, those skilled in the art should understand that the modules or steps of the above-mentioned embodiments of the present invention can be implemented by a general computing device, they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices, and optionally, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, and in some cases, the steps shown or described can be executed in a different order from that here, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. In this way, the embodiments of the present invention are not limited to any specific combination of hardware and software.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the embodiments of the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A normalization method for a wave impedance curve, characterized in that: include: Obtaining the lithology data of the drilling well and classifying the lithology types in the lithology data; wherein, the lithology classification is performed based on density and velocity; Assign a grade to each lithology type, and perform calibration on the grade assigned to each lithology type to obtain a lithology curve; Normalize the wave impedance curve to its absolute value; Adding the wave impedance curve after the absolute value is normalized and the lithology curve at the corresponding depth to obtain the normalized wave impedance curve and the histogram of the wave impedance curve after normalization according to the lithology grade; In the process of obtaining the lithological data of the drilling, any form of lithological data or interpreted lithological data is obtained, and the lithological data including the depth data is processed; Assign a grade to each lithology type, including: The grade is assigned according to the impedance of each lithology type, and the size of the impedance is proportional to the size of the grade assigned; The grade assignment of each lithology type is scaled to obtain the lithology curve, including: The grade value of each lithology type is multiplied by the base value of the wave impedance curve, and then the product is added with the difference between the base value and the peak value of the wave impedance curve to obtain a lithology curve; Also includes: Before the wave impedance curve is normalized to an absolute value, the wave impedance curve is high-pass filtered; wherein, in the process of normalizing the wave impedance curve to an absolute value, the maximum and minimum values ​​of the filtered wave impedance curve are counted, abnormal values ​​are eliminated, and then amplitude normalization is performed.

2. A wave impedance curve normalization device, characterized in that: include: A data acquisition module is used to acquire the lithology data of the drilling well and classify the lithology types in the lithology data; wherein the lithology classification is performed according to density and velocity; in the process of acquiring the lithology data of the drilling well, any form of lithology data or interpreted lithology data is acquired and processed to obtain lithology data including depth data; The lithology data processing module is used to assign a grade to each lithology type, and to scale the grade assigned to each lithology type to obtain a lithology curve; Absolute value normalization module, used to perform absolute value normalization on the wave impedance curve; A curve normalization module, used for adding the wave impedance curve normalized by absolute value and the lithology curve at the corresponding depth to obtain the normalized wave impedance curve and the histogram of the wave impedance curve normalized by lithology grade; The lithology data processing module is specifically used to assign a grade according to the impedance of each lithology type, and the magnitude of the impedance is proportional to the magnitude of the grade assigned; The lithology data processing module is specifically used to multiply the grade value of each lithology type by the base value of the wave impedance curve, and then add the product to the difference between the base value and the peak value of the wave impedance curve to obtain the lithology curve; Also includes: The filtering module is used to perform high-pass filtering on the wave impedance curve before performing absolute value normalization on the wave impedance curve; wherein, in the process of performing absolute value normalization on the wave impedance curve, the maximum and minimum values ​​of the filtered wave impedance curve are counted, abnormal values ​​are eliminated, and then amplitude normalization is performed.

3. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the normalization method of the wave impedance curve described in claim 1 is implemented.

4. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for normalizing a wave impedance curve according to claim 1 is implemented.

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