A method, device, equipment and medium for predicting sand body thickness based on frequency domain

Abstract

This article provides a method, device, equipment and medium for predicting sand body thickness based on frequency domain, including when predicting an unknown sand body, querying a qualitative prediction measurement version of sand body thickness according to the energy interval where the energy curves corresponding to the main frequency energy accumulation attribute, the high frequency energy accumulation attribute and the difference energy accumulation attribute of the unknown sand body are located, and determining the sand body thickness interval where the unknown sand body is located; within the sand body thickness interval, predicting the thickness of the unknown sand body according to the sand body thickness prediction equation corresponding to the sand body thickness interval, thereby achieving accurate prediction of the thickness of thin sand bodies through the qualitative prediction measurement version of sand body thickness, and reducing the manpower and material resources consumed in identifying the thickness of thin sand bodies.

Description

Technical Field

[0001] The invention relates to earth geography technology and can be applied to the field of sand body thickness prediction, in particular to a method, device, equipment and medium for predicting sand body thickness based on frequency domain. Background Art

[0002] When testing the thickness of thin sand bodies (less than 1 / 4 seismic wavelet) with thin thickness, small deposition scale and fast lateral transformation, due to the limitation of seismic wavelet resolution, when the sand body thickness is less than the seismic wavelet resolution limit, it is impossible to determine the top and bottom interfaces of the thin sand body based on the main wave crest and main wave trough of the composite wave in the seismic wavelet, and it is difficult to determine the thickness of the sand body in the time domain using seismic wavelets. Therefore, it is difficult to predict the thickness of the top and bottom interfaces of the sand body using conventional time domain technical means, resulting in the inability to effectively solve the problems of accurate identification of thin sand bodies and thickness prediction. Summary of the invention

[0003] In view of the above problems in the prior art, the purpose of this article is to provide a method, device, equipment and medium for predicting sand body thickness based on frequency domain, so as to solve the problem that conventional technical means in the prior art cannot predict the thickness of thin sand bodies.

[0004] In order to solve the above technical problems, the specific technical solutions of this article are as follows:

[0005] On the one hand, this paper provides a method for predicting sand body thickness based on frequency domain, including:

[0006] Determine energy attributes of several preset frequencies of the sand body according to the wedge-shaped model of the sand body, wherein the energy attributes of the preset frequencies include: main frequency energy accumulation attribute, high frequency energy accumulation attribute and difference energy accumulation attribute;

[0007] According to the energy properties of each preset frequency, an energy curve of each preset frequency is drawn;

[0008] Determining the sand body thickness interval according to the intersection of the preset energy interval of the sand body and the energy curve of each preset frequency;

[0009] Determine a qualitative prediction version of sand body thickness according to each sand body thickness interval and a preset energy interval corresponding to the sand body thickness interval;

[0010] Analyze the monotonicity and maximum slope of the energy curve of each preset frequency within each sand body thickness interval;

[0011] According to the analysis results of each sand body thickness interval, an energy curve with monotonicity and maximum slope is screened out from energy curves of each preset frequency within each sand body thickness interval;

[0012] Determine the sand body thickness equation according to the energy curve;

[0013] According to the sand body thickness interval, the sand body thickness equation is mapped to the sand body thickness qualitative prediction measurement version;

[0014] When predicting the thickness of a sand body, the thickness of the sand body is determined according to the qualitative prediction measurement version of the sand body thickness.

[0015] As an embodiment of the present invention, before determining the energy attributes of the sand body at several preset frequencies according to the wedge-shaped model of the sand body, the method includes:

[0016] Obtaining the density of the sand body and the longitudinal wave velocity of the sand body according to the well logging data of the sand body;

[0017] The wedge-shaped model is established according to the density of the sand body and the longitudinal wave velocity of the sand body.

[0018] As an embodiment of the present invention, the step of determining the energy attributes of the sand body at several preset frequencies according to the wedge-shaped model of the sand body further includes:

[0019] Performing spectrum analysis on the actual seismic data to obtain the main frequency of the actual seismic data;

[0020] synthesizing seismic forward modeling wavelet according to the main frequency;

[0021] Convolving the wedge-shaped model with the seismic forward modeling wavelet, and forward modeling to obtain a forward synthetic seismic record of the wedge-shaped model;

[0022] Performing spectrum analysis on the forward modeled synthetic seismic record to obtain a time-frequency spectrum diagram of the forward modeled synthetic seismic record;

[0023] Extracting time-frequency ridges according to the time-frequency spectrum diagram;

[0024] The energy attributes of several preset frequencies of the sand body are obtained according to the time-frequency ridges and normalized.

[0025] As an embodiment of this invention, drawing the energy curve of each preset frequency according to the energy attribute of each preset frequency further includes:

[0026] For each energy attribute of a preset frequency corresponding to each sand body thickness, the maximum value among the energy attributes of the preset frequency is selected as the energy value of the preset frequency;

[0027] The thickness of the sand body is used as the abscissa, and the energy value of each preset frequency is used as the ordinate, and the energy curves of each preset frequency are drawn respectively.

[0028] As an embodiment of the present invention, determining the sand body thickness interval according to the intersection of the preset energy interval of the sand body and the energy curve of each preset frequency further includes:

[0029] In the energy curve of each preset frequency, determining the dividing point of the preset energy interval of the sand body;

[0030] The sand body thickness interval is determined according to the division points.

[0031] As an embodiment of the present invention, according to the analysis results of each sand body thickness interval, the energy curve having monotonicity and maximum slope is screened out from the energy curves of each preset frequency within each sand body thickness interval, further comprising:

[0032] In each sand body thickness interval, if there is only one monotonic curve, the monotonic energy curve is screened out;

[0033] In each sand body thickness interval, if there are two monotonic curves, the energy curve with the largest slope is selected.

[0034] As an embodiment of this invention, the energy curves selected from each sand body thickness interval are fitted to obtain a sand body thickness equation, further comprising:

[0035] The abscissa of the screened energy curve is used as the ordinate of the fitting curve, and the ordinate of the screened energy curve is used as the abscissa of the fitting curve;

[0036] Points on the fitting curve are selected to perform equation fitting to obtain the sand body thickness prediction equation that characterizes the fitting curve.

[0037] On the other hand, a device for predicting sand body thickness based on frequency domain is also provided, comprising:

[0038] An energy determination unit is used to determine energy attributes of several preset frequencies of the sand body according to the wedge-shaped model of the sand body, wherein the energy attributes of the preset frequencies include: main frequency energy accumulation attribute, high frequency energy accumulation attribute and difference energy accumulation attribute;

[0039] A curve drawing unit, used for drawing an energy curve of each preset frequency according to the energy attribute of each preset frequency;

[0040] An interval division unit, used for determining the sand body thickness interval according to the intersection of the preset energy interval of the sand body and the energy curve of each preset frequency;

[0041] A measurement version establishing unit is used to determine a qualitative prediction measurement version of sand body thickness according to each sand body thickness interval and a preset energy interval corresponding to the sand body thickness interval;

[0042] A judgment unit, used to analyze the monotonicity and maximum slope of the energy curve of each preset frequency within each sand body thickness interval;

[0043] A screening unit is used to screen out an energy curve having monotonicity and a maximum slope from energy curves of each preset frequency within each sand body thickness interval according to the analysis results of each sand body thickness interval;

[0044] An equation fitting unit, used for determining a sand body thickness equation according to the energy curve;

[0045] A mapping unit, used for mapping the sand body thickness equation to the sand body thickness qualitative prediction measurement version according to the sand body thickness interval;

[0046] The prediction unit is used to determine the thickness of the sand body according to the qualitative prediction measurement version of the sand body thickness when predicting the thickness of the sand body.

[0047] On the other hand, a computer device is also provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, any one of the methods for predicting sand body thickness based on the frequency domain is implemented.

[0048] On the other hand, a computer-readable storage medium is also provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, any one of the methods for predicting sand body thickness based on the frequency domain is implemented.

[0049] In this paper, an energy curve is established in the frequency domain, and the energy curve that best reflects the actual sand body thickness in the interval is intercepted according to the sand body thickness interval for equation fitting. By establishing a qualitative prediction version of sand body thickness that conforms to the actual scenario, the established sand body thickness equation can accurately predict the thickness of thin sand bodies, reducing the manpower and material resources consumed in identifying the thickness of thin sand bodies.

[0050] In order to make the above and other purposes, features and advantages of this article more obvious and easy to understand, the following specifically cites preferred embodiments and describes them in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of this article or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of this article. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0052] Figure 1 An overall system diagram of predicting sand body thickness based on frequency domain in an embodiment of this invention is shown;

[0053] Figure 2A schematic diagram of the steps of a method for predicting sand body thickness based on the frequency domain in an embodiment of this invention is shown;

[0054] Figure 3 A schematic diagram of establishing a sand body thickness qualitative prediction measurement version of a method for predicting sand body thickness based on frequency domain in an embodiment of this invention is shown;

[0055] Figure 4 A schematic diagram of a wedge-shaped model of a method for predicting sand body thickness based on the frequency domain in an embodiment of this invention is shown;

[0056] Figure 5 A schematic diagram of the steps of determining energy attributes of a method for predicting sand body thickness based on frequency domain in an embodiment of this invention is shown;

[0057] Figure 6 A schematic diagram of seismic records of a method for predicting sand body thickness based on frequency domain in an embodiment of this invention is shown;

[0058] Figure 7 A schematic diagram of frequency domain analysis of a method for predicting sand body thickness based on frequency domain in an embodiment of this invention is shown;

[0059] Figure 8 A schematic diagram of time-frequency ridge lines of a method for predicting sand body thickness based on frequency domain in an embodiment of this invention is shown;

[0060] Figure 9 (a)-(b) shows a schematic diagram of energy accumulation attributes of a method for predicting sand body thickness based on frequency domain in an embodiment of this invention;

[0061] Fig.10 A schematic diagram of an energy curve for predicting sand body thickness based on frequency domain is shown in an embodiment of this invention;

[0062] Fig.11 A schematic diagram of a difference energy accumulation curve of a method for predicting sand body thickness based on frequency domain in an embodiment of this invention is shown;

[0063] Figure 12 (a)-(d) shows a schematic diagram of a fitting curve of a method for predicting sand body thickness based on frequency domain in an embodiment of this invention;

[0064] Fig.13 A schematic diagram of a device for predicting sand body thickness based on frequency domain according to an embodiment of this invention is shown;

[0065] Fig.14 A schematic diagram of a device for establishing a sand body thickness prediction equation based on frequency domain prediction of sand body thickness according to an embodiment of this invention is shown;

[0066] Fig.15 A schematic diagram of an energy determination unit of a device for predicting sand body thickness based on frequency domain in an embodiment of this invention is shown;

[0067] Fig.16A data flow chart of an overall system for predicting sand body thickness based on frequency domain according to an embodiment of this invention is shown;

[0068] Fig.17 A schematic diagram of a computer device according to an embodiment of this invention is shown.

[0069] Description of the accompanying symbols:

[0070] 101. Database; 102. Operation server; 103. Control terminal; 104. Sound wave synthesizer; 1301. Interval prediction unit; 1302. Thickness prediction unit; 1401. Energy attribute determination unit; 1402. Interval division unit; 1403. Thickness determination unit; 1404. Curve selection unit; 1405. Equation selection unit; 1406. Correspondence unit; 1407. Quantity plate creation unit; 14011. Time-frequency spectrum extraction unit; 14012. Time-frequency ridge extraction unit; 14013. Energy attribute extraction unit; 1702. Computer device; 1704. Processor; 1706. Memory; 1708. Driving mechanism; 1710. Input / output module; 1712. Input device; 1714. Output device; 1716. Presentation device; 1718. Graphical user interface; 1720. Network interface; 1722. Communication link; 1724. Communication bus. DETAILED DESCRIPTION

[0071] The following will be combined with the drawings in the embodiments of this article to clearly and completely describe the technical solutions in the embodiments of this article. Obviously, the described embodiments are only part of the embodiments of this article, not all of the embodiments. Based on the embodiments of this article, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this article.

[0072] It should be noted that the terms "first", "second", etc. in the specification and claims of this article and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of this article described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, device, product or equipment that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0073] The existing technology fits the mathematical mapping relationship between multiple seismic attributes and sandstone thickness, and directly converts the attribute value of the sand body into the sand body thickness value according to the fitted mathematical mapping relationship. This type of method is currently widely used, but there are problems such as sensitive attribute optimization, information redundancy, and complicated optimization algorithm selection. In addition, a large amount of data is required to generate the mathematical mapping relationship, which consumes a lot of manpower and material resources, so it is not reproducible and takes a long time.

[0074] In the existing sand body thickness measurement method, seismic data analysis instruments are usually used to analyze seismic data, and the top and bottom interfaces of the thin sand body are determined by the main peaks and main troughs of the seismic data, and then the thickness of the sand body is calculated using the top and bottom interfaces.

[0075] As the oil and gas exploration process continues to deepen, the exploration targets are becoming increasingly complex. Most of the exploration and development targets have the characteristics of thin thickness, small sedimentary scale, and rapid lateral changes. Since the seismic data analysis instrument is limited by the resolution of seismic data, when the sand body thickness is less than the seismic data resolution limit (1 / 4 seismic wavelet wavelength), it is impossible to determine the top and bottom interfaces of the thin sand body based on the main wave crest and main wave trough of the composite wave. No matter how the true thickness of the formation changes, the apparent thickness of the seismic data analysis instrument will no longer change, that is, it is difficult to identify the thickness of a single sand body using seismic data at this time. However, the thickness of the thin sand bodies faced by today's exploration and development is often less than 1 / 4 of the seismic wavelet wavelength, and the sedimentary phase changes rapidly, and the lateral distribution of the sand body is unstable. The conventional method cannot accurately predict the thickness of the sand body. The accurate identification of thin sand bodies and the thickness prediction problems are becoming increasingly prominent.

[0076] Through the above analysis, it is known that analysis in the time domain can no longer meet the thickness identification requirements of thin sand bodies, and time-frequency analysis technology is one of the important tools for non-steady-state signal processing, which can be a means of finding thin reservoirs. This technology transforms seismic data into the frequency domain, and studies the lateral variation law of the reservoir by tuning the corresponding relationship of the amplitude in the frequency domain, so that the seismic data analysis instrument can obtain a time resolution result higher than the conventional seismic main frequency corresponding to 1 / 4 of the seismic wavelet wavelength, and thus can identify smaller sand bodies.

[0077] like Figure 1 The overall system diagram for predicting sand body thickness based on frequency domain includes a database 101 , a computing server 102 , a control terminal 103 , and an acoustic wave synthesizer 104 .

[0078] When a standard target sand body is obtained, the computing server 102 can establish a qualitative prediction version of sand body thickness according to the sand body, specifically including:

[0079] The database 101 stores the seismic data of the sand body to be predicted, and can obtain the main frequency of the sand body according to the spectrum analysis result of the sand body. When the control terminal 103 needs to use the seismic data, the seismic data is sent to the operation server 102. The operation server 102 synthesizes the relevant parameters of the seismic forward modeling wavelet according to the main frequency of the sand body, and sends it to the sound wave synthesizer 104. The sound wave synthesizer 104 transmits the seismic forward modeling wavelet to the sand body at different angles according to the relevant parameters of the seismic forward modeling wavelet, receives several reflected sound waves of the seismic forward modeling wavelet, and summarizes and stores the time of the reflected sound wave. The operation server 102 obtains the time of the reflected sound wave from the sound wave synthesizer 104 and the density logging data, calculates the propagation speed of the seismic forward modeling wavelet of the sand body according to the time of the reflected sound wave, and calculates the density of the sand body according to the density logging data. The operation server 102 establishes a wedge model according to the main frequency of the sand body, the density of the sand body and the propagation speed of the sand body to the seismic forward modeling wavelet.

[0080] When the control terminal 103 inputs a calculation instruction, the operation server 102 can determine the energy attributes of several frequencies according to the wedge-shaped model of the sand body, including high-frequency energy accumulation attributes and main frequency energy accumulation attributes, and draw energy curves of various frequencies according to the energy accumulation attributes. The frequency can be input by the control terminal 103 or pre-configured in the operation server 102. After the operation server 102 completes drawing the energy curve, the control terminal 103 receives the instruction and sets the energy interval. The energy interval can be input by the user or pre-configured in the operation server 102. After the operation server 102 receives the energy interval, the sand body thickness interval can be calculated according to the energy interval, and then the energy curve can be screened and intercepted according to the calculated sand body thickness interval. Finally, a fitting operation is performed according to the energy curve to obtain a sand body thickness equation with an interval mark, that is, a sand body thickness prediction equation corresponding to the energy curve in each sand body thickness interval. In this way, a qualitative prediction version of sand body thickness is established.

[0081] After completing the creation of the qualitative prediction measurement version of the sand body thickness, the qualitative prediction measurement version of the sand body thickness is sent to the operation server 102. When the user sends a prediction of an unknown sand body through the control terminal 103, the operation server 102 first extracts various parameters of the unknown sand body in the database 101, and calculates the intervals of the main frequency energy accumulation attribute, high frequency energy accumulation attribute and difference energy accumulation attribute of the unknown sand body, and roughly determines the sand body thickness interval of the unknown sand body according to the qualitative prediction measurement version of the sand body thickness.

[0082] After the computing server 102 determines the sand body thickness interval where the unknown sand body is located, the sand body thickness prediction equation corresponding to the sand body thickness interval is selected according to the sand body thickness qualitative prediction version, and the energy accumulation attribute of the sand body is substituted as an independent variable into the sand body thickness prediction equation to obtain the thickness of the unknown sand body.

[0083] In this way, construction personnel can store the seismic data and main frequency about the sand body in the database 101, and store the qualitative prediction version of the sand body thickness in the operation server 102. When it is necessary to predict the thickness of the sand body, the seismic data and main frequency can be obtained through the operation server 102, and the operation end can be isolated from the data input end to ensure efficient storage of data. The seismic forward wavelet can be sent in coordination with the acoustic wave synthesizer 104 to quickly establish a wedge-shaped model of the sand body. After the wedge-shaped model is established, the segmented sand body thickness equation can be quickly obtained.

[0084] In the process of predicting the thickness of sand bodies, affected by the main frequency resolution, the existing technology is often unable to predict the thickness of thin sand bodies less than 1 / 4 of the seismic wavelet wavelength. Therefore, at this stage, there is an urgent need for a sand body thickness prediction method that can predict thin sand bodies based on the frequency domain characteristics of the sand body.

[0085] In order to solve the above problems, the embodiment of this article provides a method for predicting sand body thickness based on frequency domain, which can establish a fitting equation for predicting sand body thickness. Figure 2 It is a schematic diagram of the steps of a method for predicting sand body thickness based on the frequency domain provided in the embodiment of this article. It can be applied to the field of sand body thickness prediction technology and can be used in the field of earth geography. The above-mentioned problems can be solved by using this method. This specification provides method operation steps as described in the embodiment or flow chart, but it may include more or fewer operation steps based on conventional or non-creative labor. The order of steps listed in the embodiment is only one way of executing the steps among many, and does not represent the only execution order. When the system or device product is executed in practice, it can be executed in the order of the method shown in the embodiment or the accompanying drawings or in parallel. Specifically, Figure 2 As shown, the method may include:

[0086] Step 201: When predicting an unknown sand body, query the qualitative prediction plate of sand body thickness according to the energy interval of the energy curve corresponding to the main frequency energy accumulation attribute, the high frequency energy accumulation attribute and the difference energy accumulation attribute of the unknown sand body, and determine the sand body thickness interval where the unknown sand body is located.

[0087] Step 202: predicting the thickness of the unknown sand body within the sand body thickness interval according to a sand body thickness prediction equation corresponding to the sand body thickness interval.

[0088] It should be noted that, through the above method, the sand body thickness interval where the unknown sand body is located can be roughly estimated based on several types of energy accumulation attributes that can be directly measured from the unknown sand body, and after estimating the sand body thickness interval where the unknown sand body is located, the thickness of the sand body can be accurately obtained through the sand body thickness prediction equation corresponding to the sand body thickness interval.

[0089] like Figure 3 A schematic diagram of establishing a sand body thickness qualitative prediction measurement version of a method for predicting sand body thickness based on frequency domain is shown. As an embodiment of this invention, the method for establishing the sand body thickness qualitative prediction measurement version includes:

[0090] Step 301: determining energy attributes of several preset frequencies of the sand body according to the wedge-shaped model of the sand body, wherein the energy attributes of the preset frequencies include: main frequency energy accumulation attribute, high frequency energy accumulation attribute and difference energy accumulation attribute.

[0091] Step 302: Draw an energy curve for each preset frequency according to the energy attributes of each preset frequency, wherein the energy curves of the main frequency energy accumulation attribute and the high-frequency energy accumulation attribute are divided into a first energy interval, a second energy interval, and a third energy interval according to the size of the energy, and the difference energy accumulation attribute is divided into a fourth energy interval and a fifth energy interval according to the size of the difference between the main frequency energy accumulation attribute and the high-frequency energy accumulation attribute.

[0092] Step 303: Determine the sand body thickness interval according to the intersection of the preset seismic trace interval of the sand body and the energy curve of each preset frequency.

[0093] Step 304: In each sand body thickness interval, an energy curve with the best fitting effect is selected from energy curves corresponding to the main frequency energy accumulation attribute or the high frequency energy accumulation attribute.

[0094] Step 305: Calculate the sand body thickness prediction equation corresponding to the selected energy curve.

[0095] Step 306: correspond the sand body thickness prediction equation to each sand body thickness interval in the sand body thickness qualitative prediction measurement version.

[0096] Step 307: Create the qualitative prediction version of the sand body thickness according to the correspondence between each sand body thickness interval and the energy interval where the energy curves of the main frequency energy accumulation attribute, the high frequency energy accumulation attribute and the difference energy accumulation attribute are located.

[0097] In this paper, the frequency is related to the thickness of the sand body. The frequency can be preset and the energy attributes corresponding to the frequency can be divided into high-frequency energy accumulation attributes and main frequency energy accumulation attributes. Previous studies have shown that high-frequency energy is more concentrated in the location of thin sand bodies, and main frequency energy is more concentrated in the location of thick sand bodies. According to this law, the energy attributes are utilized, and based on the difference between the high-frequency energy accumulation attribute and the main frequency energy accumulation attribute, the laws of the two are summarized to obtain a sand body thickness prediction equation that can describe the sand body thickness.

[0098] It should be noted that, for the sake of convenience, the first energy interval, the second energy interval and the third energy interval in this article can be replaced by strong, medium and weak intervals, and because the difference energy accumulation attribute is the difference, the fourth energy interval and the fifth energy interval can be positive intervals and negative intervals.

[0099] Through the above method, the relationship between sand body thickness and energy curve can be quantitatively described, and the sand body thickness prediction equation of the sand body can be obtained by selecting the better curve segment in the energy curve for fitting operation, and the corresponding relationship between the sand body thickness interval and the sand body thickness prediction equation can be determined.

[0100] like Figure 4 A schematic diagram of a wedge-shaped model of a method for predicting sand body thickness based on frequency domain is shown. As an embodiment of this invention, before determining the energy attribute of the preset frequency of the sand body according to the wedge-shaped model of the sand body, it includes:

[0101] The density of the sand body and the longitudinal wave velocity of the sand body are obtained according to the logging data of the sand body.

[0102] The wedge-shaped model is established according to the density of the sand body and the longitudinal wave velocity of the sand body.

[0103] In this step, the main frequency of the sand body is its inherent property, that is, the main frequency of each type of sand body is different, and for those skilled in the art, spectrum analysis of the sand body is a relatively conventional technical means, so it will not be repeated here. In the prior art, relevant parameters about the seismic forward wavelet can be generated according to the main frequency of the sand body, and then the seismic forward wavelet is generated and then emitted to the sand body. When the sand body receives the seismic forward wavelet, it will be reflected at the upper and lower interfaces. The instrument that receives the seismic forward wavelet can analyze the propagation speed of the sand body for the seismic forward wavelet according to the time difference between the received reflected sound waves.

[0104] When a technician in this field obtains the main frequency of the sand body, the density of the sand body and the propagation speed of the sand body for the seismic forward wavelet, it is easy to obtain a wedge model of the sand body. In this wedge model, the ordinate is time, which represents the interval time of the reflected sound waves returned by the sand body for the seismic forward wavelet, and the abscissa represents the seismic trace. In this wedge model, there are 200 seismic traces, that is, each seismic trace can represent the thickness of the wedge model.

[0105] like Figure 5 The schematic diagram of the steps of determining energy accumulation attributes of a method for predicting sand body thickness based on frequency domain is shown as an embodiment of this invention. Step 301 determines the energy attribute of the preset frequency of the sand body according to the wedge-shaped model of the sand body, and further includes:

[0106] Step 501: Perform spectrum analysis on the actual seismic data to obtain the main frequency of the actual seismic data.

[0107] Step 502: synthesize the seismic forward modeling wavelet according to the main frequency.

[0108] Step 503: Convolve the wedge-shaped model and the seismic forward modeling wavelet to obtain a forward modeling synthetic seismic record of the wedge-shaped model.

[0109] Step 504: Perform spectrum analysis on the forward modeled synthetic seismic record to obtain a time-frequency spectrum diagram of the forward modeled synthetic seismic record.

[0110] In this step, if Figure 6 The schematic diagram of a method for predicting sand body thickness based on frequency domain is shown in Figure 1. The forward modeling of the wedge-shaped model is used to synthesize seismic records. Figure 6 In the figure, CDP corresponds to the seismic trace, and the shadows between adjacent seismic traces represent the spectrum energy clusters between different seismic traces. When CDP increases from 0 to 200, the thickness of the sand body gradually increases.

[0111] like Figure 7 The schematic diagram of frequency domain analysis of a method for predicting sand body thickness based on frequency domain is shown in FIG. The smoothed pseudo-Wigner-Ville distribution is used to perform time-frequency analysis on the seismic recording results. Figure 7 It can be clearly seen that as the frequency increases, the spectrum energy group gradually moves toward the tip of the wedge-shaped model, which means that high-frequency energy can identify thinner sand bodies.

[0112] Step 505: extract the time-frequency ridges of the time-frequency spectrum diagram.

[0113] like Figure 8 A schematic diagram of time-frequency ridge lines showing a method for predicting sand body thickness based on frequency domain.

[0114] In the present invention, the time-frequency ridgeline is defined as the peak frequency corresponding to the maximum energy of the seismic signal at each moment in the spectrum. According to the time-frequency analysis results of each channel of seismic data, the peak frequency corresponding to each sampling point of each channel is picked up based on the modulus maximum method, and the peak frequencies of all sampling points of each channel are connected in sequence to obtain the time-frequency ridgeline of each channel.

[0115] Determine the first frequency translation parameter of the time-frequency ridge line and the second frequency translation parameter of the time-frequency ridge line. In this example, the first frequency translation parameter of the time-frequency ridge line = 5Hz, and the second frequency translation parameter of the time-frequency ridge line = 20Hz. Subtract the first frequency translation parameter from each time-frequency ridge line to obtain the first standard line of each time-frequency spectrum ( Figure 8 Line I in ); add the first frequency translation parameter to each time-frequency ridge line to obtain the second standard line of each time-frequency spectrum ( Figure 8Line II in ); add the second frequency shift parameter to each time-frequency ridge line to obtain the third standard line of each time-frequency spectrum ( Figure 8 Line III in ).

[0116] Step 506: Obtain energy attributes of several preset frequencies of the sand body according to the time-frequency ridges and normalize them.

[0117] 9(a)-(b) are schematic diagrams of energy accumulation attributes of a method for predicting sand body thickness based on the frequency domain.

[0118] In this paper, energy attributes include main frequency energy accumulation attributes and high frequency energy accumulation attributes.

[0119] The spectrum energy between the first standard line and the second standard line of each channel is accumulated and normalized to obtain the main frequency energy accumulation attribute, as shown in Figure 9(b). The main frequency energy accumulation attribute includes most of the energy in the spectrum diagram to reflect the macroscopic distribution characteristics of the sand body. The spectrum energy between the second standard line and the third standard line of each channel is accumulated and normalized to obtain the high frequency energy accumulation attribute as shown in Figure 9(a).

[0120] As an embodiment of this invention, step 302 draws an energy curve of each preset frequency according to the energy attribute of each preset frequency, wherein the energy curve of the main frequency energy accumulation attribute and the high frequency energy accumulation attribute is divided into a first energy interval, a second energy interval and a third energy interval according to the energy size, and the difference energy attribute is divided into a fourth energy interval and a fifth energy interval according to the size of the difference between the main frequency energy attribute and the high frequency energy attribute. Specifically, it includes:

[0121] For each energy attribute of a preset frequency corresponding to each sand body thickness interval, the maximum value of the energy attribute of the preset frequency is screened out as the energy value of the preset frequency.

[0122] The thickness of the sand body is used as the abscissa, and the energy value of each preset frequency is used as the ordinate, and the energy curves of each preset frequency are drawn respectively.

[0123] exist Fig.10 It can be seen that the top horizontal axis corresponds to the sand body thickness interval, the rightmost is the energy interval of the main frequency energy accumulation attribute and the high frequency energy accumulation attribute, the strong, medium and weak intervals, and the corresponding sand body thickness intervals are divided into several independent grids. For example, in the sand body thickness interval I, the main frequency energy accumulation curve and the high frequency energy accumulation curve are both weak intervals, while in the sand body thickness interval III, the main frequency energy accumulation curve and the high frequency energy accumulation curve are one strong interval and the other medium interval. In this way, the energy curves are corresponded to the sand body thickness intervals respectively.

[0124] In this step, because the main frequency energy accumulation attribute and the high frequency energy accumulation attribute have been normalized and the corresponding CDPs are consistent, the main frequency energy accumulation attribute and the high frequency energy accumulation attribute can be placed in the same scale. According to Figure 9 (a)-(b), the darker energy in the spectrum energy group passed by the main frequency energy accumulation attribute and the high frequency energy accumulation attribute of each CDP can be used as the vertical coordinate, and the CDP can be used as the horizontal coordinate. Because CDP can characterize the thickness of the sand body, the sand body thickness can also be used as the horizontal coordinate. Using this method, according to Figure 9 (a)-(b), Fig.10 Schematic diagram of an energy accumulation curve for predicting sand body thickness based on frequency domain.

[0125] exist Fig.10 In the figure, the solid line is the main frequency energy accumulation curve, and the dotted line is the high frequency energy accumulation curve. The maximum value of the ordinate of the main frequency energy accumulation curve and the high frequency energy accumulation curve in this article is 1, the minimum value is 0, and the range of the abscissa is 0-200.

[0126] like Fig.10 As shown in the figure, because there are multiple energy accumulation curves that can characterize the relationship between sand body energy and sand body thickness in the same sand body thickness interval, a curve with the best fitting basis is selected to fit the relationship between sand body energy and sand body thickness in the sand body thickness interval. For example, this paper selects the curve with the largest slope and monotonicity. In the sand body thickness interval I, the high-frequency energy accumulation curve is selected for fitting, and in the sand body thickness interval IV, the monotonic main frequency energy accumulation curve is selected for fitting.

[0127] As an embodiment of this invention, the step of drawing the energy curve of each preset frequency according to the energy attribute of each preset frequency further includes:

[0128] For the main frequency energy attribute corresponding to each sand body thickness, the maximum value of the main frequency energy attribute is screened out as the energy value of the main frequency energy attribute.

[0129] For the high-frequency energy attribute corresponding to each sand body thickness, the maximum value of the high-frequency energy attribute is screened out as the energy value of the high-frequency energy attribute.

[0130] The thickness of the sand body is used as the abscissa, and the energy values ​​of the main frequency energy attribute and the high frequency energy attribute are used as the ordinate, and energy curves of the main frequency energy attribute and the high frequency energy attribute are drawn respectively.

[0131] For the difference energy attribute, under the same horizontal coordinate, the vertical coordinate of the high frequency energy attribute is subtracted from the vertical coordinate of the main frequency energy attribute to obtain an energy curve of the difference energy attribute.

[0132] like Fig.10As shown in the figure, in the sand body thickness interval I and the sand body thickness interval VIII, the main frequency energy accumulation curve and the high frequency energy accumulation curve are both weak intervals and weak intervals, so in order to avoid ambiguity, the two curves are subtracted. Under the same horizontal axis, the high frequency energy accumulation curve is subtracted from the main frequency energy accumulation curve to obtain the difference energy accumulation curve, as shown in Fig.11 The figure shows a schematic diagram of a difference energy accumulation curve of a method for predicting sand body thickness based on frequency domain, that is, in the sand body thickness interval I and the sand body thickness interval VIII, the difference energy accumulation curve is one positive and the other negative, which strengthens the distinction between different sand body thickness intervals.

[0133] As an embodiment of this invention, the step of determining the sand body thickness interval according to the intersection of the preset energy interval of the sand body and the energy attribute of each preset frequency further includes:

[0134] In the energy curve of each preset frequency, the dividing points of the preset energy interval of the sand body are determined.

[0135] The sand body thickness interval is determined according to the division points.

[0136] In this step, the energy curves of the preset frequency are the main frequency energy accumulation curve and the high-frequency energy accumulation curve mentioned above. According to actual needs, the 0-1 interval on the vertical axis can be divided into three parts. In this article, 0-0.4 is a weak interval, 0.4-0.7 is a medium interval, and 0.7-1.0 is a strong interval. The strong, medium and weak intervals shown in Figures 9 (a)-(b) correspond to the strong interval, medium interval and weak interval in this article. The intersection of the two dividing lines of the three intervals and the main frequency energy accumulation curve and the high-frequency energy accumulation curve is used as the dividing point of the preset energy interval.

[0137] After determining the division point, take the division point as the reference and draw a vertical line to the horizontal axis of the main frequency energy accumulation curve and the high frequency energy accumulation curve to divide into eight intervals, corresponding to the uppermost Ⅰ-Ⅷ in Figure 9 (a)-(b). At the intersection of the main frequency energy accumulation curve and the high frequency energy accumulation curve with the straight line separating the strong, medium and weak intervals, draw a vertical line to the horizontal axis of the coordinate axis, and the interval between each vertical line is the sand body thickness interval.

[0138] In this step, it is necessary to select a curve that can better reflect the sand body thickness and energy within the sand body thickness range. For example, in Figure 9 (a)-(b), Ⅰ, Ⅱ and Ⅲ can be classified as one type of area. In this area, there are two monotonous curves. In order to better characterize the corresponding relationship, a curve with a larger slope should be selected, that is, the high-frequency energy accumulation curve is selected as the representative within Ⅰ, Ⅱ and Ⅲ.

[0139] In area IV, area IV can be classified as a type of area because the high-frequency energy accumulation curve first increases and then decreases, while the main frequency energy accumulation curve is monotonically increasing. Therefore, the main frequency energy curve is selected as the most representative, so that when performing coordinate conversion, there will be no situation where one horizontal coordinate corresponds to two values.

[0140] In area V, area V can be classified as a type of area because the main frequency energy accumulation curve first increases and then decreases, while the high-frequency energy accumulation curve is monotonically increasing. Therefore, the high-frequency energy curve is selected as the most representative, so that when performing coordinate conversion, there will be no situation where one horizontal axis corresponds to two values.

[0141] In areas VI, VII and VIII, areas VI, VII and VIII can be classified as one type of area. Because the high-frequency energy accumulation curve and the main frequency energy accumulation curve are all monotonically increasing, the main frequency energy curve with a larger slope is selected as the most representative. In this way, when performing coordinate transformation, the relationship between sand body thickness and energy can be better characterized.

[0142] As an embodiment of this invention, the qualitative prediction measurement version of the sand body thickness is created according to the correspondence between each sand body thickness interval and the energy interval where the energy curves of the main frequency energy attribute, the high frequency energy attribute and the difference energy attribute are located, further comprising:

[0143] In the sand body thickness interval, the energy intervals of the energy curves of the main frequency energy attribute and the high frequency energy attribute are determined, and the energy interval of the energy curve of the difference energy attribute is determined.

[0144] The energy interval where the energy curves of the main frequency energy attribute, the high frequency energy attribute and the difference energy attribute corresponding to the sand body thickness interval are located is used as a row of the sand body thickness qualitative prediction measurement plate.

[0145] By using the above method, the energy intervals where the energy curves of the main frequency energy attribute, the high frequency energy attribute and the difference energy attribute correspond to all the sand body thickness intervals are located are obtained in turn, and the qualitative prediction measurement version of the sand body thickness is created.

[0146] In this step, each sand body thickness interval, such as the sand body thickness intervals I-VIII, corresponds to a segment of energy accumulation attribute curve according to the above method, that is, corresponds to a sand body thickness prediction equation.

[0147] For example, in the sand body thickness interval I, the high-frequency energy accumulation curve is selected as the corresponding prediction equation, and the weak interval of the main frequency energy accumulation curve, the weak interval of the high-frequency energy accumulation curve, and the positive interval of the difference energy accumulation curve correspond to the sand body thickness interval I, and are used as a row of the sand body thickness qualitative prediction measurement plate. The sand body thickness qualitative prediction measurement plate is shown in Table 1 below:

[0148] Table 1

[0149] Sand body thickness area Main frequency energy accumulation attribute High frequency energy accumulation properties Energy Difference Properties I(0~4 / 80λ) weak weak just II(4 / 80~7 / 80λ) weak middle just III(7 / 80~11 / 80λ) middle powerful just IV(11 / 80~23 / 100λ) powerful powerful Can be positive or negative V(23 / 100~22 / 80λ) powerful middle burden VI (22 / 80~30 / 80λ) powerful weak burden VII(30 / 80~37 / 80λ) middle weak burden VIII(30 / 80~1 / 2λ) weak weak burden

[0150] It can be seen from Table 1 above that each row in the sand body thickness interval has corresponding main frequency energy accumulation attributes, high frequency energy accumulation attributes and difference energy attributes. When predicting unknown sand bodies, the corresponding sand body thickness can be determined according to the high frequency energy accumulation attributes, main frequency energy accumulation attributes and difference energy accumulation attributes that can be directly measured in the unknown sand body. Then, the corresponding sand body thickness bottom qualitative prediction equation can be found in the sand body thickness interval to accurately measure the thickness of the sand body.

[0151] As shown in FIG. 12 (a)-(d), a schematic diagram of a fitting curve of a method for predicting sand body thickness based on frequency domain is shown. As an embodiment of this invention, the step of determining the sand body thickness equation according to the energy curve further includes:

[0152] In the sand body thickness range, the abscissa of the screened energy curve is used as the ordinate of the fitting curve, and the ordinate of the screened energy curve is used as the abscissa of the fitting curve.

[0153] Points on the fitting curve are selected to perform equation fitting to obtain the sand body thickness equation that characterizes the fitting curve.

[0154] In order to facilitate the fitting equation and take the sand body thickness represented by CDP as the dependent variable, it is necessary to transform the coordinate system, and use the abscissa of the current screened main frequency energy accumulation curve or the high-frequency energy accumulation curve as the ordinate of the fitting curve, and use the ordinate of the current screened main frequency energy accumulation curve or the high-frequency energy accumulation curve as the abscissa of the fitting curve.

[0155] After the coordinate system is converted, the points on the fitting curve are selected to obtain the corresponding relationship between the normalized energy and the sand body thickness CDP. The corresponding relationship is imported into the equation fitting tool to obtain the sand body thickness equation that characterizes the fitting curve.

[0156] As shown in Figure 12(a), the thickness regions of sand bodies Ⅰ, Ⅱ and Ⅲ are characterized. When the sand body thickness is 0-0.15λ, λ is the main frequency of the sand body, and the equation h = 0.1233x can be fitted. 3 -0.153x 2 +0.1662x+0.0002, when the sand body thickness is estimated to be 0-0.15λ, this equation can be used to accurately calculate the thickness of the sand body. By comparing with the actual high-frequency energy accumulation curve, the fitting degree of the equation R 2 is 0.9987.

[0157] As shown in Figure 12(b), the thickness region of the IV sand body is characterized. When the sand body thickness is 0.12-0.24λ, λ is the main frequency of the sand body, and the equation h = 4.2331x can be fitted. 3 -10.27x 2 +8.5083x-2.2427. When the sand body thickness is estimated to be 0.12-0.24λ, this equation can be used to accurately calculate the thickness of the sand body. By comparing with the actual main frequency energy accumulation curve, the fitting degree of this equation is 0.9958.

[0158] As shown in Figure 12(c), the sand body thickness region V is characterized. When the sand body thickness is 0.22-0.28λ, λ is the main frequency of the sand body, and the equation h = -0.2623x can be fitted. 3 +0.4575x 2 -0.4118x+0.3846. When the sand body thickness is estimated to be 0.22-0.28λ, this equation can be used to accurately calculate the thickness of the sand body. By comparing with the actual high-frequency energy accumulation curve, the fitting degree of the equation is 1.

[0159] As shown in Figure 12(d), the thickness of the sand bodies VI, VII and VIII is characterized. When the sand body thickness is 0.25-0.55λ, λ is the main frequency of the sand body, and the equation h = -0.4251x can be fitted. 3 +0.7611x 2 -0.7172x+0.6532. When the sand body thickness is estimated to be 0.25-0.55λ, this equation can be used to accurately calculate the thickness of the sand body. By comparing with the actual main frequency energy accumulation curve, the fitting degree of this equation is 0.9987.

[0160] As an embodiment of this invention, the step is to correspond the sand body thickness equation to the qualitative prediction measurement version of the sand body thickness according to the sand body thickness interval.

[0161] When predicting the thickness of a sand body, determining the thickness of the sand body according to the qualitative prediction measurement version of the sand body thickness further includes:

[0162] In Table 1, several types of sand body thickness are given, such as 0-1 / 2λ, and each sand body thickness interval is corresponded to the sand body thickness qualitative prediction measurement plate. The sand body thickness interval of 0-0.15λ in the sand body thickness qualitative prediction measurement plate is calculated using the equation h=0.1233x 3 -0.153x 2 +0.1662x+0.0002 characterization.

[0163] The sand body thickness interval of 0.12-0.24λ in the sand body thickness qualitative prediction version is calculated using the equation h=4.2331x 3 -10.27x 2 +8.5083x-2.2427 characterization.

[0164] The sand body thickness interval of 0.22-0.28λ in the sand body thickness qualitative prediction version is calculated using the equation h=-0.2623x 3 +0.4575x 2 -0.4118x+0.3846 characterization.

[0165] The sand body thickness interval of 0.25-0.55λ in the sand body thickness qualitative prediction version is calculated using the equation h=-0.4251x 3 +0.7611x 2 -0.7172x+0.6532 characterization.

[0166] When an unknown sand body to be predicted is obtained, it is only necessary to use conventional means to determine its corresponding main frequency energy accumulation attribute, high frequency energy accumulation attribute, and difference energy accumulation attribute, select the corresponding equation in the sand body thickness qualitative prediction version, and then obtain the thickness of the sand body to be predicted based on the equation.

[0167] Through this method, the thickness of thin sand bodies can be predicted according to the sand body thickness equation in the frequency domain, which is not affected by the main frequency resolution of the sand body and has good prediction effect. The use of this sand body thickness equation can reduce manpower and material resources and improve productivity.

[0168] like Fig.13 A schematic diagram of a device for predicting sand body thickness based on frequency domain is shown, comprising:

[0169] The interval prediction unit 1301 is used to query the qualitative prediction version of the sand body thickness according to the energy interval of the energy curve corresponding to the main frequency energy accumulation attribute, the high frequency energy accumulation attribute and the difference energy accumulation attribute of the unknown sand body when predicting an unknown sand body, and determine the sand body thickness interval where the unknown sand body is located.

[0170] The thickness prediction unit 1302 is used to predict the thickness of the unknown sand body within the sand body thickness interval according to the sand body thickness prediction equation corresponding to the sand body thickness interval.

[0171] like Fig.14 A schematic diagram of a device for establishing a sand body thickness prediction equation based on frequency domain prediction of sand body thickness is shown, comprising:

[0172] The energy attribute determination unit 1401 is used to determine the energy attributes of several preset frequencies of the sand body according to the wedge-shaped model of the sand body, wherein the energy attributes of the preset frequencies include: main frequency energy accumulation attribute, high frequency energy accumulation attribute and difference energy accumulation attribute.

[0173] The interval division unit 1402 is used to draw the energy curve of each preset frequency according to the energy attributes of each preset frequency, wherein the energy curves of the main frequency energy accumulation attribute and the high-frequency energy accumulation attribute are divided into a first energy interval, a second energy interval and a third energy interval according to the size of the energy, and the difference energy accumulation attribute is divided into a fourth energy interval and a fifth energy interval according to the size of the difference between the main frequency energy accumulation attribute and the high-frequency energy accumulation attribute.

[0174] The thickness determination unit 1403 is used to determine the thickness interval of the sand body according to the intersection of the preset seismic trace interval of the sand body and the energy curve of each preset frequency.

[0175] The curve selection unit 1404 is used to select an energy curve with the best fitting effect from the energy curves corresponding to the main frequency energy accumulation attribute or the high frequency energy accumulation attribute within each sand body thickness interval.

[0176] The equation selection unit 1405 is used to calculate the sand body thickness prediction equation corresponding to the selected energy curve.

[0177] The corresponding unit 1406 is used to correspond the sand body thickness prediction equation to each sand body thickness interval in the sand body thickness qualitative prediction measurement version.

[0178] The measurement board creation unit 1407 is used to create the sand body thickness qualitative prediction measurement board according to the correspondence between each sand body thickness interval and the energy interval where the energy curves of the main frequency energy accumulation attribute, the high frequency energy accumulation attribute and the difference energy accumulation attribute are located.

[0179] Through the above device, the corresponding energy curve can be quickly drawn according to the wedge-shaped model of the sand body, and the sand body thickness interval can be divided according to the preset energy interval. A curve with better fitting performance is selected in the sand body thickness interval for fitting, and the sand body thickness equation in the sand body thickness interval is obtained. When the sand body thickness equations in several sand body thickness intervals are obtained, the thickness of the sand body to be predicted can be roughly estimated. For example, when the thickness of the sand body to be estimated is 0-0.15λ, the corresponding sand body thickness equation can be selected, and the main frequency energy of the sand body can be obtained according to the actual geological data of the sand body, and the main frequency energy is brought into the sand body thickness equation to obtain the corresponding sand body thickness. The user can determine the thickness of the sand body according to the sand body thickness equation.

[0180] like Fig.15The schematic diagram of an energy determination unit of a device for predicting sand body thickness based on frequency domain is shown. As an embodiment of this invention, the energy attribute determination unit 1401 further includes:

[0181] The time-frequency spectrum extraction unit 14011 is used to perform forward synthesis on the wedge-shaped model to obtain a time-frequency spectrum of sand body thickness.

[0182] The time-frequency ridge extraction unit 14012 is used to extract the time-frequency ridge according to the time-frequency spectrum.

[0183] The energy attribute extraction unit 14013 is used to obtain the energy attributes of several preset frequencies of the sand body according to the time-frequency ridges and normalize them.

[0184] like Fig.16 The data flow chart of an overall system for predicting sand body thickness based on frequency domain is shown, including:

[0185] Step 1601 , the computing server 102 extracts the seismic data and main frequency of the sand body from the database 101 .

[0186] Step 1602 : The computing server 102 synthesizes the relevant parameters of the seismic forward modeling wavelet according to the main frequency, and sends the relevant parameters of the seismic forward modeling wavelet to the acoustic wave synthesizer 104 .

[0187] Step 1603 , the sound wave synthesizer 104 calculates the time difference of the reflected sound wave of the seismic forward modeling wavelet, determines the propagation speed of the seismic forward modeling wavelet according to the time difference, and sends it to the operation server 102 .

[0188] Step 1604: The computing server 102 establishes a wedge-shaped model based on the seismic data of the sand body and the propagation velocity of the seismic forward modeling wavelet, and determines the energy curve of the sand body.

[0189] Step 1605 : Delimit the energy interval on the energy curve through the control terminal 103 .

[0190] Step 1606: The computing server 102 determines the sand body thickness interval according to the energy interval, and selects the optimal energy curve within the sand body thickness interval.

[0191] Step 1607 : the computing server 102 fits the sand body thickness equation according to the optimal energy curve and sends it to the control terminal 103 .

[0192] Step 1608: The control terminal 103 receives the measured energy of the sand body and calculates the thickness of the sand body according to the sand body thickness equation.

[0193] like Fig.17As shown, a computer device provided in an embodiment of the present invention, the computer device 1702 may include one or more processors 1704, such as one or more central processing units (CPUs), each of which may implement one or more hardware threads. The computer device 1702 may also include any memory 1706, which is used to store any kind of information such as code, settings, data, etc. Non-restrictive, for example, the memory 1706 may include any one or more combinations of the following: any type of RAM, any type of ROM, flash memory device, hard disk, optical disk, etc. More generally, any memory may use any technology to store information. Further, any memory may provide volatile or non-volatile retention of information. Further, any memory may represent a fixed or removable component of the computer device 1702. In one case, when the processor 1704 executes an associated instruction stored in any memory or a combination of memories, the computer device 1702 may perform any operation of the associated instruction. The computer device 1702 also includes one or more drive mechanisms 1708 for interacting with any memory, such as a hard disk drive mechanism, an optical disk drive mechanism, etc.

[0194] The computer device 1702 may also include an input / output module 1710 (I / O) for receiving various inputs (via input device 1712) and for providing various outputs (via output device 1714). A specific output mechanism may include a presentation device 1716 and an associated graphical user interface (GUI) 1718. In other embodiments, the input / output module 1710 (I / O), input device 1712, and output device 1714 may not be included, and the computer device 1702 may be used as a computer device in a network. The computer device 1702 may also include one or more network interfaces 1720 for exchanging data with other devices via one or more communication links 1722. One or more communication buses 1724 couple the components described above together.

[0195] The communication link 1722 may be implemented in any manner, for example, through a local area network, a wide area network (e.g., the Internet), a point-to-point connection, etc., or any combination thereof. The communication link 1722 may include any combination of hardwired links, wireless links, routers, gateway functions, name servers, etc. governed by any protocol or combination of protocols.

[0196] Corresponds to Figure 2 and Figure 3 The method in this article also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method are executed.

[0197] The embodiment of the present invention also provides a computer readable instruction, wherein when the processor executes the instruction, the program therein causes the processor to execute the following Figure 2 and Figure 3 The method shown.

[0198] It should be understood that in the various embodiments of this document, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this document.

[0199] It should also be understood that in the embodiments of this article, the term "and / or" is only a description of the association relationship of the associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0200] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this article.

[0201] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0202] In the several embodiments provided herein, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of the units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, or can be electrical, mechanical or other forms of connection.

[0203] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of this article.

[0204] In addition, each functional unit in each embodiment of this invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of software functional unit.

[0205] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this article is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of this article. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0206] Specific embodiments are used in this article to illustrate the principles and implementation methods of this article. The description of the above embodiments is only used to help understand the methods and core ideas of this article. At the same time, for general technicians in this field, according to the ideas of this article, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on this article.

Claims

1. A method for predicting sand body thickness based on frequency domain, characterized in that: include: When predicting an unknown sand body, according to the energy interval of the energy curve corresponding to the main frequency energy accumulation attribute, high frequency energy accumulation attribute and difference energy accumulation attribute of the unknown sand body, the qualitative prediction measurement version of the sand body thickness is queried to determine the sand body thickness interval where the unknown sand body is located; Within the sand body thickness interval, predicting the thickness of the unknown sand body according to a sand body thickness prediction equation corresponding to the sand body thickness interval; The method for creating the qualitative prediction version of sand body thickness includes: Determine energy attributes of several preset frequencies of the sand body according to the wedge-shaped model of the sand body, wherein the energy attributes of the preset frequencies include: main frequency energy accumulation attribute, high frequency energy accumulation attribute and difference energy accumulation attribute; According to the energy attributes of each preset frequency, an energy curve of each preset frequency is drawn, wherein the energy curves of the main frequency energy accumulation attribute and the high frequency energy accumulation attribute are divided into a first energy interval, a second energy interval and a third energy interval according to the magnitude of the energy, and the difference energy accumulation attribute is divided into a fourth energy interval and a fifth energy interval according to the positive and negative values ​​of the difference between the main frequency energy accumulation attribute and the high frequency energy accumulation attribute; Determining the sand body thickness interval according to the intersection of the preset seismic trace interval of the sand body and the energy curve of each preset frequency; In each sand body thickness interval, an energy curve with the best fitting effect is selected from the energy curves corresponding to the main frequency energy accumulation attribute or the high frequency energy accumulation attribute; Calculate the sand body thickness prediction equation corresponding to the selected energy curve; The sand body thickness prediction equation is respectively corresponded to each sand body thickness interval in the sand body thickness qualitative prediction measurement version; The qualitative prediction version of the sand body thickness is created according to the correspondence between each sand body thickness interval and the energy interval where the energy curves of the main frequency energy accumulation attribute, the high frequency energy accumulation attribute and the difference energy accumulation attribute are located.

2. The method for predicting sand body thickness based on frequency domain according to claim 1, characterized in that: The step of selecting an energy curve with the best fitting effect from among the energy curves corresponding to the main frequency energy accumulation attribute or the high frequency energy accumulation attribute within each sand body thickness interval further includes: Analyzing the monotonicity and maximum slope of the energy curve of the main frequency energy accumulation attribute or the high frequency energy accumulation attribute within each sand body thickness interval; According to the analysis results of each sand body thickness interval, an energy curve with monotonicity and maximum slope is screened out from the energy curves of the main frequency energy accumulation attribute or the high frequency energy accumulation attribute in each sand body thickness interval as a curve with the best fitting effect.

3. The method for predicting sand body thickness based on frequency domain according to claim 1, characterized in that: The step of determining the energy attributes of the sand body at a plurality of preset frequencies according to the wedge-shaped model of the sand body further comprises: Convolving the wedge-shaped model with the seismic forward modeling wavelet of the sand body, and forward modeling to obtain a forward synthetic seismic record of the wedge-shaped model; Performing spectrum analysis on the forward modeled synthetic seismic record to obtain a time-frequency spectrum diagram of the forward modeled synthetic seismic record; Extracting the time-frequency ridges of the time-frequency spectrum diagram; The main frequency energy accumulation attribute and the high frequency energy accumulation attribute of the sand body are obtained according to the time-frequency ridge and normalized.

4. The method for predicting sand body thickness based on frequency domain according to claim 1, characterized in that: Drawing the energy curve of each preset frequency according to the energy attribute of each preset frequency further includes: For the main frequency energy accumulation attribute corresponding to each sand body thickness, the maximum value of the main frequency energy accumulation attribute is selected as the energy value of the main frequency energy accumulation attribute; For the high-frequency energy accumulation attribute corresponding to each sand body thickness, the maximum value of the high-frequency energy accumulation attribute is selected as the energy value of the high-frequency energy accumulation attribute; Using the sand body thickness as the abscissa and the energy values ​​of the main frequency energy accumulation attribute and the high frequency energy accumulation attribute as the ordinate, energy curves of the main frequency energy accumulation attribute and the high frequency energy accumulation attribute are drawn respectively; For the difference energy accumulation attribute, under the same horizontal coordinate, the energy value of the main frequency energy accumulation attribute is subtracted from the energy value of the high frequency energy accumulation attribute to obtain an energy curve of the difference energy accumulation attribute.

5. The method for predicting sand body thickness based on frequency domain according to claim 3, characterized in that: The qualitative prediction measurement version of the sand body thickness is created according to the correspondence between each sand body thickness interval and the energy interval where the energy curves of the main frequency energy accumulation attribute, the high frequency energy accumulation attribute and the difference energy accumulation attribute are located, further comprising: In the sand body thickness interval, determine the energy interval of the energy curves of the main frequency energy accumulation attribute and the high frequency energy accumulation attribute, and determine the energy interval of the energy curve of the difference energy accumulation attribute; The energy interval where the energy curves of the main frequency energy accumulation attribute, the high frequency energy accumulation attribute and the difference energy accumulation attribute corresponding to the sand body thickness interval are located is taken as a row of the sand body thickness qualitative prediction measurement version; By the above method, the energy intervals where the energy curves of the main frequency energy accumulation attribute, the high frequency energy accumulation attribute and the difference energy accumulation attribute corresponding to all sand body thickness intervals are located are obtained in turn, and the qualitative prediction measurement version of the sand body thickness is created.

6. The method for predicting sand body thickness based on frequency domain according to claim 1, characterized in that: When predicting an unknown sand body, according to the energy interval of the energy curve corresponding to the main frequency energy accumulation attribute, the high frequency energy accumulation attribute and the difference energy accumulation attribute of the unknown sand body, the qualitative prediction measurement version of the sand body thickness is queried to determine the sand body thickness interval where the unknown sand body is located, further comprising: Determine the correspondence between the energy curves of the main frequency energy accumulation attribute and the high frequency energy accumulation attribute of the unknown sand body and the first energy interval, the second energy interval and the third energy interval; Determine the corresponding relationship between the difference energy accumulation attribute of the unknown sand body and the fourth energy interval and the fifth energy interval; The qualitative prediction measurement version of the sand body thickness is queried according to the above correspondence to determine the sand body thickness interval where the unknown sand body is located.

7. A device for predicting sand body thickness based on frequency domain, characterized in that: include: The interval prediction unit is used to query the qualitative prediction measurement version of the sand body thickness according to the energy interval where the energy curves corresponding to the main frequency energy accumulation attribute, high frequency energy accumulation attribute and difference energy accumulation attribute of the unknown sand body are located when predicting an unknown sand body, so as to determine the sand body thickness interval where the unknown sand body is located; wherein the interval prediction unit is further used to determine the energy attributes of several preset frequencies of the sand body according to the wedge-shaped model of the sand body, wherein the energy attributes of the preset frequencies include: main frequency energy accumulation attribute, high frequency energy accumulation attribute and difference energy accumulation attribute; according to the energy attributes of each preset frequency, draw the energy curve of each preset frequency, wherein the energy curves of the main frequency energy accumulation attribute and the high frequency energy accumulation attribute are divided into a first energy interval, a second energy interval and a third energy interval according to the size of the energy, and the difference energy accumulation attribute is divided into a second energy interval and a third energy interval according to the size of the energy The sum attribute is divided into a fourth energy interval and a fifth energy interval according to the positive and negative difference between the main frequency energy sum attribute and the high frequency energy sum attribute; the sand body thickness interval is determined according to the intersection of the preset seismic trace interval of the sand body and the energy curve of each preset frequency; in each sand body thickness interval, an energy curve with the best fitting effect is selected from the energy curves corresponding to the main frequency energy sum attribute or the high frequency energy sum attribute; the sand body thickness prediction equation corresponding to the selected energy curve is calculated; the sand body thickness prediction equation is respectively corresponded to each sand body thickness interval in the sand body thickness qualitative prediction measurement version; according to the correspondence between each sand body thickness interval and the energy interval where the energy curves of the main frequency energy sum attribute, the high frequency energy sum attribute and the difference energy sum attribute are located, the sand body thickness qualitative prediction measurement version is created; The thickness prediction unit is used to predict the thickness of the unknown sand body within the sand body thickness interval according to the sand body thickness prediction equation corresponding to the sand body thickness interval.

8. 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 method for predicting sand body thickness based on the frequency domain as described in any one of claims 1 to 6 is implemented.

9. 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 predicting sand body thickness based on the frequency domain as described in any one of claims 1 to 6 is implemented.

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