Anisotropy detection method and system based on orthogonal orientation attribute difference fusion

Abstract

The present invention provides an anisotropy detection method and system based on orthogonal azimuth attribute difference fusion, the method comprising: obtaining multiple seismic attributes at different seismic wave incident angles and seismic line azimuths according to the seismic azimuth gather of the target stratum; obtaining the maximum orthogonal azimuth difference value and the orthogonal azimuth corresponding to each seismic attribute through the seismic wave incident angle, the seismic line azimuth and the multiple seismic attributes; determining the anisotropy direction of the target stratum according to the orthogonal azimuth; performing weighted fusion processing on the multiple maximum orthogonal azimuth difference values ​​to obtain the anisotropy strength of the target stratum, so as to obtain the anisotropy detection result of the target stratum according to the anisotropy direction and the anisotropy strength. The present invention improves the calculation accuracy while reducing the amount of calculation, and realizes the stable solution of stratum anisotropy.

Description

Technical Field

[0001] The present invention relates to the field of seismic exploration technology, and in particular to an anisotropy detection method and system based on orthogonal azimuth attribute difference fusion. Background Art

[0002] Anisotropy refers to a property in which the physical properties of a medium change with the change of the observation direction. In the process of geological sedimentation, there are usually two causes that cause the anisotropy of underground media. One is the intrinsic cause, which is caused by the inherent structure or characteristics of the rock, such as the directional arrangement of mineral particles and the periodic deposition of thin interlayers; the other is the induced cause, which is generally related to the stress field or directional cracks. Since anisotropy is often related to the degree of reservoir development in seismic exploration and even affects the trajectory design of drilling, it is of great practical significance to study the anisotropy of underground rock formations and predict their development direction and strength.

[0003] Anisotropy detection methods are generally divided into three categories, including methods based on genetic analysis, methods based on shear wave splitting, and methods based on longitudinal wave azimuthal anisotropy. Among them, the genetic analysis method is an indirect prediction method, which is usually based on thin plate theory and considers the changing factors such as stratigraphic structure and sedimentary lithology to predict the development characteristics of anisotropy. Since this method uses macroscopic stratigraphic sedimentary information, it is suitable for large-scale anisotropy research. However, for the fine target characterization of reservoirs, the accuracy of this method needs to be further improved. The shear wave splitting method uses the travel time difference information of the fast and slow waves formed by the splitting of seismic shear waves after passing through anisotropic media to predict the direction and intensity of anisotropy. This method directly applies the wave information related to anisotropy, so it has a clear physical meaning, but due to the high cost of shear wave exploration, low data signal-to-noise ratio, and difficulty in static correction processing, the practical application of this method is limited. Compared with shear wave exploration, longitudinal wave exploration has the advantages of relatively low cost, high data quality and mature processing technology. Therefore, the use of longitudinal wave data for anisotropy detection has received widespread attention in practical applications.

[0004] In the existing anisotropy detection methods based on longitudinal waves, the anisotropy solution methods based on azimuth gather inversion or ellipse fitting have huge computational complexity and are easily affected by noise and fitting algorithms, resulting in deviations in the calculation results, which affects the accuracy of anisotropy detection. Therefore, there is an urgent need for an anisotropy detection method and system based on orthogonal azimuth attribute difference fusion to solve the above problems. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides an anisotropy detection method and system based on orthogonal orientation attribute difference fusion.

[0006] The present invention provides an anisotropy detection method based on orthogonal orientation attribute difference fusion, comprising:

[0007] According to the seismic azimuth gathers of the target stratum, multiple seismic attributes at different seismic wave incident angles and seismic line azimuths are obtained;

[0008] Obtaining the maximum orthogonal azimuth difference value and the orthogonal azimuth corresponding to each seismic attribute through the seismic wave incident angle, the seismic survey line azimuth and the multiple seismic attributes;

[0009] Determining the anisotropy direction of the target formation according to the orthogonal azimuth;

[0010] A weighted fusion process is performed on a plurality of the maximum orthogonal azimuth difference values ​​to obtain the anisotropic strength of the target formation, so as to obtain the anisotropic detection result of the target formation according to the anisotropic direction and the anisotropic strength.

[0011] According to an anisotropy detection method based on orthogonal azimuth attribute difference fusion provided by the present invention, after obtaining the maximum orthogonal azimuth difference value and the orthogonal azimuth corresponding to each seismic attribute through the seismic wave incident angle, the seismic line azimuth and the multiple seismic attributes, the method further includes:

[0012] Constructing an orthogonal azimuth attribute difference set corresponding to the target stratum according to the maximum orthogonal azimuth difference value and the orthogonal azimuth angle;

[0013] Based on core data or well logging data, obtaining fracture information of the target formation;

[0014] According to the fracture information, the seismic attributes in the orthogonal azimuthal attribute difference set are optimized according to the sensitivity of the difference set to obtain an orthogonal azimuthal attribute difference sensitivity set, so as to obtain the anisotropy detection result of the target formation according to the orthogonal azimuthal attribute difference sensitivity set.

[0015] According to an anisotropy detection method based on orthogonal azimuth attribute difference fusion provided by the present invention, before obtaining multiple seismic attributes at different seismic wave incident angles and seismic line azimuths according to the seismic azimuth gathers of the target stratum, the method further includes:

[0016] Based on the time difference correction technology, the seismic azimuth gathers are flattened to obtain the flattened seismic azimuth gathers;

[0017] The method of obtaining multiple seismic attributes at different seismic wave incident angles and seismic line azimuths according to the seismic azimuth gathers of the target stratum includes:

[0018] Through the flattened seismic azimuth gather, multiple seismic attributes at different seismic wave incident angles and seismic line azimuths are obtained.

[0019] According to an anisotropy detection method based on orthogonal azimuth attribute difference fusion provided by the present invention, the maximum orthogonal azimuth difference value and the orthogonal azimuth corresponding to each seismic attribute are obtained through the seismic wave incident angle, the seismic line azimuth and the multiple seismic attributes, including:

[0020] Based on the anisotropy solution formula of different seismic attributes, the maximum orthogonal azimuth difference value and orthogonal azimuth corresponding to each seismic attribute are obtained through the seismic wave incident angle, the seismic line azimuth and the multiple seismic attributes. The anisotropy solution formula is:

[0021]

[0022] Among them, D x Indicates the maximum orthogonal azimuth difference value and orthogonal azimuth angle corresponding to different seismic attributes, d x (θ) represents the azimuth angle of the seismic line θ and The relative ratio of the difference in seismic attributes between the two, i represents the incident angle of the seismic wave, x represents P Represents different earthquake attributes.

[0023] According to an anisotropy detection method based on orthogonal azimuth attribute difference fusion provided by the present invention, the anisotropy direction of the target formation is determined according to the orthogonal azimuth angle, including:

[0024] Based on core data or well logging data, obtaining fracture information or fault information of the target formation;

[0025] Based on the fracture information or fault information, the anisotropy direction of the target formation is determined through the orthogonal azimuth.

[0026] According to an anisotropy detection method based on orthogonal azimuth attribute difference fusion provided by the present invention, the weighted fusion processing of the plurality of maximum orthogonal azimuth difference values ​​is performed to obtain the anisotropy strength of the target formation, including:

[0027] Normalizing each of the maximum orthogonal orientation difference values ​​to obtain a normalized maximum orthogonal orientation difference value;

[0028] Based on core data or well logging data, determine the weight coefficient corresponding to each seismic attribute;

[0029] According to the weight coefficient, all the normalized maximum orthogonal azimuth difference values ​​are weightedly fused to obtain the anisotropic strength of the target formation.

[0030] The present invention also provides an anisotropy detection system based on orthogonal orientation attribute difference fusion, comprising:

[0031] A seismic attribute data acquisition module is used to obtain multiple seismic attributes at different seismic wave incident angles and seismic line azimuths according to the seismic azimuth gathers of the target stratum;

[0032] An orthogonal azimuth attribute difference calculation module, used for obtaining the maximum orthogonal azimuth difference value and the orthogonal azimuth angle corresponding to each seismic attribute through the seismic wave incident angle, the seismic line azimuth angle and the multiple seismic attributes;

[0033] An anisotropy direction determination module, used to determine the anisotropy direction of the target formation according to the orthogonal azimuth;

[0034] The anisotropic strength calculation module is used to perform weighted fusion processing on the multiple maximum orthogonal azimuth difference values ​​to obtain the anisotropic strength of the target formation, so as to obtain the anisotropic detection result of the target formation according to the anisotropic direction and the anisotropic strength.

[0035] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, an anisotropy detection method based on orthogonal orientation attribute difference fusion as described in any one of the above is implemented.

[0036] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the anisotropic detection method based on orthogonal orientation attribute difference fusion as described in any one of the above is implemented.

[0037] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the anisotropy detection method based on orthogonal orientation attribute difference fusion as described in any one of the above is implemented.

[0038] The anisotropy detection method and system based on orthogonal azimuth attribute difference fusion provided by the present invention obtain the anisotropy strength and anisotropy direction of the formation by analyzing different seismic attributes in the formation and utilizing the maximum orthogonal azimuth difference value and orthogonal azimuth angle of each seismic attribute, thereby reducing the amount of calculation and improving the calculation accuracy, thereby achieving a stable solution to the anisotropy of the formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 A schematic flow chart of an anisotropy detection method based on orthogonal orientation attribute difference fusion provided by the present invention;

[0041] Figure 2 The overall flow chart of the anisotropy detection method based on orthogonal orientation attribute difference fusion provided by the present invention;

[0042] Figure 3 A schematic diagram of the structure of an anisotropy detection system based on orthogonal orientation attribute difference fusion provided by the present invention;

[0043] Figure 4 This is a schematic structural diagram of an electronic device provided by the present invention. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] Anisotropy detection is an important task in seismic exploration, especially in the study of unconventional reservoirs, which has important reference value for the prediction of high-quality reservoirs and the design of drilling trajectories. Based on the propagation law of seismic P-waves in anisotropic media, a variety of information can be used to study the anisotropy of formations. Under the premise of weak anisotropy, Thomsen first proposed three parameters to describe the anisotropy characteristics, representing the anisotropy coefficients of P-waves, near-symmetry axis directions and S-waves. On this basis, Rüger derived the relationship between the P-wave reflection coefficient and the incident angle and azimuth; Tsvankin et al. discussed the relationship between the dynamic correction velocity and the corresponding time difference under the influence of anisotropy; Kempton studied the azimuthal variation of seismic wave frequency; Qu Shouli proposed to use the variation law of azimuthal wave impedance to predict fracture-type reservoirs related to anisotropy; Sayers proposed an analysis method based on the azimuthal variation of Young's modulus; Chen Huaizhen et al. discussed the relationship between the azimuthal and incident angle variations of elastic impedance.

[0046] Based on the reflection information that can be extracted from seismic longitudinal wave data, there are generally two types of methods for anisotropy detection. One is based on inversion, which is based on azimuth pre-stack gathers, uses reflection characteristics, the relationship between the incident angle and the azimuth angle, simplifies or approximates the inversion target equation, and then obtains the anisotropy parameters through nonlinear solution. This type of method has a clear expression and the physical meaning of the solution is relatively clear, but the amount of calculation is large. In addition, it is limited by the number of coverage times and signal-to-noise ratio, and the stability and accuracy of this method are usually affected. The other type is a method based on azimuthal feature fitting. Due to the influence of anisotropy, P-wave information such as amplitude, velocity and travel time will show elliptical variation characteristics as the azimuth changes. Therefore, the anisotropy of the formation is determined by extracting characteristic information in different azimuths and using ellipse fitting. Commonly used fitting methods include Hough transform method, Kalman filtering method, least squares median method and least squares method. This type of method usually uses azimuthal post-stack data, which reduces the amount of data and improves the coverage times and signal-to-noise ratio. Therefore, it can improve the calculation efficiency to a certain extent. However, when fitting the ellipse, it is easily affected by isolated points and noise, which leads to deviations in the fitting results and affects the calculation accuracy.

[0047] In order to improve the reliability and accuracy of anisotropy detection for reservoir characterization, the present invention proposes an anisotropy detection method based on orthogonal azimuthal attribute difference fusion, which is mainly used to detect the anisotropy direction and strength of the formation. By establishing an orthogonal azimuthal attribute difference set based on seismic data, using prior information such as core, well logging and geology, the orthogonal azimuthal attribute difference set is optimized for sensitive information, and then the anisotropy direction of the formation is determined by the azimuthal characteristics. Finally, the sensitive orthogonal azimuthal attribute differences are used for weighted fusion processing to obtain the anisotropy strength of the formation. This method improves the accuracy of anisotropy detection while reducing the amount of calculation, and realizes the stable solution of the anisotropy direction and strength of the formation, which has important application value for seismic exploration.

[0048] Figure 1 The flowchart of the anisotropy detection method based on orthogonal orientation attribute difference fusion provided by the present invention is as follows: Figure 1 As shown, the present invention provides an anisotropy detection method based on orthogonal orientation attribute difference fusion, comprising:

[0049] Step 101, obtaining a plurality of seismic attributes at different seismic wave incident angles and seismic line azimuths according to the seismic azimuth gathers of the target stratum.

[0050] For isotropic formations, when seismic waves are incident on the surface of the medium, their reflection characteristics will change with the change of the incident angle, while in anisotropic formations, the propagation of seismic waves will be affected by the azimuth at the same time, resulting in the reflection characteristics being related not only to the incident angle but also to the azimuth. In the present invention, through step 101, after selecting geometric or wave characteristics (i.e., multiple seismic attributes) such as amplitude, frequency, gradient and attenuation related to the target formation, multiple seismic attributes at different seismic wave incident angles and seismic line azimuths of the target formation are obtained based on the seismic azimuth gathers obtained by anisotropic migration.

[0051] Step 102, obtaining the maximum orthogonal azimuth difference value and the orthogonal azimuth corresponding to each seismic attribute through the seismic wave incident angle, the seismic survey line azimuth and the multiple seismic attributes.

[0052] Since the anisotropy of the formation not only affects the amplitude characteristics of the seismic wave, but also affects other seismic attributes, such as frequency, attenuation and gradient, in step 102, after determining the seismic attributes required for anisotropy detection of the target formation, these seismic attributes are used to represent the characteristics of the anisotropy intensity changing with the azimuth, and the anisotropy is solved through the anisotropy solution formula to extract the maximum orthogonal azimuth difference value and the corresponding orthogonal azimuth of each seismic attribute.

[0053] Step 103: determining the anisotropy direction of the target formation according to the orthogonal azimuth.

[0054] In the present invention, for the maximum orthogonal orientation difference value, each attribute difference can obtain a corresponding orthogonal orientation angle θ || and θ ⊥ However, due to the differences in different attributes, the determination of the anisotropy direction of the formation will be different, such as the amplitude seismic attribute and θ || The seismic attributes of the attenuation class are consistent with θ ⊥ Therefore, the present invention can determine the orthogonal azimuths corresponding to different seismic attributes according to the prior information and the orthogonal azimuths, and then extract the anisotropy direction of the target stratum.

[0055] Step 104 , performing weighted fusion processing on the plurality of maximum orthogonal azimuth difference values ​​to obtain the anisotropic strength of the target formation, so as to obtain the anisotropic detection result of the target formation according to the anisotropic direction and the anisotropic strength.

[0056] In the present invention, for the obtained multiple maximum orthogonal azimuth difference values, standardization processing is first performed to normalize different attribute value ranges to the same data range, and the data representation direction is adjusted, that is, a smaller value indicates a low anisotropy intensity, and a larger value indicates a high anisotropy intensity. Further, in one embodiment, the weight coefficient corresponding to each seismic attribute can be determined through prior information, so that the anisotropy parameters of the target formation are obtained by weighted fusion processing of multiple maximum orthogonal azimuth difference values, that is, the anisotropy intensity of the target formation is obtained, so as to complete the anisotropy detection of the target formation.

[0057] The anisotropy detection method based on orthogonal azimuth attribute difference fusion provided by the present invention obtains the anisotropy strength and anisotropy direction of the formation by analyzing different seismic attributes in the formation and utilizing the maximum orthogonal azimuth difference value and orthogonal azimuth angle of each seismic attribute, thereby reducing the amount of calculation and improving the calculation accuracy, thereby achieving a stable solution to the anisotropy of the formation.

[0058] On the basis of the above embodiment, after obtaining the maximum orthogonal azimuth difference value and the orthogonal azimuth corresponding to each seismic attribute through the seismic wave incident angle, the seismic line azimuth and the multiple seismic attributes, the method further includes:

[0059] Constructing an orthogonal azimuth attribute difference set corresponding to the target stratum according to the maximum orthogonal azimuth difference value and the orthogonal azimuth angle;

[0060] Based on core data or well logging data, obtaining fracture information of the target formation;

[0061] According to the fracture information, the seismic attributes in the orthogonal azimuthal attribute difference set are optimized according to the sensitivity of the difference set to obtain an orthogonal azimuthal attribute difference sensitivity set, so as to obtain the anisotropy detection result of the target formation according to the orthogonal azimuthal attribute difference sensitivity set.

[0062] In the present invention, due to the differences between the research target (i.e., the target stratum) and the basic data, in the orthogonal azimuth attribute difference set, different seismic attribute categories have different degrees of characterization of anisotropy, so it is necessary to perform sensitive orthogonal azimuth attribute difference information optimization. Specifically, in one embodiment, the anisotropic characteristics at the local well point can be determined by core data or logging data. Since fractures are the most intuitive information of anisotropic characteristics, this embodiment uses core data or imaging logging data to directly obtain the anisotropic characteristics of the stratum at the well point by statistically analyzing the density and occurrence of fracture development. In another embodiment, the macroscopic stratum anisotropy can also be inferred by sedimentary structural features, such as the fault strike, and all of this information can be used as a priori knowledge to judge the reliability of the difference information of various seismic attributes. Through comparison and verification, the orthogonal azimuth difference values ​​that can reliably characterize anisotropy are extracted, and the orthogonal azimuth attribute difference sensitive set is constructed. Then, according to the orthogonal azimuth attribute difference sensitive set, the anisotropy detection result of the target stratum is obtained, thereby improving the calculation efficiency and accuracy.

[0063] On the basis of the above embodiment, before acquiring multiple seismic attributes at different seismic wave incident angles and seismic line azimuths according to the seismic azimuth gathers of the target stratum, the method further includes:

[0064] Based on the time difference correction technology, the seismic azimuth gathers are flattened to obtain the flattened seismic azimuth gathers;

[0065] The method of obtaining multiple seismic attributes at different seismic wave incident angles and seismic line azimuths according to the seismic azimuth gathers of the target stratum includes:

[0066] Through the flattened seismic azimuth gather, multiple seismic attributes at different seismic wave incident angles and seismic line azimuths are obtained.

[0067] In the present invention, for the seismic azimuth gathers obtained by anisotropic migration, the azimuth time difference correction technology is adopted to eliminate the travel time difference related to the azimuth in the seismic azimuth gathers, so that the seismic azimuth gathers are flattened, which is convenient for the subsequent extraction and analysis of seismic attributes.

[0068] On the basis of the above embodiment, the maximum orthogonal azimuth difference value and the orthogonal azimuth corresponding to each seismic attribute are obtained through the seismic wave incident angle, the seismic line azimuth and the multiple seismic attributes, including:

[0069] Based on the anisotropy solution formula of different seismic attributes, the maximum orthogonal azimuth difference value and orthogonal azimuth corresponding to each seismic attribute are obtained through the seismic wave incident angle, the seismic line azimuth and the multiple seismic attributes. The anisotropy solution formula is:

[0070]

[0071] Among them, D x Indicates the maximum orthogonal azimuth difference value and orthogonal azimuth angle corresponding to different seismic attributes, d x (θ) represents the azimuth angle of the seismic line θ and The relative ratio of the difference in seismic attributes between the two, i represents the incident angle of the seismic wave, x represents P Represents different earthquake attributes.

[0072] In the present invention, since the anisotropy of the stratum has an impact on multiple properties of seismic waves, such as amplitude, frequency, attenuation and gradient, the anisotropy solution of the stratum can be obtained by analyzing these seismic attributes and using the anisotropy solution formula of each seismic attribute. Taking the reflection amplitude as an example, combined with the above anisotropy solution formula, the anisotropy solution formula corresponding to the longitudinal wave reflection amplitude is:

[0073]

[0074] Among them, D R Indicates the maximum orthogonal azimuth difference value and orthogonal azimuth angle obtained using the amplitude attribute, d R Indicates the relative ratio of amplitude difference.

[0075] Specifically, the derivation process of the above formula (1) is explained. The reflection coefficient expression of seismic longitudinal waves when propagating in anisotropic media is:

[0076]

[0077]

[0078]

[0079]

[0080] Among them, R p represents the longitudinal wave reflection coefficient, that is, the longitudinal wave reflection amplitude; i represents the incident angle of the seismic wave; represents the angle between the seismic line azimuth θ and the anisotropy direction ψ; z represents the longitudinal wave impedance, α represents the longitudinal wave velocity, and β represents the shear wave velocity; G represents the shear modulus, which can be expressed as ρβ 2 , ρ represents density; Δ represents the difference between the upper and lower parameters of the interface (i.e., the boundary between the upper and lower layers of the medium, for example, the upper layer of the interface is above the boundary, and the lower layer of the interface is below the boundary). The superscript “—” represents the average value of the upper and lower parameters of the interface; δ (v) , ε (v) and γ are Thomsen three parameters describing anisotropy.

[0081] Since formula (2) is relatively complex, it is usually simplified. Considering that the incident angle i of the seismic wave is not large, the third term of the equation is close to zero, and it becomes:

[0082]

[0083] Let X(i) = Bsin 2 i,Y(i)=Dsin 2 i, then:

[0084]

[0085] The above formula (4) is the expression of the longitudinal wave reflection coefficient of anisotropic media under small angle incidence conditions (taking reflection amplitude as an example). The expression is divided into two parts. One part is [A+X(i)], which is independent of the azimuth angle; the other part is is related to the azimuth. Therefore, it is precisely because The existence of the longitudinal wave reflection coefficient is affected by the azimuth, resulting in anisotropy of the reflection amplitude. In order to separate the two parts, the present invention uses The periodicity of is defined as:

[0086]

[0087]

[0088] Among them, formula (5) is the sum of the orthogonal azimuth amplitudes, and its value is only related to the incident angle and does not reflect anisotropy. Formula (6) is the difference of the orthogonal azimuth amplitudes, and its value is related to the incident angle and is affected by the azimuth angle, reflecting the change of anisotropy. Therefore, the relative ratio of the amplitude difference can be defined as To reflect the anisotropy strength of the medium The change in value, that is:

[0089]

[0090] In order to further enhance the stability of formula (7), considering the consistent characteristics of anisotropy corresponding to different incident angles, formula (7) is superimposed in the direction of the incident angle, that is:

[0091]

[0092] Among them, i min and i max They represent the minimum and maximum values ​​of the incident angle, respectively. When θ=ψ, When the value is zero, formula (8) obtains the maximum value, which reflects the maximum change caused by anisotropy. The corresponding two seismic lines are parallel to the anisotropy direction ψ (θ|| ) and vertical (θ ⊥ ).

[0093] Since the azimuth of the seismic survey line is known in practice, formula (8) is further converted into a form expressed in azimuth θ, that is:

[0094]

[0095] By scanning the azimuth of the seismic line, the maximum value of formula (9) is obtained, thereby obtaining the anisotropy direction and intensity based on the amplitude, that is:

[0096]

[0097] Since the anisotropy of the stratum not only affects the amplitude characteristics of the seismic wave, but also affects other attributes such as frequency, attenuation, gradient, etc., all this information can be used to obtain the anisotropy solution of different seismic attributes by analogy with formula (1). Taking the frequency attribute as an example, its expression is:

[0098]

[0099] Among them, F P (i,θ) represents the longitudinal wave reflection frequency at the seismic wave incident angle i and the seismic line azimuth θ; d F (θ) represents the azimuth angle θ of the seismic line and The relative ratio of the frequency difference at reflects the change of the anisotropy intensity expressed by frequency with the azimuth angle; F It indicates the anisotropy direction and intensity obtained by using the frequency attribute. By analogy, the anisotropy solution of other seismic attributes can be obtained. It should be noted that since different seismic attributes have different sensitivities to anisotropy, the anisotropy solution results obtained by using different orthogonal azimuthal attribute differences can be weighted and fused to further improve the stability of formation anisotropy detection. For example, when performing anisotropy detection on a single attribute, D F It can represent the anisotropy direction and intensity. When anisotropy detection is performed on multiple seismic attributes, D F It indicates that the maximum orthogonal azimuth difference value and orthogonal azimuth angle are obtained by using the frequency attribute, and then weighted fusion processing is performed according to the maximum orthogonal azimuth difference value and orthogonal azimuth angle corresponding to each seismic attribute, and finally the detection result of formation anisotropy is obtained.

[0100] Based on the above embodiment, determining the anisotropy direction of the target formation according to the orthogonal azimuth angle includes:

[0101] Based on core data or well logging data, obtaining fracture information or fault information of the target formation;

[0102] Based on the fracture information or fault information, the anisotropy direction of the target formation is determined through the orthogonal azimuth.

[0103] In the present invention, in the orthogonal azimuth attribute difference sensitive set (it can also be analyzed based on the orthogonal azimuth attribute difference set), each seismic attribute difference can obtain the corresponding orthogonal azimuth angle θ || and θ ⊥ However, due to the differences in different attributes, the determination of the anisotropy direction of the formation will be different. For example, the amplitude attribute and θ || Consistent, decay-like properties and θ ⊥ In the present invention, the best solution is still to use prior information such as core data, logging data or sedimentary structure to determine the directional characteristics, that is, to select the direction consistent with the fracture or fault trend, and then extract the direction of formation anisotropy.

[0104] Based on the above embodiment, the weighted fusion processing is performed on the multiple maximum orthogonal azimuth difference values ​​to obtain the anisotropic strength of the target formation, including:

[0105] Normalizing each of the maximum orthogonal orientation difference values ​​to obtain a normalized maximum orthogonal orientation difference value;

[0106] Based on core data or well logging data, determine the weight coefficient corresponding to each seismic attribute;

[0107] According to the weight coefficient, all the normalized maximum orthogonal azimuth difference values ​​are weightedly fused to obtain the anisotropic strength of the target formation.

[0108] In the present invention, for the orthogonal azimuthal attribute difference sensitive set, firstly, a standardization process is performed to normalize different attribute value ranges to the same data range, and in addition, the data characterization direction is adjusted, that is, a small value represents a low anisotropy intensity, and a large value represents a high anisotropy intensity; then, a weight coefficient corresponding to each attribute is given. Specifically, by comparing with prior information such as core data, logging data or sedimentary structure, a larger weight is set for the maximum orthogonal azimuthal difference value corresponding to the attribute with high consistency, and a smaller weight is set for the maximum orthogonal azimuthal difference value corresponding to the attribute with low consistency, and the sum of all weights is 1. Then, a weighted fusion process is performed to finally obtain the intensity of formation anisotropy. Figure 2 The overall flow chart of the anisotropy detection method based on orthogonal azimuthal attribute difference fusion provided by the present invention and the overall calculation process of the intensity and direction of the anisotropy of the target formation can be referred to Figure 2 shown.

[0109] The anisotropy detection system based on orthogonal orientation attribute difference fusion provided by the present invention is described below. The anisotropy detection system based on orthogonal orientation attribute difference fusion described below and the anisotropy detection method based on orthogonal orientation attribute difference fusion described above can be referred to each other.

[0110] Figure 3 The schematic diagram of the structure of the anisotropic detection system based on orthogonal orientation attribute difference fusion provided by the present invention is as follows: Figure 3 As shown, the present invention provides an anisotropy detection system based on orthogonal azimuth attribute difference fusion, including a seismic attribute data acquisition module 301, an orthogonal azimuth attribute difference calculation module 302, an anisotropy direction determination module 303 and an anisotropy intensity calculation module 304, wherein the seismic attribute data acquisition module 301 is used to obtain multiple seismic attributes at different seismic wave incident angles and seismic line azimuths according to the seismic azimuth gathers of the target stratum; the orthogonal azimuth attribute difference calculation module 302 is used to obtain the anisotropy direction determination module 303 and the anisotropy intensity calculation module 304 according to the seismic wave incident angles, The azimuth of the seismic survey line and the multiple seismic attributes are used to obtain the maximum orthogonal azimuth difference value and the orthogonal azimuth corresponding to each seismic attribute; the anisotropy direction determination module 303 is used to determine the anisotropy direction of the target formation according to the orthogonal azimuth; the anisotropy strength calculation module 304 is used to perform weighted fusion processing on the multiple maximum orthogonal azimuth difference values ​​to obtain the anisotropy strength of the target formation, so as to obtain the anisotropy detection result of the target formation according to the anisotropy direction and the anisotropy strength.

[0111] The anisotropy detection system based on orthogonal azimuth attribute difference fusion provided by the present invention obtains the anisotropy strength and anisotropy direction of the formation by analyzing different seismic attributes in the formation and utilizing the maximum orthogonal azimuth difference value and orthogonal azimuth angle of each seismic attribute, thereby reducing the amount of calculation and improving the calculation accuracy, thereby achieving a stable solution to the anisotropy of the formation.

[0112] The system provided by the present invention is used to execute the above-mentioned method embodiments. Please refer to the above-mentioned embodiments for the specific processes and detailed contents, which will not be repeated here.

[0113] Figure 4 A schematic diagram of the structure of an electronic device provided by the present invention, such as Figure 4As shown, the electronic device may include: a processor (Processor) 401, a communication interface (Communications Interface) 402, a memory (Memory) 403 and a communication bus 404, wherein the processor 401, the communication interface 402, and the memory 403 communicate with each other through the communication bus 404. The processor 401 can call the logic instructions in the memory 403 to execute an anisotropy detection method based on orthogonal azimuth attribute difference fusion, the method comprising: obtaining multiple seismic attributes at different seismic wave incident angles and seismic line azimuths according to the seismic azimuth track gather of the target formation; obtaining the maximum orthogonal azimuth difference value and the orthogonal azimuth corresponding to each seismic attribute through the seismic wave incident angle, the seismic line azimuth and the multiple seismic attributes; determining the anisotropy direction of the target formation according to the orthogonal azimuth; performing weighted fusion processing on the multiple maximum orthogonal azimuth difference values ​​to obtain the anisotropy strength of the target formation, so as to obtain the anisotropy detection result of the target formation according to the anisotropy direction and the anisotropy strength.

[0114] In addition, the logic instructions in the above-mentioned memory 403 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions for 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 the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0115] On the other hand, the present invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the anisotropy detection method based on orthogonal azimuth attribute difference fusion provided by the above-mentioned methods, the method including: according to the seismic azimuth track gather of the target formation, obtaining multiple seismic attributes at different seismic wave incident angles and seismic line azimuths; obtaining the maximum orthogonal azimuth difference value and orthogonal azimuth corresponding to each seismic attribute through the seismic wave incident angle, the seismic line azimuth and the multiple seismic attributes; determining the anisotropy direction of the target formation according to the orthogonal azimuth; performing weighted fusion processing on multiple maximum orthogonal azimuth difference values ​​to obtain the anisotropy strength of the target formation, so as to obtain the anisotropy detection result of the target formation according to the anisotropy direction and the anisotropy strength.

[0116] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the anisotropy detection method based on orthogonal azimuth attribute difference fusion provided in the above-mentioned embodiments, the method comprising: acquiring multiple seismic attributes at different seismic wave incident angles and seismic line azimuths according to the seismic azimuth track gather of the target formation; obtaining the maximum orthogonal azimuth difference value and the orthogonal azimuth corresponding to each seismic attribute through the seismic wave incident angle, the seismic line azimuth and the multiple seismic attributes; determining the anisotropy direction of the target formation according to the orthogonal azimuth; performing weighted fusion processing on multiple maximum orthogonal azimuth difference values ​​to obtain the anisotropy strength of the target formation, so as to obtain the anisotropy detection result of the target formation according to the anisotropy direction and the anisotropy strength.

[0117] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0118] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for anisotropy detection based on orthogonal orientation attribute difference fusion, characterized in that: include: According to the seismic azimuth gathers of the target stratum, multiple seismic attributes at different seismic wave incident angles and seismic line azimuths are obtained; Obtaining the maximum orthogonal azimuth difference value and the orthogonal azimuth corresponding to each seismic attribute through the seismic wave incident angle, the seismic survey line azimuth and the multiple seismic attributes; Determining the anisotropy direction of the target formation according to the orthogonal azimuth; Performing weighted fusion processing on a plurality of the maximum orthogonal azimuth difference values ​​to obtain the anisotropic strength of the target formation, so as to obtain an anisotropic detection result of the target formation according to the anisotropic direction and the anisotropic strength; The maximum orthogonal azimuth difference value and the orthogonal azimuth corresponding to each seismic attribute are obtained through the seismic wave incident angle, the seismic survey line azimuth and the multiple seismic attributes, including: Based on the anisotropy solution formula of different seismic attributes, the maximum orthogonal azimuth difference value and orthogonal azimuth corresponding to each seismic attribute are obtained through the seismic wave incident angle, the seismic line azimuth and the multiple seismic attributes. The anisotropy solution formula is: Among them, D x Indicates the maximum orthogonal azimuth difference value and orthogonal azimuth angle corresponding to different seismic attributes, d x (θ) represents the azimuth angle of the seismic line θ and The relative ratio of the difference in seismic attributes between the two, i represents the incident angle of the seismic wave, x represents P Represents different earthquake attributes.

2. The anisotropy detection method based on orthogonal orientation attribute difference fusion according to claim 1 is characterized in that: Before acquiring a plurality of seismic attributes at different seismic wave incident angles and seismic line azimuths according to the seismic azimuth gathers of the target stratum, the method further comprises: Based on the time difference correction technology, the seismic azimuth gathers are flattened to obtain the flattened seismic azimuth gathers; The method of obtaining multiple seismic attributes at different seismic wave incident angles and seismic line azimuths according to the seismic azimuth gathers of the target stratum includes: Through the flattened seismic azimuth gather, multiple seismic attributes at different seismic wave incident angles and seismic line azimuths are obtained.

3. The anisotropy detection method based on orthogonal orientation attribute difference fusion according to claim 1, characterized in that: Determining the anisotropy direction of the target formation according to the orthogonal azimuth angle includes: Based on core data or well logging data, obtaining fracture information or fault information of the target formation; Based on the fracture information or fault information, the anisotropy direction of the target formation is determined through the orthogonal azimuth.

4. The anisotropy detection method based on orthogonal orientation attribute difference fusion according to claim 1, characterized in that: The step of performing weighted fusion processing on the plurality of maximum orthogonal azimuth difference values ​​to obtain the anisotropic strength of the target formation includes: Normalizing each of the maximum orthogonal orientation difference values ​​to obtain a normalized maximum orthogonal orientation difference value; Based on core data or well logging data, determine the weight coefficient corresponding to each seismic attribute; According to the weight coefficient, all the normalized maximum orthogonal azimuth difference values ​​are weightedly fused to obtain the anisotropic strength of the target formation.

5. An anisotropy detection system based on orthogonal orientation attribute difference fusion, characterized in that: include: A seismic attribute data acquisition module is used to obtain multiple seismic attributes at different seismic wave incident angles and seismic line azimuths according to the seismic azimuth gathers of the target stratum; An orthogonal azimuth attribute difference calculation module, used for obtaining the maximum orthogonal azimuth difference value and the orthogonal azimuth angle corresponding to each seismic attribute through the seismic wave incident angle, the seismic line azimuth angle and the multiple seismic attributes; An anisotropy direction determination module, used to determine the anisotropy direction of the target formation according to the orthogonal azimuth; an anisotropy strength calculation module, used for performing weighted fusion processing on a plurality of the maximum orthogonal azimuth difference values ​​to obtain the anisotropy strength of the target formation, so as to obtain the anisotropy detection result of the target formation according to the anisotropy direction and the anisotropy strength; The orthogonal orientation attribute difference calculation module is specifically used for: Based on the anisotropy solution formula of different seismic attributes, the maximum orthogonal azimuth difference value and orthogonal azimuth corresponding to each seismic attribute are obtained through the seismic wave incident angle, the seismic line azimuth and the multiple seismic attributes. The anisotropy solution formula is: Among them, D x Indicates the maximum orthogonal azimuth difference value and orthogonal azimuth angle corresponding to different seismic attributes, d x (θ) represents the azimuth angle of the seismic line θ and The relative ratio of the difference in seismic attributes between the two, i represents the incident angle of the seismic wave, x represents P Represents different earthquake attributes.

6. An electronic 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 anisotropy detection method based on orthogonal orientation attribute difference fusion as described in any one of claims 1 to 4 is implemented.

7. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the anisotropic detection method based on orthogonal orientation attribute difference fusion as claimed in any one of claims 1 to 4 is implemented.

8. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the anisotropic detection method based on orthogonal orientation attribute difference fusion as described in any one of claims 1 to 4 is implemented.

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