Phase axis picking method and apparatus

Abstract

The application discloses a method and device for picking up a same phase axis, and the method comprises the following steps: fitting each same phase axis in an angle domain imaging point gather by using a quadratic function to obtain a fitting curve of each same phase axis in the imaging gather; determining a fitting curve of the imaging gather according to the fitting curve of each same phase axis in the imaging gather; determining a top and bottom boundary of the fitting curve of the imaging gather, and taking the fitting curve in a top and bottom boundary range of the imaging gather profile as a final picked fitting curve. The same phase axis in the gather can be fitted by the quadratic function, the picking up precision of the same phase axis can be improved without being limited by the resolution of the seismic data, and the picked same phase axis can well coincide with the real same phase axis. Meanwhile, the picking up of the same phase axis does not need manual intervention and assistance, and the picking up efficiency of the same phase axis can be improved.

Description

Technical Field

[0001] This invention relates to the field of oil and gas seismic exploration technology, and in particular to a method and apparatus for picking up phase axes. Background Technology

[0002] This section is intended to provide background or context for the embodiments of the invention set forth in the claims. The description herein is not an admission that it is prior art simply because it is included in this section.

[0003] Tomographic velocity inversion is an effective velocity modeling technique in seismic exploration. It utilizes received seismic wave information to invert parameters of the subsurface medium, constructing a velocity field that reflects the low-frequency characteristics of the subsurface medium. There are many branches of tomographic velocity inversion methods, with imaging domain tomographic inversion being widely used due to its stability and effectiveness. In imaging domain tomographic velocity inversion, it is necessary to extract the in-phase axis curvature information of the angular domain imaging point gathers. Extraction methods generally include manual and automatic extraction.

[0004] However, existing conventional methods for picking up in-phase axes are not only inefficient, but also inaccurate. Summary of the Invention

[0005] This invention provides a method for picking up in-phase shafts to improve the picking efficiency and accuracy of in-phase shafts. The method includes:

[0006] By fitting a quadratic function to each in-phase axis in the angular domain imaging point gather, the fitting curve of each in-phase axis in the imaging gather is obtained.

[0007] The fitting curve of the imaging gather is determined based on the fitting curve of each in-phase axis within the imaging gather.

[0008] Determine the top and bottom boundaries of the imaging gather fitting curve, and use the fitting curve within the range of the top and bottom boundaries of the imaging gather profile as the final picked fitting curve.

[0009] This invention also provides a co-phase shaft pickup device to improve co-phase shaft pickup efficiency and pickup accuracy. The co-phase shaft pickup device includes:

[0010] The in-phase axis fitting module is used to fit each in-phase axis in the angular domain imaging point gather using a quadratic function to obtain the fitting curve of each in-phase axis in the imaging gather.

[0011] The gather curve fitting module is used to determine the fitting curve of the imaging gather based on the fitting curve of each in-phase axis within the imaging gather.

[0012] The final fitting determination module is used to determine the top and bottom boundaries of the imaging gather fitting curve, and the fitting curve within the range of the top and bottom boundaries of the imaging gather profile is used as the final picked fitting curve.

[0013] This invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above-described method for picking up the same phase axis.

[0014] This invention also provides a computer-readable storage medium storing a computer program that performs the above-described co-phase axis pickup method.

[0015] In this embodiment of the invention, a quadratic function is used to fit each phase axis in the angular domain imaging point gather to obtain a fitted curve for each phase axis within the imaging gather. Based on the fitted curves of each phase axis within the imaging gather, the fitted curve of the imaging gather is determined. The top and bottom boundaries of the fitted curves of the imaging gather are determined, and the fitted curves within the range of the top and bottom boundaries of the imaging gather profile are used as the final picked-up fitted curves. This embodiment of the invention, by fitting phase axes using a quadratic function, is not limited by the resolution of seismic data and can closely match the actual phase axes, improving the accuracy of phase axis picking. Furthermore, phase axis picking requires no manual interference or assistance, thus improving the efficiency of phase axis picking. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0017] Figure 1 A flowchart illustrating the implementation of the co-phase shaft pickup method provided in this embodiment of the invention;

[0018] Figure 1-1 This is a scanning schematic diagram of an angle domain imaging point gather provided in an embodiment of the present invention;

[0019] Figure 1-2 A schematic diagram of an imaging gather provided in an embodiment of the present invention;

[0020] Figure 1-3 A schematic diagram of the in-phase axis curve of the final picked-up imaging gather provided in an embodiment of the present invention;

[0021] Figure 2 This is another implementation flowchart of the co-phase shaft picking method provided in the embodiments of the present invention;

[0022] Figure 3 This is a flowchart illustrating the implementation of step 201 in the co-phase shaft picking method provided in this embodiment of the invention.

[0023] Figure 4 This is another implementation flowchart of the co-phase shaft picking method provided in the embodiments of the present invention;

[0024] Figure 5 This is a flowchart illustrating the implementation of step 101 in the co-phase shaft picking method provided in this embodiment of the invention.

[0025] Figure 5-1 A schematic diagram of a coordinate system established around the zero-angle vertex provided in an embodiment of the present invention;

[0026] Figure 5-2 A schematic diagram of the initial pseudo-co-phase axis gather of the in-phase axis in the angle domain co-imaging point gather provided in an embodiment of the present invention;

[0027] Figure 6 This is a flowchart illustrating the implementation of step 501 in the co-phase shaft picking method provided in this embodiment of the invention.

[0028] Figure 7 This is a flowchart illustrating the implementation of step 102 in the co-phase shaft picking method provided in this embodiment of the invention.

[0029] Figure 8 This is a functional block diagram of the co-phase shaft pickup device provided in an embodiment of the present invention;

[0030] Figure 9 This is another functional module diagram of the co-phase shaft pickup device provided in an embodiment of the present invention;

[0031] Figure 10 This is a structural block diagram of the preprocessing module 901 in the co-phase shaft pickup device provided in an embodiment of the present invention;

[0032] Figure 11 This is another functional module diagram of the co-phase shaft pickup device provided in the embodiments of the present invention;

[0033] Figure 12 This is a structural block diagram of the in-phase axis fitting module 801 in the in-phase axis pickup device provided in an embodiment of the present invention;

[0034] Figure 13 This is a structural block diagram of the initial gather fitting unit 1201 in the in-phase shaft pickup device provided in an embodiment of the present invention;

[0035] Figure 14 This is a structural block diagram of the gather curve fitting module 802 in the co-phase axis pickup device provided in an embodiment of the present invention. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0037] Figure 1 The implementation flow of the in-phase shaft pickup method provided by the embodiment of the present invention is shown. For ease of description, only the parts related to the embodiment of the present invention are shown, and are detailed below:

[0038] like Figure 1 As shown, the method for picking up the same phase axis includes:

[0039] Step 101: Use a quadratic function to fit each in-phase axis in the angular domain imaging point gather to obtain the fitting curve of each in-phase axis in the imaging gather.

[0040] Step 102: Determine the fitting curve of the imaging gather based on the fitting curve of each in-phase axis within the imaging gather.

[0041] Step 103: Determine the top and bottom boundaries of the imaging gather fitting curve, and use the fitting curve within the range of the top and bottom boundaries of the imaging gather profile as the final picked fitting curve.

[0042] In tomographic velocity modeling, imaging domain tomography is a relatively mature velocity modeling method. Imaging domain tomography obtains the depth residual caused by the difference between the predicted model and the true model based on the extracted common imaging point gathers. This residual is then transformed into an equation to invert the velocity using a series of methods. Among these methods, the acquisition of the in-phase axis of the common imaging point gathers is crucial and requires high accuracy.

[0043] When there is a difference between the initial velocity model and the true velocity model, the angle domain imaging point gather is a curved curve. Figure 1-1 The diagram illustrates the scanning of the angle-domain imaging point gather. Figure 1-2 The diagram illustrates an imaging gather. When picking the phase axes of a seismic gather, the imaging point gather is first acquired. For example, the input angle-domain imaging point gather is received. Then, a quadratic function is used to fit the phase axes in the angle-domain imaging point gather. The angle-domain imaging point gather contains multiple phase axes. By fitting with a quadratic function, a fitting curve for each phase axis can be obtained.

[0044] However, after obtaining the fitting curve for each in-phase axis within the imaging gather by fitting a quadratic function, these fitting curves contain invalid fitting curves, which need to be filtered out to obtain valid fitting curves.

[0045] Finally, given that the fitted curve of the imaging gather is infinitely continuous, after obtaining the fitted curve of the imaging gather, the top and bottom boundaries of the fitted curve are determined, and the fitted curve within the range of the top and bottom boundaries is used as the final picked curve. Figure 1-3 The diagram shows the in-phase axis curve of the final picked-up imaging gather provided by an embodiment of the present invention.

[0046] In this embodiment of the invention, a quadratic function is used to fit each phase axis to obtain a fitted curve for each phase axis. The top and bottom boundaries of the fitted curves are determined, and the fitted curves within the range of the top and bottom boundaries are used as the final picked curves. This embodiment of the invention, by fitting phase axes using a quadratic function, is not limited by the resolution of seismic data and can closely match the actual phase axes, improving the accuracy of phase axis picking. Furthermore, phase axis picking requires no manual interference or assistance, thus improving the efficiency of phase axis picking.

[0047] Figure 2 Another implementation flow of the co-phase shaft pickup method provided in an embodiment of the present invention is shown. For ease of description, only the parts related to the embodiment of the present invention are shown, and are detailed below:

[0048] In one embodiment of the present invention, in order to further improve the pickup accuracy of the same phase axis, such as Figure 2 As shown above, in the above Figure 1 Based on the steps shown, the in-phase shaft picking method also includes:

[0049] Step 201: Preprocess the angle domain imaging point gather to obtain the preprocessed angle domain imaging point gather;

[0050] Step 101: Fit each in-phase axis in the angular domain imaging point gather using a quadratic function to obtain the fitting curve for each in-phase axis within the imaging gather, including:

[0051] Step 202: Use a quadratic function to fit each in-phase axis in the preprocessed angle domain imaging point gather to obtain the fitting curve of each in-phase axis in the imaging gather.

[0052] In the process of picking up in-phase axis gathers, the acquired angle domain imaging point gathers can first be preprocessed to obtain preprocessed angle domain imaging point gathers. Then, a quadratic function is used to fit each in-phase axis in the preprocessed angle domain imaging point gathers, thereby improving the in-phase axis picking accuracy.

[0053] In this embodiment of the invention, the angle domain imaging point gather is preprocessed to obtain a preprocessed angle domain imaging point gather. Then, a quadratic function is used to fit each in-phase axis in the preprocessed angle domain imaging point gather to obtain a fitting curve for each in-phase axis, which can further improve the in-phase axis picking accuracy.

[0054] Figure 3 The implementation flow of step 201 in the co-phase shaft pickup method provided by the embodiment of the present invention is shown. For ease of description, only the parts related to the embodiment of the present invention are shown, and are detailed below:

[0055] In one embodiment of the present invention, preprocessing includes one or more of the following: frequency filtering, shot point removal, and automatic gain control. To improve the in-phase axis pickup accuracy, such as... Figure 3 As shown, step 201 involves preprocessing the angle domain imaging point gather to obtain a preprocessed angle domain imaging point gather, including:

[0056] Step 301: Perform frequency filtering on the angle domain imaging point gather to obtain a frequency-filtered angle domain imaging point gather; and / or

[0057] Step 302: Perform shot point cut-off on the angle domain imaging point gather to obtain the angle domain imaging point gather after shot point cut-off; and / or

[0058] Step 303: Perform automatic gain control on the angle domain imaging point gather to obtain the angle domain imaging point gather after automatic gain control.

[0059] Preprocessing may include frequency filtering and shot removal, etc. Those skilled in the art will understand that it may also include other preprocessing methods besides frequency filtering and shot removal, such as automatic gain control, etc. The embodiments of the present invention do not impose any special limitations on this.

[0060] To reduce labor costs, a pre-collection and post-filtering acquisition strategy is considered. First, the entire gather undergoes preprocessing including denoising, frequency filtering, shot point removal, and automatic gain control to ensure energy balance and easier identification. Due to limitations of the observation system, in-phase axes with significant amplitude differences from the effective range may appear at the top and edges of the data. To eliminate these interferences, narrow bands in the top, bottom, left, and right areas are excluded from the processing.

[0061] This involves performing one of the aforementioned preprocessing steps, such as frequency filtering, shot removal, and automatic gain control, on the angle-domain imaging point gather. For example, only frequency filtering, or only one preprocessing step such as shot removal or automatic gain control, can be performed on the angle-domain imaging point gather. Alternatively, multiple preprocessing steps, such as frequency filtering, shot removal, and automatic gain control, can be performed simultaneously on the angle-domain imaging point gather. For example, all three preprocessing steps, including frequency filtering, shot removal, and automatic gain control, can be performed simultaneously on the angle-domain imaging point gather.

[0062] In this embodiment of the invention, frequency filtering is performed on the angle domain imaging point gather to obtain a frequency-filtered angle domain imaging point gather; shot point removal is performed on the angle domain imaging point gather to obtain a shot point removed angle domain imaging point gather; and automatic gain control is performed on the angle domain imaging point gather to obtain an automatically gain controlled angle domain imaging point gather, which can improve the in-phase axis pickup accuracy respectively.

[0063] Figure 4 This paper illustrates another implementation flow of the co-phase shaft pickup method provided by an embodiment of the present invention. For ease of description, only the parts related to the embodiment of the present invention are shown, and are detailed below:

[0064] In one embodiment of the present invention, the coefficients of the quadratic term and the constant term of the quadratic function reflect the curvature and longitudinal offset of the fitted in-phase axis gather, respectively. To improve in-phase axis pickup efficiency while maintaining resolution, such as... Figure 4 As shown, based on the above method steps, the in-phase shaft picking method further includes:

[0065] Step 401: Store the fitted curve for each in-phase axis by recording the degree of curvature and longitudinal offset.

[0066] The quadratic fitting function used to fit the co-phase axis can be expressed as:

[0067] y = ax 2 +b;

[0068] Where y represents the pseudo-congruent phase axis, x represents the angle of the phase axis of the angular domain imaging point gather in the coordinate system, a reflects the curvature of the pseudo-congruent phase axis, and b reflects the longitudinal offset of the pseudo-congruent phase axis in the coordinate system.

[0069] After picking up the co-phase axes, they need to be stored. Traditional gather storage methods store a few feature points of the gather and then interpolate them during use. This approach not only has limited resolution but also increases computational costs. We take a different approach, assuming that each co-phase axis can be fitted using a quadratic function. During storage, we only need to store the position of the gather's zero points and the value of its curvature (parameters) to record the entire gather. This storage method can compress redundant data without sacrificing resolution, improving the efficiency of co-phase axis picking.

[0070] In this embodiment of the invention, by recording the degree of curvature and longitudinal offset and storing the fitting curve of each in-phase axis, the picking efficiency of the in-phase axis can be improved while ensuring resolution.

[0071] Figure 5 The implementation flow of step 101 in the co-phase shaft pickup method provided by the embodiment of the present invention is shown. For ease of description, only the parts related to the embodiment of the present invention are shown, and are detailed below:

[0072] In one embodiment of the present invention, in order to improve the accuracy of the simulated co-phase axis and thus improve the picking accuracy of the co-phase axis, such as... Figure 5 As shown, step 101 involves fitting a quadratic function to each in-phase axis within the angular domain imaging point gather to obtain the fitting curve for each in-phase axis within the imaging gather, including:

[0073] Step 501: Establish a coordinate system around the zero-angle vertex of each in-phase axis in the angle domain imaging point gather, and use a quadratic function to fit each in-phase axis in the angle domain imaging point gather to obtain multiple initial fitting curves corresponding to each in-phase axis.

[0074] Step 502: Compare the amplitude and absolute value of each initial fitted curve corresponding to each phase axis, and take the fitted curve with the largest amplitude and absolute value as the fitted curve for each phase axis.

[0075] Tomographic inversion assumes that velocity perturbations are small, so the curvature of the phase axis of the angular domain common imaging point gather is also small, resulting in a relatively flat phase axis suitable for quadratic function fitting. When the estimated layer velocity is smaller than the true layer velocity, the phase axis (quadratic function shape) of the angular domain common imaging point gather bends upward; when the estimated layer velocity is larger than the true layer velocity, the phase axis (quadratic function shape) bends downward. There will always be a vertex at zero angle, around which a model can be built... Figure 5-1 The coordinate system is shown. Then, a quadratic function is used to fit each in-phase axis in the angle domain imaging point gather. During fitting, multiple initial fitting curves can be obtained for each in-phase axis.

[0076] After preprocessing, the common imaging point gather in the angle domain is scanned. A zero-angle point is selected as the starting point of the scan, and the gather morphology at this zero-angle point is fitted starting from a negative value, such as... Figure 5-2 As shown, the continuously increasing values ​​cause changes in the curvature of the fitted function. Changing the scan step size can improve fitting accuracy, but it will decrease efficiency. Based on experiments, the increment value is generally taken as 10. -3 Up to 10 -4 It is appropriate.

[0077] When the velocity value is small, the zero angle is the vertex of the common imaging point gather in the angle domain. The curvature of the fitted curve is changed by changing the value of the curvature 'a' of the fitted curve. Then, it is compared with the real in-phase axis to obtain the fitted curve that best matches the real in-phase axis.

[0078] The shape of the phase axis is similar to that of the wavelet, generally exhibiting one peak and two troughs. If the initial fitted curve matches the shape of the true phase axis, the amplitudes along the path of the initial fitted curve will superimpose to obtain a maximum value. Conversely, if the shape of the initial fitted curve does not match the shape of the phase axis, the amplitude values ​​along the path of the fitted phase axis gather will inevitably have both positive and negative values, resulting in a relatively small value after superposition. This pattern allows us to determine whether the shape of the initial fitted curve is correct.

[0079] Therefore, the sum of the absolute values ​​of the amplitudes on each initial fitted curve path corresponding to each phase axis can be compared, and the initial fitted curve with the largest amplitude and absolute value can be used as the fitted curve of the phase axis.

[0080] In this embodiment of the invention, a coordinate system is established around the zero-angle vertex of each in-phase axis in the angle-domain imaging point gather. A quadratic function is used to fit each in-phase axis in the angle-domain imaging point gather, obtaining multiple initial fitting curves corresponding to each in-phase axis. The amplitude and absolute value of each initial fitting curve corresponding to each in-phase axis are compared, and the fitting curve with the largest amplitude and absolute value is taken as the fitting curve of the in-phase axis. This embodiment of the invention improves the accuracy of fitting the in-phase axis by using a quadratic function to fit the in-phase axis and determining the fitting curve of the in-phase axis using amplitude and absolute value, thereby improving the in-phase axis picking accuracy.

[0081] Figure 6 The implementation flow of step 501 in the co-phase shaft pickup method provided by the embodiment of the present invention is shown. For ease of description, only the parts related to the embodiment of the present invention are shown, and are detailed below:

[0082] In one embodiment of the present invention, in order to improve the accuracy of the initial fitted curvature and thus improve the in-phase axis picking accuracy, such as... Figure 6 As shown, in step 501, a coordinate system is established around the zero-angle vertex of each in-phase axis in the angle domain imaging point gather. A quadratic function is used to fit each in-phase axis in the angle domain imaging point gather to obtain multiple initial fitting curves corresponding to each in-phase axis, including:

[0083] Step 601: Establish a coordinate system around the zero-angle vertex of each in-phase axis in the angle domain imaging point gather. Use the first quadratic function to fit the part of each in-phase axis in the angle domain imaging point gather where the angle is not greater than zero. Use the second quadratic function to fit the part of each in-phase axis in the angle domain imaging point gather where the angle is greater than zero, and obtain the initial fitting curve corresponding to each in-phase axis.

[0084] Due to factors such as the dip angle of the underground reflective interface, the in-phase axis of the co-image point gather in the angle domain has unique characteristics, and its shape may be distorted. Consider using two quadratic functions, left and right, to fit the co-phase axis gather, with different degrees of curvature (parameters) on the left and right sides, which can accommodate the distortion of the in-phase axis gather.

[0085] Therefore, when fitting each in-phase axis, the zero-angle vertex of each in-phase axis gather in the angle domain imaging point gather is first established as follows: Figure 5-1 The coordinate system is then used to fit the portion of each in-phase axis in the angle domain imaging point gather where the angle is not greater than zero, thereby determining the left portion of the initial fitted in-phase axis. Then, the second quadratic function is used to fit the portion of each in-phase axis in the angle domain imaging point gather where the angle is greater than zero, thereby determining the right portion of the initial fitted in-phase axis.

[0086] Finally, the left part of the initial fitting curve is merged with the right part of the initial fitting curve to determine the initial fitting curve corresponding to each in-phase axis.

[0087] The initial fitted curve can be represented as follows:

[0088]

[0089] Where y represents the fitted curve, a1 represents the curvature of the left side of the fitted curve, a2 represents the curvature of the right side of the fitted curve, b represents the longitudinal offset of the fitted curve in the coordinate system, and x represents the angle of the in-phase axis of the angle domain imaging point gather in the coordinate system.

[0090] In this embodiment of the invention, a coordinate system is established around the zero-angle vertex of each in-phase axis gather in the angle domain imaging point gather. A first quadratic function is used to fit the portion of each in-phase axis in the angle domain imaging point gather where the angle is not greater than zero; a second quadratic function is used to fit the portion of each in-phase axis in the angle domain imaging point gather where the angle is greater than zero, thus obtaining a fitting curve corresponding to each in-phase axis. This embodiment of the invention utilizes the first and second quadratic functions to fit both the portion of each in-phase axis in the angle domain imaging point gather where the angle is not greater than zero and the portion where the angle is greater than zero, respectively, obtaining a fitting curve corresponding to each in-phase axis. This can reduce or even eliminate gather distortion, improve the accuracy of the fitting curve, and thus improve the in-phase axis picking accuracy.

[0091] Figure 7 The implementation flow of step 102 in the co-phase shaft pickup method provided by the embodiment of the present invention is shown. For ease of description, only the parts related to the embodiment of the present invention are shown, and are detailed below:

[0092] In one embodiment of the present invention, in order to further improve the pickup accuracy of the same phase axis, such as Figure 7As shown, step 102, determining the fitting curve of the imaging gather based on the fitting curve of each in-phase axis within the imaging gather, includes:

[0093] Step 701: Use the average amplitude of the in-phase axis fitting curve within the imaging gather as the picking and filtering threshold of the imaging gather.

[0094] Step 702: Use the fitted curve with an amplitude not less than the picking filter threshold as the fitted curve of the imaging gather.

[0095] When determining the fitting curves for the imaging gather, the entire imaging gather is scanned to obtain the fitting curve for each in-phase axis within the imaging gather. Then, the average amplitude of the fitting curves for each in-phase axis within the imaging gather is calculated, and this average amplitude is used as the filtering threshold for the imaging gather. Using this filtering threshold, fitting curves with amplitudes not less than the imaging gather filtering threshold are used as the fitting curves for the imaging gather, while fitting curves with amplitudes less than the imaging gather filtering threshold are filtered out.

[0096] In this embodiment of the invention, the average amplitude of the fitted curve of each in-phase axis within the imaging gather is used as the filtering threshold of the imaging gather, and the fitted curve with an amplitude not less than the filtering threshold of the imaging gather is used as the fitted curve of the imaging gather. By using the average amplitude of the fitted curve as the filtering threshold of the imaging gather, this embodiment of the invention can filter the fitted curves within the imaging gather, thereby further improving the in-phase axis pickup accuracy.

[0097] This invention also provides a co-phase shaft pickup device, as described in the following embodiments. Since the principle behind these devices is similar to that of the co-phase shaft pickup method, the implementation of these devices can be found in the implementation of the method, and repeated details will not be elaborated further.

[0098] Figure 8 The functional modules of the co-phase shaft pickup device provided in the embodiments of the present invention are shown. For ease of explanation, only the parts related to the embodiments of the present invention are shown, and are described in detail below:

[0099] refer to Figure 8 The various modules included in the co-phase shaft pickup device are used to perform... Figure 1 For details of each step in the corresponding embodiment, please refer to [link / reference]. Figure 1 as well as Figure 1 The relevant descriptions in the corresponding embodiments will not be repeated here. In this embodiment of the invention, the in-phase axis picking device includes an in-phase axis fitting module 801, a gather curve fitting module 802, and a final fitting determination module 803.

[0100] The in-phase axis fitting module 801 is used to fit each in-phase axis in the angular domain imaging point gather using a quadratic function to obtain the fitting curve of each in-phase axis in the imaging gather.

[0101] The gather curve fitting module 802 is used to determine the top and bottom boundaries of the imaging gather fitting curve, and uses the fitting curve within the range of the top and bottom boundaries of the imaging gather profile as the final picked fitting curve.

[0102] The final fitting determination module 803 is used to determine the top and bottom boundaries of the imaging gather fitting curve, and the fitting curve within the range of the top and bottom boundaries of the imaging gather profile is used as the final picked fitting curve.

[0103] In this embodiment of the invention, the phase axis fitting module 801 uses a quadratic function to fit each phase axis in the angular domain imaging point gather, obtaining a fitting curve for each phase axis within the imaging gather. The gather curve fitting module 802 determines the top and bottom boundaries of the imaging gather fitting curves, and uses the fitting curves within the top and bottom boundary range of the imaging gather profile as the final picked fitting curves. The final fitting determination module 803 is used to determine the top and bottom boundaries of the imaging gather fitting curves, and uses the fitting curves within the top and bottom boundary range of the imaging gather profile as the final picked fitting curves. This embodiment of the invention, by fitting the phase axis using a quadratic function, is not limited by the resolution of seismic data and can closely match the actual phase axis, improving the accuracy of phase axis picking. Simultaneously, phase axis picking requires no manual interference or assistance, thus improving the efficiency of phase axis picking.

[0104] Figure 9 Another functional module of the co-phase shaft pickup device provided in an embodiment of the present invention is shown. For ease of explanation, only the part related to the embodiment of the present invention is shown, and is described in detail below:

[0105] In one embodiment of the present invention, in order to further improve the pickup accuracy of the co-phase axis, a reference is made. Figure 9 The various modules included in the co-phase shaft pickup device are used to perform... Figure 2 For details of each step in the corresponding embodiment, please refer to [link / reference]. Figure 2 as well as Figure 2 The relevant descriptions in the corresponding embodiments will not be repeated here. In the embodiments of the present invention, in the above... Figure 8 Based on the module structure shown, the co-phase shaft pickup device also includes a preprocessing module 901.

[0106] The preprocessing module 901 is used to preprocess the angle domain imaging point gather to obtain the preprocessed angle domain imaging point gather.

[0107] The in-phase axis fitting module 801 is also used to fit each in-phase axis in the preprocessed angle domain imaging point gather using a quadratic function to obtain the fitting curve of each in-phase axis in the imaging gather.

[0108] In this embodiment of the invention, the preprocessing module 901 preprocesses the angle domain imaging point gather to obtain the preprocessed angle domain imaging point gather. Then, the in-phase axis fitting module 801 uses a quadratic function to fit each in-phase axis in the preprocessed angle domain imaging point gather to obtain the fitting curve of each in-phase axis in the imaging gather, which can further improve the in-phase axis picking accuracy.

[0109] Figure 10 The diagram shows the structure of the preprocessing module 901 in the co-phase shaft pickup device provided in an embodiment of the present invention. For ease of explanation, only the parts related to the embodiment of the present invention are shown, and are described in detail below:

[0110] In one embodiment of the present invention, preprocessing includes one or more of the following: frequency filtering, shot point removal, and automatic gain control. To improve the in-phase axis pickup accuracy, reference is made. Figure 10 The preprocessing module 901 includes various units for performing... Figure 3 For details of each step in the corresponding embodiment, please refer to [link / reference]. Figure 3 as well as Figure 3 The relevant descriptions in the corresponding embodiments will not be repeated here. In this embodiment of the invention, the preprocessing module 901 includes a frequency filtering unit 1001, a shot point removal unit 1002, and an automatic gain control unit 1003.

[0111] Frequency filtering unit 1001 is used to perform frequency filtering on the angle domain imaging point gather to obtain a frequency-filtered angle domain imaging point gather. and / or

[0112] The shot point removal unit 1002 is used to remove shot points from the angle-domain imaging point gather, obtaining the angle-domain imaging point gather after shot point removal. And / or

[0113] Automatic gain control unit 1003 is used to perform automatic gain control on the angle domain imaging point gather to obtain the angle domain imaging point gather after automatic gain control.

[0114] In this embodiment of the invention, the frequency filtering unit 1001 performs frequency filtering on the angle domain imaging point gather to obtain a frequency-filtered angle domain imaging point gather; the shot point removal unit 1002 performs shot point removal on the angle domain imaging point gather to obtain a shot point-removed angle domain imaging point gather; and the automatic gain control unit 1003 performs automatic gain control on the angle domain imaging point gather to obtain an automatically gain-controlled angle domain imaging point gather, which can improve the in-phase axis pickup accuracy respectively.

[0115] Figure 11 This illustration shows another functional module of the co-phase shaft pickup device provided in an embodiment of the present invention. For ease of explanation, only the parts related to the embodiment of the present invention are shown, and are described in detail below:

[0116] In one embodiment of the present invention, the coefficients of the quadratic term and the constant term of the quadratic function reflect the curvature and longitudinal offset of the fitted curve, respectively. To improve the in-phase axis pickup efficiency while maintaining resolution, reference is made... Figure 11 The various modules included in the co-phase shaft pickup device are used to perform... Figure 4 For details of each step in the corresponding embodiment, please refer to [link / reference]. Figure 4 as well as Figure 4 The relevant descriptions in the corresponding embodiments will not be repeated here. In this embodiment of the invention, based on the above-described module structure, the co-phase shaft pickup device further includes a storage module 1101.

[0117] Storage module 1101 is used to store the fitted curve of each phase axis by recording the degree of curvature and longitudinal offset.

[0118] In this embodiment of the invention, the storage module 1101 stores the fitting curve of each in-phase axis by recording the degree of curvature and longitudinal offset, which can improve the in-phase axis picking efficiency while ensuring resolution.

[0119] Figure 12 The diagram illustrates the structure of the in-phase axis fitting module 801 in the in-phase axis pickup device provided in an embodiment of the present invention. For ease of explanation, only the parts related to the embodiment of the present invention are shown, and are described in detail below:

[0120] In one embodiment of the present invention, in order to improve the accuracy of the simulated co-phase axis, reference is made to... Figure 12 The various units included in the in-phase axis fitting module 801 are used to perform... Figure 5 For details of each step in the corresponding embodiment, please refer to [link / reference]. Figure 5 as well as Figure 5 The relevant descriptions in the corresponding embodiments will not be repeated here. In this embodiment of the invention, the in-phase axis fitting module 801 includes an initial gather fitting unit 1201 and a fitted gather determination unit 1202.

[0121] The initial gather fitting unit 1201 is used to establish a coordinate system around the zero-angle vertex of each in-phase axis in the angle domain imaging point gather, and to fit each in-phase axis in the angle domain imaging point gather using a quadratic function to obtain multiple initial fitting curves corresponding to each in-phase axis.

[0122] The fitting gather determination unit 1202 is used to compare the amplitude and absolute value of each initial fitting curve corresponding to each phase axis, and to take the fitting curve with the largest amplitude and absolute value as the fitting curve of each phase axis.

[0123] In this embodiment of the invention, the initial gather fitting unit 1201 establishes a coordinate system around the zero-angle vertex of each in-phase axis in the angle domain imaging point gather, and uses a quadratic function to fit each in-phase axis in the angle domain imaging point gather to obtain multiple initial fitting curves corresponding to each in-phase axis. The gathered fitting unit 1202 compares the amplitude and absolute value of each initial fitting curve corresponding to each in-phase axis, and selects the fitting curve with the largest amplitude and absolute value as the fitting curve for each in-phase axis. This embodiment of the invention improves the accuracy of fitting the in-phase axis by fitting the in-phase axis with a quadratic function and determining the fitting curve of the in-phase axis using amplitude and absolute value, thereby improving the in-phase axis picking accuracy.

[0124] Figure 13 The diagram illustrates the structure of the initial gather fitting unit 1201 in the in-phase shaft pickup device provided in an embodiment of the present invention. For ease of explanation, only the parts related to the embodiment of the present invention are shown, and are described in detail below:

[0125] In one embodiment of the present invention, in order to improve the accuracy of the initial matching co-phase axis gather, and thus improve the co-phase axis picking accuracy, a reference is made. Figure 13 The subunits included in the initial gather fitting unit 1201 are used to perform... Figure 6 For details of each step in the corresponding embodiment, please refer to [link / reference]. Figure 6 as well as Figure 6 The relevant descriptions in the corresponding embodiments will not be repeated here. In this embodiment of the invention, the initial gather fitting unit 1201 includes a fitting subunit 1301.

[0126] The fitting subunit 1301 is used to establish a coordinate system around the zero-angle vertex of each in-phase axis in the angle domain imaging point gather. It uses a first quadratic function to fit the part of each in-phase axis in the angle domain imaging point gather where the angle is not greater than zero; and uses a second quadratic function to fit the part of each in-phase axis in the angle domain imaging point gather where the angle is greater than zero, to obtain the initial fitting curve corresponding to each in-phase axis.

[0127] In this embodiment of the invention, the fitting subunit 1301 establishes a coordinate system around the zero-angle vertex of each in-phase axis in the angle domain imaging point gather. It uses a first quadratic function to fit the portion of each in-phase axis in the angle domain imaging point gather where the angle is not greater than zero; and uses a second quadratic function to fit the portion of each in-phase axis in the angle domain imaging point gather where the angle is greater than zero, thus obtaining an initial fitting curve corresponding to each in-phase axis. This embodiment of the invention utilizes the first and second quadratic functions to fit both the portion of each in-phase axis in the angle domain imaging point gather where the angle is not greater than zero and the portion where the angle is greater than zero, respectively, obtaining an initial fitting curve corresponding to each in-phase axis gather. This can reduce or even eliminate gather distortion, improve the accuracy of the initial fitting curve, and thus improve the in-phase axis picking accuracy.

[0128] Figure 14 The diagram illustrates the structure of the gather curve fitting module 802 in the in-phase shaft pickup device provided in an embodiment of the present invention. For ease of explanation, only the parts relevant to the embodiment of the present invention are shown, and are described in detail below:

[0129] In one embodiment of the present invention, in order to further improve the pickup accuracy of the co-phase axis, a reference is made. Figure 14 The various units included in the gather curve fitting module 802 are used to perform... Figure 7 For details of each step in the corresponding embodiment, please refer to [link / reference]. Figure 7 as well as Figure 7 The relevant descriptions in the corresponding embodiments will not be repeated here. In this embodiment of the invention, the gather curve fitting module 802 includes a filter threshold determination unit 1401 and a gather determination unit 1402.

[0130] The filtering threshold determination unit 1401 is used to take the average amplitude of the fitting curve of the same phase axis within the imaging gather as the picking filtering threshold of the imaging gather.

[0131] The gather determination unit 1402 is used to use the fitting curve with an amplitude not less than the picking filter threshold as the fitting curve of the imaging gather.

[0132] In this embodiment of the invention, the filtering threshold determination unit 1401 uses the average amplitude of the fitting curve of the in-phase axis within the imaging gather as the picking filtering threshold of the imaging gather, and the gather determination unit 1402 uses the fitting curve with an amplitude not less than the picking filtering threshold as the fitting curve of the imaging gather. By using the average amplitude of the fitting in-phase axis as the filtering threshold of the imaging gather, this embodiment of the invention can filter the fitting curve within the imaging gather, thereby further improving the in-phase axis picking accuracy.

[0133] In imaging domain tomography, the purpose of picking subsurface strata is to find reflection point information that corresponds to angular domain gathers. If a picked stratum has no corresponding reflection point, the information contained in that point is invalid. This invention uses the picked angular domain imaging point gathers as a basis, determining the zero-angle point of the angular domain common imaging point gather as the reflection point, which conforms to the assumptions of imaging point gathers. Simultaneously, the scanned angular domain common imaging point gathers can be matched based on amplitude and other information to find the reflection axis of the same stratum, providing stratigraphic dip data for tomography. Even without picking strata, the relationship between reflection points and travel time residuals can be found, avoiding accuracy loss between various transformations.

[0134] The method of fitting the phase axis of the common imaging point gather in the angle domain using a quadratic function can obtain high-precision depth residual information that is not limited by the resolution of seismic data. It is also highly efficient, requires no manual interference, and improves the efficiency of tomographic velocity inversion.

[0135] Compared to conventional methods for picking up in-phase axes, the quadratic function fitting scanning method considers the characteristics of the common imaging point gather in the angle domain itself. It approaches the problem from both morphological and waveform perspectives, scanning the in-phase axis across the entire common imaging point gather in the angle domain. The hyperbola exhibited by the common imaging point gather in the angle domain when velocity is inaccurate can be fitted using a quadratic function, which can reconstruct the shape of the in-phase axis relatively well. By combining the amplitude information on the fitted path with background noise for comparison and differentiation, interfering in-phase axes are removed, ultimately achieving the goal of accurately picking up the in-phase axis.

[0136] This method has the following advantages: 1. Unlike other in-phase axis picking methods, this invention fully considers the characteristics of the in-phase axis of the common imaging point gather and uses a quadratic function for fitting; 2. It makes full use of the amplitude information of the common imaging point gather in the angle domain and is less affected by noise interference; 3. It is conducive to scanning by fitting, requires less storage space, and the fitting resolution exceeds the resolution of the common imaging point gather in the angle domain. It can match the in-phase axis well, pick up accurate depth residuals, establish accurate equations for subsequent inversion, and thus obtain accurate velocity update.

[0137] This invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above-described method for picking up the same phase axis.

[0138] This invention also provides a computer-readable storage medium storing a computer program that performs the above-described co-phase axis pickup method.

[0139] In summary, in this embodiment of the invention, a quadratic function is used to fit each phase axis to obtain a fitted curve for each phase axis. The top and bottom boundaries of the fitted curve of the imaging gather are determined, and the fitted curve within the range of the top and bottom boundaries is used as the final picked curve. This embodiment of the invention, by fitting the phase axis using a quadratic function, is not limited by the resolution of seismic data and can closely match the actual phase axis, improving the accuracy of phase axis picking. Furthermore, phase axis picking requires no manual interference or assistance, thus improving picking efficiency.

[0140] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0141] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0142] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0143] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0144] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for picking up in-phase axes, characterized in that, include: By fitting a quadratic function to each in-phase axis in the angular domain imaging point gather, the fitting curve of each in-phase axis in the imaging gather is obtained. The fitting curve of the imaging gather is determined based on the fitting curve of each in-phase axis within the imaging gather. Determine the top and bottom boundaries of the imaging gather fitting curve, and use the fitting curve within the range of the top and bottom boundaries of the imaging gather profile as the final picked fitting curve. The coefficients of the quadratic term and the constant term of the quadratic function reflect the curvature and longitudinal offset of the in-phase axis after fitting, respectively. The in-phase axis picking method also includes: The fitted curve for each in-phase axis is stored by recording the degree of curvature and longitudinal offset; The quadratic fitting function used to fit the co-phase axis is expressed as: ； in, Indicates the proposed contract phase axis. This represents the angle of the in-phase axis of the angular domain imaging point gather in the coordinate system. Reflects the degree of bending of the proposed coaxial shaft. It reflects the longitudinal offset of the proposed coherent axis in the coordinate system; By fitting a quadratic function to each in-phase axis in the angular domain imaging point gather, the fitting curve for each in-phase axis within the imaging gather is obtained, including: A coordinate system is established around the zero-angle vertex of each in-phase axis in the angle domain imaging point gather. A quadratic function is used to fit each in-phase axis in the angle domain imaging point gather to obtain multiple initial fitting curves corresponding to each in-phase axis. The initial fitted curve is shown below: ； in, Represents the fitted curve. This indicates the degree of curvature on the left side of the fitted curve. This indicates the degree of curvature on the right side of the fitted curve. This represents the vertical offset of the fitted curve in the coordinate system. This represents the angle of the in-phase axis of the angular domain imaging point gather in the coordinate system. The amplitude and absolute value of each initial fitted curve corresponding to each phase axis are compared, and the fitted curve with the largest amplitude and absolute value is taken as the fitted curve for each phase axis.

2. The method for picking up in-phase axes as described in claim 1, characterized in that, Also includes: Preprocess the angle domain imaging point gather to obtain the preprocessed angle domain imaging point gather. By fitting a quadratic function to each in-phase axis in the angular domain imaging point gather, the fitting curve for each in-phase axis within the imaging gather is obtained, including: By fitting each in-phase axis in the preprocessed angle domain imaging point gather with a quadratic function, the fitting curve of each in-phase axis in the imaging gather is obtained.

3. The method for picking up in-phase axes as described in claim 2, characterized in that, Preprocessing includes one or more of the following: frequency filtering, shot point removal, and automatic gain control. This preprocessing of the angle-domain imaging point gather yields a preprocessed angle-domain imaging point gather, including: Frequency filtering is applied to the angle domain imaging point gather to obtain the frequency-filtered angle domain imaging point gather; and / or Shot point cut-off is performed on the angle domain imaging point gather to obtain the angle domain imaging point gather after shot point cut-off; and / or Automatic gain control is applied to the angle domain imaging point gather to obtain the angle domain imaging point gather after automatic gain control.

4. The method for picking up in-phase axes as described in claim 1, characterized in that, A coordinate system is established around the zero-angle vertex of each in-phase axis in the angle-domain imaging point gather. A quadratic function is used to fit each in-phase axis in the angle-domain imaging point gather, obtaining multiple initial fitting curves corresponding to each in-phase axis, including: A coordinate system is established around the zero-angle vertex of each in-phase axis in the angle domain imaging point gather. The first quadratic function is used to fit the portion of each in-phase axis in the angle domain imaging point gather where the angle is not greater than zero. The second quadratic function is used to fit the portion of each in-phase axis in the angle domain imaging point gather where the angle is greater than zero, thus obtaining the initial fitting curve corresponding to each in-phase axis.

5. The method for picking up in-phase axes as described in claim 1, characterized in that, The fitting curve of the imaging gather is determined based on the fitting curve of each in-phase axis within the imaging gather, including: The average amplitude of the fitting curve of the in-phase axis within the imaging gather is used as the picking and filtering threshold of the imaging gather. The fitted curve with an amplitude not less than the picking filter threshold is used as the fitted curve for the imaging gather.

6. A co-phase shaft pickup device, characterized in that, include: The in-phase axis fitting module is used to fit each in-phase axis in the angular domain imaging point gather using a quadratic function to obtain the fitting curve of each in-phase axis in the imaging gather. The gather curve fitting module is used to determine the fitting curve of the imaging gather based on the fitting curve of each in-phase axis within the imaging gather. The final fitting determination module is used to determine the top and bottom boundaries of the imaging gather fitting curve, and the fitting curve within the range of the top and bottom boundaries of the imaging gather profile is used as the final picked fitting curve. The coefficients of the quadratic term and the constant term of the quadratic function reflect the curvature and longitudinal offset of the fitted in-phase axis, respectively. The in-phase axis pickup device also includes: The storage module is used to store the fitted curve of each in-phase axis by recording the degree of curvature and longitudinal offset; The quadratic fitting function used to fit the co-phase axis is expressed as: ； in, Indicates the proposed contract phase axis. This represents the angle of the in-phase axis of the angular domain imaging point gather in the coordinate system. Reflects the degree of bending of the proposed coaxial shaft. It reflects the longitudinal offset of the proposed coherent axis in the coordinate system; The in-phase axis fitting module includes: The initial gather fitting unit is used to establish a coordinate system around the zero-angle vertex of each in-phase axis in the angle domain imaging point gather. It uses a quadratic function to fit each in-phase axis in the angle domain imaging point gather to obtain multiple initial fitting curves corresponding to each in-phase axis. The initial fitted curve is shown below: ； in, Represents the fitted curve. This indicates the degree of curvature on the left side of the fitted curve. This indicates the degree of curvature on the right side of the fitted curve. This represents the vertical offset of the fitted curve in the coordinate system. This represents the angle of the in-phase axis of the angular domain imaging point gather in the coordinate system. The fitting gather determination unit is used to compare the amplitude and absolute value of each initial fitting curve corresponding to each phase axis, and select the fitting curve with the largest amplitude and absolute value as the fitting curve for each phase axis.

7. The co-phase shaft pickup device as described in claim 6, characterized in that, Also includes: The preprocessing module is used to preprocess the angle domain imaging point gather to obtain the preprocessed angle domain imaging point gather. The phase axis fitting module is also used to fit each phase axis in the preprocessed angle domain imaging point gather using a quadratic function to obtain the fitting curve of each phase axis in the imaging gather.

8. The co-phase shaft pickup device as described in claim 7, characterized in that, Preprocessing includes one or more of the following: frequency filtering, shot point removal, and automatic gain control. The preprocessing module includes: The frequency filtering unit is used to perform frequency filtering on the angle domain imaging point gather to obtain a frequency-filtered angle domain imaging point gather; and / or The shot cutout unit is used to cut shot points from the angle-domain imaging point gather, obtaining the angle-domain imaging point gather after shot point cutout; and / or An automatic gain control unit is used to perform automatic gain control on the angle domain imaging point gather to obtain the angle domain imaging point gather after automatic gain control.

9. The co-phase shaft pickup device as described in claim 6, characterized in that, The initial gather fitting unit includes: The fitting sub-unit is used to establish a coordinate system around the zero-angle vertex of each in-phase axis in the angle domain imaging point gather. The first quadratic function is used to fit the part of each in-phase axis in the angle domain imaging point gather where the angle is not greater than zero; the second quadratic function is used to fit the part of each in-phase axis in the angle domain imaging point gather where the angle is greater than zero, so as to obtain the initial fitting curve corresponding to each in-phase axis.

10. The co-phase shaft pickup device as described in claim 6, characterized in that, The gather curve fitting module includes: The filtering threshold determination unit is used to take the average amplitude of the in-phase axis fitting curve within the imaging gather as the picking filtering threshold of the imaging gather. The fitting curve determination unit is used to select the fitting curve with an amplitude not less than the picking filter threshold as the fitting curve of the imaging gather.

11. 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, it implements the same-phase axis pickup method according to any one of claims 1 to 5.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a computer program that, when executed by a processor, implements the co-phase axis pickup method of any one of claims 1 to 5.

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