A method and system for marine orthogonal matrix bidirectional towed cable seismic acquisition

Abstract

This invention belongs to the field of computer-aided design and exploration data measurement technology, and particularly relates to a method and system for marine orthogonal matrix bidirectional towed cable seismic acquisition. It includes determining the center point of the transverse A-cell, determining the center point of the longitudinal B-cell, and determining the center points of both transverse A and longitudinal B-cells. This invention solves the problem in the prior art that, during bidirectional seismic acquisition, the uneven reflection points within the acquisition cells lead to uneven coverage within the cells. This invention achieves the beneficial technical effects of uniform coverage within the orthogonal bidirectional seismic acquisition cells and reflection points at the center points of the cells.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of computer-aided design and exploration data measurement, and particularly relates to a marine orthogonal matrix dual-azimuth streamer seismic acquisition method and system. BACKGROUND

[0002] Marine streamer seismic acquisition is one of common methods for obtaining exploration detection data in marine oil and gas exploration. In different exploration stages, dual-azimuth seismic data acquisition is needed to meet the exploration needs of complex targets. In the seismic data acquisition and processing stage, bin is a basic unit of seismic data, and bin attributes directly reflect the quality of seismic data. The bin size of streamer acquisition is determined by the trace interval, cable interval and shot line interval of the observation system. In dual-azimuth seismic acquisition, a suitable acquisition method is needed to ensure the uniformity of coverage in the bin.

[0003] In summary, the prior art has the problem that in dual-azimuth seismic acquisition, the reflection drop points in the acquisition bin are not uniform, resulting in uneven coverage in the bin. SUMMARY

[0004] The application provides a marine orthogonal matrix dual-azimuth streamer seismic acquisition method and system to solve the problem of uneven coverage in the bin caused by uneven reflection drop points in the acquisition bin in the prior art.

[0005] The technical problem solved by the application is realized by the following technical scheme:

[0006] A marine orthogonal matrix dual-azimuth streamer seismic acquisition method, comprising:

[0007] Based on the dual-azimuth seismic data of the mutually perpendicular horizontal A and vertical B directions acquired together, the following is adopted:

[0008] Determining the horizontal A bin center point: based on the horizontal A geophone interval, cable interval and source interval, the horizontal A bin center point is obtained through a horizontal A data reflection drop point estimation method;

[0009] Determining the vertical B bin center point: based on the vertical B geophone interval, cable interval and source interval, the vertical B bin center point is obtained through a vertical B data reflection drop point estimation method;

[0010] Determining the horizontal A and vertical B bin center points: based on the A bin center point matrix and the B bin center point matrix, the horizontal A and B bin center points are obtained through a horizontal A and vertical B matrix data reflection drop point fitting method.

[0011] Further, the determination of the horizontal A bin center point further comprises:

[0012] The lateral A data reflection drop point estimation method comprises:

[0013] If the lateral A seismic data acquisition uses a lateral A source interval ds, a seismic detector interval dr, and a cable interval dc;

[0014] Then:

[0015] By a lateral A bin center point estimation function, the reflection point drop point of the lateral A bin dA is determined as the A bin center point. Further, the lateral A data reflection drop point estimation method further comprises:

[0016] The cable interval estimation function is:

[0017] dc = 2 × ds = 8 × dr;

[0018] The dc is a cable interval;

[0019] The ds is a source interval;

[0020] The dr is a seismic detector interval.

[0021] Further, the lateral A data reflection drop point estimation method further comprises:

[0022] The rectangular bin estimation function is:

[0023]

[0024] The dA is a lateral A bin;

[0025] The lA is a lateral A bin length;

[0026] The wA is a lateral A bin width;

[0027] The lateral A bin center point estimation function is:

[0028] pA x = dr4 + dr2 × m;

[0029] pA y = ds4 + ds2 × n;

[0030] The pA x is an X coordinate of the A bin center point;

[0031] The pA y is a Y coordinate of the A bin center point;

[0032] The m is a lateral bin number of the A bin;

[0033] The n is a longitudinal bin number of the A bin.

[0034] Further, the determining the longitudinal B surface element center point further comprises:

[0035] The longitudinal B data reflection drop point estimation method comprises:

[0036] If the longitudinal B seismic data acquisition uses the longitudinal B source interval ds, the seismic detector interval dr, and the cable interval dc; then:

[0037] By the longitudinal B surface element center point estimation function, the reflection point drop point of the longitudinal B surface element dB is determined as the B surface element center point. Further, the longitudinal B data reflection drop point estimation method further comprises:

[0038] The cable interval estimation function is:

[0039] dc′=2×ds=8×dr;

[0040] The dc′ is the cable interval;

[0041] The ds is the source interval;

[0042] The dr is the seismic detector interval.

[0043] Further, the longitudinal B data reflection drop point estimation method further comprises:

[0044] The rectangular surface element estimation function is:

[0045]

[0046] The dB is the longitudinal B surface element;

[0047] The lB is the longitudinal B surface element length;

[0048] The wB is the longitudinal B surface element width;

[0049] The longitudinal B surface element center point estimation function is:

[0050] pB x =ds4+ds2×j;

[0051] pB y =ds4+ds2×k;

[0052] The pB x is the X coordinate of the B surface element center point;

[0053] The pB y is the Y coordinate of the B surface element center point;

[0054] The j is the B surface element transverse surface element number;

[0055] The k is the B surface element longitudinal surface element number.

[0056] Further, the determining the center points of the transverse A and longitudinal B surface elements further comprises:

[0057] The transverse A and longitudinal B matrix data reflection point fitting method comprises:

[0058] If the surface element side length estimation function is defined as the surface element side length of the total surface element dAB of the transverse A and longitudinal B;

[0059] Then:

[0060] The total surface element dAB comprises four transverse A surface elements dA x {dA1, dA2, dA3, dA4} and four longitudinal B surface elements dB y {dB1, dB2, dB3, dB4}, and the reflection point of the total surface element dAB of the transverse A and longitudinal B is determined as the center point of the AB surface element by the transverse A and longitudinal B matrix data reflection point fitting function.

[0061] The N is a positive integer not less than 1.

[0062] Further, the transverse A and longitudinal B matrix data reflection point fitting method further comprises:

[0063] The surface element side length estimation function is:

[0064] dd = ds2;

[0065] The dd is the surface element side length of the total surface element dAB;

[0066] The ds is the source interval;

[0067] The transverse A and longitudinal B matrix data reflection point fitting method further comprises:

[0068] The transverse A and longitudinal B matrix data reflection point fitting function is:

[0069]

[0070] The trace tr(ddAB) of the matrix ddAB is the data value of the surface element center point;

[0071] The ddA1, ddA2, ddA3, ddA4 are the data values of the transverse A surface elements dA1, dA2, dA3 and dA4;

[0072] The ddB1, ddB2, ddB3 and ddB4 are the data values of the longitudinal B surface elements dB1, dB2, dB3 and dB4.

[0073] Meanwhile, the present invention also provides a marine orthogonal matrix two-way towed cable seismic acquisition system, comprising: a seismic acquisition platform constructed based on the above-mentioned seismic acquisition method, the seismic acquisition platform comprising: a module for determining the center point of the transverse A-plane element: used to obtain the center point of the transverse A-plane element based on the spacing of the seismic detectors, cable spacing, and source spacing in the transverse A-plane, through a method for estimating the reflection point of the transverse A-plane; a module for determining the center point of the longitudinal B-plane element: used to obtain the center point of the longitudinal B-plane element based on the spacing of the seismic detectors, cable spacing, and source spacing in the longitudinal B-plane, through a method for estimating the reflection point of the longitudinal B-plane; and a module for determining the center points of the transverse A-plane and longitudinal B-plane elements: used to obtain the center points of the transverse A-plane and B-plane elements based on the center point matrix of the A-plane element and the center point matrix of the B-plane element, through a method for fitting the reflection point of the transverse A-plane and longitudinal B-plane matrix data.

[0074] Beneficial technical effects:

[0075] This patent utilizes bidirectional seismic data from two mutually perpendicular directions, lateral (A) and longitudinal (B). It determines the center point of the lateral A-area element by estimating the reflection point of the seismic detectors, cables, and seismic sources in the lateral A direction using a method for estimating the reflection point of the lateral A data. Similarly, it determines the center point of the longitudinal B-area element by estimating the reflection point of the lateral B data using the same method. Finally, it determines the center points of both the lateral A and longitudinal B-area elements by fitting the reflection point of the data from the A-area and B-area element center point matrices. This invention aims to obtain the center points of horizontal A and B surface elements. Since the concept and technology of this invention aim to explore an efficient bidirectional acquisition and observation system to improve the quality of seismic data, thereby enhancing the accuracy of data interpretation and target evaluation, the method involves: first, obtaining the center points of horizontal A surface element and vertical B surface element; then, obtaining the center points of horizontal A and B surface elements through reflection point fitting. Because bidirectional seismic data from both the horizontal (A) and vertical (B) directions are acquired, a suitable acquisition method is used to ensure uniform coverage within the surface elements during bidirectional seismic acquisition. Specifically, the method involves: first, using a seismic data tow cable for bidirectional acquisition, utilizing two perpendicular directions... For simultaneous acquisition in both directions A and B, seismic data acquisition in direction A uses cable spacing dc, source spacing ds, and geophone spacing dr, where dc = 2 * ds = 8 * dr. The size of the underground reflector rectangular element dA is (ds / 2)m in length and (dr / 2)m in width. In direction B, which forms a 90-degree angle with direction A, cable spacing dcm, source spacing dsm, and geophone spacing drm are used, where dc = 2 * ds = 8 * dr. The size of the underground reflector rectangular element dB is (dr / 2)m in length and (ds / 2)m in width. Then, according to the definition of a square element dAB with a side length of (ds / 2)m, a... The data within the dAB surface element includes data from four dA surface elements formed in the A direction (ddA1, ddA2, ddA3, and dA4) and data from four dB surface elements formed in the B direction (ddB1, ddB2, ddB3, and ddB4). Finally, based on the center point data of the dAB surface element, a reflection point fitting matrix is ​​used to calculate the center points of the horizontal A and B surface elements. This method, through the design of the seismograph spacing, cable spacing, and source spacing of the observation system for bidirectional seismic data acquisition in two perpendicular directions, and the calculation of the data landing points within the surface element, achieves uniform coverage within the orthogonal bidirectional seismic acquisition surface element and ensures that the reflection landing points are at the center points of the surface element. This invention, through the design of the orthogonal bidirectional seismic acquisition method, effectively solves the problem of uneven reflection landing points within the bidirectional seismic data acquisition surface element, achieving uniform coverage within the orthogonal bidirectional seismic acquisition surface element and ensuring that the reflection landing points are at the center points of the surface element. Attached Figure Description

[0076] Figure 1 This is the overall flowchart of the towed cable seismic acquisition method of the present invention;

[0077] Figure 2 This is a flowchart illustrating the specific process of the towed cable seismic acquisition method of the present invention;

[0078] Figure 3 This is a schematic diagram of the lateral A-square seismic data acquisition method of the present invention using the towed seismic acquisition method;

[0079] Figure 4 This is a schematic diagram of the subsurface reflection surface of the transverse A-square seismic data in the towed seismic acquisition method of the present invention;

[0080] Figure 5 This is a schematic diagram of the longitudinal B-square seismic data acquisition method of the present invention using a towed seismic acquisition cable.

[0081] Figure 6 This is a schematic diagram of the underground reflection surface of the longitudinal B-plane seismic data in the towed seismic acquisition method of the present invention;

[0082] Figure 7 This is a single-sided element dAB schematic diagram of the towed cable seismic acquisition method of the present invention;

[0083] Figure 8 This is a data distribution diagram within a single-sided element dAB of the towed seismic acquisition method of the present invention;

[0084] Figure 9 This is a multi-faceted dAB data distribution diagram of the towed cable seismic acquisition method of the present invention. Detailed Implementation

[0085] The present invention will be further described below with reference to the accompanying drawings:

[0086] In the picture:

[0087] S101 - Determine the center point of the horizontal A-plane element;

[0088] S102 - Determine the center point of the longitudinal B-plane element;

[0089] S103 - Determine the center points of the horizontal A and vertical B surface elements;

[0090] S1001 - Based on the spacing between seismic detectors, cables, and seismic sources in the transverse A region, the center point of the transverse A surface element is obtained through the method of estimating the reflection point of transverse A data.

[0091] S1002 - Based on the longitudinal B seismic detector spacing, cable spacing and source spacing, the center point of the longitudinal B surface element is obtained by estimating the reflection point of longitudinal B data.

[0092] S1003 - Based on the center point matrix of surface element A and the center point matrix of surface element B, the center points of surface elements A and B are obtained by fitting the reflection points of the data of the horizontal A and vertical B matrices.

[0093] Example:

[0094] This embodiment: as follows Figure 1 , 3 As shown, a method for marine orthogonal matrix two-way towed cable seismic acquisition includes: based on jointly acquired two-way seismic data in mutually perpendicular directions A and B, using:

[0095] Determine the center point S101 of the transverse A-plane element: Based on the spacing of the seismic detectors, cables, and seismic sources in the transverse A-plane, the center point S1001 of the transverse A-plane element is obtained by estimating the reflection point of the transverse A-plane data.

[0096] Determine the center point S102 of the transverse A-plane element: Based on the spacing of the seismic detectors, cables, and seismic sources in the longitudinal B-plane, the center point S1002 of the longitudinal B-plane element is obtained by estimating the reflection point of the longitudinal B-plane data.

[0097] Determine the center point S103 of the horizontal A and vertical B surface elements: Based on the center point matrix of surface element A and the center point matrix of surface element B, obtain the center point S1003 of the horizontal A and B surface elements by fitting the reflection landing point of the horizontal A and vertical B matrix data.

[0098] Since the seismic data are acquired from both horizontal (A) and vertical (B) directions and are mutually perpendicular, the following methods are used to determine the center point of the horizontal A-plane element: Based on the spacing between seismic detectors, cables, and seismic sources in the horizontal A direction, the center point of the horizontal A-plane element is obtained using a method for estimating the reflection point of the horizontal A data. Similarly, the center point of the vertical B-plane element is determined based on the spacing between seismic detectors, cables, and seismic sources in the vertical B direction, using a method for estimating the reflection point of the vertical B data. Finally, the center points of both the horizontal A and vertical B-plane elements are determined using a method for fitting the reflection point of the horizontal A and vertical B matrix data, based on the center point matrices of the A-plane element and the B-plane element. This invention aims to obtain the center points of horizontal A and B surface elements. Since the concept and technology of this invention aim to explore an efficient bidirectional acquisition and observation system to improve the quality of seismic data, thereby enhancing the accuracy of data interpretation and target evaluation, the method involves: first, obtaining the center points of horizontal A surface element and vertical B surface element; then, obtaining the center points of horizontal A and B surface elements through reflection point fitting. Because bidirectional seismic data from both the horizontal (A) and vertical (B) directions are acquired, a suitable acquisition method is used to ensure uniform coverage within the surface elements during bidirectional seismic acquisition. Specifically, the method involves: first, using a seismic data tow cable for bidirectional acquisition, utilizing two perpendicular directions... For simultaneous acquisition in both directions A and B, seismic data acquisition in direction A uses cable spacing dc, source spacing ds, and geophone spacing dr, where dc = 2 * ds = 8 * dr. The size of the underground reflector rectangular element dA is (ds / 2)m in length and (dr / 2)m in width. In direction B, which forms a 90-degree angle with direction A, cable spacing dcm, source spacing dsm, and geophone spacing drm are used, where dc = 2 * ds = 8 * dr. The size of the underground reflector rectangular element dB is (dr / 2)m in length and (ds / 2)m in width. Then, according to the definition of a square element dAB with a side length of (ds / 2)m, a... The data within the dAB surface element includes data from four dA surface elements formed in the A direction (ddA1, ddA2, ddA3, and dA4) and data from four dB surface elements formed in the B direction (ddB1, ddB2, ddB3, and ddB4). Finally, based on the center point data of the dAB surface element, a reflection point fitting matrix is ​​used to calculate the center points of the horizontal A and B surface elements. This method, through the design of the seismograph spacing, cable spacing, and source spacing of the observation system for bidirectional seismic data acquisition in two perpendicular directions, and the calculation of the data landing points within the surface element, achieves uniform coverage within the orthogonal bidirectional seismic acquisition surface element and ensures that the reflection landing points are at the center points of the surface element. This invention, through the design of the orthogonal bidirectional seismic acquisition method, effectively solves the problem of uneven reflection landing points within the bidirectional seismic data acquisition surface element, achieving uniform coverage within the orthogonal bidirectional seismic acquisition surface element and ensuring that the reflection landing points are at the center points of the surface element.

[0099] The determination of the center point S101 of the horizontal A-plane element also includes:

[0100] The method for estimating the reflection point of the horizontal A data includes:

[0101] If the seismic data acquisition in the transverse direction A uses the source spacing ds, seismic detector spacing dr, and cable spacing dc in the transverse direction A;

[0102] but:

[0103] By using the center point estimation function of the horizontal A-surface element, the reflection point of the horizontal A-surface element dA is determined as the center point of the A-surface element.

[0104] like Figure 3 As shown, the method for determining the center point of the transverse A-plane element also includes: the transverse A data reflection landing point estimation method includes: if the transverse A seismic data acquisition uses the source spacing ds, seismic detector spacing dr, and cable spacing dc; then: through the transverse A-plane element center point estimation function, the reflection point landing point of the transverse A-plane element dA is determined as the center point of the A-plane element. Since the A-direction seismic data acquisition uses the cable spacing dc, source spacing ds, and seismic detector spacing dr, the transverse A-plane element center point estimation function calculates and obtains the center point of the transverse A-plane element based on the cable spacing, source spacing, and seismic detector spacing. Its essence is to calculate based on professional data, thereby finally obtaining the center point of the transverse A-plane element.

[0105] The method for estimating the reflection point of horizontal A data also includes:

[0106] The cable spacing estimation function is:

[0107] dc = 2 × ds = 8 × dr;

[0108] dc refers to the cable spacing;

[0109] ds represents the distance between seismic sources;

[0110] dr refers to the spacing between seismic detectors.

[0111] The method for estimating the reflection point of the transverse A data also includes: the cable spacing estimation function is: dc = 2 × ds = 8 × dr; since the acquisition of seismic data in the A direction uses cable spacing dc, source spacing ds, and seismic detector spacing dr, in this scheme, the cable spacing, seismic detector spacing, source spacing, and cable spacing are first determined. They have a fixed relationship. Based on the seismic detector spacing, the source spacing and cable spacing are determined.

[0112] The method for estimating the reflection point of horizontal A data also includes:

[0113] The estimation function for the rectangular surface element is:

[0114]

[0115] The dA is a horizontal A-plane element;

[0116] The lA is the length of the horizontal A-plane element;

[0117] wA is the width of the horizontal A-plane element;

[0118] The method for estimating the reflection point of the lateral A data also includes: the estimation function for the rectangular element is: like Figure 4 As shown, where dc = 2 x ds = 8 x dr; the resulting subsurface reflection element is a rectangular element dA with a length of (ds / 2) and a width of (dr / 2); the length (ds / 2) of the transverse subsurface reflection element A depends on the source spacing, and the width depends on the seismic detector (dr / 2). This rectangular element is essentially a foundation element; four transverse foundation elements can form a square total element. This determined square total element transversely covers the entire seismic surface, providing a fundamental guarantee for transverse seismic data acquisition.

[0119] The estimation function for the center point of the horizontal A-plane element is:

[0120] pA x =dr4 + dr2 × m;

[0121] pA y = ds4 + ds2 × n;

[0122] pA x Here is the X-coordinate of the center point of surface element A;

[0123] pA y The Y-coordinate of the center point of surface element A;

[0124] m is the number of horizontal face elements in face element A;

[0125] n is the number of vertical facets in facet A.

[0126] Since the center point estimation function of the horizontal A-plane element is used: pA x =dr4+dr2×m; pA y =ds4 + ds2 × n; for example Figure 4 As shown, the spacing between the center points of the horizontal A-plane element in the Y-coordinate direction is 4 times the spacing in the X-coordinate direction. Through this relationship coefficient, the X and Y coordinates of the center points of the A-plane element are finally determined.

[0127] The determination of the center point S102 of the horizontal A-plane element also includes:

[0128] The method for estimating the impact point of longitudinal B data reflections includes:

[0129] If longitudinal B seismic data acquisition uses longitudinal B source spacing ds, seismic detector spacing dr, and cable spacing dc;

[0130] but:

[0131] By using the longitudinal B-plane element center point estimation function, the reflection point of the longitudinal B-plane element dB is determined as the center point of the B-plane element.

[0132] like Figure 5 As shown, the method for determining the center point of the longitudinal B-plane element also includes: the estimation method for the reflection point of the longitudinal B data includes: if the longitudinal B seismic data acquisition uses the source spacing ds, seismic detector spacing dr, and cable spacing dc; then: through the longitudinal B-plane element center point estimation function, the reflection point of the longitudinal B-plane element dB is determined as the center point of the B-plane element. Since the B direction forms a 90-degree angle with the A direction, the seismic data acquisition also uses the cable spacing dcm, source spacing dsm, and seismic detector spacing drm, where dc = 2 * ds = 8 * dr. Similar to determining the cable spacing first, the seismic detector spacing, source spacing, and cable spacing have a fixed relationship. Based on the seismic detector spacing, the source spacing and cable spacing are determined.

[0133] The longitudinal B-data reflection landing point estimation method also includes:

[0134] The cable spacing estimation function is:

[0135] dc′=2×ds=8×dr;

[0136] dc′ is the cable spacing;

[0137] ds represents the distance between seismic sources;

[0138] dr refers to the spacing between seismic detectors.

[0139] like Figure 6 As shown, the longitudinal B-data reflection point estimation method further includes: the rectangular element estimation function is:

[0140] The longitudinal B-data reflection landing point estimation method also includes:

[0141] The estimation function for the rectangular surface element is:

[0142]

[0143] The dB refers to the vertical B-plane element;

[0144] The lB is the length of the vertical B-plane element;

[0145] wB is the width of the vertical B-plane element;

[0146] like Figure 6 As shown, the longitudinal B-data reflection point estimation method further includes: the rectangular element estimation function is: The length of the longitudinal B underground reflection element depends on the seismic detector, and the width depends on the distance between seismic sources. The rectangular element mentioned above is actually a foundation element. Four longitudinal foundation elements can form a square total element. This determined square total element longitudinally covers the entire seismic surface, providing a basic guarantee for longitudinal seismic data acquisition.

[0147] The estimation function for the center point of the longitudinal B-plane element is:

[0148] pB x =ds4 + ds2 × j;

[0149] pB y =dr4 + dr2 × k;

[0150] pB x Here is the X coordinate of the center point of surface element B;

[0151] pB y The Y-coordinate of the center point of surface element B;

[0152] j represents the number of horizontal face elements in face B;

[0153] k represents the number of vertical facets in facet B.

[0154] like Figure 6 As shown, since the longitudinal B-plane element center point estimation function is: pB x =ds4+ds2×j; pB y =ds4+ds2×k; The distance between the center points of surface element A in the vertical direction in the X coordinate direction is 4 times the distance between the center points in the Y coordinate direction. Through this relationship coefficient, the X and Y coordinates of the center point of surface element B are finally determined.

[0155] The determination of the center point S103 of the horizontal A and vertical B surface elements also includes:

[0156] The method for fitting the reflection points of the horizontal A and vertical B matrix data includes:

[0157] If the function for estimating the side length of a square element is defined as the side length of the total number of elements dAB (horizontal A and vertical B);

[0158] but:

[0159] The total number of face elements dAB is determined to include 4 horizontal face elements dA. x {dA1, dA2, dA3, dA4} and 4 vertical B-plane elements dBy {dB1, dB2, dB3, dB4}, and by fitting the reflection point function of the matrix data of horizontal A and vertical B, the reflection point of the total surface element dAB of horizontal A and vertical B is determined as the center point of the surface element AB.

[0160] N is a positive integer not less than 1.

[0161] like Figure 7 As shown, determining the center points of the horizontal A and vertical B facets further includes: the method for fitting the reflection points of the horizontal A and vertical B matrix data includes: if the side length estimation function of the square facet is defined as the facet side length of the total facet dAB of horizontal A and vertical B; then: the total facet dAB includes 4 horizontal A facets dA. x {dA1, dA2, dA3, dA4} and 4 vertical B-plane elements dB y {dB1, dB2, dB3, dB4}, and by fitting the reflection point of the horizontal A and vertical B matrix data, the reflection point of the total surface element dAB of the horizontal A and vertical B is determined as the center point of the AB surface element; N is a positive integer not less than 1. Since the A and B directions are collected together, a square surface element dAB with a side length of (ds / 2)m is defined. Then, the data in one surface element dAB includes the data ddA1, ddA2, ddA3 and dA4 of 4 dA surface elements (dA1, dB2, dB3 and dB4) and the data ddB1, ddB2, ddB3 and ddB4 of 4 dB surface elements (dB1, dB2, dB3 and dB4). Figure 5 Since ddA1 and ddA4, ddA2 and ddA3, ddB1 and ddB4, and ddB2 and ddB3 are symmetrical about the center point o of the surface element dAB, the center point data of the surface element dAB is calculated using a matrix based on their distance from the center point.

[0162] The method for fitting the reflection points of the horizontal A and vertical B matrix data also includes:

[0163] The function for estimating the side length of the surface element is:

[0164] dd = ds2;

[0165] dd is the side length of the total surface element dAB;

[0166] ds represents the distance between seismic sources;

[0167] like Figure 8 , 9As shown, the method for fitting the reflection points of the horizontal A and vertical B matrix data also includes: the side length estimation function of the surface element is: dd = ds2; thus forming a total square surface element with a side length of dd, containing 4 horizontal surface elements and 4 vertical surface elements. The horizontal and vertical surface elements together provide basic support, realizing the acquisition of seismic data in both directions.

[0168] The method for fitting the reflection points of the horizontal A and vertical B matrix data also includes:

[0169] The fitting function for the reflection points of the horizontal A and vertical B matrix data is:

[0170]

[0171] The trace tr(ddAB) of the matrix ddAB is the data value of the center point of the surface element;

[0172] ddA1, ddA2, ddA3, and ddA4 are the data values ​​of the horizontal A-plane elements dA1, dA2, dA3, and dA4;

[0173] ddB1, ddB2, ddB3, and ddB4 are the data values ​​of the vertical B-plane elements dB1, dB2, dB3, and dB4.

[0174] like Figure 8 , 9 As shown, the method for fitting the reflection points of the horizontal A and vertical B matrix data further includes: the fitting function for the reflection points of the horizontal A and vertical B matrix data is:

[0175]

[0176] The fitting function uses an inverse distance weighting method, where the weighting coefficient decreases as the distance from the total surface element decreases. The distance from all reflection points within the total surface element to the center point of the total surface element is considered as 1. Among them, the weighting coefficients of the four reflection points ddA1, ddA4, ddB1, and ddB4, which are far from the center point of the total surface element, are 1 / 16, and the weighting coefficients of the eight reflection points ddA2, ddA3, ddB2, and ddB3, which are close to the center point of the total surface element, are 3 / 16. The sum of the coefficients of the eight reflection points is 1. Since the horizontal and vertical surface elements provide the combined seismic data acquisition from both directions, and through the estimation of the above matrix, the reflection points within the acquisition surface elements are balanced, ensuring sufficient seismic data acquisition.

[0177] The above function achieves uniform coverage within orthogonal bidirectional seismic acquisition cells and ensures that the reflection point is at the center of the cell. This invention, through the design of the bidirectional seismic acquisition method, effectively solves the problem of uneven reflection point distribution within bidirectional seismic data acquisition cells.

[0178] A marine orthogonal matrix bidirectional towed seismic acquisition system includes: a seismic acquisition platform constructed based on the seismic acquisition method described in claims 1-9, wherein the seismic acquisition platform includes:

[0179] The module for determining the center point S101 of the transverse A-plane element is used to obtain the center point S1001 of the transverse A-plane element based on the spacing of seismic detectors, cable spacing, and source spacing of transverse A-plane element, through the method of estimating the reflection point of transverse A-plane data.

[0180] The module for determining the center point S102 of the transverse A-plane element is used to obtain the center point S1002 of the longitudinal B-plane element based on the spacing of seismic detectors, cable spacing, and source spacing in the longitudinal B-plane.

[0181] The module for determining the center points of the horizontal A and vertical B facets, S103, is used to obtain the center points S1003 of the horizontal A and B facets based on the center point matrix of facet A and the center point matrix of facet B, through a method of fitting the reflection points of the horizontal A and vertical B matrix data.

[0182] Meanwhile, this invention also provides a marine orthogonal matrix bidirectional towed seismic acquisition system, comprising: a seismic acquisition platform constructed based on the above-mentioned seismic acquisition method, the seismic acquisition platform comprising: a module for determining the center point of the transverse A-area: used to obtain the center point of the transverse A-area based on the spacing of the seismic detectors, cable spacing, and source spacing in transverse A, through a method for estimating the reflection point of the transverse A data; a module for determining the center point of the longitudinal B-area: used to obtain the center point of the longitudinal B-area based on the spacing of the seismic detectors, cable spacing, and source spacing in longitudinal B, through a method for estimating the reflection point of the longitudinal B data; and a module for determining the center points of the transverse A and longitudinal B-area: used to obtain the center points of the transverse A and B-area based on the center point matrix of the A-area and the center point matrix of the B-area, through a method for fitting the reflection point of the transverse A and longitudinal B matrix data. Similarly, this system, by designing the spacing of the seismic detectors, cable spacing, and source spacing of the observation system for bidirectional seismic data acquisition in two vertical directions, and calculating the data reflection point within the area, achieves uniform coverage within the orthogonal bidirectional seismic acquisition area and ensures that the reflection point is at the center point of the area. This invention, through the design of an orthogonal bidirectional seismic acquisition method, effectively solves the problem of uneven reflection points within the acquisition area of ​​bidirectional seismic data. It achieves uniform coverage within the orthogonal bidirectional seismic acquisition area and ensures that the reflection points are located at the center of the area.

[0183] Working principle:

[0184] This patent utilizes bidirectional seismic data from two mutually perpendicular directions, lateral (A) and longitudinal (B), to determine the center point of the lateral A-area element. This is achieved by estimating the reflection point of the lateral A-area data based on the spacing between seismic detectors, cables, and seismic sources in lateral A. Similarly, the center point of the longitudinal B-area element is determined by estimating the reflection point of the longitudinal B-area data based on the spacing between seismic detectors, cables, and seismic sources in longitudinal B. Finally, the center points of both the lateral A and longitudinal B-area elements are determined by fitting the reflection point data of the lateral A and longitudinal B matrixes. This invention aims to obtain the center points of horizontal A and B surface elements. Since the concept and technology of this invention aim to explore an efficient bidirectional acquisition and observation system to improve the quality of seismic data, thereby enhancing the accuracy of data interpretation and target evaluation, the method involves: first, obtaining the center points of horizontal A surface element and vertical B surface element; then, obtaining the center points of horizontal A and B surface elements through reflection point fitting. Because bidirectional seismic data from both the horizontal (A) and vertical (B) directions are acquired, a suitable acquisition method is available to ensure uniform coverage within the surface elements during bidirectional seismic acquisition. Specifically, the method involves: first, using a seismic data tow cable for bidirectional acquisition using two perpendicular directions... Joint acquisition is performed in both directions A and B. Seismic data acquisition in direction A uses cable spacing dc, source spacing ds, and geophone spacing dr, where dc = 2 * ds = 8 * dr. The size of the underground reflector rectangular element dA is (ds / 2)m in length and (dr / 2)m in width. Direction B forms a 90-degree angle with direction A, using cable spacing dcm, source spacing dsm, and geophone spacing drm, where dc = 2 * ds = 8 * dr. The size of the underground reflector rectangular element dB is (dr / 2)m in length and (ds / 2)m in width. Then, according to the definition, a square element dAB with a side length of (ds / 2)m is... The data within each surface cell dAB includes data from four surface cells dA formed in the A direction (ddA1, ddA2, ddA3, and dA4) and data from four surface cells dB formed in the B direction (ddB1, ddB2, ddB3, and ddB4). Finally, the center points of the horizontal A and B surface cells are obtained by calculating the reflection point fitting matrix based on the center point data of surface cell dAB. This method achieves uniform coverage within the orthogonal bidirectional seismic acquisition surface cells and ensures that the reflection point is at the center point of the surface cell by designing the spacing between seismographs, cables, and sources of the observation system for towed seismic data acquisition in two perpendicular directions, as well as calculating the data points within the surface cells.

[0185] This invention addresses the problem in existing technologies where uneven reflection points within acquisition cells lead to uneven coverage during bidirectional seismic acquisition. This invention achieves the beneficial technical effects of uniform coverage within orthogonal bidirectional seismic acquisition cells and reflection points centered on the cell.

[0186] Any technical solution that utilizes the technical solution of this invention, or any similar technical solution designed by those skilled in the art under the inspiration of the technical solution of this invention, and achieves the above-mentioned technical effects, falls within the protection scope of this invention.

Claims

1. A method of marine orthogonal matrix dual-azimuth streamer seismic acquisition, the method comprising: The application relates to a method for determining the center points of a transverse A and a longitudinal B of a common acquisition dual-azimuth seismic data. The method comprises the following steps: Determining the center point of the transverse A: based on the seismic detector interval, the cable interval and the source interval of the transverse A, the center point of the transverse A bin is obtained through a reflection point estimation method of the transverse A data; The reflection point estimation method of the transverse A data comprises the following steps: If the source interval ds, the seismic detector interval dr and the cable interval dc of the transverse A are used in the acquisition of the transverse A seismic data; Then, The reflection point of the transverse A bin dA is determined as the center point of the transverse A bin through a center point estimation function of the transverse A bin; Determining the center point of the longitudinal B: based on the seismic detector interval, the cable interval and the source interval of the longitudinal B, the center point of the longitudinal B bin is obtained through a reflection point estimation method of the longitudinal B data; The reflection point estimation method of the longitudinal B data comprises the following steps: If the source interval ds, the seismic detector interval dr and the cable interval dc of the longitudinal B are used in the acquisition of the longitudinal B seismic data; Then, The reflection point of the longitudinal B bin dB is determined as the center point of the longitudinal B bin through a center point estimation function of the longitudinal B bin; Determining the center points of the transverse A and the longitudinal B bins: based on the center point matrix of the transverse A bin and the center point matrix of the longitudinal B bin, the center points of the transverse A bin and the longitudinal B bin are obtained through a reflection point fitting method of the transverse A and longitudinal B matrix data; The reflection point fitting method of the transverse A and longitudinal B matrix data comprises the following steps: If the bin side length of the total bin dAB is defined as the bin side length of the transverse A and longitudinal B total bin through a square bin side length estimation function; Then, determining total bin dAB includes 4 lateral A bins dA x {dA1, dA2, dA3, dA4} and 4 longitudinal B bins dB y {dB1, dB2, dB3, dB4}, and by fitting the function of the reflection point drop of the lateral A and longitudinal B matrix data, the reflection point drop of the total bin dAB of the lateral A and longitudinal B is determined as the center point of the AB bin.

2. The seismic acquisition method of claim 1, wherein, The reflection point estimation method of the transverse A data further comprises the following steps: The cable interval estimation function is as follows: dc=2*ds=8*dr; The dc is the cable interval; The ds is the source interval; The dr is the seismic detector interval.

3. The seismic acquisition method of claim 1, wherein, The reflection point estimation method of the transverse A data further comprises the following steps: The rectangular bin estimation function is as follows: The dA is the transverse A bin; The lA is the length of the transverse A bin; The wA is the width of the transverse A bin; The center point estimation function of the transverse A bin is as follows: The pA x is the X coordinate of the center point of the A plane element; The pA y Y coordinate of the center point of the A plane element; The m is the transverse bin number of the A bin; The n is the longitudinal bin number of the A bin.

4. The seismic acquisition method of claim 1, wherein, The reflection point estimation method of the longitudinal B data further comprises the following steps: The cable interval estimation function is as follows: dc'=2*ds=8*dr; The dc' is the cable interval; The ds is the source interval; The dr is the seismic detector interval.

5. The seismic acquisition method of claim 1, wherein, The reflection point estimation method of the longitudinal B data further comprises the following steps: The rectangular bin estimation function is as follows: The dB is the longitudinal B bin; The lB is the length of the longitudinal B bin; The wB is the width of the longitudinal B bin; The center point estimation function of the longitudinal B bin is as follows: pB x = ds / 4 + ds / 2 x j pB y = ds / 4 + ds / 2 x k The pB x X coordinate of the center point of the B surface element; The pB y Y coordinate of the center point of the B surface element; The j is the transverse bin number of the B bin; The k is the longitudinal bin number of the B bin.

6. The seismic acquisition method of claim 1, wherein, The reflection point fitting method of the transverse A and longitudinal B matrix data further comprises the following steps: The square bin side length estimation function is as follows: dd=ds / 2; The dd is the bin side length of the total bin dAB; The ds is the source interval; The reflection point fitting method of the transverse A and longitudinal B matrix data further comprises the following steps: The reflection point fitting function of the transverse A and longitudinal B matrix data is as follows: a trace tr(ddAB) of the matrix ddAB is a bin center point data value; the ddA1, ddA2, ddA3, ddA4 are data values of the transverse A bins dA1, dA2, dA3 and dA4; the ddB1, ddB2, ddB3 and ddB4 are data values of the longitudinal B bins dB1, dB2, dB3 and dB4.

7. An offshore orthogonal matrix dual-azimuth streamer seismic acquisition system, characterized in that, comprising: a seismic acquisition platform constructed based on the seismic acquisition method as claimed in any one of claims 1-6, the seismic acquisition platform comprising: a transverse A bin center point determination module for obtaining a transverse A bin center point through a transverse A data reflection drop point estimation method based on a transverse A geophone spacing, a cable spacing and a source spacing; a longitudinal B bin center point determination module for obtaining a longitudinal B bin center point through a longitudinal B data reflection drop point estimation method based on a longitudinal B geophone spacing, a cable spacing and a source spacing; a transverse A and longitudinal B bin center point determination module for obtaining a transverse A and longitudinal B bin center point through a transverse A and longitudinal B matrix data reflection drop point fitting method based on an A bin center point matrix and a B bin center point matrix.

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