Seismic data processing method for OVT continuous piece processing

Abstract

The invention belongs to the technical field of seismic exploration and detection, and particularly relates to a seismic data processing method for OVT continuous processing. The seismic data processing method for OVT contiguous processing comprises the following steps: acquiring contiguous processing seismic data A including unilateral blasting data A1 and bilateral blasting data A2, respectively assigning a detection point coordinate value and a shot point coordinate value of the seismic data A1 to an idle header word, and then assigning a detection point coordinate value in the header word to a shot point coordinate value; and assigning the shot point coordinate values to the detection point coordinates to obtain single-side blasting data B2 with interchanged shot point coordinates, combining A1 and B2 to form pseudo double-side blasting data B3, and combining B3 and A2 to obtain double-side blasting seismic data C for continuous processing. According to the method, the reversible principle of wave propagation is applied, OVT piece data on the missing side are compensated, pseudo bilateral blasting seismic data are obtained, OVT piece connecting processing can be achieved, and seismic data interpretation, reservoir prediction and crack prediction precision is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of exploration and detection of earthquakes, and particularly relates to a seismic data processing method for OVT patch processing. BACKGROUND

[0002] With the continuous progress of seismic exploration technology, wide-azimuth seismic exploration has become an important direction of the development of seismic exploration technology at the present stage. Compared with narrow-azimuth three-dimensional seismic technology, wide-azimuth seismic technology has greater advantages in structure, lithology exploration and fluid detection. With the wide application of wide-azimuth seismic technology, the corresponding wide-azimuth seismic data processing technology (OVT technology) has become increasingly normalized. Zhao Zhonghua in the paper "Wide-azimuth seismic data OVT domain five-dimensional interpolation technology and application" published in "China Petroleum Society 2022 Geophysical Technology Symposium Proceedings" introduced that in the processing process, five-dimensional (three-dimensional spatial coordinates + offset + azimuth) information containing offset and azimuth at the same time was established. These technologies are collectively referred to as offset vector patch technology, simply referred to as OVT technology.

[0003] In the paper "Offset vector patch technology for wide-azimuth seismic processing" published in "Petroleum Geophysical Prospecting" in 2011, Duan Wensheng et al. introduced that a series of processing of five-dimensional data in the OVT domain can obtain the final pre-stack gathers containing offset and azimuth, and then five-dimensional seismic data interpretation, reservoir prediction and fluid identification can be carried out. With the progress of OVT technology in processing, some processing personnel also apply this technology to the processing of narrow-azimuth seismic data (usually defined, seismic data with the aspect ratio of the acquisition geometry greater than 0.5 is wide-azimuth seismic data, and vice versa is narrow-azimuth seismic data). Especially when multiple three-dimensional seismic data are patch processed, due to different acquisition years and different observation systems, there are wide-azimuth seismic data and narrow-azimuth seismic data in the patch-processed seismic data. At this time, the processing personnel will select or interpolate some OVT patches with uneven data distribution to meet the requirements of OVT processing.

[0004] In the 1990s, the single-side shooting observation system was widely used in the process of seismic data acquisition due to the limited receiving capacity of the acquisition equipment; later, with the improvement of the receiving capacity, the double-side shooting observation system was widely used in the process of seismic data acquisition (when a single shot is fired, all receiving points are on the same side of the shot point, which is called a single-side shooting observation system; when the receiving points are distributed on both sides of the shot point, it is called a double-side shooting observation system). When the single-side shooting data and the double-side shooting data are connected and processed by OVT, the OVT piece of the single-side shooting data will be missing on the left side or the right side, that is, only one side of the OVT piece of the single-side shooting data has data, and the other side is missing. In this case, the interpolation processing lacks effective data; if the missing data is discarded, a large amount of double-side shooting data will be lost, and the processing can only be performed in the common offset domain.

[0005] Liu Xiaoliang published a paper entitled "Application and Effect of Five-dimensional Interpolation Technology in OVT Domain Migration" in the "Proceedings of the 2022 China Petroleum Exploration Academic Conference" (Volume 1), which introduced a least squares inversion data reconstruction technology and process using irregular Fourier transform, regularized the gather data, and constructed a missing trace method. This method can reduce the influence of irregular acquisition on OVT domain processing to some extent, and improve the imaging effect of micro-amplitude structure and faults of the OVT domain pstm data body. However, this method does not introduce the content of single-side shooting seismic data OVT connection processing.

[0006] A kind of orthogonal anisotropic medium OVT domain imaging gather extraction method and system are disclosed in Chinese invention patent with authorization announcement number CN112578432B authorized on May 26, 2023, which extracts the imaging gather of orthogonal anisotropic OVT domain by calculating the travel time field information of orthogonal anisotropic medium, performing extrapolation for each shot to obtain the imaging result. The invention solves the problem of velocity analysis and does not involve the content of single-side shooting seismic data OVT connection processing.

[0007] Therefore, the seismic data processing method for OVT connection processing of single-side shooting seismic data and double-side shooting seismic data still has the problem of poor processing result precision, which reduces the precision of seismic data interpretation, reservoir prediction and fracture prediction. SUMMARY

[0008] The present application provides a seismic data processing method for OVT connection processing, which solves the problem of poor precision in the prior art when single-side shooting seismic data and double-side shooting seismic data are connected and processed by OVT.

[0009] In order to solve the above technical problems, the technical scheme of the seismic data processing method for OVT connection processing of the present application is as follows:

[0010] A seismic data processing method for OVT joint processing, comprising the following steps:

[0011] 1) obtaining joint seismic data A, the seismic data A comprising single-sided shooting data A1 and double-sided shooting data A2;

[0012] 2) assigning the coordinates of the geophone and the shot point in A1 to the empty trace header respectively, and then assigning the coordinates of the geophone in the trace header to the coordinates of the shot point, and assigning the coordinates of the shot point to the coordinates of the geophone, to obtain single-sided shooting data B2 with the coordinates of the shot point and the geophone interchanged;

[0013] 3) merging A1 and B2 into pseudo-double-sided shooting data B3, and merging B3 and A2 to obtain double-sided shooting seismic data C for OVT joint processing.

[0014] The present application is an improvement on the prior art, and provides a seismic data processing method for OVT joint processing, which applies the reversible principle of wave propagation to compensate for the missing OVT piece data on one side, and converts single-sided shooting data into pseudo-double-sided shooting seismic data, thereby avoiding the situation that single-sided shooting seismic data cannot be processed by OVT when joint processing is performed, or a large amount of double-sided shooting seismic data on one side is discarded for OVT processing, which can only be processed in the common offset domain, resulting in poor processing accuracy. The data processing method of the present application realizes OVT joint processing, effectively improves the accuracy of seismic data interpretation, reservoir prediction and fracture prediction, and reduces the workload of deploying new double-sided shooting seismic acquisition work for realizing OVT joint processing, greatly reducing exploration expenses.

[0015] In order to further improve the simplicity of data processing, preferably, the step 2) is to assign the X1, Y1 coordinates of the geophone in A1 to the empty trace header a1, b1 respectively, and assign the X2, Y2 coordinates of the shot point to the empty trace header a2, b2 respectively, to obtain single-sided shooting common shot point domain data B1 with empty attributes, and then assign the coordinates of a1, b1 to the coordinates of the shot point X2, Y2 respectively, and assign the coordinates of a2, b2 to the coordinates of the geophone X1, Y1 respectively, to obtain single-sided shooting common shot point domain data B2 with the coordinates of the shot point and the geophone interchanged.

[0016] In order to further improve the accuracy of the processed data, preferably, the seismic data A in the step 1) is seismic data after denoising, amplitude compensation, static correction and velocity analysis.

[0017] In order to further improve the imaging effect of the seismic data, preferably, the double-sided shooting seismic data C is subjected to OVT joint processing, and the OVT joint processing comprises OVT piece division and pre-stack migration processing on the OVT pieces. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 a schematic diagram of single-side shooting and receiving;

[0019] Figure 2 a flow chart of embodiment 1 of the seismic data processing method for OVT continuous processing of the application;

[0020] Figure 3 a single-shot schematic diagram of double-side shooting seismic data;

[0021] Figure 4 a single-shot schematic diagram of single-side shooting seismic data;

[0022] Figure 5 a schematic diagram of OVT slice distribution of single-side shooting data;

[0023] Figure 6 a schematic diagram of OVT slice distribution of single-side shooting data after conversion of shotpoint coordinates;

[0024] Figure 7 a schematic diagram of OVT slice division of pseudo-double-side shooting seismic data;

[0025] Figure 8 a schematic diagram of OVT continuous processing profile of the missing side of data before processing by the processing method of the application.

[0026] Figure 9 a schematic diagram of OVT continuous processing profile of the missing side of data after processing by the processing method of the application. DETAILED DESCRIPTION

[0027] The technical concept of the seismic data processing method for OVT continuous processing of the application is as follows:

[0028] A seismic data processing method for OVT continuous processing, comprising the following steps:

[0029] 1) obtaining continuous seismic data A, the seismic data A comprising single-side shooting data A1 and double-side shooting data A2;

[0030] 2) assigning the coordinate values of the geophone and shotpoint in A1 to the empty trace headers respectively, and then assigning the coordinate values of the geophone in the trace header to the coordinate of the shotpoint, and assigning the coordinate values of the shotpoint to the coordinate of the geophone, to obtain single-side shooting data B2 with interchanged shotpoint and geophone;

[0031] 3) merging A1 and B2 into pseudo-double-side shooting data B3, and merging B3 and A2 to obtain double-side shooting seismic data C for OVT continuous processing.

[0032] When single-side shooting seismic data is received, the single-shot excitation and reception schematic diagram is as follows: Figure 1As shown, the seismic wave is emitted from the shot point S, reflected by the bottom interface, and reaches the receiver point R. Assuming that the receiver point R is regarded as a new shot point S', and the shot point S is regarded as a new receiver point R', the seismic wave is emitted from the new shot point S', reflected by the bottom interface, and reaches the new receiver point R'. Under the influence of no external conditions and excitation factors, the seismic information generated by the two processes is consistent, because the CMP points (common midpoint points of the shot point and the receiver point) of the two processes are the same point, the reflected seismic information is the seismic information of the same refraction point, and the paths of the two processes are the same, so it can be considered that the seismic information of the two processes is equal.

[0033] On the basis, through coordinate exchange, the azimuth of the single-side shooting data A1 (the azimuth of the seismic data is the angle between the ray from the shot point to the receiver point and the reference line in the observation system, and the receiver line is usually taken as the reference line) is rotated by 180° to obtain the single-side shooting data B2 after the shot-receiver point coordinate exchange. The seismic data B2 and the seismic data A1 only have the difference in the azimuth, and other seismic properties are the same.

[0034] When the OVT slice division is performed, the division is performed according to the four seismic properties of the receiver line, the shot line, the offset distance and the azimuth. If the azimuth of the data is rotated by 180°, the data information in the OVT slice does not change when the OVT slice is divided, but the distribution of the OVT slice is rotated to the diagonal position of the original position. At this time, the seismic data B2 after the shot-receiver point coordinate exchange and the seismic data A1 before the coordinate exchange form a pseudo double-side shooting seismic data in a broad sense, and then a complete seismic data of the OVT slice can be obtained. Therefore, the double-side shooting seismic data C can be obtained by combining A and B2, and at this time, the OVT splicing processing can be performed on the spliced three-dimensional seismic data. Through the above principle explanation, it is ensured that the stratum information reflected by the seismic information obtained by the seismic data processing method is real and reliable.

[0035] The seismic data processing method of the present application applies the reversible principle of wave propagation to compensate for the missing OVT slice data on one side, converts the single-side shooting data into a pseudo double-side shooting seismic data, so that the OVT processing cannot be performed on the single-side shooting seismic data splicing processing, or a large amount of double-side shooting seismic data on one side is discarded for OVT processing, and only the processing in the common offset distance domain can be performed, resulting in poor processing result precision. The data processing method of the present application realizes the OVT splicing processing, effectively improves the seismic data interpretation, reservoir prediction and fracture prediction precision, and reduces the workload of deploying new double-side shooting seismic acquisition work for realizing the OVT splicing processing, greatly reducing the exploration cost.

[0036] In order to make the purpose, technical scheme and technical effects of the present application more clear, the present application is further described in detail below with reference to the drawings and specific embodiments.

[0037] Embodiment of the seismic data processing method for OVT continuous processing of the present application.

[0038] The flow chart of the seismic data processing method for OVT continuous processing of embodiment 1 is shown in Figure 2 , and the processing method is as follows:

[0039] 1) Obtain continuous seismic data A, which has been processed by denoising, amplitude compensation, static correction and velocity analysis, and which includes two pieces of 3D seismic data: single-side shooting data A1 and double-side shooting data A2, Figure 3 is a single-shot schematic diagram of double-side shooting seismic data, Figure 4 is a single-shot schematic diagram of single-side shooting seismic data.

[0040] 2) Assign the coordinates of geophone X1 and Y1 in single-side shooting common shotpoint domain data A1 to the free header words a1 and b1 respectively, and assign the coordinates of shotpoint X2 and Y2 to the free header words a2 and b2 respectively, to obtain single-side shooting common shotpoint domain data B1 with free attributes;

[0041] 3) Assign the coordinates of a1 and b1 to the coordinates of shotpoint X2 and Y2 respectively, and assign the coordinates of a2 and b2 to the coordinates of geophone X1 and Y1 respectively, to obtain single-side shooting common shotpoint domain data B2 with interchanged shotpoint and geophone coordinates;

[0042] 4) Form pseudo-double-side shooting common shotpoint data B3 from A1 and B2, and combine B3 and A2 to obtain double-side shooting seismic data C;

[0043] 5) Perform OVT slice division on seismic data C, and perform pre-stack migration processing on each OVT slice;

[0044] The division schematic diagram of OVT slices before and after processing of single-side shooting data is shown in Figure 5 and Figure 6 , Figure 5 is a schematic diagram of OVT slice distribution of single-side shooting data, Figure 5 The intersection of the two OVT slices with the deepest color on the left side in the middle is the division reference point of the OVT slices, and the OVT slices with different colors and depths are distributed on the right side of the reference point according to the differences in offset and azimuth, while there is no OVT slice distribution on the left side of the reference point; the OVT slice data on the other side of single-side shooting is obtained after interchanging the shotpoint and geophone coordinates, Figure 6 is a schematic diagram of OVT slice distribution after converting the shotpoint and geophone coordinates of the single-side shooting data of the present application, at this time, seismic data A1 and seismic data B2 form a pseudo-double-side shooting seismic data in a broad sense, and a complete OVT slice seismic data can be obtained, as shown in Figure 7 , Figure 7The figure is a schematic diagram of OVT slice division of pseudo double-sided shooting seismic data.

[0045] Therefore, the combination of A and B2 can obtain continuous double-sided shooting seismic data C, and the continuous three-dimensional seismic data can be processed by OVT. Figure 8 and 9 The figure is a schematic diagram of OVT slice division of pseudo double-sided shooting seismic data C, and the continuous three-dimensional seismic data can be processed by OVT. Figure 8 The figure is a schematic diagram of OVT slice division of pseudo double-sided shooting seismic data C, and the continuous three-dimensional seismic data can be processed by OVT. Figure 9 The figure is a schematic diagram of OVT slice division of pseudo double-sided shooting seismic data C, and the continuous three-dimensional seismic data can be processed by OVT. Figure 8 It can be seen that, due to the missing of one-sided OVT slice data of single-sided shooting data, the double-sided shooting data has data in the OVT slice, and therefore, when the offset processing is performed on the two data joint edges, the arc phenomenon occurs; through Figure 8 and Figure 9 It can be seen that, due to the missing of one-sided OVT slice data of single-sided shooting data, the double-sided shooting data has data in the OVT slice, and therefore, when the offset processing is performed on the two data joint edges, the arc phenomenon occurs; through

[0046] Finally, it should be noted that: the above only describes the preferred embodiments of the present application, and is not used to limit the present application, although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced, any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application, should be included in the protection scope of the present application.

Claims

1. A seismic data processing method for OVT binning processing, characterized in that, The method comprises the following steps: 1) obtaining continuous seismic data A, the seismic data A comprising single-sided shooting data A1 and double-sided shooting data A2; 2) assigning the coordinates of the receiver points and the shot points in A1 to the empty trace headers respectively, and then assigning the coordinates of the receiver points in the trace headers to the coordinates of the shot points, and assigning the coordinates of the shot points to the coordinates of the receiver points, to obtain single-sided shooting data B2 with the coordinates of the shot points and the receiver points interchanged; 3) merging A1 and B2 to obtain pseudo-double-sided shooting data B3, and merging B3 and A2 to obtain double-sided shooting seismic data C for OVT continuous processing.

2. The seismic data processing method for OVT panel processing of claim 1, wherein, In the step 2), the coordinates of the receiver points X1 and Y1 in A1 are assigned to the empty trace headers a1 and b1 respectively, the coordinates of the shot points X2 and Y2 are assigned to the empty trace headers a2 and b2 respectively, to obtain single-sided shooting data B1 with empty attributes, and then the coordinates of a1 and b1 are assigned to the coordinates of the shot points X2 and Y2 respectively, and the coordinates of a2 and b2 are assigned to the coordinates of the receiver points X1 and Y1 respectively, to obtain single-sided shooting common-shot-domain data B2 with the coordinates of the shot points and the receiver points interchanged.

3. The seismic data processing method for OVT panel processing of claim 1, wherein, In the step 1), the seismic data A is seismic data after denoising, amplitude compensation, static correction and velocity analysis.

4. The seismic data processing method for OVT panel processing of claim 1, wherein, The double-sided shooting seismic data C is subjected to OVT continuous processing, and the OVT continuous processing comprises OVT slice division and pre-stack migration processing on the OVT slices.

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