A full node seismic data cut processing method

Abstract

This invention provides a method for removing seismic data across all nodes, comprising: acquiring a target layer and velocity; determining the position of the effective wave in the first arrival of the seismic data based on the target layer and velocity; calculating the lower limit of the effective wave removal for the seismic data based on the position of the effective wave, and obtaining the lower limit of the single-shot removal time for the seismic data; acquiring a defined region based on the lower limit of the single-shot removal time, and performing first arrival attenuation within the defined region to obtain the single shot after the attenuated first arrival; calculating the single-shot removal time for the seismic data based on the lower limit of the single-shot removal time and the lower limit of the single-shot removal time; and applying the single-shot removal time of the seismic data to the single shot after the attenuated first arrival to complete the removal of the seismic data across all nodes. Compared with conventional seismic data removal methods, this method retains more down-reflection information, yields more reasonable results, and improves accuracy.

Description

Technical Field

[0001] This invention relates to the field of oil and gas exploration data processing, and in particular to a method for processing seismic data cutoff at all nodes. Background Technology

[0002] Cut-off processing is a necessary step in seismic data processing. Conventional seismic data cut-off processing sets the amplitude values ​​of the first arrival wave and its vicinity to zero, and the cut-off data generally does not contain effective subsurface reflection information. Whole-node seismic data is a novel seismic technology. The whole-node seismic data acquired using this technology differs significantly from conventional wired seismic data. Because it is not affected by factors such as cable capacity and long cable length, detectors can be deployed across the entire exploration area. Whole-node seismic data acquisition covers a larger area, with greater data offsets, and the first arrival wave intersects with effective subsurface reflection information. If traditional cut-off methods are used, the effective information in whole-node seismic data will inevitably be removed, affecting the processing results. Traditional cut-off methods can no longer meet the needs of whole-node seismic data processing.

[0003] Traditional seismic data stripping processes reset the amplitude values ​​of the first arrival and nearby data to zero, typically removing data that does not contain effective subsurface reflection information. However, whole-node seismic data contains rich information over large offsets, with a more pronounced interweaving of first arrivals and effective subsurface reflections. Using traditional stripping methods would remove these interwoven subsurface reflections, failing to meet the "all-time" and "all-space" requirements of whole-node seismic data and hindering improvements in processing quality. Summary of the Invention

[0004] In view of the above problems, the present invention is proposed to provide a method for processing full-node seismic data removal that overcomes or at least partially solves the above problems.

[0005] According to one aspect of the present invention, a method for processing all-node seismic data removal is provided, comprising:

[0006] Obtain the target layer and speed;

[0007] Based on the target layer and the velocity, determine the position of the effective wave in the first arrival wave of the full-node seismic data, and obtain the position of the effective wave.

[0008] The lower limit of the effective wave cutoff is calculated based on the position of the effective wave, and the lower limit of the single-shot cutoff time of the whole node seismic data is obtained.

[0009] Based on the lower limit of the conventional cut-off time of seismic data and the start time of a single shot, a limited area is obtained, and the first arrival wave is attenuated within the limited area to obtain a single shot after the attenuation of the first arrival wave.

[0010] The single-shot cutoff time of the whole-node seismic data is calculated based on the lower limit of the single-shot cutoff time and the lower limit of the conventional single-shot cutoff time for the whole-node seismic data.

[0011] The single-shot cutoff time of the full-node seismic data is applied to the single shot after the attenuated first arrival wave to complete the full-node seismic data cutoff process.

[0012] Optionally, obtaining the position and velocity of the target layer specifically includes:

[0013] Collect reflection time and velocity information of the target layer;

[0014] The target layer is selected as H0 from the superimposed cross-section;

[0015] Pick the in-phase axis velocity V0 corresponding to the target layer from the single shot and / or velocity spectrum of the seismic data.

[0016] Optionally, determining the location of the effective wave in the first arrival of the full-node seismic data based on the target layer and the velocity specifically includes:

[0017] On a single shot of full-node seismic data, the effective wave phase axis reflection time of the target layer

[0018]

[0019] Where x is the seismic trace offset, H0 is the target layer, and V0 is the velocity.

[0020] Optionally, calculating the lower limit of effective wave cutoff for the full-node seismic data to obtain the lower limit of effective wave cutoff specifically includes:

[0021] Lower limit of resection:

[0022] T qx =T qjd -x t

[0023] Among them, T qjd x is the effective phase axis reflection time of the target layer. t The time interval represents the length of the seismic wavelet.

[0024] Optionally, the first-arrival attenuation specifically includes:

[0025] Using the lower limit of conventional resection time T for first arrival of a single shot cg The initial arrival time of a single shot forms a defined region; and the initial arrival wave attenuation is performed within the defined region.

[0026] Optionally, the calculation of the single-shot cutoff time for all-node seismic data based on the effective wave cutoff lower limit and the single-shot cutoff time lower limit specifically includes:

[0027] The lower limit of the resection time T cg With the lower limit of resection T qx Compare the values, obtain the smaller value, and use the smaller value as the final total node single-shot cut-off time T. zj .

[0028] Optionally, the application of the whole-node seismic data cut-off based on the attenuated first arrival wave and the whole-node single-shot cut-off time specifically includes:

[0029] The single-shot cutoff time of the entire node T zj All the above earthquake amplitude values ​​were set to zero, completing the process of removing all node seismic data.

[0030] This invention provides a method for removing seismic data from all nodes, comprising: acquiring a target layer and velocity; determining the position of the effective wave in the first arrival of the all-node seismic data based on the target layer and velocity, thereby obtaining the effective wave position; calculating the lower limit of the removal time for the effective wave in the all-node seismic data, thereby obtaining the lower limit of the single-shot removal time for the all-node seismic data; obtaining a defined region based on the lower limit of the conventional removal time for seismic data and the single-shot start time, and attenuating the first arrival within the defined region to obtain the single shot after the attenuated first arrival; calculating the single-shot removal time for the all-node seismic data based on the lower limit of the single-shot removal time and the lower limit of the conventional single-shot removal time; and applying the single-shot removal time of the all-node seismic data to the single shot after the attenuated first arrival to complete the removal processing of the all-node seismic data. Compared with conventional seismic data removal methods, the method provided by this invention retains more down-reflection information, resulting in more reasonable results and improved accuracy.

[0031] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. 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.

[0033] Figure 1 A flowchart of the whole-node seismic data receiver point domain processing method provided in an embodiment of the present invention;

[0034] Figure 2 A schematic diagram of single-shot cutout of seismic data from all nodes;

[0035] Figure 3 This is a single-shot display before the removal of seismic data for all nodes in the BN work area;

[0036] Figure 4 For the BN work area, the seismic data of all nodes were processed using conventional methods to create single-shot displays after removal;

[0037] Figure 5 This method was used to perform single-shot display after removal of seismic data from all nodes in the BN work area;

[0038] Figure 6 This is a single-shot display before the removal of seismic data for all nodes in the QYJ work area;

[0039] Figure 7 For the seismic data of all nodes in the QYJ work area, single-shot display after removal was performed using conventional methods;

[0040] Figure 8 This method was used to perform single-shot display of all nodes in the QYJ seismic data. Detailed Implementation

[0041] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0042] The terms "comprising" and "having," and any variations thereof, in the specification, embodiments, claims, and drawings of this invention are intended to cover non-exclusive inclusion, such as including a series of steps or units.

[0043] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0044] A method for processing all-node seismic data removal includes:

[0045] Obtain the target layer and velocity; collect reflection time and velocity information of the target layer; or pick the target layer of the work area as H0 from the stacked profile; pick the in-phase axis velocity V0 corresponding to the target layer from the velocity spectrum of the seismic data.

[0046] The location of the effective wave in the first arrival of the full-node seismic data is determined based on the target layer and the velocity, thus obtaining the effective wave location; on a single shot of the full-node seismic data, the reflection time of the effective wave in phase axis at the target layer is...

[0047]

[0048] Where x is the seismic trace offset, H0 is the target layer, and V0 is the velocity.

[0049] Calculate the lower limit of effective wave cutoff for the entire node seismic data to obtain the lower limit of effective wave cutoff; Lower limit of cutoff:

[0050] T qx =T qjd -x t

[0051] Among them, T qjd x is the effective phase axis reflection time of the target layer. t The time interval represents the length of the seismic wavelet.

[0052] Obtain the lower limit of single-shot cutoff time for the full-node seismic data.

[0053] Perform conventional cut-off on a single shot and obtain the lower limit T of the conventional cut-off time for the first arrival of the single shot. cg The lower limit of the conventional cut-off time for the first arrival of a single shot and the start time of the single shot form a defined region, and the first arrival wave is attenuated within the defined region to obtain the single shot after the attenuation of the first arrival wave.

[0054] The single-shot cutoff time for the whole-node seismic data is calculated based on the lower limit of the effective wave cutoff time for the whole-node seismic data and the lower limit of the conventional cutoff time for a single shot; the lower limit of the cutoff time T is then used to calculate the cutoff time for the whole-node seismic data. cg With respect to the lower limit of resection time T qx Compare the values, obtain the smaller value, and use the smaller value as the final total node single-shot cut-off time T. zj .

[0055] The single-shot cutoff time of the full-node seismic data is applied to the single shot after the attenuated first arrival wave to complete the full-node seismic data cutoff processing; the single-shot cutoff time T is... zj All the above earthquake amplitudes were set to zero, completing the removal of all nodal seismic data.

[0056] This study uses 3D seismic data from the BN area of ​​the XX oilfield as the target area and applies the proposed method to process this data to verify its effectiveness. A detailed flowchart is shown below. Figure 1 The actual data was collected using full-node technology, covering a total area of ​​163 square kilometers, with a data volume of 35TB and a sampling interval of 1ms. The data was then processed using the methods described above.

[0057] 1) First, proceed to step 1 to obtain the target layer and velocity. This work area is a mature exploration area with relatively accurate results on underground structure and velocity. Directly load the required target layer and velocity information into the single shot data track.

[0058] 2) Then, based on step 2, and according to the valid information stored in the trace head, use the formula provided in step 2 to determine the position of the valid wave in the first arrival wave of the whole node seismic data.

[0059] 3) Calculate the lower limit of the removal of effective waves in the whole node seismic data according to step 3. In order to protect the effective waves, the effective waves interleaved in the first arrival are generally not removed. The time length of the seismic wavelet is taken as 30ms to determine the lower limit of the removal of effective waves in the whole node seismic data.

[0060] 4) Based on step 4, the lower limit of the conventional resection time for a single shot is obtained using the traditional two-point picking method.

[0061] 5) Based on step 5, combine the single shot start time and the results in step 4 to form a closed region, and perform first arrival wave attenuation within this region.

[0062] 6) Based on step 6, calculate the final cut-off amount of a single shot in the full-node seismic data.

[0063] 7) Based on step 7, apply the calculated final cutoff amount to the full-node seismic data cutoff process. Figure 3 No single blasting unit in this work area underwent removal treatment. Figure 4 It is a single shot after resection using conventional resection methods. Figure 5 The images are single shots after applying the whole-node seismic data removal processing method proposed in this paper. The comparison of single shots shows that the method proposed in this paper can protect the effective signals converging in the first arrival to the maximum extent, taking into account the characteristics of whole-node seismic data. It eliminates the influence of the first arrival and protects the effective information, which shows that the method is indeed feasible and has outstanding effect.

[0064] This study uses 3D seismic data from the QYJ area of ​​the XX oilfield as the target area and applies the proposed method to process this data to verify its effectiveness. A detailed flowchart is shown below. Figure 1 The actual data was collected using full-node technology, covering a work area of ​​600 square kilometers, with a data volume of 200TB and a sampling interval of 1ms. The data was then processed using the methods described above.

[0065] 1) First, proceed to step 1 to obtain the target layer and velocity. This work area is a new exploration area, and there are no existing results on the underground structure and velocity. Pick the stratigraphic information of the target layer from the initial superposition profile of this area, and pick the velocity of the corresponding target layer from the velocity spectrum.

[0066] 2) Then, based on step 2, and according to the valid information stored in the trace head, use the formula provided in step 2 to determine the position of the valid wave in the first arrival wave of the whole node seismic data.

[0067] 3) Calculate the lower limit of the removal of effective waves in the whole node seismic data according to step 3. In order to protect the effective waves, the effective waves interleaved in the first arrival are generally not removed. The time length of the seismic wavelet is taken as 50ms to determine the lower limit of the removal of effective waves in the whole node seismic data.

[0068] 4) Based on step 4, the lower limit of single-shot cut time for all-node seismic data is obtained using the traditional cut method.

[0069] 5) Based on step 5, combine the single shot start time and the results in step 4 to form a closed region, and perform first arrival wave attenuation within this region.

[0070] 6) Based on step 6, calculate the final cut-off amount of a single shot in the full-node seismic data.

[0071] 7) Based on step 7, apply the calculated final cutoff amount to the full-node seismic data cutoff process. Figure 6 No single blasting unit in this work area underwent removal treatment. Figure 7 It is a single shot after the excision is performed using conventional excision methods.

[0072] Figure 8 The images are single shots after applying the whole-node seismic data removal processing method proposed in this paper. The comparison of single shots shows that the method proposed in this invention can protect the effective signals converging in the first arrival to the maximum extent, taking into account the characteristics of whole-node seismic data. It eliminates the influence of the first arrival and protects the effective information, which shows that the method is indeed feasible and has outstanding effect.

[0073] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above 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 processing all-node seismic data, characterized in that, The processing method includes: Obtain the target layer and speed; Based on the target layer and the velocity, determine the position of the effective wave in the first arrival wave of the full-node seismic data, and obtain the position of the effective wave. The lower limit of the effective wave cutoff is calculated based on the position of the effective wave, and the lower limit of the single-shot cutoff time of the whole node seismic data is obtained. Based on the lower limit of the conventional cut-off time of seismic data and the start time of a single shot, a limited area is obtained, and the first arrival wave is attenuated within the limited area to obtain a single shot after the attenuation of the first arrival wave. The single-shot cutoff time of the whole-node seismic data is calculated based on the lower limit of the single-shot cutoff time and the lower limit of the conventional single-shot cutoff time for the whole-node seismic data. The single-shot cutoff time of the full-node seismic data is applied to the single shot after the attenuated first arrival wave to complete the full-node seismic data cutoff process.

2. The method for processing all-node seismic data as described in claim 1, characterized in that, The acquisition of the target layer and speed specifically includes: Collect reflection time and velocity information of the target layer; or pick up the target layer from the stacking profile. , Extract the in-phase axis velocity corresponding to the target layer from single shots or velocity spectra of seismic data. .

3. The method for processing all-node seismic data removal according to claim 1, characterized in that, The step of determining the position of the effective wave in the first arrival wave of the full-node seismic data based on the target layer and the velocity, specifically includes: On a single shot of full-node seismic data, the effective wave phase axis reflection time of the target layer in, This is the seismic trace offset. To pick out the target layer from the stacked profile, To pick up the in-phase axis velocity corresponding to the target layer.

4. The method for processing all-node seismic data as described in claim 1, characterized in that, The calculation of the lower limit for the cutoff of the full-node seismic data, specifically to obtain the lower limit for the single-shot cutoff time of the full-node seismic data, includes: Lower limit of resection: in, for Effective wave in-phase axis reflection time at the target layer The time interval represents the length of the seismic wavelet.

5. The method for processing all-node seismic data as described in claim 1, characterized in that, The attenuation of the first arrival wave in the defined region specifically includes: Perform conventional cuts on a single shot to obtain the lower limit of the conventional cut time for the initial arrival of the single shot. The first arrival wave is attenuated within a defined region, which is then combined with the start time of a single shot to obtain the single shot after the first arrival wave has been attenuated.

6. The method for processing all-node seismic data as described in claim 1, characterized in that, The calculation of the single-shot cut-off time of the whole-node seismic data based on the cut-off lower limit of the whole-node seismic data and the conventional cut-off time lower limit of the first arrival of the single shot specifically includes: The lower limit of the conventional resection time for the first arrival of the single shot Lower limit of cutoff for the full-node seismic data Compare the values, obtain the smaller value, and use the smaller value as the final single-shot cutoff time for all nodes. .

7. The method for processing all-node seismic data as described in claim 1, characterized in that, Applying the full-node seismic data cut-off time to a single shot after the attenuated first arrival wave to complete the full-node seismic data cut-off process specifically includes: The single-shot cutoff time after the attenuated first arrival wave. All the above earthquake amplitudes were set to zero, completing the removal of all nodal seismic data.

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