A method for fast checking of a node seismic data acquisition system

Abstract

The present application relates to the technical field of seismic data acquisition, in particular to a kind of node seismic data observation system fast checking method.The method comprises the following steps: the seismic data of node acquisition is sorted into common receiver gather;Theoretical first arrival time is calculated;Automatic picking first arrival in the time window opened near theoretical first arrival;The time difference of the theoretical first arrival and the picked first arrival of each trace is calculated;The first arrival time difference of each common receiver gather is counted;The common receiver gather with abnormal first arrival time difference is checked.The method of the present application can quickly and accurately judge whether the observation system is wrong by counting the time difference between theoretical first arrival and picked first arrival in common receiver gather.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of seismic data acquisition, in particular to a node seismic data observation system rapid inspection method. BACKGROUND

[0002] In oil seismic exploration, errors in the seismic data observation system can cause confusion in the receiving relationship and can seriously affect single-shot quality and subsequent processing work. Node high-efficiency acquisition requires the recovery of a large amount of node data every day, and these data need to be processed for a long time through multiple steps before they can be synthesized into normal shot gather data. Conventional shot gather observation system quality control methods seriously restrict the efficiency of node high-efficiency acquisition.

[0003] Chinese patent application CN111352152A discloses a seismic data observation system rapid quality control method, which includes obtaining seismic data of field instruments, relationship files, source files and receiving files; extracting parameter information in the seismic data, the parameter information including shot point coordinates of a single shot, and channel numbers, line point numbers and geophone point coordinates of a single shot receiving line; generating a migration result according to the shot point coordinates of the single shot, the geophone point coordinates of the single shot receiving line, the source file and the receiving file; and generating a loss result according to the channel numbers, line point numbers of the single shot receiving line and the relationship file. This invention realizes rapid inspection of the seismic data observation system by rapidly detecting seismic data and various files, to ensure that the seismic data meets relevant technical requirements and industry standards, improve the efficiency and accuracy of massive data observation system inspection, eliminate quality problems associated with the observation system, and reduce the cost of high-efficiency acquisition exploration.

[0004] At present, a rapid inspection method is still needed for node seismic data. SUMMARY

[0005] The main purpose of the present application is to provide a node seismic data observation system rapid inspection method. The present application method can more quickly and accurately determine whether the observation system is incorrect by calculating the time difference between the theoretical first arrival and the picked first arrival in the common geophone gather.

[0006] To achieve the above purpose, the present application adopts the following technical solutions:

[0007] The present application provides a node seismic data observation system rapid inspection method, which includes the following steps: sorting the node-acquired seismic data into common geophone gathers; calculating the theoretical first arrival time; automatically picking the first arrival near the theoretical first arrival time; calculating the time difference between the theoretical first arrival and the picked first arrival of each gather; statistically analyzing the first arrival time difference of each common geophone gather; and inspecting the common geophone gather with abnormal first arrival time difference.

[0008] Further, the original data collected by the node is cut according to the shooting time of each shot to remove invalid data, then is combined into normal trace data, and then is sorted according to the geophone stake number to form a common geophone gather, and the common geophone gather is sorted according to the shot point stake number.

[0009] Further, if the surface structure is simple, the method for calculating the theoretical first arrival time is:

[0010] According to the offset, the theoretical first arrival time is calculated by the following formula:

[0011] t=t0+d / v

[0012] In the formula, t is the theoretical first arrival time, t0 is the zero offset wellhead time, d is the offset, and v is the refracted wave velocity.

[0013] The offset is calculated by the coordinates of the shot point and the coordinates of the geophone, and the calculation formula of the offset is:

[0014]

[0015] In the formula, d is the offset, (x s ,y s ) is the coordinates of the shot point, and (x d ,y d ) is the coordinates of the geophone.

[0016] Further, the offset and the first arrival time table generated by manually picking up the first arrival can be used to fit and interpolate to calculate the theoretical first arrival time.

[0017] Further, when the near-surface structure is complex, the theoretical first arrival time is calculated by using the near-surface velocity model forward.

[0018] Further, a time window is opened around the theoretical first arrival time to automatically pick up the first arrival, and the time window has a middle point of the theoretical first arrival time and extends 200-300 ms upward and downward.

[0019] Further, the average value of the absolute value of the first arrival time difference of each common geophone gather is calculated, and a gather-average value crossplot is drawn.

[0020] Further, the average value of the absolute value of the time difference is calculated by the following formula:

[0021]

[0022] In the formula, |Δt i | is the absolute value of the first arrival time difference of the i-th trace in the common geophone gather, and n is the number of seismic traces contained in the common geophone gather.

[0023] Furthermore, based on the intersection plot and the first arrival picking of the gathers, appropriate thresholds for the average value and standard deviation are set, and common receiver gathers exceeding the thresholds are checked.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] The method of this invention can quickly and accurately detect erroneous common receiver gathers in the observation system, providing an effective technical means for achieving efficient and accurate monitoring of node acquisition quality. The method of this invention can meet the needs of on-site quality control of field node acquisition and has broad application prospects in node acquisition projects. Attached Figure Description

[0026] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0027] Figure 1 This is a flowchart of a rapid inspection method for a nodal seismic data observation system according to a specific embodiment of the present invention;

[0028] Figure 2 The figure shows the accurate common-detector point gather and its calculated theoretical first arrival for the observation system described in a specific embodiment of the present invention. The black line in the figure represents the calculated theoretical first arrival.

[0029] Figure 3 for Figure 2 The path collection and its initial arrival in the diagram are shown in white lines.

[0030] Figure 4 The figure shows the erroneous common detector gather of the observation system according to a specific embodiment of the present invention and its calculated theoretical first arrival. The black line in the figure represents the calculated theoretical first arrival.

[0031] Figure 5 for Figure 4 The map shows the initial arrival of the path and its acquisition. The white line in the map represents the initial arrival of the acquisition.

[0032] Figure 6 This is a cross-plot of the mean absolute value of the gather-first arrival time difference according to a specific embodiment of the present invention. Detailed Implementation

[0033] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0034] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0035] In order to enable a person skilled in the art to more clearly understand the technical solutions of the present application, the technical solutions of the present application will be described in detail below in combination with specific embodiments.

[0036] Embodiment 1

[0037] As shown in the figure, the node seismic data observation system rapid inspection method comprises the following steps: Figure 1

[0038] Step 101. Sort the node-acquired seismic data into common receiver gathers:

[0039] The original data acquired by the node is cut according to the shooting time of each shot to remove invalid data, and then is combined into normal trace data. The trace header contains the shot-receiver pile number, coordinates and elevation information. Then, the common receiver gathers are sorted according to the receiver pile number, and the common receiver gathers are sorted according to the shot pile number.

[0040] Step 102. Calculate the theoretical first arrival time according to the offset:

[0041] The offset is calculated by the shot-receiver coordinates. The calculation formula of the offset is:

[0042]

[0043] In the formula, d is the offset, (x s ,y s ) is the shot coordinate, and (x d ,y d ) is the receiver coordinate.

[0044] Then, the theoretical first arrival time of each trace is calculated. In this embodiment, the near-surface structure of the work area is simple, and the following formula is used to calculate the theoretical first arrival time:

[0045] t = t0 + d / v

[0046] In the formula, t is the theoretical first arrival time, t0 is the wellhead time of a large number of statistics with zero offset, d is the offset, and v is the refracted wave velocity.

[0047] ​Step 103. Automatically picking up the first arrival in the time window opened around the theoretical first arrival time: opening a time window around the theoretical first arrival time, the time window is opened with the theoretical first arrival time as the middle point, extending 200 ms upward and 300 ms downward, automatically picking up the first arrival in the time window.

[0048] Step 104. Calculating the time difference between the theoretical first arrival and the picked first arrival of each trace: Δt = t a -t b

[0049] In the formula, Δt is the time difference, t a is the theoretical first arrival time, and t b is the picked first arrival time.

[0050] Step 105. Statistics of the first arrival time difference of each common receiver gather;

[0051] Statistics of the average value of the absolute value of the first arrival time difference in each common receiver gather,

[0052] The average value of the absolute value of the time difference:

[0053] In the formula, Δti is the first arrival time difference of the ith trace in the common receiver gather, |Δti| is the absolute value of Δti, and n is the number of seismic traces contained in the common receiver gather.

[0054] Drawing a gather-first arrival time difference absolute value average crossplot.

[0055] Step 106. Checking the common receiver gather with abnormal first arrival time difference: selecting a suitable threshold value according to the crossplot and the gather first arrival picking situation. Generally, 5% of the maximum value of the absolute value of the first arrival time difference in the work area is removed, and then the average value of the absolute value of the first arrival time difference is calculated. The threshold value can be selected as 1.5 to 2 times of the average value, and the specific value should be determined according to the deviation of the theoretical first arrival and the picked first arrival. In this embodiment, the threshold value of the average value of the absolute value of the first arrival time difference can be selected as 100. Checking the common receiver gather greater than the threshold value, checking whether the shotpoint coordinates, elevation and other information in the observation system are incorrect.

[0056] The common receiver gather with correct observation system and the calculated theoretical first arrival thereof are shown in Figure 2 , the gather and the picked first arrival thereof are shown in Figure 3 . The common receiver gather with incorrect observation system and the calculated theoretical first arrival thereof are shown in Figure 4 , the gather and the picked first arrival thereof are shown in Figure 5 , and the gather-first arrival time difference absolute value average crossplot is shown in Figure 6 .

[0057] Embodiment 2

[0058] The node seismic data observation system rapid checking method comprises the following steps:

[0059] Step 1. The node collected seismic data is sorted into common receiver gathers:

[0060] The original data collected by the node is subjected to data cutting according to the shooting time of each shot to remove invalid data, and then is combined into normal trace data, the trace header of which contains the shot-receiver point pile number, coordinates and elevation information, and then is sorted into common receiver gathers according to the receiver point pile number, and the common receiver gathers are sorted according to the shot point pile number.

[0061] Step 2. The first arrival time is calculated by fitting and interpolating the first arrival produced by artificial picking with the shot-receiver distance and first arrival time table. The work area of this embodiment has a simple near-surface structure.

[0062] Step 3. Automatically picking the first arrival in the time window opened near the theoretical first arrival time: opening the time window with the theoretical first arrival time as the middle point, extending 300 ms upward and 200 ms downward, and automatically picking the first arrival in the time window range.

[0063] Step 4. Calculating the time difference between the theoretical first arrival and the picked first arrival of each trace: Δt = t a -t b

[0064] In the formula, Δt is the time difference, t a is the theoretical first arrival time, and t b is the picked first arrival time.

[0065] Step 5. Statistics of the first arrival time difference of each common receiver gather:

[0066] Statistics of the average value of the absolute value of the first arrival time difference and the standard deviation of the first arrival time difference in each common receiver gather:

[0067] Average value of the absolute value of the time difference:

[0068] In the formula, Δti is the first arrival time difference of the i-th trace in the common receiver gather, |Δti| is the absolute value of Δti, and n is the number of seismic traces contained in the common receiver gather.

[0069] Drawing a gather-first arrival time difference absolute value crossplot.

[0070] Step 6. Checking the common receiver gather with abnormal first arrival time difference: selecting a suitable threshold value according to the crossplot and the gather first arrival picking condition. Checking the common receiver gather greater than the threshold value to check whether the shot-receiver point coordinates, elevation and other information in the observation system are incorrect.

[0071] Embodiment 3

[0072] The node seismic data observation system rapid checking method comprises the following steps:

[0073] Step 1. The node collected seismic data is sorted into common receiver gathers:

[0074] The original data collected by the node is subjected to data cutting according to the shooting time of each shot to remove invalid data, and then is combined into normal trace data, the trace header of which contains the shot-receiver pile number, coordinates and elevation information, and then is sorted into common receiver gathers according to the receiver pile number, and the common receiver gathers are sorted according to the shot pile number.

[0075] Step 2. The theoretical first arrival time is calculated by using a near-surface velocity model. The near-surface structure of the work area in this embodiment is complex.

[0076] Step 3. The first arrival is automatically picked up in a time window opened near the theoretical first arrival time: the time window is opened with the theoretical first arrival time as the middle point, extended upward by 300 ms and downward by 200 ms, and the first arrival is automatically picked up in the time window range.

[0077] Step 4. The time difference between the theoretical first arrival and the picked first arrival of each trace is calculated: Δt = t a -t b

[0078] In the formula, Δt is the time difference, t a is the theoretical first arrival time, and t b is the picked first arrival time.

[0079] Step 5. The first arrival time difference of each common receiver gather is counted.

[0080] The average value of the absolute value of the first arrival time difference and the standard deviation of the first arrival time difference in each common receiver gather are counted:

[0081] The average value of the absolute value of the time difference:

[0082] In the formula, Δti is the first arrival time difference of the i-th trace in the common receiver gather, |Δti| is the absolute value of Δti, and n is the number of seismic traces contained in the common receiver gather.

[0083] A gather-first arrival time difference absolute value crossplot is drawn.

[0084] Step 6. The common receiver gather with abnormal first arrival time difference is checked: a suitable threshold value is selected according to the crossplot and the gather first arrival picking condition. The common receiver gather greater than the threshold value is checked to check whether the shot-receiver coordinates, elevation and other information in the observation system are incorrect.

[0085] In summary, the node seismic data observation system rapid checking method of the present application can quickly detect the incorrect node data of the observation system, can meet the needs of field node acquisition record monitoring, and has very important practical significance for guiding acquisition construction and improving data quality.

[0086] The above embodiment is the preferred embodiment of the present application, but the embodiment of the present application is not limited to the above embodiment, and any change, modification, substitution, combination, simplification made without departing from the spirit and principle of the present application should be an equivalent replacement mode, and all are included in the protection scope of the present application.

Claims

1. A method for fast checking of a node seismic data acquisition system, characterized in that, It includes the following steps: The node collected seismic data is sorted into common receiver gathers; The theoretical first break time is calculated; The first break is automatically picked up by opening a time window near the theoretical first break time; the time difference between the theoretical first break and the picked first break of each trace is calculated; The first break time difference of each common receiver gather is counted; the common receiver gather with abnormal first break time difference is checked; The original data collected by the node is cut according to the shooting time of each shot to remove invalid data, then merged into normal trace data, and sorted into common receiver gathers according to the receiver stake number, and sorted by shot stake number within the common receiver gather; The first break is automatically picked up by opening a time window near the theoretical first break time; the time window is extended 200-300 ms up and down from the theoretical first break time as the middle point; The average value of the absolute value of the first break time difference and the standard deviation of the first break time difference of each common receiver gather are counted, and the gather-average value crossplot and the gather-standard deviation crossplot are drawn; The average value of the absolute value of the time difference is calculated as follows: ； In the formula | Δt i |For the first common detection point gather i The absolute value of the first arrival time difference of the trace, where n is the number of seismic traces contained in the common receiver gather; According to the crossplot and the first break picking condition of the gather, the threshold values of the average value and the standard deviation are set, and the common receiver gather exceeding the threshold value is checked.

2. The inspection method of claim 1, wherein When the surface structure is simple, the method for calculating the theoretical first break time is as follows: The theoretical first break time is calculated according to the offset distance by the following formula: t=t0+d / v; In the formula, t is the theoretical first break time, t0 is the wellhead time of zero offset distance, d is the offset distance, and v is the refracted wave velocity; The offset distance is calculated through the shotpoint coordinates, and the calculation formula of the offset distance is as follows: ； In the formula, d is the shot-receiver distance, ( x s , y s ) are the coordinates of the shot point, ( x d , y d ( ) represents the coordinates of the detector point.

3. The inspection method of claim 2, wherein, The theoretical first break time can also be calculated by fitting and interpolating the offset distance and the first break time table generated by manually picking up the first break.

4. The inspection method of claim 1, wherein When the near-surface structure is complex, the theoretical first break time is calculated by forward modeling using the near-surface velocity model.

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