Seismic data acquisition obstacle avoidance design method and system based on spatial information

Abstract

The invention relates to a seismic data acquisition obstacle avoidance design method based on spatial information. The method comprises the following steps: importing known underground obstacle spatial information into an obstacle avoidance area calculation system; simplifying an underground obstacle into an ideal cylinder model; selecting obstacle avoidance by a calculation system in an obstacle avoidance area to calculate parameters of each small layer, and calculating to obtain a reflection angle theta i of each small layer from a common center point of a target layer part to a ground receiving point; according to the common midpoint depth hOO of the target layer part and the obstacle bottom interface depth hBC, the depth hBC is calculated; giving an initial reflection angle tan-1 (dSO ' / hOO') of a seismic reflected wave with a common midpoint depth from the ground to a target layer part, performing angle range scanning according to a fixed angle step length, and stopping scanning until the offset distance of the reflected wave reaching the bottom interface of the obstacle is greater than or equal to half of the diameter of the bottom interface of the obstacle, determining a reflection angle theta1 of the seismic reflection wave reaching the ground receiving point position; and according to the reflection angle theta1, calculating the final ground reaching range value of the seismic reflected wave. According to the method, the signal-to-noise ratio of acquired data and the precision of a processing result are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas exploration, and in particular relates to a seismic data acquisition obstacle avoidance design method and system based on spatial information. Background Art

[0002] In the process of seismic data acquisition, both surface and underground obstacles are unfavorable factors. First, obstacles will affect the layout of the seismic observation system and increase the difficulty of construction; second, the existence of obstacles will reduce the quality of the collected seismic data, thereby affecting the subsequent seismic data processing and interpretation, resulting in deviations or misleading in the study of stratigraphic targets; finally, obstacles may bring danger to the construction of seismic data acquisition.

[0003] Therefore, it is necessary to investigate obstacles before the acquisition and take appropriate obstacle avoidance methods according to the survey results to design the seismic data acquisition observation system. With the improvement of onshore oil and gas exploration and development, the cost of seismic data acquisition is also rising. How to balance the acquisition cost and acquisition quality is an important factor to be considered in seismic data acquisition.

[0004] In the actual seismic data collection process, the observation system needs to be changed due to the existence of surface and underground obstacles. In the current related technologies, 3S technology (i.e. GPS positioning technology, satellite remote sensing technology (RS) and geographic information system (GIS) technology) is combined to automatically identify surface obstacles through satellite, three-dimensional camera and other technologies to achieve obstacle avoidance design of indoor seismic data collection observation system, but the avoidance of underground obstacles is not involved.

[0005] At present, the obstacle avoidance design of seismic data acquisition and observation systems at home and abroad mainly studies obstacles on the ground or at sea, and there are mainly the following problems:

[0006] 1) Underground obstacles such as underground pipelines and oil storage tanks are not considered. The impact of such near-surface underground obstacles on seismic data acquisition is different from that of near-surface weathering layers, and special methods are needed to deal with them. Existing technologies mainly automatically identify surface obstacles and then perform obstacle avoidance design, but rarely consider the existence of underground obstacles in the work area. For example, satellite remote sensing and 3D camera robot technology can well identify surface obstacles, but there is no good solution for underground obstacles.

[0007] 2) Pay attention to the impact of surface obstacles on the layout of shot checkpoints, pay less attention to the shielding effect of underground obstacles on seismic waves, and then ignore the impact of underground obstacles on data quality during seismic data acquisition. From the perspective of seismic wave kinematics, seismic waves excited on the surface propagate underground and encounter underground reflection interfaces, such as the top or bottom interface of the target layer. They will be reflected and propagate upward, and finally the signal of the reflected wave is received at the receiving point on the surface to complete the seismic data acquisition. When the seismic wave propagation route encounters underground obstacles, the seismic wave energy is completely or mostly reflected or absorbed by the obstacles, forming a shielding effect, and cannot continue to propagate downward to the target layer, affecting the number of coverage of the common middle point (CMP) of some target layers, thereby affecting the signal strength of the CMP point, weakening the signal continuity, and reducing the signal-to-noise ratio of the acquisition signal. Similarly, when the seismic wave encounters obstacles on the upward propagation route, due to the shielding effect, some detectors located directly above the underground obstacles will also be unable to receive seismic signals. Summary of the invention

[0008] In response to the above problems, the present invention proposes a seismic data acquisition obstacle avoidance design method and system based on spatial information. By converting the spatial information of underground obstacles into an underground ideal cylindrical model and importing it into the algorithm, the target layer CMP point is calculated through the principle of seismic wave kinematics. Under the conditions of a general observation system, the seismic reflection wave and the low-quality seismic reflection wave signal area affected by obstacles cannot be received (which can be called the seismic data acquisition obstacle avoidance area) so that in the presence of underground obstacles, seismic exploration and acquisition designers can evaluate and optimize the observation system design to obtain high-quality data that meets the needs of seismic data acquisition.

[0009] The technical solution adopted by the present invention is as follows: a seismic data acquisition obstacle avoidance design method based on spatial information, the method comprising the following steps:

[0010] Importing the spatial information of known underground obstacles into the obstacle avoidance zone calculation system;

[0011] Simplify the spatial information of underground obstacles into an ideal cylindrical model;

[0012] In the obstacle avoidance area calculation system, select the parameters of each small layer for obstacle avoidance calculation, and calculate the reflection angle θ of each small layer from the common center point of the target layer to the ground receiving point. i ;

[0013] According to the depth of the target layer part common center point h OO’ , obstacle bottom interface depth h BC , given the initial reflection angle tan of the seismic reflection wave from the ground to the target layer at the common center point depth -1 (d SO’ / h OO’), scan the angle range at a fixed angle step size until the offset distance when the reflected wave reaches the bottom interface of the obstacle is greater than or equal to half the diameter of the bottom interface of the obstacle, then stop scanning and determine the reflection angle θ1 when the seismic reflected wave reaches the position of the ground receiving point;

[0014] According to the reflection angle θ1, the final ground range of the seismic reflection wave is calculated, which is the diameter d of the obstacle avoidance zone. SR .

[0015] Furthermore, the obstacle avoidance calculation parameters of each sub-layer include: the speed V of each sub-layer underground i , the density of each underground layer ρ i and the travel time t of the seismic wave in each layer i ; Wherein, i represents the sequence number of the stratum, i=1,2,3,...,n, and n is the total number of strata.

[0016] Furthermore, the obstacle avoidance calculation system selects the parameters of each small layer for obstacle avoidance calculation, and calculates the reflection angle θ of each small layer from the common center point of the target layer to the ground receiving point. i Specifically:

[0017] The one-way propagation path S of seismic waves in each layer i For: S i =V i ×t i ;

[0018] The thickness of each underground layer h i For: h i =S i ×cosθ i =V i ×t i ×cosθ i ;

[0019] The offset distance d of the seismic wave from the incident point on the top interface of the small layer after passing through the small layer i for:

[0020]

[0021] in, From Snell's law we get:

[0022] but

[0023] Furthermore, the reflection angle θ1 of the seismic reflection wave arriving at the ground receiving point R is determined as:

[0024] Assuming that the bottom interface of the obstacle is located at the mth layer, when the reflected wave from the common center point of the target layer reaches the bottom interface of the mth layer obstacle, the distance of the reflection point deviation is When the reflected wave reaches the boundary point C at the bottom interface of the obstacle, the horizontal displacement of the reflected wave in layer m is At this time, the displacement of the reflected wave path on the vertical normal line in layer m is When the reflection angle tangent function tanθm of layer m satisfies When , the reflection angle scan is terminated, and the seismic reflection wave of the target layer just passes through the obstacle boundary point C; where dBC represents the diameter of the obstacle bottom interface; and hBC represents the depth of the obstacle bottom interface.

[0025] Furthermore, the reflection angle θ1 of the seismic reflection wave at the ground receiving point is calculated as follows:

[0026]

[0027] Furthermore, the obstacle avoidance zone diameter d SR The calculation formula is:

[0028]

[0029] Furthermore, simplifying the spatial information of underground obstacles into an ideal cylindrical model includes: simplifying the obstacle into an ideal cylindrical model according to the lateral extension range and vertical height of the underground obstacle, and simplifying the situation of multiple adjacent obstacles into a single cylindrical obstacle surrounding multiple obstacles.

[0030] Furthermore, performing the angle range scanning at a fixed angle step size specifically includes: performing the reflected wave angle range scanning at an increment or decrement of 1° each time from the initial angle.

[0031] In addition, the present invention also provides a seismic data acquisition obstacle avoidance design system based on spatial information, the system includes an import module, a simplification module, a first calculation module, a scanning module and a second calculation module: the import module is used to import the known underground obstacle spatial information into the obstacle avoidance area calculation system; the simplification module is used to simplify the underground obstacle spatial information into an ideal cylindrical model; the first calculation module is used to select the obstacle avoidance calculation parameters of each small layer in the obstacle avoidance area calculation system, and calculate the reflection angle θ of each small layer from the common center point of the target layer to the ground receiving point i The scanning module is used to calculate the depth h of the target layer according to the central point of the target layer. OO’ , obstacle bottom interface depth h BC , given the initial reflection angle tan of the seismic reflection wave from the ground to the target layer at the common center point depth -1 (d SO’ / h OO’), scanning the angle range at a fixed angle step size until the offset distance when the reflected wave reaches the bottom interface of the obstacle is greater than or equal to half the diameter of the bottom interface of the obstacle, then stopping scanning, and determining the reflection angle θ1 of the seismic reflection wave at the position of the ground receiving point; the second calculation module is used to calculate the final ground range value of the seismic reflection wave according to the reflection angle θ1, which is the obstacle avoidance area diameter d SR .

[0032] Furthermore, the scanning module is used to determine the depth h of the central point of the target layer. OO’ , obstacle bottom interface depth h BC , given the initial reflection angle tan of the seismic reflection wave from the ground to the target layer at the common center point depth -1 (d SO’ / h OO’ ), scan the angle range at a fixed angle step until the offset distance when the reflected wave reaches the bottom interface of the obstacle is greater than or equal to half the diameter of the bottom interface of the obstacle, stop scanning, and determine the reflection angle θ1 when the seismic reflection wave reaches the ground receiving point:

[0033] The scanning module is used to determine the depth h of the central point of the target layer. OO’ , obstacle bottom interface depth h BC , given the initial reflection angle tan of the seismic reflection wave from the ground to the target layer at the common center point depth -1 (d SO’ / h OO’ ), scan the reflected wave angle range from the initial angle by 1° increment or decrement each time, until the offset distance when the reflected wave reaches the bottom interface of the obstacle is greater than or equal to half the diameter of the bottom interface of the obstacle, stop scanning, and determine the reflection angle θ1 when the seismic reflection wave arrives at the ground receiving point.

[0034] The present invention has the following technical effects: the spatial coordinates of obstacles are obtained based on spatial information, and the observation system design that meets the actual situation of the work area is completed indoors, thereby reducing the cost of ground exploration and improving the quality of seismic data acquisition; by obtaining the spatial information of underground obstacles, the acquisition design is optimized from the perspective of ray tracing; the calculated design parameters can be downloaded for use by other seismic data acquisition design systems, thereby improving the quality of the acquired data, the signal-to-noise ratio, and the accuracy of the processing results.

[0035] Other features and advantages of the present invention will be described in the following description, and part of them will become obvious from the description, or be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 A schematic cross-sectional diagram of seismic data acquisition under underground obstacle conditions in an embodiment of the present invention is shown;

[0038] Figure 2 A schematic diagram of a field acquisition and observation system for seismic data in an embodiment of the present invention is shown;

[0039] Figure 3 A flow chart of a seismic data acquisition obstacle avoidance design method based on spatial information in an embodiment of the present invention is shown;

[0040] Figure 4 A seismic data acquisition and observation system that does not adopt the obstacle avoidance design of the method described in the present invention;

[0041] Figure 5 For the obstacle avoidance design not performed by the method of the present invention, after the seismic data are collected, the seismic profile is obtained by processing the seismic data;

[0042] Figure 6 A seismic data acquisition and observation system for obstacle avoidance design using the method of the present invention;

[0043] Figure 7 In order to use the method of the present invention to perform obstacle avoidance design, after seismic data acquisition, a seismic profile is obtained through seismic data processing;

[0044] Figure 8 A schematic diagram of a seismic data acquisition obstacle avoidance design system based on spatial information in an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] The abbreviations and key terms used in the present invention are defined as follows:

[0047] Spatial information: information that reflects the spatial distribution characteristics of geographic entities; spatial distribution characteristics include the location and shape of entities, the spatial relationship between entities, and the regional spatial structure.

[0048] Obstacles: refers to the collective name for all objects that affect the shot points, detection points, survey line layout, and seismic data acquisition quality during the seismic data acquisition process. Usually includes ground objects or areas such as villages, scenic spots, protected areas, waters, buildings, etc., and also includes underground obstacles such as underground pipelines and underground oil storage depots.

[0049] Observation system: the relative position relationship between the excitation point and the receiving point of the seismic wave. In order to find out the underground structural form, it is necessary to continuously track the seismic waves of the underground reflection interface, that is, to conduct continuous observation. Therefore, it is necessary to excite at multiple excitation points along the survey line and receive at multiple receiving points. Moreover, the relative positions of the excitation points and the receiving points must maintain a certain relationship to ensure that the stratum interface can be continuously tracked.

[0050] CMP (Common Middle Point): Common center point refers to the center point of the common gun inspection line.

[0051] Coverage times: the number of channels contributing to a superposition channel, that is, the number of center points of each CMP bin. Total coverage times = coverage times in the longitudinal direction × coverage coefficient in the transverse direction;

[0052] Among them, the number of times covered in the longitudinal direction = the number of receiving channels × the detection point distance (channel spacing) / (2 × gun spacing);

[0053] The number of times the horizontal line is covered = half of the number of receiving lines of the arrangement piece.

[0054] Obstacle avoidance area: refers to the area that needs to be avoided when laying out shot points and detection points in order to obtain high-quality seismic data acquisition results.

[0055] The currently commonly used 3D seismic exploration on-site simulation acquisition design method does not consider the influence of underground obstacles in the acquisition area. The present invention imports the known underground obstacle spatial information into the obstacle avoidance zone calculation system, simplifies the obstacle into an ideal cylinder according to the lateral extension range and vertical height of the underground obstacle (the situation of multiple obstacles adjacent to each other can be simplified to a single cylindrical obstacle with multiple obstacles outside, and the situation of multiple obstacles far away and affecting each other is not considered in the present invention), and converts it into a mathematical model. According to the principle of seismic wave kinematics, spatial geometry calculation is performed to obtain the relationship between the acquisition target, observation system, spatial information, CMP attributes and other information, and the obstacle avoidance zone calculation system is calculated and displayed to avoid the obstacle area that needs special treatment during acquisition. The seismic data acquisition designer analyzes the acquisition effect according to the calculation results, and further optimizes the 3D exploration seismic data acquisition observation system that meets the actual situation of the work area.

[0056] The present invention provides a seismic data acquisition obstacle avoidance design method based on spatial information, such as Figure 3 As shown, the method comprises the following steps: importing the known underground obstacle space information into the obstacle avoidance zone calculation system; simplifying the underground obstacle space information into an ideal cylindrical model; selecting the obstacle avoidance calculation parameters of each small layer in the obstacle avoidance zone calculation system, and calculating the reflection angle θ of each small layer from the common center point of the target layer to the ground receiving point i ; According to the depth h of the common center point of the target layer OO’ , obstacle bottom interface depth h BC , given the initial reflection angle tan of the seismic reflection wave from the ground to the target layer at the common center point depth -1 (d SO’ / h OO’ ), perform angle range scanning at a fixed angle step size until the offset distance when the reflected wave reaches the bottom interface of the obstacle is greater than or equal to half the diameter of the bottom interface of the obstacle, then stop scanning and determine the reflection angle θ1 of the seismic reflection wave of the first layer at the position of the ground receiving point at this time; calculate the final ground range value of the seismic reflection wave based on the reflection angle θ1, which is the obstacle avoidance area diameter d SR .

[0057] Specifically, Figure 1 The figure shows the schematic diagram of seismic data acquisition profile under underground obstacle conditions. Figure 1 The medium seismic wave is excited at the shot point position (S) on the surface, propagates downward, encounters the reflection interface (stratum) of the target layer, and is reflected upward and received by the ground detection point. Figure 1 The rectangular box with slashes in the middle is the vertical section of the cylindrical obstacle along the survey line direction), which causes the detection point in the SR area (i.e., the circular area with SR as the diameter) to fail to receive the seismic wave signal of point O in the target layer, affecting the quality of seismic acquisition data.

[0058] In this method Figure 2 The seismic acquisition model assumes that the underground stratum is an ideal horizontal layered isotropic medium in a uniform half-space and should meet the following conditions: (1) the underground stratum is a horizontal layered isotropic medium; (2) the propagation law of seismic waves considers the kinematics of seismic waves; and (3) it is assumed that seismic waves are totally reflected after propagating to obstacles.

[0059] Specifically, the obstacle avoidance calculation parameters for each sub-layer include: the speed V of each sub-layer underground i , the density of each underground layer ρ i and the travel time t of the seismic wave in each layer i ; Wherein, i represents the sequence number of the stratum, i=1,2,3,...,n, and n is the total number of strata.

[0060] The one-way propagation path S of seismic waves in each layer i For: S i =V i ×t i (1);

[0061] The thickness of each underground layer h i For: h i =S i ×cosθ i =V i ×t i ×cosθ i (2);

[0062] The offset distance d of the seismic wave from the incident point on the top interface of the small layer after passing through the small layer i for:

[0063]

[0064] Then the length of the radius r of the obstacle avoidance zone is SO′, which is the offset distance d of the seismic wave from the incident point on the top interface of the small layer after passing through the small layer. i sum:

[0065]

[0066] The reflection angle θ from the target layer O to the bottom interface of each small layer at the ground receiving point is obtained by calculation i , the radius of the obstacle avoidance zone on the ground can be calculated.

[0067] According to the trigonometric relationship, we can get

[0068] From Snell's law we get:

[0069] but

[0070] Transforming formula (7), we can obtain the calculation formula of the reflection angle θ1 when the seismic reflection wave reaches the ground receiving point:

[0071] Figure 1 According to the depth h of the CMP point OO’ and the depth h of the obstacle bottom interface BC BC , given the initial reflection angle tan from the surface to the point depth -1 (d SO’ / h OO’ ), and on this basis, scan within an angle range at a fixed step length (calculate the reflection wave ray path by incrementing or decrementing by 1° from the initial angle each time), so that when the seismic reflection wave ray reaches the bottom depth of the obstacle (the depth of the BC line), the calculated di The size is equal to half the diameter of the bottom surface of the obstacle (d BC / 2) (at this time, the reflected wave ray just passes through the boundary point C of the obstacle bottom interface BC), stop the angle scanning, and determine the reflection angle θ1 as the key calculation parameter of the obstacle avoidance area. The process of determining the reflection angle θ1 is as follows:

[0072] Assuming that the bottom interface of the obstacle is located at the mth layer, when the reflected wave from the common center point position O of the target layer reaches the bottom interface of the mth layer obstacle, the deviation distance of the reflection point is When the reflected wave reaches the boundary point C at the bottom interface of the obstacle, the horizontal displacement of the reflected wave in layer m is At this time, the displacement of the reflected wave path on the vertical normal line in layer m is When the reflection angle θ of layer m m (The m layer is the layer number where the bottom interface of the obstacle is located. The reflection angle of the bottom interface of the obstacle and the reflection angle of the mth layer may not be equal) Tangent function tanθ m satisfy When d BC represents the diameter of the obstacle bottom interface; h BC Indicates the depth of the obstacle bottom interface.

[0073] The above relationship (9) is the termination condition of the reflection angle scan. When the reflection angle tangent function of layer m satisfies the formula (9), the seismic reflection wave of the target layer just passes through the obstacle boundary point C. At this time, the reflection angle θ1 of the seismic reflection wave arriving at the ground receiving point R can be calculated by the formula (8).

[0074] The diameter d of the obstacle avoidance zone is calculated by using the reflection angle θ1 to calculate the range where the seismic wave finally reaches the ground R from point S. SR The calculation formula is:

[0075]

[0076] Shallow special geological bodies, such as low-velocity bodies, can also be approximated as underground obstacles. It is necessary to consider such factors and perform obstacle avoidance design when collecting seismic data. Taking the actual seismic work area in a certain study area of ​​the Tarim Basin as an example, the method of the present invention is used to perform obstacle avoidance design for seismic data collection, and re-collect seismic data. The results of this embodiment are as follows:

[0077] The seismic data collected in the past did not take into account the influence of underground low-velocity bodies. Figure 4 As shown, Figure 4The projection of the entire work area on the ground. The small black dots along the straight line are the seismic wave excitation points, and the gray circle in the middle is the projection of the obstacle on the ground. The acquisition design does not consider the impact of underground obstacles on seismic waves. After processing the seismic data, it was found that the special geological bodies in the shallow layer have a great impact on the quality of seismic data (such as Figure 5 As shown in the figure, it can be seen that the signal-to-noise ratio of the seismic signal below the obstacle is low, and the formation is difficult to image; combined with the seismic data acquisition obstacle avoidance design and re-acquisition, the observation system is as follows Figure 6 As shown, Figure 6 The projection of the entire work area on the ground. The small black dots along the straight line are the seismic wave excitation points. The gray circle in the middle is the projection of the obstacle on the ground. The acquisition design considers avoiding the area where underground obstacles are projected on the ground, and the excitation points originally designed to be directly above the obstacle projection are deployed around it. After the same seismic data processing, it is found that the obstacle avoidance design has a significant improvement in the quality of seismic data. After the seismic data processing, it can be seen that the signal-to-noise ratio is significantly improved (such as Figure 7 The imaging of deep strata beneath obstacles is greatly improved.

[0078] In addition, the present invention also provides a seismic data acquisition obstacle avoidance design system based on spatial information, such as Figure 8 As shown, the system includes an import module, a simplification module, a first calculation module, a scanning module and a second calculation module:

[0079] The import module is used to import the known underground obstacle space information into the obstacle avoidance zone calculation system;

[0080] The simplification module is used to simplify the spatial information of underground obstacles into an ideal cylindrical model;

[0081] The first calculation module is used to select the parameters of each small layer in the obstacle avoidance calculation system in the obstacle avoidance area, and calculate the reflection angle θ of each small layer from the common center point of the target layer to the ground receiving point. i ;

[0082] The scanning module is used to determine the depth h of the central point of the target layer. OO’ , obstacle bottom interface depth h BC , given the initial reflection angle tan of the seismic reflection wave from the ground to the target layer at the common center point depth -1 (d SO’ / h OO’ ), scan the angle range at a fixed angle step size until the offset distance when the reflected wave reaches the bottom interface of the obstacle is greater than or equal to half the diameter of the bottom interface of the obstacle, then stop scanning and determine the reflection angle θ1 when the seismic reflected wave reaches the position of the ground receiving point;

[0083] The second calculation module is used to calculate the final ground range of the seismic reflection wave according to the reflection angle θ1, which is the obstacle avoidance zone diameter d SR .

[0084] Specifically, the scanning module is used to determine the depth h of the target layer according to the central point of the target layer. OO’ , obstacle bottom interface depth h BC , given the initial reflection angle tan of the seismic reflection wave from the ground to the target layer at the common center point depth -1 (d SO’ / h OO’ ), perform angle range scanning at a fixed angle step length until the offset distance when the reflected wave reaches the bottom interface of the obstacle is greater than or equal to half the diameter of the bottom interface of the obstacle, stop scanning, and determine the reflection angle θ1 at the position of the seismic reflection wave reaching the ground receiving point. Specifically, the scanning module is used to determine the reflection angle θ1 at the position of the ground receiving point according to the depth h of the central point of the target layer. OO’ , obstacle bottom interface depth h BC , given the initial reflection angle tan of the seismic reflection wave from the ground to the target layer at the common center point depth -1 (d SO’ / h OO’ ), scan the reflected wave angle range from the initial angle by 1° increment or decrement each time, until the offset distance when the reflected wave reaches the bottom interface of the obstacle is greater than or equal to half the diameter of the bottom interface of the obstacle, stop scanning, and determine the reflection angle θ1 when the seismic reflection wave arrives at the ground receiving point.

[0085] In summary, the present invention obtains the spatial coordinates of obstacles based on spatial information, completes the design of an observation system that meets the actual situation of the work area indoors, reduces ground exploration costs, and improves the quality of seismic data acquisition; by obtaining the spatial information of underground obstacles, the acquisition design is optimized from the perspective of ray tracing; the calculated design parameters can be downloaded for use by other seismic data acquisition design systems, thereby improving the quality of the acquired data, the signal-to-noise ratio, and the accuracy of the processing results.

[0086] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A seismic data acquisition obstacle avoidance design method based on spatial information, the method comprising the following steps: Importing the spatial information of known underground obstacles into the obstacle avoidance zone calculation system; Simplify the spatial information of underground obstacles into an ideal cylindrical model; In the obstacle avoidance area calculation system, select the parameters of each small layer for obstacle avoidance calculation, and calculate the reflection angle θ of each small layer from the common center point of the target layer to the ground receiving point. i ; According to the depth of the target layer part common center point h OO’ , obstacle bottom interface depth h BC , given the initial reflection angle tan of the seismic reflection wave from the ground to the target layer at the common center point depth -1 (d SO’ / h OO’ ), scan the angle range at a fixed angle step size until the offset distance when the reflected wave reaches the bottom interface of the obstacle is greater than or equal to half the diameter of the bottom interface of the obstacle, then stop scanning and determine the reflection angle θ1 when the seismic reflected wave reaches the position of the ground receiving point; According to the reflection angle θ1, the final ground range of the seismic reflection wave is calculated, which is the diameter d of the obstacle avoidance zone. SR .

2. The method according to claim 1, wherein: The obstacle avoidance calculation parameters for each sub-layer include: the speed V of each sub-layer in the underground i , the density of each underground layer ρ i and the travel time t of the seismic wave in each layer i ; Wherein, i represents the sequence number of the stratum, i=1,2,3,...,n, and n is the total number of strata.

3. The method according to claim 2, wherein: In the obstacle avoidance area calculation system, select the parameters of each small layer for obstacle avoidance calculation, and calculate the reflection angle θ of each small layer from the common center point of the target layer to the ground receiving point. i Specifically: The one-way propagation path S of seismic waves in each layer i For: S i =V i ×t i ; The thickness of each underground layer h i For: h i =S i ×cosθ i =V i ×t i ×cosθ i ; The offset distance d of the seismic wave from the incident point on the top interface of the small layer after passing through the small layer i for: in, From Snell's law we get: but 4. The method according to claim 3, wherein: The reflection angle θ1 of the seismic reflection wave arriving at the ground receiving point R is determined as follows: Assuming that the bottom interface of the obstacle is located at the mth layer, when the reflected wave from the common center point of the target layer reaches the bottom interface of the mth layer obstacle, the distance of the reflection point deviation is When the reflected wave reaches the boundary point C at the bottom interface of the obstacle, the horizontal displacement of the reflected wave in layer m is At this time, the displacement of the reflected wave path on the vertical normal line in layer m is When the reflection angle tangent function tanθ of layer m m satisfy When , the reflection angle scan is terminated, and the seismic reflection wave of the target layer just passes through the obstacle boundary point C; Among them, d BC represents the diameter of the obstacle bottom interface; h BC Indicates the depth of the obstacle bottom interface.

5. According to the method of claim 3 or 4, the calculation formula of the reflection angle θ1 of the seismic reflection wave at the position of the ground receiving point is:

6. The method according to claim 5, wherein: Obstacle avoidance zone diameter d SR The calculation formula is:

7. The method according to any one of claims 1 to 4 or claim 6, wherein: Simplifying the spatial information of underground obstacles into an ideal cylindrical model includes: According to the lateral extension and vertical height of the underground obstacle, the obstacle is simplified into an ideal cylindrical model. The situation of multiple adjacent obstacles is simplified into a single cylindrical obstacle surrounding multiple obstacles.

8. The method according to claim 7, wherein: The angle range scanning according to the fixed angle step size is specifically: the reflected wave angle range scanning is performed at an increment or decrement of 1° each time from the initial angle.

9. A seismic data acquisition obstacle avoidance design system based on spatial information, the system comprising an import module, a simplification module, a first calculation module, a scanning module and a second calculation module: The import module is used to import the known underground obstacle space information into the obstacle avoidance zone calculation system; The simplification module is used to simplify the spatial information of underground obstacles into an ideal cylindrical model; The first calculation module is used to select the parameters of each small layer in the obstacle avoidance calculation system in the obstacle avoidance area, and calculate the reflection angle θ of each small layer from the common center point of the target layer to the ground receiving point. i ; The scanning module is used to determine the depth h of the central point of the target layer. OO’ , obstacle bottom interface depth h BC , given the initial reflection angle tan of the seismic reflection wave from the ground to the target layer at the common center point depth -1 (d SO’ / h OO’ ), scan the angle range at a fixed angle step size until the offset distance when the reflected wave reaches the bottom interface of the obstacle is greater than or equal to half the diameter of the bottom interface of the obstacle, then stop scanning and determine the reflection angle θ1 when the seismic reflected wave reaches the position of the ground receiving point; The second calculation module is used to calculate the final ground range of the seismic reflection wave according to the reflection angle θ1, which is the obstacle avoidance zone diameter d SR .

10. The system according to claim 9, wherein: The scanning module is used to determine the depth h of the central point of the target layer. OO’ , obstacle bottom interface depth h BC , given the initial reflection angle tan of the seismic reflection wave from the ground to the target layer at the common center point depth -1 (d SO’ / h OO’ ), scan the angle range at a fixed angle step until the offset distance when the reflected wave reaches the bottom interface of the obstacle is greater than or equal to half the diameter of the bottom interface of the obstacle, stop scanning, and determine the reflection angle θ1 when the seismic reflection wave reaches the ground receiving point: The scanning module is used to determine the depth h of the central point of the target layer. OO’ , obstacle bottom interface depth h BC , given the initial reflection angle tan of the seismic reflection wave from the ground to the target layer at the common center point depth -1 (d SO’ / h OO’ ), scan the reflected wave angle range from the initial angle by 1° increment or decrement each time, until the offset distance when the reflected wave reaches the bottom interface of the obstacle is greater than or equal to half the diameter of the bottom interface of the obstacle, stop scanning, and determine the reflection angle θ1 when the seismic reflection wave arrives at the ground receiving point.

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