Equivalent undulating surface physical model solid surface acquisition method and device

Abstract

The invention discloses an equivalent undulating surface physical model solid surface acquisition method and device. The method comprises the following steps: establishing an initial three-dimensional depth-velocity model according to stratum morphological characteristics and logging velocity of a target area; based on the initial three-dimensional depth-speed model, converting the real undulating surface into an equivalent undulating surface with a horizontal surface, and replacing the real speed of the undulating surface with the equivalent speed of the undulating surface to obtain an equivalent three-dimensional depth-speed model; manufacturing to obtain an equivalent physical model; coating the upper surface of the equivalent physical model with a coupling agent; vertically mounting an excitation probe and a receiving probe on the upper surface of the equivalent physical model; and horizontally moving the excitation probe and the receiving probe according to a preset track, and carrying out solid surface acquisition on the equivalent physical model. The method realizes physical model solid surface acquisition, thereby simulating a land acquisition mode and being suitable for any land exploration scene.

Description

Technical Field

[0001] This invention relates to the technical field of earthquake physics simulation experimental research, and in particular to a method and apparatus for collecting solid surface data from an equivalent undulating surface physical model. Background Technology

[0002] Field seismic exploration is mainly divided into two categories: land exploration and marine exploration. Land exploration begins at the surface, and the stratigraphic structure includes the surface, near-surface, and subsurface structures. During the exploration process, the seismic source is located at the surface, and artificial seismic waves are generated through explosions or heavy impacts from seismograph vehicles. These seismic waves propagate downwards through the near-surface into various subsurface strata, are reflected by the strata, and then propagate upwards again, finally passing near the surface a second time to be received by geophones buried in the ground. In this process, the seismic waves pass near the surface twice, and the undulating surface and complex near-surface structure exacerbate the diversity of the seismic wave field, seriously affecting the quality of seismic data and bringing many difficulties to seismic data processing and interpretation. Marine seismic exploration, on the other hand, involves excitation and reception within a body of water. Seawater is a homogeneous body relative to the near-surface of land, so the static correction problems, noise problems represented by surface waves, and absorption attenuation problems involved in land data do not exist in marine seismic data. Marine exploration and land exploration employ completely different processing and imaging approaches and technologies for near-surface processing.

[0003] Global resource surveys predict that land covering 30% of the Earth's surface contains abundant oil and gas resources, accounting for 56% of global oil and gas resources. Land exploration plays a crucial role in overall geophysical exploration. From the perspective of seismic data acquisition conditions, the proportion of complex surfaces characterized by mountains, deserts, loess plateaus, and Gobi is increasing. The strata between the surface and the high-velocity top interface are called the near-surface or low-velocity zone. This zone largely restricts the progress of land exploration. The unique characteristics of the near-surface—"free surface, low velocity, high absorption"—have a significant impact on the seismic wavefield. This is mainly manifested in two aspects: First, static correction problems arise because the undulation of surface elevation and the lateral variation of near-surface velocity cause distortion of seismic waves reflected from underground strata interfaces during their travel. Second, strong noise interference waves are generated near the surface. The source depth is usually much smaller than the seismic wave wavelength, and the source pressure pulse interacts with the free surface through the near-surface medium, generating surface waves and other secondary interferences, thus complicating the wavefield.

[0004] Identifying weak signals in deep layers within complex tectonic zones with three-dimensional undulating surfaces is a global challenge, primarily influenced by two factors: complex near-surface and complex shallow-to-medium-depth structures. The complex near-surface includes thick loess layers, piedmont zones, and gravel layers. The near-surface strongly absorbs and scatters seismic wave energy; in some exploration areas, 60%-70% or even more of the energy is lost near the surface. Simultaneously, the near-surface velocity varies significantly in both longitudinal and lateral directions, leading to complex seismic wave propagation paths and making deep imaging difficult. In complex tectonic regions, after absorption, attenuation, and multiple wave interference from the near-surface and overlying complex structures, the energy, amplitude, phase, and frequency of seismic waves propagating to the middle and deep layers are significantly altered, resulting in the development of interference waves, low signal-to-noise ratios, and weak signals in the deep layers. In many exploration areas, it is difficult to identify the true seismic response characteristics of the strata during the interpretation of deep seismic data, directly leading to well placement failures. Deep oil drilling is a high-investment, high-risk underground project. Therefore, forward modeling technology is urgently needed to guide actual production, and physical modeling laboratories are playing an increasingly important role as scientific research bases.

[0005] Current physical simulation experiments involve immersing the model in a water tank and placing the excitation and receiving probes at a certain depth underwater, using water as a coupling agent to simulate excitation and reception. This is because ultrasonic waves attenuate very quickly when propagating in air, but in liquids, the ultrasonic transducer achieves excellent coupling performance with the medium, allowing energy to be transferred into the model. This simulation method is similar to marine seismic exploration; even if the model is designed with undulating surfaces and near-surface low-velocity zones, once placed in the water tank, it is equivalent to a rugged seabed and a layer of unformed silt. Currently, the most widespread application of seismic physical simulation is in the theoretical study of seismic waves in single complex structural models with horizontal surfaces, such as the theoretical study of elastic wave propagation in acoustic, elastic, anisotropic, and two-phase media, as well as the study of wave field propagation mechanisms and imaging methods for single complex structures without near-surface surfaces. It cannot be used for terrestrial simulation and acquisition studies of truly undulating surfaces. Summary of the Invention

[0006] To increase the selection space of physical model acquisition methods and enrich the types of physical model acquisition products, this invention provides a method and apparatus for acquiring solid surfaces of equivalent undulating terrain physical models.

[0007] In a first aspect, embodiments of the present invention provide a method for acquiring solid surface data from an equivalent undulating surface physical model, comprising:

[0008] Based on the stratigraphic features and logging rate of the target area, an initial three-dimensional depth-velocity model is established; the initial three-dimensional depth-velocity model includes the actual undulating surface and the underlying strata located below the actual undulating surface;

[0009] Based on the initial three-dimensional depth-velocity model, the real undulating surface is converted into an equivalent undulating surface with a horizontal surface, and the real velocity of the undulating surface is replaced with the equivalent velocity of the undulating surface to obtain an equivalent three-dimensional depth-velocity model.

[0010] Based on the equivalent three-dimensional depth-velocity model, an equivalent physical model is created;

[0011] A coupling agent is coated on the upper surface of the equivalent physical model;

[0012] The excitation probe and the receiving probe are vertically mounted on the upper surface of the equivalent physical model;

[0013] The excitation probe and the receiving probe are moved horizontally along a preset trajectory to collect solid surface data from the equivalent physical model.

[0014] In one or more optional embodiments, the step of converting the real undulating surface into an equivalent undulating surface with a horizontal surface based on the initial three-dimensional depth-velocity model, and replacing the real velocity of the undulating surface with the equivalent velocity of the undulating surface to obtain an equivalent three-dimensional depth-velocity model, includes:

[0015] Based on the elevation range of the actual undulating surface in the initial three-dimensional depth-velocity model, determine the equivalent undulating surface elevation;

[0016] For each horizontal point in the initial three-dimensional depth-velocity model, the equivalent velocity of the undulating surface is calculated based on Equations 1 and 2, according to the elevation of the high-velocity top interface of the underlying stratum, the actual undulating surface elevation, the equivalent undulating surface elevation, and the actual velocity of the undulating surface:

[0017] t i =(h i -h i0 ) / v i =(h ia -h i0 ) / v ia , formula 1;

[0018] v ia =(h ia -h i0 ) / t i =(h ia -h i0 )*v i / (h i -h i0 ), formula 2;

[0019] In the formula, h i h represents the actual undulating surface elevation at point i in the model. ia h is the equivalent undulating surface elevation.i0 v is the elevation of the high-speed top interface at point i in the model; i v represents the actual velocity of the undulating ground surface at point i in the model. ia The undulating surface equivalent velocity at point i in the model; t i The seismic wave travel time at point i in the model;

[0020] Based on the initial three-dimensional depth-velocity model, the real undulating surface is converted into an equivalent undulating surface with a horizontal surface according to the equivalent undulating surface elevation. Furthermore, for each horizontal position point in the initial three-dimensional depth-velocity model, the real velocity of the undulating surface is replaced with the equivalent velocity of the undulating surface to obtain the equivalent three-dimensional depth-velocity model.

[0021] In one or more optional embodiments, determining the equivalent undulating surface elevation based on the elevation range of the actual undulating surface of the initial three-dimensional depth-velocity model includes:

[0022] Based on the elevation range of the actual undulating surface of the initial three-dimensional depth-velocity model, the average elevation of the actual undulating surface of the initial three-dimensional depth-velocity model is calculated, and the average elevation is used as the equivalent undulating surface elevation.

[0023] In one or more optional embodiments, determining the equivalent undulating surface elevation based on the elevation range of the actual undulating surface of the initial three-dimensional depth-velocity model includes:

[0024] Within the elevation range of the actual undulating surface of the initial three-dimensional depth-velocity model, any elevation value is selected as the equivalent undulating surface elevation.

[0025] In one or more optional embodiments, the step of vertically mounting the excitation probe and the receiving probe on the upper surface of the equivalent physical model includes:

[0026] The excitation probe and the receiving probe are vertically mounted on the upper surface of the equivalent undulating ground surface of the equivalent physical model.

[0027] A force-applying fixing mechanism is installed on the upper part of the excitation probe and the receiving probe so that the excitation probe and the receiving probe are in close contact with the upper surface of the equivalent physical model.

[0028] In one or more optional embodiments, establishing an initial three-dimensional depth-velocity model based on the formation morphology and logging rate of the target area includes:

[0029] Define the scope of the target area and set the grid size for the target area;

[0030] Based on the stratigraphic features of the target area, determine the X, Y, and Z coordinates of each grid point;

[0031] Based on the logging velocity in the target area, determine the velocity value for each grid point;

[0032] Based on the X, Y, and Z coordinates and velocity values ​​of each grid point, the initial three-dimensional depth-velocity model is established according to a preset scale.

[0033] In one or more optional embodiments, the step of creating an equivalent physical model based on the equivalent three-dimensional depth-velocity model includes:

[0034] Based on the equivalent three-dimensional depth-velocity model, the equivalent undulating surface of the equivalent physical model is fabricated using 3D multi-material printing technology.

[0035] In one or more alternative embodiments, the coupling agent is honey or petroleum jelly.

[0036] Secondly, embodiments of the present invention provide a solid surface acquisition device for an equivalent undulating surface physical model, including an equivalent physical model, an excitation probe, and a receiving probe;

[0037] The excitation probe and the receiving probe are vertically mounted on the upper surface of the equivalent physical model;

[0038] The upper surface of the equivalent physical model is coated with a coupling agent;

[0039] The equivalent physical model includes an equivalent undulating surface and an underlying stratum located beneath the equivalent undulating surface;

[0040] The surface of the equivalent undulating ground is a horizontal plane;

[0041] The equivalent undulating surface is obtained by converting the real undulating surface through the initial three-dimensional depth-velocity model;

[0042] The equivalent physical model has an equivalent velocity of the undulating surface corresponding to the equivalent undulating surface.

[0043] The equivalent velocity of the undulating surface is obtained by replacing the actual velocity of the undulating surface with that of the initial three-dimensional depth-velocity model.

[0044] In one or more alternative embodiments, a force-applying fixing mechanism is mounted on the upper part of the excitation probe and the receiving probe.

[0045] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0046] The solid surface acquisition method for equivalent undulating surface physical models provided in this invention is based on the isochronous principle, where propagation distance is proportional to propagation speed. It transforms the real undulating surface into an equivalent horizontal undulating surface and replaces the real velocity of the undulating surface with the equivalent velocity, ensuring that the seismic wave travel time remains unchanged. This avoids the conventional approach of seeking new acquisition devices. By changing the surface morphology and internal structure of the physical model, and using conventional excitation and receiving probes, it acquires the equivalent seismic wave field on the horizontal model surface, realizing solid surface acquisition of the physical model. This simulates a land acquisition mode and is applicable to any land exploration scenario, showing good application prospects and technological leadership.

[0047] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0048] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0049] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0050] Figure 1 This is a schematic flowchart of the solid surface acquisition method for the equivalent undulating surface physical model provided in this embodiment of the invention;

[0051] Figure 2 This is a cross-sectional view of the initial three-dimensional depth-velocity model provided in this embodiment of the invention;

[0052] Figure 3 This is a cross-sectional view of the equivalent three-dimensional depth-velocity model provided in the embodiments of the present invention;

[0053] Figure 4 This is a schematic diagram of the equivalent physical model acquisition device provided in the embodiments of the present invention;

[0054] Figure 5 This is a schematic diagram of the structure of a traditional water tank collection device provided in an embodiment of the present invention. Detailed Implementation

[0055] 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.

[0056] The inventors discovered that current physical simulation experiments of undulating surfaces are similar to marine seismic exploration. Even if the model is designed with undulating surfaces and near-surface low-velocity zones, once placed in a water tank, it becomes equivalent to a rugged seabed and a layer of unformed silt. In the physical simulation of undulating surfaces, the elevations of different points on the undulating physical model surface are not uniform, and the influence of the overlying water layer is difficult to eliminate uniformly, making it impossible to conduct true land simulation data acquisition research on undulating surfaces. To conduct seismic physical simulation of dual complex tectonic zones on three-dimensional undulating surfaces, a probe with a diameter small enough to be perpendicularly attached to the undulating surface is needed, and the probe also needs to be able to move freely on the surface of the undulating surface. Existing equipment cannot meet these experimental requirements.

[0057] Based on this, the present invention provides a method and apparatus for collecting solid surface data from an equivalent undulating surface physical model, which will be described in detail below through specific embodiments.

[0058] Example 1

[0059] This invention provides a method for collecting solid surface data from an equivalent undulating surface physical model, referring to... Figure 1 As shown, it includes:

[0060] S101: Based on the stratigraphic features and logging rate of the target area, establish an initial three-dimensional depth-velocity model; the initial three-dimensional depth-velocity model includes the actual undulating surface and the underlying strata located below the actual undulating surface;

[0061] S102: Based on the initial three-dimensional depth-velocity model, the real undulating surface is converted into an equivalent undulating surface with a horizontal surface, and the real velocity of the undulating surface is replaced with the equivalent velocity of the undulating surface to obtain an equivalent three-dimensional depth-velocity model.

[0062] S103: Based on the equivalent three-dimensional depth-velocity model, an equivalent physical model is created;

[0063] S104: Coat the upper surface of the equivalent physical model with a coupling agent;

[0064] S105: The excitation probe and the receiving probe are vertically mounted on the upper surface of the equivalent physical model;

[0065] S106: Move the excitation probe and the receiving probe horizontally according to the preset trajectory to collect solid surface data of the equivalent physical model.

[0066] In this embodiment of the invention, based on the principle of invariant travel time in seismic exploration—that is, the travel time of seismic waves is always equal to the thickness divided by the velocity—the actual undulating surface is converted into an equivalent undulating surface with a horizontal surface. The thickness difference between these two surfaces and the high-velocity top interface of the underlying strata is converted into a velocity difference. The original actual velocity of the undulating surface plus the velocity difference yields the equivalent velocity of the undulating surface. During the construction of the equivalent physical model, the actual undulating surface is replaced with a horizontal equivalent undulating surface, and the material ratio and model construction are based on the calculated equivalent velocity of the undulating surface, thereby maintaining the invariant travel time of the undulating surface and achieving true solid surface acquisition in the physical model.

[0067] The solid surface acquisition method for equivalent undulating surface physical models provided in this invention is based on the isochronous principle, where propagation distance is proportional to propagation speed. It transforms the real undulating surface into an equivalent horizontal undulating surface and replaces the real velocity of the undulating surface with the equivalent velocity, ensuring that the seismic wave travel time remains unchanged. This avoids the conventional approach of seeking new acquisition devices. By changing the surface morphology and internal structure of the physical model, and using conventional excitation and receiving probes, it acquires the equivalent seismic wave field on the horizontal model surface, realizing solid surface acquisition of the physical model. This simulates a land acquisition mode and is applicable to any land exploration scenario, showing good application prospects and technological leadership.

[0068] In an optional implementation, step S101: Establishing an initial three-dimensional depth-velocity model based on the formation morphology and logging velocity of the target area refers to constructing an initial three-dimensional depth-velocity model that reflects the morphological characteristics of the formation under study and the longitudinal and lateral velocity variation patterns within the target area, using modeling software according to a certain scale, based on the actual conditions of the target area under study. Specifically, this includes:

[0069] By locating four coordinates in the study area, the extent of the target area is determined according to the actual orientation, and the grid size of the target area is set.

[0070] Based on the stratigraphic characteristics of the target area, the X, Y, and Z coordinates of each grid point in each stratum within the target area are output using methods such as seismic data interpretation, interpolation, and smoothing.

[0071] Based on the logging velocity of the target area, the average velocity of the formation is extracted using interpolation, smoothing and other methods, thereby determining the velocity value of each grid point;

[0072] Set various scales between the model and the target area;

[0073] Based on the X, Y, and Z coordinates and velocity values ​​of each grid point, the initial three-dimensional depth-velocity model is established according to a predefined scale.

[0074] The various scales between the model and the target area can specifically include: a horizontal scale (X and Y directions), a vertical scale (Z direction), a wavelet scale (excitation frequency), a velocity scale, and a density scale. For example, the model's horizontal area is controlled within 1m x 1m, and its thickness within 0.5m. The horizontal and vertical scales between the model and the target area are 1 / 10000, and the model's excitation frequency is controlled at approximately 30Hz. The model's velocity range is approximately 700-3000 m / s, while the actual formation velocity range is approximately 2000-7000 m / s. The density scale is designed based on the actual formation velocity to ensure that the model's formation material velocity falls within a stable region, facilitating subsequent detection and data acquisition.

[0075] For example, refer to Figure 2 As shown, the initial 3D depth-velocity model includes the actual undulating surface and the underlying strata beneath it. The top red curve represents the elevation of the actual undulating surface, and the second red curve represents the high-velocity top interface of the underlying strata. The actual velocity v of the undulating surface lies between these two interfaces. i Below the high-speed top interface (shown by brown lines) lies the underlying geological structure.

[0076] The inventors discovered that in seismic exploration, travel time is a known parameter. Based on a field observation system, geophones (receivers) are placed on the ground, and artificial earthquakes are used to excite the seismic waves at designed locations. The excited seismic wavelets propagate downwards from the ground, undergoing refraction, transmission, reflection, and scattering at various strata underground. The reflected waves are downward seismic wave fields, which are reflected at the interfaces between different strata, converting into upward wave fields that propagate upwards. The upward wave fields reaching the ground are received by geophones, and the received information includes time (i.e., the travel time of the seismic wave) and amplitude. Therefore, the travel time (the time it takes for the seismic wave to traverse each stratum) is a known parameter, while the velocity and depth parameters of each stratum are unknown parameters. The key task in seismic exploration is to invert stratum velocity and depth information based on travel time information, and the principle of travel time invariance is followed when calculating velocity and depth parameters. The relationship between time, distance, and velocity is: t = h / v; where: t is the travel time, h is the stratum thickness, and v is the stratum velocity. Since travel time is the actual propagation time of seismic waves received by the detector, while the parameters of formation velocity and depth are unknown, based on the principle of invariant travel time, if the propagation distance changes, the propagation velocity will also change. Distance and velocity are directly proportional; as the propagation distance increases, the propagation velocity increases, and as the propagation distance decreases, the propagation velocity decreases. For the same fixed travel time, there can be countless depth-velocity pairs, but the actual depth-velocity relationship is only one pair; therefore, all others are equivalent depth-velocity pairs.

[0077] Therefore, by converting the real undulating surface into an equivalent undulating surface with a horizontal surface, and converting the thickness difference between these two surfaces and the high-velocity top interface of the underlying strata into a velocity difference, the original real velocity of the undulating surface plus the velocity difference yields the equivalent velocity of the undulating surface, which ensures that the travel time remains unchanged. Thus, solid surface data acquisition of the physical model can be achieved by changing the near-surface strata morphology and structure and the velocity equivalence method. Based on this, step S102: Based on the initial three-dimensional depth-velocity model, the real undulating surface is converted into an equivalent undulating surface with a horizontal surface, and the real velocity of the undulating surface is replaced with the equivalent velocity of the undulating surface to obtain an equivalent three-dimensional depth-velocity model, which may specifically include:

[0078] Based on the elevation range of the actual undulating surface in the initial three-dimensional depth-velocity model, determine the equivalent undulating surface elevation;

[0079] For each horizontal position point of the initial three-dimensional depth-velocity model, i.e., each (x) point of the initial three-dimensional depth-velocity model i y i Based on the coordinates of the high-velocity top interface of the stratum at that point, the actual undulating surface elevation, the equivalent undulating surface elevation, and the actual velocity of the undulating surface, the equivalent velocity of the undulating surface is calculated using Formulas 1 and 2:

[0080] t i =(h i -h i0 ) / v i =(h ia -h i0 ) / v ia , formula 1;

[0081] v ia =(h ia -h i0 ) / t i =(h ia -h i0 )*v i / (h i -h i0 ), formula 2;

[0082] In the formula, h i For (x) i y i The actual elevation of the ground at point h; ia h is the equivalent undulating surface elevation. i0 For (x) i y i Elevation of the high-speed top interface at point (v); i For (x) i y i The actual velocity of the undulating ground surface at point (v) ia For (x) i y i The equivalent velocity of the undulating ground surface at point t; i For (x) i y i Seismic waves travel through point )

[0083] Based on the initial three-dimensional depth-velocity model, the real undulating surface is converted into an equivalent undulating surface with a horizontal surface according to the equivalent undulating surface elevation. Furthermore, for each horizontal position point in the initial three-dimensional depth-velocity model, the real velocity of the undulating surface is replaced with the equivalent velocity of the undulating surface to obtain the equivalent three-dimensional depth-velocity model.

[0084] For example, by Figure 2 The initial 3D depth-velocity model shown is obtained by equivalent replacement. Figure 3 The equivalent three-dimensional depth-velocity model is shown. Figure 3 In the diagram, the top horizontal line represents the equivalent horizontal plane of the undulating surface, i.e., the equivalent elevation of the undulating surface. The red curve below the horizontal line represents the high-velocity top interface of the underlying strata. The area between these two interfaces is the equivalent velocity v of the undulating surface. iaBelow the high-velocity top interface (shown by brown lines), the underlying strata structure remains unchanged, and the underlying strata structure and velocity below the high-velocity top interface remain unchanged.

[0085] Furthermore, the method for determining the equivalent undulating surface elevation based on the elevation range of the actual undulating surface in the initial three-dimensional depth-velocity model can include: calculating the average of the maximum and minimum actual elevation values ​​of the actual undulating surface in the initial three-dimensional depth-velocity model based on the elevation range of the actual undulating surface in the initial three-dimensional depth-velocity model, obtaining the average elevation of the actual undulating surface, and using this average elevation as the equivalent undulating surface elevation; or, selecting any elevation value within the elevation range of the actual undulating surface in the initial three-dimensional depth-velocity model as the equivalent undulating surface elevation.

[0086] In an optional implementation, step S103: Based on the equivalent three-dimensional depth-velocity model, an equivalent physical model is created, specifically including:

[0087] Based on the equivalent 3D depth-velocity model, an equivalent physical model is created using a combination of 3D multi-material printing technology and traditional model-making techniques. 3D multi-material printing technology can create geological materials with arbitrary velocities by mixing multiple materials in arbitrary proportions, used to construct the equivalent undulating surface portion. Traditional model-making techniques utilize materials such as talc and silicone rubber to construct the strata below the high-velocity top interface. The equivalent model construction consists of two parts: the equivalent undulating surface and the underlying geological structure below the high-velocity top interface. Specifically, the geological materials between the equivalent undulating surface and the high-velocity top interface are configured according to the equivalent 3D depth-velocity model, ensuring their velocity values ​​equal to the equivalent velocity of the undulating surface; the geological materials for the underlying geological structure are configured according to the equivalent 3D depth-velocity model, ensuring their velocity values ​​reflect the propagation velocity of the underlying strata.

[0088] In this embodiment of the invention, by coating the upper surface of the equivalent physical model with a coupling agent, the coupling between the equivalent physical model and the excitation and receiving probes is enhanced. Furthermore, the coupling agent acts as a lubricant when the excitation and receiving probes need to slide on the top of the model to change position, thus improving working efficiency. Optionally, the coupling agent may include, but is not limited to, petroleum jelly and honey.

[0089] In an optional implementation, step S105: vertically mounting the excitation probe and the receiving probe on the upper surface of the equivalent physical model, specifically includes:

[0090] The excitation probe and the receiving probe are vertically mounted on the surface of the equivalent undulating ground of the equivalent physical model;

[0091] A force-applying fixing mechanism is installed on the upper part of the excitation probe and the receiving probe to ensure that the excitation probe and the receiving probe are in close contact with the upper surface of the equivalent physical model. For example, the force-applying fixing mechanism can be a spring force-applying mechanism, in which a compressed spring is placed against the upper part of the excitation probe and the receiving probe, and the compression of the spring applies a large downward pressure to the excitation probe and the receiving probe, so that the excitation probe and the receiving probe are in close contact with the model surface.

[0092] The solid surface acquisition method of the equivalent undulating surface physical model provided in this invention ensures close contact between the excitation probe and the receiving probe and the model surface by adding a force-fixing mechanism, thereby achieving a high degree of coupling between the probe and the model surface. This ensures that most of the energy emitted by the excitation probe is transferred into the model, and that most of the energy is received by the receiving probe after being reflected inside the model.

[0093] In this embodiment of the invention, after steps S101-S105, the following is obtained: Figure 4 The equivalent physical model shown is equipped with the probe and coated with coupling agent. After fixing the excitation and receiving probes to the equivalent physical model and connecting them to the machine tool, the model can move horizontally under the control of the machine tool according to the set coordinate system and movement trajectory, and excite and receive seismic wavelets at various positions, thereby completing the actual solid surface acquisition.

[0094] Reference Figure 5 As shown, current physical simulation experiments involve completely immersing the physical model in a water tank, with the water level above the model surface at a certain distance. During data acquisition, the excitation and receiving probes are suspended at a certain depth underwater using machine tool control, without contacting the model surface. Water is used as the coupling agent for simulated excitation and reception. This simulation method is similar to marine seismic exploration and cannot truly simulate land solid surface acquisition. The equivalent undulating surface physical model solid surface acquisition method provided in this invention, by changing the surface morphology and internal structure of the physical model, uses conventional excitation and receiving probes to perform equivalent seismic wave field acquisition on the horizontal model surface, thus achieving solid surface acquisition of the physical model and simulating land acquisition mode, applicable to any land exploration scenario.

[0095] Example 2

[0096] Based on the same inventive concept, embodiments of the present invention also provide a solid surface acquisition device for an equivalent undulating surface physical model, referring to... Figure 4 As shown, it includes an equivalent physical model, an excitation probe, and a receiving probe;

[0097] The excitation probe and the receiving probe are vertically mounted on the upper surface of the equivalent physical model;

[0098] The upper surface of the equivalent physical model is coated with a coupling agent;

[0099] The equivalent physical model includes an equivalent undulating surface and an underlying stratum located beneath the equivalent undulating surface;

[0100] The surface of the equivalent undulating ground is a horizontal plane;

[0101] The equivalent undulating surface is obtained by converting the real undulating surface through the initial three-dimensional depth-velocity model;

[0102] The equivalent physical model has an equivalent velocity of the undulating surface corresponding to the equivalent undulating surface.

[0103] The equivalent velocity of the undulating surface is obtained by replacing the actual velocity of the undulating surface with that of the initial three-dimensional depth-velocity model.

[0104] In this embodiment of the invention, the equivalent physical model is created based on the equivalent three-dimensional depth-velocity model established on the modeling software. The equivalent three-dimensional depth-velocity model is obtained by converting the initial three-dimensional depth-velocity model, specifically including: establishing an initial three-dimensional depth-velocity model based on the formation morphology characteristics and logging rate of the target area;

[0105] Based on the initial three-dimensional depth-velocity model, the real undulating surface is converted into an equivalent undulating surface with a horizontal surface, and the real velocity of the undulating surface is replaced with the equivalent velocity of the undulating surface to obtain an equivalent three-dimensional depth-velocity model.

[0106] In this embodiment of the invention, a force-applying fixing mechanism is installed on the upper part of the excitation probe and the receiving probe.

[0107] In this embodiment of the invention, the equivalent undulating surface physical model solid surface acquisition device corresponds to the equivalent undulating surface physical model solid surface acquisition method described in Embodiment 1. Its specific application process can refer to the application process of the equivalent undulating surface physical model solid surface acquisition method described in Embodiment 1. Where it is repeated, it will not be described again.

[0108] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for solid surface acquisition of an equivalent rough earth physical model, characterized in that, The method comprises the following steps: establishing an initial three-dimensional depth-velocity model according to the stratigraphic morphological characteristics and logging velocities of a target area; the initial three-dimensional depth-velocity model comprises a real undulating surface and underlying strata located below the real undulating surface; based on the initial three-dimensional depth-velocity model, the real undulating surface is converted into an equivalent undulating surface with a surface level, and the real undulating surface velocity is replaced by an equivalent undulating surface velocity to obtain an equivalent three-dimensional depth-velocity model; an equivalent physical model is prepared according to the equivalent three-dimensional depth-velocity model; a coupling agent is coated on the upper surface of the equivalent physical model; a transmitting probe and a receiving probe are vertically installed on the upper surface of the equivalent physical model; the transmitting probe and the receiving probe are moved horizontally along a preset trajectory to collect solid surface data of the equivalent physical model.

2. The physical model of an equivalent rough surface for solid surface acquisition method according to claim 1, wherein, The step of converting the real undulating surface into an equivalent undulating surface with a surface level and replacing the real undulating surface velocity with an equivalent undulating surface velocity based on the initial three-dimensional depth-velocity model to obtain an equivalent three-dimensional depth-velocity model comprises the following steps: determining the elevation range of the equivalent undulating surface according to the elevation range of the real undulating surface of the initial three-dimensional depth-velocity model; for each horizontal position point of the initial three-dimensional depth-velocity model, the equivalent undulating surface velocity is calculated based on formulas 1 and 2 according to the high-speed top interface elevation of the underlying strata, the real undulating surface elevation, the equivalent undulating surface elevation, and the real undulating surface velocity. t i = (h i -h i0 ) / v i = (h ia -h i0 ) / v ia , Equation 1; v ia = (h ia -h i0 ) / t i = (h ia -h i0 )*v i / (h i -h i0 ), equation 2; where h i is the true relief surface elevation at point i of the model; h ia is the equivalent relief surface elevation; h i0 is the high velocity top interface elevation at point i of the model; v i is the true relief surface velocity at point i of the model; v ia is the equivalent relief surface velocity at point i of the model; t i is the seismic wave travel time at point i of the model; based on the initial three-dimensional depth-velocity model, the real undulating surface is converted into an equivalent undulating surface with a surface level according to the equivalent undulating surface elevation, and for each horizontal position point of the initial three-dimensional depth-velocity model, the real undulating surface velocity is replaced by the equivalent undulating surface velocity to obtain the equivalent three-dimensional depth-velocity model.

3. The physical model of an equivalent rough surface for solid surface acquisition method according to claim 2, wherein, The step of determining the equivalent undulating surface elevation according to the elevation range of the real undulating surface of the initial three-dimensional depth-velocity model comprises the following steps: the average value of the elevations of the real undulating surface of the initial three-dimensional depth-velocity model is calculated according to the elevation range of the real undulating surface of the initial three-dimensional depth-velocity model, and the average value is taken as the equivalent undulating surface elevation.

4. The physical model of an equivalent rough surface for solid surface acquisition method according to claim 2, wherein, The step of determining the equivalent undulating surface elevation according to the elevation range of the real undulating surface of the initial three-dimensional depth-velocity model comprises the following steps: any elevation value within the elevation range of the real undulating surface of the initial three-dimensional depth-velocity model is selected as the equivalent undulating surface elevation.

5. The physical model of an equivalent rough surface for solid surface acquisition method according to claim 1, wherein, The step of vertically installing the transmitting probe and the receiving probe on the upper surface of the equivalent physical model comprises the following steps: vertically installing the transmitting probe and the receiving probe on the upper surface of the equivalent undulating surface of the equivalent physical model; installing a force-adding fixing mechanism on the upper part of the transmitting probe and the receiving probe to make the transmitting probe and the receiving probe tightly adhere to the upper surface of the equivalent physical model.

6. The physical model of an equivalent rough surface for solid surface acquisition method of claim 1, wherein, The step of establishing an initial three-dimensional depth-velocity model according to the stratigraphic morphological characteristics and logging velocities of a target area comprises the following steps: determining the range of the target area and setting the grid size of the target area; According to the stratigraphic feature of the target area, the X coordinate, Y coordinate and Z coordinate of each grid point are determined; According to the logging velocity of the target area, the velocity value of each grid point is determined; Based on the X coordinate, Y coordinate, Z coordinate and velocity value of each grid point, the initial three-dimensional depth-velocity model is established according to a preset scale.

7. The method of claim 1, wherein the method further comprises: The equivalent physical model is made according to the equivalent three-dimensional depth-velocity model, including: According to the equivalent three-dimensional depth-velocity model, an equivalent relief surface of the equivalent physical model is made by using 3D multi-material printing technology.

8. The physical model of an equivalent rough surface method of claim 1, wherein, The coupling agent is honey or vaseline.

9. A solid surface acquisition device for an equivalent rough earth physical model, characterized by, The equivalent physical model, the excitation probe and the receiving probe are included; The excitation probe and the receiving probe are vertically installed on the upper surface of the equivalent physical model; The upper surface of the equivalent physical model is coated with a coupling agent; The equivalent physical model includes an equivalent relief surface and an underlying stratum below the equivalent relief surface; The surface of the equivalent relief surface is a horizontal plane; The equivalent relief surface is converted from the real relief surface of the initial three-dimensional depth-velocity model; The equivalent physical model has a relief surface equivalent velocity corresponding to the equivalent relief surface; The relief surface equivalent velocity is replaced by the relief surface real velocity of the initial three-dimensional depth-velocity model.

10. The solid surface acquisition device of the equivalent rough earth physical model of claim 9, wherein, A force fixing mechanism is installed on the upper part of the excitation probe and the receiving probe.

Images