CN117406269A - Surface layer constraint inversion modeling method and device based on ray depth matching - Google Patents

Abstract

The present disclosure relates to a method and apparatus for surface layer constraint inversion modeling based on ray depth matching, the method comprising: determining thickness distribution characteristics of a low deceleration strip in a surface medium of an exploration area; dividing the low deceleration strip into one or more thickness regions according to the thickness distribution characteristics; determining a target tomographic inversion ray depth matched with the smaller depth in the position relation and a corresponding target tomographic inversion offset according to the position relation between the surface layer investigation depth and each thickness region in the low-speed-down zone; taking the target chromatographic inversion offset distance as a constraint condition, performing surface layer constraint chromatographic inversion, and establishing a low-deceleration strip model; and carrying out inversion on the basis of the low-speed-reduction band model to obtain a surface layer model, wherein the surface layer model is used for representing the structural characteristics of the low-speed-reduction band in the surface layer medium or the structural characteristics of the low-speed-reduction band and the area below the low-speed-reduction band. The constructed surface model has higher precision.

Description

Surface layer constraint inversion modeling method and device based on ray depth matching

Technical Field

The disclosure relates to the technical field of oil and gas exploration and tomographic inversion, in particular to a surface layer constraint inversion modeling method and device based on ray depth matching.

Background

In the oil and gas exploration process, geological structures are usually explored based on seismic waves, and the propagation and echo of the seismic waves in the geological structures are utilized to analyze and obtain the geological physical structures and characteristics.

Aiming at some areas, the double complex exploration characteristics of the earth surface and the underground structure exist, and the underground structure is complex, the target is more and more hidden, and the lithology, the speed, the thickness and the like of the earth surface medium are changed severely, so that the signal-to-noise ratio of the obtained seismic data is extremely low. In particular, modeling accuracy caused by complex surface layer structure is not high, the influence of complex static correction on imaging is difficult to solve, the pre-stack depth migration imaging effect is influenced, and the method becomes a main difficulty for preventing high-precision imaging of seismic data in double complex areas from breaking through.

Disclosure of Invention

In order to solve or at least partially solve the technical problems found below: when facing complex terrains, when surface layer investigation points are arranged, the investigation depth of each investigation point is different in depth and uneven in dispersion, so that the constraint on the tomographic inversion is inaccurate, and the inversion error is larger; the speed anomaly zone is generated due to the mutual influence during inversion according to the constraint conditions established by the surface survey results with different depths and larger depth differences, so that the inversion model has lower precision; the embodiment of the disclosure provides a surface layer constraint inversion modeling method and device based on ray depth matching.

In a first aspect, embodiments of the present disclosure provide a method of surface-constrained inversion modeling based on ray depth matching. The method comprises the following steps: determining thickness distribution characteristics of a low deceleration strip in a surface medium of an exploration area; dividing the low deceleration strip into one or more thickness regions according to the thickness distribution characteristics; determining a target tomographic inversion ray depth matched with the smaller depth in the position relation and a corresponding target tomographic inversion offset according to the position relation between the surface layer investigation depth and each thickness region in the low-speed-down zone; taking the target chromatographic inversion offset distance as a constraint condition, performing surface layer constraint chromatographic inversion, and establishing a low-deceleration strip model; and carrying out inversion on the basis of the low-speed-reduction band model to obtain a surface layer model, wherein the surface layer model is used for representing the structural characteristics of the low-speed-reduction band in the surface layer medium or the structural characteristics of the low-speed-reduction band and the area below the low-speed-reduction band.

According to an embodiment of the present disclosure, determining, according to a positional relationship between a surface layer investigation depth and each thickness region in the low-speed-down zone, a target tomographic inversion ray depth and a corresponding target tomographic inversion offset that are matched with a smaller one of the positional relationships includes: determining whether the surface layer investigation depth of the investigation point in the current region is consistent with the thickness of the current region or not according to the thickness regions in the low-speed-down zone; determining a relatively smaller one of the surface layer investigation depth in the current region and the thickness of the current region if the position relationship is consistent; and determining the depth of the target tomographic inversion ray matched with the object to be matched and the corresponding target tomographic inversion offset by taking the relatively smaller object as the object to be matched.

According to the embodiment of the disclosure, when the surface layer investigation depth in the current area is greater than the thickness of the current area, determining a first tomographic inversion ray depth matched with the thickness of the current area as the target tomographic inversion ray depth, wherein the value of the first tomographic inversion ray depth exceeds the thickness of the current area by a preset grid size; the target tomographic inversion offset distance is a tomographic inversion offset distance corresponding to the first tomographic inversion ray depth; when the surface layer investigation depth in the current area is smaller than the thickness of the current area, determining a second tomographic inversion ray depth matched with the surface layer investigation depth in the current area as the target tomographic inversion ray depth, wherein the value of the second tomographic inversion ray depth exceeds the surface layer investigation depth maximum value of the current area by another preset grid size; the target tomographic inversion offset is a tomographic inversion offset corresponding to the second tomographic inversion ray depth.

According to an embodiment of the present disclosure, determining, according to a positional relationship between a surface layer investigation depth and each thickness region in the low-speed-down zone, a target tomographic inversion ray depth and a corresponding target tomographic inversion offset that are matched with a smaller one of the positional relationships, further includes: under the condition that the position relations are inconsistent, determining that the target position relation with relatively more checking points in the current area is a first position relation with the surface layer investigation depth smaller than the thickness of the current area or a second position relation with the surface layer investigation depth larger than the thickness of the current area; when the target positional relationship is a first positional relationship, determining a second tomographic inversion ray depth matching the surface layer investigation depth in the current region as a first tomographic inversion ray depth, and determining a first tomographic inversion ray depth matching the thickness of the current region as a second tomographic inversion ray depth, wherein the target tomographic inversion ray depth includes the first tomographic inversion ray depth and the second tomographic inversion ray depth, and the target tomographic inversion offset distance includes: a first-order tomographic inversion offset distance corresponding to the first-order tomographic inversion ray depth and a second-order tomographic inversion offset distance corresponding to the second-order tomographic inversion ray depth.

According to an embodiment of the present disclosure, performing surface-layer constrained tomographic inversion using the target tomographic inversion offset as a constraint condition, and establishing a low-deceleration strip model, including: performing surface layer constraint tomographic inversion based on the first-order tomographic inversion offset distance as a constraint condition to obtain a basic low-speed-down band model; and continuing surface layer constraint tomography inversion based on the secondary tomography inversion ray depth as a constraint condition on the basis of the basic low-deceleration strip model to obtain the low-deceleration strip model.

According to an embodiment of the present disclosure, determining, according to a positional relationship between a surface layer investigation depth and each thickness region in the low-speed-down zone, a target tomographic inversion ray depth and a corresponding target tomographic inversion offset that are matched with a smaller one of the positional relationships, further includes: and when the target position relation is a second position relation, determining a first tomographic inversion ray depth matched with the thickness of the current area as a target tomographic inversion ray depth, wherein the target tomographic inversion offset distance is a tomographic inversion offset distance corresponding to the first tomographic inversion ray depth.

According to an embodiment of the present disclosure, inversion is performed on the basis of the low-deceleration strip model to obtain a surface layer model, including: maintaining the model of the low-speed-reduction zone unchanged, and performing inversion and space domain (CMP) hierarchical control point constraint based on an adjustment offset distance, wherein the adjustment offset distance is an offset distance corresponding to an adjustment ray depth with a depth greater than the depth of the target tomographic inversion ray, so as to obtain speed information of an area below the surface layer investigation depth in the low-speed-reduction zone or speed information of a high-speed zone below the low-speed-reduction zone; generating a supplementary model according to the speed information; and integrating the low deceleration strip model and the supplementary model to obtain a surface layer model.

In a second aspect, embodiments of the present disclosure provide an apparatus for surface-constrained inversion modeling based on ray depth matching. The device comprises: the device comprises a thickness distribution determining module, a region dividing module, a ray depth matching module and a constraint inversion module. The thickness distribution determining module is used for determining thickness distribution characteristics of a low deceleration strip in a surface medium of an exploration area. The region dividing module is used for dividing the low-speed reducing belt into one or more thickness regions according to the thickness distribution characteristics. The ray depth matching module is used for determining a target tomographic inversion ray depth matched with the smaller depth in the position relation and a corresponding target tomographic inversion offset according to the position relation between the surface layer investigation depth and each thickness area in the low-speed-down zone. The constraint inversion module is used for performing surface layer constraint tomography inversion by taking the target tomography inversion offset as a constraint condition, and establishing a low-deceleration strip model. The constraint inversion module is further used for performing inversion on the basis of the low-speed-down band model to obtain a surface layer model, wherein the surface layer model is used for representing structural characteristics of the low-speed-down band in the surface layer medium or structural characteristics of the low-speed-down band and a region below the low-speed-down band.

In a third aspect, embodiments of the present disclosure provide an electronic device. The electronic equipment comprises a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory are communicated with each other through the communication bus; a memory for storing a computer program; and the processor is used for realizing the surface layer constraint inversion modeling method based on ray depth matching when executing the program stored in the memory.

In a fourth aspect, embodiments of the present disclosure provide a computer-readable storage medium. The computer readable storage medium has stored thereon a computer program which, when executed by a processor, implements a method of ray depth matching based surface layer constraint inversion modeling as described above.

Some technical solutions provided by the embodiments of the present disclosure at least have some or all of the following advantages:

dividing a low-speed-down zone into one or more thickness zones by determining thickness distribution characteristics of the low-speed-down zone in an exploration zone, and determining a target tomographic inversion ray depth matched with the lesser depth in the position relationship and a corresponding target tomographic inversion offset distance according to the position relationship between the surface layer investigation depth and each thickness zone in the low-speed-down zone, wherein the target tomographic inversion ray depth can be matched with different position relationships between the surface layer investigation depth and the low-speed-down zone. When facing to geological environments with complex surface, complex underground structure or double complex surface and underground structure, aiming at the situation that the surface investigation depth H is smaller than the thickness H of the corresponding thickness area or the surface investigation depth H is larger than at least one position relation above the thickness of the corresponding thickness area H, the method can be suitable for various position relations to obtain the adaptive target tomographic inversion ray depth and the corresponding target tomographic inversion offset, realizes effective combination and matching of surface discrete information with uneven depth and first-arrival information (the target tomographic inversion ray depth and the corresponding target tomographic inversion offset) in different ranges, avoids the under constraint phenomenon, reduces inversion errors caused by under constraint, ensures that the low-speed-down-belt speed information is accurate and true as far as possible, is not equivalent speed, and provides a high-precision speed field for static correction calculation and front depth offset imaging treatment of a complex region of a stack while solving the static correction problem.

Some technical solutions provided by the embodiments of the present disclosure at least have some or all of the following advantages:

when the surface layer investigation depth H is smaller than the thickness H of the corresponding thickness region or the surface layer investigation depth H is larger than the thickness H of the corresponding thickness region, the method can adapt to various positional relationships to obtain the adaptive target tomographic inversion ray depth and the corresponding target tomographic inversion offset. For example, when H > H, the depth of the target tomographic inversion ray matching the smaller depth in the above positional relationship can ensure that the thickness (also may be described as depth) of the low-speed zone matches the tomographic velocity, avoiding the homogenization effect of the deep ray on the shallow low-speed zone velocity, and the corresponding depth of the target tomographic inversion ray contains all the information of the surface layer investigation information, without the phenomenon of under-constraint, and the surface layer constraint depth reaches the high-speed layer. When H is smaller than H, the depth of the target chromatographic inversion ray matched with the person with smaller depth in the position relation can ensure that the constraint condition for carrying out chromatographic inversion is matched with the actual surface layer investigation information, and the ray depth contains all information of the surface layer investigation information at the moment, so that the phenomenon of under constraint is avoided, the problem of inaccurate equivalent speed caused by the data between H and H contained in the constraint condition can be avoided, and the fact that the information of the low deceleration band speed is accurate and true as much as possible and is not equivalent speed is ensured; the low-speed-down band model obtained by tomographic inversion construction is higher in accuracy, inversion is further carried out based on the low-speed-down band model, inversion can be carried out on areas with insufficient surface layer investigation depth H in the low-speed-down band, for example, areas between H and H (corresponding to the situation that H is less than H), or radiation tomographic inversion detection is carried out on areas with deeper layers below the low-speed-down band (areas with depth greater than H, for example, high-speed layers), and a final surface layer model is obtained.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description, serve to explain the principles of the disclosure.

In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings that are required to be used in the description of the embodiments or the related art will be briefly described below, and it will be apparent to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.

FIG. 1 schematically illustrates a flow chart of a method of ray depth matching based surface layer constraint inversion modeling in an embodiment of the present disclosure;

FIG. 2 schematically illustrates an effect diagram of dividing a low-speed down band into one or more thickness regions according to a thickness profile feature of the low-speed down band of an embodiment of the present disclosure;

FIG. 3 schematically illustrates a schematic diagram of determining a target tomographic inversion ray depth and a corresponding target tomographic inversion offset that match the lesser depth of the above-described positional relationship when the positional relationship within a certain region is that the surface layer investigation depth H is greater than the thickness H of the corresponding thickness region, in an embodiment of the present disclosure;

FIG. 4 schematically illustrates a schematic diagram of determining a target tomographic inversion ray depth and a corresponding target tomographic inversion offset that match the lesser depth of the above-described positional relationship when the positional relationship within a certain region is that the surface layer investigation depth H is less than the thickness H of the corresponding thickness region, in an embodiment of the present disclosure;

FIG. 5 schematically illustrates a detailed implementation flowchart of step S130 of an embodiment of the present disclosure;

FIG. 6 schematically illustrates a block diagram of an apparatus for ray depth matching based surface constraint inversion modeling in accordance with an embodiment of the present disclosure; and

fig. 7 schematically shows a block diagram of an electronic device provided by an embodiment of the present disclosure.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present disclosure more apparent, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present disclosure, and it is apparent that the described embodiments are some, but not all, embodiments of the present disclosure. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the disclosure, are within the scope of the disclosure.

A first exemplary embodiment of the present disclosure provides a method of surface-constrained inversion modeling based on ray depth matching.

FIG. 1 schematically illustrates a flow chart of a method of ray depth matching based surface layer constraint inversion modeling in an embodiment of the present disclosure.

Referring to fig. 1, a method for surface layer constraint inversion modeling based on ray depth matching according to an embodiment of the present disclosure includes the following steps: s110, S120, S130, S140, and S150. Steps S110 to S150 may be performed by an electronic device having a display screen.

In step S110, a thickness profile characteristic of a low deceleration strip in a surface medium of the survey area is determined.

In the oil and gas exploration process, a plurality of shot points are arranged on the surface of an exploration area, seismic waves are sent out by the shot points to explore a geological structure, and the propagation and echo of the seismic waves in the geological structure are utilized to analyze and obtain a geological physical structure and characteristics.

Due to the spatial variation of elevation, thickness and speed, when the seismic wave passes through the near surface, unequal delay time differences are generated on the near surface, so that the reflection time-distance curve of the seismic wave carries a large amount of noise. The surface media are divided into a low-velocity layer (typically less than 1000 m/s), a velocity-reducing layer (typically between 1000m/s and 2000 m/s) and a high-velocity layer (typically greater than 2000 m/s), typically a diagenetic layer, which in embodiments of the present disclosure are collectively referred to as a low-velocity zone.

In one embodiment, in the step S110, the thickness distribution characteristics of the low deceleration strip in the surface medium of the exploration area are obtained through first arrival layering in the spatial domain (CMP domain), which specifically includes: acquiring single shot first arrival data; displaying single shot first arrival data at different positions in a CMP domain, and carrying out refraction layering on the display data to obtain the thickness of a low speed reducing belt in surface layer media at different positions in the exploration area; and obtaining thickness distribution characteristics according to the thickness of the low deceleration strip in the surface layer medium at different positions. In practice, the thickness of the low descent speed zone is measured from the perspective of the ground down the plumb line, and can also be considered as depth.

In step S120, the low deceleration strip is divided into one or more thickness regions according to the thickness distribution characteristics.

Fig. 2 schematically illustrates an effect diagram of dividing a low-speed-down band into one or more thickness regions according to a thickness distribution feature of the low-speed-down band of an embodiment of the present disclosure.

For example, referring to fig. 2, the surface interface 210 is shown in thick solid lines, the low-deceleration strip interface 220 is shown in thin solid lines, the shots 201 are shown in circles distributed at different locations of the surface interface 210, and the thickness of the low-deceleration strip refers to the depth dimension from the surface interface 210 to the low-deceleration strip interface 220. In the embodiment corresponding to the topography illustrated in fig. 2, the thickness profile features are, in order from left to right along the horizontal line in fig. 2: huge thickness, thick, thinner, thicker, etc., dividing the huge and thick front region into the thickness region of the mountain front belt 231, the thinner middle region into the thickness region of the construction top 232, and the thicker tail region into the thickness region of the construction wing 233.

In step S130, a target tomographic inversion ray depth and a corresponding target tomographic inversion offset distance, which are matched with the one having the smaller depth in the above-mentioned positional relationship, are determined according to the positional relationship between the surface layer investigation depth and each thickness region in the above-mentioned low-speed zone.

The velocity model is established based on the tomographic inversion, various phenomena of seismic wave propagation in near-surface medium are considered, the longitudinal and transverse changes of the seismic wave velocity in a complex near-surface velocity structure can be described, and the method is a surface modeling technology with strong adaptability. However, as a generalized linear inversion algorithm, the tomographic inversion has the problem of multi-solution and equivalence in practical application. Therefore, initial condition constraint is required to be added in the inversion process, so that the accuracy of the inversion model is improved. In some embodiments, inversion constraints may be imposed by employing surface survey information, which is typically obtained by means of surface surveys of small refraction, micro-logs, and the like. The small refraction mode is suitable for the flat ground surface with a simple surface structure; the 'double complex' areas with severe relief and complex underground structures generally adopt a micro-logging investigation mode.

In the process of realizing the technical conception of the present disclosure, it is found that, for complex terrains, for example, for dual complex terrains with complex surface structures and subsurface structures, the existing surface investigation mode has a plurality of technical defects: the method is comprehensively influenced by the arrangement length, the drilling capability of micro-well logging, the earth surface structure, the construction environment, the cost investment and the like, and the actual detection depth of micro-well logging or small refraction is different in depth and uneven in spread; the investigation result of the points is used for restricting thinner speed change, inversion errors caused by 'under restriction' of relatively deep parts are larger, and surface layer information with shallow investigation depth is difficult to effectively use; meanwhile, the surface survey results with different depths and larger depth difference are mutually influenced during constraint inversion, so that a speed abnormal region is easy to form, and adverse effects are brought to a speed model.

In view of this, according to the embodiment of the disclosure, the depth of the target tomographic inversion ray and the corresponding target tomographic inversion offset distance matched with the depth in the above-mentioned positional relationship are determined according to the positional relationship between the depth of the surface investigation and each thickness region in the above-mentioned low-speed-down zone, and the low-speed-down zone model is built by using this target tomographic inversion offset distance as the constraint condition of the tomographic inversion, so that the error of the obtained low-speed-down zone model is small and the accuracy is high, and the model is suitable for the situation that the actual detection depth is different and the under-constraint phenomenon can be avoided.

Based on step S130, when at least one of the surface layer investigation depth H is smaller than the thickness H of the corresponding thickness region or the surface layer investigation depth H is greater than the thickness of the corresponding thickness region H is present, the adapted target tomographic inversion ray depth and the corresponding target tomographic inversion offset can be obtained in accordance with various positional relationships.

The target tomographic inversion offset can be adapted to each thickness region and skin investigation depth.

Fig. 3 schematically illustrates a schematic diagram of determining a target tomographic inversion ray depth and a corresponding target tomographic inversion offset that match the lesser depth of the above-described positional relationship when the positional relationship in a certain region is that the surface layer investigation depth H is greater than the thickness H of the corresponding thickness region in the embodiment of the present disclosure.

In fig. 3, the positional relationship among the three thickness regions of the mountain front band 231, the structural top 232, and the structural wing 233 is: h > H as an example, in other embodiments, there may be some positional relationship of H < H in the thickness region, such as shown in the embodiment described later with reference to FIG. 4, where H < H is present in the pre-mountain strap 231.

In this embodiment, referring to fig. 3, when H > H, the target tomographic inversion ray depth matching the depth smaller (thickness H of the thickness region) in the above positional relationship is determined in step S130, so that it is possible to ensure that the thickness (which may also be described as depth) of the low deceleration strip matches the tomographic ray velocity, avoid the homogenization effect of the deep rays on the shallow low deceleration strip velocity, and the corresponding target tomographic inversion ray depth contains all the surface layer investigation information (for example, information including the geological structure corresponding to the surface layer investigation depth), and there is no under-constraint phenomenon, and the surface layer constraint depth reaches the high-speed layer.

In some embodiments, in a certain thickness region, the thickness of the region may be slightly greater than the thickness H of the current thickness region, for example, by a preset mesh size exceeding the thickness H of the current thickness region, where the preset mesh size may be a preset parameter, for example, 1-2 meshes. For example, the preset mesh size is, for example, 5m to 10m for a thickness of about 200 m.

Fig. 4 schematically illustrates a schematic diagram of determining a target tomographic inversion ray depth and a corresponding target tomographic inversion offset that match the lesser depth of the above-described positional relationship when the positional relationship in a certain region is that the surface layer investigation depth H is smaller than the thickness H of the corresponding thickness region according to the embodiment of the present disclosure. The surface layer depth of investigation is illustrated in fig. 4 by columns.

Referring to fig. 4, the positional relationship in the area of the mountain front belt 231 is: h < H is an example. When H is smaller than H, the target tomographic inversion ray depth matched with the smaller depth (surface layer investigation depth H) in the position relation can ensure that the constraint condition for performing tomographic inversion is matched with the actual surface layer investigation information (such as the information of a geological structure corresponding to the surface layer investigation depth H), at the moment, the ray depth contains all the information of the surface layer investigation information, the phenomenon of under constraint is avoided, the problem of inaccurate equivalent speed caused by the data between H and H contained in the constraint condition can be avoided, and the fact that the information of a low speed-reducing belt is accurate and true as far as possible is not equivalent speed is ensured; the low-speed-down band model obtained by tomographic inversion construction is higher in accuracy, inversion is further carried out based on the low-speed-down band model, inversion can be carried out on areas with insufficient surface layer investigation depth H in the low-speed-down band, for example, areas between H and H (corresponding to the situation that H is less than H), or radiation tomographic inversion detection is carried out on areas with deeper layers below the low-speed-down band (areas with depth greater than H, for example, high-speed layers), and a final surface layer model is obtained.

In step S140, the surface layer constraint tomographic inversion is performed using the target tomographic inversion offset as a constraint condition, and a low deceleration strip model is established.

In step S150, inversion is performed on the basis of the low-deceleration strip model to obtain a surface model, where the surface model is used to characterize structural features of the low-deceleration strip in the surface medium or structural features of the low-deceleration strip and a region below the low-deceleration strip.

Based on the steps S110 to S150, by determining the thickness distribution characteristics of the low deceleration strip in the exploration area, the low deceleration strip is divided into one or more thickness areas, and a target tomographic inversion ray depth and a corresponding target tomographic inversion offset distance, which are matched with the lesser depth of the positional relationship, are determined according to the positional relationship between the surface layer investigation depth and each thickness area in the low deceleration strip, the target tomographic inversion ray depth being capable of being matched with the different positional relationship between the surface layer investigation depth and the low deceleration strip. When facing to geological environments with complex surface, complex underground structure or double complex surface and underground structure, aiming at the situation that the surface investigation depth H is smaller than the thickness H of the corresponding thickness area or the surface investigation depth H is larger than at least one position relation above the thickness of the corresponding thickness area H, the method can be suitable for various position relations to obtain the adaptive target tomographic inversion ray depth and the corresponding target tomographic inversion offset, realizes effective combination and matching of surface discrete information with uneven depth and first-arrival information (the target tomographic inversion ray depth and the corresponding target tomographic inversion offset) in different ranges, avoids the under constraint phenomenon, reduces inversion errors caused by under constraint, ensures that the low-speed-down-belt speed information is accurate and true as far as possible, is not equivalent speed, and provides a high-precision speed field for static correction calculation and front depth offset imaging treatment of a complex region of a stack while solving the static correction problem.

In the same thickness region, a plurality of investigation points exist at the same time, the position relation between the surface investigation depth of each investigation point and the thickness of the current region is consistent in most cases, and in some implementation scenarios, the position relation may be inconsistent, for example, in the same thickness region, the surface investigation depth of some investigation points is greater than the thickness of the current region, and the surface investigation depth of some investigation points is less than the thickness of the current region. For such a scenario, embodiments of the present disclosure also propose processing logic to determine target tomographic inversion ray depths and corresponding target tomographic inversion offsets based on whether the positional relationships are consistent. For a scene where the normal positional relationship is consistent, the branching of the positional relationship may be executed. Details are described below in conjunction with fig. 5.

Fig. 5 schematically shows a detailed implementation flowchart of step S130 of an embodiment of the present disclosure.

According to an embodiment of the present disclosure, referring to fig. 5, in step S130, determining, according to a positional relationship between a surface layer investigation depth and each thickness region in the low-speed-down zone, a target tomographic inversion ray depth and a corresponding target tomographic inversion offset distance, which are matched with a depth smaller in the positional relationship, includes: s510, S520a, and S530a.

In step S510, it is determined whether or not the positional relationship between the surface layer investigation depth of the investigation point in the current region and the thickness of the current region is identical for each thickness region in the low deceleration strip.

In step S520a, in the case where the positional relationship is identical, the surface layer investigation depth in the current region is determined to be relatively smaller than the thickness of the current region.

In step S530a, the relatively smaller object is used as the object to be matched, and the target tomographic inversion ray depth and the corresponding target tomographic inversion offset matched with the object to be matched are determined.

According to an embodiment of the present disclosure, when the surface layer investigation depth H in the current region is greater than the thickness H of the current region, for example, as shown in fig. 3, when H > H, a first tomographic inversion ray depth matching the thickness of the current region is determined as the target tomographic inversion ray depth, and the target tomographic inversion offset is a tomographic inversion offset corresponding to the first tomographic inversion ray depth. The depth of the first tomographic inversion ray exceeds the thickness H of the current region by a predetermined mesh size (for example, 1 to 2 mesh sizes). The corresponding target tomographic inversion offset for the thickness region when H > H is denoted herein as L.

For example, in one embodiment, for the case of H > H, offset inversion scans are performed using all shots: preliminary tomographic inversion experiments of offset first arrival data were performed using 100m, 200m, 300m, 400m, … …, etc. Based on the matching of the depth of the tomographic inversion ray and the thickness of the low-speed-down band, determining the surface inversion offset range of different areas, for example, the thickness of the thickness area of the front mountain area 231 in the low-speed-down band is 200m, and obtaining the maximum thickness (slightly larger than the preset mesh size of the maximum thickness of the thickness area and the example, which is not described in detail herein) of the tomographic inversion ray depth of the thickness area of the front mountain area 231 when the offset is 600m through an offset inversion experiment, so that the target tomographic inversion offset of the thickness area of the front mountain area 231 can be determined to be about 600 m; similarly, the thickness of the thickness region of the top 232 constructed in the low deceleration strip is 50m, and the corresponding target tomographic inversion offset is 200m based on the same inversion test mode; the thickness of the build wing 233 in the low deceleration strip is 100m, corresponding to a target tomographic inversion offset of 400m.

The first arrival offset range of different areas is realized: and selecting shots of the area according to the determined offset range of the areas with different thicknesses, and limiting the range of the inversion first arrival data. For example, the first-arrival data of the shots of the pre-mountain zone 231 is limited to the range of 0-600m, the first-arrival data of the shots of the structural top 232 is limited to the range of 0-200m, and the first-arrival data of the shots of the structural wing 233 is limited to the range of 0-400m, so that the low-speed-reduction zone thickness is ensured to be matched with the chromatographic ray speed, and the homogenization influence of deep rays on the shallow low-speed-reduction zone speed is avoided.

When the low-deceleration strip model is established by performing the tomographic inversion based on the range limitation as the constraint condition, the constraint condition corresponding to the ray depth contains all information of the surface layer investigation information, and the phenomenon of under constraint does not exist.

According to an embodiment of the present disclosure, when the surface layer investigation depth H in the current region is smaller than the thickness H of the current region, for example, as shown in fig. 4, when H < H, a second tomographic inversion ray depth that matches the surface layer investigation depth H in the current region is determined as the target tomographic inversion ray depth, and the target tomographic inversion offset is a tomographic inversion offset corresponding to the second tomographic inversion ray depth. The second tomographic inversion ray depth is greater than the surface survey depth maximum value of the current region by another predetermined grid size (e.g., 0, 1, or 2 grid sizes, etc.). The corresponding target tomographic inversion offset for the thickness region when H < H is denoted here as r.

In this embodiment, when H < H, the ray depth is selected to be slightly larger than the surface layer investigation maximum depth, and the offset range (denoted as r) at this time is determined, and the ray depth includes all the surface layer investigation information at this time, so that the under-constraint phenomenon does not exist. And adopting the offset range r to perform constraint inversion. When H is smaller than H, the offset distance of r is used as a constraint condition in the region, surface layer constraint tomography inversion is carried out, and a low-deceleration strip model is built.

According to an embodiment of the present disclosure, referring to fig. 5, the above step S130 includes the following steps in addition to the above steps S510, S520a, and S530 a: s520b and S531b; in other embodiments, as shown with reference to the dashed box in fig. 5, a branching step S532b of the target positional relationship being the second positional relationship may be further included.

In step S520b, if the position relationships are inconsistent, it is determined that the target position relationship with a relatively large number of check points in the current region is the first position relationship in which the surface layer investigation depth H is smaller than the thickness H of the current region or the second position relationship in which the surface layer investigation depth H is greater than the thickness H of the current region.

In step S531b, when the target positional relationship is the first positional relationship, determining a second tomographic inversion ray depth matching the surface layer investigation depth H in the current region as a first tomographic inversion ray depth, and determining a first tomographic inversion ray depth matching the thickness H of the current region as a second tomographic inversion ray depth, wherein the target tomographic inversion ray depth includes the first tomographic inversion ray depth and the second tomographic inversion ray depth, and the target tomographic inversion offset distance includes: a first-order tomographic inversion offset corresponding to the first-order tomographic inversion ray depth and a second-order tomographic inversion offset corresponding to the second-order tomographic inversion ray depth, for example, include: the first-order tomographic inversion offset corresponds to a target tomographic inversion offset r when H < H, and the second-order tomographic inversion offset corresponds to a target tomographic inversion offset L when H > H.

In the embodiment including step S531b, in step S140, performing surface-layer constrained tomographic inversion using the target tomographic inversion offset as a constraint condition, and establishing a low-deceleration strip model includes: performing surface layer constraint tomographic inversion based on the first-order tomographic inversion offset (r for example) as a constraint condition to obtain a basic low-speed-down band model; and continuing surface layer constraint tomography inversion based on the secondary tomography inversion ray depth (for example, L) serving as a constraint condition on the basis of the basic low-deceleration strip model to obtain the low-deceleration strip model.

In step S532b, when the target positional relationship is the second positional relationship, the first tomographic inversion ray depth matching the thickness H of the current region is determined as the target tomographic inversion ray depth, and the target tomographic inversion offset is a tomographic inversion offset corresponding to the first tomographic inversion ray depth.

In the embodiment including the steps { S510, S520a and S530a }, or { S510, S520a, S530a, S520b and S531b }, or { S510, S520a, S530a, S520b, S531b and S532b }, the depth of the low-speed band (which may be described as depth) can be ensured to match the velocity of the chromatographic beam, and the depth of the corresponding target chromatographic inversion beam includes all the information of the surface layer investigation information, and the phenomenon of under-constraint is avoided, and the depth of the surface layer constraint reaches the high-speed layer, regardless of whether the certain thickness region is H > H, H < H, or the condition that H > H and H < H exist in the same thickness region, and when H > H, the depth of the target chromatographic inversion beam matches with the smaller depth of the above positional relationship. When H is smaller than H, the depth of the target tomographic inversion ray matched with the person with smaller depth in the position relation can ensure that the constraint condition for tomographic inversion is matched with the actual surface layer investigation information, at the moment, the depth of the ray contains all information of the surface layer investigation information, the phenomenon of under constraint is avoided, the problem of inaccurate equivalent speed caused by the data between H and H contained in the constraint condition can be avoided, and the fact that the information of the low deceleration band speed is accurate and true as much as possible and is not equivalent speed is ensured.

In step S150, the low deceleration strip model obtained in the foregoing step S140 is used as a basis (it is guaranteed that the low deceleration strip speed information is as accurate and true as possible, and is not equivalent speed), the shallow base model is kept as unchanged as possible (inversion weight setting is achieved through professional software), the deep reliable speed information below the high-speed top is obtained by adopting large offset inversion and CMP domain layered control point constraint, and a surface layer model is built, so as to lay a foundation for the subsequent prestack depth offset modeling.

In an embodiment, in the step S150, inversion is performed on the basis of the low-deceleration strip model to obtain a surface model, which includes: maintaining the model of the low-speed-reduction zone unchanged, and performing inversion and space domain (CMP) hierarchical control point constraint based on an adjustment offset distance, wherein the adjustment offset distance is an offset distance corresponding to an adjustment ray depth with a depth greater than the depth of the target tomographic inversion ray, so as to obtain speed information of an area below the surface layer investigation depth in the low-speed-reduction zone or speed information of a high-speed zone below the low-speed-reduction zone; generating a supplementary model according to the speed information; and integrating the low deceleration strip model and the supplementary model to obtain a surface layer model.

Because the accuracy of the constructed low-speed-down band model is higher, inversion is further carried out based on the low-speed-down band model, and inversion can be continuously carried out on areas with insufficient surface layer investigation depth H in the low-speed-down band, for example, areas between H and H (corresponding to the situation that H is less than H), or radiation tomography inversion detection is carried out on areas with deeper layers below the low-speed-down band (areas with depth greater than H, for example, high-speed layers), so that a final surface layer model (which is a surface layer speed model) is obtained.

In an application example, the method provided by the embodiment of the disclosure is adopted to perform actual exploration and application in the three-dimensional earthquake depth migration treatment of double complex terrain areas such as a hero area of a Qidamu basin, a grotto area of a spring basin and the like. By the application of the method, the application effect of the surface survey speed information of the micro-logs with different depths is fully exerted, the modeling precision of the surface model in the double complex scene of the surface structure and the underground structure of the region is improved, the equivalent mode of conventionally adopting the surface speed is broken through, the surface model is enabled to be closer to the real speed, and the precision of the pre-stack depth migration imaging of the seismic data of the complex region is improved.

It will be appreciated that although embodiments of the present disclosure may effectively address the problem of low model accuracy for complex terrain, the method may be equally applicable to simple terrain.

A second exemplary embodiment of the present disclosure provides an apparatus for surface-constrained inversion modeling based on ray depth matching.

FIG. 6 schematically illustrates a block diagram of an apparatus for ray depth matching based surface layer constraint inversion modeling in accordance with an embodiment of the present disclosure.

Referring to fig. 6, an apparatus 600 for surface constraint inversion modeling based on ray depth matching according to an embodiment of the present disclosure includes: a thickness profile determination module 601, a region division module 602, a ray depth matching module 603, and a constraint inversion module 604.

The thickness profile determination module 601 is configured to determine thickness profile characteristics of low deceleration strips in the surface medium of the survey area.

The region dividing module 602 is configured to divide the low-speed zone into one or more thickness regions according to the thickness distribution characteristics.

The ray depth matching module 603 is configured to determine, according to a positional relationship between a surface layer investigation depth and each thickness region in the low-speed-down band, a target tomographic inversion ray depth and a corresponding target tomographic inversion offset that are matched with a depth that is smaller in the positional relationship.

The constraint inversion module 604 is configured to perform surface-layer constraint tomographic inversion using the target tomographic inversion offset as a constraint condition, and establish a low-deceleration strip model.

The constraint inversion module 604 is further configured to invert the model of the low-deceleration strip to obtain a surface model, where the surface model is used to characterize structural features of the low-deceleration strip or structural features of the low-deceleration strip and a region below the low-deceleration strip in the surface medium.

Each functional module in the apparatus provided in this embodiment may further include a functional module or a sub-module that can implement each refinement step corresponding to the first embodiment, which may be understood with reference to the refinement step in the first embodiment, and will not be described herein again.

Any of the thickness profile determination module 601, the region division module 602, the ray depth matching module 603, and the constraint inversion module 604 described above may be incorporated in one module to be implemented, or any of the modules may be split into a plurality of modules. Alternatively, at least some of the functionality of one or more of the modules may be combined with at least some of the functionality of other modules and implemented in one module. At least one of the thickness profile determination module 601, the region division module 602, the ray depth matching module 603, and the constraint inversion module 604 may be implemented at least in part as a hardware circuit, such as a Field Programmable Gate Array (FPGA), a Programmable Logic Array (PLA), a system on a chip, a system on a substrate, a system on a package, an Application Specific Integrated Circuit (ASIC), or may be implemented in hardware or firmware in any other reasonable manner of integrating or packaging the circuit, or in any one of or a suitable combination of three of software, hardware, and firmware. Alternatively, at least one of the thickness profile determination module 601, the region division module 602, the ray depth matching module 603, and the constraint inversion module 604 may be at least partially implemented as a computer program module that, when executed, performs the corresponding functions.

A third exemplary embodiment of the present disclosure provides an electronic device.

Fig. 7 schematically shows a block diagram of an electronic device provided by an embodiment of the present disclosure.

Referring to fig. 7, an electronic device 700 provided by an embodiment of the present disclosure includes a processor 701, a communication interface 702, a memory 703, and a communication bus 704, where the processor 701, the communication interface 702, and the memory 703 complete communication with each other through the communication bus 704; a memory 703 for storing a computer program; the processor 701 is configured to implement the method of surface constraint inversion modeling based on ray depth matching as described above when executing the program stored in the memory.

The fourth exemplary embodiment of the present disclosure also provides a computer-readable storage medium. The computer readable storage medium has stored thereon a computer program which, when executed by a processor, implements a method of ray depth matching based surface layer constraint inversion modeling as described above.

The computer-readable storage medium may be embodied in the apparatus/means described in the above embodiments; or may exist alone without being assembled into the apparatus/device. The computer-readable storage medium carries one or more programs which, when executed, implement methods in accordance with embodiments of the present disclosure.

According to embodiments of the present disclosure, the computer-readable storage medium may be a non-volatile computer-readable storage medium, which may include, for example, but is not limited to: a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this disclosure, a computer-readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

It should be noted that in this document, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The foregoing is merely a specific embodiment of the disclosure to enable one skilled in the art to understand or practice the disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A method of surface layer constraint inversion modeling based on ray depth matching, comprising:

determining thickness distribution characteristics of a low deceleration strip in a surface medium of an exploration area;

dividing the low deceleration strip into one or more thickness regions according to the thickness profile;

determining a target tomographic inversion ray depth matched with the smaller depth in the position relation and a corresponding target tomographic inversion offset according to the position relation between the surface layer investigation depth and each thickness region in the low-speed-down zone;

taking the target chromatographic inversion offset distance as a constraint condition, performing surface layer constraint chromatographic inversion, and establishing a low-deceleration strip model;

And carrying out inversion on the basis of the low-speed-reduction belt model to obtain a surface layer model, wherein the surface layer model is used for representing the structural characteristics of the low-speed-reduction belt in the surface layer medium or the structural characteristics of the low-speed-reduction belt and the area below the low-speed-reduction belt.

2. The method of claim 1, wherein determining a target tomographic inversion ray depth and a corresponding target tomographic inversion offset that match the lesser of the locations based on the locations of the skin survey depth and the thickness regions in the low deceleration strip comprises:

determining whether the surface layer investigation depth of the investigation point in the current region is consistent with the thickness of the current region or not according to the thickness regions in the low-speed-reduction zone;

determining a relatively smaller one of the surface layer investigation depth in the current region and the thickness of the current region if the position relationship is consistent;

and taking the relatively smaller object as an object to be matched, and determining the depth of the target tomographic inversion ray matched with the object to be matched and the corresponding target tomographic inversion offset.

3. The method of claim 2, wherein the step of determining the position of the substrate comprises,

when the surface layer investigation depth in the current area is larger than the thickness of the current area, determining a first tomographic inversion ray depth matched with the thickness of the current area as the target tomographic inversion ray depth, wherein the value of the first tomographic inversion ray depth exceeds the thickness of the current area by a preset grid size; the target tomographic inversion offset distance is a tomographic inversion offset distance corresponding to the first tomographic inversion ray depth;

When the surface layer investigation depth in the current area is smaller than the thickness of the current area, determining a second tomographic inversion ray depth matched with the surface layer investigation depth in the current area as the target tomographic inversion ray depth, wherein the value of the second tomographic inversion ray depth exceeds the surface layer investigation depth maximum value of the current area by another preset grid size; and the target tomographic inversion offset distance is a tomographic inversion offset distance corresponding to the depth of the second tomographic inversion ray.

4. The method of claim 2, wherein determining a target tomographic inversion ray depth and a corresponding target tomographic inversion offset that match the lesser of the locations based on the locations of the skin survey depth and the thickness regions in the low deceleration strip further comprises:

under the condition that the position relations are inconsistent, determining that the target position relation with relatively more checking points in the current area is a first position relation with the surface layer investigation depth smaller than the thickness of the current area or a second position relation with the surface layer investigation depth larger than the thickness of the current area;

when the target position relationship is a first position relationship, determining a second tomographic inversion ray depth matched with the surface layer investigation depth in the current region as a first tomographic inversion ray depth, and determining a first tomographic inversion ray depth matched with the thickness of the current region as a second tomographic inversion ray depth, wherein the target tomographic inversion ray depth comprises the first tomographic inversion ray depth and the second tomographic inversion ray depth, and the target tomographic inversion offset distance comprises: a first-order tomographic inversion offset corresponding to the first-order tomographic inversion ray depth and a second-order tomographic inversion offset corresponding to the second-order tomographic inversion ray depth.

5. The method of claim 4, wherein performing surface-constrained tomography inversion using the target tomography inversion offset as a constraint, and establishing a low-deceleration strip model, comprises:

performing surface layer constraint tomographic inversion based on the first-order tomographic inversion offset distance as a constraint condition to obtain a basic low-speed-down band model;

and continuing to perform surface layer constraint tomography inversion based on the secondary tomography inversion ray depth as a constraint condition on the basis of the basic low-deceleration strip model to obtain the low-deceleration strip model.

6. The method of claim 4, wherein determining a target tomographic inversion ray depth and a corresponding target tomographic inversion offset that match the lesser of the locations based on the locations of the skin survey depth and the thickness regions in the low deceleration strip further comprises:

and when the target position relationship is a second position relationship, determining a first tomographic inversion ray depth matched with the thickness of the current region as a target tomographic inversion ray depth, wherein the target tomographic inversion offset distance is a tomographic inversion offset distance corresponding to the first tomographic inversion ray depth.

7. The method of claim 1, wherein inverting based on the low deceleration strip model results in a skin model, comprising:

maintaining the model of the low-speed-reduction zone unchanged, and carrying out inversion and space domain layering control point constraint based on an adjustment offset distance, wherein the adjustment offset distance is an offset distance corresponding to an adjustment ray depth with a depth greater than the depth of the target tomographic inversion ray, so as to obtain speed information of an area below the surface layer investigation depth in the low-speed-reduction zone or speed information of a high-speed zone below the low-speed-reduction zone;

generating a supplementary model according to the speed information;

and integrating the low deceleration strip model and the supplementary model to obtain a surface layer model.

8. A ray depth matching-based surface constraint inversion modeling apparatus, comprising:

the thickness distribution determining module is used for determining thickness distribution characteristics of a low speed reduction zone in a surface medium of the exploration area;

the region dividing module is used for dividing the low speed reducing belt into one or more thickness regions according to the thickness distribution characteristics;

the ray depth matching module is used for determining a target tomographic inversion ray depth matched with the smaller depth in the position relation and a corresponding target tomographic inversion offset according to the position relation between the surface layer investigation depth and each thickness area in the low-speed-down zone;

The constraint inversion module is used for performing surface layer constraint tomography inversion by taking the target tomography inversion offset as a constraint condition, and establishing a low deceleration strip model;

the constraint inversion module is further used for performing inversion on the basis of the low-speed-reduction zone model to obtain a surface layer model, and the surface layer model is used for representing structural characteristics of the low-speed-reduction zone in the surface layer medium or structural characteristics of the low-speed-reduction zone and a region below the low-speed-reduction zone.

9. The electronic equipment is characterized by comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory are communicated with each other through the communication bus;

a memory for storing a computer program;

a processor for implementing the method of any of claims 1-7 when executing a program stored on a memory.

10. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the method of any of claims 1-7.