Method and device for determining anisotropy parameters in a formation, and storage medium

Abstract

The application discloses a method and device for determining anisotropy parameters in a stratum and a storage medium. The method comprises the following steps: determining a detection point; controlling an excitation point around the detection point to excite a wave, and obtaining a detection first-arrival time length corresponding to the excitation point at a predetermined receiving depth position below the detection point, wherein the receiving depth position is in a corresponding predetermined stratum, and the detection first-arrival time length is a time length required for a wave excited by the excitation point to reach the receiving depth position for the first time; determining a plurality of candidate anisotropy parameters; determining reflection wave time lengths corresponding to the plurality of candidate anisotropy parameters respectively in the receiving depth position based on a preset target direction angle; and determining a target anisotropy parameter of the predetermined stratum at the target direction angle based on the reflection wave time lengths corresponding to the plurality of candidate anisotropy parameters respectively and the detection first-arrival time length. The application solves the technical problem that the accuracy of anisotropy parameters in the related art is not ideal.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of seismic exploration data acquisition, in particular to a method and device for determining anisotropy parameters in a stratum and a storage medium. BACKGROUND

[0002] Seismic exploration is a main method for finding and exploring oil and natural gas. Conventional seismic data processing methods are all based on the assumption of an isotropic medium model. However, research and exploration show that the azimuthal velocity anisotropy of a stratum is generally present, that is, the velocity of a seismic wave propagating in a medium will be different due to different propagation directions. With the gradual improvement of exploration accuracy, seismic data processing based on an isotropic medium cannot meet the requirement of accurately describing complex underground structures. In particular, in a region with complex surface conditions, such as a mountain front transition zone, a desert and the like, there is strong anisotropy in a shallow surface layer, which further leads to the problem of inaccurate determination of anisotropy parameters.

[0003] At present, no effective solution has been proposed for the above problem. SUMMARY

[0004] The embodiments of the present application provide a method and device for determining anisotropy parameters in a stratum and a storage medium, to at least solve the technical problem of inaccurate anisotropy parameters in the related art.

[0005] According to an aspect of the embodiments of the present application, a method for determining anisotropy parameters in a stratum is provided, including: determining a detection point; controlling a shot point around the detection point to excite a wave, and obtaining a detection first arrival time length corresponding to the shot point at a predetermined receiving depth position below the detection point, wherein the receiving depth position is in a corresponding predetermined stratum, and the detection first arrival time length is a time length required for a wave excited by the shot point to first reach the receiving depth position; determining a plurality of candidate anisotropy parameters; determining reflection wave time lengths corresponding to the plurality of candidate anisotropy parameters respectively in the receiving depth position based on a preset target direction angle; and determining a target anisotropy parameter of the predetermined stratum at the target direction angle based on the reflection wave time lengths corresponding to the plurality of candidate anisotropy parameters respectively and the detection first arrival time length.

[0006] Optionally, the determining the target anisotropy parameter of the predetermined formation at the target direction angle based on the reflection time length corresponding to each of the plurality of candidate anisotropy parameters and the detection first arrival time length comprises: performing elevation difference correction on the detection first arrival time length of the receiving depth position to obtain a corrected first arrival time length of the receiving depth position; determining the target anisotropy parameter based on the reflection time length corresponding to each of the plurality of candidate anisotropy parameters of the receiving depth position and the corrected first arrival time length of the receiving depth position.

[0007] Optionally, the plurality of excitation points are provided, and the performing elevation difference correction on the detection first arrival time length of the receiving depth position to obtain a corrected first arrival time length of the receiving depth position comprises: determining direction angles of the plurality of excitation points towards the detection point respectively; determining a first number of excitation points in a predetermined angle range based on the direction angles corresponding to the plurality of excitation points respectively, wherein the predetermined angle range is determined based on the target direction angle; determining detection first arrival time lengths corresponding to the first number of excitation points respectively; performing elevation difference correction on the detection first arrival time lengths corresponding to the first number of excitation points respectively based on a first elevation of the detection point, a second elevation of the excitation point and a vertical average velocity to obtain first arrival time lengths corresponding to the first number of excitation points respectively, wherein the vertical average velocity is an average velocity from a ground surface of the detection point to the receiving depth position; and determining the corrected first arrival time length based on the first arrival time lengths corresponding to the first number of excitation points respectively.

[0008] Optionally, the determining the target anisotropy parameter of the predetermined formation at the target direction angle based on the reflection time length corresponding to each of the plurality of candidate anisotropy parameters and the detection first arrival time length comprises: determining time length error values corresponding to the plurality of candidate anisotropy parameters respectively based on the reflection time length corresponding to each of the plurality of candidate anisotropy parameters and the detection first arrival time length obtained at the receiving depth position; in a case where the receiving depth position is a plurality of receiving depth positions, determining average error values corresponding to the plurality of candidate anisotropy parameters based on the time length error values corresponding to the plurality of candidate anisotropy parameters respectively of each of the plurality of receiving depth positions; and determining the target anisotropy parameter as the candidate anisotropy parameter with the minimum average error value in the plurality of candidate anisotropy parameters.

[0009] Optionally, determining the detection point includes: determining a three-dimensional work area obtained by performing three-dimensional modeling on the work area where the detection point is located, wherein the three-dimensional work area is composed of multiple sub-areas, and the multiple sub-areas respectively correspond to sub-area gathers, and the sub-area gathers are composed of common center point gathers of the corresponding sub-areas; performing ellipse fitting on the multiple sub-area gathers respectively to determine the major axis and minor axis of the ellipse corresponding to the multiple sub-area gathers respectively; based on the major axis and minor axis of the ellipse corresponding to the multiple sub-area gathers respectively, determining the apparent anisotropy strength corresponding to the multiple sub-areas respectively; and determining the detection point based on the apparent anisotropy strength corresponding to the multiple sub-areas respectively.

[0010] Optionally, after determining the detection point, the method further includes: obtaining the formation thickness and layer velocity corresponding to multiple formations at the location of the detection point, wherein the multiple formations include the predetermined formation; based on the formation thickness and layer velocity corresponding to the multiple formations, and the predetermined high-speed layer velocity, determining the well source distance between the detection point and the excitation point on the surface.

[0011] Optionally, the isotropic medium characteristics at the detection point match the characteristics of the transversely isotropic medium of the horizontal column symmetry axis, and the target anisotropy parameter includes a first parameter and a second parameter, the first parameter is used to represent the velocity difference of the longitudinal wave in the direction parallel to the symmetry axis and the direction perpendicular to the symmetry axis, and the second parameter is used to represent the velocity difference of the longitudinal wave in the direction perpendicular to the symmetry axis and the direction parallel to the symmetry axis.

[0012] According to another aspect of an embodiment of the present invention, a device for determining anisotropic parameters in a formation is provided, comprising: a positioning module for determining a detection point; an excitation module for controlling excitation points around the detection point to excite waves, and obtaining a detection first arrival time corresponding to the excitation point at a predetermined receiving depth position below the detection point, wherein the receiving depth position is in a corresponding predetermined formation, and the detection first arrival time is the time required for the wave excited by the excitation point to first reach the receiving depth position; a first determination module for determining a plurality of preset candidate anisotropic parameters; a calculation module for determining, based on a preset target direction angle, the reflection wave durations corresponding to the plurality of candidate anisotropic parameters at the receiving depth position; and a second determination module for determining a target anisotropic parameter of the predetermined formation at the target direction angle based on the reflection wave durations corresponding to the plurality of candidate anisotropic parameters and the detection first arrival time.

[0013] According to another aspect of an embodiment of the present invention, a non-volatile storage medium is provided, wherein the non-volatile storage medium stores a plurality of instructions, wherein the instructions are suitable for being loaded by a processor and executed by any one of the methods for determining anisotropic parameters in a formation.

[0014] According to another aspect of an embodiment of the present invention, an electronic device is provided, comprising: one or more processors and a memory, wherein the memory is used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement any one of the methods for determining anisotropic parameters in a formation.

[0015] In an embodiment of the present invention, a detection point is determined; excitation points around the detection point are controlled to excite waves, and the detection first arrival time corresponding to the excitation point is obtained at a predetermined receiving depth position below the detection point, wherein the receiving depth position is in a corresponding predetermined stratum, and the detection first arrival time is the time required for the wave excited by the excitation point to first reach the receiving depth position; multiple preset candidate anisotropy parameters are determined; based on a preset target direction angle, the reflection wave duration corresponding to each of the multiple candidate anisotropy parameters at the receiving depth position is determined; based on the reflection wave duration corresponding to each of the multiple candidate anisotropy parameters and the detection first arrival time, the target anisotropy parameter of the predetermined stratum at the target direction angle is determined. The purpose of obtaining the anisotropy parameters corresponding to each of the multiple strata through layer-by-layer inversion is achieved, and the technical effect of improving the accuracy of the anisotropy parameters is realized, thereby solving the technical problem of unsatisfactory accuracy of the anisotropy parameters in the related art. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 is a flow chart of an optional method for determining anisotropic parameters in a formation provided according to an embodiment of the present invention;

[0018] Figure 2 is a schematic diagram of ellipse fitting of an optional method for determining anisotropic parameters in a formation provided by an embodiment of the present invention;

[0019] Figure 3 is a schematic diagram of apparent anisotropy intensity of an optional method for determining anisotropy parameters in a formation provided according to an embodiment of the present invention;

[0020] Figure 4 is a detection schematic diagram of an optional method for determining anisotropy parameters in a formation provided according to an embodiment of the present invention;

[0021] Figure 5 is a schematic diagram of the direction angle of an optional method for determining anisotropy parameters in a formation provided according to an embodiment of the present invention;

[0022] Figure 6 is a schematic diagram of a formation according to an optional method for determining anisotropic parameters in a formation provided by an embodiment of the present invention;

[0023] Figure 7 1 is a schematic diagram of an application of an optional method for determining anisotropic parameters in a formation provided by an embodiment of the present invention;

[0024] Figure 8 is a first arrival time correction diagram of an optional method for determining anisotropy parameters in a formation provided by an embodiment of the present invention;

[0025] Figure 9 is an error diagram of an optional method for determining anisotropy parameters in a formation provided according to an embodiment of the present invention;

[0026] Figure 10 is a schematic diagram of the effect of an optional method for determining anisotropy parameters in a formation provided according to an embodiment of the present invention; and

[0027] Figure 11 Schematic diagram of an optional device for determining anisotropic parameters in a formation provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0029] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0030] For ease of description, some nouns or terms involved in the embodiments of the present application are explained below:

[0031] A Common Midpoint Gather (CMP Gather) is a collection of seismic data recorded from different shot points (also called excitation points) and receiver locations, with the same central point as the reference. In 3D exploration, observations are typically made using multiple shot points and receiver locations, with each combination corresponding to a CMP gather. CMP gathers record seismic wave data from different locations and can be used to analyze the properties and structure of the subsurface.

[0032] A subarea gather (SG) is a collection of all the common-center gathers within a 3D exploration area, representing a rectangular area encompassing two adjacent receiver lines and shot lines. A SG contains seismic data from different locations within the subarea and can be used for seismic data processing, imaging, and interpretation. SGs are designed to facilitate analysis and processing of localized areas, improving the accuracy and reliability of geological structure interpretation. SGs enable more detailed and nuanced analysis of localized seismic data, yielding more accurate information about the subsurface.

[0033] Anisotropy parameters, where the term anisotropy refers to the fact that physical properties in a formation have different characteristics or behaviors in different directions. Simply put, anisotropy refers to the different responses of a formation to a certain physical measurement indicator (such as wave velocity, resistivity, etc.) in different directions. This difference can be caused by factors such as geological structure, rock structure, and stress state. Anisotropy parameters are of great significance in formation exploration. They can provide information on rock types, fracture and pore properties, stress distribution, etc. in the formation, and have important guiding significance for oil and gas exploration, mineral resource assessment, geological disaster research, etc. In addition, for technologies such as seismic exploration, geoelectric exploration, and geothermal exploration, considering anisotropy can improve the accuracy and reliability of exploration interpretation.

[0034] Shot interval refers to the distance between two adjacent shot points (excitation points) in seismic exploration. In seismic exploration, a series of shot points are typically placed on the surface. Each shot emits seismic energy, which propagates through the subsurface and is recorded by a seismic receiver (seismograph). The choice of shot interval affects the resolution and signal-to-noise ratio of seismic data. A larger shot interval increases the depth at which seismic waves propagate, but the resolution and signal-to-noise ratio decrease accordingly. The choice of shot interval requires comprehensive consideration of factors such as the characteristics of the subsurface medium, the exploration objectives, and the actual exploration conditions.

[0035] The apparent anisotropy strength refers to the degree of change of the properties of underground rocks or strata in different directions in geological exploration. It describes the anisotropic response ability of the geological medium to the propagation of seismic waves. When the underground rocks or strata are isotropic, the change of the properties in different directions is the same, and the speed and propagation path of the seismic wave propagation are also uniform. However, when the underground rocks or strata are anisotropic, the change of the properties in different directions is different, and the speed and propagation path of the seismic wave propagation will change. The apparent anisotropy strength describes the degree of change. It can be used to explain the non-uniformity of the speed and path of the seismic wave propagation underground, and has important significance for geological exploration, earthquake source positioning, seismic waveform analysis and the like.

[0036] According to the method for determining anisotropy parameters in strata provided in the embodiments of the present application, it should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that here.

[0037] Figure 1 The method for determining anisotropy parameters in strata according to the embodiments of the present application is shown in the flowchart as shown in Figure 1 The method comprises the following steps:

[0038] Step S102, determining a detection point;

[0039] It can be understood that the detection point is used to detect the anisotropy parameters in the shallow layer of the work area.

[0040] In an optional embodiment, the isotropic medium characteristics of the position of the detection point match the characteristics of the transverse isotropic medium of the horizontal column symmetry axis, the target anisotropy parameters include a first parameter and a second parameter, the first parameter is used to represent the speed difference of the longitudinal wave in the direction parallel to the symmetry axis and the direction perpendicular to the symmetry axis, and the second parameter is used to represent the speed difference of the longitudinal wave in the direction perpendicular to the symmetry axis and the direction parallel to the symmetry axis.

[0041] It can be understood that azimuthal velocity anisotropy of strata is ubiquitous, that is, the velocity of seismic waves propagating in the medium will vary depending on the propagation direction. Anisotropic media mainly include orthotropic media and transversely isotropic media. Transversely isotropic media (TI media for short) refers to media with a cylindrical symmetry axis and is the most widely used anisotropic medium model in the field of exploration seismology. Depending on whether its symmetry axis is oriented vertically, horizontally, or tilted in space, they are called VTI media, HTI media, and TTI media, respectively. The isotropic medium characteristics at the detection point position match the characteristics of the transversely isotropic medium with a horizontal cylindrical symmetry axis and can be expressed as an HTI medium. In order to characterize the anisotropy intensity, anisotropic parameters are used for description. The first parameter can be expressed as ε, which is used to represent the difference in velocity of the longitudinal wave in the direction parallel to the symmetry axis and the direction perpendicular to the symmetry axis, reflecting the strength of the longitudinal wave anisotropy. ε = 0 means no longitudinal wave anisotropy. The second parameter can be expressed as δ, which is used to represent the velocity difference between the longitudinal wave in the direction perpendicular to the symmetry axis and the direction parallel to the symmetry axis, and describes the strength of the anisotropy of the longitudinal wave velocity near the direction perpendicular to the symmetry axis.

[0042] It should be noted that other types of anisotropy parameters exist, such as φ and γ. φ represents the angle between the symmetry axis and the vertical axis; φ = 0 indicates a VTI medium, and φ = 90 indicates an HTI medium. γ represents the difference in shear wave velocity parallel to and perpendicular to the symmetry axis, reflecting the strength of the shear wave anisotropy; γ = 0 indicates no shear wave anisotropy.

[0043] In an optional embodiment, determining the detection point includes: determining a three-dimensional work area obtained by performing three-dimensional modeling on the work area where the detection point is located, wherein the three-dimensional work area is composed of a plurality of sub-areas, the plurality of sub-areas respectively correspond to sub-area gathers, and the sub-area gathers are composed of common center point gathers of the corresponding sub-areas; performing ellipse fitting on the plurality of sub-area gathers respectively to determine the ellipse major axis and the ellipse minor axis corresponding to the plurality of sub-area gathers respectively; determining the apparent anisotropy strength corresponding to the plurality of sub-areas based on the ellipse major axis and the ellipse minor axis corresponding to the plurality of sub-area gathers respectively; and determining the detection point based on the apparent anisotropy strength corresponding to the plurality of sub-areas respectively.

[0044] It can be understood that the location selection of the above-mentioned detection points has a great influence on the determination of the anisotropy parameters. It is not a subjective choice, but is determined based on the simulation of the three-dimensional work area. The above-mentioned three-dimensional work area is composed of multiple sub-areas, each of which is a rectangular area composed of two adjacent detection lines and shot lines. The sub-area data set is composed of the data set of the common center point of the corresponding sub-area. In order to determine the apparent anisotropy intensity in each sub-area, ellipse fitting processing can be performed separately to determine the major axis and minor axis of the ellipse corresponding to the multiple sub-area data sets. Based on the major axis and minor axis of the ellipse corresponding to the multiple sub-area data sets, the apparent anisotropy intensity corresponding to the multiple sub-areas can be determined. Locations with high anisotropy intensity are often accompanied by complex changes in the strata, and this complexity will have a significant impact on the propagation of seismic waves. Therefore, selecting locations with high anisotropy intensity to set detection points can improve the resolution and accuracy of the anisotropy parameters.

[0045] It should be noted that in geological exploration, the receiver line refers to the line connecting multiple seismic detectors (seismic detectors are set at predetermined detection points) arranged on the ground. Seismic detectors can be seismic recorders, seismic sensors, etc., which are used to receive information such as reflection, refraction, and scattering during the propagation of seismic waves. Through the multiple detectors on the receiver line, the reception of seismic waves at different positions can be recorded and analyzed, thereby obtaining underground geological information. The shot line refers to the line connecting multiple seismic energy sources (seismic energy sources are set at predetermined excitation points) arranged on the ground. The seismic energy source will generate seismic waves, propagate through the underground medium, and be reflected, refracted, and scattered at the interfaces of different layers underground. The shot line is usually arranged to intersect with the receiver line so as to obtain information on the underground geological structure through the propagation and reflection of seismic waves underground. Detection lines and shot lines are often used together in geological exploration. By setting up excitation points and detection points, the propagation and reflection of seismic waves underground are recorded to obtain information on the underground geological structure, including the thickness, lithology, and structure of the strata.

[0046] Optionally, for one of the multiple sub-areas, in order to determine the duration of the first arrival and the corresponding azimuth within a specified offset range in the corresponding sub-area gather, the offset range can be processed as follows:

[0047] offset∈[(2×H-Δx / 2), (2×H+Δx / 2)]

[0048] Where H represents the total thickness of the shallow medium-low velocity reduction layer, and Δx is the half-length of the diagonal of one of the multiple subregions. It can be understood that H is the total thickness of the multiple layers at the detection point, and the multiple layers are shallow medium-low velocity reduction layers.

[0049] Optionally, for one of the multiple sub-areas, an ellipse is fitted to the sub-area gather with the center point of the corresponding sub-area gather as the pole, the azimuth as the polar angle, and the first arrival time as the polar axis length to obtain the ellipse major axis L of the fitted ellipse. a and the minor axis L of the ellipse b The apparent anisotropy intensity S of the sub-region is obtained by the following method Anti .

[0050]

[0051] Figure 2 This is a schematic diagram of an ellipse fitting of an optional method for determining anisotropic parameters in a formation provided by an embodiment of the present invention. The units of the horizontal and vertical coordinates are 500m (meters)*10 4 , Figure 2 The small ellipse in the figure is obtained by fitting the ellipse of multiple sub-area gathers. The major axis and minor axis of each small ellipse are marked. According to the apparent anisotropy intensity, it can be understood that the major axis L a The larger the ellipse minor axis L b The smaller the anisotropy strength S is, the Anti The bigger.

[0052] Figure 3 FIG. 1 is a schematic diagram of apparent anisotropy intensity of an optional method for determining anisotropy parameters in a formation according to an embodiment of the present invention, wherein the apparent anisotropy intensity corresponding to each sub-region is visually marked, such as Figure 3 As shown in the figure, the irregular area marked with oblique lines is the area with larger apparent anisotropy intensity, and the center point of the sub-area gather with the largest apparent anisotropy intensity is marked with concentric circles as the selected detection point.

[0053] In an optional embodiment, after determining the detection point, the method further includes: obtaining the formation thickness and layer velocity corresponding to multiple formations at the location of the detection point, wherein the multiple formations include a predetermined formation; based on the formation thickness and layer velocity corresponding to the multiple formations, and the predetermined high-speed layer velocity, determining the well source distance between the detection point and the excitation point on the surface.

[0054] It can be understood that the distance between the detection point and the excitation point is called the well-source distance, and its size determines the nature of the wave received by the detection point. In order to ensure that the first arrival wave is a transmitted wave and avoid the first arrival wave being a refracted wave, it is necessary to determine the well-source distance based on the formation thickness and layer velocity corresponding to the multiple formations where the detection point is located, as well as the predetermined high-speed layer velocity. Through the above method, the distance between the detection point and the excitation point can be set accurately, which is conducive to improving the accuracy of the anisotropy parameters.

[0055] It should be noted that high-velocity layer velocity refers to the speed at which waves propagate within these layers, which are typically composed of solid rock and have relatively high velocities. By measuring the arrival times of seismic waves received at different locations, the velocity of these layers can be calculated.

[0056] It's important to note that transmitted waves and refracted waves are two different types of waves that occur when seismic waves propagate through underground media. Transmitted waves are waves that enter the second medium directly through an interface when they propagate from one medium to another. When a seismic wave propagates from one medium to another, a portion of its energy passes through the interface and continues propagating in the other medium. The propagation direction of the transmitted wave is the same as that of the incident wave. Refracted waves are waves that are deflected during propagation due to changes in density and velocity between the two media. When a seismic wave propagates from one medium to another, the wave velocity changes due to the different densities and velocities between the two media, causing the wave's propagation direction to deflect. The propagation direction of the refracted wave is different from that of the incident wave. The difference between the two is that transmitted waves are waves that enter the second medium directly through an interface, while refracted waves are waves that are deflected during propagation due to changes in density and velocity between the two media. The propagation direction of the transmitted wave is the same as that of the incident wave, while the propagation direction of the refracted wave is different from that of the incident wave. It is understood that the propagation paths and speeds of transmitted and refracted waves differ because the physical properties of the medium vary. Transmitted and refracted waves have different characteristics in seismic exploration and have different significance and applications in studying the properties and structure of subsurface media.

[0057] Optionally, the plurality of strata mentioned above belong to shallow layers in the geological structure, and the plurality of strata belong to low velocity reduction layers, which are distinguished from predetermined high velocity layers.

[0058] Alternatively, the well source distance X is determined by:

[0059]

[0060] Among them, NL represents the total number of layers at the detection point (multiple layers belong to low velocity reduction layers), H r represents the thickness of the rth layer, V r represents the interval velocity of the rth layer, V NL+1 Indicates the predetermined high-speed layer speed, and floor indicates the rounding-down function.

[0061] Optionally, in the case where there are multiple excitation points, the distances between the multiple excitation points and the detection point are all well-source distances, which can be regarded as radius.

[0062] Step S104: Control the excitation points around the detection point to excite waves, and obtain the detection first arrival time corresponding to the excitation point at a predetermined receiving depth position below the detection point, wherein the receiving depth position is in the corresponding predetermined stratum, and the detection first arrival time is the time required for the wave excited by the excitation point to first reach the receiving depth position;

[0063] As can be understood, the excitation points around the detection point are controlled to excite waves, which can be understood as seismic waves. The first arrival duration of the waves excited by the excitation points can be detected at the receiving depth in the stratum below the detection point. The first arrival duration can indicate the propagation velocity in the predetermined stratum and is very important for analyzing the structural parameters of the predetermined stratum.

[0064] Optionally, before controlling the excitation process, the performance of the controllable source set at the excitation point and the performance of the detector are tested, and when it is determined that the performance meets the predetermined equipment conditions, the seismic wave excitation process is performed.

[0065] Optionally, a variety of seismic detectors, such as fiber optic detectors, can be set up at the detection point to conduct detection in the predetermined formation along the micro-well wellhead set at the detection point. Stone buried well coupling can also be used to set up micro-wells at the detection point, which can also be called the source well method. Figure 4 FIG. 1 is a schematic diagram of a detection method for determining anisotropic parameters in a formation according to an embodiment of the present invention. Figure 4 As shown, the detector is shown as the wave excited by the excitation point downward from the detection point, the intersection of the excitation point and the detector is the schematic diagram of the receiving depth position, and the plane where the detection point and the excitation point are located is the schematic diagram of the ground surface.

[0066] Step S106, determining a plurality of preset candidate anisotropy parameters;

[0067] It can be understood that a plurality of candidate anisotropy parameters may be set for a predetermined formation.

[0068] Step S108, determining the reflection wave durations corresponding to the plurality of candidate anisotropy parameters at the receiving depth position based on the preset target direction angle;

[0069] It can be understood that the target direction angle indicates that the anisotropy parameter in the direction needs to be detected, and the reflection wave durations corresponding to the multiple candidate anisotropy parameters at the receiving depth position can be obtained.

[0070] Step S110 : determining a target anisotropy parameter of a predetermined stratum at a target direction angle based on the reflection wave durations corresponding to a plurality of candidate anisotropy parameters and the detection first arrival durations.

[0071] It can be understood that by taking the target direction angle as the orientation and using the reflection wave durations corresponding to the multiple candidate anisotropy parameters determined, the measured first arrival durations can be compared with each other, thereby facilitating the improvement of the accuracy of characterizing the multiple candidate anisotropy parameters.

[0072] In an optional embodiment, based on the reflection wave durations corresponding to multiple candidate anisotropy parameters and the detection first arrival time, the target anisotropy parameters of the predetermined formation at the target direction angle are determined, including: performing elevation difference correction on the detection first arrival time of the receiving depth position to obtain the corrected first arrival time of the receiving depth position; and determining the target anisotropy parameters based on the reflection wave durations corresponding to multiple candidate anisotropy parameters at the receiving depth position and the corrected first arrival time of the receiving depth position.

[0073] It is understandable that there may be a surface elevation difference between the detection point and the excitation point in a specific application environment, and it is difficult for them to be directly in the same horizontal plane, so the detection time of the seismic wave will be affected. This is because when the wave propagates in different media, refraction and reflection will occur, and the elevation difference will cause the seismic wave to be deflected or reflected on the propagation path, thereby changing the detection time of the seismic wave. Therefore, it is necessary to consider the elevation difference between the detection point and the excitation point to obtain the target anisotropy parameter more accurately. The detection time of the receiving depth position is corrected for the elevation difference to obtain the corrected arrival time of the receiving depth position, thereby reducing the interference caused by the elevation difference. Then, based on the reflection wave duration corresponding to multiple candidate anisotropy parameters at the receiving depth position, and the corrected arrival time of the receiving depth position, a target anisotropy parameter with better accuracy is determined.

[0074] It should be noted that if the detection point is at a higher position relative to the excitation point, the seismic wave needs to overcome more gravitational potential energy before reaching the detection point, and the propagation speed will slow down, resulting in a longer first arrival time. On the contrary, if the detection point is at a lower position, the seismic wave will propagate downhill before reaching the detection point, and the propagation speed will increase, resulting in a shorter first arrival time. In addition, the elevation difference will also cause the seismic wave to reflect on the propagation path, forcing the seismic wave to bypass obstacles or propagate a longer distance along the surface, thereby extending the first arrival time. Conversely, if there are no obstacles on the seismic wave propagation path, the impact of the elevation difference on the first arrival time may be smaller.

[0075] In an optional embodiment, the excitation points are multiple, and the elevation difference correction is performed on the detection initial arrival time of the receiving depth position to obtain a corrected initial arrival time of the receiving depth position, including: determining the direction angles of the multiple excitation points respectively towards the detection point; determining a first number of excitation points in a predetermined angle range based on the direction angles of the multiple excitation points respectively, wherein the predetermined angle range is determined based on a target direction angle; determining the detection initial arrival times of the first number of excitation points respectively; performing elevation difference correction on the detection initial arrival times of the first number of excitation points respectively based on the first elevation of the detection point, the second elevation of the excitation point, and the vertical average velocity to obtain the first initial arrival times of the first number of excitation points respectively, wherein the vertical average velocity is the average velocity from the ground surface of the detection point to the receiving depth position; and determining the corrected initial arrival time based on the first initial arrival times of the first number of excitation points respectively.

[0076] It can be understood that the excitation points can be multiple, and the direction angle of each excitation point towards the detection point can be determined. The predetermined angle range is determined based on the target direction angle, and the first number of excitation points satisfying the predetermined angle range can be selected according to the direction angles of the multiple excitation points respectively. The elevation difference correction is performed on the detection initial arrival times of the first number of excitation points respectively based on the first elevation of the detection point, the second elevation of the excitation point, and the vertical average velocity to obtain the first initial arrival times of the first number of excitation points respectively. The corrected initial arrival time can be determined based on the first initial arrival times of the first number of excitation points respectively. Through the above processing, the first number of excitation points in the predetermined angle range can be used to complete the processing of the corrected initial arrival time of the receiving depth position.

[0077] Optionally, the first number is an integer greater than or equal to 2.

[0078] Optionally, the direction angles of the multiple excitation points are determined as a kind of azimuth fitting mode, denoted as

[0079]

[0080] Wherein, X R and Y R respectively represent the east coordinate and north coordinate of the detection point, and respectively represent the east coordinate and north coordinate of the i-th excitation point, and atan represents the inverse tangent function, represents the azimuth angle corresponding to the i-th excitation point.

[0081] Suppose that 5° equidistant azimuth angles in the range of [0°, 90°] are given which can be expressed as:

[0082]

[0083] Figure 5 is a schematic diagram of the direction angle of an optional method for determining anisotropic parameters in a formation according to an embodiment of the present invention, wherein the target direction angle is set to k0∈k, the predetermined angle range can be determined as Figure 5 For the sake of clarity, only some of the excitation points are marked. Figure 5 The predetermined angle range is marked in dashed lines. The first number of excitation points selected in the predetermined angle range is represented as m∈[k0-1,k0+1], the first first arrival durations corresponding to the first number of excitation points are determined in the following manner and recorded as:

[0084]

[0085] Among them, T m,j It represents the duration of the first arrival of the detection at the jth receiving depth position at the mth excitation point, represents the elevation of the i-th excitation point, E R Indicates the elevation of the detection point, Vav j represents the vertical distance from the surface to the jth receiving depth position.

[0086] Towards the average speed, T' m,j It represents the duration of the first arrival of the jth receiving depth position at the mth excitation point.

[0087] At the target direction angle, the corrected first arrival time of the jth receiving depth position can be obtained by the following method, which is recorded as T” k0,j :

[0088] T” k0,j =mean(T' m,j )

[0089] Here, mean represents the mean value function.

[0090] In an optional embodiment, based on the reflection wave durations corresponding to multiple candidate anisotropy parameters and the detection first arrival time, the target anisotropy parameter of the predetermined formation at the target direction angle is determined, including: determining the duration error values ​​corresponding to the multiple candidate anisotropy parameters at the receiving depth position based on the reflection wave durations corresponding to the multiple candidate anisotropy parameters and the detection first arrival time obtained at the receiving depth position; in the case of multiple receiving depth positions, determining the average error values ​​corresponding to the multiple candidate anisotropy parameters based on the duration error values ​​corresponding to the multiple candidate anisotropy parameters at each receiving depth position included in the multiple receiving depth positions; and determining the candidate anisotropy parameter with the smallest average error value as the target anisotropy parameter.

[0091] It can be understood that, with the horizontal layer at the receiving depth position as the reflection interface, the duration error values ​​corresponding to the multiple candidate anisotropy parameters at the receiving depth position can be determined based on the reflection wave durations corresponding to the multiple candidate anisotropy parameters and the detection first arrival durations obtained at the receiving depth position. The same predetermined stratum can have multiple receiving depth positions, and the corresponding duration error values ​​can be determined at each receiving depth position using multiple candidate anisotropy parameters. Then, the same processing is performed on the multiple receiving depth positions to determine the average error values ​​corresponding to the multiple candidate anisotropy parameters. The candidate anisotropy parameter with the smallest average error value is determined as the target anisotropy parameter for the predetermined stratum.

[0092] Optionally, the detection first arrival time obtained at the receiving depth position may be corrected for elevation difference to obtain a corrected first arrival time.

[0093] Optionally, the predetermined stratum can be any one of the multiple strata, and the multiple strata can be processed in the same way as the predetermined stratum. The above-mentioned multiple strata can respectively correspond to different stratum depths or stratum velocities to obtain target anisotropic parameters corresponding to the multiple strata. Figure 6 is a schematic diagram of a formation according to an optional method for determining anisotropic parameters in a formation provided by an embodiment of the present invention. Figure 6 It shows that there may be corresponding reflection interfaces according to the receiving depth position, and illustrates the reflection process of the wave emitted from the excitation point on the above reflection interface.

[0094] Optionally, the predetermined stratum can be assumed to be the first stratum with the surface as the starting point and the maximum depth being D1. There can be multiple receiving depth positions in the predetermined stratum. Assuming there are J receiving depth positions, the jth receiving depth position can be expressed as D j , D j∈[0,D1]. When the anisotropic parameter includes a first parameter and a second parameter, the first layer has a preset anisotropic parameter range, which is [-0.5,0) for the first parameter and [-0.5,0) for the second parameter. There can be multiple (set to Q) candidate first parameters within the range of the first parameter, and the step size is selected as a predetermined value. The qth candidate first parameter is recorded as ε q , ε q ∈[-0.5,0). There can be multiple (set to W) candidate second parameters in the range of the second parameter, and the step size is selected as a predetermined value. The wth candidate second parameter is recorded as δ w , δ w ∈[-0.5,0).

[0095] For the jth receiving depth position in the predetermined formation, at the target direction angle In the direction, using the qth candidate first parameter, the wth candidate second parameter, and taking twice the well-source distance as the reflection path length, the reflection wave duration can be obtained.

[0096] The difference between the duration of the reflected wave at each receiving depth position and the duration of the first arrival of the detection at the receiving depth position is taken as the duration error value corresponding to the anisotropy parameter value. The duration error values ​​corresponding to the anisotropy parameter values ​​at multiple receiving depth positions are accumulated to obtain the average error value under the anisotropy parameter value. At the jth receiving depth position, for the anisotropy parameter value ε q and δ w The average error value in the case can be expressed as follows:

[0097]

[0098] Among them, error q,w Indicates that when using ε q and δ w The average error value in the case of T k0,j is the corrected first arrival time of the jth receiving depth position.

[0099] It can be understood that there are at most Q*W ways to take the value of the anisotropic parameter. Q*W average error values ​​can be obtained at the j-th receiving depth position. Similarly, the J receiving depth positions are processed in the same way as the j-th receiving depth position. For a predetermined stratum, there can be Q*W*J average error values. Among the Q*W*J values, the value of the anisotropic parameter with the smallest average error value is selected, such as ε1 and δ1, as the target anisotropic parameter.

[0100] Optionally, the target anisotropy parameters obtained above can be applied to various application scenarios, such as shallow imaging, deep imaging, or shallow surface horizontal velocity. Figure 7 FIG. 1 is a schematic diagram of an application of an optional method for determining anisotropic parameters in a formation according to an embodiment of the present invention. Figure 7 As shown in FIG, the inverted anisotropic parameters are used to calculate the horizontal velocity at the detection point, which is used for subsequent calibration of three-dimensional anisotropic velocity modeling and other applications.

[0101] Through the above steps S102 to S110, the purpose of obtaining the anisotropic parameters corresponding to multiple strata by layer-by-layer inversion is achieved, and the technical effect of improving the accuracy of the anisotropic parameters is achieved, thereby solving the technical problem of unsatisfactory accuracy of the anisotropic parameters in related technologies.

[0102] Based on the above embodiments and optional embodiments, the present invention proposes an optional implementation method, which is applied to a shallow HTI medium in a basin landform.

[0103] Step S1: Determine a target work area and collect 3D seismic data from that area, including first arrival times. Ellipse fitting is performed on multiple sub-areas within the target work area, and the point with the greatest apparent anisotropy intensity is identified as the detection point. A microwell is set up at this detection point, and a fiber optic detector is installed in the well. 72 excitation points are arranged in a circular pattern at 5-degree intervals, centered around the wellhead. The wellhead is 100 meters from the source, and the fiber optic detector receives data throughout the entire well section.

[0104] Step S2: Excite each excitation point one by one to obtain the first arrival time of the seismic wave excited by each excitation point at the receiving depth. Use the detection point and the excitation point to correct the first arrival time for the elevation difference to obtain the corrected first arrival time. Figure 8 is a first arrival time correction diagram of an optional method for determining anisotropic parameters in a formation provided according to an embodiment of the present invention, such as Figure 8 As shown in the figure, by making all the excitation points at the same horizontal position and reducing the problems caused by measurement errors and receiving well inclination, the first arrival time needs to be corrected according to the equally spaced azimuths. Figure 7 The comparison between the first arrival time before correction (i.e., the detection first arrival time) and the first arrival time after correction (i.e., the correction first arrival time) is given in Figure 2. It can be seen that the same change trend exists before and after correction.

[0105] In step S3, there are multiple strata in the shallow layer, and each stratum is set with a value range of anisotropy parameters, which may include a first parameter ε and a second parameter δ. Starting from the first stratum, the average error values ​​corresponding to multiple candidate anisotropy parameters can be determined based on the first arrival time of the detection, and the target anisotropy parameters of the stratum can be obtained. The other strata are processed in the same way. Figure 9 This is an error diagram of an optional method for determining anisotropic parameters in a formation provided according to an embodiment of the present invention. The time error values ​​generated by the anisotropic parameters are visualized, and the grayscale legend from dark to shallow can be represented as the time error values ​​from small to large.

[0106] Figure 10 FIG. 1 is a schematic diagram showing the effect of an optional method for determining anisotropic parameters in a formation according to an embodiment of the present invention. Figure 10 As shown in the figure, it shows that for azimuth angles ranging from 0 degrees to 360 degrees, the changing trends between the detection first arrival time and the reflection wave time are basically consistent, which can reflect the reliability of the target anisotropy parameters.

[0107] The above optional implementation at least achieves the effect of improving the accuracy of determining anisotropic parameters, which is beneficial to improving the processing means of applying anisotropic parameters.

[0108] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0109] This embodiment also provides a device for determining anisotropic parameters in a formation. This device is used to implement the above-mentioned embodiments and preferred embodiments, and details already described will not be repeated. As used below, the terms "module" and "device" may refer to a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented using software, implementation using hardware, or a combination of software and hardware, is also possible and contemplated.

[0110] According to an embodiment of the present invention, there is also provided an embodiment of a device for implementing a method for determining anisotropic parameters in a formation. Figure 11 FIG. 1 is a schematic diagram of a device for determining anisotropic parameters in a formation according to an embodiment of the present invention. Figure 11 As shown, the above-mentioned device for determining anisotropic parameters in the formation includes: a positioning module 1102, an excitation module 1104, a first determination module 1106, a calculation module 1108, and a second determination module 1110. The device is described below.

[0111] Positioning module 1102, used to determine the detection point;

[0112] The excitation module 1104 is connected to the positioning module 1102 and is used to control the excitation points around the detection point to excite waves and obtain the detection first arrival time corresponding to the excitation point at a predetermined receiving depth position below the detection point, wherein the receiving depth position is in the corresponding predetermined stratum, and the detection first arrival time is the time required for the wave excited by the excitation point to first reach the receiving depth position;

[0113] A first determination module 1106, connected to the excitation module 1104, is used to determine a plurality of preset candidate anisotropy parameters;

[0114] The calculation module 1108 is connected to the first determination module 1106 and is used to determine the reflection wave durations corresponding to the multiple candidate anisotropy parameters at the receiving depth position based on the preset target direction angle;

[0115] The second determination module 1110 is connected to the calculation module 1108 and determines the target anisotropy parameter of the predetermined formation at the target direction angle based on the reflection wave duration corresponding to the multiple candidate anisotropy parameters and the detection first arrival duration.

[0116] In an apparatus for determining anisotropic parameters in a formation provided by an embodiment of the present invention, a positioning module 1102, an excitation module 1104, a first determination module 1106, a calculation module 1108, and a second determination module 1110 are provided. The apparatus achieves the purpose of obtaining anisotropic parameters corresponding to multiple formations through layer-by-layer inversion, thereby achieving the technical effect of improving the accuracy of anisotropic parameters and thereby resolving the technical problem of unsatisfactory anisotropic parameter accuracy in related technologies.

[0117] It should be noted that the above modules can be implemented by software or hardware. For example, for the latter, it can be implemented in the following ways: the above modules can be located in the same processor; or the above modules can be located in different processors in any combination.

[0118] It should be noted that the positioning module 1102, the triggering module 1104, the first determination module 1106, the calculation module 1108, and the second determination module 1110 described above correspond to steps S102 to S110 in the embodiment. The examples and application scenarios implemented by the modules and corresponding steps are the same, but are not limited to the contents disclosed in the above embodiment. It should be noted that the modules described above, as part of the apparatus, can be run on a computer terminal.

[0119] It should be noted that the optional or preferred implementation of this embodiment can be found in the relevant description in the embodiment, which will not be repeated here.

[0120] The above-mentioned device for determining anisotropic parameters in the formation may also include a processor and a memory, and the positioning module 1102, the excitation module 1104, the first determination module 1106, the calculation module 1108, the second determination module 1110, etc. are all stored in the memory as program units, and the processor executes the above-mentioned program units stored in the memory to realize the corresponding functions.

[0121] The processor includes a kernel, which retrieves the corresponding program unit from memory. There can be one or more kernels. Memory may include non-permanent memory in a computer-readable medium, random access memory (RAM), and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory includes at least one memory chip.

[0122] An embodiment of the present invention provides a non-volatile storage medium having a program stored thereon. When the program is executed by a processor, a method for determining anisotropic parameters in a formation is implemented.

[0123] An embodiment of the present invention provides an electronic device comprising a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, the following steps are implemented: determining a detection point; controlling excitation points around the detection point to excite waves, and obtaining a detection first arrival time corresponding to the excitation point at a predetermined receiving depth position below the detection point, wherein the receiving depth position is in a corresponding predetermined stratum, and the detection first arrival time is the time required for the wave excited by the excitation point to first reach the receiving depth position; determining multiple preset candidate anisotropy parameters; determining, based on a preset target azimuth, the reflection wave durations corresponding to each of the multiple candidate anisotropy parameters at the receiving depth position; and determining, based on the reflection wave durations corresponding to each of the multiple candidate anisotropy parameters and the detection first arrival time, a target anisotropy parameter for the predetermined stratum at the target azimuth. The device herein may be a server, a PC, or the like.

[0124] The present invention also provides a computer program product, which, when executed on a data processing device, is suitable for executing a program initialized with the following method steps: determining a detection point; controlling the excitation points around the detection point to excite waves, and obtaining the detection first arrival time corresponding to the excitation point at a predetermined receiving depth position below the detection point, wherein the receiving depth position is in a corresponding predetermined stratum, and the detection first arrival time is the time required for the wave excited by the excitation point to reach the receiving depth position for the first time; determining a plurality of preset candidate anisotropy parameters; based on a preset target direction angle, determining the reflection wave durations corresponding to the plurality of candidate anisotropy parameters in the receiving depth position; based on the reflection wave durations corresponding to the plurality of candidate anisotropy parameters and the detection first arrival time, determining the target anisotropy parameters of the predetermined stratum at the target direction angle.

[0125] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0126] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0127] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0128] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0129] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0130] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0131] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0132] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0133] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0134] The above are merely embodiments of the present invention and are not intended to limit the present invention. It will be apparent to those skilled in the art that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are intended to be included within the scope of the claims of the present invention.

Claims

1. A method for determining anisotropic parameters in a formation, characterized in that: include: Determine the detection point; Controlling the excitation points around the detection point to excite waves, and obtaining the detection first arrival time corresponding to the excitation point at a predetermined receiving depth position below the detection point, wherein the receiving depth position is in a corresponding predetermined stratum, and the detection first arrival time is the time required for the wave excited by the excitation point to first reach the receiving depth position; determining a plurality of preset candidate anisotropy parameters; Determining, based on a preset target direction angle, the reflection wave durations corresponding to the plurality of candidate anisotropy parameters at the receiving depth position; Determining a target anisotropy parameter of the predetermined stratum at the target direction angle based on the reflection wave durations respectively corresponding to the plurality of candidate anisotropy parameters and the detection first arrival duration; Wherein, determining the target anisotropy parameter of the predetermined stratum at the target direction angle based on the reflection wave durations respectively corresponding to the multiple candidate anisotropy parameters and the detection first arrival time includes: performing elevation difference correction on the detection first arrival time at the receiving depth position to obtain the corrected first arrival time at the receiving depth position; determining the target anisotropy parameter based on the reflection wave durations respectively corresponding to the multiple candidate anisotropy parameters at the receiving depth position and the corrected first arrival time at the receiving depth position; Wherein, there are multiple excitation points, and the elevation difference correction is performed on the detection initial arrival time of the receiving depth position to obtain the corrected initial arrival time of the receiving depth position, including: determining the direction angles of multiple excitation points toward the detection point; determining a first number of excitation points in a predetermined angle range based on the direction angles corresponding to the multiple excitation points, wherein the predetermined angle range is determined based on the target direction angle; determining the detection initial arrival time corresponding to the first number of excitation points; performing elevation difference correction on the detection initial arrival time corresponding to the first number of excitation points based on the first elevation of the detection point, the second elevation of the excitation point, and the vertical average velocity to obtain the first initial arrival time corresponding to the first number of excitation points, wherein the vertical average velocity is the average velocity from the surface of the detection point to the receiving depth position; determining the corrected initial arrival time based on the first initial arrival time corresponding to the first number of excitation points.

2. The method according to claim 1, characterized in that The determining of the target anisotropy parameter of the predetermined stratum at the target direction angle based on the reflection wave durations respectively corresponding to the plurality of candidate anisotropy parameters and the detection first arrival duration includes: Determining, based on the reflection wave durations respectively corresponding to the multiple candidate anisotropy parameters and the detection first arrival durations obtained at the receiving depth position, the duration error values ​​respectively corresponding to the multiple candidate anisotropy parameters at the receiving depth position; In the case where there are multiple receiving depth positions, determining average error values ​​corresponding to the multiple candidate anisotropy parameters based on the duration error values ​​corresponding to the multiple candidate anisotropy parameters at each receiving depth position included in the multiple receiving depth positions; The anisotropic parameter with the smallest average error value among the multiple candidate anisotropic parameters is determined as the target anisotropic parameter.

3. The method according to claim 1, characterized in that Determining the detection point includes: Determine a three-dimensional work area obtained by three-dimensionally modeling the work area where the detection point is located, wherein the three-dimensional work area is composed of a plurality of sub-areas, the plurality of sub-areas respectively correspond to sub-area gathers, and the sub-area gathers are composed of common center point gathers of the corresponding sub-areas; Performing ellipse fitting on the plurality of sub-area gathers respectively to determine the ellipse major axis and the ellipse minor axis corresponding to the plurality of sub-area gathers respectively; Determining apparent anisotropy intensities corresponding to the plurality of sub-areas based on the ellipse major axes and the ellipse minor axes corresponding to the plurality of sub-area gathers respectively; The detection point is determined based on the apparent anisotropy intensities respectively corresponding to the multiple sub-areas.

4. The method according to claim 1, wherein After determining the detection point, the method further includes: Obtaining stratum thicknesses and stratum velocities corresponding to a plurality of strata at the location of the detection point, wherein the plurality of strata include the predetermined stratum; Based on the formation thicknesses and layer velocities respectively corresponding to the multiple formations and a predetermined high-speed layer velocity, a well-source distance between the detection point and the excitation point on the surface is determined.

5. The method according to any one of claims 1 to 4, characterized in that The isotropic medium characteristics at the detection point match the characteristics of the transversely isotropic medium of the horizontal cylindrical symmetry axis. The target anisotropy parameter includes a first parameter and a second parameter. The first parameter is used to represent the velocity difference of the longitudinal wave in the direction parallel to the symmetry axis and the direction perpendicular to the symmetry axis. The second parameter is used to represent the velocity difference of the longitudinal wave in the direction perpendicular to the symmetry axis and the direction parallel to the symmetry axis.

6. A device for determining anisotropic parameters in a formation, characterized in that: include: Positioning module, used to determine the detection point; an excitation module, configured to control excitation points around the detection point to excite waves, and obtain a detection first arrival time corresponding to the excitation point at a predetermined receiving depth position below the detection point, wherein the receiving depth position is in a corresponding predetermined stratum, and the detection first arrival time is the time required for the wave excited by the excitation point to first reach the receiving depth position; A first determining module, configured to determine a plurality of preset candidate anisotropy parameters; a calculation module, configured to determine, based on a preset target direction angle, the duration of the reflected waves corresponding to the plurality of candidate anisotropy parameters at the receiving depth position; A second determining module determines a target anisotropy parameter of the predetermined stratum at the target direction angle based on the reflection wave durations corresponding to the plurality of candidate anisotropy parameters and the detection first arrival duration; The second determination module is further configured to perform elevation difference correction on the detected first arrival time of the receiving depth position to obtain the corrected first arrival time of the receiving depth position; and determine the target anisotropy parameter based on the reflection wave durations corresponding to the multiple candidate anisotropy parameters of the receiving depth position and the corrected first arrival time of the receiving depth position; Wherein, the second determination module is further used to determine the direction angles of multiple excitation points toward the detection point; determine a first number of excitation points in a predetermined angle range based on the direction angles corresponding to the multiple excitation points, wherein the predetermined angle range is determined based on the target direction angle; determine the detection first arrival times corresponding to the first number of excitation points; perform elevation difference correction on the detection first arrival times corresponding to the first number of excitation points based on the first elevation of the detection point, the second elevation of the excitation point, and the vertical average velocity, to obtain the first first arrival times corresponding to the first number of excitation points, wherein the vertical average velocity is the average velocity from the surface of the detection point to the receiving depth position; determine the corrected first arrival time based on the first first arrival times corresponding to the first number of excitation points.

7. A non-volatile storage medium, characterized in that: The non-volatile storage medium stores a plurality of instructions, and the instructions are suitable for being loaded by a processor and executed by the method for determining anisotropic parameters in a formation according to any one of claims 1 to 5.

8. An electronic device, characterized in that: include: One or more processors and a memory, the memory being used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method for determining anisotropic parameters in a formation as described in any one of claims 1 to 5.

Images