Earthquake fault automatic interpretation method and storage medium

Abstract

The invention provides a seismic fault automatic interpretation method and a storage medium, and the method comprises the steps: obtaining stratum section image data, and the stratum section image data is obtained based on a plurality of continuous seismic data in a line number direction or a trace number direction; manually marking inflection points on the stratigraphic section image data by taking a preset number of line numbers or channel numbers as intervals so as to obtain first fault frame line segments; according to two adjacent first fault frame line segments, performing automatic interpolation on the middle stratum section image through a linear interpolation algorithm to obtain a second fault frame line segment; and performing residual error correction processing and smoothing processing on the second fault frame line segment, and outputting an automatic seismic fault interpretation result. According to the method, rapid positioning of the fault structure position is realized based on manual labeling and a linear interpolation algorithm, zero closing error of fault interpretation is realized in combination with residual correction of fault projection points, and the efficiency and accuracy of fault interpretation are greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of geological exploration technology, and in particular to an automatic interpretation method for earthquake faults and a storage medium. Background Art

[0002] Faults are structures where rocks in the surface layer of the earth's crust break under stress, and the rocks on both sides of the fault surface undergo significant relative displacement. Faults vary in size. The larger ones can extend hundreds of kilometers along the strike, often consisting of many faults, which can be called fault zones, while the smaller ones are only tens of centimeters. Large faults often constitute the regional geological framework, which not only controls the structural evolution of regional geology, but also controls and affects oil and gas accumulation and mineralization. Some small and medium-sized faults often directly determine the distribution of oil and gas reservoirs. Faults are widely developed in the earth's crust and are the most important structures in the earth's crust. Whether it is the accumulation, migration or accumulation of oil and gas, faults, as an important structural form, play a very important role. The study of faults is of great significance to the development process of oil and gas reservoirs. The specific work of seismic fault interpretation includes displaying the seismic data on the screen in the form of images, and then the user uses the mouse to interactively draw line segments (i.e., fault frame segments) on the fault structure position of the seismic section to mark the fault structure position.

[0003] However, seismic fault interpretation is one of the most time-consuming tasks in seismic interpretation. Traditional fault interpretation is mainly based on manual annotation. With the emergence of more and more large basin-level work areas, large structures, and complex structures, the workload of fault interpretation using manual annotation is very huge. In addition, there are still problems with distinguishing geological structures in areas with rich fault development, which further increases the difficulty of fault interpretation using manual annotation and makes it difficult to guarantee its accuracy.

[0004] Therefore, an efficient and accurate automatic interpretation method for earthquake faults is urgently needed in this field. Summary of the invention

[0005] In order to solve the problems of large workload and low efficiency in seismic data fault interpretation, in one aspect of the present invention, a method for automatic interpretation of seismic faults is proposed, the method comprising: acquiring stratigraphic profile image data, the stratigraphic profile image data being obtained based on a plurality of continuous seismic data along a line number direction or a track number direction; manually marking inflection points of the stratigraphic profile image data at intervals of a preset number of line numbers or track numbers to obtain a first fault framework segment; automatically interpolating an intermediate stratigraphic profile image through a linear interpolation algorithm based on two adjacent first fault framework segments to obtain a second fault framework segment; performing residual correction processing and smoothing processing on the second fault framework segment, and outputting a result of automatic interpretation of seismic faults.

[0006] In one or more embodiments, the method further includes determining whether the number of inflection points in the two adjacent first fault frame segments is the same before automatically interpolating the intermediate stratigraphic profile image through a linear interpolation algorithm based on the inflection points of the two adjacent first fault frame segments to obtain the second fault frame segment; in response to the different number of inflection points, filling in the inflection points at the same position as the last inflection point in the first fault frame segment with the smaller number of inflection points.

[0007] In one or more embodiments, the method of automatically interpolating the intermediate stratigraphic profile image by a linear interpolation algorithm based on the inflection points of two adjacent first fault frame segments to obtain the second fault frame segment includes: numbering the inflection points in the two adjacent first fault frame segments from small to large according to their stratigraphic depth coordinates; automatically interpolating the intermediate stratigraphic profile image based on a linear interpolation algorithm based on two adjacent inflection points with the same number to determine the interpolation inflection point; and connecting multiple interpolation inflection points by a line segment to obtain the second fault frame segment.

[0008] In one or more embodiments, the automatic interpolation of the intermediate stratigraphic section image by a linear interpolation algorithm comprises:

[0009] Automatic interpolation calculation is performed based on the following formula:

[0010] t=(lineNo-line1) / (line2-line1),

[0011] cmpNo=pt11.cmp+t*(pt21.cmp-pt11.cmp),

[0012] z=pt11.z+t*(pt21.z-pt11.z);

[0013] Among them, line1 and line2 are respectively the line number coordinates of the two inflection points with the same number in the two adjacent first fault frame segments, and lineNo is the line number coordinate of the interpolation inflection point; pt11cmp and pt21cmp are respectively the track number coordinates of the two inflection points with the same number in the two adjacent first fault frame segments, and cmpNo is the track number coordinate of the interpolation inflection point; pt11z and pt21z are respectively the stratigraphic depth coordinates of the two inflection points with the same number in the two adjacent first fault frame segments, and z is the stratigraphic depth coordinate of the interpolation inflection point.

[0014] In one or more embodiments, the method also includes performing residual correction and smoothing processing on the inflection point of the second fault frame segment and outputting the automatic interpretation result of the seismic fault, obtaining the vertically intersecting stratigraphic profile image corresponding to the intermediate stratigraphic profile image, and determining the intersection of the third fault frame segment in the vertically intersecting stratigraphic profile image and the intermediate stratigraphic profile image; judging whether the track number coordinate of the intersection is located between the track number coordinates of the two interpolation inflection points; in response to the track number coordinate of the intersection being located between the track number coordinates of the two interpolation inflection points, further judging whether the vertical distance from the intersection to the line segment connecting the two interpolation inflection points is less than a preset threshold; in response to the vertical distance from the intersection to the line segment connecting the two interpolation inflection points being less than a preset threshold, taking the intersection as a new interpolation inflection point to obtain the second fault frame segment.

[0015] In one or more embodiments, the residual correction processing of the inflection point of the second fault frame line segment includes: using the new interpolation inflection point determined by the intersection as the first interpolation inflection point; using the interpolation inflection point determined by the linear interpolation algorithm as the second interpolation inflection point; and correcting the second interpolation inflection point by a residual correction algorithm according to the first interpolation inflection point.

[0016] In one or more embodiments, correcting the second interpolation inflection point through a residual correction algorithm based on the first interpolation inflection point includes: determining two of the first interpolation inflection points located on both sides of the second interpolation inflection point based on the track number coordinates; and correcting the stratigraphic depth coordinates of the second interpolation inflection point based on the distance ratio between the second interpolation inflection point and the track number coordinates of the two first interpolation inflection points.

[0017] In one or more embodiments, the smoothing of the second fault frame line segment includes: smoothing the second fault frame line segment by using a Gaussian filtering smoothing algorithm.

[0018] In one or more embodiments, the acquiring of stratigraphic profile image data comprises: collecting the seismic data by detection points continuously arranged along the line number direction and along the track number direction, in the stratigraphic profile image data formed based on multiple seismic data along the line number direction, each inflection point has the same line number coordinate and multiple track number coordinates, in the stratigraphic profile image data formed based on multiple seismic data along the track number direction, each inflection point has the same track number coordinate and multiple line number coordinates.

[0019] In a second aspect of the present invention, a readable storage medium is provided, comprising: an executable computer program, wherein when the computer program is executed by an executor, the computer program is used to implement the steps of a method for automatic interpretation of seismic faults as in any of the above embodiments.

[0020] The beneficial effects of the present invention include: the present invention uses a method based on linear interpolation of parameterized equations of spatial straight line segments to realize automatic interpretation of faults. When a large fault framework (using manual annotation) has been established, the structural position can be accurately and quickly located, and then the fault projection points are used for correction to achieve zero closure error in fault interpretation. The output requirements can be met by fine-tuning through a smoothing algorithm. The present invention realizes semi-automation of fault interpretation and greatly improves the efficiency of fault interpretation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic diagram of the distribution of detection points for seismic data acquisition according to an embodiment of the present invention;

[0023] Figure 2 The stratigraphic section image stored and named by line number according to an embodiment of the present invention;

[0024] Figure 3 The stratigraphic cross-section image at the line number 2100 of the embodiment of the present invention;

[0025] Figure 4 A flowchart of an automatic seismic fault interpretation method according to an embodiment of the present invention;

[0026] Figure 5 The stratigraphic cross-section image at the line number 2200 of the embodiment of the present invention;

[0027] Figure 6 A schematic diagram of a process of interpolating an intermediate stratigraphic section image with line number 2116 according to an embodiment of the invention;

[0028] Figure 7 This is a schematic diagram of the result of automatically interpolating the intermediate formation section image with line number 2116 according to an embodiment of the present invention;

[0029] Figure 8 This is a schematic diagram of the result of manually labeling the intermediate stratigraphic section image with line number 2116 according to an embodiment of the present application;

[0030] Fig. 9 A schematic diagram of inserting an intersection point into a second fault frame line segment according to an embodiment of the present invention;

[0031] Fig.10It is a schematic diagram of performing residual correction on interpolation points through intersection points according to an embodiment of the present invention;

[0032] Fig.11 The image is an image obtained by performing residual correction on the automatic interpolation result of the intermediate formation section image with line number 2116 according to an embodiment of the present invention;

[0033] Fig.12 It is a schematic diagram of smoothing continuous fault frame line segments according to an embodiment of the present invention;

[0034] Fig.13 is a flow chart of processing a stratigraphic section image according to an embodiment of the present invention;

[0035] Fig.14 It is a schematic diagram of a situation where a plurality of fault frame line segments exist simultaneously in a stratigraphic section image according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0037] It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are for distinguishing two non-identical entities with the same name or non-identical parameters. It can be seen that "first" and "second" are only for the convenience of expression and should not be understood as limitations on the embodiments of the present invention. The subsequent embodiments will not explain this one by one.

[0038] See also Figure 1 , which shows a schematic diagram of the distribution of detection points for seismic data acquisition according to an embodiment of the present invention. Figure 1 As shown, in order to obtain seismic data, it is necessary to arrange multiple shot points (in the direction of the channel number) within a certain range, and arrange detection lines (in the direction of the line number) with each shot point as the center, and arrange multiple detection points on each detection line at a preset interval. When a stratigraphic profile image is formed using multiple seismic data obtained from each detection point, a stratigraphic profile image perpendicular to the channel number direction (named by the channel number) and a stratigraphic profile image perpendicular to the line number direction (named by the line number) can be formed according to different profile directions; it can be understood that when one detection point is the center, there will be two mutually perpendicular stratigraphic profile images (named by the channel number and the line number, respectively), which show the stratigraphic structure in different profile directions, thereby realizing a three-dimensional display of the stratigraphic structure.

[0039] See also Figure 2 , which shows a stratigraphic cross-section image stored by line number naming according to an embodiment of the present invention. Figure 2 In the diagram, the horizontal axis represents the track number, and the vertical axis represents the formation depth (i.e., the Z axis). Figure 2After manually marking the inflection point, Figure 3 .

[0040] See also Figure 3 , which shows the stratigraphic cross-section image at the line number 2100 position of the embodiment of the present invention. Figure 3 The position of the obvious fault in the view. Each inflection point is actually determined by a three-dimensional coordinate: line number (line), channel number (cmp) and formation depth (Z) to determine its position in the formation structure. Connecting the inflection points in the view with line segments will form a fault frame line segment.

[0041] The main work of the present invention is to manually interpret the faults of a small amount of stratigraphic profile image data with clear stratigraphic structures - marking the inflection points, and then automatically interpolate the remaining stratigraphic profile image data based on the manual marking to determine the inflection points, thereby realizing the automatic interpretation of earthquake faults. The scheme of the present invention is as follows:

[0042] See also Figure 4 , which shows a workflow diagram of an automatic interpretation method for seismic faults in an embodiment of the present invention. In this embodiment, the workflow of the method of the present invention includes: step S1, obtaining stratigraphic profile image data, the stratigraphic profile image data is obtained based on a plurality of continuous seismic data along the line number direction or the track number direction; step S2, manually marking inflection points of the stratigraphic profile image data at intervals of a preset number of line numbers or track numbers to obtain a first fault frame segment; step S3, automatically interpolating the intermediate stratigraphic profile image according to two adjacent first fault frame segments through a linear interpolation algorithm to obtain a second fault frame segment; step S4, performing residual correction processing and smoothing processing on the second fault frame segment, and outputting the automatic interpretation result of the seismic fault.

[0043] The theoretical basis of this embodiment is that in actual work, the inventor found that there are similarities in fault structures within a small range, and there is a nearly linear relationship between the fault frame line segments in the middle and the fault frame line segments on both sides thereof. In step S2, a certain number of line numbers or track numbers are used as intervals to ensure the similarity between the fault frame line segments, and whether to use a certain number of line numbers as intervals or a certain number of track numbers as intervals depends on whether the current stratigraphic profile image data being processed is saved by naming with line numbers or by track numbers. In the actual processing process, it is necessary to manually annotate the stratigraphic profile image data saved with track numbers and the stratigraphic profile image data saved with line numbers respectively. The intermediate stratigraphic profile image in step S3 is the stratigraphic profile image located in the middle of the stratigraphic profile images where the two first fault frame line segments are located, and the positional relationship between the three will be determined specifically by line numbers or track numbers.

[0044] See also Figure 5, which shows the stratigraphic cross-section image at the line number 2200 of the embodiment of the present invention. In a specific embodiment of the present invention, the present invention will manually mark the inflection points of the stratigraphic cross-section images at the line number 2100 and the line number 2200 at intervals of 100 line numbers, and determine two adjacent first fault frame line segments; accordingly, this embodiment needs to automatically interpolate the stratigraphic cross-section images with line numbers from 2101 to 2199 to determine the second fault frame line segment, so as to interpret the fault structure therein.

[0045] In a further embodiment, the method of the present invention also includes determining whether the number of inflection points in two adjacent first fault frame segments is the same before automatically interpolating the intermediate stratigraphic profile image through a linear interpolation algorithm based on the inflection points of the two adjacent first fault frame segments to obtain the second fault frame segment; in response to the different number of inflection points, filling the inflection points at the same position as the last inflection point in the first fault frame segment with the smaller number of inflection points.

[0046] In this embodiment, since the interpolation process of the intermediate stratigraphic profile image is implemented based on the corresponding inflection points in two adjacent first fault frame line segments, when the number of inflection points in the two adjacent first fault frame line segments is different, it is necessary to fill in the number of inflection points of the side with fewer inflection points so that the number of inflection points between the two is equal. The filling method adopted in this embodiment is to fill in the inflection points at the same position as the last inflection point in the first fault frame line segment with fewer inflection points, that is, in this embodiment, the last inflection point in the side with fewer inflection points corresponds to multiple inflection points in the other fault frame line segment to determine multiple interpolations.

[0047] In a further embodiment, the specific process of step S3 of the present invention, automatically interpolating the intermediate stratigraphic profile image by a linear interpolation algorithm according to the inflection points of two adjacent first fault frame segments to obtain a second fault frame segment, includes: numbering the inflection points in two adjacent first fault frame segments from small to large according to their stratigraphic depth coordinates; automatically interpolating the intermediate stratigraphic profile image based on a linear interpolation algorithm according to two adjacent inflection points with the same number to determine the interpolation inflection point; and connecting multiple interpolation inflection points by a line segment to obtain a second fault frame segment.

[0048] In this embodiment, the inflection points in the two first fault frame line segments are numbered from small to large according to their stratum depth coordinates in order to ensure the correspondence between the inflection points and avoid the problem of inconsistent stratum depths of corresponding inflection points due to image inversion.

[0049] In a further embodiment, the linear interpolation algorithm used in the present invention includes:

[0050] t=(lineNo-line1) / (line2-line1),

[0051] cmpNo=pt11.cmp+t*(pt21.cmp-pt11.cmp),

[0052] z=pt11.z+t*(pt21.z-pt11.z);

[0053] Among them, line1 and line2 are the line number coordinates of the two inflection points with the same number in the two adjacent first fault frame segments, and lineNo is the line number coordinate of the interpolation inflection point; among them, line1, line2 and lineNo are all known quantities; pt11cmp and pt21cmp are the track number coordinates of the two inflection points with the same number in the two adjacent first fault frame segments, and cmpNo is the track number coordinate of the interpolation inflection point; among them, pt11cmp and pt21cmp are known quantities, and cmpNo is an unknown quantity, that is, the track number coordinate of the interpolation inflection point to be obtained; pt11z and pt21z are the stratigraphic depth coordinates of the two inflection points with the same number in the two adjacent first fault frame segments, and z is the stratigraphic depth coordinate of the interpolation inflection point, among them, pt11z and pt21z are known quantities, and z is an unknown quantity, that is, the stratigraphic depth coordinate of the interpolation inflection point to be obtained.

[0054] It can be seen that the calculation of t in the above actually utilizes the linear proportional relationship between line segments (determined by three known line number coordinates); therefore, in some embodiments, t can also be calculated as: t=(lineNo-line1) / (line2-lineNo), and the subsequent formulas for calculating cmpNo and z can also be changed accordingly.

[0055] See also Figure 6 , which shows a schematic diagram of the process of interpolating the intermediate stratigraphic profile image with line number 2116 according to an embodiment of the invention. Among them, the L1 original fault line and the L2 original fault line are the two adjacent first fault frame line segments in the above embodiment, and the L interpolation result line is the result after interpolating the intermediate stratigraphic profile image. It should be noted that this embodiment does not fill the inflection points of the L1 original fault line, but directly determines the interpolation inflection points pt4 and pt5 by corresponding the last inflection point pt14 in the L1 original fault line to the inflection points pt24 and pt25 in the L2 original fault line respectively. The actual interpolation result of this embodiment is shown in FIG. Figure 7 shown.

[0056] See also Figure 7 , which shows the result of automatic interpolation of the intermediate stratum section image with line number 2116 according to an embodiment of the present invention. To compare the feasibility of automatic interpolation, please refer to Figure 8, which shows the result of manually labeling the intermediate stratum section image with line number 2116 in the embodiment of the present application. Figure 7 and Figure 8 It can be seen that the fault shapes shown by the two are generally similar, and there is only a difference in the specific position of the inflection point. In order to further improve the accuracy of interpolation, the method of the present invention also proposes to perform residual correction processing and smoothing processing on the second fault frame line segment.

[0057] In a further embodiment, the method of the present invention also includes obtaining a vertically intersecting stratigraphic profile image corresponding to the intermediate stratigraphic profile image before performing residual correction and smoothing processing on the inflection point of the second fault frame segment and outputting the automatic interpretation result of the seismic fault, and determining the intersection of the third fault frame segment in the vertically intersecting stratigraphic profile image and the intermediate stratigraphic profile image; judging whether the track number coordinate of the intersection is located between the track number coordinates of the two interpolation inflection points; in response to the track number coordinate of the intersection being located between the track number coordinates of the two interpolation inflection points, further judging whether the vertical distance from the intersection to the line segment connecting the two interpolation inflection points is less than a preset threshold; in response to the vertical distance from the intersection to the line segment connecting the two interpolation inflection points being less than the preset threshold, taking the intersection as a new interpolation inflection point to obtain the second fault frame segment.

[0058] In this embodiment, the vertically intersecting stratigraphic profile image is another stratigraphic profile image that vertically intersects with the current intermediate stratigraphic profile image. It can be understood that the two are displays of the same fault structure in different profile directions. The intersection of the third fault framework line segment and the intermediate stratigraphic profile image is also called the fault projection point. The addition of the fault projection point can enrich the details of the second fault framework line segment on the one hand, and on the other hand, it is also used for the subsequent residual correction of the second fault framework line segment.

[0059] In a further embodiment, residual correction processing is performed on the inflection point of the second fault frame line segment, including: taking the new interpolation inflection point determined by the intersection as the first interpolation inflection point; taking the interpolation inflection point determined by the linear interpolation algorithm as the second interpolation inflection point; and correcting the second interpolation inflection point by the residual correction algorithm according to the first interpolation inflection point.

[0060] In a further embodiment, correcting the second interpolation inflection point by a residual correction algorithm according to the first interpolation inflection point includes: determining two first interpolation inflection points located on both sides of the second interpolation inflection point based on the track number coordinates; and correcting the stratigraphic depth coordinates of the second interpolation inflection point according to the distance ratio between the second interpolation inflection point and the track number coordinates of the two first interpolation inflection points. The formula of the correction algorithm is expressed as follows:

[0061] Assume that the numbers of the two inserted projection points are 2 and 4 respectively, then the point numbered 3 between 2 and 4 (point 3 is the inflection point obtained by interpolation of the original two frame lines) is corrected for residual errors. The correction algorithm is as follows:

[0062] Get the cmp number of point 3: cmp = pt3.cmp,

[0063] Calculate the ratio of the cmp value of point 3 to the cmp of points 2 and 4.

[0064] t=(cmp-pt2.cmp)*1.0 / (pt4.cmp-pt2.cmp), then the z value of point 3 is:

[0065] z=pt2.z+t*(pt4.z-pt2.z).

[0066] The effects of the above operations on the interpolation inflection point and the second fault frame segment are as follows: Fig. 9 As shown:

[0067] See also Fig. 9 , which shows a schematic diagram of inserting an intersection point into a second fault frame line segment according to an embodiment of the present invention, wherein pt2, pt4, pt6 are inserted projection points, and pt1, pt3, pt3, pt7 are points inserted by a linear interpolation algorithm.

[0068] See also Fig.10 , which shows a schematic diagram of residual correction of interpolation points through intersections according to an embodiment of the present invention. The thick line is the original line, and the thin line is the result line. By comparing the original line and the result line, it can be found that the second fault frame line segment has changed significantly.

[0069] See also Fig.11 , which shows an image after residual correction is performed on the automatic interpolation result of the intermediate stratum section image with line number 2116 according to an embodiment of the present invention. Figure 8 It can be seen that Fig.11 The second fault frame segment shown in Figure 8 It can be seen that the residual correction in this embodiment can make the automatic interpolation result closer to the manual annotation result.

[0070] In a further embodiment, after residual correction is performed on all interpolation points in the second fault frame segment, the method of the present invention also includes smoothing the second fault frame segment through a Gaussian filtering smoothing algorithm. After smoothing, a smooth fault frame segment is formed. The number of data points after smoothing remains unchanged, but each point may be offset in the horizontal and vertical directions.

[0071] See also Fig.12 , which shows a schematic diagram of smoothing continuous fault frame line segments according to an embodiment of the present invention.

[0072] See also Fig.13, which shows the processing flow of stratigraphic cross-section images of some embodiments of the present invention. The processing flow includes: step 100, displaying the cross-section and manually marking a part of the stratigraphic cross-section image and obtaining the fault frame line; step 200, automatically switching the stratigraphic cross-section image, and cyclically executing the following steps:

[0073] Step 300, determine whether the current section has no interpreted fault and whether the previous and next sections have fault frame segments; Step 400, if yes, linearly interpolate the fault line (i.e. determine the second frame segment), otherwise, end; Step 500, use the fault projection point to perform residual correction; Step 600, curve smoothing; Step 700, save the interpretation result.

[0074] It should be noted that in the present invention, the intermediate stratigraphic section image automatically interpolated may have multiple fault frame line segments at the same time, which depends on whether there are multiple fault frame line segments in the manually annotated stratigraphic section images on both sides of the intermediate stratigraphic section image. For the situation where multiple fault frame line segments exist at the same time, please refer to Fig.14 .

[0075] As in the above-mentioned embodiment, the automatic interpolation method of the present invention can realize automatic interpolation of a large number of stratigraphic profile images to determine fault lines based on a small amount of manual annotation, which greatly saves the manpower spent on fault interpretation of seismic data and greatly improves the efficiency; through residual correction and smoothing processing, an effect close to manual annotation can be obtained; in practical applications, manual annotation can be performed only on some stratigraphic profile images with clear fault structures, while automatic interpolation can be used to realize automatic interpolation of stratigraphic profile images with unclear fault structures. For these stratigraphic profile images with unclear fault structures, the accuracy of automatic interpolation can exceed the accuracy of manual annotation.

[0076] The following will fully illustrate the workflow of the present invention through an embodiment:

[0077] 1) After obtaining seismic data, the seismic data is displayed in a graphical form on the computer screen to form a seismic data profile graph (such as Figure 2 ); Specifically, the profile here is a two-dimensional figure along the line or cmp direction within the three-dimensional space, and the line or cmp position of the figure remains unchanged. For example, for a seismic profile along the line direction, the line number of the profile remains unchanged, the horizontal cmp number increases from small to large from left to right, and the vertical z value increases from small to large from top to bottom. The present invention provides an automatic interpretation method for calculating faults in two directions, namely, the line (line number) direction and the cmp (track number) direction. This embodiment is described in detail with respect to the automatic interpretation of profile faults along the line direction. The calculation method along the cmp direction is the same, except that the line and cmp related variables are interchanged in the algorithm formula;

[0078] 2) Generate fault frame segments on the 3D seismic profile in a continuous point-by-point manner using the mouse interactively. At least two fault frame segments should be generated for one fault, one at the starting profile position of the fault and the other at the ending profile position of the fault (e.g. Figure 3 and Figure 5 As shown, two fault frame lines are explained at line2100 and line2200 respectively);

[0079] 3) Put the inflection point positions of the two fault frame segments into the data container in the order of acquisition, such as using Pt1, Pt2, ..., Ptn. Each inflection point data records the section position, including (line, cmp, z) coordinate information, line and cmp represent the horizontal positions, and z represents the vertical position (i.e., stratum depth);

[0080] 4) Assume that the section line number of the fault to be interpreted is determined between the sections where the two fault frame segments are located as lineNo (e.g. Figure 7 The section number is line2116);

[0081] 5) Preprocess the seed point data (i.e. preprocess the manually marked inflection points). If the z value of the first point is smaller than the z value of the last point, reverse the fault line and reverse the order of the inflection points of the fault line from the beginning to the end to ensure that the order of the inflection points of the line segment is from small to large in the z direction. For example, the order of the seed points after the inversion is Ptn, Ptn-1, ..., Pt1;

[0082] 6) Compare the number of inflection points of the two fault line segments, fill the number of inflection points of the line segment with fewer inflection points to the same number as the line segment with more inflection points, and fill the last point of the line segment with fewer inflection points to the end of the line segment one by one until the number of inflection points of the two segments is the same;

[0083] 7) Perform interpolation processing between the inflection points of the two fault line segments according to the sequence number of the points. This method uses linear interpolation based on the parameterized equation of the spatial straight line segment to obtain the spatial position nodes of the fault line to be inserted according to the corresponding fault line inflection point connecting the line segments and the position of the fault line to be inserted (the current profile line number), and constructs the initial fault line. For example, when interpolating between the first points of the two segments, the first points of the two segments are respectively marked with pt11 and pt21 to interpolate pt1, and the second points are respectively marked with pt12 and pt22 of the two segments to interpolate pt2. And so on, interpolate pt3,...,ptn point by point (such as Figure 6 ). The interpolated pt1, pt2, ..., ptn are sequentially placed in the data container array; wherein the interpolation method used in the present invention is a linear interpolation method, and firstly the position ratio relationship t between the current section and the sections where the first two frame line segments are located is obtained by using the formula:

[0084] t=(lineNo-line1) / (line2-line1) (1)

[0085] After calculating t, the cmpNo of the interpolation point is obtained as:

[0086] cmpNo=pt11.cmp+t*(pt21.cmp-pt11.cmp) (2)

[0087] The z value is:

[0088] z=pt11.z+t*(pt21.z-pt11.z) (3)

[0089] Then the coordinates of the first new interpolated point are pt1(lineNo,cmpNo,z);

[0090] 8) Read the fault segments on the sections that intersect with the current section (cross-intersect with the current section) from the database, calculate the intersection points of these fault segments with the current section (these intersection points are also called fault projection points), and the coordinate information of the fault projection point positions is also recorded using (line, cmp, z);

[0091] 9) Compare the cmp position size of the fault projection point calculated by 8) with the interpolation point calculated by 7). If the cmp value of a certain projection point is between the cmp values ​​of two interpolation points, and the vertical distance from the projection point to the line segment connecting the two interpolation points is less than the threshold value thresholdValue (such as thresholdValue is determined to be 10, which can also be set by the user), then insert this projection point into the interpolation point data container, and the number of data in the container increases by 1; if the cmp of the projection point is greater than the cmp value of the second point interpolated by 7), and less than the cmp value of the third point, then insert the projection point between the second and third points and become the third point in the data sequence. The original third point becomes the fourth point, and so on. The number of subsequent points is uniformly increased by 1. The original number of interpolation points is 4 in total, and now it becomes 7 after inserting 3 projection points (such as Fig. 9 );

[0092] 10) Using 9) to insert all projection points into the data container array of 7) point by point, and record the serial position of each projection point inserted into the array, and put the serial position into the serial data container index;

[0093] 11) Perform residual correction on the original point data array generated by 7) between all inserted projection points. For example, if the serial numbers of the two inserted projection points are 2 and 4 respectively, then perform residual correction on the point with serial number 3 between 2 and 4 (point 3 is the point interpolated from the original two frame lines). The correction method is as follows:

[0094] Get the cmp number of point 3:

[0095] cmp=pt3.cmp (4)

[0096] Calculate the ratio of the cmp value of point 3 to the cmp of points 2 and 4:

[0097] t=(cmp-pt2.cmp)*1.0 / (pt4.cmp-pt2.cmp) (5)

[0098] Then the z value of point 3 is:

[0099] z=pt2.z+t*(pt4.z-pt2.z) (6)

[0100] 12) By analogy, all the original points inserted between the projection points are corrected for residual errors using 11) (e.g. Figure 8 Residual correction was performed on pt3 and pt5);

[0101] 13) Smoothing all point data after residual correction in step 12) to form a smoothed data. The number of data points remains unchanged after smoothing, but each point may be offset in the horizontal and vertical directions (such as Fig.10 ).

[0102] Specifically, the present invention uses a Gaussian filter-type smoothing algorithm to smooth the curve of the tracking point set to obtain a fault segment curve that meets the geological feature requirements. At the same time, the bell-shaped weight function used in the filter template used for convolution operation in the smoothing is optimized. On the basis of satisfying the smoothness and the offset of the control point after smoothing, the stability of the algorithm is guaranteed when processing sparse and uneven seed points.

[0103] 14) Display the smoothed fault data points on the section by drawing lines and save the data at the same time, thus completing the automatic interpretation of a fault line (e.g. Fig.11 ).

[0104] 15) Repeat 1) to 14) to complete the automatic interpretation of all fault data (the specific process is as follows Fig.13 ).

[0105] As shown in the above embodiment, the present invention uses a method based on linear interpolation of parameterized equations of spatial straight line segments to realize automatic interpretation of faults. When a large fault framework (using manual annotation) has been established, the structural position can be accurately and quickly located, and then the fault projection points are used for correction to achieve zero closure error in fault interpretation. The output requirements can be met by fine-tuning through a smoothing algorithm. The present invention realizes semi-automation of fault interpretation and greatly improves the efficiency of fault interpretation.

[0106] In a second aspect of the present invention, a readable storage medium is also proposed, comprising: an executable computer program, which, when executed by an executor, is used to implement the steps of a method for automatic interpretation of seismic faults in any of the above embodiments.

[0107] The above are exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications may be made without departing from the scope disclosed in the embodiments of the present invention as defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.

[0108] It should be understood that, as used herein, the singular forms "a", "an" are intended to include the plural forms as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations including one or more of the associated listed items.

[0109] The serial numbers of the embodiments disclosed in the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0110] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the embodiments of the present invention as above, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A method for automatic interpretation of earthquake faults, characterized in that: The method comprises: Acquiring stratigraphic cross-section image data, wherein the stratigraphic cross-section image data is obtained based on a plurality of continuous seismic data in a line number direction or a track number direction; Manually marking inflection points of the stratigraphic section image data at intervals of a preset number of line numbers or track numbers to obtain a first fault framework line segment; Automatically interpolating the intermediate stratigraphic section image by a linear interpolation algorithm according to two adjacent first fault frame line segments to obtain a second fault frame line segment; The second fault frame line segment is subjected to residual correction and smoothing processing, and an automatic interpretation result of the earthquake fault is output.

2. The method for automatic interpretation of earthquake faults according to claim 1, characterized in that: The method further includes, before automatically interpolating the intermediate stratigraphic section image by a linear interpolation algorithm according to the inflection points of two adjacent first fault frame line segments to obtain the second fault frame line segment, Determining whether the number of inflection points in the two adjacent first fault frame line segments is the same; In response to the different numbers of inflection points, inflection points are supplemented at the same position as the last inflection point in the first fault frame line segment having a smaller number of inflection points.

3. The method for automatic interpretation of earthquake faults according to claim 2, characterized in that: The method of automatically interpolating the intermediate stratum section image by a linear interpolation algorithm according to the inflection points of two adjacent first fault frame line segments to obtain a second fault frame line segment comprises: Numbering the inflection points in the two adjacent first fault frame line segments from small to large according to their stratum depth coordinates; Automatically interpolating the middle stratigraphic section image based on two adjacent inflection points with the same number based on a linear interpolation algorithm to determine an interpolation inflection point; The line segment connects a plurality of interpolation inflection points to obtain the second fault frame line segment.

4. The method for automatic interpretation of earthquake faults according to claim 3, characterized in that: The automatic interpolation of the intermediate stratum profile image by a linear interpolation algorithm comprises: Automatic interpolation calculation is performed based on the following formula: t=(lineNo-line1) / (line2-line1), cmpNo=pt11.cmp+t*(pt21.cmp-pt11.cmp), z=pt11.z+t*(pt21.z-pt11.z); Wherein, line1 and line2 are line number coordinates of two inflection points with the same number in the two adjacent first fault frame line segments, respectively, and lineNo is the line number coordinate of the interpolation inflection point; pt11cmp and pt21cmp are the track number coordinates of two inflection points with the same number in the two adjacent first fault frame line segments, and cmpNo is the track number coordinate of the interpolation inflection point; Pt11z and pt21z are respectively the stratum depth coordinates of two inflection points with the same number in the two adjacent first fault frame line segments, and z is the stratum depth coordinate of the interpolation inflection point.

5. The automatic interpretation method of earthquake fault according to claim 1 or 4, characterized in that: The method further comprises performing residual correction processing and smoothing processing on the inflection point of the second fault frame line segment and outputting the automatic interpretation result of the earthquake fault, Acquire a vertically intersecting stratigraphic section image corresponding to the intermediate stratigraphic section image, and determine an intersection point between a third fault frame line segment in the vertically intersecting stratigraphic section image and the intermediate stratigraphic section image; Determine whether the track number coordinates of the intersection point are located between the track number coordinates of the two interpolation inflection points; In response to the track number coordinate of the intersection being located between the track number coordinates of the two interpolation inflection points, further determining whether a vertical distance from the intersection to a line segment connecting the two interpolation inflection points is less than a preset threshold; In response to a vertical distance from the intersection point to the two interpolation inflection point connecting line segments being less than a preset threshold, the intersection point is used as a new interpolation inflection point to obtain the second fault framework line segment.

6. The method for automatic interpretation of earthquake faults according to claim 5, characterized in that: The performing residual correction processing on the inflection point of the second fault frame line segment comprises: Using a new interpolation inflection point determined by the intersection point as a first interpolation inflection point; Using the interpolation inflection point determined by the linear interpolation algorithm as the second interpolation inflection point; The second interpolation inflection point is corrected by a residual correction algorithm according to the first interpolation inflection point.

7. The method for automatic interpretation of earthquake faults according to claim 6, characterized in that: The correcting the second interpolation inflection point by using a residual correction algorithm according to the first interpolation inflection point comprises: Determine two of the first interpolation inflection points located on both sides of the second interpolation inflection point based on the track number coordinates; The stratum depth coordinates of the second interpolation inflection point are corrected according to the distance ratio between the second interpolation inflection point and the track number coordinates of the two first interpolation inflection points.

8. The method for automatic interpretation of earthquake faults according to claim 7, characterized in that: The step of smoothing the second fault frame line segment includes: The second fault frame line segment is smoothed by using a Gaussian filtering smoothing algorithm.

9. The method for automatic interpretation of earthquake faults according to claim 1, characterized in that: The step of acquiring stratigraphic profile image data comprises: The seismic data are collected by detection points continuously arranged along the line number direction and along the track number direction. In the stratigraphic profile image data formed based on the multiple seismic data along the line number direction, each inflection point has the same line number coordinate and multiple track number coordinates. In the stratigraphic profile image data formed based on the multiple seismic data along the track number direction, each inflection point has the same track number coordinate and multiple line number coordinates.

10. A readable storage medium, characterized in that: include: An executable computer program, which, when executed by an executor, is used to implement the steps of a method for automatic interpretation of seismic faults as described in any one of claims 1 to 9 above.

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