A method and storage medium for automatic interpretation of earthquake faults

Abstract

The present invention proposes a method and storage medium for automatic interpretation of seismic faults, wherein the method includes: obtaining stratigraphic profile image data, the stratigraphic profile image data being obtained based on multiple 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 frame segment; automatically interpolating the intermediate stratigraphic profile image using a linear interpolation algorithm based on two adjacent first fault frame segments to obtain a second fault frame segment; performing residual correction and smoothing on the second fault frame segment, and outputting the automatic interpretation result of the seismic fault. The present invention achieves rapid positioning of the fault structure based on manual labeling and a linear interpolation algorithm, and achieves zero closure error in fault interpretation by combining residual correction of fault projection points, greatly improving the efficiency and accuracy of fault interpretation.

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 in the Earth's crust where rocks fracture under stress, resulting in significant relative displacement of rock blocks along the fracture surface. Faults vary in size, with large ones extending for hundreds of kilometers along their strike, often consisting of multiple faults and referred to as fault zones, while small ones can be as small as tens of centimeters. Large faults often form the regional geological framework, controlling not only the tectonic evolution of regional geology but also controlling and influencing oil and gas accumulation and mineralization. Small and medium-sized faults often directly determine the distribution of oil and gas reservoirs. Faults are widespread in the Earth's crust and are its most important structures. As a crucial tectonic form, faults play a crucial role in the accumulation, migration, and accumulation of oil and gas. Their study is crucial for the development of oil and gas reservoirs. Seismic fault interpretation involves displaying seismic data on the screen as an image, and then interactively drawing lines (fault framework lines) on the seismic profile to identify the fault structure.

[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 is still the problem of difficulty in 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 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 in the line number direction or the 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 frame segment; 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; performing residual correction processing and smoothing processing on the second fault frame segment, and outputting the automatic interpretation result of the seismic fault.

[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 using a linear interpolation algorithm based on the inflection points of the two adjacent first fault frame segments to obtain the second fault frame segment; and 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 automatic interpolation of the intermediate stratigraphic profile image using 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 using a line segment to obtain the second fault frame segment.

[0008] In one or more embodiments, automatically interpolating the intermediate stratigraphic section image using a linear interpolation algorithm includes:

[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 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 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 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 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 channel number coordinate of the intersection is located between the channel number coordinates of the two interpolation inflection points; in response to the channel number coordinate of the intersection being located between the channel 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.

[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 according to the first interpolation inflection point using the residual correction algorithm.

[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 ratio of the distances 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 using a Gaussian filtering smoothing algorithm.

[0018] In one or more embodiments, the acquiring of stratigraphic profile image data includes: 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 the computer program is used to implement the steps of a method for automatic interpretation of earthquake faults as described in any one of the above embodiments when executed by an executor.

[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 following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below 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 any creative work.

[0022] Figure 1 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 cross-section image stored and named by line number according to an embodiment of the present invention;

[0024] Figure 3 This is a stratigraphic cross-section image at line number 2100 according to an embodiment of the present invention;

[0025] Figure 4 This is a workflow diagram of an automatic earthquake fault interpretation method according to an embodiment of the present invention;

[0026] Figure 5 This is a stratigraphic cross-section image at line number 2200 according to an embodiment of the present invention;

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

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

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

[0031] Figure 10This is a schematic diagram of performing residual correction on interpolation points through intersections according to an embodiment of the present invention;

[0032] Figure 11 This 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] Figure 12 This is a schematic diagram of smoothing continuous fault frame segments according to an embodiment of the present invention;

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

[0035] Figure 14 This is a schematic diagram of a situation where a stratigraphic cross-section image according to an embodiment of the present invention simultaneously contains multiple fault frame segments. 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 conjunction 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. Subsequent embodiments will not explain this one by one.

[0038] See 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, to obtain seismic data, multiple shot points (in the channel number direction) are arranged within a certain range. Detection lines (in the line number direction) are arranged centered around each shot point, with multiple detection points arranged at preset intervals on each detection line. When forming a stratigraphic profile image using the multiple seismic data obtained at 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, depending on the profile direction. It can be understood that, with a single detection point as the center, two mutually perpendicular stratigraphic profile images (named by the channel number and the line number, respectively) will simultaneously exist, displaying the stratigraphic structure in different profile directions, thereby achieving a three-dimensional representation of the stratigraphic structure.

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

[0040] See Figure 3 , which shows the stratigraphic cross-section image at line number 2100 of the embodiment of the present invention. Figure 3 The location of a distinct fault in the image. Each inflection point is actually defined by a 3D coordinate: line number (line), trace number (cmp), and formation depth (Z). Connecting the inflection points in the view with a line segment forms a fault frame segment.

[0041] The main work of the present invention is to manually interpret the faults of a small amount of stratigraphic cross-section image data with clear stratigraphic structure, marking the inflection points. Then, based on the manual annotations, the remaining stratigraphic cross-section image data is automatically interpolated to determine the inflection points, thereby achieving automatic interpretation of earthquake faults. The scheme of the present invention is as follows:

[0042] See Figure 4 , which shows a workflow diagram of an automatic seismic fault interpretation method according to an embodiment of the present invention. In this embodiment, the workflow of the method of the present invention includes: step S1, acquiring stratigraphic cross-section image data, where the stratigraphic cross-section 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 cross-section 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 cross-section image using a linear interpolation algorithm based on two adjacent first fault frame segments to obtain a second fault frame segment; step S4, performing residual correction and smoothing processing on the second fault frame segment, and outputting the automatic seismic fault interpretation result.

[0043] The theoretical basis for this embodiment is that, in actual work, the inventors discovered that within a small range, fault structures exhibit similarities, with a near-linear relationship between the intermediate fault frame segment and the fault frame segments on either side. The use of a certain number of line numbers or trace numbers as intervals in step S2 is intended to ensure similarity between the fault frame segments. Whether to use a certain number of line numbers or a certain number of trace numbers as intervals depends on whether the stratigraphic profile image data currently being processed is stored by line number or trace number. In actual processing, manual labeling is required for stratigraphic profile image data stored by trace number and stratigraphic profile image data stored by line number, respectively. The intermediate stratigraphic profile image in step S3 is the stratigraphic profile image located between the stratigraphic profile images containing the two first fault frame segments. Specifically, the positional relationship between the three is determined by line number or trace number.

[0044] See Figure 5, which shows a stratigraphic cross-section image at line number 2200 according to an embodiment of the present invention. In a specific embodiment of the present invention, the present invention manually annotates inflection points on the stratigraphic cross-section images at line numbers 2100 and 2200 at intervals of 100 line numbers, and determines two adjacent first fault frame segments. Correspondingly, this embodiment automatically interpolates the stratigraphic cross-section images at line numbers 2101 to 2199 to determine the second fault frame segment, thereby interpreting 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 using 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.

[0046] In this embodiment, the interpolation process for the intermediate stratigraphic cross-section image is based on corresponding inflection points in two adjacent first fault-frame line segments. Therefore, if the number of inflection points in the two adjacent first fault-frame line segments differs, the number of inflection points in the segment with the fewer inflection points needs to be compensated to equalize the number of inflection points in the two segments. This compensation method employed in this embodiment is to compensate inflection points at the same position as the last inflection point in the first fault-frame line segment with the fewer inflection points. In other words, this embodiment uses the last inflection point in the segment with the fewer inflection points to correspond to multiple inflection points in the other fault-frame line segment to determine multiple interpolated values.

[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 based on the inflection points of two adjacent first fault frame segments to obtain a 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 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 correspondence between the inflection points and avoid the problem of mismatch in stratum depths of corresponding inflection points due to image inversion.

[0049] In a further embodiment, the linear interpolation algorithm employed by 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 interpolated 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 interpolated inflection point; among them, pt11cmp and pt21cmp are known quantities, and cmpNo is an unknown quantity, that is, the track number coordinate of the interpolated inflection point to be obtained; pt11z and pt21z are the stratum depth coordinates of the two inflection points with the same number in the two adjacent first fault frame segments, and z is the stratum depth coordinate of the interpolated inflection point, among them, pt11z and pt21z are known quantities, and z is an unknown quantity, that is, the stratum depth coordinate of the interpolated 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 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 directly using the last inflection point pt14 in the L1 original fault line to correspond to the inflection points pt24 and pt25 in the L2 original fault line. The actual interpolation result of this embodiment is shown in FIG. Figure 7 shown.

[0056] See Figure 7 , which shows the result of automatic interpolation of the middle 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 manual annotation of the middle 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, with only the specific positions of the inflection points being different. In order to further improve the accuracy of interpolation, the method of the present invention also proposes to perform residual correction and smoothing on the second fault frame 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 processing 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 point is located between the track number coordinates of the two interpolation inflection points; in response to the track number coordinate of the intersection point being located between the track number coordinates of the two interpolation inflection points, further judging whether the vertical distance from the intersection point 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 point to the line segment connecting the two interpolation inflection points being less than the preset threshold, taking the intersection point 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 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 frame 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 frame segment on the one hand, and on the other hand, it is also used for subsequent residual correction of the second fault frame segment.

[0059] In a further embodiment, residual correction processing is performed on the inflection point of the second fault frame line segment, including: 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 according to the first interpolation inflection point using the residual correction algorithm.

[0060] In a further embodiment, correcting the second interpolation inflection point using a residual correction algorithm based on 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 based on a distance ratio between the second interpolation inflection point and the track number coordinates of the two first interpolation inflection points. 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 interpolating the original two frame lines) is corrected for the residual error. 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 values ​​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: Figure 9 As shown:

[0067] See Figure 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. PT2, PT4, and PT6 are inserted projection points, while PT1, PT3, PT3, and PT7 are points inserted using a linear interpolation algorithm.

[0068] See Figure 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 and result lines, it can be seen that the second fault frame segment has changed significantly.

[0069] See Figure 11 , which shows the image after residual correction of the automatic interpolation result of the intermediate stratum section image with line number 2116 according to the embodiment of the present invention. Figure 8 It can be seen that Figure 11 The second fault frame segment shown in Figure 8 It can be seen from this 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 further includes smoothing the second fault frame segment using a Gaussian filter smoothing algorithm. After smoothing, a smoothed 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 Figure 12 , which shows a schematic diagram of smoothing continuous fault frame line segments according to an embodiment of the present invention.

[0072] See Figure 13, which illustrates the process of processing stratigraphic cross-section images in some embodiments of the present invention. The process includes: step 100, displaying the cross-section and manually annotating a portion of the stratigraphic cross-section image to obtain 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 faults 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 points to perform residual correction; Step 600: Smooth the curve; Step 700: Save the interpretation results.

[0074] It should be noted that in the present invention, the automatically interpolated intermediate stratigraphic section image may contain multiple fault frame segments at the same time, which depends on whether there are multiple fault frame segments in the manually annotated stratigraphic section images on both sides of the intermediate stratigraphic section image. For the case where multiple fault frame segments exist at the same time, please refer to Figure 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 efficiency; through residual correction and smoothing processing, an effect close to manual annotation can be obtained; in actual application, manual annotation can only be performed 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 is a complete description of the workflow of the present invention through an embodiment:

[0077] 1) Under the premise of acquiring 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 an earthquake 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 a method for automatically interpreting faults in two directions: 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 interaction method. At least two fault frame segments should be generated for one fault, one at the starting section position of the fault and the other at the ending section position of the fault (e.g. Figure 3 and Figure 5 As shown, two fault frame lines are interpreted at line 2100 and line 2200 respectively);

[0079] 3) Place the inflection points of the two fault frame segments into data containers in the order in which they were acquired, labeled Pt1, Pt2, ..., Ptn. Each inflection point records its section location, including (line, cmp, z) coordinate information, where line and cmp represent the horizontal position, and z represents the vertical position (i.e., formation 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, and is lineNo (e.g. Figure 7 The section number is line2116);

[0081] 5) Preprocess the seed point data (i.e., preprocess the manually annotated 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, ensuring 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 segment with fewer inflection points to the same number as the segment with more inflection points, and fill the last point of the segment with fewer inflection points one by one to the end of the segment until the number of inflection points of the two segments is the same;

[0083] 7) Perform interpolation between the inflection points of the two fault line segments according to the sequence of the points. This method uses the 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 connection segment and the position of the fault line to be inserted (the current profile line number) to form 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 point by point to get pt3, ..., ptn (such as Figure 6 ). The interpolated pt1, pt2, ..., ptn are sequentially placed into the data container array; wherein, the interpolation method used in the present invention is a linear interpolation method. First, the position ratio relationship t between the current section and the sections where the first two frame segments are located is obtained 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] 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 points 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 is increased 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 Figure 9 );

[0092] 10) Using 9) to insert all projection points into the data container array of 7) one by one, 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, 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 values ​​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) Smooth all the point data after residual correction in step 12) to form a smooth data. After smoothing, the number of data points remains unchanged, but each point may be offset in the horizontal and vertical directions (such as Figure 10 ).

[0102] Specifically, the present invention uses a Gaussian filter-based smoothing algorithm to smooth the curve of the tracking point set, obtaining a fault segment curve that meets the geological characteristics requirements. At the same time, the bell-shaped weight function used in the filter template used for the convolution operation in the smoothing process is optimized. On the basis of satisfying the smoothness and the offset of the control points 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 cross section by drawing lines and save the data at the same time, thus completing the automatic interpretation of a fault line (e.g. Figure 11 ).

[0104] 15) Repeat 1) to 14) to complete the automatic interpretation of all fault data (the specific process is as follows Figure 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 further provided, comprising: an executable computer program, which, when executed by an executor, is used to implement the steps of a method for automatic interpretation of earthquake 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 of the embodiments disclosed 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 expressly limited to the singular.

[0108] It should be understood that, as used herein, the singular forms "a" and "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" is intended to include any and all possible combinations of 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] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative 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. Within the spirit of the embodiments of the present invention, the technical features of the above embodiments or different embodiments may be combined, and there are many other variations of different aspects of the above embodiments of the present invention, 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 scope of protection 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 on the stratigraphic section image data at intervals of a preset number of line numbers or trace numbers to obtain a first fault frame line segment; Automatically interpolating the intermediate stratum section image using a linear interpolation algorithm according to two adjacent first fault frame line segments to obtain a second fault frame line segment; performing residual correction and smoothing processing on the second fault frame line segment, and outputting an automatic interpretation result of the earthquake fault; The method of automatically interpolating the intermediate stratigraphic section image using a linear interpolation algorithm based on 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 stratigraphic depth coordinates; automatically interpolating the intermediate stratigraphic section image based on the linear interpolation algorithm based on two adjacent inflection points with the same number to determine an interpolation inflection point; and connecting the multiple interpolation inflection points by a line segment to obtain the second fault frame line segment; The automatic interpolation of the intermediate stratum section image by the linear interpolation algorithm includes performing automatic interpolation calculation based on the following formula: ， ， ； 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; 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; 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.

2. The automatic interpretation method of earthquake faults according to claim 1, characterized in that: The method further includes, before automatically interpolating the intermediate stratum section image by a linear interpolation algorithm according to the inflection points of the 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 added at the same position as the last inflection point in the first fault frame line segment having fewer inflection points.

3. The automatic interpretation method of earthquake faults according to claim 1, characterized in that: The method further includes performing residual correction and smoothing processing on the inflection point of the second fault frame line segment and outputting the earthquake fault automatic interpretation result before: 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; Determining 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 line segment connecting the two interpolation inflection points being smaller than a preset threshold, the intersection point is used as a new interpolation inflection point to obtain the second fault frame line segment.

4. The automatic interpretation method of earthquake faults according to claim 3, characterized in that: The performing residual correction processing on the inflection point of the second fault frame line segment includes: 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 a second interpolation inflection point; The second interpolation inflection point is corrected using a residual correction algorithm according to the first interpolation inflection point.

5. The automatic interpretation method of earthquake faults according to claim 4, characterized in that: Correcting the second interpolation inflection point by using 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; The stratum depth coordinate of the second interpolation inflection point is corrected according to the ratio of the distance between the second interpolation inflection point and the track number coordinates of the two first interpolation inflection points.

6. The automatic interpretation method of earthquake faults according to claim 5, characterized in that: The smoothing of the second fault frame line segment includes: The second fault frame line segment is smoothed using a Gaussian filter smoothing algorithm.

7. The automatic interpretation method of earthquake faults according to claim 1, characterized in that: The obtaining of stratigraphic cross-section 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 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.

8. A readable storage medium, characterized in that: include: An executable computer program, which is used to implement the steps of the automatic interpretation method of earthquake faults as described in any one of claims 1 to 7 when executed by an executor.

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