A method for quickly constructing total fall-distance curve of complex fault zone

Abstract

The patent relates to the technical field of seismic data processing method, in particular to a quick construction method of total throw-distance curve of complex fault zone, which comprises the following steps: S1: rotating the complex fault zone to the east-west direction; S2: establishing a plurality of equidistant vertical lines covering the length and width of the complex fault zone according to the length and width range of the complex fault zone, the plurality of vertical lines intersecting with the fault structure lines to produce a plurality of intersection points, and respectively calculating the horizontal coordinates and vertical coordinates of each intersection point and the corresponding throw; S3: grouping and summing up the throws of the intersection points located on the same vertical line to obtain the total throw of each vertical line of the complex fault zone, and then connecting the horizontal coordinates of the intersection points of each vertical line and the total throw as coordinate points to form a total throw curve, and shifting the total throw curve of the complex fault zone to the left to the origin of the rectangular coordinate system to construct the total throw-distance curve of the complex fault zone, which is strong in operability and fast, and can effectively construct the total throw-distance curve of the complex fault zone.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of seismic data processing method, and particularly relates to a quick construction method of total throw-distance curve of complex fault zone. BACKGROUND

[0002] At present, the construction of fault throw-distance curve is mainly completed through the following ways: (1) using the existing structure map or three-dimensional seismic data to interpret the distribution of faults; (2) through artificial statistics of the fault throw on the seismic profile with fixed interval and the distance of the profile from the left end point of the fault, and connecting the distance and throw array into a curve to form the fault throw-distance curve.

[0003] When processing complex fault zone with a large number of faults, variable trend, complex position relationship and wide extension, the following shortcomings exist:

[0004] (1) The existing technology makes the throw-distance curve of each fault by artificial statistics respectively, and the curves obtained all start from the origin (0, 0) of the rectangular coordinate, which leads to the fact that the total throw of the complex fault zone at the same position cannot be obtained, and the horizontal variation of the total throw of the complex fault zone along the distance cannot be reflected.

[0005] (2) For the case that the lengths of the faults in the complex fault zone are greatly different, although the fixed large interval is used for throw statistics, it is suitable for the faults with long extension, but for the faults with short extension, it may lead to incomplete statistical information, and the statistical method with fixed small interval will greatly increase the workload; the statistical method with different intervals of the profile is used for the faults with different extension lengths and different position distributions, which will cause the interval size of the distance value to be not uniform, and is not conducive to the quick calculation of the total throw.

[0006] (3) In the complex fault zone, due to the inconsistency of the fault trend, the statistical method of the seismic profile with fixed direction and interval cannot accurately reflect the actual throw of each fault. SUMMARY

[0007] The present application aims to provide a quick construction method of total throw-distance curve of complex fault zone to solve the problems proposed in the background.

[0008] In order to achieve the above purpose, the basic scheme of the present application is as follows: a quick construction method of total throw-distance curve of complex fault zone, comprising the following steps:

[0009] S1: using the three-dimensional seismic data in depth domain to make a seismic horizon structure map, determining the plane range of the complex fault zone and the fault structure line according to the seismic horizon structure map, measuring the trend of all fault structure lines of the complex fault zone, and calculating the arithmetic mean value of the trend Wherein θ iAzimuth angle of the i-th fracture, the strike arithmetic mean value represents the numerical value of the average strike line of the complex fracture zone, the complex fracture zone is rotated so that the average strike line of the complex fracture zone becomes east-west, the horizontal coordinate X1 and the vertical coordinate Y1 capable of representing the plane position of the fracture structure line after rotation are recorded, the fracture structure line drop Z1 is generated according to the contour map around the complex fracture zone after rotation, so that the fracture structure line contains three columns of data: horizontal coordinate X1 and vertical coordinate Y1 and drop Z1;

[0010] S2: the length range and the width range of the complex fracture zone after rotation are measured along the rectangular coordinate system respectively, a plurality of equidistant vertical lines covering the length and width of the complex fracture zone are established according to the length range and the width range of the complex fracture zone, the interval of a plurality of the vertical lines is equal to the seismic trace interval, a plurality of intersection points are produced by the intersection of a plurality of the vertical lines and the fracture structure line, the horizontal coordinate X2 and the vertical coordinate Y2 of each intersection point and the corresponding drop Z2 are calculated respectively;

[0011] S3: the drops Z2 of the intersection points located on the same vertical line are grouped and summed up to obtain the total drop C of each vertical line of the complex fracture zone, then the horizontal coordinate X2 of each vertical line intersection point and the total drop C are connected as coordinate points to form a total drop curve, the total drop curve is processed by maximum percentile filtering to remove abnormal points in the curve, and the total drop curve of the complex fracture zone is drawn, finally the total drop-distance curve of the complex fracture zone is constructed by shifting the total drop curve of the complex fracture zone as a whole to the origin of the rectangular coordinate system.

[0012] Further, the step S2 and the step S3 further include a step S2-2: the intersection points are observed by mapping to ensure that the intersection of the vertical line and the fracture structure line has the corresponding intersection point calculated.

[0013] The beneficial effects of the scheme are: (1) by uniformly rotating the average strike line of the complex fracture zone, the relative position relationship of the internal fractures of the complex fracture zone is preserved, and the drop values of the internal fractures are extracted through the seismic horizon structure map under the condition that the relative positions are unchanged, so that reliable data sources of spatial positions are obtained for constructing the total drop-distance curve of the complex fracture zone.

[0014] (2) the drop obtained on the seismic horizon structure map is completely retained on the fracture structure line, the dense vertical lines with the seismic trace interval as the interval value are established by measuring the length and width range of the complex fracture zone, and the drop values of different fracture lines on the vertical lines are collected, the sampling method of the drops of different fractures in the complex fracture zone is unified, so that the complex fracture zone total drop curve has a consistent method for construction.

[0015] (3) the scheme is by rotating the average trend of the complex fault zone to the east-west direction, extracting the fault drop on the structure map, not relying on the fixed interval seismic profile drop value statistics, converting the total drop of the complex fault zone into the geometric analysis and digital signal analysis problem between the dense vertical line and the fault structure line, making the construction process of the total drop of the complex fault zone become visualized and specific, strong operability and fast, and can effectively construct the total drop-distance curve of the complex fault zone. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 the flowchart of the embodiment of the present application is shown in the figure;

[0017] Figure 2 the seismic horizon structure map in the embodiment of the present application is shown in the figure;

[0018] Figure 3 the complex fault zone structure map in the embodiment of the present application is shown in the figure;

[0019] Figure 4 the rotated complex fault zone structure map in the embodiment of the present application is shown in the figure;

[0020] Figure 5 the fault structure line drop map of the rotated complex fault zone in the embodiment of the present application is shown in the figure;

[0021] Figure 6 the schematic diagram of the fault structure line and the several vertical lines in the embodiment of the present application is shown in the figure;

[0022] Figure 7 the local schematic diagram of the intersection point of the fault structure line and the several vertical lines in the embodiment of the present application is shown in the figure;

[0023] Figure 8 the complex fault zone total drop curve before filtering in the embodiment of the present application is shown in the figure;

[0024] Figure 9 the complex fault zone total drop curve after filtering in the embodiment of the present application is shown in the figure;

[0025] Figure 10 the complex fault zone total drop-distance curve in the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0027] EMBODIMENT

[0028] The basics are as follows: Figure 1 As shown: A rapid method for constructing the total elevation drop-distance curve of a complex fault zone, comprising the following steps:

[0029] S1: Combination Figure 2 As shown, a seismic stratigraphic map is created using depth-domain 3D seismic data, combined with... Figure 3 As shown, the planar extent and fault lines of the complex fault zone are determined based on the seismic stratigraphic map. The strikes of all fault lines in the complex fault zone are measured, and the arithmetic mean of the strikes is calculated. in θ i Let be the azimuth angle of the i-th fault, and let be the arithmetic mean of the strike, representing the value of the average strike line of the complex fault zone, combined with . Figure 4 As shown, rotating the complex fault zone causes its average strike line to change to an east-west direction, combined with... Figure 5 As shown, the abscissa X1 and ordinate Y1 that represent the plane position of the fracture structure line after rotation are recorded. The fracture structure line elevation Z1 is generated based on the contour map around the rotated complex fracture zone, so that the fracture structure line contains three columns of data: abscissa X1, ordinate Y1 and elevation Z1.

[0030] S2: Combination Figure 6 As shown, the length and width ranges of the rotated complex fault zone are measured along a rectangular coordinate system. Based on these ranges, several equally spaced vertical lines covering the length and width of the complex fault zone are established. The spacing between these vertical lines is equal to the seismic trace spacing. Figure 7 As shown, several vertical lines intersect with the fracture structure line to produce several intersection points. The horizontal coordinate X2 and vertical coordinate Y2 of each intersection point and the corresponding drop Z2 are calculated respectively.

[0031] S3: Project and observe the intersection points to ensure that each intersection of the vertical line and the fault structure line corresponds to a calculated intersection point. Group and sum the elevation differences Z2 of the intersection points located on the same vertical line to obtain the total elevation difference C for each vertical line of the complex fault zone. Then, connect the x-coordinate X2 of each vertical line intersection point with the total elevation difference C to form a total elevation difference curve (e.g., ...). Figure 8 As shown), the total elevation drop curve is subjected to maximum percentile filtering to remove outliers, and the total elevation drop curve of the complex fault zone is plotted (e.g., ...). Figure 9 As shown), finally, the total elevation curve of the complex fault zone is shifted to the left to the origin of the rectangular coordinate system to construct the total elevation-distance curve of the complex fault zone (as shown). Figure 10 (As shown).

[0032] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other presenters can view. That is, although the present application is described in terms of particular embodiments and illustrative figures, it should be appreciated that the language and combinations of words are intended to be interpreted broadly and liberally to include other related structures and methodologies. It is intended that the present application encompass all technologically equivalent structures and methodologies that might fall within the scope of the claims. It is to be understood that any reference to prior art contained herein is not, and should not be taken as, an acknowledgment or any form of suggestion that such prior art forms part of the common general knowledge in the art in any country in the world, or that the patentees should be taken to admit that such prior art can be part of the prior art, or that the patentees should be taken to admit that such prior art would be obvious to any person skilled in the art in the absence of an enabling disclosure.

[0033] The above description is only some embodiments of the present application, and the common knowledge of the specific structure and characteristics in the scheme is not described too much. The ordinary skilled person in the art knows all the ordinary technical knowledge in the field of the present application before the filing date or the priority date, can know all the prior art in the field, and has the ability to apply the conventional experimental means before that date. The ordinary skilled person in the art can perfect and implement the present scheme under the guidance of the present application, combined with their own ability. Some typical known structures or known methods should not be an obstacle for the ordinary skilled person in the art to implement the present application. It should be noted that for those skilled in the art, without departing from the structure of the present application, a number of modifications and improvements can be made, which should be considered as the protection scope of the present application. These will not affect the effect and practicality of the present application. The protection scope of the present application should be subject to the content of its claims, and the specific embodiments in the specification can be used to explain the content of the claims.

Claims

1. A method for rapidly constructing the total elevation drop-distance curve of a complex fault zone, characterized in that: Includes the following steps: S1: Using depth-domain 3D seismic data, a seismic stratigraphic map is created. Based on this map, the planar extent and fault lines of complex fault zones are determined. The strikes of all fault lines within the complex fault zones are measured, and their arithmetic mean is calculated. in θ i Let X be the azimuth angle of the i-th fracture. The arithmetic mean of the strike represents the value of the average strike line of the complex fracture zone. The complex fracture zone is rotated so that the average strike line of the complex fracture zone becomes east-west. The x-coordinate X1 and y-coordinate Y1 that can represent the plane position of the fracture structure line after rotation are recorded. The fracture structure line drop Z1 is generated based on the contour map around the rotated complex fracture zone, so that the fracture structure line contains three columns of data: x-coordinate X1, y-coordinate Y1 and drop Z1. S2: Measure the length and width of the rotated complex fault zone along the rectangular coordinate system. Based on the length and width of the complex fault zone, establish several equally spaced vertical lines covering the length and width of the complex fault zone. The spacing between the vertical lines is equal to the seismic trace spacing. The vertical lines intersect with the fault structure line to produce several intersection points. Calculate the x-coordinate X2 and y-coordinate Y2 of each intersection point and the corresponding elevation difference Z2. S3: Group and sum the elevation differences Z2 at the intersection points on the same vertical line to obtain the total elevation difference C at each vertical line of the complex fault zone. Then, connect the x-coordinate X2 of each vertical line intersection point with the total elevation difference C as coordinate points to form a total elevation difference curve. Perform maximum percentile filtering on the total elevation difference curve to remove outliers in the curve and draw the total elevation difference curve of the complex fault zone. Finally, shift the total elevation difference curve of the complex fault zone to the left to the origin of the rectangular coordinate system to construct the total elevation difference-distance curve of the complex fault zone.

2. The method for rapidly constructing the total elevation difference-distance curve of a complex fault zone according to claim 1, characterized in that: The step between step S2 and step S3 also includes step S2-2: projecting the intersection points for observation to ensure that there is a corresponding intersection point at the intersection of the vertical line and the fracture structure line.

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