Construction unit boundary determination method based on geological boundary line change degree

Abstract

The invention belongs to the technical field of tectonic geology and oil-gas exploration, and discloses a tectonic unit boundary determination method based on the change degree of a geological boundary. Comprising the following steps: acquiring discrete data which reflects target stratum area distribution and structural fluctuation characteristics, changes of a geological boundary corresponding to a certain kind of geological information, and comprises an area position and geological information parameters; constructing quantitative parameters representing changes of the geological boundary lines, quantitatively representing changes of any discrete data point i of the geological information on the geological boundary lines of any degree to similar geological information on adjacent geological boundary lines on the two sides, and solving a geological boundary line change degree index; and the change of the'geological boundary change degree index 'of all discrete points is used as a basis for determining the boundary of the structural unit, so that the boundaries of different structural units are determined, and the structural unit division is carried out. According to the method, the construction unit boundary determination basis which is suitable for various-order construction units, has geological significance and is determined according to quantitative parameters instead of subjective judgment can be provided.

Description

Technical Field

[0001] This invention belongs to the field of structural geology and oil and gas exploration technology, specifically relating to a method for determining the boundary of a tectonic unit based on the degree of change in geological boundaries. Background Technology

[0002] The division of tectonic units is an important foundation for analyzing the structure of sedimentary basins and guiding the selection of oil and gas exploration areas. The reliability of the division of tectonic units is directly related to the accurate identification of favorable zones within the source area.

[0003] Currently, there are three main types of methods for determining unit boundaries in the division of sedimentary basin tectonic units, both domestically and internationally:

[0004] (1) Semi-quantitative geological boundary: Based on regional tectonic interpretation, the pinch-out line of a major fault or important stratigraphic segment that plays a significant role in sedimentation and tectonics, as well as the trend line of its appropriate extension, are taken as the boundary of the tectonic unit. This method provides specific, intuitive boundaries with clear geological significance, but its applicability is limited and it cannot determine the boundary of a low-order tectonic unit without controlling faults or stratigraphic pinch-out.

[0005] (2) Qualitative geological boundaries: Based on topographic relief, changes in stratum thickness or gravity and magnetic intensity are used as responses to topographic relief. The trend lines of these changes are used as the boundaries of tectonic units on maps such as thickness maps, gravity anomaly maps, and magnetic anomaly maps. This method is theoretically applicable to the division of tectonic units at all levels and has certain geological significance. However, the determination of boundaries is controlled by the researcher's subjective judgment and is subject to arbitrariness and multiple interpretations.

[0006] (3) Artificially Designated Boundaries: A specific isobath of the target layer, an isopythmite of an important stratigraphic segment, a hypothetical concealed major fault, a surface river, or the boundary of an oil reservoir or reserve block are artificially designated as the boundary of a tectonic unit. This method is often used for tectonic units without major fault constraints and with relatively gentle stratigraphic development and tectonic deformation. While this method ensures the integrity of the overall division scheme, it lacks geological significance and practical value at the boundaries, and is highly arbitrary and prone to multiple interpretations.

[0007] Existing patent CN109885936A discloses a method and system for tracking and identifying geological boundaries in a two-dimensional geological cross-section map, belonging to the field of civil engineering technology. The aforementioned method for tracking and identifying geological boundaries in a two-dimensional geological cross-section map includes the following steps: S1, basic data preparation; S2, geological information standardization; S3, borehole benchmark point identification; S4, geological boundary extraction; S5, geological boundary tracking; a) comparison of the relative positions of the geological boundary and the borehole; b) correction of the identification code of the starting point of the geological boundary; c) correction of the identification code of the ending point of the geological boundary; d) geological boundary tracking; S6, coordinate transformation; S7, attribute information identification; S8, standard data output. By adopting the above technical solution, this patent integrates and further identifies geological boundaries in a two-dimensional geological cross-section map. It features human-computer interaction, strong controllability, high efficiency, and can meet the needs of large-scale applications. However, this patent belongs to the field of civil engineering, which is significantly different from the technical field to which this invention pertains. In terms of application effect, the core of this patent is to extract and track a certain geological boundary, which is a line identification. It cannot quantitatively characterize the degree of change of the geological boundary, or measure the structural undulations and change characteristics of a target layer in a certain area. In other words, it cannot achieve surface analysis. In addition, the important data basis of this patent is borehole data, but the spatial range of boreholes is limited, and the application scope is relatively limited.

[0008] Existing patent CN109872393A discloses a method for processing three-dimensional geological data based on above-ground and underground geological information, which includes the following steps: S1, data acquisition; S2, data vectorization processing; S3, constructing the top surface of a three-dimensional geological model; processing data and synthesizing a three-dimensional geological model. This patented method can process three-dimensional geological data using geological maps and topographic maps and relevant software, greatly saving data processing costs, improving data processing efficiency, and saving data processing time. However, the core of this patented method in terms of application effect is the formation of a comprehensive three-dimensional data volume integrating above-ground and underground geological information. It is a fine-scale construction of the volume and does not target the structural undulations and changes of a specific area. To synthesize an effective three-dimensional geological model, this patent requires the collection and processing of various types and information from above-ground and underground sources, which is highly complex. Achieving "determination of structural unit boundaries" presents significant challenges in application and operational feasibility. Summary of the Invention

[0009] This invention aims to address the problems of some tectonic units lacking limiting geological boundaries such as control faults and stratigraphic pinch-outs as the basis for boundary determination, the strong ambiguity of qualitative boundary determination based on geological information change trends, and the low practicality of artificially agreed boundaries that are detached from geological information. It provides a method for determining the boundaries of tectonic units based on the degree of change of geological boundaries. This method is applicable to tectonic units of various orders from high to low, and determines the boundaries of tectonic units based on quantitative parameters rather than subjective judgment. It has geological significance and practical value.

[0010] To achieve the above technical objectives, the present invention adopts the following technical solution:

[0011] A method for determining the boundary of a tectonic unit based on the degree of variation of geological boundaries, the method comprising the following steps:

[0012] Step S1: Obtain discrete data that reflects the regional distribution and structural undulation characteristics of the target layer, the geological boundary changes corresponding to a certain type of geological information, and includes both regional location parameters and geological information parameters.

[0013] Step S2: Construct quantitative parameters to characterize changes in geological boundaries, quantitatively characterize the degree of change of any discrete data point i on a geological boundary at any level relative to the same type of geological information on the adjacent geological boundaries on both sides, and calculate the "geological boundary change degree index".

[0014] Step S3: Use the changes in the "geological boundary change index" of all discrete points as the basis for determining the boundaries of tectonic units, and then determine the boundaries of different tectonic units and carry out the division of tectonic units.

[0015] Further, step S1 specifically includes:

[0016] Step S11: Directly or indirectly obtain a geological boundary plan map corresponding to a certain type of geological information that characterizes the distribution and tectonic undulation features of the target layer region;

[0017] Step S12: Vectorize the geological boundary plan map and extract discrete data in (X, Y, Z) form that reflects the planar changes of the target layer by the geological information reflected by this type of geological boundary. Here, X and Y are parameters indicating the location of the area, and Z is a parameter indicating the geological information reflected by the geological boundary.

[0018] Furthermore, Z is a parameter indicating the geological information reflected by the geological boundary, including at least thickness, structural depth, or curvature.

[0019] Further, step S2 specifically includes:

[0020] Step S21: Based on any discrete data point i(X) on the geological boundary line i Y i Z i ), and discrete data points n(X) on the adjacent geological boundaries on both sides of point i. n Y n Z n ) and point m(X) m Y m Z mWe construct a "quantitative characterization function for geological boundary changes" to measure the degree of change of any discrete data point i on a geological boundary at any level with respect to the geological information on the adjacent geological boundaries on both sides.

[0021] Step S22: Introduce the KD-tree principle, taking point i as the target point, and obtain the points n0 and m0 that are closest to point i on the adjacent geological boundary line;

[0022] Step S23: Substitute the coordinate parameters of point i, point n0, and point m0 ​​into the "Quantitative Characterization Function of Geological Boundary Change" in step S21 to calculate and obtain the "Geological Boundary Change Degree Index" corresponding to the discrete data point i.

[0023] Furthermore, in step S21, a "quantitative characterization function for geological boundary changes" is constructed:

[0024] Kz i =[f(Z) n )+f(Z m )] / 2

[0025]

[0026] In the above formula, Kz i A quantitative characterization function for changes in geological boundaries; f(Z) n f(Z) represents the rate of change of geological information between point i and discrete data point n on the adjacent geological boundary; m ) represents the rate of change of geological information between point i and discrete data point m on the adjacent geological boundary on the other side; ΔZ n Let ΔZ be the geological information change value between point i and discrete data point n on the adjacent geological boundary. n =|Z i -Z n |;d n Let be the distance between point i and discrete data point n on the adjacent geological boundary line. ΔZ m Let ΔZ be the geological information change value between point i and discrete data point m on the adjacent geological boundary on the other side. m =|Z i -Z m |;d m Let be the distance between point i and discrete data point m on the adjacent geological boundary.

[0027] Further, step S22 specifically includes:

[0028] Step S221: Construct a KD-tree for discrete data in the form of (X, Y, Z) on the adjacent geological boundaries on both sides of point i;

[0029] Step S222: On the KD-tree corresponding to the adjacent geological boundary on one side, search for the point n0 that is closest to point i, and on the KD-tree corresponding to the adjacent geological boundary on the other side, search for the point m0 ​​that is closest to point i.

[0030] Furthermore, step S221 specifically includes:

[0031] Step S2211: Input the data points to be processed;

[0032] Step S2212: Initialize the splitting axis: Calculate the variance of the data in each dimension, and take the dimension with the largest variance as the splitting axis;

[0033] Step S2213: Determine the node: Search the current data according to the split axis dimension, find the median data, and put it into the current node;

[0034] Step S2214: Divide into two branches: In the current dividing axis dimension, divide all values ​​less than the median into the left branch, and divide all values ​​greater than or equal to the median into the right branch;

[0035] Step S2215: Replace another dimension as the new dividing axis;

[0036] Step S2216: Determine child nodes: Determine the left node, and backtrack to step S2213 in the data of the left branch to continue; Determine the right node: Backtrack to step S2213 in the data of the right branch to continue;

[0037] When all discrete data in the form of (X, Y, Z) are assigned to the left or right branch of a certain level and become a certain node, step S2216 ends, and a KD-tree is now constructed.

[0038] Further, step S222 specifically includes:

[0039] Step S2221: Calculate the distance between the target point i and the first node of the KD-tree, denoted as a1;

[0040] Step S2222: Compare the value of the target point i with the size of the split point on the dimension corresponding to the current split axis of the KD-tree;

[0041] Step S2223: Select the next lower-level dividing axis:

[0042] If the corresponding value of target point i is less than the dividing point, then select the lower-level left branch;

[0043] If the corresponding value of target point i is greater than or equal to the split point, then select the next lower right branch;

[0044] Step S2224: Calculate the distance between the target point i and the lower-level node of the KD-tree, denoted as a2;

[0045] Step S2225: Compare a1 and a2:

[0046] If a2 is less than a1, return to step S2222, continue to select the next level dividing axis and calculate and compare the distance;

[0047] If a2 is greater than or equal to a1, or if the node is empty after entering a branch of the next level segmentation axis according to step S2222, then backtrack to the previous level node and calculate the distance between the target point i and the segmentation axis where the previous level node is located, denoted as b.

[0048] Step S2226: Compare the distance a between the target point i and the node at the same level when calculating b. b With b, if a b If a is less than b, then a b The corresponding node is the point closest to the target point i;

[0049] Step S2227: If a b If the value is greater than or equal to b, then directly proceed to the other branch that has not been searched in the lower level of the segmentation axis corresponding to b when it was calculated, and perform the search again according to step S2222 until the point closest to the target point i is found.

[0050] Furthermore, step S3 specifically includes:

[0051] Step S31: Following the method in Step S2, take all discrete data points reflecting the planar changes in geological information in the target layer as target points, calculate the corresponding "geological boundary change index", and form a data set {Kz} of the "geological boundary change index" for the target layer. i-max};

[0052] Step S32: Using the dataset {Kz} of the target layer's "geological boundary change index" i-max Based on the basic parameters, a "geological boundary variation plane map" of the target layer is formed. The high-value zones with prominent variation and their appropriate extension trends are used as the basis for determining the boundaries of tectonic units, thereby determining the boundaries of different tectonic units and carrying out tectonic unit division.

[0053] Compared with the prior art, the beneficial effects of the present invention are:

[0054] (1) Comparison with semi-quantitative geological boundary method: The semi-quantitative geological boundary method integrates rich seismic, non-seismic, drilling data and geological analysis, which can finely depict the distribution of major faults and the pinch-out line of the target layer, and thus determine the unit boundary. However, it requires huge investment of manpower, financial and material resources, and not every structural unit has obvious major faults or stratigraphic pinch-out lines controlling the boundary. In contrast, after obtaining the basic information of the geological boundary corresponding to a certain geological information that characterizes the regional distribution and structural undulation of the target layer, this method can directly calculate the degree of change of the geological boundary and carry out the division of structural units and boundary determination, without having to invest a lot of resources to finely depict faults or stratigraphic pinch-out lines. Furthermore, the boundaries between different structural units must exhibit variations in certain geological information of the target layer. Just as the deep and shallow areas in a swimming pool resemble protrusions and depressions in a structural unit, the boundary between deep and shallow areas can be represented by changes in water depth, eliminating the need for a separate warning line. Water depth can distinguish between deep and shallow areas not only in a swimming pool but also on a larger scale in lakes and oceans, and on a smaller scale in puddles and pools. Similarly, the boundaries of structural units such as protrusions and depressions can be represented by geological information such as the thickness of the target layer. There is no need to painstakingly delineate faults or stratigraphic pinch-out lines as boundary markers. Moreover, regardless of whether it is thousands of square kilometers or just a few square kilometers, as long as the target layer exists, it will definitely have thickness. Thickness can be used to reflect the differences in structural units. Furthermore, in geology, in addition to thickness, geological information that can reflect the regional distribution and structural undulation characteristics of the target layer can also include the structural burial depth of the target layer, gravity anomalies, bedding curvature, etc. These geological information are all related to the changes in structural units. Therefore, this invention has a wider range of selectable basic data, applicable spatial scope, and distinguishable structural unit levels than existing methods.

[0055] (2) Compared with the qualitative geological boundary method: The qualitative geological boundary method identifies topographic relief by showing changes in the thickness of strata or the level of gravity and magnetic force on relevant maps. This method is affected by a variety of subjective factors such as visual perception, personal standards, and work experience, and the boundary has a strong ambiguity. In contrast, this method uses mathematical calculations to obtain the degree of change of a certain geological information corresponding to a quantitative geological boundary and uses it as the basis for boundary determination, which greatly reduces the influence of subjective factors and is more objective and accurate.

[0056] (3) Comparison with the artificially agreed boundary method: In addition to the disadvantages of the qualitative geological boundary method, which are greatly affected by subjective factors and have multiple interpretations, the artificially agreed boundary method also has the disadvantages of lacking geological significance or practical value. In contrast, this method is based on the geological boundary corresponding to a certain geological information of the target layer. The geological information reflected by this boundary, such as thickness or structural burial depth, is a comprehensive response of various geological processes such as tectonic and sedimentary processes experienced by the strata. It is closely related to the sedimentary environment, infill type and hydrocarbon accumulation conditions, and has indicative significance for hydrocarbon exploration. Therefore, it does not have the above-mentioned problems.

[0057] (4) By using the method of the present invention, the structural units are determined by quantitatively characterizing the degree of change of geological boundaries. It can measure the structural undulations and variation characteristics of the target layer in a certain area, realize surface analysis, and provide a basis for determining the boundaries of structural units that are applicable to multiple levels from high to low, have geological significance, and are based on quantitative parameters rather than subjective judgment. This can better analyze the structure of sedimentary basins and guide the selection of oil and gas exploration areas. At the same time, the data basis of this application is the basic information of geological boundaries corresponding to a certain geological information that characterizes the regional distribution and structural undulation characteristics of the target layer. The form can be a plan map directly corresponding to the geological information, or a plan map corresponding to several related plan maps or related discrete data formed by specific calculations. The source can be obtained by satellite remote sensing, underground seismic detection, drilling, etc. The types include, but are not limited to, various parameters that can reflect the structural undulation characteristics of the target layer such as thickness, structural burial depth or curvature. It is not limited in spatial range, has great advantages in application scope, and also has great advantages in application difficulty and operational feasibility. Attached Figure Description

[0058] Figure 1 This is a flowchart of the method for determining the boundary of tectonic units based on the degree of change of geological boundaries in an embodiment of the present invention;

[0059] Figure 2 This is a hypothetical thickness plan of a certain layer in a certain region.

[0060] Figure 3 For Figure 2 For point i on a geological boundary with a thickness of 20, and for point n on a geological boundary with a thickness of 10, calculate f(Z). n A schematic diagram;

[0061] Figure 4 To be with Figure 2 Taking point i on a geological boundary with a thickness of 20 as an example, and point n on a geological boundary with a thickness of 10 adjacent to point i on a geological boundary with a thickness of 20, a construction is performed. Figure 2 A schematic diagram of the principle of a KD-tree for discrete data in the form of (X, Y, Z) along a geological boundary of any thickness.

[0062] Figure 5 exist Figure 4 A schematic diagram illustrating the principle of searching for the closest point to point i on the constructed KD-tree;

[0063] Figure 6 This is a plan view showing the thickness of a specific layer in a specific region.

[0064] Figure 7 To utilize traditional methods, based on Figure 6 A schematic diagram defining the boundaries of the structural unit;

[0065] Figure 8 To utilize the method of the present invention, based on Figure 6 A planar diagram showing the degree of thickness variation;

[0066] Figure 9 To utilize the method of the present invention, based on Figure 8 A schematic diagram for determining the boundaries of the structural unit. Detailed Implementation

[0067] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0068] Example 1

[0069] Combination Figure 1 As shown, this embodiment of the invention provides a method for determining the boundary of a tectonic unit based on the degree of change in geological boundaries. The method includes the following steps:

[0070] Step S1: Obtain discrete data reflecting the regional distribution and tectonic undulations of the target layer, including changes in geological boundaries corresponding to a specific type of geological information, and containing both regional location parameters and geological information parameters; specifically including:

[0071] Step S11: Directly or indirectly obtain a geological boundary plan map corresponding to a certain type of geological information that characterizes the distribution and tectonic undulation features of the target layer region. This can be a directly obtained plan map, or a plan map formed by several related plan maps or related discrete data through specific calculations.

[0072] Step S12: Vectorize the geological boundary plan map and extract discrete data in (X, Y, Z) form that reflects the planar changes of the target layer by the geological information reflected by this type of geological boundary. Here, X and Y are parameters indicating the location of the area, and Z is a parameter indicating the geological information reflected by the geological boundary, such as thickness, structural depth, curvature, etc.

[0073] In step S1, a geological boundary plan map corresponding to a certain type of geological information of the target layer is obtained, including direct or indirect acquisition methods. Indirect acquisition methods include: first obtaining the structural depth data table of the top and bottom surfaces of the target layer, or first obtaining the T0 map of the seismic interpretation of the target layer, and then processing these data, such as subtracting the structural depth data to form the top and bottom surface structural maps, or performing time-depth conversion on the T0 map, etc., to form a geological boundary plan map corresponding to a certain type of geological information of the target layer, such as a layer thickness plan map or a layer structural map.

[0074] Step S2: Construct quantitative parameters to characterize changes in geological boundaries. This quantitatively characterizes the degree of change in geological information at any discrete data point i on a geological boundary at any given level relative to the geological information on both adjacent geological boundaries, and calculates the "geological boundary change degree index." Specifically, this includes the following steps:

[0075] Step S21: Based on any discrete data point i(X) on the geological boundary line i Y i Z i ), and discrete data points n(Xn, Yn) on the adjacent geological boundaries on both sides of point i. n Z n ) and point m(Xm, Ym) m Z m We construct a "quantitative characterization function for geological boundary changes" to measure the degree of change of any discrete data point i on a geological boundary at any given level with respect to the geological information on the adjacent geological boundaries on both sides.

[0076] Kz i =[f(Z) n )+f(Z m )] / twenty one)

[0077]

[0078] In equation (1) above, Kz i A quantitative characterization function for changes in geological boundaries; f(Z) n f(Z) represents the rate of change of geological information between point i and discrete data point n on the adjacent geological boundary; m ) represents the rate of change of geological information between point i and discrete data point m on the adjacent geological boundary on the other side; ΔZ nLet ΔZ be the geological information change value between point i and discrete data point n on the adjacent geological boundary. n =|Z i -Z n |;d n Let be the distance between point i and discrete data point n on the adjacent geological boundary line. ΔZ m Let ΔZ be the geological information change value between point i and discrete data point m on the adjacent geological boundary on the other side. m =|Z i -Z m |;d m Let be the distance between point i and discrete data point m on the adjacent geological boundary.

[0079] Step S22: Introducing the KD-tree principle, with point i as the target point, obtain the points n0 and m0 on the adjacent geological boundary lines that are closest to point i; specifically including:

[0080] Step S221: Construct a KD-tree for discrete data in the form of (X, Y, Z) on the adjacent geological boundaries on both sides of point i;

[0081] Step S222: On the KD-tree corresponding to the adjacent geological boundary on one side, search for the point n0 that is closest to point i; on the KD-tree corresponding to the adjacent geological boundary on the other side, search for the point m0 ​​that is closest to point i.

[0082] Step S23: Substitute the coordinate parameters of point i, point n0, and point m0 ​​into the "quantitative characterization function of geological boundary change" from step S21 to calculate the obtained Kz. i This refers to the "geological boundary change index" Kz corresponding to the defined discrete data point i. i-max .

[0083] Step S3: Using the changes in the "geological boundary change index" of all discrete points as the basis for determining the boundaries of tectonic units, the boundaries of different tectonic units are determined and tectonic unit division is carried out; specifically, the following steps are included:

[0084] Step S31: Following the method in Step S2, take all discrete data points reflecting the planar changes in geological information in the target layer as target points, calculate the corresponding "geological boundary change index", and form a data set {Kz} of the "geological boundary change index" for the target layer. i-max};

[0085] Step S32: Using the dataset {Kz} of the target layer's "geological boundary change index" i-maxBased on the basic parameters, a "geological boundary variation plan" is formed for the target layer. This variation represents the degree of planar variation of geological information reflected by this type of geological boundary on the target layer. The high-value zones with prominent variation and their appropriate extension trends are used as the basis for determining the boundaries of tectonic units, thereby determining the boundaries of different tectonic units and carrying out tectonic unit division.

[0086] The method of this invention can provide a basis for determining the boundaries of tectonic units that are applicable to multiple tectonic levels from high to low, have geological significance, and are based on quantitative parameters rather than subjective judgments. This can better analyze the structure of sedimentary basins and guide the selection of oil and gas exploration sites.

[0087] Example 2

[0088] The following is in conjunction with the appendix Figure 2-9 The method in Example 1 will be described in an exemplary, clear and complete manner.

[0089] It should be understood that geological boundaries that can reflect the regional distribution and structural undulations of the target layer are diverse. They can be thickness contour lines that reflect thickness, structural lines that reflect structural depth, or geological boundaries that reflect other geological information.

[0090] This embodiment uses "thickness contour lines" and the "thickness" of the target layer they reflect as examples only to make the disclosure of this application thorough and complete, and to fully convey the concept of these exemplary embodiments to those skilled in the art. These exemplary embodiments can of course be implemented by many different forms and many different geological boundaries, and should not be construed as being limited to the embodiments set forth herein.

[0091] Specifically, embodiments of the present invention include the following steps:

[0092] Step S1: Obtain discrete data reflecting the regional distribution and tectonic undulations of the target layer, including changes in geological boundaries corresponding to a specific type of geological information, and containing both regional location and thickness parameters; specifically including:

[0093] Step S11: Directly or indirectly obtain a geological boundary plan map corresponding to a certain type of geological information that characterizes the distribution and tectonic undulation features of the target layer region.

[0094] This embodiment uses "thickness" as geological information reflecting the structural undulations of the target layer. Therefore, the basic information obtained could be a thickness data table, a thickness planar map, or a thickness planar map obtained by subtracting structural maps of the top and bottom surfaces of the target layer. Alternatively, it could be two data tables on the structural depths of the top and bottom surfaces of the target layer, or a T0 map of the top and bottom surfaces of the target layer obtained through joint seismic and geological interpretation, converted to time-depth to obtain a structural map, and then processed to obtain a thickness map. Therefore, there are multiple direct or indirect methods to characterize the thickness of the target layer, and appropriate processing methods are necessary to obtain, for example... Figure 2 The floor plan shown is preferable.

[0095] Step S12: Vectorize the geological boundary planar map. In this embodiment, discrete data in (X, Y, Z) form reflecting the planar variation of the target layer thickness is extracted, where X and Y are parameters indicating the location of the region, and Z is a parameter indicating the thickness. Each planar data point has planar location coordinates, such as latitude and longitude coordinates or geodetic coordinates for each location. If not, it can be done as follows: Figure 2 The diagram shows how to assign virtual X and Y axes and extract the corresponding X and Y values.

[0096] Step S2: Construct quantitative parameters to characterize changes in geological boundaries. In this embodiment, the degree of change of the thickness of a discrete data point i on any thickness contour line with respect to the thickness of adjacent thickness contour lines on both sides is quantitatively characterized, and the "thickness change index" is obtained.

[0097] like Figure 3 As shown, the thickness difference ΔZ between any point i on any thickness contour line of any target layer at any location and the thickness of adjacent thickness contour lines is a constant value of 10m, but the distance d between point i and different discrete data points n on adjacent thickness contour lines is... n Not entirely the same, but there is one and only one point n that is closest to point i, then that point n is n0, and the corresponding f(Z) is... n The maximum value is obtained by finding Kz. i Only then is the maximum value Kz i-max This is also known as the "geological boundary change index," which corresponds to the "thickness change index" in this embodiment. Therefore, it is necessary to further determine the point n0 that is closest to point i on the adjacent thickness contour line of point i, with point i as the target point, and determine the point m0 ​​that is closest to i on the other adjacent contour line.

[0098] Tectonic unit division usually involves a large research scope and a large amount of discrete data in (X, Y, Z) that reflects the regional distribution and tectonic undulation characteristics of the target layer and the changes in geological boundaries corresponding to a certain type of geological information. Introducing the KD-tree principle has a significant advantage in improving data processing efficiency.

[0099] like Figure 4 and Figure 5 As shown, step S2 specifically includes the following steps:

[0100] Step S21: Based on any discrete data point i(X) on the geological boundary line i Y i Z i ), and discrete data points n(X) on the adjacent geological boundaries on both sides of point i. n Y n Z n ) and point m(X) m Y m Z m We construct a "quantitative characterization function for geological boundary changes" to measure the degree of change of any discrete data point i on a geological boundary at any level with respect to the geological information on the adjacent geological boundaries on both sides.

[0101] This embodiment constructs a "thickness quantitative characterization function"; the formula for the "thickness quantitative characterization function" is formula (1)-(3) in embodiment 1. After obtaining the points n0 and m0 that are closest to point i on the adjacent thickness contour lines of point i, the relevant parameters of point i, point n0 and point m0 ​​are substituted into the above formula to obtain Kz. i That is, Kz i-max , Kz i-max Defined as the "thickness variation index";

[0102] Step S22: Introducing the KD-tree principle, with point i as the target point, obtain the points n0 and m0 on the adjacent geological boundaries that are closest to point i. In this embodiment, the closest points n0 and m0 on the adjacent thickness contour lines of point i are obtained; specifically including:

[0103] Step S221: Construct a KD-tree for discrete data in the form of (X, Y, Z) on the adjacent thickness contour lines on both sides of point i. The process includes:

[0104] Step S2211: Input the data points to be processed;

[0105] Step S2212: Initialize the segmentation axis: Calculate the variance of the data in each dimension and take the dimension with the largest variance as the segmentation axis. In this embodiment, since the Z value of the same thickness contour line is the discrete data in the form of (X, Y, Z), the actual data only exists in two dimensions, X and Y, that is, it is only segmented by the X-axis and Y-axis.

[0106] Step S2213: Determine the node: Search the current data according to the split axis dimension, find the median data, and put it into the current node;

[0107] Step S2214: Divide into two branches: In the current dividing axis dimension, divide all values ​​less than the median into the left branch, and divide all values ​​greater than or equal to the median into the right branch;

[0108] Step S2215: Replace another dimension as the new dividing axis;

[0109] Step S2216: Determine child nodes: Determine the left node, and backtrack to step S2213 in the data of the left branch to continue; Determine the right node: Backtrack to step S2213 in the data of the right branch to continue;

[0110] When all discrete data in the form of (X, Y, Z) are assigned to the left or right branch of a certain level and become a certain node, step S2216 ends, and a KD-tree is now constructed.

[0111] Step S222: On the KD-tree corresponding to the thickness contour lines on one side, search for the point n0 that is closest to point i; on the KD-tree corresponding to the adjacent geological boundary on the other side, search for the point m0 ​​that is closest to point i; the search process includes:

[0112] Step S2221: Calculate the distance between the target point i and the first node of the KD-tree, denoted as a1;

[0113] Step S2222: Compare the value of the target point i with the size of the split point on the dimension corresponding to the current split axis of the KD-tree;

[0114] Step S2223: Select the next lower-level dividing axis:

[0115] If the corresponding value of target point i is less than the dividing point, then select the lower-level left branch;

[0116] If the corresponding value of target point i is greater than or equal to the split point, then select the next lower right branch;

[0117] Step S2224: Calculate the distance between the target point i and the lower-level node of the KD-tree, denoted as a2;

[0118] Step S2225: Compare a1 and a2:

[0119] If a2 is less than a1, return to step S2222, continue to select the next level dividing axis and calculate and compare the distance;

[0120] If a2 is greater than or equal to a1, or if the node is empty after entering a branch of the next level segmentation axis according to step S2222, then backtrack to the previous level node and calculate the distance between the target point i and the segmentation axis where the previous level node is located, denoted as b.

[0121] Step S2226: Compare the distance a between the target point i and the node at the same level when calculating b. b With b, if a b If a is less than b, then a b The corresponding node is the point closest to the target point i;

[0122] Step S2227: If a b If the value is greater than or equal to b, it means that there may be a point closer to the target point i. We need to directly enter the other branch that has not been searched in the lower level of the segmentation axis corresponding to the calculation of b, and perform the search again according to step S2222 until the point closest to the target point i is found.

[0123] Figure 5 The illustrations illustrate steps S2221, S2222, S2223, S2224, and S2225, specifically the case where "a2 is greater than or equal to a1," and the situation in S2226. It should be understood that because... Figure 5 The constructed KD-tree is relatively simple, so the illustrated S2224 only calculates up to a2. However, in reality, with massive amounts of data, the KD-tree will obviously be much more complex, potentially calculating a3, a4, a5, and so on. For the same reason, the result of "if a2 is greater than or equal to a1" in S2225 returns the first node. Figure 5 The calculation of a in S2226 is illustrated in the diagram. b That is, a1, while in reality a b Of course, it could also be a3, a4, a5...; for the same reason. Figure 5 The situation in S2227 was not illustrated. Regarding the "another branch that was not searched in the lower level of the corresponding segmentation axis when calculating b" mentioned in S2227, if... Figure 5 For example, "the other branch" is the left branch of the first node n5.

[0124] Through steps S21-S22, with i as the target point, we can obtain the points n0 and m0 that are closest to i on the adjacent geological boundary line.

[0125] Step S23: Substitute the coordinate parameters of points i, n0, and m0 into the "quantitative characterization function of geological boundary changes" from step S21 to obtain... This refers to the "geological boundary change index" Kz corresponding to point i. i-max In this embodiment, this is the "thickness variation index" corresponding to point i.

[0126] Step S3: Using the changes in the "geological boundary variation index" of all discrete points (in this embodiment, the changes in the "thickness variation index") as the basis for determining the boundaries of tectonic units, the boundaries of different tectonic units are determined and tectonic unit division is carried out; specifically, the following steps are included:

[0127] Step S31: Following the method in Step S2, take all discrete data points reflecting the planar changes in geological information in the target layer as target points, and calculate the corresponding geological boundary change index (in this embodiment, the corresponding "thickness change index") to form a data set {Kz} of the geological boundary change index of the target layer (in this embodiment, the "thickness change index") i-max};

[0128] Step S32: Using the data set {Kz} of the target layer geological boundary variation index (in this embodiment, the target layer “thickness variation index”) i-max Based on the basic parameters, a planar map of the degree of change of the geological boundary of the target layer is formed (in this embodiment, a planar map of the degree of change of the thickness of the target layer is formed). This degree of change represents the degree of planar change of the geological information reflected by this type of geological boundary on the target layer (in this embodiment, the degree of planar change of the thickness of the target layer is represented). The high-value zones with prominent degree of change and their appropriate extension trend are used as the basis for determining the boundary of the tectonic unit, and then the boundaries of different tectonic units are determined and the tectonic unit division is carried out.

[0129] Example 3

[0130] To further verify the application effect of the present invention, the embodiments of the present invention select the following... Figure 6 The image shows a thickness plan view of a specific layer in a certain region. Then, traditional methods are used based on... Figure 6 The work of determining the boundaries of the structural elements was carried out, and the results are as follows: Figure 7 As shown.

[0131] exist Figure 7 In the central region, the boundaries of the structural units are not specific and have multiple solutions, so it is possible to divide them into Scheme 1, Scheme 2 or more.

[0132] In contrast, such as Figure 8 The image shows the application of the present invention based on Figure 6 The resulting thickness variation planar diagram, then, Figure 8 Based on this, the boundary determination of the structural unit was carried out, and the results are as follows: Figure 9 As shown.

[0133] from Figure 9 As can be seen, the high-value zone with prominent thickness variation, which serves as the basis for determining the boundary of the structural unit, and its appropriate extension trend line are more clearly defined. The boundary of the structural unit divided based on this is shown as a "double-dot line", which greatly reduces the ambiguity and can more accurately guide the division of the boundary of the structural unit.

[0134] The above description is merely an embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the scope of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for determining the boundary of a tectonic unit based on the degree of variation of geological boundaries, characterized in that, The method includes the following steps: Step S1: Obtain discrete data that reflects the regional distribution and structural undulation characteristics of the target layer, the geological boundary changes corresponding to a certain type of geological information, and includes both regional location parameters and geological information parameters. Step S2: Construct quantitative parameters to characterize changes in geological boundaries, quantitatively characterize the degree of change of any discrete data point i on a geological boundary at any level relative to the same type of geological information on the adjacent geological boundaries on both sides, and calculate the "geological boundary change degree index". Step S3: Use the changes in the "geological boundary change index" of all discrete points as the basis for determining the boundaries of tectonic units, and then determine the boundaries of different tectonic units and carry out the division of tectonic units.

2. The method for determining the boundary of a tectonic unit based on the degree of change in geological boundaries according to claim 1, characterized in that, Step S1 specifically includes: Step S11: Directly or indirectly obtain a geological boundary plan map corresponding to a certain type of geological information that characterizes the distribution and tectonic undulation features of the target layer region; Step S12: Vectorize the geological boundary plan map and extract discrete data in (X, Y, Z) form that reflects the planar changes of the target layer by the geological information reflected by this type of geological boundary. Here, X and Y are parameters indicating the location of the area, and Z is a parameter indicating the geological information reflected by the geological boundary.

3. The method for determining the boundary of a tectonic unit based on the degree of change in geological boundaries according to claim 2, characterized in that, Z is a parameter indicating the geological information reflected by the geological boundary, including at least thickness, structural depth, or curvature.

4. The method for determining the boundary of a tectonic unit based on the degree of change in geological boundaries according to claim 1, characterized in that, Step S2 specifically includes: Step S21: Based on any discrete data point i(X) on the geological boundary line i Y i Z i ), and discrete data points n(X) on the adjacent geological boundaries on both sides of point i. n Y n Z n ) and point m(X) m Y m Z m We construct a "quantitative characterization function for geological boundary changes" to measure the degree of change of any discrete data point i on a geological boundary at any level with respect to the geological information on the two adjacent geological boundaries. Step S22: Introduce the KD-tree principle, taking point i as the target point, and obtain the points n0 and m0 that are closest to point i on the adjacent geological boundary line; Step S23: Substitute the coordinate parameters of point i, point n0, and point m0 ​​into the "Quantitative Characterization Function of Geological Boundary Change" in step S21 to calculate and obtain the "Geological Boundary Change Degree Index" corresponding to the discrete data point i.

5. The method for determining the boundary of a tectonic unit based on the degree of change in geological boundaries according to claim 4, characterized in that, In step S21, a "quantitative characterization function for geological boundary changes" is constructed: Kz i =[f(Z n )+f(Z m )] / 2 In the above formula, Kz i A quantitative characterization function for changes in geological boundaries; f(Z) n f(Z) represents the rate of change of geological information between point i and discrete data point n on the adjacent geological boundary; m ) represents the rate of change of geological information between point i and discrete data point m on the adjacent geological boundary on the other side; ΔZ n Let ΔZ be the geological information change value between point i and discrete data point n on the adjacent geological boundary. n =|Z i -Z n |;d n Let be the distance between point i and discrete data point n on the adjacent geological boundary line. ΔZ m Let ΔZ be the geological information change value between point i and discrete data point m on the adjacent geological boundary on the other side. m =|Z i -Z m |;d m Let be the distance between point i and discrete data point m on the adjacent geological boundary.

6. The method for determining the boundary of a tectonic unit based on the degree of change in geological boundaries according to claim 4 or 5, characterized in that, Step S22 specifically includes: Step S221: Construct a KD-tree for discrete data in the form of (X, Y, Z) on the adjacent geological boundaries on both sides of point i; Step S222: On the KD-tree corresponding to the adjacent geological boundary on one side, search for the point n0 that is closest to point i, and on the KD-tree corresponding to the adjacent geological boundary on the other side, search for the point m0 ​​that is closest to point i.

7. The method for determining the boundary of a tectonic unit based on the degree of change of geological boundaries according to claim 6, characterized in that, Step S221 specifically includes: Step S2211: Input the data points to be processed; Step S2212: Initialize the splitting axis: Calculate the variance of the data in each dimension, and take the dimension with the largest variance as the splitting axis; Step S2213: Determine the node: Search the current data according to the split axis dimension, find the median data, and put it into the current node; Step S2214: Divide into two branches: In the current dividing axis dimension, divide all values ​​less than the median into the left branch, and divide all values ​​greater than or equal to the median into the right branch; Step S2215: Replace another dimension as the new dividing axis; Step S2216: Determine child nodes: Determine the left node, and backtrack to step S2213 in the data of the left branch to continue; Determine the right node: Backtrack to step S2213 in the data of the right branch to continue; When all discrete data in the form of (X, Y, Z) are assigned to the left or right branch of a certain level and become a certain node, step S2216 ends, and a KD-tree is now constructed.

8. The method for determining the boundary of a tectonic unit based on the degree of change of geological boundaries according to claim 6, characterized in that, Step S222 specifically includes: Step S2221: Calculate the distance between the target point i and the first node of the KD-tree, denoted as a1; Step S2222: Compare the value of the target point i with the size of the split point on the dimension corresponding to the current split axis of the KD-tree; Step S2223: Select the next lower-level dividing axis: If the corresponding value of target point i is less than the dividing point, then select the lower-level left branch; If the corresponding value of target point i is greater than or equal to the split point, then select the next lower right branch; Step S2224: Calculate the distance between the target point i and the lower-level node of the KD-tree, denoted as a2; Step S2225: Compare a1 and a2: If a2 is less than a1, return to step S2222, continue to select the next level dividing axis and calculate and compare the distance; If a2 is greater than or equal to a1, or if the node is empty after entering a branch of the next level segmentation axis according to step S2222, then backtrack to the previous level node and calculate the distance between the target point i and the segmentation axis where the previous level node is located, denoted as b. Step S2226: Compare the distance a between the target point i and the node at the same level when calculating b. b With b, if a b If a is less than b, then a b The corresponding node is the point closest to the target point i; Step S2227: If a b If the value is greater than or equal to b, then directly proceed to the other branch that has not been searched in the lower level of the segmentation axis corresponding to b when it was calculated, and perform the search again according to step S2222 until the point closest to the target point i is found.

9. The method for determining the boundary of a tectonic unit based on the degree of change of geological boundaries according to claim 1, characterized in that, Step S3 specifically includes: Step S31: Following the method in Step S2, take all discrete data points reflecting the planar changes of geological information in the target layer as target points, calculate the corresponding "geological boundary change index", and form a data set {Kz} of the "geological boundary change index" of the target layer. i-max }; Step S32: Using the dataset {Kz} of the target layer's "geological boundary change index" i-max Based on the basic parameters, a "geological boundary variation plane map" of the target layer is formed. The high-value zones with prominent variation and their appropriate extension trends are used as the basis for determining the boundaries of tectonic units, thereby determining the boundaries of different tectonic units and carrying out tectonic unit division.

Images