A method and system for determining the dip and occurrence of a structure at a well
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA UNIV OF PETROLEUM (EAST CHINA)
- Filing Date
- 2026-05-20
- Publication Date
- 2026-08-07
AI Technical Summary
但这类测井技术仅探测井壁数个厘米甚至更小的范围，不能测量构造在井外的延伸，且还需排除井壁垮塌和钻井诱导裂缝等不利因素的影响
本申请提供了一种井旁构造倾角和赋存特征的确定方法及系统，通过获取目标井段的声波远探测数据并进行波场分离和偏移成像处理，得到井旁构造的二维反射成像数据，解决了相关测井技术仅能探测井壁表面（小于2米范围）、无法测量构造在井外延伸的问题，实现了对井旁数米至数十米范围内地层构造的有效探测，拓展了测井技术的探测深度和范围。通过基于二维反射成像数据确定二维空间数据阵列集合，并分别对每个二维子空间数据阵列在预设角度范围内按预设角度步长进行多个角度的扫描相干叠加处理，得到每个阵列对应的多个角度相干能量值，解决了从成像数据中快速、定量提取构造倾角和赋存特征的问题，实现了对井旁构造倾角的高效计算，同时利用相干叠加方式有效压制了随机噪声和线性度差的干扰信号，提高了处理结果的可靠性。通过基于每个二维子空间数据阵列对应的多个角度相干能量值中的最大值，确定目标井段深度位置范围内的最大相干值测井曲线、赋存特征相干图和倾角测井曲线，解决了相关技术无法定量表征井旁构造赋存状态（如声阻抗反差）的问题，实现了构造倾角（仰角）的定量输出，同时通过相干图的色标强度反映构造的声波反射强度，进而表征构造与地层的声阻抗反差，为储层预测和油气运移分析提供了重要的参考依据。
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Abstract
Description
Technical Field
[0001] This application relates to the field of acoustic logging technology, and in particular to a method and system for determining the dip angle and occurrence characteristics of well-side structures. Background Technology
[0002] Acoustic long-range sounding technology uses reflected signals generated by a sound source in the well to image the surrounding formation. This technology has become increasingly mature and widely used in oil and gas exploration and geological engineering. The processing and interpretation of the imaging results from this long-range sounding technology has thus become a crucial issue. One fundamental problem is how to quantitatively extract information on the occurrence (such as azimuth and dip) and occurrence (such as acoustic impedance contrast, which characterizes the difference between the structure and the formation). The former is an important parameter for structural interpretation, hydrocarbon migration, and geological modeling, while the latter is closely related to reservoir prediction. For example, the reflective "bright spots" formed in the formation by fracture structures with high oil and gas content can serve as a characteristic of fractured reservoirs.
[0003] Related technologies employ wellbore electrical imaging, ultrasonic reflection imaging, and downhole television to extract structural attitude parameters from the wellbore. However, these logging techniques only detect a few centimeters or even smaller areas of the wellbore and cannot measure the extension of the structure outside the well. Furthermore, the effects of adverse factors such as wellbore collapse and drilling-induced fractures must be excluded.
[0004] Therefore, there is an urgent need for a method to determine the dip angle and occurrence characteristics of well-side structures in order to solve the problem of being unable to quickly and quantitatively extract the dip angle and occurrence characteristics of well-side structures from acoustic remote sensing imaging data, thereby improving the accuracy and efficiency of well-side structure interpretation. Summary of the Invention
[0005] The purpose of this application is to provide a method and system for determining the dip angle and occurrence characteristics of well-side structures. This method can efficiently obtain quantitative information on the dip angle, elevation angle, and acoustic reflection intensity of the surrounding stratigraphic structures based on acoustic remote sensing imaging data, thereby characterizing the occurrence and occurrence state of the structures.
[0006] To achieve the above objectives, this application provides the following solution: Firstly, this application provides a method for determining the dip angle and occurrence characteristics of well-side structures, including: Acquire remote acoustic data within the depth range of the target well section; the remote acoustic data includes acoustic reflection signals from structures near the well. The remote acoustic wave data is subjected to wavefield separation and offset imaging processing to obtain two-dimensional reflection imaging data of the well-side structure; Based on the two-dimensional reflection imaging data, a set of two-dimensional spatial data arrays for the well-side structure is determined; the set of two-dimensional spatial data arrays includes a set of two-dimensional spatial data arrays for the upper plate and a set of two-dimensional spatial data arrays for the lower plate. Each two-dimensional subspace data array in the two-dimensional spatial data array set is subjected to multiple angle scanning coherent superposition processing within a preset angle range and at a preset angle step size to obtain multiple angle coherent energy values corresponding to each two-dimensional subspace data array. Based on the maximum value among multiple angular coherence energy values corresponding to each two-dimensional subspace data array, the maximum coherence logging curve, the stored characteristic coherence map, and the dip logging curve within the depth range of the target well section are determined.
[0007] Secondly, this application provides a system for determining the dip angle and occurrence characteristics of well-side structures, including: The data acquisition module is used to acquire remote acoustic wave data collected within the depth range of the target well section; the remote acoustic wave data includes acoustic wave reflection signals from structures near the well. An imaging processing module is used to perform wavefield separation and offset imaging processing on the remote sound wave data to obtain two-dimensional reflection imaging data of the well-side structure. An array construction module is used to determine a set of two-dimensional spatial data arrays for well-side construction based on the two-dimensional reflection imaging data; the set of two-dimensional spatial data arrays includes a set of two-dimensional spatial data arrays for the upper plate and a set of two-dimensional spatial data arrays for the lower plate. The coherent superposition module is used to perform coherent superposition processing on each two-dimensional subspace data array in the two-dimensional spatial data array set at multiple angles within a preset angle range and at a preset angle step size, so as to obtain multiple angle coherent energy values corresponding to each two-dimensional subspace data array. The results generation module is used to determine the maximum coherence logging curve, stored characteristic coherence map and dip logging curve within the depth range of the target well section based on the maximum value among the multiple angular coherence energy values corresponding to each two-dimensional subspace data array.
[0008] Thirdly, this application provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method for determining the dip angle and occurrence characteristics of the wellside structure as described above.
[0009] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for determining the wellside structural dip angle and occurrence characteristics as described above.
[0010] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the method for determining the wellside structural dip angle and occurrence characteristics as described above.
[0011] According to the specific embodiments provided in this application, the following technical effects are disclosed: This application provides a method and system for determining the dip angle and occurrence characteristics of well-side structures. By acquiring acoustic remote sensing data of the target well section and performing wavefield separation and migration imaging processing, two-dimensional reflection imaging data of the well-side structures are obtained. This solves the problem that related logging technologies can only detect the wellbore surface (within 2 meters) and cannot measure the extension of structures outside the well. It enables effective detection of formation structures within a range of several meters to tens of meters around the well, expanding the detection depth and range of logging technology. By determining a two-dimensional spatial data array set based on the two-dimensional reflection imaging data, and performing coherent superposition processing on each two-dimensional subspace data array at multiple angles within a preset angle range and at a preset angle step size, multiple angle coherent energy values corresponding to each array are obtained. This solves the problem of quickly and quantitatively extracting the dip angle and occurrence characteristics of structures from imaging data, achieving efficient calculation of the dip angle of well-side structures. At the same time, the coherent superposition method effectively suppresses random noise and interference signals with poor linearity, improving the reliability of the processing results. By determining the maximum coherence logging curve, occurrence characteristic coherence map, and dip logging curve within the target well depth range based on the maximum value among multiple angular coherence energy values corresponding to each two-dimensional subspace data array, this solves the problem that related technologies cannot quantitatively characterize the occurrence state of structures near the well (such as acoustic impedance contrast). It achieves quantitative output of structure dip angle (elevation angle), and at the same time, the intensity of the color scale of the coherence map reflects the acoustic wave reflection intensity of the structure, thereby characterizing the acoustic impedance contrast between the structure and the formation, providing an important reference for reservoir prediction and hydrocarbon migration analysis. Attached Figure Description
[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0013] Figure 1 This is a flowchart illustrating a method for determining the dip angle and occurrence characteristics of a well-side structure according to an embodiment of this application.
[0014] Figure 2 This is a schematic diagram illustrating the principle of a method for determining the dip angle and occurrence characteristics of a well-side structure according to an embodiment of this application.
[0015] Figure 3 This is a schematic diagram illustrating the determination of stratigraphic dip angle and occurrence characteristics according to an embodiment of this application; wherein, Figure 3(a) in the figure is a schematic diagram of the logging curve of the maximum coherence value of the hanging wall and the coherence diagram of the hanging wall at different dip angles; Figure 3 (b) in the image is a two-dimensional reflection imaging diagram for long-range detection; Figure 3 (c) in the diagram is a schematic diagram of the logging curve of the maximum coherence value of the footwall and the coherence diagram of the footwall at different dip angles.
[0016] Figure 4 This is a schematic diagram illustrating the results of low-dip structures in sandstone and mudstone strata provided in one embodiment of this application; wherein, Figure 4 (a) is a schematic diagram of the natural gamma (GR) curve of the sandstone and mudstone strata; Figure 4 (b) is a schematic diagram of the maximum coherence value logging curve of the hanging wall of a low-dip structure in sandstone and mudstone formations and the coherence diagram of the hanging wall at different dip angles; Figure 4 (c) is a two-dimensional reflection image of a low-dip structure in a sandstone-mudstone stratum; Figure 4 (d) is a schematic diagram of the maximum coherence value logging curve of the footwall of a low-dip structure in sandstone and mudstone formations and the coherence diagram of the footwall at different dip angles.
[0017] Figure 5 This is a schematic diagram illustrating the result of well-passing folding structures in sandstone and mudstone formations according to an embodiment of this application; wherein, Figure 5 (a) is a schematic diagram of the GR curve of the well-passing fold structure in the sandstone and mudstone strata; Figure 5 (b) is a schematic diagram of the maximum coherence value logging curve of the hanging wall of the fold structure of the sandstone and mudstone formation and the coherence diagram of the hanging wall at different dip angles. Figure 5 (c) is a two-dimensional reflection image of the fold structure of the well-passing strata in the sandstone and mudstone strata; Figure 5 (d) is a schematic diagram of the maximum coherence value logging curve of the footwall of the folded structure in the sandstone and mudstone formation and the coherence diagram of the footwall at different dip angles.
[0018] Figure 6 for Figure 5 Rose diagram of dip angle distribution of fold structures in well-passed strata within medium-sandstone mudstone formations; among which, Figure 6 (a) is a rose diagram composed of the dip angles of the hanging wall and the footwall in the depth range of 3040m-3090m; Figure 6 (b) is a rose diagram composed of the dip angles of the hanging wall and the footwall in the depth range of 3090m-3140m; Figure 6 (c) is a rose diagram composed of the dip angles of the hanging wall and the footwall in the depth range of 3140m-3190m; Figure 6 (d) in the diagram is a rose diagram composed of the dip angles of the upper and lower sides in the depth range of 3190m-3240m; Figure 6 (e) in the diagram is a rose diagram combining the dip angles of the hanging wall and the footwall in the depth range of 3240m-3290m; Figure 6(f) in the figure is a rose diagram composed of the dip angles of the hanging wall and the footwall in the depth range of 3290m-3340m; Figure 6 In the diagram, (g) is a rose diagram composed of the dip angles of the hanging wall and the footwall in the depth range of 3340m-3390m. Figure 6 (h) in the diagram is a rose diagram composed of the dip angles of the hanging wall and the footwall in the depth range of 3390m-3440m. Figure 6 (i) is a rose diagram composed of the dip angles of the upper and lower plates in the depth range of 3440m-3490m; Figure 6 In the diagram, (j) is a rose diagram composed of the dip angles of the upper and lower plates in the depth range of 3490m-3530m. Detailed Implementation
[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0020] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0021] In one exemplary embodiment, such as Figure 1 As shown, this application provides a method for determining the dip angle and occurrence characteristics of a well-side structure, comprising the following steps 101 to 105. Wherein: Step 101: Acquire remote acoustic data within the depth range of the target well section; the remote acoustic data includes acoustic reflection signals from structures near the well.
[0022] Step 102: Perform wavefield separation and offset imaging processing on the remote sound wave data to obtain two-dimensional reflection imaging data of the well-side structure.
[0023] Step 103: Based on the two-dimensional reflection imaging data, determine the set of two-dimensional spatial data arrays for the well-side structure. The set of two-dimensional spatial data arrays includes a set of two-dimensional spatial data arrays for the upper plate and a set of two-dimensional spatial data arrays for the lower plate.
[0024] Step 104: Perform coherent scanning and superposition processing on each two-dimensional subspace data array in the two-dimensional spatial data array set at multiple angles within a preset angle range and with a preset angle step size to obtain multiple angle coherent energy values corresponding to each two-dimensional subspace data array. The preset angle range is 0... o Up to 90 o The preset angle step size is 1.o .
[0025] Step 105: Based on the maximum value among the multiple angular coherence energy values corresponding to each two-dimensional subspace data array, determine the maximum coherence logging curve, the stored characteristic coherence map, and the dip logging curve within the depth range of the target well section.
[0026] By implementing steps 101 to 105 above, this application can efficiently and quantitatively extract the dip angle and occurrence characteristics of well-side structures from acoustic remote detection imaging data, overcome the shortcomings of conventional logging in detecting off-well structures, and provide a reliable basis for interpreting well-side structures for oil and gas exploration and geological engineering.
[0027] In another exemplary embodiment of this application, the two-dimensional reflection imaging data includes upper disk two-dimensional reflection imaging data and lower disk two-dimensional reflection imaging data. Step 102 specifically includes: Wavefield separation is performed on the remote acoustic data to extract the up-reflection wave and down-reflection wave of the well-side structure. Wavefield separation includes processing the remote acoustic data using at least one of the following methods: FK filtering, linear prediction filtering, median filtering, Radon transform, or multi-scale correlation.
[0028] The upward reflected wave is offset imaging to obtain two-dimensional reflection imaging data of the upper disk.
[0029] The down-reflected wave is offset imaging to obtain two-dimensional reflection imaging data of the lower disk.
[0030] In another exemplary embodiment of this application, step 103 specifically includes: Slide the preset window along the well axis at preset axial imaging intervals within the depth range of the target well section. Perform the following steps at each sliding position until the entire target well section is covered: Using preset windows, the two-dimensional reflection imaging data of the upper plate and the two-dimensional reflection imaging data of the lower plate are respectively cropped to obtain the two-dimensional subspace data arrays of the upper plate and the lower plate at the current sliding position; both the two-dimensional subspace data arrays of the upper plate and the lower plate are composed of... M × N It consists of 10 data points.
[0031] in, ; M This represents the total number of data points along the well axis of the two-dimensional subspace data array; N This represents the total number of data points along the radial direction of the two-dimensional subspace data array; Indicates the length of the preset window along the well axis. Indicates the length of the preset window along the radial direction of the well; Indicates the preset axial imaging interval; This indicates the preset radial imaging interval.
[0032] Add the upper two-dimensional subspace data array obtained from all sliding positions to the upper two-dimensional space data array set, and add the lower two-dimensional subspace data array obtained from all sliding positions to the lower two-dimensional space data array set.
[0033] In another exemplary embodiment of this application, step 104 specifically includes: Each can be calculated using the following formulas. k Multiple angular coherence energy values corresponding to the disk two-dimensional subspace data array: .
[0034] in, Indicates the angle as hour k In the set of disk two-dimensional spatial data arrays k The angular coherence energy value corresponding to the disk two-dimensional subspace data array; k ={1, 2}, k =1 indicates the upper plate. k =2 indicates the lower body; express k Disk-based two-dimensional subspace data array; m express k The first along the well axis in the two-dimensional subspace data array of the disk m One data point; n express k The first 2D subspace data array along the well radial direction n Data points.
[0035] In another exemplary embodiment of this application, the maximum coherence logging curve includes the hanging wall maximum coherence logging curve and the footwall maximum coherence logging curve; the stored characteristic coherence map includes coherence maps of the hanging wall at different dip angles and coherence maps of the footwall at different dip angles; the dip angle logging curve includes the hanging wall dip angle logging curve and the footwall dip angle logging curve, which are presented in the form of a rose diagram in this example. Step 105 specifically includes: By traversing the two-dimensional spatial data array set of the upper plate, the coherent energy values of the upper plate at multiple angles at all sliding positions are arranged by depth and angle to obtain coherence maps of the upper plate at different dip angles.
[0036] By traversing the two-dimensional spatial data array set of the lower plate, the coherent energy values of the lower plate at multiple angles at all sliding positions are arranged by depth and angle to obtain coherent maps of the lower plate at different tilt angles.
[0037] Traverse all sliding positions in the coherence diagram under different tilt angles of the upper plate, take the maximum value among multiple angular coherence energy values corresponding to the current sliding position along the angular direction and record it as the maximum coherence energy value of the upper plate, and take the angle corresponding to the maximum coherence energy value of the upper plate as the tilt angle of the upper plate at the corresponding sliding position.
[0038] Simultaneously, all sliding positions in the coherence diagram under different tilt angles of the lower plate are traversed, and the maximum value among multiple angular coherence energy values corresponding to the current sliding position along the angular direction is recorded as the maximum coherence energy value of the lower plate. The angle corresponding to the maximum coherence energy value of the lower plate is taken as the tilt angle of the lower plate at the corresponding sliding position.
[0039] After traversing all slip positions in the coherence maps of the hanging wall and footwall at different dip angles, the hanging wall dip angles of all slip positions are arranged by depth to obtain the hanging wall dip angle logging curves; the footwall dip angles of all slip positions are arranged by depth to obtain the footwall dip angle logging curves; the maximum coherence energy values of the hanging wall at all slip positions are arranged by depth to obtain the hanging wall maximum coherence value logging curves; and the maximum coherence energy values of the footwall at all slip positions are arranged by depth to obtain the footwall maximum coherence value logging curves.
[0040] In this application, the inclination angle of a well-side structure relative to the horizontal plane is defined as the dip angle. In particular, when the structure is located on the hanging wall of the wellbore, its dip angle is specifically manifested as an elevation angle.
[0041] The following example illustrates this application using the determination process of specific well-side structural dip angles and occurrence characteristics.
[0042] The basis for extracting stratigraphic occurrence information from remote sensing imaging data is that structural images show a linear distribution within a range of several to tens of meters outside the well. This phenomenon is very common, as seen in images of fractures or stratigraphic interfaces outside the well.
[0043] Therefore, this application performs linear fitting on the structural imaging along its distribution direction, and the angle between the fitted line and the horizontal line can give the dip angle of the structure. In the actual processing of imaging data, the data is truncated along the radial and axial directions of the well and combined into a two-dimensional spatial coherence array; linear correlation processing is performed on the array data, and the slope of the line corresponding to the maximum coherence value can give the dip angle of the structure. The magnitude of the coherence value corresponds to the acoustic reflectivity of the structure, which is related to the acoustic impedance contrast between the structure and the formation, and can reflect its occurrence in the formation.
[0044] In one exemplary embodiment, such as Figure 2The diagram illustrates a principle of a method for determining the dip angle and occurrence characteristics of a well-side structure. The background is a well-side (formational) structure (given by actual data imaging) and an acoustic logging instrument within the well. Logging proceeds from bottom to top; in the lower (upper) hanging wall section of the structure, acoustic waves emitted by the sound source are reflected by the structure and propagate downwards (upwards) into the well, where they are collected by the instrument's receiving array. Wavefield separation is performed on the array data to extract the upward and downward reflected waves generated by the structure. These are then offset and imaged to obtain the images of the lower hanging wall (left side of the well) and upper hanging wall (right side of the well) of the structure, as shown in the diagram.
[0045] To further extract the dip angle of the structure in the image, the two-dimensional spatial data (right side of the well) obtained from imaging was loaded onto... Figure 2 The rectangular preset window shown. The lengths of the preset window along the well axis and radial direction are respectively... and ,Depend on It consists of 10 data points, among which .
[0046] Next, the well-side structure is scanned and coherently superimposed at multiple angles within a preset angle range using each two-dimensional subspace data array within a preset window, at preset angle step sizes. For the given range of angles... The following formula is used to calculate the result by superimposing the ingredients. Angular coherence energy value for the parameter: 。 (1)。
[0047] in, Indicates the angle as hour k In the set of disk two-dimensional spatial data arrays k The angular coherence energy value corresponding to the disk two-dimensional subspace data array; k ={1, 2}, k =1 indicates the upper plate. k =2 indicates the lower body; express k Disk-based two-dimensional subspace data array; m express k The first along the well axis in the two-dimensional subspace data array of the disk m One data point; n express k The first 2D subspace data array along the well radial direction n Data points.
[0048] The geometric meaning of the above formula is: to put Along the slope is The linear projections are then coherently superimposed; when When the tilt angle coincides with the structural tilt angle, the coherence is optimal and the coherence function reaches its maximum value. Therefore, given... By finding the extreme value of the coherence function within the range, the dip angle of the structure can be determined. In addition, the angular coherence energy value can also reflect the occurrence state of the structure in the strata (such as the strength of the contrast with the acoustic impedance of the strata).
[0049] The coherent superposition method in this application is similar to the time difference extraction method for array acoustic waves. The difference is that a normalized coherence function is used in the time difference extraction, as shown in equation (2).
[0050] (2).
[0051] The normalized coherence function (called Semblance) will have a strong coherence value even for weak signals. Unlike the wellbore acoustic signals with good regularity, remote sensing imaging data contains various noise interferences. Equation (1) can effectively suppress these interferences. This is because Equation (1) represents the coherence energy of the signal along a straight line at a given angle; if the interference signal has strong randomness or poor linearity, its coherence energy will not be high and will therefore be eliminated. In reflection imaging, structures with strong coherence energy correspond to high reflection intensity, indicating a large difference in acoustic impedance between them and the background strata, which can be used to characterize the occurrence state of the structure.
[0052] The data windowing, dip angle, and coherence value extraction methods described above also apply to the imaging data of the hanging wall on the left side of the well. In this case, the angle between the hanging wall and the well radial direction can be called the hanging wall dip angle (elevation angle). After processing the data windows on the left and right sides of the well, the preset window is slid upwards (or downwards) at a preset axial imaging interval and processed sequentially to obtain the logging curve of the coherence value of the structure in the target well section, as well as the coherence chart reflecting the strength of coherence and angle changes in different well sections, such as... Figure 3 As shown.
[0053] In summary, the specific process for determining the dip angle and occurrence characteristics of the well-side structure in this application is as follows: Step 1: Perform acoustic logging on the target well section to collect remote acoustic data. Perform wave field separation and migration imaging processing on the remote acoustic data to obtain two-dimensional reflection imaging data of the wellside structure.
[0054] Step 2: Evaluate the geometry and size of the well-side structure based on the two-dimensional reflection imaging data, and determine the two-dimensional spatial data array set of the well-side structure based on the two-dimensional subspace data array.
[0055] Step 3: Take rectangular windows for the left and right side imaging data containing the upper and lower plates of the structure; the lengths of the windows along the well axis and the well diameter are respectively... and The values of these two parameters, as well as the starting point of the window in the radial direction, should be chosen to construct a sufficiently linear distribution within the window.
[0056] Step 4, remove the window A two-dimensional subspace data array in a given interval (e.g.) Perform an angle scan within the area. Let Angles are spaced at a certain step size (e.g.) The value is taken within the interval, and the angular coherence energy value is calculated by formula (1) (or formula (2)). The maximum value and the corresponding angle value are output, as well as the angular coherence energy value over the entire interval (for plotting and quality monitoring).
[0057] Step 5: Move the preset window described in Step 2 along the well axis at preset axial imaging intervals, repeating the calculations in Steps 3 and 4 each time it moves, until the entire target well section is covered. This yields the logging curves showing the maximum coherence value of the dip angle (elevation angle) of the well-side structure within the depth range of the target well section, as well as coherence maps at different dip angles. Figure 3 As shown. Figure 3 It is Figure 2 The two-dimensional reflection imaging data in the well is processed using the above process. During processing, the two-dimensional reflection imaging data on the left and right sides of the well are windowed. The preset length of the window along the well axis and the length along the well radial direction are 15m and 25m, respectively. The preset axial and radial imaging intervals are 0.1524m and 0.082m, respectively. Then, the coherence function is calculated for the data in the window using Equation (1). Figure 3 (a) and (c) in the text respectively give Figure 2 Correlograms and maximum coherence values for the upper and lower hanging walls at different angles within the 100m well section are presented. The intensity (color scale) of the coherence chart and the amplitude of the coherence curve reflect the intensity of reflection from external reflectors at that dip angle within this depth range. This processing result effectively characterizes the well-side structural information. The dip angle (elevation angle) of the structure, read from the peak values of the coherence charts at different angles on the upper and lower hanging walls, is approximately 50°. o , and the structure in Figure 2 The geometric dimensions obtained are consistent; the depth at which the peak appears corresponds to the structural section passing through the well, and its intensity variation is controlled by the dip logging curves of the upper and lower plates. The amplitudes of the coherence map color scale and the logging curve of the maximum coherence value correspond well to the intensity variations of the well-side structural imaging (e.g., Figure 3 The weaker coherence peak in (c) corresponds to Figure 3 The arrow points to a somewhat blurry structure image, and the strong coherence peaks on it correspond to... Figure 3 The strongest structural imaging (STEM) can be used to characterize the intensity of acoustic wave reflection by structures and the contrast between their acoustic impedance and that of the strata.
[0058] In one exemplary embodiment, the main application of the method of this application is to extract the formation dip angle in conjunction with step 1 of the processing flow. In most cases, the formation dip angle is small (such as in the case of near-horizontal bedding in a vertical well), and the sound waves radiated by the sound source in the well are only reflected back into the well within a limited range around the well. In this case, it is only necessary to use the sound wave data to image the structure within a few meters around the well, and then process the imaging data using the above process to obtain relevant information about the low-dip structure around the well. Figure 4 As shown, a schematic diagram of the results of low-dipping structures in sandstone and mudstone strata is provided. Figure 4 (a) is a schematic diagram of the GR (Natural Gamma Ray) curve of low-dip structures in sandstone and mudstone strata; Figure 4 (b) is a schematic diagram of the maximum coherence value logging curve of the hanging wall of a low-dip structure in sandstone and mudstone formations and the coherence diagram of the hanging wall at different dip angles; Figure 4 (c) is a two-dimensional reflection image of a low-dip structure in a sandstone-mudstone stratum; Figure 4 (d) is a schematic diagram of the maximum coherence value logging curve of the footwall of a low-dip structure in sandstone and mudstone formations and the coherence diagram of the footwall at different dip angles; Figure 4 (c) in the figure gives the two-dimensional reflection imaging data of the low-dipping structure within 3m of the well. The two-dimensional reflection imaging data of the low-dipping structure is windowed with an axial length of 5m and a radial length of 2.5m, and imaging intervals of 0.1524m and 0.02m, respectively. Then, the coherence function is calculated for the data within the window using equation (1). Figure 4 (b) and Figure 4 Figure (d) shows the coherence maps and maximum coherence logging curves for the upper and lower plates of the low-dip structure within the 260m well section at different dip angles. The changes in the color scale of the coherence map and the amplitude of the dip logging curves are highly consistent with the changes in the strength of the structural imaging, demonstrating the effectiveness of the proposed method for low-dip structures. The variation range of the peak values in the coherence maps of the upper and lower plates indicates that the dip angle of the formation in this sandstone-mudstone section is around 20°. o By 30 o between.
[0059] In one exemplary embodiment, such as Figure 5 As shown, two-dimensional reflection imaging data of well-passing fold structures are used to illustrate the universality of the proposed method for complex structures. A schematic diagram of the GR curves of well-passing fold structures in sandstone and mudstone formations is shown below. Figure 5 As shown in (a) in the figure. Figure 5As shown in (c), the exploration well intersects the fold structure at the top, and the dip angle of the structure changes continuously from top to bottom. Windowing is performed on the two-dimensional reflection imaging data of the left and right sides of the well. The axial and radial lengths of the window are 15m and 25m, respectively, and the imaging intervals are 0.1524m and 0.082m, respectively. Then, the angular coherence energy value is calculated on the data within the window using Equation (1). Figure 5 (b) and Figure 5 Figure (d) shows the coherence diagrams and maximum coherence logging curves for the upper and lower plates at different angles within the stratigraphic structure of this well section. The peak points on the coherence diagrams and the maximum coherence logging curves correspond to the locations of the main structural interfaces passing through the well. These peak points (and some smaller secondary peak points) are discontinuously distributed over a large angle range, corresponding to the changes in secondary structures within the fold; the angle variations and their ranges (dip logging curves) are determined by… Figure 6 The rose diagram of the tilt angle distribution is given. Figure 6 It gives a certain depth range ( Figure 6 The distribution of the upper plate dip angle (i.e., the elevation angle (upper left branch of the rose diagram, extracted from the upper plate coherence diagram) and the lower plate dip angle (lower right branch of the rose diagram, extracted from the lower plate coherence diagram) was statistically analyzed (with a height of 50m). Figure 6 The numbers represent depth ranges, such as 3040-3090, indicating that a rose diagram is plotted for the curves within the depth range of 3040m to 3090m. The larger the radius of the rose diagram, the more data points fall within that range. Figure 6 It can be seen that although the variation of the dip angle (elevation angle) of this fold structure is relatively complex, the overall increasing trend of the angle from top to bottom is still very obvious (from 50 degrees at the top). o The change was to the lower 80 o The processing results not only correspond to the structural variation trends on the two-dimensional reflection imaging map, but also quantitatively provide the range of variation and the acoustic impedance contrast between the structure and the background strata.
[0060] In summary, this application can detect stratigraphic structures several to tens of meters away from the well. By employing an array correlation method, two-dimensional reflection imaging data is combined along the well axis and radial direction into a two-dimensional spatial data array, effectively extracting dip angle and reflectivity information for various linearly distributed structures (such as fractures, faults, and stratigraphic bedding). Combining this method with dipole shear wave long-range acoustic detection technology with azimuth recognition capabilities can further obtain comprehensive information on the dip angle and strike of the structures. The method of this application has a clear principle and is easy to operate. Its applicability and reliability have been verified in applications involving different types of stratigraphic structures, providing a practical and effective method for expanding the application of acoustic long-range acoustic detection technology.
[0061] Based on the same inventive concept, this application also provides a system for determining the dip angle and occurrence characteristics of well-side structures, used to implement the method for determining the dip angle and occurrence characteristics of well-side structures described above. The solution provided by this system is similar to the solution described in the above method. Therefore, the specific limitations of one or more embodiments of the system for determining the dip angle and occurrence characteristics of well-side structures provided below can be found in the limitations of the method for determining the dip angle and occurrence characteristics of well-side structures described above, and will not be repeated here.
[0062] In one exemplary embodiment, a system for determining the dip angle and occurrence characteristics of a well-side structure is provided, comprising: The data acquisition module is used to acquire remote acoustic wave data collected within the depth range of the target well section; the remote acoustic wave data includes acoustic wave reflection signals from structures near the well.
[0063] The imaging processing module is used to perform wavefield separation and offset imaging processing on the remote sound wave data to obtain two-dimensional reflection imaging data of the well-side structure.
[0064] An array construction module is used to determine a set of two-dimensional spatial data arrays constructed near the well based on the two-dimensional reflection imaging data.
[0065] The coherent superposition module is used to perform coherent superposition processing on each two-dimensional subspace data array in the two-dimensional spatial data array set at multiple angles within a preset angle range and at a preset angle step size, so as to obtain multiple angle coherent energy values corresponding to each two-dimensional subspace data array.
[0066] The results generation module is used to determine the maximum coherence logging curve, stored characteristic coherence map and dip logging curve within the depth range of the target well section based on the maximum value among the multiple angular coherence energy values corresponding to each two-dimensional subspace data array.
[0067] In one exemplary embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.
[0068] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.
[0069] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.
[0070] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.
[0071] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).
[0072] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.
[0073] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0074] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A method for determining the dip angle and occurrence characteristics of a well-side structure, characterized in that, include: Acquire remote acoustic data within the depth range of the target well section; The acoustic remote detection data includes acoustic reflection signals from well-side structures; The remote acoustic wave data is subjected to wavefield separation and offset imaging processing to obtain two-dimensional reflection imaging data of the well-side structure; Based on the two-dimensional reflection imaging data, a set of two-dimensional spatial data arrays for the well-side structure is determined; The two-dimensional spatial data array set includes an upper two-dimensional spatial data array set and a lower two-dimensional spatial data array set; Each two-dimensional subspace data array in the two-dimensional spatial data array set is subjected to multiple angle scanning coherent superposition processing within a preset angle range and at a preset angle step size to obtain multiple angle coherent energy values corresponding to each two-dimensional subspace data array. Based on the maximum value among multiple angular coherence energy values corresponding to each two-dimensional subspace data array, the maximum coherence logging curve, the stored characteristic coherence map, and the dip logging curve within the depth range of the target well section are determined.
2. The method for determining the dip angle and occurrence characteristics of well-side structures according to claim 1, characterized in that, Two-dimensional reflection imaging data includes upper disk two-dimensional reflection imaging data and lower disk two-dimensional reflection imaging data; The remote acoustic wave data is subjected to wavefield separation and migration imaging processing to obtain two-dimensional reflection imaging data of the well-side structure, specifically including: Wavefield separation was performed on the remote acoustic data to extract the up-reflection wave and down-reflection wave of the well-side structure; The upward reflected wave is offset imaging to obtain two-dimensional reflection imaging data of the upper disk; The down-reflected wave is offset imaging to obtain two-dimensional reflection imaging data of the lower disk.
3. The method for determining the dip angle and occurrence characteristics of well-side structures according to claim 2, characterized in that, Based on the two-dimensional reflection imaging data, a set of two-dimensional spatial data arrays for the well-side structure is determined, specifically including: Slide the preset window along the well axis at preset axial imaging intervals within the depth range of the target well section. Perform the following steps at each sliding position until the entire target well section is covered: Using preset windows, the two-dimensional reflection imaging data of the upper plate and the two-dimensional reflection imaging data of the lower plate are respectively cropped to obtain the two-dimensional subspace data arrays of the upper plate and the lower plate at the current sliding position; both the two-dimensional subspace data arrays of the upper plate and the lower plate are composed of... M × N Composed of 10 data points; in, ; M This represents the total number of data points along the well axis of the two-dimensional subspace data array; N This represents the total number of data points along the radial direction of the two-dimensional subspace data array; Indicates the length of the preset window along the well axis. Indicates the length of the preset window along the radial direction of the well; Indicates the preset axial imaging interval; Indicates the preset radial imaging interval; Add the upper two-dimensional subspace data array obtained from all sliding positions to the upper two-dimensional space data array set, and add the lower two-dimensional subspace data array obtained from all sliding positions to the lower two-dimensional space data array set.
4. The method for determining the dip angle and occurrence characteristics of well-side structures according to claim 3, characterized in that, For each two-dimensional subspace data array in the two-dimensional spatial data array set, perform coherent superposition processing at multiple angles within a preset angle range and at a preset angle step size to obtain multiple angle coherent energy values corresponding to each two-dimensional subspace data array, specifically including: Each can be calculated using the following formulas. k Multiple angular coherence energy values corresponding to the disk two-dimensional subspace data array: ； in, Indicates the angle as hour k In the set of disk two-dimensional spatial data arrays k The angular coherence energy value corresponding to the disk two-dimensional subspace data array; k ={1, 2}, k =1 indicates the upper plate. k =2 indicates the lower body; express k Disk-based two-dimensional subspace data array; m express k The first along the well axis in the two-dimensional subspace data array of the disk m One data point; n express k The first 2D subspace data array along the well radial direction n Data points.
5. The method for determining the dip angle and occurrence characteristics of well-side structures according to claim 4, characterized in that, The maximum coherence logging curves include the maximum coherence logging curves for the hanging wall and the footwall; the occurrence characteristic coherence maps include coherence maps for the hanging wall at different dip angles and coherence maps for the footwall at different dip angles; the dip angle logging curves include the dip angle logging curves for the hanging wall and the footwall. Based on the maximum value among multiple angular coherence energy values corresponding to each two-dimensional subspace data array, the maximum coherence logging curve, the storage characteristic coherence map, and the dip angle logging curve within the depth range of the target well section are determined, specifically including: By traversing the two-dimensional spatial data array set of the upper plate, the coherent energy values of the upper plate at multiple angles at all sliding positions are arranged by depth and angle to obtain coherent maps of the upper plate at different dip angles; Traverse the two-dimensional spatial data array set of the lower plate, arrange the coherent energy values of the lower plate at multiple angles of all sliding positions according to depth and angle, and obtain coherent maps of the lower plate at different tilt angles; Traverse all sliding positions in the coherence diagram under different tilt angles of the upper plate, take the maximum value among multiple angle coherence energy values corresponding to the current sliding position along the angle direction and record it as the maximum coherence energy value of the upper plate, and take the angle corresponding to the maximum coherence energy value of the upper plate as the tilt angle of the upper plate corresponding to the sliding position; Meanwhile, all sliding positions in the coherence map under different tilt angles of the lower plate are traversed, and the maximum value among multiple angle coherence energy values corresponding to the current sliding position is taken along the angle direction and recorded as the maximum coherence energy value of the lower plate. The angle corresponding to the maximum coherence energy value of the lower plate is taken as the tilt angle of the lower plate at the corresponding sliding position. After traversing all slip positions in the coherence maps of the hanging wall and footwall at different dip angles, the hanging wall dip angles of all slip positions are arranged by depth to obtain the hanging wall dip angle logging curves; the footwall dip angles of all slip positions are arranged by depth to obtain the footwall dip angle logging curves; the maximum coherence energy values of the hanging wall at all slip positions are arranged by depth to obtain the hanging wall maximum coherence value logging curves; and the maximum coherence energy values of the footwall at all slip positions are arranged by depth to obtain the footwall maximum coherence value logging curves.
6. The method for determining the dip angle and occurrence characteristics of well-side structures according to claim 1, characterized in that, The preset angle range is 0. o Up to 90 o The preset angle step size is 1. o .
7. A system for determining the dip angle and occurrence characteristics of a well-side structure, characterized in that, The system for determining the dip angle and occurrence characteristics of the well-side structure is based on the method for determining the dip angle and occurrence characteristics of the well-side structure according to any one of claims 1-6, and the system for determining the dip angle and occurrence characteristics of the well-side structure includes: The data acquisition module is used to acquire remote acoustic wave data collected within the depth range of the target well section; the remote acoustic wave data includes acoustic wave reflection signals from structures near the well. An imaging processing module is used to perform wavefield separation and offset imaging processing on the remote sound wave data to obtain two-dimensional reflection imaging data of the well-side structure. An array construction module is used to determine a set of two-dimensional spatial data arrays for well-side construction based on the two-dimensional reflection imaging data; the set of two-dimensional spatial data arrays includes a set of two-dimensional spatial data arrays for the upper plate and a set of two-dimensional spatial data arrays for the lower plate. The coherent superposition module is used to perform coherent superposition processing on each two-dimensional subspace data array in the two-dimensional spatial data array set at multiple angles within a preset angle range and at a preset angle step size, so as to obtain multiple angle coherent energy values corresponding to each two-dimensional subspace data array. The results generation module is used to determine the maximum coherence logging curve, stored characteristic coherence map and dip logging curve within the depth range of the target well section based on the maximum value among the multiple angular coherence energy values corresponding to each two-dimensional subspace data array.
8. A computer device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the method for determining the dip angle and occurrence characteristics of the well-side structure as described in any one of claims 1-6.
9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the method for determining the dip angle and occurrence characteristics of the wellside structure as described in any one of claims 1-6.
10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the method for determining the dip angle and occurrence characteristics of the wellside structure as described in any one of claims 1-6.