Coal mine area treatment anticipated profile accurate correction method based on three-dimensional earthquake time profile

Abstract

The invention discloses a three-dimensional earthquake time profile-based coal mine area treatment anticipated profile accurate correction method, and belongs to the fields of coal mine water prevention and control, ground area exploration and treatment, horizontal directional drilling track design and optimization, geological exploration and the like. The method comprises the following steps: constructing an anticipated geological profile; constructing a three-dimensional seismic time profile; carrying out fusion correction on the three-dimensional seismic time profile and an expected geological profile to obtain an aligned time profile; acquiring time profile information of the aligned time profile; comprehensively correcting the expected geological section according to the time section information to obtain an optimized geological section; and according to the optimized geological section, generating a high-precision anticipated geological section map. According to the method, the layer following rate of the drilled hole in the target treatment layer and the drilling accuracy of a target structure (especially a fault) can be improved, construction rework is reduced, and the effect and efficiency of a regional exploration treatment project are guaranteed.

Description

Technical Field

[0001] This invention relates to the fields of coal mine water control, surface area exploration and management, horizontal directional drilling trajectory design and optimization, and geological exploration, specifically to a method for accurate correction of the expected profile for coal mine area management based on three-dimensional seismic time profiles. Background Technology

[0002] Surface exploration and remediation are core technologies for ensuring safe coal seam mining in North China-type coalfields (especially complex mining areas such as Huainan) and preventing water hazards in Ordovician limestone and roof and floor sandstone. In coal mine remediation areas with sparse borehole distribution and complex geological structures (such as faults and folds), traditional methods mainly rely on contour maps of the coal seam floor to design the expected geological profile of branch boreholes (referred to as "expected profile").

[0003] However, this method has significant limitations:

[0004] 1. Limited accuracy: The accuracy of coal seam floor contour maps is limited by the density of the original data and the interpolation method, especially in areas without borehole control.

[0005] 2. Insufficient structural representation: For small-scale geological structures (such as small faults (fault displacement is less than contour interval), small-amplitude folds, lithological body boundaries, etc.), contour maps are difficult to accurately depict their morphology and spatial location.

[0006] 3. Spatial location deviation: Due to the above factors, the predicted stratigraphic undulations and fault locations (especially dip, dip angle, and fault depth) in the prospective profile often deviate significantly from the actual underground conditions.

[0007] These limitations lead to serious problems in actual construction:

[0008] 1. The borehole trajectory has a low "hit rate" in the target treatment layer (such as the target limestone or sandstone layer).

[0009] 2. The actual location of the fault encountered during drilling is expected to deviate significantly, which may lead to missing key structures or ineffective exposure.

[0010] 3. Ultimately, this leads to a low borehole qualification rate and a large amount of rework, which not only causes huge economic losses (including drilling, equipment, and time costs), but also delays the construction period and may even fail to achieve the expected exploration and treatment objectives, leaving safety hazards. Summary of the Invention

[0011] The purpose of this invention is to provide a method for accurately correcting the anticipated profile of coal mine area remediation based on three-dimensional seismic time profiles. This method aims to significantly improve the prediction accuracy of stratigraphic undulations and fault spatial locations in the anticipated profile, thereby increasing the borehole's success rate in the target remediation strata and the accuracy of drilling into target structures (especially faults), reducing construction rework, and ensuring the effectiveness and efficiency of regional exploration and remediation projects.

[0012] To address the aforementioned technical problems, this invention provides a method for accurately correcting the anticipated profile of coal mine area governance based on three-dimensional seismic time profiles, comprising the following steps:

[0013] Construct the envisioned geological profile;

[0014] Constructing a three-dimensional seismic time profile;

[0015] The three-dimensional seismic time profile is fused and corrected with the expected geological profile to obtain the aligned time profile.

[0016] Obtain the time profile information of the aligned time profile;

[0017] Based on the time profile information, the expected geological profile is comprehensively corrected to obtain the optimized geological profile;

[0018] Based on the optimized geological profile, a high-precision expected geological profile map is generated.

[0019] Preferably, constructing the desired geological profile specifically includes the following steps:

[0020] Based on existing 3D seismic data, regional geological data, and stratigraphic data revealed by existing surface boreholes, a preliminary geological profile of the exploration and treatment branch boreholes is drawn using the bottom contour map of the target coal seam.

[0021] Preferably, the target coal seam is coal seam 1 or coal seam 5.

[0022] Preferably, constructing a three-dimensional seismic time profile specifically includes the following steps:

[0023] The profile direction is obtained by analyzing the branch borehole trajectory or the expected geological profile, and the corresponding three-dimensional seismic time profile is extracted from the three-dimensional seismic data volume.

[0024] Preferably, the method further includes the following steps:

[0025] Gain adjustment and filtering are applied to the 3D seismic time profile to highlight small faults, minor structural features, and stratigraphic contact relationships.

[0026] Preferably, the fusion and correction of the anticipated geological profile and the three-dimensional seismic time profile specifically includes the following steps:

[0027] Select key marker layers that are stable, continuous, and easily identifiable on seismic profiles within the region;

[0028] Align the marker layer on the time profile and the anticipated geological profile.

[0029] Preferably, the main marker layer is the in-phase axis of the reflected wave of coal seam 1 or coal seam 5.

[0030] Preferably, the time profile information includes stratigraphic trend information, fault spatial location information, and structural development morphology information.

[0031] Preferably, the anticipated geological profile is comprehensively corrected based on the time profile information to obtain an optimized geological profile, specifically including the following steps:

[0032] The stratigraphic trend information, fault spatial location information, and structural development morphology information of the aligned time profile are comprehensively compared and analyzed with regional geological data and stratigraphic data revealed by existing surface boreholes to obtain an optimized geological profile.

[0033] Preferably, the stratigraphic trend information, fault spatial location information, and structural development morphology information of the aligned time profile are comprehensively compared and analyzed with the initial framework of the anticipated geological profile and the actual stratigraphic data exposed at corresponding locations by drilled boreholes to obtain the optimized geological profile. This specifically includes the following steps:

[0034] The stratigraphic trend on the aligned time profile is compared with the initial predicted trend of the expected geological profile. If the aligned time profile shows a continuous updip, while the expected geological profile is horizontal or downdip, the stratigraphic attitude and depth change trend of the expected geological profile are corrected based on the time profile information.

[0035] The fault locations and dips identified on the aligned time profiles are mapped to the corresponding locations on the anticipated geological profiles. Combined with the fault displacement estimated from the aligned time profiles and the actual fault conditions revealed by nearby boreholes, the predicted depths and fault attitudes of the fault points on the anticipated geological profiles are corrected.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] 1. Significantly improves the accuracy of structural identification: 3D seismic time profiles provide richer and higher resolution information on underground structures than contour maps. In particular, the ability to identify small faults (fault displacement less than 5-10 meters), small-amplitude folds (amplitude less than contour intervals), and lithological body boundaries is greatly enhanced, effectively reducing structural omissions and misjudgments.

[0038] 2. Precise spatial location correction: Through the precise calibration and comprehensive interpretation of key marker layers, the true depth of stratigraphic boundaries and the true spatial location of faults (faults) (including dip, dip angle, and fault depth) can be determined more accurately, significantly reducing spatial location prediction bias.

[0039] 3. Significantly improve the borehole-to-layer ratio: Based on the borehole trajectory designed with high-precision profile after correction, the actual layer-to-layer ratio in the target treatment layer (such as L1-4 lime, Taihui aquifer or main sandstone aquifer) is significantly improved.

[0040] 4. Improve the accuracy of drilling into faults: The actual location (depth, dip) of the fault revealed by the borehole matches the predicted location significantly, ensuring effective exploration and control of the target structure.

[0041] 5. Effectively reduces construction rework: Due to the improved profile accuracy, the number of boreholes that are scrapped or require major adjustments (such as side drilling) due to "losing" the target layer or missing the target fault is greatly reduced, significantly reducing drilling costs, material waste and project delays.

[0042] 6. Ensuring treatment effectiveness and safety: Ultimately, it improved the targeting and effectiveness of regional exploration and treatment projects, provided more reliable geological protection for safe coal seam mining, and reduced the risks of Ordovician limestone water hazards and roof water hazards. Attached Figure Description

[0043] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0044] Figure 1 This is a preliminary prospective cross-section diagram drawn based on coal seam contour maps. It shows the stratigraphic and fault morphology predicted using traditional methods.

[0045] Figure 2 This is a schematic diagram of a three-dimensional seismic time profile taken along the direction of the branch borehole trajectory. It shows higher resolution stratigraphic reflection features, small faults (F1, F2), and stratigraphic undulation details on the time profile.

[0046] Figure 3 This is a schematic diagram illustrating the results of a comprehensive analysis and correction of the time profile and the expected profile. It shows the results after alignment with marker layers (such as coal seam 1), utilizing time profile information (stratigraphic trend, fault location) and actual drilling data. Figure 1 A high-precision cross-section after correction of the initial envisioned profile. The figure should show the differences before and after the correction (such as adjustments to stratigraphic depth and fault location).

[0047] Figure 4 This is a flowchart illustrating a method for accurately correcting the anticipated profile of coal mine area governance based on a three-dimensional seismic time profile, according to the present invention. Detailed Implementation

[0048] Numerous specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0049] The terminology used in one or more embodiments of this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the one or more embodiments of this specification. The singular forms “a,” “described,” and “the” as used in one or more embodiments of this specification and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in one or more embodiments of this specification refers to and includes any or all possible combinations of one or more associated listed items.

[0050] It should be understood that although the terms first, second, etc., may be used to describe various information in one or more embodiments of this specification, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first may also be referred to as second without departing from the scope of one or more embodiments of this specification, and similarly, second may also be referred to as first. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to a determination."

[0051] The present invention will now be described in further detail with reference to the accompanying drawings:

[0052] This invention proposes a method for accurately correcting the anticipated profile of coal mine area governance based on three-dimensional seismic time profiles. The core of this method lies in deeply integrating three-dimensional seismic time profile data into the construction and correction process of the anticipated profile, and resolving the correspondence between the time domain and the depth domain. Specific technical solutions are as follows: Figure 4 As shown, it includes:

[0053] 1. Initial Geological Profile Construction: Based on existing 3D seismic data, regional geological data, and stratigraphic data revealed by existing surface boreholes, and using the bottom contour map of the target coal seam (e.g., No. 1 coal seam, No. 5 coal seam), a preliminary geological profile of the exploration and treatment branch boreholes is drawn (see...). Figure 1 This map reflects the stratigraphic and structural features predicted based on existing data (mainly contour lines).

[0054] 2. 3D Seismic Time Profile Extraction: To address the insufficient accuracy of contour maps, a 3D seismic time profile is introduced. Along the planned branch borehole trajectory (or the profile direction that needs to be focused on based on the preliminary profile analysis), the corresponding time profile is precisely extracted from the 3D seismic data volume (see [link to seismic data]). Figure 2Three-dimensional seismic time profiles have higher resolution and can more accurately identify and characterize small-scale geological features, such as:

[0055] ① Small faults (fault displacement is less than contour interval).

[0056] ②Small-amplitude folds.

[0057] ③ Lateral boundary variations of lithological bodies (such as limestone, sandstone, and mudstone).

[0058] ④ The subtle undulations and changes in the strata.

[0059] 3. Fusion and correction of time profile and expected profile:

[0060] Domain Conversion and Stratigraphic Calibration: Since the horizontal axis of the time profile is distance / direction and the vertical axis is two-way travel time (TWT), it cannot be directly compared with the anticipated profile in the depth domain (vertical axis is depth / elevation). Key calibration steps: Select a stable, continuous, and easily identifiable major marker layer in the region on the seismic profile (such as the reflection phase axis of coal seam 1 or 5; coal seams 1 and 5 are the main mineable coal seams in the region, with relatively thick layers, and their three-dimensional seismic reflections are stable and easily identifiable). Accurately align (calibrate) this marker layer on both the time profile and the anticipated profile.

[0061] 4. Detailed Identification and Stratigraphic Trend Analysis: Based on marker bedding alignment, detailed interpretation of time profiles is performed.

[0062] Analyze the stratigraphic attitude changes (updip, downdip, trend changes) identified on the time profile.

[0063] Identify the exact location, dip, and possible displacement of the fault (in conjunction with seismic reflection characteristics).

[0064] Identify other structural features (such as small folds) or lithological anomalies.

[0065] 5. Comprehensive Correction: The meticulously identified stratigraphic trends, fault spatial locations (dip, predicted depth), and structural morphology information from the time profile are comprehensively compared and analyzed with regional geological data and stratigraphic data (lithology, layer thickness, depth, fault points, etc.) revealed by existing surface boreholes. The focus is on correcting the anticipated profile.

[0066] ① Depth and undulation of stratigraphic boundaries.

[0067] ② The spatial location (especially the depth of the fault point), dip, and dip angle of the fault.

[0068] ③ Add or refine the identified minor structures.

[0069] 6. Generate a high-precision pre-defined profile after correction based on time profiles and actual drilling data (see...). Figure 3This diagram serves as a reliable geological model for ultimately guiding borehole design and construction.

[0070] To better illustrate the technical effects of the present invention, the present invention provides the following specific embodiments to illustrate the above technical process:

[0071] Example 1: A method for accurately correcting the anticipated profile of coal mine area governance based on three-dimensional seismic time profiles, comprising the following steps:

[0072] 1. Data preparation:

[0073] ① Collect complete 3D seismic exploration data volumes and their processing results for the treatment area.

[0074] ② Collect all available surface borehole data, including logging curves (gamma, resistivity, etc.), logging lithology descriptions, stratigraphic data, fault point data, final borehole depth, coordinates, etc.

[0075] ③ Collect the bottom contour map and related geological maps of the target coal seam (such as No. 1 coal seam and No. 5 coal seam).

[0076] ④ Determine the target strata for regional governance (such as No. 5 coal seam, No. 1 coal seam, Taiyuan Formation limestone, key sandstone layers) and key exploration structures (major faults).

[0077] 2. Draw the initial envisioned cross-section ( Figure 1 ):

[0078] ① Based on regional geological analysis, select the design trajectory lines of the branch boreholes that need to be explored and treated.

[0079] ② On the selected profile direction, using the contour maps of the bottom plate of coal seams such as No. 1 and No. 5 as the main basis, and combining the regional stratigraphic attitude and existing borehole exposure data, a preliminary geological profile map of the section should be drawn. The map should include the predicted stratigraphic boundaries, the location and attitude of major faults, and the target strata.

[0080] 3. Extracting time profiles ( Figure 2 ):

[0081] ① Using professional seismic interpretation software (such as Landmark, Petrel, GeoFrame, etc.), precisely extract the time profile from the 3D seismic data volume, strictly following the direction of the branch borehole trajectory line designed in step 2 (or the direction that needs to be analyzed in detail). Ensure that the profile direction is consistent with the borehole trajectory direction.

[0082] ② Perform necessary display optimizations on the extracted time profiles (such as gain adjustment and filtering) to highlight details such as small faults, minor structural features, and stratigraphic contact relationships.

[0083] 4. Comprehensive correction between time profile and expected profile ( Figure 3):

[0084] ① Stratigraphic calibration: Identify and accurately calibrate the same major marker layer (such as the strong reflection phase axis of coal seam 1 or 5) on both the time profile and the anticipated profile. This is the basis for achieving time-depth domain conversion and comparison. Find the strong phase axis T0 corresponding to this marker layer on the time profile, and its known depth H0 on the anticipated profile. Use this point as the reference point.

[0085] ②Detailed interpretation of time profile:

[0086] Near the marker layer, a detailed analysis of the phase axis morphology of reflected waves on the time profile was conducted to identify whether the strata exhibited an updip, downdip, or horizontal trend.

[0087] Identify and label all faults (F) visible on the time profile, determine their location on the profile line (CDP number or distance), fault dip (based on the direction of reflected wave faulting or cross-sectional wave), and estimate the possible vertical fault displacement (based on the combined velocity of the faulting amount of the same phase axis).

[0088] Identify features such as possible minor folds and lithological change boundaries.

[0089] ③Comprehensive analysis and correction:

[0090] Compare the stratigraphic trend (e.g., updip direction) on the time profile interpreted in step 4 with the initial predicted trend of the intended profile. If there is a significant difference (e.g., the time profile shows a continuous updip, while the intended profile is horizontal or downdip), then adjust the stratigraphic attitude and depth variation trend of the intended profile based on the time profile information.

[0091] The fault locations (CDP / distance) and dips identified on the time profile are mapped to their corresponding locations on the projected profile (correlated with marker bedding points). The predicted depths and fault attitudes (dip, dip angles) of the fault points on the projected profile are corrected by combining the fault displacement estimated from the time profile with the actual fault conditions (depth, true displacement) revealed by nearby boreholes. Newly identified small faults on the time profile should be added to the projected profile.

[0092] Taking into account the structural details revealed by the time profile and the actual drilling conditions, necessary fine adjustments were made to the stratigraphic boundary depth in the expected profile to better match the morphology revealed by the seismic activity and the actual drilling control points.

[0093] ④ Generate a high-precision profile after correction: After completing the above comparative analysis and correction, draw the final high-precision geological profile map, which has been comprehensively corrected by 3D seismic time profile and actual drilling data. This map should clearly show the corrected stratigraphic morphology, accurate fault locations and attitudes, target strata, etc.

[0094] 5. Application: The corrected high-precision pre-defined profile map serves as the core geological basis for branch hole trajectory design, borehole construction tracking, and dynamic adjustment, guiding regional exploration and remediation projects.

[0095] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for accurately correcting the anticipated profile of coal mine area governance based on three-dimensional seismic time profiles, characterized in that, Includes the following steps: Construct the envisioned geological profile; Constructing a three-dimensional seismic time profile; The three-dimensional seismic time profile is fused and corrected with the expected geological profile to obtain the aligned time profile. Obtain the time profile information of the aligned time profile; Based on the time profile information, the expected geological profile is comprehensively corrected to obtain the optimized geological profile; Based on the optimized geological profile, a high-precision expected geological profile map is generated.

2. The method for accurate correction of the anticipated profile for coal mine regional governance based on three-dimensional seismic time profiles according to claim 1, characterized in that, Constructing the envisioned geological profile includes the following steps: Based on existing 3D seismic data, regional geological data, and stratigraphic data revealed by existing surface boreholes, a preliminary geological profile of the exploration and treatment branch boreholes is drawn using the bottom contour map of the target coal seam.

3. The method for accurate correction of the anticipated profile for coal mine regional governance based on three-dimensional seismic time profiles according to claim 2, characterized in that: The target coal seam is either seam 1 or seam 5.

4. The method for accurate correction of the anticipated profile for coal mine regional governance based on three-dimensional seismic time profiles according to claim 3, characterized in that, Constructing a three-dimensional seismic time profile includes the following steps: The profile direction is obtained by analyzing the branch borehole trajectory or the expected geological profile, and the corresponding three-dimensional seismic time profile is extracted from the three-dimensional seismic data volume.

5. The method for accurate correction of the anticipated profile for coal mine regional governance based on three-dimensional seismic time profiles according to claim 4, characterized in that, It also includes the following steps: Gain adjustment and filtering are applied to the 3D seismic time profile to highlight small faults, minor structural features, and stratigraphic contact relationships.

6. The method for accurate correction of the anticipated profile for coal mine regional governance based on three-dimensional seismic time profiles according to claim 5, characterized in that, The process of fusing and correcting the anticipated geological profile and the 3D seismic time profile includes the following steps: Select key marker layers that are stable, continuous, and easily identifiable on seismic profiles within the region; Align the marker layer on the time profile and the anticipated geological profile.

7. The method for accurate correction of the anticipated profile for coal mine regional governance based on three-dimensional seismic time profiles according to claim 6, characterized in that: The main marker layer is the in-phase axis of the reflected waves from coal seam 1 or coal seam 5.

8. The method for accurate correction of the anticipated profile for coal mine regional governance based on three-dimensional seismic time profiles according to claim 7, characterized in that: The time profile information includes stratigraphic trend information, fault spatial location information, and structural development morphology information.

9. The method for accurate correction of the anticipated profile for coal mine regional governance based on three-dimensional seismic time profiles according to claim 8, characterized in that, Based on the time profile information, the anticipated geological profile is comprehensively corrected to obtain the optimized geological profile, which includes the following steps: The stratigraphic trend information, fault spatial location information, and structural development morphology information of the aligned time profile are comprehensively compared and analyzed with regional geological data and stratigraphic data revealed by existing surface boreholes to obtain an optimized geological profile.

10. The method for accurate correction of the anticipated profile for coal mine regional governance based on three-dimensional seismic time profiles according to claim 9, characterized in that, The stratigraphic trend information, fault spatial location information, and structural development morphology information of the aligned time profile are comprehensively compared and analyzed with the initial framework of the anticipated geological profile and the actual stratigraphic data exposed at corresponding locations by drilled boreholes to obtain the optimized geological profile. The specific steps include: The stratigraphic trend on the aligned time profile is compared with the initial predicted trend of the expected geological profile. If the aligned time profile shows a continuous updip, while the expected geological profile is horizontal or downdip, the stratigraphic attitude and depth change trend of the expected geological profile are corrected based on the time profile information. The fault locations and dips identified on the aligned time profiles are mapped to the corresponding locations on the anticipated geological profiles. Combined with the fault displacement estimated from the aligned time profiles and the actual fault conditions revealed by nearby boreholes, the predicted depths and fault attitudes of the fault points on the anticipated geological profiles are corrected.

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