Method for determining longitudinal cut-through capability of strike-slip fault zone

Abstract

The invention discloses a method for determining the longitudinal cut-through capability of a strike-slip fault zone, and the method comprises the steps: building a strike-slip fault zone cut-through capability index after precisely reading the thickness of each component of a layer, the total thickness of a stratum and the longitudinal cut-through depth of the strike-slip fault zone, building an evaluation standard of the strike-slip fault zone for the longitudinal cut-through capability of the stratum, and determining the longitudinal cut-through capability of the strike-slip fault zone. A space change mode of the longitudinal cut-through capability of the strike-slip fault zone is determined, a mathematical method of the longitudinal cut-through capability of the strike-slip fault zone to the stratum is accurately determined, and the difference of the longitudinal cut-through capability of different parts of the strike-slip fault zone can be objectively and quantitatively evaluated. The condition that the stratum thickness is obviously different in the same area due to the difference of the original stratum deposition degree or the difference of the later weathering denudation degree in the same area and different strike-slip fault zones in the same area and different parts of the same strike-slip fault zone can be reasonably avoided; and therefore, the defect that the longitudinal cut-through capability of the strike-slip fault zone cannot be evaluated according to the standard in a unified manner can be overcome.

Description

Technical Field

[0001] The present application relates to the field of geological technology, and in particular to a method for determining the longitudinal cutting capacity of a strike-slip fault zone. Background Art

[0002] In recent years, a large number of strike-slip faults have been discovered in the Tarim Basin in China. Studies on strike-slip fault zones have shown that they have typical characteristics of "controlling reservoirs, controlling reservoirs, and controlling enrichment". Under the multi-stage transformation of strike-slip fault zones, the deep-ultra-deep Ordovician carbonate reservoirs in the Tarim Basin are mostly characterized by development along strike-slip fault zones, and oil and gas are enriched and accumulated inside strike-slip fault zones. Based on this special phenomenon, a large number of scholars have established a deep-ultra-deep fault-controlled oil and gas accumulation model in the strike-slip fault zone of the Tarim Basin. However, with the continuous deepening of research on strike-slip faults, people have gradually realized that although different parts of strike-slip faults all show the characteristics of high and steep occurrence and direct penetration into the basement, there are great differences in their ability to cut through the formation along the strike of the fault. The difference in this feature will greatly affect the coupling of strike-slip faults and source-fossil systems, resulting in differences in oil and gas enrichment in carbonate reservoirs at different parts of the same strike-slip fault, further affecting the success rate of well deployment.

[0003] With the continuous development of oil and gas resources, oil and gas exploration technology has been significantly developed worldwide. In oil and gas exploration, the study of fault zones is particularly important, especially strike-slip fault zones, which not only affect the distribution of reservoirs, but are also directly related to the enrichment and flow of oil and gas. Strike-slip fault zones often become important channels for oil and gas enrichment due to their unique structural characteristics. In areas with typical strike-slip fault zones such as the Tarim Basin, strike-slip fault zones have an important control effect on the accumulation and enrichment of oil and gas. Therefore, how to accurately evaluate the longitudinal cutting ability of strike-slip fault zones has become a technical problem that needs to be solved in the field of oil and gas exploration.

[0004] At present, the research on strike-slip fault zones mainly focuses on the development characteristics of shallow reservoirs, especially on the lateral distribution and impact range of fault zones. However, there is still a large technical gap in the research on the vertical penetration capacity of strike-slip fault zones. Existing technologies mainly describe strike-slip fault zones through seismic reflection data or drilling data, but most studies lack quantitative analysis methods and often rely on empirical judgment, resulting in large differences in the evaluation of the vertical penetration capacity of strike-slip fault zones by different researchers in the same area. In addition, when facing different strike-slip fault zones in the same area and different parts of the same strike-slip fault zone, existing technologies cannot effectively avoid the influence of factors such as sedimentation differences, weathering and erosion, and cannot provide a unified evaluation standard, which directly affects the accuracy of oil and gas exploration and the success rate of well deployment.

[0005] Therefore, in the oil and gas exploration of strike-slip fault zones, the lack of quantitative criteria for the evaluation method of longitudinal cutting ability, the influence of formation thickness differences on the evaluation accuracy, and the difficulty of accurately depicting the spatial variation characteristics of strike-slip fault zones by existing technologies have become urgent problems to be solved. Summary of the Invention

[0006] This application provides a method for determining the longitudinal cutting ability of strike-slip fault zones, aiming to solve the problem that it is difficult for existing technologies to accurately depict the spatial variation characteristics of strike-slip fault zones.

[0007] A method for determining the longitudinal cutting ability of strike-slip fault zones, the method comprising:

[0008] S1: Based on actual seismic data, extract fracture-sensitive attributes, and clarify the dominant development positions of the strike-slip fault zone on the plane and the continuity degree on the section;

[0009] S2: Determine the horizons involved in the rating of the longitudinal cutting ability of the strike-slip fault zone, and calibrate the evaluation accuracy of the longitudinal cutting ability of the strike-slip fault zone;

[0010] S3: According to the target accuracy requirements, calculate the thickness of each sub-layer and the total formation thickness of the horizons involved in the rating for each sampling section, measure the longitudinal cutting depth of the strike-slip fault zone, and obtain the longitudinal cutting ability values of the strike-slip faults in different sections;

[0011] S4: Construct an index of the cutting ability of the strike-slip fault zone, establish an evaluation standard for the longitudinal cutting ability of the strike-slip fault zone on the formation, draw a curve graph of the change of the cutting ability index of the strike-slip fault zone, and clarify the spatial variation pattern of the longitudinal cutting ability of the strike-slip fault zone.

[0012] In the above solution, optionally, step S1 includes:

[0013] S11: Based on actual seismic data, determine the development positions of strike-slip faults and analyze the scale of strike-slip faults;

[0014] S12: According to the scale of the strike-slip fault, specifically extract the fracture-sensitive attributes of the strike-slip fault;

[0015] S13: Based on seismic attributes, clarify the dominant development positions of the strike-slip fault zone on the plane and the continuity degree of the strike-slip fault zone on the section;

[0016] In the above solution, optionally, in step S11, the development positions of strike-slip faults are determined by applying the interruption, dislocation or distortion of seismic reflection isochrones in actual seismic data, and the extensibility of the strike-slip fault shown on the seismic section is traced through the continuation of the interruption, dislocation or distortion of seismic reflection isochrones longitudinally on the seismic section. Combining the width of the interruption, dislocation or distortion of seismic reflection isochrones transversely on the seismic section, the scale of the strike-slip fault zone is jointly determined;

[0017] If the seismic reflection event axis is obviously observed to be interrupted or dislocated on the seismic profile, and the seismic reflection event axis has a large fault distance and a large width due to the interruption or dislocation, the fault distance is greater than 20ms for a large fault distance, and the width is greater than 40ms for a large width, and it has a preset impact on the stratum and structural pattern, then the scale of the strike-slip fault is large;

[0018] If the seismic reflection event axis is obviously observed to be interrupted or dislocated on the seismic profile, and the seismic reflection event axis has a certain fault distance and width due to the interruption or dislocation, with a fault distance of 0 to 20 ms and a width of 10 to 40 ms, and the impact on the stratum and structure is limited, then the scale of the strike-slip fault is moderate;

[0019] If distortion of seismic reflection event axes with a width of less than 10 ms is observed on the seismic profile, it is considered that the scale of the strike-slip fault is small.

[0020] In the above scheme, optionally, in step S12, the coherence body or ant body attributes are extracted from the large-scale strike-slip fault zone to reflect the boundary and spatial distribution of the strike-slip fault zone; the ant body or likelihood body attributes are extracted from the medium-scale strike-slip fault zone to reflect the boundary and spatial distribution of the strike-slip fault zone; the likelihood body or curvature body attributes are extracted from the small-scale strike-slip fault zone to reflect the boundary and spatial distribution of the strike-slip fault zone;

[0021] If the same strike-slip fault zone has interruptions, dislocations or distortions in the seismic reflection phase axis on the seismic section, resulting in the strike-slip fault zone's fault throw and width changing frequently, and the size of the strike-slip fault zone cannot be effectively distinguished, the method of fusing multiple seismic attributes can be used to combine the advantages of different attributes to jointly characterize the boundary and spatial distribution of the strike-slip fault zone;

[0022] In step S13, after extracting the seismic attributes, by making time slices, the differences in the plane distribution of the strike-slip fault zone on different time slices are observed, and the dominant development position of the strike-slip fault zone on the plane is determined according to the changes in the plane continuity of the strike-slip fault zone on different time slices; by cutting longitudinal sections, the longitudinal extension of the strike-slip fault zone on different sections is observed, and the continuity of the strike-slip fault zone on the section is determined according to the changes in the continuity of the strike-slip fault zone on different sections;

[0023] On the time slice and profile, the higher the plane continuity of the strike-slip fault zone and the stronger its linear extension ability, the more developed the strike-slip fault zone is and it is the dominant development site; the lower the plane continuity and the more discontinuous the appearance, the weaker the development of the strike-slip fault zone is.

[0024] In the above solution, optionally, step S2 includes:

[0025] S21: Determine the horizons involved in the rating of the longitudinal cutting ability of the strike-slip fault zone based on the continuity degree of the strike-slip fault zone on the seismic attribute section.

[0026] S22: Define the evaluation accuracy of the longitudinal cutting ability of the strike-slip fault zone based on the dominant development areas of the strike-slip fault zone on the seismic attribute plane.

[0027] In the above solution, optionally, in step S21, when determining the horizons involved in the rating of the longitudinal cutting ability of the strike-slip fault zone, it is clear that the continuity degree of the strike-slip fault zone determined by applying the seismic attribute section at this time is the minimum continuity degree and the maximum continuity degree of the entire strike-slip fault zone; the minimum continuity degree of the current entire strike-slip fault zone represents the minimum value of the horizons that the strike-slip fault zone can longitudinally cut through, which is the weakest cutting ability value of the entire strike-slip fault zone, and the horizon closest to the deep part on the section is recorded as the first cutting horizon C1; the maximum continuity degree of the current entire strike-slip fault zone represents the maximum value of the horizons that the strike-slip fault zone can longitudinally cut through, which is the strongest cutting ability value of the entire strike-slip fault zone, and the horizon closest to the shallow part on the section is recorded as the third cutting horizon C3; the second cutting horizon C2 is selected between the two horizons according to the actual exploration and development requirements and the actual formation thickness.

[0028] In step S22, after clarifying the horizons involved in the rating of the longitudinal cutting ability of the strike-slip fault zone, if there is a large formation undulation, extract the targeted seismic attributes along the horizon to accurately judge the dominant development areas of the strike-slip fault zone on the target horizon; then, by counting the number of dominant development areas of the strike-slip fault zone on the plane and measuring the widths of the corresponding dominant development areas of each strike-slip fault zone, comprehensively define the evaluation accuracy of the longitudinal cutting ability of the strike-slip fault zone.

[0029] The dominant development areas of the strike-slip fault zone on the plane are the areas with high continuity degree and good linear extension on the plane attribute map, ensuring that at least the two ends and the middle of any dominant development area of the strike-slip fault zone on the plane are covered by sampling profiles, and the three sampling profiles are used as the lower limit for defining the evaluation accuracy of the longitudinal cutting ability of the strike-slip fault zone.

[0030] In the above solution, optionally, step S3 includes:

[0031] S31: Based on the actual accuracy requirements, determine the thickness of each formation layer, the total formation thickness, and the sampling profile locations and numbers Nn for measuring the longitudinal cutting depth of the strike-slip fault zone involved in the rating.

[0032] S32: Calculate the thickness of each formation layer Hf and the total formation thickness Hz of the horizons involved in the rating on different sampling profiles.

[0033] S33: Measure the actual longitudinal cutting depth Sn of the strike-slip fault zone according to the actual continuity degree of the strike-slip fault on different sampling profiles.

[0034] S34: Subtract the respective formation sub - thickness Hf, the total formation thickness Hz, and the actual longitudinal penetration depth Sn of the strike - slip fault zone of each layer involved in the section rating, and calculate the strike - slip fault longitudinal penetration ability value Qn of different sections.

[0035] In the above - mentioned solution, optionally, in step S31, when determining the sampling section location based on the actual accuracy requirements, it is determined that all sampling sections need to be arranged at equal distances; all sampling sections need to be arranged perpendicular to the strike - slip fault zone trend.

[0036] In step S32, the formation sub - thickness Hf of the layer involved in the rating on different sections is the true thickness value of the actual layer corresponding to the section; when calculating the formation sub - thickness Hf of the layer involved in the rating on the section, it is jointly determined by combining the minimum continuity degree of the entire strike - slip fault zone representing the minimum value of the layer that the strike - slip fault can penetrate longitudinally, the maximum continuity degree of the entire strike - slip fault zone representing the maximum value of the layer that the strike - slip fault can penetrate longitudinally, and the actual exploration and development requirements.

[0037] When calculating the total formation thickness Hz and the respective formation sub - thicknesses Hf of the layer involved in the rating on the section, calculate according to the degree of basic data for interpreting the actual exploration and development layer.

[0038] After determination, measure the depth values Df1, Df2, and Df3 corresponding to the first penetration layer C1, the second penetration layer C2, and the third penetration layer C3 of each section respectively, and calculate the formation sub - thicknesses Hf1 and Hf2.

[0039] H f1 = D f1 - D f2 ;

[0040] H f2 = D f2 - D f3 ;

[0041] In step S32, the total formation thickness Hz of the layer involved in the rating on different sections is the thickness difference between the shallowest formation depth value Dq that the top of the strike - slip fault zone can penetrate under the maximum continuity degree of the strike - slip fault zone in the current exploration and development and the depth value Df2 corresponding to the second penetration layer C2.

[0042] H z = D q - D f2 ;

[0043] In step S33, during the actual interpretation of strike-slip faults, there are significant differences in the continuity of actual strike-slip faults in different sampling profiles. When measuring the actual vertical penetration depth Sn of the strike-slip fault zone, if the strike-slip fault zone appears intermittently on the profile and, excluding the influence caused by gypsum-salt rock strata, the intermittent interval exceeds 60 - 80 ms, then the intermittently appearing strike-slip fault here is not a product of the same stage. When measuring the actual vertical penetration depth Sn of the strike-slip fault zone, only the length of the strike-slip fault zone in the shallow layer segment can be measured as the actual vertical penetration depth Sn of the strike-slip fault zone; if the strike-slip fault zone appears intermittently on the profile, the strata are gypsum-salt rock or the intermittent interval is less than 60 ms, then the intermittently appearing strike-slip fault here is a product of the same stage. When measuring the actual vertical penetration depth Sn of the strike-slip fault zone, the upper and lower segments are connected according to the trend and jointly used as the actual vertical penetration depth Sn of the strike-slip fault zone;

[0044] In step S33, during the actual interpretation of strike-slip faults, after the strike-slip fault zone often cuts through the horizons interpreted in actual oil and gas exploration and development, there is still a phenomenon of a small distance continuation into the shallow strata. When actually measuring the vertical penetration depth Sn of the strike-slip fault zone, this part of the excess distance is ignored; ensure that the topmost part of the actual vertical penetration depth Sn of the strike-slip fault zone is the same as the shallowest strata of the horizons involved in the rating;

[0045] In step S34, by successively measuring the total thickness Hz of the strata of the horizons involved in the rating of each profile and the actual vertical penetration depth Sn of the strike-slip fault zone, the difference between the two can be used to obtain the strike-slip fault vertical penetration ability value Qn of the corresponding profile;

[0046] Q n =S n -H z 。

[0047] Step S4 includes: S41: Based on the positive or negative value of the strike-slip fault vertical penetration ability value Qn, select the corresponding formation sub-thickness Hf accordingly, so as to construct the "penetration ability index Zn" of the strike-slip fault zone.

[0048] S42: According to the value of the "penetration ability index Zn" of the strike-slip fault zone, divide the interval and establish the evaluation standard for the vertical penetration ability of the strike-slip fault zone to the strata.

[0049] S43: Corresponding to the profile number Nn of the strike-slip fault zone, draw a curve graph of the change of the penetration ability index of the strike-slip fault zone to clarify the spatial change pattern of the vertical penetration ability of the strike-slip fault zone.

[0050] In the above solution, optionally, in step S41, if the strike-slip fault longitudinal penetration ability value Qn is positive, it means that the actual longitudinal penetration depth Sn of the strike-slip fault zone is greater than the total formation thickness Hz of the formation levels involved in the section rating, indicating that the strike-slip fault zone can actually longitudinally penetrate the second penetration level C2. At this time, the formation sub-thickness Hf2 should be selected as the index for constructing the "penetration ability index Zn" of the strike-slip fault zone;

[0051] Z n = Q n / H f2 ;

[0052] If the strike-slip fault longitudinal penetration ability value Qn is negative, it means that the actual longitudinal penetration depth Sn of the strike-slip fault zone is less than the total formation thickness Hz of the formation levels involved in the section rating, indicating that the strike-slip fault zone cannot actually longitudinally penetrate the second penetration level C2 and can only penetrate the first penetration level C1. At this time, the formation sub-thickness Hf1 should be selected as the index for constructing the "penetration ability index Zn" of the strike-slip fault zone;

[0053] Z n = Q n / H f1 ;

[0054] In step S42, an interval is divided according to the "penetration ability index Zn" value of the strike-slip fault zone, and an evaluation standard for the longitudinal penetration ability of the strike-slip fault zone to the formation is established; when the penetration ability index Zn is positive and Zn > 1, it means that the strike-slip fault can longitudinally penetrate the second penetration level C2 and can penetrate the third penetration level C3; when the penetration ability index Zn is positive and 0 < Zn ≤ 1, it means that the strike-slip fault can longitudinally penetrate the second penetration level C2 and cannot penetrate the third penetration level C3; when the penetration ability index Zn is negative and -1 < Zn ≤ 0, it means that the strike-slip fault can longitudinally penetrate the first penetration level C1 and cannot penetrate the second penetration level C2; when the penetration ability index Zn is negative and Zn ≤ -1, it means that the strike-slip fault cannot longitudinally penetrate the first penetration level C1;

[0055] In step S43, with the profile number Nn of the corresponding strike-slip fault zone as the abscissa and the "penetration ability index Zn" of the corresponding strike-slip fault zone profile as the ordinate, a rectangular coordinate system is established, and a change curve graph of the penetration ability index of the strike-slip fault zone is drawn. By the change of the "penetration ability index Zn" values of different profiles on the curve graph, the spatial change pattern of the longitudinal penetration ability of the strike-slip fault zone is clarified.

[0056] Compared with the prior art, the present application has at least the following beneficial effects:

[0057] Based on further analysis and research of the problems in the prior art, it is recognized that it is difficult for the prior art to accurately depict the spatial variation characteristics of strike-slip fault zones. After accurately reading the respective thicknesses of each layer involved in the rating of each sampling profile, the total formation thickness, and the longitudinal penetration depth of the strike-slip fault zone, the longitudinal penetration ability values of the strike-slip fault in different profiles are obtained, an index of the penetration ability of the strike-slip fault zone is constructed, an evaluation standard for the longitudinal penetration ability of the strike-slip fault zone into the formation is established, and the spatial variation pattern of the longitudinal penetration ability of the strike-slip fault zone is clarified, so as to accurately determine the mathematical method for the longitudinal penetration ability of the strike-slip fault zone into the formation. Through this method, the differences in the longitudinal penetration ability of different parts of the strike-slip fault zone can be objectively and quantitatively evaluated, and it can reasonably avoid the deficiency that when the formation thickness varies significantly in the same area due to the differences in the original formation deposition degree or the later weathering and erosion degree in different strike-slip fault zones in the same area or different parts of the same strike-slip fault zone in the same area, it is impossible to uniformly compare the standards to evaluate the longitudinal penetration ability of the strike-slip fault zone. It provides a practical solution for the structural analysts studying strike-slip faults in oil and gas geological exploration and development. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 FIG. is a schematic flow chart of a method for determining the longitudinal penetration ability of a strike-slip fault zone provided by an embodiment of the present application;

[0059] Figure 2 FIG. is a schematic principle diagram of a method for determining the longitudinal penetration ability of a strike-slip fault zone provided by an embodiment of the present application;

[0060] Figure 3 FIG. is a schematic diagram of a calculation method for the "penetration ability index Zn" of the 50th profile of the strike-slip fault zone provided by an embodiment of the present application;

[0061] Figure 4 FIG. is a schematic diagram of a calculation method for the "penetration ability index Zn" of the 84th profile of the strike-slip fault zone provided by an embodiment of the present application;

[0062] Figure 5 FIG. is a change curve diagram of the "penetration ability index" of the strike-slip fault zone provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0063] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0064] In one embodiment, as Figure 1 shown, a method for determining the longitudinal penetration ability of a strike-slip fault zone is provided, including the following steps:

[0065] S1: Based on actual seismic data, extract fracture-sensitive attributes to clarify the dominant development areas of the strike-slip fault zone on the plane and the continuity degree in the section.

[0066] S2: Determine the horizons involved in the rating of the vertical cutting ability of the strike-slip fault zone and define the evaluation accuracy of the vertical cutting ability of the strike-slip fault zone.

[0067] S3: According to the target accuracy requirements, calculate the thickness of each sub-layer and the total formation thickness of the horizons involved in the rating for each sampling section, measure the vertical cutting depth of the strike-slip fault zone, and obtain the vertical cutting ability values of the strike-slip fault for different sections.

[0068] S4: Construct an index for the cutting ability of the strike-slip fault zone, establish an evaluation standard for the vertical cutting ability of the strike-slip fault zone on the formation, draw a curve of the change in the cutting ability index of the strike-slip fault zone, and clarify the spatial change pattern of the vertical cutting ability of the strike-slip fault zone.

[0069] In this embodiment, step S1 includes:

[0070] S11: Based on actual seismic data, determine the development areas of the strike-slip faults and analyze the scale of the strike-slip faults.

[0071] S12: According to the scale of the strike-slip faults, specifically extract the fracture-sensitive attributes.

[0072] S13: Based on the seismic attributes, clarify the dominant development areas of the strike-slip fault zone on the plane and the continuity degree of the strike-slip fault zone in the section.

[0073] In this embodiment, in step S11, the development areas of the strike-slip faults are determined by applying the situations of interruption, dislocation or distortion of the seismic reflection event axes in the actual seismic data. The extensibility of the strike-slip faults shown on the seismic section is traced through the continuation of the interruption, dislocation or distortion of the seismic reflection event axes longitudinally on the seismic section. Combining the width of the interruption, dislocation or distortion of the seismic reflection event axes transversely on the seismic section, the scale of the strike-slip fault zone is jointly determined.

[0074] If it is clearly observed on the seismic section that the seismic reflection event axes are interrupted or dislocated, and due to the interruption or dislocation, there are large offsets and large widths of the seismic reflection event axes. The offset > 20 ms is a large offset, and the width > 40 ms is a large width, and there is a preset impact on the formation and tectonic pattern, then the scale of the strike-slip fault is large.

[0075] If it is clearly observed on the seismic section that the seismic reflection event axes are interrupted or dislocated, and due to the interruption or dislocation, there are certain offsets and certain widths of the seismic reflection event axes. The offset of 0 - 20 ms is a certain offset, and the width of 10 - 40 ms is a certain width, and the impact on the formation and structure is limited, then the scale of the strike-slip fault is moderate.

[0076] If the seismic reflection event axis is distorted and the width is <10 ms on the seismic profile, it is considered that the scale of the strike-slip fault is small.

[0077] In this embodiment, in step S12, for large-scale strike-slip fault zones, coherent body or ant body attributes are extracted to reflect the boundary and spatial distribution of the strike-slip fault zones; for medium-scale strike-slip fault zones, ant body or likelihood body attributes are extracted to reflect the boundary and spatial distribution of the strike-slip fault zones; for small-scale strike-slip fault zones, likelihood body or curvature body attributes are extracted to reflect the boundary and spatial distribution of the strike-slip fault zones.

[0078] If there is a situation where the fault offset and width of the strike-slip fault zone are large and small and change frequently due to the interruption, dislocation or distortion of the seismic reflection event axis of the same strike-slip fault zone on the seismic profile, making it impossible to effectively distinguish the scale of the strike-slip fault zone, the method of fusing multiple seismic attributes is used to combine the advantages of different attributes to jointly depict the boundary and spatial distribution of the strike-slip fault zone.

[0079] In step S13, after extracting the seismic attributes, by making time slices, observe the planar distribution differences of the strike-slip fault zone on different time slices, and determine the dominant development area of the strike-slip fault zone on the plane based on the changes in the planar continuity of the strike-slip fault zone on different time slices; by cutting longitudinal profiles, observe the longitudinal extension of the strike-slip fault zone on different profiles, and judge the continuity degree of the strike-slip fault zone on the profile based on the changes in the continuity degree of the strike-slip fault zone on different profiles.

[0080] On the time slices and profiles, the higher the planar continuity of the strike-slip fault zone and the stronger the linear extension ability, the more developed the strike-slip fault zone is, which is the dominant development area; the lower the planar continuity, manifested as intermittent appearance, the weaker the development degree of the strike-slip fault zone.

[0081] In this embodiment, step S2 includes:

[0082] S21: Determine the horizons involved in the rating of the longitudinal cutting ability of the strike-slip fault zone according to the continuity degree of the strike-slip fault zone on the seismic attribute profile.

[0083] S22: Determine the evaluation accuracy of the longitudinal cutting ability of the strike-slip fault zone based on the dominant development area of the strike-slip fault zone on the seismic attribute plane.

[0084] In this embodiment, in step S21, when determining the horizons involved in the longitudinal cutting ability rating of the strike-slip fault zone, it is specified that the degree of continuity of the strike-slip fault zone determined by applying the seismic attribute profile at this time is the minimum and maximum degrees of continuity of the entire strike-slip fault zone; the minimum degree of continuity of the current entire strike-slip fault zone represents the minimum value of the horizons that the strike-slip fault zone can cut through longitudinally, which is the weakest cutting ability value of the entire strike-slip fault zone, and the horizon closest to the deep part in the profile is recorded as the first cutting horizon C1; the maximum degree of continuity of the current entire strike-slip fault zone represents the maximum value of the horizons that the strike-slip fault zone can cut through longitudinally, which is the strongest cutting ability value of the entire strike-slip fault zone, and the horizon closest to the shallow part in the profile is recorded as the third cutting horizon C3; between the two horizons, the second cutting horizon C2 is selected according to the actual exploration and development requirements and the actual formation thickness.

[0085] In step S22, after clarifying the horizons involved in the longitudinal cutting ability rating of the strike-slip fault zone, if there is a large formation undulation, by extracting targeted seismic attributes along the horizons, accurately judge the dominant development positions of the strike-slip fault zone on the target horizons; then, by counting the number of dominant development positions of the strike-slip fault zone on the plane and measuring the widths of the corresponding dominant development positions of each strike-slip fault zone, comprehensively determine the accuracy of the longitudinal cutting ability evaluation of the strike-slip fault zone.

[0086] The dominant development positions of the strike-slip fault zone on the plane are the positions with high continuity and good linear extension on the plane attribute map. Ensure that at least both ends and the middle of any dominant development position of the strike-slip fault zone on the plane are covered by sampling profiles, and use the three sampling profiles as the lower limit for determining the accuracy of the longitudinal cutting ability evaluation of the strike-slip fault zone.

[0087] In this embodiment, step S3 includes:

[0088] S31: Based on the actual accuracy requirements, determine the thickness of each formation, the total formation thickness, and the sampling profile positions and numbers Nn for measuring the longitudinal cutting depth of the strike-slip fault zone for the horizons involved in the rating.

[0089] S32: Calculate the thickness of each formation Hf and the total formation thickness Hz of the horizons involved in the rating on different sampling profiles.

[0090] S33: Measure the actual longitudinal cutting depth Sn of the strike-slip fault zone according to the actual continuity degree of the strike-slip fault on different sampling profiles.

[0091] S34: Combine the thickness of each formation Hf, the total formation thickness Hz, and the actual longitudinal cutting depth Sn of the strike-slip fault zone of the horizons involved in each profile to find the difference, and obtain the longitudinal cutting ability value Qn of the strike-slip fault for different profiles.

[0092] In this embodiment, in step S31, when determining the sampling profile positions based on the actual accuracy requirements, it is determined that all sampling profiles need to be arranged at equal distances; all sampling profiles need to be arranged perpendicular to the strike of the strike-slip fault zone;

[0093] In step S32, the formation sub-thickness Hf of the horizons involved in the rating on different profiles is the true thickness value of the corresponding profile of the actual horizon; when calculating the formation sub-thickness Hf of the horizons involved in the rating on the profile, it is jointly determined in combination with the minimum continuity degree of the entire strike-slip fault zone, which represents the minimum value of the horizons that the entire strike-slip fault zone can cut through vertically, and the maximum continuity degree of the entire strike-slip fault zone, which represents the maximum value of the horizons that the entire strike-slip fault zone can cut through vertically, as well as the actual exploration and development requirements;

[0094] When calculating the total formation thickness Hz and the formation sub-thickness Hf of the horizons involved in the rating on the profile, the calculation is carried out according to the degree of the basic data for the interpretation of the actual exploration and development horizons;

[0095] After the determination is completed, the depth values Df1, Df2, and Df3 corresponding to the first horizon cut C1, the second horizon cut C2, and the third horizon cut C3 are measured for each profile respectively, and the formation sub-thicknesses Hf1 and Hf2 are obtained;

[0096] H f1 = D f1 - D f2 ;

[0097] H f2 = D f2 - D f3 ;

[0098] In step S32, the total formation thickness Hz of the horizons involved in the rating on different profiles is the thickness difference between the depth value Dq of the shallowest formation in the current exploration and development that the top of the strike-slip fault zone can cut through under the maximum continuity degree of the strike-slip fault zone and the depth value Df2 corresponding to the second horizon cut C2;

[0099] H z = D q - D f2 ;

[0100] In step S33, during the actual interpretation of strike-slip faults, there are significant differences in the continuity of strike-slip faults in different sampling profiles. When measuring the actual vertical penetration depth Sn of the strike-slip fault zone, if the strike-slip fault zone appears intermittently on the profile and, excluding the influence of evaporite rocks in the formation, the intermittent interval exceeds 60 - 80 ms, then the intermittently appearing strike-slip fault here is not a product of the same stage. When measuring the actual vertical penetration depth Sn of the strike-slip fault zone, only the length of the strike-slip fault zone in the shallow layer can be measured as the actual vertical penetration depth Sn of the strike-slip fault zone; if the strike-slip fault zone appears intermittently on the profile, the formation is evaporite rock or the intermittent interval is less than 60 ms, then the intermittently appearing strike-slip fault here is a product of the same stage. When measuring the actual vertical penetration depth Sn of the strike-slip fault zone, the upper and lower sections are connected according to the trend and jointly used as the actual vertical penetration depth Sn of the strike-slip fault zone;

[0101] In step S33, during the actual interpretation of strike-slip faults, after the strike-slip fault zone often cuts through the horizons interpreted in actual oil and gas exploration and development, there is still a phenomenon of a small distance continuation into the shallow strata. When actually measuring the vertical penetration depth Sn of the strike-slip fault zone, this part of the excess distance is ignored; ensure that the top of the actual vertical penetration depth Sn of the strike-slip fault zone is the same as the shallowest strata of the horizons involved in the rating;

[0102] In step S34, by successively measuring the total thickness Hz of the strata of the horizons involved in the rating of each profile and the actual vertical penetration depth Sn of the strike-slip fault zone, the difference between the two can be used to obtain the vertical penetration ability value Qn of the strike-slip fault for the corresponding profile;

[0103] Q n =S n -H z 。

[0104] In this embodiment, step S4 includes:

[0105] S41: Based on the positive or negative value of the vertical penetration ability value Qn of the strike-slip fault, select the formation sub-thickness Hf correspondingly, so as to construct the "penetration ability index Zn" of the strike-slip fault zone.

[0106] S42: According to the value of the "penetration ability index Zn" of the strike-slip fault zone, divide the interval and establish the evaluation standard for the vertical penetration ability of the strike-slip fault zone to the strata.

[0107] S43: Corresponding to the profile number Nn of the strike-slip fault zone, draw a curve graph of the change of the penetration ability index of the strike-slip fault zone to clarify the spatial change pattern of the vertical penetration ability of the strike-slip fault zone.

[0108] In this embodiment, in step S41, if the strike-slip fault longitudinal cutting ability value Qn is positive, it means that the actual longitudinal cutting depth Sn of the strike-slip fault zone is greater than the total formation thickness Hz of the formation layers involved in the profile rating, indicating that the strike-slip fault zone can actually longitudinally cut through the second cutting layer C2. At this time, the formation sub-thickness Hf2 should be selected as the index for constructing the "cutting ability index Zn" of the strike-slip fault zone;

[0109] Z n =Q n / H f2 ;

[0110] If the strike-slip fault longitudinal cutting ability value Qn is negative, it means that the actual longitudinal cutting depth Sn of the strike-slip fault zone is less than the total formation thickness Hz of the formation layers involved in the profile rating, indicating that the strike-slip fault zone cannot actually longitudinally cut through the second cutting layer C2 and can only cut through the first cutting layer C1. At this time, the formation sub-thickness Hf1 should be selected as the index for constructing the "cutting ability index Zn" of the strike-slip fault zone;

[0111] Z n =Q n / H f1 ;

[0112] In step S42, according to the value range of the "cutting ability index Zn" of the strike-slip fault zone, an evaluation standard for the longitudinal cutting ability of the strike-slip fault zone on the formation is established; when the cutting ability index Zn is positive and Zn>1, it means that the strike-slip fault can longitudinally cut through the second cutting layer C2 and can also cut through the third cutting layer C3; when the cutting ability index Zn is positive and 0<Zn≤1, it means that the strike-slip fault can longitudinally cut through the second cutting layer C2 but cannot cut through the third cutting layer C3; when the cutting ability index Zn is negative and -1<Zn≤0, it means that the strike-slip fault can longitudinally cut through the first cutting layer C1 but cannot cut through the second cutting layer C2; when the cutting ability index Zn is negative and Zn≤-1, it means that the strike-slip fault cannot longitudinally cut through the first cutting layer C1;

[0113] In step S43, with the profile number Nn of the corresponding strike-slip fault zone as the abscissa and the "cutting ability index Zn" of the corresponding strike-slip fault zone profile as the ordinate, a rectangular coordinate system is established, and a change curve graph of the cutting ability index of the strike-slip fault zone is drawn. By the change of the "cutting ability index Zn" values of different profiles on the curve graph, the spatial change pattern of the longitudinal cutting ability of the strike-slip fault zone is clarified.

[0114] This embodiment provides a method for determining the longitudinal cutting ability of strike-slip fault zones. To address the problems in the current research on strike-slip fault zones, such as the weak research on the longitudinal extension and cutting ability of strike-slip fault zones, and the lack of an objective and quantitative method to avoid differences and unify the comparison of the calculation methods for the longitudinal cutting ability of strike-slip fault zones in the same area, different strike-slip fault zones, and different parts of the same strike-slip fault zone in the same area, a method is provided. After accurately reading the respective thicknesses of each layer involved in the rating of each sampling profile, the total formation thickness, and the longitudinal cutting depth of the strike-slip fault zone according to the actual accuracy requirements, the longitudinal cutting ability values of the strike-slip faults in different profiles are obtained, the "cutting ability index" of the strike-slip fault zone is constructed, the evaluation criteria for the longitudinal cutting ability of the strike-slip fault zone on the formation are established, and the spatial variation pattern of the longitudinal cutting ability of the strike-slip fault zone is clarified, so as to accurately determine the longitudinal cutting ability of the strike-slip fault zone on the formation. This method provides an effective solution for professional and technical personnel studying the homology, "reservoir control, hydrocarbon accumulation control, and enrichment control" characteristics of strike-slip fault zones and well placement.

[0115] In this embodiment, a method for determining the longitudinal cutting ability of strike-slip fault zones is provided, and the method includes:

[0116] S1: Based on actual seismic data, extract fracture-sensitive attributes to clarify the dominant development positions of the strike-slip fault zone on the plane and the continuity degree on the profile.

[0117] S2: Determine the layers involved in the rating of the longitudinal cutting ability of the strike-slip fault zone and define the evaluation accuracy of the longitudinal cutting ability of the strike-slip fault zone.

[0118] S3: According to the actual accuracy requirements, calculate the respective thicknesses of each layer involved in the rating, the total formation thickness, and measure the longitudinal cutting depth of the strike-slip fault zone for each sampling profile, and obtain the longitudinal cutting ability values of the strike-slip faults in different profiles.

[0119] S4: Construct the "cutting ability index" of the strike-slip fault zone, establish the evaluation criteria for the longitudinal cutting ability of the strike-slip fault zone on the formation, draw the change curve of the "cutting ability index" of the strike-slip fault zone, and clarify the spatial variation pattern of the longitudinal cutting ability of the strike-slip fault zone.

[0120] In this embodiment, step S1 includes:

[0121] S11: Based on actual seismic data, determine the development positions of the strike-slip faults and analyze the scale of the strike-slip faults.

[0122] S12: According to the scale of the strike-slip faults, specifically extract the fracture-sensitive attributes of the strike-slip faults.

[0123] S13: Based on the seismic attributes, clarify the dominant development positions of the strike-slip fault zone on the plane and the continuity degree of the strike-slip fault zone on the profile.

[0124] In this embodiment, in step S11, the occurrence of interruption, dislocation or distortion of seismic reflection isochrones in actual seismic data is applied to determine the developed positions of strike-slip faults. Then, by tracing the extension of the strike-slip faults shown on the seismic profile through the continuation of the interruption, dislocation or distortion of seismic reflection isochrones longitudinally on the seismic profile, and combining the width of the interruption, dislocation or distortion of seismic reflection isochrones transversely on the seismic profile, the scale of the strike-slip fault zone is generally determined together.

[0125] In this embodiment, if the interruption and dislocation of seismic reflection isochrones can be clearly observed on the seismic profile, and due to the interruption and dislocation, there is a large fault offset (fault offset > 20 ms) and a large width (width > 40 ms) of the seismic reflection isochrones, and it has a certain impact on the stratigraphy and tectonic pattern, it can be considered that the scale of this strike-slip fault is large. If the interruption and dislocation of seismic reflection isochrones can be clearly observed on the seismic profile, and due to the interruption and dislocation, there is a certain fault offset (fault offset 0 - 20 ms) and a certain width (width 10 - 40 ms) of the seismic reflection isochrones, and the impact on the stratigraphy and structure is limited, it can be considered that the scale of this strike-slip fault is moderate. If only the distortion of seismic reflection isochrones with a width < 10 ms can be observed on the seismic profile, then it is considered that the scale of this strike-slip fault is small.

[0126] In this embodiment, in step S12, for large-scale strike-slip fault zones, coherent body or ant body attributes can be extracted to reflect the boundaries and spatial distribution of the strike-slip fault zones; for medium-scale strike-slip fault zones, ant body or likelihood body attributes can be extracted to reflect the boundaries and spatial distribution of the strike-slip fault zones; for small-scale strike-slip fault zones, likelihood body or curvature body attributes can be extracted to reflect the boundaries and spatial distribution of the strike-slip fault zones.

[0127] In this embodiment, if there is a strike-slip fault zone where the fault offset and width of the strike-slip fault zone caused by the interruption, dislocation or distortion of seismic reflection isochrones on the seismic profile are large and small, and change frequently, making it difficult to effectively distinguish the scale of the strike-slip fault zone, the method of fusing multiple seismic attributes can be adopted to combine the advantages of different attributes to jointly depict the boundaries and spatial distribution of this strike-slip fault zone.

[0128] In this embodiment, in step S13, after extracting seismic attributes, time slices can be made to clearly observe the planar distribution differences of the strike-slip fault zone shown on different time slices. Based on the changes in the planar continuity of the strike-slip fault zone on different time slices, the dominant developed positions of the strike-slip fault zone on the plane can be determined; by cutting longitudinal profiles, the longitudinal extension of the strike-slip fault zone shown on different profiles can be clearly observed. Based on the changes in the continuity of the strike-slip fault zone on different profiles, the continuity degree of the strike-slip fault zone on the profile can be accurately judged.

[0129] In this embodiment, on the time slice and section, the higher the planar continuity degree of the strike-slip fault zone and the stronger the linear extension ability, the more developed the strike-slip fault zone is, which is the dominant development area; the lower the planar continuity degree, manifested as intermittent appearance, the weaker the development degree of the strike-slip fault zone.

[0130] In this embodiment, step S2 includes: S21: Determine the horizons involved in the rating of the longitudinal cutting ability of the strike-slip fault zone according to the continuity degree of the strike-slip fault zone on the seismic attribute section.

[0131] S22: Based on the dominant development area of the strike-slip fault zone on the seismic attribute plane, determine the evaluation accuracy of the longitudinal cutting ability of the strike-slip fault zone.

[0132] In this embodiment, in step S21, when determining the horizons involved in the rating of the longitudinal cutting ability of the strike-slip fault zone, it should be clear that the continuity degree of the strike-slip fault zone determined by applying the seismic attribute section at this time should be the minimum continuity degree and the maximum continuity degree of the entire strike-slip fault zone. The current minimum continuity degree of the entire strike-slip fault zone represents the minimum value of the horizons that the strike-slip fault zone can cut through longitudinally, which is the weakest cutting ability value of the entire strike-slip fault zone, and the horizon closest to the deep part on the section is recorded as the first cutting horizon C1; the current maximum continuity degree of the entire strike-slip fault zone represents the maximum value of the horizons that the strike-slip fault zone can cut through longitudinally, which is the strongest cutting ability value of the entire strike-slip fault zone, and the horizon closest to the shallow part on the section is recorded as the third cutting horizon C3; the second cutting horizon C2 is selected between the two horizons according to the actual exploration and development requirements and the actual formation thickness.

[0133] In this embodiment, in step S22, after clarifying the horizons involved in the rating of the longitudinal cutting ability of the strike-slip fault zone, if there is a large formation undulation, the dominant development area of the strike-slip fault zone on the target horizon can be accurately judged by further extracting targeted seismic attributes along the horizon. Then, by counting the number of dominant development areas of the strike-slip fault zone on the plane and measuring the widths of the corresponding dominant development areas of each strike-slip fault zone, the evaluation accuracy of the longitudinal cutting ability of the strike-slip fault zone is comprehensively determined.

[0134] In this embodiment, the dominant development area of the strike-slip fault zone on the plane is the area with high continuity degree and good linear extension on the planar attribute map, and it usually tends to appear in the development area of the strike-slip fault overlapping segment. It should be ensured that at least both ends and the middle of any dominant development area of the strike-slip fault zone on the plane are covered by sampling profiles, so three sampling profiles are used as the lower limit for determining the evaluation accuracy of the longitudinal cutting ability of the strike-slip fault zone.

[0135] In this embodiment, step S3 includes: S31: Based on the actual accuracy requirements, determine the thickness of each formation, the total formation thickness, and the sampling profile location and number Nn for measuring the longitudinal cutting depth of the strike-slip fault zone for the horizons involved in the rating.

[0136] S32: Calculate the respective formation sub - thicknesses Hf and the total formation thickness Hz of the horizons involved in the rating for different sampling profiles.

[0137] S33: Measure the actual longitudinal penetration depth Sn of the strike - slip fault zone according to the actual degree of strike - slip fault continuity of different sampling profiles.

[0138] S34: Calculate the difference by combining the respective formation sub - thicknesses Hf, the total formation thickness Hz of the horizons involved in the rating for each profile, and the actual longitudinal penetration depth Sn of the strike - slip fault zone, and obtain the longitudinal penetration ability value Qn of the strike - slip fault for different profiles.

[0139] In this embodiment, in step S31, when determining the sampling profile location based on the actual accuracy requirements, first, it should be ensured that all sampling profiles are arranged at equal distances; second, all sampling profiles should be arranged perpendicular to the strike - slip fault zone trend. This improves the analyzability of the sampling data and ensures that the sampling meets the requirements of actual structural analysis.

[0140] In this embodiment, in step S32, the formation sub - thickness Hf of the horizons involved in the rating for different profiles should be the true thickness value of the actual horizons corresponding to the profiles. When calculating the formation sub - thickness Hf of the horizons involved in the rating for the profiles, it should be jointly determined by combining the minimum value of the horizons that the entire strike - slip fault zone can longitudinally penetrate, which is represented by the minimum degree of continuity of the entire strike - slip fault zone, and the maximum value of the horizons that the entire strike - slip fault zone can longitudinally penetrate, which is represented by the maximum degree of continuity of the entire strike - slip fault zone, as well as the actual exploration and development requirements.

[0141] In this embodiment, during the actual oil and gas exploration and development process, layer - horizon analysis is often only carried out on key horizons, target horizons, and regional unconformities, etc. Therefore, when calculating the total formation thickness Hz and the respective formation sub - thicknesses Hf of the horizons involved in the rating for the profiles, reasonable calculations should be carried out according to the degree of basic data of actual exploration and development layer - horizon interpretation.

[0142] In this embodiment, in step S32, after determination, measure the depth values D f1, Df2, and Df3 corresponding to the first penetrated horizon C1, the second penetrated horizon C2, and the third penetrated horizon C3 for each profile respectively, and then obtain the formation sub - thicknesses Hf1 and Hf2.

[0143] H f1 =D f1 -D f2 ;H f2 =D f2 -D f3 ;

[0144] In this embodiment, in step S32, the total formation thickness Hz of the horizons involved in the rating on different profiles should be the thickness difference between the shallowest formation depth value Dq that the top of the strike-slip fault zone can cut through under the maximum continuity degree of the strike-slip fault zone and the depth value Df2 corresponding to the second cut-through horizon C2 in the current exploration and development.

[0145] H z =D q -D f2 ;

[0146] In this embodiment, in step S33, during the actual interpretation of the strike-slip fault, it can be clearly found that there are significant differences in the actual continuity degree of the strike-slip fault on different sampling profiles. When measuring the actual vertical cutting depth Sn of the strike-slip fault zone, if the strike-slip fault zone appears intermittently on the profile and, excluding the influence of gypsum-salt rock formations, the intermittent interval exceeds 60 - 80 ms, it can be considered that the intermittently appearing strike-slip fault here is not a product of the same period. When measuring the actual vertical cutting depth Sn of the strike-slip fault zone, only the length of the strike-slip fault zone in the relatively shallow section can be measured as the actual vertical cutting depth Sn of the strike-slip fault zone. If the strike-slip fault zone appears intermittently on the profile, the formation is gypsum-salt rock or the intermittent interval is less than 60 ms, it can be considered that the intermittently appearing strike-slip fault here is a product of the same period. When measuring the actual vertical cutting depth Sn of the strike-slip fault zone, the upper and lower sections need to be connected according to the trend and jointly used as the actual vertical cutting depth Sn of the strike-slip fault zone.

[0147] In this embodiment, in step S33, during the actual interpretation of the strike-slip fault, it can also be clearly found that there is often a phenomenon that after the strike-slip fault zone cuts through the horizons interpreted in the actual oil and gas exploration and development, it still extends a small distance into the shallow formations. When actually measuring the vertical cutting depth Sn of the strike-slip fault zone, this part of the extra distance needs to be ignored. This ensures that the top of the actual vertical cutting depth Sn of the strike-slip fault zone is the same as the shallowest formation of the horizons involved in the rating. And further ensures that the strength of the vertical cutting ability of the strike-slip fault zone completely depends on the depth that the bottom of the strike-slip fault zone can cut through.

[0148] In this embodiment, in step S34, by successively measuring the total formation thickness Hz of the horizons involved in the rating of each profile and the actual vertical cutting depth Sn of the strike-slip fault zone, the difference between the two can be used to obtain the strike-slip fault vertical cutting ability value Qn of the corresponding profile.

[0149] Q n =S n -H z ;

[0150] In this embodiment, step S4 includes:

[0151] S41: Based on the positive or negative value of the longitudinal cutting ability value Qn of the strike-slip fault, select the formation sub-thickness Hf correspondingly, so as to construct the "cutting ability index Zn" of the strike-slip fault zone.

[0152] S42: According to the value of the "cutting ability index Zn" of the strike-slip fault zone, divide the interval and establish the evaluation standard for the longitudinal cutting ability of the strike-slip fault zone on the formation.

[0153] S43: Corresponding to the profile number Nn of the strike-slip fault zone, draw the change curve of the "cutting ability index" of the strike-slip fault zone to clarify the spatial change pattern of the longitudinal cutting ability of the strike-slip fault zone.

[0154] In this embodiment, in step S41, if the longitudinal cutting ability value Qn of the strike-slip fault is positive (Qn > 0), it means that the actual longitudinal cutting depth Sn of the strike-slip fault zone is greater than the total formation thickness Hz of the layer involved in the profile rating, indicating that the strike-slip fault zone can actually longitudinally cut through the second cutting layer C2. At this time, the formation sub-thickness Hf2 should be selected as the index for constructing the "cutting ability index Zn" of the strike-slip fault zone.

[0155] Z n =Q n / H f2 ;

[0156] If the longitudinal cutting ability value Qn of the strike-slip fault is negative (Qn < 0), it means that the actual longitudinal cutting depth Sn of the strike-slip fault zone is less than the total formation thickness Hz of the layer involved in the profile rating, indicating that the strike-slip fault zone cannot actually longitudinally cut through the second cutting layer C2 and can only cut through the second cutting layer C1. At this time, the formation sub-thickness Hf1 should be selected as the index for constructing the "cutting ability index Zn" of the strike-slip fault zone.

[0157] Z n =Q n / H f1 ;

[0158] In this embodiment, in step S42, since the "penetration ability index Zn" value of the strike-slip fault zone is the ratio of the vertical penetration ability value Qn of the strike-slip fault to the formation thickness Hfn. Therefore, the interval can be divided according to the "penetration ability index Zn" value of the strike-slip fault zone, and the evaluation standard for the vertical penetration ability of the strike-slip fault zone to the formation can be established. When the penetration ability index Zn is positive and Zn > 1, it means that the strike-slip fault can vertically penetrate the second penetration horizon C2 and can penetrate the third penetration horizon C3; when the penetration ability index Zn is positive and 0 < Zn ≤ 1, it means that the strike-slip fault can vertically penetrate the second penetration horizon C2 but cannot penetrate the third penetration horizon C3; when the penetration ability index Zn is negative and -1 < Zn ≤ 0, it means that the strike-slip fault can vertically penetrate the first penetration horizon C1 but cannot penetrate the second penetration horizon C2; when the penetration ability index Zn is negative and Zn ≤ -1, it means that the strike-slip fault cannot vertically penetrate the first penetration horizon C1.

[0159] In this embodiment, in step S43, taking the profile number Nn corresponding to the strike-slip fault zone as the abscissa and the "penetration ability index Zn" of the profile corresponding to the strike-slip fault zone as the ordinate, a rectangular coordinate system is established, and the change curve of the "penetration ability index" of the strike-slip fault zone is drawn. By the change of the "penetration ability index Zn" values of different profiles on the curve, the spatial change pattern of the vertical penetration ability of the strike-slip fault zone can be clarified.

[0160] In a specific embodiment, this example conducts a study on the vertical penetration ability of the strike-slip fault zone by applying the method for determining the vertical penetration ability of the strike-slip fault zone, as Figure 2 shown.

[0161] First, based on the three-dimensional seismic data of the Tahe area in the Tarim Basin, the location of the strike-slip fault zone is determined by observing the interruption, dislocation or distortion of the seismic reflection phase axis on the seismic profile. Further, according to the continuity of the interruption, dislocation or distortion of the seismic reflection phase axis in the longitudinal direction of the seismic profile, the extension capacity of the strike-slip fault zone on the seismic profile is traced, and then combined with the width of the interruption, dislocation or distortion of the seismic reflection phase axis in the lateral direction of the seismic profile, the scale of the strike-slip fault zone is roughly determined. The strike-slip fault zone in the Tahe area has a large span of fault throw changes along the fault strike, ranging from 0 to 38 ms, and the width changes are also large, ranging from 10 to 42 ms. After refining the scale of the strike-slip fault zone according to the size of the fault throw, the strike-slip fault with a fault throw of more than 20ms, a width of more than 40ms, and a certain impact on the stratum and structural pattern can be considered as a large-scale strike-slip fault; the fault throw of 0-20ms, a width of 10-40ms, has limited impact on the stratum and structure, and is considered to be a moderate-scale strike-slip fault; the fault throw of 0ms, a width of less than 10ms, and only a weak distortion of the seismic reflection phase axis can be observed, which is considered to be a small-scale strike-slip fault. For this kind of situation where the fault throw changes over a large span and the fault throw is sometimes large and sometimes small, this time we use the method of integrating the three seismic attributes of coherence, ant body, and curvature body to jointly characterize the boundary and spatial distribution of the strike-slip fault zone. After extracting seismic attributes, by making time slices, it can be clearly found that the strike-slip fault zone in the area has a development depth between -3850 and -5120ms, and the strike-slip fault zone has a strong plane continuity and a good linear extension state in the intervals of -3800 to -3980ms, -4190 to -4250ms, -4480 to -4520ms and -4850 to -4900ms, and the dominant development position of the strike-slip fault zone can be clearly observed. By cutting the longitudinal section, it is found that the continuity of the strike-slip fault zone varies greatly in different sections.

[0162] Based on the continuity degree of the strike-slip fault zone observed from seismic attributes on the section in the Tahe area, it can be found that the first penetrated horizon C1 corresponding to the location with the minimum continuity degree of the entire strike-slip fault zone should be T80, and the third penetrated horizon C3 corresponding to the location with the maximum continuity degree of the entire strike-slip fault zone should be T90. According to the actual exploration and development requirements and the actual formation thickness between the two horizons, the second penetrated horizon C2 should be T81. Since there is a characteristic of higher in the NE and lower in the SW in these three horizons in the Tahe area, the method of using time slices to observe the dominant development location of the strike-slip fault plane is obviously not applicable. It is necessary to extract seismic attributes along the three horizons respectively, and specifically observe the distribution of the dominant development locations of the strike-slip fault at different horizons to determine the evaluation accuracy of the longitudinal penetration ability of the strike-slip fault zone. After extracting seismic attributes along the horizon, it is found that the minimum range of the dominant development location of the strike-slip fault among the three horizons is 1352 m. Therefore, to ensure that there are at least three sampling profiles for the dominant development location of any strike-slip fault zone on each plane, the lower limit of the evaluation accuracy of the longitudinal penetration ability of the strike-slip fault zone is set to 400 m, and sampling is carried out every 400 m.

[0163] After confirming the sampling accuracy, based on the accuracy requirements, the formation sub-thickness Hf, the total formation thickness Hz, the longitudinal penetration depth Sn of the strike-slip fault zone, and the longitudinal penetration ability value Qn of the strike-slip fault are measured and calculated successively at equal intervals and perpendicular to the strike direction of the strike-slip fault zone for each section rating-related horizon, as Figure 2 shown. For the Tahe area, taking the 50th section of a certain strike-slip fault zone as an example, the total formation thickness is the thickness difference between the depth value Dq of the shallowest formation (T74) in the current exploration and development and the depth value Df2 corresponding to the second penetrated horizon C2: H z = D q - D f2 = -3750 - (-4500 ms) = 750 ms. The two formation sub-thicknesses are respectively: Hf1 is the thickness difference between the depth value Df2 of the second penetrated horizon C2 (T81) and the depth value Df1 of the first penetrated horizon C1 (T80): H f1 = D f1 - D f2 = -4225 - (-4500) = 275 ms; Hf2 is the thickness difference between the depth value Df2 of the second penetrated horizon C2 (T81) and the depth value Df3 of the third penetrated horizon C3 (T90): H f1 = D f2 - D f3 = -4500 - (-4888) = 388 ms; The longitudinal penetration ability value Q of the strike-slip fault n = S n - H z= 1231 - 750 = 481 ms. At this time, the longitudinal cutting ability value Qn of the strike-slip fault is positive (Qn > 0). The formation sub-thickness Hf2 should be selected as the index for constructing the "cutting ability index Zn" of the strike-slip fault zone, Z n = Q n / H f2 = 481 / 388 = 1.24, as Figure 3 shown. Taking the 84th section of this strike-slip fault zone as an example, the total formation thickness is the thickness difference between the depth value Dq of the shallowest formation (T74) in the current exploration and development and the depth value Df2 corresponding to the second penetrated horizon C2: H z = D q - D f2 = -3768 - (-4521 ms) = 753 ms. The two formation sub-thicknesses are respectively: Hf1 is the thickness difference between the depth value Df2 of the second penetrated horizon C2 (T81) and the depth value Df1 of the first penetrated horizon C1 (T80): H f1 = D f1 - D f2 = -4245 - (-4521) = 276 ms; Hf2 is the thickness difference between the depth value Df2 of the second penetrated horizon C2 (T81) and the depth value Df3 of the third penetrated horizon C3 (T90): H f1 = D f2 - D f3 = -4521 - (-4913) = 392 ms; The longitudinal cutting ability value Q of the strike-slip fault n = S n - H z = 634 - 753 = -119 ms. At this time, the longitudinal cutting ability value Qn of the strike-slip fault is negative (Qn < 0). The formation sub-thickness Hf1 should be selected as the index for constructing the "cutting ability index Zn" of the strike-slip fault zone, Z n = Q n / H f2 = -119 / 276 = -0.43, as Figure 4As shown in the figure. By this method, the "penetration ability index Zn" of each profile of the entire fault zone is obtained. Then, according to the value of the "penetration ability index Zn" of the strike-slip fault zone, four intervals are divided, and an evaluation standard for the vertical penetration ability of the strike-slip fault zone into the strata is established. The study found that 54.8% of this fault zone has a positive penetration ability index Zn and Zn > 1, which proves that 54.8% of the area of this strike-slip fault can vertically penetrate the third penetration horizon C3 (T90) after penetrating the second penetration horizon C2 (T81); 30.5% of the area of this fault zone has a positive penetration ability index Zn and 0 < Zn ≤ 1, which proves that 30.5% of the area of this strike-slip fault cannot vertically penetrate the third penetration horizon C3 (T90) after penetrating the second penetration horizon C2 (T81); 14.7% of the area of this fault zone has a negative penetration ability index Zn and -1 < Zn ≤ 0, which proves that 14.7% of the area of this strike-slip fault cannot vertically penetrate the third penetration horizon C2 (T81) after penetrating the first penetration horizon C1 (T80); there is no situation where the penetration ability index Zn of this strike-slip fault is negative and Zn ≤ -1, which proves that the weakest part of this strike-slip fault zone can penetrate the first penetration horizon C1 (T80).

[0164] After the data calculation of each profile is completed, with the profile number Nn of the corresponding strike-slip fault zone as the abscissa and the "penetration ability index Zn" of the corresponding strike-slip fault zone profile as the ordinate, a rectangular coordinate system is established, and a change curve graph of the "penetration ability index" of the strike-slip fault zone is drawn. By the change of the numerical value of the "penetration ability index Zn" of different profiles on the curve graph, the spatial change pattern of the vertical penetration ability of the strike-slip fault zone can be clarified, such as Figure 5 shown.

[0165] This embodiment provides a method for determining the vertical penetration ability of a strike-slip fault in oil and gas exploration and development. After accurately reading the thickness of each layer involved in the rating of each sampling profile, the total thickness of the formation, and the vertical penetration depth of the strike-slip fault zone according to the actual accuracy requirements, the vertical penetration ability value of the strike-slip fault of different profiles is obtained, the "penetration ability index" of the strike-slip fault zone is constructed, an evaluation standard for the vertical penetration ability of the strike-slip fault zone into the strata is established, and the spatial change pattern of the vertical penetration ability of the strike-slip fault zone is clarified, so as to accurately determine the vertical penetration ability of the strike-slip fault zone into the strata. This patent solves the deficiencies of subjective research methods and inability to be quantified in the study of the longitudinal extension and penetration ability of the strike-slip fault zone, and solves the problem of lacking a method to avoid differences and unify comparisons when evaluating the vertical penetration ability of different strike-slip fault zones in the same area and different parts of the same strike-slip fault zone in the same area.

[0166] This embodiment mainly provides a mathematical method for accurately determining the longitudinal cutting ability of strike-slip faults. According to the actual accuracy requirements of oil and gas exploration and development, after accurately reading the respective sub-thicknesses of the layers involved in the rating of each sampling profile, the total formation thickness, and the longitudinal cutting depth of the strike-slip fault zone, the longitudinal cutting ability values of different profiles are obtained, the "cutting ability index" of the strike-slip fault zone is constructed, the evaluation criteria for the longitudinal cutting ability of the strike-slip fault zone on the formation are established, and the spatial variation pattern of the longitudinal cutting ability of the strike-slip fault zone is clarified. Through this method, the differences in the longitudinal cutting ability of different parts of the strike-slip fault zone can be objectively and quantitatively evaluated, and it can reasonably avoid the deficiency that when the formation thickness varies significantly in the same area due to differences in the original formation deposition degree or later weathering and erosion degree in different strike-slip fault zones in the same area or different parts of the same strike-slip fault zone in the same area, it is impossible to uniformly compare the criteria to evaluate the longitudinal cutting ability of the strike-slip fault zone. It provides a practical solution for structural analysts studying strike-slip faults in oil and gas geological exploration and development.

[0167] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, 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, it should be considered as within the scope described in this specification.

Claims

1. A method for determining the longitudinal cutting capacity of a strike-slip fault zone, characterized in that: The method comprises the following steps: S1: Based on actual seismic data, extract fault sensitivity attributes and clarify the dominant development locations of strike-slip fault zones on the plane and the degree of continuity on the profile; S2: Determine the strata involved in the evaluation of the longitudinal cutting capacity of the strike-slip fault zone and determine the accuracy of the evaluation of the longitudinal cutting capacity of the strike-slip fault zone; S3: According to the target accuracy requirements, each sampling section is graded, involving the calculation of each layer thickness, the total stratum thickness and the measurement of the longitudinal penetration depth of the strike-slip fault zone, and the longitudinal penetration capacity of the strike-slip fault of different sections is obtained; S4: Construct a strike-slip fault zone cutting capacity index, establish an evaluation standard for the strike-slip fault zone's longitudinal cutting capacity of the strata, draw a curve of the strike-slip fault zone cutting capacity index change, and clarify the spatial variation pattern of the strike-slip fault zone's longitudinal cutting capacity.

2. The method according to claim 1, characterized in that Step S1 includes: S11: Based on actual seismic data, determine the location of strike-slip faults and analyze the scale of strike-slip faults; S12: According to the scale of strike-slip faults, sensitive attributes of strike-slip faults are extracted in a targeted manner; S13: Based on seismic attributes, clarify the dominant development locations of strike-slip fault zones on the plane and the degree of continuity of strike-slip fault zones on the profile.

3. The method according to claim 2, characterized in that In step S11, the location of the strike-slip fault is determined by using the interruption, displacement or distortion of the seismic reflection event in the actual seismic data, and the extension of the strike-slip fault on the seismic section is traced by the continuation of the interruption, displacement or distortion of the seismic reflection event in the longitudinal direction of the seismic section, and the scale of the strike-slip fault zone is determined by combining the width of the interruption, displacement or distortion of the seismic reflection event in the lateral direction of the seismic section; If the seismic reflection event axis is obviously observed to be interrupted or dislocated on the seismic profile, and the seismic reflection event axis has a large fault distance and a large width due to the interruption or dislocation, the fault distance is greater than 20ms for a large fault distance, and the width is greater than 40ms for a large width, and it has a preset impact on the stratum and structural pattern, then the scale of the strike-slip fault is large; If the seismic reflection event axis is obviously observed to be interrupted or dislocated on the seismic profile, and the seismic reflection event axis has a certain fault distance and width due to the interruption or dislocation, with a fault distance of 0 to 20 ms and a width of 10 to 40 ms, and the impact on the stratum and structure is limited, then the scale of the strike-slip fault is moderate; If distortion of seismic reflection event axes with a width of less than 10 ms is observed on the seismic profile, it is considered that the scale of the strike-slip fault is small.

4. The method according to claim 2, characterized in that: In step S12, the coherence body or ant body attributes are extracted from the large-scale strike-slip fault zone to reflect the boundary and spatial distribution of the strike-slip fault zone; the ant body or likelihood body attributes are extracted from the medium-scale strike-slip fault zone to reflect the boundary and spatial distribution of the strike-slip fault zone; the likelihood body or curvature body attributes are extracted from the small-scale strike-slip fault zone to reflect the boundary and spatial distribution of the strike-slip fault zone; If the same strike-slip fault zone has interruptions, dislocations or distortions in the seismic reflection phase axis on the seismic section, resulting in the strike-slip fault zone's fault throw and width changing frequently, and the size of the strike-slip fault zone cannot be effectively distinguished, the method of fusing multiple seismic attributes can be used to combine the advantages of different attributes to jointly characterize the boundary and spatial distribution of the strike-slip fault zone; In step S13, after extracting the seismic attributes, by making time slices, the differences in the plane distribution of the strike-slip fault zone on different time slices are observed, and the dominant development position of the strike-slip fault zone on the plane is determined according to the changes in the plane continuity of the strike-slip fault zone on different time slices; by cutting longitudinal sections, the longitudinal extension of the strike-slip fault zone on different sections is observed, and the continuity of the strike-slip fault zone on the section is determined according to the changes in the continuity of the strike-slip fault zone on different sections; On the time slice and profile, the higher the plane continuity of the strike-slip fault zone and the stronger its linear extension ability, the more developed the strike-slip fault zone is and it is the dominant development site; the lower the plane continuity and the more discontinuous the appearance, the weaker the development of the strike-slip fault zone is.

5. The method according to claim 1, characterized in that Step S2 includes: S21: According to the continuity of the strike-slip fault zone on the seismic attribute section, determine the layers involved in the longitudinal penetration capacity rating of the strike-slip fault zone; S22: Based on the dominant development locations of strike-slip fault zones on the seismic attribute plane, determine the accuracy of the evaluation of the longitudinal cutting capacity of strike-slip fault zones.

6. The method according to claim 5, characterized in that In step S21, when determining the strata involved in the longitudinal penetration rating of the strike-slip fault zone, it is clear that the continuity degree of the strike-slip fault zone determined by the seismic attribute profile at this time is the minimum continuity degree and the maximum continuity degree of the entire strike-slip fault zone; the current minimum continuity degree of the entire strike-slip fault zone represents the minimum value of the strata that can be penetrated in the longitudinal direction of the entire strike-slip fault zone, which is the weakest penetration value of the entire strike-slip fault zone, and the stratum closest to the deep part on the profile is recorded as the first penetration stratum C1; the current maximum continuity degree of the entire strike-slip fault zone represents the maximum value of the strata that can be penetrated in the longitudinal direction of the entire strike-slip fault zone, which is the strongest penetration value of the entire strike-slip fault zone, and the stratum closest to the shallow part on the profile is recorded as the third penetration stratum C3; The second cutting layer C2 is selected between the two layers according to the actual exploration and development requirements and the actual formation thickness; In step S22, after the strata involved in the evaluation of the longitudinal penetration capacity of the strike-slip fault zone are clarified, if there is a situation where the stratum fluctuation is large, the dominant development position of the strike-slip fault zone on the target stratum is accurately determined by extracting targeted seismic attributes along the strata; then, the number of dominant development positions of the strike-slip fault zone on the plane is counted, the width of each corresponding dominant development position of the strike-slip fault zone is measured, and the accuracy of the evaluation of the longitudinal penetration capacity of the strike-slip fault zone is comprehensively determined; The plane dominant development position of the strike-slip fault zone is the position with high continuity and good linear extension on the plane attribute map. It is ensured that at least the two ends and the middle of any plane dominant development position of the strike-slip fault zone are covered by sampling sections. The three sampling sections are used as the lower limit of the accuracy of determining the longitudinal cutting ability evaluation of the strike-slip fault zone.

7. The method according to claim 1, characterized in that Step S3 includes: S31: Based on the actual accuracy requirements, determine the sampling section locations and numbers Nn for measuring the thickness of each stratum involved in the rating, the total stratum thickness, and the longitudinal penetration depth of the strike-slip fault zone; S32: Calculate the thickness of each stratum Hf and the total thickness of the stratum Hz involved in the rating on different sampling sections; S33: According to the actual continuity of strike-slip faults in different sampling sections, the actual longitudinal penetration depth Sn of the strike-slip fault zone is measured; S34: By combining the thickness of each stratum Hf, the total stratum thickness Hz and the actual longitudinal penetration depth Sn of the strike-slip fault zone involved in the rating of each profile, the longitudinal penetration capacity value Qn of the strike-slip fault in different profiles is calculated.

8. The method according to claim 7, characterized in that In step S31, when the sampling section location is determined based on the actual accuracy requirement, it is determined that all sampling sections must be arranged at equal distances; all sampling sections must be arranged perpendicular to the strike-slip fault zone; In step S32, the stratigraphic thickness Hf of the layers involved in the rating on different sections is the real thickness value of the section corresponding to the actual layer; when calculating the stratigraphic thickness Hf of the layers involved in the rating on the section, it is determined by combining the minimum value of the layers that can be cut through in the longitudinal direction of the entire strike-slip fault zone represented by the minimum continuity degree of the entire strike-slip fault zone at present, the maximum value of the layers that can be cut through in the longitudinal direction of the entire strike-slip fault zone represented by the maximum continuity degree of the entire strike-slip fault zone at present, and the actual exploration and development needs; When calculating the total thickness Hz of the strata involved in the rating on the profile and the thickness Hf of each stratum, the calculation is carried out according to the degree of basic data interpretation of the actual exploration and development strata; After the determination is completed, the depth values ​​Df1, Df2 and Df3 corresponding to the first cut-through layer C1, the second cut-through layer C2 and the third cut-through layer C3 are measured for each section respectively, and the stratum thickness Hf1 and Hf2 are obtained; H f1 =D f1 -D f2 ; H f2 =D f2 -D f3 ; In step S32, the total thickness Hz of the strata involved in the rating on different sections is the thickness difference between the shallowest stratum depth Dq that can be cut through the top of the strike-slip fault zone under the maximum continuity of the strike-slip fault zone in the current exploration and development and the depth Df2 corresponding to the second cut-through stratum C2; H z =D q -D f2 ; In step S33, in the actual interpretation process of the strike-slip fault, the continuity degree of the actual strike-slip fault of different sampling profiles is quite different. When measuring the actual longitudinal penetration depth Sn of the strike-slip fault zone, if the strike-slip fault zone appears intermittently on the profile, and the influence of the formation being gypsum salt rock is excluded, and the intermittent interval exceeds 60-80ms, then the intermittent strike-slip fault here is not a first-phase product. When measuring the actual longitudinal penetration depth Sn of the strike-slip fault zone, only the length of the strike-slip fault zone in the shallow layer can be taken as the actual longitudinal penetration depth Sn of the strike-slip fault zone; if the strike-slip fault zone appears intermittently on the profile, the formation is gypsum salt rock or the intermittent interval is less than 60ms, then the intermittent strike-slip fault here is a first-phase product. When measuring the actual longitudinal penetration depth Sn of the strike-slip fault zone, the upper and lower sections are connected according to the trend and are jointly used as the actual longitudinal penetration depth Sn of the strike-slip fault zone; In step S33, in the actual interpretation process of strike-slip faults, the strike-slip fault zone often continues for a short distance to the shallow strata after cutting through the strata interpreted in the actual oil and gas exploration and development. When the longitudinal penetration depth Sn of the strike-slip fault zone is actually measured, this part of the excess distance is ignored; it is ensured that the top of the actual longitudinal penetration depth Sn of the strike-slip fault zone is the same as the shallowest stratum of the strata involved in the rating; In step S34, the total stratum thickness Hz of the layers involved in each profile rating and the actual longitudinal penetration depth Sn of the strike-slip fault zone are measured in sequence, and the difference between the two can be used to obtain the longitudinal penetration capacity value Qn of the strike-slip fault of the corresponding profile; Q n =S n -H z 。 9. The method according to claim 1, characterized in that: Step S4 includes: S41: Based on the positive and negative values ​​of the longitudinal penetration capacity value Qn of the strike-slip fault, the formation thickness Hf is correspondingly selected to construct the "penetration capacity index Zn" of the strike-slip fault zone; S42: according to the "cutting capacity index Zn" value of the strike-slip fault zone, the interval is divided and the evaluation standard of the vertical cutting capacity of the strike-slip fault zone on the formation is established; S43: Corresponding to the strike-slip fault zone section number Nn, a curve of the strike-slip fault zone cutting capacity index change is drawn to clarify the spatial variation pattern of the longitudinal cutting capacity of the strike-slip fault zone.

10. The method according to claim 9, characterized in that In step S41, if the strike-slip fault longitudinal penetration capacity value Qn is positive, it means that the strike-slip fault zone's actual longitudinal penetration depth Sn is greater than the total stratum thickness Hz of the layers involved in the profile rating, which means that the strike-slip fault zone can actually longitudinally penetrate the second penetration layer C2. At this time, the stratum thickness Hf2 should be selected as the indicator for constructing the strike-slip fault zone's "cutting capacity index Zn"; Z n =Q n / H f2 ; If the strike-slip fault longitudinal penetration capacity value Qn is negative, it means that the actual longitudinal penetration depth Sn of the strike-slip fault zone is less than the total stratum thickness Hz of the layers involved in the profile rating, which means that the strike-slip fault zone cannot actually longitudinally penetrate the second penetration layer C2, and can only penetrate the second penetration layer C1. In this case, the stratum thickness Hf1 should be selected as the indicator for constructing the "cutting capacity index Zn" of the strike-slip fault zone; Z n =Q n / H f1 ; In step S42, the interval is divided according to the "cutting ability index Zn" value of the strike-slip fault zone, and an evaluation standard for the longitudinal cutting ability of the strike-slip fault zone to the formation is established; when the cutting ability index Zn is positive, and Zn>1, it means that the strike-slip fault can longitudinally cut through the second cutting layer C2, and can cut through the third cutting layer C3; when the cutting ability index Zn is positive, and 0<Zn≤1, it means that the strike-slip fault can longitudinally cut through the second cutting layer C2, and cannot cut through the third cutting layer C3; when the cutting ability index Zn is negative, and -1<Zn≤0, it means that the strike-slip fault can longitudinally cut through the first cutting layer C1, and cannot cut through the second cutting layer C2; when the cutting ability index Zn is negative, and Zn≤-1, it means that the strike-slip fault cannot longitudinally cut through the first cutting layer C1; In step S43, a rectangular coordinate system is established with the corresponding strike-slip fault zone section number Nn as the horizontal coordinate and the corresponding "cutting ability index Zn" of the strike-slip fault zone section as the vertical coordinate, and a curve chart of the cut-through ability index change of the strike-slip fault zone is drawn. Through the changes in the values ​​of the "cut-through ability index Zn" of different sections on the curve chart, the spatial variation pattern of the longitudinal cut-through ability of the strike-slip fault zone is clarified.

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