Method for identifying hidden strike-slip fracture and related device

Abstract

The invention discloses a method for identifying hidden strike-slip fracture and a related device. The method comprises the steps that according to the distribution characteristic that strike-slip fracture development has near-equal-interval performance, the stratum characteristics of areas where hidden strike-slip fractures possibly occur are judged, and hidden strike-slip fracture development areas are qualitatively recognized; calculating the strike-slip amount of the hidden strike-slip fracture of the stratum which may generate the hidden strike-slip fracture in the development area through a seismic reflection category method, and determining whether the stratum which may generate the hidden strike-slip fracture actually generates the hidden strike-slip fracture or not; and comprehensive analysis is carried out by combining drilling information, a seismic section and an optimized fracture identification technology, and distribution of the actually generated hidden strike-slip fracture on the graph is depicted. The method provided by the invention is a new thought for controlling and identifying the hidden strike-slip fracture step by step, the hidden strike-slip fracture can be accurately identified and depicted, the efficiency of finding the dessert reservoir is improved, the yield of a single well is improved, and the exploration and development investment is saved.

Description

Technical Field

[0001] The present invention relates to the field of strike-slip fault prediction in the petroleum industry, and in particular to a method for identifying hidden strike-slip faults and related devices. Background Art

[0002] Strike-slip faults are widely distributed around the world and are closely related to oil and gas exploration. Strike-slip faults determine the hydrocarbon generation capacity of source rocks, provide oil and gas migration channels, and improve the storage performance of reservoirs. Therefore, in-depth identification and research of strike-slip faults are of great significance to oil and gas exploration. With the continuous deepening of seismic exploration, it is found that there are a large number of strike-slip faults on seismic profiles that are not obvious with traditional strike-slip fault identification signs, that is, hidden strike-slip faults. However, these hidden strike-slip faults are difficult to accurately identify and characterize with existing technical means due to their small fault distance and nearly vertical. Summary of the invention

[0003] In view of the above problems, an object of the present invention is to provide a method and related device for identifying hidden strike-slip faults.

[0004] In a first aspect, an embodiment of the present invention provides a method for identifying a hidden strike-slip fault, comprising the following steps:

[0005] According to the distribution characteristics of strike-slip faults with nearly equal spacing, the stratigraphic characteristics of the area where hidden strike-slip faults may occur are judged, and the hidden strike-slip fault development area is qualitatively identified;

[0006] On the basis of the qualitative identification of the hidden strike-slip fault development zone, the strike-slip amount of the hidden strike-slip fault in the formation where the hidden strike-slip fault may occur in the development zone is calculated by the seismic reflection classification method, and according to the calculated strike-slip amount, it is determined whether the hidden strike-slip fault actually occurs in the formation where the hidden strike-slip fault may occur;

[0007] According to the calculated strike-slip amount, a comprehensive analysis is performed in combination with drilling information, seismic profiles and the optimal fault identification technology to depict the distribution of the actual hidden strike-slip faults on the map.

[0008] In one embodiment, the method of calculating the strike-slip amount of the hidden strike-slip fault of the formation where the hidden strike-slip fault may occur in the development area by the seismic reflection classification method, and determining whether the hidden strike-slip fault actually occurs in the formation where the hidden strike-slip fault may occur according to the calculated strike-slip amount, comprises:

[0009] Applying a method of splicing seismic sections on both sides of a vertical hidden strike-slip fault, and / or applying a method of comparing seismic sections on both sides of a parallel hidden strike-slip fault, to calculate the strike-slip amount of the hidden strike-slip fault in the stratum where the hidden strike-slip fault may occur;

[0010] When the calculated strike-slip amount is greater than zero, it is determined that a hidden strike-slip fault actually occurs.

[0011] In one embodiment, a method for splicing seismic profiles on both sides of a vertical hidden strike-slip fault is applied to calculate the strike-slip amount, including:

[0012] A seismic section perpendicular to the hidden strike-slip fault is randomly selected as the first seismic section;

[0013] A plurality of second seismic sections perpendicular to the hidden strike-slip fault are sequentially selected along the sliding direction of the hidden strike-slip fault;

[0014] Matching the left half of the first seismic profile located at the hidden strike-slip fault with the right half of the plurality of second seismic profiles respectively;

[0015] Determine a second seismic profile that meets the optimal matching relationship between the left half screenshot and the right half screenshot;

[0016] The sliding distance in the sliding direction between the first seismic profile and the second seismic profile that meets the optimal matching relationship is calculated to obtain the strike-slip amount.

[0017] In one embodiment, the method of calculating the strike-slip amount by comparing seismic profiles on both sides of a parallel hidden strike-slip fault includes:

[0018] Select two seismic sections parallel to the hidden strike-slip fault along both sides of the hidden strike-slip fault;

[0019] The two seismic sections are placed in parallel and aligned, and two abnormal geological bodies having the same geological morphological characteristics are searched on the two seismic sections respectively;

[0020] The distance between the two abnormal geological bodies along the hidden strike-slip fault is calculated to obtain the strike-slip amount.

[0021] In one embodiment, the step of searching for two abnormal geological bodies having the same geological morphological characteristics includes: obtaining a first abnormal geological body on any one of the two seismic profiles;

[0022] Obtaining a preliminarily identified abnormal geological body on the other of the two seismic profiles;

[0023] The initially identified abnormal geological body is moved leftward and / or rightward by a certain number of traces on the seismic profile to obtain at least one derived abnormal geological body of the initially identified abnormal geological body;

[0024] Calculate the waveform deviation value of each seismic trace in the first abnormal geological body, the initially identified abnormal geological body and the derived abnormal geological body according to the seismic waveform deviation formula;

[0025] According to the obtained waveform deviation value of each seismic trace in the first abnormal geological body, the initially identified abnormal geological body and the derived abnormal geological body, a second abnormal geological body having the waveform deviation value of each seismic trace of the first abnormal geological body that meets the best matching relationship is determined from the initially identified abnormal geological body and the derived abnormal geological body;

[0026] The first abnormal geological body and the second abnormal geological body are two abnormal geological bodies having the same geological morphological characteristics.

[0027] In one embodiment, the selecting two seismic sections parallel to the hidden strike-slip fault comprises:

[0028] Select two seismic profiles whose profile lengths are consistent with the corresponding line and track numbers and whose distances from the hidden strike-slip fault are within a preset range.

[0029] In one embodiment, the step of determining the stratigraphic characteristics of a region where a hidden strike-slip fault may occur and qualitatively identifying a region where a hidden strike-slip fault may develop includes:

[0030] According to the seismic profile, on both sides of the possible hidden fault, the hidden strike-slip fault development zone can be qualitatively identified according to whether the strata thickness on both sides of the hidden fault are consistent, whether the occurrence is coordinated, and whether the structure and tectonic style have changed.

[0031] In a second aspect, an embodiment of the present invention provides a device for identifying a hidden strike-slip fault, comprising:

[0032] The qualitative identification module is used to identify the stratigraphic characteristics of the area where hidden strike-slip faults may occur based on the distribution characteristics of strike-slip faults with nearly equal spacing, and qualitatively identify the development area of ​​hidden strike-slip faults;

[0033] A determination module is used to calculate the strike-slip amount of the hidden strike-slip fault in the formation where the hidden strike-slip fault may occur in the development zone based on the qualitative identification of the hidden strike-slip fault development zone by using a seismic reflection classification method, and determine whether the hidden strike-slip fault actually occurs in the formation where the hidden strike-slip fault may occur according to the calculated strike-slip amount;

[0034] The characterization module is used to perform a comprehensive analysis based on the calculated strike-slip amount, combined with drilling information, seismic profiles and the optimal fault identification technology, to characterize the distribution of the actual hidden strike-slip faults on the map.

[0035] In a third aspect, an embodiment of the present invention provides a computing device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the aforementioned method for identifying hidden strike-slip faults when executing the program.

[0036] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the aforementioned method for identifying hidden strike-slip faults is implemented.

[0037] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0038] The above-mentioned method and related device for identifying hidden strike-slip faults provided by the embodiment of the present invention first qualitatively determine whether hidden strike-slip faults are developed and the preliminary location where hidden strike-slip faults may occur; then calculate the slip amount of hidden strike-slip faults, quantitatively determine whether hidden strike-slip faults are developed; finally accurately depict the distribution of hidden strike-slip faults on the map. The whole process from qualitative identification, quantitative determination to accurate depiction is realized, and a new idea and method for step-by-step control and identification of hidden strike-slip faults are proposed. This method overcomes the defects that the identification marks of hidden strike-slip faults on seismic data are not obvious, and it is difficult for geophysical exploration technology to fully depict them. The method for identifying hidden strike-slip faults provided by the present invention can accurately identify and depict hidden strike-slip faults, improve the efficiency of finding sweet spot reservoirs, increase the production of single wells, save exploration and development investment, and has good application prospects.

[0039] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0041] Figure 1 is a flow chart of a method for identifying a hidden strike-slip fault in an embodiment of the present invention;

[0042] Figure 2 This is a schematic diagram of the Permian Maokou Formation fault in the study area in the embodiment of the present invention;

[0043] Figure 3 It is a schematic diagram of a method for splicing seismic profiles on both sides of a vertical hidden strike-slip fault in an embodiment of the present invention;

[0044] Figure 4 Schematic diagram of a method for comparing seismic profiles on both sides of a parallel hidden strike-slip fault in an embodiment of the present invention;

[0045] Figure 5a -d is a schematic diagram of searching for abnormal geological bodies with the same characteristics in an embodiment of the present invention;

[0046] Figure 6is the hidden strike-slip fault F in the embodiment of the present invention. Ⅱ 3 Actual distribution diagram on the plane;

[0047] Figure 7 This is a flowchart of the step-by-step identification technology of hidden strike-slip faults in an embodiment of the present invention;

[0048] Figure 8 Schematic diagram of the structure of a device for identifying hidden strike-slip faults in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] This embodiment provides a method for identifying a hidden strike-slip fault. Although the accompanying drawings show exemplary embodiments of the present disclosure, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. Specifically, the following steps are included:

[0050] The embodiment of the present invention provides a method for identifying a hidden strike-slip fault, referring to Figure 1 As shown, the method comprises the following steps:

[0051] S11. Based on the distribution characteristics of strike-slip faults with nearly equal spacing, the stratigraphic characteristics of the area where hidden strike-slip faults may occur are determined, and the hidden strike-slip fault development area is qualitatively identified;

[0052] S12. On the basis of qualitatively identifying the hidden strike-slip fault development zone, calculating the strike-slip amount of the hidden strike-slip fault in the stratum where the hidden strike-slip fault may occur in the development zone by using the seismic reflection classification method, and determining whether the hidden strike-slip fault actually occurs in the stratum where the hidden strike-slip fault may occur according to the calculated strike-slip amount;

[0053] S13. Based on the calculated strike-slip amount, a comprehensive analysis is performed in combination with seismic attributes, seismic profiles and drilling information to depict the distribution of actual hidden strike-slip faults on the map.

[0054] In step S11, on the fault outline map, based on the fact that the strike-slip faults have nearly equidistant development characteristics, the possible hidden strike-slip faults can be preliminarily determined from the missing strike-slip faults. Then, based on the seismic profile, on both sides of the judged hidden faults, the stratigraphic characteristics on both sides, such as whether the strata thickness on both sides where the hidden faults may occur are consistent, whether the occurrence is coordinated, and whether the structure and structural style have changed, are comprehensively compared, so as to qualitatively identify the hidden strike-slip fault development area. If the stratigraphic characteristics on both sides, such as the strata thickness on both sides, the occurrence coordination, or the structure and structural style, one or more of the above-mentioned stratigraphic characteristics have changed, such as inconsistent strata thickness on both sides, inconsistent occurrence, or changes in the structure and structural style, etc., then there is reason to qualitatively identify the area as a hidden strike-slip fault development area.

[0055] In step S12, the quantitative calculation of the strike-slip amount of the strike-slip fault can fundamentally determine whether a hidden strike-slip fault exists.

[0056] Specifically, the calculation of the strike-slip amount of a hidden strike-slip fault can be achieved, for example, by the following two methods: namely, applying a method of splicing seismic profiles on both sides of a vertical hidden strike-slip fault, and / or applying a method of comparing seismic profiles on both sides of a parallel hidden strike-slip fault. When the final calculated strike-slip amount is greater than zero, it is determined that a hidden strike-slip fault has actually occurred.

[0057] It should be noted that the above two methods can be used alone or in combination. When used in combination, the slip amounts of hidden strike-slip faults obtained by the two methods are respectively obtained, and then the arithmetic mean is calculated, etc., to obtain the average of each slip amount, etc., as the value of the actual slip amount.

[0058] In one embodiment, the method for splicing seismic profiles on both sides of a vertical hidden strike-slip fault can be implemented in the following manner:

[0059] 1.1. Randomly select a seismic section perpendicular to the hidden strike-slip fault as the first seismic section;

[0060] 1.2. Select multiple second seismic sections perpendicular to the hidden strike-slip fault in sequence along the sliding direction of the hidden strike-slip fault; match the left half of the first seismic section located at the hidden strike-slip fault with the right half of the second seismic section respectively;

[0061] 1.3, determining a second seismic section that has an optimal matching relationship between the left half screenshot of the first seismic section and all the right half screenshots of the second seismic sections;

[0062] 1.4. Calculate the sliding distance in the sliding direction between the first seismic profile and the second seismic profile that meets the optimal matching relationship to obtain the strike-slip amount.

[0063] Of course, it is easy for those skilled in the art to imagine that the right half of the first seismic profile can also be matched with the left half of the second seismic profile, that is:

[0064] 2.1. Randomly select a seismic section perpendicular to the hidden strike-slip fault as the first seismic section;

[0065] 2.2. Select multiple second seismic sections perpendicular to the hidden strike-slip fault in sequence along the sliding direction of the hidden strike-slip fault; match the right half of the first seismic section located at the hidden strike-slip fault with the left half of the second seismic section respectively;

[0066] 2.3, determining a second seismic section that has an optimal matching relationship between the right half screenshot of the first seismic section and all the left half screenshots of the second seismic sections;

[0067] Through the above step 2.2, the second seismic profile having the best matching relationship with the right half of the screenshot during the sliding process can be determined.

[0068] 2.4. Calculate the sliding distance in the sliding direction between the first seismic profile and the second seismic profile that meets the optimal matching relationship to obtain the strike-slip amount.

[0069] When applying the method of splicing seismic sections on both sides of a vertical hidden strike-slip fault, the following method can be used to determine the second seismic section that meets the optimal matching relationship:

[0070] For example, for the above steps 1.1 to 1.4, first, the number of peaks and troughs in the left half of the first seismic profile and the right half of the multiple second seismic profiles are calculated; secondly, the amplitude change rate of the left half of the first seismic profile and the right half of the multiple second seismic profiles near the hidden strike-slip fault is calculated; then, the waveform mean of the left half of the first seismic profile and the right half of the multiple second seismic profiles near the hidden strike-slip fault is calculated; finally, the above calculated waveforms of the multiple second seismic profiles are added to the right half of the multiple second seismic profiles. The number of peaks and troughs, amplitude change rate and waveform mean of the right half screenshot are compared with the number of peaks and troughs, amplitude change rate and waveform mean of the left half screenshot of the first seismic profile. Among the multiple right half screenshots of the second seismic profiles, the second seismic profile whose three parameters of number of peaks and troughs, amplitude change rate and waveform mean are closest to the three parameters of number of peaks and troughs, amplitude change rate and waveform mean of the left half screenshot of the first seismic profile is determined as the second seismic profile that meets the optimal matching relationship.

[0071] For the waveform mean, the concept of the mean of the particle size analysis parameters in petrology is introduced, and the waveform mean is defined to quantitatively characterize the similarity of the seismic waveform shape.

[0072] For example, the mean value of earthquake waveform is calculated as follows:

[0073] SW avg =(T 16 +T 50 +T 84 ) / 3;

[0074] Among them, SW avg is the waveform mean, T 16 , T 50 , T 84 They are the time values ​​when the cumulative amplitude content in the seismic waveform reaches 16%, 50% and 84% of the total respectively.

[0075] Similarly, for the above steps 2.1 to 2.4, the same method as above can be used to determine the second seismic profile that meets the optimal matching relationship, which will not be repeated here.

[0076] In the embodiment of the present invention, only to distinguish an arbitrarily selected seismic section from a seismic section that matches the selected seismic section during sliding, the former is referred to as a first seismic section and the latter is referred to as a second seismic section.

[0077] In the above method, for example, a quick calculation can be performed in the seismic profile diagram by using the number of traces and the trace spacing between the first seismic profile and the second seismic profile that meets the optimal matching relationship, that is, the strike-slip amount is equal to the product of the number of traces and the trace spacing in the above method.

[0078] The embodiment of the present invention does not limit which method of splicing seismic profiles on both sides of the vertical hidden strike-slip fault is used.

[0079] In one embodiment, the following method can be used to compare seismic profiles on both sides of a parallel hidden strike-slip fault:

[0080] 3.1. Select two seismic sections parallel to the hidden strike-slip fault on both sides of the hidden strike-slip fault.

[0081] 3.2. Place the two seismic sections in parallel and search for two abnormal geological bodies with the same geological morphological characteristics on the two seismic sections;

[0082] 3.3. Calculate the distance between two abnormal geological bodies along the hidden strike-slip fault to obtain the strike-slip amount.

[0083] When applying this method, two seismic profiles parallel to the hidden strike-slip fault are selected, whose profile lengths are consistent with the corresponding line and track numbers, and whose distances to the hidden strike-slip fault are within a preset range (satisfying the requirement of being close to the hidden strike-slip fault).

[0084] The method for finding two abnormal geological bodies with the same geological morphological characteristics is:

[0085] Acquire the first abnormal geological body on any one of the two seismic sections;

[0086] Obtaining preliminary identification of abnormal geological bodies on the other of the two seismic sections;

[0087] The initially identified abnormal geological body is moved leftward and / or rightward by a certain number of traces on the seismic profile to obtain at least one derived abnormal geological body of the initially identified abnormal geological body;

[0088] According to the seismic waveform deviation formula, the waveform deviation value of each seismic trace in the first abnormal geological body, the initially identified abnormal geological body and the derived abnormal geological body is calculated;

[0089] According to the obtained waveform deviation value of each seismic trace in the first abnormal geological body, the initially identified abnormal geological body and the derived abnormal geological body, a second abnormal geological body having the waveform deviation value of each seismic trace of the first abnormal geological body that meets the best matching relationship is determined from the initially identified abnormal geological body and the derived abnormal geological body;

[0090] For example, the earthquake waveform deviation value is calculated using the following formula:

[0091]

[0092] Where, σ is the waveform deviation value, T 84 、T 16 、T 95 T and T5 are the time values ​​when the cumulative amplitude content in the seismic waveform reaches 84%, 16%, 95% and 5% of the total respectively. a and b are parameters determined by experience.

[0093] For example, similar to the aforementioned method of splicing seismic profiles on both sides of a vertical hidden strike-slip fault, in the above method, a rapid calculation can be performed in the seismic profile diagram by using the number of traces and the trace spacing between two abnormal geological bodies along the hidden strike-slip fault, that is, the strike-slip amount is equal to the product of the number of traces and the trace spacing in the above method.

[0094] When actually calculating the strike-slip amount, the two methods of vertical seismic profile splicing method on both sides of the hidden strike-slip fault and parallel seismic profile comparison method on both sides of the hidden strike-slip fault can also be used for calculation. For example, the final strike-slip amount of the strike-slip fault can be obtained by weighted averaging the two strike-slip amounts obtained by the above two methods, wherein the weight values ​​of the strike-slip amounts obtained by different methods are determined according to the errors of the two methods in actual working conditions or according to experience, so as to ensure the accuracy of the data of the final strike-slip amount. The embodiment of the present invention does not limit the method for determining the weight.

[0095] Furthermore, in the above step S13, the best fault identification technology is selected by combining the drilling information and the seismic profile, so as to depict the distribution of invisible strike-slip faults on the map, and to depict their distribution on the plane, and to further depict their three-dimensional distribution in space. The fault identification technology may include, for example, a fault enhancement technology based on coherent attributes, a fault identification technology based on spectral decomposition, and a high-resolution fault automatic identification technology, etc. The specific implementation method may refer to the prior art. The specific fault identification technology to be used shall be determined according to the actual situation, and the present invention does not limit this.

[0096] The embodiment of the present invention proposes a method for identifying hidden strike-slip faults, firstly qualitatively determining whether hidden strike-slip faults are developed and the preliminary location where hidden strike-slip faults may occur; then calculating the slip amount of hidden strike-slip faults to quantitatively determine whether hidden strike-slip faults occur; finally accurately determining the distribution of hidden strike-slip faults. The embodiment of the present invention makes full use of geological knowledge and combines seismic attributes to realize a new method for identifying hidden strike-slip faults from qualitative identification to quantitative calculation and then to accurate characterization.

[0097] The above method of identifying hidden strike-slip faults is illustrated by a specific example.

[0098] Taking the Permian Maokou Formation in a certain area of ​​a basin in the west as an example, we identify whether there are hidden strike-slip faults in the area step by step. The outline map of the faults in the study area is shown in Figure 2 shown.

[0099] The first step is to find the distribution characteristics of strike-slip faults, which are nearly equidistant. Figure 2 In the fault outline diagram shown in the figure, it is observed that on the strike-slip fault F Ⅰ 6 and F Ⅱ There is a gap between 11, so it is judged that the strike-slip fault F Ⅰ 6 and F Ⅱ There is a hidden strike-slip fault in the middle of 11, namely F Ⅱ 3 (indicated by the dotted line), where Figure 2 In addition to the possible hidden strike-slip fault F Ⅱ 3 is indicated by a dotted line, and the rest of the strike-slip faults are indicated by solid lines. Ⅱ 3, the formation thickness, formation occurrence, formation structure and structural style on both sides of the Ⅱ The stratigraphic characteristics on both sides of 3 have changed significantly, so the F Ⅰ 6 and F Ⅱ There is a hidden strike-slip fault development zone between 11.

[0100] The second step is to qualitatively identify the hidden strike-slip fault development zone and calculate the strike-slip amount of the hidden strike-slip fault in the formation where the hidden strike-slip fault may occur in the development zone by using the seismic reflection classification method. According to the calculated strike-slip amount, it is determined whether the formation where the hidden strike-slip fault may occur actually has the hidden strike-slip fault. The strike-slip amount of the hidden strike-slip fault is calculated by the following method:

[0101] Firstly, the seismic profile splicing method on both sides of the vertical invisible strike-slip fault is used for calculation. Figure 3 As shown, arbitrarily select a seismic profile perpendicular to the hidden strike-slip fault as the first seismic profile AA'; select multiple second seismic profiles perpendicular to the hidden strike-slip fault in sequence along the sliding direction of the hidden strike-slip fault; match the left half screenshot G of the first seismic profile AA' located at the hidden strike-slip fault with the right half screenshots of multiple second seismic profiles respectively; determine the right half screenshot G' that meets the best matching relationship between the left half screenshot G of the first seismic profile and the right half screenshots of multiple second seismic profiles, and the corresponding second seismic profile that meets the best matching relationship is BB'; calculate the sliding distance in the sliding direction between the first seismic profile AA' and the second seismic profile BB' that meets the best matching relationship, and the strike-slip amount is obtained.

[0102] First, the number of peaks and troughs in the left half screenshot G of the first seismic profile AA' and the right half screenshots G' of multiple second seismic profiles BB' are calculated; secondly, the amplitude change rate of the left half screenshot G of the first seismic profile AA' and the right half screenshots G' of multiple second seismic profiles BB' near the hidden strike-slip fault is calculated; then, the seismic waveform mean formula is used to calculate the waveform mean of the left half screenshot G of the first seismic profile AA' and the right half screenshots G' of multiple second seismic profiles BB' near the strike-slip fault; finally, the multiple second seismic profiles BB' calculated above are added to the waveform mean. The number of peaks and troughs, amplitude change rate and waveform mean of the right half screenshot G' are compared with the number of peaks and troughs, amplitude change rate and waveform mean of the left half screenshot G of the first seismic profile AA'. Among the multiple second seismic profiles BB' right half screenshots G', the second seismic profile BB' whose three parameters of the number of peaks and troughs, amplitude change rate and waveform mean are closest to the three parameters of the number of peaks and troughs, amplitude change rate and waveform mean of the left half screenshot G of the first seismic profile AA' is determined as the second seismic profile BB' that meets the optimal matching relationship. .

[0103] The inventors have found that, for example, the waveform mean can be used to characterize the search for the optimal matching relationship. The concept of the mean of the particle size analysis parameter in petrology is introduced, and the waveform mean is defined to quantitatively characterize the similarity of the seismic waveform shape.

[0104] For example, the mean value of earthquake waveform is calculated as follows:

[0105] SW avg =(T 16 +T 50 +T 84 ) / 3;

[0106] Among them, SW avg is the waveform mean, T 16 , T 50 , T 84 They are the time values ​​when the cumulative amplitude content in the seismic waveform reaches 16%, 50% and 84% of the total respectively.

[0107] For example, the number of traces between the first seismic profile AA' and the second seismic profile BB' is 9, and the distance between each trace is 12.5 m, so the calculated strike-slip amount is Z1 = 112.5 m.

[0108] In addition, the seismic profile comparison method on both sides of the parallel hidden strike-slip fault is also used to calculate the strike-slip amount. Figure 4 As shown in FIG. 1 , two seismic profiles parallel to the hidden strike-slip fault are selected along the two sides of the hidden strike-slip fault, namely, seismic profile AA' and seismic profile BB'; seismic profile AA' and seismic profile BB' are placed parallel to each other, and two abnormal geological bodies with the same geological morphological characteristics are found on seismic profile AA' and seismic profile BB', namely, abnormal geological body g and abnormal geological body g'; the distance between the two abnormal geological bodies along the hidden strike-slip fault (i.e., Figure 4 h) in the equation, the strike-slip amount is obtained.

[0109] First, the seismic waveform deviation formula is used to calculate the waveform deviation of each seismic trace in the first geological anomaly body g in the seismic profile AA'. The schematic diagram is shown in Figure 5a As shown; secondly, the preliminary identified geological anomaly body g' in the seismic profile BB' is identified by computer image recognition technology, and the waveform deviation of each seismic trace of the preliminary identified geological anomaly body g' is calculated, as shown in the schematic diagram Figure 5c Then, the initially identified geological anomaly body g′ is moved to the left and right by one track spacing to obtain two derived geological anomaly bodies, and the waveform deviation is calculated. The schematic diagrams are shown in Figure 5b and Figure 5d As shown in the figure; finally, the waveform deviation of each seismic trace in the first geological anomaly body, the preliminary identified geological anomaly body and the two derived geological anomaly bodies is calculated, and the waveform deviation values ​​of each seismic trace calculated from the above different geological anomaly bodies are compared. From the preliminary identified geological anomaly body and the two derived geological anomaly bodies, the second geological anomaly body closest to the waveform deviation value of each trace in the first geological anomaly body is found. The second geological anomaly body finally determined is Figure 5c The preliminary identified geological anomaly is shown.

[0110] The inventors have found that abnormal geological bodies with the same characteristics can be characterized by using characteristic parameters of seismic wave dynamics (including amplitude, frequency, phase, waveform, etc.). In actual work, the multiple solutions of using seismic waveform characteristic parameters to characterize are small. The deviation direction and degree of the extreme values ​​in the seismic waveforms of different seismic channels are different. The deviation of the particle size analysis parameter in petrology is introduced to quantitatively characterize these deviation phenomena of different degrees.

[0111] For example, the earthquake waveform deviation is calculated as follows:

[0112]

[0113] Where, σ is the waveform deviation value, T 84 , T 16 , T 95 T and T5 are the time values ​​when the cumulative amplitude content in the seismic waveform reaches 84%, 16%, 95% and 5% of the total respectively. a and b are parameters determined by experience.

[0114] In this example, based on experience, the value of a is 4 and the value of b is 6.6.

[0115] For example, the number of traces between the above-mentioned seismic profiles AA' and BB' is 10, and the distance between each trace is 12.5 m, so the calculated strike-slip amount is Z2 = 125 m.

[0116] It can be seen that the slip amounts calculated by the above two methods are both greater than zero, so it can be determined that F Ⅱ 3 is the actual hidden strike-slip fault.

[0117] Next, in order to obtain the final strike-slip amount, the strike-slip amounts obtained by the above two methods were weighted averaged, where the weight of the strike-slip amount calculated by the seismic profile splicing method on both sides of the vertical invisible strike-slip fault was 20%, and the weight of the strike-slip amount calculated by the seismic profile comparison method on both sides of the parallel invisible strike-slip fault was 80%. Ⅱ The slip amount of 3 is Z=122.5m. The weight of each slip amount is selected by experience according to the actual working conditions. The present invention does not limit which slip amount calculation method is used. If the weighted average is used to calculate the slip amount, the weight of each slip amount is also not limited.

[0118] The third step is to combine drilling information and seismic profiles to select the best fault identification technology and complete the identification of the hidden strike-slip fault F. Ⅱ 3 Accurate depiction on the graph. High-resolution fault automatic identification technology was selected from the fault identification technology to depict the hidden strike-slip fault F Ⅱ 3 The actual distribution on the plane, see Figure 6 As shown, the strike-slip fault FⅠ 6 and F Ⅱ The dotted line between 1 and 1 is the hidden strike-slip fault F Ⅱ 3. In addition, the sections of the hidden strike-slip fault in different directions in space can be depicted to obtain the three-dimensional distribution of the hidden strike-slip fault to be identified. The embodiment of the present invention does not limit which fault identification technology is preferred in this step.

[0119] In summary, the implementation process in the embodiment of the present invention can be summarized as follows: Figure 7 The flowchart of the step-by-step identification technology of hidden strike-slip faults is shown.

[0120] Based on the same inventive concept, an embodiment of the present invention also provides a device for identifying hidden strike-slip faults. Since the principle of the problem solved by the device is similar to the aforementioned method for identifying hidden strike-slip faults, the implementation of the device can refer to the implementation of the aforementioned method, and the repeated parts will not be repeated.

[0121] The embodiment of the present invention provides a device for identifying a hidden strike-slip fault, referring to Figure 8 As shown, including:

[0122] Qualitative identification module 81, used to identify the stratigraphic characteristics of the area where hidden strike-slip faults may occur based on the distribution characteristics of strike-slip faults with nearly equal spacing, and qualitatively identify the hidden strike-slip fault development area;

[0123] A determination module 82 is used to calculate the strike-slip amount of the hidden strike-slip fault in the formation where the hidden strike-slip fault may occur in the development zone based on the qualitative identification of the hidden strike-slip fault development zone by using a seismic reflection classification method, and determine whether the hidden strike-slip fault actually occurs in the formation where the hidden strike-slip fault may occur according to the calculated strike-slip amount;

[0124] The characterization module 83 is used to perform a comprehensive analysis based on the calculated strike-slip amount, combined with drilling information, seismic profiles and the optimal fault identification technology, to characterize the distribution of the actual hidden strike-slip faults on the map.

[0125] An embodiment of the present invention provides a computing device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the method for identifying hidden strike-slip faults as described above is implemented.

[0126] An embodiment of the present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the method for identifying hidden strike-slip faults as described above is implemented.

[0127] Obviously, those skilled in the art can make various changes to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these changes.

Claims

1. A method for identifying hidden strike-slip faults, characterized in that: include: According to the distribution characteristics of strike-slip faults with nearly equal spacing, the stratigraphic characteristics of the area where hidden strike-slip faults may occur are judged, and the hidden strike-slip fault development area is qualitatively identified; On the basis of the qualitative identification of the hidden strike-slip fault development zone, the strike-slip amount of the hidden strike-slip fault in the formation where the hidden strike-slip fault may occur in the development zone is calculated by the seismic reflection classification method, and according to the calculated strike-slip amount, it is determined whether the hidden strike-slip fault actually occurs in the formation where the hidden strike-slip fault may occur; According to the calculated strike-slip amount, a comprehensive analysis is performed in combination with drilling information, seismic profiles and the optimal fault identification technology to depict the distribution of the actual hidden strike-slip faults on the map.

2. The method according to claim 1, characterized in that The method of calculating the strike-slip amount of the hidden strike-slip fault in the formation where the hidden strike-slip fault may occur in the development area by the seismic reflection classification method, and determining whether the hidden strike-slip fault actually occurs in the formation where the hidden strike-slip fault may occur according to the calculated strike-slip amount, comprises: Applying a method of splicing seismic sections on both sides of a vertical hidden strike-slip fault, and / or applying a method of comparing seismic sections on both sides of a parallel hidden strike-slip fault, to calculate the strike-slip amount of the hidden strike-slip fault in the stratum where the hidden strike-slip fault may occur; When the calculated strike-slip amount is greater than zero, it is determined that a hidden strike-slip fault actually occurs.

3. The method according to claim 2, characterized in that The strike-slip amount is calculated by splicing seismic sections on both sides of the vertical hidden strike-slip fault, including: A seismic section perpendicular to the hidden strike-slip fault is randomly selected as the first seismic section; A plurality of second seismic sections perpendicular to the hidden strike-slip fault are sequentially selected along the sliding direction of the hidden strike-slip fault; Matching the left half screenshot of the first seismic profile located at the hidden strike-slip fault with the right half screenshots of the plurality of second seismic profiles respectively, and determining a second seismic profile that meets the best matching relationship between the left half screenshot and the right half screenshot; The sliding distance in the sliding direction between the first seismic profile and the second seismic profile that meets the optimal matching relationship is calculated to obtain the strike-slip amount.

4. The method according to claim 2, characterized in that The method of using the seismic profile comparison method on both sides of the parallel hidden strike-slip fault to calculate the strike-slip amount includes: Select two seismic sections parallel to the hidden strike-slip fault along both sides of the hidden strike-slip fault; The two seismic sections are placed in parallel and aligned, and two abnormal geological bodies having the same geological morphological characteristics are searched on the two seismic sections respectively; The distance between the two abnormal geological bodies along the hidden strike-slip fault is calculated to obtain the strike-slip amount.

5. The method according to claim 4, characterized in that The method of searching for two abnormal geological bodies having the same geological morphological characteristics includes: Acquire a first abnormal geological body on any one of the two seismic profiles; Obtaining a preliminarily identified abnormal geological body on the other of the two seismic profiles; The initially identified abnormal geological body is moved to the left and / or right by a certain number of traces on the seismic profile to obtain at least one derived abnormal geological body of the initially identified abnormal geological body; Calculate the waveform deviation value of each seismic trace in the first abnormal geological body, the initially identified abnormal geological body and the derived abnormal geological body according to the seismic waveform deviation formula; According to the obtained waveform deviation value of each seismic trace in the first abnormal geological body, the initially identified abnormal geological body and the derived abnormal geological body, a second abnormal geological body having the waveform deviation value of each seismic trace of the first abnormal geological body that meets the best matching relationship is determined from the initially identified abnormal geological body and the derived abnormal geological body; The first abnormal geological body and the second abnormal geological body are two abnormal geological bodies having the same geological morphological characteristics.

6. The method according to claim 4, characterized in that The selecting of two seismic profiles parallel to the hidden strike-slip fault comprises: Select two seismic profiles whose profile lengths are consistent with the corresponding line and track numbers and whose distances from the hidden strike-slip fault are within a preset range.

7. The method according to any one of claims 1 to 6, characterized in that: The stratigraphic characteristics of the area where hidden strike-slip faults may occur are identified qualitatively, including: According to the seismic profile, on both sides of the possible hidden fault, the hidden strike-slip fault development zone can be qualitatively identified according to whether the strata thickness on both sides of the hidden fault are consistent, whether the occurrence is coordinated, and whether the structure and tectonic style have changed.

8. A device for identifying hidden strike-slip faults, characterized in that: include: The qualitative identification module is used to identify the stratigraphic characteristics of the area where hidden strike-slip faults may occur based on the distribution characteristics of strike-slip faults with nearly equal spacing, and qualitatively identify the development area of ​​hidden strike-slip faults; A determination module is used to calculate the strike-slip amount of the hidden strike-slip fault in the formation where the hidden strike-slip fault may occur in the development zone based on the qualitative identification of the hidden strike-slip fault development zone by using a seismic reflection classification method, and determine whether the hidden strike-slip fault actually occurs in the formation where the hidden strike-slip fault may occur according to the calculated strike-slip amount; The characterization module is used to perform a comprehensive analysis based on the calculated strike-slip amount, combined with drilling information, seismic profiles and the optimal fault identification technology, to characterize the distribution of the actual hidden strike-slip faults on the map.

9. A computing device, characterized in that include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method for identifying hidden strike-slip faults as described in any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for identifying a hidden strike-slip fault according to any one of claims 1 to 7 is implemented.

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