A method and related device for identifying hidden strike-slip faults

Abstract

The present invention discloses a method for identifying hidden strike-slip faults and related devices. The method includes: based on the distribution characteristics of strike-slip faults with nearly equal spacing, the formation characteristics of the area where hidden strike-slip faults may occur are judged, and the hidden strike-slip fault development area is qualitatively identified; by using the seismic reflection classification method, the strike-slip amount of the hidden strike-slip faults in the formation where hidden strike-slip faults may occur in the development area is calculated, and it is determined whether the formation where hidden strike-slip faults may occur actually has hidden strike-slip faults; a comprehensive analysis is performed in combination with drilling information, seismic profiles and the optimized fault identification technology to depict the distribution of the hidden strike-slip faults that actually occurred on the map. The method proposed by the present invention is a new idea for step-by-step control and identification of hidden strike-slip faults. It can accurately identify and depict hidden strike-slip faults, improve the efficiency of finding sweet spot reservoirs, increase the production of single wells, and save exploration and development investment.

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 worldwide and are closely related to oil and gas exploration. They determine the hydrocarbon generation capacity of source rocks, provide pathways for oil and gas migration, and improve reservoir performance. Therefore, in-depth identification and research of strike-slip faults are of great significance to oil and gas exploration. With the continuous advancement of seismic exploration, a large number of strike-slip faults, known as hidden strike-slip faults, have been discovered on seismic profiles that lack the obvious identification features of traditional strike-slip faults. However, due to their small throw and nearly vertical nature, these hidden strike-slip faults are difficult to accurately identify and characterize using existing technologies. Summary of the Invention

[0003] In view of the above problems, the 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] Based on the nearly equidistant distribution of strike-slip faults, the stratigraphic characteristics of potential hidden strike-slip fault areas are determined, and the hidden strike-slip fault development areas are qualitatively identified.

[0006] Based on the qualitative identification of 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 within the development zone by using a 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 based on the calculated strike-slip amount;

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

[0008] In one embodiment, 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 using a 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 based on the calculated strike-slip amount, includes:

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

[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 of splicing seismic sections on both sides of a vertical implicit strike-slip fault is applied to calculate the strike-slip amount, including:

[0012] An earthquake section perpendicular to the hidden strike-slip fault is arbitrarily selected as the first earthquake 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;

[0015] Determining a second seismic profile that satisfies an 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 calculation of the strike-slip amount by using a method of comparing seismic profiles on both sides of a parallel implicit 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] Aligning the two seismic sections in parallel, and searching for two abnormal geological bodies with the same geological morphological characteristics 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 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 sections;

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

[0023] Shifting the initially identified abnormal geological body 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;

[0024] Calculating 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] Based on the obtained waveform deviation values ​​of each seismic trace in the first abnormal geological body, the preliminarily identified abnormal geological body, and the derived abnormal geological body, a second abnormal geological body is determined from the preliminarily identified abnormal geological body and the derived abnormal geological body, the second abnormal geological body having the best matching relationship with the waveform deviation values ​​of each seismic trace of the first 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 determining of 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, the hidden strike-slip fault development zone is qualitatively identified on both sides of the hidden fault, depending on whether the strata 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 hidden strike-slip faults, comprising:

[0032] The qualitative identification module is used to determine the stratigraphic characteristics of potential hidden strike-slip fault areas based on the nearly equidistant distribution of strike-slip faults, and qualitatively identify hidden strike-slip fault development areas.

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

[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 optimized 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 storing a computer program, which implements the aforementioned method for identifying hidden strike-slip faults when executed by a processor.

[0037] The beneficial effects of the above technical solutions provided by the embodiments 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 have developed and the preliminary location of possible hidden strike-slip faults; then calculate the strike-slip amount of the hidden strike-slip faults to quantitatively determine whether hidden strike-slip faults have developed; and 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 that geophysical exploration technology is difficult 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 This is a flow chart of a method for identifying hidden strike-slip faults 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 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 implicit 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 for hidden strike-slip faults in an embodiment of the present invention;

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

[0049] This embodiment provides a method for identifying hidden strike-slip faults. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. Instead, 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 includes the following steps:

[0051] S11. Based on the nearly equidistant distribution of strike-slip faults, the stratigraphic characteristics of potential hidden strike-slip fault areas are determined, and the hidden strike-slip fault development areas are qualitatively identified.

[0052] S12. Based on the qualitative identification of the hidden strike-slip fault development zone, calculating the strike-slip amount of the hidden strike-slip fault in the formation where the hidden strike-slip fault may occur within the development zone by using a 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 based on 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, based on the fact that strike-slip faults have nearly equidistant development characteristics on the fault outline map, a preliminary judgment can be made on the possible existence of hidden strike-slip faults from the missing strike-slip faults. Then, based on the seismic profile, on both sides of the suspected hidden fault, a comprehensive comparison is made of the stratigraphic characteristics on both sides, such as whether the thickness of the strata on both sides of the suspected hidden fault is consistent, whether the occurrence is coordinated, and whether the structure and structural style have changed, so as to qualitatively identify the hidden strike-slip fault development zone. If one or more of the stratigraphic characteristics on both sides, such as the thickness of the strata on both sides, the occurrence coordination, or the structure and structural style, have changed, such as the inconsistent thickness of the strata on both sides, the inconsistency of the occurrence, or the change of the structure and structural style, then there is reason to qualitatively identify the area as a hidden strike-slip fault development zone.

[0055] In step S12, the quantitative calculation of the strike-slip amount of the strike-slip fault can fundamentally determine whether the 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: 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 selected separately or used in combination. When used in combination, the strike-slip amount of the hidden strike-slip fault obtained by the two methods is obtained respectively, and then the arithmetic mean is calculated, etc., to obtain the mean value of each strike-slip amount, etc., as the value of the actual strike-slip amount.

[0058] In one embodiment, the method for splicing seismic profiles on both sides of a vertical implicit 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 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. Determine a second seismic profile that has an optimal matching relationship between the left half of the first seismic profile and all the right half of the second seismic profiles;

[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 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. Determine a second seismic profile that has an optimal matching relationship between the right half of the first seismic profile and all the left half of the second seismic profiles;

[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 implicit 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, calculate the number of peaks and troughs in the left half of the first seismic section and the right half of the multiple second seismic sections; second, calculate the amplitude change rate of the left half of the first seismic section and the right half of the multiple second seismic sections near the implicit strike-slip fault; then, calculate the waveform mean of the left half of the first seismic section and the right half of the multiple second seismic sections near the implicit strike-slip fault; finally, calculate the amplitude change rate of the left half of the first seismic section and the right half of the multiple second seismic sections near the implicit strike-slip fault; 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 parameter 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 These 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 profile from a seismic profile that matches the selected seismic profile during sliding, the former is referred to as a first seismic profile and the latter is referred to as a second seismic profile.

[0077] In the above method, for example, a quick calculation can be performed in the seismic profile diagram 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 of the above-mentioned methods for splicing seismic profiles on both sides of a 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 implicit strike-slip fault:

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

[0081] 3.2. Align 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. The strike-slip amount can be obtained by calculating the distance between two abnormal geological bodies along the implicit strike-slip fault.

[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 (meeting 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] Acquiring a first abnormal geological body on any one of the two seismic sections;

[0086] Obtaining a preliminary identification of anomaly 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] Calculate the waveform deviation value of each seismic trace in the first abnormal geological body, the preliminarily identified abnormal geological body, and the derived abnormal geological body according to the seismic waveform deviation formula;

[0089] Based on the obtained waveform deviation values ​​of each seismic trace in the first abnormal geological body, the preliminarily identified abnormal geological body, and the derived abnormal geological body, a second abnormal geological body is determined from the preliminarily identified abnormal geological body and the derived abnormal geological body, the second abnormal geological body having the best matching relationship with the waveform deviation values ​​of each seismic trace of the first 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 and are determined by experience.

[0093] For example, similar to the aforementioned method of splicing seismic profiles on both sides of a vertical implicit strike-slip fault, in the above method, a rapid calculation can be performed in the seismic profile using the number of traces and the trace spacing between two abnormal geological bodies along the implicit 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 calculating the strike-slip amount, a combination of two methods, namely, splicing seismic profiles perpendicular to and comparing seismic profiles parallel to the underlying strike-slip fault, can be used. For example, the final strike-slip amount for the strike-slip fault can be obtained by taking a weighted average of the two strike-slip amounts obtained by the two aforementioned methods. The weights of the strike-slip amounts obtained by the different methods are determined based on the error between the two methods in actual working conditions or based on experience to ensure the accuracy of the final strike-slip data. The present invention does not limit the method for determining the weights.

[0095] Furthermore, in step S13, the optimal fault identification technology is selected by combining drilling information and seismic profiles. This allows the distribution of invisible strike-slip faults to be depicted on the map, either in a plane or in three dimensions. Examples of such techniques include coherent attribute-based fracture enhancement, spectral decomposition-based fracture identification, and high-resolution automatic fracture identification. Specific implementation methods can refer to existing technologies. The specific fracture identification technology to be used depends on the actual situation and is not limited in this invention.

[0096] This embodiment of the present invention proposes a method for identifying hidden strike-slip faults. The method first qualitatively determines the presence of hidden strike-slip faults and their potential locations. It then calculates the slip magnitude of the hidden strike-slip faults to quantitatively determine their presence. Finally, it accurately determines the distribution of hidden strike-slip faults. This embodiment leverages geological knowledge and incorporates seismic attributes to achieve a novel method for identifying hidden strike-slip faults, encompassing a comprehensive process from qualitative identification to quantitative calculation and 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 western basin as an example, we identify whether there are hidden strike-slip faults in the area step by step. The fault outline map of 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 equally spaced. Figure 2 In the fault outline diagram shown, it is observed that 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, which is F shown in the figure. Ⅱ 3 (shown 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 thickness, occurrence, structure and structural style of the strata on both sides of the F 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 stratum where hidden strike-slip faults may occur within the development zone using the seismic reflection classification method. Based on the calculated strike-slip amount, it is determined whether the stratum where hidden strike-slip faults may occur actually has a hidden strike-slip fault. The strike-slip amount of the hidden strike-slip fault is calculated using the following method:

[0101] First, the seismic profile splicing method on both sides of the vertical invisible strike-slip fault is used for calculation. Figure 3 As shown, an earthquake profile perpendicular to the hidden strike-slip fault is arbitrarily selected as the first earthquake profile AA'; a plurality of second earthquake profiles perpendicular to the hidden strike-slip fault are sequentially selected along the sliding direction of the hidden strike-slip fault; the left half screenshot G of the first earthquake profile AA' located at the hidden strike-slip fault is matched with the right half screenshots of the plurality of second earthquake profiles respectively; the right half screenshot G' that meets the optimal matching relationship between the left half screenshot G of the first earthquake profile and the right half screenshots of the plurality of second earthquake profiles is determined, and the corresponding second earthquake profile that meets the optimal matching relationship is BB'; the sliding distance in the sliding direction between the first earthquake profile AA' and the second earthquake profile BB' that meets the optimal matching relationship is calculated to obtain the strike-slip amount.

[0102] First, the number of peaks and troughs in the left half of the first seismic profile AA' and the right half of the second seismic profiles BB' is calculated; secondly, the amplitude change rate of the left half of the first seismic profile AA' and the right half of the second seismic profiles BB' near the implicit strike-slip fault is calculated; then, the waveform mean of the left half of the first seismic profile AA' and the right half of the second seismic profiles BB' near the strike-slip fault is calculated using the seismic waveform mean formula; finally, the waveform mean of the second seismic profiles BB' calculated above is calculated. The peak and trough counts, amplitude change rate, and waveform mean of the right half screenshot G' are compared with those of the left half screenshot G of the first seismic profile AA'. Among the multiple second seismic profiles BB' (right half screenshot G'), the second seismic profile BB' that most closely matches the three parameters of peak and trough counts, amplitude change rate, and waveform mean of the left half screenshot G of the first seismic profile AA' is determined to be the second seismic profile BB' that meets the optimal matching relationship.

[0103] The inventors have discovered that, for example, the waveform mean can be used to characterize the optimal matching relationship. The concept of the mean of grain size analysis parameters in petrology is introduced, and the waveform mean is defined to quantitatively characterize the similarity of seismic waveform shapes.

[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 These 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 method of comparing seismic sections on both sides of the parallel implicit strike-slip fault is also used to calculate the strike-slip amount. Figure 4 As shown in FIG, two seismic sections parallel to the implicit strike-slip fault are selected along both sides of the implicit strike-slip fault, namely, seismic section AA' and seismic section BB'; seismic section AA' and seismic section BB' are aligned in parallel, and two abnormal geological bodies with the same geological morphological characteristics are found on seismic section AA' and seismic section BB', namely, abnormal geological body g and abnormal geological body g'; the distance between the two abnormal geological bodies along the implicit strike-slip fault (i.e., Figure 4 The strike-slip amount is obtained by adding h) in .

[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 as follows: Figure 5a As shown; secondly, the preliminary identified geological anomaly 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 g' is calculated, as shown in the schematic diagram Figure 5c Then, the initial identified geological anomaly body g′ is moved to the left and right by one trace spacing to obtain two derived geological anomaly bodies, and the waveform deviation is calculated. The schematic diagrams are shown as follows: Figure 5b and Figure 5d As shown in the figure; finally, the waveform deviation of each seismic trace in the above-mentioned 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 for the above-mentioned 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 with the closest waveform deviation value to 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 discovered that seismic wave dynamics parameters (including amplitude, frequency, phase, waveform, etc.) can be used to characterize anomalous geological bodies with the same characteristics. In practice, characterization using seismic waveform characteristic parameters has low ambiguity. The direction and degree of deviation of extreme values ​​in seismic waveforms from different seismic traces vary. Grain size analysis parameter deviations, a technique used in petrology, were introduced to quantitatively characterize these varying degrees of deviation.

[0111] For example, 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 and are 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 are weighted averaged, where the strike-slip amount calculated by the method of splicing seismic sections on both sides of the vertical invisible strike-slip fault is weighted as 20%, and the strike-slip amount calculated by the method of comparing seismic sections on both sides of the parallel invisible strike-slip fault is weighted as 80%. Therefore, the final F Ⅱ The slip amount of 3 is Z = 122.5m. The weights of the slip amounts are selected based on experience according to the actual working conditions. The present invention does not limit the method used to calculate the slip amount. If the weighted average is used to calculate the slip amount, the weights of the slip amounts are 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 cross-sections of the hidden strike-slip fault in different directions in space can be characterized to obtain the three-dimensional distribution of the hidden strike-slip fault to be identified. The embodiment of the present invention does not limit the preferred fault identification technology 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 hidden strike-slip fault identification technology is shown in the figure.

[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 that of 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 hidden strike-slip faults, referring to Figure 8 As shown, including:

[0122] Qualitative identification module 81 is used to determine the stratigraphic characteristics of the area where hidden strike-slip faults may occur based on the nearly equidistant distribution characteristics of strike-slip faults, and qualitatively identify the area where hidden strike-slip faults are developed;

[0123] A determination module 82 is configured to calculate, based on the qualitative identification of the hidden strike-slip fault development zone, the strike-slip amount of the hidden strike-slip fault in the stratum where the hidden strike-slip fault may occur within the development zone by using a seismic reflection classification method, and determine whether the hidden strike-slip fault actually occurs in the stratum where the hidden strike-slip fault may occur based on 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 optimized 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, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the aforementioned method for identifying hidden strike-slip faults is implemented.

[0126] An embodiment of the present invention provides a computer-readable storage medium storing 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 and their equivalents, the present invention is intended to include these modifications.

Claims

1. A method for identifying hidden strike-slip faults, characterized in that: include: Based on the nearly equidistant distribution of strike-slip faults, the stratigraphic characteristics of potential hidden strike-slip fault areas are determined, and the hidden strike-slip fault development areas are qualitatively identified. Based on the qualitative identification of the hidden strike-slip fault development zone, a seismic profile comparison method is applied on both sides of the 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 the hidden strike-slip fault has actually occurred; The method of using a parallel seismic profile comparison method on both sides of a 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 includes: selecting two seismic profiles parallel to the hidden strike-slip fault along both sides of the hidden strike-slip fault; aligning the two seismic profiles in parallel, and searching for two abnormal geological bodies with the same geological morphological characteristics on the two seismic profiles; and calculating the distance between the two abnormal geological bodies along the hidden strike-slip fault to obtain the strike-slip amount. The method 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; obtaining a preliminarily identified abnormal geological body on the other of the two seismic profiles; shifting the preliminarily identified abnormal geological body 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 preliminarily identified abnormal geological body; calculating the waveform deviation value of each seismic trace in the first abnormal geological body, the preliminarily identified abnormal geological body, and the derived abnormal geological body according to a seismic waveform deviation formula; and determining, from the preliminarily 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 best matches the waveform deviation value of each seismic trace of the first abnormal geological body, based on the obtained waveform deviation value of each seismic trace in the first abnormal geological body, the preliminarily identified abnormal geological body, and the derived abnormal geological body; the first abnormal geological body and the second abnormal geological body being the two abnormal geological bodies having the same geological morphological characteristics; Based on the calculated strike-slip amount, a comprehensive analysis is performed in combination with drilling information, seismic profiles and the optimized fault identification technology to depict the distribution of the actual hidden strike-slip faults on the map.

2. The method according to claim 1, wherein The strike-slip amount is calculated by splicing seismic sections on both sides of a vertical implicit strike-slip fault, including: An earthquake section perpendicular to the hidden strike-slip fault is arbitrarily selected as the first earthquake 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 of the first seismic profile located at the hidden strike-slip fault with the right half of the second seismic profiles, respectively, to determine a second seismic profile that has an optimal matching relationship between the left half and the right half; 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.

3. The method according to claim 1, wherein The two seismic profiles parallel to the hidden strike-slip fault are selected, including: 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.

4. The method according to any one of claims 1 to 3, wherein The stratigraphic characteristics of the areas where hidden strike-slip faults may occur are identified qualitatively, including: According to the seismic profile, the hidden strike-slip fault development zone is qualitatively identified on both sides of the hidden fault, depending on whether the strata on both sides of the hidden fault are consistent, whether the occurrence is coordinated, and whether the structure and tectonic style have changed.

5. A device for identifying hidden strike-slip faults, characterized in that: include: The qualitative identification module is used to determine the stratigraphic characteristics of potential hidden strike-slip fault areas based on the nearly equidistant distribution of strike-slip faults, and qualitatively identify hidden strike-slip fault development areas. A determination module is used to calculate the strike-slip amount of the hidden strike-slip fault in the stratum where the hidden strike-slip fault may occur by applying the seismic profile comparison method on both sides of the parallel hidden strike-slip fault on the basis of the qualitative identification of the hidden strike-slip fault development zone; when the calculated strike-slip amount is greater than zero, it is determined that the hidden strike-slip fault has actually occurred; the application of the seismic profile comparison method on both sides of the 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 comprises: selecting two seismic profiles parallel to the hidden strike-slip fault along both sides of the hidden strike-slip fault; aligning the two seismic profiles in parallel, and searching for two abnormal geological bodies with the same geological morphological characteristics on the two seismic profiles; calculating the distance between the two abnormal geological bodies along the hidden strike-slip fault to obtain the strike-slip amount; the searching for two abnormal geological bodies with the same geological morphological characteristics comprises: obtaining the two seismic profiles parallel to the hidden strike-slip fault; A first abnormal geological body on any one of the seismic profiles; obtaining a preliminarily identified abnormal geological body on the other of the two seismic profiles; shifting the preliminarily identified abnormal geological body 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 preliminarily identified abnormal geological body; calculating the waveform deviation value of each seismic trace in the first abnormal geological body, the preliminarily identified abnormal geological body, and the derived abnormal geological body according to a seismic waveform deviation formula; determining, from the preliminarily identified abnormal geological body and the derived abnormal geological body, a second abnormal geological body having an optimal matching relationship with the waveform deviation value of each seismic trace of the first abnormal geological body, based on the obtained waveform deviation value of each seismic trace in the first abnormal geological body, the preliminarily identified abnormal geological body, and the derived abnormal geological body; the first abnormal geological body and the second abnormal geological body being the two abnormal geological bodies having the same geological morphological characteristics; 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 optimized fault identification technology, to characterize the distribution of the actual hidden strike-slip faults on the map.

6. 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 a hidden strike-slip fault according to any one of claims 1 to 4 is implemented.

7. 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 4 is implemented.

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