Quantitative evaluation method for multi-element earthquake excitation receiving observation system

Abstract

The invention discloses a quantitative evaluation method for a multivariate earthquake excitation receiving observation system, which fully utilizes prior information for constraint, defines evaluation factors under different earthquake excitation parameters and receiving equipment combination styles in the same construction work area, and has the advantages of rigorous derivation, clear physical significance, simple and convenient calculation, reasonable conclusion and the like. The key quality parameters of the single shot are collected in different earthquake excitation parameters and receiving equipment combination styles to be used in earthquake collection data quality control, the evaluation mode of the earthquake collection observation system is changed, and the scientificity and accuracy of the evaluation of the earthquake collection observation system are improved.

Description

Technical Field

[0001] The present invention relates specifically to the technical field of seismic acquisition observation systems, and in particular to a quantitative evaluation method for a multi-element seismic excitation and reception observation system. Background Art

[0002] Seismic exploration technology has a wide range of applications, including but not limited to detecting underground structural characteristics, helping to discover and describe oil and gas resources, coal seams, aquifers, geothermal anomalies, etc.; in recent years, with the rapid development of urban industry and the continued large-scale promotion and application of seismic exploration work, seismic acquisition projects are facing increasingly complex surface conditions in construction; in order to improve the integrity of underground reflection information acquisition in complex surface areas, multi-type excitation source and receiving equipment combined mixed sampling technology has been widely used.

[0003] During the construction of seismic acquisition projects, in order to ensure the quality of collected data, construction personnel need to conduct a similarity comparison analysis and evaluation between the seismic acquisition observation system and the theoretically designed observation system, so as to check the rationality of the layout results of field excitation points and receiving points, discover construction quality problems, and take timely remedial measures; among them, the coverage number attribute of the surface element is a key indicator to measure whether the field observation system meets the design requirements; in the past, the evaluation of seismic acquisition observation systems with the surface element coverage number attribute as the core was to calculate the coverage number of a given surface element based on the relative spatial position relationship and combination relationship of all field-laid excitation points and receiving points, and compare and analyze the field layout calculation results with the theoretically designed observation system; this method ignores the differences in the quality of seismic acquisition records under different excitation parameters and receiving equipment conditions, resulting in insufficient accuracy of the evaluation results and certain limitations. Summary of the Invention

[0004] To this end, the present invention proposes a quantitative evaluation method for a multi-element seismic excitation and reception observation system to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a quantitative evaluation method for a multi-element seismic excitation and reception observation system, comprising the following steps:

[0006] Step 1: Acquire the seismic excitation parameters and receiving equipment combination patterns involved in previous seismic acquisitions in the construction area, and build a library of seismic excitation parameters and receiving equipment combination patterns for the construction area;

[0007] Step 2: Obtain single shot records collected under different combinations of excitation parameters and receiving equipment in the construction area, and establish a single shot attribute library X under different combinations of seismic excitation parameters and receiving equipment;

[0008] Step 3: Taking the combination of seismic excitation parameters and receiving equipment with the highest proportion as the benchmark, the evaluation factor P of different combinations of seismic excitation parameters and receiving equipment is calculated based on six attributes: full permutation energy, main frequency, difference between the maximum and minimum values ​​of the effective frequency band, effective frequency band energy, and effective frequency band signal-to-noise ratio, and an evaluation model is constructed.

[0009] Step 4: Collect and organize the coverage times Nr of all earthquake excitation parameters and receiving equipment combinations in the construction area on the independent observation system bins;

[0010] Step 5: Calculate the facet coverage times Nr attribute weighted by the evaluation factor;

[0011] Step 6: Compare the calculated result Nr in step 5 with the number of surface element coverage Nt of the theoretically designed observation system to quantitatively evaluate the field collection observation system.

[0012] Furthermore, preferably, in step 1, the library of combination patterns of seismic excitation parameters and receiving equipment should contain all combination patterns of seismic excitation parameters and receiving equipment in the construction area.

[0013] Furthermore, as a preference, in step 2, the single shot attribute library should contain all seismic excitation parameters and receiving equipment combination patterns of the construction area, and the collected single shot records should all be excellent shots, including a total of six attributes: full array energy, main frequency, difference between the maximum value and the minimum value of the effective frequency band, effective frequency band energy, and effective frequency band signal-to-noise ratio; the arithmetic mean of the attributes of all single shots under each combination pattern is calculated to establish the attribute library X, that is,

[0014] X = (X1, X2, ..., Xn), where n is the number of combinations of seismic excitation parameters and receiving equipment included in the construction area;

[0015] Xi = (Xi1, Xi2, Xi3, Xi4, Xi5, Xi6), i = 1, 2, ..., n, where Xi is the sample library of single-shot attributes collected for the i-th combination of excitation parameters and receiving equipment. Xi1, Xi2, Xi3, Xi4, Xi5, and Xi6 are the average full-range energy, main frequency, minimum value of the effective frequency band, maximum value of the effective frequency band, effective frequency band energy, and effective frequency band signal-to-noise ratio attributes of all collected single shots under the i-th combination of excitation parameters and receiving equipment.

[0016] (i=1, 2, ..., n; j=1, 2, ..., p); wherein Xiju is the jth attribute of the uth acquisition single shot of the i-th combination of excitation parameters and receiving equipment.

[0017] Furthermore, preferably, in step 3, the evaluation factor P for different combinations of seismic excitation parameters and receiving devices is obtained by the following steps:

[0018] Step 3.1: Set the combination of seismic excitation parameters and receiving equipment with the highest proportion as the evaluation benchmark pattern, and the evaluation factor is 1;

[0019] Step 3.2: Use the attribute values ​​in the single-shot attribute library of other combination styles to obtain the corresponding evaluation factor. The expression is as follows:

[0020] Wherein, i=1, 2,…, n.

[0021] Furthermore, preferably, in step 4, the coverage times on the independent observation system surface elements under all earthquake excitation parameters and receiving equipment combination patterns in the construction area are collected and sorted.

[0022] Furthermore, preferably, in step 5, the bin coverage times Nr weighted by the evaluation factor are calculated according to the following expression:

[0023] Nr is the sum of the bin coverage times obtained by weighting the evaluation factors under different combinations of seismic excitation parameters and receiving equipment actually collected in the field.

[0024] Furthermore, as a preference, in said step 6, the result Nr calculated in step 5 is compared with the number of facet coverages Nt of the theoretically designed observation system. In areas where Nr is lower than Nt, the field acquisition effect is lower than the design expectation, and it is necessary to optimize and adjust the layout of the field acquisition excitation points and receiving points, usually by increasing the number of excitation and receiving points to strengthen the field acquisition observation system and achieve the expected design effect; otherwise, no adjustment is required.

[0025] The present invention adopts the above technology and has the following beneficial effects compared with the existing technology: a quantitative evaluation method of a multivariate seismic excitation receiving observation system based on weighted single-shot evaluation factors of the present invention fully utilizes prior information for constraints, defines evaluation factors under different seismic excitation parameter and receiving equipment combination styles under the same construction area, has the advantages of rigorous derivation, clear physical meaning, simple calculation, and reasonable conclusions, and uses the key quality parameters of single shots collected under different seismic excitation parameter and receiving equipment combination styles in the quality control of seismic acquisition data, changes the evaluation method of the seismic acquisition observation system, and improves the scientificity and accuracy of the seismic acquisition observation system evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a technical flow chart of the present invention;

[0027] Figure 2 The combination pattern of seismic excitation parameters and receiving equipment involved in the seismic acquisition construction area in area A in the embodiment of the present invention;

[0028] Figure 3 This is an attribute sample library of single shot records collected under different combinations of earthquake excitation parameters and receiving equipment constructed in region A in the embodiment of the present invention;

[0029] Figure 4 Evaluation factors for different combinations of earthquake excitation parameters and receiving devices constructed in region A in an embodiment of the present invention;

[0030] Figure 5 Graphs of independently weighted back-element coverage parameters for two combinations of 2kg explosive charge well shot excitation and 5Hz natural frequency geophone single-point reception, and 2kg explosive charge well shot excitation and 5Hz underwater piezoelectric geophone single-point reception, calculated for region A in the embodiment of the present invention.

[0031] Figure 6 Graphs of independently weighted back-end coverage parameters for two combinations of 4kg explosive charge well gun excitation and 5Hz natural frequency geophone single-point reception, and 4kg explosive charge well gun excitation and 5Hz underwater piezoelectric geophone single-point reception, calculated for region A in the embodiment of the present invention.

[0032] Figure 7 Graphs of independently weighted back-end coverage parameters for two combinations of 6kg explosive charge well gun excitation and 5Hz natural frequency geophone single-point reception, and 6kg explosive charge well gun excitation and 5Hz underwater piezoelectric geophone single-point reception, calculated for region A in the embodiment of the present invention.

[0033] Figure 8 Graphs of independently weighted back-element coverage parameters for two combinations of 28t low-frequency vibroseis excitation and 5Hz natural frequency geophone single-point reception, and 28t low-frequency vibroseis excitation and 5Hz underwater piezoelectric geophone single-point reception, calculated for region A in an embodiment of the present invention.

[0034] Figure 9 Graphs of independently weighted back-element coverage parameters for the combination of airgun source excitation, 5 Hz natural frequency geophone single-point reception, and airgun source excitation, 5 Hz underwater piezoelectric geophone single-point reception, calculated for region A in an embodiment of the present invention;

[0035] Figure 10 This is a comparison diagram of the bin coverage times attribute calculated conventionally for newly acquired 3D seismic data in region A in an embodiment of the present invention and the bin coverage times attribute calculated using the method of the present invention;

[0036] Figure 11 This is an attribute difference diagram of the bin coverage times calculated by the method of the present invention and the bin coverage times calculated conventionally for newly acquired 3D seismic data in area A in an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] Example: Please see the attached Figures 1 to 11 The present invention provides a technical solution: a quantitative evaluation method for a multi-element seismic excitation and reception observation system, which comprises the following steps:

[0039] Step 1: Obtain the seismic excitation parameters and receiving equipment combination patterns involved in previous seismic acquisitions in the construction area, and build a library of seismic excitation parameters and receiving equipment combination patterns for the construction area;

[0040] Step 2: Obtain single shot records collected under different combinations of excitation parameters and receiving equipment within the construction area, and establish a single shot attribute library X under different combinations of seismic excitation parameters and receiving equipment;

[0041] For details, please refer to the attached Figure 3 , obtain single-shot records collected under different excitation parameter and receiving device combinations in the construction area, extract six attribute information of the single-shot records, including full-range energy, main frequency, minimum value of the effective frequency band, maximum value of the effective frequency band, energy of the effective frequency band, and signal-to-noise ratio of the effective frequency band, calculate the average value of the above six attribute information of the single-shot records collected under different excitation parameter and receiving device combinations, and establish a sample library of single-shot attributes collected under different seismic excitation parameter and receiving device combinations;

[0042] Step 3: Taking the combination of seismic excitation parameters and receiving equipment with the highest proportion as the benchmark, the evaluation factor P of different combinations of seismic excitation parameters and receiving equipment is calculated based on six attributes: full permutation energy, main frequency, difference between the maximum and minimum values ​​of the effective frequency band, effective frequency band energy, and effective frequency band signal-to-noise ratio, and an evaluation model is constructed.

[0043] For details, please refer to the attached Figure 4 , the evaluation factor of the combination of seismic excitation parameters and receiving equipment with the highest proportion in the construction area is set to 1. The evaluation factors of other combination patterns are the weighted sum of the full permutation energy, main frequency, difference between the maximum and minimum values ​​of the effective frequency band, effective frequency band energy, effective frequency band signal-to-noise ratio and the corresponding attribute ratio of the combination of seismic excitation parameters and receiving equipment with the highest proportion in the corresponding single shot attribute sample library. The weight coefficient of each attribute ratio is 0.2;

[0044] Step 4: Collect and organize the coverage times Nr of all earthquake excitation parameters and receiving equipment combinations in the construction area on the independent observation system bins;

[0045] For details, please refer to the attached Figures 5 to 9 , mainly with the help of 3D observation system design software, the number of bin coverages under different combinations of seismic excitation parameters and receiving equipment is calculated, and the number of bin coverages on independent observation systems under all combinations of seismic excitation parameters and receiving equipment in the construction area is collected and sorted out;

[0046] Step 5: Calculate the facet coverage times Nr attribute weighted by the evaluation factor;

[0047] For details, please refer to the attached Figure 10 , multiply the evaluation factor constructed in step 3 by the independent observation system bin coverage number of different seismic excitation parameter and receiving device combination patterns obtained in step 4 to obtain the independent weighted bin coverage parameter under different seismic excitation parameter and receiving device combination patterns; then numerically sum the weighted coverage numbers to obtain the bin coverage number attribute that can be used for quantitative evaluation of the multi-element excitation and reception observation system; the higher the value, the better the observation system under the multi-element excitation and reception mode; the lower the value, the worse the observation system under the multi-element excitation and reception mode;

[0048] Step 6: Compare the calculated result Nr in step 5 with the number of surface element coverage Nt of the theoretically designed observation system to quantitatively evaluate the field collection observation system.

[0049] In this embodiment, in step 1, the seismic excitation parameter and receiving device combination pattern library should include all seismic excitation parameter and receiving device combination patterns in the construction area.

[0050] In this embodiment, in step 2, the single shot attribute library should contain all the seismic excitation parameters and receiving equipment combination patterns of the construction area. The collected single shot records should all be good shots, including six attributes: full array energy, main frequency, difference between the maximum and minimum values ​​of the effective frequency band, effective frequency band energy, and effective frequency band signal-to-noise ratio. The arithmetic mean of the attributes of all single shots under each combination pattern is calculated to establish the attribute library X, that is,

[0051] X = (X1, X2, ..., Xn), where n is the number of combinations of seismic excitation parameters and receiving equipment included in the construction area;

[0052] Xi = (Xi1, Xi2, Xi3, Xi4, Xi5, Xi6), i = 1, 2, ..., n, where Xi is the sample library of single-shot attributes collected for the i-th combination of excitation parameters and receiving equipment. Xi1, Xi2, Xi3, Xi4, Xi5, and Xi6 are the average full-range energy, main frequency, minimum value of the effective frequency band, maximum value of the effective frequency band, effective frequency band energy, and effective frequency band signal-to-noise ratio attributes of all collected single shots under the i-th combination of excitation parameters and receiving equipment.

[0053] (i=1, 2, ..., n; j=1, 2, ..., p); wherein Xiju is the jth attribute of the uth acquisition single shot of the i-th combination of excitation parameters and receiving equipment.

[0054] In this embodiment, in step 3, the evaluation factor P for different combinations of seismic excitation parameters and receiving devices is obtained as follows:

[0055] Step 3.1: Set the combination of seismic excitation parameters and receiving equipment with the highest proportion as the evaluation benchmark pattern, and the evaluation factor is 1;

[0056] Step 3.2: Use the attribute values ​​in the single-shot attribute library of other combination styles to obtain the corresponding evaluation factor. The expression is as follows:

[0057] Wherein, i=1, 2,…, n.

[0058] In this embodiment, in step 5, the bin coverage times Nr weighted by the evaluation factor are calculated according to the following expression:

[0059] Nr is the sum of the bin coverage times obtained by weighting the evaluation factors under different combinations of seismic excitation parameters and receiving equipment actually collected in the field.

[0060] In this embodiment, in step 6, the result Nr calculated in step 5 is compared with the number of surface element coverages Nt of the theoretically designed observation system. In areas where Nr is lower than Nt, the field acquisition effect is lower than the design expectation, and it is necessary to optimize and adjust the layout of the field acquisition excitation points and receiving points. Usually, the number of excitation and receiving points is increased to strengthen the field acquisition observation system and achieve the expected design effect; otherwise, no adjustment is required.

[0061] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A quantitative evaluation method for a multi-element seismic excitation and reception observation system, characterized in that: It includes the following steps: Step 1: Acquire the seismic excitation parameters and receiving equipment combination patterns involved in previous seismic acquisitions in the construction area, and build a library of seismic excitation parameters and receiving equipment combination patterns for the construction area; Step 2: Obtain single shot records collected under different combinations of excitation parameters and receiving equipment in the construction area, and establish a single shot attribute library X under different combinations of seismic excitation parameters and receiving equipment; Step 3: Taking the combination of seismic excitation parameters and receiving equipment with the highest proportion as the benchmark, the evaluation factor P of different combinations of seismic excitation parameters and receiving equipment is calculated based on six attributes: full permutation energy, main frequency, difference between the maximum and minimum values ​​of the effective frequency band, effective frequency band energy, and effective frequency band signal-to-noise ratio, and an evaluation model is constructed. Step 4: Collect and organize the coverage times Nr of all earthquake excitation parameters and receiving equipment combinations in the construction area on the independent observation system bins; Step 5: Calculate the facet coverage times Nr attribute weighted by the evaluation factor; Step 6: Compare the calculated result Nr in step 5 with the number of surface element coverage Nt of the theoretically designed observation system to quantitatively evaluate the field collection observation system.

2. The quantitative evaluation method of a multi-element seismic excitation and reception observation system according to claim 1, characterized in that: In step 1, the seismic excitation parameter and receiving device combination pattern library should include all seismic excitation parameter and receiving device combination patterns in the construction area.

3. The quantitative evaluation method of a multi-element seismic excitation and reception observation system according to claim 1, characterized in that: In step 2, the single shot attribute library should contain all the seismic excitation parameters and receiving equipment combination patterns of the construction area. The collected single shot records should all be good shots, including six attributes: full array energy, main frequency, difference between the maximum and minimum values ​​of the effective frequency band, effective frequency band energy, and effective frequency band signal-to-noise ratio. The arithmetic mean of the attributes of all single shots under each combination pattern is calculated to establish the attribute library X, that is, X = (X1, X2, ..., Xn), where n is the number of combinations of seismic excitation parameters and receiving equipment included in the construction area; Xi = (Xi1, Xi2, Xi3, Xi4, Xi5, Xi6), i = 1, 2, ..., n, where Xi is the sample library of single-shot attributes collected for the i-th combination of excitation parameters and receiving equipment. Xi1, Xi2, Xi3, Xi4, Xi5, and Xi6 are the average full-range energy, main frequency, minimum value of the effective frequency band, maximum value of the effective frequency band, effective frequency band energy, and effective frequency band signal-to-noise ratio attributes of all collected single shots under the i-th combination of excitation parameters and receiving equipment. (i=1, 2, ..., n; j=1, 2, ..., p); wherein Xiju is the jth attribute of the uth acquisition single shot of the i-th combination of excitation parameters and receiving equipment.

4. The quantitative evaluation method of a multi-element seismic excitation and reception observation system according to claim 1, characterized in that: In step 3, the evaluation factor P for different combinations of seismic excitation parameters and receiving equipment is obtained as follows: Step 3.1: Set the combination of seismic excitation parameters and receiving equipment with the highest proportion as the evaluation benchmark pattern, and the evaluation factor is 1; Step 3.2: Use the attribute values ​​in the single-shot attribute library of other combination styles to obtain the corresponding evaluation factor. The expression is as follows: Wherein, i=1, 2,…, n.

5. The quantitative evaluation method of a multi-element seismic excitation and reception observation system according to claim 1, characterized in that: In step 4, the coverage times on the independent observation system bins under all earthquake excitation parameters and receiving equipment combination patterns in the construction area are collected and sorted.

6. The quantitative evaluation method of a multi-element seismic excitation and reception observation system according to claim 1, characterized in that: In step 5, the bin coverage times Nr weighted by the evaluation factor are calculated according to the following expression: Nr is the sum of the bin coverage times obtained by weighting the evaluation factors under different combinations of seismic excitation parameters and receiving equipment actually collected in the field.

7. The quantitative evaluation method of a multi-element seismic excitation and reception observation system according to claim 1, characterized in that: In step 6, the result Nr calculated in step 5 is compared with the number of surface element coverages Nt of the theoretically designed observation system. In areas where Nr is lower than Nt, the field acquisition effect is lower than the design expectation, and it is necessary to optimize and adjust the layout of the field acquisition excitation points and receiving points. Usually, the number of excitation and receiving points is increased to strengthen the field acquisition observation system and achieve the expected design effect; otherwise, no adjustment is required.

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