A method, device and related application for converting wave static correction

Abstract

The application provides a conversion wave static correction method and device and related application, the conversion wave static correction method constructs the construction item of a longitudinal wave component and the construction item of a conversion wave component, eliminates the construction item of the longitudinal wave component to obtain a common receiver point stacking profile of the longitudinal wave component, eliminates the construction item of the conversion wave component to obtain a common receiver point stacking profile of the conversion wave component, converts the common receiver point stacking profile of the longitudinal wave component and the common receiver point stacking profile of the conversion wave component of the inclined stratum into the common receiver point stacking profile of the longitudinal wave component and the common receiver point stacking profile of the conversion wave component which are relatively flat, so as to reflect the real stratum structure underground, pick up accurate horizon information, improve the accuracy of static correction, obtain the static correction amount of the conversion wave receiving point by the method, and solve the conversion wave static correction problem in the area with an underground structure inclination, and remove the limitation on the application range of multi-wave and multi-component seismic exploration.

Description

Technical Field

[0001] This invention relates to the field of converted wave seismic data processing technology, and in particular to a converted wave static correction method, apparatus, and related applications. Background Technology

[0002] Conventional P-wave seismic exploration technology has reached its technical ceiling in terms of accuracy when exploring low-porosity, low-permeability, fractured, and unconventional oil and gas reservoirs. Therefore, multi-wave multi-component seismic exploration technology has emerged. This technology comprehensively utilizes multiple seismic wave fields, including P-waves, S-waves, and converted waves, for detailed exploration of oil and gas reservoirs. It has great potential in areas such as gas cloud imaging, fluid identification, fracture detection, and reducing exploration risks. The mainstream acquisition method for multi-wave multi-component seismic exploration involves exciting the P-wave from a source, and then receiving the P-wave and S-wave components separately using three-component geophones. The received P-wave component is the same as that obtained in conventional P-wave seismic exploration, while the received S-wave component is generated by the conversion of the P-wave excited by the source at the formation reflection interface; it is a converted wave. Figure 1 As shown, the downlink wave of the converted wave is a P-wave, while the uplink wave is a S-wave (P-SV) converted from the downlink P-wave, resulting in an asymmetrical propagation path. The common conversion point (CCP) is not located at the same position as the common center point (CMP) of the conventional P-wave. Furthermore, the location of the converted wave conversion point varies with offset distance and depth. These characteristics make static correction of the converted wave far more difficult than that of the P-wave. The static correction of the converted wave includes two parts: the P-wave static correction at the excitation point and the S-wave static correction at the receiver point. While the P-wave static correction at the excitation point can be obtained from the P-wave component data, obtaining the S-wave static correction at the receiver point is the most challenging aspect. Currently, the mainstream research approach is to comprehensively utilize P-wave and converted wave data, using model methods to jointly determine the S-wave static correction at the receiver point, such as the common receiver point superposition profile correlation method and the P-wave structural constraint method. Summary of the Invention

[0003] The inventors of this application have discovered that the existing converted wave static correction method can only be used in areas with gentle underground structures. However, in areas with inclined underground structures, the seismic reflections on the co-detector stacked profiles of the P-wave component and the converted wave component exhibit an imbricate pattern, which cannot reflect the true underground stratigraphic structure and cannot pick up accurate stratigraphic information on the P-wave and converted wave stacked profiles. This results in poor accuracy of static correction and severely restricts the application scope of multi-wave multi-component seismic exploration.

[0004] In view of the above problems, it is necessary to propose a converted wave static correction method to solve or partially solve the above problems. The technical solution proposed by this invention is as follows:

[0005] In a first aspect, the present invention proposes a converted wave static correction method, comprising:

[0006] Obtain the converted wave component and the P-wave component from the same seismic source;

[0007] Based on the P-wave component and its corresponding final P-wave component static correction, the common center point stacking profile of the P-wave component is determined, and on the common center point stacking profile of the P-wave component, the static correction corresponding to the smooth surface of the marker layer time that meets the preset conditions is determined, thus obtaining the construction item of the P-wave component.

[0008] Within the time range of the marker stratigraphic position that meets the preset conditions, several time ratio coefficients are obtained between the marker stratigraphic position time of the superimposed profile of the common center point of the P-wave component corresponding to the same stratum and the marker stratigraphic position time of the superimposed profile of the common conversion point of the converted wave component. Using the several time ratio coefficients and the construction term of the P-wave component, the construction term of the converted wave component is constructed.

[0009] Obtain the common receiver gather of the longitudinal wave component and the common receiver gather of the converted wave component at the same receiver point;

[0010] Based on the common center point gather of the P-wave component after dynamic correction and the construction term of the P-wave component, the common center point gather with the construction term removed is obtained. The common center point gather with the construction term removed and the common receiver gather of the P-wave component corresponding to the same marker layer time are superimposed to obtain the common receiver superimposed profile of the P-wave component.

[0011] Based on the common conversion point gather of the converted wave component after dynamic correction and the construction term of the converted wave component, the common conversion point gather with the construction term removed is obtained. The common conversion point gather with the construction term removed corresponding to the same marker layer time is superimposed with the common receiver gather of the converted wave component to obtain the common receiver superposition profile of the converted wave component.

[0012] Cross-correlation calculations are performed on the marker stratigraphic time of the common detector stacked profile of the converted wave component and the marker stratigraphic time of the common detector stacked profile of the longitudinal wave component to obtain the medium- and long-wavelength shear wave static correction amount at the converted wave receiving point.

[0013] The converted wave component is processed by a preset converted wave residual static correction iterative method to obtain the short-wavelength shear wave static correction amount at the converted wave receiving point.

[0014] The static correction amount of the medium- and long-wavelength shear wave, the static correction amount of the short-wavelength shear wave, and the construction term of the converted wave component are superimposed to obtain the static correction amount of the converted wave receiving point.

[0015] Furthermore, the construction of the converted wave component using the aforementioned time scaling factors and the construction terms of the longitudinal wave component includes:

[0016] The construction terms of the converted wave components are obtained by multiplying the aforementioned time scaling coefficients with the construction terms of the P-wave components corresponding to the time of the marker layer.

[0017] Furthermore, the step of obtaining several time ratio coefficients between the marker horizon time of the common midpoint stacked profile of the P-wave component corresponding to the same stratum and the marker horizon time of the common conversion point stacked profile of the converted wave component includes:

[0018] On the common conversion point superposition profile of the converted wave component after subtracting the excitation point static correction and the initial static correction of the receiver point of the converted wave component, the marker stratigraphic time corresponding to the structural term of the P-wave component is identified, and the ratio of the marker stratigraphic time of the common center point superposition profile of the P-wave component corresponding to the same stratum to the marker stratigraphic time of the common conversion point superposition profile of the converted wave component is determined, thereby obtaining several time scaling coefficients.

[0019] Furthermore, the excitation point static correction and the initial receiver static correction of the converted wave component are obtained by the following method:

[0020] Based on the obtained static excitation point correction of the longitudinal wave component, determine the static excitation point correction of the converted wave component.

[0021] The initial static correction value of the receiver point of the acquired longitudinal wave component is obtained by multiplying the longitudinal and transverse wave scaling factors.

[0022] Furthermore, the transverse and longitudinal wave proportionality coefficients are obtained through the following method:

[0023] The ratio of P-wave to S-wave velocity was scanned using the proportional coefficient scanning method to obtain several preliminary proportional coefficients.

[0024] Multiply the aforementioned preliminary proportional coefficients and the static correction amount of the receiving point of the longitudinal wave component by the receiving point to obtain the preliminary static correction amount of the receiving point of the converted wave component.

[0025] Subtract the preliminary static correction amount of the receiving point of each of the converted wave components from the converted wave components to obtain several converted wave components after preliminary static correction.

[0026] The seismic traces of the common conversion point assemblies corresponding to the aforementioned preliminary statically corrected converted wave components are superimposed to obtain several superimposed seismic traces.

[0027] The preliminary scaling factor corresponding to the seismic trace with the largest amplitude among the several superimposed seismic traces is taken as the shear and longitudinal wave scaling factor.

[0028] Furthermore, the final static correction value for the longitudinal wave component is obtained by the following method:

[0029] The first arrival information of the longitudinal wave component is picked up;

[0030] First-arrival tomographic static correction calculations are performed on the first-arrival information of the P-wave component to obtain the basic static correction amount of the P-wave component;

[0031] Based on a preset residual static correction method for reflected waves, the residual static correction amount of the longitudinal wave component is determined;

[0032] The final static correction of the P-wave component is obtained by adding the basic static correction of the P-wave component to the residual static correction of the P-wave component.

[0033] Furthermore, cross-correlation is performed on the marker stratigraphic time of the common detector stacked profile of the converted wave component and the marker stratigraphic time of the common detector stacked profile of the P-wave component to obtain the medium-to-long wavelength shear wave static correction at the converted wave receiving point, including:

[0034] Calculate the P-wave and S-wave velocity ratio parameters at the same marker layer time for the common detector stack profile of the P-wave component and the common detector stack profile of the converted wave component.

[0035] By using the P-wave / S-wave velocity ratio parameter and the co-detector point superposition profile of the P-wave component, the co-detector point superposition profile of the P-wave component in the converted wave time domain is obtained.

[0036] The cross-correlation time difference between the marker stratigraphic time of the common detector point superposition profile of the converted wave component and the marker stratigraphic time of the common detector point superposition profile of the longitudinal wave component in the converted wave time domain is determined to obtain the medium- and long-wavelength shear wave static correction amount at the converted wave receiving point.

[0037] Furthermore, the determination of the cross-correlation time difference between the marker stratigraphic time of the common receiver stacked profile of the converted wave component and the marker stratigraphic time of the common receiver stacked profile of the P-wave component in the converted wave time domain includes:

[0038] A cross-correlation function is established between the marker stratigraphic time of the common receiver point superposition profile of the converted wave component and the marker stratigraphic time of the common receiver point superposition profile of the P-wave component in the converted wave time domain. The time corresponding to the maximum value of the cross-correlation function is determined to obtain the cross-correlation time difference.

[0039] Secondly, this invention proposes the application of the static correction amount of the converted wave receiving point obtained by the converted wave static correction method described above in seismic exploration or oil and gas exploration.

[0040] Thirdly, this invention proposes a converted wave static correction device, comprising a data acquisition module, a P-wave component construction term module, a converted wave component construction term module, a P-wave component common receiver point superposition profile module, a converted wave component common receiver point superposition profile module, and a static correction amount determination module, wherein:

[0041] The data acquisition module is used to acquire the converted wave component and the P-wave component with the same source, and to acquire the common receiver point gather of the P-wave component and the common receiver point gather of the converted wave component at the same receiver point.

[0042] The P-wave component construction module is used to determine the common center point stacking profile of the P-wave components based on the P-wave components and their corresponding final P-wave component static corrections, and to determine the static corrections corresponding to the smooth surface of the marker layer time that meets the preset conditions on the common center point stacking profile of the P-wave components, thereby obtaining the construction items of the P-wave components.

[0043] The converted wave component construction term module is used to calculate a number of time ratio coefficients between the marker time of the common center point superimposed profile of the P-wave component corresponding to the same stratum and the marker time of the common conversion point superimposed profile of the converted wave component within the marker time range that meets the preset conditions, and to construct the construction term of the converted wave component using the number of time ratio coefficients and the construction term of the P-wave component.

[0044] The common detector point superposition profile module for P-wave components is used to obtain a common center point gather with the removal of the construction terms based on the common center point gather of the dynamically corrected P-wave components and the construction terms of the P-wave components, and to superimpose the common center point gather with the common receiver point gather of the P-wave components corresponding to the same marker layer time to obtain a common detector point superposition profile of the P-wave components.

[0045] The common detector point superposition profile module for converted wave components is used to obtain a common conversion point gather with the construction terms of the converted wave components after dynamic correction, and to superimpose the common conversion point gather with the common receiver point gather of the converted wave components corresponding to the same marker layer time with the common receiver point gather of the converted wave components to obtain a common detector point superposition profile of the converted wave components.

[0046] The static correction determination module is used to perform cross-correlation calculations based on the marker stratigraphic time of the co-detector superposition profile of the converted wave component and the marker stratigraphic time of the co-detector superposition profile of the P-wave component to obtain the medium- and long-wavelength S-wave static correction at the converted wave receiving point; to process the converted wave component using a preset converted wave residual static correction iteration method to obtain the short-wavelength S-wave static correction at the converted wave receiving point; and to superimpose the medium- and long-wavelength S-wave static correction, the short-wavelength S-wave static correction, and the construction terms of the converted wave component to obtain the static correction at the converted wave receiving point.

[0047] Based on the above technical solution, the beneficial effects of the present invention compared with the prior art are as follows:

[0048] This invention discloses a converted wave static correction method. By constructing construct terms for the P-wave component and the converted wave component, and based on the common conversion point gathers of the dynamically corrected converted wave component and the construct terms of the converted wave component, a common conversion point gather with eliminated construct terms is obtained. The common conversion point gathers with eliminated construct terms corresponding to each marker stratigraphic time are superimposed with the common receiver gathers to eliminate the construct terms of the P-wave component, resulting in a common receiver stack profile of the P-wave component. Similarly, based on the common conversion point gathers of the dynamically corrected converted wave component and the construct terms of the converted wave component, a common conversion point gather with eliminated construct terms is obtained. The common conversion point gathers with eliminated construct terms corresponding to each marker stratigraphic time are superimposed with the common receiver gathers to eliminate the construct terms of the converted wave component, resulting in a common receiver stack profile of the converted wave component. The method transforms the stacked profiles of the P-wave component and the converted wave component in inclined strata into stacked profiles of the P-wave component and the converted wave component in relatively flat structures. This allows for a more accurate reflection of the actual subsurface stratigraphic structure and the acquisition of accurate stratigraphic information from these stacked profiles, thus improving the accuracy of static correction. Furthermore, the obtained static correction values ​​for medium- and long-wavelength shear waves and short-wavelength shear waves are superimposed with the structural terms of the converted wave component to recover the structural terms and obtain the static correction value for the converted wave receiver point. This solves the problem of converted wave static correction in inclined subsurface structures and removes limitations on the application scope of multi-wave multi-component seismic exploration. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of multi-wave and multi-component seismic acquisition received by a three-component geophone excited by a P-wave source, as described in the background technology of this invention.

[0050] Figure 2 This is a schematic flowchart of the converted wave static correction method in an embodiment of the present invention;

[0051] Figure 3 In this embodiment of the invention, before eliminating the construction terms, a common detector point superposition profile of the converted wave components of the excitation point static correction and the receiver point initial static correction is applied.

[0052] Figure 4 In this embodiment of the invention, after eliminating the construction terms, the common detector point superposition profile of the converted wave components of the excitation point static correction and the receiver point initial static correction is applied.

[0053] Figure 5 In this embodiment of the invention, after eliminating the construction terms, the common detector point superposition profile of the converted wave component after applying the long-wavelength shear wave static correction is applied in the common detector point superposition domain.

[0054] Figure 6 This is a common conversion point superposition profile of the converted wave components of the excitation point static correction and the receiver point initial static correction in an embodiment of the present invention.

[0055] Figure 7 In this embodiment of the invention, after eliminating the construction terms, in Figure 6 Based on this, the common conversion point superposition profile of the converted wave components after applying the medium and long wavelength shear wave static correction at the converted wave receiving point is further applied.

[0056] Figure 8 In this embodiment of the invention, after eliminating the construction terms, in Figure 7 Based on this, the common conversion point superposition profile of the converted wave components after applying the short-wavelength shear wave static correction at the converted wave receiver is further obtained.

[0057] Figure 9 This is a common conversion point superposition profile of the converted wave components after applying the static correction amount of the converted wave receiving point in an embodiment of the present invention.

[0058] Figure 10 In this embodiment of the invention, the common conversion point superposition profile of the converted wave components after applying the static correction amount of the converted wave receiving point obtained based on the longitudinal wave construction constraint method is described. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0060] The meanings of the various terms in the embodiments of this invention are as follows:

[0061] In seismic data acquisition, if the subsurface interface is horizontal, the projection of the common reflection point onto the ground must be the center point of the receiver distance of the common reflection points in the shot collection; therefore, it is called the common center point. Traces from different shot collections that share the common center point are extracted to form a new set, called the common center point gather (also known as the CMP gather).

[0062] The gather of all seismic traces received by the same receiver point from different shot points is called the common receiver gather of that receiver point.

[0063] The gathers formed by all seismic traces obtained from different shot points and converted at the same conversion point are called common conversion point gathers (also known as CCP gathers).

[0064] Example 1

[0065] This embodiment proposes a converted wave static correction method, such as... Figure 2 As shown, it includes:

[0066] Step S11: Obtain the converted wave component and the P-wave component from the same seismic source.

[0067] Step S12: Based on the P-wave component and its corresponding final P-wave component static correction, determine the common center point superposition profile of the P-wave component, and on the common center point superposition profile of the P-wave component, determine the static correction corresponding to the smooth surface of the marker layer time that meets the preset conditions, and obtain the construction item of the P-wave component.

[0068] In this step, the preset condition is that continuous tracking of the middle and shallow layers is possible. The P-wave component applies a final static correction value, specifically by subtracting the final static correction value from the P-wave component. For example... Figure 3 On the common center point superposition profile after applying the final static correction of the P-wave component, a smooth surface of the marker layer time that can be continuously tracked in the shallow and middle layers is picked out, and the static correction corresponding to the smooth surface of the marker layer time is used as the construction term of the P-wave component.

[0069] Step S13: Within the time range of the marker stratigraphic position that meets the preset conditions, calculate a number of time ratio coefficients between the marker stratigraphic position time of the common midpoint superimposed profile of the P-wave component corresponding to the same stratum and the marker stratigraphic position time of the common conversion point superimposed profile of the converted wave component. Use the number of time ratio coefficients and the construction term of the P-wave component to construct the construction term of the converted wave component.

[0070] Specifically, the construction principle of the conversion wave component is based on the principle of stratigraphic identity, that is, the reflection time of the P-wave and the conversion wave corresponding to the same stratigraphic layer is different, but the stratigraphic layer reflected is unique. The different proportional coefficients of the times of the several same marker stratigraphic layers are multiplied by the construction term of the P-wave component corresponding to the time of the marker stratigraphic layer to obtain the construction term of the conversion wave component on the superimposed profile of the common conversion point of the conversion wave component.

[0071] Step S14: Obtain the common receiver gather of the longitudinal wave component and the common receiver gather of the converted wave component at the same receiver point.

[0072] Step S15: Based on the common center point gather of the dynamically corrected P-wave component and the construction term of the P-wave component, obtain the common center point gather with the construction term removed, and superimpose the common center point gather with the common receiver gather of the P-wave component corresponding to the same marker layer time to obtain the common receiver stack profile of the P-wave component.

[0073] In this step, based on the common center point gather of the dynamically corrected P-wave component and the construction term of the P-wave component, a common center point gather with construction term removed is obtained. Specifically, this includes: superimposing all seismic traces in the common center point gather of the dynamically corrected P-wave component with the construction term of the P-wave component to obtain a common center point gather with construction term removed.

[0074] Step S16: Based on the common conversion point gather of the dynamically corrected converted wave component and the construction term of the converted wave component, obtain the common conversion point gather with the construction term removed, and superimpose the common conversion point gather with the common receiver gather of the converted wave component corresponding to the same marker layer time to obtain the common receiver superimposed profile of the converted wave component.

[0075] In this step, based on the common conversion point gathers of the dynamically corrected converted wave components and the construction terms of the converted wave components, a common conversion point gather with construction terms removed is obtained. Specifically, this means: superimposing all seismic traces in the common conversion point gathers of the dynamically corrected converted wave components with the construction terms of the converted wave components to obtain common conversion point gathers with construction terms removed. Superimposing the common conversion point gathers with construction terms removed at the same marker horizon time with the common receiver gathers of the converted wave components yields, as shown below. Figure 4 The cross-sectional view of the common receiver points of the converted wave component is shown. Figure 4 The white lines in the diagram represent the interpretation of marker horizons on the common receiver stack profile of the converted wave components after eliminating structural terms, in comparison with... Figure 3 As shown, it can be seen that Figure 4 The common detector point superposition profile of the converted wave component in the model eliminates the converted wave construction term and the structure is relatively gentle.

[0076] Step S17: Perform cross-correlation calculation on the marker layer time of the common detector point superposition profile of the converted wave component and the marker layer time of the common detector point superposition profile of the longitudinal wave component to obtain the medium-long wavelength transverse wave static correction amount of the converted wave receiving point.

[0077] After applying the medium- and long-wavelength shear wave static correction, the effect of applying the medium- and long-wavelength shear wave static correction to the common detector point superposition profile of the converted wave component is as follows: Figure 5 As shown, comparison Figure 4 As shown, Figure 5 In the common-detector stacked profile of the converted wave component obtained after applying the medium-to-long wavelength shear wave static correction, the continuity of the reflection phase axis reflecting the subsurface strata is better and the structural morphology is clearer. The effect of applying the medium-to-long wavelength shear wave static correction to the common-conversion-point stacked profile of the converted wave component is as follows: Figure 7 As shown, comparison Figure 6 As shown, in the superposition profile of the common conversion point of the converted wave component obtained after applying the long-wavelength transverse wave static correction, the continuity of the reflection phase axis is better and clearer.

[0078] Step S18: Process the converted wave component using a preset converted wave residual static correction iterative method to obtain the short-wavelength transverse wave static correction amount at the converted wave receiving point.

[0079] exist Figure 7 Based on this, after superimposing it with the short-wavelength transverse wave static correction at the converted wave receiving point, we obtain the following: Figure 8 The superimposed cross-section of the converted wave common conversion point, showing the application of short-wavelength transverse wave static correction, reveals a shape that is relatively... Figure 7 It is clearer.

[0080] Step S19: Superimpose the static correction amount of the medium-long wavelength shear wave, the static correction amount of the short wavelength shear wave, and the construction term of the converted wave component to obtain the static correction amount of the converted wave receiving point.

[0081] like Figure 9 As shown, on the common conversion point superposition profile of the converted wave components after applying the static correction at the converted wave receiver point, it can be seen that this method can effectively solve the static correction problem of converted waves in both gently sloping structural regions and anticline structural regions on both flanks, resulting in a significant improvement in imaging quality; Figure 10 In the cross-section of the common conversion point of the converted wave components after applying the static correction amount of the converted wave receiver point obtained by the longitudinal wave structure constraint method, it can be seen that in the gently sculpted region, the conventional method can solve the static correction problem well, but in the anticline structure region, the imaging effect is very poor.

[0082] The converted wave static correction method disclosed in this invention constructs a construction term for the P-wave component and a construction term for the converted wave component. Based on the common conversion point gather of the dynamically corrected converted wave component and the construction term of the converted wave component, a common conversion point gather with construction term elimination is obtained. The common conversion point gather with construction term elimination corresponding to each marker stratigraphic time is superimposed with the common receiver gather to eliminate the construction term of the P-wave component, resulting in a common receiver stack profile of the P-wave component. Based on the common conversion point gather of the dynamically corrected converted wave component and the construction term of the converted wave component, a common conversion point gather with construction term elimination is obtained. The common conversion point gather with construction term elimination corresponding to each marker stratigraphic time is superimposed with the common receiver gather to eliminate the construction term of the converted wave component, resulting in a converted wave component static correction method. The co-detector stacking profile of the P-wave component transforms the co-detector stacking profiles of the P-wave component and the converted wave component in inclined strata into a co-detector stacking profile of the P-wave component and the converted wave component in relatively flat strata. This reflects the true subsurface stratigraphic structure and can pick up accurate stratigraphic information on the co-detector stacking profiles of the P-wave component and the converted wave component, thereby improving the accuracy of static correction. In addition, the obtained total shear wave static correction is superimposed with the tectonic term of the converted wave component to recover the tectonic term of the converted wave component, obtaining the static correction of the converted wave receiver point. This can solve the problem of converted wave static correction in inclined strata and remove the limitation on the application scope of multi-wave multi-component seismic exploration.

[0083] In one embodiment, step S12, the step of obtaining several time ratio coefficients between the marker stratigraphic time of the common midpoint superposition profile of the P-wave component corresponding to the same stratum and the marker stratigraphic time of the common conversion point superposition profile of the converted wave component, includes: identifying the marker stratigraphic time corresponding to the structural term of the P-wave component on the common conversion point superposition profile of the converted wave component after subtracting the excitation point static correction and the receiver initial static correction of the converted wave component; determining the ratio of the marker stratigraphic time of the common midpoint superposition profile of the P-wave component corresponding to the same stratum to the marker stratigraphic time of the common conversion point superposition profile of the converted wave component; and obtaining several time ratio coefficients.

[0084] Specifically, in such Figure 6 On the common conversion point superposition profile of the converted wave component after subtracting the excitation point static correction and the initial static correction of the receiver point, the marker stratigraphic time corresponding to the construction term of the P-wave component is identified, and the different scaling factors of the common center point superposition profile of the P-wave component and the common conversion point superposition profile of the converted wave component at several same marker stratigraphic times are calculated.

[0085] In a further embodiment, the excitation point static correction and the initial static correction of the receiving point of the converted wave component are obtained by the following method: obtaining the excitation point static correction and the receiving point static correction of the longitudinal wave component; the excitation point static correction of the converted wave component is equal to the excitation point static correction of the longitudinal wave component; and multiplying the receiving point static correction of the longitudinal wave component by the transverse and longitudinal wave scaling factors to obtain the initial static correction of the receiving point of the converted wave component.

[0086] In this embodiment, since the converted wave is excited by the P-wave source and received by the S-wave, the static correction at the excitation point of the converted wave component is the same as the static correction at the excitation point of the P-wave component, and the initial static correction at the receiving point of the converted wave component is the product of the static correction at the receiving point of the P-wave component and the P-wave / S-wave proportionality coefficient.

[0087] In a further embodiment, the shear-pionage ratio coefficients are obtained by the following method: scanning the P-wave and S-wave velocity ratios using a ratio coefficient scanning method to obtain several preliminary ratio coefficients; multiplying the several preliminary ratio coefficients by the receiver static correction of the P-wave component to obtain several preliminary receiver static corrections of the converted wave component; subtracting the several preliminary receiver static corrections of the converted wave component from each of the converted wave components to obtain several pre-statically corrected converted wave components; superimposing all seismic traces in the common conversion point trace set corresponding to the several pre-statically corrected converted wave components to obtain several superimposed seismic traces; and taking the preliminary ratio coefficient corresponding to the seismic trace with the largest amplitude among the several superimposed seismic traces as the shear-pionage ratio coefficients.

[0088] Specifically, taking the P-wave velocity ratio *r* for a specific marker horizon time as the center, scanning is performed at 5% intervals from 80% to 120% of *r* to obtain several preliminary scaling factors. The product of these preliminary scaling factors and the receiver static correction of the P-wave component is used as the preliminary receiver static correction of the converted wave component. Then, the preliminary receiver static correction of the converted wave component is subtracted from the converted wave component to obtain the preliminarily statically corrected converted wave component. All seismic traces in the common conversion point set of the preliminarily statically corrected converted wave component are stacked to obtain the stacked seismic trace S(t). Where: S(t) is the superimposed seismic trace, N is the total number of traces in the common conversion point gather, and X... i(t) represents the i-th seismic trace within the common conversion point gather, and t represents time. The initial scaling factor corresponding to the superimposed seismic trace S(t) with the largest amplitude is taken as the shear and p-wave scaling factor. The initial static correction of the receiver point of the converted wave component is the product of the static correction of the receiver point of the p-wave component and the shear and p-wave scaling factor. The scaling factor scanning method can effectively solve most of the medium and long wavelength static correction problems, improve the converted wave imaging quality, and lay the foundation for time picking of marker horizons on the common conversion point superimposed profile of the converted wave components.

[0089] In one specific embodiment, the final static correction amount of the P-wave component in step S11 is obtained by the following method: picking up the first arrival information of the P-wave component; performing first arrival tomographic static correction calculation on the first arrival information of the P-wave component to obtain the basic static correction amount of the P-wave component; determining the residual static correction amount of the P-wave component based on a preset residual static correction method for reflected waves; and adding the basic static correction amount of the P-wave component to the residual static correction amount of the P-wave component to obtain the final static correction amount of the P-wave component.

[0090] In one specific embodiment, the step of cross-correlation calculation of the marker stratigraphic time of the common detector point superposition profile of the converted wave component and the marker stratigraphic time of the common detector point superposition profile of the P-wave component to obtain the medium-to-long wavelength shear wave static correction at the converted wave receiving point includes:

[0091] Calculate the P-wave and S-wave velocity ratio parameters at the same marker layer time for the common detector stack profile of the P-wave component and the common detector stack profile of the converted wave component.

[0092] By using the P-wave / S-wave velocity ratio parameter and the co-detector point superposition profile of the P-wave component, the co-detector point superposition profile of the P-wave component in the converted wave time domain is obtained.

[0093] The cross-correlation time difference between the marker stratigraphic time of the common detector point superposition profile of the converted wave component and the marker stratigraphic time of the common detector point superposition profile of the longitudinal wave component in the converted wave time domain is determined to obtain the medium- and long-wavelength shear wave static correction amount at the converted wave receiving point.

[0094] In a further embodiment, determining the cross-correlation time difference between the marker stratigraphic time of the co-detector point superposition profile of the converted wave component and the marker stratigraphic time of the co-detector point superposition profile of the P-wave component in the converted wave time domain includes: establishing a cross-correlation function between the marker stratigraphic time of the co-detector point superposition profile of the converted wave component and the marker stratigraphic time of the co-detector point superposition profile of the P-wave component in the converted wave time domain, determining the time corresponding to the maximum value of the cross-correlation function, and obtaining the cross-correlation time difference.

[0095] Specifically, let the reflected signals of the common-detector point superposition profile of the converted wave component and the common-detector point superposition profile of the P-wave component in the converted wave time domain be represented by functions X(t) and Y(t), respectively, and their signal models are as follows:

[0096] X(t) = W(t) + N1(t) (1);

[0097] Y(t)=W(tD)+N2(t) (2);

[0098] In the formula, W(t) is the seismic reflection signal corresponding to the same underground reflection point, D represents the delay time, and N1(t) and N2(t) are independent Gaussian white noise with zero mean. Cross-correlation is performed on equations (1) and (2), and their cross-correlation function Rt XY (t) is:

[0099] R XY (t)=R WW (tD)+R WN2 (tD)+R SN1 (t)+R N1N2 (t) (3);

[0100] The signal W(t) and noise N1(t) and N2(t) satisfy the assumption of mutual uncorrelation. Therefore, the cross-correlation between the signal and random noise is approximately zero, i.e.:

[0101] R WN2 (tD)=0;R SN1 (t) = 0; R N1N2 (t) = 0;

[0102] Then equation (3) can be simplified to R XY (t)=R WW (tD)

[0103] Due to the autocorrelation property |R WW (tD)|≤R WW (0) It can be known that when tD=0, R XY (t) represents the maximum value. R XY The time by which the maximum value of (t) deviates from the central time line quantitatively reflects the time delay D between signals X(t) and Y(t). D can be displayed as a curve in the cross-correlation output window or output as text. By reading the time delay D, the cross-correlation time difference between the marker stratigraphic time on the common receiver stacked profile of the converted wave component and the marker stratigraphic time on the common receiver stacked profile of the P-wave component in the converted wave time domain can be obtained.

[0104] Example 2

[0105] This invention proposes the application of the static correction amount of the converted wave receiving point obtained by the converted wave static correction method described in Embodiment 1 in seismic exploration or oil and gas exploration.

[0106] In this embodiment of the invention, the static correction amount of the converted wave receiving point obtained by the converted wave static correction method described in Embodiment 1 is more accurate and reliable, and the static correction amount of the converted wave receiving point has a wider range of applications in seismic exploration or oil and gas exploration.

[0107] Example 3

[0108] This invention provides a converted wave static correction device, comprising a data acquisition module, a P-wave component construction term module, a converted wave component construction term module, a P-wave component common receiver point superposition profile module, a converted wave component common receiver point superposition profile module, and a static correction amount determination module, wherein:

[0109] The data acquisition module is used to acquire the converted wave component and the P-wave component with the same source, and to acquire the common receiver point gather of the P-wave component and the common receiver point gather of the converted wave component at the same receiver point.

[0110] The P-wave component construction module is used to determine the common center point stacking profile of the P-wave components based on the P-wave components and their corresponding final P-wave component static corrections, and to determine the static corrections corresponding to the smooth surface of the marker layer time that meets the preset conditions on the common center point stacking profile of the P-wave components, thereby obtaining the construction items of the P-wave components.

[0111] The converted wave component construction term module is used to calculate a number of time ratio coefficients between the marker time of the common center point superimposed profile of the P-wave component corresponding to the same stratum and the marker time of the common conversion point superimposed profile of the converted wave component within the marker time range that meets the preset conditions, and to construct the construction term of the converted wave component using the number of time ratio coefficients and the construction term of the P-wave component.

[0112] The common detector point superposition profile module for P-wave components is used to obtain a common center point gather with the removal of the construction terms based on the common center point gather of the dynamically corrected P-wave components and the construction terms of the P-wave components, and to superimpose the common center point gather with the common receiver point gather of the P-wave components corresponding to the same marker layer time to obtain a common detector point superposition profile of the P-wave components.

[0113] The common detector point superposition profile module for converted wave components is used to obtain a common conversion point gather with the construction terms of the converted wave components after dynamic correction, and to superimpose the common conversion point gather with the common receiver point gather of the converted wave components corresponding to the same marker layer time with the common receiver point gather of the converted wave components to obtain a common detector point superposition profile of the converted wave components.

[0114] The static correction determination module is used to perform cross-correlation calculations based on the marker stratigraphic time of the co-detector superposition profile of the converted wave component and the marker stratigraphic time of the co-detector superposition profile of the P-wave component to obtain the medium- and long-wavelength S-wave static correction at the converted wave receiving point; to process the converted wave component using a preset converted wave residual static correction iteration method to obtain the short-wavelength S-wave static correction at the converted wave receiving point; and to superimpose the medium- and long-wavelength S-wave static correction, the short-wavelength S-wave static correction, and the construction terms of the converted wave component to obtain the static correction at the converted wave receiving point.

[0115] The converted wave static correction device proposed in this invention constructs a construction term for the P-wave component and a construction term for the converted wave component. Based on the common conversion point gather of the dynamically corrected converted wave component and the construction term of the converted wave component, a common conversion point gather with eliminated construction terms is obtained. The common conversion point gather with eliminated construction terms corresponding to each marker layer time is superimposed with the common receiver gather to eliminate the construction term of the P-wave component, resulting in a common receiver stack profile of the P-wave component. Similarly, based on the common conversion point gather of the dynamically corrected converted wave component and the construction term of the converted wave component, a common conversion point gather with eliminated construction terms is obtained. The common conversion point gather with eliminated construction terms corresponding to each marker layer time is superimposed with the common receiver gather to eliminate the construction term of the converted wave component, resulting in a converted wave static correction device. The co-detector stacking profile of the P-wave component transforms the co-detector stacking profiles of the P-wave component and the converted wave component in inclined strata into a co-detector stacking profile of the P-wave component and the converted wave component in relatively flat strata. This reflects the true subsurface stratigraphic structure and can pick up accurate stratigraphic information on the co-detector stacking profiles of the P-wave component and the converted wave component, thereby improving the accuracy of static correction. In addition, the obtained total shear wave static correction is superimposed with the tectonic term of the converted wave component to recover the tectonic term of the converted wave component, obtaining the static correction of the converted wave receiver point. This can solve the problem of converted wave static correction in inclined strata and remove the limitation on the application scope of multi-wave multi-component seismic exploration.

[0116] In the detailed description above, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features in a single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, with each claim representing a separate preferred embodiment of the invention.

[0117] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

Claims

1. A converted wave static correction method, characterized in that, include: Obtain the converted wave component and the P-wave component from the same seismic source; Based on the P-wave component and its corresponding final P-wave component static correction, the common center point stacking profile of the P-wave component is determined, and on the common center point stacking profile of the P-wave component, the static correction corresponding to the smooth surface of the marker layer time that meets the preset conditions is determined, thus obtaining the construction item of the P-wave component. Within the time range of the marker stratigraphic position that meets the preset conditions, several time ratio coefficients are obtained between the marker stratigraphic position time of the superimposed profile of the common center point of the P-wave component corresponding to the same stratum and the marker stratigraphic position time of the superimposed profile of the common conversion point of the converted wave component. Using the several time ratio coefficients and the construction term of the P-wave component, the construction term of the converted wave component is constructed. Obtain the common receiver gather of the longitudinal wave component and the common receiver gather of the converted wave component at the same receiver point; Based on the common center point gather of the P-wave component after dynamic correction and the construction term of the P-wave component, the common center point gather with the construction term removed is obtained. The common center point gather with the construction term removed and the common receiver gather of the P-wave component corresponding to the same marker layer time are superimposed to obtain the common receiver superimposed profile of the P-wave component. Based on the common conversion point gather of the converted wave component after dynamic correction and the construction term of the converted wave component, the common conversion point gather with the construction term removed is obtained. The common conversion point gather with the construction term removed corresponding to the same marker layer time is superimposed with the common receiver gather of the converted wave component to obtain the common receiver superposition profile of the converted wave component. Cross-correlation calculations are performed on the marker stratigraphic time of the common detector stacked profile of the converted wave component and the marker stratigraphic time of the common detector stacked profile of the longitudinal wave component to obtain the medium- and long-wavelength shear wave static correction amount at the converted wave receiving point. The converted wave component is processed by a preset converted wave residual static correction iterative method to obtain the short-wavelength shear wave static correction amount at the converted wave receiving point. The static correction amount of the medium- and long-wavelength shear wave, the static correction amount of the short-wavelength shear wave, and the construction term of the converted wave component are superimposed to obtain the static correction amount of the converted wave receiving point.

2. The converted wave static correction method as described in claim 1, characterized in that, The construction of the converted wave component using the aforementioned time scaling factors and the construction terms of the longitudinal wave component includes: The construction terms of the converted wave components are obtained by multiplying the aforementioned time scaling coefficients with the construction terms of the P-wave components corresponding to the time of the marker layer.

3. The converted wave static correction method as described in claim 2, characterized in that, The method of determining several time ratio coefficients for the marker horizon time of the superimposed profile of the common midpoint of the P-wave component corresponding to the same stratum and the marker horizon time of the superimposed profile of the common conversion point of the converted wave component includes: On the common conversion point superposition profile of the converted wave component after subtracting the excitation point static correction and the initial static correction of the receiver point of the converted wave component, the marker stratigraphic time corresponding to the structural term of the P-wave component is identified, and the ratio of the marker stratigraphic time of the common center point superposition profile of the P-wave component corresponding to the same stratum to the marker stratigraphic time of the common conversion point superposition profile of the converted wave component is determined, thereby obtaining several time scaling coefficients.

4. The converted wave static correction method as described in claim 3, characterized in that, The static correction values ​​at the excitation point and the initial static correction values ​​at the receiving point of the converted wave component are obtained through the following methods: Based on the obtained static excitation point correction of the longitudinal wave component, determine the static excitation point correction of the converted wave component. The initial static correction value of the receiver point of the acquired longitudinal wave component is obtained by multiplying the longitudinal and transverse wave scaling factors.

5. The converted wave static correction method as described in claim 4, characterized in that, The transverse and longitudinal wave proportionality coefficients are obtained through the following method: The ratio of P-wave to S-wave velocity was scanned using the proportional coefficient scanning method to obtain several preliminary proportional coefficients. Multiply the aforementioned preliminary proportional coefficients and the static correction amount of the receiving point of the longitudinal wave component by the receiving point to obtain the preliminary static correction amount of the receiving point of the converted wave component. Subtract the preliminary static correction amount of the receiving point of each of the converted wave components from the converted wave components to obtain several converted wave components after preliminary static correction. The seismic traces of the common conversion point assemblies corresponding to the aforementioned preliminary statically corrected converted wave components are superimposed to obtain several superimposed seismic traces. The preliminary scaling factor corresponding to the seismic trace with the largest amplitude among the several superimposed seismic traces is taken as the shear and longitudinal wave scaling factor.

6. The converted wave static correction method as described in claim 1, characterized in that, The final static correction value for the longitudinal wave component is obtained by the following method: The first arrival information of the longitudinal wave component is picked up; First-arrival tomographic static correction calculations are performed on the first-arrival information of the P-wave component to obtain the basic static correction amount of the P-wave component; Based on a preset residual static correction method for reflected waves, the residual static correction amount of the longitudinal wave component is determined; The final static correction of the P-wave component is obtained by adding the basic static correction of the P-wave component to the residual static correction of the P-wave component.

7. The converted wave static correction method as described in claim 1, characterized in that, Cross-correlation is performed on the marker stratigraphic time of the common detector stacked profile of the converted wave component and the marker stratigraphic time of the common detector stacked profile of the P-wave component to obtain the medium-to-long wavelength shear wave static correction at the converted wave receiver, including: Calculate the P-wave and S-wave velocity ratio parameters at the same marker layer time for the common detector stack profile of the P-wave component and the common detector stack profile of the converted wave component. By using the P-wave / S-wave velocity ratio parameter and the co-detector point superposition profile of the P-wave component, the co-detector point superposition profile of the P-wave component in the converted wave time domain is obtained. The cross-correlation time difference between the marker stratigraphic time of the common detector point superposition profile of the converted wave component and the marker stratigraphic time of the common detector point superposition profile of the longitudinal wave component in the converted wave time domain is determined to obtain the medium- and long-wavelength shear wave static correction amount at the converted wave receiving point.

8. The converted wave static correction method as described in claim 7, characterized in that, The determination of the cross-correlation time difference between the marker stratigraphic time of the common receiver stacked profile of the converted wave component and the marker stratigraphic time of the common receiver stacked profile of the P-wave component in the converted wave time domain includes: A cross-correlation function is established between the marker stratigraphic time of the common receiver point superposition profile of the converted wave component and the marker stratigraphic time of the common receiver point superposition profile of the P-wave component in the converted wave time domain. The time corresponding to the maximum value of the cross-correlation function is determined to obtain the cross-correlation time difference.

9. The application of the static correction amount of the converted wave receiving point obtained by the converted wave static correction method according to any one of claims 1-8 in seismic exploration or oil and gas exploration.

10. A converted wave static correction device, characterized in that, It includes a data acquisition module, a P-wave component construction module, a converted wave component construction module, a P-wave component common receiver point superposition profile module, a converted wave component common receiver point superposition profile module, and a static correction determination module, wherein: The data acquisition module is used to acquire the converted wave component and the P-wave component with the same source, and to acquire the common receiver point gather of the P-wave component and the common receiver point gather of the converted wave component at the same receiver point. The P-wave component construction module is used to determine the common center point stacking profile of the P-wave components based on the P-wave components and their corresponding final P-wave component static corrections, and to determine the static corrections corresponding to the smooth surface of the marker layer time that meets the preset conditions on the common center point stacking profile of the P-wave components, thereby obtaining the construction items of the P-wave components. The converted wave component construction term module is used to calculate a number of time ratio coefficients between the marker time of the common center point superimposed profile of the P-wave component corresponding to the same stratum and the marker time of the common conversion point superimposed profile of the converted wave component within the marker time range that meets the preset conditions, and to construct the construction term of the converted wave component using the number of time ratio coefficients and the construction term of the P-wave component. The common detector point superposition profile module for P-wave components is used to obtain a common center point gather with the construction terms of the dynamically corrected P-wave components and the construction terms of the P-wave components, and to superimpose the common center point gather with the common receiver point gather of the P-wave components corresponding to the same marker layer time with the common receiver point gather of the P-wave components to obtain a common detector point superposition profile of the P-wave components. The common detector point superposition profile module for converted wave components is used to obtain a common conversion point gather with the construction terms of the converted wave components after dynamic correction, and to superimpose the common conversion point gather with the common receiver point gather of the converted wave components corresponding to the same marker layer time with the common receiver point gather of the converted wave components to obtain a common detector point superposition profile of the converted wave components. The static correction determination module is used to perform cross-correlation calculations based on the marker stratigraphic time of the co-detector superposition profile of the converted wave component and the marker stratigraphic time of the co-detector superposition profile of the P-wave component to obtain the medium- and long-wavelength S-wave static correction at the converted wave receiving point; to process the converted wave component using a preset converted wave residual static correction iteration method to obtain the short-wavelength S-wave static correction at the converted wave receiving point; and to superimpose the medium- and long-wavelength S-wave static correction, the short-wavelength S-wave static correction, and the construction term of the converted wave component to obtain the static correction at the converted wave receiving point.

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