Modeling method of converted wave depth domain velocity model and related device
By establishing a converted wave depth domain velocity model through joint inversion of P-waves and S-waves, the modeling difficulties caused by the asymmetry of the converted wave propagation path are solved, and accurate imaging and reservoir prediction of converted waves are realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA OILFIELD SERVICES LTD
- Filing Date
- 2023-05-26
- Publication Date
- 2026-05-08
AI Technical Summary
In existing technologies, the asymmetry of the propagation path of converted waves makes velocity analysis, common midpoint extraction, and depth domain velocity modeling difficult, and pre-stack time migration imaging is inaccurate, affecting reservoir prediction.
By inverting and updating the P-wave depth domain velocity model, and combining it with the joint inversion of P-wave and S-wave, a converted wave depth domain velocity model is established. The P-wave and converted wave gathers are then used for joint inversion to optimize the converted wave migration gathers and avoid uncertainties in the gamma field.
It improves the accuracy of converted wave depth domain velocity modeling, ensures that the phase axes of longitudinal waves and converted waves are aligned in the depth domain, realizes accurate imaging of converted waves, and solves the problem of unsatisfactory imaging in the middle and deep layers.
Smart Images
Figure CN116466397B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of oil and gas field exploration technology, specifically to a modeling method and apparatus for a converted wave depth domain velocity model, a computing device, and a computer storage medium. Background Technology
[0002] Currently, a large amount of converted wave data in my country's marine environment remains undeveloped, and the marine area is increasing year by year. Converted waves are the most critical factor in compensating for the shortcomings of P-wave exploration. How to process converted waves has always been a challenge for the industry, with very few successful cases from domestic and foreign companies, and even fewer successful cases of converted wave depth migration technology. Converted waves can be simply understood as P-waves incident and S-waves exiting, with geometrically asymmetrical ray paths. The propagation laws of S-waves and converted waves between strata are far more complex than those of P-waves. These characteristics of converted waves are the direct cause of difficulties in velocity analysis, common midpoint extraction, and depth-domain velocity modeling.
[0003] Due to the asymmetry of the propagation path of the converted wave, the common conversion point must be found through the gamma field when performing pre-stack time migration imaging. The key parameter for finding the conversion point is the gamma field. At the same time, the migration process requires three parameters: VP, VS, and gamma. These three parameters are difficult to obtain. The human factors in the gamma field have too much influence and are full of uncertainties. The imaging position obtained by time migration is inaccurate, which affects the subsequent interpretation and reservoir prediction work. Summary of the Invention
[0004] In view of the above problems, the present invention is proposed to provide a modeling method, apparatus, computing device and computer storage medium for a converted wave depth domain velocity model that can effectively avoid the uncertainties in the converted wave pre-stack time migration technique.
[0005] According to one aspect of the present invention, a method for modeling a converted wave depth domain velocity model is provided, comprising:
[0006] Step S1: Invert and update the P-wave depth domain velocity model to obtain the P-wave velocity;
[0007] Step S2: Based on the longitudinal wave velocity, perform a one-dimensional inversion update on the converted wave depth domain velocity model to update the converted wave velocity.
[0008] Step S3: Obtain the P-wave gather by performing depth migration using the P-wave depth domain velocity model, obtain the converted wave gather by performing depth migration using the converted wave depth domain velocity model, and obtain the converted wave migrated gather by performing joint inversion using the P-wave gather and the converted wave gather.
[0009] Step S4: Determine whether the offset converted wave superposition profile and the converted wave offset gather are reasonable, and whether the phase axes of the longitudinal wave and the converted wave are flattened. If not, perform three-dimensional inversion update on the converted wave depth domain velocity model and execute step S2; if yes, output the converted wave depth domain velocity model.
[0010] In one alternative approach, the P-wave depth domain velocity model is used to define the ray path from the shot point to the imaging point; the converted wave depth domain velocity model is used to define the ray path from the receiver point to the imaging point.
[0011] In an alternative embodiment, prior to step S1, the method further includes: establishing an initial P-wave depth domain velocity model and an initial converted wave depth domain velocity model, wherein the initial converted wave depth domain velocity model is established based on logging data, gamma field parameters, and velocity scans.
[0012] In an alternative embodiment, step S2 further includes:
[0013] Stratified interpretation of P-waves and converted waves in the depth domain;
[0014] Based on the layer matching requirement, the converted wave velocity to be updated is obtained according to the longitudinal wave velocity;
[0015] Based on the converted wave velocity to be updated, a one-dimensional inversion update is performed on the converted wave depth domain velocity model.
[0016] In one alternative approach, the three-dimensional inversion update of the converted wave depth domain velocity model further includes:
[0017] Residual curvature is picked up based on converted wave offset gathers;
[0018] Dip angle information is picked up based on the superimposed converted wave profile;
[0019] Based on the picked-up residual curvature and tilt angle information, tomographic inversion is performed to calculate the shear wave velocity disturbance.
[0020] Based on the shear wave velocity disturbance, the converted wave depth domain velocity model is updated using three-dimensional inversion.
[0021] In an alternative embodiment, after the output converted wave depth domain velocity model, the method further includes:
[0022] Based on the converted wave depth domain velocity model, the converted wave data in the depth domain are obtained;
[0023] The converted wave data in the depth domain is converted to the time domain to obtain converted wave data in the time domain.
[0024] According to another aspect of the present invention, a modeling apparatus for a converted wave depth domain velocity model is provided, comprising:
[0025] The P-wave inversion and update module is used to invert and update the P-wave depth domain velocity model to obtain the P-wave velocity.
[0026] The one-dimensional inversion update module is used to perform a one-dimensional inversion update of the converted wave depth domain velocity model based on the longitudinal wave velocity, in order to update the converted wave velocity.
[0027] The offset gather acquisition module is used to obtain a P-wave gather by performing depth migration through a P-wave depth domain velocity model, obtain a converted wave gather by performing depth migration through a converted wave depth domain velocity model, and obtain a converted wave offset gather by performing joint inversion of the P-wave gather and the converted wave gather.
[0028] The three-dimensional inversion update module is used to determine whether the offset converted wave superposition profile and the converted wave offset gather are reasonable, and whether the phase axes of the P-wave and the converted wave are flattened. If not, the three-dimensional inversion update is performed on the converted wave depth domain velocity model, triggering the one-dimensional inversion update module; if yes, the converted wave depth domain velocity model is output.
[0029] According to another aspect of the present invention, a computing device is provided, comprising: a processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other via the communication bus;
[0030] The memory is used to store at least one executable instruction, which causes the processor to perform the operation corresponding to the modeling method of the converted wave depth domain velocity model described above.
[0031] According to another aspect of the present invention, a computer storage medium is provided, wherein at least one executable instruction is stored therein, the executable instruction causing a processor to perform an operation corresponding to the modeling method of the converted wave depth domain velocity model described above.
[0032] According to the scheme provided by the present invention, the P-wave depth domain velocity model is inverted and updated to obtain the P-wave velocity; based on the P-wave velocity, the converted wave depth domain velocity model is inverted and updated in one dimension to update the converted wave velocity; P-wave gathers are obtained by depth migration through the P-wave depth domain velocity model, and converted wave gathers are obtained by depth migration through the converted wave depth domain velocity model; the converted wave gathers and converted wave gathers are jointly inverted to obtain the converted wave migrated gathers; it is determined whether the migrated converted wave stacking profile and converted wave migrated gathers are reasonable, and whether the phase axes of the P-wave and converted waves are flattened; if not, the converted wave depth domain velocity model is inverted and updated in three dimensions, triggering a one-dimensional inversion update; if so, the converted wave depth domain velocity model is output. This invention improves the accuracy of converted wave depth domain velocity modeling by jointly inverting P-waves and S-waves, while also effectively avoiding the uncertainties introduced by the GAMMA field in time migration processing.
[0033] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description
[0034] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:
[0035] Figure 1 A flowchart illustrating the modeling method of the converted wave depth domain velocity model according to an embodiment of the present invention is shown.
[0036] Figure 2 A schematic diagram of the combined longitudinal and transverse wave imaging process according to an embodiment of the present invention is shown;
[0037] Figures 3a to 3b A schematic diagram showing the correspondence between P-wave and S-wave shot-receiver points according to an embodiment of the present invention is shown.
[0038] Figure 4 A schematic diagram of the joint modeling process for longitudinal and transverse waves according to an embodiment of the present invention is shown;
[0039] Figure 5 A schematic diagram of the three-dimensional tomographic inversion process according to an embodiment of the present invention is shown;
[0040] Figure 6 A schematic diagram of the superposition, gather, and residual curvature spectrum γ before the shear wave velocity update in an embodiment of the present invention is shown.
[0041] Figure 7 This diagram illustrates the matching of P-wave and S-wave depth domains after the shear wave velocity update according to an embodiment of the present invention.
[0042] Figure 8 A schematic diagram of the modeling device for the converted wave depth domain velocity model according to an embodiment of the present invention is shown;
[0043] Figure 9 A schematic diagram of the structure of a computing device according to an embodiment of the present invention is shown. Detailed Implementation
[0044] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
[0045] Before implementing the embodiments of the present invention, the technical terms used below are uniformly explained as follows:
[0046] P-wave: P stands for Primary or Pressure, and it is a longitudinal wave in which the direction of particle vibration is parallel to the direction of wave propagation.
[0047] S-wave: S stands for secondary or shear, and it is a transverse wave in which the direction of particle vibration is perpendicular to the direction of wave propagation.
[0048] Converted waves, also known as converted reflected waves or C-waves, generate reflected transverse waves, reflected longitudinal waves, transmitted transverse waves, and transmitted longitudinal waves simultaneously when either longitudinal or transverse waves are incident obliquely on an elastic interface. For example, when a longitudinal wave (P-wave) is incident on a reflective layer interface at a non-zero angle of incidence, the following types of waves can be formed: reflected upward P-wave (PP), transmitted downward P-wave, converted upward S-wave (PS), and converted transmitted S-wave.
[0049] PP wave: also known as reflected longitudinal wave.
[0050] PS wave: also known as reflected transverse wave, PS wave is a type of S wave.
[0051] PSDM: Pre-stack depth migration is a processing technique for spatial repositioning of geological structures.
[0052] CMP: Common Midpoint Gathering (CMP) refers to extracting traces from different shot sets that share a common midpoint, forming a new set called the Common Midpoint Gathering.
[0053] CCP: Common Conversion Point (CCP).
[0054] ACP: Asymptotic Conversion Point (ACP).
[0055] CIG: Common Image Gather (CIG).
[0056] CDP: Common Depth Point (or Common Reflection Point) Gather.
[0057] To more clearly describe this embodiment Figure 1 The flowchart shown is a modeling method for the converted wave depth domain velocity model. First, the purpose of this invention is described.
[0058] When performing pre-stack depth migration imaging, imaging can be performed simply by obtaining VP (P-wave velocity) and VS (S-wave velocity) in the depth domain. Theoretically, improving the accuracy of depth migration velocity modeling can achieve accurate converted-wave depth migration imaging. Furthermore, the accuracy of tomographic inversion can be effectively improved through joint P-wave and S-wave inversion techniques, resulting in ideal converted-wave depth domain imaging. Therefore, this invention has the following three main objectives:
[0059] 1. Existing converted wave pre-stack time migration techniques must rely on GAMMA fields, while pre-stack depth migration effectively avoids the uncertainties of GAMMA fields.
[0060] 2. Existing converted wave pre-stack time migration can only obtain time domain results, while depth migration of the velocity model obtained by joint modeling of P-waves and S-waves in the depth domain can simultaneously obtain depth domain, converted wave time domain, and P-wave time domain migration results to meet various needs.
[0061] 3. In the process of obtaining the time migration velocity, the GAMMA field in the middle and deep layers is close to 1, which means that the P-wave and S-wave velocity ratio is difficult to adjust in the middle and deep layers, resulting in unsatisfactory converted wave time migration imaging in the middle and deep layers. However, depth migration velocity modeling can obtain the P-wave and S-wave velocities through joint inversion of P-wave and S-wave, which can accurately image the middle and deep layers.
[0062] Figure 1This diagram illustrates a flowchart of a modeling method for the converted-wave depth-domain velocity model according to an embodiment of the present invention. This method improves the accuracy of converted-wave depth-domain velocity modeling by jointly inverting P-waves and S-waves. Specifically, as... Figure 1 As shown, it includes the following steps:
[0063] Step S101: Invert and update the P-wave depth domain velocity model to obtain the P-wave velocity.
[0064] An initial velocity model in the depth domain of the P-wave is established, and the P-wave depth domain velocity model is updated by inversion to obtain a more accurate P-wave velocity.
[0065] In an alternative embodiment, prior to step S101, the method further includes: establishing an initial P-wave depth domain velocity model and an initial converted wave depth domain velocity model, wherein the initial converted wave depth domain velocity model is established based on logging data, gamma field parameters, and velocity scans.
[0066] In an alternative approach, a P-wave depth domain velocity model is used to define the ray path from the shot point to the imaging point.
[0067] For example, the P-wave (Vp0) velocity model is used to define the ray path from the shot point to the imaging point.
[0068] Step S102: Based on the longitudinal wave velocity, perform a one-dimensional inversion update on the converted wave depth domain velocity model to update the converted wave velocity.
[0069] For example, after the PP wave velocity model is established, a higher accuracy P-wave velocity can be obtained, and the initial model for PS wave velocity can be updated based on the P-wave velocity.
[0070] In an alternative approach, a converted wave depth domain velocity model is used to define the ray path from the detector point to the imaging point.
[0071] For example, the S-wave (Vs0) velocity model is used to define the ray path from the detector point to the imaging point.
[0072] In an alternative embodiment, step S102 further includes:
[0073] Stratified interpretation of P-waves and converted waves in the depth domain;
[0074] Based on the layer matching requirement, the converted wave velocity to be updated is obtained according to the longitudinal wave velocity;
[0075] Based on the converted wave velocity to be updated, a one-dimensional inversion update is performed on the converted wave depth domain velocity model.
[0076] Step S103: The P-wave gather is obtained by depth migration using the P-wave depth domain velocity model, the converted wave gather is obtained by depth migration using the converted wave depth domain velocity model, and the converted wave gather is obtained by joint inversion using the P-wave gather and the converted wave gather.
[0077] The theoretical basis for converted wave velocity modeling is that the phase axes of the PP and PS are located at the same position in the depth domain and have a good correspondence with geological stratification. Therefore, the PP and PS gathers can be flattened by updating the anisotropy model. For example... Figure 2 The P-wave and S-wave combined imaging process is shown, in which the PS wave depth migration combined with the travel time tables of the shot point and receiver point is used to image at the common conversion point, replacing the common center point. Figures 3a to 3b The correspondence between the P-wave and S-wave gun receivers is shown.
[0078] The PS wave velocity model is directly related to the PP wave. In this embodiment, to ensure accurate velocity updates, the P-wave velocity is first modeled with high precision before the S-wave velocity is calculated. Then, the P-wave and S-wave velocity are jointly inverted to achieve the final consistency between the P-wave and the converted wave in the depth domain imaging position. Figure 4 As shown, the P-wave velocity model is obtained by PP wave tomography inversion of the P-wave depth domain velocity model (i.e., P-wave velocity). Based on the P-wave velocity, Delta / epsilon (Delta / epsilon is the anisotropic quantity of the far offset, used to flatten the gather), etc., the converted wave depth domain velocity model is updated by 1D (one-dimensional) inversion to update the converted wave velocity.
[0079] During propagation, the converted wave's descending wave is a longitudinal wave, while after reflection, it generates a transverse wave, which is received by a velocity detector. Therefore, a joint inversion of the two signals is required, namely, a joint inversion of the longitudinal and transverse waves. After obtaining an accurate longitudinal wave velocity model through tomographic inversion, the transverse wave is iteratively updated to obtain the final depth-migrated converted wave velocity model.
[0080] Specifically, the P-wave gather is obtained by depth migration of the P-wave using the P-wave depth domain velocity model, and the converted wave gather is obtained by depth migration using the converted wave depth domain velocity model. The converted wave gather is obtained by joint inversion of the P-wave gather and the converted wave gather.
[0081] Step S104: Determine whether the offset converted wave superimposed profile and converted wave offset gather are reasonable, and whether the phase axes of the P-wave and the converted wave are flattened. If not, perform three-dimensional inversion update on the converted wave depth domain velocity model and execute step S102; if yes, output the converted wave depth domain velocity model.
[0082] Specifically, the reasonableness of the offset converted wave stacking profile and converted wave offset gather is determined, as well as the reasonableness of the velocity and whether there is room for improvement, based on whether the phase axes of the P-wave and the converted wave are leveled. If not (i.e., unreasonable or without room for improvement), a three-dimensional inversion update is performed on the converted wave depth domain velocity model. After the three-dimensional inversion update, step S102 (triggering the one-dimensional inversion update again) is executed; if yes, the converted wave depth domain velocity model is output. Figure 5 As shown, depth migration is performed on the P-wave velocity model and the converted wave velocity model to obtain P-wave gathers and converted wave gathers, respectively. The reasonableness of the converted wave stacking profile and gathers, the leveling of the phase axis, and the reasonableness of the velocity are determined, and there is room for improvement. If improvement is possible, the remaining curvature and dip angle information are picked up on the converted wave migration gathers, and the converted wave depth domain velocity model is updated by 3D inversion. After the 3D inversion update, the 1D inversion update is triggered again.
[0083] In one alternative approach, the three-dimensional inversion update of the converted wave depth domain velocity model further includes:
[0084] Residual curvature is picked up based on converted wave offset gathers;
[0085] Dip angle information is picked up based on the superimposed converted wave profile;
[0086] Based on the picked-up residual curvature and dip angle information, tomographic inversion is performed to calculate the shear wave velocity disturbance.
[0087] Based on the shear wave velocity disturbance, the converted wave depth domain velocity model is updated using three-dimensional inversion.
[0088] Specifically, residual curvature and dip angle information are picked up from the migrated converted wave migration gather and the converted wave stacking profile. Tomographic inversion is performed based on the picked residual curvature and dip angle information to calculate the shear wave velocity perturbation, update the shear wave velocity model, and then perform a one-dimensional inversion update on the updated shear wave velocity model. If the velocity, accuracy, etc., of the shear wave velocity model are unreasonable or have room for improvement, a second round of depth migration is performed using the newly obtained shear wave velocity model until a reasonable shear wave velocity model is obtained. To obtain good depth migration results, multiple rounds of velocity update iterations are usually required, and the changing trend of the velocity model and the rationality of the CIG picking parameters must be carefully controlled. Only when the trend of each velocity update is correct can the reliability and quality of the final migration results be guaranteed.
[0089] Optionally, the depth domain velocity model of the P-wave is updated and inverted first to obtain a more accurate velocity, and the CDP gathers of the P-wave and the converted wave are optimized to pick up their respective residual curvature and dip angle information.
[0090] Optionally, the velocity models of the P-wave and S-wave, along with their respective residual curvature and dip angle information, can be input simultaneously for joint nonlinear tomographic inversion.
[0091] Optionally, for data that cannot be conventionally inverted, a more accurate velocity can be obtained from the shear wave velocity model by methods such as scanning and filling.
[0092] In this embodiment, both P-wave and converted wave imaging in the depth domain satisfy the condition of tomography based on the residual curvature of the converted wave offset gather. During the joint inversion of P-wave and S-wave, the residual curvature of the converted wave offset gather needs to be picked up separately for both, and the joint inversion of P-wave and S-wave is performed using a data-driven approach.
[0093] like Figure 6 The image shows the stack, gather, and velocity spectrum corresponding to the shear wave velocity model before the update. It can be seen that the gather is not flattened, and the energy clusters in the velocity spectrum are not centered. Therefore, it is necessary to pick up the remaining delay. The velocity is then updated by picking up the remaining delay. Specifically, based on the initial layer velocity model, Kirchhoff pre-stack depth migration is used to obtain the depth-domain CIG and converted wave stacking profile (50m*50m*5m grid). The remaining curvature is picked up based on the CIG, and the dip angles in the X and Y directions are picked up based on the converted wave stacking profile. Three-dimensional tomographic inversion is then performed to update the depth-layer velocity volume. After several rounds of updates, the remaining curvature of the CIG gradually decreases, and the velocity becomes more accurate.
[0094] After several rounds of iterative updates, the accuracy of shear wave velocity has improved. Theoretically, P-waves and converted waves in the same stratum have the same imaging position in the depth domain. The updated converted wave results need to be matched and compared with P-waves in the depth domain. Figure 7 The imaging of P-waves and S-waves in the depth domain is shown. The imaging of the two at the same location is basically consistent, indicating that the S-wave velocity obtained by the joint inversion of P-waves and S-waves has high accuracy.
[0095] In an alternative embodiment, after outputting the converted wave depth domain velocity model, the method further includes:
[0096] Based on the converted wave depth domain velocity model, converted wave data in the depth domain are obtained;
[0097] Converted wave data in the depth domain is converted to the time domain to obtain converted wave data in the time domain.
[0098] By combining P-wave and S-wave inversion and matching the imaging depths of P-wave and S-wave, better converted wave depth domain imaging quality can be obtained. For example, converting the converted wave data in the depth domain to the time domain can yield time domain results, which can be used for subsequent interpretation, reservoir prediction, fracture prediction, fluid detection and other work.
[0099] The solution provided in the above embodiments of the present invention involves inverting and updating the P-wave depth domain velocity model to obtain the P-wave velocity; based on the P-wave velocity, performing a one-dimensional inversion and update of the converted wave depth domain velocity model to update the converted wave velocity; obtaining the P-wave gather through depth migration using the P-wave depth domain velocity model, obtaining the converted wave gather through depth migration using the converted wave depth domain velocity model, and obtaining the converted wave migrated gather through joint inversion of the P-wave gather and the converted wave gather; determining whether the migrated converted wave stacking profile and the converted wave migrated gather are reasonable, and whether the phase axes of the P-wave and the converted wave are flattened; if not, performing a three-dimensional inversion and update of the converted wave depth domain velocity model to trigger a one-dimensional inversion and update; if yes, outputting the converted wave depth domain velocity model. This invention improves the accuracy of converted wave depth domain velocity modeling by jointly inverting P-waves and S-waves. At the same time, in the converted wave depth migration imaging process, the P-wave velocity model is used to define the ray path from the shot point to the imaging point, and the S-wave velocity model is used to define the ray path from the receiver point to the imaging point. This effectively avoids the uncertainty brought about by the GAMMA field in time migration processing and effectively solves the problem of depth domain velocity modeling.
[0100] Figure 8 A schematic diagram of the modeling device for the converted wave depth domain velocity model according to an embodiment of the present invention is shown. The modeling device for the converted wave depth domain velocity model includes: a longitudinal wave inversion update module 810, a one-dimensional inversion update module 820, a migration gather acquisition module 830, and a three-dimensional inversion update module 840.
[0101] The P-wave inversion update module 810 is used to invert and update the P-wave depth domain velocity model to obtain the P-wave velocity.
[0102] The one-dimensional inversion update module 820 is used to perform a one-dimensional inversion update on the converted wave depth domain velocity model based on the longitudinal wave velocity, so as to update the converted wave velocity.
[0103] The offset gather acquisition module 830 is used to obtain a P-wave gather by performing depth migration through a P-wave depth domain velocity model, obtain a converted wave gather by performing depth migration through a converted wave depth domain velocity model, and obtain a converted wave offset gather by performing joint inversion of the P-wave gather and the converted wave gather.
[0104] The three-dimensional inversion update module 840 is used to determine whether the offset converted wave superposition profile and the converted wave offset gather are reasonable, and whether the phase axes of the longitudinal wave and the converted wave are flattened. If not, the three-dimensional inversion update is performed on the converted wave depth domain velocity model, triggering the one-dimensional inversion update module; if yes, the converted wave depth domain velocity model is output.
[0105] In one alternative approach, the P-wave depth domain velocity model is used to define the ray path from the shot point to the imaging point; the converted wave depth domain velocity model is used to define the ray path from the receiver point to the imaging point.
[0106] In an alternative embodiment, the apparatus further includes an initial model building module (not shown in the figure) for establishing an initial P-wave depth domain velocity model and an initial converted wave depth domain velocity model, wherein the initial converted wave depth domain velocity model is established based on logging data, gamma field parameters, and velocity scans.
[0107] In an alternative embodiment, the one-dimensional inversion update module 820 is further configured to:
[0108] Stratified interpretation of P-waves and converted waves in the depth domain;
[0109] Based on the layer matching requirement, the converted wave velocity to be updated is obtained according to the longitudinal wave velocity;
[0110] Based on the converted wave velocity to be updated, a one-dimensional inversion update is performed on the converted wave depth domain velocity model.
[0111] In an alternative embodiment, the three-dimensional inversion update module 840 is further configured to:
[0112] Residual curvature is picked up based on converted wave offset gathers;
[0113] Dip angle information is picked up based on the superimposed converted wave profile;
[0114] Based on the picked-up residual curvature and tilt angle information, tomographic inversion is performed to calculate the shear wave velocity disturbance.
[0115] Based on the shear wave velocity disturbance, the converted wave depth domain velocity model is updated using three-dimensional inversion.
[0116] In an alternative embodiment, the apparatus further includes: a converted wave data generation module (not shown in the figure), used to obtain converted wave data in the depth domain based on the converted wave depth domain velocity model;
[0117] The converted wave data in the depth domain is converted to the time domain to obtain converted wave data in the time domain.
[0118] The solution provided in the above embodiments of the present invention involves inverting and updating the P-wave depth domain velocity model to obtain the P-wave velocity; based on the P-wave velocity, performing a one-dimensional inversion and update of the converted wave depth domain velocity model to update the converted wave velocity; obtaining the P-wave gather through depth migration using the P-wave depth domain velocity model, obtaining the converted wave gather through depth migration using the converted wave depth domain velocity model, and obtaining the converted wave migrated gather through joint inversion of the P-wave gather and the converted wave gather; determining whether the migrated converted wave stacking profile and the converted wave migrated gather are reasonable, and whether the phase axes of the P-wave and the converted wave are flattened; if not, performing a three-dimensional inversion and update of the converted wave depth domain velocity model to trigger a one-dimensional inversion and update; if yes, outputting the converted wave depth domain velocity model. This invention improves the accuracy of converted wave depth domain velocity modeling by jointly inverting P-waves and S-waves. At the same time, in the converted wave depth migration imaging process, the P-wave velocity model is used to define the ray path from the shot point to the imaging point, and the S-wave velocity model is used to define the ray path from the receiver point to the imaging point. This effectively avoids the uncertainty brought about by the GAMMA field in time migration processing and effectively solves the problem of depth domain velocity modeling.
[0119] Figure 9 The diagram shows a structural schematic of an embodiment of the computing device of the present invention. The specific embodiments of the present invention do not limit the specific implementation of the computing device.
[0120] like Figure 9 As shown, the computing device may include: a processor 902, a communications interface 904, a memory 906, and a communications bus 908.
[0121] The processor 902, communication interface 904, and memory 906 communicate with each other via communication bus 908. Communication interface 904 is used to communicate with other network elements, such as clients or other servers. Processor 902 executes program 910, specifically performing the relevant steps in the above-described embodiment of the modeling method for the converted wave depth domain velocity model.
[0122] Specifically, program 910 may include program code that includes computer operation instructions.
[0123] Processor 902 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. The computing device includes one or more processors, which may be processors of the same type, such as one or more CPUs; or processors of different types, such as one or more CPUs and one or more ASICs.
[0124] Memory 906 is used to store program 910. Memory 906 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.
[0125] This invention provides a non-volatile computer storage medium storing at least one executable instruction that can execute the modeling method of the converted wave depth domain velocity model in any of the above method embodiments.
[0126] The algorithms or displays provided herein are not inherently related to any particular computer, virtual system, or other device. Various general-purpose systems can also be used in conjunction with the teachings herein. The required structure for constructing such systems is apparent from the above description. Furthermore, the embodiments of the present invention are not directed to any particular programming language. It should be understood that the content of the invention described herein can be implemented using various programming languages, and the above description of specific languages is for the purpose of disclosing the best mode of implementation of the invention.
[0127] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.
[0128] Similarly, it should be understood that, in order to simplify the invention and aid in understanding one or more of the various inventive aspects, features of the embodiments of the invention are sometimes grouped together in a single embodiment, figure, or description thereof in the above description of exemplary embodiments of the invention. However, this disclosure should not be construed as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the following claims, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into this detailed description, wherein each claim itself is a separate embodiment of the invention.
[0129] Those skilled in the art will understand that modules in the device of the embodiments can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or components in the embodiments can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components. Except where at least some of such features and / or processes or units are mutually exclusive, any combination can be used to combine all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or device so disclosed. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.
[0130] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination.
[0131] The various component embodiments of the present invention can be implemented in hardware, or as software modules running on one or more processors, or a combination thereof. Those skilled in the art will understand that microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions of some or all of the components according to the embodiments of the present invention. The present invention can also be implemented as a device or apparatus program (e.g., a computer program and computer program product) for performing part or all of the methods described herein. Such programs implementing the present invention can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.
[0132] It should be noted that the above embodiments are illustrative of the invention and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be construed as limiting the order of execution.
Claims
1. A modeling method for a converted wave depth domain velocity model, characterized in that, include: Step S1: Invert and update the P-wave depth domain velocity model to obtain the P-wave velocity; Step S2: Based on the P-wave velocity, perform a one-dimensional inversion update on the converted wave depth domain velocity model to update the converted wave velocity; wherein, in the depth domain, perform layer interpretation on the P-wave and converted wave; based on the layer matching requirements, obtain the converted wave velocity to be updated based on the P-wave velocity; perform a one-dimensional inversion update on the converted wave depth domain velocity model based on the converted wave velocity to be updated. Step S3: Obtain P-wave gathers by performing depth migration using the P-wave depth domain velocity model, obtain converted wave gathers by performing depth migration using the converted wave depth domain velocity model, and obtain converted wave migrated gathers by performing joint inversion using the P-wave gathers and the converted wave gathers; wherein, the P-wave depth domain velocity model is used to define the ray path from the shot point to the imaging point; the converted wave depth domain velocity model is used to define the ray path from the receiver point to the imaging point; Step S4: Determine whether the offset converted wave stacking profile and the converted wave offset gather are reasonable, and whether the phase axes of the P-wave and the converted wave are flattened. If not, pick the remaining curvature based on the converted wave offset gather; pick the dip angle information based on the converted wave stacking profile; perform tomographic inversion based on the picked remaining curvature and dip angle information to calculate the shear wave velocity perturbation; perform three-dimensional inversion update on the converted wave depth domain velocity model based on the shear wave velocity perturbation, and execute step S2 after the three-dimensional inversion update; if yes, output the converted wave depth domain velocity model.
2. The method according to claim 1, characterized in that, Before step S1, the method further includes: establishing an initial P-wave depth domain velocity model and an initial converted wave depth domain velocity model, wherein the initial converted wave depth domain velocity model is established based on logging data, gamma field parameters, and velocity scan.
3. The method according to claim 1, characterized in that, Following the output converted wave depth domain velocity model, the method further includes: Based on the converted wave depth domain velocity model, the converted wave data in the depth domain are obtained; The converted wave data in the depth domain is converted to the time domain to obtain converted wave data in the time domain.
4. A modeling apparatus for a converted wave depth domain velocity model, characterized in that, include: The P-wave inversion and update module is used to invert and update the P-wave depth domain velocity model to obtain the P-wave velocity. The one-dimensional inversion update module is used to perform a one-dimensional inversion update of the converted wave depth domain velocity model based on the P-wave velocity, in order to update the converted wave velocity. Specifically, the P-wave and converted wave are interpreted at the horizon in the depth domain; based on the horizon matching requirements, the converted wave velocity to be updated is obtained from the P-wave velocity; and the converted wave depth domain velocity model is updated in one dimension based on the converted wave velocity to be updated. The offset gather acquisition module is used to obtain a P-wave gather by performing depth migration using a P-wave depth domain velocity model, and to obtain a converted wave gather by performing depth migration using a converted wave depth domain velocity model. The P-wave gather and the converted wave gather are then jointly inverted to obtain a converted wave offset gather. The P-wave depth domain velocity model is used to define the ray path from the shot point to the imaging point; the converted wave depth domain velocity model is used to define the ray path from the receiver point to the imaging point. The three-dimensional inversion update module is used to determine whether the offset converted wave stacking profile and the converted wave offset gather are reasonable, and whether the phase axes of the P-wave and the converted wave are flattened. If not, it picks the residual curvature based on the converted wave offset gather; picks the dip angle information based on the converted wave stacking profile; performs tomographic inversion based on the picked residual curvature and dip angle information to calculate the shear wave velocity perturbation; performs three-dimensional inversion update on the converted wave depth domain velocity model based on the shear wave velocity perturbation; and triggers the one-dimensional inversion update module after the three-dimensional inversion update. If so, it outputs the converted wave depth domain velocity model.
5. A computing device, comprising: The processor, memory, communication interface, and communication bus are provided, wherein the processor, memory, and communication interface communicate with each other via the communication bus. The memory is used to store at least one executable instruction, which causes the processor to perform the operation corresponding to the modeling method of the converted wave depth domain velocity model as described in any one of claims 1-3.
6. A computer storage medium storing at least one executable instruction, the executable instruction causing a processor to perform an operation corresponding to the modeling method of the converted wave depth domain velocity model as described in any one of claims 1-3.
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