Patent classifications
G01V2210/679
Computer-implemented method and system for obtaining a subsurface stack image, subsurface angle gathers, and a subsurface velocity model, over an entire survey region having high velocity contrast geo-bodies
A computer-implemented method and computing system apparatus programmed to perform operations of the computer-implemented method for obtaining a subsurface stack image, subsurface angle gathers, and a subsurface velocity model over an entire survey region having high velocity contrast geo-bodies. Particularly, user inputs, input velocity models, and surface-seismic data are obtained by fixed source and receiver pairs and then used by the computer program product embedded within the computing system apparatus to minimize the number of iterations, required to obtain a final velocity model, a final stack image, and final angle gathers wherein their flatness deviation is equal to, or less than, a user-defined flatness value. Therefore, the attributes developed by said computer-implemented method and system can help solve the imaging problem of sub high velocity contrast geo-bodies like subsalt, or salt overhung deep mini basins.
REVERSE TIME MIGRATION IN ANISOTROPIC MEDIA WITH STABLE ATTENUATION COMPENSATION
A method, including: obtaining Earth models including velocity, anisotropy, and attenuation reconstructing a source wavefield using the Earth models; reconstructing a receiver wavefield using the Earth models, wherein the reconstructing the source wavefield and the receiver wavefield each include applying an attenuation operator that increases an amplitude of down-going wavefields within an attenuation body and that decreases an amplitude of up-going wavefields within the attenuation body; applying an imaging condition to the source wavefield and receiver wavefield for a plurality of shots; and generating a subsurface image by stacking images for the plurality of shots.
Migrating a Horizontal Component of a Wavefield
A horizontal component of marine seismic survey data from an ocean bottom seismic survey can be migrated using a primary wave velocity model. The horizontal component can comprise a shear converted wave. An image of a subsurface location can based on the migration can be produced. Migrating the horizontal component can comprise wave-equation migrating the horizontal component, where the horizontal component is input as both a source wavefield and a receiver wavefield.
Interpretive-guided velocity modeling seismic imaging method and system, medium and device
The present disclosure belongs to the technical field of seismic exploration imaging, and relates to an interpretive-guided velocity modeling seismic imaging method and system, a medium and a device. The method comprises the following steps: S1. performing first imaging on a given initial velocity model to obtain a first imaging result; S2. performing relative wave impedance inversion on the first imaging result to obtain a relative wave impedance profile; S3. performing Curvelet filtering on the relative wave impedance profile to obtain a first interpretation scheme; S4. superposing the first interpretation scheme and the initial velocity model to obtain a new migration velocity field; S5. performing second imaging on a new migration velocity field to obtain a second imaging result; and S6. repeating steps S2-S4 for the obtained second imaging result until a final seismic imaging result is obtained.
SYSTEM AND METHOD FOR ROBUST SEISMIC IMAGING
A method is described for seismic imaging including receiving a pre-stack seismic dataset and an earth model at one or more computer processors; performing least-squares reverse time migration of the pre-stack seismic dataset using the earth model to create a digital seismic image, wherein the least-squares reverse time migration includes wave-equation forward modeling based on an asymptotic expression for reflection in a subsurface Kirchhoff integral; and generating a display of the digital seismic image on a graphical user interface.
Diffraction imaging using pseudo dip-angle gather
Systems, methods, and apparatuses for generating a subsurface image using diffraction energy information are disclosed. The systems, methods, and apparatuses may include converting a shot gather into one or more plane-wave gather using a Radon transform. The plane-wave gathers may be extrapolated into source-side wavefields and receiver-side wavefields and further generate a pseudo dip-angle gather. The diffraction energy information may be extracted from the pseudo dip-angle gather, and an image containing subsurface features may be generated from the extracted diffraction energy information. The receiver-side wavefields may be decomposed using a recursive Radon transform.
Seismic imaging with visco-acoustic reverse-time migration using pseudo-analytical method
In one embodiment, a reverse time migration module is configured with a visco-acoustic wave equation for media with heterogeneous attenuation solved using a pseudo-analytical method. Seismic data is obtained for a zone of interest, and a model is created for the zone of interest. The model has spatial variability in velocity and quality factor. Pseudo-analytic Q-compensating reverse time migration (PA-Q-RTM) is performed using the reverse time migration module and the model for the zone of interest to obtain PA-Q-RTM seismic data. In another embodiment, a system for processing seismic data includes a reverse time migration module configured with a visco-acoustic wave equation that is solved from the pseudo-analytical method. The system operates to obtain seismic data for a zone of interest and perform PA-Q-RTM using a model for the zone of interest to obtain PA-Q-RTM seismic data for the zone of interest. Other embodiments and features are also disclosed.
FWI With Areal And Point Sources
A method, including performing, with a computer, up/down separation of geophysical data, which produces an approximate up-going wavefield and an approximate down-going wavefield; creating an areal source based at least in part on the down-going wavefield; and performing, with a computer, a full wavefield inversion process with the areal source, and an objective function measuring a misfit between modeled up-going wavefields and recorded up-going wavefields, wherein the full wavefield inversion process generates a final subsurface physical property model.
METHOD AND APPARATUS FOR ESTIMATING SURFACE WAVE CODA USING TIME-REVERSAL EXPERIMENTS
Surface wave coda in seismic data recorded with a data acquisition system over an underground formation is estimated using time-reversal experiments. First time-reversal experiments use a first time-reversal mirror including a target source and one or more other sources to obtain estimates of surface waves traveling from other receivers to a target receiver. Second time-reversal experiments obtain a coda estimate for a surface wave traveling from the target source to the target receiver using a second time-reversal mirror including the target receiver and the other receivers.
Seismic data processing
A method includes the steps of receiving a wavefield generated by reflections in a subsurface region and recorded by a plurality of seismic receivers and compensating the recorded wavefield for amplitude attenuation. The method further includes modelling a propagation of a source wavefield forward in time, from an initial time-state to a final time-state through an earth model that is representative of the subsurface region, wherein the modelling includes phase and amplitude effects of attenuation and modelling a propagation of the compensated recorded wavefield backward in time from a final time-state to an earlier time-state through the earth model, wherein the subsurface region has an absorption characteristic that dampens the recorded wavefield wherein the modelling includes phase and amplitude effects of attenuation.