There is described embodiments relating to a method of determining a wave field in an anisotropic subsurface of the Earth. The method includes numerically solving a decoupled quasi-acoustic single wave mode wave equation based on spatially varied anisotropic parameters, to determine the wave field in the anisotropic subsurface.

A system and method is provided for restoring a 3D tomographic model of the Earth's subsurface geology from the present-day to a past restoration time. Whereas at the present time all faults represent active discontinuities, at a past restoration time some faults have not yet formed. Accordingly, the restored model divides the fault network into -active faults (discontinuous surfaces for faults that intersect the layer deposited at the past restoration time) and -inactive faults (continuous surfaces for faults that do not intersect the layer deposited at the past restoration time). A new 3D restoration transformation is also provided that uses linear geological constraints to process the restoration model in less time and generate more accurate geological images.

A method for seismic processing includes steps of seismic signal forward propagation and seismic data back propagation. The subsurface medium image is created after correlating and summarizing forward and backward propagation results. To address migration footprint and noise due to the incomplete data acquisition aperture and migration approximation in the migration operator, the iteration inversion strategy incorporates tensor flow calculated from seismic image. A regularization operator based on structure tensor of image is applied to seismic image inversion.

In one aspect, a method includes continuously combining seismic migration results using a massively parallel processing (MPP) database. In another aspect, an apparatus includes electronic hardware circuitry configured to continuously combine seismic migration results using a massively parallel processing (MPP) database. In a further aspect, an article includes a non-transitory computer-readable medium that stores computer-executable instructions. The instructions cause a machine to continuously combine seismic migration results using a massively parallel processing (MPP) database.

A method is described for seismic imaging of the subsurface using dip-guided optimized stacking. The method computes weighting functions for a plurality of single-shot migrated images, unstacked seismic images, or partially stacked seismic images based on a slant stack performed using an input dip dataset; applying the plurality of weighting functions to the plurality of single-shot migrated images, unstacked seismic images, or partially stacked seismic images, or a plurality of dip-filtered images to create a plurality of weighted images; and summing the plurality of weighted images into a stacked seismic image. The method may be executed by a computer system.

Iterative methods for inversion of seismic data to update a physical property model are disclosed. Such methods may comprise iteratively updating the model until a first predetermined resolution is achieved, using full wavefield inversion of the seismic data up to a first frequency threshold and assuming the seismic data is free of attenuation effects; extracting geobodies from the updated model; obtaining a Q model using the geobodies; and updating the physical property model using an inversion process, wherein the Q model is incorporated into the inversion process. These steps may be repeated until a second predetermined resolution of the physical property model is achieved, wherein the first frequency threshold is progressively increased in each repetition. The Q model may be updated with seismic data at all available frequencies to obtain a full-band Q model; and the physical property model may be updated using full-band migration and the full-band Q model.

Methods and devices according to various embodiments perform full-wave inversion jointly for datasets acquired at different times over the same underground formation using a time-lag cost function with target regularization terms. This approach improves the 4D signal within reservoirs and suppresses 4D noise outside.

The present invention is in the field of seismic imaging of underground structures. The invention is a method for solving the uncertainty and instability generated in reservoir geometries due to salt bodies which causes the presence of artifacts in the velocity fields. The method is based in a desalting process and a further specific reconstruction of the sediments located in the domain of the image. Desalting means to remove salt volumes located within the domain wherein said process is followed by the replacement of good sediment velocity values and a careful iterative process avoiding the generation of artifacts.

The present disclosure describes methods and systems, including computer-implemented methods, computer program products, and computer systems, for modeling angle domain common image gathers (ADCIG) from reverse time migration (RTM). One computer-implemented method includes calculating seismic source and receiver wavefields based on seismic data, calculating characteristic source and receiver wavefields from the seismic source and receiver wavefields, calculating propagation angles for the characteristic source and receiver wavefields, applying a wavefield decomposition algorithm on the characteristic source and receiver wavefields to obtain corresponding directional source and receiver wavefields, the wavefield decomposition algorithm decomposing wavefield amplitude of a wavefield in an angle interval centered on a propagation angle of the wavefield, and forming ADCIG by applying an image condition to the obtained directional source and receiver wavefields.

Methods for updating a physical properties model of a subsurface region that combine advantages of FWI and tomography into a joint inversion scheme are provided. One method comprises obtaining measured seismic data; generating simulated seismic data using an initial model; computing at least one of an FWI gradient and a tomography gradient; minimizing a joint objective function E, wherein the objective function E is based on a combination of the FWI gradient and the tomography gradient or preconditioning of the FWI gradient or the tomography gradient; generating a final model based on the minimized joint objective function E; and using the final model to generate a subsurface image. The joint objective function E may be a function of one or both a FWI objective function C.sub.FWI and a tomography objective function C.sub.Tomo. The joint objective function E may be defined as a weighted sum of C.sub.FWI and C.sub.Tomo.