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.

A method may include obtaining seismic data regarding a geological region of interest. The method may further include obtaining a property model regarding the geological region of interest. The method may further include determining an adjoint migration operator based on the property model. The method may further include updating the property model using the seismic data and a conjugate gradient solver in a least-squares reverse time migration to produce a first updated property model. The conjugate gradient solver is based on the adjoint migration operator. The method may further include updating the first updated property model using a threshold shrinkage function to produce a second updated property model. The threshold shrinkage function comprises a sign function and a maximum function that are applied to the first updated property model. The method may further include generating a seismic image of the geological region of interest using the second updated property model.

Disclosed is a method and associated computer program and apparatus for characterising changes within a subsurface volume between a first time and a second time. The method comprises obtaining first seismic data corresponding to the first time and processing this data to obtain a seismic image of the subsurface volume. This processing is reversed for relevant portions of the seismic image to obtain relevant portions of first seismic data. Changes within the subsurface volume between the first time and the second time are characterised by estimating the changes between second seismic data corresponding to the second time and the relevant portions of first seismic data.

A method and apparatus for hydrocarbon management including generating an image of a subsurface formation by: obtaining simultaneous-source survey data, an earth model, and a first and a second velocity model of the subsurface formation; generating synthetic survey data with at least one of the earth model, the first velocity model, and the second velocity model. The method and apparatus may include directly migrating the simultaneous-source survey data; migrating the synthetic survey data; and subtracting the migrated synthetic survey data from the migrated simultaneous-source survey data. The method and apparatus may include subtracting the synthetic survey data from the simultaneous-source survey data; and directly migrating the result of the subtraction. The method and apparatus may include generating an artifact-reduced image.

The present disclosure includes a method for combining controlled and uncontrolled seismic data. The method includes accessing one or more controlled signals, each controlled signal associated with a respective receiver of a plurality of receivers. The method also includes accessing one or more uncontrolled signals, each uncontrolled signal associated with a respective receiver of the plurality of receivers. The method also includes generating one or more reconstructed signals based on the one or more uncontrolled signals. The method also includes generating a composite image based at least on the one or more controlled signals and the one or more reconstructed signals. The present disclosure may also include associated systems and apparatuses.

A method may include obtaining an initial velocity model regarding a subterranean formation of interest. The method may further include generating various seismic migration gathers with different cross-correlation lag values based on a migration-velocity analysis and the initial velocity model. The method may further include selecting a predetermined cross-correlation lag value automatically using the seismic migration gathers and based on a predetermined criterion. The method may further include determining various velocity boundaries within the initial velocity model using a trained model, wherein the trained model is trained by human-picked boundary data and augmented boundary data. The method may further include updating, by the computer processor, the initial velocity model using the velocity boundaries, the automatically-selected cross-correlation lag value, and the migration-velocity analysis to produce an updated velocity model. The method may further include generating an image of the subterranean formation of interest using the updated velocity model.

The present disclosure provides a method of high-resolution amplitude-preserving seismic imaging for a subsurface reflectivity model, including: performing reverse time migration (RTM) to obtain an initial imaging result, performing Born forward modeling on the initial imaging result to obtain seismic simulation data, and performing RTM on the seismic simulation data to obtain a second imaging result; performing curvelet transformation on the two imaging results, performing pointwise estimation in a curvelet domain, and using a Wiener solution that matches two curvelet coefficients as a solution of a matched filter; and applying the estimated matched filter to the initial imaging result to obtain a high-resolution amplitude-preserving seismic imaging result.

A method is described for stochastic modeling of seismic velocity and anisotropic parameters, including receiving 3D bounds of normal moveout velocity (V.sub.nmo) and anisotropic parameter η; modeling 3D bounds for vertical velocity V and anisotropic parameter δ based on the 3D bounds of V.sub.nmo and η; generating 3D model realizations of V, η, and δ within the 3D bounds; and testing detectability of each of the 3D model realizations to create a detectable subset of model realizations wherein the detectability identifies which 3D model realizations will produce images with flat migrated gathers. The method may be executed by a computer system.

A method for seismic imaging of a subsurface using a full waveform inversion, FWI, includes the steps of obtaining an initial P-velocity model that describes how a seismic wave propagates through the subsurface, generating an S-velocity model based on the initial P-velocity model, generating an elastic synthetic dataset p based on the initial P-velocity model and the S-velocity model, receiving a recorded seismic dataset d of the subsurface, updating the P-velocity model based on a comparison between the synthetic dataset p and the recorded seismic dataset d, updating a reflectivity at various locations in the subsurface based on the updated P-velocity model, and generating an image of the subsurface based on the reflectivity.

Methods and systems for forming a three-dimensional (“3D”) seismic image of a subterranean region of interest is disclosed. The method includes obtaining a seismic dataset a seismic trace for each of a plurality of pairs of one source and one receiver location and obtaining a 3D travel-time cube for each source location and each receiver location. The method further includes dividing the seismic dataset into a plurality of seismic subsets composed of set of source locations, set of receiver locations a seismic trace for each pair of source and receiver location and the 3D travel-time cube for each source for each receiver location. The method still further includes transmitting, to a random-access memory block of a computer processing unit the seismic subset, and forming a seismic partial image based on the seismic subset, and determining the 3D seismic image based on a combination of the seismic partial images.