A technique for reconstructing a seismic wavefield includes receiving data over one or more channels of a plurality of channels from a plurality of stations. The data is recorded by a plurality of seismic receivers and represent measurements of properties of the seismic wavefield. Each station includes a region in space including one or more seismic receivers. Each channel either measures a property of the seismic wavefield or a property of the seismic wavefield after the seismic wavefield has undergone a known transformation. At least one channel is derived as a function of one or more other channels. The technique includes using a processor based machine to process the data to model the seismic wavefield as a sum of basis functions; apply to the basis functions at least one forward transformation that describes the measurements received over the channel(s); and determine optimum basis functions based at least in part on the measurements.

A technique includes receiving data acquired by an acoustic measurement tool in a well, where the data represents multiple acoustic modes, including a first order formation flexural acoustic mode and a higher order formation flexural acoustic mode. The technique includes processing the data to identify the higher order formation flexural acoustic mode; and determining a shear slowness based at least in part on slowness values that are associated with the identified higher order formation flexural acoustic mode.

A method, system, and non-transitory computer readable media for seismic imaging of a subterranean formation. The operations include receiving data representing seismic traces corresponding to seismic waves propagating in the subterranean formation, and determining, from the seismic traces, travel time data and a data covariance matrix. The operations include determining a prior velocity model and a prior model covariance matrix for common midpoint locations and generating an objective function based on the travel time data, the data covariance matrix, the prior velocity model, and the prior model covariance matrix. The operations include determining, by minimizing the objective function, values for one-dimensional velocity models and a set of accuracy values. The operations include generating a pseudo-3D model and a set of accuracy values for the pseudo-3D model. Based on the pseudo-3D model and the set of accuracy values for the pseudo-3D model, a seismic image representing the subterranean formation is generated.

A method can include receiving seismic data of a subsurface region; performing an iterative full waveform inversion using at least a portion of the seismic data to generate a model of the subsurface region, where the performing includes, after one or more iterations of the full waveform inversion, automatically selecting one or more parts of the seismic data for inclusion in the at least a portion of the seismic data based on data classification using one or more quality attributes; and outputting the model of the subsurface region.

A method includes receiving a seismic data volume including target traces. The method also includes sparse sampling the target traces to produce a subset of representative target traces. The method also includes generating a broad area map for each representative target trace. The area map includes multiple downward reflection points (DRPs) laid out as a grid and multiple blocks. The method also includes convolving a seismic trace pair for each DRP to produce a convolved trace. The method also includes calculating a contribution weight based on a root mean square (RMS) and a semblance attribute for each block at each time window. The method also includes summing the contribution weight for each block. The method also includes selecting a set of blocks that have summed contribution weight above a threshold value. The method also includes determining one or more apertures that encompass the set of blocks.

A method is described for performing full waveform inversion with partial variation regularization on seismic data to generate the multi-dimensional map of physical properties of the earth's subsurface. The method must be executed by a computer system.