A simultaneous sources seismic acquisition method is described that introduces notch diversity to improve separating the unknown contributions of one or more sources from a commonly acquired set of wavefield signals while still allowing for optimal reconstruction properties in certain diamond-shaped regions. In particular, notch diversity is obtained by heteroscale encoding.

Systems and methods for generating seismic images of subterranean features including: receiving raw seismic data of a subterranean formation; selecting a portion of the raw seismic data; transforming the selected portion of the raw seismic data from a first domain to a second domain; generating soft constraint data corresponding to the selected portion of the raw seismic data; calculating at least one weight using the generated soft constraint data; generating a weighted transformed data set by applying at least one weight to the transformed selected portion of the raw seismic data; selecting at least one data point of the generated weighted transformed data set; and removing the selected at least one data point from the weighted transformed data set to generate revised seismic data.

Methods of analyzing and optimizing a seismic survey design are described. Specifically, the sampling quality is analyzed as opposed to the overall quality of the whole survey. This allows for analysis of the impact of the offsets, obstacles, and other aspects of the survey on the sampling quality, which will improve the ability to compress the resulting data and minimize acquisition footprints.

Waves from cement bond logging with a sonic logging-while-drilling tool (LWD-CBL) are often contaminated with tool waves and may yield biased CBL amplitudes. The disclosed LWD-CBL wave processing corrects the first echo amplitudes of LWD-CBL before calculating the BI. The LWD-CBL wave processing calculates a tool wave amplitude and a phase angle difference as the difference of the phases between the tool waves and casing waves. The tool waves are then used to correct the LWD-CBL casing wave amplitude and remove errors introduced from tool waves. In conjunction with the sets of operations described, the LWD-CBL wave processing also include array preprocessing operations. Array preprocessing may employ variation of bandpass filtering and frequency-wavenumber (F-K) filtering operations to suppress tool wave.

Processes and systems are described for generating an image of a subterranean formation from seismic data recorded during a marine survey that employed a moving vibrational source. Processes and systems compute an up-going pressure wavefield from pressure data and vertical velocity data recorded in the marine survey. A direct incident downgoing vertical velocity wavefield that includes Doppler effects created by the moving vibrational source and characterizes a source wavefield and source ghost of the moving vibrational source is computed and deconvolved from the upgoing pressure wavefield to generate a subsurface reflectivity wavefield. The subsurface reflectivity wavefield is effectively free of contamination from the source wavefield, the source ghost, and the Doppler related effects. Processes and systems generate an image of the subterranean formation based on the subsurface reflectivity wavefield, thereby enhancing resolution of the image by attenuating the source-motion effects, source signature, and source ghost of the moving vibration source.

A method for calculating a velocity vp(f, T.sub.opt) of a spatially aliased wave that propagates along a cable includes tensioning the cable, wherein plural sensors are distributed along the cable; measuring with the plural sensors a parameter that is associated with vibrations that propagate along the cable; calculating a phase velocity vp(f) of the spatially aliased wave that propagates along the cable, as a function of a time frequency fin a spatial-temporal frequency domain FK; calculating a model-based velocity vp(f, T) of the spatially aliased wave as a function of the time frequency f and a tension T in the cable; and calculating the velocity vp(f, T.sub.opt) of the spatially aliased wave using a model-guided regression, which is based on the phase velocity vp(f) and the model-based velocity vp(f, T). The velocity vp(f, T.sub.opt) is a function of the temporal frequency f.

A method for deblending seismic signals includes entering as input to a computer recorded signals comprising seismic energy from a plurality of actuations of one or more seismic energy sources. A model of deblended seismic data and a blending matrix are initialized. A blending matrix inversion is performed using the initialized model. The inversion includes using a scaled objective function. The inversion is constrained by a thresholding operator. The thresholding operator is arranged to recover coefficients of the model of the deblended seismic data that are substantially nonzero, against a Gaussian white noise background. The thresholded model is projected into data space. Performing the blending matrix inversion is repeated if a data residual exceeds a selected threshold and the inversion is terminated if the data residual is below the selected threshold. At least one of storing and displaying an output of the blending matrix inversion is performed when the blending matrix inversion is terminated.

Disclosed are methods, systems, and computer-readable medium for a full seismic wavefield de-aliasing workflow. To achieve the de-aliasing, the workflow employs a four-dimension (4D) anti-leakage anti-aliasing regularization algorithm. The workflow involves application of successive de-aliasing steps while restricting computations only to the significant spatial dimensions. In areas of strong elastic property variation in the near-surface, the benefit of de-aliasing the full wavefield is both significant and demonstrable. In addition to achieving de-aliased sampling of the full wavefield, the workflow reduces the complexity of both the computational and geophysical aspects of the problem of de-aliasing full wavefields.

Systems and methods that include receiving reservoir data of a hydrocarbon reservoir, receive an indication related to selection of a wavefield propagator, application of the wavefield propagator utilizing Fourier Finite Transforms and Finite Differences to model a wavefield associated with a Tilted Orthorhombic media representative of a region of a subsurface comprising the hydrocarbon reservoir, and processing the reservoir data in conjunction the wavefield propagator to generate an output for use with seismic exploration above a region of a subsurface comprising the hydrocarbon reservoir and containing structural or stratigraphic features conducive to a presence, migration, or accumulation of hydrocarbons.

A method for calculating a velocity vp(f, T.sub.opt) of a spatially aliased wave that propagates along a cable includes tensioning the cable, wherein plural sensors are distributed along the cable; measuring with the plural sensors a parameter that is associated with vibrations that propagate along the cable; calculating a phase velocity vp(f) of the spatially aliased wave that propagates along the cable, as a function of a time frequency fin a spatial-temporal frequency domain FK; calculating a model-based velocity vp(f, T) of the spatially aliased wave as a function of the time frequency f and a tension T in the cable; and calculating the velocity vp(f, T.sub.opt) of the spatially aliased wave using a model-guided regression, which is based on the phase velocity vp(f) and the model-based velocity vp(f, T). The velocity vp(f, T.sub.opt) is a function of the temporal frequency f.