Computing device, computer instructions and method for up-down separation of seismic data. The method includes receiving the seismic data, which includes hydrophone data and particle motion data; performing a first up-down separation, which is independent of a ghost model, using as input the hydrophone data and the particle motion data, to obtain first up-down separated data; performing a second up-down separation by using as input a combination of (i) the hydrophone data and/or the particle motion data and (ii) the first up-down separated data, wherein an output of the second up-down separation is second up-down separated data; and generating an image of the subsurface based on the second up-down separated data.

Methods and apparatuses for processing marine seismic data with a process of combined deghosting and sparse -p transformation. The process is formulated as an optimization problem. The optimization problem has an objective function that is a weighted sum of two norms: one norm is an Lp norm of the differences between the modeled data and acquired survey wherein the modeled data are derived from a model and a set of adaptive filters; the other norm is an Lq norm of the model; and the optimization variables and solutions are the coefficients of the model and coefficients of the adaptive filters.

An acoustic logging system determines slowness picks using acoustic waveform phase and amplitude data. An amplitude-based first-arrival-picking (FAP) technique is applied to acquired waveforms to derive a first set of slowness picks, and a waveform phase coherence technique is also applied to derive a second set of slowness picks. The first and second slowness pick sets are then compared in a variety of ways to determine a final set of slowness picks.

An acoustic logging system identifies hydrocarbon formation types by a real-time model-constrained mud wave slowness determination method using borehole guided waves. The system also combines data processing from different acoustic waveform processing techniques using an information sharing procedure, for example, using monopole source data and dipole source data, to further improve the processing results and to achieve more stable and reliable real-time shear slowness answers.

An acoustic logging method includes obtaining first horizontal transverse isotropy (HTI) angles resulting from a time domain HTI algorithm. The method further includes obtaining one or more second HTI angles resulting from a frequency domain HTI algorithm. The method further includes generating a first HTI anisotropy log including a relative angle log based on the first and second HTI angles. The method further includes generating a first color map of the first HTI anisotropy log and displaying the first color map.

Methods for well logging may comprise recording a pressure wave at a dipole receiver, processing the pressure wave with a Fourier transform, computing a frequency semblance from the Fourier transform, computing an adaptive weighting function, and estimating a shear wave slowness. A method for well logging may further comprise disposing a downhole tool into a borehole, activating the dipole transmitter, sensing the pressure wave with the dipole receiver, recording the pressure wave, processing the pressure wave with a Fourier transform, computing a frequency semblance from the Fourier transform, and estimating a shear wave slowness. Estimating shear wave slowness may comprise producing one or more adaptive weights, a combination of a coherence map, and a dispersion curve. Estimating shear wave slowness may further comprise preparing an acoustic well log from the adaptive weights, the combination of the coherence map, and the dispersion curve.

Computing device, computer instructions and method for improving accuracy of an image of a surveyed subsurface. The method includes a step of receiving seismic data (D) recorded with seismic sensors; a step of deghosting the seismic data (D) using a sparse.sub.T-Pinversion algorithm together with a low-rank optimization scheme and a high-cut filter to calculate ghost-free wave-fields (U.sub.0(t,x,y)) in the time-space domain; and a step of processing the ghost-free wave-fields (U.sub.0(t,x,y)) to generate the image of the surveyed subsurface.

Aspects of the disclosure provide for a method using clusters of sonic peaks from a logging tool to generate a log of an acoustic property of the formation as a function of depth.

Computing device, computer instructions and method for processing input seismic data d associated with a surveyed subsurface. The method includes: receiving the input seismic data d recorded in a first domain by seismic receivers that travel in water, the input seismic data d including pressure data and particle motion data; generating a model p in a second domain, which is different from the first domain, to describe the input seismic data d; processing the model p to generate an output seismic dataset with attenuated noise; and generating an image of the surveyed subsurface based on the output seismic dataset.

Methods are provided for determining properties of an anisotropic formation (including both fast and slow formations) surrounding a borehole. A logging-while-drilling tool is provided that is moveable through the borehole. The logging-while drilling tool has at least one dipole acoustic source spaced from an array of receivers. During movement of the logging-while-drilling tool, the at least one dipole acoustic source is operated to excite a time-varying pressure field in the anisotropic formation surrounding the borehole. The array of receivers is used to measure waveforms arising from the time-varying pressure field in the anisotropic formation surrounding the borehole. The waveforms are processed to determine a parameter value that represents shear directionality of the anisotropic formation surrounding the borehole.