Production capability of cased hole perforations in a cased completed well lined with a casing in an under-pressured gas producing reservoir is tested. A sonde of a dipole shear or array sonic (full waveform) acoustic well logging tool is moved in a well bore of the cased completed well in the reservoir across a depth interval of interest, which covers cased hole perforations zones in the reservoir. The well logging sonde has in it an acoustic energy source and acoustic energy receivers. Responses are logged at depth intervals of interest to the transit of Stoneley waves along the casing walls from the acoustic energy source to the acoustic energy receivers. Measures of characteristics (e.g., travel time and attenuation) of the Stoneley wave are obtained. The responses are then processed to indicate production capability of the cased hole perforations.

The embodiments of the present application disclose a method for acquiring a converted wave, an electronic device, and a readable storage medium, wherein the method for acquiring a converted wave comprises: acquiring a relational expression between a P-wave reflection coefficient and an incident angle by Zoeppritz equation; simplifying the relational expression between the P-wave reflection coefficient and the incident angle; calculating a derivative for the simplified relational expression between the P-wave reflection coefficient and the incident angle, to obtain an expression of a wave to be converted; correcting parameters in the expression of the wave to be converted to obtain a converted wave.

A sonic logging method is provided that transmits acoustic signals using a high order acoustic source and processes waveform data to identify a set of arrival events and time picks by automatic and/or manual methods. Ray tracing inversion is carried out for each arrival event over a number of possible raypath types that include at least one polarized shear raypath type to determine two-dimensional reflector positions and predicted inclination angles of the arrival event for the possible raypath types. One or more three-dimensional slowness-time coherence representations are generated for the arrival event and raypath type(s) and evaluated to determine azimuth, orientation and raypath type of a corresponding reflector. The method outputs a three-dimensional position and orientation for at least one reflector. The information derived from the method can be conveyed in various displays and plots and structured formats for reservoir understanding and also output for use in reservoir analysis and other applications.

A method is described that includes obtaining a multicomponent seismic data set for a subterranean region of interest and determining, using a computer processor, a PP stacked time-domain seismic image and a PS stacked time-domain seismic image from the multicomponent seismic data set. The method further includes transforming a recording-time axis of at least one of the PP stacked time-domain seismic image and the PS stacked time-domain seismic image to produce a pair of coarsely-registered PP and PS seismic images and filtering at least one of the pair to produce a pair of spectrally-matched PP and PS seismic images. Further, the method includes dynamically warping at least one of the pair of spectrally-matched PP and PS seismic images to produce a pair of fully-registered PP and PS seismic images.

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.

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.

An Earth model of a subsurface is created from acquired seismic data by migrating at least one of the incident wavefields and reflected wavefields to generate angle gathers for the seismic data and identifying for the subsurface an elastic Earth model equation for the incident wavefields and the reflected wavefields in the acquired seismic data. The elastic Earth model is a function of reflection angle between the incident wavefields and reflected wavefields and elastic parameters and is fit to the generated angle gathers through perturbation in the elastic parameters. The generated perturbations are used to create the Earth model of the subsurface.

Disclosed are systems and methods for high precision acoustic logging processing for compressional and shear slowness. The method comprises measuring, by a sonic logging tool, sonic data associated with a formation within a borehole, attempting a detection of a first arrival within the sonic data determining whether the attempted detection of the first arrival is accurate, and in response to an accurate detection of the first arrival determining a travel time of the first arrival, generating a coherence map including the first arrival, and determining, based on the coherence map, a characteristic of the formation.

Production capability of cased hole perforations in a cased completed well lined with a casing in an under-pressured gas producing reservoir is tested. A sonde of a dipole shear or array sonic (full waveform) acoustic well logging tool is moved in a well bore of the cased completed well in the reservoir across a depth interval of interest, which covers cased hole perforations zones in the reservoir. The well logging sonde has in it an acoustic energy source and acoustic energy receivers. Responses are logged at depth intervals of interest to the transit of Stoneley waves along the casing walls from the acoustic energy source to the acoustic energy receivers. Measures of characteristics (e.g., travel time and attenuation) of the Stoneley wave are obtained. The responses are then processed to indicate production capability of the cased hole perforations.

Methods and systems for identifying and locating fractures within a wellbore are described herein. One such method includes generating an acoustic wave. At least a first portion of the acoustic wave travels along a wall of the wellbore. The first portion of the acoustic wave interacts with a feature on the wall of the wellbore, such as a fracture, and generates a second acoustic wave. The second acoustic wave is detected to obtain acoustic data. A chevron pattern is identified within the acoustic data and a location for the feature is determined using the identified chevron pattern.