Method of estimating azimuthal amplitude gradient is disclosed. This method uses a correlation of seismic attributes within a sliding volume of data to obtain azimuthal gradient.

A method can include receiving data sets where each of the data sets corresponds to one of a plurality of individual emitter-detector arrangements; calculating a multi-dimensional similarity metric for one of the data sets; and, based at least in part on the multi-dimensional similarity metric, assessing the one data set.

Fracture orientation ambiguity in the results of amplitude variation with offset and azimuth inversion is overcome by using additional geological information. Methods, apparatus and executable codes stored on non-transitory media cause, for each interface encountered by traces in a CMP gather, calculating angle-dependent azimuthal Fourier coefficients, performing a nonlinear inversion of amplitude versus offset and azimuth, AVOAz, equations built using the angle-dependent azimuthal Fourier coefficients to determine possible fracture orientations, and selecting one of the possible fracture orientations using constraints based on the additional geological information.

A method is described for predicting fault seal from a digital pre-stack seismic image including defining a window based on the at least one fault surface; calculating, via the computer processor, a seismic amplitude vs reflection angle (AVA) pattern at each spatial location on the at least one fault surface by obtaining a median value of all amplitudes within the window centered on the spatial location for a given reflection angle, and repeating the calculating for each angle in the digital pre-stack seismic image to create a complete AVA pattern along the fault surface; evaluating the complete AVA pattern along the fault surface to generate a predicted fault seal; and identifying geologic features based on the predicted fault seal. The method may be executed by a computer system.

Amplitude-versus-angle analysis for quantitative interpretation can include creation of a plurality of angle gathers from imaging a subsurface location with multiples in a near-offset range and imaging primaries outside the near-offset range and application of an amplitude-versus-angle analysis to the plurality of angle gathers to produce a quantitative interpretation pertaining to the subsurface location.

A method for generating seismic attribute gathers, the method including: computing, with a computer, seismic images with a field dataset; generating, with a computer, synthetic data corresponding to the seismic images; computing, with a computer, an attribute volume by applying an expectation method to the synthetic data; mapping, with a computer, the attribute volume to the seismic images; and generating, with a computer, seismic attribute gathers by stacking the seismic images mapped to the attribute volume.

A method is described for a manner of geologic analysis using seismic data. The method includes steps to produce improved amplitude versus angle (AVA) information that may be used for analysis of geologic features of interest including estimation of pore fluid content and quantitative probabilities of different fluid contents and/or rock properties. The method assesses the probability of hydrocarbons in a subterranean reservoir based on seismic amplitude variations along offsets or angles for portions of a seismic horizon. The method may be executed by a computer system.

The present disclosure discloses a fracture AVO inversion method for a fractured medium, wherein, said method includes: acquiring seismic data from the fractured medium; obtaining a reflection coefficient of the fractured medium, by an AVO inversion for the seismic data based on a newly-built equation. The present disclosure also provides a fracture AVO inversion apparatus and device for a fractured medium. The present invention can flexibly and accurately obtain properties of a fractured medium with impedance contrast (rock properties of the host media plus properties of thee fracture).

A computer-implemented method is described for a manner of geologic analysis using time-lapse seismic data. The method includes steps of receiving a first seismic attribute volume inverted from a seismic dataset recorded at a first time, a second digital seismic attribute volume inverted from a seismic dataset recorded at a second time, and a range of geological and geophysical parameters possible in the subsurface volume of interest; identifying a layer and area of interest; computing an attribute difference volume from the seismic attribute volumes; performing probabilistic attribute analysis of at least two of the first digital seismic attribute volume, the second digital seismic attribute volume, and the attribute difference volume using the range of geological and geophysical parameters; estimating time-lapse reservoir properties based on the probabilistic attribute analysis; and outputting visual information depicting the time-lapse reservoir properties via a user interface.

A system and method for analyzing geologic features including fluid estimation and lithology discrimination may include the steps of identifying areas of interest on a seismic horizon, computing statistical data ranges for the seismic amplitudes within the areas of interest, and analyzing the geologic features based on the amplitude variation with offset (AVO) or angle (AVA) curves including the statistical data ranges.