Amoco Corporation

Bp Amoco Corporation

Kurt J Marfurt

R Lynn Kirlin

Steven L Farmer

Michael S Bahorich

Adam Gersztenkorn

James M Gridley

Rhoda H Bucker

Gregory A Partyka

Timothy D Stanley

Norman D Whitmore, Jr

The present invention is directed generally toward a method of processing seismic data to provide improved quantification and visualization of subtle seismic thin bed tuning effects and other sorts of lateral rock discontinuities. A reflection from a thin bed has a characteristic expression in the frequency domain that is indicative of the thickness of the bed: the reflection has a periodic sequence of notches in its amplitude spectrum, with the notches being spaced a distance apart that is inversely proportional to the temporal thickness of the thin bed. Further, this characteristic expression may be used to track thin bed reflections through a 3-D volume and estimate their thicknesses and lateral extent. The usefulness of this invention is enhanced by a novel method of frequency domain whitening that emphasizes the geologic information present within the spectrum. Although the present invention is preferentially applied to a 3-D seismic volume, it is alternatively applied to any collection of spatially related seismic traces.

Spectral decomposition for seismic interpretation

The present invention relates generally to the field of seismic exploration and, in more particular, to methods of quantifying and visualizing structural and stratigraphic features in three dimensions through the use of eigenvector and eigenvalue analyses of a similarity matrix. This invention also relates to the field of seismic attribute generation and the use of seismic attributes derived from similarity matrices to detect the conditions favorable for the origination, migration, accumulation, and presence of hydrocarbons in the subsurface. Additionally, the methods disclosed herein provide a new means for analyzing unstacked seismic data to uncover AVO effects. The invention disclosed herein will be most fully appreciated by those in the seismic interpretation and seismic processing arts.

Method of seismic attribute generation and seismic exploration

A method, a map and an article of manufacture for the exploration of hydrocarbons. In one embodiment of the invention, the method comprises the steps of: accessing 3D seismic data; dividing the data into an array of relatively small three-dimensional cells; determining in each cell the semblance/similarity, the dip and dip azimuth of the seismic traces contained therein; and displaying dip, dip azimuth and the semblance/similarity of each cell in the form a two-dimensional map. In one embodiment, semblance/similarity is a function of time, the number of seismic traces within the cell, and the apparent dip and apparent dip azimuth of the traces within the cell; the semblance/similarity of a cell is determined by making a plurality of measurements of the semblance/similarity of the traces within the cell and selecting the largest of the measurements. In addition, the apparent dip and apparent dip azimuth, corresponding to the largest measurement of semblance/similarity in the cell, are deemed to be estimates of the true dip and true dip azimuth of the traces therein. A color map, characterized by hue, saturation and lightness, is used to depict semblance/similarity, true dip azimuth and true dip of each cell; true dip azimuth is mapped onto the hue scale, true dip is mapped onto the saturation scale, and the largest measurement of semblance/similarity is mapped onto the lightness scale of the color map.

Method and apparatus for seismic signal processing and exploration

The present invention relates generally to a method for color mapping geophysical data. More particularly, the present invention provides a method for combining two or more components of multicomponent geophysical data, so as to produce unique color displays of the combined components of the multicomponent geophysical data.

Method for color mapping geophysical data

The present invention relates generally to a method of geophysical exploration and more particularly to a novel method for imaging multicomponent seismic data to obtain better depth images of the earth's subsurface geological structure as well as better estimates of compressional and shear wave interval velocities. In particular, measures are obtained of imparted seismic wavefields incident on reflecting interfaces in the earth's subsurface and of resulting seismic wavefields scattered therefrom. The incident and scattered seismic wavefields are employed to produce time-dependent reflectivity functions representative of the reflecting interfaces. By migrating the time-dependent reflectivity functions, better depth images of the reflecting interfaces can be obtained. For a dyadic set of multicomponent seismic data, the dyadic set of multicomponent seismic data are partitioned so as to separate the variously coupled incident and reflected wavefields in the recorded multicomponent seismic data. The incident and reflected wavefields are cross-correlated to form time-dependent reflectivity functions. The time-dependent reflectivity functions are then iteratively migrated according to a model of wavefield velocities of propagation to obtain better estimates of the compressional and shear wave interval velocity. The migrated reflectivity functions can then be stacked to produce better depth images of the earth's subsurface geological structures.

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Tulsa, OK, United States of America

Kurt J Marfurt