Abstract: A workstation computer system, and its associated method and program storage device, stores a novel software package known as "Variance Cube". The computer system is responsive to a plurality of seismic signals propagating through a cubic volume of an earth formation for generating a cube, representing said cubic volume of earth, where the cube includes a plurality of seismic data samples and where each seismic data sample has a corresponding "variance value" assigned thereto. The computer system also generates one or more maps, such as a time slice map, representing one or more slices through the cube. Each map displays and is used to determine certain geologic features which exist along the corresponding slice through the cube, each map including a plurality of the variance values representing the geologic features, each such variance value being defined as the degree to which an amplitude of each seismic data sample in the cube at a particular reflection time "t" varies about an average amplitude.

Abstract: Formation tops correlation is interpreted between sampled log curves by a weighted combination of covariance, the ratio of standard deviation, and the ratio of summed amplitude. This covariance function is computed and evaluated appropriately for the geologic environment over a sliding analysis window. Correlations are determined for any number of wells and any number of events in each well. Geologic rules are used to establish a parameter for the algorithm operation and for the analysis of the resulting function. The geologic rules include bounding guide horizons, sequence rules, and a covariance cutoff parameter. Bounding horizons are picked from pre-existing seismic or geologic interpretations and from map grids. The rule set includes onlap, truncated, conformable, and unstructured sequence definitions. Additional geologic complexity such as crossover, repeat sections, and inverted sections are accommodated by the rule set.

Abstract: An interpretation workstation based apparatus having an "Auto Fault" software stored therein automatically identifies a plurality of fault cuts in each of a plurality of horizons in a seismic data volume in response to a plurality of predetermined "horizon time structures".

Abstract: A method and associated apparatus for generating time slice maps and/or horizon maps, representative of a time slice or a horizon in an earth formation that is subject to a seismic operation, in response to received seismic data includes the steps of: (a) cross correlating a plurality of seismic traces from the seismic data and a corresponding plurality of quadrature traces associated, respectively, with the plurality of seismic traces to obtain a corresponding plurality of cross correlation functions "Q(.tau.)", (b) obtaining a plurality of particular values from the plurality of cross correlation functions "Q(.tau.)", at least one particular value being obtained from each cross correlation function, and (c) assigning the plurality of particular values to a respective plurality of reflection points on a map, each particular value being assigned to a different one of the reflection points, thereby constructing the time slice map and/or the horizon map.

Abstract: A processing system stores a special software known as the Cubemath software. The Cubemath software allows the processing system to process, analyze, and interpret a second set of seismic data relative to a first set of seismic data obtained from either a repeat seismic operation or a single seismic two processing method operation. A first set of 3D seismic data is collected at a particular location on the surface of the earth at time "t1", and a second set of 3D seismic data is collected at that same particular location on the surface of the earth (at a different time "t2" when the repeat seismic operation is being performed).