Abstract: A method and software are disclosed for processing data values of a data array at equally spaced locations in two dimensions where the desired data values are nulls in the data array. The method and software first searches for linear ranges of contiguous nulls, and then performs incidental interpolation of all points in such range.

Abstract: A computer program and a method incorporated therein, called ContourFill, provides several features that enhance the display of contour maps. Even without using color, tick marks and gray-scale shading provide useful and cheaply reproducible representations of contoured surfaces. More dramatic effects are achieved when using color. Occasionally localized peculiarities are observed in the graphical outputs. These are usually traceable to data illegalities such as intersection of contour lines with other lines or penetration of contour lines into blanked areas. The localization of such effects is a tribute to the robustness of the computational algorithms.

Abstract: A method for filling the space between two neighboring polyline ribs is disclosed. The method, called ladder triangulation, likens two ribs, which generally outline a complex structure, to the two rails of a ladder. The ladder triangulation is built by adding rungs, each rung connecting a node on one rib to a node on the other rib and thereby (after the first rung) creating one more triangle. In essence the first rung connects node 1 of polyline 1 to node 1 of polyline 2, and the second rung connects either node 1 polyline 1 to node 2 polyline 2 or else node 1 polyline 2 to node 2 polyline 1, whichever rung is shorter. There are (n1+n2)/2 such rungs where n1 and n2 are the respective node counts of the two polylines, and computation is linear with node count. Where there are multiple polylines, the same process is repeated between polylines 2 and 3, 3 and 4, etc. and may also be repeated between the last polyline and the first one (cyclic rib fill).

Abstract: A method and apparatus including a programmed computer for carrying out the method is disclosed for identifying valid fault curves on a vertical seismic section, which typically is one vertical seismic section of a three dimensional volume of seismic data. A method for automatically picking or snapping two user seed nodes to valid nodes of a valid fault curve is provided. The invention includes a process for extending a two node valid fault curve in a vertical section upwards and downwards throughout such section. A method of translating a fault curve found in one section to another parallel and vertical section and to all other desired vertical sections of the volume is also disclosed.

Abstract: A two dimensional display is prepared representing a cross section of the earth and designed to establish natural data lineations. The vertical axis is marked in terms of a parameter of depth below the earth's surface and along the horizontal axis, are marked seismic receiver stations. For each station, a graph of an intrinsic lithologic property as a function of depth is computed and plotted beneath the corresponding station. Contour crossing points are determined at unit intervals along the plotted graph together with the sign of the corresponding derivative. Contour crossing points, beneath adjacent stations, that match as to numerical value and derivative sign are connected by contour segments. Shading patterns are applied to the zones between contour segments to enhance the natural lineation of the chosen intrinsic lithologic function.