ABSTRACT: Horizon Slices over Reservoir Interfaces

Alistair R. Brown

Now that horizon slices are 10 yr old it is appropriate to review what they have contributed to the stratigraphic and reservoir interpretation of three-dimensional (3-D) seismic data. A horizon slice reconstitutes a depositional surface, once the surface of the solid earth, by slicing through a 3-D data volume along one structurally interpreted seismic horizon. Normally, seismic amplitude is the parameter displayed. Most interactive interpretation workstations make the generation of horizon slices routine and the use of color for their display straightforward.

Horizon slices provide spatial patterns in seismic amplitude that can be related readily to the shapes of geologic features. Many channels and sand bars have been identified this way. Horizon slices are particularly effective in Tertiary clastic sequences like the Gulf of Mexico, from which most of my examples are taken. Patterns of overlapping sand bodies indicate the thickest, most porous areas where a reservoir is most effective. Thus, horizon slices are of great value in reservoir development as they indicate where the reserves are greatest and also give indications of reservoir connectivity. Amplitude extrapolation often gives an accurate map of reservoir extent in addition to, or instead of, that resulting from structural delineation.

AAPG Search and Discovery Article #91003©1990 AAPG Annual Convention, San Francisco, California, June 3-6, 1990