1. n. [Reservoir Characterization]

Variograms and semivariograms that have a directional component in addition to the normal distance component. Directional variograms and semivariograms are commonly used where geological features are heterogeneous. For example, fluvial environments dominated by valleys, channels and point bars are likely to have directional components that are detectable and that will influence the behavior of fluids in these formations. Geostatistical models that use directional variograms can be expected to be more reliable in these circumstances.

See: channel,  geostatistical modeling,  heterogeneous formation,  point bar,  variogram