Final depth-structure map from a reservoir at Paradis Field in Louisiana.
Colors represent horizon depth obtained from depth-conversion,
without residual depth-error correction.
Contours represent the final depth surface adjusted for residual error at wells,
then manually edited for vertical separation along fault polygons
in order to infuse some geologic common sense.

A solid and reliable structure map is key for any subsequent work.

Final depth-structure map from a reservoir at Maybulak Field in Kazakhstan.
Previous geologist interpreted the 10 m of missing section in the middle well
as stratigraphic thinning. After a 3D was shot ofver the field the missing section
was re-interpreted as a fault, the trace of which runs just north of the well
(see map).

Final depth-structure map from a reservoir at Maybulak Field in Kazakhstan.
Over the most important part of the field (where production takes place),
contours have been carefully hand-edited to honor all available data from wells.
Contours have to be properly offset across faults to reflect the amount of
vertical separation from fault cuts picked in wells.