The Geophysical Corner is a regular column in the EXPLORER, produced cooperatively by the AAPG Geophysical Integration and SEG Interpretation committees, and edited by M. Ray Thomasson. This month's column is titled "VSP -- The Link Between Geology and Geophysics."
VSP Links Geology, Geophysics
By RONALD C. HINDS and RICHARD KUZMISKI
Editor's note: Hinds is a senior geophysicist for PanCanadian Resources, Calgary, Canada; Kuzmiski is responsible for VSP and acoustic log processing at Computalog, Calgary.
Click on the figure below to view greater detail.
The full wavefield (both up- and downgoing events) zero-offset VSP data
in (A) shows high amplitude downgoing events. The upgoing events in
(B) can only be seen easily after wavefield separation (downgoing waves
are isolated and subtracted out of the data). In (C), the upgoing events
are aligned in two-way traveltime (+TT) and can be tied to the surface
seismic stacked section. The upgoing event colored orange intersects
the first break curve at the trace representing the depth of the interface
which caused the reflection.