1. Thin beds have almost no impact due to destructive interference
Impact of Blocking
For typical seismic data, blocking on the order of m (10 ft) is the recommended minimum
Using coarser blocking helps identify the major stratigraphic contributors to the peaks and troughs
Sonic
Log
Sonic
Log RC
Synthetic RC
Synthetic - + - +
Time (sec)
SLIDE 11
Rather then inputting the sonic and density logs directly, we ‘block’ the logs to capture significant changes
This helps us associate major lithologic changes with specific peaks or troughs
The blocking process does not “corrupt” the synthetic trace
As shown here within the magenta rectangle, closely-spaced reflection coefficients of opposite sign results in destructive interference and, as a result, the closely-spaced RCs have almost no response on the final synthetic trace
Our experience is that logs can be blocked with a 3 m (10 ft) minimum layer spacing
Thin beds have almost no impact due to destructive interference
Coarse Blocking
Fine Blocking
Courtesy of ExxonMobil
L 7 – Well-Seismic 1