Topic:
Time depth curve from sonic does not match that from checkshot data.

Description:
User has gone into Mode > Velocity survey and has selected a sonic log and a
checkshot and the two curves (red and blue) are the same above the top of the
sonic log but below top of log the slopes vary dramatically.  The drift error
curve is also huge negative drift of up to 800 ms.  

Solution:
The problem is that the sonic log does not have any units or may have units GF
does not recognise and so it assumes they are m/s whereas they should be
usec/ft.  

Need to use log curve editor and click on log curve and then on general
attribute editor and scroll to bottom of list and change storage units to
usecs/ft.



Last Modified on: 11-SEP-98