Reply to Mr. Brooks
Warren G. Hicks · Geophysics · 1959
I agree that we have too long considered geophone surveys sacred. However, if a true two‐receiver log is run it should neither be sensitive to spacings nor to elapsed time since drilling. If, as in Figure 3, three logs are run yielding three different answers, at least two of them are incorrect. Inconsistencies among logs necessitate a standard check. The geophone survey is useful as a standard in measuring times over long intervals and has been of value in pointing out deficiencies in our logs. If logs are run which are insensitive to spacing, a valid argument exists for ignoring computed shot times which disagree with the log.