Print this pageSalvaging Dipmeters Using an Oil 
Field
"Dinosaur"
BREIMAYER, ANITA R. P. and LAURA BIGLEY PUZIO
Accurate, directly measured dip data is critical in today's high-tech
exploration environment. Dipmeters provide direct dip measurements at the
wellbore. They are integral to resolving velocities in 3-D surveys, essential in
evaluating thin-bedded lithologies, and useful in defining bed dips in sub-salt
or structurally complex plays.
Too often, an explorationist views the tadpole plot itself as measured data.
This is an error. The tadpole plot is simply one INTERPRETATION of the original
dipmeter resistivity data. The optimal display of this data is the 60" = 100'
scale playback. This display was the only record of the raw data before digital
tapes and computer correlation were developed. Technology has rendered this "oil
field dinosaur" nearly extinct. However, far from extraneous, 60" playback is
the key to dipmeter quality control. The correct correlation among the different
resistivity curves is the heart of the dipmeter computation.
We will offer a multi-step quality control procedure for maximizing dipmeter
quality through the logging and computing process. Examples of 60" data
illustrating several raw data problems that can result in confusing or
unreliable tadpole plots will be presented. This information will help the
explorationist assess the reliability of a tadpole plot, so that the dipmeter
data
can be used, or even discarded, in an appropriate, informed manner.