The Storage Logging Method

For the logging of geophysical parameters, one cost-effective and minimum-risk method for drilling projects is the application of so-called memory-logging sondes. These sondes are not run on a logging cable, but measure autonomously at the end of the drill string after they have been dropped into the drill string (very much like an inner core barrel), and land on the landing shoulder in the outer core barrel at the drill bit. When the drill string is pulled out of the borehole (trip-out), the sondes are pulled along with it and the data are stored in the sonde, which is why this method is commonly referred to as “logging while tripping”.