Early CIS – From the Backpack to the Slurpy Cell

This paper covers the earliest application of CIS, then called by its developer Computerized Potential Logging (CPL).  An  Alaska pipeline company did 100 miles of CPL in 1979. The paper includes the technical aspects of CIS as well as some anecdotes about those early days of CIS application.  After several years of working with contractors, the author of the paper, and Senior Corrosion Engineer for this pipeline company from 1978 through 1985, assembled and programmed equipment to do CIS at a time when off-the-shelf equipment was not available.  After that, the pipeline company no longer needed to rely on outside service providers to do their annual pipeline survey.  This application of CIS on the Alaska pipeline grew from a simple need for something better, to the first conception and application of the time-based survey which enabled CIS data interpretation to be done in the face of significant telluric current interference.  Regarding the paper’s title; the backpack refers to the first CPL unit to arrive in Alaska in 1979, it was hand-made and the size of a camper’s backpack, and the Slurpy Cell was the name given to the disposable reference electrodes that were made to facilitate the time-based telluric current survey.