You normalize well log the data to accentuate the geologic responses while minimizing the effects of well log vintage, bore hole conditions, well logging company and well log calibration to name a few.

From experience in dealing with digital well log data from multiple wells, almost all interpretation busts or failures, aside from using the wrong interpretation procedures, can be linked back to poorly calibrated data and not doing a proper and consistent normalization prior to analysis.

Given the well log data from 100 wells in an area where there is a spread in vintage and logging company, experience would suggest that at least 1/3 of the gamma rays will be miscalibrated, 60% of the neutron data will be miscalibrated, 10-25% of the bulk density data will be miscalibrated and 5-10% of the deep resistivity and acoustic data will be miscalibrated. Of course pretty well all the SP data will be different from well to well due to the variation in drilling muds but even that can be resolved through specialized detailed analysis and normalization procedures.

Can you afford not to normalize?

Leave a comment...
Copyright © Hitchner Exploration Services Limited, Calgary, Alberta
hitchner@nucleus.com