Field Results of the Natural Gamma Ray Spectralog


P. A. Wichmann, V. C. McWhirter, E. C. Hopkinson, Dresser Industries, Inc.

5th Formation Evaluation Symposium of the Canadian Well Logging Society
in Calgary, May 5-7, 1975



The natural gamma ray Spectralog" was first run by Dresser Atlas in the late 1960’s and described in the literature in 1971 by Lock and Hoyert of Exxon Research. Since that time additional development of the system has resulted in imporved calibration that gives quantitative definition of the three most common sources of natural radioactivity, the uranium and thorium series and potassium-40. This is accomplished through spectral stripping processes and a more sophisticated computer panel.