Dual-Detector Lithology Measurements with a New Spectral Density Log


W. E. Schultz, A. Nunley, J. G. Kampfer, H. D. Smith, Jr.,
Welex, a Halliburton Company


The addition of a photoelectric factor (P.) measurement to density logging has proven to be quite useful in lithology identification. However, because of limited depth of investigation and strong sensitivity to elements with large atomic number, P. measurements have been adversely affected by borehole rugosity, mudcake, washout, and barite in the drilling mud. A new Spectral Density Log has been developed that provides a reduction in borehole sensitivity for lithology determination.