LITHOLOGY DETERMINATION FROM THE CALCIUM AND MAGNESIUM ACTIVATION LINES

摘要

ABSTRACT OF THE DISCLOSUREIn the illustrative embodiments of the inventiondisclosed, the lithology of an earth formation traversedby a well bore is investigated by irradiating the formationwith a neutron source and generating an energy spectrum ofthe activation gamma rays resulting therefrom. From thespectrum thus obtained, the levelsof the activation gammaradiation emitted by 27Mg and that emitted by 49Ca aredetermined. The two intensity measurements are then combined,e.g. by forming a cross-plot or ratio thereof, to providean indication of the lithology of the earth formationand, in particular, of the extent of dolomitization of theformation.