Novel scintillators for logging while drilling

Abstract

The quality and characteristics of scintillating materials has improved in recent decades but mineral exploration gamma-logging tools have failed to capitalize upon these newer developments. Most tools still incorporate NaI crystals, which have been in use since the 1960s. Though well understood, reliable and robust the relatively low density of NaI makes for an inefficient detector. The challenges of incorporating gamma-ray spectroscopy sensors in a logging while drilling environment necessitate a re-evaluation of the important factors in scintillator choice for such sensors. Further, logging-while-drilling offers the potential to apply more sophisticated analytical techniques to the natural gamma-ray spectrum. We report on our study of newer and overlooked scintillation crystals and identify some key characteristics that we see as important for spectral analysis in logging while drilling.