Gamma spectrometry lithological sensor - has natural gamma radiation determined in particular energy spectral bands as function of characteristics of each formation

摘要

The method is for determining the lithological characteristics of geological formations which are undergoing sensing. The sensor provides measurement signals which enable many quantities linked with the natural gamma radiation from the formations to be determined. Each quantity depends on the intensity of the radiation in a certain energy spectral band. A determination is made of the values of several numerical coefficients as a function of one or more characteristics of each formation. From these coefficients, and the quantities associated with the gamma radiation, it is possible to derive resultant quantities representing lithological characteristics which are related to the measurable quantities by several linear relationships. The numerical coefficient have fixed values determined by calibration. The need to perform acoustic measurements, as well as gamma spectrometry; is eliminated.