Portable XRF spectrometer with helium flow as a tool for lithological interpretation

Abstract

Portable EDXRF (Energy Dispersive X-Ray Fluorescence) spectrometer with the ability to perform rock tests in a helium atmosphere was applied to prepare unique calibration coefficients and mineralogical models. These data could be used for the chemical profiling, chemostratigraphy, gamma-ray, TOC and lithological interpretation of borehole geological profile. The measurements were conducted on 19 samples of sandstones and compared to the XRF data without helium flow. The acquired dataset was calibrated to the chemical laboratory tests (ICP-MS), gamma-ray spectrometry measurements (RT-50) and combined with the mineralogical data (XRD). The new methodology enables the measurement of sodium and enhances the possibility of detecting magnesium, thorium and uranium, compared to standard handheld XRF spectrometers. The applied method is dedicated to whole cores (without sample preparation) or cuttings which must be cleaned, dried, milled and pressed.