Correction of natural gamma radiation logs for the effects of gamma ray emission from and attenuation by the borehole fluid

摘要

Disclosed are a method and a system for natural gamma radiation well logging in which the radiation detected in five energy windows is converted into a log of thorium, uranium and potassium (Th,U,K) which is corrected for the presence of gamma radiation emitting materials (e.g., potassium) and strong gamma radiation attenuators (e.g., barite and/or hematite) in the borehole fluid.