Vol. 7, Issue 2, Part A (2025)

This theoretical paper looks at gamma spectrometry methods for finding and measuring radioactivity in petroleum. It focuses on Sodium Iodide doped with Thallium (NaI(Tl)) and High-Purity Germanium (HPGe) detector systems. The comparison looks at how well the detectors work, how much energy they can resolve, how they work, and how to use math to figure out what the spectral data means. In this study, theoretical frameworks and computer simulations are used to show how both types of detectors work together in the petroleum business. There are mathematical models for figuring out activity concentration, spectral unfolding, and how to calibrate efficiency. There are also methods for estimating error. Simulations using Monte Carlo show how detectors react to different measurement shapes and sample types that are common in oil settings. In the petroleum industry, the results show the technical pros and cons of each detector system when used with naturally occurring radioactive materials (NORM). They also suggest the best detector to use based on monitoring needs and operational limitations.