Naturally occurring radioactive materials (NORM) and petroleum origin

The presence of natural radioactivity in crude oil has been known since the beginning of this century. In the first half of the century, several theories proposed that alpha particles would play a role in petroleum origin. There are data available in the literature indicating 226Ra and 228Ra activity concentrations in radioactive scales in the order of 1.0 × 103 kBq/kg. It is reasonable to assume that these radionuclides had been concentrated about 100 times in the radioactive scales, taking into account the concentration factors typical of the fossilized organisms that originate the scales. Such data are consistent with petroleum formed some 25 million years ago. The implications of the activity concentrations of NORM found in oil fields to the validation of a new version of the alpha radiation theory of petroleum origin is examined.