API PUBL 7104 : 1997

The build-up of Naturally Occurring Radionuclides (NOR's), leading to the production of various types of Naturally Occurring Radioactive Material (NORM), is often encountered during gas and oil production c.q. treatment This gives rise to increased health hazards to personnel and to an environmentai waste management problem. Both the NOR's considered to be relevant for E&P samples and their analytical results in terms of activity concentration were found to be strongly dependent on the analytical contractor laboratory selected. This is caused by the lack of standardized procedures for the analysis of E&P NORM. In anticipation to future, more stringent NORM legislation on disposal and associated quantitative risk assessment projects, which may become endorsed by national authorities, the gas and oil industry is helped by quality assured, standardised NORM analysis procedures. Therefore, the identification of relevant NOR's and the validation of their analysis in various types of E&P NORM samples has been Investigated at Shell Research Amsterdam by carrying out a literature study and an (dutch) Interlaboratory test programme, respectively. The certification of the analytical results has been perfomed by a foreign (i.c.non-Dutch) institute. Only after the implementation of corrective actions as agreed by the participants, standardised analytical methods for E&P NORM samples could be defined. The standardised methods arrived at are described in general term in this paper.