Radiological and elemental analysis of well cuttings from Rajian oil field, Potohar Basin, Pakistan

A study was undertaken to assess the trace elemental concentrations and changes in these elemental concentrations with well depth of Well-09 of Rajian Oilfield in the Potohar Basin using neutron activation analysis (NAA). Well cuttings and rock samples were provided by the Oil and Gas Company Limited Pakistan (OGDCL). Principal component analysis (PCA) was applied which was helpful in identifying and grouping the elements whose concentrations vary with depth. Activity concentrations and annual dose rates were measured by calculating naturally occurring radionuclides in Rajian Oilfield samples. Annual dose rates were found to be in the safe limits. Contamination indices; i.e., pollution index (PI), integrated pollution index (IPI), Geo accumulation index (Igeo) and enrichment factor (EF) were also calculated. Pollution level was found from low to moderate. Enrichment factors (EF) for Samples RJS7and RJS10 were found to be extremely polluted in Hf, Rb, Sb, Sm, Ce, Sb and Sm.