Isotopic ratio of Ni-60/Ni-61 has been studied in kerogen and bitumen sampl
es from three geologically and geographically different Indian petroliferou
s basins. It is observed that the ratio shows significant variation in kero
gen and bitumen samples, which is specific to a basin and also depends upon
type and nature of organic matter. This can be useful in oil source correl
ation and oil exploration.