Research progress and prospects for the Re-Os dating of petroleum systems

The rhenium-osmium (Re-Os) radiogenic isotope system has been widely applied on the geochronology of the key timings of the petroleum systems. Here we focus on the application of Re-Os isochron age constructed with crude oil and low-maturity bitumen samples while discussing the optimization of Re-Os dating based on the understanding of the Re-Os systematics of crude oil. The commonly low Re and Os contents, limited (OS)-O-187/Os-188 homogenization, prolonged geological processes and the heat-related crude oil transformation processes encumber the construction of Re-Os isochron age with multiple crude oil samples. The main Re and Os bearer in crude oil is asphaltene while the Re and Os concentrations are higher in the fractions of asphaltene which are easier to precipitate. Heterogeneity in the Re-Os isotope composition may exist within the crude oil. This may be disadvantageous for multiple oil dating while opening the possibility of using the fractions of a single crude oil for Re-Os isochron dating. Continuing practical application and artificial experiments are still key for the proper application and understanding of the Re-Os systematics in petroleum systems in the future.