Quantitative Estimation of Property Parameters of Crude Oil Using Two-Dimensional 13 C– 1 H J -resolved Nuclear Magnetic Resonance Spectroscopy (HET-JRES)

Abstract

The physical and chemical properties of crude oil depend on the type and relative amount of hydrocarbons present. When it is not possible to elucidate the exact composition of the oil, “average structural information” may be a meaningful description of the bulk properties of the oil. In this paper, the application of NMR for this purpose has been extended by the use of two-dimensional (2D) ¹³C–¹H J-resolved spectroscopy (HET-JRES) to obtain the average structural information of a set of crude oils. This makes it possible to estimate the molar concentration of the different CH _n (n = 0, 1, 2, 3) spin systems in the sample. It is demonstrated here that structural information, derived from HET-JRES, correlates with the density and viscosity of the crude oils. Hence this new approach, which is rapid, may represent a useful method for crude oil characterization.