SOLID STATE 13C NMR FOR CHARACTERISING SOURCE ROCKS

Abstract

13C NMR has been used to measure the fraction of carbon which is aromatic, fa, in coaly source rocks from the Brent group, North Sea. Both cross-polarisation and Bloch decay techniques have been used. Good correlations are found with fa and inertinite content, and with Hydrogen index measured by Rock-Eval. Mean vitrinite reflectance was only found to correlate with fa when vitrinite concentrates were compared. These results demonstrate the potential of 13C NMR to estimate source rock potential in cases where Rock-Eval or petrographic analyses can give anomalous results.