EPR study of kerogens from three Alaskan North Slope wells

Whole rock and isolated kerogens from the Seabee, Inigok, and Ikpikpuk wells of the Alaskan North Slope have been analyzed by electron paramagnetic resonance (EPR) spectroscopy. The sample suite includes representatives of the Torok, Kingak, Lisburne, Sadlerochit and Endicott formations. Power saturation studies show a definite correlation with the downhole maturation, the extent of aromaticity of the sample as defined by 13C NMR, and with the beginning of the oil window for the Kingak formation. Strong correlations within formations across the depositional basin are seen. Abrupt changes in EPR parameters indicate a change in the nature of the organic matter present and may reflect a facies change. Peak widths and spin densities correlate with maturity as indicated by vitrinite reflectance and sample aromaticity as measured in solid state 13C NMR spectra.