Kerogen thermal maturity and content of organic-rich mudrocks determined using stochastic linear regression models applied to diffuse reflectance IR Fourier transform spectroscopy (DRIFTS)

Estimating the kerogen content of mudrocks using infrared (IR) spectroscopy is challenging because the absolute intensities of aliphatic and aromatic CH absorption bands in infrared spectra are influenced by both kerogen concentration and composition, and composition changes as a function of maturity and type. A scaling factor for type II kerogen standard spectra has been derived as a function of maturity, such that the maturity estimate from the model is used to apply the scaling necessary to estimate kerogen content. The resulting kerogen concentrations agree with reference concentrations within about 1.5 wt% for marine mudrocks. Thus, this approach provides a rapid and integrated analysis of kerogen maturity and content, in addition to established mineral analysis.