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

摘要

A method is presented to estimate thermal maturity and concentration of sedimentary organic matter (kerogen) in organic-rich mudrocks using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The maturity estimate is based on stochastic regression model built on a diverse set of mudrocks containing type II kerogen and spanning a range of age, lithology, kerogen content, and maturity. The model accounts for variations in intensities of both aliphatic and aromatic C-H absorption bands. It has been validated on over forty mudrock samples with vitrinite reflectance values from similar to 0.3 to 3 %Ro. The maturity estimate is accurate on average to better than 0.2 %Ro up to vitrinite reflectance values of at least 3 %Ro, on par with uncertainties associated with vitrinite reflectance measurements.