Methods for simultaneous estimation of quantitative minerology, kerogen content and maturity in gas shale and oil-bearing shale

A method for estimating characteristics of a formation, comprising:

• (a) collecting and preparing a subterranean rock formation sample, wherein the preparing yields a non-demineralized formation sample;
• (b) measuring a Fourier transform infrared (FTIR) spectrum of the non-demineralized formation sample prepared in (a);
• (c) analyzing a spectral feature of the FTIR spectrum measured in (b) in a window including 2900 cm−1 to obtain an estimate of a maturity of kerogen in non-demineralized formation sample prepared in (a);
• (d) defining a representative kerogen standard spectrum from the maturity of kerogen estimated in (c);
• and
• (e) inverting the infrared spectrum measured in (b) using the representative kerogen standard spectrum defined in (d) to yield a quantitative mineralogy and a kerogen content of the non-demineralized formation sample prepared in (a) such that the kerogen maturity, kerogent content, and quantitiative mineralogy of the sample are obtained from a single FTIR measurement.