The amount of organic carbon present in a rock is a determinant factor in a rock’s ability to generate hydro-carbons. Hence, Total Organic Content (TOC) is a key parameter in the evaluation of source rocks and shale reservoirs. It is determined from an open-system pyrolysis in which the produced amount of CO2 is measured. The measurement is performed after removing carbonates from the system.
Additionally, the same analysis can be applied to estimate the total Carbon Content (TC) and calculate the inorganic carbon content (TIC). Using isotope measurements, even more precise total and organic carbon contents can be measured. A more in-depth investigation of the organic matter includes characterization of carbon, nitrogen and sulphur or a RockEval analysis to estimate the type and maturity of the organics.