TOC in the Oil and Gas IndustryPowered by COBUILD (ti oʊ si) or total organic carbon
(Extractive engineering: Petroleum geology) TOC is the concentration of organiccarbon in source rock. ⇒ TOC is a measurement of the organic richness of sedimentary rocks. ⇒ The main purpose of the TOC measurement is determination of the total amount of organic carbon preserved in a sediment, shale, or coal. ⇒ TOC is the concentration of organic carbon in source rock.