total organic carbon — Oil & Gas Glossary
The concentration of organic material in source rocks as represented by the weight percent of organic carbon. A value of approximately 0.5% total organic carbon by weight percent is considered the minimum for an effective source rock, although values of 2% are considered the minimum for shale gas reservoirs; values exceeding 10% exist, although some geoscientists assert that high total
Detailed Explanation
organic carbon values indicate the possibility of kerogen filling pore space rather than other forms of hydrocarbons. Total organic carbon is measured from 1-g samples of pulverized rock that are combusted and converted to CO or CO2. If a sample appears to contain sufficient total organic carbon to generate hydrocarbons, it may be subjected to pyrolysis.