Source Identification of Hydrocarbons in Carbonate Rocks -A Case Study of the Coqen Basin in Tibet

Carbonate rocks are both source rocks and reservoir rocks. Therefore, it is very difficult for us to deter-mine if they are reservoir rocks and contain hydrocarbons having migrated from other source rocks. But it is very important in decision making of oil exploration whether the oil in carbonate rocks is generated in situ or is transported from other sources. This paper describes the source identification method of hydrocarbons in car-bonate rocks with the Rock-Eval technology. Meanwhile, we also show the indicators of source identification for carbonate rocks including the oil potential identification parameter, P, Tmax and free hydrocarbon content S1. The Coqen basin in Tibet is an example of the hydrocarbon source identification for carbonate rocks. It has been proven that it is reliable to use the Rock-Eval technology to determine the carbonate rocks containing mi-grating hydrocarbons.