This study was made for investigating the relationship between iodine and hydrocarbon accumulations and to determine iodine contents of formation waters in the Southeastern Anatolia basin oilfields where have been produced almost all of the Turkey oils (more than 95%). Formation water samples have taken from 234 production wells in 49 oilfields which have different geological structures where oil and gas production has performed by the Turkish Petroleum Company (TPAO). Also, the drilling mud samples from EBY-17 oilwell in Elbeyli (Adıyaman) field has collected, and their iodine analyses were carried out. Although the fields in the Southeastern Anatolia basin are old and some fields the secondary production methods are used, the high relationship between the oil and gas deposits and iodine were proved. As well as in other oil and gas fields in the world, not all reservoir waters in the Southeastern Anatolia basin are saline. However, all of them are rich in iodine. Therefore, the iodine-rich waters are a direct indicator for oil and gas producible reservoirs (containing mature hydrocarbon). Reservoir-targeted iodine geology and hydrogeology methods have simple sampling process, and laboratory analyses can result at a short time. The results are low cost, reliable and consistent. In the case when these data are utilized with other geological and geophysical methods, it is determined will be a practical and useful tool to reduce the hydrocarbon exploration risk to a minimum and to discover new deposits suitable for commercial production.

https://doi.org/10.19111/bulletinofmre.501519