Source rock assessment of the Lower Cretaceous Ulus Formation of NW Turkey: implication to petroleum exploration

Abstract

The Ulus Basin of the Western Black Sea of Turkey contains Upper Jurassic-Recent sediments. Mudstone-marl and turbiditic shales of the Lower Cretaceous Ulus Formation have moderate source rock potential because total organic carbon (TOC) contents range from 0.34% to 1.18%. HI values are between 20 and 259. T-max values have been measured between 438 and 457 degrees C. Thus, maturity of the shales of the Ulus Formation is ranging from early mature-to mature. The formation was produced oil and wet gas-condensate. The Ulus Basin has several reservoirs, seals and traps. Although three exploration wells were drilled by Turkish Petroleum Company, the wells were abandoned as dry because of not reach to reservoirs.