Master Thesis Organic Geochemistry of the Qahash Formation in the Offshore Well A1-NC 128, Cyrenaica Basin, NE Libya

Abstract

The purpose of this thesis is to characterize the organic matter content of two source rocks (shale and coal) collected from the Qahash Formation in the offshore Well Al-NC 128, Cyrenaica Basin, NE Libya. Petrographically, the studied samples are dominantly composed of Vitrinite macerals, followed by moderate Liptinite and low Inertinite macerals. However, the samples also contain a large amount of Framboidal pyrite. The TPI, GI, GWI and VI indices point towards Limno-Telmatic condition during the deposition of the shales and coals under mesotrophic to rheotrophic basin conditions. Geochemically, the Qahash Shale has a fair quality, whereas the Qahash Coal is considered as a poor source rock. Moreover, the Qahash Shale contains type II / III kerogen (mixed organic matter), while the Qahash Coal behaves as kerogens of type III and IV (Terrigenous organic matter). The organic matter is thermally immature. The Qahash Formation was deposited in a high salinity marine environment.