Thermal maturity and hydrocarbon generation modelling for the Lower Rudeis source rock and petroleum system analysis in Garra area, Gulf of Suez Rift, Egypt

Abstract

The Lower Rudeis Formation is an active source rock in the Garra region, which is characterized by a good hydrocarbon generative potential. The Lower Rudeis source rock reached the early mature stage in the Middle Miocene Langhian (15.5 Ma) and went through the mid mature stage at 0.9 Ma.. It was generated from a clay source rock, deposited under sub-oxic to oxic conditions and derived from an organic material composed mainly of terrestrial organic material. The Lower Rudeis source rock went through two phases of hydrocarbon generation and expulsion. The first phase occurred from 6.0 Ma to 3.4 Ma, while the second phase started at 3.4 Ma and continued until the present time, with a transformation ratio estimated of 42%. The oil expulsion increased to 16 mg/gTOC and gas expulsion to 40 mg/gTOC, thus the expelled hydrocarbons are mainly composed of mainly gas and some oil. In contrast to the southern province, the Garra region has a single petroleum system which is charged by pre-Miocene and Miocene, Lowers Rudeis, source rocks along vertical and lateral migration routes and the main Kareem-Rudeis reservoirs that were sealed by the Belayim evaporite. The current study is based on the geological, geochemical, biomarker and stable carbon isotope data, which were analyzed, interpreted and presented as burial, thermal and maturity models using the petroleum systems and basin analysis program (BasinMod software).