The Upper Senonian Dawi Formation of Belayim Marine Oil Field, Gulf Of Suez, Egypt, is a promising source rock. However, the generation and expulsion of hydrocarbons from it are not assigned yet. This study throws the light on the maturation (generation and expulsion) of hydrocarbons from Dawi formation through the construction and evaluation of a multi-1D approach within the framework of a fully integrated dynamic geologic model which was performed with PetroMod software. The first step in a new basin model is to construct a conceptual model, so in this study, the penetrated preserved stratigraphic sequence divided into uninterrupted time series based on petrophysical interpretation of the logged sequence and age-equivalent formations. Detailed well log interpretation was performed for the reservoirs and organic-rich source rock intervals and integrated into a conceptual model used for 1D basin modeling. Geochemical data is used to calibrate the log interpretation in this respect, which enabled basin modeling with extraordinarily high resolution of the stratigraphic sequence, resulting in a detailed and calibrated burial and thermal model. The simulations for four wells in the study area show differences in burial, thermal history and maturity, and, in consequence, differences in petroleum generation and expulsion with time. The maturity of the organic-rich interval varies from immature to mature with a different tendency to produce oil depending on the kerogen type, basin evolution, and burial through time. The Dawi Formation of the Upper Senonian age has relatively high organic carbon content and the capacity to generate petroleum liquids and possibly gas by secondary cracking. The Dawi Formation generated oil around the Late Miocene-Messinian (∼5.88 Mabp) during deposition of the Zeit Formation at oil windows’ depth of 2384 m (TVDss). The organic-rich interval of the Dawi Formation in Belayim Marine Oil Field concession, Dawi-S, entered the oil windows close to the Late Miocene (Messinian ∼5.88 Mabp) during the deposition of Zeit Formation and has been in the wet gas windows (gas onset) since ∼5.42 Mabp (Late Miocene-Messinian). The oil windows’ depths range between 2329 m (∼3.5 Mabp Pliocene-Piacenzian) at BM-23 well and 2384 m (∼5.88 Mabp Late Miocene-Messinian) at 113-M-27 well, before the maximum burial was reached. The expulsion of hydrocarbons mainly related to basin evolution due to the Messinian Time Event ∼5.2 to ∼4 Mabp (Pliocene-Zanclean) and it started at ∼5.2 Mabp. If sufficient residual kerogen has remained, increased temperature, according to the combined effect of Tertiary deposition and elevated temperature in the Late Tertiary, may have led to late-stage oil expulsion in favorable parts of the basin. |
