Organic petrographic, geochemical, and sequence stratigraphic analyses for evaluating the hydrocarbon potential of Middle Jurassic–Lower Cretaceous rocks in Shushan Basin, northwestern Egypt

Integrated organic petrographic and geochemical analyses were made on organic-rich marine carbonate mixed clastic-carbonate rocks of Middle–Late Jurassic Early Cretaceous age from the Shushan Basin, Egypt to evaluate their hydrocarbon potential. Analyses allowed identification depositional settings, paleoclimate, three third order genetic stratigraphic sequences (SQ) with deposits assigned highstand (HST), lowstand (LST) transgressive systems tracts (TST). Deposition source in rifting Basin resulted interaction between Neotethyan sea level changes, tectonic, climate. The good reducing conditions developed during (Bajocian–Kimmeridgian) second rises climatically induced sedimentation deposition carbonates Khatatba Formation (SQ 1, early–middle TST) inner–middle shelf settings under anoxic–dysoxic conditions. Late (late Kimmeridgian) uplifting organic-lean clastic–carbonate strata Masajid latest same shelfal conditions, which experienced a notable dilution matter. late TST SQ 1 are very oil-producing rocks, where they show average generative potential mature oil-to early wet gas-window) highly oil-prone (Valanginian–Albian) associated overprinted Valanginian–Hauterivian rises, Aptian level, Albian rise. coeval climatic shift toward more humid clastic-dominated regressive units 2 (HST LST Alam El Bueib, Alamein, Dahab formations) 3 lower–upper Kharita Formation) marginal oxic HST poor richness early–mid (early–peak oil-window) oil/gas-prone gas/oil-prone matter, respectively exhibit fair oil rock no gas generation.