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Organic facies and hydrocarbon potential of the early-middle Albian Kharita
Formation in the Abu Gharadig Basin, Egypt, as demonstrated by
palynology, organic petrology, and geochemistry

Research Authors
Thomas Gentzisa, Humberto Carvajal-Ortiz, Sameh S. Tahoun, Amr Deaf, Seare Ocubalidet
Research Abstract

During the past decades, exploration activities carried out in the Western Desert of Egypt by several oil companies
revealed the oversimplified approach to the study of sedimentary basins in this region. The current study
evaluates and discusses the palynology and palynofacies of the clastic succession of the Kharita Formation
(Albian) in one of the most petroliferous, deep seated, fault controlled basins in the Western Desert of Egypt, the
Abu Gharadig Basin. Although the focus is on the palynofacies association, the hydrocarbon potential of the
Kharita Formation will also be addressed by means of organic petrology and Rock-Eval pyrolysis. Marine
Cretaceous source rocks have generated substantial quantities of oil and gas in the Abu Gharadig rift Basin.
Moreover, Abu Gharadig Basin is characterized by containing not only oil/gas generating source rocks but also
reservoir rocks with appreciable porosities and permeabilities. Palynological, TOC/Rock-Eval pyrolysis, and
vitrinite reflectance (VRo%) data from 26 cuttings samples recovered from the Kharita Formation in the BED 2-
1× well, are presented. The palynological age dating (AL-2 Palynozone) confirmed early to middle Albian age
based on the first downhole appearance of the marker Concavisimisporites punctatus. The optical and visual
characterization of the palynofacies associations showed two distinct palynofacies associations that alternated
with each other. Kerogen type III to III/II was recorded based on the dominance of phytoclasts and opaque
organics. Some intervals showed a slight dominance of amorphous organic matter (AOM). Thermal Alteration
Index (TAI) values of 2+/3-measured on the psilate trilete spores, in combination with vitrinite reflectance
(VRo) values in the range from 0.51 to 0.62%, and the yellow to dull-yellow colors of the liptinite macerals
exhibited under UV light excitation indicate immature to the early stage of the oil window. Tmax values from
Rock-Eval pyrolysis range from 426 to 438 °C also confirm the low maturity of the organic matter. Thin coal
stringers were recorded within the Kharita Formation having slightly higher VRo,ran values (0.64 to 0.76%),
which is possibly the result of differences in mineral matrix variations within the Kharita Formation. Based on
the low TOC (avg. 0.71 wt%), S2 (avg. 0.97 mg HC/g rock), and HI (avg. 149 mg HC/g TOC) values from pyrolysis,
the hydrocarbon potential of the Kharita Formation in the studied well is considered to be low.

Research Department
Research Journal
International Journal of Coal Geology
Research Member
Research Publisher
Elsevier B.V.
Research Rank
1
Research Vol
209
Research Website
www.elsevier.com/locate/coal
Research Year
2019
Research Pages
27–39