Organic geochemical, palynofacies, and petrographic analyses examining the hydrocarbon potential of the Kharita Formation (Albian) in the Matruh Basin, northwestern Egypt

Abstract

A recent study of selected samples from the Cretaceous (Albian) Kharita Formation of Egypt revealed very good to excellent source rock (SR) potential for six intraformational, organic-rich intervals. This work investigates the SR potential of the entire Kharita Formation across the Matruh Basin, using samples from two wells: the Abu Tunis 1X well from the central part of the basin, and the Siqeifa 1X well drilled on the eastern margin of the basin. More strongly reducing conditions were developed in the centre of the basin, and resulted in the deposition of more organic-rich shales by comparison to the less reducing conditions that prevailed on the eastern basin margin, where the shales contain less organic matter. Deltaic intraformational shales and carbonates in the Kharita Formation of Abu Tunis 1X constitute a significant 120 m net of the potential SR. The lower Kharita Formation contains 34 m net shale SR of good to very good/excellent organic richness, yielding values of 1.14-11.59 wt % total organic carbon (TOC). The organic matter has low Hydrogen Index (HI) values (184-389 mg HC/g TOC) and amorphous organic matter (AOM) and relatively high non-opaque phytoclast frequencies indicating mainly gas/oil-prone organofacies (kerogen types II/III). The upper Kharita is more important, containing 86 m net shale/carbonate SR that has fair to good organic richness (0.8-1.8 wt % TOC), and lower HI (126-250 mg HC/g TOC), a dominance of non-opaque phytoclasts, and subordinate AOM frequencies, which together indicate gas/oil-prone organofacies (kerogen Types III/II). In the Siqeifa 1X well, Kharita deltaic intraformational shales and shaley dolostones comprise 80 m net SR, which has mainly fair to good to less very good organic richness (0.8-2.1 wt % TOC), whilst low HI (93-220 mg HC/g TOC), dominance of non-opaque phytoclasts and subordinate AOM indicate gas-prone organofacies (kerogen Type III). A relative upward increase in deposition of lignite and coaly carbonaceous material supports a gas-prone organofacies. Whilst thermal maturity indices only point to immature to early mature (pre-to early oil-window) SRs in both the Abu Tunis 1X and Siqeifa 1X wells, hydrocarbon exploration focussing on this potential source rock may be justified in areas to the southeast of the Matruh Basin, where modelling indicates this unit may have reached the late mature oil-to main gas-generation window.

Petrographic, palynological and geochemical recognition of dispersed organic matter in the black Anthracosia Shales (Sudetes, south-west Poland)

“…The study also in volved palynological and geochem i cal re search. Such re search pro ce dures are com monly ap plied to de ter mine both the hy dro car bon po ten tial and the depositional en vi ron ments of po ten tial source rocks (Carvajal-Ortiz and Gentzis, 2018;Ndip et al, 2019;Deaf et al, 2020;Körmösa et al, 2020;Mansour et al, 2020;Mohamed et al, 2020;Abou El-Anwar et al, 2021). We in clude a dis cus sion of re la tion ships be tween the con tent and types of macerals, palynofacies and Rock-Eval data for de ter mi na tion of the hydro car bon po ten tial of the Anthracosia Shales.…”

3D geological and petrophysical modeling of Alam El-Bueib Formation using well logs and seismic data in Matruh Field, northwestern Egypt

“…However, the coaly shale Sample 13 at depth (13,084 ft/3988 m) shows a relatively high S 2 value (2.74 mg HC/g rock) and high genetic potential (GP = S1 + S2) value (3.6 mg HC/g rock) (Fig. 8C) due to its higher organic richness 21,23 . The sum of S1 and S2 that represents the genetic potential (G.P.)…”

“…of the source rock (Fig. 8C) refers to the maximum quantity of oil and gas that a specific amount of the rock may generate under ideal conditions of burial depth and duration 23 . While the Production Index (PI), expressed as S1/(S1 + S2) (Fig.…”

Assessing Thermal Maturity through a Multi-Proxy Approach: A Case Study from the Permian Faraghan Formation (Zagros Basin, Southwest Iran)

“…), its inapplicability to pre-Devonian sedimentary successions that are devoid of higher plant fragments, and the suppression/retardation of its reflectance (e.g., [29][30][31][32][33][34][35][36][37][38]). In this case, the use of other optical approaches, with a different applicability, could represent a valid alternative to determine the thermal maturity of OM and the integration with geochemical results [39,40].…”