Bulk pyrolysis and biomarker fingerprints of Late Cretaceous Galhak Shale Formation in the northern Melut Basin, Sudan: implications on lacustrine oil-source rock

Geochemical characteristics and genetic types of crude oils from a variety of geological reservoir rocks (Cretaceous–Palaeogene) in the Melut Basin, southern Sudan based on biomarker and carbon isotope composition

“…To determine the genetic link between the studied oils and their potential source rock, and as a result, oil–source rock correlation, this study used the lipid biomarker distributions and depositional environment‐related features for the analysed oil samples and the principal source rocks in the studied basin from the previous works of Dou et al (2007) and Hakimi et al (2021).…”

“…Consequently, the Melut Basin's most important oil‐prone source rocks are the Cretaceous Al‐Gayger and Galhak formation shales (Dou et al, 2007; Hakimi et al, 2021). These shales contain high OM content and contain mainly hydrogen‐rich Types I and II kerogen, indicating strong oil generation potential (Dou et al, 2007; Hakimi et al, 2021).…”

“…Consequently, the Melut Basin's most important oil‐prone source rocks are the Cretaceous Al‐Gayger and Galhak formation shales (Dou et al, 2007; Hakimi et al, 2021). These shales contain high OM content and contain mainly hydrogen‐rich Types I and II kerogen, indicating strong oil generation potential (Dou et al, 2007; Hakimi et al, 2021). Therefore, these features of the organic‐rich shale horizons in the Cretaceous Al‐Gayger and Galhak formations are considered to be the primary oil‐prone source rock and may have generates most of the produced oil in the basin.…”

“…However, these organic‐rich shales had biomarker features, including high Ph/Ph and Tm/Ts ratios and high C 29 and C 27 regular steranes compared with C 28 regular sterane as well as low C 29 /C 30 and C 31 R/C 30 hopane ratios (Dou et al, 2007; Hakimi et al, 2021). These features demonstrated that the clay‐rich source rocks in the Cretaceous Al‐Gayger and Galhak formation were deposited in a lacustrine environment under relatively oxic depositional conditions and are charactersied by the abundance of aquatic and land‐derived organic matter (Dou et al, 2007; Hakimi et al, 2021).…”

“…These Cretaceous rocks, including the Al‐Gayger and Galhak formations, are significant source rocks because of their lithofacies and distribution. The organic‐rich Galhak and Al‐Gayger sediments contain up to 5% total organic carbon and are likely the result of deposition in relatively oxic to suboxic lacustrine environments (e.g., Dou et al, 2007; Hakimi et al, 2021).…”