Application of biological markers in the recognition of the geochemical characteristics of some crude oils from Abu Gharadig Basin, north Western Desert – Egypt

Abstract

The objective of this study is to establish the relationship between the hydrocarbons recovered from the Abu Gharadig Basin and Middle Jurassic Khatatba Formation, as well as the previously established Upper Cretaceous Abu Roash-F Member. A suite of fourteen crude oil and condensate samples from the Mesozoic reservoirs (Jurassic-Cretaceous) of the Abu Gharadig Basin (Western Desert, Egypt) was analyzed and geochemically compared with extracts from source rocks of the Middle Jurassic (Khatatba Formation) and the Upper Cretaceous (Abu Roash-F Member). Based on molecular indicators of organic source input, depositional environment and age-diagnostic biomarkers, at least two petroleum systems operate in the Abu Gharadig Basin; those derived from Late Cretaceous marine shales and Jurassic-Early Cretaceous non-marine organic-rich shales as source rocks and possibly a third system appears to be a mixture of them both. The correlation of some Abu Gharadig oils to a Late Cretaceous source establishes a petroleum system involving these marine Cretaceous source rocks.