Sequence Stratigraphical Applications of Organic Microfacies Analysis to the Devonian Rocks, Faghur Basin, Western Desert, Egypt

The Paleozoic rocks of Egypt’s Western Desert remain under limited exploration. The complex subsurface structures create stratigraphic challenges that hinder petroleum exploration. This study evaluates the application of organic microfacies as a stratigraphic tool to address their exploration challenges and enhance our understanding of environmental changes. The Faghur-1X well penetrated the Devonian Zeitoun Formation, yielding numerous successful core recoveries. Seven of these cores were analyzed to delineate the lithological and stratigraphical variations. Three distinct organic microfacies types were identified within the studied section. These organic microfacies reveal significant paleoenvironmental shifts that represent key correlative events within the Devonian. These include liptinite-dominated–medium-organic-density distal facies (A) (cores 19-A, 18-B, and 17-A); vitrinite-dominated–high-organic-density proximal facies (B) (cores 14-A and 20-A/Band 20-C); and ironstone-rich and low-organic-density condensed section/distal facies (cores 18-A, 16-A, 15-A, and 15-B). These organic facies exhibit unique characteristics resulting from the interaction of organic matter with the rock matrix and environmental processes. These unique characteristics facilitate intra-basinal stratigraphic correlation. While commonly applied to hydrocarbon source rock evaluation, this study investigates the stratigraphic significance of organic microfacies for resolving subsurface geological problems.