Integrating Kerogen and Bitumen Analyses to Enhance Characterization of Source Rocks in the Northwestern Desert of Egypt

By

 A.S. Alsharhan¹, E.A. Abd El-Gawad¹

(1) United Arab Emirates University, Al Ain, United Arab Emirates

 A close examination of the oil and gas potential of the Egyptian Western Desert confirms it as an area with substantial remaining reserves which have yet to be intensively explored. In the Western Desert, the source rocks are typically shale sequences associated with the transgressive front of the Upper Jurassic and Upper Cretaceous. The organic facies and the thermal maturity of these Mesozoic source rocks still need clarification. This study aims to integrate the geochemical data, obtained from kerogen and bitumen analyses, in the most effective combinations for evaluating and detecting new horizons as potential petroleum source rocks. This intends to promote and facilitate more exploration and development activities in the study area and its environs.

Core samples and selected cutting samples from Meleiha area were analyzed for total organic carbon, Rock-Eval pyrolysis, visual kerogen analysis, vitrinite reflectance measurements, bitumen analysis, biomarker studies and carbon isotope determinations. Four distinct organic facies are recognized in the well: Organic Facies I consists of the sandy shale sequences of the Bahariya, Kharita and Alam El-Bueib formations; Facies II and Facies III include the organically lean Alamein Dolomite and Masajid formations; and Facies IV comprises the organically rich interval of the Khatatba Formation at the base of the section penetrated. Only the rocks of organic facies IV are organically rich enough to act as principal petroleum source rocks. Maturity levels in the area range from immature to peak oil generation. The oil window is entered at approximately 8000 ft.