New Vision of the Shuaiba at a Regional Scale

This reference is for an abstract only. A full paper was not submitted for this conference. Abstract The regional integration of well data, seismic observations and published information from the southern part of the Arabian Peninsula has led to a breakthrough in understanding the stratigraphy and depositional history of the Shuaiba and in extracting implications regarding hydrocarbon prospectivity. The Shuaiba Formation is composed of system tracts from two supersequences, and the following subdivision is proposed: The Lower Shuaiba contains a TST and HST of a supersequence (Early Aptian, earliest late Aptian), while the Upper Shuaiba is a LST prograding package of the next supersequence (late Aptian).The TST of the older supersequence is distributed more or less equally over the entire Shuaiba province and the HST of the same supersequence is characterized by the development of the Bab Basin with a well-marked differentiation between basin and margins. An unconformity separates this supersequence from the LST of the next Supersequence during which new carbonate facies prograded into the BabBasin. On the basis of this subdivision, we propose a new, unified stratigraphic nomenclature for the Shuaiba. Depositional facies associated with the 3 supersequence systems tracts are markedly different. Monotonous, widespread carbonate facies dominated the older supersequence. During the HST, organic-rich fine carbonates accumulated in the Bab Basin while rudist-rich facies lined and vertically enhanced the southern and western basin margin or developed as relatively large isolated platforms on the eastern slope of the Bab Basin. In the LST of the younger supersequence, new platforms prograded into the Bab Basin in a series of sub-linear, regular clinoforms that grew either parallel to the pre-existing southern and western margins of the Bab Basin or in a series of concentric rings, away from pre-existing isolated platforms. Extracting the detailed sequence stratigraphy of the clinoforms and understanding reservoir quality, presence of intraformational seals and trap configuration has allowed us to identify and predict areas of higher HC prospectivity in the southern part of the Arabian Peninsula.