Chemostratigraphy and Sedimentology of Upper Cretaceous Sediments, North Central Rub’ Al-Khali Basin, Saudi Arabia:- An Integrated Approach to Reservoir Correlation

N.W. Craigie¹ and Reid¹

Abstract

Chemostratigraphy is a reservoir correlation tool involving the application of inorganic geochemical data. It is most effective when integrated with other techniques (e.g. sedimentology).

The current study involved the analysis of samples extracted from the Late Cretaceous interval (Albian to Turonian) in five wells located in the North Central Rub’ Al-Khali Basin, Saudi Arabia. Particular attention was given to the detailed correlation and sedimentologial interpretation of the Khafiji, Safaniya, Mauddud, Wara-Ahmadi, Rumaila and Mishrif Members of the Wasia Formation and the Lower Aruma Formation. This succession is dominated by platform carbonates alternating with thinner intervals of calcareous mudstones, silty mudstones, organic-rich laminated shales and fine-grained glauconitic sandstones. The shallow marine carbonates represent highstand progradations of distally steepened carbonate ramps. The muddier and sandier facies are thought to record late lowstand progradations (lowstand wedges) of pro-deltaic facies within an intrashelf basin. The organic-rich laminated shales probably represent periods of maximum flooding and anoxia. Platform carbonates are particularly well developed during the Cenomanian, and included well-developed porous reservoir facies formed by in rudist shoals and banks. Additional reservoirs are provided by fractured lagoonal carbonates, immediately below the Pre-Aruma Unconformity.

AAPG Search and Discovery Article #90188 ©GEO-2014, 11th Middle East Geosciences Conference and Exhibition, 10-12 March 2014, Manama, Bahrain