Sedimentary model for the organic reefs from the Lower Cretaceous Shuaiba Formation in the United Arab Emirates

Sedimentary characteristics of the organic reefs from the Lower Cretaceous Shuaiba Formation in the United Arab Emirates are discussed on the basis of outcrop and drilling data in integration with regional geological background. During the deposition of the Lower Cretaceous Shuaiba Formation,abundant reef-building organisms such as rudists and algae were well developed in the United Arab Emirates. The carbonate platforms in the Shuaiba Formation appear as the "ramp-rimmed platforms",and basinwards display the arrangement of shallow-sea low-energy carbonate shelf,shallow-sea high-energy carbonate shelf,deep-water low-energy carbonate shelf,basin-slope facies and deep-sea basin facies. The shallow-sea high-energy carbonate shelf and basin-slope facies zones are believed to be the profic areas due to the development of organic reefs. The high-energy facies zone on the shallow-sea shelf margins is delineated as the favourable area for the development of the rudistid reefs. The sedimentary models for the development of organic reefs and division of sedimentary facies for the favourable reservoirs are constructed for the Shuaiba Formation,and will be of significance to the oil and gas exploration in the organic reef reservoirs in the study area.