Abstract
The field under study is an anticline carbonate reservoir onshore Abu Dhabi, UAE. It produces from Lower Cretaceous Reservoir. The integration of core data, log data and laboratory chemical analyses highlighted the presence of bitumen at the base of the reservoir in many wells. The bitumen has a negative impact on reservoir performance; it acts as a permeability barrier for production and injection, and also reduces effective porosity; i.e. affects both flowing and storage capacities of the field. Moreover, it reduces the recoverable oil from the field.
This paper discusses the methodology used to evaluate the bitumen in the reservoir in terms of the occurrence in the wells, the thickness, and the distribution across the field. It suggests the structure evolution of the bitumen to help in tracing it in non cored wells and also to define the bitumen intervals in new wells. The paper also highlights the technique used to incorporate the results in the 3D reservoir model.
Implementation of the results allows better understanding of the reservoir performance due to the presence of bitumen intervals and enhances the reservoir history match of the 3D reservoir model. The results are currently used as inputs in several ongoing full field reservoir studies such as PVT, and wax & asphalting scale deposit studies.
