Hydrocarbon Volume Uncertainty of Mishrif Reservoir in Rumaila Field;Implications from Surveillance Data

Summary Mishrif reservoir is estimated to have contained more than 40% original reserve and approximately 50% remaining recoverable oil of Rumaila field. It is the most important reservoir affecting production profile of whole field in the long term future. The amount and spatial distribution of original reserve and final recoverable reserve are vital for development planning and subsequent surface processing capacity design. So, it is valuable to evaluate the reserve uncertainty of Mishrif reservoir. Presently, the reserve of Mishrif in Rumaila field is estimated by using porosity and permeability cut-offs empirically determined from static data, dynamic surveillance results and economic conditions are not incorporated during this process. The cut-offs are vital for reserve estimation and hence for development planning. But, there is no standard process and universal criteria for cut-offs determination in any type of reservoir, and there do exist some uncertainties. In this study, dynamic surveillance data like RFT, PLT are incorporated to evaluate the uncertainty of cut-offs and its impact on original reserve.