Investigation of the effect of tortuosity, hydrocarbon saturation and porosity on enhancing reservoir characterization

Abstract

Reservoir characterization and rock typing studies are required before implementing any enhanced oil recovery projects to select the most suitable technique. Effective characterization of the reservoir provides a comprehensive description of the entire reservoir, which reduces the errors in secondary and enhanced hydrocarbon recovery projects. Characterization of the reservoir insufficiently and inadequately will lead to the failure of most of the field development plans in terms of determining how to deal with a particular field and will also affect the effectiveness of secondary and enhanced hydrocarbon recovery. This study aimed to investigate and assess the effects of tortuosity, porosity and hydrocarbon saturation to enhance reservoir characterization. The characterization number and the capillary pressure equations were modified with the consideration of the tortuosity, hydrocarbon saturation, and porosity using core data obtained from an Egyptian oil field to improve the accuracy in determining the number of rock types available which will help in obtaining a permeability correlation for uncored wells and in the generation of static and dynamic models to predict the reservoir performance in the field development plan stages as well. Results showed that the characterization number and the capillary pressure equations that not taking into consideration important parameters such as the tortuosity, hydrocarbon saturation and porosity in their derived expressions led to a decrease in the accuracy and also an inaccurate number of rock types in some cases. This study developed permeability correlations for Egypt carbonate reservoirs to determine the permeability of uncored wells. Results also confirmed that the modifications on the characterization number and the capillary pressure equations could be implemented including these important parameters in the characterization methodologies. Results revealed the importance of these parameters in the characterization number methodology through the observed changes in the correlation R2 coefficients associated with the characterization number (CN) for five different rock types.