Application of New Techniques for Characterization of an Eocene Carbonate Reservoir in the Gulf of Suez, Egypt (SPE 154461)

A variety of recently developed techniques are available to improve carbonate rock characterization. This paper reviews the application of these techniques on an Eocene carbonate reservoir from the Gulf of Suez. Dolomite content was computed from spectroscopy data for direct extraction of the magnesium yield. This allowed computation of the dolomite volume while the photoelectric factor could not be used. Small amounts of dolomite were computed overall, with minimum impact of the dolomitization process over the porosity and permeability. Since rock texture has a strong impact on porosity and permeability in carbonates, it is necessary to include texture-sensitive tools in the evaluation. Based on NMR data, porosity partitioning analysis showed that the porosity is dominated by micro and meso pore sizes. While the default correlations used for NMR in carbonates considerably overestimate permeability, a modified SDR equation was applied to predict permeability more accurately, providing a good match to core data. Hydrocarbon properties have been found to vary vertically. NMR fluid identification stations were used to characterize the variation. Tar was identified based on the comparison of total porosity and NMR porosity. This is an important parameter as tar can affect the reservoir producibility. Fracture analysis was performed on a data set of micro-resistivity image and Stoneley data. The analysis performed on the Oil Based Mud micro-Imager identified the orientation of the fracture system and the sonic Stoneley wave processing determined that the majority of the fractures encountered in the reservoir were healed. This conclusion was supported by the core analysis results. The work presented in this paper demonstrates how it is necessary to integrate the measurements from various tools and sources to gain a good understanding of reservoir producibility in carbonates. The integrated evaluation was validated with core and well test results.