Petrophysical evaluation and parameters relations investigation of Nubia formation in October field, Gulf of Suez, Egypt.

Abstract

October Field is one of the most prolific and giant oil fields in Gulf of Suez. It has been decades producing since its exploration in the late seventies of the last century with hundreds of wells drilled.Petrophysical parameters such as shale volume, porosity, permeability, net reservoir thickness, net pay thickness and the ratio between them are highly important in oil industry as it indicates the best intervals in the reservoir to perforate and produce. This study aims to reach a reasonable evaluation of these parameters by calculating them from conventional well logs (Gamma ray, density, neutron and sonic logs) as well as integration of core data obtained from routine core analysis of 4 wells: OCT-A2B, OCT-B8, OCT-B6, OCT-K5.In light of the petrophysical characters for the Nubia reservoir, it shows good reservoir quality with porosity ranges from 13 to 16 percent and shale volume ranges from 18 to 20 percent. In addition, excellent pay thickness for the Nubia reservoir as it ranges from 74 to 96 percent and good oil saturation as it ranges from 36 to 47 percent. Empirical equations from plotting porosity versus permeability of routine core analysis is used to predict permeability in un-cored intervals, this method lead to low R2 correlation coefficient (0.03 in horizontal permeability and 0.21 in vertical permeability). In addition, information obtained of the possible direction trends of enhanced petrophysical parameters as loops with Northwest-Southeast of increasing porosity and decreasing shale volume were found. This indicates sweet spots for development opportunities.