SUBSURFACE AND PETROPHYSICAL STUDIES ON HILAL OIL FIELD AREA- SOUTHERN GULF OF SUEZ-EGYPT

Abstract

The present work deals with the well logging analysis and fonnation evaluation of some rock units (Nukhul and Nubia fonnations), for eleven wells selected in the Hila! Oil Field area. The available logging data used were the resistivity, porosity tools (density, neutron and sonic logs), gamma ray logs and conventional and special core analysis.

Two well Jogging analysis techniques were carried out. The first is the graphical well logging analysis; in the fonn of Porosity-resistivity cross plots, Dia­ porosity cross plots, and Tri-porosity cross plots for the two respective fonnations of the Gulf of Suez sequence. The second is the analytical well logging analysis for the calculating the petrophysical parameters for the subsurface fonnation evaluation of the studied fonnations.

The accomplished analytical well logging analysis was in the fonn of the computer program (PETCOM). Such program was utilized for calculating fonnation water resistivity, total porosity, effective porosity, shale volume, the rock constituents through Litho-porosity cross plots, M-N and MID plots, and fluid saturation. The results of both the graphical and analytical fonnation evaluations are presented in different litho-saturation cross plots and a number of iso-parametric maps.

An evaluation for subsurface geologic data was carried out through isopach maps, lithofacies maps and structural relief maps. Also, the hydrocarbon potentialities of the studied area in the southern Gulf of Suez was discussed by using the obtained results of well logging data and subsurface evaluation. Regarding Nukhul fonnation, porosity ranging from 11% to 17% with low water saturation ( 15% to 100%) and shale volume of 30% to 60%. Nubia fonnation, on the other hand, shows a range of porosity from 12% to 21% with low water saturation (10% to 100%) and shale volume ofO% to 6%.