PETROLOGICAL AND PETROPHSICAL STUDIES ON UPPER RUDEIS IN WEST JULY AREA, CENTRAL GULF OF SUEZ, EGYPT

Abstract

This study represents 3D static geological model (stochastic and deterministic models) were prepared as a new approach to investigate Early Miocene Upper Rudeis reservoir, As! and Hawara formations of western offshore July Field area, Central Gulf of Suez. The work represents a major part of a sedimentological and petrofacies analysis revealed by petrophysical measurements of pore types and fluid saturations concerns with pore characteristics as arbiters of production performance of the reservoir. The aims of which were to model reservoir rock types and geometry, and to predict areas of best reservoir potential. The study is based on interpretation of cores, cuttings, special core analysis (SCAL) data, and wire line logs database of whole July field area and the wells distributed over some 25 km2 located in west July field area restricted between

latitudes 28° 241 58.111 and 28° 3i 35.9 11 N and longitudes 33" 21 1 00.011 and 33° 251

46.i1 E.

The Upper Rudeis of the study area forms a part of an extensive syn-rift stratigraphic sequence of the Gulf of Suez Rift basin. It represents a deposition on a slope of a large delta system represented by pulses of coarse grained sediment progradation from the western shoulder of the rift and controlled by a major structural transfer zone and has been uplifted as a normal fault bounded, resulted in dramatic lateral changes in thickness and facies. The large scale reservoir framework was defined to incorporate detailed reservoir layering and facies variation. Reservoir characteristics are controlled primarily by depositional and diagenetic heterogeneity at megascopic (field), macroscopic (well), and microscopic (rock sample) levels. Sequence stratigraphic analy'sis dramatically improved the understanding of the spatial variability of the reservoir properties. Spatial analysis of porosity and permeability were performed by considering heterogeneity in three dimensions. Core data was used to assess the heterogeneity of the permeability at different vertical and horizontal scales.