الفهرس 
Introduction
Subsurface geologyOnly 14 pages are availabe for public view
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Abstract
The present study deals with evaluating the petrophysical parameters, building a sedimentary model of the Late Pliocene-Early Pleistocene El Wastani Formation and evaluates its hydrocarbon potentialities. This is achieved through analysis and interpretation of the available surface geological data and wire line logs for detecting the lateral and vertical variations of both reservoir and non reservoir facies of six wells distributed in the Rosetta gas field, offshore Nile Delta, Egypt.
The Rosetta Field lie in the western part of the offshore Nile delta between the Abu Madi and the Abu Qir trends. Gas was trapped in Pliocene El Wastani sandstones in the hanging wall section of the NE-SW trending Rosetta Fault. The sandstones reservoirs are informally termed from “A” to “F” with increasing depth concerning the “A”, “B” and “F” reservoirs we actually don’t have enough data, so that our main target of the evaluation was the “B”, “C”, “D” sands and Sequoia channel. The maximum reached thickness of that El Wastani Formation in the study area is 1245m at the Rosetta-5 well. The gross sand thickness of El-Wastani formation attains the maximum value of 425m at the down thrown side of the Rosetta fault while abruptly decrease at the up thrown side recording the minimum value of 60m East ward.
Gas encountered in the Rosetta accumulations is predominantly very dry methane with small amounts of condensate (CGR of 0.5-2 bbls/Mmscf). Although a biogenic gas source cannot be totally overruled, the presence of condensate proves at lease a partial thermogenic origin. Maturity model suggests that major gas generation began relatively recently, coincident with Plio-Pleistocene delta progradation.
The petrophysical analysis of El-Wastani Formation was determined by utilizing a complete set of wireline logs including resistivity, density, neutron, and natural gamma ray. The petrophysical parameters presented through some isoperimetric maps for showing the distribution of clay volume, effective porosity, and both of water and hydrocarbon saturation through the study area. The clay type and distribution was determined based on the relation ship between potassium and thorium it was found that its type is structural and or laminar so it doesn’t effect on the effective porosity within the formation.
The sedimentary model of the study area was built based on the geological interpretation of the formation micro image (FMI) which including deltaic mouth bars at the south represented by reservoirs from A to F and then changed to be sub marine channels at the north represented by Sequoia channel reservoir