الفهرس 
CHAPTER 1: INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Obaiyed field is the largest producing asset for Shell-Bapetco organization in Egypt both in terms volume and in area, which spans about 25km along N-S and 20km across E-W. The field is a gas condensate field located in the western desert about 500 km west of Cairo and discovered in 1992 with the first exploration well (OBA 2-2) which was tested for 13.7 Million Standard Cubic Feet per Day (MMSCF/D) and 1470 Barrel Condensate per Day (BCD). The estimated GIIP for the field was between 3 and 3.5 TCF from which more than 90% is present in Lower Safa Member of the Khatatba Formation.The main reservoir in Obaiyed field is the deep Jurassic sands in Khatatba Formation, especially Lower Safa sands that is considered a tight sand stone reservoir. The Lower Safa Reservoir is contained in a faulted dip-closure at a depth of about 4000 m True Vertical Depth Sub-Sea (mTVDSS). The reservoir is characterized by a high Net to Gross system, extended over the field with heterogeneous sand development. Formation evaluation in heterogeneous reservoirs can be very challenging especially in extensive fields, such as our field of study, which extend for several kilometers areas where the permeability varies from 0.01 mD up to 1 D within the same narrow range of porosity. A new petrophysical evaluation methodology was followed for performing the formation evaluation for the Lower Safa Reservoir. It depends on integrating well logs, core data and minerals analysis to overcome the reservoir heterogeneity in the field. Firstly, the Reservoir was separated into different Hydraulic Flow Units (HFU) using data of four cored wells covering different reservoir properties “permeability” in the field. Secondly, Electro-Facies model “Indexed and Probabilized Self-Organizing Map (IPSOM)” was built using suite of well logs analyzed into their principal components as the model input along with the rock typing data (HFU) derived from the cores as the model learning The final step was to tie between the X-Ray Diffraction Data (XRD) core analysis data result and that from the Electro-Facies model to assess the clay occurrence in each rock type. The aim of this study is to assess the reservoir heterogeneity and provide an illustration and reasoning for the permeability variations through analyzing well logs, core data and clay minerals distribution.