Three Dimensional Seismic Attributes And Density Models Of The Hydrocarbon Plays Inferred From Deep Seismic Reflection And Bouguer Gravity Data At Fayum Area, Western Desert, Egypt.

Abstract

El-Fayum Concession is located in the Northern part of the Western Desert of Egypt, south of Gindi Basin and north of Beni-Seuif Concession. The area under study is located 100 km to the southwest of Cairo city, in the northeastern portion of the Western Desert and northwest of Beni-Suef about 30 km, principally it covers area to the north of El-Fayum City and south of Qarun Lake and its one of vicinity El-Gindi basin. It is located between latitudes 29˚10’N, 29˚20'N and longitudes 30˚50'E,31˚00'E The present work is devoted to study the subsurface geologic structural features of the tops of Abu Roash, Bahariya and Kharita Formations, Dahab Member and Bsement Relif at central part of El-Fayum concession, Western Desert, Egypt.This study aims also at the evaluation of the petroleum system in the deep targets in the study area. The available data used in the present work include: 1) Bouguer gravity map of the study area, 2) Seismic data comprises (study area shot-point location map, twenty seismic lines selected from the seismic cube, velocity measurements in the form of vertical seismic profiles (VSP) for two wells (Silah-1X and North Silah Deep-1X) and synthetic seismograms of the Sinnouris Deep-1X and Fedyamen-1X wells. The purpose of gravity work is to investigate the subsurface geologic densities of the studied sections, using the available gravity data. In order to achieve the goal of this work, the following steps are carried out: compiling the Bouguer gravity map of the study area in one sheet, digitizing the Bouguer gravity map of the study area, interpreting the Bouguer gravity map of the study area qualitatively, selecting a profile for applying the stripping technique for all the studied geologic formations, determining the gravity effect and density values along the selected profiles, applying two-dimensional modeling to detect the basement depth, establishing the depth to basement map, drawing 3D view of the basement relief and finally carrying out structural map in the study area. A detailed gravity stripping technique is applied on selected profile. From the interpretation of this profile, we can concludethat, the density values are abruptly changed at the northeast location from Apollonia to Abu Roash-E which suggests high density with respect to the surroundings for Apollonia and Khoman Formations and low density with respect to the adjacent locations for Abu Roash A, B, C, D and E Members. The abrupt decrease in density of Abu Roash A, B, C, D and EMembers gives an indication of high porosity values which suggest carbonate built-up at these localities. The 2D depth map and the 3D view of the basement relief in addition to the structural orientation were studied and interpreted in the ranges of 2 km and 6 km to obtain the northeast southwest and northwest southeast main structural trends. The seismic interpretation indicatesthe structurally highs and lows in the study area that are inferred from the constructed seismic (time and depth) structural maps that show many prospective closures. These structural maps are matched with the thickness variations in the 3D isochrones maps for all the picked formations horizons. The study area is affected by the compressional forces of the Syrian Arc System of folding that took place during Santonian-Middle Eoc