الفهرس 
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Abstract
The Upper Miocene sequences is characterized by its high hydrocarbon potentialities in the study area and onshore Nile Delta Basin and represented by Qawasim and Abu Madi Formation. The study area lies approximately 6 km South of El Mansoura city. It is located between Lat. 30 ° 54’ 00”, 31° 00’ 00”N and Long. 31° 20’ 00”, 31°25` 00”E approximately. The materials used in this study include available previous geological and geophysical studies as well as internal reports of companies are helpful to study the general stratigraphic column of the Nile Delta basin with special emphasis on the study area. Also, subsurface data are read in the form of lithostratigraphic information , and was used complete log sets from six wells to evaluate Abu Madi Formation and complete log sets from eight wells to evaluate Qawasim Formation in the study area, including the Gamma Ray (GR), Spontaneous Potential (SP), Caliper, Deep , intermediate and Shallow resistivities (HRLA, AIT), Micro-Spherically Focused log (MSFL), Photoelectric factor (PEF), and porosity tools (Density, Neutron, and Sonic), In the form of (LAS Format) and Formation micro image (FMI) in the form of (DLIS Format) and also twenty seismic lines in the study area. The data entry and corrected and interpreted by Special Soft wares as Petrel (Schlumberger, 2015) ,Techlog (Schlumberger, 2015) and Interactive Petrophysics (IP) v4.4 (@ Senergy, 2016). The Sedimentary Section in Nile Delta basin ranges in age from Paleozoic to Recent above Basement rocks. The penetrated succession of the study area ranges in age from Sidi Salim Formation (Middle Miocene age) to Recent. It consists of clastic and non-clastic rocks.
The total organic carbon log model results for the studied wells in south Mansoura area emphasis the shale of Kafr El Sheikh Formation is excellent quality source with mean value of (wt% TOC) ranges from 1.6 to 6%.also the shale of Sidi Salim Formation is very good quality source with maximum value of (wt% TOC) is 3%. on the other hand in Messinian sequences the Qawasim shales is is very good quality source with mean value of (wt% TOC) ranges from 1.37 to 2.5%.
Petrography and well logs interpretation: Petrography analysis of side wall core samples of Messinian reservoir rocks in Aga -1 well clarifies Abu Madi Formation (Level II) and Qawasim Formation (Level I & II) are mainly subarkosic arenite sandstone. Abu madi level II consists of coarse-grained to pebbly sandstone with the moderate to poor sorting and subangular to subrounded roundness. Common dispersed pore filling detrital clay matrix is observed .the dominate minerals are quartz, feldspar and rock fragments are rare. Qawasim sand levels consists of very fine-grained to medium grained sandstone with the moderate to well sorting and subangular to subrounded roundness. Evidence of grey to green clay matrix and shale fragments in the sandstones is mostly observed. The dominate minerals are quartz, feldspar, glauconite, and rock fragments are also abundant. Poorly cemented with patchy pore filling and grain replacive calcite/dolomite . The petrophysical evaluation results for Aga-1 Well proved the all Abu Madi and Qawasim sandstone levels are water bearing on the other hand Abu Madi level II sandstones is gas bearing in Salaka-1 Well and Qawasim Level I sandstone in Salaka-1 Well is gas bearing , Turbay -1 and Turbay-1 St Wells are hydrocarbon bearing.
Seismic interpretation: Several structural features were identified: normal faults, reverse faults, and anticline rollover structures and erosional channels of Messinian age. typical sequence stratigraphic features such as incised valleys, clinoforms, foresets, topsets and onlaps are identified and traced on the seismic lines allowing an extensive insight into sequence stratigraphic history of the Nile Delta, especially in the Messinian sedimentary succession.
Facies analysis and geological model: based on Formation micro image interpretation and side wall core analysis for Aga-1 well there are Seven lithofacies types were encountered in the Abu Madi Formation in South Mansoura area. These lithofacies are Massive conglomeratic sandstones, Cross-bedded Sandstones, laminated mudstones, parallel laminated sandstone, Massive sandstones, Massive mudstones and cross-laminated Sandstones. And there are four Facies association are fluvial channel deposits, marine-influenced tidal channel, Tidal channel /Bar complex and Channel fill complex. The Abu Madi facies are recorded through two zones fluvial and tidal estuarine in the study area. In the study area, the Eonile canyon is infilled by two main seismic units corresponding to two major sedimentary phases. The lower unit Abu Madi Level II consists of high-amplitude, continuous and parallel seismic reflectors. Abu Madi level II subdivided into two main cycles : the lower cycle is thick bedded basal sands grading into thinner beds and finer grained textures demonstrate fining up at various scales in this sequence .current bedding is dominantly medium to high angle and oriented between north and east with little variation .basal conglomerates as well as coarse lag deposits in some sandstones suggest deposition in a fluvial dominated environment with uni-directional flow properties which consider very good quality reservoir with average porosity 24% and average shale volume is 10% .these circumstance can be present in a rapidly prograding wedge with low sinuosity fluvial streams or within a system of braided rivers. The upper cycle is finer grained represents the gradual deepening of this environment with deposition interpreted in a, at times tidally influenced, floodplain or estuarine environment deposits brought in during relative highstand in this system whereas the cleaner sands present the fluvial dominated lowstand periods. The upper unit Abu Madi Level I divided into three cycles the lower cycle is sharp based, fining up, crossbedded sandstone at the base of this cycle is considered a channel fill sandstone. The diverse range of crossbed orientations suggests that no lateral restrictions on flow were present at this time allowing the channel to meander freely. The wide range of crossbeds azimuths suggest a high sinuosity channel. The middle cycle is thinner sandstones overlying the lower cycle, it show evidence of coarsening up textures and gradational bases typical for bar type sands, likely in a transitional environment as suggested by the infrequent shale drapes present. The upper cycle becomes much finer grained and is considered to represent a shallow marine mudstone with minor thin sheet sandstones interbedded. Possible conglomeratic layers may represent storm lag deposits in this environment. In Qawasim Formation there are nine lithofacies types were encountered in the Qawasim Formation in south mansoura area. These lithofacies are parallel laminated sandstone, laminated mudstone, cross-bedded sandstone, parallel-thin bedded sandstone, laminated siltstone, massive sandstone, massive mudstone, cross-laminated sandstone. And there are four facies association, Tidally-influenced fluvial channels, Overbank deposits, Estuarine tidal channel and Estuarine tidal bar. The sea level cycle shows that the (Lower Messinian) Qawasim Formation in the study area was deposited during the back filling of the previously formed incision. The back-fill is an interaction between the pure fluvial and marine depositional environments. Qawasim Formation in the study area is divided into two main levels, Qawasim level I &II. Qawasim level II is considered mainly tidally influenced fluvial a channeling system at the base of the Lower Messinian incision improve very good quality reservoir with average porosity is 21% and average shale volume is 9 %. On the other hand, during the deposition of the Qawasim level I, the transgression started to be the dominant regime according to the sea level cycles. This transgression turned the system to be an estuarine filling regime with tidal currents influx. This tidal influx affected Qawasim level I facies associations and formed estuarine tidal bars and channels deposits.