الفهرس 
GEOLOGIC SETTINGOnly 14 pages are availabe for public view
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Abstract
The area of study is located in the Razzak oil field, the Early Cretaceous Alamein basin, in the northern part of the Western Desert of Egypt. In the present study, integration occurred between the geologic and well log data of four wells (ERZK-115X, ERZK-15X, ERZK-100X and ERZK-98X wells), as well as the geophysical data represented by 30 seismic section to study the structural setting
,stratigraphic features and petrophysical parameters of the Apollonia , AR-G
,Baharyia ,Alamein and AEB formations.
The results of seismic interpretation are presented the form of time contour maps, average velocity maps and depth contour maps. These contoured maps illustrate the occurrence of NNE-SSW faults trend related to the Late Paleozoic rifting and the NE-SW faults trend related to the Late Cretaceous - Early Tertiary. Contour maps of the Alamien, Baharyia and Abu Roash formations show WNW-ESE trending normal faults of Late Tertiary, the structure type is a three-way dip closure, also termed faulted anticline dissected by normal faults of NW-SE trend of the Early Tertiary, that are downthrown to the southeastern direction. The NE-SW trend is most probably synchronous with the lower part of the Alpine orogeny, that produced the Syrian arc system of folding and dip-slip faulting during the Middle Mesozoic to the Late Mesozoic, Contour map of the Apollonia Formation reveals only the NW-SE trend of the Early Tertiary.
Also, seismic attributes technique was applied to enhance the information that might be subtle in seismic imaging, leading to better geological and geophysical interpretation. Several types of seismic attributes are performed, both structural and stratigraphic, as: Root mean square detecting amplitude variations for channels with density changes to the surround, local structural dip utilized to detect faults and stratigraphic terminations, Ant-tracking reveals the discontinuities in the seismic data useful for structural and stratigraphic terminations, Sweetness for hydrocarbon sand detection can be used for channel development and Relative acoustic impedance reflects geometrical property
contrast of the stratigraphic layering. After integrating the stratigraphic and structural analysis with the seismic attribute, a geologic model established for the study area geologic events for the characteristic stratigraphic features and the intervening structural elements.
The petrophysical properties of the Apollonia, AR/G and Baharyia formations in the study area have been evaluated, using complete wireline log suites extracted from four wells. The lithologic distribution predicted from the log data exhibits the lithology of the Baharyia Formation, as dominated by sandstones intercalated with calcareous shale. The petrophysical well log results of porosity of the Apollonia Formation ranges from 10 % to 60 %, porosity of the AR/G Member varies from 8 to 20 %, porosity of the Baharyia Formation varies from 17% to 20 %, the Apollonia Formation water saturation ranges from 36% to 85%, the AR/G Member water saturation ranges 15 to 95 %, the Baharyia Formation water saturation ranges 5 to 30 % respectively.
The isoparametic maps illustrate the reservoir characterizations (net-pay thickness, net-gross thickness, volume of shale, effective porosity, water and hydrocarbon saturations, and give better drilling results at the middle part of the area, while the productivity fades toward the northeastern and southern direction Facies and effective porosity modeling are established, to calculate the hydrocarbon reserves most accurately and rapidly. Results confirmed that, the Apollonia and Baharyia sandstone reservoirs having good petrophysical properties. Finally, after integration the constructed facies model and effective porosity petrophysical model, a geologic model established for the study area,
regarding the petrophysical and facies conditions.
Log curve shapes of the gamma-ray identified the depositional environments of both the AR/G Member and Baharyia Formation, where their curve shapes show a fining upward sequences, representing near shelf environment, and a coarsening upward sequence of the Baharyia Formation representing fluvio-marine environment.
Petroleum system of the study area showed that, the Cretaceous shales
were sampled from specific boreholes at the Alamien field. Their initial geochemical analysis exhibited that they contain sufficient organic carbon to generate hydrocarbons. The shales were found to contain marine, amorphous sapropelic and structured liptinite macerals (mainly Types I and II kerogen).
Organic-rich rocks with excellent potential to generate mainly oil are present in the Middle Jurassic Khatatba Formation, which entered the late mature stage of oil and gas generation window, at vitrinite reflectance measurements ranged between 1.0 and 1.3 Ro% during the Late Cretaceous. Meanwhile, good to fair source rocks of Alam El-Bueib Formation and Abu Roash G Member, within the early to mid and mature stages of oil generation window (with vitrinite reflectance measurements varied from 0.5 to 1.0 Ro%), developed at a time spawning from Late Cretaceous to Late Eocene.
Shales in the Abu Roash E and G Members reached the oil window during the Late Paleocene-Early Eocene, after the formation of structural traps, which occurred during the Late Cretaceous of the Alamien basin. Shales in the underlying Baharyia and Betty formations reached the oil window before the traps were formed. However, continued burial caused these formations to reach the wet-gas zone during the Late Miocene-Pliocene. Therefore, shales in the Abu Roash Formation E and G Members are considered to be the source rock for liquid hydrocarbons at Alamien basin. The Jurassic Ras Qattara and Khatatba formations are important oil and gas sources. Samples have been collected from both formations, to study the organic geochemical and some organic petrographic characteristics. The sediments of Ras Qattara and Khatatba Formations contain types III and mixed type II-III kerogen, with Hydrogen Index (HI) values ranging between 100 and 260mgHC/g TOC. Vitrinite reflectance data show that, the Ras Qattara and Khatatba sediments have reached the mature to late mature stages for hydrocarbon generation, as consistent with the Rock- Eval pyrolysis Tmax values. Based on these results, the Jurassic sequences have attained sufficient burial depth history and thermal maturity for significant hydrocarbon generation, migration and accumulation.