A.Y. El-Naggar

API gravities, vanadium, nickel, sulfur, and their relation to gross composition: Implications for the origin and maturation of crude oils in Western Desert, Egypt

ABSTRACT In the present study, the geochemical analyses of API gravities, vanadium, nickel, sulfur, and bulk composition were performed on eight samples from productive wells in Gindi, South Deep Abu-gharadig, Abu-gharadig, Dahab-Merier, and Faghure basins locates in the North Western Desert. The results were used to describe the source organic matter input, depositional environment, assess the degree of thermal maturity, and to correlate between crude oils to determine the genetic relationship between hydrocarbon generation and their source rock for the studied oil samples. The results showed that a wide range of crude oil parameters exists in this data, indicating that a variety of oil types is represented. Crude oils range from unaltered to altered by vanadium, nickel, and sulfur concentrations, V/Ni and saturate fraction were used to classify the oils. Oils are classified into two groups. Group I contains oil samples from Gindi, South deep Abu-gharadig and Abu-gharadig, and Dahab-Merier that are generated from organic matter input deposited in marine environment under anoxic to suboxic conditions. Group II from Faghur basin possess high Pr/Ph ratios suggesting high contribution of terreginous organic matter deposited under relatively oxic conditions.

Petroleum geochemistry of crude oils and oil: source rock correlation of some wells in the North Western Desert, Egypt

Three crude oil and three extract samples collected from three source rocks namely Bahariya, Alam El Bueib, and Khatatba Formations from the Egyptian productive wells namely: Bed 2-1, Bed-2, and AG-1 oil fields. The oils were analyzed geochemically, including sulfur content and API gravity. Capillary gas chromatographic analysis was applied on each saturated hydrocarbons from oils and extracts to assess the correlation between the crude oils and the potential source rocks in order to confirm the indigenous sources for the petroleum generation of studied oil fields. The results show that the oil samples are originated mainly from marine organic sources deposited in reducing environment. By correlation between the source rocks and crude oils, we show that there is a good correlation between the extracts of Alam El Bueib and Khatatba source rocks with crude oils; while the extracts of Bahariya source rock show no correlation with the studied samples. These evidences indicate that Alam El Bueib and Khatatba source rocks seem to act as a source and reservoirs for oil generation in the studied oil fields.

An Organic Geochemical Characterization of Crude Oils from El Hamd and Bakr Oilfields in the Gulf of Suez, Egypt

Abstract Seven crude oil samples were collected from wells of the El Hamd and Bakr oil fields located in the central Gulf of Suez and their chemical composition, API gravity, sulfur content, and asphaltene content were determined. Nickel and vanadium contents were measured using atomic absorption spectroscopy. Saturated paraffinic hydrocarbon fractions were subjected to gas chromatography in order to investigate carbon number distribution. Terpanes and steranes biomarker distributions have been determined using gas chromatography-mass spectroscopy in order to characterize the type of organo-facies, oil classes, depositional environments of the studied crude oils, and to assess the thermal maturity level for oil generation. It has been found that mature oils are generated from marine shales and carbonates are enriched in marine algae with a contribution from terrestrial organic matters.

Application of Molecular and Polycyclic Aromatic Sulfur Compounds in Evaluation of Some Egyptian Crude Oils

Abstract The molecular markers (n-alkanes, dibenzothiophene, phenanthrene, methyldibenzothiophene, and methylphenanthrene) have been determined in eight oil samples from different Egyptian oil fields. These parameters are used together to provide information on source organic matter input, depositional environment, and the maturity of crude oils. The results showed that the crude oil samples are classified into moderately mature oil, which includes Yidma-6, N. Ras Qattara-3, Alamein-1, and Ghana-1 wells, generated from mixed organic sources in reducing environment, characterized by low wax content, and low to moderate sulfur content. Mature oils are generated from source rocks deposited in lacustrine palaeoenvironmental conditions and include oils from IF 37-1, Balayim Land, E. Wadi Araba-3, and NDR wells characterized by high wax and high sulfur contents. Therefore, it is recommended that the molecular and polycyclic aromatic sulfur compounds play an important and powerful role in characterization and evaluation of crude oils.

Transformer oil quality in view of its physicochemical, electrical properties and dissolved gas analysis

Abstract Five transformer oil samples were collected from Western Region of Saudi Arabian from Electricity Companies during operation. The efficiency of transformer oils as insulation and cooling in power station was evaluated by studying their physicochemical and electrical characteristics. The sulfur compounds in transformer oils were evaluated via X-ray sulfur meter. Also, the dissolved gases in the studied transformer oils were vacuum extracted and analyzed by capillary gas chromatography. The excitation transformers have low dielectric strength compared with the other oil samples may be due to water contamination, reflecting the low efficiency of this oil as electrical insulator and decrease its safety around high-voltage equipment.