الفهرس 
Chemistry of biomarkersOnly 14 pages are availabe for public view
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Abstract
This thesis aims to fingerprint several crude oils from different Egyptian petroleum basins via their biomarker distribution. Chemical fingerprinting has dual benefits in both geochemical and environmental studies. For the petroleum geochemists, the comparable chemical fingerprinting gained from oil biomarker is an exploration and assessment tool that provides information on hydrocarbon source faces, age, kerogen quality, depositional environments and thermal maturation history.
For environmental scientists, biomarkers fingerprinting is an important component of oil spill investigations and site assessments and often supports determining responsibility for the pollution.
The thesis describes a comprehensive geochemical study on seventeen crude oils from both Gulf of Suez and Western Desert using gas chromatography (GC) and gas chromatography mass spectrometry (GC-MS). Chapter I describes a brief introduction of terms, chemistry and chemical structure, genesis and fingerprints of biomarkers. Details of the experimental procedures and techniques have been described in Chapter II.
In Chapter III, the results of bulk geochemical analysis (API, Sulfur content, Ni and V contents), isoprenoids and n-alkanes distributions and hopanes and steranes biomarkers distributions of seventeen crude oils are deeply discussed. It could be briefly summarized in:
• Bulk geochemical properties
Based on the API gravity, total sulfur content and metals contents (mainly nickel and vanadium) of the studied oils, initial genetic information could be provided. The highest API gravity and lower sulfur and metal contents were observed for Fagure basin crude oils from western desert. However, the lowest API gravity and higher sulfur and metal contents were observed for off shore samples (S3 and S4) from central province of Gulf of Suez basin.
• Isoprenoids and n-alkanes distributions
The relative abundances of certain n-alkanes are commonly used to deduce the source of organic matter. The predominance of C27, C29 and C31 n-alkanes has been linked with land plant source while those of C15, C17 and C19 n-alkanes are associated with algal input of organic. For example, Faghure basin samples show the predominance of C27, C29 and C31 n-alkanes while Gulf of Suez crude oils show the predominance of light C15, C17 and C19 n-alkanes.
Pristane and Phytane isoprenoids and their relations to the corresponding n-alkanes are commonly used to deduce the depositional environment. The great variability of studied samples coordinates from different basins shows the variability of their depositional environment.• Hopanes and steranes biomarkers distributions
Hopanes (m/z 191) and steranes (m/z 217) are the most significant compounds capable of yielding very specific information regarding source and depositional environment as they are closely related to compounds occurring in living organisms.
Hopane biomarkers parameters including C35/C34 homohopane, Homohopane Index, C29 17α(H)30-norhopane/C3017α(H)30-norhopane, C3017α-diahopane/C2918α (H)-30-norneohopane, Gammacerane Index, oleanane, C32 22S / (22S + 22R), mor etane / hopane and Tricyclic and Tetracyclic Terpanes were used in this study to estimate the source of organic matter and the depositional environment and also applied to assess the maturity levels.
Various steranes biomarkers parameters were also applied. These include the distribution of C27, C28 and C29 steranes, C29 diasteranes/C29 steranes ratio and C29 20S / (20S + 20R) sterane.
The considerable variation in these ratios enables us to emphasize the source of the organic matter, depositional environment and the level of thermal maturity.
The crude oils from are derived from the source rocks containing marine organic matter (algal or bacterial) deposited under anoxic depositional environment as evidenced from the predominance of C23 TT compared to C19 TT and the relative abundance C27 steranes distribution. However, the crude oils from Faghur basin are derived from the source rocks containing mixed organic matter predominately terrestrial with chief contribution of clastic rocks deposited under oxic depositional environment as evidenced from the relative abundance of C19 TT, C20 TT and C24 TeT versus C23 TT, relative abundance of C30 17α(H)-diahopane and C29 steranes distribution. On contrary, the crude oils from Gindi, Abu-Gharadig, south deep Abu-Gharadig and Dahab Mirier were generated from marine carbonate source rock deposited under anoxic depositional environment.