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The study is paying attention to the variation of the comparative abundance of naphthalenes, phenanthrenes of aromatic fractions separated from seven different Egyptian crude oils, and were studied by GC–MS to assess the thermal maturity and recognize the organic matter input. Tetramethylnaphthalenes (TeMN), Trimethylnaphthalenes (TMN), Dimethylnaphthalenes (DMN), Methylnaphthalenes (MN) and Naphthalene (N), in addition to Phenanthrene (P), and their mono, di and tri -methyl substituted isomers (MP, DMP and TMP) have been identified. Ratios depending on the differences in the thermal stability of the isomers were studied (MPI, MPr, MNr, DMNr, TMNr). The ratios of β- to α-substituted isomers of both methylnaphthalenes and methylphenanthrenes imply higher thermal maturity of WD1 from Faghur and ND1 from Nile Delta basin compared to the rest samples. WD2 crude oil sample from Faghur basin was found to has high amount of 1,3,7- and 2,3,7-trimethylnaphthalenes (TMN) with (TMNr = 2.16) and high Pristan/Phytane ratio (Pr/Ph = 3.49) compared to WD1 from the same basin suggesting in-reservoir oil mixing. [ABSTRACT FROM AUTHOR]

The levels of Total Petroleum Hydrocarbons (TPH) have been reported for ten commercially important fish species from the northwestern Gulf of Suez, Egypt. Target compounds were analytically determined with gas chromatography–flame ionization detector and High-performance liquid chromatography analysis. Results showed that total petroleum hydrocarbon varied from 21700 to 1503100 ng/g wet wt., Argyrops Spinifer showed the highest level of TPH in the muscle tissue followed by Euthynnus affinis 1459800 ng/g wet wt. These data are very important for coming pollution monitoring program to the Suez Gulf. Polycyclic aromatic hydrocarbons (16 PAHs) varied between 81.499 and 5895.608 ng/g wet wt. The diagnostic indices used showed that the hydrocarbons in the area were from both biogenic and anthropogenic sources. Hence, there is need for adequate regulation and control of all activities contributing to the levels of petroleum hydrocarbon in the marine environment for the safety of human, and fish species lives in the area. [ABSTRACT FROM AUTHOR]

Oil hydrocarbon fingerprints derived from polycyclic aromatic and aliphatic hydrocarbon were analyzed in marine organisms of various aquatic species muscles collected from 10 different sites along Suez Gulf, Egypt. All samples were analyzed for n-alkanes (C15–C37) and polycyclic aromatic hydrocarbons (EPA list of PAHs). n-Alkanes in ten aquatic species were found to be in the range of 11.391–96.747 ng/g wet weight with a mean value of 60.755 ng/g wet weights. Different indices were calculated for the n-alkanes to assess their sources as carbon preference index (CPI), average chain length (ACL), terrigenous/aquatic ratio (TAR), natural n-alkane ratio (NAR) and proxy ratio (Paq). Most of the various species of n-alkanes were discovered to be from natural sources. Polycyclic aromatic hydrocarbons (PAHs) varied between 81.499 and 5895.608 ng/g wet weight with an average of 2521.126 ng/g wet weight. The contents of ƩPAHs were the highest in the tissues. The carcinogenic risks for humans from residual ƩPAHs in the various fish tissues higher than10−5. [ABSTRACT FROM AUTHOR]

This study represents the concentrations of 16 PAHs in a commercial aquatic species Sauridaund squamis;Euthynnus affinis; Rhabdosargus haffara; Argyrops Spinifer; Nemipterus Japonicus, Oreochromis Niloticus; Trachurus Indicus; Peneus Japonicas; Scomber Japonicus; and Pomadasys Stridens, which were collected from the coastal area of the Suez Gulf waters. The analyses of polycyclic aromatic hydrocarbons (PAHs) were determined using HPLC to identify the sources of PAHs. The results revealed that low molecular weight of PAHs were more than high molecular weight in aquatic species, Benzo (a)Anthracene/(Benzo (a) Anthracene + Chrysene) BaA/(BaA + Chr), Indeno (1,2,3-cd) pyrene/(Indeno (1,2,3-cd) pyrene + Benzo (ghi) perylene) IP/(IP + BP) and Fluoranthene/Pyrene (Fl/Pyr), they reflected that the PAHs sources in aquatic species are petrogenic as a main sources, pyrogenic sources. The study area was generally contaminated with hydrocarbons and continuous consumption of food from this area may pose public health hazards. [ABSTRACT FROM AUTHOR]

Late Jurassic Madbi shale samples from Al-Qarn-01 well in the NW Say'un-Masila Basin, Eastern Yemen are analyzed using conventional geochemical data such as total organic carbon (TOC) content and Rock-Eval pyrolysis. The results in this study are used to evaluate the gas resource potentiality in the basin. The analyzed shales have high TOC content between 1.00% and 3.12%, and their HIs range from 77 to 177 mg HC/g TOC. These values indicate that the investigated Madbi shale intervals contain Type III kerogen and are considered to be very good gas-source rocks. Furthermore, the relatively high Rock-Eval pyrolysis Tmax (447–459 °C) and PI (0.09–0.44) values indicate mainly peak to late mature oil window. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Specific geochemical analyses included API gravity, sulfur content, gas chromatography, and the advanced gas chromatography-mass spectrometry for biomarker distributions, in conjunction with stable carbon isotope geochemistry, to characterize the depositional environmental conditions and maturation assessment of the studied crude oils. For this purpose ten crude oils were collected from Miocene, Upper Cretaceous, and Nubia Sandstone representing the central-southern Gulf of Suez. The results showed that two different oil types identified as Miocene oils are characterized by a dominant oleanane and low gammacerane biomarkers, suggesting an overall angiosperm land plants input of terrigenous organofacies source rock. Pre-Miocene oils are distinguished by a dominant gammacerane and low oleanane biomarker distributions, which may be generated from fully mature marine carbonate source rocks. The higher sterane isomerization parameters, C29αßß/(αßß + ααα) and C29 ααα 20S/(S+R), further support the higher thermal maturation level for the Pre-Miocene oils rather than the Miocene type. [ABSTRACT FROM PUBLISHER]

The geochemical analyses of Specific gravity (API), sulfur content, nickel and vanadium, porphyrins, bulk compositions, and saturated fraction obtained from gas chromatography have been studied with the aim of throwing more light on the geochemical aspects of the crude oil formation, migration, and maturation. Seven samples were collected from Sudr, October, GS-283, Belayim land, Belayim marine, Kareem, and July oilfields in the Gulf of Suez. These samples are representative for the producing horizon zones of Rudeis and Nuhkul formations of Middle-Lower Miocene age ranging in depths from 1344 to 3558 m. The studied crude oils are classified into heavy and/or intermediate oils. The crude oils have high concentrations of nickel and vanadium contents. Vanadyl porphyrins indicate mature to moderately mature oils. A gross composition reveals marine organic sources. The n-alkanes and isoprenoids in crude oils are derived from marine organic matter, deposited under anoxic/hypersaline to oxic or carbonate environments associated with evaporate and carbonate depositional environment. [ABSTRACT FROM PUBLISHER]

Different analytical techniques, including API gravity; sulfur–nickel–vanadium contents; liquid chromatographic separation; and gas chromatography, were utilized to investigate oil families of three crude oils collected from Bakr oilfield of middle-lower Miocene age and characterized by limestone facies at various depth locations in the central Gulf of Suez. These geochemical aspects were used to assess source input and maturation of oil families. The results showed that the studied oils indicate a close genetic relationship between studied crude oils, and classified as aromatic intermediate oils. These types of oils are characterized by mature sources derived mainly from marine inputs such as biomass from algae and plankton from different saline environments. [ABSTRACT FROM PUBLISHER]

Oil–oil and oil–source rock correlations are used in this study in order to achieve their relationship, depositional environments and diagenetic processes in the source rocks. Three oil samples and source rock hydrocarbon extracts were analyzed using relative geochemical analyses, and gas chromatography–mass spectrometry are used for this purpose. The results revealed that the extracts of the Alam El Bueib and Khatatba formations are derived from mixed organic sources in which terrestrial dominates marine sources, and deposited in transitional environments under less anoxic conditions. The extracts of Bahariya formation are derived from mixed marine inputs with a limited terrestrial contribution. The Alam El Bueib oil shows more contribution of terrestrial than marine sources. Also, a genetic close relation between them supported the indigenous mixed source of Alam El Bueib oil which related to different sources including the Khatatba, Alam El Bueib and Bahariya formations. Accordingly, the Alam El Bueib formation can be considered as an important source for petroleum generation in the Northern Western Desert. [ABSTRACT FROM AUTHOR]

The timing of petroleum generation of source rocks is recognized to investigate the maturation level of the proven potential source formations for oil preservation dead lines, and predict the levels of thermal maturity of the studied sequences in terms of hydrocarbon generation and expulsion. For theses purposes four thermal burial history and maturity profiles were constructed of the Abu Gharaig-1 SW Umbaraka-1, GPZ-1, and GPX-1 wells. The results showed Abu Roash and Bahariya formations are immature to mature source rocks and have poor to fair potential to generate both oil and gas and still are within the early stage of hydrocarbon generation till the present time. Alam El Bueib and Masajid formations bear mature source rocks and have good generating capability for generating both oil and gas and entered the oil window since Cretaceous to Miocene times and lies within oil and gas windows at present time. Khatatba Formation bears a mature source rock and has good generating capability for both oil and gas and entered the oil window during Late Cretaceous to Eocene times. [ABSTRACT FROM PUBLISHER]

Four representative oil samples have been collected from productive wells, namely: Gharib-164, Gharib-163, Gharib-106, and Gharib-116, scattered within the Ras Gharib oilfield located in the central Gulf of Suez. Their chemical composition, API gravity, sulfur content, and asphaltene content were determined. Saturated hydrocarbon fractions were subjected to gas chromatography. Terpanes and steranes biomarkers have been determined using gas chromatography-mass spectroscopy in order to characterize the type of organo-facies, oil classes, depositional environments, and to assess the thermal maturity level for oil generation. The results showed that the studied oils are belonging to normal oil classes with no heavy biodegradation. It has been found that mature oils are generated from marine shales and carbonates are enriched in marine algae with contributions from terrestrial organic matters. Biomarker analyses suggest that the crude oils are more mature and sources are derived mainly from mixed organic sources from terrestrial and marine inputs contribution to the biomass from algae and plankton in different saline environments. [ABSTRACT FROM PUBLISHER]

The present work aims to evaluate the organic geochemistry of the crude oils recovered from Ashrafi and GH oilfields within the Gulf of Suez to assess and investigate oil characterization, maturation, source depositional environments and oil families. The saturated hydrocarbons were determined by gas chromatography and gas chromatography/mass spectrometry. Pristane/phytane, isoprenoids/n-alkanes, CPI, homohopane, diasteranes, gammacerane index, C29 20S/20S+20R, C29/C30 hopane and Ts/Tm are determined. The results suggest that the studied crude oils belong to marine oil and are characterized by high level of maturation and sourced mainly from organic matters of marine origin with few terrestrial inputs. [ABSTRACT FROM AUTHOR]

API gravity, sulfur content, gas chromatography, and gas chromatography-mass spectrometry analyses were carried out for eight oil samples collected from different wells in the Gulf of Suez. The results showed that two types of oils could be recognized: (a) heavy oils, which are oils from Zafarana, Rahmi, West Bakr, and Ras Gharib wells, are of low maturation and originated mainly from terrestrial organic sources; and (b) light oils, which are oils from Um El Yuser, Ras El Ush, Gemsa-SE, and Hurghada wells, have a high level of maturation and orginate mainly from marine organic sources. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM PUBLISHER]

The oil–source rock correlation between oils from Baharyia and Abu Roash “E” member from the EWD 19–1x oilfield and extracts of Kharita and Abu Roash “F” member from the Qarun 2-1 oilfield were carried out through the advanced gas chromatography–mass spectrometry analyses of four extracts and oil samples from the oilfields to characterize the depositional environments and to assess the thermal maturity of the respective source rocks. The results show that the oil sample from Bahariya reservoir originated from mixed organic matters and is more mature. The oil sample of Abu Roash “E” reservoir is originated from source rocks rich in marine derived organic matters with little input from mixed sources and is less mature. The extracts of Kharita formation and Abu Roash “F” Member originated mainly from mixed and marine organic sources, respectively. The oil–source correlation indicates that there is well correlation between oils from the Bahariya and Abu Roash “E” reservoirs and extracts of source rocks including Kharita formation and Abu Roash “F” member. [ABSTRACT FROM PUBLISHER]

The aromatic hydrocarbons were investigated by high resolution of gas chromatography—mass spectrometry of nine crude oil samples from a number of producing wells in the North Western Desert and South Gulf of Suez. A series of molecular indicators of benzothiophenes and dibenzothiophenes were utilized to recognize the significance and their applications in identifying the source depositional environments and maturation of crude oils. The results showed that the studied crude oils were derived from silici-clastic source rocks (Salam-3, El Kharita-1, Zeit Bay-2 and Gemsa-SE oils), and crude oils were derived from carbonate source rocks (Kahraman-1, Tut-1, Meleiha-4, Yasser-1, and E. Esh El Mellaha wells). The maturity parameters 4-MDBT/1-MDBT and 2-+3-MDBT/1-MDBT ratios indicate that the studied crude oils were originated at advanced levels of thermal maturity. Therefore, aromatic hydrocarbons have a powerful way to infer crude oil source rocks depositional environments and maturation. [ABSTRACT FROM AUTHOR]

Crude oils together with extracts from the Middle Jurassic (Khatatba Formation), Barremian-Early Aptian Alam El Bueib Formation, and Early Albian Kharita Formation were collected from five wells (Ras Qattara-Zarif-5, Ras Qattara-Zarif-3, and Zarif-1, Zarif-2, SW Zarif-1) in the North Qattara Depression. Biomarkers (pristane/phytane, isoprenoids/n-alkanes, steranes, triterpanes, C29 steranes 20S/20S + 20R, C23 tricyclic/C30 hopane, Ts/Tm, C30 moretane/C30 hopane ratios, homohopane and gammacerane indices) of the saturated hydrocarbon fraction were analyzed in order to assess the source and maturity of the crude oils and the extracts. The results suggested that the oils from Khatatba and Alam El Bueib formations are mature, derived from source rocks containing marine and terrestrial organic matter, respectively. The source environments and maturity of the oil from the Khatatba Formation is similar to that of the Khatatba source rock extract. The oil from the Alam El Bueib formation differs from the extracts of the Alam El Bueib and Kharita formations. The Khatatba formation seems to be an effective source rock in the North Qattara Depression. [ABSTRACT FROM AUTHOR]

Seven representative oil show samples from wells in the north and north central Sinai have been characterized by means of a variety of organic geochemical techniques (C 7 hydrocarbon and biomarker analyses), to illustrate origin, differences, and similarity among oils. These oils were obtained from Cretaceous and Jurassic reservoirs. The C 7 oil correlation star diagram (OCSD) suggests closely related oils, derived mainly from similar source rocks, while the C 7 oil transformation star diagram (OTSD) and C 7 light hydrocarbon analyses indicate a minor degree of transformation of some oils, as Misri-1, Halal-1, and Nakhl-1 oils were subjected to evaporative fractionation. Moreover, the studied oils show no sign of water washing and biodegradation. Molecular characteristics suggest pre-Tertiary shales and carbonate source rocks, deposited under a saline oxic environment, rich in terrigeneous organic sources with significant bacterial and algal input. Since the studied oils are of mixed marine and terrestrial origin, C 7 signature of these oils is not representative of their origin and should be supported by other geochemical evidence (e.g., biomarkers) to predict their origin. [ABSTRACT FROM AUTHOR]

Sixteen cutting and four core samples, in addition two crude oil samples are representative for the Miocene source rocks and reservoirs in some wells in the southern part of Gulf of Suez. These samples were subjected to advanced geochemical tools (pyrolysis, elemental analyses, gas chromatography, and gas chromatography-mass spectrometry). In addition, burial history model of the deepest well is recognized. The results showed that the Middle-Upper Miocene source rocks are immature, originated mainly from mixed organic sources, have poor to fair potentiality to produce oil, and did not reach the early stage of hydrocarbon generation until the present time. Lower Miocene source rocks are mature, derived from marine organic sources, have good potential to generate oil and gas, and entered the early stage of hydrocarbon generation and oil window till present time. The crude oil samples are mature, originated mainly from marine sources, and show good correlation with the Lower Miocene source rocks. Therefore, the Lower Miocene source rocks may be considered an effective source for oil generation in the southern part of Gulf of Suez. [ABSTRACT FROM AUTHOR]

Physical and specific geochemical analyses are used in detail for the petroleum geochemical studies to permit the correlation of six crude oil samples from Western Desert Egypt. Different analytical techniques, including liquid chromatographic separation, gas chromatography, and gas chromatography-mass spectrometry (GC-MS), were used to characterize the oil samples. The oils were identified using oil characterization parameters including specific gravity (°API), sulfur content, distribution of n-alkanes, carbon preference index (CPI), pristane/phytane ratio, isoprenoid/n-alkane ratios, and detailed biological marker analysis. All these parameters showed that the studied oil samples are correlated with each other, where they are similar in their oil type maturation and source depositional environments. [ABSTRACT FROM AUTHOR]

The results of the geochemical evaluation for eleven crude oil samples from some Meleiha oil fields revealed that, these oils have high specific gravity (°API), low sulfur content and rich in saturated hydrocarbons. Two oil classes were recognized. The first is carbonate oils of high maturity level, originated from marine origin. The second, deltaic oils of moderately level of maturation, derived mainly from terrigenous sources. Oil: source correlation for the productive oils and the extracts of the potential source beds revealed a genetic close relationship between oils and extracts of Khatatba and Alam El Bueib formations. This indicates that the source of the oils in the study area may be related to mixed sources of these formations. [ABSTRACT FROM AUTHOR]

[Display omitted] • The shales of the Kom Ombo Formation are organic-rich sediments, with TOC value of up to 6.61 wt%. • The organic facies are predominantly of Types II and II/III kerogen. • Kom Ombo shales were deposited in a marine under anoxic environmental conditions. • The shales reached peak oil-window and generated commercial amounts of oil. This study uses organic geochemical and petrographic analyses to characterise the organic-rich shales from the Lower Cretaceous Kom Ombo Formation in the Kom Ombo Basin. The overall results show that the Kom Ombo shales are considered to have good petroleum source rock potential with total organic carbon (TOC) content > 1 wt% and hydrocarbon yields of up to 27.62 mg hydrocarbons/g rock. Based on lipid biomarker ratios and carbon isotopes, the Kom Ombo shale contains a blend of organic matter derived primarily from algal marine and other aquatic organic matter, with some terrigenous land plants, deposited under anoxic conditions. These findings of organic matter (OM) input and depositional conditions are consistent with the high TOC content of up to 6.61 wt% and mainly Types II and II/III kerogen, with small amounts of Type III kerogen, thus yielding both oil and gas, with oils of high to low wax contents. Geochemically, the dominance of oil generation potential is in agreement with the presence of considerable concentration of fluorescent liptinite macerals. The chemical and optical maturity results show that the majority of the examined Kom Ombo shale samples have entered the main stage of oil generation, exhibiting a range of early-mature to late-mature. Therefore, as highlighted in this study, the oil generation potential of the Kom Ombo shales may represent a good opportunity for future conventional petroleum exploration. [ABSTRACT FROM AUTHOR]

Abstract The Mukalla Formation is one of the important petroleum source rocks in the Jiza-Qamar Basin, Eastern Yemen. In this study, coal, coaly shale and shale samples from three wells (Al-Fatak-1, 16/G-1 and 16/E-1) in the offshore Jiza-Qamar Basin were studied. The organic matter richness, kerogen type, thermal maturity, and petroleum generation potential of the Mukalla organic-rich samples were investigated. The analysed Mukalla source rock samples are potentially rich in organic matter of 1.01–84.40% TOC, ranging from good to excellent source rocks. The Mukalla source rocks primarily contain Types II, II–III and III kerogen, anticipating generating mainly oil and gas. This is generally consistent with the pyrolysis–gas chromatography results and further indicates that the Mukalla source rocks can produce high wax oil and condensate/gas. The thermal maturity parameters reveal the Mukalla source rocks are in mature to late-mature and are capable of generating oil and wet gas at the present time. In addition, this study was integrated the geochemical, geo-thermal and geological data in term of basin modeling study to simulate the timing of hydrocarbon generation and expulsion from the Mukalla deltaic source rocks. The basin model results indicate that the oil generation commenced during the late Eocene to late Oligocene, with a conversion ratio of 10–50 TR%. Furthermore, based on TRs of more than 50%, the most of oil was expelled along the micro-fracturing of the Mukalla source rocks and then trapped in the Mukalla Formation itself during the latest Oligocene and continued to present-day. Highlights • The Mukalla Formation in the offshore Jiza-Qamar Basin is considered as a deltaic source rock. • Basin models were constructed from three wells in the offshore Jiza-Qamar Basin. • Mukalla source rocks reached the late oil-window in the present-day. • The oil was generated during late Eocene to late Oligocene, with a conversion ratio of 10–50%. • The oil was then expelled along the micro-fracturing of the Mukalla source rocks. [ABSTRACT FROM AUTHOR]