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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]

Organic matters from the KK 85-1and HH 83-1wells in the Central Gulf of Suez were analyzed by two well-proven organic geochemical methods: Rock-Eval pyrolysis and gas chromatography–mass spectrometry (GC–MS) analyses. These techniques were used to obtain independent parameters of organic matter composition, thermal maturity, and environment of deposition. The study reveals a close concordance between Rock-Eval pyrolysis data and biomarkers parameters such as steranes and triterpanes. Rock-Eval pyrolysis in conjunction with GC–MS analyses shows that the organic matters contain two types of kerogen (Type-II/III and Type III), which lie dominantly prior to the peak stage of the conventional oil window (end of diagensis–beginning of catagensis). The case study shows that these methods are suitable for a proper assessment of the petroleum potential of source rocks and the rapid geochemical characterization of sedimentary organic matter. [ABSTRACT FROM PUBLISHER]

The present work aims to evaluate the nature and origin of the source rock potentiality of subsurface Middle Jurassic and Lower Cretaceous source rocks in Melleiha G-1x well. This target was achieved throughout the evaluation of total organic carbon, rock Eval pyrolysis and vitrinite reflectance for fifteen cutting samples and three extract samples collected from Khatatba, Alam El Bueib and Kharita formations in the studied well. The result revealed that the main hydrocarbon of source rocks, for the Middle Jurassic (Khatatba Fm.) is mainly mature, and has good capability of producing oil and minor gas. Lower Cretaceous source rocks (Alam El Bueib Fm.) are mature, derived from mixed organic sources and have fair to good capability to generate gas and oil. Kharita Formation of immature source rocks originated from terrestrial origin and has poor to fair potential to produce gas. This indicates that Khatatba and Alam El Bueib formations take the direction of increasing maturity far away from the direction of biodegradation and can be considered as effective source potential in the Melleiha G-1x well. [ABSTRACT FROM AUTHOR]

In this study, we apply geochemical and statistical analyses for evaluating source rocks in Ras Gharib oilfield. The geochemical analysis includes pyrolysis data as total organic carbon (TOC%), generating source potential (S2), production index (PI), oxygen and hydrogen indices (OI, HI) and (Tmax). The results show that the Cretaceous source rocks are poor to good source rocks with kerogen of type III and have the capability of generating gas while, the Miocene source rocks are good to excellent source rocks with kerogen of type III–II and type II and have the capability of generating oil and gas. The analyzed data were treated statistically to find some factors, clusters, and relations concerning the evaluation of source rocks. These factors can be classified into organic richness and type of organic matter, hydrocarbon potentiality and thermal maturity. In addition, cluster analysis separated the source rocks in the study area into two major groups. (1) Source rocks characterized by HI >300 (mg/g), TOC from 0.76 to 11.63 wt%, S1 from 0.44 to 9.49 (mg/g) and S2 from 2.59 to 79.61 (mg/g) indicating good to excellent source rocks with kerogen of type III–II and type II and are capable of generating oil and gas. (2) Source rocks characterized by HI <300 (mg/g), TOC from 0.31 to 2.07 wt%, S1 from 0.17 to 1.29 (mg/g) and S2 from 0.31 to 3.34 (mg/g) indicating poor to good source rocks with kerogen of type III and are capable of generating gas. Moreover, Pearson’s correlation coefficient shows a strong positive correlation between TOC and S1, S2 and HI and no correlation between TOC and Tmax, highly negative correlation between TOC and OI and no correlation between Tmax and HI. [ABSTRACT FROM AUTHOR]

Forty-two rock samples representing seven formations (Ras Qattara, Khatatba, Masajid, Alam El Bueib, Kharita, Baharyia, and Abu Roash) and six thermal burial history modeling of wells (Tut-1x, Kahraman-1, Yasser-1, Salam-3x, Meleiha-4x, and El-Kharita-1x) were used to characterize potential source rocks for generating capability of oil preservation in terms of hydrocarbon generation and expulsion. The results showed that Ras Qattara Formation started to generate hydrocarbons during Paleocene, Khatatba Formation during Late Cretaceous-Eocene, Masajid Formation during Late Cretaceous-Late Miocene, Alam El Bueib Formation during Late Cretaceous-Oligocene, and Kharita Formation during Miocene times. Bahariya and Abu Roash formations are still immature and do not reach the onset of hydrocarbon generation. [ABSTRACT FROM PUBLISHER]

Regression lines obtained from TOC versusS2graphs of organic rich samples were collected from Rahmi, West Bakr, Ras Gharib, and Esh El Melleha wells in the Gulf of Suez. By applying the hydrogen index values obtained fromS2versus TOC graph and mass balance calculations obtained from the results of Rock-Eval pyrolysis, the original hydrocarbon generative capacity and the amounts of the hydrocarbons generated are estimated. Calculation results indicate that the amounts of original hydrocarbons and the hydrocarbon generative capacities of the two methods are similar and correlated with the results of the Rock-Eval pyrolysis. This indicates that such calculations can be applied in the hydrocarbons evaluation of source rocks. [ABSTRACT FROM AUTHOR]

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 lithostratigraphic cross-sections, thickness variations, and lithofacies changes of the Jurassic (Khatatba) and Cretaceous (Alam El Bueib and Bahariya) Formations, as well as time of hydrocarbon generation were discussed in the study area. The results showed that the thickness of the Jurassic and Cretaceous rock units increases from east to west. Results also showed shallow marine environment for the Khatatba Formation, a fluvio-deltaic environment for the Alam El Bueib Formation, and a fluvial to shallow marine environment for the Bahariya Formation. Also, the Khatatba Formation entered the early stage of hydrocarbon generation during the Late Cretaceous-Eocene and Alam El Bueib Formation during the Late Cretaceous-Oligocene. Bahariya Formation is still immature and do not reach the onset of hydrocarbon generation. [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]

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]