Ahmed Najaf - Academia.edu (original) (raw)

Papers by Ahmed Najaf

Iraqi journal of science, Nov 30, 2021

Proceedings, Apr 30, 2012

il exploratory wells , Makhul-2 (Mk-2),Qarachuq-1 (Qc-1) and Qarachuq-2(Qc-2), TaqTaq-1(Taq-1), B... more il exploratory wells , Makhul-2 (Mk-2),Qarachuq-1 (Qc-1) and Qarachuq-2(Qc-2), TaqTaq-1(Taq-1), Butmah-15 (Bm-15), Ajeel-8 (Aj-8)and Jabal kand( Jk -1) ,encountered from Butmah Formation ( Lower-Middle Liassic) , Sargelu Formation (Middle Jurassic ) and Naokelekan Formation (upper Jurassic ) .The value of palynological analyses in the undertaken study is to resolve stratigraphic and palaeoenvironmental consequences of Jurassic Period in Iraq , thus the profuse of plant cuticle of translucent phytoclast in the basin of deposition refers to proximal depositional environment due to their specific gravity of this type of plant cuticle , whereas the opaque organic matter produced either from highly oxidized environment or from forest fire residues could refer due to its light specific gravity to distal depositional environment that this type could transported far from the continents toward the aquatic environment . Recurring Type A Amorphous kerogen indicates Oil –Prone beside various amorphous types (B, C, D) within Zagros Fold Belt. The specified palynomorphs recovered from palynological analysis declared so many indications to determine the potentiality of source rocks .Almost all slides shows spores and pollen, phytoclasts and amorphous organic matter. Extracted resins and pigments are indicating toxic environment of type II-III kerogen that generates oil with subordinate gas.Geochemical analysis can aid also the undertaken study by determination the Terrestrial origin and kerogen type II-III .Previously proved that all crude oils within this sub- basin is belong to family A (sourced from Middle Jurassic Sargelu Formation) nearby local basins of family B (sourced from U. Triassic Kurra chine, and Rhaetic Baluti Shale Formation). Jurassic Period is considered as a generative hydrocarbon rock unit by means of both optical and chemical approaches definitely in the Great Kirkuk region and surrounding areas in North Iraq. Meanwhile the current studies focused on the western desert as promising reservoirs related with hydrocarbon pathways from Mesopotamian Basin.

Marine and Petroleum Geology, Dec 1, 2016

Crude oil samples from Cretaceous and Tertiary reservoir sections in the Zagros Fold Belt oil fie... more Crude oil samples from Cretaceous and Tertiary reservoir sections in the Zagros Fold Belt oil fields, southern Iraq were investigated using non-biomarker and biomarker parameters. The results of this study have been used to assess source of organic matter, and the genetic link between oils and their potential source rocks in the basin. The oils are characterized by high sulphur and trace metal (Ni, V) contents and relatively low API gravity values (17.4–22.7° API). This indicates that these oils are heavy and generated from a marine source rock containing Type II-S kerogen. This is supported by their biomarker distributions of normal alkanes, regular isoprenoids, terpanes and steranes and the bulk carbon isotope compositions of their saturated and aromatic hydrocarbons. The oils are characterized by low Pr/Ph ratios (<1), high values of the C35 homohopane index and C31-22R/C30 hopane ratios, relatively high C27 sterane concentrations, and the predominance of C29-norhopane. These biomarkers suggest that the oils were generated predominantly from a marine carbonate source rock, deposited under reducing conditions and containing plankton/algal and microorganisms source input. The presence of gammacerane also suggests water column stratification during source rock deposition. The biomarker characteristics of the oils are consistent with those of the Middle Jurassic Sargelu carbonate as the effective source rock in the basin. Biomarker maturity data indicate that the oils were generated from early maturity source rocks.

Al-Mustansiriyah Journal of Sciences, 2011

Chemical analysis were carried out to evaluate the potentiality of rock samples having hydrocarbo... more Chemical analysis were carried out to evaluate the potentiality of rock samples having hydrocarbon characteristics , identified by chemical method as one of the approaches to evaluate the source rocks encountered from ,Sehkanian , Sargelu, Naokelekan, Sarmord, Ghia Kara of (Middle to Upper Jurassic-Lower cretaceous) stratigraphic sequence of Iraq,

Iraqi journal of science, 2012

Iraqi Journal of Science, 2021

The undertaken study includes investigating the performance and effluent characteristics of the t... more The undertaken study includes investigating the performance and effluent characteristics of the treatment plant of Al-Doura refinery. Influent concentrations for some important contaminants, which are TDS, oil and grease, TSS, COD, BOD, and turbidity were 2595 mg/L, 13934 mg/L, 466.45 mg/L, 2538.9 mg/L, 1739.2 mg/L, and 89.18 NTU, respectively, while the effluent concentrations were 1337.8 mg/L, 0.53mg/L, 21.7mg/L, 25.45 mg/L, 17.81 mg/L, and 7.08 NTU, respectively, giving removal efficiencies of 44.47%, 99.99%, 94.4%, 98.96%, 98.96% and 92.05%, respectively. All these results indicate that Al-Doura wastewater treatment plant was efficient in removing contaminants according to Iraqi and EPA specifications. Hence, the second part of this study concentrated on finding a simple and efficient treatment method to treat the effluent so that it can be reused in the boiler system. A pilot plant was designed and dedicated for this purpose, including three units of granular activated carbon f...

The attempts for determining the potentiality of Sargelu Formation adequately performed is by the... more The attempts for determining the potentiality of Sargelu Formation adequately performed is by the application of various organic geochemical studies. The indications refer to this formation as being one of the most important source rocks and have its economic horizon generating the majority of oil and gas in Iraq. Basin modeling assist to declare the scope and will already perform the complementary view by acquiring all previous and current data, and create a new version of basin modeling, depending mainly on real and perfect studies that differ from the former studies that depends mainly on estimations because no rock samples were available, but in the undertaken study, rock samples (core and cuttings) were extracted from Butmah-15, Jabal Kand-1, Qara chuq-1 and Ajeel-8 oil exploratory wells. One dimension petroleum-system modeling of key wells were developed using Integrated Exploration System (IES). PetroMod software to evaluate burial-thermal history, source-rock maturity, and t...

Journal of Al-Nahrain University Science, 2017

A new homologous series of Schiff base esters comprising a terminal alkoxy substituent N-{(nalkox... more A new homologous series of Schiff base esters comprising a terminal alkoxy substituent N-{(nalkoxy-4``-bezoyloxy)-4`-benzylidene}-4-butyl aniline was studied. The alkyloxy substituent contributes to the molecular polarizability, thus, affecting intermolecular interactions, hence, resulting in nematic polymorphism. The mesomorphic properties were studied using polarizing optical microscope (POM). The lower members, n-methoxy and n-ethoxy derivatives were nonmesogens, enantiotropic nematogenic phase was observed on further lengthening of the alkyl chain from C3 to C6 and smectogenic phase was observed for compounds C7 and C8. FT-IR, 1 HNMR, 13 CNMR, EI-MS and elemental analysis were employed to elucidate the molecular structure of the title compounds whereas the liquid crystal properties were determined by POM analysis. The mesomorphic behaviors of the homologous compounds are rationalized based on the varying lengths of the alky chain.

Journal of Al-Nahrain University Science, 2007

Profuse and well preserved Paleozoic acritarch assemblage were recovered from subsurface lower Ju... more Profuse and well preserved Paleozoic acritarch assemblage were recovered from subsurface lower Jurassic sediments from oil exploration well Makhul_2 Northern Iraq. Acritarch assemblages have been recorded from Butmah Formation(early Jurassic). The recovered acritarch are originally come from Ordovician and Silurian sediments Landmass, situated nearby during complete erosion, Later the fluctuation companied were all have been transported and deposited in lower Jurassic sediments.

Journal of Petroleum Science and Engineering, 2019

Organic geochemical methods were performed on four oil seep samples collected from the Abu-Jir Fa... more Organic geochemical methods were performed on four oil seep samples collected from the Abu-Jir Fault Zone (AJFZ) in the Al-Anbar Governorate, western Iraq. These oil seeps have undergone biodegradation, showing large unresolved complex mixture (UCM) shapes, with degradation of normal alkanes and isoprenoids. The inorganic elements of the Abu-Jir oil seeps, i.e., S, Ni and V, suggest a marine carbonate-rich source rock deposited under reducing environment conditions. The biomarker ratios and parameters of hopane and sterane further suggest that the oil seeps were derived from source rock rich in lipids from phytoplankton and bacteria with less contribution of terrigenous organic debris. The chemical maturity indicators show that the Abu-Jir oil seeps were generated from early mature sulfur-rich source rock, thus in association with a high S content of more than 1.93%. The geochemical characteristics of the analyzed oil seep samples are similar, which is consistent with most of the crude oils in the northern and southern basins in Iraq, and were generated from the Middle Jurassic Sargelu Formation. The overall geochemical correlations and geological information confirm that the Abu-Jir Faultoil seeps in the western Iraq were sourced from the Middle Jurassic Sargelu Formation that reached an early maturity level of oil-generation window and that they migrated into the ground surface through the Abu-Jir major fault during the middle Miocene.

Journal of Petroleum Science and Engineering, 2018

Middle Jurassic Sargelu Formation is an important oil-source rock in the Iraqi Kurdistan oilfield... more Middle Jurassic Sargelu Formation is an important oil-source rock in the Iraqi Kurdistan oilfields, northern Zagros Fold Belt. The Sargelu source rock is characterised by high organic matter and sulphur content with Type II-S kerogen, which can be expected to generate oil at low maturity stages. A 1D basin modelling was performed by integrating geological and geochemical data of the Sargelu source rock from six wells in the Kurdistan region, north Iraq. The basin modelling results was used to reconstruct the burial and thermal history and to simulate and predict the timing of petroleum generation and expulsion for the Middle Jurassic Sargelu source rock. Burial/thermal history models indicate that the Sargelu source rock had passed the peak-oil generation window during the Late Eocene to Late Miocene. Onset of oil-generation began during the Middle Eocene-Late Miocene (51-11 Ma), whereas the maximum rates of oil with limited gas were generated during the Late Eocene to Late Miocene (52-10 Ma). The models also show that the oil was expelled from the Sargelu source rock since Late Eocene to presentday (44-0 Ma), with transformation ratio higher than 50%. The subsequent high transformation ratio higher than 80% suggests that the generated oil was cracked to gas during the Early Oligocene and continued to present day. These basin modeling results also suggest that the Sargelu Formation acts as an effective oil-source where

Egyptian Journal of Petroleum, 2017

Seven crude oils from Cretaceous Mishrif reservoir rocks in the southern Mesopotamian Basin, Sout... more Seven crude oils from Cretaceous Mishrif reservoir rocks in the southern Mesopotamian Basin, South Iraq were studied to describe oil characteristics, providing information on the source of organic matter input and the genetic link between oils and their potential source rock in the basin. This study is based on biomarker and non-biomarker analyses performed on oil samples. The analysed oils are aromatic intermediate oils as indicated by high aromatic hydrocarbon fractions with more that 50%. These oils are also characterized by high sulfur and trace metal (Ni, V) contents and relatively low API gravity values (19.0-27.2°API). The results of this study indicate that these oils were derived from a marine carbonate source rocks bearing Type II-S kerogen that were deposited under sulphate-reducing conditions. This is primary achieved from their biomarkers and bulk carbon isotope and inorganic element contents (i.e., S, Ni and V). The absence of 18a (H)-oleanane biomarker also suggests a source age older than Late Cretaceous. The biomarker characteristics of these oils are consistent with those of the Late Jurassic to Early Cretaceous source rocks in the basin. However, biomarker maturity data also indicate that the oils were generated from early maturity source rocks. This appears to result from the type of kerogen of the source rock, characterized by a highS kerogen (Type II-S).

Marine and Petroleum Geology, 2016

Arabian Journal of Geosciences, 2016

Geochemical exploration processes were applied to characterize, analyze, identify, and correlate,... more Geochemical exploration processes were applied to characterize, analyze, identify, and correlate, 11 crude oils and five source rock samples (core and cuttings), which were recovered from oil exploratory wells within the Mesopotamian basin; this basin is considered as one of the most formative, potential, and promising basin in the Middle East. Remarkable total organic carbon (TOC) identifies good source rocks encountered from Upper and Middle Jurassic deep wells and also extracts from Upper Cretaceous Shiranish formations. Two main families recognized (family A) subsidy to subfamily (a) and subfamily (b), generated by different source rock types, and different ages has been established on the basis of biomarker. This family was generated by marine carbonate-intrashelf subbasin source rocks, occurring in Jurassic-Cretaceous-Neogene reservoir rocks in both Zagros Fold Belt and Mesopotamian basin which are geochemically similar to the extracts from the Middle-Upper Jurassic age (Sargelu and Naokelekan Formations), yielding the majority of petroleum oil and gas fields in Iraq. (Family B) of the Upper Triassic Kurra Chine Formation, shallow marine-lagoonal environment, Upper Cretaceous Shiranish formation. Shale beds of the Middle Jurassic Sargelu formations are the major sources of oil in Iraq; these strata were deposited in euxinic marine environment, and most of rock sample are highly mature, with TOC attaining 16.20 wt% and average hydrogen index (HI) of 499 with relatively low values of oxygen index (OI) and maximum temperature (T max) 446.

... source rocks are well known on the Arabian Plate, especially from The Emirates, Qatar, Saudi ... more ... source rocks are well known on the Arabian Plate, especially from The Emirates, Qatar, Saudi Arabia, Kuwait, and southern Iraq. Much less is known about Middle Jurassic sediments as possible source horizons. To this end, forty (40) potential source rock samples from the ...

The continuous monitoring by the different international agencies which support the undertaken st... more The continuous monitoring by the different international agencies which support the undertaken study represented by Inter Governmental Panel on climate change (IPCC), Environmental Pollution Agencies (EPA) and the claims and activities of the Non Governmental Organizations (NGO) which are focused on providing reliable environment to all peoples around the world , and also the previous environmental studies on various carbon monoxide and carbon dioxide emissions scenarios, determine as one of the most threaten gases, in addition to the other green house gases (ghg). The incremental variations of this type of gases already heat our planet earth, indicated by the application of standard deviation for the end of this century attain to 2.5, and output climate pattern that the anthropogenic with natural (volcanoes, solar, green house gases, sulfates and ozone) will lead to desertification and climate changes, decreases of rain and convert wide areas around the world to arid zones. Predict...

First EAGE Workshop on Iraq - Hydrocarbon Exploration and Field Development, 2012

Arabian Journal of Geosciences, 2012

Dr Ala has been closely associated with the oil industry for more than 30 years both as an explor... more Dr Ala has been closely associated with the oil industry for more than 30 years both as an exploration geologist with an independent oil company and as a consultant. He has a BSc in Oil Technology and an MSc, PhD and DIC in Petroleum Geology from Imperial College, University of London. In 1972 he joined Seagull Exploration International and was involved in exploration studies and prospect evaluation in many parts of the world including Africa, northwest Europe, eastern Mediterranean, the Caribbean, South America and the Middle East. In 1976 he became the company's General Manager in London, responsible for its north European and Middle Eastern operations. In 1981 he joined the academic staff in the Earth Science Department of Imperial College, rising to the post of Director of the internationally recognized MSc Petroleum Geoscience Course in 1994. He is co-founder (1988) and Director of Hydrocarbons Venture Limited, a UK based organisation involved in consultancy and participati...