Egyptian Crude Research Articles

Specification for Light Rare Earth Concentrates Prepared from Egyptian Crude Monazite Spectrophotometrically

Specification for Light Rare Earth Concentrates Prepared from Egyptian Crude Monazite Spectrophotometrically

Investigating of Erosion-Corrosion Behavior of Carbon Steel in Egyptian Crude Oil-Water Mixture Using Electrochemical Method

Abstract An in-situ electrochemical polarization study was used to investigate the erosion-corrosion (E-C) behavior of C-steel in Egyptian crude oil-water mixture (ECWM) under mimetic different conditions. The anodic polarization responses for C-steel in ECWM are recognized active-passive region. Flow rate, sand particles and temperature increased the E-C rate. Disintegration rate to erosion rate proportion (E/C) was calculated and talked about.

A Current Viscosity of Different Egyptian Crude Oils: Measurements and Modeling Over a Certain Range of Temperature and Pressure

Viscosity is an important characteristic of crude oil. The viscosity has significant effect for all events in the pipeline transportation of crude oil. The changing in viscosity of crude oil is depending on the temperature, pressure and chemical composition of the crude. In the determination process of crude oil viscosity operations, it is usual to use only temperature dependence of viscosity while the pressure is neglected. Therefore, the essential goal of this study is to obtain a model that can successfully calculate the viscosity in a wide range of temperatures and pressures. Moreover, at this study a mathematical model of changing the current viscosity of Egyptian crude oil with changing of temperature and pressure is determined. Different API gravities of 6 oil samples ranging from 13.4 to 40.4 are tested. The current viscosity measured at the temperature and pressure ranges from 20 to 140°C and from 14.7 to 132.3 psi. These measurements are determined by using the quartz process viscometer apparatus. The comparison between the experimental data and the calculated values is indicated that the proposed model successfully calculate the experimental data with an average absolute percentage relative error of less than 3 and correlation coefficients of 0.991. It is noted that it’s possible to predict a correlation for the dead crude oil viscosity using temperature and pressure change, because the pressure is important for the viscosity and cannot be neglected.

A New Bubble point Pressure Correlation of Egyptian Crude Oils

A New Bubble point Pressure Correlation of Egyptian Crude Oils

A New Oil Formation Volume Factor Correlation of Egyptian Crude Oils

Knowledge of reservoir fluid properties is very important in reservoir engineering calculations such as reserve estimates and numerical reservoir simulations. Laboratory measurements are the most dependable methods for pressure-volume-temperature (PVT) analysis of reservoir fluid properties. Under circumstances, the absences of such measurements are unavailable, hence, resorted to use empirical PVT correlations. Within the current research, a new correlation for estimating oil formation volume factor at bubblepoint pressure of Egyptian crude oils using nonlinear multiple regression technique has been developed. In developing the correlation, 162 PVT data sets from Egyptian crude oils were used. The data were collected from different fields in Egypt and covered a wide range of crude oils ranging from heavy to volatile oils. The data consisted of oils with oil formation volume factor at bubblepoint pressure ranging from 1.068 to 2.43 bbl/stb, o API of 17 to 46, solution gas oil ratio of 52 to 2254 scf/stb, gas gravity of 0.6 to 1.474 and temperature of 107 to 310 o F. The developed correlation was taken as a function of solution gas oil ratio, oil gravity, gas relative density and reservoir temperature. Statistical and graphical analyses have been used to evaluate the performance of the developed correlation. Correlation performance was also compared with published correlations. It was found that the new correlation estimates oil formation volume factor at bubblepoint pressure of Egyptian crude oils much better than the published ones. The obtained outcomes include an average relative error (ARE) of 0.06, an average absolute error (AARE) of 2 and coefficient of regression (R 2 ) of 0.98.In the current research, PVT data sets were collected from Egyptian reservoirs and regression analysis were used to obtain oil FVF correlation.

Dispersion of Asphaltene Precipitation in Egyptian Crude Oil Using Corrosion Inhibitors

Three corrosion inhibitors are examined in this work to control asphaltene precipitation in Egyptian heavy crude oil. Dodecylbenzenesulfonic acid (DBSA), 4-nonylphenyl-polyethylene glycol, and synthetic cationic gemini surfactant: N2,N3-didodacyl-N2,N2,N3,N3-tetramethylbutane diaminium bromide displayed highest capacity to inhibit asphaltene deposition. The H1-NMR spectroscopy was used to confirm the chemical structure of the synthetic inhibitor. The efficiency of the studied additives as corrosion inhibitors are evaluated by weight loss method using the same crude oil. The effect of the mentioned corrosion inhibitors as asphaltene inhibitors is studied. The studied inhibitors are with dual nature for inhibition of both corrosion and asphaltene precipitation.

Determination of Wax Content in Egyptian Crude Oils

Wax precipitation is one of the most important flow assurance problems. Unfortunately, experimental data are very scarce to confirm existing models for prediction of such production impairment and other hazardous risk; while its curative approaches and production losses add to colossal economic sabotage to the petroleum industry. The present work deals with studying the determination of wax in Egyptian crude oil by gravimetric determination precipitation with lowering temperature of the crude oil .The crude oil studied was from Egyptian western desert (waxy paraffinic crude). Waxes may precipitate due to a temperature decrease because their solubility is so low that a solid phase can appear. The experiments investigated the effect of initial weight of the crude, the time of cooling, and the temperature on the amount of wax produced. The highest amount of wax was produced with 150gm of the crude oil, at temperature of 0C and this was done within two hours of the time of experiment. Finally the effect of using solvent on the amount wax content was also studied and it was found that the ratio (3:1) of solvent mixture increases achievement of the maximum amount of wax produced.

Mathematical Correlation Predicting Stock Tank Oil Density for Egyptian Crude Oils at Standard Conditions

Liquid density is one of the most important governing physical parameter of the fluid flow. Generally, oil density measured at standard conditions (14.65 psia and 60 °F) via Density Meter. Since there is a remarkable difference between calculated density from compositional analysis and measured one at standard conditions. So it is of great importance to use an accurate correlation to calculate the oil density at standard conditions. The proposed correlation correlates measured density with measured molecular weight, calculated molecular weight and calculated density which calculated from compositional analysis. Here, based on measured Egyptian oil reservoirs data; new correlation has been developed for prediction of oil density at standard conditions (14.65 psia and 60 °F). Validity and accuracy of this correlation has been confirmed by comparing the obtained results of this correlation with experimental data for Egyptian oil samples. Checking the results of this correlation shows that the developed correlation results are in a high agreement with the experimental data.

A New Optimisation based Retrofit Approach for Revamping an Egyptian Crude Oil Distillation Unit

Crude oil atmospheric distillation systems are an energy intensive processes; it was evaluated that the energy requirement for such plants is equivalent to a 2% of the total crude oil processed [1]. An existing crude oil atmospheric unit is very expensive to modify due its complex configuration and interactions, and existing constraints of structure, limited space area, matches, bottlenecked equipments, etc. Thus, a few new crude distillation units are built and projects for revamping existing equipments are rather common. Revamping an existing plant is a difficult task, more complex than a new process design; many parameters must be considered and sometimes it is not possible to quantify all of them.This paper presents a new methodology based on rigorous simulation and optimisation framework that addresses both the distillation column and the heat exchanger network simultaneously to maximise the use of existing equipments. The methodology considers process changes and structural modifications together with the interactions between the existing distillation process and heat recovery system. The new method includes multiple objective functions such as energy savings, emissions reduction, capacity enhancement, and profit improvement.An actual atmospheric plant for MIDOR, an Egyptian refinery, has been considered for applications of the new optimisation methodology. Several retrofit solutions have been obtained, ranging from zero-modifications and simple additional exchanger areas to additional units or equipments.

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

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.

Influence of Ethylene Acrylic Alkyl Ester Copolymer Wax Dispersants on the Rhological Behavior of Egyptian Crude Oil

A variety of techniques have been employed in order to reduce problems caused by the crystallization of paraffin during the production and/or transportation of paraffin oils and derivatives. Ethylene acrylic acid copolymer, PEAA, was esterified with 1-docosanol, DcA, in the presence of p-toluene sulfonic acid, PTSA, as a catalyst and xylene as a solvent. The produced ester was characterized by FTIR and 1H NMR. The polymeric additive was added at different doses ranged from 1000 to 5000 ppm to crude oil to reduce its pour point and viscosity. The copolymer achieved a large reduction in the pour point and the viscosity of samples of Egyptian wax crude oils. The polymer was show good reduction of pour point temperature and viscosity of the crude oil tested depending on the composition of crude oil.

Effect of Cooling Rate on the Flow Behavior of Waxy Crude Oils

The flow behavior of waxy crude oils is markedly affected by the lowering temperature due to the cooling during shutdown. Pipeline engineers must consider two problems, both of which are related to the flow behavior of waxy crude oils. The problems are restartability of a pipeline after a prolonged shutdown and continual deposition of heavy organic materials on the inner wall of the pipeline. The main goal for this article is to study the effect of cooling rates on the flow behavior and deposition of heavy organic materials when statistically cooled. To achieve this purpose, two Egyptian crudes were investigated, namely, “sample A” (high waxy crude) and “sample B” (containing a high amount of asphaltene). The results showed that the flow behavior of the tested crudes was affected, to a large extent, by the cooling rates. Also, the restart-up pressure (restartability) required to initiate the flow of the crude, which contained a high portion of asphaltene, is high at a low cooling rate and vice versa was observed for high wax content crude.

Significance of Aromatic Hydrocarbons in Recognizing Source Depositional Environments and Maturation of Some Egyptian Crude Oils

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.

Effect of Surfactant on the Growth of Onset Aggregation of Some Egyptian Crude Oils

This work pertains to study the asphaltenes aggregates' settling behavior of crude oil in absence and presence of oil‐soluble surfactants including long‐chain fatty acid in the form of amidation and estrification. First, the onset points as a function of light absorbed asphaltenes aggregates were quantified before and after adding asphaltenes dispersants using ultra violet spectroscopy, and the photograph fractal‐like aggregate structures were quantified using Carl Zeiss Trinocular microscope. Second the shear rates against shear stress induced aggregation were also measured in absence and presence of different concentrations of asphaltenes dispersants using Brookfield digital rheometer model LVDV‐III+. The results reviled that the asphaltenes aggregates are found to depend on toluene–heptane ratios. In absence of dispersant the accumulated and aggregates clusters of asphaltenes are formed at heptane: toluene ratio of 50∶50. Whereas, in the presence of dispersant the asphaltenes are solvated at heptane: toluene ratio of 60∶40, followed by appearance of stronger and dots aggregates clusters at a ratio of 70∶30, and finally, a larger aggregates growing at heptane: toluene ratio of 80∶20. The dispersant solvates the asphaltenes and maintains them in solution, while their surface activity remains high. This means that the dispersant apparently functioned well in decreasing the degree of flocculation and precipitation beyond the critical micelle concentration (CMC) of asphaltenes at 0.0027 g/L. Also, the reduction in the viscosity in presence of dispersant suggests that the asphaltenes aggregates are highly porous and very fragile.

Poly(Cinnamoyloxy Ethyl Methacrylate-Co-Octadecyl Acrylate) as Flow Improver for Egyptian Waxy Crude Oils

The octadecyl acrylate–cinnamoyloxy ethyl methacrylate linear copolymers (CEMA-ODA) were designed to be applied as pour point depressants. The preparation scheme involved synthesis of cinnamoyloxy ethyl methacrylate (CEMA) monomer and then copolymerization with octadecyl acrylate (ODA) at different molar ratios in the feedstock. The efficiency of these copolymers to depress pour points and rheological characteristics for waxy crude oils using different concentrations of CEMA-ODA additives were studied. It was observed that the synthesized copolymers showed nonNewtonian pseudoplastic relationships at different concentrations of synthesized additives. CEMA-ODA copolymer with molar ratio 1:3 has good ability to disperse wax crystals and improve the flow behavior of tested crude oils even at temperatures below their pour points. The results showed that there is a good correlation between viscosity measurements and pour point characteristics.

Effect of Interfacially Active Fractions of Some Egyptian Crude Oils on Their Emulsion Stability

Four samples from different crude oils were used for this study: light and heavy crude oils from Iran and two crude oils from Egypt, namely, Ras Gharb and Suez mix. The asphaltenes were separated from these crude oils and then the maltene (non‐asphaltenic fraction) was fractionated into waxes, aromatics, and resins. All fractions were characterized using FTIR and UV spectroscopic analyses in addition to gel permeation chromatograph (GPC). These fractions were tested for their emulsion stability. For chemometric analysis different parameters (variables) have been used to study the effect of different fractions (objects) on the emulsion stability. Such variables included the integrated areas under the stretching absorption peaks of CH in the range of 3000–2800 cm−1, C˭O in the range of 1750–1650 cm−1, and the aromatic C˭C in the range of 1650–1550 cm−1, as well as UV absorption value at 235 nm and average molecular weight (MW). Principal component analysis (PCA) and multiple linear regression (MLR) were conducted for examining the relationship between multiple variables and the stability of water‐in‐crude oil emulsions. The results of PCA explain the interrelationships between the observations and variables in multivariate data. The correlation coefficients between different parameters derived from PCA reveals that the UV absorption value and MW are strongly correlated with emulsion stability. It also reveals that the resins, asphaltenes, and maltene have better emulsion stability than waxes and lower molecular weight aromatics. The linear relationship between the parameters and the stability of water‐in‐crude oil emulsions using MLR was modeled according to the better statistical results. The obtained mathematical model can be used to predict the stability of water‐in‐crude oil emulsions from the chemical groups and functionalities in each crude oil fraction.

Asphaltenes as Adsorbents in GC. II. Separation of Some Homologous Series and Isomeric Compounds

Four different asphaltenes were separated from Egyptian crudes and employed as gas chromatography (GC) adsorbents. Each asphaltene was used to coat (10% by wt) chromosorb-p having 100–120 mesh size and packed into a 1/4” × 7′ stainless steel column. Asphaltene columns are found to be highly efficient in the separation of some condensed ring compounds, homologous series of alkylated and halogenaled benzenes, some ketones, C3-C5 alcohols, several halogenated alphatics, and cresols. This study reveals that asphaltenes are selective toward the separation of the given condensed ring compounds and have a normal behavior toward the other separations. Asphaltenes can be used as polyfunctional adsorbents for separating different compound classes.

Utilization of GC/AED for Investigating the Effect of Maturity on the Distribution of Thiophenic Compounds in Egyptian Crude Oils

The polyaromatic compositions of 12 Egyptian crude oil samples from the Western Desert and Gulf of Suez regions were analyzed using gas chromatography in conjunction with sulfur-selective atomic emission detection. The results show the variation in distributions of benzothiophenes and dibenzothiophenes in oils with different maturity levels. The ratio of benzothiophenes to dibenzothiophenes has been applied successfully as tool to evaluate maturity changes where it correlates well with other maturity parameters. A cross-plot of benzothiophenes/dibenzothiophenes versus isoprenoid/n-alkane ratios consistently classified oils according to their maturity rank.

Source diagnostic and weathering indicators of tar balls utilizing acyclic, polycyclic and S-heterocyclic components

This study represents a forensic chemical analysis to define the liability for the coastal bitumens polluting the beaches of the Mediterranean city of Alexandria. Six tar balls collected from several locations along the coast of the city were analyzed for their acyclic and polycyclic hydrocarbons as well as sulfur heterocycles using GC/FID, GC/AED and gas chromatography/mass spectrometry techniques. The analysis of one Egyptian crude oil is also included as a possible source oil. The tar ball samples were at early stages of weathering. Based on the GC traces and biomarker signatures, the tar balls could be genetically different. One sample collected from the Eastern Harbor region appears to be a Bunker C type fuel produced from Egyptian crudes. The refining process has removed the low molecular weight components. On the other hand, the wide n-alkane distribution together with the absence of an unresolved complex mixture suggests that crude oils probably from tank washings, ballast discharges or accident spills from tankers could have contributed significantly to the other tar ball samples. The distribution of source specific hopane and sterane markers revealed that the tar samples probably originate from different oil fields.

Toxicity of Third Generation Dispersants and Dispersed Egyptian Crude Oil on Red Sea Coral Larvae

Harmful effects of five third-generation oil dispersants (Inipol IP-90, Petrotech PTI-25, Bioreico R-93, Biosolve and Emulgal C-100) on planula larvae of the Red Sea stony coral Stylophora pistillata and the soft coral Heteroxenia fuscescense were evaluated in short-term (2–96 h) bioassays. Larvae were exposed to Egyptian oil water soluble fractions (WSFs), dispersed oil water accommodated fractions (WAFs) and dispersants dissolved in seawater, in different concentrations. Mortality, settlement rates and the appearance of morphological and behavioural deformations were measured. While oil WSF treatments resulted in reductions in planulae settlement only, treatments by all dispersants tested revealed a further decrease in settlement rates and additional high toxicity. Dispersed oil exposures resulted in a dramatic increase in toxicity to both coral larvae species. Furthermore, dispersants and WAFs treatments caused larval morphology deformations, loss of normal swimming behaviour and rapid tissue degeneration. Out of the five tested dispersion agents, the chemical Petrotech PTI-25 displayed the least toxicity to coral larvae. We suggest avoidance of the use of chemical dispersion in cases of oil spills near or within coral reef habitats.