نتایج جستجو برای: especially crude oils
تعداد نتایج: 453404 فیلتر نتایج به سال:
High-temperature gas chromatography (HTGC) has enhanced our ability to characterize hydrocarbons extending to C120 in crude oils. As a result, hydrocarbons in waxes (> C20) have been observed to vary signi®cantly between crude oils, even those presumed to originate from the same source. Prior to this development, microcrystalline waxes containing hydrocarbons above C40 were not characterized on...
one of the most important problems in the upstream oil industries is heavy organic and asphaltene deposition that cause to plug in formations, production surface facilities, wellbore, and flow lines. determination of asphaltene precipitation, flocculation and aggregation mechanisms and asphaltene flocculation onset point are too important subjects in asphaltene deposition management. in this wo...
Sulfur chemical structures present in crude oil products such as petroleum asphaltenes, resins, and maltenes obtained from two different oils have been determined using X-ray absorption nearedge structure (XANES) spectroscopy. Maltenes are pentane soluble portions, resins are pentane insoluble and heptane soluble portions, and asphaltenes are heptane insoluble portions of crude oil. The sulfur ...
This model is motivated by the need to explain anomalous features associated with production from reservoirs of so-called foamy oils. These oils are described by some of their properties of response to pressure declines; it is noted that they nucleate dispersed gas bubbles and display obvious foaminess in well head samples produced by solution gas drive in which oil and gas is produced by the d...
Crude oil is complex mixture of hydrocarbons that occur in the earth in liquid form. It constitutes an important part of primary fossil fuels. Crude oil was used as a medicine by the ancient Egyptians, presumably as wound dressing, liniment and laxative. Several centuries later, Spanish explorers discovered crude oil in Cuba, Mexico, Boliva and Peru. The industrial revolution brought increasing...
The rheological properties of four different Kuwaiti crude oils in the presence of polyacrylamide (PAA) were investigated. PAA was varied at three different concentrations of 25, 50, and 75 ppm to study the viscoelastic properties in the untreated samples. Four different temperatures (25, 30, 35, and 40 °C) were used to evaluate different viscoelastic parameters of the treated and untreated Kuw...
The chemical composition and antimicrobial activity of essential oils obtained from three Brazilian plant species-leaves and branches of Eremanthus erythropappus (Asteraceae), leaves of Plectranthus barbatus, and leaves of P. amboinicus (Lamiaceae)-were determined. Analysis by GC/MS and determination of Kovats indexes both indicated δ-elemene (leaves-42.61% and branches-23.41%) as well as (-)-α...
The acute toxic effect of different crude oils (heavy crude oil and bonny light crude oil) on embryos of marine medaka Oryzias melastigma was measured and evaluated by exposure to the water-accommodated fraction (WAF) in the present study. The cardiac function of medaka embryos was used as target organ of ecotoxicological effect induced by oil exposure. Results showed that the developing marine...
the rheological properties of four different kuwaiti crude oils in the presence of polyacrylamide (paa) were investigated. paa was varied at three different concentrations of 25, 50, and 75 ppm to study the viscoelastic properties in the untreated samples. four different temperatures (25, 30, 35, and 40 °c) were used to evaluate different viscoelastic parameters of the treated and untreated kuw...
Reasons for Blending Crude Oils at a Refinery Oil refineries, and especially their on-process units that process the primary crude feed stocks, are not uniform in either design or operation. The refinery process units and the combination of units built and in service at a given refinery location are part of a plan to accommodate a certain slate of crudes based on their properties. These decisio...
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