Crude oils types

Selecting the naphtha type can be an important processing procedure. For example, a paraffinic-base naphtha is a better feedstock for steam cracking units because paraffins are cracked at relatively lower temperatures than cycloparaffins. Alternately, a naphtha rich in cycloparaffins would be a better feedstock to catalytic reforming units because cyclo-paraffins are easily dehydrogenated to aromatic compounds. Table 2-5 is a typical analysis of naphtha from two crude oil types. 

Polymers can be used for mobility control. The interaction between polymers and surfactants is shown to be affected by pH, ionic strength, crude oil type, and the properties of the polymers and surfactants [642]. 

The selection of crude oil type is critical to the design and economic success of a crude oil refinery. Different crude oil types require a different refining strategy, and depending on the crude oil type, it may be easier or more difficult to achieve a specific product slate. The product slate is often determined by regional markets, unless the products are specifically earmarked for export. This also holds true for Fischer-Tropsch syncrude. 

Crude Supply and Blending This area includes receiving facilities and a tank area (tank farm) where all crude oil types are received and either blended or sent directly to the production system. 

Crude oil type. Strickland examined the effect of three crude oil types on dispersed-gas oil removal and found a significant difference. Oil concentration, drop size distribution, and water composition (10% NaCI) were the same for all tests. 

In a modern refinery the different hydrocarbon streams contain a variety of sulphur compounds, including hydrogen sulphide, mercaptans, sulphides, disulphides, and thiophenes. The amount and the type of the sulphur compounds depends highly on the used crude oil type, but even the most sweet (low sulphur) crudes contain considerable amounts of sulphur. For different reasons the sulphur concentration of the product streams of the crude destination train must be reduced ... 

The interfacial films formed by different crude oils have different characteristics. The physical characteristics of the films are a function of the crude-oil type and gas content, the composition and pH of water, the temperature, the presence of nonionic polar molecules in the water, the extent to which the adsorbed film is compressed, and the contact time allowed for adsorption and concentration of polar molecules in the oil phase 14, 22,23). The rheological properties of the adsorbed emulsifier film have an important effect on the stability of emulsions. 

Oil producers will typically set standards for oil-in-water content ranging from less than 10 ppm in very light crude oils to several hundred parts per million in very heavy crude oils. These specifications are usually site-specific and are dependent on equipment available and crude-oil type. Oil producers in Canada usually have the advantage of disposal wells or water-flood schemes in which produced water is disposed. Failure to meet self-imposed oil-in-water limits usually results in loss of hydrocarbon product back to the formation. For an oil production facility that disposes of 1000 m of water per day with an oil content of 1000 ppm, 365 m of oil is lost per year. At 25 (Canadian) per barrel, this amount of oil translates to a product loss worth approximately 57,000 per year, plus any maintenance costs and well stimulation costs to restore injectivity lost as a result of formation plugging from oil-wet solids. Oil-wet solids in water-flood systems may damage formation permeability and reduce recovery. 

Emulsion breakers are typically specific for site or crude-oil type. Conventional emulsion breakers are most commonly formulated from the following types of chemistries polyglycols and polyglycol esters, ethoxylated alcohols and amines, ethoxylated resins, ethoxylated phenol formaldehyde resins, ethoxylated nonylphenols, polyhydric alcohols, and sulfonic acid salts. Commercial emulsion breakers may contain but one type of active ingredient or intermediate or a variety of intermediate types. 

The petroleum industry often characterises crude oils according to their geological origin, each having different and unique properties. They can vary in consistency from a light volatile fluid to a semi-solid and are classified according to the US environmental protection agency as crude oil Types A, B, C and D as follows ... 

A. A. Abbasov has studied how the quantity of residual coke changes depending on the density and viscosity of the crude oil and its H/C ratio and C content. In his published works, Abbasov gives these data for a number of crude oil types. 

In the following discussions the published experimental findings are presented interrelatedly first in terms of internal oil chemistry at the interface and instabilities based on its composition, secondly in terms of effects of water chemistry, and thirdly in terms of demulsifier interaction. We include the activity of interfacial components involved in the structure of the protective skin, the behavior(s) of this structure with changes to water chemistry or solvency, or the effects of changes in film stmeture itself due to modification of relative proportions of interfacially active components. In some examples, developments in interfacial rheology, which is both a tool for understanding stable films and a means of rationalizing the effects of demulsifiers in demulsification, are discussed interrelatedly. Films may be sensitive to crude oil type, gas content, aqueous pH, salt content, temperature, age, and the presence of demulsifiers. Demulsifier performance is also influenced by many of these variables. 

Liquid fuels are made from coal by reacting the coal with hydrogen gas under high pressure in the presence of catalysts (hydrogenating the coal). The process produces hydrocarbons like those in petroleum. The resulting crude oil type of material can be fractionally distilled to give fuel oil, gasoline, and certain hydrocarbons used in the manufacture of plastics, medicines, and other commodities. About 5.5 barrels of liquid are produced for each ton of coal. At the present time, the cost of a barrel of liquid from coal liquefaction is about double that of a barrel of crude oil. However, as petroleum supplies diminish and the cost of crude oil increases, coal liquefaction will become economically feasible. 

The acquisition of a commercial crude oil assay library with periodical updates is a common alternative, which could help refiners solve the planning problem appearing with crude oils type B (Figure 1). However, this approach is not effective with crude oils type C), and the cost is a factor to be considered. 

An assay varies in depth and complexity depending upon the crude oil type and its final use. The assay can be an inspection assay or comprehensive assay. There are various types of assays, which vary considerably in the amount of determined experimental information ... 

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