Lighter crudes

Partial oxidation is mainly used in refineries, since the raw materials, i.e., refining residues, are available here at low cost. As far as the hydrogen produced is concerned, it can be assumed that this is primarily used by the refineries themselves, since the availability of lighter crudes is decreasing and hydrogen is being increasingly used to process heavier oils.9... 

From this equation It is evident that the parameters which control the falling velocity of water particle are the droplet else, density difference and viscosity of oil. Application of heat will reduce the oil gravity as well as viscosity. However, heat will cause loss of lighter crude fractions. Thus, adjusting the crude viscosity and gravity hy heat has economic limits. Therefore, the most practical approach would be to attempt to increase the particle size. 

The declining reserves of lighter crude oil has resulted in an increasing need to develop options (Chapter 8) to upgrade the abundant supply of known heavy oil reserves. In addition, there is considerable focus and renewed efforts on adapting recovery techniques to the production of heavy oil. In fact, the occurrence of petroleum and its use as the source of much-needed liquid fuels is the key to the future of liquid fuels production (Table 1-2). 

Micellar/polymer systems are generally applicable to the lighter crudes with low viscosity which have little natural acidity. In micellar/polymer systems hardness is also detrimental in that it causes instability in the micellar phase and decreased viscosity in the polymer phase. Therefore, in many instances a preflush is required to protect the micellar/ polymer slugs from the connate brine of the reservoir. To effectively displace these hardness ions and reduce their effect, sodium orthosilicate is used as the preflush chemical. This was done in the Bell Creek Field by Gary Energy Corp. who used a 0.16 PV preflush of 0.45% sodium orthosilicate (16). 

The second alternative was the dilution with lighter crude oils or refinery cuts such as gas oil or kerosene (8, 26). Dilution would answer not only the viscosity problem but also the dehydration and desalting of these, very often, heavier-than-water crude oils, facilitating the process and enabling conventional units to be used for the purpose. This... 

H Cabrera. Production and transport of heavy oils by blending with lighter crudes. Second UNTTAR International Conference on Heavy Crudes and Tar Sands. Caracas, Venezuela, 1982. 

Natural surfactants (mainly asphaltenes and resins) extracted from one crude are added to a lighter crude or a condensate. 

Improper storage that can result in evaporation of water and the lighter crude components, changes in clays and the oxidation of surfaces. 

Increased vaporization of the lighter crude through the preheat exchanger train and furnace increases pressure drop, which reduces the capacity of the crude charge pump. 

The furnace duty must increase to vaporize a higher percentage of the lighter crude. 

In 2008 there were significant shortages of butadiene monomer. This was because the yields of butadiene from ethylene plant production were down at that time because these plants were running on lighter crudes rather than heavy crudes (which give a higher yield of butadiene monomer). Because of this change in yield, many synthetic rubber plants were on allocation. 

Calculate the 14.7 psia EFV curves for the distillates. Plot these curves and extrapolate to minus 20 volume percent vaporized in order to approximate the effect of the equilibrium solubility of the lighter crude oil components in the liquid leaving the draw tray. 

Heavier crude oils are getting renewed attention as supplies of lighter crude oil dwindle. In 1967, the U.S. Bureau of Mines (now part of the U.S. Department of Energy) defined heavy crudes as those of 25°API or less. More recently, the American Petroleum Institute proposed to use 20°API or less as the distinction for heavy crude oils. 

This test method was evaluated in round robin testing using crude oils in the 0.75 to 0.95 g/mL range. Lighter crude oil can require special handling to prevent vapor losses. Heavier crudes can require measurements at higher temperatures to eliminate air bubbles in the sample. 

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