What is the viscosity of heavy oil?
10,000 centipoises
In 2010, the World Energy Council defined extra heavy oil as crude oil having a gravity of less than 10° and a reservoir viscosity of more than 10,000 centipoises. When reservoir viscosity measurements are not available, extra-heavy oil is considered by the WEC to have a lower limit of 4° API.
What is viscosity of emulsion?
The viscosity of an emulsion depends on the initial viscosity of the bulk phase, η 0 and the volume fraction of the drops, φ. This is OK for solids but less suited for emulsions. In the app φc is assumed to be 0.74. The factor of 2.5 is the default value for the “intrinsic viscosity” term.
Which oil is used for oil emulsion?
For produced oilfield emulsions, one of the liquids is aqueous and the other is crude oil. The amount of water that emulsifies with crude oil varies widely from facility to facility. It can be less than 1% and sometimes greater than 80%.
Why are emulsions viscous?
In general, these W/O emulsions form spontaneously due to the presence of natural surfactants existing in the oil phase and are stable. It is known that the viscosity of a W/O emulsions is strongly augmented by increasing its water volume ratio and by decreasing the temperature (Krieger and Dougherty, 1959).
What is heavy oil?
What is Heavy Oil and How is it Formed? As defined by the U.S. Geological Survey (USGS), heavy oil is a type of crude oil characterized by an asphaltic, dense, viscous nature (similar to molasses), and its asphaltene (very large molecules incorporating roughly 90 percent of the sulfur and metals in the oil) content.
What is emulsion in crude oil?
An oil emulsion is a mixture of oil, water, and an emulsifying agent. It contains fine water droplets dispersed in oil. In a crude oil emulsion, the quantity of water droplets is usually less than 10%. Occasionally, an emulsion occurs that contains droplets of oil dispersed in water.
Why oil is an emulsion?
How is heavy oil made?
The formation of heavy oil and bitumen, like other forms of petroleum, originated with plant life millions of years ago. After oil is formed, continued pressure from overlying rocks causes it to migrate through permeable rock layers until it becomes trapped in reservoirs of porous rocks such as sandstone or limestone.
How is heavy oil produced?
Crude oil becomes heavy after considerable degradation, after entrapment and during devolatilization. Degradation occurs through chemical and biological processes when oil reservoirs become contaminated by bacteria through subsurface water.
How to reduce the viscosity of heavy crude oil?
A method of reducing the viscosity in heavy and extra heavy crude oil using the viscosity reducer is also disclosed. No aromatic base solvents are needed. A reduction in diluent usage is achieved using the viscosity reducer based on vegetable extracts.
What are water-in-oil emulsions and why are they a problem?
Water-in-oil emulsions are one of the major problems in the petroleum industry has to deal with during recovery, treatment, and transportation of crude oil [ 2, 3 ]. The presence of emulsions reduces the quality of crude oil.
What is the viscosity of heavy crude oil from the North Sea?
Heavy crude oil from the North Sea is of high viscosity and is capable of forming stable water-in-crude oil (w/o) emulsions without introducing any synthetic surfactants. The aqueous phase volume content was varied from 1 to 40%, and the temperature was varied from 0 to 30 °C.
What is the volume content of aqueous phase in emulsions?
The aqueous phase volume content was varied from 1 to 40%, and the temperature was varied from 0 to 30 °C. The w/o emulsion viscosity increased sharply when the aqueous phase content exceeds 20%, being more pronounced at the lower temperatures.