How to calc. visc. of oil-water mix? 1

[yimc]

I am looking for a way to determine the viscosity of an oil water mixture. Typically, all the information I have available is the API of the oil, and the density of the brine and %'s of each.

Can anyone offer any insight?
Thanks in advance.

 

[andrey]

yimc,

one of the correlations you can use for an oil-water mixutre is

mu/mu_o=1 + 2.5 f + 10 f^2

where:
mu = the emulsion viscosity
mu_o = the viscosity of the clean oil
f = volume fraction of the water phase (vol water/total vol)

for this correlation you will need the clean oil viscosity which can be calculated using the Beggs and Robinson method:

mu_o = 10^x - 1

where:
x = y*T^(-1.163)
y = 10^z
z = 3.0324 - 0.02023*API

mu_o = viscosity, cp
T = temperature, F
API = API gravity of the oil

Andrey

 

[yimc]

Thanks Andrey!

Where did you find this at? Is there a single "production" reference (i.e., text book?)

 

[yimc]

Never mind Andrey! Found it!

Thanks again.

yimc

 

[jmw]

Beware that though most hydrocarbons can be treated as newtonian and water is newtonian, oil/water emulsions are non-newtonian. e.g bitumen emulsions, Fuel Water Emulsions etc. (pseudoplastic, i believe).
Andrey, i would be interested in your source for the calcs if you care to dibvulge!

 

[Fausto]

A word of caution here: the word "emulsion" has been
loosely employed in several articles and texts, quite
often defining *mixtures* of oil and water where no
actual emulsion had been formed.

Having that said, I must point out that AFAIK there is
no acceptably successful correlation to describe the
viscosity of a *mixture* of oil & water whatever the
proportions, or volume fractions, of the mixture are.
Contrary to density, where only mass and volume of each
phase is important to determine the density of the mixture,
viscosity is deeply related to intermolecular (so to speak)
effects. It is therefore no wonder that those "black oil"
correlations aimed at determining the viscosities of
*pure crudes* work so poorly when compared to lab-measured
viscosity data of several oils. API, Rs, etc, seem not to
be enough a crude's viscosity.

Incidentally, there is something strange with the formula
mu/mu_o = 1 + 2.5*f + 10*f^2 This is clearly an eqn for
emulsions as the viscosity of the mixture is always higher
than that of the clean oil. But then it also says that the
more water an emulsion has the more viscous it is?! There
must be a range of validity for "f", I mean, there must
exist an upper limit for the water fraction above which
the formula above is no longer valid.

Cheers,

---Fausto

 

[NeilatNEL]

yimc,

we did some work on this subject a couple of years ago at the National Engineering Laboratory.

More information can be found at

http://www.flowprogramme.co.uk/projects/proj_marg.htm

Cheers,

Neil

 

[MAStair]

I am seeking a correlation to relate mixture viscosity to water fraction for and oil and water system. I can calculate the pure fluid viscosities. I would appreciate having a reference for the equation sited above:

mu/mu_o = 1 + 2.5*f + 10*f^2

Thank you.

Mark

 

[25362]

Fausto, Andrey is most probably referring to W/O emulsions which may have a high viscosity, several times that of the oil.

 

[KernOily]

Guys what about the Woelflin correlation? Any comments on that one?

Thanks!
Pete