Urgent pls.

[yasiobasio123]

Dear all

I came across a sandstone reservoir that has high value of saturation exponent (n=2.5 to 3 from core data).
Please let me know:

1. what is the reason it is so high
2. if n is high, water saturation will be high or low?

thanks

[DAH7542]

I found this:

1. "n" increases as rock wettability to oil increases. This was shown in this paper: Keller (1953) "Effect of wettability on the electrical resistivity of sands". The author reported "n" values as high as 11.7.
I found another paper you'll probably find useful at:

[link Point to another website Only the registered members can access]
2. The greater the "n" value the higher the Sw. Use excel and define some fixed values for all other parameters in Archie eq. and plot "n" vs Sw and you'll see it by yourself.

[yasiobasio123]

@ DAH7542, thanks
n value measured from core plug, should it be corrected to reservoir conditions?