developing saturation height function

[yarubi]

Hi everyone,
I got some questions and hope you can help me.
In developing saturation height function (SHF) from capillary pressure, if I got mercury and centrifuge capillary pressure data should I change the mercury to equivalent water-brine first (if yes how?) then I convert all data to reservoir conditions.
Also, if I am using J-Leverett function in normalizing the data, j=a*(Sw-Swirr)^b, I got the constants (a and b) from regression. Then I found many versions of saturation equation, some of them with logs, exponential, permeability, porosity ... how to decide which one to use? I could not find a book or a paper explaining the step by step of developing SHF if anyone can help I will really be thankful

[yarubi]

anyone has an idea about SHF please do share

[endy]

Try with this SPE paper: 151602

[dipak_m]

1. Assuming you have a function of lab measured capillary pressure as a function of water saturation and permeability Pc = Fn(Sw, K)

Depending on how you measured the capillary pressure, you first need to convert to equivalent reservoir conditions -> Pc(Res) = Pc(lab) X SigmaCos(Theta)Res/SigmaCos(Theta)Lab

Lab Conditions Interfacial tension x Cos(Contact Angle) aka Sigma Cos(Theta)
Air-Water 72
Oil-Water 42
Air-Mercury 367
Air-Oil 24

Reservoir Conditions
Water-Oil 26
Water-Gas 50

So, if your capillary pressure function is lab measured Air-Mercury test, and you have a Water oil reservoir system, the first conversion is;

Pc(Res) = Pc(lab) X 26 / 367

Then, to convert this reservoir pressure to a hydrocarbon column height you do the following;
h (ft) = Pc(res)/((Rho Water - Rho Hydrocarbon) x 0.433) Rho is in SG

You now have transformed your lab capillary pressure function into a saturation height function;
h = fn(Sw, K)

Rearrange to get Sw = fn(h, K) (Where h = height above free water level)