Dear engineers,
I want to calculate Recovery Factor of an oil field,
For this I must have Cw. Cf
How can I calculate Cw (compressibility factor) with following information:

Ca(calcium): 2000 ppm
Na(sodium): 218000 ppm
Wt: 73.6 pcf
pH: 6.4
Pr: 4219 psi @ 2877m Reservoir pressure.

and for Cf (rock compressibility):
porosity = 0.2

and final, can I use this formula for RF:

RF= Ce*Dp*(Boi/Bo)
Ce: effective compressibility
Dp: Pi-P
Bo: OFVF

thank you