Oil Formation volume factor FVF Bo

[bayan]

inquiring regarding FVF IF WE HAVE RESERVOIR PRODUCED UNDER BUBBLE POINT PRESSURE THEN WATER INJECTION WAS IMPLEMENT WITH GOOD EFFECT ON THE PRESSURE SINCE THE RESERVOIR PRESSURE BACK TO THE INTIAL RESERVOIR PRESSURE .....MY INQUIRE IS THE FVF BACK TO THE INTIAL FVF AT BUBBLE POINT PRESSURE Bop?

ANY COMMENTS ARE HIGHLY APPRECIATED
THANK YOU

[i-anuar]

hi,
if i understood correctly, your field was producing below saturation pressure for some time until water injection started bringing/increasing reservoir pressure back to initial. i think you could check what is current solution GOR and then estimate current formation volume factor for a given pressure, GOR, temperature etc. don't forget to add scenario where secondary gascap has formed. with secondary or primary gascap although relatively little gas has produced less gas remained in solution as some of it migrated up... anyways good luck.

[bayan]

Hi i-inuar, Thank you so much for your valuable comments ..... the case is as you understood exactly . do you think if the reservoir pressure back to initial pressure (by water injection) is the FVF will back to the original FVF. Thank you in advance.

Best Regards

[i-anuar]

hi bayan,
if your reservoir did not reach saturation pressure and initial GOR is the same then i would have thought that FVF could be back to initial once reservoir pressure increase again. if however your reservoir is below oil saturation pressure and some gas come out of solution (either migrating updip or flowing to the wells) then FVF should be different.
Did you produce a lot of oil compared to STOIIP? Do you have gas measurements? Plot producing GOR vs time and see if your reservoir is producing below saturation pressure (Psat). GOR would decrease below Psat if gas is migrating updip or GOR can increase if gas that become free is produced through the wells...

[bayan]

Dear i-anuar
Thank you so much for your comments.

Best Regards