The image above represents the total formation volume factor (FVF).

To compute for the total FVF, four essential parameters are needed and these parameters are **oil FVF (B _{o}), gas FVF (B_{g}), initial gas solubility (R_{si}) and current gas solubility (R_{s}).**

The formula for calculating the total FVF:

B_{T} = B_{o} + (R_{si} – R_{s})B_{g}

Where;

B_{T} = Total FVF

B_{o} = Oil FVF

B_{g} = Gas FVF

R_{si} = Initial Gas Solubility

R_{s} = Current Gas Solubility

Let’s solve an example;

Find the total FVF when the oil FVF is 14, gas FVF is 15, initial gas solubility is 26 and current gas solubility is 17.

This implies that;

B_{o} = Oil FVF = 14

B_{g} = Gas FVF = 15

R_{si} = Initial Gas Solubility = 26

R_{s} = Current Gas Solubility = 17

B_{T} = B_{o} + (R_{si} – R_{s})B_{g}

B_{T} = 14 + (26 – 17)15

B_{T} = 14 + (9)15

B_{T} = 14 + 135

B_{T} = 149

Therefore, the **total FVF **is **149.**

**Calculating the Oil FVF when the Total FVF, Gas FVF, Initial Gas Solubility and Current Gas Solubility is Given.**

B_{o} = B_{T} – (R_{si} – R_{s})B_{g}

Where;

B_{o} = Oil FVF

B_{T} = Total FVF

B_{g} = Gas FVF

R_{si} = Initial Gas Solubility

R_{s} = Current Gas Solubility

Let’s solve an example;

Find the oil FVF when the total FVF is 44, gas FVF is 17, initial gas solubility is 21 and current gas solubility is 19.

This implies that;

B_{T} = Total FVF = 44

B_{g} = Gas FVF = 17

R_{si} = Initial Gas Solubility = 21

R_{s} = Current Gas Solubility = 19

B_{o} = B_{T} – (R_{si} – R_{s})B_{g}

B_{o} = 44 – (21 – 19)17

B_{o} = 44 – (2)17

B_{o} = 44 – 34

B_{o} = 10

Therefore, the **oil FVF **is **10.**

**Calculating the Gas FVF when the Total FVF, Oil FVF, Initial Gas Solubility and Current Gas Solubility is Given.**

B_{g} = ^{BT – Bo} / _{R}_{si} – R_{s}

Where;

B_{g} = Gas FVF

B_{o} = Oil FVF

B_{T} = Total FVF

R_{si} = Initial Gas Solubility

R_{s} = Current Gas Solubility

Let’s solve an example;

Find the gas FVF when the total FVF is 48, oil FVF is 16, initial gas solubility is 20 and current gas solubility is 12.

This implies that;

B_{o} = Oil FVF = 16

B_{T} = Total FVF = 48

R_{si} = Initial Gas Solubility = 20

R_{s} = Current Gas Solubility = 12

B_{g} = ^{BT – Bo} / _{Rsi – Rs}

B_{g} = ^{48 – 16} / _{20 – 12}

B_{g} = ^{32} / _{8}

B_{g} = 4

Therefore, the **gas FVF **is **4.**