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} / _{Rsi – Rs}

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.**

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

R_{si} = ^{BT – Bo} / _{Bg} + R_{s}

Where;

R_{si} = Initial Gas Solubility

B_{T} = Total FVF

B_{g} = Gas FVF

B_{o} = Oil FVF

R_{s} = Current Gas Solubility

Let’s solve an example;

Find the initial gas solubility when the total FVF is 54, oil FVF is 14, gas FVF is 12 and current gas solubility is 24.

This implies that;

B_{T} = Total FVF = 54

B_{g} = Gas FVF = 14

B_{o} = Oil FVF = 12

R_{s} = Current Gas Solubility = 24

R_{si} = ^{BT – Bo} / _{Bg} + R_{s}

R_{si} = ^{54 – 12} / _{14} + 24

R_{si} = ^{42} / _{14} + 24

R_{si} = 3 + 24

R_{si} = 27

Therefore, the **initial gas solubility **is **27.**

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

R_{s} = R_{si} – ^{BT – Bo} / _{Bg}

Where;

R_{s} = Current Gas Solubility

R_{si} = Initial Gas Solubility

B_{T} = Total FVF

B_{g} = Gas FVF

B_{o} = Oil FVF

Let’s solve an example;

Find the current gas solubility when the total FVF is 14, oil FVF is 6, gas FVF is 10 and initial gas solubility is 5.

This implies that;

R_{si} = Initial Gas Solubility = 5

B_{T} = Total FVF = 14

B_{g} = Gas FVF = 10

B_{o} = Oil FVF = 6

R_{s} = R_{si} – ^{BT – Bo} / _{Bg}

R_{s} = 5 – ^{14 – 6} / _{10}

R_{s} = 5 – ^{8} / _{10}

R_{s} = 5 – 0.8

R_{s} = 4.2

Therefore, the **current gas solubility **is **4.2**

Nickzom Calculator – **The Calculator Encyclopedia** is capable of calculating the total FVF.

To get the answer and workings of the total FVF using the **Nickzom Calculator – The Calculator Encyclopedia. **First, you need to obtain the app.

You can get this app via any of these means:

**Web** – https://www.nickzom.org/calculator-plus

To get access to the **professional **version via web, you need to **register** and **subscribe **for** NGN 1,500 **per** annum** to have utter access to all functionalities.

You can also try the **demo **version via https://www.nickzom.org/calculator

**Android (Paid)** – https://play.google.com/store/apps/details?id=org.nickzom.nickzomcalculator

**Android (Free)** – https://play.google.com/store/apps/details?id=com.nickzom.nickzomcalculator

**Apple (Paid)** – https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8

Once, you have obtained the calculator encyclopedia app, proceed to the **Calculator Map, **then click on **Petroleum **under **Engineering**

Now, Click on **Reservoir Fluid Flow **under **Petroleum**

Now, Click on **Total FVF**** **under **Reservoir Fluid Flow**

The screenshot below displays the page or activity to enter your value, to get the answer for the total FVF according to the respective parameter which are the **oil FVF (B _{o}), gas FVF (B_{g}), initial gas solubility (R_{si}) and current gas solubility (R_{s}).**

Now, enter the value appropriately and accordingly for the parameter as required by the **oil FVF (B _{o})** is

**14**,

**gas FVF (B**is

_{g})**15**,

**initial gas solubility (R**is

_{si})**26**and

**current gas solubility (R**is

_{s})**17**.

Finally, Click on Calculate

As you can see from the screenshot above, **Nickzom Calculator**– The Calculator Encyclopedia solves for the total FVF and presents the formula, workings and steps too.