The image above represents the gas pore volume.

To compute for the gas pore volume, three essential parameters are needed and these parameters are **Initial Gas FVF (B _{gi}), Initial Water Saturation (S_{wi}) and Initial Gas in Place (G)**.

The formula for calculating the gas pore volume:

(PV)_{g} = ^{GBgi} / _{1 – Swi}

Where;

(PV)_{g} = Gas Pore Volume

B_{gi} = Initial Gas FVF

S_{wi} = Initial Water Saturation

G = Initial Gas in Place

Let’s solve an example;

Find the gas pore volume when the initial gas FVF is 12, initial water saturation is 9 and initial gas in place is 13.

This implies that;

B_{gi} = Initial Gas FVF = 12

S_{wi} = Initial Water Saturation = 9

G = Initial Gas in Place = 13

(PV)_{g} = ^{GBgi} / _{1 – Swi}

(PV)_{g} = ^{13 x 12} / _{1 – 9}

(PV)_{g} = ^{156} / _{-8}

(PV)_{g} = -19.5

Therefore, the **gas pore volume **is **-19.5**

**Calculating the Initial Gas FVF when the Gas Pore Volume, Initial Water Saturation and Initial Gas in Place is Given.**

B_{gi} = ^{(PV)g (1 – Swi)} / _{G}

Where;

B_{gi} = Initial Gas FVF

(PV)_{g} = Gas Pore Volume

S_{wi} = Initial Water Saturation

G = Initial Gas in Place

Let’s solve an example;

Find the initial gas FVF when the gas pore volume is 19, initial water saturation is 11 and initial gas in place is 16.

This implies that;

(PV)_{g} = Gas Pore Volume = 19

S_{wi} = Initial Water Saturation = 11

G = Initial Gas in Place = 16

B_{gi} = ^{(PV)g (1 – Swi)} / _{G}

B_{gi} = ^{19 (1 – 11)} / _{16}

B_{gi} = ^{19 (-10)} / _{16}

B_{gi} = ^{-190} / _{16}

B_{gi} = -11.875

Therefore, the **initial gas FVF **is **-11.875.**

**Calculating the Initial Water Saturation when the Gas Pore Volume, Initial Gas FVF and Initial Gas in Place is Given.**

S_{wi} = 1 – ^{GBgi} / _{(PV)g}

Where;

S_{wi} = Initial Water Saturation

G = Initial Gas in Place

(PV)_{g} = Gas Pore Volume

B_{gi} = Initial Gas FVF

Let’s solve an example;

Find the initial water saturation when the initial gas FVF is 24, initial gas in place is 6 and gas pore volume is 46.

This implies that;

G = Initial Gas in Place = 6

(PV)_{g} = Gas Pore Volume = 46

B_{gi} = Initial Gas FVF = 24

S_{wi} = 1 – ^{GBgi} / _{(PV)g}

S_{wi} = 1 – ^{6 x 24} / _{46}

S_{wi} = 1 – ^{144} / _{46}

S_{wi} = 1 – 3.13

S_{wi} = -2.13

Therefore, the **initial water saturation **is **-2.13.**

**Calculating the Initial Gas in Place when the Gas Pore Volume, Initial Gas FVF and Initial Water Saturation is Given.**

G = ^{(PV)g (1 – Swi)} / _{Bgi}

Where;

G = Initial Gas in Place

(PV)_{g} = Gas Pore Volume

B_{gi} = Initial Gas FVF

S_{wi} = Initial Water Saturation

Let’s solve an example;

Find the initial gas in place when the initial gas FVF is 18, initial water saturation is 8 and gas pore volume is 12.

This implies that;

(PV)_{g} = Gas Pore Volume = 12

B_{gi} = Initial Gas FVF = 18

S_{wi} = Initial Water Saturation = 8

G = ^{(PV)g (1 – Swi)} / _{Bgi}

G = ^{12 (1 – 8)} / _{18}

G = ^{12 (-7)} / _{18}

G = ^{-84} / _{18}

G = -4.667

Therefore, the **initial gas in place **is **-4.667.**

Nickzom Calculator – **The Calculator Encyclopedia** is capable of calculating the gas pore volume.

To get the answer and workings of the gas pore volume 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 **gas pore volume**** **under **Reservoir Fluid Flow**

The screenshot below displays the page or activity to enter your value, to get the answer for the gas pore volume according to the respective parameter which are the **Initial Gas FVF (B _{gi}), Initial Water Saturation (S_{wi}) and Initial Gas in Place (G).**

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

**12**,

**Initial Water Saturation (S**is

_{wi})**9**

**and Initial Gas in Place (G)**is

**13.**

Finally, Click on Calculate

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