The above image represents Water – Oil Ratio.

To compute for the water – oil ratio, six essential parameters are needed and these parameters are **(μ _{o})Oil Viscosity, (μ_{w})Water Viscosity, (k_{rw})Relative Permeability to Water, (k_{ro})Relative Permeability to Oil, (B_{w})Water Formation Volume Factor **and

**(B**

_{o})Oil Formation Volume Factor.The formula for calculating the water – oil ratio:

WOR = [^{krw }/_{ kro}] [^{μoBo }/ _{μwBw }]

Where;

WOR = Water Oil Ratio

μo = Oil Viscosity

μ_{w} = Water Viscosity

k_{rw} = Relative Permeability to Water

k_{ro} = Relative Permeability to Oil

B_{w} = Water Formation Volume Factor

B_{o} = Oil Formation Volume Factor

Let’s solve an example;

Find the water – oil ratio when the oil viscosity is 9, water viscosity is 11 with a relative permeability to water of 21, relative permeability to oil of 7 and a water formation volume factor of 14 with oil formation volume factor of 27.

This implies that;

μo = Oil Viscosity = 9

μ_{w} = Water Viscosity = 11

k_{rw} = Relative Permeability to Water = 21

k_{ro} = Relative Permeability to Oil = 7

B_{w} = Water Formation Volume Factor = 14

B_{o} = Oil Formation Volume Factor = 27

WOR = [^{krw }/_{ kro}] [^{μoBo }/ _{μwBw }]

WOR = [21/7] [9 x 27 /11 x 14]

WOR = [21/7] [243/154]

WOR = [21/7] [1.5779]

WOR = [3] [1.5779]

WOR = 4.73

Therefore, the **Water – Oil Ratio **is** 4.73.**

Nickzom Calculator – **The Calculator Encyclopedia** is capable of calculating the water – oil ratio.

To get the answer and workings of the water – oil ratio 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 **Water – Oil Ratio**** **under **Reservoir Fluid Flow**

The screenshot below displays the page or activity to enter your value, to get the answer for the water – oil ratio according to the respective parameter which are the **(μ _{o})Oil Viscosity, (μ_{w})Water Viscosity, (k_{rw})Relative Permeability to Water, (k_{ro})Relative Permeability to Oil, (B_{w})Water Formation Volume Factor **and

**(B**

_{o})Oil Formation Volume Factor.Now, enter the value appropriately and accordingly for the parameter as required by the **oil viscosity is 9**, **water viscosity is 11** with a **relative permeability to water of 21**, **relative permeability to oil of 7** and a **water formation volume factor of 14** with **oil formation volume factor of 27.**

Finally, Click on Calculate

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