# How to Calculate and Solve for Well, External and Dimensionless Radius | Nickzom Calculator The image above represents dimensionless radius.

To compute for the dimensionless radius, two essential parameters are needed and these parameters are external radius (re) and well radius (rw).

The formula for calculating the dimensionless radius:

rD = re / rw

Where;

rD = Dimensionless Radius
re = External Radius
rw = Well Radius

Let’s solve an example;
Given that the external radius is 18 and the well radius is 16.
Find the dimensionless radius?

This implies that;

re = External Radius = 18
rw = Well Radius = 16

rD = re / rw
rD = 18 / 16
rD = 1.125

Therefore, the dimensionless radius is 1.125.

Calculating for the External Radius when the Dimensionless Radius and the Well Radius is Given.

re = rD x rw

Where;

re = External Radius
rD = Dimensionless Radius
rw = Well Radius

Let’s solve an example;
Given that the dimensionless radius is 9 and the well radius is 20.
Find the external radius?

This implies that;

rD = Dimensionless Radius = 9
rw = Well Radius = 20

re = rD x rw
re = 9 x 20
re = 180

Therefore, the external radius is 180.

Calculating for the Well Radius when the Dimensionless Radius and the External Radius.

rw = re / rD

Where;

rw = Well Radius
rD = Dimensionless Radius
re = External Radius

Let’s solve an example;
Given that the dimensionless radius is 10 and the external radius is 90.
Find the well radius?

This implies that;

rD = Dimensionless Radius = 10
re = External Radius = 90

rw = re / rD
rw = 90 / 10
rw = 9

Therefore, the well radius is 9.

Nickzom Calculator – The Calculator Encyclopedia is capable of calculating the dimensionless radius.

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

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Once, you have obtained the calculator encyclopedia app, proceed to the Calculator Map, then click on Petroleum under Engineering Now, Click on Well Testing under Petroleum Now, Click on Dimensionless Radius under Well Testing The screenshot below displays the page or activity to enter your values, to get the answer for the dimensionless radius according to the respective parameters which are the external radius (re) and well radius (rw). Now, enter the values appropriately and accordingly for the parameters as required by the external radius (re) is 18 and well radius (rw) is 16. Finally, Click on Calculate As you can see from the screenshot above, Nickzom Calculator– The Calculator Encyclopedia solves for the dimensionless radius and presents the formula, workings and steps too.