Enter the CFM, hole diameter, and pipe diameter into the calculator to determine the uphole velocity.

## Uphole Velocity Formula

The following equation is used to calculate the Uphole Velocity.

UHV = 183.4*CFM / (HD^2-PD^2)
• Where UHV is the uphole velocity (ft/s)
• CFM is the flow rate uphole (ft^3/min)
• HD is the hole diameter (in)
• PD is the pipe diameter (in)

## What is a Uphole Velocity?

Definition:

Uphole velocity describes the linear speed of flow in the uphole portion of a drilling operation.

## How to Calculate Uphole Velocity?

Example Problem:

The following example outlines the steps and information needed to calculate the Uphole Velocity.

First, determine the flow rate uphole. In this example, the flow rate uphole is found to be 200 ft^3/s.

Next, determine the hole diameter. For this problem, the hole diameter is found to be 7in.

Next, determine the pipe diameter. In this case, the pipe diameter is measured to be 4in.

Finally, calculate the Uphole Velocity using the formula above:

UHV = 183.4*CFM / ((HD^2-PD^2)

UHV = 183.4*200 / ((7^2-4^2))

UHV = 1111.51 ft/s