Enter the average velocity of the oil in feet per second (ft/s).
Please enter valid positive numbers for both fields.
Barrels per Day (BPD):–
Gallons per Minute (GPM):–
Cubic Meters per Hour (m³/h):–
Cubic Feet per Second (cfs):–
How to Calculate Oil Flow Rate
Understanding the volumetric flow rate of oil through a pipeline is a fundamental aspect of petroleum engineering and production monitoring. Whether you are managing a transport pipeline, a refinery intake, or a wellhead, accurate calculation of the flow rate ensures operational efficiency and safety.
The Flow Rate Formula
The most common method for calculating liquid flow rate inside a pipe is based on the relationship between the pipe's cross-sectional area and the velocity of the fluid. The fundamental equation is:
Q = A × v
Where:
Q = Volumetric Flow Rate
A = Cross-sectional Area of the pipe
v = Average Velocity of the fluid
Step-by-Step Calculation Logic
To use this formula manually for oil industry standards, you typically follow these steps:
Determine the Radius: First, take your pipe's Inner Diameter (ID) in inches. Divide by 2 to get the radius, and divide by 12 to convert it to feet.
Calculate Area (A): Use the formula A = π × r² to get the area in square feet.
Multiply by Velocity (v): Multiply the area (ft²) by the fluid velocity (ft/s) to get the flow rate in cubic feet per second (cfs).
Convert Units: Convert the result into industry-standard units like Barrels per Day (bpd) or Gallons per Minute (gpm).
Common Unit Conversions
In the oil and gas industry, converting between units is daily routine. Here are the standard multipliers used in our calculator:
1 Cubic Foot = 7.4805 Gallons (US)
1 Barrel (bbl) = 42 Gallons (US)
1 Day = 1,440 Minutes = 86,400 Seconds
Why Inner Diameter Matters
It is critical to use the Inner Diameter (ID) rather than the Outer Diameter (OD) or nominal pipe size. The wall thickness of the pipe reduces the available flow area. For example, a nominal 4-inch pipe with Schedule 80 thickness has a smaller ID than a Schedule 40 pipe, resulting in a higher velocity for the same flow rate or a lower flow rate for the same velocity.
Example Calculation
Let's say you have a pipe with an ID of 6 inches and the oil is flowing at 5 ft/s.