On IPR curves, which variable is plotted on the x-axis?

On IPR curves, which variable is plotted on the x-axis?

• A. Flow rate
• B. Time
• C. Pressure
• D. Depth

Answer: (A)

On an Inflow Performance Relationship curve, the well’s production rate is the response to the drive provided by pressure. The independent variable is pressure, so the x-axis is bottom-hole flowing pressure. As this pressure falls, the production rate tends to rise until other limits (like formation or equipment constraints) bound the deliverability. Time and depth aren’t the variables varied to generate the IPR curve; time would relate to transient behavior, and depth is a fixed property/location. Therefore, pressure is plotted on the x-axis, with flow rate on the y-axis.

On an Inflow Performance Relationship curve, the well’s production rate is the response to the drive provided by pressure. The independent variable is pressure, so the x-axis is bottom-hole flowing pressure. As this pressure falls, the production rate tends to rise until other limits (like formation or equipment constraints) bound the deliverability. Time and depth aren’t the variables varied to generate the IPR curve; time would relate to transient behavior, and depth is a fixed property/location. Therefore, pressure is plotted on the x-axis, with flow rate on the y-axis.