Drawdown %

This is a plot of Δp / p_i X 100% versus time. It indicates the degree of drawdown.

The shape of the inflow performance relationship (IPR) curve shows that in high drawdown situations, the rate becomes insensitive to pressure.

Reasons for inconsistencies:

• At low drawdown, if the flowing pressure decreases (increases), and the rate does not increase (decrease), it means that one or the other is incorrect.
• At high drawdown, the well is operating in the low pressure region of the IPR curve. If the flowing pressure changes but the flow rate does not, it is not a cause for concern.
• At high drawdown, a lack of correlation between rate and pressure is not a cause for concern.