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Production EngineeringInflow Performance

Productivity Index and Straight-Line IPR Calculator

J=qoPr−PwfJ = \frac{q_o}{P_r - P_{wf}}

Enter flow rate, reservoir pressure, and flowing bottomhole pressure. The calculator returns productivity index or related IPR values.

Tabular solver

Inputs

Defaults provide a quick field-unit example for the equation.

3 variables

Calculation runs locally with the shared TypeScript engine.

Formula reference

Productivity index relates liquid production rate to drawdown for straight-line inflow performance in a producing well.

View formula, units, and source

Assumptions

  • The pressure-rate relationship is linear over the evaluated range.
  • Reservoir and flowing bottomhole pressures are representative.
  • Rate and pressure units match the formula constants used.

Common mistakes

  • Using wellhead pressure instead of flowing bottomhole pressure.
  • Applying a straight-line PI model to strongly nonlinear inflow.
  • Mixing liquid-rate units.