Maximum surface production rate with zero bottomhole pressure ( p_{wf} = 0).
The concept of AOL may apply to various fluids and normally makes clear in a given context, the most popular being the maximum surface production rate of oil and surface production rate of gas.
In single-layer formation can be estimated as:
| (1) | q_{AOF} = J_r \cdot p_r |
where
J_r is Drainarea Productivity Index,
p_r is drainarea-average formation pressure.