1. n. [Production Testing]

A situation in which the well and the reservoir are continuously monitored. On the basis of this information, the well completion may be adjusted remotely to adapt to changes in downhole conditions. A permanent well monitoring system is composed of the following:

• inflow control valves that enable choking or shutting off different zones according performance such as drawdown, GOR, or water cut
• downhole sensors that register pressure, fluid flow rate, and temperature
• control lines for power transmission and transferring of monitored downhole data captured by downhole sensors
• a surface control unit to handle the monitored data and for remote operation of the downhole inflow control valves.

Wells with permanent monitoring systems are commonly called intelligent or smart wells. Permanent well monitoring is commonly used in multilateral wells, where hydraulically independent valves control the flow of each lateral and in deepwater wells, where well-intervention operations are often prohibitively expensive. Permanent well monitoring helps improve reservoir management by quickly choking or shutting off zones, avoiding expensive well intervention. It also helps maximize production and optimize recovery.