Fluid Identification - Cased-Hole Log Analysis and Reservoir Performance Monitoring - page 86

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Fluid Identification

Production logging tools that can differentiate between oil, gas, and water in a
producing well allow diagnosis of completion and production problems. They offer
the operator assistance in planning remedial work and in monitoring reservoir per-
formance. In particular, these tools help:

(a) To pinpoint gas, oil, and water entries into, and exits from, the production string
(b) To determine, in combination with flow measurements, how much of which
fluid is produced from which zone

Tools Available

Devices used for fluid identification can be broadly categorized into two groups:

1. Those that respond directly to the physical properties of wellbore fluids (such as
density, dielectric constant, resistivity, etc.)
2. Those that respond to the physical effects caused by the actual flow of fluids
(such as temperature changes, noise, etc.)

The devices in the second group require that the well be flowing in order to func-
tion, but the devices from the first group work even if the wellbore fluids are static.