Page 237 - Standard Handbook Petroleum Natural Gas Engineering VOLUME2

406 Reservoir Engineering

Figure 5-127. Temperature log showing water flow behind the casing. Water
is flowing down to the producing interval [221].

At flow rates less than 2,000 bopd, F is negligible and p+ = pr [221]. The
kinetic term is important when logging from tubing into the casing. Fluid velocity
changes become significant at the change in hole diameter. The change causes
a sharp pressure increase on the log. The friction term is important at high
flow rates in casing and when logging in small-diameter tubing or casing [221].
Another log similar to the gradiomanometer is the water-holdup meter. The
main limitation is that it only reads water holdup and cannot be used if water
is not present. It has the advantage over the gradiomanometer where sensitivity is
required; small differences in density may not be seen by the gradiomanometer.

Flowmeters. Flowmeters are designed to measure fluid flow in the casing. This
measurement is then related to volume of fluid being produced. Three types
of flowmeters are available:
1. Fullbore-spinner flowmeter.
2. Continuous flowmeter.
3. Packer flowmeter.
Each is used in certain circumstances and is combinable with other devices
so that improved flow rates can be obtained.
Fullbore-Spinner Flowmeter. This device measures velocities of fluid moving
up the casing. These velocities are then related to volume of fluid moved with