Flow Regimes - Cased-Hole Log Analysis and Reservoir Performance Monitoring - page 49

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Flow Regimes

In this chapter, types of fluid flow will be discussed. In particular, three important
concepts will be covered:

1. Laminar and turbulent flow
2. Superficial velocity
3. Holdup

A proper understanding of these concepts is essential before any quantitative
interpretation of production logs is possible.

Laminar and Turbulent Flow

The flow of fluids in pipes can take place in a smooth, “streamlined” fashion or in a
turbulent mode. The controlling factors are the fluid density, the superficial velocity,
the pipe diameter, and the fluid density. The superficial velocity ( V ) is defined as the
volumetric flow rate divided by the area of the pipe available for flow; that is,

2

Vqd = 4 / p .

The actual velocity of the fluid will be greater than V in the center of the pipe and
less than V at the fluid/pipe interface, just as a river flows more rapidly at its middle
than at its banks. A plot of fluid velocity across the pipe is shown in Fig. 4.1 . Note
that the velocity contrast between the center of the pipe and the superficial (or aver-
age) velocity is greater in the case of laminar flow than in the case of turbulent flow.