Flowmeters - Cased-Hole Log Analysis and Reservoir Performance Monitoring - page 69

Figure 5.12a shows the position of the tool in the flow stream together with the flow
profile. The flow profile across the pipe is a function of the Reynolds number (see
Chap. 4 ) . Use of the fluid speed measured by a flowmeter without correction would
overestimate true flow rate. The correction factor as a function of the Reynolds
number is shown in Fig. 5.12b . In most cases, this factor is between 0.84 and 0.85.
It is applied as follows:

V = V ´ Correctionfactor .

superficial measured

Fig. 5.12 Flowmeter correction factor. ( a ) Courtesy Schlumberger and ( b ) Courtesy Baker Atlas

Question #5.1
A flowmeter survey completed 6 passes. The cable speed, direction, and corre-
sponding spinner rps were as follows:

Tool speed (ft/min) rps rps

Logging down 10 5

60 10

110 15

Logging up −110 −5

−160 −10

−210 −15

(a) Plot these points on linear graph and determine the fluid speed.
(b) Use a correction factor of 0.85 and determine the flow rate in B/D for 7-in. 20-lb
pipe.