Jökull - 01.12.1966, Page 31

ing tube which was traversed diametrally across
the mouth of a discharging well. It was assumed
that at each location it accepted a representa-
tive sample of mixture. The sample so collected
was directed into a mobile calorimeter to mea-
sure enthalpy and mass efflux. A critical ap-
praisal of this device was made by Ryley (1964).
MEASUREMENTS OF DISCHARGE
MADE IN ICELAND
The first systematic attempts at flow mea-
surement were made using separation equip-
ment designed and constructed by the Depart-
ment of Natural Heat, State Electricity Author-
ity. A diagram of this equipment is given in
Fig. 1. The principle is to separate the entire
efflux into liquid and vapour fractions. Crude
separation takes place by causing the mixture
to traverse a single pipe bend, A, and the wet
vapour then extracted is passed through a
cyclone B, where the remaining entrained
liquid is centrifuged out. The vapour then
passes through the measuring orifices C con-
tained in long 16" bore pipes. The liquid both
from the bend A and the cyclone B is flashed
in closed vessels, the flash steam being mea-
sured in the smaller orifice D. The surviving
liquid fraction is measured finally at weirs E
and E.
The apparatus is believed to be reasonably
accurate although there is evidence that it
overestimates the rnass flow of the vapour
fraction. The enthalpy of the total efflux,
as computed on the basis of the measured
data, has consistently been larger than the
values which are to be expected on the basis
of bottom-hole temperature data which are
known with great accuracy. There is the pos-
sibility that this could also be the result of a
deficiency in the measurement of the liquid
fraction, but this is rather unlikely. The reason
Fig. 1. Diagram of Separation Plant for Well Discharge Measurement.
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