Steam flow measurement using alcohol tracers

Tracer flow testing procedures are increasingly being used for routine measurement of well output in operating geothermal fields. A new procedure developed in New Zealand uses low boiling-point, liquid alcohol (isopropanol or butan-2-ol) as the steam-phase tracer. The use of alcohol tracers allows major simplifications to field procedures, including injection with conventional liquid-dosing pumps, sampling into open sample bottles and preparation of composite steam/water tracers. These practical benefits far outweigh the only drawback of alcohol tracers, which is the need to correct for alcohol gas dissolved in the liquid phase. This paper reviews development work with alcohol tracers over the past five years and discusses the properties of alcohols and the practical aspects of their use in tracer-dilution testing. (C) 2001 Published by Elsevier Science Ltd on behalf of CNR.