Capacitance transducers for non-intrusive measurement of water in crude oil
Abstract
A water-in-oil monitor has been developed which is suitable for monitoring water content in older producing fields, water content in the crude from separators, and water content in oil/water emulsions during oil skimming at sea as in anti-pollution operations. The transducer developed significantly extends the range of water contents measurable (0 to 80%), and is non-intrusive. The sensor has a smooth inner surface which aligns with the pipe wall (1 in to 12 in, i.e. 25–305 mm) eliminating any possibility of internal obstruction. The water-in-oil monitor has been tested by Conoco's research and development department in Ponca City and by Norsk Hydro. The accuracy is ±1.5% water fraction at 0–15% water content and ±1% water fraction at 15–80%. The repeatability is better than 1.0% water fraction. To increase the accuracy, a helical-shaped surface plate electrode system is introduced creating a 180° rotated field from one end of the transducer to the other. Theoretical models and experimental results show that these electrodes are much less dependent on variation in the flow regime and thus can measure the water content with higher accuracy.
- Publication:
-
Flow Measurement and Instrumentation
- Pub Date:
- January 1989
- DOI:
- 10.1016/0955-5986(89)90010-1
- Bibcode:
- 1989FloMI...1...51H
- Keywords:
-
- capacitance transducers;
- water content measurement;
- crude oil