The Design And Development Of Parallel-Plate-Capacitor Water-cut Meter

Water-cut meter is an important instrument in the oilfield measurement. The capacitive water-cut meters have been widely used in oilfields for the simple principle, low development cost. In the application ,many problems and defects appeared. So, further more efforts should be done to improve the technology and perfect the existing capacitive water-cut meters. A new three-parallel-plates-capacitor is first presented as well as the detailed configuration. The CAV424 is an integrated C/V converter and has an excellent performance in transforming the capacitive signal, which in this design is the original signal, to voltage signal. The model of the water-cut meter is completed.Many experiments have been done first on the low water-cut oil samples with water-cut range from 0 to 20%.A few different experimental means are used to test the model, and lots of experimental data and diagrams are obtained. The experiments indicate that the model has a quick response and high sensitivity. The experiment results also indicate that the model has good conformity and repeatability, and the measurement accuracy can meet the field measurement requirement. Based on the results of the low water-cut tests, a layer of insulating media is coated on one pole of the plates. After coating, the water-cut samples with the full range water-cut from 0 to 100% are tested and satisfying results are obtained. This attempt lays a foundation for the development of full range capacitive water-cut meter in the future.