Monitoring oil-water mixture separation by time domain reflectometry

Effective separation of water and oil is an essential part of petroleum production. Time domain reflectometry (TDR) can be used to profile the separation of hydrocarbon oil-water mixtures. In such two-component systems, metal electrodes will become oil-coated due to their affinity to oil. This coating layer will impact water content measurements. By combining the TDR signals from two probes in a novel configuration, the thickness of the oil layer on the electrodes can be estimated and its effect on the TDR measurements corrected for. The probes consist of two rods of different diameter and spacing to a common ground/guard electrode. The measurement principle is demonstrated using a light fuel oil and a thicker organic oil. The results indicate that oil and water levels can be monitored during separation if the metal electrode oil-coating effect is accounted for.