ALBERT

Description: Multiphase gravity separators are widely used in the petroleum industry to separate the produced stream of oil, water and natural gas into pure (single-phase) streams. These equipment work based on the density differences of each fluid which tend to settle into layers when dwelled for some time in the separator. It is fundamental to monitor the levels of these phases inside the vessel, so that this information can be used in control strategies in order to increase the efficiency and safety of the process. In this work, we present a novel multiphase level sensor based on capacitance and inductance measurements of planar multi-electrodes and multi-coils. The sensor is low-cost, fast and does not apply ionizing radiation, being therefore simple to operate. The prototype sensor was constructed in standard printed-circuit board (PCB) technology and highly sensitive capacitance and inductance measurements are acquired with modern integrated circuit devices. Since the capacitive sensor readings depend on the water salinity, we perform simultaneous inductance measurements to compensate for such dependence. We have tested the prototype from two different approaches: varying the water salinity and for different water/oil mixtures. Preliminary results have shown the capability of the sensor to differentiate each one of the produced fluids, i.e., salty water, oil and gas, as well as the interfaces between them. A 16 electrodes capacitive-only sensor prototype was also built and tested.