Ultrasonic Techniques for Characterizations of Oils and Their Emulsions and Monitoring Oil Layer Depth of Spill
Abstract
Oil-water emulsions encountered during production and refining of crude oil, as well as oil spills present technical challenges. There is need for low-cost technology to understand characteristics such as composition, droplets size distribution and other rheological properties of oils and their emulsions and monitor oil layer depth of spill.
The main purpose of the first part of this work was to develop and test ultrasonic based technology to characterize oils and their emulsions using their acoustic velocities and attenuations. The technique captured an increase in both acoustic velocity and attenuation with asphaltenes concentration in crude oil. Thus, the fast response and low-cost ultrasonic techniques provide a plausible means of monitoring this impurity level in treated and upgraded crude oils. Tests with emulsions of oil samples exhibited that both acoustic velocity and attenuation decreased with time, which indicated water droplets settling. This was confirmed by direct measurements of water separation with time which were consistent with ultrasonic results. These findings have opened a new perspective for the ultrasonic technique to monitor and characterize emulsions online.
The main purpose of the last part of this work was to develop a low-cost ultrasonic-based technique to monitor the oil layer depth of the spills. Layers of water-in-oil emulsion and mineral and crude oil samples were added to the DI water surface at an increment of 1 mm thickness in a jacketed vessel. Acoustic velocity decreased with the thickness of oils and their emulsions layers, while attenuation increased as expected. This is significant progress towards the development of ultrasonic technology to detect and monitor oil spill depth. A suitable device configuration is proposed for further development and field testing.