The feasibility of optically detecting air and water bubbles flowing through the oil is presented. By scanning wavelengths it is possible to add functionalities by implementing a spectroscopy based chemical detection that can directly lead to chemical detection and imaging and/or chemical species tomography of flowing fluids. In this article, a halogen lamp (175 - 1000 W and centered at 1.2 mm) and an IR-array camera (8-12 μm, 31 x 32 pixels and 10 fps) is used to observe the three-phase flow involving oil, air and water.
A fiber design that allows the characterization of high and low refractive index materials is proposed and demonstrated. This fiber consists of an air-silica photonic crystal fiber supporting a Gaussian like mode confined in the fiber core and a ring mode in a region between the structured area and the fiber cladding. This versatile fiber design finds applications in the oil industry where materials of different refractive indices are found. The characterization of petroleum and CO2 using the new fiber is demonstrated.
Optical fiber Bragg grating strain sensors are used to characterize the multiphase flow of water and air in a laboratory
test bed. The load applied by the fluid flow on the fiber gratings is the underlying mechanism of the sensor and different
flow conditions with distinct void fractions and flow rates were investigated. The optical fiber sensors performance was
compared against that of a wire-mesh system which is conventionally used as a reference high performance measurement
tool for multiphase flow. Results are in good agreement showing the potential of the technique.