Sensing Hydrates in Pipes by a Combined Electrical and Optical Fiber Sensor

This paper presents the development and application of an electrical impedance sensor allied with an optical fiber Bragg grating (FBG) sensor whereby both are integrated in fiberglass composite material. The use of composite material allows the integration of the sensors according to the desired geometry. In the field of oil and gas production it is of great importance to monitor the formation of clathrate hydrates (crystalline structures) because such solids may disrupt the flow causing risks and increasing extraction costs. As there is no fully established method for this sensing application, impedance spectroscopy allied to temperature technique is explored for the purpose. Hence, impedance spectra from 1 kHz to 5 MHz along with temperature readings are obtained during an exemplary hydrates experiment, showing that the developed system is able to monitor the hydrates formation in pipes.