Disclosed are embodiments of hydrocarbon leak detection cables that utilize time domain reflectometry to indicate the location of changes in impedance in a hydrocarbon leak detection cable. In addition, an embodiment of a hydrocarbon leak detection optical fiber is disclosed.

In some examples of monitoring pipeline integrity using fiber optics, a first set of values that represent an attenuation of a light signal transmitted through an optical fiber positioned adjacent a pipeline to carry fluids and a second set of values that represent a dispersion of the light signal transmitted through the optical fiber are received. An attenuation profile of the light signal and a dispersion profile of the light signal through the optical fiber are generated based on the first and second sets of values, respectively. Using the profiles, a light-based profile signature describing an environment surrounding the optical fiber is generated, and compared with a baseline light-based profile signature describing an environment surrounding the optical fiber under a normal operating condition. A notification describing an operation of the pipeline is provided in response to the comparing.

A method of distributed fibre optic sensing is described. In an example, a series of interrogations are launched into an optical fibre, each interrogation comprising interrogating radiation in at least one pulse pair, wherein the pulses of a pulse pair are introduced to the optical fibre with a time interval therebetween. Radiation backscattered therefrom is sampled, so as to obtain at least one sample from each interrogation. Phase modulation in the samples is determined and components of the phase modulation which are below a threshold frequency are isolated. Such a method of sensing could be used, for example, to monitor changes in temperature of the optical fibre.

A leakage detection apparatus according to the present disclosure includes: at least one memory storing instructions; and at least one processor configured to execute the instructions to transmit pulsed light to an optical fiber laid in a pipe through which a fluid flows and receive backscattered light from the optical fiber, generate sound data indicating a state of the fluid flowing through the pipe, based on the backscattered light, and detect leakage of the fluid by analyzing the sound data.

Leakage detection for pressurized fuel tanks. To provide facilitated leakage detection, a leakage detection device for pressurized fuel tanks for storing a pressurized fuel includes a fuel-sensing tracer and a light-wave conducting component. The fuel sensing tracer is configured to alter its optical properties in the presence of a predetermined fuel. The light-wave conducting component is in optical contact with the fuel sensing tracer. Light travelling within the light-wave conducting component is modifiable by altered optical properties of the fuel sensing tracer such that modified light is indicative of the presence of fuel at the location of the fuel sensing tracer.

Direct detection of carbon dioxide leakage in a carbon storage well is obtained using an optical fiber adapted to be positioned in the carbon storage well, a detection unit operatively connected to the optical fiber, and a leak sensor section incorporated in the optical fiber.