Harsh Environments

Harsh environment optical fibers are designed for use at elevated temperatures and pressures in aggressive chemical environments. Typical applications include the oil & gas and geothermal industries, where the fibers are used for real-time downhole temperature and pressure measurements, data transmission, acoustic, seismic and imaging applications. AFL's Verrillon® harsh environment fibers are manufactured with a wide range of polymeric coatings including Polyimide, Silicone, Silicone-PFA and High Temperature Acrylates. In addition, our Verrillon optical fibers are available with a hermetic coating that prevents hydrogen, moisture and acid ingression. The fibers are suitable for operation over a wide range of temperatures up to 300ºC, depending on the coating combination selected. They are also available in a variety of different waveguide designs, including Multimode, Single-mode, Pure Silica Core, Bend-Insensitive and custom profiles.

Carbon Coating Technology: The Ultimate Barrier to Hydrogen Diffusion

AFL’s Verrillon hermetically-sealed optical fibers have been successfully deployed in downhole applications worldwide. The unique composition and method of manufacturing of our carbon coating make it the most reliable barrier against hydrogen for temperatures exceeding 150°C. Our online monitoring system ensures the integrity of the carbon layer throughout the entire length of the fiber. Additionally our state-of-the-art hydrogen testing facility simulates well conditions and provides performance predictions for our customers.
 

Glass Technology: The Ultimate Resistance to Hydrogen Darkening at High Temperatures

As the global demand for oil and gas increases, fiber optic sensing technologies have become crucial for oil recovery and reservoir optimization. This high demand spurred numerous distributed monitoring techniques to measure various well parameters such as temperature, pressure, strain, flow, seismic and acoustic waves. With the development of these emerging monitoring technologies, the need for optical fibers and cables that withstand high temperatures (up to 300ºC) and high partial pressures of hydrogen in downhole environments increased dramatically. For example, steam injected wells using techniques such as SAGD or CSS require robust fiber optic sensing systems that can survive the heat, steam, hydrogen ingression and water permeation. This field of high temperature, hydrogen-rich environments has been the focus of AFL in recent years.

Although the carbon technology is extremely reliable for the mid-temperature range, its effectiveness diminishes at temperatures higher than 200ºC in hydrogen-rich conditions. Therefore, the need for another protection strategy became necessary. Our approach to the high temperature, high hydrogen partial pressures is to make the glass of the optical fiber inherently resistant to hydrogen attack, without the need of external protection. This research culminated in the VHM5000 Series of fibers is immune to hydrogen-induced loss. The Verrillon VHM5000 technology is the result of a uniquely optimized glass design that is exclusively available from AFL.

 
AFL's Verrillon VHM7000 Series graded-index, bend-insensitive multimode fiber is suitable for mid-range temperatures where the carbon coating is a true barrier against hydrogen diffusion that causes undesirable optical absorption in the operating spectral region of most optical sensors. It has the added benefit of low bend loss for use in tight bend applications.
Verrillon® VHM5000 Series Graded-Index (GI) multimode optical fibers feature unique glass chemistry that is designed to perform in hydrogen-rich severe downhole environments. VHM5000 is the best high-temperature hydrogen-resistant fiber in the world. Tens of mega-meters of Verrillon VHM5000 fibers have been successfully deployed in extremely harsh environments over the last decade.
Verrillon® Harsh Environment VHM4000 Series is a family of Step-Index (SI) multimode fibers with excellent resistance to hydrogen darkening at high temperatures and pressures. These SI fibers are suitable for applications where moderate lengths of fiber are required and where hydrogen is present in high concentrations. VHM4000 fibers are available in 50/125 and 62.5/125 micron designs.
Verrillon® VHM3000 Series Graded-Index (GI) multimode optical fibers are suitable for high temperature applications up to 300°C in hydrogen containing environments. The high bandwidth of these fibers allows Distributed Temperature Sensing (DTS) systems to achieve extremely short spatial resolution in multi-kilometer deep/long deployments.
Verrillon® VHM2000 Series graded-index multimode fiber is suitable for for mid-range temperatures where the carbon coating is a true barrier against hydrogen diffusion that causes undesirable optical absorption in the operating spectral region of most optical sensors.
Verrillon® VHS700 is an Ultra-Low Bend-Insensitive, harsh environment, hermetically-sealed single-mode optical fiber. It is compatible with standard dual-wavelength (1310/1550 nm) single-mode fiber, with the added benefit of ultra-low bend loss for use in tight bend applications and demanding cable structures.
Verrillon® VHS500 is a Pure Silica Core Single-mode Fiber with an entirely fluorinated cladding for superior bend performance and excellent resistance to hydrogen darkening at elevated temperatures. This 1550 nm operating design is available with all Verrillon harsh environment coatings including our renowned hermetic carbon technology.
Verrillon® VHS300 Series is a Pure Silica Core Single-mode Fiber designed to operate at both 1310 and 1550 nm wavelengths in environments where high temperatures and high concentrations of molecular hydrogen affect the optical performance of standard single-mode fibers.
Verrillon® VHS100 Series Single-mode Fibers, combined with our hermetic carbon coating are suitable for mid-range temperature applications where free hydrogen, water and corrosive chemicals are present. These fibers are compatible with standard single-mode fiber and operate at both 1310 and 1550 nm.